Solid-liquid hybrid electrolyte membrane and method for manufacturing same

Abstract

The present disclosure relates to a method of manufacturing a solid-liquid mixed electrolyte membrane, comprising the steps of: (S1) preparing a dispersion comprising a plurality of solid polymer particles dispersed in a liquid electrolyte and a volatile organic solvent; (S2) applying the dispersion to a substrate, and then drying to form a porous structure; and (S3) pressurizing the porous structure to obtain a solid-liquid mixed electrolyte membrane, in which the solid polymer particles in the porous structure are deposited while being in contact with each other, and the porous structure includes pore structures formed between the solid polymer particles, and a liquid electrolyte surrounding the inside of the pores of the porous structure, in a portion in which the solid polymer particles are in surface contact with each other, or on the surfaces of the solid polymer particles, the content of the liquid electrolyte being 1% by weight to 20% by weight based on the total weight of the solid-liquid mixed electrolyte membrane, and the volatile organic solvent has a higher volatility than the liquid electrolyte.

Description

[0001] This application is a divisional application of a patent application for invention with an application date of January 20, 2021, an application number of 202180010261.X, and an invention title of "Solid-Liquid Hybrid Electrolyte Membrane and Method for Manufacturing the Same". Technical Field

[0002] This application claims priority to Korean Patent Application No. 10-2020-0007480, filed in Korea on January 20, 2020. The present disclosure relates to a solid-liquid hybrid electrolyte membrane and a method for manufacturing the same. Background Art

[0003] With the increasing use of transportation means, computers, and portable terminals, the importance of lithium secondary batteries has also increased. In particular, there is a great need to develop lithium secondary batteries that have a low weight and provide a high energy density. A lithium secondary battery can be obtained by interposing a separator between a positive electrode and a negative electrode and injecting a liquid electrolyte therein, or by interposing a solid electrolyte membrane between the positive electrode and the negative electrode.

[0004] However, in the case of a lithium ion battery using a liquid electrolyte, the negative electrode and the positive electrode are separated from each other by a separator. Therefore, when the separator is damaged by deformation or an external shock, a short circuit may occur, causing risks such as overheating or explosion.

[0005] In contrast, a lithium secondary battery (ALL SOLID STATE BATTERY) using a solid electrolyte has the advantage of enhanced safety and prevention of electrolyte leakage to improve the reliability of the battery. However, even when using a solid electrolyte, there is still a need to develop a solid electrolyte membrane having a high energy density and improved processability. In addition, in the case of a solid electrolyte, it has a low ionic conductivity, resulting in a problem of reduced performance.

[0006] Furthermore, such a solid electrolyte membrane shows a significantly greater thickness compared to the thickness of a conventional porous polyolefin-based separator, resulting in a loss of energy density. In these cases, a technical solution capable of overcoming these problems is needed. Summary of the Invention

[0007] Technical Problem

[0008] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure relates to providing a solid-liquid hybrid electrolyte membrane having a reduced thickness compared to commercially available solid electrolyte membranes while ensuring ionic conductivity.

[0009] The present disclosure also relates to providing a solid-liquid hybrid electrolyte membrane having improved mechanical strength even as a membrane thinner than commercially available solid electrolyte membranes.

[0010] In addition, the present disclosure relates to providing a solid-liquid hybrid electrolyte membrane that has an improved energy density per unit weight based on thickness even as a membrane thinner than a solid electrolyte membrane available as a product.

[0011] Further, the present disclosure relates to providing a method for manufacturing a solid-liquid hybrid electrolyte membrane that provides improved processability and an increased level of product completion.

[0012] These and other objects and advantages of the present disclosure will be understood from the following detailed description. In addition, it is to be readily understood that the objects and advantages of the present disclosure can be achieved by the means shown in the appended claims and combinations thereof.

[0013] Technical Solutions

[0014] In one aspect of the present disclosure, there is provided a method for manufacturing a solid-liquid hybrid electrolyte membrane according to any one of the following embodiments.

[0015] According to a first embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid hybrid electrolyte membrane, including the following steps: (S1) preparing a dispersion including a plurality of solid polymer particles dispersed in a liquid electrolyte and a volatile organic solvent;

[0016] (S2) applying the dispersion to a substrate and then drying to form a porous structure; and

[0017] (S3) pressing the porous structure to obtain a solid-liquid hybrid electrolyte membrane,

[0018] wherein the solid polymer particles in the porous structure are stacked while being in contact with each other, and the porous structure includes a pore structure formed between the solid polymer particles,

[0019] the liquid electrolyte surrounds the inside of the pores of the porous structure, a portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles,

[0020] the content of the liquid electrolyte is 1 wt% to 20 wt% based on the total weight of the solid-liquid hybrid electrolyte membrane, and

[0021] the volatile organic solvent has a higher volatility than the liquid electrolyte.

[0022] According to a second embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid hybrid electrolyte membrane as defined in the first embodiment, wherein the volatile organic solvent has a boiling point of 30°C to 200°C.

[0023] According to a third embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in the first embodiment or the second embodiment, wherein the volatile organic solvent includes acrylonitrile, methyl ethyl ketone, acetone, tetrahydrofuran, pentane, hexane, benzene, chloroform, ether, dichloromethane, ethyl acetate, acetonitrile, methanol, methylene chloride, carbon disulfide, carbon tetrachloride, or a mixture of two or more of them.

[0024] According to a fourth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to third embodiments, wherein the solid polymer particles include engineering plastic resins.

[0025] According to a fifth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to fourth embodiments, wherein the engineering plastic resins include any one selected from polyphenylene sulfide, polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyoxymethylene, polycarbonate, polypropylene, polyethylene, and poly(methyl methacrylate), or a mixture of two or more of them.

[0026] According to a sixth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to fifth embodiments, wherein the liquid electrolyte includes an organic solvent and a lithium salt, and the organic solvent is at least one of a linear carbonate, a linear ester, and a linear ether.

[0027] According to a seventh embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to sixth embodiments, wherein the weight ratio of the volatile organic solvent to the liquid electrolyte is 83:17 to 66:34.

[0028] According to an eighth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to seventh embodiments, wherein the pressing in step (S3) is a step of physically or chemically bonding the solid polymer particles to each other to obtain a porous structure having a pore structure formed between the solid polymer particles.

[0029] According to a ninth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to eighth embodiments, wherein the substrate includes a porous polymer substrate or a non-woven mesh substrate.

[0030] According to a tenth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in any one of the first to ninth embodiments, wherein the pores of the substrate are filled with the liquid electrolyte.

[0031] According to an eleventh embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane including a plurality of solid polymer particles and a liquid electrolyte,

[0032] wherein the solid polymer particles are stacked while being in contact with each other and include a porous structure having a pore structure formed between the solid polymer particles,

[0033] the liquid electrolyte surrounds the inside of the pores of the porous structure, a portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles, and

[0034] the content of the liquid electrolyte is 1 wt% to 20 wt% based on the total weight of the solid-liquid mixed electrolyte membrane.

[0035] According to a twelfth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in the eleventh embodiment, the solid-liquid mixed electrolyte membrane further including a porous polymer substrate or a non-woven mesh substrate.

[0036] According to a thirteenth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in the eleventh or twelfth embodiment, wherein the pores of the substrate are filled with the liquid electrolyte.

[0037] According to a fourteenth embodiment of the present disclosure, there is provided a lithium ion secondary battery including a positive electrode, a negative electrode, and a solid-liquid mixed electrolyte membrane interposed between the negative electrode and the positive electrode, wherein the solid-liquid mixed electrolyte membrane is the same as that defined in any one of the eleventh to thirteenth embodiments, and the negative electrode, the positive electrode, or both include a solid electrolyte material.

[0038] Advantageous Effects

[0039] According to an embodiment of the present disclosure, a deformable solid-liquid hybrid electrolyte membrane can be obtained by using solid polymer particles instead of inorganic particles.

[0040] In addition, since particulate polymers that can be compressed are used, a solid-liquid hybrid electrolyte membrane having improved mechanical strength can be provided. Also, since a solid electrolyte is not used, a solid-liquid hybrid electrolyte membrane that can be deformed by external pressure can be provided. Further, the polymer particles are physically bonded to each other, which is advantageous for porosity and pore channel formation.

[0041] According to an embodiment of the present disclosure, since an adhesive polymer is not used, a solid-liquid hybrid electrolyte membrane showing low resistance can be provided.

[0042] Meanwhile, according to an embodiment of the present disclosure, a small amount of liquid electrolyte is used to ensure improved ionic conductivity compared to a conventional solid electrolyte battery while preventing electrolyte leakage.

[0043] In addition, a solid-liquid hybrid electrolyte membrane having an improved energy density per unit weight based on thickness can be provided.

[0044] Further, a method for manufacturing a solid-liquid hybrid electrolyte membrane that provides improved processability and an increased level of product completion can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the following disclosure, are used to provide a further understanding of the technical features of the present disclosure. Accordingly, the present disclosure should not be construed as being limited to the drawings. Also, the shapes, sizes, scales, or ratios of some of the constituent elements in the drawings may be exaggerated for clearer description.

[0046] Figure 1 is a schematic diagram illustrating a method for manufacturing a solid-liquid hybrid electrolyte membrane according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure on the basis of the principle that allows the inventor to appropriately define the terms for the best interpretation. Therefore, the description presented herein is only a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure. Thus, it should be understood that other equivalents and improvements can be made without departing from the scope of the present disclosure.

[0048] Throughout the specification, the expression "a part includes an element" does not exclude the existence of any other element, but means that the part may further include other elements, unless otherwise indicated.

[0049] As used herein, the terms "about", "substantially", or the like, when implying acceptable manufacturing and material tolerances unique to the claimed meaning, are used to mean starting from or contiguous to the claimed value, and are used to prevent an inadvertent infringer from inappropriately using the claimed disclosure including the exact or absolute values provided to assist in understanding the present disclosure.

[0050] As used herein, the expression "A and / or B" means "A, B, or both of them".

[0051] The specific terms used in the following description are for illustrative purposes and are not restrictive. Terms such as "right", "left", "top surface", and "bottom surface" indicate directions in the drawings in which they are referred to. Terms such as "inward" and "outward" respectively indicate the directions toward and away from the geometric center of the corresponding device, system, and its elements. "Front", "rear", "top", and "bottom" and related words and expressions indicate positions and points in the drawings in which they are referred to and should not be restrictive. These terms include the words listed above, their derivatives, and words with similar meanings.

[0052] The present disclosure relates to a solid-liquid mixed electrolyte membrane and a method for manufacturing the same.

[0053] In one aspect of the present disclosure, a solid-liquid mixed electrolyte membrane including a plurality of solid polymer particles and a small amount of liquid electrolyte is provided. Herein, the liquid electrolyte covers a portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles, and the amount of the liquid electrolyte used herein is small. Thus, even when the solid-liquid mixed electrolyte membrane is pressurized during its manufacture, there is no leakage of the electrolyte, and the solid-liquid mixed electrolyte membrane provides an ionic conductivity equal to or similar to that of a conventional solid electrolyte membrane and shows a uniform ionic conductivity.

[0054] In the solid-liquid mixed electrolyte membrane, the solid polymer particles are stacked while being in contact with each other, and a small amount of liquid electrolyte is introduced into the pore channels formed by the solid polymer particles or the liquid electrolyte covers a portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles.

[0055] The solid-liquid mixed electrolyte membrane can be deformed by using polymer particles instead of inorganic particles, and can be deformed by external pressurization by using polymer particles instead of inorganic particles. In addition, the solid polymer particles are physically bonded to each other, which is advantageous for porosity and pore channel formation.

[0056] At the same time, since the solid-liquid mixed electrolyte membrane includes a small amount of liquid electrolyte, electrolyte leakage can be prevented while ensuring improved ionic conductivity compared to a conventional solid electrolyte membrane.

[0057] The solid-liquid mixed electrolyte membrane can be obtained by coating a porous structure formed by stacking solid polymer particles with a small amount of liquid electrolyte.

[0058] The present inventors have conducted in-depth research to obtain a solid-liquid mixed electrolyte membrane, particularly to develop a solid-liquid mixed electrolyte membrane having a high energy density per unit weight based on thickness.

[0059] The thin-film type solid-liquid mixed electrolyte membrane can be obtained by the following method: first, a thick film is formed by using a porous structure formed by solid polymer particles, and then pressurization is carried out to obtain a thin film.

[0060] However, in order to obtain a thin-film type electrolyte membrane, even after the porous structure is formed, the porous structure should maintain its solid state, i.e., shape, while the dispersion applied to the substrate for forming the porous structure should maintain its fluidity during application.

[0061] To solve the above-mentioned problems, a solvent having a higher volatility than the liquid electrolyte is used according to the present disclosure, thereby providing a thin-film type solid-liquid mixed electrolyte membrane.

[0062] Figure 1It is a schematic diagram illustrating a method of manufacturing a solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure. Hereinafter, the present disclosure will be explained in more detail with reference to the accompanying drawings.

[0063] Referring to Figure 1 (a), a dispersion 14 including a plurality of solid polymer particles 11 dispersed in a liquid electrolyte 12 and a volatile organic solvent 13 was prepared.

[0064] The solid polymer particles 11 exist in a solid state at room temperature and are polymer materials having low solubility in the electrolyte.

[0065] Meanwhile, according to the present disclosure, the solid polymer particles are surrounded by the liquid electrolyte and preferably have low solubility in the liquid electrolyte. In addition, the solid polymer particles are preferably polymers having excellent chemical resistance.

[0066] In particular, when impregnated with a liquid electrolyte or an organic solvent that can be used as a component of the liquid electrolyte, such as ethylene carbonate: ethyl methyl carbonate = 30:70 (vol%), the solid polymer particles have a solubility of less than 30% by weight at 20°C to 30°C. More particularly, the solid polymer particles may have a solubility of less than 20%, less than 15%, or less than 10%. Therefore, even when the solid polymer particles are dispersed in the solvent, they can exist in a solid state.

[0067] In particular, the solid polymer particles may be engineering plastic resins.

[0068] Herein, the engineering plastic resins may include any one selected from polyphenylene sulfide (PPS), polyetheretherketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyoxymethylene, polycarbonate, polypropylene, polyethylene, and poly(methyl methacrylate)), or a mixture of two or more of them.

[0069] In the present disclosure, the engineering plastic resin may have a molecular weight of 100,000 - 10,000,000 Da.

[0070] Unlike the inorganic particles available in the conventional market, the solid polymer particles have compressibility. Accordingly, a lithium secondary battery having an increased energy density per unit weight based on thickness can be provided. In addition, a deformable solid-liquid hybrid electrolyte membrane can be provided by using solid polymer particles instead of a conventional solid electrolyte. The solid polymer particles have ductility and thus can physically or chemically adhere, bond, or interconnect under pressure or heating. As a result, the solid-liquid hybrid electrolyte membrane according to the present disclosure does not require a separate binder polymer. That is, the solid-liquid hybrid electrolyte membrane is free of a binder polymer. Accordingly, a solid-liquid hybrid electrolyte membrane showing a reduced resistance can be provided.

[0071] For example, the solid polymer particles may have an average particle diameter of 100 nm to 20 μm, 100 nm to 10 μm, 200 nm to 5 μm, or 500 nm to 2 μm. When the solid polymer particles have a particle diameter controlled within the above-defined range, an appropriate pore size can be obtained, short circuit can be prevented, and sufficient impregnation with a liquid electrolyte can be allowed.

[0072] The liquid electrolyte is present in the portion where the solid polymer particles are in surface contact with each other, or around the surface of the solid polymer particles, that is, all or at least a part of the surface of the solid polymer particles can be coated with the liquid electrolyte.

[0073] Due to the presence of the liquid electrolyte as described above, a solid-liquid hybrid electrolyte membrane having a high ionic conductivity can be provided.

[0074] According to an embodiment of the present disclosure, the liquid electrolyte cannot dissolve the solid polymer particles and has excellent chemical resistance and electrochemical resistance.

[0075] For example, the electrolyte is a salt having an A + B - structure, where A + includes alkali metal cations such as Li + , Na + , K + , or a combination thereof, and B - includes such as PF6 - , BF4 - , Cl - , Br - , I - , ClO4 - , AsF6 - , CH3CO2 - , CF3SO3 -, N(CF3SO2)2 - , C(CF2SO2)3 - , or an anion such as a combination thereof, wherein the salt is soluble or dissociable in an organic solvent such as propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), gamma-butyrolactone (γ-butyrolactone), or a mixture thereof, but is not limited thereto.

[0076] According to the present disclosure, the volatile organic solvent has a higher volatility than the liquid electrolyte. That is, the volatile organic solvent is a factor that rapidly evaporates after the dispersion is coated on the substrate as described below, while ensuring the fluidity of the dispersion, and thus assists in forming a porous structure.

[0077] Therefore, the volatile organic solvent may have a boiling point of 30 °C to 200 °C, 40 °C to 150 °C, or 50 °C to 100 °C.

[0078] In addition, the volatile organic solvent may have a boiling point that is 5 °C to 100 °C, 10 °C to 90 °C, or 30 °C to 80 °C lower than the boiling point of the liquid electrolyte used in the dispersion.

[0079] In addition, the volatile organic solvent may have a vapor pressure that is 10% to 10000%, 20% to 1000%, or 50% to 500% higher than the vapor pressure of the liquid electrolyte.

[0080] In addition, the volatile organic solvent cannot dissolve the solid polymer particles and has excellent chemical resistance and electrochemical resistance.

[0081] According to an embodiment of the present disclosure, the volatile organic solvent may include acrylonitrile, methyl ethyl ketone, acetone, tetrahydrofuran, pentane, hexane, benzene, chloroform, ether, dichloromethane, ethyl acetate, acetonitrile, methanol, methylene chloride, carbon disulfide, carbon tetrachloride, or a mixture of two or more of them.

[0082] Herein, the weight ratio of the liquid electrolyte to the volatile organic solvent may be 83:17 to 66:34, 50:50 to 34:66, or 17:83 to 9:91. When the weight ratio of the liquid electrolyte to the volatile organic solvent falls within the range defined above, post-treatment such as roll pressing can be advantageously performed after the dispersion is applied to the substrate, and the resulting solid-liquid mixed electrolyte membrane exhibits a qualified level of ionic conductivity.

[0083] Next, as Figure 1As shown in (b), the dispersion 14 is applied to the substrate 15 and then dried to form a porous structure (S2).

[0084] In the present text, the method of applying the dispersion to the substrate can be any method conventionally used in the art. For example, the method may include dip coating, spray coating, or drop coating.

[0085] In addition, the method of drying the dispersion can be any method conventionally used in the art without particular limitation.

[0086] However, preferably, the liquid electrolyte in the dispersion does not evaporate but remains therein while the volatile organic solvent evaporates.

[0087] Accordingly, the drying temperature can vary with the specific types of the liquid electrolyte and the volatile organic solvent. In particular, the dispersion can be dried in a temperature range where the liquid electrolyte does not evaporate while the volatile organic solvent evaporates.

[0088] In the present text, the substrate can be any one selected from a release film, a porous polymer substrate, and an electrode. When the substrate is a release film, the release film is removed from the finished solid-liquid mixed electrolyte film. The release film only serves as a mold in the manufacture of the solid-liquid mixed electrolyte film. Therefore, when the release film is applied to an electrochemical device such as a secondary battery, it is removed from the solid-liquid mixed electrolyte film and is not included as a structural element of the electrochemical device. In this way, by applying and drying the dispersion, a porous structure can be formed, which includes solid polymer particles stacked therein and a liquid electrolyte introduced into the space where the solid polymer particles are in surface contact with each other.

[0089] Then, as Figure 1 shown in (c), the porous structure is pressed to form a solid-liquid mixed electrolyte film.

[0090] In the present text, the solid polymer particles and the liquid electrolyte in the porous structure are rearranged by pressing to provide a thin-film type electrolyte film with a reduced thickness.

[0091] At the same time, the solid polymer particles are physically bonded to each other by pressing to provide a mixed electrolyte film with an increased bonding force. At the same time, in the present disclosure, the solid polymer particles have ductility and do not require a separate binder polymer. In this way, a solid-liquid mixed electrolyte film showing a reduced resistance can be obtained ( Figure 1 (d)).

[0092] Meanwhile, according to an embodiment of the present disclosure, the liquid electrolyte is present in a small amount after drying the dispersion. Accordingly, a solid-liquid hybrid electrolyte membrane having improved ionic conductivity compared to a conventional solid electrolyte membrane can be provided. For example, the content of the liquid electrolyte can be 1 wt% to 20 wt% based on the total weight of the solid-liquid hybrid electrolyte membrane. More particularly, the content of the liquid electrolyte can be 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, or 5 wt% or more, and 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, or 16 wt% or less based on the total weight of the solid-liquid hybrid electrolyte membrane. Meanwhile, according to an embodiment of the present disclosure, a solid-liquid hybrid electrolyte membrane having high ionic conductivity even when the liquid electrolyte is present in a small amount can be provided. This is because the liquid electrolyte is uniformly dispersed on the surface of the solid polymer particles or at a portion where the solid polymer particles are in surface contact with each other.

[0093] As described above, when incorporating such a small amount of the liquid electrolyte into the solid-liquid hybrid electrolyte membrane, the solid-liquid hybrid electrolyte membrane can have a porosity of 0 vol% to 49 vol%, 1 vol% to 40 vol%, 2 vol% to 20 vol%, or 5 vol% to 10 vol% based on the total volume of the solid polymer particles.

[0094] As used herein, the term "pore" can have various types of pore structures, and any type of pore having an average pore size that satisfies the above-defined average pore size as measured by using a porosimeter or as observed by field emission scanning electron microscopy (FE-SEM) falls within the scope of the present disclosure.

[0095] As described above, since the solid-liquid hybrid electrolyte membrane is uniformly impregnated with a small amount of the liquid electrolyte, a solid-liquid hybrid electrolyte membrane having a high ionic conductivity of 10 -4 S / cm to 5x10 -3 S / cm can be provided.

[0096] According to an embodiment of the present disclosure, the solid-liquid hybrid electrolyte membrane may further include a porous polymer substrate or a non-woven mesh substrate. In particular, the solid-liquid hybrid electrolyte membrane according to an embodiment of the present disclosure has a large amount of the liquid electrolyte and is impregnated with the liquid electrolyte. Accordingly, when forming the solid-liquid hybrid electrolyte membrane on the porous polymer substrate or the non-woven mesh substrate, or when inserting a separate porous polymer substrate or non-woven mesh substrate, there is an advantage of high mechanical strength. Meanwhile, according to an embodiment of the present disclosure, when the solid-liquid hybrid electrolyte membrane further includes a porous polymer substrate or a non-woven mesh substrate, the porous polymer substrate or the non-woven mesh substrate is preferably impregnated with the liquid electrolyte so that the internal pores can be filled with the liquid electrolyte.

[0097] In particular, the nonwoven web substrate may include polyolefins such as polyethylene or polypropylene, polyethylene terephthalate, polyester, polyamide, polyacetal, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenylene ether, polyphenylene sulfide, polyethylene naphthalate, or a mixture thereof.

[0098] Meanwhile, the solid polymer particles may be partially embedded in the pores of the nonwoven web substrate. Herein, a liquid electrolyte may surround the surfaces of the solid polymer particles and the substrate.

[0099] Meanwhile, the solid polymer particles may be disposed on at least one surface of the nonwoven web substrate. Herein, a liquid electrolyte may surround the surfaces of the solid polymer particles and the substrate.

[0100] According to an embodiment of the present disclosure, the solid-liquid mixed electrolyte membrane is a thin film that may have a thickness of 10 μm to 500 μm, 20 μm to 300 μm, or 40 μm to 100 μm. When manufacturing a secondary battery subsequently, such a thin film type separator according to an embodiment of the present disclosure can be provided, which is advantageous in terms of energy density.

[0101] Hereinafter, a secondary battery including the solid-liquid mixed electrolyte membrane according to the present disclosure will be explained. The secondary battery includes a negative electrode, a positive electrode, and a solid-liquid mixed electrolyte membrane interposed between the negative electrode and the positive electrode. Herein, the term "secondary battery" refers to a system that converts external electrical energy into chemical energy, stores the chemical energy, and then generates electricity when necessary. Generally, secondary batteries include lead storage batteries, nickel-cadmium batteries (NiCd), nickel-metal hydride storage batteries (NiMH), lithium-ion batteries, or the like. According to an embodiment of the present disclosure, the secondary battery may be a lithium-ion secondary battery.

[0102] The positive electrode includes a positive electrode current collector and a positive electrode active material layer formed on at least one surface of the positive electrode current collector, wherein the positive electrode active material layer includes a positive electrode active material and a conductive material, and may include at least one of an adhesive resin and a solid electrolyte material. In addition to this, the positive electrode active material layer may further include various additives to supplement or improve the electrochemical properties.

[0103] The positive electrode active material layer may have pores formed by vacant spaces between the positive electrode active material or the like, and thus may have a porous structure. The positive electrode active material layer may have a porosity of about 12 vol% to about 35 vol%.

[0104] The positive electrode active material is not particularly limited as long as it can be used as the positive electrode active material of a lithium ion secondary battery. Non-limiting examples of the positive electrode active material may include any one selected from the following: layered compounds such as lithium manganese composite oxides (LiMn2O4, LiMnO2, etc.), lithium cobalt oxide (LiCoO2), and lithium nickel oxide (LiNiO2), or those compounds substituted with one or more transition metals; such as those represented by the chemical formula Li 1+x Mn 2-x O4 (where x is 0 - 0.33), lithium manganese oxides such as LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); lithium vanadium oxides such as LiV3O8, LiV3O4, V2O5, and Cu2V2O7; Ni-site type lithium nickel oxides represented by the chemical formula LiNi 1-x M x O2 (where M is Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x is 0.01 - 0.3); lithium manganese composite oxides represented by the chemical formula LiMn 2-x M x O2 (where M is Co, Ni, Fe, Cr, Zn, or Ta), and x is 0.01 - 0.1) or Li2Mn3MO8 (where M is Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which Li is partially substituted with alkaline earth metal ions; disulfide compounds; and Fe2(MoO4)3, or a mixture of two or more of them.

[0105] Meanwhile, the negative electrode includes a negative electrode current collector and a negative electrode active material layer formed on at least one surface of the negative electrode current collector, where the negative electrode active material layer includes a negative electrode active material and a conductive material, and may include at least one of an adhesive resin and a solid electrolyte material. In addition, the negative electrode active material layer may further include various additives to supplement or improve electrochemical properties.

[0106] The negative electrode active material layer may have pores formed by void spaces between the negative electrode active material or the like, and thus may have a porous structure. The negative electrode active material layer may have a porosity of about 15 vol% to about 40 vol%.

[0107] The negative electrode active material can be any negative electrode active material as long as it can be used as the negative electrode active material of a lithium ion secondary battery. Specific examples of the negative electrode active material include any one selected from the following: carbons such as non-graphitized carbon and graphite-based carbon; such as Li x Fe2O3 (0 ≤ x ≤ 1), Li x WO2 (0 ≤ x ≤ 1), Sn x Me 1-x Me’y O z (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of Group 1, 2 or 3 in the periodic table, halogens; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8) and the like metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5, or the like; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; titanium oxides; and lithium titanium oxides, or two or more of them. According to a specific embodiment, the negative electrode active material may include a carbonaceous material and / or Si.

[0108] Meanwhile, according to the present disclosure, each of the positive electrode current collector and the negative electrode current collector includes a metal plate having conductivity and may be one appropriately selected depending on the polarity of the electrodes known in the field of secondary batteries.

[0109] According to the present disclosure, the conductive material is generally added in an amount of 1 wt% to 30 wt% based on the total weight of the mixture including the electrode active material. The conductive material is not particularly limited as long as it does not cause a chemical change in the corresponding battery and has conductivity. For example, the conductive material includes any one selected from the following: graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; conductive fibers such as carbon fibers or metal fibers; metal powders such as carbon fluoride, aluminum, or nickel powder; conductive whiskers such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxides; and conductive materials such as polyphenylene derivatives, or a mixture of two or more of them.

[0110] According to the present disclosure, the binder resin is not particularly limited as long as it is a component that assists in bonding the electrode active material and the conductive material and bonds to the current collector. Specific examples of the binder resin include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers, or the like. Generally, the binder resin can be used in an amount of 1 wt% to 30 wt% or 1 wt% to 10 wt% based on 100 wt% of the electrode active material layer.

[0111] Meanwhile, according to the present disclosure, if necessary, each electrode active material layer may include at least one additive, such as an oxidation stabilizer, a reduction stabilizer, a flame retardant, a heat stabilizer, an antifogging agent, or the like.

[0112] Preferably, the solid electrolyte material may be a solid electrolyte with high reduction stability. Since the solid electrolyte material is mainly used to conduct lithium ions, any material with a high ionic conductivity such as 10 -5 S / cm or greater, or 10 -5 S / cm or greater can be used, and the solid electrolyte material is not limited to any specific composition.

[0113] The solid electrolyte material may include at least one of a sulfide-based solid electrolyte material, an oxide-based solid electrolyte material, and a polymer solid electrolyte material.

[0114] The polymer solid electrolyte material may be a polymer solid electrolyte formed by adding a polymer resin to a solvated electrolyte salt, or a polymer gel electrolyte including a polymer resin impregnated with an organic electrolyte containing an organic solvent and an electrolyte salt, an ionic liquid, a monomer, or an oligomer, or the like.

[0115] Specific examples of the polymer solid electrolyte according to an embodiment of the present disclosure may include a polyether polymer, a polycarbonate polymer, an acrylate polymer, a polysiloxane polymer, a phosphazene polymer, a polyether derivative, an alkylene oxide derivative, a polyphosphate polymer, a poly agitation lysine, a polyester sulfide, a polyvinyl alcohol, a polyvinylidene fluoride, a polymer containing an ion dissociable group, or the like.

[0116] The polymer solid electrolyte may include a branched copolymer, a comb-like polymer, and a crosslinked polymer resin, including a polyethylene oxide (PEO, poly ethylene oxide) backbone copolymerized with a comonomer containing at least one amorphous polymer selected from PMMA, polycarbonate, polysiloxane (pdms), and phosphazene, or a mixture thereof.

[0117] In addition, the polymer gel electrolyte includes an organic electrolyte containing an electrolyte salt and a polymer resin, and the organic electrolyte is used in an amount of 60 parts by weight to 400 parts by weight based on the weight of the polymer resin. The polymer used for the gel electrolyte is not particularly limited, and specific examples thereof include polyether polymers, PVC polymers, PMMA polymers, polyacrylonitrile (PAN), polyvinylidene fluoride (PVdF), poly(vinylidene fluoride - hexafluoro propylene) (PVdF - HFP), or the like. Mixtures of these polymers can also be used.

[0118] In addition, the electrolyte salt can be an ionizable lithium salt represented by Li + X - Preferably, such a lithium salt can be selected from the group consisting of LiTFSI, LiCl, LiBr, LiI, LiClO4, LiBF4, LiB 10 Cl 10 , LiPF6, LiAsF6, LiSbF6, LiAlCl4, LiSCN, LiCF3CO2, LiCH3SO3, LiCF3SO3, LiN(SO2CF3)2, LiN(SO2C2F5)2, LiC4F9SO3, LiC(CF3SO2)3, (CF3SO2)2NLi, lithium chloroborate, lithium lower aliphatic carboxylate, lithium 4 - phenylborate imide, and combinations thereof. More preferably, the lithium salt can be LiTFSI (lithium bistrifluoromethanesulfonimide).

[0119] According to the present disclosure, the sulfide - based solid electrolyte material includes sulfur (S), has conductivity with metal ions belonging to Group 1 or Group 2 of the periodic table, and may include Li - P - S - based glass or Li - P - S - based glass ceramics. Non - limiting examples of the sulfide - based solid electrolyte include at least one of Li2S - P2S5, Li2S - LiI - P2S5, Li2S - LiI - Li2O - P2S5, Li2S - LiBr - P2S5, Li2S - Li2O - P2S5, Li2S - Li3PO4 - P2S5, Li2S - P2S5 - P2O5, Li2S - P2S5 - SiS2, Li2S - P2S5 - SnS, Li2S - P2S5 - Al2S3, Li2S - GeS2, Li2S - GeS2 - ZnS, or the like. However, the scope of the present disclosure is not limited thereto.

[0120] In addition, the oxide-based solid electrolyte material includes oxygen (O) and has the conductivity of metal ions belonging to Group 1 or Group 2 of the periodic table. Non-limiting examples of the oxide-based solid electrolyte include LLTO-based compounds, Li6La2CaTa2O 12 , Li6La2ANb2O 12 (where A is Ca or Sr), Li2Nd3TeSbO 12 , Li3BO 2.5 N 0.5 , Li9SiAlO8, LAGP-based compounds, LATP-based compounds, Li 1+x Ti 2-x Al x Si y (PO4) 3-y (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1), LiAl x Zr 2-y (PO4)3 (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1), LiTi x Zr 2-y (PO4)3 (where 0 ≤ x ≤ 1, 0 ≤ y ≤ 1), at least one of LISICON-based compounds, LIPON-based compounds, perovskite-based compounds, NASICON-based compounds, and LLZO-based compounds. However, the scope of the present disclosure is not limited thereto.

[0121] Meanwhile, the secondary battery according to the present disclosure can be obtained by forming an electrode assembly including one or more negative electrodes, a solid-liquid mixed electrolyte membrane, and a positive electrode stacked in sequence, and introducing the electrode assembly into a battery case. The electrode assembly can be provided in either a bi-cell type in which the outermost electrodes both have different polarities, or a mono-cell type in which the outermost electrodes both have the same polarity. In addition, the electrode assembly can be prepared in a jelly roll type, a stacked type, or a stacked / folded type depending on the desired battery characteristics.

[0122] According to an embodiment of the present disclosure, the lithium-ion battery can be provided in the form of a solid-state battery, and except for the electrode assembly, there is no need to additionally inject a liquid electrolyte into the battery case. Otherwise, in addition to the liquid electrolyte included in the solid-liquid mixed electrolyte membrane, a liquid electrolyte can be additionally injected. Here, when referring to the additionally injected liquid electrolyte, the solid-liquid mixed electrolyte membrane will be referred to.

[0123] Now, examples and test examples will be described. The following examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0124] Example 1

[0125] First, prepare a dispersion of powdered polyphenylene sulfide (average particle size: 10 μm) as solid polymer particles in a liquid electrolyte (ethylene carbonate: ethyl methyl carbonate = 3:7 (vol%), 1 M LiPF6, 0.5 wt% vinylene carbonate, 1 wt% fluoroethylene carbonate) and acetonitrile (Acentonitrile) as a volatile organic solvent at a weight ratio of 20:40:40.

[0126] Next, place a separator (polyethylene, thickness 9 μm) on a peeled poly(ethylene terephthalate) (PET) film, and apply 3 mL of the dispersion onto the separator. The resulting structure is dried overnight to obtain a solid-liquid mixed electrolyte film with a thickness of 53 μm. Then, roll pressing is performed to increase the contact force between particles and / or between particles and the separator and reduce the thickness, thereby providing a solid-liquid mixed electrolyte film with a thickness of 33 μm. After that, the peeled poly(ethylene terephthalate) film is removed.

[0127] Example 2

[0128] A solid-liquid mixed electrolyte film is obtained in the same manner as in Example 1, except that the dispersion has a component weight ratio of 20:20:60, the solid-liquid mixed electrolyte film has a thickness of 48 μm after drying and a thickness of 26 μm after roll pressing.

[0129] Example 3

[0130] A solid-liquid mixed electrolyte film is obtained in the same manner as in Example 2, except that methyl ethyl ketone is used as the volatile organic solvent instead of acetonitrile, the dispersion has a component weight ratio of 20:20:60, the solid-liquid mixed electrolyte film has a thickness of 50 μm after drying and a thickness of 28 μm after roll pressing.

[0131] Example 4

[0132] A solid-liquid mixed electrolyte film is obtained in the same manner as in Example 2, except that a separator is not used during coating with the dispersion but the dispersion is directly coated on a PET release film, the solid-liquid mixed electrolyte film has a thickness of 235 μm after drying and a thickness of 155 μm after roll pressing.

[0133] Comparative Example 1

[0134] An electrolyte membrane was obtained in the same manner as in Example 1, except that: during the preparation of the dispersion, no volatile organic solvent was introduced, and the weight ratio of the solid polymer particles to the liquid electrolyte was 20:80. The resulting product had a thickness of 51 μm after drying, but an electrolyte membrane could not be obtained during rolling due to the too low adhesion between the solid polymer particles.

[0135] Comparative Example 2

[0136] An electrolyte membrane was obtained in the same manner as in Example 1, except that: during the preparation of the dispersion, no volatile organic solvent was introduced, and the weight ratio of the solid polymer particles to the liquid electrolyte was 50:50. However, the dispersion did not have fluidity and thus could not be coated on the separator.

[0137] Comparative Example 3

[0138] An electrolyte membrane was obtained in the same manner as in Example 2, except that: dimethylformamide was used as the non-volatile organic solvent instead of acetonitrile as the volatile organic solvent. An electrolyte membrane with a thickness of 47 μm after drying and 28 μm after rolling was obtained. Here, for the purpose of removing dimethylformamide, the drying conditions were vacuum drying at 100 °C for 24 hours.

[0139] Comparative Example 4

[0140] No separator was used, and the dispersion according to Comparative Example 1 was directly coated on the release film. The resulting product had a thickness of 244 μm after drying, but an electrolyte membrane could not be obtained during rolling due to the too low adhesion between the particles.

[0141] Comparative Example 5

[0142] Polyethyleneoxide (PEO, Mw = 4,000,000 g / mol) was dissolved in acetonitrile (AN) as the volatile organic solvent to prepare a polymer solution with a concentration of 4 wt%. Here, LiTFSI as the lithium salt was added thereto to [EO] / [Li +The molar ratio of [] is 18 / 1. The obtained mixture was stirred overnight at 70 °C so that PEO and the lithium salt could be fully dissolved in the polymer solution. Next, an additive solution including an initiator and a curing agent was prepared. The curing agent was polyethylene glycol diacrylate (PEGDA, Mw = 575), and the initiator was benzoyl peroxide (BPO). PEGDA was used in an amount of 20 wt% based on PEO, and BPO was used in an amount of 1 wt% based on PEGDA. Acetonitrile was used as the solvent. The additive solution was stirred for about 1 hour so that the components introduced therein could be thoroughly mixed. Then, the additive solution was added to the polymer solution, and the two solutions were thoroughly mixed. The mixed solution was applied to and coated on a release film using a doctor blade. The coating gap was set to 300 μm, and the coating rate was set to 20 mm / min. The release film coated with the solution was transferred onto a glass plate and kept flat, dried overnight at room temperature, and dried under vacuum at 100 °C for 12 hours. In this way, a solid electrolyte membrane was obtained. The obtained solid electrolyte membrane had a thickness of about 50 μm.

[0143] Measurement of the ionic conductivity of the solid-liquid mixed electrolyte membrane

[0144] Each solid-liquid mixed electrolyte membrane according to the examples and comparative examples was cut into a circular shape with a size of 1.7671 cm 2 and the electrolyte membrane was interposed between two stainless steel sheets to obtain a coin cell. Then, the electrochemical impedance was measured at room temperature using an analyzer (VMP3, Biologic science instrument) under the conditions of an amplitude of 10 mV and a scanning range of 500 kHz to 0.1 MHz. Based on this, the ionic conductivity was calculated.

[0145] Herein, the ionic conductivity of each of Examples 1 to 4 and Comparative Examples 1 to 4 was measured at room temperature, and the ionic conductivity of Comparative Example 5 was measured at 60 °C.

[0146] [Table 1]

[0147]

[0148] As can be seen from [Table 1], according to an embodiment of the present disclosure, a self-supporting film can be obtained by using a dispersion to which a volatile solvent is added. The dispersion has a reduced concentration for coating and an appropriate volatile solvent is added to increase the final solid content after coating and ensure strength, while sufficiently controlling the ratio of the solid phase to the liquid phase, and thus a self-supporting film can be obtained. Compared with the conventional solid electrolyte (Comparative Example 5) exemplified by polyethylene oxide, the solid-liquid mixed electrolyte membrane according to the embodiment of the present disclosure shows excellent properties such as physical properties and ionic conductivity. In particular, a solid-liquid mixed electrolyte membrane having excellent ionic conductivity can be obtained by a dispersion coating process using a combination of a structure including particles and an electrolyte. In addition, when a separator is introduced, a thin film type electrolyte membrane having a thickness of less than 50 μm can be obtained.

[0149] [Reference Signs]

[0150] 100: Solid-liquid mixed electrolyte membrane

[0151] 11: Solid polymer particles

[0152] 12: Liquid electrolyte

[0153] 13: Volatile organic solvent

[0154] 14: Dispersion

[0155] 15: Substrate

Claims

1. A method for manufacturing a solid-liquid mixed electrolyte membrane, comprising the following steps: (S1) Prepare a dispersion comprising a plurality of solid polymer particles dispersed in a liquid electrolyte and a volatile organic solvent; (S2) Apply the dispersion onto a substrate and then dry it to form a porous structure; and (S3) Pressurize the porous structure to obtain a solid-liquid mixed electrolyte membrane, wherein the solid polymer particles in the porous structure are stacked while being in contact with each other, and the porous structure comprises a pore structure formed between the solid polymer particles, the liquid electrolyte surrounds the interior of the pores of the porous structure, the portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles, the content of the liquid electrolyte is 1 wt% to 20 wt% based on the total weight of the solid-liquid mixed electrolyte membrane, the weight ratio of the volatile organic solvent to the liquid electrolyte is 83:17 to 9:91, and the volatile organic solvent has a higher volatility than the liquid electrolyte.

2. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the volatile organic solvent has a boiling point of 30°C to 200°C.

3. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the volatile organic solvent comprises acrylonitrile, methyl ethyl ketone, acetone, tetrahydrofuran, pentane, hexane, benzene, chloroform, ether, dichloromethane, ethyl acetate, acetonitrile, methanol, methylene chloride, carbon disulfide, carbon tetrachloride, or a mixture of two or more thereof.

4. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the solid polymer particles comprise an engineering plastic resin.

5. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the solid polymer particles comprise an engineering plastic resin, and the engineering plastic resin comprises any one selected from polyphenylene sulfide, polyether ether ketone, polyimide, polyamideimide, liquid crystal polymer, polyetherimide, polysulfone, polyarylate, polyethylene terephthalate, polybutylene terephthalate, polyoxymethylene, polycarbonate, polypropylene, polyethylene, and polymethyl methacrylate, or a mixture of two or more thereof.

6. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the liquid electrolyte comprises an organic solvent and a lithium salt, and the organic solvent is at least one of a linear carbonate, a linear ester, and a linear ether.

7. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the weight ratio of the volatile organic solvent to the liquid electrolyte is 83:17 to 66:

34.

8. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 1, wherein the pressurization in step (S3) is a step of physically or chemically bonding the solid polymer particles to each other to obtain a porous structure having a pore structure formed between the solid polymer particles.

9. The method for manufacturing a solid-liquid hybrid electrolyte membrane according to claim 1, wherein the substrate comprises a porous polymer substrate or a non-woven mesh substrate.

10. The method for manufacturing a solid-liquid hybrid electrolyte membrane according to claim 9, wherein the pores of the substrate are filled with the liquid electrolyte.

11. The method for manufacturing a solid-liquid hybrid electrolyte membrane according to claim 1, wherein the weight ratio of the volatile organic solvent to the liquid electrolyte is from 50:50 to 34:

66.

12. The method for manufacturing a solid-liquid hybrid electrolyte membrane according to claim 1, wherein the weight ratio of the volatile organic solvent to the liquid electrolyte is from 17:83 to 9:

91.

13. A solid-liquid hybrid electrolyte membrane obtained by the method as defined in any one of claims 1 to 12, the solid-liquid hybrid electrolyte membrane comprising a plurality of solid polymer particles, a volatile organic solvent, and a liquid electrolyte, wherein the solid polymer particles are stacked while being in contact with each other and comprise a porous structure having a pore structure formed between the solid polymer particles, the liquid electrolyte surrounds the interior of the pores of the porous structure, at the portions where the solid polymer particles are in surface contact with each other, or on the surface of the solid polymer particles, and the content of the liquid electrolyte is from 1 wt% to 20 wt% based on the total weight of the solid-liquid hybrid electrolyte membrane.

14. The solid-liquid hybrid electrolyte membrane according to claim 13, the solid-liquid hybrid electrolyte membrane further comprising a porous polymer substrate or a non-woven mesh substrate.

15. The solid-liquid hybrid electrolyte membrane according to claim 14, wherein the pores of the substrate are filled with the liquid electrolyte.

16. The solid-liquid hybrid electrolyte membrane according to claim 13, wherein the volatile organic solvent comprises acrylonitrile, methyl ethyl ketone, acetone, tetrahydrofuran, pentane, hexane, benzene, chloroform, ether, dichloromethane, ethyl acetate, acetonitrile, methanol, methylene chloride, carbon disulfide, carbon tetrachloride, or a mixture of two or more thereof.

17. The solid-liquid hybrid electrolyte membrane according to claim 13, wherein the volatile organic solvent has a higher volatility than the liquid electrolyte.

18. The solid-liquid hybrid electrolyte membrane according to claim 13, wherein the volatile organic solvent has a boiling point of from 30°C to 200°C.

19. The solid-liquid hybrid electrolyte membrane according to claim 13, wherein the volatile organic solvent has a boiling point that is 5°C to 100°C lower than the boiling point of the liquid electrolyte used in the dispersion.

20. The solid-liquid hybrid electrolyte membrane according to claim 13, wherein the volatile organic solvent has a vapor pressure that is 10% to 10,000% higher than the vapor pressure of the liquid electrolyte.

21. A lithium-ion secondary battery comprising a positive electrode, a negative electrode, and a solid-liquid hybrid electrolyte membrane interposed between the negative electrode and the positive electrode, wherein the solid-liquid hybrid electrolyte membrane is the same as that defined in claim 13, and the negative electrode, the positive electrode, or both comprise a solid electrolyte material.

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