KR20130141234A - A separator having porous coating layer and electrochemical device including the same - Google Patents

Abstract

Disclosed are a separator having a porous coating layer and an electrochemical device including the same. The separator according to the present invention includes a porous substance, and a porous coating layer formed on at least on one side of the porous substance and including inorganic particles, binder macromolecules, and polydopamine. According to the present invention, the safety of the electrochemical device can be improved by controlling those inorganic particles not to be separated by stress taking place in assembling the electrochemical device with improved binding strength between the porous substance and the porous coating layer while the output and cycle property of the electrochemical device can be also increased by improving the affinity between the separator and the electrolyte, thereby improving the wetness of the electrolyte.

Description

TECHNICAL FIELD [0001] The present invention relates to a separator including a porous coating layer and an electrochemical device including the porous coating layer,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separator used in an electrochemical device such as a lithium secondary battery and an electrochemical device including the separator. More particularly, the present invention relates to a separator with improved safety including a porous coating layer and an electrochemical device including the separator .

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. The electrochemical device has received the most attention in this respect. Of these, the development of a rechargeable secondary battery has become a focus of attention. Recently, in developing such a battery, Research and development on the design of electrodes and batteries are underway.

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 .

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 is overheated and thermal explosion occurs or an explosion occurs when the separator is penetrated. Particularly, a polyolefin-based porous substrate commonly used as a separator of an electrochemical device exhibits extreme heat shrinkage behavior at a temperature of 100 ° C or higher owing to the characteristics of the manufacturing process including material properties and elongation, . ≪ / RTI >

In order to solve such a safety problem of the electrochemical device, a separator in which a porous coating layer is formed by coating a mixture of inorganic particles and a binder polymer on at least one surface of a porous substrate having a plurality of pores has been proposed. In such a separator, the inorganic particles in the porous coating layer formed on the porous substrate serve as a kind of spacer capable of maintaining the physical form of the porous coating layer, thereby suppressing heat shrinkage of the porous substrate when the electrochemical device is overheated, and porous Even if the substrate is damaged, direct contact between the cathode and the anode is prevented. In addition, an interstitial volume exists between the inorganic particles to form micropores.

As described above, the porous coating layer contributes greatly to the safety of the separator. However, in order to suppress the heat shrinkage of the porous substrate, the inorganic particles must be contained in a predetermined amount or more. However, as the content of the inorganic particles increases, the content of the binder polymer becomes relatively low. Therefore, there is a possibility that the inorganic particles are separated due to the stress generated in the assembling process of the electrochemical device due to deterioration of binding with the electrode. For this reason, the inorganic particles desorbed act as local defects of the electrochemical device, adversely affecting the safety of the electrochemical device. In addition, if the both electrodes and the separator are not sufficiently adhered to each other, the performance of the electrochemical device may deteriorate.

Further, in the electrochemical device, the wettability of the electrolytic solution in the porous coating layer of the separator may be lowered, resulting in a problem that the manufacturing process becomes time-consuming and costly. Particularly, in manufacturing a large-capacity battery, it takes a long time to inject the electrolyte, so a solution is also needed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a separator comprising a porous coating layer which improves adhesion of a porous substrate and a porous coating layer to improve safety of an electrochemical device and improves affinity with an electrolytic solution, And an electrochemical device including the same.

According to an aspect of the present invention, there is provided a porous substrate comprising: a porous substrate; And a porous coating layer formed on at least one surface of the porous substrate, the porous coating layer including inorganic particles, a binder polymer, and polypodamine.

Here, the average particle diameter of the inorganic particles may be 0.001 μm to 10 μm.

The inorganic particles may be inorganic particles selected from the group consisting of inorganic particles having a dielectric constant of 5 or more, inorganic particles having lithium ion transporting ability, and mixtures thereof.

Here, the inorganic particles is greater than or equal to the dielectric constant of _{5, BaTiO 3, Pb (Zr x} , Ti 1 -x) O 3 (PZT, where, 0 <x <1 _{Im), Pb 1 - x La x} Zr 1 -y Ti _y O ₃ (PLZT, where, 0 <x <1, 0 <y <1 Im), (1-x) Pb (Mg 1/3 Nb 2/3) O 3 -xPbTiO 3 (PMN-PT, where , 0 <x <1), hafnia (HfO ₂ ), SrTiO ₃ , SnO ₂ , CeO ₂ , MgO, NiO, CaO, ZnO, ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , SiC and TiO ₂ Or a mixture of two or more of them.

The inorganic particles having the 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), (LiAlTiP) _x O _y- 0 <y <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 , x <4, 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 < 7) series glass, or a mixture of two or more thereof.

The binder polymer may be at least one selected from the group consisting of polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichlorethylene, But are not limited to, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, Cyanoethylcellulose, cyanoethylcellulose, One selected from the group consisting of cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer and polyimide; And mixtures of two or more thereof.

The content of the binder polymer may be 1 to 15 parts by weight based on 100 parts by weight of the inorganic particles.

The content of the polypodamine may be 1 to 15 parts by weight based on 100 parts by weight of the inorganic particles.

The thickness of the porous coating layer may be 0.01 to 50 탆.

The porous substrate may be formed of at least one selected from the group consisting of polyolefine, polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate ) Selected from the group consisting of polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, and polyethylenenaphthalene. Any one or a mixture of two or more thereof may be used.

Meanwhile, according to another aspect of the present invention, in an electrochemical device including a cathode, an anode, a separator interposed between the cathode and the anode, and an electrochemical device in which the separator is the separator of the present invention is provided. .

Here, the electrochemical device may be a lithium secondary battery.

According to an embodiment of the present invention, the adhesion force between the porous substrate and the porous coating layer is improved, and the inorganic particles that can be removed by the stress generated in the assembling process of the electrochemical device are controlled to improve the safety of the electrochemical device .

Further, by improving the affinity between the separator and the electrolytic solution and improving the wettability of the electrolytic solution, the output and cycle characteristics of the electrochemical device can be improved.

Hereinafter, the present invention will be described in detail. 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. Therefore, the configuration described in the embodiments described herein is only one of the most preferred embodiments of the present invention, and does not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be variations and variations.

A separator according to the present invention comprises: a porous substrate; And a porous coating layer formed on at least one surface of the porous substrate, the porous coating layer including inorganic particles, a binder polymer, and polydodamine.

The polydodamine is a polymer produced by polymerization reaction of 3,4-dyhydroxy-L-phenylalanine (DOPA), which is a catechol amine represented by the following formula (1).

However, in the present invention, the polydopamine includes not only the polymer of DOPA but also all the polydopamine which satisfies the required characteristics by modifying the functional group of the polydodamine within the range not hindering the object of the present invention.

The porous coating layer formed on at least one side of the porous substrate includes polydodamine, which improves the adhesion between the porous coating layer and the porous substrate. In addition, it prevents the inorganic particles contained in the porous coating layer from desorbing.

Further, by improving the adhesion between the porous coating layer and the porous substrate, the lithium ion can be efficiently transferred and the internal resistance can be reduced.

And, since polydopamine has a high affinity with the electrolytic solution, it improves the wettability of the electrolytic solution to the separator. In the present invention, the affinity with the electrolytic solution means that the electrolytic solution impregnates the separator at high speed or impregnates a large capacity.

That is, not only the safety of the electrochemical device is improved by including the inorganic coating layer containing the inorganic particles and the polypodamine as the binder polymer, but also the improvement of the interfacial adhesion between the separator and the electrode and the high affinity with the electrolyte, Can be improved. Also, the irreversible capacity is reduced and the C-rate is improved, which means that the charge / discharge cycle life is improved.

The average particle size of the inorganic particles is not particularly limited, but may be, but is not limited to, 0.001 μm to 10 μm for formation of a porous coating layer having a uniform thickness and proper porosity.

In addition, the inorganic particles that can be used in the present invention 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, the inorganic particles may include high-permittivity inorganic particles having a dielectric constant of 5 or more, or 10 or more. Nonlimiting examples of inorganic particles having a dielectric constant of 5 or more include BaTiO ₃ , Pb (Zr _x , Ti _{1 -x} ) O ₃ (PZT, where 0 <x <1), Pb _{1 -x} La _x Zr _{1- y} Ti _y O ₃ (PLZT, where, 0 <x <1, 0 <y <1 Im), (1-x) Pb (Mg 1/3 Nb 2/3) O 3 -xPbTiO 3 (PMN-PT, where, 0 <x <1 Im), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, CaO, ZnO, ZrO 2, Y 2 O 3, Al 2 O 3, SiC and TiO ₂ , or a mixture of two or more 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 (0 <x <4, 0 <y <13), lithium lanthanum titanate (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), Li (LiAlTiP) _x O _y series glass _{3 .25} Ge _{0 .25} P _{0 .75} S ₄ Lithium, such as germanium Mani help thiophosphate lithium nitro, such as _{(Li x Ge y P z S} w, 0 <x <4, 0 <y <1, 0 <z <1, 0 <w <5), Li 3 N (Li _x N _y , 0 <x <4, 0 <y <2), Li ₃ PO ₄ -Li ₂ S-SiS ₂ SiS ₂ based glass, such as _{(Li x Si y S z,} 0 <x <3, 0 <y <2, 0 <z <4), LiI-Li 2 SP 2 S 5 There is 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 as such.

The binder polymer may be at least one selected from the group consisting of polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichlorethylene, But are not limited to, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, Cyanoethylcellulose, cyanoethylcellulose, One selected from the group consisting of cyanoethylsucrose, pullulan, carboxyl methyl cellulose, acrylonitrile-styrene-butadiene copolymer and polyimide; And mixtures of two or more thereof. However, the present invention is not limited thereto.

The content of the binder polymer may be 1 to 30 parts by weight, or 1 to 15 parts by weight based on 100 parts by weight of the inorganic particles, and the content of the polypodamine may be 1 to 30 Parts by weight, or 1 to 15 parts by weight. When the content of the binder polymer and the content of the polypodamine satisfy the above ranges, it is possible to appropriately prevent the inorganic particles from desorbing, prevent an increase in internal resistance of the electrochemical device, and maintain a proper porosity of the porous coating layer .

In the porous coating layer, the binder polymer and the polydodamine are each coated on a part or the entire surface of the inorganic particles, and the inorganic particles are connected and fixed to each other by the binder polymer and the polydopamine in close contact, It is preferable that the pores are formed due to the empty space existing between them. That is, the inorganic particles of the porous coating layer exist in close contact with each other, and the void space generated when the inorganic particles are in close contact becomes the pores of the porous coating layer. The size of the void space present between the inorganic particles is preferably equal to or smaller than the average particle size of the inorganic particles.

The thickness of the porous coating layer including the inorganic particles, the binder polymer, and the polydodamine is not particularly limited. However, in order to prevent the internal resistance increase and ensure the safety of the electrochemical device, the thickness may be 0.01 탆 to 50 탆, or 0.5 탆 to 10 탆 have.

The porous substrate may be any porous substrate commonly used in an electrochemical device. For example, a polyolefin-based porous membrane or a nonwoven fabric may be used. However, the porous substrate is not particularly limited thereto.

Examples of the polyolefin-based porous film include polyolefin-based polymers such as polyethylene, polypropylene, polybutylene, and polypentene, such as high density polyethylene, linear low density polyethylene, low density polyethylene and ultra high molecular weight polyethylene, One membrane can be mentioned.

The nonwoven fabric may be, for example, polyethylene terephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate, or polycarbonate. ), Polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyethylenenaphthalene, etc., alone or separately The nonwoven fabric formed from the polymer which mixed these is mentioned. The structure of the nonwoven fabric may be a spun bond nonwoven fabric or a meltblown nonwoven fabric composed of long fibers.

The thickness of the porous substrate is not particularly limited, but is 1 탆 to 100 탆, or 5 탆 to 50 탆.

The pore size and pore present in the porous substrate are also not particularly limited, but may be 0.001 μm to 50 μm and 10% to 95%, respectively.

On the other hand, the electrochemical device according to the present invention includes a cathode, an anode, a separator interposed between the cathode and the anode and a nonaqueous electrolyte, the separator is characterized in that the separator of the present invention described above.

The electrochemical device of the present invention includes all devices that perform an electrochemical reaction, and specific examples thereof 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 electrode to be applied to the electrochemical device according to the present invention is not particularly limited, and according to a conventional method known in the art, the electrode active material may be prepared in a form bound to the electrode current collector. Non-limiting examples of the cathode active material of the electrode active material may be a conventional cathode active material that can be used for the cathode of the conventional electrochemical device, in particular lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide or a combination thereof One lithium composite oxide can be used. Non-limiting examples of the anode active material may be a conventional anode active material that can be used in the anode of the conventional electrochemical device, in particular lithium metal or lithium alloys, carbon, petroleum coke, activated carbon, Lithium adsorbents such as graphite or other carbons are preferred. Non-limiting examples of the cathode current collector include aluminum, nickel, or a combination thereof, and examples of the anode current collector include copper, gold, nickel, or a copper alloy or a combination thereof Foil to be manufactured, and the like.

The electrolyte salt contained in the nonaqueous electrolyte solution which can be used in the present invention is a lithium salt. The lithium salt can be used without limitation as those conventionally used in an electrolyte for a lithium secondary battery. For example is the above lithium salt anion ^{F -, Cl -, Br -} , I -, NO 3 -, N (CN) 2 -, BF 4 -, ClO 4 -, PF 6 -, (CF 3) 2 PF _{^{4 -, (CF 3) 3}} PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 SO 3 -, CF 3 CF 2 SO 3 - _{, (CF 3 SO 2) 2} N -, (FSO 2) 2 N -, CF 3 CF 2 (CF 3) 2 CO -, (CF 3 SO 2) 2 CH -, (SF 5) 3 C -, ( CF ₃ SO ₂ ) ₃ C ^- , CF ₃ (CF ₂ ) ₇ SO ₃ ^- , CF ₃ CO ₂ ^- , CH ₃ CO ₂ ^- SCN ^- and (CF ₃ CF ₂ SO ₂ ) ₂ N ^- .

Examples of the organic solvent included in the above-mentioned non-aqueous electrolyte include those commonly used in electrolytic solutions for lithium secondary batteries, such as ether, ester, amide, linear carbonate, cyclic carbonate, etc., Can be mixed and used.

Among them, a carbonate compound which is typically a cyclic carbonate, a linear carbonate, or a mixture thereof may be included.

Specific examples of the cyclic carbonate compound include ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, Propylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, vinylethylene carbonate, and halides thereof, or a mixture of two or more thereof. Examples of such halides include, but are not limited to, fluoroethylene carbonate (FEC) and the like.

Specific examples of the linear carbonate compound include any one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethyl methyl carbonate (EMC), methyl propyl carbonate and ethyl propyl carbonate And mixtures of two or more of them may be used as typical examples, but the present invention is not limited thereto.

In particular, ethylene carbonate and propylene carbonate, which are cyclic carbonates in the carbonate-based organic solvent, are high-viscosity organic solvents having a high dielectric constant and can dissociate the lithium salt in the electrolyte more easily. In addition, such cyclic carbonates can be used as dimethyl carbonate and diethyl carbonate When a low viscosity, low dielectric constant linear carbonate is mixed in an appropriate ratio, an electrolyte having a higher electric conductivity can be produced.

As the ether in the organic solvent, any one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether and ethyl propyl ether or a mixture of two or more thereof may be used , But is not limited thereto.

Examples of the ester in the organic solvent include methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate,? -Butyrolactone,? -Valerolactone,? -Caprolactone,? -Valerolactone, ε-caprolactone, or a mixture of two or more thereof, but the present invention is not limited thereto.

The injection of the nonaqueous electrolyte solution can be performed at an appropriate stage of the manufacturing process of the electrochemical device according to the manufacturing process and required properties of the final product. That is, it can be applied before assembling the electrochemical device or in the final stage of assembling the electrochemical device.

The electrochemical device according to the present invention is capable of lamination, stacking, and folding processes of a separator and an electrode in addition to a conventional winding process. The outer shape of the electrochemical device is not particularly limited, but may be a cylindrical shape, a square shape, a pouch shape, a coin shape, or the like using a can.

Hereinafter, embodiments of the present invention will be described in detail to facilitate understanding of the present invention. However, embodiments according to the present invention can be modified in many different forms, the scope of the invention should not be construed as limited to the following examples. Embodiments of the invention are provided to more fully describe the present invention to those skilled in the art.

Example

(1) Manufacture of separator

Polydopamine  Produce

Dopamine was dissolved in a basic buffer solution (pH 8.5, 20 mM Tris-HCl buffer) at a concentration of 2 mg / ml, and the dopamine was polymerized under a gentle swirling condition at room temperature for 24 hours.

The porous coating layer PVdF - CTFE  Of Al ₂ O ₃ ) formation

A polyvinylidene fluoride-hexafluorofluoropropylene copolymer (PVdF-HFP) polymer was added to acetone at 5 wt% and dissolved at 50 ° C. for at least about 12 hours to prepare a binder polymer solution. Then, a binder polymer solution, Al ₂ O ₃ powder and polydodamine were added so that the weight ratio of the binder polymer solution: Al ₂ O ₃ powder: polypodamine = 5: 90: 5 was used, and the mixture was ball milled for 12 hours or longer And the Al ₂ O ₃ powder was crushed and dispersed to prepare a slurry. The slurry thus prepared was coated and dried on both sides of a polyethylene porous substrate having a thickness of 12 μm (porosity of 45%) by a dip coating method, thereby forming a porous coating layer on both sides of the porous substrate.

(2) manufacture of a lithium secondary battery

Anode  Produce

(PVDF) as a binder, and carbon black as a conductive material in an amount of 96 wt%, 3 wt%, and 1 wt%, respectively, and a solvent N-methyl-2 Pyrrolidone (NMP) to prepare an anode mixture slurry. The anode mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 占 퐉 and dried to produce an anode, followed by a roll press.

Cathode  Produce

92% by weight of a lithium cobalt composite oxide as a cathode active material, 4% by weight of carbon black as a conductive material and 4% by weight of PVdF as a binder were added to N-methyl-2-pyrrolidone (NMP) . The cathode mixture slurry was applied to an aluminum (Al) thin film of a cathode current collector having a thickness of 20 탆 and dried to form a cathode, followed by roll pressing.

Manufacture of batteries

A coin cell type battery was manufactured through the separator between the prepared cathode and anode. As the nonaqueous electrolyte, ethylene carbonate (EC): ethylmethyl carbonate (EMC) = 1: 2 (volume ratio) in which 1 M lithium hexafluoro phosphate (LiPF ₆ ) was dissolved was used.

Claims (12)

A porous substrate; And
And a porous coating layer formed on at least one surface of the porous substrate and including inorganic particles, a binder polymer, and polydopamine. The method of claim 1,
Wherein an average particle diameter of the inorganic particles is 0.001 to 10 mu m. The method of claim 1,
Wherein the inorganic particles are inorganic particles selected from the group consisting of inorganic particles having a dielectric constant of 5 or more, inorganic particles having a lithium ion transporting ability, and mixtures thereof. The method of claim 3,
Inorganic particles is greater than or equal to the dielectric constant of _{5, BaTiO 3, Pb (Zr x} , Ti 1 -x) O 3 (PZT, where, 0 <x <1 _{Im), Pb 1 - x La x} Zr 1 -y Ti y O ₃ (PLZT, where, 0 <x <1, 0 <y <1 Im), (1-x) Pb (Mg 1/3 Nb 2/3) O 3 -xPbTiO 3 (PMN-PT, where 0 (x <1), hafnia (HfO ₂ ), SrTiO ₃ , SnO ₂ , CeO ₂ , MgO, NiO, CaO, ZnO, ZrO ₂ , Y ₂ O ₃ , Al ₂ O ₃ , SiC and TiO ₂ , Or a mixture of two or more thereof. The method of claim 3,
Wherein the inorganic particles having lithium ion transferring ability are selected from the group consisting of lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (Li _x Ti _y (PO ₄ ) ₃ , 0 <x <2, 0 <y < 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 thiophosphate (Li _x Ge _y P _z S _w , 4, 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 <7) series glass, or a mixture of two or more thereof. The method of claim 1,
The binder polymer may be at least one selected from the group consisting of polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichlorethylene, But are not limited to, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, Cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylpolyvinylalcohol, Ethyl cellulose (cyanoethylcellulose), cyanoethyl sucrose (cy an acrylonitrile-styrene-butadiene copolymer, and a polyimide, or an anion selected from the group consisting of an anionic surfactant, an anionic surfactant, an anionic surfactant, an anionic surfactant, an anionic surfactant, an anionic surfactant, an anionic surfactant, an anionic surfactant, Wherein the mixture is a mixture of two or more species. The method of claim 1,
Wherein the content of the binder polymer is 1 to 15 parts by weight based on 100 parts by weight of the inorganic particles. The method of claim 1,
Wherein the content of the polypodamine is 1 to 15 parts by weight based on 100 parts by weight of the inorganic particles. The method of claim 1,
Wherein the porous coating layer has a thickness of 0.01 占 퐉 to 50 占 퐉. The method of claim 1,
The porous substrate may be formed of a material selected from the group consisting of polyolefine, polyethyleneterephthalate, polybutyleneterephthalate, polyester, polyacetal, polyamide, polycarbonate, One selected from the group consisting of polyimide, polyetheretherketone, polyethersulfone, polyphenylene oxide, polyphenylenesulfide, and polyethylenenaphthalene. Or a mixture of two or more thereof. In the electrochemical device comprising a cathode, an anode, a separator interposed between the cathode and the anode and a nonaqueous electrolyte,
The electrochemical device according to any one of claims 1 to 10, wherein the separator is a separator. 12. The method of claim 11,
Wherein the electrochemical device is a lithium secondary battery.