Porous support used for impregnation of solid polymer electrolyte, secondary battery comprising same, and manufacturing method therefor

Abstract

The present invention relates to a porous support used for the impregnation of a solid polymer electrolyte, a secondary battery comprising same, and a manufacturing method therefor. More specifically, the present invention relates to a porous support used for the impregnation of a solid polymer electrolyte, a secondary battery comprising same, and a manufacturing method therefor, the porous support being capable of utilizing a roll-to-roll process to which in-situ crosslinking is applied.

Description

Porous support used for impregnation of solid polymer electrolyte, secondary battery including same, and manufacturing method thereof

[0001] The present invention relates to a porous support used for impregnation of a solid polymer electrolyte, a secondary battery including the same, and a method for manufacturing the same, and more particularly, to a porous support used for impregnation of a solid polymer electrolyte that can utilize a roll-to-roll process using an in-situ crosslinking method, a secondary battery including the same, and a method for manufacturing the same.

[0002] The need for lithium secondary batteries has increased recently due to the popularization of small electronic devices such as smartphones and tablet PCs and the growing demand for environmentally friendly electric vehicles that can solve air pollution problems.

[0003] Lithium secondary batteries can be classified into liquid electrolyte lithium secondary batteries and solid electrolyte lithium secondary batteries.

[0004] Liquid electrolyte lithium secondary batteries have safety issues such as explosion and fire that can occur when electrolyte leakage occurs due to external impact or short circuit.

[0005] Solid electrolytes can be classified into oxide-based, sulfide-based, and polymer-based electrolytes.

[0006] Among these, polymer-based solid electrolytes have superior chemical and thermal stability compared to liquid electrolytes, and, unlike oxide-based and sulfide-based solid electrolytes, have the advantages of excellent flexibility and mass production unique to polymers.

[0007] However, solid polymer electrolytes have a problem in that it is difficult to express battery characteristics due to the large interfacial resistance between the positive or negative electrode active material and the solid electrolyte.

[0008] To address the above issues, in-situ cross-linking of solid polymer electrolytes can be employed. However, the precursors of solid polymer electrolytes have high viscosity, making them difficult to impregnate into porous supports. Furthermore, freestanding film-type solid electrolytes made solely of solid polymer electrolytes have lower tensile strengths than those required in roll-to-roll processes.

[0009] Accordingly, the inventors of the present invention have completed the invention of a porous support having large pore size and excellent air permeability, so that a precursor of a solid polymer electrolyte can be easily impregnated therein, and excellent tensile strength, so that a roll-to-roll process using an in-situ crosslinking method can be utilized, a secondary battery including the same, and a manufacturing method thereof, in order to solve the above problems.

[0010] The purpose of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having large pore size and improved air permeability, and a method for producing the same.

[0011] Another object of the present invention is to provide a porous support having high impregnability of a solid polymer electrolyte and used for impregnation of a solid polymer electrolyte, and a method for producing the same.

[0012] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having strong mechanical strength required in a roll-to-roll process and a method for producing the same.

[0013] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte, which maintains mechanical strength even when impregnated with the solid polymer electrolyte and is cured, and a method for producing the same.

[0014] Another object of the present invention is to provide a porous support suitable for in-situ crosslinking polymerization of solid polymer electrolyte and impregnation of solid polymer electrolyte in a roll-to-roll process, and a method for producing the same.

[0015] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having reduced interfacial resistance between a positive or negative electrode active material and a solid polymer electrolyte.

[0016] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having improved ionic conductivity.

[0017] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte that stably maintains a high discharge capacity.

[0018] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte with improved reaction stability with lithium metal.

[0019] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having improved electrochemical oxidation stability.

[0020] In order to solve the above conventional problems, the present invention provides a porous support comprising a polyolefin polymer, used for impregnation of a solid polymer electrolyte, and characterized by a pore diameter of 0.05 to 0.9 ㎛.

[0021] In addition, the polyolefin polymer may include at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR), and polybutene-I (PB-I), and may be characterized by having a mixed structure of amorphous and crystalline structures.

[0022] Additionally, the solid polymer electrolyte may include at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator.

[0023] Additionally, the air permeability of the porous support may be 0.03 to 1 cfm.

[0024] According to another aspect of the present invention, the present invention provides a porous support characterized in that the porous support is coated with a nano membrane.

[0025] Additionally, the nano membrane may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK).

[0026] Additionally, it may be characterized in that the porous support is impregnated with a solid polymer electrolyte.

[0027] According to another aspect of the present invention, the present invention provides a secondary battery comprising the porous support, a negative electrode active material, and a positive electrode active material.

[0028] In addition, the negative electrode active material may include at least one selected from the group consisting of natural graphite, artificial graphite, coke, lithium metal, silicon, and tin, and the positive electrode active material may include at least one selected from the group consisting of lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel oxide (LNO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese aluminum oxide (NCMA), and lithium iron phosphate (LFP).

[0029] According to another aspect of the present invention, the present invention provides a method for manufacturing a porous support, comprising the steps of (a-1) heating a polyolefin-based polymer to perform a first stretching; and (a-2) heating the first-stretched polyolefin-based polymer to perform a second stretching; wherein the polyolefin-based polymer is formed into a mixed structure of an amorphous and crystalline structure through the step (a-1), the pore size is controlled to 0.05 to 0.9 μm through the step (a-2), and the porous support is used for impregnation of a solid polymer electrolyte.

[0030] In addition, the method may further include a step of (a-3) impregnating the precursor of the solid polymer electrolyte into the secondarily stretched polyolefin after the step (a-2); and a step of (a-4) heating the precursor of the solid polymer electrolyte.

[0031] Additionally, in the step (a-3), the precursor of the solid polymer electrolyte may include at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, a dispersant, and a curing initiator.

[0032] In addition, the mass ratio of the plasticizer, crosslinking agent, lithium salt, additive, and curing initiator may be 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight.

[0033] Additionally, in the step (a-4), heating can be performed at 50 to 150°C for 1 minute to 10 hours.

[0034] According to another aspect of the present invention, the present invention provides a porous support manufactured by the above method for manufacturing a porous support.

[0035] According to another aspect of the present invention, the present invention provides a method for manufacturing a porous support, comprising the steps of: (b-1) manufacturing a nano membrane by electrospinning; (b-2) applying a thermoplastic resin to one surface of the nano membrane; and (b-3) adsorbing the porous support to the surface of the nano membrane on which the thermoplastic resin is applied.

[0036] In addition, in the step (b-1), the nano membrane may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK).

[0037] Additionally, in the above step (b-2), the thermoplastic resin may be one selected from the group consisting of polyurethane, polyester, polypropylene, polyamide, polyethylene, and ethylene vinyl acetate.

[0038] In addition, in the above step (b-2), the application is 0.1 g / m 2 0.3 g / m 2 can be performed.

[0039] In addition, in the above step (b-2), adsorption can be performed at a temperature of 90°C to 130°C and a pressure of 0.2 MPa to 0.5 MPa.

[0040] In addition, after the step (b-3), the method may further include a step (b-4) of impregnating the porous support with a precursor of a solid polymer electrolyte; and a step (b-5) of heating the precursor of the solid polymer electrolyte.

[0041] Additionally, in the step (b-4), the precursor of the solid polymer electrolyte may include at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, a dispersant, and a curing initiator.

[0042] In addition, the mass ratio of the plasticizer, crosslinking agent, lithium salt, additive, and curing initiator may be 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight.

[0043] Additionally, in the step (b-5), heating can be performed at 50 to 150°C for 1 minute to 10 hours.

[0044] According to another aspect of the present invention, a porous support manufactured by the above method for manufacturing a porous support is provided.

[0045] The porous support according to the present invention has a large pore size and improved air permeability.

[0046] The porous support according to the present invention has a high impregnation effect for solid polymer electrolyte.

[0047] The porous support according to the present invention has excellent mechanical strength and has the effect of maintaining excellent mechanical strength even after being impregnated with a solid polymer electrolyte and cured.

[0048] The porous support according to the present invention has the effect of being usable in an in-situ crosslinking polymerization method and a roll-to-roll process.

[0049] The porous support according to the present invention has the effect of reducing the interfacial resistance that occurs between the positive or negative electrode active material and the solid polymer electrolyte.

[0050] The porous support according to the present invention has the effect of improving ionic conductivity.

[0051] The porous support according to the present invention has the effect of stably maintaining a high discharge capacity.

[0052] The porous support according to the present invention has the effect of improving the reaction stability with lithium metal.

[0053] The porous support according to the present invention has the effect of improving electrochemical oxidation stability.

[0054] Figure 1a is a process diagram of a method for manufacturing a porous support according to another embodiment of the present invention.

[0055] Figure 1b is a process diagram of a method for manufacturing a porous support coated with a nano membrane according to one embodiment of the present invention.

[0056] Figure 2a is a compound included in a precursor of a solid polymer electrolyte according to one embodiment of the present invention.

[0057] Figure 2b is another compound included in the precursor of a solid polymer electrolyte according to one embodiment of the present invention.

[0058] Figure 3a is a photograph of the surface of a porous support according to a comparative example taken at low magnification using a scanning electron microscope (SEM).

[0059] Figure 3b is a photograph of the surface of a porous support according to a comparative example taken at high magnification using a scanning electron microscope (SEM).

[0060] FIG. 3c is a photograph of the surface of a porous support according to one embodiment of the present invention taken at low magnification using a scanning electron microscope (SEM).

[0061] FIG. 3d is a photograph of the surface of a porous support according to one embodiment of the present invention taken at high magnification using a scanning electron microscope (SEM).

[0062] Figure 4 is a graph showing the ionic conductivity of a secondary battery cell according to one embodiment, another embodiment, and a comparative example of the present invention.

[0063] Figure 5a is a graph showing the change in resistance according to a chemical reaction with lithium metal in a lithium secondary battery cell according to a comparative example.

[0064] Figure 5b is a graph showing the change in resistance according to a chemical reaction with lithium metal in a lithium secondary battery cell according to another comparative example.

[0065] Figure 5c is a graph showing a change in resistance due to a chemical reaction with lithium metal in a lithium secondary battery cell according to one embodiment of the present invention.

[0066] FIG. 5d is a graph showing a change in resistance due to a chemical reaction with lithium metal in a lithium secondary battery cell according to another embodiment of the present invention.

[0067] Figure 6a is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to a comparative example.

[0068] Figure 6b is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another comparative example.

[0069] Figure 6c is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another comparative example.

[0070] Figure 6d is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to one embodiment of the present invention.

[0071] Figure 6e is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another embodiment of the present invention.

[0072] FIG. 6f is a graph comparing charge / discharge rate characteristics of lithium secondary battery cells according to one embodiment of the present invention, another embodiment, and a comparative example.

[0073] Figure 7a is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to a comparative example.

[0074] Figure 7b is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another comparative example.

[0075] Figure 7c is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another comparative example.

[0076] Figure 7d is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to one embodiment of the present invention.

[0077] Figure 7e is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to another embodiment of the present invention.

[0078] FIG. 7f is another graph comparing charge / discharge rate characteristics of lithium secondary battery cells according to one embodiment, another embodiment, and a comparative example of the present invention.

[0079] FIG. 8a is a graph showing the tensile strength according to the strain of a porous support according to one embodiment and another embodiment of the present invention.

[0080] FIG. 8b is another graph showing the tensile strength according to the strain of a porous support according to one embodiment and another embodiment of the present invention.

[0081] FIG. 9 is a photograph showing the measurement of the contact angle between a porous support and a precursor of a solid polymer electrolyte according to one embodiment and another embodiment of the present invention.

[0082] FIG. 10 is a graph showing the results of a lithium plating / stripping experiment in a lithium secondary battery cell according to one embodiment and another embodiment of the present invention.

[0083] Figure 11a is a graph showing the charge / discharge cycle characteristics of a lithium secondary battery cell according to a comparative example of the present invention.

[0084] Figure 11b is a graph showing the charge / discharge cycle characteristics of a lithium secondary battery cell according to one embodiment of the present invention.

[0085] Figure 11c is a graph showing the charge / discharge cycle of a lithium secondary battery cell according to another embodiment of the present invention.

[0086] FIG. 11d is a graph comparing charge and discharge cycles of lithium secondary battery cells according to one embodiment of the present invention, another embodiment, and a comparative example.

[0087] FIG. 12a is a graph showing the results of cyclic voltammetry measurement of a lithium secondary battery cell according to one embodiment and another embodiment of the present invention.

[0088] FIG. 12b is a graph showing the results of linear scanning method measurements of lithium secondary battery cells according to one embodiment and another embodiment of the present invention.

[0089] The purpose of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having large pore size and improved air permeability, and a method for producing the same.

[0090] Another object of the present invention is to provide a porous support having high impregnability of a solid polymer electrolyte and used for impregnation of a solid polymer electrolyte, and a method for producing the same.

[0091] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having strong mechanical strength required in a roll-to-roll process and a method for producing the same.

[0092] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte, which maintains mechanical strength even when impregnated with the solid polymer electrolyte and is cured, and a method for producing the same.

[0093] Another object of the present invention is to provide a porous support suitable for in-situ crosslinking polymerization of solid polymer electrolyte and impregnation of solid polymer electrolyte in a roll-to-roll process, and a method for producing the same.

[0094] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having reduced interfacial resistance between a positive or negative electrode active material and a solid polymer electrolyte.

[0095] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having improved ionic conductivity.

[0096] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte that stably maintains a high discharge capacity.

[0097] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte with improved reaction stability with lithium metal.

[0098] Another object of the present invention is to provide a porous support used for impregnation of a solid polymer electrolyte having improved electrochemical oxidation stability.

[0099] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0100] The advantages and features of the present invention and the method for achieving them will become clear with reference to the embodiments described in detail below together with the attached drawings.

[0101] However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform a person having ordinary skill in the art to which the present invention pertains of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0102] In addition, when describing the present invention, if it is determined that related known technologies, etc. may obscure the gist of the present invention, a detailed description thereof will be omitted.

[0103] Hereinafter, the present invention will be described in detail.

[0104]

[0105] The present invention provides a porous support comprising a polyolefin polymer, used for impregnation of a solid polymer electrolyte, and having a pore diameter of 0.05 to 0.9 μm.

[0106] Polyolefin polymers are made of olefin monomers (C n H 2n ) refers to a type of polymer manufactured by polymerization.

[0107] The above polyolefin polymer includes at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR), and polybutene-I (PB-I), and may have a mixed structure of amorphous and crystalline structures.

[0108] The above polyethylene (PE) refers to a polyolefin made by polymerizing an ethylene monomer (C2H4), and the above polypropylene (PP) refers to a polyolefin made by polymerizing a propylene monomer (C3H6).

[0109] When polyolefin polymers such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR) or polybutene-I (PB-I) are used, ionic conductivity is excellent, interfacial resistance stability with lithium metal is improved, and mechanical strength (e.g., tensile strength) is improved (see Experimental Examples 2, 3 and 6).

[0110] The above amorphous structure means a structure in which molecules or atoms, etc. are irregularly and not repeatedly arranged, the above crystalline structure means a structure in which molecules or atoms, etc. are regularly and repeatedly arranged, and the above mixed structure of amorphous structure and crystalline structure means a structure in which the above amorphous structure and crystalline structure are mixed.

[0111] The mechanical strength, pore size, and air permeability of the porous support can be controlled through the mixed structure of the amorphous structure and the crystalline structure.

[0112] The above solid polymer electrolyte may include at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator.

[0113] The plasticizer may include at least one selected from the group consisting of polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464], polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 250], trimethylolpropane ethyl ether [Trimethylolpropane ethyl ether (TMPEE), number average molecular weight 572], and ethylene oxide-propylene oxide plasticizer [EO-PO copolymer, number average molecular weight 572], and preferably includes polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464] (see FIG. 2a), but is not limited thereto.

[0114] The crosslinking agent may include at least one selected from the group consisting of bisphenol A ethoxylate diacrylate [Ethoxylated (4) bisphenol A diacrylate (Bis A), number average molecular weight 688], ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692], and ethoxylated tetramethylbutane tetraacrylate [Ethoxylated (4) Tetramethylbutane tetraacrylate, number average molecular weight 528], and preferably includes ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692] (see FIG. 2b), but is not limited thereto.

[0115] The lithium salt may include at least one selected from the group consisting of LiTFSI, LiClO4, LiCF3SO3, LiBF4, LiPF6, LiAsF6 and LiN(SO2CF3)2, and preferably includes LiTFSI, but is not limited thereto.

[0116] The above additive may be, but is not limited to, fluoroethylene carbonate (FFC).

[0117] The above curing initiator may be a photocuring initiator or a thermocuring initiator, and may preferably be tert-Butyl Peroxypivalate (t-BPP), but is not limited thereto.

[0118] The photocurable initiator is selected from the group consisting of ethylbenzoin ether, isopropylbenzoin ether, α-methylbenzoin ethyl ether, benzoin phenyl ether, α-acyloxime ester, α,α diethoxyacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one [Darocur 1173 from Ciba Geigy], 1-hydroxycyclohexylphenyl ketone [Irgacure 184, Darocur 1116, Irgacure 907 from Ciba Geigy], anthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, thioxanthone, isopropylthioxanthone, chlorothioxanthone, benzophenone, It may include, but is not limited to, one or more selected from the group consisting of p-chlorobenzophenone, benzyl benzoate, benzoyl benzoate, and mikler ketone.

[0119] The above-mentioned thermosetting initiator is benzoyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide, a-cumyl peroxyneodecanoate, a-cumyl peroxyneopeptanoate, t-amyl peroxyneodecanoate, di-(2-ethylhexyl) peroxy-dicarbonate, t-amyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5 bis(2-ethyl-hexanoylperoxy) hexane, dibenzoyl peroxide, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, 1,1-di-(t-amyl peroxy) cyclohexane, 1,1-di-(t-butyl peroxy) 3,3,5-trimethylcyclohexane, It may include at least one selected from the group consisting of peroxide initiators such as 1,1-di-(t-butylperoxy)cyclohexane, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxybenzoate, t-butylperoxybenzoate, ethyl 3,3-di-(t-amylperoxy)butyrate, ethyl 3,3-di-(t-butylperoxy)butyrate, dicumylperoxide, 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 4,4'-azobis(4-cyanovaleric acid), but is not limited thereto.

[0120] The diameter of the pores of the porous support may be 0.05 to 0.9 μm, and preferably 0.06 to 0.45 μm.

[0121] When the diameter of the pores of the porous support is 0.05 to 0.9 ㎛, a precursor of a high-viscosity solid polymer electrolyte is easily impregnated, and accordingly, a roll-to-roll process using an in-situ crosslinking method can be utilized for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance occurring between the positive or negative electrode active material and the solid polymer electrolyte, and an effect of enabling segmental movement of the polymer so that lithium ions can be transferred.

[0122] At this time, utilizing an in-situ cross-linking method for a solid polymer electrolyte means a polymerization process through a cross-linking reaction by placing a porous support impregnated with a liquid polymer electrolyte precursor between the positive and negative electrodes and applying heat.

[0123] By utilizing the in-situ crosslinking method for the above solid polymer electrolyte, the roll-to-roll process used in liquid electrolytes can be utilized, resulting in excellent economic efficiency.

[0124] If the diameter of the pores of the above porous support is less than 0.05 ㎛, there is a problem that it is difficult to impregnate the precursor of a high-viscosity solid polymer electrolyte, and if it exceeds 0.9 ㎛, there is a problem that the mechanical strength is weak and a short circuit may occur between the electrodes.

[0125] The air permeability of the porous support may be 0.03 to 1 cfm, preferably 0.1 to 0.3 cfm.

[0126] Air permeability refers to the ability of air to pass through a porous support. Permeability can be determined by measuring the vertical flow rate through a given area of ​​the sample over a given period of time under conditions of a specified pressure difference.

[0127] In other words, air permeability is a value that indicates how much a certain amount of fluid, such as air, flows over a certain period of time. The smaller the air permeability, the lower the pore size and permeability, meaning that a small amount of air can pass through. The larger the air permeability, the larger the pore size and permeability, meaning that a large amount of air can pass through.

[0128] The unit of ventilation above (cfm) is an abbreviation for Cubic Feet per Minute, which is 1 cubic foot (1 ft) per minute (1 min). 3 ) refers to the amount of fluid flowing in a volume.

[0129] When the porous support has a permeability of 0.03 to 1 cfm, a precursor of a high-viscosity solid polymer electrolyte is easily impregnated into the porous support, and accordingly, a roll-to-roll process using an in-situ crosslinking method can be utilized for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance occurring between the positive or negative electrode active material and the solid polymer electrolyte, and an effect of enabling segmental movement of the polymer so that lithium ions can be transferred.

[0130] At this time, utilizing an in-situ cross-linking method for a solid polymer electrolyte means a polymerization process through a cross-linking reaction by placing a porous support impregnated with a liquid polymer electrolyte precursor between the positive and negative electrodes and applying heat.

[0131] By utilizing the in-situ crosslinking method for the above solid polymer electrolyte, the roll-to-roll process used in liquid electrolytes can be utilized, resulting in excellent economic efficiency.

[0132] When the air permeability of the porous support is less than 0.03 cfm, there is a problem that the precursor of a high-viscosity solid polymer electrolyte is not easily impregnated into the porous support, and when the air permeability of the porous support exceeds 1 cfm, there is a problem that the mechanical strength of the porous support is weak and a short circuit between electrodes may occur.

[0133] Another aspect of the present invention provides a porous support coated with a nano membrane.

[0134] The above nano membrane means a membrane in which nanofibers of 30 to 1000 nm are laminated in any shape, and preferably means a membrane in which nanofibers of 50 to 500 nm are laminated in any shape.

[0135] When both sides of the above porous support are coated with a nano membrane, a precursor of a high-viscosity solid polymer electrolyte is easily impregnated into the porous support, and accordingly, a roll-to-roll process using an in-situ crosslinking method can be utilized for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance occurring between the positive or negative electrode active material and the solid polymer electrolyte (see Experimental Example 7) and an effect of improving electrochemical stability (see Experimental Examples 8 and 10).

[0136] The above nano membrane may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK), and preferably includes polyvinylidene fluoride (PVDF), but is not limited thereto.

[0137] The porous support or porous support coated with the nano membrane may be impregnated with a solid polymer electrolyte.

[0138] Even when the above porous support is impregnated with a solid polymer electrolyte, the above excellent tensile strength can be maintained (see Experimental Example 6).

[0139] Another aspect of the present invention provides a secondary battery comprising the porous support; a negative electrode active material; and a positive electrode active material.

[0140] Active material refers to an active substance that chemically reacts in the positive and negative electrodes of a battery to produce electrical energy.

[0141] The negative electrode material stores and releases lithium ions that move from the positive electrode during secondary battery discharge, generating electrical energy.

[0142] The above negative electrode active material may include, but is not limited to, one or more selected from the group consisting of natural graphite, artificial graphite, coke, lithium metal, silicon, and tin.

[0143] The cathode active material holds lithium ions and provides lithium ions to the anode when the battery is charged.

[0144] The above cathode active material may include at least one selected from the group consisting of lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel oxide (LNO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese aluminum oxide (NCMA), and lithium iron phosphate (LFP), but is not limited thereto.

[0145] The above lithium cobalt oxide (LCO) refers to lithium cobalt oxide, and when the above lithium cobalt oxide (LCO) is used as a cathode active material, it has a high stability effect.

[0146] The above lithium manganese oxide (LMO) refers to lithium manganese oxide, and when the lithium manganese oxide (LMO) is used as a cathode active material, it has the effect of excellent price competitiveness. The lithium manganese oxide (LMO) may be LiMnO2 or LiMn2O4, but is not limited thereto.

[0147] The above lithium nickel oxide (LNO) refers to lithium nickel oxide, and when lithium nickel oxide (LNO) is used as a cathode active material, it has an excellent capacity effect. The lithium nickel oxide (LNO) may be LiNiO2, but is not limited thereto.

[0148] The above lithium nickel cobalt manganese oxide (NCM) refers to a cathode active material in which a three-component system of nickel (Ni), cobalt (Co) and manganese (Mn) is combined, and the above lithium nickel cobalt manganese oxide (NCM) is NCM622 (LiNi 0.6 Co 0.2 Mn 0.2 O2), NCM811(LiNi 0.8 Co 0.1 Mn 0.1 O2) or NCM955(LiNi 0.9 Co 0.5 Mn 0.05 O2) may be, but is not limited to.

[0149] The above lithium nickel cobalt aluminum oxide (NCA) refers to a cathode active material that combines three components of nickel (Ni), cobalt (Co), and aluminum (Al).

[0150] The above lithium nickel cobalt manganese aluminum oxide (NCMA) refers to a cathode active material in which a four-component system of nickel (Ni), cobalt (Co), manganese (Mn), and aluminum (Al) is combined.

[0151] The above lithium iron phosphate (LFP) refers to LiFePO4, and when the above lithium iron phosphate (LFP) is used as a cathode active material, it has excellent economic efficiency and stability.

[0152]

[0153] Another aspect of the present invention comprises the steps of (a-1) heating a polyolefin-based polymer to perform a first stretching; and (a-2) heating the first-stretched polyolefin-based polymer to perform a second stretching; wherein, through the step (a-1), the polyolefin-based polymer is formed into a mixed structure of an amorphous and crystalline structure, and through the step (a-2), the pore size is controlled to 0.05 to 0.9 μm, and a method for manufacturing a porous support used for impregnation of a solid polymer electrolyte is provided (see FIG. 1a).

[0154] Each step is explained below.

[0155]

[0156] (a-1) Step of heating and first stretching a polyolefin polymer

[0157] Through the step of heating and first stretching the above polyolefin polymer, the polyolefin polymer can be formed into a mixed structure of amorphous and crystalline structures.

[0158] Polyolefin polymers are made of olefin monomers (C n H 2n ) refers to a type of polymer manufactured by polymerization.

[0159] The above polyolefin polymer includes at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR), and polybutene-I (PB-I), and may have a mixed structure of amorphous and crystalline structures.

[0160] The above polyethylene (PE) refers to a polyolefin made by polymerizing an ethylene monomer (C2H4), and the above polypropylene (PP) refers to a polyolefin made by polymerizing a propylene monomer (C3H6).

[0161] When polyolefin polymers such as polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR) or polybutene-I (PB-I) are used, ionic conductivity is excellent, interfacial resistance stability with lithium metal is improved, and mechanical strength (e.g., tensile strength) is improved (see Experimental Examples 2, 3 and 6).

[0162] The above amorphous structure means a structure in which molecules or atoms, etc. are irregularly and not repeatedly arranged, the above crystalline structure means a structure in which molecules or atoms, etc. are regularly and repeatedly arranged, and the above mixed structure of amorphous structure and crystalline structure means a structure in which the above amorphous structure and crystalline structure are mixed.

[0163] The mechanical strength, pore size, and air permeability of the porous support can be controlled through the mixed structure of the amorphous structure and the crystalline structure.

[0164]

[0165] (a-2) A step of heating the polyolefin polymer that has been stretched first and stretching it a second time.

[0166] Through the step of heating the first stretched polyolefin polymer and stretching it a second time, a porous support having a pore size adjusted to 0.05 to 0.9 ㎛ can be manufactured, and preferably, a porous support having a pore size adjusted to 0.06 to 0.45 ㎛ can be manufactured.

[0167] When the diameter of the pores of the porous support is 0.05 to 0.9 ㎛, a precursor of a high-viscosity solid polymer electrolyte is easily impregnated, and accordingly, a roll-to-roll process using an in-situ crosslinking method can be utilized for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance occurring between the positive or negative electrode active material and the solid polymer electrolyte, and an effect of enabling segmental movement of the polymer so that lithium ions can be transferred.

[0168] At this time, utilizing an in-situ cross-linking method for a solid polymer electrolyte means a polymerization process through a cross-linking reaction by placing a porous support impregnated with a liquid polymer electrolyte precursor between the positive and negative electrodes and applying heat.

[0169] By utilizing the in-situ crosslinking method for the above solid polymer electrolyte, the roll-to-roll process used in liquid electrolytes can be utilized, resulting in excellent economic efficiency.

[0170] If the diameter of the pores of the above porous support is less than 0.05 ㎛, there is a problem that it is difficult to impregnate the precursor of a high-viscosity solid polymer electrolyte, and if it exceeds 0.9 ㎛, there is a problem that the mechanical strength is weak and a short circuit may occur between the electrodes.

[0171] After the step (a-2), the step (a-3) of impregnating the precursor of the solid polymer electrolyte into the secondarily stretched polyolefin system; and the step (a-4) of heating the precursor of the solid polymer electrolyte may be further included.

[0172]

[0173] (a-3) Step of impregnating the precursor of the solid polymer electrolyte into the secondarily stretched polyolefin system.

[0174] Since the precursor of the solid polymer electrolyte is in a liquid state, it can be well impregnated into the inside of the positive and negative electrodes, so a roll-to-roll process using an in-situ cross-linking method can be used for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance that occurs between the positive or negative electrode active material and the solid polymer electrolyte.

[0175] The precursor of the above solid polymer electrolyte may include, but is not limited to, one or more selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator.

[0176] The plasticizer may include at least one selected from the group consisting of polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464], polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 250], trimethylolpropane ethyl ether [Trimethylolpropane ethyl ether (TMPEE), number average molecular weight 572], and ethylene oxide-propylene oxide plasticizer [EO-PO copolymer, number average molecular weight 572], and preferably includes polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464] (see FIG. 2a), but is not limited thereto.

[0177] The crosslinking agent may include at least one selected from the group consisting of bisphenol A ethoxylate diacrylate [Ethoxylated (4) bisphenol A diacrylate (Bis A), number average molecular weight 688], ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692], and ethoxylated tetramethylbutane tetraacrylate [Ethoxylated (4) Tetramethylbutane tetraacrylate, number average molecular weight 528], and preferably includes ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692] (see FIG. 2b), but is not limited thereto.

[0178] The lithium salt may include at least one selected from the group consisting of LiTFSI, LiClO4, LiCF3SO3, LiBF4, LiPF6, LiAsF6 and LiN(SO2CF3)2, and preferably includes LiTFSI, but is not limited thereto.

[0179] The above additive may be, but is not limited to, fluoroethylene carbonate (FFC).

[0180] The above curing initiator may be a photocuring initiator or a thermocuring initiator, and may preferably be tert-Butyl Peroxypivalate (t-BPP), but is not limited thereto.

[0181] The photocurable initiator is selected from the group consisting of ethylbenzoin ether, isopropylbenzoin ether, α-methylbenzoin ethyl ether, benzoin phenyl ether, α-acyloxime ester, α,α diethoxyacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one [Darocur 1173 from Ciba Geigy], 1-hydroxycyclohexylphenyl ketone [Irgacure 184, Darocur 1116, Irgacure 907 from Ciba Geigy], anthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, thioxanthone, isopropylthioxanthone, chlorothioxanthone, benzophenone, It may include, but is not limited to, one or more selected from the group consisting of p-chlorobenzophenone, benzyl benzoate, benzoyl benzoate, and mikler ketone.

[0182] The above-mentioned thermosetting initiator is benzoyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide, a-cumyl peroxyneodecanoate, a-cumyl peroxyneopeptanoate, t-amyl peroxyneodecanoate, di-(2-ethylhexyl) peroxy-dicarbonate, t-amyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5 bis(2-ethyl-hexanoylperoxy) hexane, dibenzoyl peroxide, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, 1,1-di-(t-amyl peroxy) cyclohexane, 1,1-di-(t-butyl peroxy) 3,3,5-trimethylcyclohexane, It may include at least one selected from the group consisting of peroxide initiators such as 1,1-di-(t-butylperoxy)cyclohexane, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxybenzoate, t-butylperoxybenzoate, ethyl 3,3-di-(t-amylperoxy)butyrate, ethyl 3,3-di-(t-butylperoxy)butyrate, dicumylperoxide, 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 4,4'-azobis(4-cyanovaleric acid), but is not limited thereto.

[0183] The mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator may be 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight.

[0184] When the mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator is 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight, there is an effect of forming a polymer electrolyte with excellent characteristics, and when the mass ratio is out of the above, there is a problem of the characteristics of the polymer electrolyte deteriorating.

[0185]

[0186] (a-4) A step of heating the precursor of the above solid polymer electrolyte.

[0187] The above heating can be performed at 50 to 150°C for 1 minute to 10 hours.

[0188] If the above heating is performed at less than 50°C, there is a problem that the precursor of the solid polymer electrolyte is not cured, and if it is performed at more than 150°C, there is a problem that the properties of the solid polymer electrolyte deteriorate.

[0189] If the above heating is performed for less than 10 minutes, there is a problem that the precursor of the solid polymer electrolyte is not cured, and if it is performed for more than 10 hours, there is a problem that the properties of the polymer electrolyte deteriorate.

[0190]

[0191] Another aspect of the present invention provides a porous support manufactured by the above method for manufacturing a porous support.

[0192] A porous support manufactured by the above porous support manufacturing method can have the same composition and effect as the porous support described above.

[0193]

[0194] Another aspect of the present invention provides a method for manufacturing a porous support, characterized by comprising the steps of (b-1) manufacturing a nano membrane by electrospinning; (b-2) applying a thermoplastic resin to one surface of the nano membrane; and (b-3) adsorbing the porous support to the surface of the nano membrane to which the thermoplastic resin is applied (see FIG. 1b).

[0195] Each step is explained below.

[0196]

[0197] (b-1) Step of manufacturing a nano membrane by electrospinning

[0198] The above nano membrane means a membrane in which nanofibers of 30 to 1000 nm are laminated in any shape, and preferably means a membrane in which nanofibers of 50 to 500 nm are laminated in any shape.

[0199] The above nano membrane may include at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK), and preferably may include polyvinylidene fluoride (PVDF), but is not limited thereto.

[0200]

[0201] (b-2) Step of applying thermoplastic resin to one side of the nano membrane

[0202] The thermoplastic resin may be one selected from the group consisting of, but not limited to, polyurethane, polyester, polypropylene, polyamide, polyethylene, and ethylene vinyl acetate.

[0203] The above application is 0.1 g / m 2 0.3 g / m 2 can be performed.

[0204] The above coating is 0.1 g / m 2 0.3 g / m 2 When performed, the nano membrane has excellent bonding strength with the porous support while minimizing the reduction in air permeability.

[0205] The above application 0.1 g / m 2 If performed below this, there is a problem that the nano membrane has weak bonding strength with the porous support, 0.3 g / m 2 There is a problem that if it is performed excessively, the breathability drops sharply.

[0206]

[0207] (b-3) A step of adsorbing the porous support onto the surface of the nano membrane to which the thermoplastic resin is applied.

[0208] The above adsorption can be performed at a temperature of 90°C to 130°C and a pressure of 0.2 MPa to 0.5 MPa.

[0209] The above adsorption is performed at a temperature of 90°C to 130°C and a pressure of 0.2 MPa to 0.5 MPa, which has the effect of improving the bonding strength and air permeability of the porous support and nano membrane.

[0210] If the above adsorption is performed at a temperature lower than 90°C, there is a problem that the bonding strength between the porous support and the nano membrane may be weakened, and if it is performed at a temperature higher than 130°C, there is a problem that the breathability is greatly reduced.

[0211] If the above adsorption is performed at less than 0.2 MPa, there is a problem that the bonding strength between the porous support and the nano membrane may be weakened, and if it is performed at more than 0.5 MPa, there is a problem that the breathability is greatly reduced.

[0212] After the step (b-3), the method may further include a step (b-4) of impregnating the porous support with a precursor of a solid polymer electrolyte; and a step (b-5) of heating the precursor of the solid polymer electrolyte.

[0213]

[0214] (b-4) Step of impregnating the precursor of a solid polymer electrolyte into the porous support

[0215] Since the precursor of the solid polymer electrolyte is in a liquid state, it can be well impregnated into the inside of the positive and negative electrodes, so a roll-to-roll process using an in-situ cross-linking method can be used for the solid polymer electrolyte, and there is an effect of reducing the interfacial resistance that occurs between the positive or negative electrode active material and the solid polymer electrolyte.

[0216] The precursor of the above solid polymer electrolyte may include, but is not limited to, one or more selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator.

[0217] The plasticizer may include at least one selected from the group consisting of polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464], polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 250], trimethylolpropane ethyl ether [Trimethylolpropane ethyl ether (TMPEE), number average molecular weight 572], and ethylene oxide-propylene oxide plasticizer [EO-PO copolymer, number average molecular weight 572], and preferably includes polyethylene glycol dimethyl ether [Poly(ethylene glycol)dimethyl ether (PEGDME), number average molecular weight 464] (see FIG. 2a), but is not limited thereto.

[0218] The crosslinking agent may include at least one selected from the group consisting of bisphenol A ethoxylate diacrylate [Ethoxylated (4) bisphenol A diacrylate (Bis A), number average molecular weight 688], ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692], and ethoxylated tetramethylbutane tetraacrylate [Ethoxylated (4) Tetramethylbutane tetraacrylate, number average molecular weight 528], and preferably includes ethoxylated (9) trimethylolpropane triacrylate [Ethoxylated (9) Trimethylolpropane triacrylate, number average molecular weight 692] (see FIG. 2b), but is not limited thereto.

[0219] The lithium salt may include at least one selected from the group consisting of LiTFSI, LiClO4, LiCF3SO3, LiBF4, LiPF6, LiAsF6 and LiN(SO2CF3)2, and preferably includes LiTFSI, but is not limited thereto.

[0220] The above additive may be, but is not limited to, fluoroethylene carbonate (FFC).

[0221] The above curing initiator may be a photocuring initiator or a thermocuring initiator, and may preferably be tert-Butyl Peroxypivalate (t-BPP), but is not limited thereto.

[0222] The photocurable initiator is selected from the group consisting of ethylbenzoin ether, isopropylbenzoin ether, α-methylbenzoin ethyl ether, benzoin phenyl ether, α-acyloxime ester, α,α diethoxyacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one [Darocur 1173 from Ciba Geigy], 1-hydroxycyclohexylphenyl ketone [Irgacure 184, Darocur 1116, Irgacure 907 from Ciba Geigy], anthraquinone, 2-ethylanthraquinone, 2-chloroanthraquinone, thioxanthone, isopropylthioxanthone, chlorothioxanthone, benzophenone, It may include, but is not limited to, one or more selected from the group consisting of p-chlorobenzophenone, benzyl benzoate, benzoyl benzoate, and mikler ketone.

[0223] The above-mentioned thermosetting initiator is benzoyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide, a-cumyl peroxyneodecanoate, a-cumyl peroxyneopeptanoate, t-amyl peroxyneodecanoate, di-(2-ethylhexyl) peroxy-dicarbonate, t-amyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5 bis(2-ethyl-hexanoylperoxy) hexane, dibenzoyl peroxide, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate, 1,1-di-(t-amyl peroxy) cyclohexane, 1,1-di-(t-butyl peroxy) 3,3,5-trimethylcyclohexane, It may include at least one selected from the group consisting of peroxide initiators such as 1,1-di-(t-butylperoxy)cyclohexane, t-butylperoxyacetate, t-butylperoxybenzoate, t-amylperoxybenzoate, t-butylperoxybenzoate, ethyl 3,3-di-(t-amylperoxy)butyrate, ethyl 3,3-di-(t-butylperoxy)butyrate, dicumylperoxide, 1,1'-azobis(cyclohexanecarbonitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and 4,4'-azobis(4-cyanovaleric acid), but is not limited thereto.

[0224] The mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator may be 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight.

[0225] When the mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator is 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight, there is an effect of forming a polymer electrolyte with excellent characteristics, and when the mass ratio is out of the above, there is a problem of the characteristics of the polymer electrolyte deteriorating.

[0226]

[0227] (b-5) Step of heating the precursor of the above solid polymer electrolyte

[0228] The above heating can be performed at 50 to 150°C for 1 minute to 10 hours.

[0229] If the above heating is performed at less than 50°C, there is a problem that the precursor of the solid polymer electrolyte is not cured, and if it is performed at more than 150°C, there is a problem that the properties of the solid polymer electrolyte deteriorate.

[0230] If the above heating is performed for less than 1 minute, there is a problem that the precursor of the solid polymer electrolyte is not cured, and if it is performed for more than 10 hours, there is a problem that the properties of the polymer electrolyte deteriorate.

[0231]

[0232] Another aspect of the present invention provides a porous support manufactured by the above method for manufacturing a porous support.

[0233] A porous support manufactured by the above porous support manufacturing method can have the same composition and effect as the porous support described above.

[0234]

[0235] Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by these examples. Those skilled in the art may appropriately modify or alter the following examples within the scope of the present invention.

[0236]

[0237] Example

[0238] Manufacturing Example 1: Precursor of solid polymer electrolyte

[0239] (1) Prepare 0.8 g of poly(ethylene glycol)dimethyl ether (PEGDME) (see Figure 2a).

[0240] (2) Prepare 0.2 g of ethoxylated (9) trimethylolpropane triacrylate (n=3) (see Fig. 2b).

[0241] (3) Prepare 0.27311 g of lithium bis((trifluoromethyl)sulfonyl)amide (LiTFSI).

[0242] (4) Prepare 0.05 g of fluoroethylene carbonate (FEC).

[0243] (5) Prepare 0.002 g of tert-Butyl peroxypivalate (t-BPP).

[0244] (6) Mix the compounds prepared in steps (1) to (5).

[0245]

[0246] Comparative Example 1: Polyolefin-based (PE) porous support (pore diameter: less than 0.05 μm)

[0247] Purchase a polyethylene (PE) porous support (product name: SB16C) with a pore diameter of less than 0.05㎛ from Celgard Co., Ltd.

[0248]

[0249] Comparative Example 2: Polyethylene terephthalate (PET) porous support

[0250] Purchase commercial products of polyethylene terephthalate (PET) porous support.

[0251]

[0252] Comparative Example 3: Polyethylene terephthalate (PET) porous support coated with polyvinylidene fluoride (PVDF)

[0253] (1) A nano membrane made of polyvinylidene fluoride (PVDF) is produced by electrospinning.

[0254] (2) 0.1 g / m of thermoplastic resin is applied to one side of the above nano membrane. 2 0.3 g / m 2 Apply thinly.

[0255] (3) The porous support of Comparative Example 2 and the thermoplastic resin-coated surface of the nano membrane are brought into contact, and a hot press roller is used to heat-fusing laminate the porous support to produce a polyvinylidene fluoride-coated polyethylene terephthalate porous support (PVDF-PET) at a temperature of 90°C to 130°C and a pressure of 0.2 MPa to 0.5 MPa.

[0256]

[0257] Example 1: Polyolefin-based (PP) porous support (pore diameter: 0.05 to 0.9 μm)

[0258] Purchase a commercial product of a polypropylene (PP) porous support having a pore diameter of 0.05 to 0.9 ㎛.

[0259]

[0260] Example 2: Polyolefin-based (PP) porous support coated with polyvinylidene fluoride (PVDF)

[0261] (1) A nano membrane made of polyvinylidene fluoride (PVDF) is produced by electrospinning.

[0262] (2) 0.1 g / m of thermoplastic resin is applied to one side of the above nano membrane. 2 0.3 g / m 2 Apply thinly.

[0263] (3) The porous support of Example 1 and the thermoplastic resin-coated surface of the nano membrane are brought into contact, and a hot press roller is used to perform thermal bonding lamination at a temperature of 90°C to 130°C and a pressure of 0.2 MPa to 0.5 MPa to produce a polyolefin-based porous support (PVDF-PP) coated with polyvinylidene fluoride.

[0264]

[0265] Comparative Example 1-A: Polyolefin-based porous support impregnated with solid polymer electrolyte (SPE)

[0266] (1) Cut the porous support of Comparative Example 1 into a size of 1 cm X 7 cm.

[0267] (2) The precursor of the polymer electrolyte according to Manufacturing Example 1 is impregnated into the porous support of Comparative Example 1.

[0268] (3) The porous support impregnated with the precursor of the polymer electrolyte is heated at about 90°C for 30 minutes.

[0269]

[0270] Comparative Example 2-A: Polyethylene terephthalate (PET) porous support impregnated with solid polymer electrolyte (SPE)

[0271] (1) Cut the porous support of Comparative Example 2 into pieces measuring 1 cm X 7 cm.

[0272] (2) The precursor of the polymer electrolyte according to Manufacturing Example 1 is impregnated into the porous support of Comparative Example 2.

[0273] (3) The porous support impregnated with the precursor of the polymer electrolyte is heated at about 90°C for 30 minutes.

[0274]

[0275] Comparative Example 3-A: Polyethylene terephthalate (PET) porous support coated with polyvinylidene fluoride (PVDF) impregnated with solid polymer electrolyte (SPE)

[0276] (1) Cut the porous support of Comparative Example 3 into a size of 1 cm X 7 cm.

[0277] (2) The precursor of the polymer electrolyte according to Manufacturing Example 1 is impregnated into the porous support of Comparative Example 3.

[0278] (3) The porous support impregnated with the precursor of the polymer electrolyte is heated at about 90°C for 30 minutes.

[0279]

[0280] Example 1-A: Polyolefin-based (PP) porous support impregnated with solid polymer electrolyte (SPE)

[0281] (1) Cut the porous support of Example 1 into a size of 1 cm X 7 cm.

[0282] (2) The precursor of the polymer electrolyte according to Manufacturing Example 1 is impregnated into the porous support of Example 1.

[0283] (3) The porous support impregnated with the precursor of the polymer electrolyte is heated at about 90°C for 30 minutes.

[0284]

[0285] Example 2-A: Polyolefin-based (PP) porous support coated with polyvinylidene fluoride (PVDF) impregnated with solid polymer electrolyte (SPE)

[0286] (1) Cut the porous support of Example 2 into a size of 1 cm X 7 cm.

[0287] (2) The precursor of the polymer electrolyte according to Manufacturing Example 1 is impregnated into the porous support of Example 2.

[0288] (3) The porous support impregnated with the precursor of the polymer electrolyte is heated at about 90°C for 30 minutes.

[0289]

[0290] Comparative Example 1-B: Secondary Battery Cell

[0291] A battery cell composed of a SUS (STEEL USE STAINLESS) film / porous support of Comparative Example 1-A / SUS (STEEL USE STAINLESS) film is manufactured.

[0292]

[0293] Comparative Example 2-B: Secondary Battery Cell

[0294] A battery cell composed of a SUS (STEEL USE STAINLESS) film / porous support of Comparative Example 2-A / SUS (STEEL USE STAINLESS) film is manufactured.

[0295]

[0296] Comparative Example 3-B: Secondary Battery Cell

[0297] A battery cell composed of a SUS (STEEL USE STAINLESS) film / porous support of Comparative Example 3-A / SUS (STEEL USE STAINLESS) film is manufactured.

[0298]

[0299] Example 1-B: Secondary battery cell

[0300] A battery cell composed of a SUS (STEEL USE STAINLESS) film / porous support of Example 1-A / SUS (STEEL USE STAINLESS) film is manufactured.

[0301]

[0302] Example 2-B: Secondary battery cell

[0303] A battery cell composed of SUS (STEEL USE STAINLESS) film / porous support of Example 2-A / SUS (STEEL USE STAINLESS) film is manufactured.

[0304]

[0305] Comparative Example 2-C: Lithium secondary battery cell

[0306] Lithium metal is uniformly applied to the negative and positive electrodes of the porous support of Comparative Example 2-A and pressure is applied.

[0307]

[0308] Comparative Example 3-C: Lithium secondary battery cell

[0309] Lithium metal is uniformly applied to the negative and positive electrodes of the porous support of Comparative Example 3-A and pressure is applied.

[0310]

[0311] Example 1-C: Lithium secondary battery cell

[0312] Lithium metal is uniformly applied to the negative and positive electrodes of the porous support of Example 1-A and pressure is applied.

[0313]

[0314] Example 2-C: Lithium secondary battery cell

[0315] Lithium metal is uniformly applied to the negative and positive electrodes of the porous support of Example 2-A and pressure is applied.

[0316]

[0317] Comparative Example 1-D: Lithium secondary battery cell (NCM622)

[0318] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 1-A and pressure is applied.

[0319] (2) NCM622 (LiNi) was added to the positive electrode of the porous support of Comparative Example 1-A. 0.6 Co 0.2 Mn 0.2 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0320]

[0321] Comparative Example 2-D: Lithium secondary battery cell (NCM622)

[0322] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 2-A and pressure is applied.

[0323] (2) NCM622 (LiNi) was added to the positive electrode of the porous support of Comparative Example 2-A. 0.6 Co 0.2 Mn 0.2 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0324]

[0325] Comparative Example 3-D: Lithium secondary battery cell (NCM622)

[0326] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 3-A and pressure is applied.

[0327] (2) NCM622 (LiNi) was added to the positive electrode of the porous support of Comparative Example 3-A. 0.6 Co 0.2 Mn 0.2 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0328]

[0329] Example 1-D: Lithium secondary battery cell (NCM622)

[0330] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Example 1-A and pressure is applied.

[0331] (2) NCM622 (LiNi) on the positive electrode of the porous support of the above Example 1-A 0.6 Co 0.2 Mn 0.2 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0332]

[0333] Example 2-D: Lithium secondary battery cell (NCM622)

[0334] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Example 2-A and pressure is applied.

[0335] (2) NCM622 (LiNi) was added to the positive electrode of the porous support of Example 2-A. 0.6 Co 0.2 Mn 0.2 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0336]

[0337] Comparative Example 1-E: Lithium secondary battery cell (NCM811)

[0338] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 1-A and pressure is applied.

[0339] (2) NCM811 (LiNi) was added to the positive electrode of the porous support of Comparative Example 1-A. 0.8 Co 0.1 Mn 0.1 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0340]

[0341] Comparative Example 2-E: Lithium secondary battery cell (NCM811)

[0342] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 2-A and pressure is applied.

[0343] (2) NCM811 (LiNi) was added to the positive electrode of the porous support of Comparative Example 2-A. 0.8 Co 0.1 Mn 0.1 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0344]

[0345] Comparative Example 3-E: Lithium secondary battery cell (NCM811)

[0346] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Comparative Example 3-A and pressure is applied.

[0347] (2) NCM811 (LiNi) was added to the positive electrode of the porous support of Comparative Example 3-A. 0.8 Co 0.1 Mn 0.1 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0348]

[0349] Example 1-E: Lithium secondary battery cell (NCM811)

[0350] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Example 1-A and pressure is applied.

[0351] (2) NCM811 (LiNi) on the positive electrode of the porous support of Example 1-A 0.8 Co 0.1 Mn 0.1 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0352]

[0353] Example 2-E: Lithium secondary battery cell (NCM811)

[0354] (1) Lithium metal is uniformly applied to the negative electrode of the porous support of Example 2-A and pressure is applied.

[0355] (2) NCM811 (LiNi) was added to the positive electrode of the porous support of Example 2-A. 0.8 Co 0.1 Mn 0.1 The positive electrode active material (O2) is uniformly applied and pressure is applied.

[0356]

[0357] Example 1-F: Lithium secondary battery coin cell

[0358] (1) The porous support of Example 1 is positioned on a lithium metal negative electrode.

[0359] (2) The polymer electrolyte precursor of Manufacturing Example 1 is impregnated into the porous support.

[0360] (3) The porous support is heated at about 90°C for about 30 minutes to harden the polymer electrolyte precursor impregnated in the porous support into a polymer electrolyte.

[0361]

[0362] Example 2-F: Lithium secondary battery coin cell

[0363] (1) The porous support of Example 2 is positioned on the lithium metal negative electrode.

[0364] (2) The polymer electrolyte precursor of Manufacturing Example 1 is impregnated into the porous support.

[0365] (3) The porous support is heated at about 90°C for about 30 minutes to harden the polymer electrolyte precursor impregnated in the porous support into a polymer electrolyte.

[0366]

[0367] Experimental Example 1: Measurement of pore size and air permeability

[0368] (1) Cut the porous support of Comparative Example 1 into a size of 0.1 cm × 0.1 cm.

[0369] (2) The porous support of the cut comparative example 1 is coated with platinum at 10 mA for 120 seconds.

[0370] (3) The porous support of Comparative Example 1 coated with platinum according to the above step (2) was photographed using a field-emission scanning electron microscopy (FE-SEM, XL30S FEG) of Philips Electron Optics.

[0371] (4) The pore size of the porous support of Comparative Example 1 coated with platinum by the above step (2) was measured using a PMI porosimeter (Capillary Flow Porometer, CFP-1200AE) and a wet solution (galwick, surface tension: 15.9 dyne / cm) by the dry up / wet up method according to ASTM F316-03.

[0372] (5) The porous support of Comparative Example 1, which was coated with platinum by the above step (2), was tested for a cross-sectional area of ​​38 m using an air permeability tester (FX-3300) from TEXTEST according to ASTM D737. 2 , air permeability was measured under the condition of applied pressure of 125Pa.

[0373] (6) In step (1) above, the same experiment is repeated for the porous supports of Comparative Example 2, Comparative Example 3, Example 1, and Example 2 instead of the porous support of Comparative Example 1.

[0374] Figure 3a is a photograph of the surface of the porous support of Comparative Example 1 taken at a magnification of 10,000 times using a scanning electron microscope (SEM).

[0375] Figure 3b is a photograph of the surface of the porous support of Comparative Example 1 taken at a magnification of 50,000 times using a scanning electron microscope (SEM).

[0376] Figure 3c is a photograph of the surface of the porous support of Example 1 taken at a magnification of 10,000 times using a scanning electron microscope (SEM).

[0377] Figure 3d is a photograph of the surface of the porous support of Example 1 taken at a magnification of 50,000 times using a scanning electron microscope (SEM).

[0378] Referring to Fig. 3a, in a 5 μm scale photograph of the porous support of Comparative Example 1 magnified 10,000 times, the pore size was very small and the porous structure was relatively not observed well.

[0379] Referring to Fig. 3b, when the porous support of Comparative Example 1 was magnified 50,000 times and the pore size was observed, a porous structure with a diameter of approximately 0.04 ㎛ could be observed.

[0380] Referring to Fig. 3c, the porous structure was clearly observed in a 5 μm scale photograph of the porous body of Example 1 magnified 10,000 times.

[0381] Referring to Figure 3d, when the porous body of Example 1 was magnified 50,000 times and the pore size was observed, a porous structure with a diameter of approximately 0.3 μm could be observed.

[0382] Therefore, it can be predicted that the porous support of Example 1 has a larger pore size than the porous support of Comparative Example 1, and thus the porous support of Example 1 will have higher air permeability than the porous support of Comparative Example 1.

[0383] Table 1 shows the pore size of the porous supports of Comparative Examples 1 to 3 and the porous supports of Examples 1 to 2.

[0384] Pore ​​size [㎛] Porous support of Comparative Example 1 0.04 Porous support of Comparative Example 2 18.63 Porous support of Comparative Example 3 0.45 Porous support of Example 1 0.13 Porous support of Example 2 0.10

[0385] Referring to FIGS. 3a to 3d and Table 1, it can be seen that the porous supports of Examples 1 and 2, unlike the porous support of Comparative Example 1, have a pore diameter of more than 0.04 μm, and thus are easily impregnated with a high-viscosity polymer electrolyte precursor. In addition, it can be seen that the porous supports of Examples 1 and 2, unlike the porous supports of Comparative Examples 2 and 3, have a pore diameter of less than 0.45 μm, and thus the mechanical strength of the porous supports is excellent.

[0386] Table 2 shows the air permeability of the porous supports of Comparative Examples 1 to 3 and the porous supports of Examples 1 to 2.

[0387] Air permeability [cfm] Porous support of Comparative Example 1 0.027 Porous support of Comparative Example 2 119 Porous support of Comparative Example 3 0.9 Porous support of Example 1 0.18 Porous support of Example 2 0.13

[0388] Referring to FIGS. 3a to 3d and Table 2, it can be seen that the porous support of Example 1 has a permeability that is about 6 times higher than that of the porous support of Comparative Example 1. In addition, it can be seen that the porous support of Example 2 has a permeability that is about 5 times higher than that of the porous support of Comparative Example 1. Therefore, it can be seen that the porous supports of Examples 1 and 2 have a higher permeability than the porous support of Comparative Example 1, and are easily impregnated with a high-viscosity polymer electrolyte precursor.

[0389]

[0390] Experimental Example 2: Evaluation of Ionic Conductivity Characteristics

[0391] (1) Connect the secondary battery cell of Comparative Example 1-B inside an oven with temperature control.

[0392] (2) The AC impedance was measured at temperature intervals of 60 ℃, 45 ℃, and 25 ℃ using an impedance meter (Zennium XC).

[0393] (3) The ionic conductivity was measured using the following equation 1 using the AC impedance measured above.

[0394] [Formula 1]

[0395] (4) In step (1) above, the same experiment is repeated for the secondary battery cells of Example 1-B and Example 2-B instead of the secondary battery cell of Comparative Example 1-B.

[0396] Figure 4 is a graph showing the ionic conductivity of the secondary battery cells of Example 1-B, Example 2-B, and Comparative Example 1-B.

[0397] Table 3 shows the ionic conductivity according to temperature of the secondary battery cells of Comparative Example 1-B, Example 1-B, and Example 2-B.

[0398] Ionic conductivity (60 ℃) Ionic conductivity (45 ℃) Ionic conductivity (25 ℃) Secondary battery cell of comparative example 1-B 1.01Х10 -4 S·cm -1 6.86Х10 -5 S·cm -1 3.59Х10 -5 S·cm -1 Secondary battery cell 1.99Х10 of Example 1-B -4 S·cm -1 1.31Х10 -4 S·cm -1 7.07Х10 -5 S·cm -1 Secondary battery cell 2.19Х10 of Example 2-B -4 S·cm -1 1.48Х10 -4 S·cm -1 8.20Х10 -5 S·cm -1

[0399] Referring to Fig. 4 and Table 3, the ionic conductivity of the secondary battery cell of Comparative Example 1-B at 25 ℃ is 3.59Х10 -5 S·cm -1 However, the ionic conductivity of the secondary battery cell of Example 1-B is 7.07Х10 -5 S·cm-1 And, the ionic conductivity of the secondary battery cell of Example 2-B is 8.20Х10 -5 S·cm -1 You can see that.

[0400] Therefore, it can be seen that the secondary battery cell of Example 1-B has higher ionic conductivity than the secondary battery cell of Comparative Example 1-B, which helps to express the ionic conductivity characteristics of the solid polymer electrolyte.

[0401] In addition, it can be seen that the secondary battery cell of Example 2-B has higher ionic conductivity than the secondary battery cell of Example 1-B.

[0402]

[0403] Experimental Example 3: Evaluation of Interfacial Resistance Stability with Lithium Metal

[0404] The resistance values ​​(Electrochemical impedance spectroscopy, EIS) of the lithium secondary battery cells of Comparative Example 2-C, Comparative Example 3-C, Example 1-C, and Example 2-C were measured every 6 hours at an open circuit voltage (OCV) state, and the results were expressed as Nyquist plots.

[0405] Figure 5a is a graph showing the change in resistance according to a chemical reaction with lithium metal in the lithium secondary battery cell of Comparative Example 2-C.

[0406] Figure 5b is a graph showing the change in resistance according to the chemical reaction with lithium metal in the lithium secondary battery cell of Comparative Example 3-C.

[0407] Figure 5c is a graph showing the change in resistance according to a chemical reaction with lithium metal in a lithium secondary battery cell according to Example 1-C.

[0408] Figure 5c is a graph showing the change in resistance according to a chemical reaction with lithium metal in a lithium secondary battery cell according to Example 2-C.

[0409] Table 4 shows the initial resistance and resistance after 42 hours measured at the open circuit voltage state of the lithium secondary battery cells of Comparative Examples 2-C to 3-C and Examples 1-C to 2-C.

[0410] Initial resistance Resistance after 42 hours Comparison Example 2-C lithium secondary battery cell Approximately 1300 Ω Approximately 1480 Ω Comparison Example 3-C lithium secondary battery cell Approximately 520 Ω Approximately 680 Ω Example 1-C lithium secondary battery cell Approximately 440 Ω Approximately 530 Ω Example 2-C lithium secondary battery cell Approximately 410 Ω Approximately 410 Ω

[0411] Referring to FIGS. 5a to 5d and Table 4, it can be seen that the lithium secondary battery cells of Comparative Examples 2-C to 3-C and Examples 1-C to 2-C all show a slight increase in interfacial resistance over time.

[0412] In addition, it can be seen that the initial resistance and the resistance after 42 hours of the lithium secondary battery cell of Comparative Example 2-C are about 3 times higher than the initial resistance and the resistance after 42 hours of the lithium secondary battery cells of Examples 1-C to 2-C, respectively.

[0413] Therefore, it can be seen that when a solid polymer solid electrolyte is applied to the polyolefin-based porous support according to the present invention, there is an effect of increasing the interfacial stability for lithium metal.

[0414] It can be seen that the initial resistance and the resistance after 42 hours of the lithium secondary battery cell of Comparative Example 2-C are each about 2.5 times higher than those of the lithium secondary battery cell of Comparative Example 3-C.

[0415] In addition, it can be seen that the initial resistance and the resistance after 42 hours of the lithium secondary battery cell of Example 1-C show higher values ​​than the initial resistance and the resistance after 42 hours of the lithium secondary battery of Example 2-C.

[0416] Therefore, it can be seen that when a solid polymer solid electrolyte is applied to a porous support coated with polyvinylidene fluoride, it has the effect of increasing the interfacial stability for lithium metal.

[0417]

[0418] Experimental Example 4: Charge / Discharge Rate Test

[0419] For the lithium secondary batteries of Comparative Examples 1-D to 3-D and Examples 1-D to 2-C, the upper limit voltage for charging was set to 4.2 V, the lower limit voltage for discharging was set to 3.0 V, and the test temperature was 60°C. Charge and discharge rate tests (C-rate) were conducted by repeating charge and discharge 5 cycles for each rate.

[0420] Figure 6a is a graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Comparative Example 1-D.

[0421] Figure 6b is a graph showing the charge / discharge rate characteristics of the lithium secondary battery cell of Comparative Example 2-D.

[0422] Figure 6c is a graph showing the charge / discharge rate characteristics of the lithium secondary battery cell of Comparative Example 3-D.

[0423] Figure 6d is a graph showing the charge / discharge rate characteristics of the lithium secondary battery cell of Example 1-D.

[0424] Figure 6e is a graph showing the charge / discharge rate characteristics of the lithium secondary battery cell of Example 2-D.

[0425] Figure 6f is a graph comparing the charge / discharge rate characteristics of the lithium secondary battery cells of Example 1-D, Example 2-D, and Comparative Example 1-D.

[0426] Table 5 compares the discharge capacities measured based on the first cycle according to each rate of the lithium secondary battery cells of Comparative Example 1-D, Example 1-D, and Example 2-D.

[0427] Comparative Example 1-D Lithium secondary battery cell Example 1-D Lithium secondary battery cell Example 2-D Lithium secondary battery cell 0.1C164 mAh·g-1 171 mAh·g -1 164 mAh·g -1 0.2C161 mAh·g -1 162 mAh·g -1 162 mAh·g -1 0.5C155 mAh·g -1 159 mAh·g -1 155 mAh·g -1 1.0C148 mAh·g -1 154 mAh·g -1 153 mAh·g -1 2.0C91 mAh·g -1 140 mAh·g -1 132 mAh·g -1 3.0C13 mAh·g -1 117 mAh·g -1 102 mAh·g -1 0.1C170 mAh·g -1 170 mAh·g -1 165 mAh·g -1

[0428] Referring to FIGS. 6A to 6F, it can be seen that the discharge capacity of the lithium secondary batteries of Comparative Examples 1-D to 3-D and Examples 1-D to 2-C decreases as the rate increases from 0.1C to 3.0C, and the discharge capacity recovers again as the rate decreases from 3.0C to 0.1C.

[0429] Comparative Example 1-D's lithium secondary battery has a capacity of 148 mAh·g at a low rate of 1.0 C. -1 It maintains a stable discharge capacity of about 91 mAh·g at a high rate of 2.0 C. -1 It exhibits a low discharge capacity of about 13 mAh·g at a high rate of 3.0 C. -1 It can be seen that it exhibits low discharge.

[0430] Therefore, it can be seen that a polyolefin-based support for liquid electrolyte is not suitable for high-rate charge / discharge in which lithium ions move rapidly.

[0431] It can be seen that the lithium secondary battery of Comparative Example 2-D was not properly charged and a short circuit occurred even at a low rate of 0.1 C.

[0432] In addition, it can be seen that the lithium secondary battery of Comparative Example 3-D exhibited an unstable charge curve shape after one cycle of charge and discharge at a low rate of 0.1 C, and discharge did not occur in the third cycle at a low rate of 0.1 C, thus failing to exhibit a stable charge and discharge shape of a lithium secondary battery.

[0433] Therefore, it can be seen that the polyethylene terephthalate porous support is not a suitable porous support for applying the in situ cross-linking method to the solid polymer solid electrolyte.

[0434] However, the lithium secondary battery of Example 1-D has a capacity of about 140 mAh·g even at a high rate of 2.0 C. -1 It stably maintains a high discharge capacity of about 117 mAh·g even at a high rate of 3.0 C. -1 It stably maintains a high discharge capacity, and when it returns to a low rate of 0.1 C, the discharge capacity is approximately 170 mAh·g. -1 It can be confirmed that the discharge capacity is well recovered.

[0435] In addition, the lithium secondary battery of Example 2-D also has a capacity of 140 mAh·g even at a high rate of 2.0 C. -1 It stably maintains a high discharge capacity of 117 mAh·g even at a high rate of 3.0 C. -1 It stably maintains a high discharge capacity, and when returned to a low rate of 0.1 C, the discharge capacity is 170 mAh·g. -1 It can be confirmed that the discharge capacity is well recovered.

[0436] Therefore, it can be seen that when a solid polymer electrolyte is impregnated into a polyolefin porous support for a solid electrolyte by applying an in-situ crosslinking method, a high discharge capacity is stably maintained even at a high rate, and when charge / discharge is performed at a low rate after charge / discharge at a high rate, the discharge capacity is well recovered.

[0437]

[0438] Experimental Example 5: Charge / Discharge Rate Test

[0439] For the lithium secondary batteries of Comparative Examples 1-E to 3-E and Examples 1-E to 2-E, the upper limit voltage for charging was set to 4.2 V, the lower limit voltage for discharging was set to 3.0 V, and the test temperature was 60°C. Charge and discharge rate tests (C-rate) were conducted by repeating charge and discharge 5 cycles for each rate.

[0440] Figure 7a is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Comparative Example 1-E.

[0441] Figure 7b is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Comparative Example 2-E.

[0442] Figure 7c is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Comparative Example 3-E.

[0443] Figure 7d is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Example 1-E.

[0444] Figure 7e is another graph showing the charge / discharge rate characteristics of a lithium secondary battery cell according to Example 2-E.

[0445] Figure 7f is another graph comparing the charge / discharge rate characteristics of lithium secondary battery cells according to Example 1-E, Example 2-E, and Comparative Example 1-E.

[0446] Table 6 compares the discharge capacities measured based on the first cycle according to each rate of the lithium secondary battery cells of Comparative Example 1-E, Example 1-E, and Example 2-E.

[0447] Lithium secondary battery cell of Comparative Example 1-E Lithium secondary battery cell of Example 1-E Lithium secondary battery cell of Example 2-E 0.1C195 mAh·g -1 190 mAh·g -1 193 mAh·g -1 0.2C186 mAh·g -1 182 mAh·g -1 190 mAh·g -1 0.5C170 mAh·g -1 174 mAh·g -1 169 mAh·g -1 1.0C158 mAh·g -1 167 mAh·g -1 167 mAh·g -1 2.0C7.5 mAh·g -1 148 mAh·g -1 148 mAh·g -1 3.0C4.3 mAh·g -1 65 mAh·g -1 82 mAh·g -1 0.1C187 mAh·g -1 191 mAh·g -1 191 mAh·g -1

[0448] Referring to FIGS. 7A to 7F and Table 6, it can be seen that the discharge capacity of the lithium secondary batteries of Comparative Examples 1-E to 3-E and Examples 1-E to 2-E decreases as the rate increases from 0.1 C to 3.0 C, and the discharge capacity recovers again as the rate decreases from 3.0 C to 0.1 C.

[0449] It can be seen that the lithium secondary battery of Comparative Example 1-E stably maintains discharge capacity at low rates of 0.1 C to 1.0 C, but hardly any discharge capacity is expressed at high rates of 2.0 C and 3.0 C.

[0450] Therefore, it can be seen that the polyolefin porous support for the liquid electrolyte has a very small pore size and low air permeability for the solid polymer solid electrolyte precursor to be impregnated, and thus hardly exhibits battery characteristics during high-rate charge / discharge.

[0451] It can be seen that the lithium secondary batteries of Comparative Examples 2-E and 3-E were not properly charged and a short circuit occurred even at a low rate of 0.1 C.

[0452] Therefore, it can be seen that the polyethylene terephthalate porous support is not suitable for the polymer solid electrolyte of the in situ cross-linking method.

[0453] However, the lithium secondary battery of Example 1-E has a capacity of 190 mAh·g based on the first cycle according to each rate. -1 (0.1 C), 182 mAh·g -1 (0.2 C), 174 mAh·g -1 (0.5 C), 167 mAh·g -1 (1.0 C), 148 mAh·g -1 (2.0 C), 65 mAh·g -1 (3.0 C), 191 mAh·g -1 (0.1 C) It can be observed that high battery characteristics are exhibited by stably maintaining high capacity for each rate.

[0454] In addition, the lithium secondary battery of Example 2-E also has 193 mAh·g based on the first cycle according to each rate. -1 (0.1 C), 190 mAh·g -1 (0.2 C), 169 mAh·g -1 (0.5 C), 167 mAh·g -1 (1.0 C), 148 mAh·g -1 (2.0 C), 82 mAh·g -1 (3.0 C), 191 mAh·g-1 (0.1 C) It can be observed that the battery exhibits high battery characteristics by stably maintaining a high capacity for each rate, and maintaining a somewhat higher discharge capacity compared to the lithium secondary battery of Example 1-E at a high rate of 3.0 C.

[0455] Therefore, it can be seen that when a solid polymer electrolyte is impregnated into a polyolefin porous support for a solid electrolyte by applying an in-situ crosslinking method, a high discharge capacity is stably maintained even at a high rate, and when charge / discharge is performed at a low rate after charge / discharge at a high rate, the discharge capacity is well recovered.

[0456] In addition, NCM811 (LiNi), a positive electrode active material with a high nickel (Ni) content, was coated on a polyolefin porous support coated with polyvinylidene fluoride. 0.8 Co 0.1 Mn 0.1 It can be seen that the high electrochemical stability and impregnation of the porous support coated with polyvinylidene fluoride have an effect on improving the battery characteristics through the high discharge capacity according to the rate change even when O2) is applied.

[0457]

[0458] Experimental Example 6: Mechanical Strength Evaluation

[0459] (1) The tensile strength of the porous supports of Examples 1, 2, 1-A, and 2-A was measured using a texture analyzer (Lloyd-TA1) under tensile test conditions of a speed of 20.0 mm / min and a temperature of 25 ℃.

[0460] (2) The above tensile strength measurement is performed 10 times and the average value is calculated.

[0461] (3) A strain-tensile strength graph is created through the above tensile strength measurement.

[0462] Figure 8a is a graph showing the tensile strength according to the strain of the porous support of Examples 1 and 2.

[0463] Table 7 shows the tensile strength values ​​of the porous supports of Examples 1 and 2.

[0464] Porous support of Example 1Porous support of Example 2Tensile strength value 42.96 MPa40.26 MPa

[0465] Figure 8b is another graph showing the tensile strength according to the strain of the porous support of Example 1-A and Example 2-A.

[0466] Table 8 shows the tensile strength values ​​of the porous supports of Examples 1-A and 2-A.

[0467] Porous support of Example 1-APorous support of Example 2-ATensile strength value44.29 MPa36.83 MPa

[0468] Referring to FIG. 8a and Table 7, it can be seen that the porous support of Example 1 exhibits a tensile strength value of about 42.96 MPa, and the porous support of Example 2 exhibits a tensile strength value of about 40.26 MPa.

[0469] Referring to FIG. 8b and Table 8, it can be seen that the porous support of Example 1-A exhibits a tensile strength value of about 44.29 MPa, and the porous support of Example 2-A exhibits a tensile strength value of about 36.83 MPa.

[0470] Therefore, it can be seen that the porous support according to the present invention exhibits strong tensile strength required in a roll-to-roll process, and can maintain strong tensile strength even when impregnated with a solid polymer solid electrolyte and cured.

[0471]

[0472] Experimental Example 7: Contact angle measurement for comparison of impregnation properties

[0473] (1) The polymer electrolyte precursor of Manufacturing Example 1 is dropped onto the porous support of Example 1.

[0474] (2) In step (1), the porous support onto which the polymer electrolyte precursor has been dropped is photographed digitally every 5 minutes for 30 minutes, and then the contact angle is measured.

[0475] (3) In the above step (2), the contact angle is measured using a 22 gauge needle at a temperature of 25°C using the Generated by surfaceware 7 software. The left contact angle and the right contact angle of the interface between the polymer electrolyte precursor and the porous support are measured three times each, and then the average is taken.

[0476] (4) In step (1) above, the same experiment is repeated for the porous support of Example 2 instead of the porous support of Example 1.

[0477] Figure 9 is a photograph showing the contact angle measured for the porous support of Examples 1 and 2 and the precursor of the solid polymer electrolyte.

[0478] Table 9 shows the contact angles for the porous supports of Examples 1 and 2 and the precursor of the solid polymer electrolyte of Preparation Example 1 over time.

[0479] Porous support of Example 1 Porous support of Example 2 0 min 68.21° 18.52° 5 min 63.80° 11.05° 10 min 63.00° 9.94° 15 min 64.60° 10.30° 20 min 63.38° 11.37° 25 min 63.52° 11.38° 30 min 61.90° 11.47°

[0480] Referring to FIG. 9 and Table 9, it can be seen that at the beginning of the experiment, the contact angle between the porous support of Example 1 and the polymer electrolyte precursor shows a value of 68.21°, and the contact angle between the porous support of Example 2 and the polymer electrolyte precursor shows a value of 18.52°. Therefore, it can be seen that the porous support of Example 2 has superior impregnation properties compared to the porous support of Example 1.

[0481] It can be seen that after 30 minutes of the experiment, the contact angle between the porous support of Example 1 and the polymer electrolyte precursor shows a value of 61.90°, and the contact angle between the porous support of Example 2 and the polymer electrolyte precursor shows a value of 11.47°.

[0482] Accordingly, it can be seen that the porous support of Example 2 has almost all of the polymer electrolyte precursor impregnated into the porous support, but the porous support of Example 1 does not have good impregnation even over time.

[0483] This experimental example shows that when polyvinylidene fluoride is coated on the surface of a porous support, it has the effect of increasing the impregnation property of a polymer electrolyte precursor.

[0484]

[0485] Experimental Example 8: Evaluation of Reaction Stability with Lithium Metal

[0486] Lithium plating / stripping experiments were performed sequentially at 45°C on lithium secondary batteries of Example 1-C and Example 2-C, with 0.1 mA per lithium area for 36,000 seconds each and 36,000 seconds each for stripping, 0.2 mA for 18,000 seconds each for stripping, 0.5 mA for 7,200 seconds each for stripping, and 1.0 mA for 3,600 seconds each for stripping.

[0487] Figure 10 is a graph showing the results of a lithium plating / stripping experiment in the lithium secondary battery cells of Examples 1-C and 2-C.

[0488] Table 10 shows the current density and voltage difference during lithium plating / stripping experiments on lithium secondary battery cells of Examples 1-C and 2-C.

[0489] Lithium secondary battery cell of Example 1-C Lithium secondary battery cell of Example 2-C 0.1 mA·cm -2 (10 hours)±0.01 V±0.008 V0.2 mA·cm -2 (5 hours)±0.03 V±0.02 V0.5 mA·cm -2 (2 hours)±0.09 V±0.05 V1.0 mA·cm -2 (1 hour)±0.17 V±0.12 V0.1 mA·cm -2 (10 hours)±0.02 V±0.02 V

[0490] Referring to Figure 8 and Table 10, the voltage change was evaluated in an environment where the repeated lithium ion deposition and stripping speed were increased, and the result was 0.1 mA·cm -2 No significant difference was observed when electrodepositing and stripping at low speeds of 0.2 mA·cm -2 , 0.5 mA·cm -2 , 1.0 mA·cm -2 When electrodepositing and stripping at a high speed, it can be seen that the lithium secondary battery cell of Example 1-C exhibits a somewhat higher overvoltage compared to the lithium secondary battery cell of Example 2-C.

[0491] Also, 1.0 mA·cm -2 When electrodeposition and stripping were performed at the highest speed, it can be seen that the lithium secondary battery cell of Example 1-C exhibited an overvoltage of ±0.17 V, but the lithium secondary battery cell of Example 2-C exhibited an overvoltage of ±0.12 V.

[0492] Therefore, it can be seen that electrochemical stability is improved by coating polyvinylidene fluoride on a porous support.

[0493] In addition, it was found that coating polyvinylidene fluoride on a porous support does not cause side reactions between the solid polymer electrolyte and lithium metal, and can greatly contribute to stabilizing the lithium metal negative electrode even in an environment where charging and discharging is performed at a high rate.

[0494]

[0495] Experimental Example 9: Charge / Discharge Cycle Test

[0496] (1) For the lithium secondary batteries of Comparative Example 1-D, Example 1-D, and Example 2-D, the upper limit voltage for charging was 4.2 V, the lower limit voltage for discharging was 3.0 V, the test temperature was 60°C, charging was 0.3 C CC, and discharging was 0.5 C CC, and charging and discharging were repeated 100 times.

[0497] (2) Calculate the capacity retention rate after 100 charge / discharge cycles according to Equation 2 below.

[0498] [Formula 2]

[0499] Figure 11a is a graph showing the charge / discharge cycle characteristics of a lithium secondary battery cell according to Comparative Example 1-D.

[0500] Figure 11b is a graph showing the charge / discharge cycle characteristics of a lithium secondary battery cell according to Example 1-D.

[0501] Figure 11c is a graph showing the charge / discharge cycle of a lithium secondary battery cell according to Example 2-D.

[0502] Figure 11d is a graph comparing charge and discharge cycles of lithium secondary battery cells according to Examples 1-D and 2-D.

[0503] Table 11 shows the capacity retention rate after charge and discharge cycles of lithium secondary battery cells according to Examples 1-D and 2-D.

[0504] Capacity retention rate comparison Example 1-D lithium secondary battery cell 15% Example 1-D lithium secondary battery cell 78% Example 2-D lithium secondary battery cell 84%

[0505] Referring to FIGS. 11a to 11d and Table 11, Comparative Example 1-D shows a capacity retention rate of approximately 15% after 100 cycles, and a rapid capacity decrease begins after 70 cycles, showing an unstable charge / discharge curve.

[0506] However, it can be seen that Example 1-D shows a capacity retention rate of about 78% from the first cycle to 100 cycles, which is about 5 times higher than that of Comparative Example 1-D.

[0507] In addition, it can be seen that the lithium secondary battery cell of Example 2-D shows the most stable charge / discharge curve with a capacity retention rate of approximately 84% from the first cycle to 100 cycles.

[0508] Therefore, it can be seen that the polyolefin-based porous support according to the present invention is suitable for applying an in-situ crosslinking method to a solid polymer electrolyte, and is effective in improving the cycle life in an actual battery environment.

[0509]

[0510] Experimental Example 10: Electrochemical Stability Evaluation

[0511] Lithium secondary battery coin cells of Example 1-F and Example 2-F at an injection speed of 1.0 mV·s -1 Cyclic voltammetry and linear voltammetry were measured at 25 ℃.

[0512] Figure 12a is a graph showing the results of cyclic voltammetry measurements of lithium secondary battery coin cells of Examples 1-F and 2-F.

[0513] Figure 12b is a graph showing the results of linear scanning method measurements of lithium secondary battery coin cells of Examples 1-F and 2-F.

[0514] Referring to Fig. 12a, it can be seen through the measurement results of the cyclic conversion injection method that the peak sizes of the reduction reaction with a negative voltage scan direction and the oxidation reaction with a positive voltage scan direction of the coin cell of Example 2-F are significantly reduced compared to the coin cell of Example 1-F.

[0515] Additionally, it can be seen that the effect is significantly enhanced at the reduction reaction peak where the voltage injection direction is negative.

[0516] Therefore, it can be seen that when polyvinylidene fluoride is coated on the surface of a polyolefin-based porous support, the reactivity with lithium metal is suppressed and the electrochemical stability is increased.

[0517] Referring to Fig. 12b, the linear voltage measurement results show that the coin cell of Example 2-F has an oxidation stability that is about 0.1 V higher than that of the coin cell of Example 1-F.

[0518] Therefore, it can be seen that the electrochemical oxidation stability is high when polyvinylidene fluoride is coated on a porous support.

[0519]

[0520] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0521] The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

[0522] The porous support according to the present invention has a large pore size and improved air permeability.

[0523] The porous support according to the present invention has a high impregnation effect for solid polymer electrolyte.

[0524] The porous support according to the present invention has excellent mechanical strength and has the effect of maintaining excellent mechanical strength even after being impregnated with a solid polymer electrolyte and cured.

[0525] The porous support according to the present invention has the effect of being usable in an in-situ crosslinking polymerization method and a roll-to-roll process.

[0526] The porous support according to the present invention has the effect of reducing the interfacial resistance that occurs between the positive or negative electrode active material and the solid polymer electrolyte.

[0527] The porous support according to the present invention has the effect of improving ionic conductivity.

[0528] The porous support according to the present invention has the effect of stably maintaining a high discharge capacity.

[0529] The porous support according to the present invention has the effect of improving the reaction stability with lithium metal.

[0530] The porous support according to the present invention has the effect of improving electrochemical oxidation stability.

Claims

1. Contains polyolefin polymers, Used for impregnation of solid polymer electrolytes, Characterized in that the pore diameter is 0.05 to 0.9㎛, Porous support.

2. In paragraph 1, The above polyolefin polymer includes at least one selected from the group consisting of polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polyisobutylene (PIB), polyolefin elastomer (POE), ethylene propylene rubber (EPR), and polybutene-I (PB-I). Characterized by a mixed structure of amorphous and crystalline structures, Porous support.

3. In paragraph 1, The above solid polymer electrolyte comprises at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator. Porous support.

4. In paragraph 1, The porous support is characterized in that the air permeability is 0.03 to 1 cfm. Porous support.

5. Characterized in that both sides of the porous support according to Article 1 are coated with a nano membrane. Porous support.

6. In paragraph 5, The above nano membrane is characterized in that it includes at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK). Porous support.

7. In paragraph 1 or paragraph 5, Characterized in that the porous support is impregnated with a solid polymer electrolyte, Porous support.

8. Porous support according to Article 7; negative electrode active material; and Containing a cathode active material; Secondary battery.

9. In paragraph 8, The above negative electrode active material includes at least one selected from the group consisting of natural graphite, artificial graphite, coke, lithium metal, silicon, and tin, The cathode active material is characterized in that it includes at least one selected from the group consisting of lithium cobalt oxide (LCO), lithium manganese oxide (LMO), lithium nickel oxide (LNO), lithium nickel cobalt manganese oxide (NCM), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese aluminum oxide (NCMA), and lithium iron phosphate (LFP). Secondary battery. 10.(a-1) A step of heating a polyolefin polymer to perform primary stretching; and (a-2) a step of heating the first stretched polyolefin polymer to perform a second stretch; Through the above step (a-1), the polyolefin polymer is formed into a mixed structure of amorphous and crystalline structures, The pore size is adjusted to 0.05 to 0.9㎛ through the above step (a-2), and is characterized in that it is used for impregnation of a solid polymer electrolyte. Method for manufacturing a porous support.

11. In paragraph 10, After the above step (a-2) (a-3) a step of impregnating a precursor of a solid polymer electrolyte into the secondarily stretched polyolefin polymer; and (a-4) characterized in that it further includes a step of heating the precursor of the solid polymer electrolyte; Method for manufacturing a porous support.

12. In paragraph 11, In the above step (a-3), the precursor of the solid polymer electrolyte is characterized in that it includes at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, a dispersant, and a curing initiator. Method for manufacturing a porous support.

13. In paragraph 12, The mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator is characterized by being 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight. Method for manufacturing a porous support.

14. In paragraph 11, In the above step (a-4), heating is characterized in that it is performed at 50 to 150 ℃ for 1 minute to 10 hours. Method for manufacturing a porous support.

15. A porous support manufactured by the method for manufacturing a porous support according to Article 10. 16.(b-1) Step of manufacturing a nano membrane by electrospinning; (b-2) a step of applying a thermoplastic resin to one side of the nano membrane; and (b-3) characterized by including a step of adsorbing a porous support according to claim 15 onto the surface of the nano membrane to which the thermoplastic resin is applied; Method for manufacturing a porous support.

17. In paragraph 16, In the above step (b-1), the nano membrane is characterized in that it includes at least one selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF-HFP), polyvinylidene fluoride trifluoroethylene (PVDF-TrFE), polyvinylidene fluoride tetrafluoroethylene (PVDF-TeFE), polyurethane (PU), polyethersulfone (PES), polyacrylonitrile (PAN), polyamide (PA), polyimide (PI), polyetherketone (PEK), and polyetheretherketone (PEEK). Method for manufacturing a porous support.

18. In paragraph 16, In the above step (b-2), the thermoplastic resin is characterized in that it is one selected from the group consisting of polyurethane, polyester, polypropylene, polyamide, polyethylene, and ethylene vinyl acetate. Method for manufacturing a porous support.

19. In paragraph 16, In the above step (b-2), the application is 0.1g / m 2 0.3 g / m 2 characterized by being performed as, Method for manufacturing a porous support.

20. In paragraph 16, In the above step (b-2), adsorption is characterized in that the temperature is 90°C to 130°C and the pressure is 0.2 MPa to 0.5 MPa. Method for manufacturing a porous support.

21. In paragraph 16, After step (b-3) above (b-4) a step of impregnating the precursor of a solid polymer electrolyte into the porous support; and (b-5) characterized in that it further includes a step of heating the precursor of the solid polymer electrolyte; Method for manufacturing a porous support.

22. In paragraph 21, In the above step (b-4), the precursor of the solid polymer electrolyte is characterized in that it includes at least one selected from the group consisting of a plasticizer, a crosslinking agent, a lithium salt, an additive, and a curing initiator. Method for manufacturing a porous support.

23. In paragraph 22, The mass ratio of the above plasticizer, crosslinking agent, lithium salt, additive and curing initiator is characterized by being 500 to 900 parts by weight: 100 to 300 parts by weight: 100 to 300 parts by weight: 20 to 70 parts by weight: 1.0 to 5.0 parts by weight. Method for manufacturing a porous support.

24. In paragraph 21, In the above step (b-5), heating is characterized in that it is performed at 50 to 150 ℃ for 1 minute to 10 hours. Method for manufacturing a porous support.

25. A porous support manufactured by the method for manufacturing a porous support according to Article 16.

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