KR101834482B1 - Separator for electrochemical device and electrochemical device with improved stability and performance comprising the same - Google Patents

Abstract

The present invention relates to a separator for an electrochemical device manufactured by forming a coating layer on a porous substrate using three groups of inorganic particles classified according to their sizes in a specific content ratio, and an electrochemical device including the separator for improved stability and performance.

Description

[0001] The present invention relates to a separator for an electrochemical device and an electrochemical device including the same and having improved stability and performance,

The present invention relates to a separator for an electrochemical device and an electrochemical device including the same, which are improved in stability and performance. More particularly, the present invention relates to an electrochemical device comprising three groups of inorganic particles classified according to size, And an electrochemical device including the same and having improved stability and performance.

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. In particular, polyolefin-based porous substrates commonly used as separators for electrochemical devices exhibit extreme thermal shrinkage behavior at a temperature of 100 ° C or higher due to their manufacturing characteristics 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 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 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. However, even in the separation membrane for an electrochemical device in which a porous coating layer is formed, there is still room for improvement in stability due to heat shrinkage and improvement in output due to reduction in separation membrane resistance.

Accordingly, the present invention provides a separation membrane for an electrochemical device and a separation membrane for an electrochemical device including the same, wherein the separation membrane for an electrochemical device having a porous coating layer formed has improved stability in terms of heat shrinkage and improved output by reducing separation membrane resistance .

In order to solve the above-mentioned technical problem, in one 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 and including inorganic particles and a binder polymer, wherein the inorganic particles include a first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, Wherein the ratio of the first inorganic particle weight to the second inorganic particle weight is in the range of 1: 2.33 to 1: 1: 9, the weight of the first inorganic particles and the second inorganic particles combined with the weight of the third inorganic particles has a ratio of 1: 2.34 to 1: 9, and the gap generated between the third inorganic particles Wherein the first inorganic particles and the second inorganic particles are distributed in the first inorganic particles and the second inorganic particles to support the third inorganic particles. Film is provided.

The porous substrate may be a polyolefin-based porous film or a polyolefin-based nonwoven fabric.

The first inorganic particles, the second inorganic particles and the third inorganic particles each independently include high-permittivity inorganic particles having a dielectric constant of 5 or more, preferably 10 or more, inorganic particles having lithium ion-transporting ability, or a mixture thereof .

The inorganic particles having a dielectric constant of 5 or more include Al ₂ O ₃ , SiO ₂ , ZrO ₂ , AlOOH, TiO ₂ , BaTiO ₃ , Pb (Zr _x Ti _{1 -x} ) O ₃ (PZT, _{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 - x PbTiO 3 (PMN-} PT, where 0 <x <1), hafnia (HfO _2), from _{SrTiO 3, SnO 2, CeO 2} , MgO, NiO, CaO, the group consisting of ZnO, 2O ₃ and SiC And may be a selected one or a mixture of two or more.

Inorganic particle having the lithium ion conductivity include lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(LixTiy (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 (0 <x <4, 0 <y <13) (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , y <1, 0 <z < 1, 0 <w <5), lithium nitrides _{(Li x N y, 0 <} x <4, 0 <y <2), SiS 2 based glass (Li _x Si _y S _z 0 <x <3, 0 <y <2, 0 <z <4) and P ₂ S ₅ series glass (Li _x P _y S _z , 7), or a mixture of two or more thereof.

The ratio of the weight of the first inorganic particles, the second inorganic particles, and the third inorganic particles to the weight of the binder polymer may be 4: 1 to 5.5: 1.

According to another aspect of the present invention, there is provided an electrochemical device including an anode, a cathode, and a separator interposed between the anode and the cathode, wherein the separator is the separator described above.

The electrochemical device may be a lithium secondary battery.

According to another aspect of the present invention, there is provided a method of manufacturing a honeycomb structured body, comprising: forming a first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, a second inorganic particle having a D50 diameter of 350 nm or more and less than 1 mu m, 3 inorganic particles and a binder polymer are added to a solvent to prepare a slurry, wherein the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles is 1: 2.33 to 1: 9, The weight of the first inorganic particles and the weight of the third inorganic particles have a ratio of 1: 2.34 to 1: 9, and coating the slurry on at least one surface of the porous substrate, Wherein the first inorganic particles and the second inorganic particles are distributed in a gap generated between the inorganic particles so that the first inorganic particles and the second inorganic particles support the third inorganic particles, Is provided.

In the present invention, the inorganic particles present in the porous coating layer are packed more densely, and therefore, the binder polymer compound can be used in a smaller amount, thereby improving the stability in terms of heat shrinkage of the separator and improving the output in terms of resistance reduction .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a separation membrane in which a porous coating layer according to the present invention is formed on a porous substrate; FIG.

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.

The separation membrane for an electrochemical device of the present invention comprises a porous substrate; And a porous coating layer formed on at least one surface of the porous substrate and including a mixture of inorganic particles and a binder polymer, wherein the inorganic particles include a first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, A second inorganic particle having a D50 diameter of less than 1 mu m and a third inorganic particle having a D50 diameter of less than 1 mu m and less than 4 mu m, wherein the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles is 1: 2.33 to 1: 9, the weight of the first inorganic particles and the second inorganic particles combined with the weight of the third inorganic particles is 1: 2.34 to 1: 9, and the gap between the third inorganic particles Wherein the first inorganic particles and the second inorganic particles are distributed in the first inorganic particles and the second inorganic particles to support the third inorganic particles.

In the present specification, the term "D50 diameter" refers to volume-based cumulative 50% diameter, and is generally measured by a method using light scattering such as laser diffraction.

1, the separator according to the present invention comprises a first inorganic particle 1, a second inorganic particle 2 and a third inorganic particle 3, and the first inorganic particle 1 ) And the weight of the second inorganic particle (2) is 1: 2.33 to 1: 9 and the weight of the combined weight of the first inorganic particle (1) and the second inorganic particle (2) (2) and the first inorganic particles (2) are formed in a gap generated between the third inorganic particles (3), wherein a porous coating layer having a ratio of 1: 2.34 to 1: 9 is formed on the porous substrate (1) are dispersed and serve to support each other.

In the porous coating layer, smaller inorganic particles are positioned between the larger inorganic particles, thereby supporting larger inorganic particles. Therefore, when larger inorganic particles and smaller inorganic particles are used in an appropriate ratio, inorganic particles can be supported even by use of a smaller amount of binder polymer as the support between inorganic particles is appropriately secured. Preferably, the ratio of the weight of the first inorganic particles, the second inorganic particles, and the third inorganic particles to the weight of the binder polymer may be 4: 1 to 5.5: 1.

In the present invention, as the inorganic particles are packed more densely, the heat shrinkage of the separator may be small even when the battery is heated. For example, the heat shrinkage is less than 10% as compared with the conventional separator.

In the present invention, when an excessively small amount of inorganic particles is contained in an excessively small amount, the pores of the porous coating layer become relatively small, and when the packing is excessively closed, the air permeability is reduced. Also, when the amount of the smaller inorganic particles is excessively small, the air permeability is excellent but a relatively large interstitial volume is formed between the inorganic particles, so a large amount of binder should be used. As used herein, the term 'interstitial volume' refers to a space defined by inorganic particles that are substantially interfaced with a closed packed or densely packed structure. In the present invention, the first inorganic particles (1), the second inorganic particles (2) and the third inorganic particles (3) are used in an optimal composition ratio, and the inorganic particles, conventionally composed of two size groups, The interstitial volume generated when the inorganic particles are in contact with each other is made available as the pores of the porous coating layer.

The porous substrate to be used in the present invention may be a membrane or a nonwoven fabric and is not particularly limited, but a polyolefin-based porous substrate may be used. Examples of the polyolefin-based porous substrate include polyethylene, polypropylene, And polyphenylene can be used. In addition, a material used in the art as a porous substrate, such as engineered plastic, may be used.

In the separator of the present invention, the first inorganic particles, the second inorganic particles, and the third inorganic particles have different sizes as described above in terms of size, but they may be the same or different from each other in terms of kinds, It is not particularly limited as long as it is 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 ion transfer ability are used, the ion conductivity in the electrochemical device can be increased to improve the performance.

When inorganic particles having a high dielectric constant are used as the inorganic particles, dissociation of an electrolyte salt, for example, a lithium salt, in the liquid electrolyte is also increased, and ion conductivity of the electrolyte can be improved.

For the above reasons, it is preferable that the inorganic particles include high-permittivity inorganic particles having a dielectric constant of 5 or more, preferably 10 or more, inorganic particles having lithium ion-transporting ability, or a mixture thereof.

Non-limiting examples of inorganic particles having a dielectric constant of 5 or more include Al ₂ O ₃ , SiO ₂ , ZrO ₂ , AlOOH, TiO ₂ , BaTiO ₃ , Pb (Zr _x Ti _{1 -x} ) O ₃ (PZT, _{<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 - x PbTiO} 3 (PMN-PT, where 0 <x <1), hafnia _{(HfO 2), SrTiO 3,} SnO 2, CeO 2, MgO, NiO, CaO, ZnO, 2O 3, SiC May be used alone or in combination of two or more.

In particular, the above-described _{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 - x PbTiO 3 (PMN-PT, where 0 <x <1), hafnia ( HfO ₂ ) exhibits a high dielectric constant with a dielectric constant of 100 or more, as well as a piezoelectricity in which a potential difference is generated between both surfaces due to the generation of charge when a certain pressure is applied to the piezoelectric element by being stretched or compressed. It is possible to prevent internal short-circuiting of both electrodes due to the impact, thereby improving the safety of the electrochemical device. Further, when the above-mentioned high-permittivity inorganic particles and inorganic particles having lithium ion transferring ability are mixed, their synergistic effect can be doubled.

In the present invention, the inorganic particles having a lithium ion transferring ability refer to inorganic particles containing a lithium element but not lithium and having a function of transferring lithium ions. The inorganic particles having lithium ion transferring ability are contained in the particle structure Since lithium ions can be transferred and transferred due to a kind of defect present, the lithium ion conductivity in the battery is improved, thereby improving battery performance. Nonlimiting examples of the inorganic particles having lithium ion transferring ability include lithium phosphate (Li ₃ PO ₄ ), lithium titanium phosphate (LixTiy (PO ₄ ) ₃ , 0 <x <2, 0 <y <3) (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 (Li _x Ge _y P _z S _w , 0 <x <4, 0 <y <1, 0 <z <1, 0) such as _{3 .25} Ge _{0 .25} P _{0 .75} S ₄ , <w <5), Li ₃ lithium nitride such as _{N (Li x N y, 0} <x <4, 0 <y <2), Li 3 PO 4 -Li 2 SiS 2 based glass such as S-SiS _{2 (Li x Si y S z,} 0 <x <3, 0 <y <2, 0 <z <4), such as _{LiI-Li 2 SP 2 S 5} 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 polymeric binder of the present invention may be selected from the group consisting of polyvinylidene fluoride-cohexafluoropropylene, polyvinylidene fluoride-cotrichloroethylene, polymethylmethacrylate, polybutyl But are not limited to, polybutyl acrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, Polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl, Alcohol (cyanoethylpolyv inylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, or carboxyl methyl cellulose may be used.

The separation membrane of the present invention comprises a first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, a second inorganic particle having a D50 diameter of 350 nm or more and less than 1 mu m and a third inorganic particle having a D50 diameter of 1 mu m or more and less than 4 mu m Adding a binder polymer to a solvent to prepare a slurry, and coating the slurry on at least one side of the nonwoven substrate.

More specifically, the first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, the second inorganic particle having a D50 diameter of 350 nm or more and less than 1 mu m, and the third inorganic particle having a D50 diameter of 1 mu m or more and less than 4 mu m Wherein the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles is 1: 2.33 to 1: 9, and the weight of the first inorganic particles and the second inorganic particles combined with the weight ratio of the third inorganic particles Is prepared to be 1: 2.34 to 1: 9. The binder polymer is dissolved in a solvent, and then the prepared first inorganic particles, second inorganic particles and third inorganic particles are added and dispersed to prepare a slurry. The dispersion method is not particularly limited.

As the solvent of the binder polymer, it is preferable that the solubility index is similar to that of the binder polymer 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 slurry is then coated on at least one side of the porous substrate.

The slurry may be coated on the porous substrate by a conventional coating method known in the art, for example, a dip coating, a die coating, a roll coating, a comma coating Or a mixture method thereof may be used.

After the slurry is coated on the porous substrate, a post-treatment process such as a drying process can be selectively added.

The separator of the present invention may be interposed between the anode and the cathode to produce an electrochemical device.

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, and super capacitors . Particularly, in the lithium secondary battery, the lithium ion secondary battery, the lithium polymer secondary battery, or the lithium ion

Polymer secondary batteries and the like are preferable.

The electrode to be used together with the separator of the present invention is not particularly limited, and electrode active materials 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 electrolytic solution which 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 ^{+ -} it 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), dipropyl (DMP), dimethylsulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethylmethyl carbonate (EMC), gamma butyrolactone -Butyrolactone), or a mixture thereof, but the present invention is not limited thereto.

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.

As a process for applying the separator of the present invention to a battery, a lamination, stacking and folding process of a separator and an electrode can be performed in addition to a general process of winding.

The separator of the present invention may be interposed between the anode and the cathode of a secondary battery, and may be interposed between adjacent cells or electrodes when assembling a plurality of cells or electrodes to form an electrode assembly. The electrode assembly may have various structures such as a simple stack type, a jelly-roll type, and a stack-folding type.

According to one embodiment, the electrode assembly may be manufactured by interposing the separator of the present invention between a positive electrode and a negative electrode coated with an active material and continuously winding the positive electrode / separator / negative electrode.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to examples. However, the embodiments according to the present invention can be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention.

Example

Example  1-1: Preparation of Membrane

The diameter D50 of 200 nm Al ₂ O ₃ first inorganic particles 1-9% by weight, D50 diameter is 500nm of Al ₂ O ₃ 2 Al ₂ O ₃ in the inorganic particles, 9-21% by weight and the D50 diameter 2㎛ 3 inorganic particles and 70 to 90% by weight of inorganic particles.

The first inorganic particles, the second inorganic particles and the third inorganic particles were dispersed in an acetone solution, and 20 parts by weight of polyvinylidene fluoride (Solef21510) as a binder polymer was added and stirred for 30 minutes using a magnetic stirrer Slurry.

The prepared slurry was coated on a separation membrane to prepare a separation membrane.

Example  1-2: Manufacture of electrochemical devices

(PVDF) as a binder polymer compound and carbon black as a conductive material in an amount of 96% by weight, 3% by weight and 1% by weight, respectively, and a solvent N-methyl- 2 pyrrolidone (NMP) to prepare a negative electrode mixture slurry. The negative electrode mixture slurry was applied to a copper (Cu) thin film as an anode current collector having a thickness of 10 탆 and dried to produce a negative electrode, followed by roll pressing.

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

A battery was prepared using the electrode thus prepared and the separator of Example 1-1. The cell was fabricated by stacking a negative electrode, a positive electrode, and a porous organic / inorganic composite separator using a stacking method. An electrolytic solution (ethylene carbonate (EC) / ethylmethyl carbonate (EMC) = 1/2 (volume ratio) , And 1 mole of lithium hexafluorophosphate (LiPF ₆ )).

Comparative Example  1-1: Preparation of Membrane

Carried out, but using the inorganic particles of the same weight to that described in Example 1-1, D50 diameter is 200nm of Al ₂ O ₃ first the first inorganic particles and Al ₂ O ₃ 2 D50 inorganic particles with a diameter of 500nm: 2.34 or 1 : 9 ratio by weight, the membrane was prepared in the same manner as in Example 1-1.

Comparative Example  1-2: Manufacture of electrochemical devices

An electrochemical device was produced in the same manner as in Example 1-2, except that the separator of Comparative Example 1-1 was used.

Claims (9)

A porous substrate; And a porous coating layer formed on at least one surface of the porous substrate and including inorganic particles and a binder polymer. In this case,
The inorganic particles are composed of a first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, a second inorganic particle having a D50 diameter of 350 nm or more and less than 1 mu m, and a third inorganic particle having a D50 diameter of 1 mu m or more and less than 4 mu m In addition,
Wherein the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles is 1: 2.33 to 1: 9,
The weight of the first inorganic particles and the second inorganic particles combined with the weight of the third inorganic particles has a ratio of 1: 2.34 to 1: 9,
The first inorganic particles and the second inorganic particles are distributed in a gap generated between the third inorganic particles so that the first inorganic particles and the second inorganic particles support the third inorganic particles,
Wherein the porous coating layer is formed with an interstitial volume defined by inorganic particles interposed in a closed packed or densely packed manner by the first inorganic particles, the second inorganic particles, and the third inorganic particles. Characterized in that
Membranes for electrochemical devices.
The method according to claim 1,
Wherein the ratio of the weight of the first inorganic particles, the second inorganic particles, and the third inorganic particles to the weight of the binder polymer is from 4: 1 to 5.5: 1.
The method according to claim 1,
Wherein the porous substrate is a polyolefin-based porous film or a polyolefin-based nonwoven fabric.
The method of claim 1,
Wherein the first inorganic particles, the second inorganic particles, and the third inorganic particles each independently comprise high-permittivity inorganic particles having a dielectric constant of 5 or more, inorganic particles having lithium ion-transferring ability, or a mixture thereof. Membranes for devices.
5. The method of claim 4,
The inorganic particles having a dielectric constant of 5 or more include Al ₂ O ₃ , SiO ₂ , ZrO ₂ , AlOOH, TiO ₂ , BaTiO ₃ , Pb (Zr _x Ti _{1 -x} ) O ₃ (PZT, _{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 - x PbTiO 3 (PMN-} PT, where 0 <x <1), hafnia (HfO _2), from _{SrTiO 3, SnO 2, CeO 2} , MgO, NiO, CaO, the group consisting of ZnO, 2O ₃ and SiC And a mixture of at least one selected from the group consisting of a metal oxide and a metal oxide.
5. The method of claim 4,
Inorganic particles having the lithium ion conductivity include lithium phosphate (Li ₃ PO _4), lithium titanium phosphate _{(LixTiy (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 (0 <x <4, 0 <y <13) (Li _x La _y TiO ₃ , 0 <x <2, 0 <y <3), lithium germanium thiophosphate (Li _x Ge _y P _z S _w , y <1, 0 <z < 1, 0 <w <5), lithium nitrides _{(Li x N y, 0 <} x <4, 0 <y <2), SiS 2 based glass (Li _x Si _y S _z 0 <x <3, 0 <y <2, 0 <z <4) and P ₂ S ₅ series glass (Li _x P _y S _z , 7). &Lt; / RTI &gt;
An electrochemical device comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode,
The electrochemical device according to any one of claims 1 to 6, wherein the separator is a separator.
8. The method of claim 7,
Wherein the electrochemical device is a lithium secondary battery.
A first inorganic particle having a D50 diameter of 10 nm or more and less than 350 nm, a second inorganic particle having a D50 diameter of 350 nm or more and less than 1 mu m, and a third inorganic particle having a D50 diameter of 1 mu m or more and less than 4 mu m, Wherein the ratio of the weight of the first inorganic particles to the weight of the second inorganic particles is 1: 2.33 to 1: 9, and the weight of the first inorganic particles and the second inorganic particles, 3 inorganic particles having a weight ratio of 1: 2.34 to 1: 9, and
And coating the slurry on at least one surface of the porous substrate to form a porous coating layer,
The first inorganic particles and the second inorganic particles are distributed in a gap generated between the third inorganic particles so that the first inorganic particles and the second inorganic particles support the third inorganic particles,
Wherein the porous coating layer is formed with an interstitial volume defined by inorganic particles interposed in a closed packed or densely packed manner by the first inorganic particles, the second inorganic particles, and the third inorganic particles. And wherein the first,
(JP) METHOD FOR MANUFACTURING SEPARATOR FILM FOR ELECTROCHEMICAL DEVICE

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