WET ELECTROLYTE CAPACITOR CONTAINING EVIDED PLANAR ANODE AND RETENTION

专利摘要:
A capacitor (10) with wet electrolyte is proposed. The capacitor (10) includes a planar anode (200, 201, 202, 203, 300, 400, 500) formed from a pressed and sintered powder, a cathode which includes a metal substrate which is coated with an electrostatic material. chemically active and an operational electrolyte in communication with the planar anode (200, 201, 202, 203, 300, 400, 500) and the cathode. The planar anode (200, 201, 202, 203, 300, 400, 500) has a recessed portion (46, 146, 246) formed in at least one of its surfaces. The capacitor (10) also includes at least one retainer (48, 148, 248) that contacts the recessed portion (46, 146, 246) and has a shape that generally corresponds to a shape of the recessed portion (46, 146, 246). The recessed portion (46, 146, 246) of the planar anode (200, 201, 202, 203, 300, 400, 500) allows stabilization of the planar anode (200, 201, 202, 203, 300, 400 , 500) via a retainer (48, 148, 248) without increasing the dimensions of the capacitor (10).
公开号:FR3031230A1
申请号:FR1561280
申请日:2015-11-24
公开日:2016-07-01
发明作者:Lotfi Djebara；James S Bates；Mitchell D Weaver
申请人:AVX Corp；
IPC主号:

专利说明:

[0001] WET ELECTROLYTE CAPACITOR CONTAINING AN EVIDED PLANE ANODE AND RETENTION High voltage electrolytic capacitors are used as energy storage tanks in many applications, including implantable medical devices. These capacitors must have a high energy density because it is desirable to minimize the total size of the implanted device. This is especially true of an Implantable Cardioverter Defibrillator (ICD), also known as an implantable defibrillator, because the high-voltage capacitors used to provide the defibrillation pulse can occupy up to one-third of the volume of the defibrillator. DCI. In addition, these capacitors experience high levels of shock and vibration conditions, so that the capacitors must be adequately stabilized to prevent capacitor failure due to movement of, for example, a tantalum anode to the capacitor. inside a housing of a wet electrolyte capacitor. Attempts have been made to stabilize the wet electrolyte capacitor anodes by placing a retainer between the outer surface of the anode chip and the housing wall. However, such an arrangement requires the use of a larger housing having a greater height in order to house the restraint (for example, a polymeric, glass or ceramic material), while still permitting, at the same time, a large housing 3031230 2 sufficient room for the operational electrolyte to create a sufficient connection path between the anode and the cathode of the capacitor. However, this is in contradiction with the use of a planar anode to reduce the total size of the DCI and results in an undesirable increase in the total size of the DCI. In addition, there may not be sufficient contact between the anode surface and the retainer to effectively stabilize the anode within the capacitor housing. As such, there is currently a need for an improved wet electrolyte capacitor for use in implantable medical devices, such as defibrillators. In accordance with one embodiment of the present invention, a wet electrolyte capacitor is disclosed. The wet electrolyte capacitor includes a planar anode, a cathode, a retainer and an operational electrolyte. The planar anode includes an anodically oxidized pellet formed from pressed sintered powder, and the planar anode has a recessed portion formed in at least one surface. The cathode includes a metal substrate coated with an electro-chemically active material. The retainer is in contact with the recessed portion and has a shape that generally corresponds to a shape of the recessed portion. In addition, the operational electrolyte is in communication with the planar anode and the cathode.
[0002] In accordance with another embodiment of the present invention, a planar anode for a wet electrolyte capacitor is disclosed. The planar anode includes an anodically oxidized pellet formed from pressed and sintered powder. A recessed portion is located in a surface of the planar anode, and the recessed portion is configured to receive a retainer. Other features and aspects of the present invention are presented in more detail below.
[0003] A complete and sufficient disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art is more particularly set forth in the remainder of the specification, which refers to the accompanying drawings in which Fig. 1 is a perspective view of an embodiment of the wet electrolyte capacitor of the present invention; Figure 2 is a top surface view of an embodiment of a planar anode that may be used in the capacitor of the present invention; Fig. 3 is a bottom surface view of an embodiment of a planar anode that may be used in the capacitor of the present invention; Figure 4 is a cross-sectional view of the planar anode of Figures 2 and 3 along its width; Figure 5 is an exploded perspective view illustrating the planar anode of Figures 2 and 3 surrounded by a housing to form the capacitor shown in Figure 1 without one or more restraints shown; Figure 6 is an exploded perspective view of the capacitor of Figure 1 including the planar anode of Figures 2 to 4 together with a retainer and a housing; Fig. 7 is a bottom surface view of the planar anode and the corresponding retainer in the capacitor of Fig. 6; Fig. 8 is a bottom surface view of an embodiment of a planar anode and corresponding restraints which may be used in the capacitor of the present invention; Fig. 9 is a bottom surface view of another embodiment of a planar anode and corresponding restraints which may be used in the capacitor of the present invention; Fig. 10 is a bottom surface view of yet another embodiment of a planar anode 20 and corresponding restraints which may be used in the capacitor of the present invention; Fig. 11 is a bottom surface view of still another embodiment of a planar anode and corresponding restraints which may be used in the capacitor of the present invention; Fig. 12 is a bottom surface view of another embodiment of a planar anode and corresponding restraints which may be used in the capacitor of the present invention; Fig. 13 is a bottom surface view of another embodiment of a planar anode and corresponding restraints which may be used in the capacitor of the present invention; Figure 14 is a cross-sectional view of the capacitor of Figure 6 along its width; Fig. 15 is an exploded perspective view illustrating another embodiment of a planar anode surrounded by a housing to form the capacitor shown in Fig. 1 without one or more restraints shown; Fig. 16 is a cross-sectional view of the planar anode of Fig. 15 along its width; Fig. 17 is an exploded perspective view of the capacitor of Fig. 15 together with a retainer and a housing; Figure 18 is a cross-sectional view of the capacitor of Figure 17 along its width; Fig. 19 is a perspective view of a retainer that may be used in the capacitor of the present invention; Fig. 20 is a cross-sectional view of the retainer of Fig. 19, at the line Ci, where a planar anode has been inserted into the retainer; Fig. 21 is a perspective view of the planar / retaining anode configuration of Fig. 20; Fig. 22 is a perspective view of another retainer that may be used in the capacitor of the present invention; and Fig. 23 is a cross-sectional view of the retainer of Fig. 22 at line C2, where a planar anode has been inserted into the retainer. The repeated use of reference characters herein and in the drawings is intended to represent like or similar features or elements of the invention. One of ordinary skill in the art will appreciate that the present disclosure is a description of illustrative embodiments only, and is not intended to limit the more general aspects of the present invention, which more general aspects are realized in the illustrative construction. The present invention relates to a wet electrolyte capacitor which contains an anodically oxidized porous planar anode body, a cathode containing a metal substrate which is coated with an electro-chemically active material, and an operational electrolyte which provides an electrolyte pathway. connection between the planar anode and the cathode. In addition, a housing may surround the planar anode, and in some embodiments the metal substrate of the cathode forms the housing. The planar anode includes at least one recessed portion on at least one of its surfaces. In addition, at least one retainer is positioned adjacent to and in contact with at least a portion of the recessed portion of the planar anode. The recessed portion of the planar anode may be shaped to generally correspond to the shape of the retainer so that the recessed portion of the planar anode can be locked in a secure position within the housing by the housing. detention. In other words, the retainer and the recessed portion of the planar anode may have complementary geometries to allow the retainer to go into the recessed portion to stabilize the planar anode within the housing. Thus, the shape of the recessed portion can generally correspond to the shape of the restraint with which it is in contact. Further, while a retainer may be in continuous contact with the entire recessed portion, it is to be understood that this is not necessary, and one or more detentions may be used in a discontinuous manner so that one or more detentions are spaced from each other in the recessed portion. As a result of the arrangement of the capacitor where the planar anode is locked in place within the housing by a retainer which goes into a recessed portion of the planar anode, the retainer can stabilize the planar anode when the capacitor is subjected to high levels of shock or vibration without increasing the overall dimensions of the capacitor. Various embodiments of the present invention will now be described in more detail.
[0004] I. Flat Anode The planar anode is typically formed from a valve metal composition. The specific charge of the composition may vary, for example from about 2000 pF * V / g to about 80000 pF * V / g, in some embodiments from about 5000 pF * V / g to about 40000 pF * V or more, and in some embodiments, from about 10,000 to about 20,000 pFV / g. The valve metal composition contains a valve metal (i.e., a metal that is capable of oxidation) or a valve metal-based compound, such as tantalum, niobium, aluminum, hafnium. , titanium, alloys thereof, oxides thereof, nitrides thereof, and so on. For example, the valve metal composition may contain an electrically conductive niobium oxide, such as niobium oxide having an atomic ratio of niobium-oxygen of 1: 1.0 ± 1.0, in certain modes of embodiment 1: 1.0 ± 0.3, in some embodiments 1: 1.0 ± 0.1, and in some embodiments, 1: 1.0 ± 0.05. The niobium oxide can be Nb00.7, Nb01.0, Nb01.1 and NbO2. Examples of such valve metal oxides are disclosed in US 6,322,912 Fife; 6,391,275 Fife et al. ; 6,416,730 Fife et al. ; 6,527,937 Fife; 6,576,099 Kimmel et al. ; 6,592,740 Fife et al. ; and 6,639,787 Kimmel et al. ; and 7,220,397 Kimmel et al., as well as US Patent Application Publication Nos. 2005/0019581 Schnitter; 2005/0103638 Schnitter et al. ; 2005/0013765 Thomas et al. To form the planar anode, a powder of the valve metal composition is generally used. The powder may contain particles of any of a variety of shapes, such as nodular, angular, flake, etc., as well as mixtures thereof. Particularly suitable powders are tantalum powders available from Cabot Corp. (eg, C255 flake powder, TU4D flake / nodular powder, etc.) and H.C. Starck (eg, NH175 nodular powder). The valve metal composition can be formed using techniques known to those skilled in the art. A precursor tantalum powder, for example, may be formed by reducing a tantalum salt (eg, potassium fluotantalate (K2TaF7), sodium fluotantalate (Na2TaF7), tantalum pentachloride (TaC15), etc.) with a reducing agent (for example, hydrogen, sodium, potassium, magnesium, calcium, etc.). Regardless of the particular method used, the resulting powder may have certain characteristics that enhance its ability to be formed into a capacitor anode. For example, the particles used in the anode may be generally flat. The degree of flatness is generally defined by the "aspect ratio", i.e., the average diameter or average particle width divided by the average thickness ("D / T"). For example, the aspect ratio of the particles may be from about 2 to about 100, in some embodiments from about 3 to about 50, in some embodiments, from about 4 to about 30. The particles may also have a surface area of about 0.5 to about 10.0 m 2 / g, in some embodiments from about 0.7 to about 5.0 m 2 / g, and in some embodiments, about 1.0 to about 4.0 m2 / g. The term "surface area" is defined in more detail above. Apparent density (also called Scott density) is also typically from about 0.1 to about 2 grams per cubic centimeter (g / cm 3), in some embodiments from about 0.2 g / cm 3 to about about 1.5 g / cm3, and in some embodiments from about 0.4 g / cm3 to about 1 g / cm3. "Bulk density" can be determined by using a flow cone and a density cut. More specifically, the sample may be poured through the cone in the cut until the sample completely fills the cup and overflows from its periphery, and after that the sample can be leveled by a spatula, without shaking. , so that it is at the same level as the top of the cup. The leveled sample is transferred to a scale and weighed to the nearest 0.1 gram to determine the density value. Such an apparatus is commercially available from Alcan Aluminum Corp. of Elizabeth, New Jersey. The particles may also have an average size (e.g., width) of from about 0.1 to about 100 microns, in some embodiments from about 0.5 to about 70 microns, and in some embodiments, about 1 to about 50 microns.
[0005] To facilitate the construction of the planar anode, some additional components may also be included in the powder. For example, the powder may optionally be mixed with a binder and / or lubricant to ensure that the particles adhere adequately to each other when pressed to form the planar anode body. Suitable binders may include, for example, polyvinyl butyral; poly (vinyl acetate); polyvinyl alcohol; polyvinylpyrrolidone; cellulosic polymers, such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose and methyl hydroxyethyl cellulose; polypropylene, atactic polyethylene; polyethylene glycol (e.g., Carbowax from Dow Chemical Co.); polystyrene, polybutadiene / styrene; polyamides, polyimides and polyacrylamides, polyethers of high molecular weight; copolymers of ethylene oxide and propylene oxide; fluoropolymers, such as polytetrafluoroethylene, polyvinylidene fluoride and fluoroolefin copolymers; acrylic polymers, such as sodium polyacrylate, poly (lower alkyl acrylates), poly (lower alkyl methacrylates) and copolymers of lower alkyl acrylates and methacrylates; and fatty acids and waxes, such as stearic and other saponaceous fatty acids, vegetable wax, micro-waxes (purified paraffins), and the like. The binder can be dissolved and dispersed in a solvent. Illustrative solvents may include water, alcohols, and so on. When used, the percentage of binders and / or lubricants can vary from about 0.1% to about 8% by weight of the total mass. It should be understood, however, that binders and / or lubricants are not necessarily required in the present invention.
[0006] The resulting powder may be compacted to form a pellet using any conventional powder press device. For example, a press mold can be used which is a single compost press containing a die and one or more punches. Alternatively, anvil compaction press molds may be used that use only one die and one lower punch. Stand-alone compacting press molds are available in several basic types, such as cam, toggle and eccentric / crank presses with various capacities, such as single action, double action, floating matrix , with movable platen, opposed piston, screw, impact, hot pressing, stamping or calibrating. The powder can be compacted around an anode lead wire. The wire may be formed from any electrically conductive material, such as tantalum, niobium, aluminum, hafnium, titanium, etc., and electrically conductive oxides and / or nitrides of them. Any binder / lubricant can be removed after pressing by heating the pellet under vacuum at a certain temperature (e.g., from about 150 ° C to about 500 ° C) for several minutes. Alternatively, the binder / lubricant may also be removed by contacting the pellet with an aqueous solution, as described in US Patent 6,197,252 Bishop et al. After that, the pellet is sintered to form a porous integral mass. The present inventors have discovered that certain sintering conditions may result in an increase in the specific charge of the resulting planar anode, as well as an increase in the breakdown voltage of the resulting capacitor. More particularly, the pellet is typically sintered at a temperature of about 800 ° C to about 2000 ° C, in some embodiments from about 1200 ° C to about 1800 ° C, and in some embodiments, about 1500 ° C to about 1700 ° C, for a period of about 5 minutes to about 100 minutes, and in some embodiments, about 8 minutes to about 15 minutes. This can happen in one or more steps. If desired, sintering can occur in an atmosphere that limits the transfer of oxygen atoms to the planar anode. For example, sintering may occur in a reducing atmosphere, such as in a vacuum, an inert gas, hydrogen, etc. The reducing atmosphere can be at a pressure of about 10 Torr to about 2000 Torr, in some embodiments from about 100 Torr to about 1000 Torr, and in some embodiments from about 100 Torr to about 930 Torr. Torr. Mixtures of hydrogen and other gases (eg, argon or nitrogen) may also be used.
[0007] When used, flake particles can better withstand the high sintering temperatures and the extended sintering periods often used in the formation of the planar anode, and produce a porous sintered body with a low shrinkage and a high shrinkage. specific surface.
[0008] When sintering, the pellet shrinks due to the development of metallurgical bonds between the particles. Since shrinkage generally increases the density of the tablet, lower ("green") press densities can be used to always achieve the desired target density. For example, the target density of the pellet after sintering is typically from about 5 to about 8 grams per cubic centimeter. As a result of the shrinkage phenomenon, however, the pellet does not need to be pressed at such high densities, but can instead be pressed at densities of less than about 6.0 grams per cubic centimeter, and in some embodiments from about 4.5 to about 5.5 grams per cubic centimeter. Among other things, the ability to use lower green densities can provide significant savings and increase processing efficiency. It should be understood that the pressed density can not always be uniform on the pellet, particularly if the compression occurs in a direction perpendicular to the longitudinal axis of the yarn. That is, the pressed density is determined by dividing the amount of material by the volume of the pressed pellet. The volume of the pellet 25 is directly proportional to the compressed length in the direction perpendicular to the longitudinal axis of the wire. The density is inversely proportional to the compressed length. Thus, the compressed length is actually lower at locations adjacent to the wire than at other locations in the chip. The pressed density is similarly larger at the locations adjacent to the yarn. For example, the density of the wafer at locations adjacent to the wafer is typically greater by at least about 10%, and in some cases by at least about 20% at the pressed density of the wafer at the other locations of the wafer. . Referring to FIGS. 2 and 3, for example, an embodiment of a planar anode 200 is shown which contains anode wire 220. The anode wire 10 extends in a longitudinal direction ("y" direction). From the planar anode 200. In order to embed the anode wire 220 in the planar anode 200, a press mold can be partially filled with the powder, and then an anode wire can be inserted. in the press mold. After that, the mold can be filled with powder and the whole package compressed into a pellet. The resulting planar anode may have a small total thickness as compared to its total length and overall width to improve the electrical performance and volumetric efficiency of the resulting capacitor. Referring to FIG. 2, for example, which shows an upper surface 42 of the anode 200, the length "L" represents the entire length of the anode 200 from a first end 60 to a second end 62. In some cases, the length "L" of the anode 200 may vary from about 1 to about 80 millimeters, in some embodiments from about 10 to about 60 millimeters, and in some embodiments, from about 20 to about 50 millimeters. In the meantime, with reference also to FIG. 2, the total width "W" of the anode may also be from about 0.5 to about 60 millimeters, in some embodiments from about 1 to 5 about 40 millimeters, and in some embodiments, about 5 to about 30 millimeters. Furthermore, with reference to Figures 4, 14, 16 and 18, typically, the total "H" thickness of the anode is about 5 millimeters or less, in some embodiments, from about 0.05 to about 4 millimeters, in some embodiments, from about 0.1 to about 3.5 millimeters, and in some embodiments from about 0.2 to about 2 millimeters. Generally, in some embodiments, the ratio of the total length "L" of the anode to the total thickness "H" of the planar anode may vary from about 5 to about 50, in some embodiments. from about 6 to about 40, and in some embodiments from about 7 to about 30. In addition, the ratio of the total width "W" of the anode to the total thickness " H "of the anode can range from about 4 to about 35, in some embodiments from about 5 to about 25, and in some embodiments from about 6 to about 20. In addition, The thickness of the planar anode may vary over the length and / or width of the planar anode due to the presence of one or more recessed portions formed in the planar anode. For example, the planar anode includes at least one recessed portion on at least one of its surfaces, such as an upper surface, a lower surface, a side wall, and the like. In addition, the recessed portion may have any shape, such as square, rectangular, U-shaped, triangular, curved, etc. In some embodiments, the recessed portion may extend over the entire circumference or over the entire edge of the planar anode, while in other embodiments the recessed portion may extend over only a portion of the planar anode. part of the circumference or edge of the planar anode. In addition, the recessed portion may be continuously or discontinuously disposed on a surface of the planar anode. In addition, multiple recessed portions may be formed on the planar anode, where such multiple recessed portions may be present on the same or different surfaces of the planar anode. For example, one or more recessed portions may be present on the top surface, the bottom surface, the side surface, or a combination thereof. Regardless of the area in which the recessed portion is located, with reference to FIGS. 4, 14, 16 and 18, the recessed portion may have a width "ig2" of about 0.005 to about 30 millimeters, in some embodiments. from about 0.01 to about 20 millimeters, and in some embodiments from about 0.1 to about 7.5 millimeters. Meanwhile, the height "H2" of the recessed portion may be from about 0.005 to about 4 millimeters, in some embodiments from about 0.01 to about 3 millimeters, and in some embodiments from about 0.05 to about 1.5 millimeters.
[0009] In addition, at least one retainer (disclosed in more detail below) is positioned adjacent to and in contact with at least a portion of the at least one recessed portion of the planar anode. The recessed portion of the planar anode may be shaped to generally correspond to the shape of the retainer such that the recessed portion of the planar anode can be locked in a secure position within the housing by the retainer. In other words, the retainer and the recessed portion of the planar anode may have complementary geometries to allow the retainer to go into the recessed portion to stabilize the anode within the housing. Thus, the shape of the recessed portion can generally correspond to the shape of the restraint with which it is in contact. Furthermore, while a restraint may be in continuous contact with the entire recessed portion, it is to be understood that this is not necessary, and one or more restraints may be used discontinuously for one or more restraints to be used. spaced from each other in the recessed portion. As a result of the arrangement of the capacitor where the planar anode is locked in place within the housing by a retainer which goes into a recessed portion of the planar anode, the retainer can stabilize the anode when the capacitor is subjected to high levels of shock or vibration without increasing the overall dimensions of the capacitor. Turning first to the planar anode of Figures 3 to 14, and as shown specifically in Figures 4, 5 and 14, a portion 3031230 19 of the planar anode 200 has a thickness "H" and a portion of the anode has a reduced thickness of "H" minus "H2", where, as disclosed above, "H2" refers to the height or thickness of a recessed portion 46 of the planar anode 200 formed in the side wall 54 of the planar anode 200. As shown in FIGS. 3 to 14, the recessed portion 46 of the anode is formed in the lower surface 40 of the planar anode 200 at the 10 of the side wall 54, and specifically on the periphery of the planar anode 200 between a circumferential edge 50 of the planar anode 200 and a circumferential edge 52 of a projecting central portion 44 of the planar anode 200. In this regard, the planar anode 200 can be described as having a shoulder shape u flange, where the central portion has a thickness greater than the thickness of the periphery of the planar anode. The thickness variance at the bottom surface 40 of the planar anode 200 between the recessed portion 46 and the central projecting portion 44 can be accomplished during formation of the planar anode depending on the shape of the press mold. used to form the planar anode 200, or the resulting anode pellet may be modified after molding to vary the thickness over the length and / or width of the planar anode. Further, it is to be understood that while Figs. 3 to 14 show the formation of the recessed portion 46 in the lower surface 40 of the planar anode, this is not necessary, and rather, the recessed portion 46 may be formed in an upper surface of the anode, a sidewall of the anode, etc. In addition, multiple recessed portions may be formed in one or more surfaces of the planar anode. Various flat anodes included by the present invention are disclosed in detail below. In FIGS. 3 to 14, the thickness variance as a consequence of the recessed portion 46 results in a planar anode 200 having a projecting central portion 44 and a recessed portion 46 at a periphery 10 of the lower surface 40, as is 3 and 5. In addition, as shown in FIGS. 3 to 11, the recessed portion 46 may extend around the planar anode 200 with a circumferential inner edge 52 of the projecting central portion 15. 44 at an outer circumferential outer edge 50 of the planar anode 200. Generally, when the recessed portion 46 is formed in a lower surface 40 of the planar anode 200, the projecting central portion 44 may have an area which is about 50% to about 99.5% of the area of the upper surface 42 of the planar anode 200 defined by the circumferential outer edge 50, regardless of the particular geometry of the projecting central portion 44, t it is determined by the circumferential inner edge 52. In another embodiment, the projecting central portion 44 may have an area that is from about 60% to about 99% of the area of the upper surface 42 However, in yet another embodiment, the projecting central portion 44 may have an area that is from about 70% to about 98% of the area of the upper surface. Similarly, the recessed portion 46 located on the periphery of the planar anode 200 may have an area which is from about 0.5% to about 50% of the area of the surface. upper 42 of the anode 200, regardless of the particular geometry of the recessed portion 46 as determined by the outer circumferential edge 50 of the planar anode 200 and the inner circumferential edge 52 of the projecting central portion 44. In another embodiment, the The recessed portion 46 may have an area that is from about 1% to about 40% of the area of the upper surface 42 of the planar anode 200. Meanwhile, in yet another embodiment, the recessed portion 46 may have an area which is from about 2% to about 30% of the area of the upper surface 42 of the planar anode 200. Further, it is to be understood that the same area ranges can be applied when the The recessed portion 46 is formed in an upper surface 42 of the planar anode 200 so that the lower surface 40 of the planar anode 200 does not include a recessed portion. As shown in FIGS. 3 and 5, the circumferential inner edge 52 of the projecting central portion 44 of the planar anode 200 may generally have the same shape, albeit on a smaller scale, than the circumferential outer edge. 50 of the anode 200. Although shown in "D-form" in FIGS. 2 and 3, and 5 to 11, it is also to be understood that the planar anode 200 and the projecting central portion 44 may be any other desired shape, such as square, rectangular, circular, oval, triangular, etc. In addition, the entire planar anode shape may include polygonal shapes having more than four (4) edges (e.g., a hexagon, an octagon, a heptagon, a pentagon, etc.), which may be desired because of their relatively high surface area. For example, in Figures 3 and 5, both the larger circumferential outer edge 50 of the entire planar anode 200 and the smaller circumferential inner edge 52 of the projecting central portion 44 of the planar anode 200 are generally However, it should be understood that the entire planar anode 200 may be of any shape, and that the projecting central portion 44 may be of any shape, and it is not necessary that the protruding central portion 44 has a shape which is the same as that of the overall shape of the planar anode 200. For example, as shown in Fig. 11, the projecting central portion 44 may be rectangular in shape as defined. by its circumferential inner edge 52, while the entire planar anode 201 may be D-shaped as defined by its circumferential outer edge 50, or vice versa (not shown). Further, it is also to be understood that the recessed portion 46 need not extend completely or completely around a surface of the planar anode, as shown in FIGS. planar anodes 200 and 201, and other recessed portion geometries are also contemplated. For example, the planar anode 202 of FIG. 12 has a D shape but includes a recessed portion 46 which is formed in the lower surface 40 of the planar anode 202 to extend around the curved portion. the circumferential edge 50 of the planar anode 202 and does not extend along the right edge of its length "L". On the other hand, the planar anode 203 of Fig. 13 has a D-shape but includes a recessed portion 46 which extends only along the right edge of its length "L" and does not extend along. of its curved portion of the circumferential edge 50 of the planar anode 203. Turning now to FIGS. 15 to 18, a further embodiment of a planar anode 300 is shown where the recessed portion 56 is formed in a wall 54 of the planar anode 300 at a location different from that of FIGS. 3 to 14. As shown in FIGS. 15 and 16, for example, the recessed portion 56 may extend around the entire circumferential edge 50 of FIGS. the anode 300 but may be formed in the middle of the side wall 54 or along any other portion of the side wall 54 in addition to the upper surface 42 or the lower surface 40. In other words, the upper surface 42 and the lower surface 40 of the anode p lane 300 may have the same dimensions while the recessed portion 56 may be disposed between the upper surface 42 and the lower surface 40 at a certain location in the sidewall 54.
[0010] Generally, the aforementioned recessed portions 46 or 56 allow the use of one or more retainers 48 to hold the planar anode 200, 201, 202, 203 or 300 in place within the housing 12 without having to increasing one or more dimensions of the housing 12, which is, as disclosed above, important for minimizing the space occupied by implantable medical devices incorporating the capacitor 10 of the present invention. Various embodiments of one or more retainers 48 which may be used in conjunction with the recessed portions 46 and 56 of the anodes described above are shown in FIGS. 6 to 14 and 17 and 18 and disclosed in greater detail. below.
[0011] In other embodiments, however, it is to be understood that the retainer may contact more than just the recessed portions of the anodes contemplated by the present invention. Turning now to Figures 19 to 23, two additional retainer and anode configurations are shown. Fig. 19 is a perspective view of an embodiment of a retainer 148 which may be used in the capacitor of the present invention. The retainer is in the form of a nest or cage which may contain a planar anode, as shown in Fig. 20, which is a cross-sectional view of the retainer of Fig. 19, at the line CI, where an anode FIG. 21 is a perspective view of the planar anode 400 / retainer 148 of FIG. 20. As shown in FIGS. 19-21, FIG. retainer 148 may have a portion 148a that is shaped to generally correspond to the recessed portion 146 of the anode 400 formed at the circumferential edge 152 of the projecting central portion 144 of the anode 400. Thus, the portion 148a of the retainer may go into the recessed portion 146 of the anode 400 to lock the anode 400 in a safe and stable position. Meanwhile, multiple tab portions 148b of the retainer 148 may extend over the circumference of the retainer 148, and the tab portions extend in the y direction or the thickness / height direction of the retainer 148. anode 400 and contact the side wall 154 of the anode 400 formed by the circumferential edge 150 of the anode 400 to further secure and stabilize the anode 400 by providing additional points of contact between the retainer 148 and the anode 400. In addition, a portion of the retainer 148c may extend circumferentially and contact the bottom surface 140 of the anode to provide further stabilization at the anode. Further, a portion of the retainer 148d may extend over the bottom surface 140 of the anode at a generally centralized location to provide additional contact between the retainer 148 and the projecting central portion 144 of the anode 400 for a additional stabilization. Fig. 22 is a perspective view of another retainer that may be used in the capacitor of the present invention. The retainer 3031230 26 is a nest or cage that may contain a planar anode, as shown in Fig. 23, which is a cross-sectional view of the retainer of Fig. 22, at line C2, where a planar anode 500 has been inserted into the retainer 248. As shown in FIGS. 22 and 23, the retainer 248 may have a portion 248a which is shaped to generally correspond to the recessed portion 246 of the anode 500 formed at the edge. 252 of the protruding central portion 244 of the anode 500, which is similar to the shape of the anode 400 of Figs. 20 and 21 except that the circumferential edge 252 has a curved geometry rather than forming an angle approximately 90 °, as the circumferential edge 152 of the anode 400 shown in FIG. 20. Thus, the portion 248a of the retainer can go into the recessed portion 246 of the anode 500 to lock the anode 500 in a posit safe and stable ion. Meanwhile, multiple tab portions 248b of the retainer 248 may extend over the circumference of the retainer 248, and the tab portions extend in the y direction or thickness / height direction of the retainer 248. anode 500 and contact the sidewall 254 of the anode 500 formed at the circumferential edge 250 of the anode 500 to further secure and stabilize the anode 500 by providing additional contact points between the retainer 248 and the anode 500. Anode 500. In addition, a portion of the retainer 248c may extend circumferentially and contact the bottom surface 240 of the anode to provide further stabilization at the anode. In addition, a portion of the retainer 248d may extend over the bottom surface 240 of the anode at a generally centralized location to provide additional contact between the retainer 248 and the projecting central portion 244 of the anode 500 for a additional stabilization. As shown in FIGS. 20 and 21 and 23, the retainers for the anode 400 and the anode 500 may be positioned adjacent to and in contact with the recessed portion of the anode, as well as at least a portion of the lower surface of the anode and at least a portion of the circumferential edge of the anode. The recessed portion of the planar anode may be shaped to generally correspond to the shape of the retainer such that the recessed portion of the planar anode can be locked in a secure position within the housing by the retainer. In other words, the retainer and the recessed portion of the planar anode may have complementary geometries to allow the retainer to go into the recessed portion to stabilize the planar anode within the housing. Thus, the shape of the recessed portion can generally correspond to the shape of the restraint with which it is in contact. As shown in Figures 20 and 21 and 23, the retainer may be in continuous contact with the entire recessed portion. Similar to the retainers of FIGS. 6 to 12, 14 and 15, and 17 and 18, as a result of the arrangement of the capacitor where the planar anode is locked in place within the housing by a restraint which goes into With a recessed portion of the planar anode, the restraint can stabilize the planar anode when the capacitor is subjected to high levels of shock or vibration without increasing the overall dimensions of the capacitor. In addition, to further improve the stability of the anode, as shown and as disclosed above, the retainer of Figs. 19-21, and the retainer of Figs. 22 and 23, may form a nest or a cage for the anode in that it may also include components that are in contact with a portion of the lower surface of the anode and a portion of the circumferential edge or the side wall of the anode, which can further help the restraint to lock the anode in place. Regardless of the particular arrangement or treatment by which the planar anode 200, 201, 202, 203, 300, 400 or 500 may be configured to include a recessed portion 46 at its bottom surface 40 or other suitable surface (eg For example, top surface, sidewall, etc.), as indicated above, the total thickness of the anode 200, 201, 202, 203, 300, 400 or 500 is generally small to improve electrical performance. and the volumetric efficiency of the resulting capacitor.
[0012] In addition, regardless of the particular geometry of the planar anode, the planar anode also contains an anodically oxidizing ("anodizing") dielectric formed of the sintered anode so that a dielectric layer is formed on and / or inside the plane anode. For example, a tantalum anode (Ta) may be anodized to tantalum pentoxide (Ta2O5). Typically, the anodization is carried out by initially applying a solution on the anode, for example by soaking the anode in the electrolyte. Aqueous solvents (eg, water) and / or non-aqueous solvents (eg, ethylene glycol) may be used. To improve the conductivity, a compound can be used which is able to dissociate in the solvent to form ions. Examples of such compounds include, for example, acids, such as those described below with respect to the electrolyte. For example, an acid (eg, phosphoric acid) may comprise from about 0.01% by weight to about 5% by weight, in some embodiments from about 0.05% by weight to about 0% by weight. , 8% by weight, and in some embodiments from about 0.1% by weight to about 0.5% by weight of the anodizing solution. If desired, acid mixtures can also be used.
[0013] A stream is passed through the anodizing solution to form the dielectric layer. The value of the formation voltage governs the thickness of the dielectric layer. For example, the power supply can initially be set to a galvanostatic mode until the required voltage is reached. After that, the power supply can be switched to a potentiostatic mode to ensure that the desired dielectric thickness is formed on the entire surface of the anode. Of course, other known methods may also be used, such as pulse or stepwise potentiostatic processes. The temperature of the anodizing solution may vary from about 10 ° C to about 200 ° C, in some embodiments from about 20 ° C to about 150 ° C, and in some embodiments, from about 30 ° C to about 100 ° C. The resulting dielectric layer may be formed on a surface of the anode and within its pores. When used, the specific nature of the powder may allow the resulting anode to achieve a high specific charge even at the high forming voltages often used in the present invention. For example, within the ranges noted above, the anode may still be capable of having a specific charge of about 2000 pF * V / g to about 20000 pF * V / g, in some embodiments of the invention. from about 5000 pF * V / g to about 15,000 pF * V / g or more, and in some embodiments from about 8000 to about 12,000 pF * V / g.
[0014] II. Cathode In addition to the anode, a cathode is also used in the capacitor, which can be constructed using any of a variety of techniques. In one embodiment, the cathode 25 contains a metal substrate, which may include any metal, such as tantalum, niobium, aluminum, nickel, hafnium, titanium, copper, silver (eg, stainless steel), alloys thereof (e.g., electrically conductive oxides), composites thereof (e.g., electrically conductive oxide coated metal), and thus which is coated with an electro-chemically active material. Titanium and tantalum, as well as alloys thereof, are particularly suitable for use in the present invention. The geometric configuration of the substrate can generally vary as is well known to those skilled in the art, for example in the form of container, box, strip, sheet, sieve, mesh, etc. Although this is not necessary, in one embodiment, for example, the metal substrate may form the capacitor housing in which the planar anode is disposed, and such a housing may be D-shaped or any other shape. which generally corresponds to the shape of the planar anode. For example, it should be understood that any geometric configuration may be used in the present invention, such as cylindrical, rectangular, triangular, prismatic, etc. The substrate may be roughened to increase its surface area and increase the degree to which an electro-chemically active material can adhere thereto. In one embodiment, for example, the surface is chemically etched, for example by applying a solution of a corrosive substance (e.g., hydrochloric acid) to the surface. The surface can also be electrochemically etched, for example by applying a voltage to a solution of the corrosive substance to undergo electrolysis. The voltage can be increased to a sufficiently high level to initiate "sparking" on the surface of the substrate, and this is believed to create high local surface temperatures sufficient to etch away the substrate. This technique is described in more detail in U.S. Patent No. 8,279,585, Dreissig et al., To which the reader is referred in its entirety for all purposes. In addition to chemical or electrochemical roughening techniques, mechanical roughening can also be used. In one embodiment, for example, the surface of the metal substrate may be abrasion-etched by propelling a stream of abrasive material (eg, sand) against at least a portion of a surface thereof. Electro-chemically active material may also be applied to the cathode substrate to prevent corrosion and also serve as a thermal barrier when the voltage is increased. The electro-chemically active material may be formed from one or more layers. The material used in one / these layer (s) may vary. Any of a variety of known electro-chemically active materials can generally be used. Suitable material is a conductive polymer, such as those which are n-conjugated and have electrical conductivity after oxidation or reduction (eg, electrical conductivity of at least about 1 μS cm-1 after oxidation). Examples of such n-conjugated conductive polymers include, for example, polyheterocycles (eg, polypyrroles, polythiophenes, polyanilines, etc.), polyacetylenes, poly-p-phenylenes, polyphenolates, and so on.
[0015] The substituted polythiophenes are particularly suitable for use as a conductive polymer in that they have particularly good mechanical strength and electrical performance. Without intending to be limited by theory, it is believed that charging the capacitor to a high voltage (e.g., greater than the forming voltage) forces electrolyte ions into coatings containing such Substituted polythiophenes. This causes the conductive polymer to "swell" and retain ions near the surface, thereby improving charge density. Since the polymer is generally amorphous and non-crystalline, it can also dissipate and / or absorb heat associated with high voltage. During the discharge, it is also believed that the substituted polythiophene "loosens" and allows ions in the electrolyte to exit the coating. By such a mechanism of swelling and relaxation, the charge density near the metal substrate can be increased without chemical reaction with the electrolyte. Therefore, mechanical strength and good electrical performance can be provided without requiring conventional conductive coatings, such as those made of activated carbon or metal oxide (eg, ruthenium oxide). In fact, excellent results can be obtained by using the coating as the main material on the metal substrate. Namely, the coating 30 may comprise at least about 90% by weight, in some embodiments at least about 92% by weight, and in some embodiments, at least about 95% by weight of the material (s). (s) present on the metal substrate. Nevertheless, it should be understood that other conductive coatings may also be used in some embodiments of the present invention. In a particular embodiment, the substituted polythiophene has the following general structure: wherein T is 0 or S; D is an optionally substituted C1 to C5 alkylene radical (for example, methylene, ethylene, n-propylene, n-butylene, n-pentylene, etc.); R7 is an optionally substituted linear or branched C1 to C18 alkyl radical (for example, methyl, ethyl, n- or iso-propyl, n-, iso-, sec- or tertbutyl, n-pentyl, 1-methylbutyl, 2- methylbutyl, 3-methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, N-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, etc.); an optionally substituted C5-C6 cycloalkyl radical (for example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc.); an optionally substituted C6-C14 aryl radical (e.g., phenyl, naphthyl, etc.); an optionally substituted C7-C18 aralkyl radical (e.g., benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2-6, 3-4-, 3 , 5-xylyl, mesityl, etc.); a hydroxyalkyl radical, or optionally substituted C1 to C4 hydroxyl radical; and q is a relative integer from 0 to 8, in some embodiments 0 to 2, and in one embodiment 0; and n is from 2 to 5000, in some embodiments from 4 to 2000, and in some embodiments from 5 to 1000. Examples of substituents for radicals "D" or "R7" include, for example, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, halogen, ether, thioether, disulfide, sulfoxide, sulfone, sulfonate, amino, aldehyde, keto, carboxylic acid ester, carboxylic acid, carbonate, carboxylate, cyano, alkylsilane and alkoxysilane groups carboxyamide groups, and so on. Particularly suitable thiophene polymers are those in which "D" is an optionally substituted C2 to C3 alkylene radical. For example, the polymer may be optionally substituted poly (3,4-ethylenedioxythiophene), which has the following general structure: Methods for forming conductive polymers, as described above, are well known in the art . For example, US Patent 6,987,663 Merker et al. describes various techniques for forming substituted polythiophenes from a monomeric precursor. The monomer precursor may, for example, have the following structure: ## STR2 ## wherein T, D, R 7 and q are defined above. [Des Des] Particularly suitable thiophene monomers are those in which D "is an optionally substituted C2 to C3 alkylene radical For example, optionally substituted 3,4-alkylenedioxythiophenes may be used which have the general structure: wherein R7 and q are as defined hereinbefore In a particular embodiment, "q" is 0. A commercially suitable example of 3,4-ethylenedioxythiophene is available from Heraeus Clevios under the name Clevios ™ M. Other suitable monomers are also disclosed in US Pat. US 5,111,327 Blohm et al and 6,635,729 to Groenendaal et al .. Derivatives of these monomers may also be used which are, for example, dimers or trimers of the monomers. above Higher molecular derivatives, ie, tetramers, pentamers, etc. monomers are suitable for use in the present invention. The derivatives may be composed of identical or different monomer units and used in pure form and in a mixture with each other and / or with the monomers. An oxidized or reduced form of these precursors may also be used. The thiophene monomers can be chemically polymerized in the presence of an oxidative catalyst. The oxidative catalyst typically includes a transition metal cation, such as iron (III), copper (II), chromium (VI), cerium (IV), manganese (IV), manganese ( VII), ruthenium (III), etc. A dopant may also be used to provide excess charge to the conductive polymer and stabilize the conductivity of the polymer. The dopant typically includes an inorganic or organic anion, such as an ion of a sulfonic acid. In some embodiments, the oxidative catalyst used in the precursor solution has both catalytic and dopant functionality in that it includes a cation (e.g., transition metal) and an anion (e.g., sulfonic acid). ). For example, the oxidative catalyst may be a transition metal salt which includes iron (III) cations, such as iron (III) halides (e.g., FeCl3) or iron (III) salts thereof. other inorganic acids, such as Fe (C104) 3 or Fe2 (SO4) 3 and iron (III) salts of organic acids and inorganic acids comprising organic radicals. Examples of iron (III) salts of inorganic acids with organic radicals include, for example, iron (III) salts of sulfur monoesters of C 1 to C 20 alkanols (eg iron salt ( III) lauryl sulphate). Similarly, examples of iron (III) salts of organic acids include, for example, iron (III) salts of C1 to C20 alkane sulfonic acids (e.g., methanesulfonic acid, ethane, propane, butane or dodecane); iron (III) salts of aliphatic perfluorosulfonic acids (e.g., trifluoromethane sulfonic acid, perfluorobutane sulfonic acid or perfluorooctane sulfonic acid); iron (III) salts of C1 to C20 aliphatic carboxylic acids (e.g., 2-ethylhexyl carboxylic acid); iron (III) salts of aliphatic perfluorocarboxylic acids (e.g., trifluoroacetic acid or perfluorooctane acid); iron (III) salts of aromatic sulfonic acids optionally substituted with C1 to C20 alkyl groups (e.g., benzene sulfonic acid, o-toluene sulfonic acid, p-toluene sulfonic acid or dodecylbenzene sulfonic acid) ; iron (III) salts of cycloalkane sulfonic acids (e.g., camphor sulfonic acid); And so on. Mixtures of these aforementioned iron (III) salts can also be used. Iron (III) -ptoluene sulfonate, iron (III) -ol-toluene sulfonate, and mixtures thereof are particularly suitable.
[0016] A commercially suitable example of iron (III) -p-toluene sulfonate is available from Heraeus Clevios as Clevios ™ C. Various methods can be used to form a conductive polymer layer. In one embodiment, the oxidative catalyst and the monomer are applied, sequentially or together, such that the polymerization reaction occurs in situ on the substrate. Suitable application techniques may include screen printing, dipping, electrophoretic coating, and sputtering, which may be used to form a conductive polymer coating. By way of example, the monomer may initially be mixed with the oxidative catalyst to form a precursor solution. Once the mixture is formed, it can be applied to the substrate and then allowed to polymerize so that the conductive coating is formed on the surface. Alternatively, the oxidative catalyst and the monomer may be applied sequentially. In one embodiment, for example, the oxidative catalyst is dissolved in an organic solvent (eg, butanol) and then applied as a dipping solution. The substrate can then be dried to remove the solvent therefrom. After that, the substrate may be dipped in a solution containing the monomer. The polymerization is typically carried out at temperatures from about -10 ° C to about 250 ° C, and in some embodiments, from about 0 ° C to about 200 ° C, depending on the oxidizing agent used and the desired reaction time. Suitable polymerization techniques, such as that described above, can be described in more detail in US Pat. No. 7,515,396 Biler. Still other methods for applying one or more conductive coating (s) can be described in US Pat. Nos. 5,457,852 to Sakata et al., 5,473,503 Sakata et al., 5,729,428 Sakata. et al., and 5,812,367 Kudoh et al. In addition to in situ application, a conductive polymer layer may also be applied as a dispersion of conductive polymer particles. Although their size may vary, it is typically desired that the particles have a small diameter to increase the area available to adhere to the substrate. For example, the particles may have an average diameter of about 1 to about 500 nanometers, in some embodiments from about 5 to about 400 nanometers, and in some embodiments from about 10 to about 300 nanometers . The D90 value of the particles (particles having a diameter less than or equal to the D90 value constitutes 90% of the total volume of all the solid particles) can be about 15 microns or less, in some embodiments about 10 microns or less, and in some embodiments, from about 1 nanometer to about 8 micrometers. The particle diameter can be determined using known techniques, such as ultracentrifugation, laser diffraction, etc.
[0017] If desired, one or more of the application steps described above may be repeated until the desired thickness of the coating is reached. In some embodiments, only a relatively thin layer of the coating is formed at a time. The total target thickness of the coating may generally vary depending on the desired properties of the capacitor. Typically, the resultant conductive polymer coating has a thickness of about 0.2 micron ("pm") to about 50 pm, in some embodiments from about 0.5 pm to about 20 pm, and in some embodiments from about 1 pm to about 5 pm. It should be understood that the thickness of the coating is not necessarily the same at all locations on the substrate. Nevertheless, the average thickness of the coating on the substrate is generally within the ranges noted above.
[0018] The conductive polymer layer may optionally be healed. Healing may occur after each application of a conductive polymer layer or may occur after application of the entire coating. In some embodiments, the conductive polymer may be healed by soaking the portion in an electrolytic solution, and thereafter applying a constant voltage to the solution until the stream 10 is reduced to a preselected level. If desired, such scarring can be accomplished in multiple steps. For example, an electrolytic solution may be a dilute solution of the monomer, catalyst and dopant in an alcohol solvent (eg, ethanol). The coating may also be washed, if desired, to remove various by-products, excess reagent, and so on.
[0019] III. Retention In addition to a planar anode and a cathode, the capacitor of the present invention includes a retainer. The retainer used in the capacitor assembly of the present invention is configured to lock the planar anode in place and prevent the planar anode from moving when the capacitor element is subjected to vibratory forces. In this regard, the retainer typically has a certain degree of resistance which allows it to retain the capacitor element in a relatively fixed position even when subjected to vibratory forces, but is not so strong that she is cracking. For example, the restraint may have a tensile strength of from about 1 to about 150 megapascals ("MPa"), in some embodiments from about 2 to about 100 MPa, in some embodiments of about 10 megapascals ("MPa"). at about 80 MPa, and in some embodiments, from about 20 to about 70 MPa, measured at a temperature of about 25 ° C. It is normally desired that the retainer 10 is not electrically conductive. While any of a variety of materials may be used that possess the desired strength properties noted above, particularly suitable materials include, for example, polymers, glass and ceramics. For example, when the retainer is a polymer retainer, the retainer may include a polyolefin (eg, polypropylene, polyethylene, etc.), a fluoropolymer (eg, polytetrafluoroethylene), a thermosetting resin (e.g., an epoxy resin, polyimide, melamine resin, ureaformaldehyde resin, polyurethane, silicone polymer, phenolic resin, etc.), an elastomer, or a combination thereof.
[0020] The particular manner in which the aforementioned components are incorporated in the capacitor is not essential and can be accomplished using a variety of techniques. In most embodiments, however, the planar anode is positioned within a housing. The housing may optionally include a cover that covers the anode, cathode, and electrolyte (disclosed below), which may be formed from the same or different material as the housing. Referring to FIGS. 1, 5, 6 and 14, for example, a capacitor 10 is shown which includes the anode 200 shown in FIGS. 2 to 4 and 7 to 11 and a housing 12. Similarly, FIGS. 15, 17 and 18 show a capacitor 100 which includes anode 300 shown in FIG. 16 and a housing 12. Although only a planar anode is shown, it is to be understood that multiple planar anodes (e.g. , a stack) can be used, as described, for example, in US Patent 7,483,260 Ziarniak et al. In the illustrated embodiments, as shown in Figures 1, 5, 6, 14, 15, 17 and 18, the planar anode 200 or 300 or any other suitable planar anode may be positioned within a housing 12 made of a first housing member 14 and a second housing member 16. The first housing member 14 may have a face wall 18 joined to a surrounding encircling wall 20 extending to 22. The second housing member 16 may be in the form of a plate and may contain a second face wall 24 having a circling edge 26. The housing members 14 and 16 may be hermetically sealed together by welding (e.g. laser welding) the overlapping edges 22 and 26 where they come into contact with each other. Although not necessary, the housing members 14 and / or 16 may be analogous to the metal substrate described above such that an electro-chemically active material (e.g. shown) can be deposited on the inner surface thereof. Alternatively, a separate metal substrate may be located adjacent to the housing member 14 and / or 16 and applied with the conductive polymer coating to serve as a cathode. In addition, the retainer (s) 48 disclosed above may be secured in their desired location within the housing member 14 or the housing member 16 by any suitable means, such as through an adhesive or glue (not shown). Alternatively or additionally, the retainer (s) 48 may be secured to the recessed portion 46 or 56 of the anode 200 or 300, respectively, by any suitable means, such as by means of an adhesive or glue (not shown) to lock the anode 200 in place and prevent its movement during use of the capacitor. For example, in order to lock the planar anode 200 of Figures 4 to 7 and 16 in place using the retainer 48, the retainer 48 can be attached to an inner surface of the second housing member 16 and then the planar anode 200 can be placed over the inner surface of the second housing member 16 so that the recessed portion 46 of the anode 200 can go over the retainer 48. In the meantime, in order to lock the planar anode 300 Figures 15 to 18 in place using retainer 48, retainer 48 may be attached to an inner surface of the first housing member 14 and then the planar anode 300 may be inclined within the first housing member 3031230 14 so that the recessed portion 56 of the anode 300 can go over the retainer 48. In another embodiment, the retainers 48 may be attached to the recessed portions 46 or 56 of the planar anodes 200, 201, 202, 203 or 300 and then the planar anodes It may be placed in the first housing member 14. Then, optionally, an adhesive or glue may be used on the appropriate housing member 14 or 16 in the area where the retainer 48 will contact the housing member. housing 14 or 16 to ensure that the retainer can lock the planar anode in place. Furthermore, it is to be understood that it is not necessary that the retainer (s) 48 be (are) attached to the housing member 14, the housing member 16, or to the recessed portion 46 or 56, and, rather, the (the) retain (s) 48 may (may) be injected into the housing 12 at the desired location between the recessed portion 46 or 56 and the organ 14 or 16 and then allowed to cool to lock the anode 200 or 300 in place within the housing 12. In any case, the retainer (s) 48 may be disposed within the recessed portion 46 of the anode 200 and the recessed portion 56 of the anode 300 so that the retainer (s) 48 is (are) generally aligned ( s) with the side wall 54 of the planar anode 200 or 300, as shown in FIGS. 14 and 18. As such, the restraint (s) 48 can (can) prevent the motion of the plane anode 200 or 300 inside the bo In addition, since the retainer (s) 48 is (are) generally aligned with the side wall 54 of the planar anode 200 or 300 and extends (extend) not beyond the total thickness "H" or the total width "W" of the planar anode 200 or 300, the size of the housing 12 may be minimized, as shown in Figures 14 and 18. Further, as shown in FIGS. 6 to 11, the retainer 48 is not limited to a particular shape or configuration as long as the retainer 48 is shaped with and can go within at least one part of the recessed portion 46 of the anode 200. In a particular embodiment, as shown in FIGS. 6 and 7, the retainer 48 may be in contact with the entire recessed portion 46 of the lower surface 40 of the anode 200 and may have generally the same shape as the shape of the recessed portion 46. In addition, as this 12 and 13, it is not necessary for the retainer to be positioned around the entire periphery of the planar anode 201 or 202. For example, in FIG. 12, the retainer 48 is only located around a portion of a recessed portion 46 which extends around the curved portion of the circumferential edge 50 of the planar anode 201 and does not extend along the right edge of its length "L". Meanwhile, in Fig. 13, the retainer 48 is only located along a straight edge portion of the length "L" of the planar anode 202 at the recessed portion 46. In other words, when a retainer 48 is used, it may extend around less than an entire hollow portion 46, as shown in Figures 12 and 13. In addition, as shown in Figures 14 and 18 the retainer 48 does not extend generally beyond the height or thickness "H2" of the recessed portion 46 or 56 or beyond the width "W2" of the recessed portion 46 or 56 of such that the overall dimensions of the housing 12 can be minimized.
[0021] In addition, although the retainer 48 is shown in Figures 6 and 7, for example, as a single component which extends around the entire hollow portion 46 at the bottom surface 40 of the anode 200 of continuously, and thus completely surrounds the projecting central portion 44 of the anode 200 at the circumferential inner edge 52 of the central projecting portion 44, and in FIG. 17 as a single component which extends around the portion entire recess 56 of the anode 300 in the middle of its side wall 54, this is not necessary, and rather multiple retainers 48 may be disposed along less than the entire recessed portion 46 in a discontinuous manner, as is In addition, the restraints may be of various shapes such as round, rectangular, square, oblong, triangular, elliptical, etc., as shown in FIGS. 6 to 13. Regardless of the shape or number of the restraints 48 used, however, the retainers 48 are capable of stabilizing the anode by locking it in place within the housing 12 without increasing the size of the housing 12. In addition to components disclosed above, although not shown, one or more separators may be used which help isolate the anode and the cathode from each other. Examples of suitable materials for this purpose include, for example, porous polymeric materials (eg, polypropylene, polyethylene, etc.), porous inorganic materials (eg, fiberglass mats, porous sandpaper, etc. .), ion exchange resin materials, etc. Particular examples include ionic perfluorinated sulfonic acid polymer membranes (e.g., Nafion ™ Nafion ™ from DuPont de Nemours & Co.), sulfonated fluorocarbon polymer membranes, polybenzimidazole (PBI) membranes, and polyether ether membranes. -Ketone ("PolyEther Ether Ketone" or PEEK). Although preventing direct contact between the anode and the cathode, the separator 20 allows the flow of ionic current from the electrolyte to the electrodes. A passageway 30 may also be used which electrically insulates the anode wire 220 from the housing 12. The passageway 30 extends from the inside of the housing 12 to the outside thereof. A hole 34 may be provided in the encircling side wall 20 of the housing member 14 in which the passage 30 extends. The passageway 30 may, for example, be a glass-to-metal seal (GTMS) which contains a ferrule (not shown) with an internal cylindrical bore of constant inner diameter.
[0022] An insulating glass can thus provide a hermetic seal between the bore and the anode wire 220 passing therethrough. After assembly and sealing (eg welding), the electrolyte may optionally be introduced into the housing through a fill port. Filling can be accomplished by placing the capacitor in a vacuum chamber so that the fill port extends into a reservoir of the electrolyte. When the chamber is emptied, the pressure is reduced inside the capacitor. When the vacuum is released, the pressure inside the capacitor rebalances, and the electrolyte is drawn through the fill port into the capacitor.
[0023] IV. Operational Electrolyte The capacitor of the present invention also utilizes an operational electrolyte which is disposed within the housing and is the electrically active material which provides the connection path between the anode and cathode. The working electrolyte can generally be in the form of a liquid, such as a solution (for example, aqueous or non-aqueous), a dispersion, a gel, etc. If desired, the anode 25 may initially be impregnated with an electrolyte (not shown) before being positioned within the housing. The electrolyte may also be added to the capacitor at a later stage of production. Various suitable electrolytes are disclosed in U.S. Patents 5,369,547 and 6,594,140 Evans et al., To which the reader is referred in their entirety for all purposes. Typically, the electrolyte is ionically conductive in that it has an ionic conductivity of from about 1 to about 100 milliSiemens per centimeter ("mS / cm"), in some embodiments from about 5 to about 80 mS / cm, in some embodiments from about 15 mS / cm to about 70 mS / cm, and in some embodiments from about 20 to about 60 mS / cm, determined at a temperature of 25 ° C using any known electrical conductivity meter (eg, Oakton Con Series 11). Within the noted ranges, the electric field is as intense as the dielectric but can extend into the electrolyte to a length (Debye length) sufficient to result in significant charge separation. This extends the potential energy of the dielectric to the electrolyte so that the resulting capacitor is able to store even more potential energy than is predicted by the thickness of the dielectric. In other words, the capacitor can be charged to a voltage that is close to, or even exceeds, the dielectric forming voltage. The ratio of the voltage at which the capacitor can be charged to the forming voltage may, for example, be from about 0.80 to about 2.00, and in some embodiments from about 0, 85 to about 1.50, and in some embodiments, about 0.86 to about 1.20. By way of example, the voltage at which the capacitor is charged can be from about 150 volts to about 300 volts, in some embodiments from about 180 volts to about 260 volts, and in some embodiments, from about 200 volts to about 240 volts. The forming voltage may similarly vary from about 180 volts to about 320 volts, in some embodiments from about 200 volts to about 280 volts, and in some embodiments from about 220 volts to about 250 volts. volts.
[0024] The operational electrolyte is also relatively neutral and thus has a pH value of about 4.5 to about 8.0, in some embodiments from about 5.0 to about 7.5, in some embodiments. from about 5.5 to about 7.0, and in some embodiments from about 6.0 to about 6.5. Among other things, such a pH can improve the ability of hydrogen ions present in an aqueous electrolyte to interact with the cathode material to obtain maximum capacity and thus energy density. The desired ionic conductivity can be obtained by selecting one or more ionic compound (s) (for example, acids, bases, salts, and so on) within certain concentration ranges.
[0025] In a particular embodiment, weak organic acid salts can be effective to achieve the desired electrolyte conductivity. The cation of the salt may include monoatomic cations, such as alkali metals (e.g., Li +, Na +, K +, Rb + or Cs +), alkaline earth metals (e.g., Be2 +, Mg2 +, Ca2 +, Sr2 + or Ba2 +) , transition metals 3031230 (for example, Ag +, Fe2 +, Fe3 +, etc.), as well as polyatomic cations, such as NH4. Ammonium (NH4), sodium (K1 and lithium monovalent are particularly suitable cations for use in the present invention.) The organic acid used to form the salt anion is "weak" in the in that it typically has a first acid dissociation constant (pK, I) of from about 0 to about 11, in some embodiments from about 1 to about 10, and in some embodiments, from about 2 to about 10, determined at 25 ° C. Any suitable weak organic acids may be used in the present invention, such as carboxylic acids, such as acrylic acid, methacrylic acid, malonic acid, succinic acid, salicylic acid, sulfosalicylic acid, adipic acid, maleic acid, malic acid, oleic acid, gallic acid, tartaric acid (e.g. dextotartaric acid, mesotartaric acid, etc.), citric acid, Acetic acid, glycolic acid, oxalic acid, propionic acid, phthalic acid, isophthalic acid, glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, itaconic acid, trifluoroacetic acid, barbituric acid, cinnamic acid, benzoic acid, 4-hydroxybenzoic acid, aminobenzoic acid, and the like. ; mixtures of these, and so on. Polyprotic acids (e.g., diprotics, triprotics, etc.) are particularly desirable for use in salt formation, such as adipic acid (pKai of 4.43 and p <1, 2 of 5). , 41), α-tartaric acid (pKai of 2.98 and p1 <", 2 of 4.34), mesotartaric acid (pKai of 3.22 and pI <", 2 of 4.82 ), oxalic acid (pKai of 1.23 and p1 <", 2 of 4.19), lactic acid (pKaI of 3.13, pI <", 2 of 4.76, and pl <" , 3 of 6, 40), etc. Although the actual amounts may vary depending on the particular salt used, their solubility in the solvent (s) used in the electrolyte, and the presence of other components, such salts of Low organic acids are typically present in the electrolyte in an amount of from about 0.1 to about 40% by weight, in some embodiments from about 0.2 to about 35% by weight, in some embodiments. from about 0.3 to about 30% by weight, and in some embodiments from about 0.5 to about 25% by weight. The electrolyte is typically aqueous in that it contains an aqueous solvent, such as water (e.g., deionized water). For example, water (e.g., deionized water) may be from about 20% by weight to about 95% by weight, in some embodiments from about 30% by weight to about 90% by weight. in weight, and in some embodiments, from about 40% by weight to about 85% by weight of the electrolyte. A secondary solvent may also be used to form a solvent mixture. Suitable secondary solvents may include, for example, glycols (eg, ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, hexylene glycol, polyethylene glycols, ethoxydiglycol, dipropylene glycol, etc.); glycol ethers (e.g., methyl glycol ether, ethyl glycol ether, isopropyl glycol ether, etc.); alcohols (for example, methanol, ethanol, n-propanol, iso-propanol and butanol); ketones (for example, acetone, methyl ethyl ketone and methyl isobutyl ketone); esters (e.g., ethyl acetate, butyl acetate, diethylene glycol ether acetate, methoxypropyl acetate, ethylene carbonate, propylene carbonate, etc.); amides (for example, dimethylformamide, dimethylacetamide, dimethylcaprylic / capric fatty acid amide and N-alkylpyrrolidones); sulfoxides or sulfones (for example, dimethylsulfoxide (DMSO) and sulfolane); And so on. Such mixtures typically contain water in an amount of from about 40% by weight to about 80% by weight, in some embodiments from about 50% by weight to about 75% by weight, and in some embodiments from about 60% by weight to about 70% by weight of the solvent system and secondary solvents in an amount of about 20% by weight to about 60% by weight, in some embodiments of about 25% by weight. from about 50 wt.%, and in some embodiments, from about 30 wt.% to about 40 wt.% of the solvent system. Similarly, when such mixtures are used, water typically constitutes from about 30% by weight to about 70% by weight, in some embodiments from about 35% by weight to about 65% by weight. by weight, and in some embodiments, from about 40% by weight to about 60% by weight of the electrolyte and secondary solvents may comprise from about 5% by weight to about 40% by weight, in some embodiments of about 10% by weight to about 35% by weight, and in some embodiments from about 15% by weight to about 30% by weight of the electrolyte.
[0026] One or more acids or pH adjusters are also used to help achieve the desired pH and conductivity values. Suitable acids may include, for example, inorganic acids, such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, polyphosphoric acid, boric acid, boronic acid, and the like. ; organic acids, including carboxylic acids, such as acrylic acid, methacrylic acid, malonic acid, succinic acid, salicylic acid, sulfosalicylic acid, adipic acid, maleic acid, malic acid, oleic acid, gallic acid, tartaric acid, citric acid, formic acid, acetic acid, ethylenediaminetetraacetic acid ("EDTA"), glycolic acid, oxalic acid, propionic acid, phthalic acid, isophthalic acid, glutaric acid, gluconic acid, lactic acid, aspartic acid, glutamic acid, itaconic acid, trifluoroacetic acid, barbituric acid, cinnamic acid, benzoic acid, 4-hydroxybenzoic acid, aminobenzoic acid, and the like. ; sulphonic acids, such as methane sulphonic acid, benzene sulphonic acid, toluene sulphonic acid, trifluoromethane sulphonic acid, styrene sulphonic acid, naphthalene disulfonic acid, hydroxybenzene sulfonic acid, etc. ; polymeric acids, such as poly (acrylic) or poly (methacrylic) acid and copolymers thereof (e.g., maleic-acrylic, sulfonic-acrylic and styrene-acrylic copolymers), carrageenic acid, carboxymethylcellulose, alginic acid, etc. ; And so on. EDTA may be particularly suitable when a gelled electrolyte is used because not only can it reduce the pH value of the electrolyte, but it can also serve as a sequestering agent for any metal impurities that may be present in the particles. Although the total acid concentration may vary, they are typically present in an amount of from about 0.01% by weight to about 10% by weight, in some embodiments from about 0.05% by weight to about 10% by weight. about 5% by weight, and in some embodiments, from about 0.1% by weight to about 2% by weight of the electrolyte. In a particular embodiment, a mixture of different acids may be used, such as a mixture of an inorganic acid and an organic acid. In such embodiments, the inorganic acids (e.g., phosphoric acid) may comprise from about 0.005 wt% to about 5 wt%, in some embodiments about 0.01 wt%. at about 3% by weight, and in some embodiments, from about 0.05% by weight to about 1% by weight of the electrolyte, and organic acids (eg, EDTA) may similarly constitute from about 0.005% by weight to about 5% by weight, in some embodiments from about 0.01% by weight to about 3% by weight, and in some embodiments about 0.05% by weight. weight at about 1% by weight of the electrolyte. The electrolyte may also contain other components that help improve the electrical performance of the capacitor. For example, a depolarizer may be used in the electrolyte to help prevent the evolution of hydrogen gas at the cathode of the electrolytic capacitor, which could otherwise cause the capacitor to swell and eventually rupture. . When used, the depolarizer is normally from about 1 to about 500 parts per million ("ppm"), in some embodiments from about 10 to about 200 ppm, and in some embodiments, from about 20 to about 150 ppm of the electrolyte. For example, depolarizers typically comprise from about 0.01% by weight to about 5% by weight, in some embodiments from about 0.05% by weight to about 2% by weight, and in some embodiments from about 0.1% by weight to about 1% by weight of the electrolyte.
[0027] Suitable depolarizers may include nitroaromatic compounds, such as 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2-nitrobenzonic acid, 3-nitrobenzonic acid, 4-nitrobenzonic acid, 2-nitrophenol, nitroacetophenone, 3-nitroacetophenone, 4-nitroacetophenone, 2-nitroanisole, 3-nitroanisole, 4-nitroanisole, 2-nitrobenzaldehyde, 3-nitrobenzaldehyde, 4-nitrobenzaldehyde, 2-nitrobenzyl alcohol, 3-nitrobenzyl alcohol, 4-nitrobenzyl alcohol, 2-nitrophthalic acid, 3-nitrophthalic acid, 4-nitrophthalic acid, and so on. Nitroaromatic depolarizers particularly suitable for use in the present invention are nitrobenzoic acids, anhydrides or salts thereof, substituted with one or more alkyl groups (eg, methyl, ethyl, propyl, butyl, etc.). Specific examples of such alkyl-substituted nitrobenzoic compounds include, for example, 2-methyl-3-nitrobenzoic acid; 2-methyl-6-nitrobenzoic acid; 3-methyl-2-nitrobenzoic acid; 3-methyl-4-nitrobenzoic acid; 3-methyl-6-nitrobenzoic acid; 4-methyl-3-nitrobenzoic acid; anhydrides or salts thereof; and so on. In a particular embodiment, the operational electrolyte may be in the form of a viscoelastic gel, which is generally defined as being a solid or semisolid colloidal suspension which contains a continuous phase and a dispersed phase, at least one of the phases being a solid and at least one of the phases being a liquid. For example, a hydrogel may be formed when the inorganic oxide particles are crosslinked to form a continuous phase and the solvent contains water as the dispersed phase which is trapped within the crosslinked network. Regardless of its exact form, the viscoelastic gel inside the capacitor is in the form of a semi-solid or solid so that it is not easily liquid at room temperature. This property can be represented by the viscoelastic phase angle δ, which is the degree to which the sinusoidal temporal variation in the stress is out of phase with respect to the sinusoidal temporal variation in the shear rate. The phase angle δ for an ideal elastic solid is 0 ° (in phase) and the phase angle θ for an ideal viscous liquid is 90 ° (out of phase). In the present invention, the gelled electrolyte typically has a phase angle of from 0 ° to about 20 °, in some embodiments from 0.1 ° to about 5 °, and in some embodiments from 0.2 ° to about 2 °. Another parameter that can represent the viscoelastic behavior of the gel is the conservation modulus, G ', which is determined by dividing the "in-phase" component of the stress (representing a behavior similar to a solid) by the maximum strain. Typically, the gel electrolyte of the present invention has a storage modulus of about 5 kilopascals ("kPa") or more, in some embodiments of about 10 kPa or more, and in some embodiments of about 15 kPa or more. at 3031230 61 about 50 kPa. The phase angle and the storage modulus can be determined at room temperature (e.g., 25 ° C) by dynamic oscillatory tests (e.g., 10 Hz frequency and 5 Pa pressure) with a rheometer having a planar configuration. -cone. To achieve the combination of high conductivity and a neutral pH value, the working electrolyte gel may contain a combination of the weak organic acid salt, the solvent system, and the acid (pH) adjuster disclosed above together. with inorganic oxide particles to help achieve the desired viscosity and electrical properties for the capacitor.
[0028] The amount of inorganic oxide particles in the electrolyte may vary depending on the degree of gelation required as well as the particular nature and concentration of other components in the electrolyte. Typically, however, inorganic oxide particles comprise from about 0.5% by weight to about 20% by weight, in some embodiments from about 1% by weight to about 15% by weight, and in some embodiments embodiments, from about 1.5% by weight to about 10% by weight of the electrolyte. The particles may have various shapes, aspects and sizes depending on the desired result. For example, the particles may be in the form of sphere, crystal, rod, disc, tube, string, etc. The average particle size may be less than about 1000 nanometers, in some embodiments from about 1 to about 500 nanometers, in some embodiments from about 2 to about 200 nanometers, and in some embodiments, From about 4 to about 50 nanometers. As used herein, the average size of a particle refers to its average length, width, height, and / or diameter. The particles also typically have a high surface area, such as from about 50 square meters per gram (m 2 / g) to about 1000 m 2 / g, in some embodiments from about 100 m 2 / g to about 600 m 2 / g. and, in some embodiments, from about 150 m 2 / g to about 400 m 2 / g. The term "surface area" generally refers to the surface as determined by Bruanauer's physical gas adsorption (B.E.T.) method, Emmet and Teller, Journal of the American Chemical Society, Vol. 60, 1938, p. 309, with nitrogen as an adsorption gas.
[0029] The assay can be performed with a MONOSORB® specific surface analyzer available from QUANTACHROME Corporation, Syosset, NY, which measures the amount of adsorbed nitrogen adsorbed on a solid surface by detecting the change in thermal conductivity of a mixture. adsorbate liquid and inert carrier gas (for example, helium). In addition, the particles may also be relatively non-porous or solid. That is, the particles may have a pore volume that is less than about 0.5 milliliters per gram (ml / g), in some embodiments less than about 0.4 milliliters per gram, in some embodiments. less than about 0.3 ml / g, and in some embodiments, about 0.2 ml / g to about 0.3 ml / g. Without intending to be limited by theory, it is believed that particles having such a small size, large area and solid nature can improve the rate of gelation and improve the uniformity and stability of the resulting slurry.
[0030] The inorganic oxide particles can be formed from a variety of materials, including, but not limited to, silica, alumina, zirconia, magnesium oxide, titanium dioxide, magnesium oxide and the like. iron oxide, zinc oxide, copper oxide, etc., as well as combinations thereof. Particles can also be formed using a pyrogenic process, precipitation, etc. Because of their larger surface area and smaller particle size, however, the pyrogenic particles are particularly suitable for use in the present invention. Pyrogenic silica, for example, is amorphous SiO 2 which can be produced by vapor phase hydrolysis of silicon tetrachloride in an oxygen-oxygen flame. Three-dimensional branched chain aggregates are produced in the flame from the melting of the primary particles. During cooling, these aggregates agglomerate into a fine powder having a particle size within the ranges noted above. The fumed silica has silanol groups which can react under acidic conditions to form a crosslinked network. The resulting siloxane crosslinking is a silicon and oxygen compound in which each silicon atom is bonded to four oxygen atoms, forming a tetrahedron structure, analogously to the bonding of carbon to hydrogen in water. methane, the bonds being about the same resistance in each case. This structure is found in the dioxide and in silicates generally, where the SiO 4 groups occur in chains or rings. By creating siloxane crosslinks, a gel is formed which traps the liquid phase of the electrolyte. Commercially suitable pyrogenic silica particles may, for example, include those available from Cabot Corporation under the name CAB-0-SILO. The components of the operational electrolyte can be combined together in a variety of different ways, before and / or after their incorporation into the capacitor. In a particular embodiment, the electrolyte may be gelled before it is placed in contact with the anode and / or the cathode. For example, when the electrolyte components are initially associated together, the electrolyte may be in the form of a sol which contains particles in the form of a dispersed phase. However, such soils can be catalyzed to cause gelation by several methods. Examples include adjusting the pH and / or the soil temperature to a point where gelation occurs. Alternatively, the soil may be subjected to a controlled form of energy (e.g., thermal, ultrasonic, ultraviolet light, electron beam radiation, etc.) to cause gelation. The use of ultrasonic energy (e.g., ultrasonic probes) is particularly desirable because it minimizes the need to change the pH or temperature of the electrolyte. The electrolyte can be incorporated into the capacitor in a variety of different ways. In one embodiment, for example, the electrolyte 10 is simply added to the capacitor after the anode and the cathode are positioned in the desired configuration. This can be accomplished, for example, by using a fill port. The anode may also be pre-impregnated with the electrolyte, for example by soaking the anode in the electrolyte before it is placed in the capacitor. Impregnation of the anode with the electrolyte can further improve the degree of contact between the anode and the electrolyte. The electrolyte may have a low initial viscosity and fluidity so that it can be precisely incorporated into the capacitor. For example, when in gel form, the electrolyte may have an initial viscosity (eg, 1 hour or less after gelation is started) within the range of about 1 to about 40 centipoise, in some embodiments of about 2 to about 30 centipoise, and in some embodiments, about 3 to about 10 centipoise, as determined using a Brookfield LVT viscometer (spindle # 3 to 60). rpm) at a temperature of 25 ° C. Similarly, the gel may have an initial phase angle of from about 50 ° to 90 °, in some embodiments from about 60 ° to 90 °, and in some embodiments from about 80 ° to about 90 °. At 90 °, as well as an initial conservation module G 'of about 1 kilopascal or less, in some embodiments about 0.1 kilopascal or less, and in some embodiments, from 0 to about 0, 01 kilopascal. After incorporation into the capacitor, however, the electrolyte may continue to gel to a viscosity, conservation modulus angle G 'within the above noted range. This transition phase 5, and / or one of the "semi-solid" target ranges or that the viscosity is increased, such as "solid" can occur relatively after the gelation is entrained, for example from about 1 to about 100 hours, in some embodiments from about 10 to about 80 hours, and in some embodiments, from about 20 to about 60 hours.
[0031] The transition may also occur before the anode is and / or after the anode is incorporated in the capacitor and placed in contact with the cathode. If desired, an additional "fill" electrolyte may be added to ensure that good electrical contact exists between the impregnated anode and the cathode. This filling electrolyte may be formed in accordance with the present invention, or it may be formed from other known components.
[0032] Regardless of its particular configuration, the capacitor of the present invention can exhibit excellent electrical properties. For example, the capacitor may have a high volumetric efficiency, such as from about 50,000 pF * V / cm3 to about 300,000 pF * V / cm3, in some embodiments from about 60,000 pF * V / cm3 to about 200,000 pF * V / cm3, and in some embodiments, from about 80000 pF * V / cm3 to about 150000 pF * V / cm3, determined at a frequency of 120 Hz and at room temperature (e.g., 25 ° C) . The volumetric efficiency is determined by multiplying the forming voltage of a portion by its capacity, and then dividing the product by the volume of the portion. For example, a forming voltage may be 175 volts for a 520 pF capacitor, resulting in a 91,000 pF * V product. If the portion occupies a volume of about 0.8 cc, this results in a volumetric efficiency of about 113750 pF * V / cm3. The capacitor may also have a high energy density which makes it suitable for use in high pulse applications. The energy density is generally determined according to the equation E = 1/2 * CV2, where C is the capacity in farads (F) and V is the capacitor operating voltage in volts (V). The capacity can, for example, be measured using a capacitance meter (for example, Keithley's 3330 Precision LCZ meter with Kelvin wires, 2-volt polarization, and 1-volt signal). at operating frequencies of 10 to 120 Hz (e.g., 120 Hz) and a temperature of 25 ° C. For example, the capacitor may have an energy density of about 2.0 joules per cubic centimeter (J / cm 3) or more, in some embodiments about 3.0 J / cm 3, in some embodiments. from about 3.5 J / cm3 to about 15.0 J / cm3, and in some embodiments from about 4.0 to about 12.0 J / cm3. The capacity can similarly be about 1 milliFarad per square centimeter ("mF / cm 2") or more, in some embodiments about 2 mF / cm 2 or more, in some embodiments from about 5 to about 50 mF. / cm 2, and in some embodiments, from about 8 to about 20 mF / cm 2. The capacitor may also have a relatively high "breakdown voltage" (voltage at which the capacitor is defective), such as about 180 volts or more, in some embodiments about 200 volts or more, and in some embodiments. from about 210 volts to about 260 volts. Equivalent 20 Series Resistance (ESR) - the extent to which the capacitor behaves like a resistor when charging and discharging in an electronic circuit - can also be less than about 15000 milliohms, in some embodiments of less than about 10,000 milliohms, in some embodiments less than about 5,000 milliohms, and in some embodiments, from about 1 to about 4500 milliohms, measured with a 2 volt bias and a DC signal. In addition, the leakage current, which generally refers to current flowing from a conductor to an adjacent conductor through an insulator, can be maintained at relatively low levels. For example, the numerical value of the normalized leakage current of a capacitor of the present invention is, in some embodiments, less than about 1 pA / pF * V, in some embodiments less than about 0.5 pA. In some embodiments, less than about 0.1 pA / pF * V, where pA is microamperes and pF * V is the product of capacity and rated voltage. The leakage current can be measured using a leakage current test meter (for example, MC 190 Leakage test, Mantracourt Electronics LTD, UK) at a temperature of 25 ° C and at a certain rated voltage. after a charging time of about 60 to about 300 seconds. Such ESR values and normalized leakage current can even be maintained after aging for a significant period of time at high temperatures. For example, values may be maintained for about 100 hours or more, in some embodiments from about 300 hours to about 2500 hours, and in some embodiments, from about 400 hours to about 1500 hours (for example, 500 hours, 600 hours, 700 hours, 800 hours, 900 hours, 1000 hours, 1100 hours or 1200 hours) at temperatures ranging from about 100 ° C to about 250 ° C, and in some embodiments of about 100 ° C to about 200 ° C (e.g., 100 ° C, 125 ° C, 150 ° C, 175 ° C or 200 ° C) The electrolytic capacitor of the present invention can be used in a variety of applications, including including, but not limited to, medical devices, such as defibrillators, pacemakers, cardiovers, neural stimulators, implantable drug delivery devices, etc. ; automotive applications; military applications, such as RADAR systems; consumer electronics, such as radios, televisions, etc. ; And so on. In one embodiment, for example, the capacitor may be used in an implantable medical device configured to provide high voltage therapeutic treatment (e.g., between approximately 500 volts and approximately 850 volts, or, desirably, approximately 600 volts and approximately 900 volts) for a patient. The device may contain a container or housing that is hermetically sealed and biologically inert. One or more conductors are electrically coupled between the device and the patient's heart via a vein. Cardiac electrodes are provided to detect cardiac activity and / or provide tension to the heart.
[0033] At least a portion of the leads (e.g., an end portion of the leads) may be provided adjacent to, or in contact with, one or more of a ventricle and a heart atrium. The device may also contain a battery of capacitors which typically contains two or more capacitors connected in series and coupled to a battery which is internal or external to the device and supplies power to the capacitor bank. Due in part to the high conductivity, the capacitor of the present invention can obtain excellent electrical properties and thus be suitable for use in the capacitor bank of the implantable medical device. These and other modifications and variations of the present invention may be practiced by one of ordinary skill in the art without departing from the spirit and scope of the present invention. Furthermore, it is to be understood that aspects of the various embodiments may be exchanged in whole or in part. In addition, one of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention.

权利要求:
Claims (24)
[0001]
REVENDICATIONS1. A wet electrolyte capacitor (10) comprising: a planar anode (200, 201, 202, 203, 300, 400, 500) comprising an anodically oxidized pellet formed from a pressed and sintered powder, the planar anode ( 200, 201, 202, 203, 300, 400, 500) having a recessed portion (46, 146, 246) formed in at least one surface; a cathode which comprises a metal substrate 10 coated with an electro-chemically active material; a retainer (48, 148, 248) that contacts the recessed portion (46, 146, 246) and has a shape that generally corresponds with a shape of the recessed portion (46, 146, 246); and an operational electrolyte in communication with the planar anode (200, 201, 202, 203, 300, 400, 500) and the cathode.
[0002]
The wet electrolyte condenser (10) of claim 1, wherein the retainer (48, 148, 248) is in contact with the entire recessed portion (46, 146, 246) of the planar anode (200, 201). , 202, 203, 300, 400, 500).
[0003]
The wet electrolyte capacitor (10) of claim 1, wherein multiple restraints (48, 148, 248) are in contact with multiple sections of the recessed portion (46, 146, 246) of the planar anode. (200, 201, 202, 203, 300, 400, 500). 3031230 73
[0004]
The wet electrolyte condenser (10) of claim 1, wherein the retainer (48, 148, 248) comprises a polymer, a glass or a ceramic.
[0005]
The wet electrolyte capacitor (10) according to claim 4, wherein the retainer (48, 148, 248) comprises a polyolefin, a fluoropolymer, an elastomer, a thermosetting resin, an epoxy resin, or a combination thereof. this.
[0006]
The wet electrolyte capacitor (10) according to claim 1, wherein the recessed portion (46, 146, 246) is formed in an upper surface (42) or a lower surface (40) of the planar anode (200). , 201, 202, 203, 300, 400, 500).
[0007]
The wet electrolyte condenser (10) according to claim 6, wherein the recessed portion (46, 146, 246) extends from a circumferential inner edge (52) of the planar anode (200, 201, 202). , 203, 300, 400, 500) at a circumferential outer edge (50) of the planar anode (200, 201, 202, 203, 300, 400, 500), the circumferential inner edge (52) defining a central portion protruding (44, 144, 244) from the planar anode (200, 201, 202, 203, 300, 400, 500).
[0008]
The wet electrolyte capacitor (10) of claim 7, wherein the projecting central portion (44, 144, 244) has an area which is from about 50% to about 99.5% of an area of planar anode (200, 201, 202, 203, 300, 400, 500) defined by the circumferential outer edge (50). 30
[0009]
The wet electrolyte capacitor (10) of claim 7, wherein the retainer (48, 148, 248) 3031230 74 is in contact with the circumferential inner edge (52) of the planar anode (200, 201, 202, 203, 300, 400, 500).
[0010]
The wet electrolyte capacitor (10) according to claim 7, wherein the circumferential inner edge (52) of the planar anode (200, 201, 202, 203, 300, 400, 500) and the circumferential outer edge ( 50) of the planar anode (200, 201, 202, 203, 300, 400, 500) generally have the same shape.
[0011]
The wet electrolyte capacitor (10) according to claim 7, wherein the circumferential inner edge (52) has a shape different from the circumferential outer edge (50) of the planar anode (200, 201, 202, 203, 300, 400, 500).
[0012]
The wet electrolyte capacitor (10) of claim 1, wherein the recessed portion (46, 146, 246) is formed in a side wall of the planar anode (200, 201, 202, 203, 300, 400, 500).
[0013]
The wet electrolyte condenser (10) according to claim 12, wherein an upper surface (42) and a lower surface (40) of the planar anode (200, 201, 202, 203, 300, 400, 500) exhibit the same shape and dimensions.
[0014]
The wet electrolyte capacitor (10) of claim 1, wherein the planar anode (200, 201, 202, 203, 300, 400, 500) has a D shape.
[0015]
The wet electrolyte capacitor (10) of claim 1, wherein the planar anode (200, 201, 202, 203, 300, 400, 500) has a shoulder shape. 3031230 75
[0016]
The wet electrolyte capacitor (10) of claim 1, wherein the electrochemically active material comprises a conductive polymer.
[0017]
17. The wet electrolyte capacitor (10) of claim 16, wherein the conductive polymer is a substituted polythiophene.
[0018]
The wet electrolyte condenser (10) of claim 1, wherein the planar anode (200, 201, 202, 203, 300, 400, 500) has a thickness of about 5 millimeters or less.
[0019]
The wet electrolyte capacitor (10) of claim 1, wherein the powder is formed from tantalum particles.
[0020]
20. The wet electrolyte capacitor (10) of claim 1, wherein the metal substrate includes titanium.
[0021]
21. The wet electrolyte condenser (10) of claim 1, wherein the metal substrate forms a housing around the planar anode (200, 201, 202, 203, 300, 400, 500).
[0022]
An implantable medical device comprising the wet electrolyte capacitor (10) of claim 1.
[0023]
23. Flat anode (200, 201, 202, 203, 300, 400, 500) for a wet electrolyte capacitor (10), the planar anode (200, 201, 202, 203, 300, 400, 500) comprising an anodically oxidized pellet formed from a pressed and sintered powder, wherein a recessed portion (46, 146, 246) is located in a surface of the planar anode (200, 201, 202, 203, 300, 400, 500), wherein the recessed portion (46, 146, 246) 76 is configured to receive a restraint (48, 148, 248).
[0024]
An implantable medical device comprising the planar anode (200, 201, 202, 203, 300, 400, 500) according to claim 23.

类似技术:

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公开号 | 公开日 | 专利标题

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FR3031230A1|2016-07-01|WET ELECTROLYTE CAPACITOR CONTAINING EVIDED PLANAR ANODE AND RETENTION

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US9105401B2|2015-08-11|Wet electrolytic capacitor containing a gelled working electrolyte

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US8687347B2|2014-04-01|Planar anode for use in a wet electrolytic capacitor

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FR2966969A1|2012-05-04|LIQUID ELECTROLYTE CAPACITOR WITH OPTIMIZED VOLUMETRIC EFFICIENCY.

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FR2988209A1|2013-09-20|WET CONDENSER CATHODE CONTAINING A CONDUCTIVE COATING FORMED BY ANODIC ELECTROCHEMICAL POLYMERIZATION OF A MICROEMULSION

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US9384901B2|2016-07-05|Wet electrolytic capacitor for use at high temperatures

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FR3029006A1|2016-05-27|WET ELECTROLYTIC CAPACITOR FOR IMPLANTABLE MEDICAL DEVICE

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FR3028659A1|2016-05-20|HERMETICALLY CLOSED CAPACITOR FOR IMPLANTABLE MEDICAL DEVICE

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US8477479B2|2013-07-02|Leadwire configuration for a planar anode of a wet electrolytic capacitor

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FR2980032A1|2013-03-15|SEALING ASSEMBLY FOR WET ELECTROLYTIC CAPACITOR

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FR2966970A1|2012-05-04|LIQUID ELECTROLYTE CAPACITOR SEALS HERMETICALLY.

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FR2984587A1|2013-06-21|LIQUID ELECTROLYTE CAPACITOR CONTAINING AN IMPROVED ANODE

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FR2965093A1|2012-03-23|CONDUCTIVE POLYMER COATING FOR A LIQUID ELECTROLYTE CAPACITOR

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FR2988211A1|2013-09-20|WET CONDENSER CATHODE CONTAINING ALKYL-SUBSTITUTED POLY |

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FR2988210A1|2013-09-20|WET CONDENSER CATHODE CONTAINING A CONDUCTIVE COATING FORMED BY ANODIC ELECTROCHEMICAL POLYMERIZATION OF A COLLOIDAL SUSPENSION.

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FR2973927A1|2012-10-12|BOX CONFIGURATION FOR SOLID ELECTROLYTIC CAPACITOR

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FR2965970A1|2012-04-13|CONDUCTIVE POLYMER CATHODE HAVING BEEN SUBJECTED TO ABRASIVE PROJECTION, USEFUL IN A LIQUID ELECTROLYTE CAPACITOR

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FR2965092A1|2012-03-23|TECHNIQUE FOR FORMATION OF A CATHODE OF A LIQUID ELECTROLYTE CAPACITOR

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FR3003391A1|2014-09-19|WET ELECTROLYTE CAPACITOR

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FR3010825A1|2015-03-20|

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IL266514A|2021-03-25|Wet electrolytic capacitor for an implantable medical device

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FR3010823A1|2015-03-20|

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FR3010824A1|2015-03-20|

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IL240774A|2020-04-30|Hermetically sealed capacitor for an implantable medical device

同族专利:

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公开号 | 公开日

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US9620294B2|2017-04-11|

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HK1221067A1|2017-05-19|

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FR3031230B1|2020-02-07|

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DE102015223278A1|2016-06-30|

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US20160189876A1|2016-06-30|

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CN105742066B|2019-01-15|

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CN105742066A|2016-07-06|

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法律状态:
2016-10-17| PLFP| Fee payment|Year of fee payment: 2 |

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2017-10-18| PLFP| Fee payment|Year of fee payment: 3 |

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2018-10-17| PLFP| Fee payment|Year of fee payment: 4 |

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2019-01-25| PLSC| Publication of the preliminary search report|Effective date: 20190125 |

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2019-10-29| PLFP| Fee payment|Year of fee payment: 5 |

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2020-10-23| PLFP| Fee payment|Year of fee payment: 6 |

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2021-10-25| PLFP| Fee payment|Year of fee payment: 7 |

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2022-03-04| CD| Change of name or company name|Owner name: KYOCERA AVX COMPONENTS CORPORATION, US Effective date: 20220125 |

优先权:

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申请号 | 申请日 | 专利标题

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US14/585354|2014-12-30|

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US14/585,354|US9620294B2|2014-12-30|2014-12-30|Wet electrolytic capacitor containing a recessed planar anode and a restraint|

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