Polymer-based solid electrolyte membrane, method for producing same, and solid

Abstract

The invention relates to a polymer-based solid-state electrolyte membrane, a manufacturing method thereof, and a solid-state electrolyte battery capable of being used at high temperature. The polymer-based solid electrolyte membrane comprises a heat-resistant polymer nanofiber membrane, an electrolyte material for impregnating and / or coating the heat-resistant polymer nanofiber membrane, and a lithium salt, the heat-resistant polymer nanofiber membrane is formed into a membrane shape through free interweaving of fibers of a heat-resistant polymer, and the heat-resistant polymer is selected from at least one of polyacrylonitrile, polyvinylpyrrolidone, polyvinyl alcohol, polyetherimide, aromatic polyamide, polyphenylene ether and polyaryletherketone. The electrolyte material is in a solid state and is selected from at least one of polyethylene oxide or polyethylene glycol diamine. The solid electrolyte battery according to the present invention comprises a positive electrode, a negative electrode, and a solid electrolyte membrane interposed between the positive electrode and the negative electrode, the solid electrolyte membrane comprising the polymer-based solid electrolyte membrane.

Description

TECHNICAL FIELD

[0001] The present application relates to a polymer-based solid-state electrolyte film and a manufacturing method thereof, and a solid-state electrolyte battery that can be used at high temperatures, and belongs to the field of secondary batteries. BACKGROUND

[0002] With the increasing demand of modern industrial systems for the working ability of energy storage devices in extreme environments, the temperature adaptability of traditional lithium-ion batteries is increasingly insufficient. Especially in high-temperature environments such as oil drilling (1000-10,000 meters deep in the well often reaches 150-250℃), special vehicles, etc., ordinary battery systems often lead to performance degradation and even safety accidents due to problems such as electrolyte evaporation, uncontrolled interfacial reaction, rapid growth of lithium dendrites, etc. It is difficult to achieve normal secondary charging and discharging use in high-temperature (e.g., up to 200℃) environments.

[0003] To meet this special demand, high-temperature special lithium batteries have begun to be explored in the field. The current mainstream direction focuses on the following technologies.

[0004] Molten salt electrolyte system (such as LiNO3-KNO3 eutectic system): Although it has good ionic conductivity within a certain temperature range, it has problems such as large electrolyte flowability, difficult interface control, complex packaging technology, etc. Especially in high-temperature long-term use, the electrolyte is prone to leakage or failure.

[0005] Ceramic solid-state electrolyte system (such as LLZO, LATP, etc.): It has excellent thermal stability and wide electrochemical window, but generally has defects such as large brittleness, easy cracking, and difficulty in forming a low-resistance interface with electrode materials, especially in high-temperature rapid cycling, which is prone to interface debonding and electrochemical degradation.

[0006] Polymer solid-state electrolyte system (SPE): Typical such as PEO system, although it has excellent film-forming property and interface adaptability, but the thermal stability is generally not more than 100℃, and it is difficult to be applied to high-temperature working conditions due to softening or decomposition at high temperatures.

[0007] Composite solid-state electrolyte: by compounding inorganic ceramic particles (such as LLZO, Li7P3S 11 ) with a high polymer matrix, trying to take advantage of both, but common polymers such as PVDF, PCL, etc. still have problems such as low melting point and high risk of thermal decomposition.

[0008] In addition, regarding the polymer solid electrolyte system, the inventors have also found that the following key problems commonly exist in the existing lithium battery system under high temperature conditions of about 200°C: insufficient thermal stability of the electrolyte, softening and decomposition of the polymer electrolyte under high temperature, leading to safety risks; easy debonding between the electrode and the electrolyte and poor contact, leading to increased internal resistance and degraded electrochemical performance; further, lack of design paths for matching high-temperature solid electrolytes and high-melting-point anode materials that can be prepared on a large scale, etc.

[0009] For example, Patent Document 1 provides a preparation process for a flame-retardant polyethylene oxide composite solid electrolyte. In the composite solid electrolyte obtained in Patent Document 1, although a polyacrylonitrile fiber membrane is used as a skeleton, such a composite solid electrolyte cannot meet the requirement of stable operation under high temperature such as 150°C, but is suitable for use in a use scenario not exceeding 80°C. This is because both the electrolyte and the polyacrylonitrile fiber membrane have insufficient stability problems, for example, materials such as butanedinitrile as a plasticizer, and polyacrylonitrile and cyclodextrin grafted components have insufficient high-temperature resistance; in addition, the adhesion between the composite solid electrolyte and the electrode (especially high-melting-point anode material) is also insufficient.

[0010] Therefore, regarding the polymer solid electrolyte system (especially the PEO system or the PEA system), there is a need for a solid electrolyte battery suitable for use in a high-temperature environment.

[0011] <Patent Document>

[0012] Patent Document 1: CN119361811A SUMMARY

[0013] <Problems to be Solved by the Invention>

[0014] In view of the above, the purpose of the present application is to provide a solid electrolyte membrane that can withstand use in a high-temperature environment, has high thermal stability, good ion permeability, good adhesion to electrodes, excellent mechanical properties, and is easy to obtain and suitable for mass production.

[0015] The purpose of the present application is to provide a method for manufacturing a solid electrolyte membrane that can withstand use in a high-temperature environment, which can be simply implemented and is suitable for mass production.

[0016] The purpose of the present application is also a solid electrolyte battery that can withstand use in a high-temperature environment and has excellent electrical properties.

[0017] <Solution to the Problem>

[0018] According to the inventors' painstaking research, it has been found that by implementing the following technical solutions, the above technical problems can be solved:

[0019] [1] A polymer-based solid electrolyte membrane comprising: a heat-resistant polymer nanofiber membrane, an electrolyte material impregnated and / or coated on the heat-resistant polymer nanofiber membrane, and a lithium salt,

[0020] the heat-resistant polymer nanofiber membrane is formed in a membrane shape by free interweaving of fibers of a heat-resistant polymer,

[0021] the heat-resistant polymer is at least one selected from the group consisting of polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyetherimide (PEI), aromatic polyamide, polyphenylene oxide (PPO), or polyaryletherketone;

[0022] the electrolyte material is solid and is at least one selected from the group consisting of polyethylene oxide (PEO) or polyethylene glycol diamine (PEA).

[0023] [2] The polymer-based solid electrolyte membrane according to [1], wherein the lithium salt includes an imide lithium salt; and / or

[0024] a molar ratio of a repeating unit (EO) of the polyether in the electrolyte material to lithium (Li) in the lithium salt is 1:1 to 20:1.

[0025] [3] The polymer-based solid electrolyte membrane according to [1] or [2], wherein the heat-resistant polymer nanofiber membrane is loaded with inorganic ceramic filler particles.

[0026] [4] The polymer-based solid electrolyte membrane according to [3], wherein the inorganic ceramic filler particles are at least one selected from the group consisting of oxide-based compounds, LLZO (Li7La3Zr2O12), LAGP (Li5Al0.5Ge1.5(PO4)3), LATP, LiAlO2, nitride-based compounds; and / or 12 1.5 0.5 1.5

[0027] the inorganic ceramic filler particles are nano- or sub-micron-sized particles.

[0028] [5] A method of manufacturing the polymer-based solid electrolyte membrane according to any one of [1] to [4], comprising the steps of:

[0029] (1) preparing a heat-resistant polymer nanofiber membrane using an electrospinning method,

[0030] ​​​​(2) applying a solution containing an electrolyte material and a lithium salt to at least one side of the heat-resistant polymer nanofiber membrane, and / or immersing the heat-resistant polymer nanofiber membrane in a solution containing an electrolyte material and a lithium salt.

[0031] [6]. The method for producing a polymer-based solid electrolyte membrane according to [5], wherein, in step (1), a dope including the heat-resistant polymer is formed into a membrane shape by constructing a three-dimensional nanonetwork structure using an electrospinning technique, and the membrane shape is subjected to densification treatment using a calendering process,

[0032] Preferably, the dope includes a solvent A selected from at least one of a pyrrolidone-based solvent and an amide-based solvent.

[0033] [7]. The method for producing a polymer-based solid electrolyte membrane according to [5] or [6], wherein, in step (2), the solution containing an electrolyte material and a lithium salt includes a solvent B including at least one selected from an ether-based solvent and a nitrile-based solvent.

[0034] [8]. The method for producing a polymer-based solid electrolyte membrane according to any one of [5] to [7], further including (3) subjecting the composite obtained in step (2) to a multi-step drying process of first performing reduced-pressure drying and then performing normal-pressure drying.

[0035] [9]. A solid electrolyte battery including: a positive electrode, a negative electrode, a solid electrolyte membrane interposed between the positive electrode and the negative electrode, the solid electrolyte membrane including a polymer-based solid electrolyte membrane according to any one of [1] to [4].

[0036]

[10] . The solid electrolyte battery according to [9], wherein the negative electrode includes a lithium metal alloy negative electrode.

[0037] <Effects of the Invention>

[0038] In the present invention, the above technical solutions achieve the following technical effects.

[0039] By including a specific heat-resistant polymer nanofiber membrane in a solid electrolyte membrane using PEO and / or PEA as an electrolyte material to construct a high-temperature stable skeleton structure, a high-temperature resistant composite solid electrolyte membrane can be obtained. Therefore, the solid electrolyte membrane of the present invention has excellent thermal stability and ion permeability. In addition, the solid electrolyte membrane of the present invention has good adhesion to various positive electrode or negative electrode materials.

[0040] Therefore, the battery using the solid electrolyte membrane can be used for multiple times with good charge-discharge performance in a high temperature environment (e.g. above 80℃, up to 200℃, or even up to 250℃).

[0041] Moreover, the solid electrolyte membrane of the present application also has excellent mechanical properties, such as high modulus, which can easily inhibit lithium dendrites, and flexibility and toughness, which are particularly suitable for high temperature packaging.

[0042] In addition, the solid electrolyte membrane of the present application can be easily obtained and is suitable for large-scale production.

[0043] The solid electrolyte membrane battery of the present application uses the above-mentioned solid electrolyte membrane of the present application, and is therefore a solid electrolyte lithium secondary battery. As described above, the battery of the present application can also have good usability in a high temperature environment.

[0044] In particular, when a high melting point lithium alloy material (such as Li-B, Li-Al, Li-Mg, Li-Si, Li-Sn, Cu-Ta-Li alloy, etc.) is used as the negative electrode, the thermal stability and cycle life of the entire battery system can be further significantly improved.

[0045] Therefore, the battery of the present application can work safely, efficiently and stably for a long time in a high temperature (up to 250℃) environment, and is suitable for energy supply needs in high temperature and extreme working conditions such as oil drilling exploration, electric vehicles, energy and power industries, chemical and metallurgical industries, electronic and semiconductor manufacturing, and food processing. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a physical photo of the high temperature resistant composite solid electrolyte obtained in Example 1.

[0047] Figure 2 It is a charge-discharge curve graph of the solid state battery obtained in Example 1 tested in an 80℃ environment (the rate current is 0.5C and 1C respectively).

[0048] Figure 3 It is a charge-discharge curve graph of the solid state battery obtained in Example 2 tested in a 130℃ environment (the first cycle and the second cycle of charge-discharge are cycled, and the rate current is 0.5C).

[0049] Figure 4 It is a charge-discharge curve graph of the solid state battery obtained in Example 3 tested in a 160℃ environment (the first cycle and the fifth cycle of charge-discharge are cycled, and the rate current is 0.5C).

[0050] Figure 5 It is a voltage change curve graph of the solid state battery obtained in Example 3 tested in a 160℃ environment during the process of standing for 24h after charging.

[0051] Figure 6 Charge-discharge curve of the solid-state battery obtained in Example 4 for 160°C environmental test (cycling charge-discharge for the first cycle and the second cycle, the rate current is 0.1C).

[0052] Figure 7 Charge-discharge curve of the pouch-type solid-state battery obtained in Example 5 for 160°C environmental test (the current is 15mA).

[0053] Figure 8 Charge-discharge curve of the solid-state battery obtained in Comparative Example 1 for 140°C environmental test (the rate current is 0.5C).

[0054] Figure 9 Charge-discharge curve of the solid-state battery obtained in Comparative Example 2 for 160°C environmental test (the rate current is 0.5C). DETAILED DESCRIPTION

[0055] Various illustrative embodiments, features and aspects of the present application are described below in detail. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0056] In addition, for the purpose of convenience and brevity, detailed descriptions of well-known devices, methods, apparatuses and steps are omitted so as not to obscure the underlying principles of the application. The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms "connected" and "coupled" and variations thereof are used broadly and encompass both direct and indirect connections and couplings.

[0057] Unless specifically stated otherwise, units used in this specification are standard international units and all numerical values, numerical ranges, should be interpreted as including system errors that are unavoidable in industrial production.

[0058] In this specification, the meaning expressed by "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0059] In this specification, "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like refer to the specific elements (e.g., features, structures, properties, and / or characteristics) described in relation to the embodiments and can or can not be present in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0060] In the present specification, a numerical range indicated using "numerical value A to numerical value B" means a range including the end point values A, B. In the present specification, a numerical range indicated using "and above" and "and below" means a range including the end point values. In the present specification, a numerical range indicated using "greater than" and "less than" means a range not including the end point values.

[0061] In the present specification, "optional" or "optionally" means that the event or circumstance described next can or can not occur, and the description includes the case where the event occurs and the case where the event does not occur.

[0062] <Polymer-based solid electrolyte membrane>

[0063] The polymer-based solid electrolyte membrane of the present application includes: a heat-resistant polymer nanofiber membrane, an electrolyte material impregnated and / or coated on the heat-resistant polymer nanofiber membrane, and a lithium salt. In the present application, the electrolyte material is in a solid state.

[0064] In some specific embodiments, the polymer-based solid electrolyte membrane of the present application includes: a heat-resistant polymer nanofiber membrane, and a solid electrolyte composition impregnated and / or coated on the heat-resistant polymer nanofiber membrane, the composition comprising an electrolyte material and a lithium salt.

[0065] In the present application, the heat-resistant polymer nanofiber membrane is formed into a membrane shape by free interweaving of fibers of a heat-resistant polymer. Here, the term "formed into a membrane shape by free interweaving of fibers of a heat-resistant polymer" means that a product formed by random free interweaving of heat-resistant polymer fibers exhibits a macroscopic membrane shape, i.e., the product as a whole exhibits a membrane shape as can be confirmed by the naked eye.

[0066] In the present application, the size of the heat-resistant polymer fibers as such is not particularly limited. In some preferred embodiments, the microdiameter of the heat-resistant polymer fibers (i.e., the average fiber diameter of the heat-resistant polymer fibers) is preferably 10 nm to 1000 nm, more preferably 50 nm to 500 nm.

[0067] In the present application, the microtopographical structure of the heat-resistant polymer fibers as such is not particularly limited, and can be solid, hollow, or porous.

[0068] In the present application, the heat-resistant polymer is at least one selected from the group consisting of polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyetherimide (PEI), aromatic polyamide, polyphenylene oxide (PPO), or polyaryletherketone.

[0069] In some preferred embodiments, the heat-resistant polymer is preferably polyacrylonitrile (PAN) and / or polyvinylpyrrolidone (PVP), more preferably polyacrylonitrile (PAN), from the viewpoint of better achieving the desired effects of the present application. Here, polyacrylonitrile refers to a homopolymer of acrylonitrile.

[0070] In addition, the heat-resistant polymer nanofiber membrane can be a polymer fiber membrane modified with an organic substance or a polymer fiber membrane not modified with an organic substance. Preferably, the heat-resistant polymer nanofiber membrane is a polymer not modified with an organic substance from the viewpoint of facilitating processing and improving heat resistance.

[0071] Here, "modified with an organic substance" refers to performing additional organic substance modification on the obtained polymer fiber membrane after obtaining the polymer fiber membrane by, for example, electrospinning, such as chemically grafting or physically loading other organic substances on the obtained polymer fiber membrane, and the like. "Not modified with an organic substance" refers to not undergoing organic substance modification.

[0072] In some preferred embodiments, the heat-resistant polymer nanofiber membrane preferably has inorganic ceramic filler particles from the viewpoint of further improving the high-temperature ionic conductivity and structural strength of the composite electrolyte.

[0073] More specifically, the inorganic ceramic filler particles are uniformly introduced into the heat-resistant polymer nanofiber membrane as the electrolyte skeleton structure. There is no particular limitation on the loading position, and the inorganic ceramic filler particles can be loaded on the surface of the heat-resistant polymer fiber or in the heat-resistant polymer fiber (for example, embedded and / or inserted, and the like, and some of the particles can be exposed on the surface of the fiber).

[0074] In some more preferred embodiments, the inorganic ceramic filler particles are preferably at least one selected from the group consisting of oxide-based compounds, LLZO (Li7La3Zr2O 12 ), LAGP (Li 1.5 Al 0.5 Ge 1.5 (PO4)3), LATP, LiAlO2, and nitride-based compounds.

[0075] In other more preferred embodiments, the inorganic ceramic filler particles are nanoscale or submicron particles.

[0076] In addition, the thickness of the single-layer heat-resistant polymer nanofiber membrane is preferably 30 to 150 μm, more preferably 70 to 100 μm.

[0077] In the present application, at least one selected from the group consisting of polyethylene oxide (PEO) and polyethylene glycol diamine (PEA) is used as the solid-state electrolyte material.

[0078] In the present application, the specific structure of polyethylene oxide (PEO) or polyethylene glycol diamine (PEA) is not particularly limited, and each can be a kind of electrolyte material known in the art.

[0079] Polyethylene oxide (PEO) has the structure of HO-(CH2CH2O) n -CH2CH2-OH (n is the degree of polymerization and is not limited, preferably, n is 2 to 1000, for example, 10 to 900).

[0080] Polyethylene glycol diamine (PEA) has the structure of H2N-[(CH2CH2O) n ]-CH2CH2-NH2, wherein n is the degree of polymerization and is not limited, preferably, n is 2 to 1000, for example, 10 to 900.

[0081] In addition, in some preferred embodiments, from the viewpoint of better achieving the desired effects of the present application, the molar ratio of the repeating unit of polyether (-CH2CH2O-, EO) in the electrolyte material to lithium (Li) in the lithium salt is preferably 1:1 to 20:1, more preferably 5:1 to 15:1.

[0082] In the present application, a lithium salt is used as an electrolyte salt. As examples of the lithium salt, LiBF4, LiClO4, LiPF6, LiAsF6, LiSbF6, LiAlCl4, LiSCN, LiCF3SO3, LiCF3CO2, Li(P(C2O4)F4), LiPF 6-x (C n F 2n+1 ) x (1 10 Cl 10 , LiCl, LiBr, LiI, chloroborane lithium, lithium salts of lower aliphatic carboxylic acids, such as Li2B4O7, Li(B(C2O4)F2), and the like borate salts, such as LiN(SO2CF3)2 (LiTFSI), LiN(SO2F)2 (LiFSI), LiN(C1F 2l+1 SO2)(C m F 2m+1 SO2){l, m is an integer of 0 or more} and the like imide salts, and the like. For the lithium salt, one kind alone can be used, or a plurality of kinds can be used in mixture.

[0083] In some preferred embodiments, from the viewpoint of further improving ionic conductivity, the lithium salt is preferably at least one selected from LiTFSI or LiFSI.

[0084] In addition, the solid electrolyte membrane of the present application can also be optionally added with other additives as needed, such as plasticizers such as succinonitrile, crosslinking agents, interfacial stabilizers such as LiF, AlF3, polydopamine (PDA), conductive materials such as carbon nanotubes, graphite, flame retardants, moisture absorbents, segment arrangement adjusting agents such as cyclodextrin, and the like. They can be used singly or in a mixture of a plurality of kinds.

[0085] In some specific embodiments, these other additives can be contained in the above-mentioned solid electrolyte composition.

[0086] In some preferred embodiments, from the viewpoint of further improving the high-temperature resistance, no plasticizer is used. In some particularly preferred embodiments, from the viewpoint of further improving the high-temperature resistance, no plasticizer, interfacial stabilizer, flame retardant, moisture absorbent, and segment arrangement adjusting agent is used.

[0087] In other preferred embodiments, from the viewpoint of improving the processing stability, no crosslinking agent is used.

[0088] In the present application, the structure of the polymer-based solid electrolyte membrane is not particularly limited, and can include only one layer of heat-resistant polymer nanofiber membrane, or can have multiple layers of heat-resistant polymer nanofiber membranes.

[0089] In addition, the thickness of the single-layer polymer-based solid electrolyte membrane is preferably 30 to 150 μm, and more preferably 70 to 100 μm.

[0090] The method for producing the polymer-based solid electrolyte membrane of the present application is not particularly limited. In some preferred embodiments, the method adopted in the following <Method for producing a polymer-based solid electrolyte membrane> is adopted.

[0091] <Method for producing a polymer-based solid electrolyte membrane>

[0092] The method for producing the polymer-based solid electrolyte membrane of the present application includes the following steps: (1) preparing a heat-resistant polymer nanofiber membrane by an electrospinning method; (2) coating at least one side of the heat-resistant polymer nanofiber membrane with a solution containing an electrolyte material and a lithium salt, and / or immersing the heat-resistant polymer nanofiber membrane in a solution containing an electrolyte material and a lithium salt.

[0093] In some preferred embodiments, in step (1), a dope including the heat-resistant polymer is formed into a film-like matter by constructing a three-dimensional nanonetwork structure using an electrospinning technique, and the film-like matter is subjected to densification treatment using a calendering process. In other words, a heat-resistant polymer nanofiber film subjected to press densification is preferably used. In this case, the heat-resistant polymer nanofiber film is a heat-resistant polymer nanofiber film densified by pressurization, and thus is more advantageous in improving the high-temperature resistance and the ion conductivity.

[0094] Here, the degree of densification is not particularly limited and can be appropriately adjusted as needed. In some preferred embodiments, the thickness of the heat-resistant polymer nanofiber film subjected to press densification is preferably reduced by 5% or more, more preferably by 10% or more, further preferably by 15% or more, and particularly preferably by 20% or more, relative to the thickness of the initial nanofiber film (i.e., the film-like matter obtained at the time of completion of electrospinning) obtained by the electrospinning technique; and is preferably reduced by 80% or less, more preferably by 70% or less, and further preferably by 60% or less.

[0095] In step (1), the electrospinning technique can employ a uniaxial electrospinning technique or a coaxial electrospinning technique. The electrospinning of the present application can be performed using a method and equipment that are conventional in the art. The parameters related to the electrospinning technique are not particularly limited in the present application and can be appropriately adjusted as needed.

[0096] In step (1), the solvent A for dissolving the heat-resistant polymer in the dope including the heat-resistant polymer is not particularly limited and can be appropriately selected from, for example, fluorinated alcohols such as trifluoroethanol and hexafluoroisopropanol, fluorinated carboxylic acids such as trifluoroacetic acid, ketones such as cyclohexanone, acetone, and butanone, ethers such as tetrahydrofuran, fluorinated alkanes such as chloroform, pyrrolidones such as pyrrolidine and N-methylpyrrolidone (NMP), and amides such as N,N-dimethylformamide (DMF), N-methylformamide, and N,N-diethylformamide.

[0097] In some preferred embodiments, the solvent A preferably includes at least one selected from the group consisting of pyrrolidone solvents and amide solvents, and more preferably includes at least one selected from the group consisting of N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF).

[0098] In addition, the concentration of the heat-resistant polymer in the dope including the heat-resistant polymer is not particularly limited. In some preferred embodiments, the concentration of the heat-resistant polymer in the dope is preferably 0.05 to 0.15% by mass, and more preferably 0.08 to 0.10% by mass.

[0099] In the case where the heat-resistant polymer nanofiber membrane is loaded with the inorganic ceramic filler particles, there is no particular limitation on the loading method. In some specific embodiments, the inorganic ceramic filler particles can be added to the spinning solution. In this case, the concentration of the inorganic ceramic filler particles in the spinning solution can be 0.1 to 5 mass%, preferably 1 to 2 mass%.

[0100] In step (2), when the solution containing the electrolyte material and the lithium salt is coated on at least one side of the heat-resistant polymer nanofiber membrane, the coating can be performed by a method known in the art, for example, a coating method such as brushing, spraying, drop coating, flow coating, and the like.

[0101] In step (2), when the heat-resistant polymer nanofiber membrane is immersed in the solution containing the electrolyte material and the lithium salt, the heat-resistant polymer nanofiber membrane can be completely immersed or partially immersed in the solution.

[0102] In step (2), there is no particular limitation on the solvent B used to dissolve the electrolyte material and the lithium salt in the solution containing the electrolyte material and the lithium salt, as long as the heat-resistant polymer nanofiber membrane is not dissolved. Examples of the solvent B include, without limitation, for example, ketones such as cyclohexanone, acetone, butanone, and the like, ethers such as tetrahydrofuran, and the like, fluoroalkanes such as chloroform, and the like, nitrile solvents such as acetonitrile, and the like.

[0103] In some preferred embodiments, the solvent B preferably includes at least one selected from the group consisting of ether solvents and nitrile solvents, more preferably at least one selected from the group consisting of tetrahydrofuran and acetonitrile.

[0104] In some specific embodiments, the electrolyte material and the lithium salt are dissolved in the solvent B in a specific ratio. As the ratio, the molar ratio of the repeating unit of polyether (-CH2CH2O-, EO) of the electrolyte material to lithium (Li) in the lithium salt is preferably 1:1 to 20:1, more preferably 5:1 to 15:1.

[0105] In addition, the above-described additives of the present application can be optionally added to the solution containing the electrolyte material and the lithium salt as needed.

[0106] Through step (2), the heat-resistant polymer nanofiber membrane can be complexed with the electrolyte material and the lithium salt (i.e., a composite is obtained).

[0107] In the present application, the method for producing a polymer-based solid-state electrolyte membrane further includes (3) subjecting the composite obtained in step (2) to a multi-step drying process in which reduced pressure drying (drying process A) is performed first, followed by atmospheric pressure drying (drying process B). More specifically, the reduced pressure drying can be vacuum drying, and the pressure can be -10 MP to -25 MP.

[0108] In addition, the drying treatment A can be performed at a temperature of, for example, 50°C to 120°C, and the drying treatment B can be performed at a temperature of, for example, 50°C to 120°C.

[0109] The atmosphere for the drying treatment is not particularly limited, and can be an air atmosphere, an air atmosphere adjusted in oxygen partial pressure, or an inert gas atmosphere such as nitrogen or argon.

[0110] <solid-state electrolyte battery>

[0111] The solid-state electrolyte battery of the present application includes a positive electrode, a negative electrode, a solid-state electrolyte film interposed between the positive electrode and the negative electrode, and the solid-state electrolyte film includes the above-described polymer-based solid-state electrolyte film of the present application.

[0112] In the present application, a button cell, a cylindrical cell, or a pouch cell can be constructed.

[0113] The solid-state electrolyte battery of the present application can be operated at a high temperature, and generally can be subjected to secondary charge-discharge at a temperature of 60°C to 250°C.

[0114] In the battery of the present application, the solid-state electrolyte film can be a single layer or a multilayer structure. When the solid-state electrolyte film is a multilayer structure, at least one layer thereof is the above-described polymer-based solid-state electrolyte film of the present application.

[0115] The positive electrode is composed of, for example, a positive electrode current collector such as a metal foil and a positive electrode active material layer formed on the positive electrode current collector. The positive electrode current collector can use a foil of a metal stable at the potential range of the positive electrode such as aluminum, a thin film having a surface layer of the metal, or the like. The positive electrode active material layer contains a positive electrode active material, a conductive material. From the viewpoint of adhesiveness to the positive electrode current collector and the like, the positive electrode active material layer preferably contains a binding material or the like.

[0116] As the positive electrode active material, a lithium complex oxide can be used. Examples include Li a CoO2, Li a NiO2, Li a MnO2, Li a CO b Ni 1-b O2, Li a CO b M 1-b O c , Li a Ni 1-b M b O c , Li a Mn2O4, Li a Mn 2-b M bO4, LiMePO4, Li2MePO4F. Here, M can be, for example, Na, Mg, Ca, Zn, Ga, Ge, Sn, Sc, Ti, V, Cr, Y, Zr, W, Mn, Fe, Co, Ni, Cu, Zn, Al, Cr, Pb, Sb, Bi, and B; Me contains at least a transition element (for example, Mn, Fe, Co, Ni, etc.); 0≤a≤1.2, 0≤b≤0.9, 2.0≤c≤2.3.

[0117] In order to further improve the safe, efficient, and stable operation of the special solid-state lithium metal battery in a high-temperature environment, as the positive electrode active material, lithium cobaltate (LiCoO2), lithium manganate (LiMn2O4), lithium iron phosphate (LiFePO4), or ternary material (NCM / NCA) is preferably used.

[0118] As the conductive material contained in the positive electrode active material layer, for example, carbon powder such as carbon black, acetylene black, ketjen black, and graphite can be used, and one kind alone or two or more kinds in combination can be used.

[0119] As the binder material contained in the positive electrode active material layer, for example, fluorine-based polymer, rubber-based polymer, PEO, PAN, polyimide-based resin, acrylic-based resin, and polyolefin-based resin can be used, and one kind alone or two or more kinds in combination can be used. Preferably, from the viewpoint of further improving the adhesion to the electrolyte membrane, PEO and / or PEA is used.

[0120] In addition, lithium salt can also be included in the positive electrode active material layer, and the same as those used in the electrolyte membrane can be listed.

[0121] The positive electrode can be obtained, for example, by coating / drying a positive electrode composite slurry containing a positive electrode active material, a binder material, a conductive material, and the like on a positive electrode current collector, thereby forming a positive electrode active material layer on the positive electrode current collector.

[0122] In some specific embodiments, the positive electrode active material, the binder material / lithium salt (such as LiTFSI) composite, and the conductive material are ball milled, a slurry of a certain viscosity is formed using an organic solvent (such as acetonitrile or NMP or a mixed solution thereof), and then uniformly coated on an aluminum foil or a carbon-coated aluminum foil, and dried. Here, the drying temperature can be 40-80°C, the drying can be performed under reduced pressure (vacuum), and the drying time can be 12-72 hours, for example, 24-48 hours. The ratio of the positive electrode active material, the binder material / lithium salt composite, and the conductive material is 30-90:10-50:5-30.

[0123] The negative electrode, for example, has a negative electrode current collector such as a metal foil and a negative electrode active material layer formed on the negative electrode current collector. The negative electrode current collector can use a foil of a metal stable in the potential range of the negative electrode such as copper, a thin film having a surface layer of the metal, or the like. The negative electrode active material layer, for example, contains a negative electrode active material, a binder material, a thickening material, and the like.

[0124] The negative electrode, for example, can be obtained by coating / drying a negative electrode composite slurry containing a negative electrode active material, a binder material on a negative electrode current collector, thereby forming a negative electrode active material layer on the negative electrode current collector, and rolling the negative electrode active material layer.

[0125] As the negative electrode active material contained in the negative electrode active material layer, there is no particular limitation as long as it is a material capable of occluding / discharging lithium ions, and examples include a carbon material, a metal capable of forming an alloy with lithium or an alloy compound containing the metal, and the like. As the carbon material, there can be used natural graphite, hard graphitizable carbon, artificial graphite, and the like, and as the alloy compound, there can be used a compound containing at least one metal capable of forming an alloy with lithium.

[0126] As the binder material contained in the negative electrode active material layer, there can be used, for example, those same as in the case of the positive electrode.

[0127] In addition, the negative electrode can also be a lithium metal negative electrode. As the forming material of the lithium metal negative electrode, there can be cited lithium monomer or a lithium metal alloy. As the lithium metal alloy, there can be used, for example, Li-B, Li-Al, Li-Mg, Li-Si, Li-Sn, Cu-Ta-Li alloy, and the like, in which the content of lithium in the alloy is 30% to 95%.

[0128] In some preferred embodiments, from the viewpoint of further improving the safety, structural stability, and cycle life of the battery in a high-temperature environment, and even ensuring high stability, high reversibility, and low interface impedance at a working condition of up to 200°C, the negative electrode of the present application includes a lithium metal alloy negative electrode. This is because, compared with pure lithium metal (melting point 180.5°C) which is easy to soften, melt, and even cause interface side reactions at a high temperature of 150°C, the lithium metal alloy material has better heat resistance.

[0129] Examples

[0130] The embodiments of the present application will be described in detail below with reference to Examples, but it will be understood by those skilled in the art that the following Examples are for illustration only and should not be taken as limiting the scope of the present application. In the Examples, specific conditions not mentioned are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained commercially.

[0131] <TEST METHODS>

[0132] (Obtaining of charge-discharge curves)

[0133] The constant current test method was used, specifically, constant current charging was first performed and then constant current discharging was performed, thereby obtaining the constant current charge-discharge curve (voltage-time / capacity curve). The charge-discharge process can be performed more than once as needed. In the figures of the present application, when the nth charge-discharge cycle process is performed, it can be marked as the nth circle, and the results obtained in the first charge-discharge process are shown without marking.

[0134] The test voltage range of all batteries was 2.5V-3.8V, the rate current range was 0.02-0.5C, and the test temperature was adjusted according to the experimental needs (usually in the range of 80℃-160℃).

[0135] According to the constant current charge-discharge curve (voltage-time / capacity curve), the charge / discharge capacity, energy and open circuit voltage (OCV) and other parameters such as working voltage platform were obtained, so as to analyze the cycle life and rate performance of the solid-state battery.

[0136] (Evaluation of self-discharge behavior at high temperature)

[0137] The obtained solid-state battery was charged to a voltage of 3.8V at a current of 0.1C. After charging, the solid-state battery was placed in an environment of 160℃ for 24 hours, and the change in voltage due to self-discharge during the placement process was measured.

[0138] <Example 1>

[0139] (Preparation of solid electrolyte membrane)

[0140] A polyacrylonitrile (PAN) nanofiber membrane was obtained by constructing a three-dimensional nanometer network structure using polyacrylonitrile (PAN) through electrospinning technology, and then densification treatment was realized on it using a simple calendering process (the thickness of the densified membrane was reduced by 30% compared to the thickness of the initial membrane obtained by electrospinning, which was 100%).

[0141] Further, PEO and LiFSI were dissolved in acetonitrile solvent at a ratio of 15:1 in terms of EO:Li molar ratio. Subsequently, the densified PAN nanofiber membrane was immersed in the acetonitrile solution of PEO and LiFSI. Subsequently, it was vacuum dried at 60℃ for 24h to obtain a high-temperature-resistant composite solid electrolyte.

[0142] Subsequently, the high-temperature-resistant composite solid electrolyte membrane was cut into a circular state with a diameter of 18mm according to the needs of the battery (see Figure 1 ).

[0143] (Construction of battery)

[0144] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material, PEO / LiFSI (mass ratio of PEO / LiFSI was 2:1) and conductive carbon powder super P were used as additives, and acetonitrile was used as a solvent (mass ratio of LiFeP04, PEO / LiFSI and conductive carbon powder was 8:1:1). After ball milling the above-mentioned substances, the slurry with a certain viscosity was prepared by using acetonitrile, and then uniformly coated on an aluminum foil. The positive electrode sheet was obtained by vacuum drying at 60°C for 24h, and further cut into a circle with a diameter of 14mm. The surface loading was 5mg / cm 2 .

[0145] Li-B alloy was used as the negative electrode (diameter 14mm).

[0146] The button cell was assembled in the positive electrode-electrolyte-negative electrode mode. The constant current charge-discharge test of the assembled solid-state battery was carried out at 80°C (see Figure 2 ).

[0147] <Example 2>

[0148] (Preparation of solid electrolyte film)

[0149] The high-temperature-resistant composite solid electrolyte film was prepared in the same manner as in Example 1, and was cut into a circle with a diameter of 18mm.

[0150] (Construction of the battery)

[0151] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material, PEO / LiFSI (mass ratio of PEO / LiFSI was 2:1) and conductive carbon powder super P were used as additives, and acetonitrile was used as a solvent (mass ratio of LiFeP04, PEO / LiFSI and conductive carbon powder was 7:2:1). After ball milling the above-mentioned substances, the slurry with a certain viscosity was prepared by using acetonitrile and NMP, and then uniformly coated on an aluminum foil. The positive electrode sheet was obtained by vacuum drying at 60°C for 24h, and the prepared positive electrode sheet was cut into a circle with a diameter of 14mm. The unit surface loading of LiFeP04 was 10mg / cm 2 .

[0152] Li-B alloy was used as the negative electrode (diameter 14mm).

[0153] The button cell was assembled according to the positive electrode-electrolyte-negative electrode layer-by-layer stacking mode. The constant current charge-discharge test of the assembled solid-state battery was carried out at 130°C (see Figure 3 ).

[0154] <Example 3>

[0155] (Preparation of solid electrolyte membrane)

[0156] A polyacrylonitrile (PAN) nanofiber membrane was prepared by electrospinning using polyacrylonitrile (PAN) to construct a three-dimensional nanonetwork structure, and then densification treatment was performed on the same using a simple calendering process (thickness reduction of 40% relative to the initial membrane obtained by electrospinning, 100%).

[0157] Further, PEO and LiTFSI were dissolved in acetonitrile solvent at a ratio of 11:1 in terms of the molar ratio of EO:Li. Subsequently, the densified PAN nanofiber membrane was immersed in the acetonitrile solution of PEO and LiTFSI. Subsequently, it was vacuum-dried at 70°C for 24h to obtain a high-temperature-resistant composite solid electrolyte. Subsequently, the high-temperature-resistant composite solid electrolyte membrane was cut into a circular shape with a diameter of 18mm according to the needs of the battery.

[0158] (Construction of battery)

[0159] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material, and PEO / LiTFSI (mass ratio of PEO / LiTFSI was 2:1), conductive carbon powder super P were used as additives, and acetonitrile was used as a solvent (the mass ratio of LiFeP04, PEO / LiTFSI and conductive carbon powder was 65:25:1). After ball milling the above-mentioned substances, they were adjusted into a slurry with a certain viscosity by dissolving them in acetonitrile and NMP, and then uniformly coated on an aluminum foil, vacuum-dried at 60°C for 24h to obtain a positive electrode sheet, and the prepared positive electrode sheet was cut into a circular shape with a diameter of 14mm, and the unit surface loading of LiFeP04 was 12mg / cm 2 .

[0160] Li-B alloy was used as the negative electrode (diameter 14mm).

[0161] According to the positive electrode-electrolyte-negative electrode layer stacking mode, a button cell was assembled. And the assembled solid-state battery was tested by constant current charge-discharge test (see Figure 4 ) and evaluated the self-discharge behavior at high temperature (see Figure 5 ).

[0162] <Example 4>

[0163] (Preparation of solid electrolyte membrane)

[0164] The high-temperature-resistant composite solid electrolyte membrane was prepared in the same manner as in Example 3, and was cut into a circular shape with a diameter of 18mm.

[0165] (Construction of battery)

[0166] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material. And using PEO / LiTFSI (the mass ratio of PEO / LiTFSI was 2:1), conductive carbon powder super P as an additive, acetonitrile as a solvent (in which the mass ratio of LiFeP04, PEO / LiTFSI and conductive carbon powder was 60:30:1). After ball milling the above-mentioned substances, using acetonitrile and NMP to dissolve and adjust the viscosity of the slurry, then uniformly coated on the aluminum foil, vacuum dried at 60°C for 24h to obtain the positive electrode sheet, the prepared positive electrode sheet was cut into a circular shape with a diameter of 14mm, and the unit surface load of LiFeP04 was 18mg / cm 2 .

[0167] Li-B alloy was used as the negative electrode (diameter 14mm).

[0168] The assembled button cell was tested by constant current charge-discharge test at 160°C environment (see Figure 6 ).

[0169] <Example 5>

[0170] (Preparation of solid electrolyte membrane)

[0171] Polyvinylpyrrolidone (PVP) was used to construct a three-dimensional nanometer network structure by electrospinning technology to obtain PVP nanofiber membrane, and a simple calendering process was used to realize the densification treatment.

[0172] Further, PEA and LiTFSI were dissolved in acetonitrile solvent at a mass ratio of 2:1. Then the densified PVP nanofiber membrane was immersed in the acetonitrile solution of PEA and LiTFSI. Then it was vacuum dried at 60°C for 24h to obtain a high-temperature-resistant composite solid electrolyte. The prepared high-temperature-resistant composite solid electrolyte membrane was cut into an oblong film piece with a size of 11cmm x 60mm as the electrolyte membrane of the soft package battery.

[0173] (Construction of battery)

[0174] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material, and PEA / LiTFSI (mass ratio of PEA / LiTFSI 2:1), conductive carbon powder super P were used as additives, and acetonitrile was used as the solvent (mass ratio of LiFeP04, PEA / LiTFSI and conductive carbon powder 70:20:1). After ball milling the above-mentioned substances, they were adjusted to a certain viscosity slurry by dissolving in acetonitrile and NMP, and then uniformly coated on an aluminum foil. The positive electrode sheet was obtained by vacuum drying at 80°C for 24h. The prepared positive electrode sheet was cut into a rectangle of 10cm x 5cm. The unit surface loading of LiFeP04 was 30mg / cm 2 .

[0175] Li-B alloy was used as the negative electrode (10cm x 5cm).

[0176] According to the positive electrode-electrolyte-negative electrode stack, a soft package battery was assembled. The performance test of the assembled solid-state battery was carried out in an environment of 160°C (see Figure 7 ).

[0177] <Comparative Example 1>

[0178] (Preparation of solid-state electrolyte film)

[0179] PEO and LiTFSI were dissolved in acetonitrile solvent at a molar ratio of EO:Li 11:1. Then the solution was placed in a mold (circular mold with a diameter of 18mm), and after cooling, an electrolyte film was formed. The thickness was about 100μm. Then PEO solid-state electrolyte was obtained after vacuum drying at 70°C for 24h.

[0180] (Construction of the battery)

[0181] In the preparation of the positive electrode, lithium iron phosphate (LiFeP04) was selected as the positive electrode active material. And PEO / LiTFSI (mass ratio of PEO / LiTFSI 2:1), conductive carbon powder super P were used as additives, and acetonitrile was used as the solvent (mass ratio of LiFeP04, PEO / LiTFSI and conductive carbon powder 8:1:1). After ball milling the above-mentioned substances, they were adjusted to a certain viscosity slurry by dissolving in acetonitrile and NMP, and then uniformly coated on an aluminum foil. The positive electrode sheet was obtained by vacuum drying at 60°C for 24h. The prepared positive electrode sheet was cut into a circle with a diameter of 14mm. The unit surface loading of LiFeP04 was 7mg / cm 2 .

[0182] Li-B alloy was used as the negative electrode (diameter 14mm).

[0183] The button cell was assembled according to the stacking mode of positive electrode-electrolyte-negative electrode layer. The assembled solid-state battery was tested by constant current charge and discharge at 140°C (see Figure 8 ).

[0184] The test results showed that under the high temperature condition of 140°C, the PEO electrolyte film was decomposed, resulting in short circuit of the battery. It was inferred that under the high temperature condition of 160°C, the battery was difficult to realize normal charge and discharge.

[0185] <Comparative Example 2>

[0186] A commercialized polyimide (PI) film was purchased as the high-temperature solid-state battery separator, with a thickness of about 20 μm. PEO and LiTFSI were dissolved in acetonitrile solvent at a molar ratio of EO:Li of 11:1. Then the solution was coated on the surface of the PI film. Then the PEO solid-state electrolyte was obtained after vacuum drying at 70°C for 24 h. Then the high-temperature resistant composite solid-state electrolyte film was cut into a circular state with a diameter of 18 mm according to the needs of the battery.

[0187] (Construction of the battery)

[0188] In the preparation of the positive electrode, lithium iron phosphate (LiFePO4) was selected as the positive electrode active material. PEO / LiTFSI (mass ratio of PEO / LiTFSI was 2:1), conductive carbon powder super P were used as additives, and acetonitrile was used as a solvent (the mass ratio of LiFePO4, PEO / LiTFSI and conductive carbon powder was 8:1:1). After ball milling the above-mentioned substances, the slurry with a certain viscosity was prepared by dissolving them in acetonitrile and NMP, and then uniformly coated on an aluminum foil. The positive electrode sheet was obtained by vacuum drying at 60°C for 24 h. The prepared positive electrode sheet was cut into a circular shape with a diameter of 14 mm, and the unit surface loading of LiFePO4 was 12 mg / cm 2 .

[0189] Li-B alloy was used as the negative electrode (diameter 14 mm).

[0190] The button cell was assembled according to the stacking mode of positive electrode-electrolyte-negative electrode layer. The assembled solid-state battery was tested by constant current charge and discharge at 160°C (see Figure 9 ).

[0191] The test results showed that the commercial PI solid-state electrolyte film was inferior to the solid-state battery of Example 3 in terms of electrochemical performance under the high temperature condition of 160°C, due to insufficient ion migration channels.

[0192] It should be noted that although the technical solutions of the present application are introduced by specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0193] Embodiments of the application have been described above, with the understanding that these embodiments are exemplary only and are not restrictive of the disclosed embodiments. Many modifications and variations of the described embodiments are possible in light of the above teachings. The selection of terms to be used in the description is not intended to limit the scope of the embodiments described herein, but rather is intended to best describe the principles of the embodiments, practical application, or technical improvements in the art, or to enable other skilled practitioners to understand the embodiments disclosed herein.

Claims

1. A polymer-based solid electrolyte membrane, characterized by, The polymer-based solid electrolyte membrane includes: a heat-resistant polymer nanofiber membrane, an electrolyte material impregnated and / or coated on the heat-resistant polymer nanofiber membrane, and a lithium salt, The heat-resistant polymer nanofiber membrane is formed into a membrane shape by free interweaving of fibers of a heat-resistant polymer, The heat-resistant polymer is at least one selected from the group consisting of polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyetherimide (PEI), aromatic polyamide, polyphenylene oxide (PPO), or polyaryletherketone. The electrolyte material is solid and is at least one selected from the group consisting of polyethylene oxide (PEO) or polyethylene glycol diamine (PEA).

2. The polymer-based solid electrolyte membrane according to claim 1, characterized by, The lithium salt includes an imide lithium salt; and / or A molar ratio of a repeating unit (EO) of the polyether in the electrolyte material to lithium (Li) in the lithium salt is 1:1 to 20:

1.

3. The polymer-based solid electrolyte membrane according to claim 1 or 2, characterized by, The heat-resistant polymer nanofiber membrane is loaded with inorganic ceramic filler particles.

4. The polymer-based solid electrolyte membrane according to claim 3, characterized by, The inorganic ceramic filler particles are at least one selected from the group consisting of an oxide-based compound, LLZO (Li7La3Zr2O 12 ), LAGP (Li 1.5 Al 0.5 Ge 1.5 (PO4)3), LATP, LiAlO2, a nitride-based compound, and / or The inorganic ceramic filler particles are nano- or sub-micron particles.

5. The method for producing a polymer-based solid electrolyte membrane according to any one of claims 1 to 4, characterized by, The method includes the following steps: (1) preparing a heat-resistant polymer nanofiber membrane using an electrospinning method, (2) coating a solution containing an electrolyte material and a lithium salt on at least one side of the heat-resistant polymer nanofiber membrane, and / or impregnating the heat-resistant polymer nanofiber membrane in a solution containing an electrolyte material and a lithium salt.

6. The method for producing a polymer-based solid electrolyte membrane according to claim 5, wherein In step (1), a spinning solution including the heat-resistant polymer is constructed into a three-dimensional nanonetwork structure by an electrospinning technique to form a membrane, and the membrane is densified using a calendering process, Preferably, the spinning solution includes a solvent A selected from at least one of a pyrrolidone-based solvent and an amide-based solvent.

7. The method for producing a polymer-based solid electrolyte membrane according to claim 5 or 6, characterized by, In step (2), the solution containing an electrolyte material and a lithium salt includes a solvent B including at least one selected from an ether-based solvent and a nitrile-based solvent.

8. The method for producing a polymer-based solid electrolyte membrane according to any one of claims 5 to 7, characterized by, Further included are: (3) performing a multi-step drying process on the composite obtained in step (2) by first performing reduced-pressure drying and then performing normal-pressure drying.

9. A solid-state electrolyte battery, characterized by It includes: a positive electrode, a negative electrode, a solid electrolyte membrane interposed between the positive electrode and the negative electrode, the solid electrolyte membrane including the polymer-based solid electrolyte membrane according to any one of claims 1 to 4.

10. The solid-state electrolyte battery of claim 9, wherein, The negative electrode includes a lithium metal alloy negative electrode.

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