KR20170062170A - Heat resisting separator for secondary battery and lithium secondary battery comprising the same - Google Patents

Abstract

The separation membrane for a secondary battery of the present invention comprises: a separation membrane substrate; And a heat resistant layer formed on at least one surface of the substrate and including a heat absorbing agent and a binder, wherein the heat absorbing agent comprises inorganic oxide particles having a positive heat of reaction at 150 to 200 캜. Such a secondary battery separator can prevent thermal runaway due to heat generated after a short circuit and subsequent ignition, and there is no problem of side reaction with an electrolyte solution. Therefore, the lithium secondary battery to which the separator is applied can secure safety against heat .

Description

TECHNICAL FIELD [0001] The present invention relates to a separator for a heat-resistant secondary battery, and a lithium secondary battery including the same. Technical Field [0001]

A separator for a secondary battery having excellent heat resistance by applying inorganic oxide particles having a large heat capacity, and a lithium secondary battery including the separator.

As consumers' demands have changed due to digitization and high performance of electronic products, market demand is changing due to the development of batteries with high capacity due to thinness, light weight and high energy density. In addition, in order to cope with future energy and environmental problems, hybrid electric vehicles, electric vehicles, and fuel cell vehicles are being actively developed, and it is required to increase the size of batteries for automobile power sources.

Secondary batteries, including high energy density and large capacity lithium ion secondary cells, lithium ion polymer batteries, and super capacitors (electric double layer capacitors and similar capacitors), must have a relatively high operating temperature range and should be continuously used at high rate charge and discharge The separator used in these cells is required to have higher heat resistance and thermal stability than those required in ordinary separators. In addition, it should have excellent cell characteristics such as rapid charge / discharge and high ion conductivity capable of coping with low temperature.

The separator is located between the anode and the cathode of the battery and provides insulation. The electrolyte maintains a path for ion conduction. When the temperature of the battery is excessively high, a shutdown function Lt; / RTI >

When the temperature rises further and the separator melts, a large hole is formed and a short circuit occurs between the anode and the cathode. This temperature is called SHORT CIRCUIT TEMPERATURE, and generally the separator should have a low shutdown temperature and a higher short-circuit temperature. In the case of a polyethylene separator, if the battery is abnormally heated to 120 ° C or more, the battery may ignite due to thermal runaway.

Therefore, it is very important to have the shutdown function for the high energy density and large-sized secondary battery, to prevent the abnormal inventions, and to have excellent heat resistance with excellent cycle performance according to high ion conductivity.

Conventional lithium secondary batteries using a conventional polyolefin separator and a lithium ion secondary battery using an electrolyte or a polymer electrolyte gel coated with a gel polymer electrolyte membrane or a polyolefin separator have been insufficient in terms of heat resistance for use in a high energy density and high capacity battery . Therefore, the heat resistance required in a high-capacity, large-area battery such as an automobile does not satisfy the safety requirement.

In order to provide a separation membrane having a heat resistant layer, an inorganic oxide particle having a high heat capacity is contained in the heat resistant layer to prevent the ignition phenomenon due to thermal runaway after a shot, and a polymer coating layer And to prevent a side reaction with an electrolyte solution.

The present invention also provides a lithium secondary battery including a separation membrane having the heat-resistant layer formed thereon and having improved safety.

In order to achieve the above object, according to an embodiment of the present invention, And a heat-resistant layer formed on at least one side of the substrate and including an endothermic material and a binder, wherein the endothermic material comprises inorganic oxide particles having a positive reaction temperature at 150 to 200 ° C. / RTI >

The inorganic oxide particles may include at least one selected from the group consisting of dicalcium silicate (Ca ₂ SiO ₄ ) and tricalcium silicate (Ca ₃ SiO ₅ ).

The average particle diameter of the inorganic oxide particles may be 1 to 100 nm.

The endothermic agent may further include a coating layer of a polymer that surrounds the surface of the inorganic oxide particles and has a melting point of 120 ° C or higher.

The thickness of the coating layer may be 60% or less of the inorganic oxide particle diameter.

The coating layer may have a porosity of 5 vol% or less.

The polymer having a melting point of 120 ° C or higher may be at least one selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyetherimide, polyamideimide, And at least one selected from the group consisting of phenylene oxide, polyphenylene sulfide, and polyethylene naphthalene.

The binder may be selected from the group consisting of polyvinylidene fluoride (PVDF), polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose , Regenerated celluloses, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyaniline, acrylonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, (Ethylene-propylene-diene terpolymer (EPDM), sulphonated EPDM (polyether sulfone), polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, fluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, , Styrene-butadiene rubber, and fluorine rubber. One can.

The endothermic agent may be included in an amount of 50 to 95% by weight based on the total weight of the heat resistant layer.

The base material for a separator is a stretched film and may include at least one selected from the group consisting of high density polyethylene, linear low density polyethylene, low density polyethylene, ultra high molecular weight polyethylene, polypropylene, polybutylene and polypentene.

The separator base material may have a porosity of 30 to 70% by volume.

The thickness of the heat resistant layer may be 5 to 15 탆.

According to another aspect of the present invention, there is provided a cathode comprising: a cathode having a cathode active material layer formed on a cathode current collector; An anode having an anode active material layer formed on the anode current collector; And a separation membrane for the secondary battery, wherein the separation membrane is sandwiched between the anode and the cathode.

The separation membrane for a secondary battery of the present invention includes inorganic oxide particles having a large heat capacity and can prevent ignition due to thermal runaway after a short circuit. The inorganic oxide particles are coated with a polymer to form inorganic oxide particles having relatively high reactivity with an electrolyte And thus the safety of the lithium secondary battery to which the separator is applied can be greatly improved.

Hereinafter, preferred embodiments of the present invention will be described in detail. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined. Therefore, the constitutions shown in the embodiments described herein are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention, so that various equivalents and variations Examples should be understood.

According to an embodiment of the present invention, And a heat resistant layer formed on at least one side of the substrate and including a heat absorbing agent and a binder, wherein the heat absorbing agent has inorganic oxide particles having a positive reaction temperature at 150 to 200 DEG C, And a coating layer of a polymer having a melting point of 120 ° C or higher.

Endotherm

The separation membrane for a secondary battery according to an embodiment of the present invention is formed with a heat resistant layer containing an endothermic agent, and the endothermic agent includes inorganic oxide particles.

Among the inorganic oxides, the inorganic oxide particles may mean an inorganic oxide having a positive heat of reaction at a temperature of 150 to 200 DEG C, that is, a substance capable of endothermic reaction at a temperature of 150 to 200 DEG C, for example, dicalcium silicate (Ca ₂ SiO ₄₎ or tricalcium silicate (Ca ₃ SiO _5), and the like can be applied, it is preferable to be applied is a dicalcium silicate.

On the other hand, if the battery is short-circuited by an external factor or some other factor, if the heat generated after the short circuit and the heat emitted by the battery itself are opposite to each other and the generated heat is large, May undergo thermal runaway and become ignited, causing serious safety problems. However, as described above, the inorganic oxide particles that undergo endothermic reaction at 150 to 200 ° C have heat capacity larger than those of conventional inorganic oxide particles (for example, Al ₂ O ₃ ), and therefore heat due to short circuit or heat It is possible to provide a buffer capable of absorbing heat, thereby preventing ignition due to thermal runaway phenomenon.

The average particle diameter of the inorganic oxide particles is not particularly limited, but may be 1 to 100 nm in order to maintain the porosity of the heat-resistant layer and the separation membrane of uniform thickness.

The endothermic agent may further include a polymer coating layer surrounding the surface of the inorganic oxide particles. The polymer may have a melting point of 120 ° C or higher. When the inorganic oxide particles are wrapped using a polymer having a melting point of 120 ° C or higher, the ability to accommodate the generated heat can be further improved because it can be utilized for the endothermic heat up to the latent heat at the melting point of the polymer when ignited at 120 ° C or higher And it is possible to solve the problem of agglomeration as an intrinsic problem of nanoscale particles, and thus it is possible to further improve the dispersibility due to the polymer coating when forming the heat resistant layer.

The polymer may have a melting point of 120 ° C or higher, preferably a melting point of 120-150 ° C. If the polymer satisfies the melting point condition, it is not particularly limited, but examples of the polymer having a melting point in the temperature range For example, there may be mentioned polyethylene, polypropylene, polyethylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyetherimide, polyamideimide, polyether sulfone, polyphenylene oxide, poly Phenylene sulfide, or polyethylene naphthalene, and preferably polyolefin such as polyethylene or polypropylene can be applied.

The coating layer of the inorganic oxide particles formed of the polymer having a melting point of 120 캜 or higher may have a thickness of 60% or less of the inorganic oxide particle diameter. If the thickness exceeds 60% of the inorganic oxide particle diameter, the endothermic reaction of the inorganic oxide particles may not be performed smoothly due to the thickness of the coating layer.

The coating layer of the polymer may have a porosity of 5 vol% or less. Since the coating layer should be present in a form that encompasses the inorganic oxide particles as much as possible, it is advantageous that the porosity is as small as possible, and not more than 5% by volume.

Heat resistant layer

The separation membrane for a secondary battery according to an embodiment of the present invention is formed with a heat-resistant layer including a heat absorbing agent and a binder on one or both surfaces of a separation membrane base material.

The binder may be the same as that contained in the slurry produced at the time of forming the electrode, or may be homogeneous. For example, there may be mentioned polyvinylidene fluoride (PVDF), polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose Polyvinyl pyrrolidone, polyethylene, polypropylene, polystyrene, polymethyl methacrylate, polyaniline, acrylonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, poly (Ethylene-propylene-diene terpolymer (EPDM), sulfonated polyphenylene sulfide (EPDM), polyphenylene sulfide, polyphenylene sulfide, polyphenylene sulfide, tetrafluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, polyethylene sulfone, polyamide, polyacetal, EPDM, styrene butadiene rubber or fluorine rubber may be applied.

The endothermic agent may be contained in an amount of 50 to 95% by weight based on the total weight of the heat resistant layer. When the amount of the endothermic agent is in the above range, it is possible to prevent the problem of desorption of the endothermic agent, to make the mechanical strength of the heat resistant layer reach the required level, and to utilize the endothermic reaction of the endothermic agent as much as possible. There is a fear that the object to be obtained by the present invention may not be obtained.

The thickness of the heat resistant layer may be 5 to 15 탆. The heat resistant layer having the above thickness can improve the heat resistance characteristics of the battery itself without hindering the mobility of the lithium ion and may be a range that does not significantly increase the volume of the battery, You can have the advantage of not having.

By forming the above-described heat resistant layer on one side or both sides of the base material for a separator, it is possible to provide a safety heat-resistant separator which can more safely prevent the ignition phenomenon caused by thermal congestion after a short circuit.

Separator film

The separation membrane for a secondary battery according to an embodiment of the present invention basically includes a separation membrane substrate used as a separation membrane.

The separator base material can be used as a separator even in the state that no heat resistant layer is formed. Various functions can be given depending on the material of the separator base material. For example, in the case of polyethylene (PE), since the melting point thereof is approximately 105 to 140 ° C, the shutdown function can be given.

The separator base material may be a polymer film such as high density polyethylene, linear low density polyethylene, low density polyethylene, ultra high molecular weight polyethylene, polypropylene, polybutylene, or polypentene. The polyolefin substrate may be produced by a wet process To form a porous structure.

The separator base material may have a porosity of about 30 to 70%, preferably about 40 to 60%, and if possible, the porosity is close to 50%. The insulation between the positive electrode and the negative electrode, And the like.

Method of manufacturing separator for secondary battery

According to another embodiment of the present invention, there is provided a process for producing a separation membrane for a secondary battery, which comprises a step of forming an endothermic agent, a step of preparing a composition for forming a heat resistant layer, an application step to a separation membrane substrate, and a separation membrane drying step.

In the endotherm formation step, a plurality of inorganic oxide particles are prepared and the polymer is coated on the surface of the plurality of inorganic oxide particles. As a method of coating a polymer having a melting point of 120 ° C or higher on the surface of inorganic oxide particles, a chemical coating method or a physical coating method is available.

The chemical coating method includes, but is not limited to, a polymerization method such as a catalytic polymerization method using a catalyst on the surface of inorganic particles, a method of bonding a high heat-resistant polymer by surface treatment of inorganic particles, a chemical vapor deposition (CVD) The same chemical deposition.

Examples of the physical coating method include a method of coating a polymer on the surface of inorganic oxide particles by a conventional method such as melt spin coating, solution spin coating or electrospinning coating, a method of bonding a polymer by heat fusion, physical deposition such as physical vapor deposition (PVD), and the like.

Here, the inorganic oxide particles to be used and the polymer having a melting point of 120 ° C or higher are not described in the same manner as described in the description of the endothermic material.

In the step of preparing the composition for forming a heat resistant layer, the composition for forming a heat resistant layer is formed by dissolving the formed endothermic agent and the binder in a solvent.

The solvent may be selected from the group consisting of acetone, tetrahydrofuran, methylene chloride, chloroform, dimethylformamide, N-methyl-2-pyrrolidone, pyrrolidone, NMP), cyclohexane, and water, or a mixture of two or more thereof.

The mixing and dispersion of the binder and the endothermic agent in a solvent can be carried out by a conventional method used in the art.

The description of the binder is the same as that described in the description of the heat resistant layer, and the description thereof will be omitted.

The step of applying to the base material for separator and the step of drying the separator can be carried out by applying the prepared composition for forming a heat resistant layer to the base material for separator, and after drying, drying by a conventional method to remove the solvent. The application method and drying method applied at this time can be a commonly used method in the art, and there is no particular limitation thereto.

Other

The heat resistant layer of the present invention can be preferably applied to a lithium secondary battery in which safety in terms of temperature is a problem. The configuration of the lithium secondary battery will be described below. The anodes, cathodes and electrolytes are as known in the art and they are either commercially available or can be readily prepared by processes and / or methods known in the art.

The lithium secondary battery has a structure in which a lithium salt-containing nonaqueous electrolyte is impregnated in an electrode assembly having a laminated structure in which a separator is interposed between an anode and a cathode. The electrode assembly generally comprises a jelly-roll type (wound type), a stacked type (laminated type), and a composite type thereof.

The anode is prepared, for example, by coating a mixture of a cathode active material, a conductive agent and a binder on a cathode current collector, and then drying the cathode active material. Optionally, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li2CuO2); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; Formula _{LiNi 1 - x M x O 2} ( where, the M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, x = 0.01 ~ 0.3 Im) Ni site type lithium nickel oxide which is represented by; Formula _{LiMn 2 - x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like. However, the present invention is not limited to these.

The cathode current collector generally has a thickness of 3 to 500 mu m. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical change in the battery, and may be formed of a material such as stainless steel, aluminum, nickel, titanium, sintered carbon, or a surface of aluminum or stainless steel Treated with carbon, nickel, titanium, silver or the like may be used. The current collector may have fine irregularities on the surface thereof to increase the adhesive force of the cathode active material, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven fabric are possible.

The conductive agent is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the cathode active material. Such a conductive agent is not particularly limited as long as it has electrical conductivity without causing a chemical change in the battery, and examples thereof include graphite such as natural graphite and artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder described above is a component that assists in bonding between the active material and the conductive agent and bonding to the collector, and is usually added in an amount of 1 to 50 wt% based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

The filler is optionally used as a component for suppressing the expansion of the anode, and is not particularly limited as long as it is a fibrous material without causing a chemical change in the battery. Examples of the filler include olefin polymers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

The negative electrode is manufactured by coating and drying the negative electrode active material on the negative electrode collector, and if necessary, the above-described components may further be included.

The negative electrode collector is generally made to have a thickness of 3 to 500 mu m. Such an anode current collector is not particularly limited as long as it has conductivity without causing chemical change in the battery, and may be formed of a material such as copper, stainless steel, aluminum, nickel, titanium, fired carbon, surface of copper or stainless steel A surface treated with carbon, nickel, titanium, silver or the like, an aluminum-cadmium alloy, or the like can be used. In addition, like the positive electrode collector, fine unevenness can be formed on the surface to enhance the bonding force of the negative electrode active material, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams and nonwoven fabrics.

The negative electrode active material may include, for example, carbon such as non-graphitized carbon or graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1 - x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 < x &lt; Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials and the like can be used.

The nonaqueous electrolyte containing a lithium salt is composed of a nonaqueous electrolyte and lithium. As the non-aqueous electrolyte, a non-aqueous electrolyte, a solid electrolyte, an inorganic solid electrolyte and the like are used.

Examples of the nonaqueous electrolytic solution include N-methyl-2-pyrrolidinone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, But are not limited to, lactone, 1,2-dimethoxyethane, tetrahydroxyfuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, formamide, dimethylformamide, Nitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester, trimethoxymethane, dioxolane derivatives, sulfolane, methyl sulfolane, 1,3-dimethyl-2-imidazolidinone, propylene carbonate derivatives , Tetrahydrofuran derivatives, ether, methyl pyrophosphate, ethyl propionate and the like can be used.

Examples of the organic solid electrolyte include a polymer electrolyte such as a polyethylene derivative, a polyethylene oxide derivative, a polypropylene oxide derivative, a phosphate ester polymer, an agitation lysine, a polyester sulfide, a polyvinyl alcohol, Vinylidene, polymers including an ionic dissociation group, and the like can be used.

Examples of the inorganic solid electrolyte include Li ₃ N, LiI, Li ₅ NI ₂ , Li ₃ N-LiI-LiOH, LiSiO ₄ , LiSiO ₄ -LiI-LiOH, Li ₂ SiS ₃ , Li ₄ SiO ₄ , Nitrides, halides and sulfates of Li such as Li ₄ SiO ₄ -LiI-LiOH and Li ₃ PO ₄ -Li ₂ S-SiS ₂ can be used.

The lithium salt is a material that is readily soluble in the non-aqueous electrolyte, for example, LiCl, LiBr, LiI, LiClO 4, LiBF 4, LiB 10 Cl 10, LiPF 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF _{6, LiSbF 6, LiAlCl 4,} CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2) 2NLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenyl borate and imide .

For the purpose of improving charge / discharge characteristics, flame retardancy, etc., non-aqueous electrolytes may be used in the form of, for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride and the like are added It is possible. In some cases, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride may be further added to impart nonflammability, or a carbon dioxide gas may be further added to improve high-temperature storage characteristics.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

Claims (15)

A separator substrate; And a heat resistant layer formed on at least one side of the base material and including a heat absorbing agent and a binder,
Wherein the heat absorbing agent comprises inorganic oxide particles having a positive heat of reaction at 150 to 200 ° C.
The method according to claim 1,
Wherein the inorganic oxide particles include at least one selected from the group consisting of dicalcium silicate (Ca ₂ SiO ₄ ) and tricalcium silicate (Ca ₃ SiO ₅ ).
The method according to claim 1,
Wherein the inorganic oxide particles have an average particle diameter of 1 to 100 nm.
The method according to claim 1,
Wherein the endothermic agent further comprises a coating layer of a polymer having a melting point of 120 DEG C or higher and covering the surface of the inorganic oxide particles.
The method according to claim 1,
Wherein the thickness of the coating layer is 60% or less of the diameter of the inorganic oxide particles.
The method according to claim 1,
Wherein the coating layer has a porosity of 5 vol% or less.
5. The method of claim 4,
The polymer having a melting point of 120 ° C or higher may be at least one selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyetherimide, polyamideimide, And at least one selected from the group consisting of phenylene oxide, polyphenylene sulfide, and polyethylene naphthalene.
The method according to claim 1,
The binder may be selected from the group consisting of polyvinylidene fluoride (PVDF), polybenzimidazole, polyimide, polyvinyl acetate, polyacrylonitrile, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose , Regenerated celluloses, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, polystyrene, polymethylmethacrylate, polyaniline, acrylonitrile butadiene styrene, phenol resin, epoxy resin, polyethylene terephthalate, (Ethylene-propylene-diene terpolymer (EPDM), sulphonated EPDM (polyether sulfone), polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, fluoroethylene, polyphenyl sulfide, polyamideimide, polyetherimide, , Styrene-butadiene rubber, and fluorine rubber. A secondary battery separator.
The method according to claim 1,
Wherein the heat absorbing agent is contained in an amount of 50 to 95% by weight based on the total weight of the heat resistant layer.
The method according to claim 1,
Wherein the separator base material is a stretched film and includes at least one selected from the group consisting of high density polyethylene, linear low density polyethylene, low density polyethylene, ultra high molecular weight polyethylene, polypropylene, polybutylene and polypentene.
The method according to claim 1,
Wherein the separator base material has a porosity of 30 to 70% by volume.
The method according to claim 1,
Wherein the thickness of the heat resistant layer is 5 to 15 占 퐉.
A cathode in which a cathode active material layer is formed on a cathode current collector;
An anode having an anode active material layer formed on the anode current collector; And
A separator for a secondary battery according to claim 1, wherein the separator is interposed between the positive electrode and the negative electrode.
14. A battery module comprising the lithium secondary battery of claim 13 as a unit cell.
A battery pack comprising the battery module of claim 14.