• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: A lithium ion polymer cell membrane and a lithium ion polymer cell comprising the same are provided to effectively enhance properties by using mica type laminated silica instead of a conventional silica. CONSTITUTION: A mica type laminated silica located between anode and cathode includes cations of metal. The mica type laminated silica has polarity compared to a talc type laminated silica which is electrically neutral. The silica is laminated in nano size, and this cooperates with polymer chains composing a membrane so that the chains can be occluded between layers. The polymer membrane including the mica type laminated silica has decreased crystallization tendency of the polymer and increased mechanical properties.
    公开号:KR20000059388A
    申请号:KR1019990006940
    申请日:1999-03-03
    公开日:2000-10-05
    发明作者:안순호；김명환；이향목
    申请人:성재갑；주식회사 엘지화학；
    IPC主号:
    专利说明:

    Membrane for lithium ion polymer battery and lithium ion polymer battery comprising same {SEPARATOR FOR LITHIUM ION POLYMER BATTERY AND LITHIUM ION POLYMER BATTERY COMPRISING THE SAME}
    The present invention relates to a separator for a lithium ion polymer battery and a lithium ion polymer battery including the same. Specifically, the present invention provides a separator for a lithium ion polymer battery, which is made of a polymer having low crystallinity and excellent mechanical properties.
    Lithium ion batteries are classified into lithium ion liquid batteries using a liquid electrolyte, lithium ion polymer batteries using a solid polymer electrolyte, and the like according to the electrolyte state to be used.
    The solid electrolyte used in the lithium ion polymer battery is a plasticizer such as dibutyl phthalate in a polymer matrix such as a copolymer of polyvinylidene fluoride and hexafluoropropylene. To impregnate the electrolyte solution. In addition to the copolymer matrix, a polymer matrix such as polyacrylonitrile may be used. The solid electrolyte prepared in this manner serves as a separator and an electrolyte, and a polymer membrane formed by adding a plasticizer before the electrolyte is impregnated is called a separator.
    In recent years, in order to increase the physical properties of the separator, silica is used to prepare the matrix. As such, the addition of silica has the following advantages. First, the mechanical properties of the separator can be increased by performing the role of a reinforcing agent in the polymer matrix. Second, the crystallinity of the separator may be lowered to increase the amount of amorphous parts. In this case, the impregnation amount of the electrolyte is increased when the electrolyte is impregnated with the separator. In other words, it is a technique developed by maintaining or improving ionic conductivity while increasing mechanical properties.
    In order to obtain such an effect, the silica added to the conventional separator mainly uses isotropic silica, such as spherical. Since the size of the silica particles is very small (7 to 40 mm), the surface area (50 to 400 m 2 / g) formed thereof is very large as a result, so that the amount of impregnation of the electrolyte solution can be increased.
    In general, the surface of the silica particles contain a hydrophilic hydroxyl group (hydroxyl group), depending on the purpose of use is often replaced with a hydrophobic ligand (ligand) through the chemical treatment of the surface. When silica is dispersed in a polymer matrix, it generally has a three-dimensional network structure. The network structure is determined by the amount of silica dispersed, the modified surface properties, and the properties of the matrix material. The network is known to be produced by van der Waals interactions, electrostatic interactions and hydrogen bonding.
    However, the effect of using the conventional spherical silica has a limit and various efforts are currently underway to develop a more efficient method.
    An object of the present invention is to provide a separator for a lithium ion polymer battery that can lower the crystallinity of the polymer and improve mechanical properties.
    Another object of the present invention is to provide a lithium ion polymer battery prepared by the separator for a lithium ion polymer battery having excellent ion conductivity and mechanical properties.
    1 is a heat flow curve measured by the separation membrane prepared according to the method of Examples and Comparative Examples (Differential Scanning Calorimetry, temperature increase rate = 10 ℃ / min).
    2 is a strain-stress curve (stretch rate = 20 mm / min) of membrane samples prepared according to the methods of Examples and Comparative Examples.
    In order to achieve the above object, the present invention is a mica-type layered silica (mica-type layered silica); And it provides a separator for a lithium ion polymer battery comprising a plasticizer.
    In addition, the present invention is an anode; Provided is a lithium ion polymer battery comprising a negative electrode and mica type layered silica positioned between the positive electrode and the negative electrode, and impregnated with an electrolyte solution.
    Hereinafter, the present invention will be described in more detail.
    The present invention provides a separator for a lithium ion battery that effectively improves the physical properties of the separator by using mica type layered silica instead of the conventionally used spherical silica.
    The separator for a lithium ion battery of the present invention contains mica type layered silica. The silica used in the present invention forms a nano-sized layered layer (interlayer distance: ˜1 nm), which interacts with the polymer chains forming the separator, and chains can be occluded between each layer. In this specification, the mica type refers to a form in which a plurality of flakes form a layer like mica.
    This mica type layered silica contains metal cations (Na + , Li + ) and the like.
    As described above, the mica type layered silica containing a metal cation in the layer used in the present invention has a polarity unlike the talc layered silica being electrically neutral.
    In general, in order to occlude the polymer chain into the layer, it must be able to control the properties of each other. That is, since the silica in the cation-containing state can only occlude chains having strong polarity such as water-soluble polymers, in order to occlude the non-polar polymer, the metal cation inside the silica layer should be replaced with a hydrophobic organic cation. As a method of replacing a metal cation with a hydrophobic organic cation, any method generally used in the method of replacing a metal cation with an organic cation can be used. A representative example thereof is a method using an ion exchange reaction. Since the polymer is occluded in the space between the silica layers (nano-sized galleries) to form a complex having a geometrical two-dimensional nano-size, the physical properties of the polymer change significantly.
    In order to use the mica layered silica in the separator of a lithium ion polymer battery, it is necessary to select an organic cation that can effectively interact with the membrane polymer. Therefore, it is a technical problem of the present invention to improve mechanical properties that can be relatively disadvantageous while preventing the crystal of the membrane polymer.
    As the organic material for substituting such metal cations, any organic material may be used as long as the material effectively interacts with the polymer constituting the separator of the battery through van der Waals attraction, hydrogen bonding, and dipole interaction. Representative examples thereof include aminoundecanoic acid and dodecyl trimethyl ammonium bromide. The organic material treated on silica can be variously adopted, and in the method, a compound having a structure that effectively induces mutual attraction can be selected and used in consideration of the properties of the polymer used in the separator.
    As such, after the silica substituted with the metal cation is added to the polymer solution, it is stirred well on the solution. As the polymer, generally any polymer used as a separator of a battery may be used, and a representative example thereof may be a copolymer of polyvinylidene-fluoride and hexafluoropropylene. A plasticizer is further added to the polymer solution. The plasticizer assembles the separator, the positive electrode, and the negative electrode, and forms pores in the electrode plate in the process of extracting the plasticizer using an organic solvent, thereby providing a space for the electrolyte to penetrate. As such a plasticizer, any compound can be used as long as it can play such a role, and a representative example thereof is dibutyl phthalate.
    After forming a film by a casting process, a polymer solution containing silica and a plasticizer is used as a separator of a lithium ion polymer battery. It is apparent that any one of ordinary skill in the art can manufacture a lithium ion polymer battery using the separator for a lithium ion polymer battery.
    The membrane of the present invention prepared by the above process is because the chain is occluded by the interaction of the polymer chain and the organic substance substituted inside the silica layer to prevent the phenomenon that the polymer chains are aligned and crystallize themselves. Moreover, crystallization disturbances can occur effectively because the distance between the silica layers has a very small nano size.
    In addition, the degree of interference with crystallization of the polymer largely depends on the interaction between the polymer constituting the separator and the organic material, or the strength thereof. In general, when the crystallinity of the polymer is relatively low, the mechanical properties are lowered. However, the membrane according to the present invention has a new shape, that is, the inner surface area of the silica layer that can interact with the polymer when it is occluded is much larger than the surface area of the normal spherical particles, and the polymer matrix and Because they form a network, they form nanocomposites that have increased mechanical properties despite relatively low crystallization.
    EXAMPLE
    Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are only one preferred embodiment of the present invention and the present invention is not limited to the following examples.
    (Example 1)
    The mica type layered silica containing a metal cation inside the layer was subjected to ion exchange using an amino undecanoic acid as an organic material. Silica in which the metal cation was substituted with the organic material was washed and then freeze-dried to obtain the modified silica.
    The polyvinylidene fluoride-hexafluoropropylene copolymer was dissolved in acetone to prepare a polymer solution. The modified silica and plasticizer were added and dissolved in this polymer solution. The obtained product was cast to prepare a film to prepare a separator for a lithium ion polymer battery.
    (Example 2)
    A separator for a lithium ion polymer battery was prepared in the same manner as in Example 1, except that dodecyl trimethyl ammonium bromide was used as the organic material.
    (Comparative Example 1)
    The same process as in Example 1 was carried out except that a spherical silica surface-treated with a trimethylsilyl group was used.
    The composition ratio of the separator prepared by the method of Example 1-2 and Comparative Example 1 is shown in Table 1 below. In Table 1, PVDF-HFP is a polyvinylidene fluoride-hexafluoropropylene copolymer, DBP is a dibutyl-phthalate plasticizer, MM0 is a silica in the form of spherical particles surface-treated with trimethylsilyl group, and MM1 is an aminoundecanoic acid. Mica type layered silica and MM2 treated with mean mica type layered silica treated with dodecyl trimethyl ammonium bromide.
    Creation costs PVDF-HFPDBPMM0MM1MM2 Example 144-One- Example 244--One Comparative Example 144One--
    Crystallization of the separators of Examples 1-2 and Comparative Example 1 was measured using a differential scanning calorimetry (raising rate of 10 ℃ / min). In addition, crystallization of the separation membrane after dibutylphthalate as a plasticizer was extracted using ether was also measured (raising rate of 10 ° C./min). The results are shown in FIG. Figure 1 shows the heat flow curves before and after DBP extraction of each separator, and shows the degree of crystallization by melting. Regardless of before and after DBP extraction, Examples 1 and 2 using layered silica were observed to have less heat of crystalline melting than Comparative Example 1 using ordinary silica. In particular, Example 2 shows the biggest difference because the organic dodecyl trimethyl ammonium bromide substituted inside the layered silica interacts more effectively with PVDF-HFP. Meanwhile, FIG. 1 also shows the heat flow curve of pure PVDF-HFP for better comparison.
    Figure 2 shows the strain-stress curve of each separator (prior to DBP extraction). Although the modulus corresponding to the initial slope is not significantly different, the stress of the separators of Examples 1 and 2 using layered silica is developed to a value greater than that of Comparative Example 1 after yielding, among which the mechanical properties of Example 2 This is observed to be the best.
    According to the present invention, when the mica-type layered silica is replaced with an appropriate organic material and used as a filler for a separator for a lithium ion polymer battery, the polymer chain is occluded into the layered layer, which effectively prevents the crystallinity of the polymer matrix and improves its mechanical properties. .
    As described above, the polymer separator including the mica-type layered silica of the present invention has a low crystallinity of the polymer and has improved mechanical properties. Batteries produced using such a separator has excellent mechanical properties due to the strong interaction between the occluded polymer and the silica is improved ionic conductivity by a small degree of crystallinity.
    权利要求:
    Claims (4)
    [1" claim-type="Currently amended] Mica type layered silica; And
    Plasticizer
    Separation membrane for a lithium ion polymer battery comprising a.
    [2" claim-type="Currently amended] The method of claim 1,
    Separation membrane for a lithium ion polymer battery, wherein the mica-type layered silica comprises an organic material therein.
    [3" claim-type="Currently amended] anode;
    cathode; And
    A separator for a lithium ion polymer battery positioned between the positive electrode and the negative electrode and including mica-type layered silica and in which an electrolyte is impregnated;
    Lithium ion polymer battery comprising a.
    [4" claim-type="Currently amended] The method of claim 3, wherein
    Lithium ion polymer battery wherein the mica layered silica comprises an organic material therein.
    类似技术:
    公开号 | 公开日 | 专利标题
    Xu et al.2018|Carbon nanomaterials for advanced lithium sulfur batteries
    Kang et al.2016|A review of recent developments in rechargeable lithium–sulfur batteries
    Zhao et al.2018|Recent developments and insights into the understanding of Na metal anodes for Na-metal batteries
    Wang et al.2015|Surface and interface engineering of electrode materials for lithium‐ion batteries
    Luo et al.2016|Critical thickness of phenolic resin-based carbon interfacial layer for improving long cycling stability of silicon nanoparticle anodes
    Park et al.2015|Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems
    Du et al.2016|Strategies to succeed in improving the lithium-ion storage properties of silicon nanomaterials
    US9543569B2|2017-01-10|Graphene-supported metal oxide monolith
    Zeng et al.2016|High performance lithium–sulfur batteries with a permselective sulfonated acetylene black modified separator
    Bae et al.2018|Designing 3D nanostructured garnet frameworks for enhancing ionic conductivity and flexibility in composite polymer electrolytes for lithium batteries
    Liu et al.2018|Ultra-long-term cycling stability of an integrated carbon–sulfur membrane with dual shuttle-inhibiting layers of graphene “nets” and a porous carbon skin
    EP2634839B1|2018-02-21|Secondary battery porous membrane, slurry for secondary battery porous membrane, and secondary battery
    Ji et al.2011|Recent developments in nanostructured anode materials for rechargeable lithium-ion batteries
    US9306240B2|2016-04-05|Solid polymeric electrolytes and lithium battery including the same
    Nan et al.2019|Nanoengineering of 2D MXene‐based materials for energy storage applications
    Pu et al.2019|Recent Progress in Rechargeable Sodium‐Ion Batteries: toward High‐Power Applications
    Abbas et al.2016|Bifunctional separator as a polysulfide mediator for highly stable Li–S batteries
    KR102071385B1|2020-01-30|Separator for rechargeable battery and rechargeable lithium battery including the same
    KR101797274B1|2017-11-13|Redox flow secondary battery and electrolyte membrane for redox flow secondary battery
    Zhao et al.2018|A review on anode for lithium-sulfur batteries: Progress and prospects
    US20180102535A1|2018-04-12|Rechargeable Alkaline Metal And Alkaline Earth Electrodes Having Controlled Dendritic Growth And Methods For Making And Using Same
    Ke et al.2007|Fabrication and properties of three-dimensional macroporous Sn–Ni alloy electrodes of high preferential | orientation for lithium ion batteries
    KR101981825B1|2019-05-23|Method for manufacturing a polymer electrolyte separator and polymer electrolyte separator therefrom
    US10243211B2|2019-03-26|Composite-coated lithium iron phosphate and preparation method therefor, and lithium ion battery
    Qu et al.2015|Graphene oxides-guided growth of ultrafine Co3O4 nanocrystallites from MOFs as high-performance anode of Li-ion batteries
    同族专利:
    公开号 | 公开日
    KR100371401B1|2003-02-07|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-03-03|Application filed by 성재갑, 주식회사 엘지화학
    1999-03-03|Priority to KR10-1999-0006940A
    2000-10-05|Publication of KR20000059388A
    2003-02-07|Application granted
    2003-02-07|Publication of KR100371401B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR10-1999-0006940A|KR100371401B1|1999-03-03|1999-03-03|Separator for lithium ion polymer battery and lithium ion polymer battery comprising the same|
    [返回顶部]