Gel polymer electrolyte, solid-state lithium ion battery, preparation method and application

Abstract

The invention discloses a gel polymer electrolyte, a solid-state lithium ion battery, a preparation method and application. The preparation method of the gel polymer electrolyte provided by the invention comprises the following steps: mixing polyethylene glycol diacrylate, pentaerythritol tetraacrylate and an electrolyte to prepare a prepolymer; uniformly mixing an initiator, a catalyst and the prepolymer, and heating to prepare a gel polymer electrolyte; wherein the electrolyte contains a lithium salt and a solvent; the solvent comprises methyl ethyl carbonate and perfluorohexanone in a mass ratio of (5-20): 1 according to the feeding amount. The gel polymer electrolyte prepared by the preparation method provided by the invention has excellent electrochemical performance, relatively high ionic conductivity and relatively good rate capability, and the obtained gel polymer electrolyte has an obvious flame-retardant effect and relatively good stability and safety.

Description

Technical Field

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

[0002] As an important part of modern energy storage, lithium-ion batteries provide efficient energy in many fields. In recent years, all-solid-state batteries are considered to be an effective way to improve energy density and safety. However, in the field of all-solid-state batteries, the electrolytes used have poor safety performance. Specifically, they cannot effectively resist the volume expansion phenomenon associated with lithium plating and stripping. In addition, when lithium dendrites penetrate the separator, short circuit problems will occur, which may lead to thermal runaway. This series of problems seriously affects the performance and safety of all-solid-state batteries, and has become a key factor restricting their widespread application and further development. It is urgent to conduct in-depth exploration and improvement of the safety of electrolytes to improve the overall quality and reliability of all-solid-state batteries. Summary of the invention

[0003] In view of the problem of poor safety of existing electrolytes, a gel polymer electrolyte, a solid-state lithium-ion battery, a preparation method and an application are provided.

[0004] In a first aspect, in some embodiments, a method for preparing a gel polymer electrolyte is provided, comprising the following steps:

[0005] Mixing polyethylene glycol diacrylate, pentaerythritol tetraacrylate and electrolyte to prepare a prepolymer;

[0006] Evenly mixing the initiator, the catalyst and the prepolymer, and heating them to prepare the gel polymer electrolyte;

[0007] The electrolyte contains lithium salt and solvent; the solvent includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (5-20):1 based on the feed amount.

[0008] In some embodiments, in the preparation method, the mass ratio of the polyethylene glycol diacrylate to the pentaerythritol tetraacrylate is (5-20):1, calculated by feed amount.

[0009] In some embodiments, in the preparation method, the mass ratio of the total mass of the polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the mass of the electrolyte is (5-8):100, calculated based on the feed amount.

[0010] In some embodiments, in the preparation method, the electrolyte satisfies one or more of the following characteristics:

[0011] The concentration of lithium salt in the electrolyte is 1 mol / L to 2 mol / L;

[0012] The lithium salt includes one or more of lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl imide) or lithium tetrafluoroborate.

[0013] In some embodiments, in the preparation method, the lithium salt in the electrolyte includes lithium bis(trifluoromethanesulfonyl)imide; and the solvent in the electrolyte includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (8-10):1 based on the feed amount.

[0014] In some embodiments, the preparation method meets one or more of the following characteristics:

[0015] Calculated by feed amount, the ratio of the total mass of the polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the total mass of the initiator and the catalyst is (40-55):1;

[0016] Calculated by feed amount, the mass ratio of the catalyst to the initiator is 1:(2-2.5);

[0017] The initiator includes azobisisobutyronitrile;

[0018] The catalyst includes dibutyltin dilaurate.

[0019] In some embodiments, in the preparation method, the heating temperature is 50° C. to 60° C., and the heating time is 8 h to 12 h.

[0020] In a second aspect, in some embodiments, a gel polymer electrolyte is provided, which is prepared by the preparation method.

[0021] In a third aspect, in some embodiments, there is provided a use of the gel polymer electrolyte in the preparation of a solid-state lithium-ion battery.

[0022] In a fourth aspect, in some embodiments, a solid-state lithium-ion battery is provided, wherein the solid-state lithium-ion battery comprises the gel polymer electrolyte.

[0023] The present application provides a method for preparing a gel polymer electrolyte based on in-situ polymerization. The gel polymer electrolyte prepared by the preparation method provided above has good rate performance, obvious flame retardant effect, high stability, good safety, excellent electrochemical properties, and high ionic conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the implementation methods and examples of the present application and to more completely understand the present application and its beneficial effects, the following is a brief introduction to the drawings required for use in the description of the implementation methods or examples. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0025] Figure 1 This is a flow chart of the preparation process of the gel polymer electrolyte in one embodiment of the present application;

[0026] Figure 2 The electrolyte rate test result diagram of Examples 1 to 3 and Comparative Example 1, wherein Cycle number is the number of cycles, and Discharge capacity is the discharge specific capacity;

[0027] Figure 3 It is a flame retardant test result diagram of Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0031] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0032] In the present application, "plurality", "multiple", "multiple times", "multiples", etc., unless otherwise specified, refer to a number greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0033] The terms "combination thereof", "any combination thereof", "any combination thereof" and the like used in this application include all suitable combinations of any two or more of the listed items.

[0034] As used in this application, "comprises," "includes," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article, or apparatus.

[0035] In this application, the "suitable" mentioned in "suitable combination", "suitable method", "any suitable method", etc. is based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0036] In the present application, "preferred", "better", "more preferred" and "suitable" are only used to describe implementation methods or examples with better effects. It should be understood that they do not constitute limitations on the scope of protection of the present application.

[0037] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0038] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0039] In the present invention, in the "first aspect", "second aspect", "third aspect", "fourth aspect", etc., the terms "first", "second", "third", "fourth", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0040] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0041] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0042] In this application, numerical values ​​represent approximate measured values ​​or range limits to cover slight deviations from given values ​​and embodiments having approximately the mentioned values ​​and embodiments having exactly the mentioned values. Except in the working examples provided at the end of the detailed description, all numerical values ​​of (such as amount or condition) parameters in this specification (including the appended claims) should be understood to be modified by the term "approximately" in all cases, regardless of whether "approximately" actually appears before the numerical value. "Approximately" means that the numerical value allows a certain slight imprecision (close to the exact value of the value to a certain extent; approximately or reasonably approximate the value; almost). If the imprecision provided by "approximately" is not understood separately in this art in this common sense, then "approximately" used herein refers to at least the deviation that can be caused by the common methods of measuring and using such parameters. For example, "approximately" may include less than or equal to 5%, optionally less than or equal to 4%, optionally less than or equal to 3%, optionally less than or equal to 2%, optionally less than or equal to 1%, optionally less than or equal to 0.5%, and optionally less than or equal to 0.1% deviation in some aspects.

[0043] Additionally, disclosure of ranges includes disclosure of all values ​​within the entire range and further subdivided ranges, including endpoints and subranges given within those ranges.

[0044] In the present application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the optional numerical distribution is considered continuous within the above numerical interval, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical range, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints. In this article, it is equivalent to directly listing each integer, such as t is an integer selected from 1 to 10, indicating that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10. In addition, when multiple ranges are provided to describe features or characteristics, these ranges can be combined. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges included therein.

[0045] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0046] In the present application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass volume percentage.

[0047] "Room temperature" in this application generally refers to 5°C ~ 30°C, for example, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, preferably refers to 25±5°C.

[0048] All-solid-state batteries are an effective way to improve energy density and safety. However, the traditional method of preparing electrolyte membranes requires the use of solvents, dispersants and plasticizers, which are harmful to the electrolyte itself and reduce ionic conductivity, seriously hindering the commercialization of all-solid-state batteries. In addition, traditional electrolytes have various defects, such as poor flexibility of oxide electrolytes, which cannot be applied to soft-pack batteries; low conductivity and poor electrochemical stability of polymer electrolytes; and poor chemical stability of sulfide electrolytes. Therefore, it is necessary to use electrolytes with better stability and higher conductivity to prepare all-solid-state batteries.

[0049] In some embodiments, a method for preparing a gel polymer electrolyte is provided, comprising the following steps:

[0050] Mixing polyethylene glycol diacrylate, pentaerythritol tetraacrylate and electrolyte to prepare a prepolymer;

[0051] The initiator, the catalyst and the prepolymer are uniformly mixed and heated to prepare the gel polymer electrolyte;

[0052] The electrolyte contains lithium salt and solvent; based on the feed amount, the solvent includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (5-20):1.

[0053] In some embodiments, a method for preparing a gel polymer electrolyte is provided, comprising the following steps:

[0054] S100: polyethylene glycol diacrylate, pentaerythritol tetraacrylate and an electrolyte are mixed to prepare a prepolymer;

[0055] S200: uniformly mixing the initiator, the catalyst and the prepolymer, and heating them to prepare a gel polymer electrolyte;

[0056] The electrolyte contains lithium salt and solvent; based on the feed amount, the solvent includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (5-20):1.

[0057] In some embodiments, in step S100, the solvent includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (5-20):1, based on the feed amount. For example, the mass ratio of ethyl methyl carbonate and perfluorohexanone is 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1 or a range selected from any two of the foregoing ratios.

[0058] In some embodiments, in step S100, the mass ratio of polyethylene glycol diacrylate to pentaerythritol tetraacrylate is (5-20):1, based on the feed amount. For example, the mass ratio of polyethylene glycol diacrylate to pentaerythritol tetraacrylate can be 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1 or a range selected from any two of the foregoing ratios.

[0059] In some embodiments, in step S100, the mass ratio of the total mass of polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the electrolyte is (5-8):100, for example, 5:100, 6:100, 7:100, 8:100 or a range selected from any two of the foregoing ratios.

[0060] In some embodiments, in step S100, the concentration of the lithium salt in the electrolyte is 1 mol / L~2 mol / L. For example, the concentration of the lithium salt in the electrolyte can be 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, 2 mol / L, etc. The concentration of the lithium salt in the electrolyte can also be a range consisting of any two of the aforementioned values.

[0061] In some embodiments, in step S100, the lithium salt includes one or more of lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, or lithium tetrafluoroborate.

[0062] In some embodiments, in step S100, the lithium salt in the electrolyte includes lithium bis(trifluoromethanesulfonyl)imide; the solvent in the electrolyte includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (8~10):1, based on the amount of feed. For example, the mass ratio of ethyl methyl carbonate and perfluorohexanone included in the solvent in the electrolyte is 8:1, 9:1, 10:1 or a range selected from any two of the foregoing ratios.

[0063] In some embodiments, in step S200, based on the amount of feed, the ratio of the total mass of polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the total mass of the initiator and the catalyst is (40-55):1. For example, the ratio of the total mass of polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the total mass of the initiator and the catalyst can be 40:1, 41:1, 42:1, 43:1, 44:1, 45:1, 46:1, 47:1, 48:1, 49:1, 50:1, 51:1, 52:1, 53:1, 54:1, 55:1 or a range selected from any two of the foregoing ratios.

[0064] In some embodiments, in step S200, the mass ratio of the catalyst to the initiator is 1:(2-2.5) based on the feed amount. For example, the mass ratio of the catalyst to the initiator can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5 or a range selected from any two of the foregoing ratios.

[0065] In some embodiments, in step S200, the initiator includes azobisisobutyronitrile.

[0066] In some embodiments, in step S200, the catalyst includes dibutyltin dilaurate.

[0067] In some embodiments, in step S200, the heating temperature is 50°C to 60°C, for example, the heating temperature is 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C or a range selected from any two of the foregoing values, and the heating time is 8h to 12h, for example, the heating time is 8h, 9h, 10h, 11h, 12h or a range selected from any two of the foregoing values.

[0068] In a non-limiting manner, a method for preparing a gel polymer electrolyte based on in-situ polymerization is provided. In a non-limiting manner, a method for preparing a flexible gel polymer electrolyte based on in-situ polymerization is provided. The gel polymer electrolyte prepared by the method has excellent electrochemical properties and can improve the safety of the battery, which is of great significance for the development of a new flexible battery with good comprehensive performance.

[0069] In some embodiments, a gel polymer electrolyte is provided, which is prepared by the aforementioned preparation method.

[0070] The provided gel polymer electrolyte comprises an organic electrolyte and a polymer matrix, and has excellent electrochemical properties, and has high ionic conductivity and good rate performance. The polymer matrix provides sufficient mechanical strength and toughness to resist volume expansion during lithium plating / stripping, as well as short circuit and thermal runaway caused by lithium dendrites penetrating the separator. In addition, the gel electrolyte ensures the physical integrity of the electrolyte, and its liquid phase has good interfacial wettability. The provided gel polymer electrolyte has flame retardancy, stability, and improves the safety of the battery.

[0071] In some embodiments, a use of a gel polymer electrolyte in preparing a solid-state lithium-ion battery is provided.

[0072] In some embodiments, a solid-state lithium-ion battery is provided, comprising the gel polymer electrolyte.

[0073] The embodiments of the present application will be described in detail below in conjunction with some examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which the conditions are not specified in the following examples are preferably referred to the guidance given in the present application, and can also be based on the experimental manual or normal conditions in the art, or can also be based on the conditions recommended by the manufacturer, or with reference to experimental methods known in the art.

[0074] 1. Preparation of gel polymer electrolyte

[0075] Example 1

[0076] S1. 0.9 g of polyethylene glycol diacrylate and 0.09 g of pentaerythritol tetraacrylate were dissolved in 17.73 g of electrolyte to prepare a prepolymer, wherein the lithium salt in the electrolyte was lithium bis(trifluoromethylsulfonyl)imide, the lithium salt concentration in the electrolyte was 1 mol / L, and the solvent was ethyl methyl carbonate and perfluorohexanone in a mass ratio of 9:1.

[0077] S2. 0.02 g of initiator and 0.009 g of catalyst were added to the prepolymer prepared in step S1, and magnetic stirring was performed. After stirring evenly, the mixture was heated at 60° C. for 12 h to prepare a flexible gel polymer electrolyte.

[0078] Example 2

[0079] A gel polymer electrolyte was prepared by a method similar to that of Example 1, except that the lithium salt was lithium hexafluorophosphate and the amount of the electrolyte was 7.971 g.

[0080] Example 3

[0081] A gel polymer electrolyte was prepared by a method similar to that of Example 1, except that the lithium salt was lithium tetrafluoroborate and the electrolyte was 5.845 g.

[0082] Comparative Example 1

[0083] A liquid electrolyte was prepared by a method similar to that of Example 1. The difference from Example 1 was that the solvent of the electrolyte was ethyl methyl carbonate and fluoroethylene carbonate in a mass ratio of 9:1.

[0084] 2. Performance Test

[0085] The electrolytes obtained in Examples 1 to 3 and Comparative Example 1 were subjected to ion conductivity tests, rate characteristics tests, and combustion tests.

[0086] The ionic conductivity test method is as follows: The electrolytes obtained in Examples 1 to 3 and Comparative Example 1 are assembled into a steel symmetrical battery for electrochemical testing.

[0087] In the rate characteristic test, the electrolytes obtained in Examples 1 to 3 and Comparative Example 1 were assembled into batteries with commercial lithium iron phosphate positive electrodes and lithium metal negative electrodes for testing. The theoretical capacity of the material is 160 mAh / g, and the test rate parameters are 0.1C, 0.2C, 0.5C, 1C, and 2C.

[0088] The combustion test method is as follows: the gel polymer electrolyte obtained in Example 1 and Comparative Example 1 is brought into contact with a lighter flame.

[0089] The ionic conductivity test results can be found in Table 1, Table 2 and Figure 2 This is the result of the rate test. Figure 3This is the flame retardant test result diagram.

[0090] Table 1

[0091]

[0092] It can be seen from Table 1 that the ionic conductivity of the gel polymer electrolytes prepared using different lithium salts is different, and the gel polymer electrolyte prepared using lithium bis(trifluoromethylsulfonyl)imide has a higher ionic conductivity.

[0093] Table 2

[0094]

[0095] From Table 2 and Figure 2 It can be seen that the gel polymer electrolyte provided by Example 1 has the best rate performance, which proves that the gel electrolyte membrane prepared by Example 1 has good interface contact. In particular, at high rates, the performance of Example 1 is better, indicating that it has good stability.

[0096] from Figure 3 It can be seen that the gel polymer electrolyte provided in Example 1 has an obvious flame retardant effect, which proves that adding perfluorohexanone as a solvent has a flame retardant effect.

[0097] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description and drawings may be used to interpret the content of the claims.

[0099] The applicant declares that the present invention illustrates the detailed process equipment and process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a gel polymer electrolyte, characterized in that: The following steps are involved: Mixing polyethylene glycol diacrylate, pentaerythritol tetraacrylate and electrolyte to prepare a prepolymer; Evenly mixing the initiator, the catalyst and the prepolymer, and heating them to prepare the gel polymer electrolyte; The electrolyte contains lithium salt and solvent; the solvent includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (5-20):1 based on the feed amount.

2. The preparation method according to claim 1, characterized in that: Calculated by feed amount, the mass ratio of the polyethylene glycol diacrylate to the pentaerythritol tetraacrylate is (5-20):

1.

3. The preparation method according to claim 1 or 2, characterized in that: Calculated by feed amount, the mass ratio of the total mass of the polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the mass of the electrolyte is (5-8):

100.

4. The preparation method according to any one of claims 1 to 3, characterized in that The electrolyte satisfies one or more of the following characteristics: The concentration of lithium salt in the electrolyte is 1 mol / L to 2 mol / L; The lithium salt includes one or more of lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl imide) or lithium tetrafluoroborate.

5. The preparation method according to claim 4, characterized in that: The lithium salt in the electrolyte includes lithium bis(trifluoromethanesulfonyl)imide; and the solvent in the electrolyte includes ethyl methyl carbonate and perfluorohexanone in a mass ratio of (8-10):1, based on the feed amount.

6. The preparation method according to any one of claims 1 to 5, characterized in that Meet one or more of the following characteristics: Calculated by feed amount, the ratio of the total mass of the polyethylene glycol diacrylate and pentaerythritol tetraacrylate to the total mass of the initiator and the catalyst is (40-55):1; Calculated by feed amount, the mass ratio of the catalyst to the initiator is 1:(2-2.5); The initiator includes azobisisobutyronitrile; The catalyst includes dibutyltin dilaurate.

7. The preparation method according to any one of claims 1 to 5, characterized in that The heating temperature is 50° C. to 60° C., and the heating time is 8 h to 12 h.

8. A gel polymer electrolyte, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the gel polymer electrolyte according to claim 8 in preparing a solid-state lithium-ion battery.

10. A solid-state lithium-ion battery, characterized in that: The solid-state lithium-ion battery comprises the gel polymer electrolyte of claim 8.

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