This application claims the benefit of priority based on Korean Patent Application No. 2019-0072712 on June 19, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[2]
The present invention relates to a coating separator for a secondary battery and a method for manufacturing the same, and specifically, a coupling agent to ensure dispersibility of metal or metal oxide hydroxide, which is an inorganic component of the separator coating layer, electrode adhesion, and heat shrinkage of the separator. It relates to a coating separator for a secondary battery comprising: and a method for manufacturing the same.
background
[3]
Since the lithium secondary battery has a higher output than the conventional secondary battery, interest in securing safety is high. Safety Reinforced Separator (hereinafter 'SRS Separator') is one of the representative separators for enhancing the safety of lithium secondary batteries. The SRS separator has a structure in which a coating layer including inorganic particles and a binder is formed on a polyolefin-based substrate and has high safety at high temperatures.
[4]
The coating layer of the SRS separator forms a pore structure by inorganic particles and a binder, and due to the pore structure, a space for the liquid electrolyte to enter increases. Therefore, the SRS separator has high lithium ion conductivity and electrolyte impregnation rate. For this reason, it is possible to simultaneously improve the performance and safety of the electrochemical device using the SRS separator.
[5]
In general, a metal oxide such as alumina (Al 2 O 3 ) is used as inorganic particles constituting the coating layer of the SRS separator , and dispersion power is secured by using a cyano-based resin. However, the metal hydroxide presented as an inorganic substitute for the metal oxide has a high flame retardancy, but has a weak dispersing power with respect to a cyano-based resin.
[6]
Accordingly, a fatty acid-based dispersant was used to secure the dispersing power of the metal hydroxide during the preparation of the slurry for forming the coating layer of the SRS separator. However, when the fatty acid-based dispersant is used, there is a problem in that the thermal contraction rate of the SRS separator increases or the electrode adhesion is low.
[7]
Various attempts have been made to solve this problem.
[8]
Patent Document 1 (Japanese Patent Application Laid-Open No. 2017-016867 (2017.01.19)) contains a vinyl alcohol polymer (A) and a phosphoric acid compound (B), and a phosphoric acid compound ( B) relates to a coating composition for a secondary battery electrode or separator, characterized in that 1 to 42 parts.
[9]
The Patent Document 1 discloses the physical properties of a coating composition containing a vinyl alcohol-based polymer and a phosphoric acid compound, but there is no recognition of a separator capable of improving dispersion and adhesion when a metal hydroxide is used as an inorganic material.
[10]
Patent Document 2 (Korean Patent Publication No. 2017-0087315 (2017.07.28)) discloses a porous coating layer comprising a porous polymer substrate, a binder resin, and a plurality of inorganic particles, and formed on at least one surface of the porous polymer substrate. Including, wherein the binder resin relates to a composite separator for an electrochemical device in which a chemical crosslinking reaction is performed by heat and/or active energy rays.
[11]
Patent Document 2 provides only the effect of using a separator coating layer including a polyfunctional acrylate and a metal oxide as the binder resin.
[12]
In order to form the coating layer of the separator with improved safety, the dispersion force of the inorganic material of the separator coating layer is improved to exhibit uniform physical properties, and there is a need for improvement in technology that can secure adhesion with the electrode and improve thermal shrinkage. So far, no clear solution has been proposed.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[13]
The present invention is to solve the above problems, specifically, by improving the dispersibility of the separator coating layer containing the hydroxide of a metal or metal oxide as an inorganic material to form a uniform coating layer, while the adhesion with the electrode is reduced An object of the present invention is to provide a coating separator for a secondary battery capable of preventing the occurrence and a method for manufacturing the same.
means of solving the problem
[14]
In order to achieve this object, the coating separator for a secondary battery according to the first aspect of the present invention includes a separator substrate made of a porous polymer resin, and a coating layer coated on at least one surface of the separator substrate, wherein the coating layer is an inorganic material and a couple A ring agent is included, wherein the inorganic material is a hydroxide of a metal or metal oxide, and the coupling agent may be a titanium-based or silane-based coupling agent.
[15]
As a second aspect, the hydroxide of the metal or metal oxide may be expressed by the following formula.
[16]
M(OH) x (wherein M is B, Al, Mg, Co, Cu, Fe, Ni, Ti, Au, Hg, Zn, Sn, Zr or an oxide thereof, and x is an integer of 1 to 4)
[17]
In a third aspect, the coupling agent may include at least one functional group selected from an alkyl group, an alkoxyl group, and an ester group.
[18]
As a fourth aspect, the content of the coupling agent may be 0.5 parts by weight to 30 parts by weight based on 100 parts by weight of the inorganic material.
[19]
As a fifth aspect, the coating layer may further include a dispersant.
[20]
In a sixth aspect, the dispersant may be at least one selected from oil-soluble polyamines, oil-soluble amine compounds, fatty acids, fatty alcohols, and sorbitan fatty acid esters.
[21]
As a seventh aspect, the coating layer may further include a binder.
[22]
As an eighth aspect, the binder is polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichloroethylene, polymethylmethacrylate, Polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-vinylacetate copolymer (polyethylene-co-vinylacetate), polyethyleneoxide , polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl Alcohol (cyanoethylpolyvinylalcohol), cyanoethylcellulose (cyanoethylcellulose), cyanoethylsucrose (cyanoethylsucrose), pullulan (pullulan) and any one selected from the group consisting of carboxylmethylcellulose (carboxylmethylcellulose) or a mixture of two or more thereof have.
[23]
In a ninth aspect, the titanium-based coupling agent is a monoalkoxy titanate, a neoalkoxy titanate, a monoalkoxy-phosphate, a monoalkoxy phosphate ester, or a monoalkoxy pyrophosphate. consisting of isopropyl tridioctylphosphate titanate, isopropyl tridioctylpyrophosphate titanate, oleyl titanate, isopropyl trioleyl titanate, isopropyl tristearyl titanate and isopropyl triisostearyl titanate It may be any one selected from the group or a mixture of two or more thereof.
[24]
As a tenth aspect, the silane-based coupling agent is a vinyl group, an epoxy group, an amino group, an acryloxy group. It may include at least two functional groups selected from the group consisting of a methacryloxy group, a methoxy group, an ethoxy group, a styryl group, an isocyanurate group, and an isocyanate group.
[25]
As an eleventh aspect, the inorganic material further comprises a metal oxide, wherein the metal oxide is selected from the group consisting of a metal oxide having a dielectric constant of 5 or more, a metal oxide having piezoelectricity, and a metal oxide having a lithium ion transport ability. may be more than one species.
[26]
As a twelfth aspect, the present invention also provides a secondary battery including the coating separator for secondary batteries.
Modes for carrying out the invention
[27]
The coating separator for a secondary battery according to the present invention has a structure in which a coating layer is applied on one or both surfaces of a separator substrate made of a porous polymer resin.
[28]
The separator substrate is capable of providing a movement path of lithium ions while preventing a short circuit by electrically insulating the negative electrode and the positive electrode, and a porous membrane having high resistance to an organic solvent, an electrolyte, and having a fine pore diameter may be used. The separator substrate can be used without any particular limitation as long as it can be used as a separator material for conventional secondary batteries, for example, polyolefin-based (polyethylene, polypropylene, polybutene, polyvinyl chloride) and mixtures or copolymers thereof. or a resin such as polyethylene terephthalate, polycycloolefin, polyethersulfone, polyamide, polyimide, polyimideamide, polyaramid, polycycloolefin, nylon, polytetrafluoroethylene, etc. . Among these, the polyolefin-based resin is preferable because it has excellent applicability of the slurry for the porous coating layer, and can increase the capacity per volume by increasing the ratio of the electrode active material layer in the battery by reducing the thickness of the separator for secondary batteries.
[29]
The inorganic material used in the coating layer has a function of improving the mechanical strength of the separator, uniformly forming the thickness of the coating layer, and is not particularly limited as long as oxidation and/or reduction reactions do not occur in the operating voltage range of the applied secondary battery. does not In particular, when inorganic particles having an ion transport ability are used, performance can be improved by increasing ion conductivity in the electrochemical device. In addition, when inorganic particles having a high dielectric constant are used as the inorganic particles, the ionic conductivity of the electrolyte can be improved by contributing to an increase in the degree of dissociation of an electrolyte salt, such as a lithium salt, in the liquid electrolyte.
[30]
Specifically, conventionally, alumina (Al 2 O 3 ) has been widely used as the inorganic material . However, in recent years, the use of hydroxides of metals or metal oxides is increasing for the purpose of improving flame retardancy.
[31]
The hydroxide of the metal or metal oxide may be expressed by the following formula, and preferably, aluminum trihydroxide (Al(OH) 3 ) and/or AlOOH may be used.
[32]
M(OH) x (wherein M is B, Al, Mg, Co, Cu, Fe, Ni, Ti, Au, Hg, Zn, Sn, Zr or an oxide thereof, and x is an integer of 1 to 4)
[33]
The particle size of the inorganic material is not particularly limited, but considering the purpose of forming a coating layer having a uniform thickness and having an appropriate porosity, D50 may be in the range of 20 nm to 10 µm, specifically, 100 nm to 2 µm can be
[34]
D50 means the particle size of the particles corresponding to 50% of the cumulative number in the particle size distribution curve of the particles, and the average particle size of the inorganic particles was measured using a Particle Size Analyzer (product name: MASTERSIZER 3000; manufacturer: Malvern).
[35]
The content of the inorganic material may be 50 parts by weight to 95 parts by weight based on the total weight of the solid content of the coating layer, and specifically 60 parts by weight to 95 parts by weight. When the content of the inorganic material is less than 50 parts by weight based on the total weight of the solid content of the coating layer, the content of the binder is excessively large and the empty space formed between the inorganic particles is reduced, and the pore size and porosity are reduced to reduce the battery performance. This may decrease, and when it exceeds 95 parts by weight, the mechanical properties of the separator itself may be deteriorated due to the weakening of the adhesion between the inorganic materials because the content of the binder is too small, which is not preferable.
[36]
Conventionally, in the case of using a metal hydroxide when manufacturing a separator coating layer, dispersing power can be secured by using a fatty acid-based dispersant in which various acid-based components such as palmitic acid and oleic acid are present as a mixture. However, the coating separator prepared by using the fatty acid-based dispersant has a problem of high thermal shrinkage and low electrode adhesion.
[37]
In order to solve the above problems, in the present invention, a titanium-based or silane-based coupling agent is used in the preparation of the coating layer slurry.
[38]
The coupling agent may include at least one functional group selected from an alkyl group, an alkoxyl group, and an ester group.
[39]
The titanium-based coupling agent is monoalkoxy titanate, neoalkoxy titanate, isopropyl tridioctyl phosphate titanate, isopropyl tridioctyl pyrophosphate titanate, oleyl titanate, isopropyl trioleyl titanate, isopropyl Any one selected from the group consisting of tristearyl titanate and isopropyl triisostearyl titanate, di(dioctylpyrophosphate)ethylene titanate, monoalkoxy-phosphate, monoalkoxy phosphate ester, and monoalkoxy pyrophosphate Or it may be a mixture of two or more of these.
[40]
The silane-based coupling agent is a vinyl group, an epoxy group, an amino group, an acryloxy group. It may include at least two functional groups selected from the group consisting of a methacryloxy group, a methoxy group, an ethoxy group, a styryl group, an isocyanurate group, and an isocyanate group.
[41]
For example, in the silane-based coupling agent, a vinyl group, an epoxy group, an amino group, an acryloxy group, or a methacryloxy group may be bonded to one side, and a methoxy group or an ethoxy group may be bonded to the other side.
[42]
The content of the coupling agent may be included in an amount of 0.5 parts by weight to 30 parts by weight based on 100 parts by weight of the inorganic material, specifically 1 part by weight to 10 parts by weight, and more specifically 1 part by weight to 5 parts by weight. may be included as a part.
[43]
When the content of the coupling agent is less than 0.5 parts by weight based on the content of the inorganic material, dispersibility is not secured, and when it is greater than 30 parts by weight, it is difficult to exert the effect of improving thermal shrinkage and electrode adhesion, so it is not preferable. .
[44]
The coating layer may further include a dispersing agent in order to further improve the dispersibility of the hydroxide of the metal or metal oxide. The dispersant functions to maintain a uniform dispersion state of metal or metal oxide hydroxides in the binder during the preparation of the coating layer slurry, for example, oil-soluble polyamines, oil-soluble amine compounds, fatty acids, fatty alcohols, sorbitan fatty acids Any one or more selected from esters may be used, and specifically, a high molecular weight polyamine amide carboxylic acid salt may be used. The content of this dispersant may be 0.2 parts by weight to 10 parts by weight based on 100 parts by weight of the inorganic material. When included, there is a problem in that the adhesion of the coating layer to the separator substrate is reduced or impurities are generated by reacting with the electrolyte during the manufacture of the secondary battery.
[45]
The coating layer may further include a binder. The binder serves to stably fix the inorganic material to the surface of the separator substrate, for example, the binder is polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride- Trichloroethylene (polyvinylidene fluoride-trichlorethylene), polymethylmethacrylate (polymethylmethacrylate), polybutylacrylate (polybutylacrylate), polyacrylonitrile (polyacrylonitrile), polyvinylpyrrolidone (polyvinylpyrrolidone), polyvinylacetate (polyvinylacetate) , polyethylene-co-vinylacetate, polyethyleneoxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate ( cellulose acetate propionate), cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan and carboxymethylcellulose (carboxylmethylcellulose) may be any one selected from the group consisting of or a mixture of two or more thereof.
[46]
The coating separator for a secondary battery according to the present invention is prepared by dissolving an inorganic material, a binder, a coupling agent, etc. in a solvent to prepare a slurry, coating it on a separator substrate, and drying it, the solvent is a dispersion of an inorganic material and a binder It is preferable that this can be made uniformly, and that it can be easily removed thereafter. Non-limiting examples of the solvent that can be used include acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone ( Nmethyl-2-pyrrolidone, NMP), cyclohexane, water, or a mixture thereof.
[47]
The slurry is coated on one or both surfaces of the separator substrate to form a separator coating layer. As a method of coating the slurry on the separator substrate, a conventional coating method well known in the art may be used, for example, dip Various methods such as (Dip) coating, die (Die) coating, roll (roll) coating, comma (commna) coating, or a mixture thereof may be used.
[48]
On the other hand, the coating separator for a secondary battery according to the present invention can be used by further mixing a metal oxide in addition to the hydroxide of a metal or metal oxide in the coating layer.
[49]
The type of the metal oxide is not particularly limited, and for example, the metal oxide is selected from the group consisting of a metal oxide having a dielectric constant of 5 or more, a metal oxide having piezoelectricity, and a metal oxide having a lithium ion transport ability. More than one species can be used.
[50]
The metal oxide having a dielectric constant of 5 or more may be SiO 2 , SrTiO 3 , SnO 2 , CeO 2 , MgO, NiO, CaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 or TiO 2 .
[51]
In the metal oxide having piezoelectricity, a potential difference is formed due to positive and negative charges generated between both sides of the particle when a constant pressure is applied, BaTiO 3 , Pb(Zr x Ti 1-x )O 3 (PZT, where 0
[59]
Polyvinylidene fluoride-hexafluoropropylene having a weight average molecular weight of 500,000, hexafluoropropylene content of 15 parts by weight, 32% by weight, cyanoethyl polyvinyl alcohol having a weight average molecular weight of 400,000 1.5% by weight, D50 as an inorganic material This 800 nm aluminum hydroxide (Al(OH) 3 ) 65% by weight and 1.5% by weight of oleyl titanate, a titanium-based coupling agent, were added to acetone and mixed to prepare a slurry for a separator coating layer. The content of solids in the final slurry is 16% by weight.
[60]
The slurry for the separator coating layer is coated on both sides of a separator substrate made of a porous polymer resin made of a polyolefin-based material having a thickness of 9 μm to a thickness of 4 μm, respectively, and gaseous water vapor is put in a steam box and dried at a temperature of 25° C. for 10 minutes. Thus, a coating separator for a secondary battery was prepared.
[61]

[62]
In Example 1, the coating separator for secondary batteries was used in the same manner as in Example 1, except that 1.5 wt% of a silane-based coupling agent, vinyl trimethoxysilane, was used instead of 1.5 wt% of oleyl titanate. prepared.
[63]

[64]
Coating for secondary batteries in the same manner as in Example 1, except that 3 wt% of cyanoethylpolyvinyl alcohol was used instead of 1.5 wt% of cyanoethylpolyvinyl alcohol and 1.5 wt% of oleyl titanate in Example 1 A separator was prepared.
[65]

[66]
A coating separator for a secondary battery was prepared in the same manner as in Example 1, except that 1.5 wt% of a fatty acid-based dispersant was used instead of 1.5 wt% of oleyl titanate in Example 1.
[67]
Adhesion evaluation
[68]
Four electrodes having a length of 60 mm and a width of 25 mm and the separators prepared in Examples 1 and 2, Comparative Examples 1 and 2 were prepared to have a length of 70 mm and a width of 25 mm. The respective electrodes and the respective separators are placed so that they are overlapped, and the electrodes and the separators are attached by pressing for 1 second at 90° C. and 8.5 MPa.
[69]
After attaching the double-sided tape to the glass plate, and attaching the electrode so that it is adhered to the double-sided tape, use UTM (Universal Testing Machine) equipment (manufacturer: Instron, product name: 3345) to peel the electrode and the attached separator at a peeling rate of 300 mm/ min, the force required to completely separate the separation membrane by pulling under the conditions of 180° of peeling angle was measured.
[70]
Sedimentation rate and particle size measurement
[71]
The slurry prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 was put into a Dispersion Analyzer (product name: Lumisizer, manufacturer: LUM), rotated at a speed of 1,000 rpm, centrifugal force was applied, and then sedimentation rate according to time was measured.
[72]
In addition, the average particle diameter of the inorganic particles included in the slurry was measured using a Particle Size Analyzer (product name: MASTERSIZER 3000; manufacturer: Malvern).
[73]
Evaluation of heat shrinkage
[74]
The separation membranes prepared in Examples 1, 2, Comparative Example 1 and Comparative Example 2 were cut to a size of 50 mm in length and 50 mm in width, placed in a convection oven, and left at 150° C. for 30 minutes, and then the shrinkage rate was measured. (MD/TD).
[75]
The results of Experimental Examples 1 to 3 are shown in Table 1.
[76]
[Table 1]
Example 1 Example 2 Comparative Example 1 Comparative Example 2
Adhesion (gf/25mm) 70 65 52 less than 10
Particle size (D50) (㎛ ) 4 or less 4 or less 16 4 or less
Settling rate (㎛/s) below 10 below 10 over 100 below 10
Heat Shrinkage (MD/TD * ) 13/11 15/12 15/12 45/45
[77]
* MD(= Machine Direction), TD(= Transverse Direction)
[78]
Referring to Table 1, the separator of Comparative Example 2 using a fatty acid-based dispersant without using a coupling agent had a significantly low adhesive strength, so bonding with the electrode was a problem, whereas the separators of Examples 1 and 2 were combined with an electrode This can be done stably.
[79]
Comparing the sedimentation rate and the particle size (D50), the inorganic material in the slurry of Example 1 had a particle size of 4 µm or less and the sedimentation rate was 10 µm/s or less, whereas the inorganic material in the slurry of Comparative Example 1 had a particle size of 16 μm, and the sedimentation rate was measured to be 100 μm/s or more. That is, the slurries of Examples 1 and 2 have excellent inorganic dispersing power and thus have small particle sizes of inorganic particles, and the slurry of Comparative Example 1 has low inorganic dispersing power and large agglomeration of inorganic particles, so the particle size is large and the sedimentation rate is high. was measured. Therefore, it can be seen that the dispersing force is high in the slurry of Example 1.
[80]
Comparing the thermal shrinkage rate, the thermal contraction rate of the separator of Comparative Example 2 was measured to be about 4 times greater than that of the separator of Example 1, and the shrinkage rate of the separator of Comparative Example 2 was greatly increased in both the MD and TD directions.
[81]
Therefore, in the case of manufacturing a secondary battery using the separator of Comparative Example 2, it is expected that the positive electrode and the negative electrode come into contact with each other due to contraction of the separator when the temperature of the secondary battery increases, and a short circuit is likely to occur.
[82]
[83]
Those of ordinary skill in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.
Industrial Applicability
[84]
As described above, the coating separator for a secondary battery according to the present invention uses a metal or a hydroxide of a metal oxide as an inorganic material of the coating layer, and thus, it is possible to secure flame retardancy compared to the case of using a conventional metal oxide.
[85]
In addition, by using the coupling agent, the dispersion power of the hydroxide of the metal or metal oxide can be secured, and the thermal shrinkage rate and electrode adhesion of the separator can be improved.
[86]
Accordingly, it is possible to prevent the separator from shrinking at a high temperature or from reducing adhesive strength, thereby providing a secondary battery with improved safety.
Claims
[Claim 1]
A separator substrate made of a porous polymer resin, and a coating layer coated on at least one surface of the separator substrate, wherein the coating layer includes an inorganic material and a coupling agent, the inorganic material is a hydroxide of a metal or metal oxide, and the coupling agent is titanium ( A coating separator for secondary batteries that is a titanate-based or silane-based coupling agent.
[Claim 2]
According to claim 1, wherein the metal or hydroxide of the metal oxide is a secondary battery coating separator represented by the following formula; M(OH) x In the above formula, M is B, Al, Mg, Co, Cu, Fe, Ni, Ti, Au, Hg, Zn, Sn, Zr or an oxide thereof, and x is an integer of 1 to 4.
[Claim 3]
The coating separator for secondary batteries according to claim 1, wherein the coupling agent is a material containing at least one functional group selected from among an alkyl group, an alkoxyl group, and an ester group.
[Claim 4]
The coating separator for a secondary battery according to claim 1, wherein the amount of the coupling agent is 0.5 parts by weight to 30 parts by weight based on 100 parts by weight of the inorganic material.
[Claim 5]
The coating separator for a secondary battery according to claim 1, wherein the coating layer further comprises a dispersant.
[Claim 6]
The coating separator for a secondary battery according to claim 5, wherein the dispersant is at least one selected from oil-soluble polyamines, oil-soluble amine compounds, fatty acids, fatty alcohols, and sorbitan fatty acid esters.
[Claim 7]
The coating separator for a secondary battery according to claim 1, wherein the coating layer further comprises a binder.
[Claim 8]
According to claim 7, wherein the binder is polyvinylidene fluoride-hexafluoropropylene (polyvinylidene fluoride-hexafluoropropylene), polyvinylidene fluoride-trichlorethylene (polyvinylidene fluoride-trichlorethylene), polymethyl methacrylate (polymethylmethacrylate) , polybutylacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinylacetate, polyethyleneoxide ), polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpoly Any one selected from the group consisting of vinyl alcohol (cyanoethylpolyvinylalcohol), cyanoethylcellulose, cyanoethylsucrose, pullulan and carboxylmethylcellulose, or a mixture of two or more thereof Coated separator for secondary batteries.
[Claim 9]
According to claim 1, wherein the titanium-based coupling agent is monoalkoxy titanate, neoalkoxy titanate, isopropyl tridioctyl phosphate titanate, isopropyl tridioctyl pyrophosphate titanate, oleyl titanate, isopropyl triole yl titanate, isopropyl tristearyl titanate and isopropyl triisostearyl titanate, di(dioctylpyrophosphate)ethylene titanate, monoalkoxy-phosphate, monoalkoxy phosphate ester and monoalkoxy pyrophosphate. A coating separator for a secondary battery, which is any one selected from the group consisting of or a mixture of two or more thereof.
[Claim 10]
According to claim 1, wherein the silane-based coupling agent is a vinyl group, an epoxy group, an amino group, an acryloxy group. A coating separator for a secondary battery comprising at least two functional groups selected from the group consisting of methacryloxy group, methoxy group, ethoxy group, styryl group, isocyanurate group and isocyanate group.
[Claim 11]
According to claim 1, wherein the inorganic material further comprises a metal oxide, wherein the metal oxide is one selected from the group consisting of a metal oxide having a dielectric constant of 5 or more, a metal oxide having piezoelectricity, and a metal oxide having a lithium ion transport ability. Coated separator for secondary batteries of more than one species.
[Claim 12]
A secondary battery comprising the coating separator for a secondary battery according to any one of claims 1 to 11.