Solid-liquid hybrid electrolyte membrane, method for manufacturing same, and lithium secondary battery including same

Abstract

Disclosed are a solid-liquid hybrid electrolyte membrane and a method for manufacturing the same, the solid-liquid hybrid electrolyte membrane comprising a plurality of solid polymer particles and a small amount of a liquid electrolyte, in which the solid polymer particles are deposited while being in contact with each other, and the solid-liquid mixed electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles, and the liquid electrolyte surrounds an interior of a pore of the porous structure, a portion where the solid polymer particles are in surface contact with each other, or a surface of the solid polymer particles. By not using a solid electrolyte, it is possible to provide a solid-liquid mixed electrolyte membrane which can be deformed by external pressure. It is also possible to provide a solid-liquid mixed electrolyte membrane exhibiting low resistance by not using a binder polymer. Meanwhile, the solid-liquid mixed electrolyte membrane includes a small amount of a liquid electrolyte, so that improved ionic conductivity can be ensured compared with a conventional solid electrolyte battery.

Description

[0001] This application is a divisional application of a patent application for invention with the application date of November 18, 2020, application number 202080044139.X, and invention title "Solid-Liquid Hybrid Electrolyte Membrane, Method for Manufacturing the Same, and Lithium Secondary Battery Comprising the Same". Technical Field

[0002] The present disclosure relates to a solid-liquid hybrid electrolyte membrane, a lithium secondary battery including the solid-liquid hybrid electrolyte membrane, and a method for manufacturing the solid-liquid hybrid electrolyte membrane.

[0003] This application claims the priority of Korean Patent Application No. 10-2019-0167041, filed in Korea on December 13, 2019, the disclosure of which is incorporated herein by reference. Background Art

[0004] As the use of vehicles, computers, and portable terminals increases, the importance of lithium secondary batteries increases. In particular, there is a great need to develop lithium secondary batteries having a low weight and providing a high energy density.

[0005] A lithium secondary battery can be obtained by inserting a separator between a positive electrode and a negative electrode and injecting a liquid electrolyte thereinto, or by inserting a solid electrolyte membrane between the positive electrode and the negative electrode.

[0006] 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 due to deformation or external shock, a short circuit may occur, leading to risks such as overheating or explosion.

[0007] The advantages of a lithium secondary battery using a solid electrolyte are that it has enhanced safety and prevents 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, there is a problem of performance degradation due to low ionic conductivity, and it shows a significantly larger thickness compared to the thickness of a conventional porous polyolefin-based separator, resulting in energy density loss. In these cases, a technical solution capable of overcoming these problems is needed. Summary of the Invention

[0008] Technical problem

[0009] The present disclosure aims to solve the problems of the prior art. Therefore, the present disclosure aims to provide a solid-liquid hybrid electrolyte membrane that has a reduced thickness compared to a commercially available solid electrolyte membrane while ensuring ionic conductivity.

[0010] The present disclosure also relates to providing a solid-liquid hybrid electrolyte membrane which, although being a thinner membrane compared to commercially available solid electrolyte membranes, has improved mechanical strength.

[0011] Furthermore, the present disclosure aims to provide a solid-liquid hybrid electrolyte membrane which can be formed into a thinner membrane compared to commercially available solid electrolyte membranes and has an increased energy density per unit weight with respect to the thickness.

[0012] These and other objects and advantages of the present disclosure will be understood from the following detailed description. Furthermore, it will 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 solution

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

[0015] According to a first embodiment of the present disclosure,

[0016] there is provided a solid-liquid hybrid electrolyte membrane which includes a plurality of solid polymer particles and a small amount of liquid electrolyte, and has an ionic conductivity of 1x10 -5 to 1x10 -1 S / cm,

[0017] wherein the solid polymer particles are stacked while being in contact with each other, and the solid-liquid hybrid electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles,

[0018] the liquid electrolyte surrounds the interior of the pores of the porous structure, the portions where the solid polymer particles are in surface contact with each other, or the surfaces of the solid polymer particles, and

[0019] the content of the liquid electrolyte is 1-20% by weight based on the total content of the solid-liquid hybrid electrolyte membrane of 100% by weight.

[0020] According to a second embodiment of the present disclosure, there is provided a solid-liquid hybrid electrolyte membrane as defined in the first embodiment,

[0021] wherein the porous structure itself has a higher porosity than the porosity of the solid-liquid hybrid electrolyte membrane.

[0022] According to a third embodiment of the present disclosure, there is provided a solid-liquid hybrid electrolyte membrane as defined in the first embodiment or the second embodiment,

[0023] which has a higher ionic conductivity than the ionic conductivity of the porous structure itself.

[0024] According to a fourth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in any one of the first to third embodiments,

[0025] wherein the solid polymer particles are engineering plastic resins.

[0026] According to a fifth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in any one of the first to fourth embodiments,

[0027] wherein the solid polymer particles 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 polymethyl methacrylate, or two or more of them.

[0028] According to a sixth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in any one of the first to fifth embodiments, which does not contain a binder polymer.

[0029] According to a seventh embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in any one of the first to sixth embodiments,

[0030] wherein the porosity of the porous structure itself is 1-90% by volume, and the porosity of the solid-liquid mixed electrolyte membrane is 0-80% by volume, which is lower than the porosity of the porous structure itself.

[0031] According to an eighth embodiment of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane as defined in any one of the first to seventh embodiments, and its thickness is 10-500 μm.

[0032] In another aspect of the present disclosure, a lithium secondary battery according to any one of the following embodiments is provided.

[0033] According to the ninth embodiment of the present disclosure,

[0034] a solid-state battery is provided, including: a positive electrode containing a solid electrolyte, a negative electrode containing a solid electrolyte, and a separator interposed between the positive electrode and the negative electrode, wherein the separator includes a solid-liquid mixed electrolyte membrane defined in any one of the first to eighth embodiments.

[0035] According to the tenth embodiment of the present disclosure,

[0036] a lithium-ion battery is provided, including: a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a liquid electrolyte, wherein the separator includes a solid-liquid mixed electrolyte membrane defined in any one of the first to eighth embodiments.

[0037] In still another aspect of the present disclosure, a method for manufacturing a solid-liquid mixed electrolyte membrane according to any one of the following embodiments is provided.

[0038] According to the eleventh embodiment of the present disclosure, a method for manufacturing a solid-liquid mixed electrolyte membrane is provided, including the following steps:

[0039] (S1) Preparing a plurality of solid polymer particles per se, or a dispersion containing a plurality of solid polymer particles dispersed in a solvent;

[0040] (S2) Applying the solid polymer particles per se or the dispersion onto a substrate, and then drying;

[0041] (S3) Pressurizing the resultant product of step (S2) to form a porous structure; and

[0042] (S4) Coating the porous structure with a small amount of liquid electrolyte,

[0043] wherein the solid polymer particles are stacked while being in contact with each other, and the solid-liquid mixed electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles,

[0044] the liquid electrolyte surrounds a portion where the solid polymer particles are in surface contact with each other, or the surface of the solid polymer particles, and

[0045] the content of the liquid electrolyte is 1-20% by weight based on the total content of the solid-liquid mixed electrolyte membrane of 100% by weight.

[0046] According to the twelfth embodiment of the present disclosure, a method for manufacturing a solid-liquid mixed electrolyte membrane as defined in the eleventh embodiment is provided,

[0047] Wherein the substrate is any one selected from a release film, a porous polymer substrate, or an electrode.

[0048] According to the thirteenth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid hybrid electrolyte membrane as defined in the eleventh embodiment or the twelfth embodiment.

[0049] Wherein the pressing in step (S3) is a step of physically or chemically binding the solid polymer particles to each other to obtain a porous structure having a pore structure formed between the solid polymer particles.

[0050] According to the fourteenth embodiment of the present disclosure, there is provided a method for manufacturing a solid-liquid hybrid electrolyte membrane as defined in any one of the eleventh embodiment to the thirteenth embodiment.

[0051] Wherein the coating in step (S4) is performed by any one of dip coating, spray coating, and drop coating.

[0052] Beneficial effect

[0053] 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.

[0054] In addition, since granular polymers that can be compressed are used, a solid-liquid hybrid electrolyte membrane with improved mechanical strength can be provided. Since solid electrolytes are not used, a solid-liquid hybrid electrolyte membrane that can be deformed by external pressing can be provided. In addition, the polymer particles are physically bonded to each other, which is beneficial for the formation of porosity and pore channels.

[0055] According to an embodiment of the present disclosure, since no binder polymer is used, a solid-liquid hybrid electrolyte membrane showing low resistance can be provided.

[0056] Meanwhile, according to an embodiment of the present disclosure, compared with a conventional solid electrolyte battery, a small amount of liquid electrolyte is used to ensure improved ionic conductivity while preventing electrolyte leakage.

[0057] In addition, a solid-liquid hybrid electrolyte membrane can be provided, which can be formed into a thinner membrane compared with a commercially available solid electrolyte membrane and has an improved energy density per unit weight with respect to the thickness. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve 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. Meanwhile, for the purpose of clearer description, the shapes, sizes, ratios, or proportions of certain components in the drawings may be enlarged.

[0059] Figure 1 is a schematic diagram showing the structure of a solid-liquid hybrid electrolyte membrane according to an embodiment of the present disclosure.

[0060] Figure 2 is a schematic diagram showing a method for manufacturing a solid-liquid hybrid electrolyte membrane according to an embodiment of the present disclosure.

[0061] Figure 3 shows an image of a solid-liquid hybrid electrolyte membrane obtained according to Example 6.

[0062] Figure 4 shows an image of an electrolyte membrane obtained according to Comparative Example 3. Detailed Description of Specific Embodiments

[0063] 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 being 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 disclosure. Accordingly, it should be understood that other equivalent substitutions and modifications can be made without departing from the scope of the present disclosure.

[0064] Throughout the specification, unless otherwise specified, the statement that "a component 'comprises' an element" does not exclude the presence of any additional elements, but means that the component may further include other elements.

[0065] As used herein, terms such as "about" and "substantially" are used to denote meanings adjacent to the stated values when presenting acceptable manufacturing and material tolerances specific to the stated meaning, and are used to prevent unscrupulous infringers from inappropriately using the disclosure that includes exact or absolute numerical values provided to assist in understanding the present disclosure.

[0066] As used herein, the expression "A and / or B" means "A, B, or both of them".

[0067] The specific terms used in the following description are for illustrative purposes only and not for limitation. Terms such as "right", "left", "top surface", and "bottom surface" denote the directions indicated in the figures. Terms such as "inward" and "outward" denote the directions toward and away from the geometric center of the corresponding device, system, and their components, respectively. Terms such as "front", "rear", "top", "bottom", and related words denote their positions and points indicated in the accompanying drawings and should not be construed as limitations. These terms include the words listed above, their derivatives, and words with similar meanings.

[0068] The present disclosure relates to a solid-liquid mixed electrolyte membrane, a method for manufacturing the solid-liquid mixed electrolyte membrane, and a lithium secondary battery including the solid-liquid mixed electrolyte membrane.

[0069] In one aspect of the present disclosure, there is provided a solid-liquid mixed electrolyte membrane including a plurality of solid polymer particles and a small amount of liquid electrolyte.

[0070] Herein, the solid polymer particles are stacked while being in contact with each other, and the solid-liquid mixed electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles.

[0071] In addition, the solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure includes a liquid electrolyte covering a portion where the solid polymer particles are in surface contact with each other or the surfaces of the solid polymer particles.

[0072] In addition, the solid polymer particles are first pressed to form a porous structure. Then, the obtained porous structure is coated with a small amount of liquid electrolyte. Therefore, there is no separate pressing step after coating the liquid electrolyte, preventing leakage of the liquid electrolyte of the solid-liquid mixed electrolyte membrane. The solid-liquid mixed electrolyte membrane exhibits an ionic conductivity equal to or similar to that of a conventional solid electrolyte membrane and has a uniform ionic conductivity.

[0073] The solid-liquid mixed electrolyte membrane uses polymer particles instead of inorganic particles and thus can be deformed. In addition, the solid-liquid mixed electrolyte membrane uses polymer particles instead of a solid electrolyte and thus can be deformed by external pressing. In addition, the solid polymer particles are physically bonded to each other, which is beneficial for the formation of pores and pore channels.

[0074] Meanwhile, since the solid-liquid mixed electrolyte membrane includes a small amount of liquid electrolyte, electrolyte leakage can be prevented and an improved ionic conductivity can be ensured as compared with a conventional solid electrolyte membrane.

[0075] Figure 1 is a schematic diagram showing the structure of a solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure. Figure 2It is a schematic diagram showing a method for manufacturing a solid-liquid hybrid 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.

[0076] Referring to Figure 1 , the solid-liquid hybrid electrolyte membrane 100 according to an embodiment of the present disclosure includes a plurality of solid polymer particles 11 and a small amount of liquid electrolyte 12.

[0077] The solid polymer particles exist in a solid state at room temperature and may be a polymer material having low solubility in the electrolyte.

[0078] 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, preferably, the solid polymer particles may be a polymer having excellent chemical resistance.

[0079] In particular, when impregnated with a liquid electrolyte such as ethylene carbonate: ethyl methyl carbonate = 30:70 (volume %), the solid polymer particles may have a solubility of less than 30%. More specifically, 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 a solvent, they can exist in a solid state.

[0080] In particular, the solid polymer particles may be an engineering plastic resin.

[0081] Here, the engineering plastic resin may 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 two or more of them. In addition, the engineering plastic resin may have a molecular weight of 100,000 - 10,000,000 Da.

[0082] Unlike conventional commercially available inorganic particles, solid polymer particles are compressible. Accordingly, a lithium secondary battery having an increased energy density per unit weight with respect to 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 can be ductile and thus can be physically or chemically joined under pressure or heat. As a result, the solid-liquid hybrid electrolyte membrane according to the present disclosure does not require a separate binder polymer. In other words, the solid-liquid hybrid electrolyte membrane can be free of a binder polymer. Accordingly, a solid-liquid hybrid electrolyte membrane showing a reduced resistance can be provided.

[0083] According to an embodiment of the present disclosure, the solid polymer particles can have an average particle diameter of 100 nm to 10 μm, 200 nm to 5 μm, or 500 nm to 2 μm. When the particle diameter of the solid polymer particles is controlled within the above range, a suitable pore diameter can be obtained to prevent short circuit and allow sufficient impregnation of the liquid electrolyte.

[0084] The solid polymer particles are stacked while being in contact with each other, and a pore structure is formed between the solid polymer particles.

[0085] Herein, the solid polymer particles can be brought into contact with each other by being stacked under an external pressure. For example, the external pressure can be uniaxial pressing, roll pressing, cold isostatic pressing (CIP), hot isostatic pressing (HIP), or the like. However, the scope of the present disclosure is not limited thereto, and any physical or chemical process capable of causing the solid polymer particles to adhere to each other can be used.

[0086] Herein, the solid polymer particles can undergo plastic deformation beyond the physical elastic region of the particles by the above external pressure, so that the contact surface between the particles may increase compared to the particles before the application of the pressure, or a volume change may occur to generate a new contact surface, or the adhesion force of the adhesion surface between the particles may increase due to the plastic deformation to form a desired structure. For example, the solid polymer particles can be granulated.

[0087] As described below, the solid-liquid hybrid electrolyte membrane includes a small amount of liquid electrolyte and thus can transport lithium ions therethrough. In other words, according to an embodiment of the present disclosure, an electrolyte membrane having a high ionic conductivity can be provided even without using a solid electrolyte.

[0088] The content of the liquid electrolyte is 1-20% by weight based on the total weight of the solid-liquid mixed electrolyte membrane. In particular, the content of the liquid electrolyte can be 1% by weight or more, 2% by weight or more, 3% by weight or more, 4% by weight or more, or 5% by weight or more based on the total weight of the solid-liquid mixed electrolyte membrane, and is 20% by weight or less, 15% by weight or less, 10% by weight or less, or 5% by weight or less based on the total weight of the solid-liquid mixed electrolyte membrane.

[0089] Even though the solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure includes a small amount of liquid electrolyte as described above, the solid polymer particles have low solubility in the liquid electrolyte, so the liquid electrolyte can cover the inside of the porous structure. In this way, the ionic conductivity of the solid-liquid mixed electrolyte membrane can be improved. In addition, since the solid-liquid mixed electrolyte membrane includes a small amount of liquid electrolyte, electrolyte leakage can be prevented, and thus stability can be maintained.

[0090] The reason why such a small amount of liquid electrolyte can be used is that the solid polymer particles form a porous structure and exhibit compatibility with the liquid electrolyte.

[0091] Meanwhile, according to an embodiment of the present disclosure, even if the liquid electrolyte is present in a small amount, a solid-liquid mixed electrolyte membrane having high ionic conductivity can be provided. This is because the liquid electrolyte is uniformly dispersed on the surface of the solid polymer particles or on the part where the solid polymer particles are in surface contact with each other. According to an embodiment of the present disclosure, dip coating, spray coating, or drop coating can be used to perform such uniform impregnation of the liquid electrolyte.

[0092] According to an embodiment of the present disclosure, the liquid electrolyte cannot dissolve the solid polymer particles and can have excellent chemical resistance and electrochemical resistance.

[0093] For example, the liquid electrolyte is a salt having the structure of A + B - where A + may include alkali metal cations such as Li + , Na + , K + or a combination thereof, and B - may include anions such as PF 6 - , BF 4 - , Cl - , Br - , I - , ClO 4 - , AsF6 - , CH 3 CO 2 - , CF 3 SO 3 - , N(CF 3 SO 2 ) 2 - , C(CF 2 SO 2 ) 3 - or a combination thereof, wherein the salt can be dissolved or dissociated in an organic solvent such as an ether-based solvent, a carbonate-based solvent, a nitrile-based solvent, etc., but not limited thereto.

[0094] For example, the ether-based organic solvents may include dimethyl ether, diethyl ether, dipropyl ether, methyl ethyl ether, methyl propyl ether, ethyl propyl ether, 1,2-dimethoxyethane, or a mixture of two or more of them.

[0095] For example, the carbonate-based organic solvents may include propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), or a mixture of two or more of them.

[0096] For example, the nitrile-based organic solvents may include acetonitrile, succinonitrile, or a mixture of two or more of them.

[0097] In addition to the above solvents, the organic solvents may include dimethyl sulfoxide, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, or a mixture thereof, but not limited thereto.

[0098] In the solid-liquid electrolyte membrane according to an embodiment of the present disclosure, the porous structure itself may have a porosity higher than that of the solid-liquid mixed electrolyte membrane.

[0099] In particular, the porous structure itself may have a porosity of 1-90% by volume, 5-80% by volume, 10-70% by volume, or 20-50% by volume.

[0100] The solid-liquid mixed electrolyte membrane may have a porosity lower than that of the porous structure itself. In particular, it may have a porosity of 0-80% by volume, 5-60% by volume, 10-30% by volume, or 15-20% by volume.

[0101] In addition, in the solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure, the ionic conductivity of the solid-liquid mixed electrolyte membrane may be higher than that of the porous structure itself.

[0102] In addition, the ionic conductivity of the solid-liquid electrolyte membrane according to an embodiment may have a higher ionic conductivity than that of the porous structure itself, and may have an ionic conductivity of 1×10 -5 to 1×10 -1 S / cm, 1×10 -4 to 1×10 -2 S / cm, or 1×10 -4 to 5×10 -3 S / cm.

[0103] As described above, although the solid-liquid mixed electrolyte membrane according to an embodiment of the present disclosure has a lower porosity than the porous structure itself, the solid-liquid mixed electrolyte membrane can exhibit a higher ionic conductivity compared to the porous structure itself.

[0104] Meanwhile, the porosity and pore size of the electrolyte membrane and the porous structure itself according to the present disclosure can be controlled by adjusting the average particle size of the solid polymer particles or the pressing conditions during the manufacturing process. For example, the porosity and pore size can be controlled by adjusting the roll gap of the roll press, controlling the temperature during the manufacturing process, or by controlling the content or particle size of the solid polymer particles.

[0105] According to an embodiment of the present disclosure, the porous structure may have a thickness of 10-500 μm, 20-300 μm, or 30-100 μm. According to an embodiment of the present disclosure, in terms of the energy density of the subsequent obtained lithium secondary battery, it is advantageous to use a thin-film type porous structure with a thickness of 10-50 μm.

[0106] According to an embodiment of the present disclosure, the solid-liquid mixed electrolyte membrane may have a thickness of 10-500 μm, 20-300 μm, or 30-100 μm. According to an embodiment of the present disclosure, a separator in the form of a thin film with a thickness of 10-50 μm can be provided, which is advantageous for the energy density of the subsequent obtained lithium secondary battery.

[0107] According to an embodiment of the present disclosure, the solid-liquid mixed electrolyte membrane may further include a porous polymer substrate or a non-woven fabric substrate.

[0108] In particular, the non-woven substrate may include polyolefins such as polyethylene or polypropylene, polyethylene terephthalate, polyester, polyamide, polyacetal, polycarbonate, polyimide, polyether ether ketone, polyether sulfone, polyphenylene ether, polyphenylene sulfide, polyethylene naphthalene, or a mixture thereof.

[0109] Herein, the porous polymer substrate or non-woven substrate may include pores having an average diameter of 10 nm to 100 μm, 100 nm to 10 μm, or 500 nm to 5 μm, and may have a porosity of 10-98 vol%, 30-90 vol%, or 40-80 vol%.

[0110] Meanwhile, the solid polymer particles may be partially embedded in the pores of the non-woven substrate, wherein the surfaces of the solid polymer particles and the substrate may be surrounded by a liquid electrolyte.

[0111] Meanwhile, the solid polymer particles may be disposed on at least one surface of the non-woven substrate, wherein the surfaces of the solid polymer particles and the substrate may be surrounded by a liquid electrolyte.

[0112] As used herein, the term "pores" may have various types of pore structures, and any type of pores having an average pore diameter that satisfies the above definition (as measured by using a porosimeter or as observed by field emission scanning electron microscopy (FE-SEM)) fall within the scope of the present disclosure.

[0113] In another aspect of the present disclosure, a lithium secondary battery according to any one of the following embodiments is provided.

[0114] In particular, a lithium ion battery is provided, which includes a positive electrode containing a solid electrolyte, a negative electrode containing a solid electrolyte, and a separator interposed between the positive electrode and the negative electrode, wherein the separator may be the above-mentioned solid-liquid mixed electrolyte membrane.

[0115] In particular, the lithium secondary battery may be a lithium ion battery further injected with a liquid electrolyte.

[0116] According to the present disclosure, each of the positive electrode and the negative electrode includes a current collector, and an electrode active material layer formed on at least one surface of the current collector, wherein the electrode active material layer includes a plurality of electrode active material particles and a solid electrolyte. In addition, the electrode may further include at least one of a conductive material and an adhesive resin. In addition, the electrode may further include various additives to supplement or improve the physicochemical properties of the electrode.

[0117] According to the present disclosure, any negative electrode active material can be used as long as it can be used as a negative electrode active material for a lithium ion secondary battery. Specific examples of the negative electrode active material may include any one selected from the following: carbon, such as non-graphitized carbon or graphitic carbon; metal composite oxides, such as Li x Fe 2 O 3 (0 ≤ x ≤ 1), Li x WO 2 (0 ≤ x ≤ 1), Sn x Me 1-x Me' y O z (Me: Mn, Fe, Pb, or Ge; Me': Al, B, P, Si, an element of Group 1, Group 2, or Group 3 of the periodic table, or a halogen; 0 < x ≤ 1; 1 ≤ y ≤ 3; 1 ≤ z ≤ 8); lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides, such as SnO, SnO 2 , PbO, PbO 2 , Pb 2 O 3 , Pb 3 O 4 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 , GeO, GeO 2 , Bi 2 O 3 , Bi 2 O 4 , Bi 2 O 5 , or the like; conductive polymers, such as polyacetylene; Li-Co-Ni-based materials; titanium oxide; and lithium titanium oxide, or the like, or two or more of them. In particular, the negative electrode active material may include a carbonaceous material and / or Si.

[0118] In the case of the positive electrode, any positive electrode active material can be used without particular limitation as long as it can be used as a positive electrode active material for a lithium ion secondary battery. Specific examples of the positive electrode active material may include, but are not limited to: layered compounds such as lithium cobalt oxide (LiCoO 2 ) and lithium nickel oxide (LiNiO 2 ), or those compounds substituted with one or more transition metals; those represented by the chemical formula Li 1+x Mn 2-x O 4 (where x is 0 - 0.33), LiMnO 3 , LiMn2 O 3 , and LiMnO 2 represented lithium manganese oxides; lithium copper oxide (Li 2 CuO 2 ); vanadium oxides such as LiV 3 O 8 , LiV 3 O 4 , V 2 O 5 , or Cu 2 V 2 O 7 ; nickel-site lithium nickel oxides represented by the chemical formula LiNi 1-x M x O 2 (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 O 2 (where M is Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 - 0.1) or Li 2 Mn 3 MO 8 (where M is Fe, Co, Ni, Cu, or Zn); lithium manganese composite oxides having a spinel structure and represented by the formula LiNi x Mn 2-x O 4 ; LiMn 2 O 4 in which Li is partially replaced by alkaline earth metal ions; disulfide compounds; Fe 2 (MoO 4 ) 3 ; or the like.

[0119] According to the present disclosure, the current collector may include a conductive metal plate and may be a current collector appropriately selected according to the polarity of the electrode known in the field of secondary batteries.

[0120] According to the present disclosure, based on the total weight of the mixture including the electrode active material, the conductive material can generally be added in an amount of 1-30% by weight. The conductive material is not particularly limited as long as it does not cause chemical changes in the corresponding battery and has electrical conductivity. For example, the conductive material can include 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, thermal black, or the like; conductive fibers, such as carbon fibers or metal fibers; metal powders, such as carbon fluoride powder, aluminum powder, or nickel powder; conductive whiskers, such as zinc oxide or potassium titanate; conductive metal oxides, such as titanium oxide; and conductive materials such as polyphenylene derivatives, or a mixture of two or more of them.

[0121] According to the present disclosure, the binder resin is not particularly limited as long as it is a component that contributes to the binding of the electrode active material and the conductive material and to binding to the current collector. Specific examples of the binder resin can include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene monomer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers, or the like. Generally, based on 100% by weight of the electrode active material layer, the binder resin can be used in an amount of 1-30% by weight, or 1-10% by weight.

[0122] Meanwhile, according to the present disclosure, each electrode active material layer can optionally include at least one additive, such as an oxidation-stable additive, a reduction-stable additive, a flame retardant, a heat stabilizer, an antifogging agent, or the like.

[0123] According to the present disclosure, the solid electrolyte can include at least one of a polymer solid electrolyte, an oxide-based solid electrolyte, and a sulfide-based solid electrolyte.

[0124] According to the present disclosure, each of the positive electrode and the negative electrode can use different solid electrolytes, or the same solid electrolyte can be used for two or more battery elements. For example, in the case of the positive electrode, a polymer electrolyte having high oxidation stability can be used as the solid electrolyte. In addition, in the case of the negative electrode, a polymer electrolyte having high reduction stability can be used as the solid electrolyte. However, the scope of the present disclosure is not limited thereto. Since the solid electrolyte mainly functions to conduct lithium ions in the electrode, any material having high ionic conductivity, such as 10 - 7 S / Cm or higher, can be used, and the solid electrolyte material is not limited to any specific component.

[0125] According to the present disclosure, the polymer electrolyte may be a solid polymer electrolyte formed by adding a polymer resin to an independently solvated lithium salt, or may be a polymer gel electrolyte prepared by impregnating a polymer resin with an organic electrolyte containing an organic solvent and a lithium salt.

[0126] In yet another aspect of the present disclosure, a secondary battery having the above structure is provided. Also provided are a battery module including the secondary battery as a unit cell, a battery pack including the battery module, and a device including the battery pack as a power source. Here, specific examples of the device may include, but are not limited to: power tools driven by an electric motor; electric vehicles, including Electric Vehicle (EV), Hybrid Electric Vehicle (HEV), Plug-in Hybrid Electric Vehicle (PHEV), or the like; electric two-wheelers, including electric bicycles (E-bike) and electric scooters (E-scooter); electric golf carts; power storage systems; or the like.

[0127] In yet another aspect of the present disclosure, a method for manufacturing a solid-liquid hybrid electrolyte membrane according to any one of the following embodiments is provided. Figure 2 It is a schematic diagram showing the method.

[0128] First, a plurality of solid polymer particles themselves or a dispersion including a plurality of solid polymer particles dispersed in a solvent is prepared (S1), as Figure 2 (a) shows. Referring to Figure 2 (a), the solid polymer particle powder can be used as the solid polymer particles themselves. In one variant, a dispersion including a plurality of solid polymer particles dispersed in a solvent can be used. Here, the description of the solid polymer particles above will be referred to. The solvent cannot dissolve the solid polymer particles but can disperse the solid polymer particles therein. For example, the solvent can be ethanol, methanol, or the like.

[0129] Next, the solid polymer particles themselves or the dispersion is applied to a substrate and then dried (S2). When using the solid polymer particles themselves, the application step can be carried out without a drying step. When using the dispersion, a drying step can be carried out to allow the solvent to evaporate. Here, the application and drying steps can be carried out in a conventional manner known to those skilled in the art. This is shown in Figure 2 (b). As Figure 2As shown in (b), solid polymer particles can be dispersed in a solvent, and then the dispersion can be coated so that the solid polymer particles are uniformly applied to the substrate 13. Here, preferably, after the dispersion is coated on the substrate, the solvent is evaporated, and thus residues may be left. However, the scope of the present disclosure is not limited thereto, and residues may be retained as needed. Here, the substrate may be any one selected from a release film, a porous polymer substrate, and an electrode.

[0130] Then, the product obtained in step (S2) can be pressed to form a porous structure (S3). According to an embodiment of the present disclosure, the solid polymer particles can form a porous structure through the pressing step. Here, the solid polymer particles can be bonded to each other under pressure or heating, so that no separate binder polymer is required. In this way, a solid-liquid mixed electrolyte membrane showing reduced resistance can be obtained, as Figure 2 shown in (c).

[0131] For example, the pressing step can be performed once or multiple times at a predetermined interval to provide a desired thickness and porosity of the porous structure and / or the solid-liquid mixed electrolyte membrane.

[0132] Thereafter, the porous structure can be impregnated with a small amount of liquid electrolyte (S4). This is shown in Figure 2 (d). Here, the impregnation of the liquid electrolyte can be performed by any one of dip coating, spraying, and drop coating, but is not limited thereto. Meanwhile, the content of the liquid electrolyte can be 1-20 wt% based on 100 wt% of the resulting solid-liquid mixed electrolyte membrane.

[0133] After step (S4), the method may further include a step of removing the substrate. For example, the method may further include a step of removing the release film.

[0134] As a result, a solid-liquid mixed electrolyte membrane can be obtained by the above method ( Figure 2 (e)).

[0135] Examples and test examples will now be described. The following examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0136] Example 1

[0137] First, 100 mg of powdered polyphenylene sulfide (average particle size: 10 μm) as solid polymer particles was dispersed on a exfoliated polyethylene terephthalate (PET) film to obtain a primary porous structure including polyphenylene sulfide dispersed therein. Here, the primary porous structure had a thickness of 850 μm. Next, the primary porous structure was pressed by passing it through a roll press having a 250-μm gap between a first roll and a second roll facing the primary porous structure to obtain a porous structure with a thickness of 250 μm.

[0138] Then, a liquid electrolyte (ethylene carbonate: ethyl methyl carbonate = 3:7 (volume %), LiPF 6 1M) was drop-coated on the porous structure and then dried. After that, the release film was removed to obtain a solid-liquid mixed electrolyte membrane. The obtained solid-liquid mixed electrolyte membrane had a thickness of 250 μm. Meanwhile, the porosity of the porous structure was 20 vol%, and after drop-coating the liquid electrolyte, the porosity of the solid-liquid mixed electrolyte membrane was 2 vol%.

[0139] In addition, the content of the liquid electrolyte in the solid-liquid mixed electrolyte membrane was 18 wt% based on the total weight of the solid-liquid mixed electrolyte membrane.

[0140] Example 2

[0141] A solid-liquid mixed electrolyte membrane was obtained in the same manner as in Example 1, except that the solid polymer particles were not used in powder form but in the form of a dispersion in which polyphenylene sulfide (average particle size: 10 μm) as solid polymer particles was dispersed in ethanol as a solvent at a concentration of 1 g / 2 mL, and 3 mL of the dispersion was applied to a exfoliated polyethylene terephthalate (PET) film and then dried.

[0142] Specifically, the dispersion was applied to a exfoliated polyethylene terephthalate (PET) film and dried thereon to obtain a primary porous structure including polyphenylene sulfide dispersed therein. Here, the primary porous structure had a thickness of 300 μm.

[0143] Next, the primary porous structure was pressed by passing it through a roll press having a 200-μm gap between a first roll and a second roll facing the primary porous structure to obtain a porous structure with a thickness of 200 μm.

[0144] Then, the liquid electrolyte (ethyl carbonate: ethyl methyl carbonate = 3:7 (volume %), LiPF 61 M, 0.5 vol% vinylene carbonate, 1 vol% fluoroethylene carbonate) was drop-coated into the pores of the porous structure and then dried. After that, the release film was removed to obtain a solid-liquid mixed electrolyte membrane. The thickness of the obtained solid-liquid mixed electrolyte membrane was 200 μm.

[0145] Example 3

[0146] A solid-liquid mixed electrolyte membrane was obtained in the same manner as in Example 2, except that: 3 mL of the dispersion according to Example 2 was applied onto a release film and dried thereon, and the obtained primary porous structure was passed through a roll press having a 150-μm gap between a first roll and a second roll.

[0147] Here, the thickness of the primary porous structure was 300 μm, and the thickness of the obtained porous structure was 150 μm. In addition, the thickness of the obtained solid-liquid mixed electrolyte membrane was 150 μm.

[0148] Example 4

[0149] A solid-liquid mixed electrolyte membrane was obtained in the same manner as in Example 2, except that: 10 μL of the dispersion according to Example 2 was applied onto a release film and dried thereon.

[0150] Here, the thickness of the primary porous structure was 300 μm, and the thickness of the obtained porous structure was 200 μm. In addition, the thickness of the obtained solid-liquid mixed electrolyte membrane was 200 μm.

[0151] Example 5

[0152] The positive electrode was obtained as follows.

[0153] First, LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), FX35 as a conductive material, and PVDF as a binder were mixed at a weight ratio of 96:2:2, and the obtained mixture was introduced into N-methyl-2-pyrrolidone as a solvent and stirred therein to prepare a positive electrode paste. The paste was applied onto an aluminum current collector having a thickness of 20 μm using a doctor blade, and the obtained product was vacuum dried at 120 °C for 4 hours. Then, the vacuum-dried product was pressed using a roll press to obtain a positive electrode having a positive electrode paste loading of 3 mAh / cm 2 and a porosity of 22 vol%.

[0154] After that, 2 mL of the dispersion prepared in Example 2 was applied to the positive electrode and then dried to obtain a primary porous structure containing polyphenylene sulfide dispersed therein. Here, the primary porous structure had a thickness of 200 μm.

[0155] Then, the primary porous structure is pressed by passing it through a roll press having a 40-μm gap between a first roll and a second roll facing the primary porous structure, to obtain a porous structure having a thickness of 40 μm.

[0156] Then, a liquid electrolyte (ethylene carbonate: ethyl methyl carbonate = 3:7 (volume %), LiPF 6 1M, vinylene carbonate 0.5 volume %, fluoroethylene carbonate 1 volume %) is drop-coated into the pores of the porous structure and then dried, thereby directly forming a solid-liquid mixed electrolyte film on the positive electrode.

[0157] The obtained solid-liquid mixed electrolyte film has a thickness of 40 μm.

[0158] Example 6

[0159] A solid-liquid mixed electrolyte film is obtained in the same manner as in Example 2, except that 2 mL of the dispersion according to Example 2 is applied to a polyethylene terephthalate nonwoven fabric (porosity 87 volume %) and dried thereon, and the obtained primary porous structure is passed through a roll press having a 40-μm gap between a first roll and a second roll.

[0160] Here, the thickness of the primary porous structure is 200 μm, and the thickness of the obtained porous structure is 40 μm. In addition, the thickness of the obtained solid-liquid mixed electrolyte film is 40 μm. Figure 3 An image of the solid-liquid mixed electrolyte film obtained according to Example 6 is shown.

[0161] Comparative Example 1

[0162] An electrolyte film is obtained in the same manner as in Example 1, except that no liquid electrolyte is impregnated.

[0163] Specifically, the electrolyte film is obtained as follows.

[0164] Powdery polyphenylene sulfide (average particle size: 10 μm) as solid polymer particles is dispersed on a peeled polyethylene terephthalate (PET) film to obtain a primary porous structure containing polyphenylene sulfide dispersed therein. Here, the primary porous structure has a thickness of 850 μm.

[0165] Next, the primary porous structure is pressed by passing it through a roll press having a 300-μm gap between a first roll and a second roll facing the primary porous structure, to obtain a porous structure having a thickness of 300 μm. Thereafter, the release film is removed to obtain an electrolyte film. The obtained electrolyte film has a thickness of 300 μm, and the porosity of the porous structure is 27 volume %.

[0166] Comparative Example 2

[0167] The electrolyte membrane is obtained by mixing a liquid electrolyte with solid polymer particles at once, rather than by subsequently impregnating a preformed porous structure with the liquid electrolyte. In particular, the electrolyte membrane is obtained as follows.

[0168] First, powdered polyphenylene sulfide (average particle size: 10 μm) is prepared as the solid polymer particles. In addition, as the liquid electrolyte, a mixture including ethylene carbonate: ethyl methyl carbonate = 3:7 (volume %), LiPF 6 1M, 0.5 volume % vinylene carbonate, and 1 volume % fluoroethylene carbonate is prepared.

[0169] After that, the solid polymer particles and the liquid electrolyte are mixed at a ratio of 7:3 (volume %) to prepare a dispersion including the solid polymer particles dispersed therein. Then, the dispersion is applied to a polyethylene terephthalate film and dried thereon. Then, the obtained product is passed through a roll press to obtain the electrolyte membrane. However, the electrolyte membrane cannot be obtained. It is considered that this is because a high content of the liquid electrolyte is used, and the contact surface between the solid polymer particles is insufficient to cause a decrease in the adhesion force between the solid polymer particles. When the coated polyethylene terephthalate film is passed through the roll press, the liquid electrolyte functions like a lubricating oil and interferes with the formation of the membrane.

[0170] Comparative Example 3

[0171] The electrolyte membrane is obtained in the same manner as in Comparative Example 2, except that: the dispersion produced in Comparative Example 2 is applied to a non-woven fabric (porosity: 87 volume %) with a thickness of 38 μm and dried thereon, instead of the polyethylene terephthalate film. In other words, in the electrolyte membrane of Comparative Example 3, the solid polymer particles are impregnated into the pores of the non-woven fabric substrate. When using the non-woven fabric to solve the problem of Comparative Example 2, the electrolyte membrane itself can be formed, but the electrolyte membrane exhibits uneven ionic conductivity, and the adhesion strength between the non-woven fabric and the solid polymer particles is low, resulting in a decrease in durability. Therefore, the maintenance of the electrolyte membrane is limited.

[0172] Figure 4 An image of the electrolyte membrane obtained according to Comparative Example 3 is shown.

[0173] Comparative Example 4

[0174] Comparative Example 4 relates to a conventional solid electrolyte membrane using a conventional solid electrolyte material.

[0175] Polyethylene oxide (PEO, Mw = 4,000,000 g / mol) was dissolved in acetonitrile (AN) as a solvent to prepare a polymer solution with a concentration of 4 wt%. Here, LiTFSI as a lithium salt was added thereto until the molar ratio of [EO] / [Li+] was 18 / 1. The resulting mixture was stirred overnight at 70 °C so that PEO and the lithium salt could be fully dissolved in the polymer solution. Then, an additive solution containing an initiator and a curing agent was prepared. The curing agent was PEGDA (M w = 575), the initiator was benzoyl peroxide (BPO), the amount of polyethylene glycol diacrylate (PEGDA) was 20 wt% based on PEO, the amount of BPO was 1 wt% based on PEGDA, and acetonitrile was used as the solvent. The additive solution was stirred for about 1 hour so that the components introduced therein could be fully mixed. Then, the additive solution was added to the polymer solution, and the two solutions were fully mixed. The mixed solution was applied 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 coating solution was transferred to a glass plate, kept horizontal, dried overnight at room temperature, and vacuum dried at 100 °C for 12 hours. In this way, a solid electrolyte membrane was obtained. The resulting solid electrolyte layer had a thickness of about 50 μm.

[0176] Comparative Example 5

[0177] An electrolyte membrane was obtained in the same manner as in Comparative Example 2, except that the solid polymer particles and the liquid electrolyte were mixed at a volume ratio of 8:2. However, due to the reduction of the liquid electrolyte, a flowable slurry itself for forming the electrolyte membrane could not be obtained.

[0178] Comparative Example 6

[0179] An electrolyte membrane was obtained in the same manner as in Comparative Example 3, except that the solid polymer particles and the liquid electrolyte were mixed at a volume ratio of 8:2. However, due to the reduction of the liquid electrolyte, a flowable slurry itself for forming the electrolyte membrane could not be obtained.

[0180] [Table 1]

[0181]

[0182]

[0183] In Table 1, the porosity (%) refers to volume%.

[0184] As can be seen from Table 1, according to the embodiments of the present disclosure, solid polymer particles without ionic conductivity are used to form a self-supporting porous structure. In addition, a small amount of liquid electrolyte is coated inside the porous structure to obtain a solid-liquid mixed electrolyte membrane with high ionic conductivity. Compared with the solid electrolyte (Comparative Example 4) taking conventional polyethylene oxide as an example, the solid-liquid mixed electrolyte membrane according to the embodiments of the present disclosure shows excellent properties such as physical properties or ionic conductivity. On the contrary, even when using the same ratio of liquid electrolyte and solid polymer particles as in Example 1, mixing the two materials at once cannot provide a self-supporting porous structure, as shown in Comparative Example 2. At the same time, when a separator such as non-woven fabric is introduced to solve the problem of Comparative Example 2, an electrolyte membrane can be formed, but the ionic conductivity in the electrolyte membrane is uneven, and the durability is reduced due to the low adhesion strength between the non-woven fabric and the solid polymer particles. In this case, the electrolyte membrane cannot be continuously maintained.

[0185] Measurement of Porosity

[0186] Each electrolyte membrane according to the examples and comparative examples was cut into a size of 1.7671 cm 2 , the weight and volume of each electrolyte membrane were measured (apparent density was measured), and the apparent density was compared with the design value (true density) to calculate the porosity. In other words, the true density of each solid electrolyte membrane was calculated from the composition ratio of the components contained in the solid electrolyte membrane and the density of each component, and then the porosity was calculated based on the difference between the apparent density and the true density.

[0187] Measurement of Ionic Conductivity of Electrolyte Membrane

[0188] Each electrolyte membrane according to the examples and comparative examples was cut into a circle with a size of 1.7671 cm 2 , and the electrolyte membrane was set between two stainless steel sheets to obtain a button cell. Then, at room temperature, under the conditions of an amplitude of 10 mV and a scan range of 500 kHz to 0.1 MHz, the electrochemical impedance was measured using an analyzer (VMP3, Biologic science instrument). Based on this, the ionic conductivity was calculated.

[0189] Determination of Content of Liquid Electrolyte in Solid-Liquid Mixed Electrolyte Membrane

[0190] The content of the liquid electrolyte in the solid-liquid mixed electrolyte membrane was calculated by the formula [weight of the solid-liquid mixed electrolyte membrane - weight of the porous structure].

Claims

1. A solid-liquid mixed electrolyte membrane, which comprises solid polymer particles and a liquid electrolyte and has an ionic conductivity of 1×10 -5 to 1×10 -1 S / cm, Wherein the solid polymer particles are stacked while being in contact with each other, and the solid-liquid mixed electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles, and the porous structure is formed by pressing the solid polymer particles. The liquid electrolyte surrounds the interior of the pores of the porous structure, the portions where the solid polymer particles are in surface contact with each other, or the surfaces of the solid polymer particles, and the solid polymer particles have a solubility of less than 30% when impregnated with the liquid electrolyte. The content of the liquid electrolyte is 1-20% by weight based on the total content of 100% by weight of the solid-liquid mixed electrolyte membrane.

2. The solid-liquid mixed electrolyte membrane according to claim 1, wherein the porous structure itself has a porosity higher than that of the solid-liquid mixed electrolyte membrane.

3. The solid-liquid mixed electrolyte membrane according to claim 1, which has an ionic conductivity higher than that of the porous structure itself.

4. The solid-liquid mixed electrolyte membrane according to claim 1, wherein the solid polymer particles are engineering plastic resins.

5. The solid-liquid mixed electrolyte membrane according to claim 1, wherein the solid polymer particles include any one selected from Polyphenylene Sulfide, Polyetheretherketone, Polyimide, Polyamideimide, Liquid crystal polymer, Polyetherimide, Polysulfone, Polyarylate, Polyethylene terephthalate, Polybutyleneterephthalate, Polyoxymethylene, Polycarbonate, Polypropylene, Polyethylene, and Poly(methylmethacrylate), or two or more of them.

6. The solid-liquid mixed electrolyte membrane according to claim 1, which does not contain a binder polymer.

7. The solid-liquid mixed electrolyte membrane according to claim 1, wherein the porosity of the porous structure itself is 1-90% by volume, and the porosity of the solid-liquid mixed electrolyte membrane is 0-80% by volume, lower than that of the porous structure itself.

8. The solid-liquid mixed electrolyte membrane according to claim 1, which has a thickness of 10-500 μm.

9. The solid-liquid mixed electrolyte membrane according to claim 1, wherein the solid polymer particles have a solubility of less than 30% when impregnated with a mixture of ethylene carbonate and ethyl methyl carbonate in a ratio of 30:70 (volume %).

10. A solid-state battery, comprising: a positive electrode containing a solid electrolyte, a negative electrode containing a solid electrolyte, and a separator interposed between the positive electrode and the negative electrode and including a solid-liquid mixed electrolyte membrane as defined in any one of claims 1 to 9.

11. A lithium-ion battery, comprising: a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a liquid electrolyte, wherein the separator includes a solid-liquid mixed electrolyte membrane as defined in any one of claims 1 to 9.

12. A method for manufacturing a solid-liquid mixed electrolyte membrane, comprising the following steps: (S1) Preparing the solid polymer particles themselves or a dispersion containing the solid polymer particles dispersed in a solvent; (S2) Applying the solid polymer particles themselves or the dispersion onto a substrate and then drying; (S3) Pressurizing the product obtained in step (S2) to form a porous structure; and (S4) Coating the porous structure with a liquid electrolyte, wherein the solid polymer particles are stacked while being in contact with each other, and the solid-liquid mixed electrolyte membrane includes a porous structure having a pore structure formed between the solid polymer particles, the liquid electrolyte surrounds the portions where the solid polymer particles are in surface contact with each other, or the surfaces of the solid polymer particles, the solid polymer particles have a solubility of less than 30% when impregnated with the liquid electrolyte, and the content of the liquid electrolyte is 1-20% by weight based on the total content of 100% by weight of the solid-liquid mixed electrolyte membrane.

13. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 12, wherein the substrate is any one selected from a release film, a porous polymer substrate, or an electrode.

14. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 12, wherein the pressurization in step (S3) is a step of physically binding the solid polymer particles to each other to obtain a porous structure having a pore structure formed between the solid polymer particles.

15. The method for manufacturing a solid-liquid mixed electrolyte membrane according to claim 12, wherein the coating in step (S4) is performed by any one of dip coating, spraying, and drop coating.

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