Separator for electrochemical device and electrochemical device comprising the same

Abstract

The present disclosure relates to a separator for an electrochemical device, the separator including a coating layer having a copolymer as a binder, the copolymer including: i) a repeating unit derived from a (meth)acrylic monomer, a (meth)acrylic salt monomer, or both; ii) a repeating unit derived from an acrylic monomer having an amide group; and iii) a repeating unit derived from a silane group monomer, a monomer having a silanol group, or both. Specifically, by including iii) a repeating unit derived from a silane group monomer, a monomer having a silanol group, or both, the copolymer can exhibit excellent adhesion to inorganic particles. Accordingly, the separator for an electrochemical device including the binder can exhibit excellent adhesion to an electrode as well as low heat shrinkage.

Description

Technical Field

[0001] This disclosure relates to a separator for an electrochemical device and an electrochemical device including the separator.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0129373, filed with the Korean Intellectual Property Office on September 24, 2024, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Electrochemical devices convert chemical energy into electrical energy through electrochemical reactions. In recent years, lithium secondary batteries, which have high energy density and voltage, long cycle life, and are suitable for various fields, have been widely used.

[0004] In the components of an electrochemical device, a separator may include a porous polymer substrate located between the positive and negative electrodes. This separator isolates the positive and negative electrodes to prevent electrical short circuits between the two electrodes, while allowing electrolytes and ions to pass through. Although the separator itself does not participate in the electrochemical reaction, physical properties such as wettability to the electrolyte, porosity, and thermal shrinkage can affect the performance and safety of the electrochemical device.

[0005] Therefore, various methods have been explored to improve the physical properties of such separators, in which a coating is added to a porous polymer substrate, and various materials are further included in the coating to improve its physical properties. For example, to improve the mechanical strength of the separator, inorganic materials can be added to the coating, or inorganic materials or hydrates can be added to the coating to improve the flame retardancy and heat resistance of the polymer substrate.

[0006] In the coating, inorganic particles can be linked together by a polymer binder to form interstitial volumes, through which lithium ions can migrate. That is, a coating containing both polymer binder and inorganic particles can be used to prevent thermal shrinkage of the separator while simultaneously promoting lithium ion migration through the separator.

[0007] Meanwhile, poly(meth)acrylic acid adhesives used as polymer binders, polyacrylamide adhesives as polyacrylic acid adhesives with amide groups, or copolymers of (meth)acrylic acid and acrylamide exhibit excellent heat resistance and, when used with inorganic particles, can advantageously reduce the thermal shrinkage problem of porous polymer substrates. However, the adhesives have low adhesion at room temperature or high temperatures, and the adhesion of the adhesives becomes weaker as the temperature increases. Therefore, separators for electrochemical devices containing adhesives in the coating suffer from the problem of deterioration in dry heat shrinkage and / or wet heat shrinkage at high temperatures. Summary of the Invention

[0008] Technical issues

[0009] This disclosure provides a separator for an electrochemical device that exhibits improved dry heat shrinkage and wet heat shrinkage at high temperatures, and an electrochemical device including the separator.

[0010] Technical solution

[0011] The separator for an electrochemical device according to a first aspect of this disclosure includes:

[0012] Porous polymer substrates; and

[0013] A coating comprising inorganic particles and an adhesive is disposed on at least one surface of the porous polymer substrate.

[0014] The adhesive comprises a copolymer comprising: i) repeating units derived from (meth)acrylic monomers, (meth)acrylate monomers, or both thereof; ii) repeating units derived from acrylic monomers having amide groups; and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both thereof.

[0015] According to the second aspect of this disclosure, in the first aspect...

[0016] The molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic acid monomers having amide groups is in the range of 1:3 to 1:5.

[0017] According to the third aspect of this disclosure, in the first or second aspect,

[0018] The molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both thereof and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both thereof is in the range of 1:0.01 to 1:0.1.

[0019] According to the fourth aspect of this disclosure, in any one of the first to third aspects,

[0020] The (meth)acrylate monomer is at least one selected from the group consisting of: sodium (meth)acrylate, potassium (meth)acrylate, lithium (meth)acrylate, and ammonium (meth)acrylate.

[0021] According to the fifth aspect of this disclosure, in any one of the first to fourth aspects,

[0022] The acrylic monomer having an amide group is at least one selected from the group consisting of: acrylamide, methacrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl) (meth)acrylamide, N,N-di(tert-butyl) (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-n-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-hydroxymethylpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-methoxyethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide.

[0023] According to the sixth aspect of this disclosure, in any one of the first to fifth aspects,

[0024] The silane monomer may be at least one selected from the group consisting of: vinyltrimethoxysilane, vinyldimethoxyethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and vinyltriacetoxysilane, and the monomer having a silanol group may be a hydrolysis product of the silane monomer.

[0025] According to the seventh aspect of this disclosure, in any one of the first to sixth aspects,

[0026] The content of the adhesive is in the range of 4 to 20 parts by weight, based on the total weight of 100 parts by weight of the coating.

[0027] According to the eighth aspect of this disclosure, in any one of the first to seventh aspects,

[0028] The weight-average molecular weight of the copolymer is in the range of 100,000 g / mol to 200,000 g / mol.

[0029] According to the ninth aspect of this disclosure, in any one of the first to eighth aspects,

[0030] Based on the total weight of 100 parts by weight of the coating, the content of the inorganic particles is in the range of 80 to 90 parts by weight.

[0031] According to the tenth aspect of this disclosure, in any one of the first to ninth aspects,

[0032] The thickness of the coating is in the range of 0.5 μm to 2 μm.

[0033] The eleventh aspect of this disclosure relates to an electrochemical device.

[0034] The electrochemical device includes a positive electrode, a negative electrode, and a separator for the electrochemical device according to any one of the first to tenth aspects; and

[0035] The separator for the electrochemical device is inserted between the positive and negative electrodes.

[0036] Beneficial effects

[0037] The separator for an electrochemical device according to this disclosure includes a coating in which a copolymer is used as a binder with inorganic particles. In addition to i) repeating units derived from (meth)acrylate monomers, (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic monomers having amide groups, the copolymer also includes iii) repeating units derived from silane monomers, monomers having silanol groups, or both. Therefore, component iii) of the copolymer can be firmly bonded to the surface of the porous polymer substrate or the surface of the inorganic particles by intermolecular forces (e.g., hydrogen bonding with the inorganic particles and the porous polymer substrate), and can also be bonded to the surface of the electrode. Therefore, the separator for an electrochemical device according to this disclosure (wherein the copolymer binder is included in the coating) exhibits a particularly improved thermal shrinkage rate at high temperatures, not only in the dry state but also in the wet state. Detailed Implementation

[0038] The following describes each configuration of this disclosure in more detail, enabling those skilled in the art to readily implement this disclosure. However, the following description is merely illustrative, and the scope of protection of this disclosure is not limited to the following description.

[0039] In this disclosure, when a section is described as "including" a component, it means that, unless otherwise stated, the section does not exclude the presence of other components, but may further include additional components.

[0040] In this disclosure, when a component is described as "arranged on a surface of another component", it means that, unless otherwise stated, other components are not excluded from being arranged between them, and additional components may be further arranged.

[0041] In this disclosure, the term "electrochemical device" can refer to, for example, a primary battery, a secondary battery, or a supercapacitor. More specifically, an electrochemical device can be a lithium-ion secondary battery and can be in the form of a pouch, cylinder, prism, or coin, but its specific shape is not limited thereto.

[0042] In this disclosure, the term "electrode" generally refers to both positive and negative electrodes, and can also refer to a structure in which an electrode active material is applied to at least one surface of a conductive material and then dried without causing a chemical change in the electrochemical device. The types of conductive and electrode active materials are not limited, as long as they are suitable for use in an electrochemical device.

[0043] In this disclosure, the term "partition" can generally refer to a functional partition in which a porous coating comprising inorganic particles and an adhesive is formed on at least one surface of a porous polymer substrate (e.g., a polyolefin substrate or a nonwoven fabric). Furthermore, the partition has porous characteristics, comprising multiple pores, and serves as a porous ion-conducting barrier that allows ions to pass through while simultaneously preventing electrical contact between the positive and negative electrodes in an electrochemical device.

[0044] In this disclosure, the feature of being porous or having pores means that an object includes a plurality of interconnected voids or pores, thereby allowing gaseous fluids and / or liquid fluids to pass from one surface of the object to another.

[0045] In this disclosure, the term "porous polymer substrate" can refer to a porous membrane having multiple pores and serving as a substrate for electrically insulating the positive and negative electrodes to prevent short circuits. For example, when the electrochemical device is a lithium secondary battery, the porous polymer substrate can serve as an ion conduction barrier, allowing lithium ions to pass through while simultaneously preventing electrical contact between the positive and negative electrodes. At least a portion of the pores can be formed in a three-dimensional network communicating between the surface and interior of the porous polymer substrate, and fluid can pass through the porous polymer substrate via the pores.

[0046] In this disclosure, the term "particle size (D)" is used. 50 ")" or "Particle size (D)" 50 "50%" refers to the particle diameter corresponding to the 50% point on the cumulative volume particle size distribution of the particles being measured. The diameter can be measured using the laser diffraction method. Specifically, after dispersing the powder to be measured in a dispersion medium, the particle size distribution can be calculated by introducing the powder into a commercially available laser diffraction particle size analyzer (e.g., Microtrac S3500) and measuring the differences in the diffraction pattern based on particle size as the particles pass through the laser beam. The average particle size (D) 50 The diameter can be determined as the particle diameter corresponding to the 50% point of the cumulative number distribution of particles of diameter in the measuring device.

[0047] In this disclosure, the term "(meth)acrylate monomer" refers to a monomer that encompasses both acrylic acid monomers and methacrylate monomers. Furthermore, the term "(meth)acrylate monomer" refers to a monomer that encompasses both acrylate monomers and methacrylate monomers.

[0048] In this disclosure, acrylic monomers having an amide group refer to acrylic series monomers having an amide group in their side chain. That is, acrylic monomers having an amide group refer to monomers containing an acrylamide structure within their molecule. For example, an acrylamide monomer can be represented by a chemical formula, such as CH2=CHC(O)ND1D2, where D1 and D2 are each independently hydrogen, nitrogen, oxygen, or a substituted or unsubstituted hydrocarbon group having 1 to 10 carbon atoms. Furthermore, acrylamide monomers are not limited to the above chemical structure (CH2=CHC(O)ND1D2) and may include additional functional groups bonded to carbon-carbon double bonds.

[0049] In this disclosure, the term "silyl monomer" refers to a monomer having a hydrolyzable silyl group, and more specifically, a silyl monomer wherein at least one alkoxy group is bonded to a silicon atom. For example, a silyl monomer can be represented by a chemical formula such as CH2=CHSi(OA)3, where A is a hydrocarbyl group containing 1 to 8 carbon atoms. During polymerization, the silyl monomer can be hydrolyzed by water or steam, allowing the alkoxy group to be replaced by a silanol group. Furthermore, the term "monomer having a silanol group" refers to a monomer having a silanol group in its side chain.

[0050] This disclosure is described in more detail below.

[0051] This disclosure provides a separator for an electrochemical device.

[0052] According to embodiments of this disclosure, a separator for an electrochemical device comprises a porous polymer substrate and a coating disposed on at least one surface of the porous polymer substrate. The coating comprises inorganic particles and a binder, and the binder comprises a copolymer comprising: i) repeating units derived from (meth)acrylate monomers, (meth)acrylate monomers, or both; ii) repeating units derived from acrylic monomers having amide groups; and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both. The copolymer can be formed by copolymerizing the monomers into a random copolymer, a graft copolymer, or a block copolymer, and specifically, the copolymer can be a random copolymer.

[0053] Polyacrylic acid adhesives or copolymer adhesives, including i) those derived from repeating units of (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and ii) those derived from repeating units of acrylic acid monomers having amide groups, have the advantage of reducing the thermal shrinkage rate of separators in the dry state due to their high glass transition temperature and low self-deformation at high temperatures. However, the adhesive has poor bonding strength with inorganic materials in the wet state, making it difficult to improve the thermal shrinkage rate in the wet state. Specifically, for example, polyacrylic acid is hydrophilic and has a high glass transition temperature, which provides the advantage of not experiencing swelling caused by electrolytes. However, due to the poor bonding strength of polyacrylic acid with inorganic particles, it is difficult to prevent or mitigate thermal shrinkage when applied alone to coatings. Meanwhile, in the case of polymers of acrylic acid monomers having amide groups, such as polyacrylamide, the advantage is that it has high rigidity and a high glass transition temperature, and therefore experiences little deformation at high temperatures. However, due to its poor bonding strength with inorganic particles, such as polyacrylic acid, there is a problem that when it is applied to the coating alone as an adhesive or as a copolymer with acrylic monomers, it is difficult to prevent or mitigate the thermal shrinkage of the partition in a humid state.

[0054] The separator for an electrochemical device according to this disclosure comprises a copolymer used as a binder in a coating along with inorganic particles. In addition to i) repeating units derived from (meth)acrylate monomers, (meth)acrylate salt monomers, or both, and ii) repeating units derived from acrylic monomers having amide groups, the copolymer also includes iii) repeating units derived from silane monomers, monomers having silanol groups, or both. Therefore, component iii) of the copolymer can be firmly bonded to the surface of the porous polymer substrate or the surface of the inorganic particles by intermolecular forces (e.g., hydrogen bonding with the inorganic particles and the porous polymer substrate), and can also be bonded to the electrode surface. Therefore, the separator for an electrochemical device according to this disclosure (where the copolymer binder is included in the coating) exhibits a particularly improved thermal shrinkage rate at high temperatures, not only in the dry state but also in the wet state.

[0055] Specifically, when a silane monomer is applied to an aqueous solvent, such as water, to form a coating, the silane monomer can be modified to include silanol groups, thereby possessing silanol groups, similar to monomers containing silanol groups. This copolymer, including silanol groups, can be firmly bonded to the surface of a porous polymer substrate, the surface of inorganic particles, or the surface of an electrode by intermolecular forces, such as hydrogen bonding. Therefore, the separator for an electrochemical device according to this disclosure, which includes a copolymer binder in the coating, exhibits a reduced rate of thermal shrinkage not only in a dry state but also in a wet state.

[0056] Furthermore, the adhesive can be a solution-based adhesive. Because the adhesive is in solution form, it can adhere to inorganic particles and porous polymer substrates with large surface areas within the coating. Therefore, compared to particulate adhesives, it can advantageously and more effectively reduce the thermal shrinkage rate of the separator. In this case, silane monomers with silanol groups obtained through hydrolysis, or silanol groups of monomers having silanol groups, can bond to the surface of the porous polymer substrate, the surface of the inorganic particles, or the surface of the electrode through intermolecular forces such as hydrogen bonding.

[0057] Furthermore, unlike silyl monomers, silicone acrylate monomers, including silicon, do not contain silyl or silanol groups. Therefore, even when silicone acrylate monomers are copolymerized with acrylic and acrylamide monomers, the resulting copolymers are unlikely to interact strongly with the surfaces of inorganic particles and porous polymer substrates. Consequently, copolymer adhesives containing silicone acrylate, acrylic, and acrylamide monomers may exhibit poor heat resistance in a wet state.

[0058] According to embodiments of this disclosure, the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic monomers having amide groups can be in the range of 1:3 to 1:5. Specifically, the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic monomers having amide groups can be 1:3 or greater, 1:3.5 or greater, or 1:4 or greater, and can also be 1:5 or less, 1:4.5 or less, or 1:4 or less. When the content of each monomer contained in the copolymer satisfies the above ranges, i) repeating units derived from (meth)acrylic acid monomers or (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic monomers having amide groups, having high glass transition temperatures, and thus exhibiting small shape deformation, can be sufficiently present in the copolymer, and the separator for an electrochemical device containing the copolymer binder in the coating can exhibit low thermal shrinkage in the dry state.

[0059] According to embodiments of this disclosure, the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both, can be in the range of 1:0.01 to 1:0.1. Specifically, the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both, can be 1:0.01 or greater, 1:0.02 or greater, 1:0.03 or greater, 1:0.04 or greater, or 1:0.05 or greater, and can also be 1:0.1 or less, 1:0.09 or less, 1:0.08 or less, 1:0.07 or less, 1:0.06 or less, 1:0.05 or less, 1:0.04 or less, or 1:0.03 or less. When the content of each monomer contained in the copolymer meets the above-mentioned range, iii) repeating units derived from silyl monomers, monomers having silanol groups, or both can be sufficiently included in the copolymer, resulting in excellent interaction between the copolymer and the inorganic particles. Therefore, the copolymer binder can exhibit excellent adhesion to inorganic particles and porous polymer substrates. Consequently, separators for electrochemical devices in which the copolymer binder is included in the coating can exhibit low thermal shrinkage at high temperatures and under humid conditions.

[0060] In summary, the molar ratio of i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both; ii) repeating units derived from acrylic monomers having amide groups; and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both can be in the range of 1:(3 to 5):(0.01 to 0.1). When the content of each monomer contained in the copolymer satisfies the above range, i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both; ii) repeating units derived from acrylic monomers having amide groups (which effectively improve adhesion in the dry state); and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both (which effectively improve adhesion in the wet state) can exist in a balanced manner, thereby achieving an improvement in the heat shrinkage rate in both the dry and wet states.

[0061] According to this disclosure, i) included in the copolymer is a repeating unit derived from (meth)acrylate monomer, (meth)acrylate salt monomer, or both thereof, wherein the (meth)acrylate salt monomer may be at least one selected from the group consisting of sodium (meth)acrylate, potassium (meth)acrylate, lithium (meth)acrylate, and ammonium (meth)acrylate.

[0062] According to embodiments of the present disclosure, in ii), the acrylic monomer having an amide group can be at least one selected from the group consisting of: acrylamide, methacrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl) (meth)acrylamide, N,N-di(tert-butyl) (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-n-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-hydroxymethylpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-methoxyethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide.

[0063] According to embodiments of the present disclosure, the silane monomer may be at least one selected from the group consisting of: vinyltrimethoxysilane, vinyldimethoxyethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and vinyltriacetoxysilane, and the monomer having a silanol group may be a hydrolysis product of the silane monomer.

[0064] According to embodiments of this disclosure, the adhesive content can range from 4 parts by weight to 20 parts by weight based on the total weight of 100 parts by weight of the coating. Specifically, based on the total weight of 100 parts by weight of the coating, the adhesive content in the coating can be 4 parts by weight or more, 8 parts by weight or more, or 12 parts by weight or more, and can also be 20 parts by weight or less, 18 parts by weight or less, 16 parts by weight or less, 14 parts by weight or less, or 12 parts by weight or less. When the adhesive content in the coating meets the above ranges, the adhesive can be sufficiently present in the coating, and therefore, the separator for an electrochemical device having the coating disposed on one surface of a porous polymer substrate can exhibit a consistently low thermal shrinkage rate in both dry and wet states.

[0065] According to embodiments of this disclosure, the weight-average molecular weight of the copolymer can be in the range of 100,000 g / mol to 200,000 g / mol. Specifically, the weight-average molecular weight of the copolymer can be 100,000 g / mol or higher, 110,000 g / mol or higher, 120,000 g / mol or higher, 130,000 g / mol or higher, 140,000 g / mol or higher, or 150,000 g / mol or higher, and can also be 200,000 g / mol or lower, 190,000 g / mol or lower, 180,000 g / mol or lower, 170,000 g / mol or lower, 160,000 g / mol or lower, 150,000 g / mol or lower, or 140,000 g / mol or lower. When the weight-average molecular weight of the copolymer meets the above-mentioned range, the copolymer can have sufficient chain length to attach to both the inorganic particles and the porous polymer substrate, thereby effectively preventing the inorganic particles from detaching from the porous polymer substrate. Therefore, the separator used in electrochemical devices (in which a coating containing a copolymer as a binder is disposed on one surface of the porous polymer substrate) can exhibit low thermal shrinkage in both dry and wet conditions.

[0066] According to embodiments of this disclosure, the content of inorganic particles can be in the range of 80 to 90 parts by weight based on 100 parts by weight of the total weight of the coating. Specifically, based on 100 parts by weight of the total solid content of the composition used to form the coating, the content of inorganic particles can be 80 parts by weight or more, 82 parts by weight or more, 84 parts by weight or more, or 86 parts by weight or more, and can also be 90 parts by weight or less, 88 parts by weight or less, or 86 parts by weight or less. When the content of inorganic particles meets the above ranges, the inorganic particles can be sufficiently contained in the coating, thereby minimizing the thermal shrinkage problem of the porous polymer substrate in the separator of the electrochemical device.

[0067] According to embodiments of this disclosure, within the operating voltage range of the electrochemical device (e.g., based on Li / Li...), + Within a voltage range of 0V to 5V, the inorganic particles may not undergo oxidation and / or reduction reactions. Specifically, the inorganic particles may be at least one selected from the group consisting of: BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT, 0) <x<1,0<y<1)、Pb(Mg 1 / 3 Nb 2 / 3The following are considered as potential sources: PbTiO3 (PMN-PT), hafnium dioxide (HfO2), SrTiO3, SnO2, CeO2, MgO, Mg(OH)2, NiO, CaO, ZnO, ZrO2, SiO2, Y2O3, Al2O3, SiC, Al(OH)3, TiO2, boehmite, aluminum peroxide, zinc tin hydroxide (ZnSn(OH)6), zinc tin oxide (Zn2SnO4, ZnSnO3), antimony trioxide (Sb2O3), antimony tetroxide (Sb2O4), and antimony pentoxide (Sb2O5). Boehmite or aluminum oxide may be specifically chosen.

[0068] According to embodiments of this disclosure, inorganic particles can have a particle size (D) ranging from 200 nm to 1 μm. 50 Specifically, the particle size of the inorganic particles can be 200 nm or larger, 300 nm or larger, 400 nm or larger, or 500 nm or larger, and the particle size can also be 1 μm or smaller, 900 nm or smaller, 800 nm or smaller, 700 nm or smaller, 600 nm or smaller, or 500 nm or smaller. When the particle size of the inorganic particles meets the above ranges, sufficient spacing can exist between the inorganic particles deposited in the coating, thereby giving the coating high porosity and thus giving the separator low electrical resistance.

[0069] According to embodiments of this disclosure, the coating thickness can be in the range of 0.5 μm to 2 μm. Specifically, the coating thickness can be 0.5 μm or more, 0.7 μm or more, or 0.9 μm or more, and can also be 2 μm or less, 1.8 μm or less, 1.6 μm or less, 1.4 μm or less, 1.2 μm or less, or 1 μm or less. When the coating thickness meets the above range, lithium ions can pass through the coating smoothly due to the reduced coating thickness, thereby providing the advantage of low separator resistance for use in electrochemical devices. Furthermore, since the total thickness of the separator for electrochemical devices including the coating can also be small, a relatively large amount of electrode active material can be included in the electrochemical device including the separator, thereby increasing the energy density of the electrochemical device.

[0070] According to embodiments of this disclosure, the porosity of the coating can be in the range of 30 vol% to 50 vol%. Specifically, the porosity of the coating can be 30 vol% or more, 35 vol% or more, or 40 vol% or more, and can also be 50 vol% or less, 45 vol% or less, or 40 vol% or less. When the porosity of the coating meets the above range, pores can be sufficiently present in the coating, allowing lithium ions to migrate smoothly through the pores, thereby resulting in low resistance of the separator used in the electrochemical device. Furthermore, compared to the case where the porosity of the coating is too high and there are too many pores in the coating, the separator for the electrochemical device according to this disclosure exhibits excellent mechanical strength.

[0071] According to embodiments of this disclosure, the porous polymer substrate can be a porous membrane having multiple pores, which electrically insulates the positive and negative electrodes to prevent short circuits. For example, when the electrochemical device is a lithium secondary battery, the porous polymer substrate can serve as an ion conduction barrier, allowing lithium ions to pass through while preventing electrical contact between the positive and negative electrodes. At least a portion of the pores can be formed in a three-dimensional network communicating between the surface and interior of the porous polymer substrate, and fluid can pass through the pores through the porous polymer substrate.

[0072] Porous polymer substrates can be made of materials that are physically and chemically stable relative to organic solvent electrolytes. For example, porous polymer substrates may include, but are not limited to: resins, such as polyolefins, including polyethylene, polypropylene, and polybutene; polyvinyl chloride; polyethylene terephthalate; polycyclic olefins; polyethersulfone; polyamides; polyimides; polyimide-amides; nylon; polytetrafluoroethylene; or copolymers or mixtures thereof. Preferably, polyolefin resins can be used. Polyolefin resins can be processed to a relatively thin thickness and allow for easy application of compositions for forming coatings, making them suitable for manufacturing electrochemical devices with high energy densities.

[0073] The porous polymer substrate can have a single-layer or multi-layer structure. It may include two or more polymer resin layers with different melting points (Tm) to provide a shut-off function in the event of thermal runaway. For example, the porous polymer film may include a polypropylene layer with a relatively high melting point and a polyethylene layer with a relatively low melting point. Preferably, the porous polymer substrate may have a three-layer structure, wherein a polypropylene layer, a polyethylene layer, and a polypropylene layer are laminated together sequentially. When the battery temperature rises above a predetermined temperature, the polyethylene layer melts and closes the pores, preventing thermal runaway.

[0074] According to embodiments of this disclosure, the thickness of the porous polymer substrate can be in the range of 6 μm to 15 μm. Specifically, the thickness of the porous polymer substrate can be 6 μm or greater, 8 μm or greater, or 10 μm or greater, and can also be 15 μm or less, 13 μm or less, 11 μm or less, or 9 μm or less. By adjusting the thickness of the porous polymer substrate within the above range, the volume of the electrochemical device can be minimized, while increasing the amount of active material contained in the electrochemical device, and making the positive and negative electrodes electrically insulated.

[0075] According to embodiments of this disclosure, the porous polymer substrate may include an average diameter (D) 50 The pore size is in the range of 0.01 μm to 1 μm. Specifically, the average diameter of the pores contained in the porous polymer substrate can be 0.01 μm or larger, 0.02 μm or larger, 0.03 μm or larger, or 0.04 μm or larger, and can also be 1 μm or smaller, 0.09 μm or smaller, 0.08 μm or smaller, 0.07 μm or smaller, or 0.06 μm or smaller. Preferably, the pore size can be in the range of 0.02 μm to 0.06 μm. By adjusting the pore size of the porous polymer substrate within the above range, the air permeability and ionic conductivity of the entire separator can be controlled.

[0076] The air permeability of the porous polymer substrate can be in the range of approximately 10 s / 100cc to 100 s / 100cc. Specifically, the air permeability of the porous polymer substrate can be 10 s / 100cc or greater, 20 s / 100cc or greater, 30 s / 100cc or greater, 40 s / 100cc or greater, or 50 s / 100cc or greater, and can also be 100 s / 100cc or less, 90 s / 100cc or less, 80 s / 100cc or less, 70 s / 100cc or less, 60 s / 100cc or less, or 50 s / 100cc or less. Preferably, the air permeability of the porous polymer substrate can be in the range of 50 s / 100cc to 70 s / 100cc. When the permeability of the porous polymer substrate is within the above range, the permeability of the resulting separator can be provided within an appropriate range, thereby ensuring the output characteristics and cycle characteristics of the electrochemical device.

[0077] Air permeability (s / 100cc) refers to the time (in seconds) required for 100cc of air to pass through a predetermined area of ​​a porous polymer substrate or separator under constant pressure. Air permeability is measured using an air permeability tester (Gurley density meter) according to ASTM D 726-58, ASTM D 726-94, or JIS-P8117. For example, at an air pressure of 0.304 kPa or a water pressure of 1.215 kN / m³. 2 Below, 100 cc of air passes through an area of ​​1 square inch (or 6.54 cm²). 2 The time required to pass through a 1 square inch sample can be measured using a Gurley 4110N instrument. For example, the time required for 100 cc of air to pass through a 1 square inch sample at room temperature and a constant water pressure of 4.8 inches can be measured using an Asahi Seiko EG01-55-1MR instrument.

[0078] According to embodiments of this disclosure, the porous polymer substrate can have a porosity ranging from 10 vol% to 70 vol%. Specifically, the porosity of the porous polymer substrate can be 10 vol% or more, 20 vol% or more, 30 vol% or more, or 40 vol% or more, and can also be 70 vol% or less, 60 vol% or less, or 50 vol% or less. Preferably, the porosity of the porous polymer substrate can be in the range of 40 vol% to 60 vol%. When the porosity of the porous polymer substrate is within the above range, the resulting separator can provide an ionic conductivity within an appropriate range to ensure the output characteristics and cycle characteristics of the electrochemical device.

[0079] The porosity mentioned above refers to the ratio of the void volume in each of the coating and the porous polymer substrate to the total volume. Porosity can be measured using methods known in the art. For example, porosity can be measured using the Brunauer-Emmett-Teller (BET) method with nitrogen adsorption, the capillary flow porometer method, or the water immersion method or mercury immersion method.

[0080] This disclosure provides an electrochemical device.

[0081] Electrochemical devices may include the separators described above for electrochemical devices.

[0082] According to embodiments of the present disclosure, an electrochemical device may include a positive electrode, a negative electrode, and a separator for the electrochemical device, and the separator for the electrochemical device may be inserted between the positive electrode and the negative electrode. In the electrochemical device according to embodiments of the present disclosure, repeated descriptions of the separator for the electrochemical device will be omitted.

[0083] An electrochemical device is a device that converts chemical energy into electrical energy through an electrochemical reaction, encompassing both primary and secondary batteries. Secondary batteries refer to rechargeable batteries, such as lithium-ion batteries, nickel-cadmium batteries, or nickel-metal hydride batteries. Lithium-ion batteries use lithium ions as the ion conductor and can include, for example: non-aqueous electrolyte secondary batteries with liquid electrolytes; all-solid-state batteries with solid electrolytes; lithium polymer batteries with gel polymer electrolytes; or lithium metal batteries using lithium metal as the negative electrode, but are not limited to these.

[0084] Because the electrochemical device includes the aforementioned separator, excellent adhesion can be achieved between the separator and the electrode. Therefore, even when the electrochemical device is operated for an extended period, safety degradation caused by separator detachment can be minimized.

[0085] According to embodiments of this disclosure, the positive electrode may include: a positive electrode current collector; and a positive electrode active material layer on at least one surface of the current collector, the positive electrode active material layer comprising a positive electrode active material, a conductive material, and an adhesive resin. The positive electrode active material may include one or a mixture of two or more of the following: layered compounds, such as lithium manganese complex oxides (e.g., LiMn2O4 or LiMnO2), lithium cobalt oxide (LiCoO2), and lithium nickel oxide (LiNiO2), or compounds substituted with one or more transition metals; lithium manganese oxides, such as those of the formula Li... 1+x Mn 2-x Those represented by O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxides (Li2CuO2); vanadium oxides, such as LiV3O8, LiV3O4, V2O5, and Cu2V2O7; and those represented by the chemical formula LiNi. 1-x M x Ni-type lithium nickel oxides represented by O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); LiMn 1-x M x Lithium manganese complex oxides represented by O2 (where M = Co, Ni, Fe, Cr, Zn or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu or Zn); LiMn2O4 wherein a portion of the Li in the chemical formula is replaced by an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0086] According to an embodiment of the present disclosure, the negative electrode may include: a negative electrode current collector; and a negative electrode active material layer on at least one surface of the current collector, the negative electrode active material layer including a negative electrode active material, a conductive material, and an adhesive resin. As the negative electrode active material, the negative electrode may include one or a mixture of two or more selected from the following: a lithium metal oxide; carbon, such as non-graphitizable carbon or graphitizable carbon; a metal composite oxide, such as Li x Fe2O3(0≤x≤1), Li x WO2(0≤x≤1), or Sn x Me 1-x Me′ y O z (where Me is Mn, Fe, Pb, or Ge; Me′ is Al, B, P, Si, an element belonging to Group 1, 2, or 3 of the periodic table, or a halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8); lithium metal; a lithium alloy; a silicon-based alloy; a tin-based alloy; metal oxides, such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5); a conductive polymer, such as polyacetylene; a Li-Co-Ni-based material; and titanium oxide.

[0087] According to an embodiment of the present disclosure, the conductive material may be, for example, one or a mixture of two or more selected from the group consisting of: graphite, carbon black, carbon fiber or metal fiber, metal powder, conductive whisker, conductive metal oxide, activated carbon, and polyphenylene ether derivative. More specifically, the conductive material may be, for example, one or a mixture of two or more selected from the group consisting of: natural graphite, artificial graphite, super p, acetylene black, ketjen black, channel black, furnace black, lamp black, pyrolytic carbon black, denka black, aluminum powder, nickel powder, zinc oxide, potassium titanate, and titanium oxide.

[0088] According to an embodiment of the present disclosure, as long as the current collector has high conductivity and does not cause chemical changes in the battery, there is no particular limitation on the current collector. For example, stainless steel, copper, aluminum, nickel, titanium, calcined carbon, or a surface treatment material obtained by treating the surface of aluminum or stainless steel with, for example, carbon, nickel, titanium, or silver may be used.

[0089] According to embodiments of this disclosure, the adhesive resin may be a polymer commonly used in the field for electrodes. Non-limiting examples of such adhesive resins may include, for example: polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-co-trichloroethylene, polymethyl methacrylate, polyethylhexyl acrylate, polybutyl acrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinyl acetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetatebutyrate, cellulose acetate propionate, cyanoethyl pullulan, cyanoethyl polyvinyl alcohol, cyanoethyl cellulose, and cyanoethyl sucrose. Sucrose, pullullan, and carboxyl methyl cellulose, but not limited to these.

[0090] According to embodiments of this disclosure, the positive electrode slurry used to prepare the positive electrode active material layer may include a dispersant, and the dispersant may be a pyrrolidone-based compound. Specifically, the dispersant may be N-methylpyrrolidone (ADC-01, LG Chem).

[0091] According to embodiments of this disclosure, the electrochemical device may further include an electrolyte salt, wherein the electrolyte salt has A + B - The structure, where A + It can include alkali metal cations such as Li + Na +K + , or ions composed of combinations thereof. Additionally, B - It can be obtained by dissolving or dissociating the salt in an organic solvent, the salt including anions, such as PF6. - BF4 - Cl - ,Br - I - ClO4 - AsF6 - CH3CO2 - CF3SO3 - N(CF3SO2)2 - C(CF2SO2)3 - The organic solvent is selected from, but is not limited to, propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone, and mixtures thereof.

[0092] Embodiments of this disclosure may provide a battery module including the electrochemical device as a unit battery cell, a battery pack including the battery module, and a device including the battery pack as a power source. Specific examples of such devices include, but are not limited to: power tools driven by battery-powered motors; electric vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs), or plug-in hybrid electric vehicles (PHEVs); electric motorcycles such as e-bikes or e-scooters; electric golf carts; and energy storage systems.

[0093] According to embodiments of this disclosure, the electrochemical device can be configured as a cylindrical secondary battery, wherein a separator for the electrochemical device is inserted between the positive and negative electrodes. In this case, the separator, positive electrode, and negative electrode can be stacked to form an electrode assembly having a separator / positive electrode / separator / negative electrode structure or a positive electrode / separator / negative electrode / separator structure and then wound. The positions of the positive and negative electrodes can be interchanged. The electrode assembly stacked as described above can be bound to a core portion, inserted into a cylindrical container, and wound to manufacture a cylindrical secondary battery.

[0094] Hereinafter, embodiments will be given and described in detail for the purpose of specifically describing this disclosure. However, embodiments according to this disclosure can be modified in various other forms, and the scope of this disclosure should not be construed as limited to the embodiments described below. The embodiments described herein are provided to explain this disclosure more fully to those skilled in the art.

[0095] Examples and Comparative Examples

[0096] Preparation of adhesives

[0097] Copolymer adhesives were prepared by changing the type and content of monomers, as shown in Table 1 below.

[0098] <Preparation Example 1>

[0099] A copolymer adhesive is prepared comprising acrylic acid (AA), acrylamide (AM), and vinyltrimethoxysilane monomer (SM) in a molar ratio of 1:4:0.05.

[0100] <Preparation Example 2>

[0101] The copolymer adhesive was prepared in the same manner as in Preparation Example 1, except that 3-acryloyloxypropyltrimethoxysilane (SM) was used instead of vinyltrimethoxysilane in Preparation Example 1.

[0102] <Preparation Example 3>

[0103] Except that the copolymer is prepared such that the molar ratio of monomers in the copolymer satisfies 1:4:0.025, the copolymer adhesive is prepared by the same method as in Preparation Example 1.

[0104] <Preparation Example 4>

[0105] Except that the copolymer is prepared such that the molar ratio of monomers in the copolymer satisfies 1:4:0.25, the copolymer adhesive is prepared by the same method as in Preparation Example 1.

[0106] <Comparative Preparation Example 1>

[0107] The copolymer adhesive was prepared using the same method as in Preparation Example 1, except that the vinyltrimethoxysilane used in Preparation Example 1 was not used.

[0108] <Comparative Preparation Example 2>

[0109] Except that the vinyltrimethoxysilane used in Preparation Example 1 was not used and the copolymer was prepared such that the molar ratio of acrylic monomer to acrylamide monomer was 1:0.7, the copolymer adhesive was prepared in the same manner as in Preparation Example 1.

[0110] <Comparative Preparation Example 3>

[0111] The copolymer adhesive was prepared in the same manner as in Preparation Example 1, except that the vinyltrimethoxysilane used in Preparation Example 1 was not used and the copolymer was prepared such that the molar ratio of acrylic monomer to acrylamide monomer was 1:0.25.

[0112] <Comparative Preparation Example 4>

[0113] The copolymer adhesive was prepared in the same manner as in Preparation Example 1, except that a monomethacrylate-terminated poly(dimethylsiloxane) (organosilicone acrylate (SA)) was used instead of the vinyltrimethoxysilane in Preparation Example 1.

[0114] [Table 1]

[0115]

[0116] The weight-average molecular weights in Table 1 were measured using GPC.

[0117] Preparation of separators for electrochemical devices

[0118] <Example 1>

[0119] A polyethylene film (thickness: 10 μm, air permeability: 54 s / 100cc) was prepared as a porous polymer substrate.

[0120] Preparation of boehmite powder (particle size (D)) 50 (500 nm) as inorganic particles. The adhesive of Preparation Example 1 was prepared as an adhesive. Sodium carboxymethyl cellulose (CMC-Na) (SG-L02, GL Chem Co. Ltd.) was prepared as a thickener, and maleic acid dispersant was prepared as a dispersant. The prepared inorganic particles, adhesive, thickener and dispersant were added to water in a weight ratio of 86:12:1:1, and then the inorganic particles were pulverized and dispersed to prepare a composition for forming a coating.

[0121] A coating is formed on one surface of a porous polymer substrate by applying a composition for forming a coating using a doctor blade and drying it with air at 50°C from a hot air gun, thereby manufacturing a separator for an electrochemical device.

[0122] At this point, based on a total weight of 100 parts by weight of coating, the binder content is 12 parts by weight and the inorganic particle content is 86 parts by weight. The porosity of the coating is 40% by volume, and the coating thickness is 1.5 μm.

[0123] <Examples 2 to 4 and Comparative Examples 1 to 4>

[0124] The separators for electrochemical devices of Examples 2 to 4 and Comparative Examples 1 to 4 were manufactured in the same manner as in Example 1, using the adhesives of Preparation Examples 2 to 4 and Comparative Examples 1 to 4 instead of the adhesive of Preparation Example 1.

[0125] The physical properties of the separators used in the electrochemical devices of the examples and comparative examples are shown in Tables 2 and 3 below.

[0126] Experimental Example

[0127] (1) Determine the dry shrinkage rate of the partition.

[0128] The separator samples for the electrochemical device of the examples and comparative examples were prepared with a size of 5cm × 5cm. After being stored in a convection oven at 180°C for 30 minutes, the separators were removed, and the thermal shrinkage rates in the longitudinal direction (MD, Machine direction) and transverse direction (TD, Transverse direction) were calculated according to the following formula: Thermal shrinkage rate = [(Initial length - Length after 0.5 hours of storage at 180°C) / Initial length] × 100 (%).

[0129] (2) Determine the wet shrinkage rate of the partition.

[0130] The separator samples for the electrochemical device from the examples and comparative examples were prepared into 5 cm × 5 cm samples and inserted into aluminum bags of 7 cm × 10 cm in size. One gram of electrolyte, as described below, was injected into each bag, and the bags were sealed.

[0131] As the electrolyte, ethylene carbonate (EC) and ethyl methyl carbonate (EMC) mixed in a weight ratio of 3:7 were used as the solvent, which contained 2% by weight of ethylene carbonate (VC) as an additive and 1M of lithium salt LiPF6. The sealed bags were stored in a convection oven at 140°C for 30 minutes, after which the separators were removed. For each separator, the thermal shrinkage rate in the MD and TD directions was calculated according to the following formula: Thermal shrinkage rate = [(Initial length - Length after 0.5 hours of storage at 140°C) / Initial length] × 100 (%). The experimental results are shown in Tables 2 and 3 below.

[0132] [Table 2]

[0133]

[0134] [Table 3]

[0135]

[0136] As shown in Tables 2 and 3, the separators for electrochemical devices in Comparative Examples 1 to 3 each comprise a copolymer adhesive of acrylic monomers and acrylamide monomers, exhibiting poor adhesion between the coating and the porous polymer substrate. The results confirmed a significantly high thermal shrinkage rate in the wet state. In contrast, the separators for electrochemical devices according to the various embodiments comprise a coating having a copolymer adhesive of acrylic monomers, acrylamide monomers, and silane monomers disposed on both surfaces of the porous polymer substrate. The results confirmed consistently low thermal shrinkage rates in both dry and wet states. Specifically, in Examples 1 to 3, where the molar ratio between acrylic monomers and silane monomers satisfies a range of 1:0.01 to 1:0.1, the separators exhibited even lower thermal shrinkage rates.

[0137] Furthermore, the separator for the electrochemical device in Comparative Example 4, whose coating contains a copolymer adhesive of acrylic monomer, acrylamide monomer, and organosilicon acrylate monomer, exhibited reduced adhesion between the coating and the porous polymer substrate due to the presence of organosilicon acrylate monomer in the copolymer. The results confirmed that its thermal shrinkage rate under humid conditions was significantly higher than that of Comparative Examples 1 to 3.

[0138] In view of the above, it has been confirmed that the separator for an electrochemical device according to the present disclosure achieves the effect of improving both the thermal shrinkage rate under dry conditions and the thermal shrinkage rate under wet conditions due to the aforementioned copolymer adhesive.

Claims

1. A separator for an electrochemical device, comprising: Porous polymer substrate; as well as A coating comprising inorganic particles and an adhesive is disposed on at least one surface of the porous polymer substrate. The adhesive comprises a copolymer, the copolymer comprising: i) repeating units derived from (meth)acrylate monomers, (meth)acrylate monomers, or both thereof; ii) repeating units derived from acrylic monomers having amide groups; and iii) repeating units derived from silyl monomers, monomers having silanol groups, or both.

2. The separator for an electrochemical device according to claim 1, wherein the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers, or both, and ii) repeating units derived from acrylic acid monomers having amide groups is in the range of 1:3 to 1:

5.

3. The separator for an electrochemical device according to claim 1, wherein the molar ratio between i) repeating units derived from (meth)acrylic acid monomers, (meth)acrylate monomers or both thereof and iii) repeating units derived from silane monomers, monomers having silanol groups or both thereof is in the range of 1:0.01 to 1:0.

1.

4. The separator for an electrochemical device according to claim 1, wherein, The (meth)acrylate monomer is at least one selected from the group consisting of: sodium (meth)acrylate, potassium (meth)acrylate, lithium (meth)acrylate, and ammonium (meth)acrylate.

5. The separator for an electrochemical device according to claim 1, wherein, The acrylic monomer having an amide group is at least one selected from the group consisting of: acrylamide, methacrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, N,N-diisopropyl (meth)acrylamide, N,N-di(n-butyl) (meth)acrylamide, N,N-di(tert-butyl) (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-n-butyl (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, N-hydroxymethylpropane (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-methoxyethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylamide.

6. The separator for an electrochemical device according to claim 1, wherein the silane monomer is at least one selected from the group consisting of: vinyltrimethoxysilane, vinyldimethoxyethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and vinyltriacetoxysilane, and The monomer having a silanol group is a hydrolysis product selected from at least one of the following groups: vinyltrimethoxysilane, vinyldimethoxyethoxysilane, vinyltriethoxysilane, 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldiethoxysilane, and vinyltriacetoxysilane.

7. The separator for an electrochemical device according to claim 1, wherein, The content of the adhesive is in the range of 4 to 20 parts by weight, based on the total weight of 100 parts by weight of the coating.

8. The separator for an electrochemical device according to claim 1, wherein, The weight-average molecular weight of the copolymer is in the range of 100,000 g / mol to 200,000 g / mol.

9. The separator for an electrochemical device according to claim 1, wherein, Based on the total weight of 100 parts by weight of the coating, the content of the inorganic particles is in the range of 80 to 90 parts by weight.

10. The separator for an electrochemical device according to claim 1, wherein, The thickness of the coating is in the range of 0.5 μm to 2 μm.

11. An electrochemical device, comprising: Positive electrode; Negative electrode ； And a separator for an electrochemical device according to any one of claims 1 to 10; The separator for the electrochemical device is inserted between the positive electrode and the negative electrode.

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