Solid-state electrolyte, preparation method and application

Abstract

The present invention relates to a solid electrolyte, a preparation method thereof and an application. The solid electrolyte includes a solid electrolyte main body and phase change microcapsules; the phase change microcapsules are dispersed in the solid electrolyte main body; the phase change microcapsules include a thermosensitive phase change shell, a diffusing agent and a poisoning agent, and the diffusing agent and the poisoning agent are located inside the thermosensitive phase change shell. When the battery has an abnormal temperature due to abuse, the thermosensitive phase change shell ruptures, and the poisoning agent and the diffusing agent located inside the thermosensitive phase change shell are released. The poisoning agent reacts with the energetic electrolyte, the positive electrode and the negative electrode of the battery, etc., so that materials such as the energetic electrolyte, the positive electrode and the negative electrode are in a stable state and no longer have reaction activity, or blocks the direct contact or gas crosstalk contact between the energetic electrolyte, the positive electrode and the negative electrode, avoiding problems such as thermal runaway, combustion, explosion, etc. caused by the exothermic reaction of the contact of the energetic components of the battery, and thus can improve the safety performance of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a solid electrolyte, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous development of battery technology, the types of batteries are increasing, and the performance of batteries is also continuously improving. Currently, the widely used lithium-ion batteries mainly use liquid electrolytes as the conductive medium, which have good performance and can better meet the usage requirements of consumers for batteries. However, with the continuous upgrading of consumer demands, the currently widely used lithium-ion batteries gradually show unsatisfactory performance in terms of energy density, and the side reactions between the ternary positive electrode and the flammable electrolyte in lithium-ion batteries also pose a great threat to the safe use of batteries, restricting the development of lithium-ion batteries.

[0003] As a supplement and extension of high-energy-density and high-safety-performance batteries, solid-state batteries and semi-solid-state batteries have emerged as the times require. Compared with the currently widely used lithium-ion batteries, solid-state batteries and semi-solid-state batteries have better performance in terms of energy density and safety. One of the reasons is that solid-state batteries and semi-solid-state batteries mainly use solid electrolytes as the conductive medium, reducing or even eliminating the use of liquid electrolytes, thereby effectively improving the energy density and safety threshold of the batteries.

[0004] Although solid-state batteries and semi-solid-state batteries have a significant improvement in terms of energy density and safety threshold compared with the currently widely used lithium-ion batteries, there are still materials such as combustible and exothermic positive electrodes, negative electrodes, and solid electrolytes in solid-state batteries and semi-solid-state batteries. Therefore, there are still certain potential safety hazards when solid-state batteries and semi-solid-state batteries are abused. When the battery temperature exceeds its safety threshold or the battery is damaged, the reaction between battery components or the reaction between battery components and oxygen in the air will also generate a large amount of heat, causing battery thermal runaway, and even leading to problems such as battery combustion and explosion. Therefore, how to further improve the safety performance of solid-state batteries and semi-solid-state batteries is of great significance for the development of batteries. Summary of the Invention

[0005] Based on this, it is necessary to provide a solid electrolyte that can effectively improve the safety performance of solid-state batteries and semi-solid-state batteries, a preparation method thereof, and an application thereof.

[0006] To solve the above technical problems, the technical solution of the present invention is as follows:

[0007] A solid electrolyte includes a solid electrolyte main body and phase change microcapsules; the phase change microcapsules are dispersed in the solid electrolyte main body; the phase change microcapsules include a thermosensitive phase change shell, a dispersant, and a poison, and the dispersant and the poison are located inside the thermosensitive phase change shell.

[0008] In one embodiment, the thermosensitive phase change housing includes a polymer thermosensitive phase change housing; and / or,

[0009] The dispersant includes at least one of polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl ether, alkyl benzene sulfonate, and alkyl naphthalene sulfonate.

[0010] In one embodiment, the poison includes at least one of amine poisons, ester poisons, ether poisons, alkane poisons, salt poisons, and hydrate poisons.

[0011] In one embodiment, the amine poisons include at least one of ethylenediamine, trihexylamine, and dibenzylamine; the ester poisons include at least one of tributyl phosphate, vinyl trifluoromethyl carbonate, and octyl diphenyl phosphate; the ether poisons include at least one of hexafluoroisopropyl methyl ether and methyl nonafluorobutyl ether; the alkane poisons include at least one of 1,1,1,2,2,3,4,5,5,5 - decafluoro - 3 - methoxy - 4 - (trifluoromethyl) pentane or 1,1,1,2,3,4,4,5,5,5 - decafluoro - 3 - methoxy - 2 - trifluoromethyl pentane; the salt poisons include at least one of 1 - ethyl - 3 - methylimidazolium bis(fluorosulfonyl)imide salt and N - methyl, propylpyrrolidinium bis(trifluoromethanesulfonyl)imide salt; the hydrate poisons include at least one of aluminum sulfate hexadecahydrate and magnesium sulfate heptahydrate.

[0012] A method for preparing a solid electrolyte includes the following steps:

[0013] Mix a thermosensitive phase change housing material, a dispersant, a poison, a catalyst, and a first solvent to in - situ prepare phase - change microcapsules;

[0014] Mix the phase - change microcapsules, a solid electrolyte main body, and a second solvent.

[0015] In one embodiment, the first solvent includes at least one of formaldehyde, glutaraldehyde, and glyoxal; and / or,

[0016] The second solvent includes at least one of water and ethanol; and / or,

[0017] The catalyst is at least one of polyvinyl alcohol, sodium dodecylbenzenesulfonate, and gum arabic.

[0018] In one embodiment, mixing a thermosensitive phase change housing material, a dispersant, a poison, a catalyst, and a first solvent to in - situ prepare phase - change microcapsules includes the following steps:

[0019] The phase change microcapsules are prepared in situ by mixing the thermosensitive phase change shell material, the dispersant, the poison, the catalyst and the first solvent at a stirring speed of 700 rpm to 900 rpm and a temperature of 60 °C to 80 °C.

[0020] In one embodiment, mixing the phase change microcapsules, the solid electrolyte matrix and the second solvent includes the following steps:

[0021] Mix the phase change microcapsules with the second solvent, and then add the solid electrolyte matrix.

[0022] In one embodiment, mixing the phase change microcapsules with the second solvent and then adding the solid electrolyte matrix includes the following steps:

[0023] Mix the phase change microcapsules with the second solvent at a stirring speed of 500 rpm to 2000 rpm and a temperature of 20 °C to 100 °C, and then add the solid electrolyte matrix.

[0024] A solid electrolyte membrane includes the solid electrolyte in any of the above embodiments; or includes the solid electrolyte prepared by the preparation method in any of the above embodiments.

[0025] A method for preparing a solid electrolyte membrane includes the following steps: performing a film-forming treatment on the solid electrolyte in any of the above embodiments; or performing a film-forming treatment on the solid electrolyte prepared by the preparation method in any of the above embodiments.

[0026] An energy storage device includes the above solid electrolyte membrane; or includes the solid electrolyte membrane prepared by the above preparation method.

[0027] The above solid electrolyte includes a solid electrolyte matrix and phase change microcapsules; the phase change microcapsules are dispersed in the solid electrolyte matrix; the phase change microcapsules include a thermosensitive phase change shell, a dispersant and a poison, and the dispersant and the poison are located inside the thermosensitive phase change shell. When the temperature of the battery becomes abnormally high due to abuse, the thermosensitive phase change shell ruptures, and the poison located inside the thermosensitive phase change shell is released. At the same time, the dispersant can reduce the surface tension of the poison, making it easy for the poison to wet and spread on the surfaces of the poisoning targets such as the energetic electrolyte, the positive electrode and the negative electrode, promoting the penetration of the poison, and causing the poison to react with the energetic electrolyte, the positive electrode and the negative electrode of the battery, so that the materials such as the energetic electrolyte, the positive electrode and the negative electrode are in a stable state and no longer have reactivity, or blocking the direct contact or gas crosstalk contact between the energetic electrolyte, the positive electrode and the negative electrode, avoiding problems such as thermal runaway, combustion and explosion caused by the exothermic reaction of the contact of the energetic components of the battery, and thus improving the safety performance of the battery.

[0028] The preparation method of the above solid electrolyte comprises the following steps: mixing a thermosensitive phase change shell material, a dispersant, a poison, a catalyst and a first solvent to in-situ prepare phase change microcapsules; mixing the phase change microcapsules, a solid electrolyte matrix and a second solvent. In the above preparation method, the phase change microcapsules are obtained in an in-situ preparation manner, which is convenient for controlling and observing and analyzing the generation process of the phase change microcapsules; then the phase change microcapsules, the solid electrolyte matrix and the second solvent are mixed to prepare the solid electrolyte. The preparation method has a simple and easy operation process, is convenient for controlling and observing and analyzing the preparation process, and is easy to realize industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural view of a solid electrolyte (solid electrolyte membrane) in an embodiment of the present invention;

[0030] Figure 2 It is a schematic structural view of a solid-state battery in an embodiment of the present invention;

[0031] Figure 3 It is the temperature rise curves of the solid-state batteries in Example 1 and Comparative Example 1 during abuse.

[0032] Description of the marks in the figures:

[0033] 100, solid electrolyte (solid electrolyte membrane); 101, solid electrolyte matrix; 102, phase change microcapsules; 200, positive electrode; 300, negative electrode; 400, solid-state battery. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0035] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the description of this invention herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0037] Please refer to Figure 1 , an embodiment of the present invention provides a solid electrolyte 100. The solid electrolyte 100 includes a solid electrolyte main body 101 and phase change microcapsules 102; the phase change microcapsules 102 are dispersed in the solid electrolyte main body 101; the phase change microcapsules 102 include a thermosensitive phase change shell (not shown in the figure), a diffusing agent (not shown in the figure), and a poisoning agent (not shown in the figure), and the diffusing agent and the poisoning agent are located inside the thermosensitive phase change shell. When the solid electrolyte 100 is applied to a battery, when the temperature of the battery becomes abnormally high due to abuse, the thermosensitive phase change shell ruptures, and the poisoning agent located inside the thermosensitive phase change shell is released. At the same time, the diffusing agent can reduce the surface tension of the poisoning agent, making it easy for the poisoning agent to wet and spread on the surfaces of poisoning targets such as the energetic electrolyte, the positive electrode, and the negative electrode, promoting the penetration of the poisoning agent, and causing the poisoning agent to react with the energetic electrolyte, the positive electrode, and the negative electrode of the battery, so that materials such as the energetic electrolyte, the positive electrode, and the negative electrode are in a stable state and no longer have reaction activity, or blocking the direct contact or gas crosstalk contact between the energetic electrolyte, the positive electrode, and the negative electrode, avoiding problems such as thermal runaway, combustion, and explosion caused by exothermic reactions due to the contact of energetic components in the battery, and thus improving the safety performance of the battery.

[0038] It can be understood that the electrolyte of a all-solid-state battery is entirely composed of solid electrolyte. The electrolyte of a semi-solid-state battery mainly uses solid electrolyte, and at the same time, a small amount of liquid electrolyte is also contained in the electrolyte of the semi-solid-state battery.

[0039] It should be noted that the phase change microcapsules 102 being dispersed in the solid electrolyte main body 101 means that all of the phase change microcapsules 102 are dispersed inside the solid electrolyte main body 101, or it can also mean that all of the phase change microcapsules 102 are dispersed on the surface of the solid electrolyte main body 101, or it can also mean that all of the phase change microcapsules 102 protrude from the surface of the solid electrolyte main body 101, or it can also mean that some of the phase change microcapsules 102 are dispersed inside the solid electrolyte main body 101, or it can also mean that some of the phase change microcapsules 102 are dispersed on the surface of the solid electrolyte main body 101, or it can also mean that some of the phase change microcapsules 102 protrude from the surface of the solid electrolyte main body 101. Specifically, in Figure 1In the shown solid electrolyte 100, there are multiple phase change microcapsules 102. The multiple phase change microcapsules 102 are dispersed in the solid electrolyte matrix 101. Among them, some phase change microcapsules 102 are dispersed inside the solid electrolyte matrix 101, some phase change microcapsules 102 are dispersed on the surface of the solid electrolyte matrix 101, and still some phase change microcapsules 102 protrude from the surface of the solid electrolyte matrix 101.

[0040] It can also be understood that, as a choice for the solid electrolyte matrix 101, the material of the solid electrolyte matrix 101 can adopt conventional solid electrolyte materials. For example, the material of the solid electrolyte matrix 101 includes at least one of oxide electrolyte materials, polymer electrolyte materials, and sulfide electrolyte materials.

[0041] In a specific example, to better match the phase change microcapsules 102 with the solid electrolyte matrix 101 and the solid electrolyte 100, the length of the phase change microcapsules 102 is 1 μm to 1000 μm. Optionally, the length of the phase change microcapsules 102 is 1 μm, 10 μm, 50 μm, 80 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or 1000 μm, etc. Of course, the length of the phase change microcapsules 102 can also be other suitable choices within the range of 1 μm to 1000 μm. Regarding the shape of the phase change microcapsules 102, it can be strip-shaped, spherical, ellipsoidal, etc.

[0042] In a specific example, the phase change temperature of the thermosensitive phase change shell is 60°C to 250°C. Selecting a thermosensitive phase change shell with a suitable phase change temperature can make the phase change temperature of the thermosensitive phase change shell match the thermal runaway temperature of the battery. When the battery has a thermal runaway problem, the thermosensitive phase change shell can phase change and rupture in time to release the diffusing agent and the poisoning agent, blocking the thermal runaway of the battery and timely avoiding problems such as combustion and explosion that the battery may suffer from thermal runaway. Optionally, the phase change temperature of the thermosensitive phase change shell is 60°C, 70°C, 80°C, 90°C, 100°C, 120°C, 150°C, 180°C, 200°C, 220°C, or 250°C. Of course, the phase change temperature of the thermosensitive phase change shell can also be other suitable choices within the range of 60°C to 250°C. It can be understood that a thermosensitive phase change shell with a suitable phase change temperature can be selected according to the thermal runaway temperature and / or the thermal failure temperature of the battery.

[0043] Specifically, as an example of the selection of the thermosensitive phase change shell, the thermosensitive phase change shell includes a polymer thermosensitive phase change shell. Optionally, the material of the thermosensitive phase change shell includes a thermosensitive polymer material. Optionally, the material of the thermosensitive phase change shell includes at least one of ethylene-vinyl acetate copolymer, low-density polyethylene, polycaprolactone, polyethylene oxide, polyethylene glycol, ethylene-octene copolymer, ethylene-acrylic acid copolymer, and polyethylene glycol succinate. Further optionally, the melting temperature of the ethylene-vinyl acetate copolymer is 180°C to 250°C; the melting temperature of the low-density polyethylene is 100°C to 130°C; the melting temperature of the polycaprolactone is 60°C to 80°C; the melting temperature of the polyethylene oxide is 60°C to 90°C; the melting temperature of the polyethylene glycol is 40°C to 70°C; the melting temperature of the ethylene-octene copolymer is 100°C to 150°C; the melting temperature of the ethylene-acrylic acid copolymer is 100°C to 200°C; the melting temperature of the polyethylene glycol succinate is 100°C to 150°C.

[0044] As an optional example of the dispersant, the dispersant includes at least one of polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl ether, alkyl benzene sulfonate, and alkyl naphthalene sulfonate. During the use of the solid electrolyte, the dispersant can reduce the surface tension of the poison, making it easy for the poison to wet and spread on the surfaces of the poison targets such as the energetic electrolyte, the positive electrode, and the negative electrode, and promoting the penetration of the poison. Further, through the selection of the above dispersants, the poison can penetrate and cover the inside of the battery cell within 30 s in the range of 60°C to 250°C, effectively improving the response speed of the poison and more timely blocking the thermal runaway of the battery, thereby improving the safety performance of the battery.

[0045] As optional examples of the poison, the poison includes at least one of amine poisons, ester poisons, ether poisons, alkane poisons, salt poisons, and hydrate poisons. Among them, the amine poison can reduce the conductivity of the electrolyte matrix, increase the charge transfer resistance, reduce the maximum temperature of thermal failure of the battery by about 50%, and reduce the heat generation of the battery by about 50%. The ester poison can undergo a polymerization reaction with the electrolyte matrix to form a physical isolation layer, reduce the solid-solid and solid-liquid interface contacts inside the battery, prevent the continuous progress of exothermic side reactions, reduce the maximum temperature of thermal failure of the battery by about 40%, and reduce the heat generation of the battery by about 60%. The ether poison can repeatedly perform redox reactions between the positive and negative electrodes to consume excess current, reduce the maximum temperature of thermal failure of the battery by about 40%, and reduce the heat generation of the battery by about 60%. The alkane poison can delay the oxygen release temperature of the phase change of the battery positive electrode, adsorb combustible gas molecules on the negative electrode side, and reduce the heat generation of the battery by about 40%. The salt poison can react with the electrolyte matrix, consume combustible components, and can also adsorb combustible gas molecules on the negative electrode side, reducing the heat generation of the battery by about 40%. The hydrate poison undergoes a dehydration reaction at high temperatures, reacts with the electrolyte matrix material and the lithium-inserting negative electrode, avoids the occurrence of thermal runaway, and can reduce the heat generation of the battery by about 70%.

[0046] Specifically, the amine poison includes at least one of ethylenediamine, trihexylamine, and dibenzylamine; the ester poison includes at least one of tributyl phosphate, vinyl trifluoromethyl carbonate, and octyl diphenyl phosphate (CAS No.: 115-88-8); the ether poison includes at least one of hexafluoroisopropyl methyl ether and methyl nonafluorobutyl ether (CAS No.: 163702-07-6); the alkane poison includes at least one of 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane or 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-trifluoromethylpentane; the salt poison includes at least one of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide salt (CAS No.: 235789-75-0) and N-methyl,propylpyrrolidinium bis(trifluoromethanesulfonyl)imide salt (CAS No.: 223436-99-5); the hydrate poison includes at least one of aluminum sulfate hexadecahydrate and magnesium sulfate heptahydrate.

[0047] It can be understood that Figure 1 The structure shown can also represent a solid electrolyte membrane 100 in an embodiment of the present invention. The solid electrolyte membrane 100 includes a solid electrolyte matrix 101 and phase change microcapsules 102; the phase change microcapsules 102 are dispersed in the solid electrolyte matrix 101; the phase change microcapsules 102 include a thermosensitive phase change shell, a dispersant, and a poison, and the dispersant and the poison are located inside the thermosensitive phase change shell.

[0048] Another embodiment of the present invention provides a method for preparing a solid electrolyte. The method for preparing the solid electrolyte includes the following steps: mixing a thermosensitive shell material, a dispersant, a poison, a catalyst, and a first solvent to in-situ prepare phase change microcapsules; mixing the phase change microcapsules, a solid electrolyte matrix, and a second solvent. In the preparation method of this embodiment, the phase change microcapsules are obtained by in-situ preparation, which is convenient for controlling and observing the generation process of the phase change microcapsules; then the phase change microcapsules, the solid electrolyte matrix, and the second solvent are mixed to prepare the solid electrolyte. The preparation method has a simple and easy operation process, is convenient for controlling and observing the preparation process, and is easy to realize industrial promotion.

[0049] In a specific example, the first solvent includes at least one of formaldehyde, glutaraldehyde, and glyoxal. The first solvent can provide a crosslinking effect for the in-situ preparation reaction.

[0050] In another specific example, the second solvent includes at least one of water and ethanol. The second solvent mainly plays a role in dilution and dispersion.

[0051] In another specific example, the catalyst is at least one of polyvinyl alcohol, sodium dodecylbenzenesulfonate, and gum arabic (CAS No.: 9000-01-5).

[0052] It can be understood that the selection of the dispersant, the poison, and the solid electrolyte matrix can be respectively selected from the dispersant, the poison, and the solid electrolyte matrix listed above, which will not be elaborated here.

[0053] In a specific example, mixing the thermosensitive shell material, the dispersant, the poison, the catalyst, and the first solvent to in-situ prepare phase change microcapsules includes the following steps: mixing the thermosensitive shell material, the dispersant, the poison, the catalyst, and the first solvent at a stirring speed of 700 rpm to 900 rpm and a temperature of 60 °C to 80 °C to in-situ prepare phase change microcapsules. Optionally, the stirring speed is 700 rpm, 720 rpm, 750 rpm, 780 rpm, 800 rpm, 820 rpm, 850 rpm, 880 rpm, or 900 rpm. Optionally, the temperature can be 60 °C, 62 °C, 65 °C, 68 °C, 70 °C, 72 °C, 75 °C, 78 °C, or 80 °C. Of course, the stirring speed can also be selected for other suitable values within the range of 700 rpm to 900 rpm, and the temperature can also be selected for other suitable values within the range of 60 °C to 80 °C.

[0054] In a specific example, after mixing a thermosensitive shell material, a dispersant, a poison, a catalyst, and a first solvent to in-situ prepare phase change microcapsules, the following steps are further included: subjecting the mixture obtained after in-situ preparing the phase change microcapsules to solid-liquid separation treatment to obtain solid-phase phase change microcapsules. Through the solid-liquid separation treatment, a solid phase and a liquid phase are obtained, and the solid phase is the phase change microcapsule. Optionally, the solid-liquid separation treatment can adopt centrifugation treatment.

[0055] In a specific example, mixing the phase change microcapsules, a solid electrolyte matrix, and a second solvent includes the following steps: mixing the phase change microcapsules with the second solvent, and then adding the solid electrolyte matrix.

[0056] Specifically, mixing the phase change microcapsules with the second solvent and then adding the solid electrolyte matrix includes the following steps: mixing the phase change microcapsules with the second solvent at a stirring speed of 500 rpm to 2000 rpm and a temperature of 20 °C to 100 °C, and then adding the solid electrolyte matrix.

[0057] In a specific example, the preparation method of the solid electrolyte includes the following steps: mixing a thermosensitive shell material, a dispersant, a poison, a catalyst, and a first solvent to in-situ prepare phase change microcapsules; subjecting the mixture obtained after in-situ preparing the phase change microcapsules to solid-liquid separation treatment to obtain solid-phase phase change microcapsules; adding a second solvent to the solid-phase phase change capsules, and then adding the solid electrolyte matrix to mix the phase change microcapsules, the solid electrolyte matrix, and the second solvent.

[0058] Specifically, when performing the solid-liquid separation treatment, the solid phase and the liquid phase are partially separated, so that the obtained solid phase still contains a certain amount of the liquid phase, and then a second solvent is added to the solid phase, and then the solid electrolyte matrix is added. More specifically, after the solid-liquid separation treatment, a second solvent is added to displace the liquid phase in the mixture after in-situ preparing the phase change microcapsules with the second solvent, and then the solid electrolyte matrix is added.

[0059] Another embodiment of the present invention provides a solid electrolyte membrane. The solid electrolyte membrane includes the above-mentioned solid electrolyte; or includes the solid electrolyte prepared by the above-mentioned preparation method.

[0060] Another embodiment of the present invention provides a preparation method of a solid electrolyte membrane. The preparation method of the solid electrolyte membrane includes the following steps: performing a film-forming treatment on the above-mentioned solid electrolyte; or performing a film-forming treatment on the solid electrolyte prepared by the above-mentioned solid electrolyte preparation method.

[0061] Specifically, the solid electrolyte membrane is formed by film-forming the above-mentioned solid electrolyte; or the solid electrolyte membrane is formed by film-forming the solid electrolyte prepared by the above-mentioned solid electrolyte preparation method.

[0062] Optionally, the film-forming treatment includes roll compaction for film formation.

[0063] Another embodiment of the present invention provides an energy storage device. The energy storage device includes the above-mentioned solid electrolyte membrane; or includes a solid electrolyte membrane prepared by the above-mentioned method for preparing a solid electrolyte membrane. In the embodiment, by introducing the solid electrolyte membrane, the energy storage device can have the performance of timely preventing thermal runaway and thermal failure, and thus the energy storage device has good use safety performance.

[0064] Optionally, the energy storage device includes a solid-state battery or a semi-solid-state battery.

[0065] In a specific example, the energy storage device includes the above-mentioned solid electrolyte membrane; the solid electrolyte membrane includes a solid electrolyte main body and phase change microcapsules; the phase change microcapsules are dispersed in the solid electrolyte main body; the phase change microcapsules include a thermosensitive phase change shell, a dispersant, and a poison agent, and the dispersant and the poison agent are located inside the thermosensitive phase change shell.

[0066] In a specific example, the energy storage device further includes a positive electrode and a negative electrode, and the positive electrode and the negative electrode are respectively located on the upper surface and the lower surface of the solid electrolyte membrane.

[0067] Please refer to Figure 2 , an embodiment of the present invention provides a solid-state battery 400, which includes a positive electrode 200, a negative electrode 300, and a solid electrolyte membrane 100. The solid electrolyte membrane 100 is located between the positive electrode 200 and the negative electrode 300. The solid electrolyte membrane 100 includes a solid electrolyte main body 101 and phase change microcapsules 102; the phase change microcapsules 102 are dispersed in the solid electrolyte main body 101; the phase change microcapsules 102 include a thermosensitive phase change shell, a dispersant, and a poison agent, and the dispersant and the poison agent are located inside the thermosensitive phase change shell.

[0068] The following are specific embodiments.

[0069] Example 1

[0070] The preparation method of the solid electrolyte in this embodiment includes the following steps:

[0071] S101: At a stirring speed of 800 rpm and a temperature of 70 °C, mix a thermosensitive shell material, a dispersant, a poison agent, a catalyst, and a first solvent to in-situ prepare phase change microcapsules.

[0072] S102: Centrifuge the mixture obtained after in-situ preparing the phase change microcapsules to obtain solid-phase phase change microcapsules.

[0073] S103: Mix the solid-phase change microcapsules and the second solvent at a stirring speed of 1000 rpm and a temperature of 50 °C, then add the solid electrolyte matrix material. After mixing and reacting, filter to obtain the solid electrolyte.

[0074] Among them, the thermosensitive phase change shell material is ethylene-vinyl acetate copolymer, the dispersant is polyoxyethylene alkyl aryl ether, the poisoner is ethylenediamine, the catalyst is polyvinyl alcohol, the first solvent is formaldehyde, the second solvent is water, and the material of the solid electrolyte matrix is an oxide electrolyte material.

[0075] The solid electrolyte prepared in this example is roll-pressed into a film to prepare a solid electrolyte film. And a solid-state battery is prepared through this solid electrolyte film. Among them, the solid-state battery includes a solid electrolyte film, a positive electrode, and a negative electrode. The positive electrode and the negative electrode are respectively located on the upper surface and the lower surface of the solid electrolyte film.

[0076] Comparative Example 1

[0077] Compared with Example 1, the difference in Comparative Example 1 is that the solid electrolyte film in the solid-state battery is obtained by roll-pressing the solid electrolyte matrix material and does not contain phase change microcapsules.

[0078] The temperature rise curves of the solid-state batteries in Example 1 and Comparative Example 1 during abuse are as Figure 3 shown. It can be seen from Figure 3 that compared with Comparative Example 1, the temperature of the solid-state battery in Example 1 during thermal runaway is significantly lower than that in Comparative Example 1, and it is not easy to cause problems such as combustion and explosion of the battery, indicating that the solid-state battery in Example 1 has higher safety performance.

[0079] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0080] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims, and the description and drawings can be used to explain the content of the claims.

Claims

1. A solid electrolyte, characterized in that, It includes a solid electrolyte matrix and phase change microcapsules; the phase change microcapsules are dispersed in the solid electrolyte matrix; the phase change microcapsules include a thermosensitive phase change shell, a dispersant, and a poison agent, and the dispersant and the poison agent are located inside the thermosensitive phase change shell; the dispersant includes at least one of polyoxyethylene alkyl aryl ether, polyoxyethylene alkyl ether, alkyl benzene sulfonate, and alkyl naphthalene sulfonate, the thermosensitive phase change shell includes a polymer thermosensitive phase change shell, and the poison agent includes at least one of amine poison agents, ester poison agents, ether poison agents, alkane poison agents, salt poison agents, and hydrate poison agents.

2. The solid electrolyte according to claim 1, wherein, The material of the thermosensitive phase change shell includes at least one of ethylene-vinyl acetate copolymer, low-density polyethylene, polycaprolactone, poly(ethylene oxide), polyethylene glycol, ethylene-octene copolymer, ethylene-acrylic acid copolymer, and polyethylene glycol succinate.

3. The solid electrolyte according to any one of claims 1 to 2, characterized in that, The length of the phase change microcapsules is 1 μm to 1000 μm.

4. The solid electrolyte according to claim 3, characterized in that, The amine poison agents include at least one of ethylenediamine, trihexylamine, and dibenzylamine; the ester poison agents include at least one of tributyl phosphate, vinylene carbonate trifluoromethyl, and octyl diphenyl phosphate; the ether poison agents include at least one of hexafluoroisopropyl methyl ether and methyl nonafluorobutyl ether; the alkane poison agents include at least one of 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane or 1,1,1,2,3,4,4,5,5,5-decafluoro-3-methoxy-2-trifluoromethylpentane; the salt poison agents include at least one of 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide salt and N-methyl,propylpyrrolidinium bis(trifluoromethylsulfonyl)imide salt; the hydrate poison agents include at least one of aluminum sulfate hexadecahydrate and magnesium sulfate heptahydrate.

5. The preparation method of the solid electrolyte according to any one of claims 1 to 4, characterized in that, It includes the following steps: Mix the thermosensitive phase change shell material, the dispersant, the poison agent, the catalyst, and the first solvent to in-situ prepare the phase change microcapsules; Mix the phase change microcapsules, the solid electrolyte matrix, and the second solvent.

6. The preparation method of the solid electrolyte according to claim 5, wherein The first solvent includes at least one of formaldehyde, glutaraldehyde, and glyoxal; and / or, The second solvent includes at least one of water and ethanol; and / or, The catalyst is at least one of polyvinyl alcohol, sodium dodecylbenzenesulfonate, and gum arabic.

7. The method for preparing a solid electrolyte according to claim 5, wherein Mixing the thermosensitive phase change shell material, the dispersant, the poison agent, the catalyst, and the first solvent to in-situ prepare the phase change microcapsules includes the following steps: Under a stirring speed of 700 rpm to 900 rpm and a temperature of 60 °C to 80 °C, mix the thermosensitive phase change shell material, the dispersant, the poison agent, the catalyst, and the first solvent to in-situ prepare the phase change microcapsules.

8. The method for preparing a solid electrolyte according to any one of claims 5 to 7, characterized in that, Mixing the phase change microcapsules, the solid electrolyte matrix, and the second solvent includes the following steps: Mix the phase change microcapsules with the second solvent, and then add the solid electrolyte matrix.

9. The method for preparing a solid electrolyte according to claim 8, wherein, Mixing the phase change microcapsules with the second solvent, and then adding the solid electrolyte matrix includes the following steps: Mix the phase change microcapsules with the second solvent at a stirring speed of 500 rpm to 2000 rpm and a temperature of 20 °C to 100 °C, and then add the solid electrolyte matrix.

10. A solid electrolyte membrane, characterized in that, Comprising the solid electrolyte according to any one of claims 1 to 4; or comprising the solid electrolyte prepared by the preparation method according to any one of claims 5 to 9.

11. A method for preparing a solid electrolyte membrane, characterized in that, Comprising the following steps: performing a film-forming treatment on the solid electrolyte according to any one of claims 1 to 4; or performing a film-forming treatment on the solid electrolyte prepared by the preparation method according to any one of claims 5 to 9.

12. An energy storage device, characterized in that, Comprising the solid electrolyte membrane according to claim 10; or comprising the solid electrolyte membrane prepared by the preparation method according to claim 11.

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