KR101581422B1 - Separator for electrochemical device and electrochemical device containing the same - Google Patents

Abstract

The separator for an electrochemical device of the present invention is a planar porous substrate; And a porous coating layer formed on at least one surface of the planar porous substrate, the inorganic coating layer being bound by a polymeric binder and containing a surfactant.
The separator having the porous organic-inorganic coating layer formed by incorporating such a surfactant has excellent thermal stability and is excellent in impregnation with the electrolytic solution. Therefore, the separator contributes to the improvement of the electrochemical device performance, Suitable for large secondary batteries.

Description

TECHNICAL FIELD [0001] The present invention relates to a separator for an electrochemical device, and an electrochemical device including the separator.

The present invention relates to a separator for an electrochemical device which forms a porous organic-inorganic coating layer on at least one surface of a porous substrate.

Recently, interest in energy storage technology is increasing. As the application fields of cell phones, camcorders, notebook PCs and even electric vehicles are expanding, efforts for research and development of electrochemical devices are becoming more and more specified. Electrochemical devices have attracted the greatest attention in this respect. Among them, the development of rechargeable secondary batteries has become a focus of attention. In recent years, in order to improve capacity density and specific energy, And research and development on the design of the battery.

Among the currently applied secondary batteries, the lithium secondary battery developed in the early 1990s has advantages such as higher operating voltage and higher energy density than conventional batteries such as Ni-MH, Ni-Cd and sulfuric acid-lead batteries using an aqueous electrolyte solution . However, such a lithium ion battery has safety problems such as ignition and explosion when using an organic electrolytic solution, and it is disadvantageous in that it is difficult to manufacture. Recently, the lithium ion polymer battery is considered to be one of the next generation batteries by improving the weak point of the lithium ion battery. However, since the capacity of the battery is still relatively low as compared with the lithium ion battery, Is urgently required.

Such electrochemical devices are produced in many companies, but their safety characteristics are different. It is very important to evaluate the safety and safety of such an electrochemical device. The most important consideration is that the electrochemical device should not injure the user in case of malfunction. For this purpose, the safety standard strictly regulates the ignition and fuming in the electrochemical device. In the safety characteristics of the electrochemical device, there is a high possibility that the electrochemical device will be overheated to cause thermal runaway or explosion if the separator is penetrated. Particularly, the polyolefin-based porous substrate commonly used as a separator of an electrochemical device exhibits extreme heat shrinkage behavior at a temperature of 100 DEG C or higher owing to the characteristics of the manufacturing process including material properties and elongation, . ≪ / RTI >

In order to solve the safety problem of such an electrochemical device, a separator has been proposed in which a porous organic-inorganic coating layer is formed by coating a mixture of an excess of inorganic particles and a polymeric binder on at least one surface of a porous substrate having a plurality of pores. The inorganic particles contained in the porous organic-inorganic coating layer are excellent in heat resistance, thereby preventing a short circuit between the anode and the cathode even when the electrochemical device is overheated.

On the other hand, in the lithium secondary battery, as the non-aqueous electrolytic solution, an aprotic organic solvent such as ethylene carbonate, diethyl carbonate, or 2-methyltetrahydrofuran is generally used. Such an electrolytic solution is sufficient to dissolve and dissociate the electrolyte salt It is a polar solvent with a polarity and is an aprotic solvent with no active hydrogen. It is often highly viscous and surface tension due to its wide interactions within the electrolyte. Therefore, the nonaqueous electrolyte solution of the lithium secondary battery has a low affinity with the separator made of polyethylene or the like, so that the separator can not be easily wetted. Therefore, due to the long wetting time of the electrolyte, it takes a long time to manufacture the battery and it is not easy to optimize the performance of the battery.

Korean Patent Publication No. 2006-21221 discloses a method for improving the impregnation property of an electrolyte by using a polymer capable of being gelled with a polymer binder of an organic-inorganic porous coating layer. However, in order to improve the performance of a battery, - a separator having an inorganic coating layer formed thereon is required.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a separator having a porous organic-inorganic coating layer formed on at least one surface of the porous substrate and having excellent impregnation properties.

In order to solve the above problems, a planar porous substrate; And a porous coating layer formed on at least one surface of the planar porous substrate, the inorganic coating layer being bound to the inorganic binder by a polymeric binder and containing a surfactant.

Such a surfactant may be contained in an amount of 0.1 to 30% by weight based on the total weight of the porous coating layer.

In addition, such a surfactant may be a nonionic surfactant, and it is preferable that the nonionic surfactant is a block copolymer having both a hydrophilic portion and a hydrophobic portion.

As the polymer binder used in the present invention, a polymer capable of gelation upon impregnation with an electrolyte solution and having a solubility index in the range of 15 to 45 MPa ^1/2 can be used.

The polymer binder that can be used is not particularly limited, but examples thereof include polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, But are not limited to, polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide but are not limited to, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol ), Cyanoethylcellulose But are not limited to, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, or polyimide. .

The inorganic particles used in the present invention may have an average particle diameter of 0.001 to 10 mu m. Such inorganic particles may be inorganic particles having a dielectric constant of 5 or more, inorganic particles having lithium ion transferring ability, .

Particularly, the inorganic particles having a dielectric constant of 5 or more are BaTiO ₃ , Pb (Zr, Ti) O ₃ (PZT), Pb _{1 -x} La _x Zr _{1 -y} Ti _y O ₃ (PLZT, 0 <x < y <1), Pb (Mg 1/3 Nb 2/3) O 3 -PbTiO 3 (PMN-PT), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, CaO, ZnO , ZrO ₂ , SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , SiC, or TiO ₂ .

The inorganic particles having lithium ion transferring ability may be lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0 <x <2, 0 <y < titanium phosphate _{(Li x Al y Ti z (} PO 4) 3, 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) x O y series glass (0 <x <4, 0 <y <13), lithium lanthanum titanate _{(Li x La y TiO 3,} 0 <x <2, 0 <y <3), lithium germanium Mani help thiophosphate _{(Li x Ge y P z S} w, 0 <x (Li _x N _y , 0 <x <4, 0 <y <2), SiS ₂ (Li _x Si (0 <y <1, 0 <z < _{y S z, 0 <x <} 3, 0 <y <2, 0 <z <4) based glass, and _{P 2 S 5 (Li x P} y S z, 0 <x <3, 0 <y <3, 0 <z <7) series glass can be used.

The weight ratio of the inorganic particles to the polymeric binder is 50:50 to 99: 1.

The porous substrate of the present invention may be a polyolefin-based porous substrate. Such a polyolefin-based porous substrate is not particularly limited, but may be made of polyethylene, polypropylene, polybutylene, polypentene or the like.

The thickness of such a porous substrate may be 5 to 50 μm, and the pore size and porosity may be 0.01 to 50 μm and 10 to 95%, respectively.

Such a separator is used in an electrochemical device, and in particular, can be used in a lithium secondary battery.

The separator having a porous organic-inorganic coating layer formed by introducing a surfactant according to the present invention is excellent in thermal stability and also has excellent impregnation with an electrolytic solution. Therefore, it contributes to the improvement of the performance of an electrochemical device, It is suitable for large secondary batteries for electric vehicles.

Hereinafter, the present invention will be described in detail with reference to the drawings. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and the inventor may appropriately define the concept of the term in order to best describe its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

The separator for an electrochemical device of the present invention is a planar porous substrate; And a porous coating layer formed on at least one surface of the planar porous substrate, wherein the inorganic coating is bound by a polymeric binder and comprises a surfactant.

The separator for electrochemical devices serves to prevent direct contact between the positive electrode and the negative electrode, and a porous substrate is generally used. For the thermal stability of the separator for an electrochemical device made of such a porous substrate, a porous organic-inorganic coating layer is introduced. In particular, the porous organic-inorganic coating layer of the present invention includes a surfactant.

In the lithium secondary battery, non-aqueous electrolytic solutions mainly include non-aqueous organic solvents such as ethylene carbonate, diethyl carbonate, and 2-methyltetrahydrofuran. These electrolytes have polarity sufficient to dissolve and dissociate electrolyte salts Is a polar solvent and an aprotic solvent that does not have active hydrogens and often has high viscosity and surface tension due to the wide interactions within the electrolyte. The surfactant is a compound having a hydrophilic portion and a hydrophobic portion, and has affinity for both hydrophilic and hydrophobic materials having opposite properties. Therefore, when the surfactant is dispersed between the polymeric binder and the inorganic particles as in the present invention, the surface tension of the electrolytic solution is weakened, and the nonporous The affinity of the polymeric binder and the inorganic particles for the polar solvent electrolytic solution is increased, so that the impregnation of the porous organic-inorganic coating layer is increased, and as a result, the impregnability of the separator is improved. In addition, since such a surfactant is presumed to exist at a high concentration on the surface portion of the coating layer due to the relatively low molecular weight of the surfactant during the formation of the organic-inorganic coating layer, the surfactant will further contribute to improvement of impregnation properties.

Such a surfactant is preferably contained in an amount of 0.1 to 30% by weight, or 0.1 to 10% by weight based on the total weight of the porous coating layer. When the content of the surfactant satisfies this range, the impregnating property improving effect can be improved.

In general, surfactants can be divided into anionic surfactants, cationic surfactants and amphoteric surfactants, which exhibit ionic properties in an aqueous solution, and nonionic surfactants that do not split into ions even in an aqueous solution. It is preferable to use a nonionic surfactant having a small effect on the electrochemical reaction.

Examples of such nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene alkylphenol ethers, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters and sucrose fatty acid esters. But is not limited thereto.

Particularly, the surfactant of the present invention is more preferably a block copolymer having a hydrophilic part and a hydrophobic part together.

Generally, a block copolymer is a copolymer in which chains of a certain amount of monomers are connected in a certain amount and chains in which a certain amount of other monomers having different characteristics are chemically bonded. As the preferred surfactant of the present invention, the block copolymer is a copolymer formed by crossing a chemical bond between a chain composed of a hydrophilic monomer and a chain composed of a hydrophobic monomer, wherein the copolymer itself has both a hydrophilic part and a hydrophobic part .

Particularly preferred examples of the block copolymer include a PEO-PPO block copolymer. The PEO-PPO block copolymer has a structure in which hydrophilic PEO (polyethylene oxide) and hydrophobic PPO (polypropylene oxide) chains are repeatedly bonded in a predetermined unit. The PEO-PPO block copolymer has very little influence on the operating mechanism of the battery, and has hydrophilic and hydrophobic regions in the molecule, thereby greatly improving the wettability of the electrolyte as described above. The PEO content of such PEO-PPO block copolymers is preferably 40 to 80% based on the weight of the total copolymer. Among the PEO-PPO block copolymers, a triblock copolymer having a PEO-PPO-PEO structure as a whole is particularly preferable. The PEO content in such a PEO-PPO-PEO triblock copolymer is particularly preferably 60 to 70% by weight, based on the weight of the total copolymer.

The polymer binder of the present invention preferably has a glass transition temperature (T _g ) of -200 to 200 ° C. This improves the mechanical properties such as flexibility and elasticity of the finally formed coating layer It is because. Such a polymer binder does not necessarily have ion conductivity, but the performance of the electrochemical device can be further improved by using a polymer having ion conductivity. Therefore, it is preferable that the polymer binder has a high permittivity constant. In fact, since the degree of dissociation of the salt in the electrolyte depends on the permittivity constant of the electrolyte solvent, the higher the permittivity constant of the polymeric binder, the better the salt dissociation in the electrolyte. The permittivity constant of the polymeric binder may be in the range of 1.0 to 100 (measurement frequency = 1 kHz), preferably 10 or more.

In addition, the polymer binder included in the organic-inorganic porous coating layer of the present invention may be a polymer capable of gelation upon impregnation with an electrolyte solution. Since the surfactant introduced in the present invention weakens the surface tension of the electrolytic solution, the affinity of the gelable polymeric binder to the electrolytic solution is improved, and the gelation of the polymeric binder And the like. By the introduction of the surfactant of the present invention, the gelation time of the polymeric binder is shortened and the gelation is further facilitated. Accordingly, a polymer having a solubility index of 15 to 45 MPa ^1/2 is preferable. Therefore, hydrophilic polymers having many polar groups are preferable to hydrophobic polymers such as polyolefins. When the solubility index exceeds 15 MPa ^1/2 and exceeds 45 MPa ^1/2 , it becomes difficult to be impregnated with a common liquid electrolyte for a battery.

Examples of such a polymer having a solubility index of 15 to 45 MPa ^1/2 include polyvinylidenefluoride-co-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene ), Polymethylmethacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyvinylpyrrolidone, But are not limited to, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol (cyanoethylpolyvinylalcohol), cyanoethyl cellulose hylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer, or polyimide. Can be used.

As the solvent of the polymeric binder, it is preferable that the solubility index is similar to that of the polymer binder to be used, and the boiling point is low. This is to facilitate uniform mixing and subsequent solvent removal. Non-limiting examples of usable solvents include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone ( N-methyl-2-pyrrolidone, NMP), cyclohexane, water or a mixture thereof.

The inorganic particles are not particularly limited as long as they are electrochemically stable. That is, the inorganic particles usable in the present invention are not particularly limited as long as oxidation and / or reduction reaction does not occur in the operating voltage range of the applied electrochemical device (for example, 0 to 5 V based on Li / Li ⁺ ). Particularly, when inorganic particles having a high dielectric constant are used as the inorganic particles, the dissociation of the electrolyte salt, for example, the lithium salt in the liquid electrolyte, can be increased, and the ion conductivity of the electrolyte can be improved.

For the reasons stated above, it is preferable that the inorganic particles include high-permittivity inorganic particles having a dielectric constant of 5 or more, preferably 10 or more. Nonlimiting examples of inorganic particles having a dielectric constant of 5 or more include BaTiO ₃ , Pb (Zr, Ti) O ₃ (PZT), Pb _{1 -x} La _x Zr _{1 -y} Ti _y O ₃ (PLZT, 0 < , 0 <y <1), Pb (Mg 1/3 Nb 2/3) O 3 -PbTiO 3 (PMN-PT), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, _{CaO, ZnO, ZrO 2, Y} 2 O 3, Al 2 O 3, TiO 2, SiC Or a mixture thereof.

As the inorganic particles, inorganic particles having a lithium ion transferring ability, that is, inorganic particles containing a lithium element but having a function of transferring lithium ions without storing lithium can be used. Non-limiting examples of inorganic particles having lithium ion transferring ability include lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0 <x <2, 0 <y < (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0 <x <2, 0 <y <1, 0 <z <3), 14Li ₂ O-9Al ₂ O ₃ -38TiO ₂ -39P ₂ O _5, including (LiAlTiP) _x O _y series glass (0 <x <4, 0 <y <13), lithium lanthanum titanate _{(Li x La y TiO 3,} 0 <x <2, 0 <y <3) (Li _x Ge _y P _z S _w , 0 <x <4, 0 <y <1, 0 <z <1, 0 <w <5) such as Li _3.25 Ge _0.25 P _0.75 S ₄ ), Li ₃ lithium nitride such as _{N (Li x N y, 0} <x <4, 0 <y <2), Li 3 PO 4 SiS 2 family, such as _{-Li 2 S-SiS 2 glass (} Li x Si _{y S z, 0 <x <} 3, 0 <y <2, 0 <z <4), LiI-Li 2 SP 2 S 5 , etc., such as P ₂ S ₅ based _{glass (Li x P y S z} , 0 <x <3, 0 <y <3, 0 <z <7), or a mixture thereof.

The average particle diameter of the inorganic particles is not particularly limited, but is preferably in the range of 0.001 to 10 mu m for the formation of the coating layer of uniform thickness and the adequate porosity. If it is less than 0.001 mu m, the dispersibility may be deteriorated, and if it exceeds 10 mu m, the thickness of the formed coating layer may increase.

The weight ratio of the inorganic particles to the polymeric binder is preferably in the range of, for example, 50:50 to 99: 1, more preferably 70:30 to 95: 5. When the content ratio of the inorganic particles to the polymeric binder is less than 50:50, the content of the polymer is increased and the pore size and porosity of the formed coating layer may be reduced. If the content of the inorganic particles exceeds 99 parts by weight, the fillerability of the formed coating layer may be weakened because the content of the polymeric binder is small.

As such a porous substrate, any porous substrate such as a porous membrane or a nonwoven fabric formed of various polymers and a planar porous substrate commonly used in an electrochemical device can be used. For example, a polyolefin porous film used as a separator of an electrochemical device, particularly, a lithium secondary battery, or a nonwoven fabric made of polyethylene terephthalate fiber may be used. The material and the shape may be variously selected depending on the purpose. For example, the polyolefin-based porous membrane may be made of a polyolefin-based polymer such as polyethylene, polypropylene, polybutylene, or polypentene, such as high-density polyethylene, linear low-density polyethylene, low-density polyethylene, ultra-high molecular weight polyethylene, And the nonwoven fabric may be made of a polyolefin-based polymer or a fiber using a polymer having higher heat resistance. The thickness of the porous substrate is not particularly limited, but is preferably 1 to 100 占 퐉, more preferably 5 to 50 占 퐉, and the pore size and porosity present in the porous substrate are also not particularly limited, but 0.01 to 50 占 퐉 and 10 To 95%.

 The separator of the present invention is laminated between the positive electrode and the negative electrode, and an electrochemical device can be manufactured using the non-aqueous electrolyte. The electrochemical device includes all devices that perform an electrochemical reaction, and specific examples include capacitors such as all kinds of primary, secondary cells, fuel cells, solar cells, or super capacitor devices. Particularly, a lithium secondary battery including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery is preferable.

The positive electrode and the negative electrode to be used together with the separator of the present invention are not particularly limited, and the electrode active material may be bound to an electrode current collector according to a conventional method known in the art. Examples of the cathode active material include, but are not limited to, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a combination thereof It is preferable to use a lithium composite oxide. As a non-limiting example of the negative electrode active material, a conventional negative electrode active material that can be used for a negative electrode of an electrochemical device can be used. In particular, lithium metal or a lithium alloy, carbon, petroleum coke, activated carbon, Lithium-adsorbing materials such as graphite or other carbon-based materials and the like are preferable. Non-limiting examples of the positive current collector include aluminum, nickel, or a combination thereof. Examples of the negative current collector include copper, gold, nickel, or a copper alloy or a combination thereof Foil to be manufactured, and the like.

The nonaqueous electrolyte solution that can be used in the electrochemical device of the present invention is a salt having a structure such as A ⁺ B ^- , wherein A ⁺ includes an alkali metal cation such as Li ⁺ , Na ⁺ , K ⁺ B ^- is _{^{PF 6 -, BF 4 -,}} Cl -, Br -, I -, ClO 4 -, AsF 6 -, CH 3 CO 2 -, CF 3 SO 3 -, N (CF 3 SO 2) 2 -, _{C (CF 2 SO 2) 3} - anion, or a salt containing an ion composed of a combination of propylene carbonate (PC) such as, ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), di (DMP), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC), gamma butyrolactone g-butyrolactone) or an organic solvent composed of a mixture thereof, but is not limited thereto . However, it is more preferable that the non-aqueous electrolyte contains a carbonate-based organic solvent.

The electrolyte injection may be performed at an appropriate stage of the battery manufacturing process, depending on the manufacturing process and required properties of the final product. That is, it can be applied before assembling the cell or at the final stage of assembling the cell.

Claims (17)

A planar porous substrate; And
A porous coating layer formed on at least one surface of the planar porous substrate, the inorganic coating layer being bound by a polymeric binder and containing a surfactant,
Here, the inorganic particles are inorganic particles having a dielectric constant of 5 or more, inorganic particles having lithium ion-transporting ability, or mixtures thereof,
Wherein the surfactant comprises a triblock copolymer of PEO-PPO-PEO structure having a PEO content of 60 to 70 wt%. The method according to claim 1,
Wherein the surfactant is contained in an amount of 0.1 to 30% by weight based on the total weight of the porous coating layer. The method according to claim 1,
Wherein the surfactant is a nonionic surfactant. The method of claim 3,
Wherein the nonionic surfactant is a block copolymer having a hydrophilic portion and a hydrophobic portion together. The method according to claim 1,
Wherein the polymeric binder is a gelable polymer when impregnated with an electrolyte and has a solubility index in the range of 15 to 45 MPa ^1/2 . 6. The method of claim 5,
The polymeric binder may be selected from the group consisting of polyvinylidene fluoride-co-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, polymethylmethacrylate, Polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, cellulose (cellulose acetate) acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, and the like. , Cyanoethyl sucrose A compound selected from the group consisting of cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer and polyimide, or 2 Wherein the mixture is a mixture of two or more species. The method according to claim 1,
Wherein the inorganic particles have an average particle diameter of 0.001 to 10 mu m. delete The method according to claim 1,
The inorganic particles having a dielectric constant of 5 or more include BaTiO ₃ , Pb (Zr, Ti) O ₃ (PZT), Pb _{1 -x} La _x Zr _{1 -y} Ti _y O ₃ (PLZT, 0 <x <_{<1), Pb (Mg 1/3} Nb 2/3) O 3 -PbTiO 3 (PMN-PT), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, CaO, ZnO, ZrO ₂ , SiO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , SiC and TiO ₂ , or a mixture of two or more of them. The method according to claim 1,
The inorganic particles having lithium ion transferring ability include lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0 <x <2, 0 <y <3), lithium aluminum titanium phosphate (Li _x Al _y Ti _z (PO ₄ ) ₃ , 0 <x <2, 0 <y <1, 0 <z <3), (LiAlTiP) _x O _y series glass <13), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , , 0 <y <1, 0 <z <1, 0 <w <5), lithium nitrides _{(Li x N y, 0 <} x <4, 0 <y <2), SiS 2 (Li x Si y S _{z, 0 <x <3,} 0 <y <2, 0 <z <4) based glass, and _{P 2 S 5 (Li x P} y S z, 0 <x <3, 0 <y <3, 0 <z &Lt; 7) series glass, or a mixture of two or more thereof. The method according to claim 1,
Wherein the weight ratio of the inorganic particles to the polymeric binder is 50:50 to 99: 1. The method according to claim 1,
Wherein the porous substrate is a polyolefin-based porous substrate. 13. The method of claim 12,
Wherein the polyolefin-based porous substrate is formed of any one selected from the group consisting of polyethylene, polypropylene, polybutylene, and polypentene. The method according to claim 1,
Wherein the porous substrate has a thickness of 5 to 50 탆, a pore size and a porosity of 0.01 to 50 탆 and 10 to 95%, respectively. An electrochemical device comprising a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolyte solution,
Wherein the separator is a separator according to any one of claims 1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13 and 14 Wherein the electrochemical device comprises: 16. The method of claim 15,
Wherein the electrochemical device is a lithium secondary battery. 16. The method of claim 15,
Wherein the non-aqueous electrolyte comprises a carbonate-based organic solvent.