A preparation method of a precursor solution, a gel polymer electrolyte and application thereof

Abstract

This invention belongs to the field of polymer-based solid-state battery technology, specifically disclosing a method for preparing a precursor solution and a gel polymer electrolyte, and their applications. The precursor solution includes a liquid monomer and an electrolyte salt dissolved in the liquid monomer, wherein: the monomer is one or more of the following: cyclic ether, cyclic carbonate, acrylamide and acrylamide derivatives containing functional groups, acrylate and acrylate oligomers containing double bonds on one side, acrylonitrile and acrylonitrile derivatives containing functional groups, cyanoacrylate and cyanoacrylate derivatives containing functional groups; the electrolyte salt is a lithium salt, potassium salt, or sodium salt. This invention utilizes electron beam irradiation to initiate the polymerization of the precursor solution inside the battery to prepare a gel polymer electrolyte or polymer-based battery, avoiding the adverse effects of using initiators on battery performance, while effectively improving the contact performance of the electrode-electrolyte interface. This preparation method is simple and efficient, and is conducive to large-scale production.

Description

Technical Field

[0001] This invention belongs to the field of polymer-based solid-state battery technology, and more specifically, relates to a method for preparing a precursor solution and a gel polymer electrolyte and their applications. Background Technology

[0002] Lithium-ion batteries are currently the most widely used rechargeable batteries. However, lithium-ion batteries using organic liquid electrolytes have potential safety issues, such as flammability of the electrolyte and electrolyte leakage. Using solid-state electrolytes can effectively improve battery safety. Solid-state electrolyte materials mainly include inorganic solid electrolytes and organic polymer electrolytes. Inorganic solid electrolytes have high room-temperature ionic conductivity and excellent thermal stability, but they have poor processability and poor electrode / electrolyte interface contact. Polymer electrolytes have good viscoelasticity and processability, which can effectively improve the performance of solid-solid interface contact, but their room-temperature ionic conductivity is low.

[0003] Gel polymer electrolytes combine the flexibility of polymer electrolytes with the high ionic conductivity of liquid electrolytes. Currently, common methods for preparing gel polymer electrolytes include chemical methods or thermally initiated free radical crosslinking polymerization. These methods require the addition of additional initiators and are carried out under heating conditions, and the initiators may adversely affect the electrolyte and electrode performance of the battery. In contrast, the method using high-energy electron beam-initiated crosslinking polymerization is green, efficient, requires no initiators, and can be applied on a large scale.

[0004] Chinese patent CN 104659413 A discloses a method for preparing a radiation-crosslinked polymeric gel electrolyte framework material. The method involves preparing a fiber membrane blend of an ion-conductive polymer and a radiation-crosslinkable polymer using electrospinning technology, followed by electron beam or gamma-ray irradiation treatment to crosslink the membrane and obtain a gel-type polymeric electrolyte framework material. No initiator or crosslinking agent is required in this process. However, the gel polymeric electrolyte prepared by this method is not conducive to constructing a tightly contacted electrode / electrolyte interface, which affects the lithium-ion transport efficiency between the electrode and the electrolyte. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing precursor solutions and gel polymer electrolytes, as well as their applications. The method involves preparing gel polymer electrolytes in situ inside a battery using electron beam irradiation, thereby solving the problem of poor contact between the electrodes and electrolytes caused by the non-in-situ preparation of existing gel polymer electrolytes.

[0006] To achieve the above objectives, the present invention provides a precursor solution for in-situ preparation of gel polymer electrolytes, comprising a liquid monomer and an electrolyte salt dissolved in the liquid monomer, wherein:

[0007] The monomer is one or more of the following: cyclic ether, cyclic carbonate, acrylamide and acrylamide derivatives containing functional groups, acrylate and acrylate oligomers that still contain double bonds on one side, acrylonitrile and acrylonitrile derivatives containing functional groups, cyanoacrylate and cyanoacrylate derivatives containing functional groups.

[0008] The electrolyte salt is a lithium salt, potassium salt, or sodium salt.

[0009] Preferably, the monomer is a cyclic ether.

[0010] Preferably, the cyclic ether is a three-membered ring, a four-membered ring, a five-membered ring, a six-membered ring, or an eight-membered ring; the cyclic carbonate is a five-membered ring with unsaturated double bonds in the side chain.

[0011] Preferably, the concentration of the electrolyte salt is 0.1 mol / L to 3 mol / L.

[0012] According to another aspect of the present invention, a method for preparing a gel polymer electrolyte is also provided, wherein the precursor solution of the present invention is subjected to electron beam irradiation, and the monomers in the precursor solution undergo ring-opening polymerization or cross-linking polymerization to obtain a gel polymer electrolyte.

[0013] Preferably, the electron beam irradiation dose is 5kGy-500kGy.

[0014] According to another aspect of the present invention, a polymer-based solid-state battery is also provided, comprising a positive electrode, a negative electrode, a separator, and an electrolyte; the electrolyte is a gel polymer electrolyte prepared by the method of the present invention; the positive electrode and the negative electrode are respectively located on both sides of the gel polymer electrolyte and in contact with it; the separator is located between the positive electrode and the negative electrode.

[0015] Preferably, the active material of the positive electrode is lithium iron phosphate, lithium cobalt oxide, ternary nickel-cobalt-manganese, sulfur positive electrode, sulfurized polyacrylonitrile, sodium iron phosphate, sodium vanadium phosphate, or Prussian blue type positive electrode.

[0016] According to another aspect of the present invention, a method for preparing a polymer-based solid-state battery is also provided, comprising the following steps:

[0017] S1. Under a protective atmosphere, the monomer and electrolyte salt are mixed uniformly in a certain proportion to obtain a precursor solution; wherein, the monomer is one or more of the following: cyclic ether, cyclic carbonate, acrylamide and acrylamide derivatives containing functional groups, acrylate and acrylate oligomers that still contain double bonds on one side, acrylonitrile and acrylonitrile derivatives containing functional groups, cyanoacrylate and cyanoacrylate derivatives containing functional groups; the electrolyte salt is a lithium salt, potassium salt or sodium salt.

[0018] S2. Under a protective atmosphere, the precursor solution obtained in step S1 is introduced into the separator by liquid injection and assembled into a battery.

[0019] S3. The assembled battery is left to stand at room temperature for a period of time. After the precursor solution wets the electrode, it is then subjected to electron beam irradiation. The monomer undergoes in-situ ring-opening polymerization or cross-linking polymerization inside the battery to form a gel polymer electrolyte, thereby obtaining a polymer-based solid-state battery.

[0020] Preferably, the settling time is 6h-12h.

[0021] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art:

[0022] (1) The precursor solution for in-situ preparation of gel polymer electrolyte provided by the present invention has no limitation on the selection of monomers. The monomers used are polymerizable materials that can be directly purchased from the market or are easy to synthesize. They can undergo ring-opening polymerization or cross-linking polymerization under high-energy electron beam irradiation.

[0023] (2) The monomer in the precursor solution of the present invention is a cyclic ether, which is more friendly to the negative electrode of polymer-based solid-state battery than esters as electrolytes, and is less likely to react with them, which is beneficial to the improvement of battery performance.

[0024] (3) The present invention prepares gel polymer electrolyte by initiating ring-opening polymerization or cross-linking polymerization by high-energy electron beam irradiation, which avoids the adverse effects of the use of photoinitiators and thermal initiators on battery performance; and prepares gel polymer electrolyte in situ in the battery to build a tightly contacted electrode / electrolyte interface, which is beneficial to improve the transport efficiency of electrolyte cations between the electrode and the electrolyte. Moreover, the preparation method is simple, efficient and practical.

[0025] (4) Compared with traditional photo-initiated or thermally-initiated monomer crosslinking polymerization, the present invention uses electron beam irradiation to prepare gel polymer electrolytes, which have a higher degree of monomer polymerization and a more complete polymerization reaction. At the same time, the electrolyte polymers formed by the monomer ring-opening polymerization or crosslinking polymerization selected in the present invention have small interaction forces with electrolyte cations, which is conducive to the migration of electrolyte cations. This makes the gel polymer electrolytes prepared in the present invention have a wide electrochemical window and a high ion mobility number, and exhibit excellent electrochemical performance after being matched with a high energy density cathode.

[0026] (5) Since the outer shell of a soft-pack battery is thinner than that of a hard-pack battery, its irradiation effect is better. The method of the present invention is particularly suitable for the preparation of soft-pack batteries. At the same time, soft-pack batteries have the advantages of light weight, high specific energy, high safety and customizable shape. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating the preparation process of the gel polymer electrolyte or polymer-based solid-state battery provided by the present invention.

[0028] Figure 2 This is a graph showing the changes in ionic conductivity of gel polymer electrolytes with different compositions prepared under different doses of electron beam irradiation in Example 5 of the present invention.

[0029] Figure 3 This is a graph showing the ionic conductivity of the gel polymer electrolyte provided in Example 6 of the present invention at different temperatures;

[0030] Figure 4 This is an ion migration number diagram of the gel polymer electrolyte provided in Example 6 of the present invention at a temperature of 27°C;

[0031] Figure 5 This is an electrochemical window diagram of the gel polymer electrolyte provided in Example 6 of the present invention;

[0032] Figure 6 This is a cycle performance diagram of the lithium / lithium iron phosphate gel polymer battery prepared in situ in Example 7 of the present invention;

[0033] Figure 7 This is a charge-discharge curve of the lithium / cobalt oxide gel polymer battery prepared in situ in Example 8 of the present invention;

[0034] Figure 8 This is a charge-discharge curve of the lithium / nickel-cobalt-manganese ternary 622 gel polymer battery prepared in situ in Example 9 of the present invention;

[0035] Figure 9 This is a cycle performance diagram of the lithium / lithium iron phosphate gel polymer soft-pack battery prepared in situ in Example 10 of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] This invention provides a precursor solution for in-situ preparation of gel polymer electrolytes, comprising a liquid monomer and an electrolyte salt dissolved in the liquid monomer, wherein:

[0038] The monomers are one or more of the following: cyclic ethers, cyclic carbonates, acrylamide and acrylamide derivatives containing functional groups, acrylates and acrylate oligomers that still contain double bonds on one side, acrylonitrile and acrylonitrile derivatives containing functional groups, cyanoacrylates and cyanoacrylate derivatives containing functional groups.

[0039] The electrolyte salt is a lithium salt, potassium salt, or sodium salt.

[0040] In some embodiments, the cyclic ether can be a three-membered, four-membered, five-membered, six-membered, or eight-membered ring, preferably 1,3-dioxolane or tetrahydrofuran. The cyclic carbonate is a five-membered ring with unsaturated double bonds in its side chain.

[0041] The lithium salt can be lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate (LiAsF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(oxalateborate)borate (LiBOB), lithium difluorooxalateborate (LiDFOB), or lithium trifluoromethanesulfonate (LiCF3SO3).

[0042] Sodium salts can be sodium hexafluorophosphate (NaPF6), sodium perchlorate (NaClO4), sodium tetrafluoroborate (NaBF4), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(oxalateborate)borate (NaBOB), sodium difluorooxalateborate (NaDFOB), and sodium trifluoromethanesulfonate (NaCF3SO3).

[0043] Potassium salts can be potassium hexafluorophosphate (KPF6), potassium hexafluoroarsenate (KAsF6), potassium perchlorate (KClO4), potassium tetrafluoroborate (KBF4), potassium bis(trifluoromethanesulfonyl)imide (KTFSI), potassium bis(trifluoromethanesulfonyl)imide (KFSI), and potassium trifluoromethanesulfonate (KCF3SO3).

[0044] The precursor solution of the present invention is a homogeneous mixed solution obtained by mixing the above monomers and electrolyte salts in a certain proportion, wherein the concentration of the electrolyte salts is 0.1 mol / L-3 mol / L.

[0045] like Figure 1 As shown, the present invention also provides a method for preparing a gel polymer electrolyte, which includes the following steps:

[0046] S1. Under a protective atmosphere, the monomer and electrolyte salt described in this invention are mixed evenly in a certain proportion to obtain a precursor solution;

[0047] S2. Under a protective atmosphere, the precursor solution obtained in step S1 is introduced into the separator by liquid injection and assembled into a battery.

[0048] S3. The assembled battery is left to stand at room temperature for a period of time until the precursor solution wets the electrodes, and then subjected to electron beam irradiation. The monomers undergo in-situ ring-opening polymerization or cross-linking polymerization inside the battery to form a gel polymer electrolyte. Specifically, cyclic ethers and cyclic carbonates undergo ring-opening polymerization under electron beam irradiation, while other monomers undergo cross-linking polymerization under electron beam irradiation.

[0049] In some embodiments, the electron beam irradiation dose is 5 kGy-500 kGy.

[0050] The present invention provides a polymer-based solid-state battery, which includes a positive electrode, a negative electrode, a separator, and an electrolyte; the electrolyte is a gel polymer electrolyte provided by the present invention; the positive electrode and the negative electrode are located on both sides of the gel polymer electrolyte and in contact with it; the separator is located between the positive electrode and the negative electrode.

[0051] The gel polymer electrolyte of this invention can be matched with different types of positive electrode materials to assemble batteries. Specifically, the active material of the positive electrode can be lithium iron phosphate, lithium cobalt oxide, ternary nickel-cobalt-manganese, sulfur positive electrode, sulfurized polyacrylonitrile, sodium iron phosphate, sodium vanadium phosphate, or Prussian blue positive electrode (such as K2Mn[Fe(CN)6]). The negative electrode is metallic lithium, metallic sodium, or metallic potassium. The separator can be a polyethylene (PE) separator, a polypropylene (PP) separator, a cellulose membrane, a non-woven membrane, a polyimide separator, or a glass fiber separator.

[0052] The polymer-based solid-state battery of the present invention can be a hard-pack battery, including cylindrical and prismatic batteries, or a soft-pack battery. The outer shell of the soft-pack battery (e.g., aluminum-plastic film) is thinner than that of the hard-pack battery, and the electron beam can penetrate the battery shell more easily. The in-situ preparation method of gel polymer electrolyte of the present invention is more suitable for the preparation of soft-pack batteries. Soft-pack batteries have many advantages such as small size, light weight, high specific energy, high safety, and flexible design.

[0053] This invention provides a method for in-situ preparation of gel polymer electrolyte and assembly of hard-pack batteries. Taking a coin cell as an example, the method includes the following steps: Under a protective atmosphere, the positive electrode shell, positive electrode sheet, separator and negative electrode sheet are assembled in sequence, and left to stand at room temperature for a period of time. After the precursor solution wets the electrode, the precursor solution undergoes in-situ ring-opening polymerization or cross-linking polymerization inside the battery under the action of high-energy electron beam irradiation to form a gel polymer electrolyte. Finally, it is assembled with the negative electrode shell of the coin cell to obtain a polymer-based solid-state battery.

[0054] This invention provides a method for in-situ preparation of gel polymer electrolyte and assembly of pouch cell, comprising the following steps: under a protective atmosphere, a positive electrode, a separator, and a negative electrode are assembled into a bare cell and then placed in an aluminum-plastic film; the precursor solution of this invention is then injected into the bare cell; vacuum sealing is performed and the cell is left to stand at room temperature for a period of time to allow the precursor solution to fully wet the electrodes; the resulting cell is then irradiated under a high-energy electron beam, and the precursor solution undergoes in-situ ring-opening polymerization or cross-linking polymerization inside the cell to form a gel polymer electrolyte, thereby obtaining a polymer-based solid-state pouch cell.

[0055] In some embodiments, the protective atmosphere is an inert gas, preferably high-purity argon, which can keep the electrolyte stable and prevent it from reacting, and prevent oxygen or water vapor from mixing into the battery.

[0056] In some embodiments, the room temperature standing time is 6-12 hours, which allows the precursor solution to fully wet the interfaces of the positive and negative electrodes of the battery, thereby constructing a tightly contacted electrode / electrolyte interface. The electron beam irradiation dose is 5 kGy-500 kGy.

[0057] The above technical solution will be described in detail below with reference to specific embodiments.

[0058] Example 1

[0059] This embodiment provides a precursor solution for in-situ preparation of gel polymer electrolytes: 1,3-dioxolane is selected as the monomer, and lithium salt is selected as the electrolyte salt. In this embodiment, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is specifically selected, and the concentration of lithium salt is 1 mol / L. The precursor solution is obtained by mixing evenly.

[0060] The diaphragm is an ultra-thin PE diaphragm with a thickness of 8μm.

[0061] The precursor solution was dropwise added onto a PE membrane and then subjected to high-energy electron beam irradiation at a dose of 50 kGy. 1,3-Dioxocyclopentane underwent ring-opening polymerization after electron beam irradiation to prepare a gel-type polymer electrolyte. The ionic conductivity of this electrolyte was then tested at 30°C, and the conductivity was found to be 1.0 × 10⁻⁶. -5 S / cm.

[0062] Example 2

[0063] The preparation method for the gel polymer electrolyte was the same as in Example 1, except that tetrahydrofuran was used as the monomer, while other conditions remained unchanged. The ionic conductivity of the electrolyte based on polytetrahydrofuran at 30°C was 2.2 × 10⁻⁶. -5 S / cm.

[0064] Example 3

[0065] The preparation method for the gel polymer electrolyte was consistent with that in Example 1, except that 2,5-dihydrofuran was used as the monomer, while other conditions remained unchanged. The electrolyte based on poly-2,5-dihydrofuran exhibited an ionic conductivity of 6.6 × 10⁻⁶ at 30°C. -6 S / cm.

[0066] Example 4

[0067] The preparation method for the gel polymer electrolyte is consistent with that in Example 1, except that propylene oxide is used as the monomer, while other conditions remain unchanged. The ionic conductivity of the propylene oxide-based electrolyte at 30°C is 6.1 × 10⁻⁶. -7 S / cm.

[0068] Example 5

[0069] The method for preparing the gel polymer electrolyte is the same as in Example 1, except that ethylene carbonate and polyethylene glycol dimethacrylate are used as monomers, and other conditions remain unchanged. The mass ratio of ethylene carbonate to polyethylene glycol dimethacrylate is 1:(0.25-1.5). In this example, five ratios of 4:6, 5:5, 6:4, 7:3, and 8:2 were used for the experiment. Figure 2 The ionic conductivity of gel polymer electrolytes with different compositions at 30°C is calculated from... Figure 2 It can be seen that as the content of the crosslinking agent polyethylene glycol dimethacrylate decreases, the ionic conductivity continuously increases.

[0070] Example 6

[0071] Similar to Example 5, the mass ratio of ethylene carbonate monomer to polyethylene glycol dimethacrylate in the precursor solution was 8:2. In this example, the ionic conductivity of the gel polymer electrolyte prepared based on this precursor solution was tested at different temperatures. Figure 3 As shown, this gel polymer electrolyte exhibits high ionic conductivity at 27°C, with a value of 1.7 × 10⁻⁶. -4 S / cm. This example also tested the ion transport number and electrochemical window of the electrolyte at 27°C, as shown below. Figure 4 and Figure 5 As shown, the lithium-ion transference number is 0.76, and the electrochemical window of this electrolyte is wide up to 5.4V.

[0072] Example 7

[0073] This embodiment fabricates a polymer-based solid-state battery, and the separator, positive electrode, and negative electrode used are as follows:

[0074] The diaphragm is an ultra-thin PE diaphragm with a thickness of 8μm;

[0075] Positive electrode sheet: The positive electrode active material, conductive agent, and binder are mixed in a mass ratio of 8:1:1 to form a slurry, which is then coated onto an aluminum foil current collector and dried. In this embodiment, lithium iron phosphate is selected as the positive electrode active material, Super P is selected as the conductive agent, and 5wt% PVDF is selected as the binder (the solvent is N-methylpyrrolidone).

[0076] The negative electrode is a lithium metal sheet.

[0077] The specific preparation method of the polymer-based solid-state battery in this embodiment is as follows:

[0078] Under a high-purity argon atmosphere, ethylene carbonate and polyethylene glycol dimethacrylate were mixed at a mass ratio of 8:2, and lithium bis(trifluoromethanesulfonyl)imide was added and mixed evenly to prepare a precursor solution with a lithium salt concentration of 1 mol / L.

[0079] Under a high-purity argon atmosphere, the positive electrode, separator, and negative electrode are sequentially composited and placed in a stainless steel positive electrode battery case, and a precursor solution is injected. The case is left to stand at room temperature for 6 hours to allow the precursor solution to fully wet the electrodes. Then, the case is subjected to high-energy electron beam irradiation with an irradiation dose of 500 kGy. After irradiation, the precursor solution undergoes in-situ cross-linking polymerization within the positive electrode battery case to form a gel polymer electrolyte. This electrolyte is then assembled with the negative electrode case under a pressure of 1.2 MPa to complete the coin cell encapsulation.

[0080] The lithium / lithium iron phosphate solid polymer battery prepared in this embodiment was subjected to cycle performance testing, such as... Figure 6 As shown, the battery can be stably cycled 160 times with a capacity retention rate of 92%.

[0081] Example 8

[0082] The method for preparing polymer-based solid-state batteries is the same as in Example 7, except that lithium cobalt oxide is used as the positive electrode active material in this example, while other conditions remain unchanged.

[0083] The lithium / cobalt oxide solid polymer battery prepared in this embodiment was subjected to charge-discharge tests, such as... Figure 7 As shown, the battery assembled with this electrolyte and lithium cobalt oxide cathode has good cycle stability.

[0084] Example 9

[0085] The method for preparing polymer-based solid-state batteries is the same as in Example 7, except that nickel-cobalt-manganese ternary 622 is used as the positive electrode active material, while other conditions remain unchanged.

[0086] The lithium / nickel-cobalt-manganese ternary 622 solid polymer battery prepared in this embodiment was subjected to charge-discharge tests, such as... Figure 8As shown, the battery assembled with this electrolyte and a nickel-cobalt-manganese ternary 622 cathode exhibits good cycle stability. Furthermore, combined with the above embodiments, it demonstrates that this electrolyte can be matched with different cathodes and has a wide range of applications.

[0087] Example 10

[0088] This embodiment prepares a polymer-based solid-state soft-pack battery, using the same precursor solution, separator, positive electrode, and negative electrode as in Example 7.

[0089] The specific packaging steps of the soft-pack battery are as follows: Under a high-purity argon atmosphere, the positive electrode, separator, and negative electrode are assembled into a bare cell and then placed in an aluminum-plastic film. The precursor solution is then injected into the bare cell, followed by vacuum sealing. The cell is left to stand at room temperature for 12 hours to allow the precursor solution to fully wet the electrodes. Then, it is subjected to high-energy electron beam irradiation with an irradiation dose of 200 kGy. After irradiation, the precursor solution undergoes in-situ cross-linking polymerization inside the battery to form a gel polymer electrolyte, thus completing the soft-pack battery packaging.

[0090] The gel polymer electrolyte-based pouch cell prepared in this embodiment was subjected to cycle performance testing, such as... Figure 9 As shown, the pouch battery can stably cycle 50 times with a capacity retention rate of 93%.

[0091] This invention prepares a gel polymer electrolyte by utilizing the fluidity of liquids. A liquid precursor is first used to fully wet the interfaces of a solid-state battery, followed by in-situ polymerization to generate the polymer electrolyte. This effectively improves the compatibility of the solid-solid interface in all-solid-state batteries. The in-situ preparation method of the gel polymer electrolyte is applicable to the polymerization of different types of monomers, avoiding the use of initiators that are detrimental to battery performance. Furthermore, this electrolyte can be matched with different types of cathodes, showing broad application prospects. The preparation method of the gel polymer electrolyte in this invention is simple and rapid, can be matched with existing battery manufacturing processes, facilitates large-scale production, and produces polymer-based solid-state batteries with good performance.

[0092] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polymer-based solid-state battery, characterized in that: Includes positive electrode, negative electrode, membrane, and electrolyte; The electrolyte is a gel polymer electrolyte prepared by electron beam irradiation of a precursor solution; the precursor solution is composed of a liquid monomer and an electrolyte salt dissolved in the liquid monomer; the liquid monomer is ethylene carbonate and polyethylene glycol dimethacrylate, and the mass ratio of ethylene carbonate to polyethylene glycol dimethacrylate is 8:2; the electrolyte salt is a lithium salt. The active material of the positive electrode is nickel-cobalt-manganese ternary 622; The negative electrode is a lithium metal sheet; The positive and negative electrodes are located on both sides of the gel polymer electrolyte and are in contact with it; the separator is located between the positive and negative electrodes. The method for preparing the polymer-based solid-state battery includes the following steps: S1. Under a protective atmosphere, the liquid monomer and the electrolyte salt are mixed evenly in a certain proportion to obtain the precursor solution; S2. Under a protective atmosphere, the precursor solution obtained in step S1 is introduced into the separator by liquid injection and assembled into a battery. S3. The assembled battery is left to stand at room temperature for a period of time until the precursor solution wets the electrode, and then subjected to electron beam irradiation at a dose of 500 kGy. The liquid monomer crosslinks and polymerizes in situ inside the battery to form a gel polymer electrolyte, thus obtaining a polymer-based solid battery.

2. The polymer-based solid-state battery according to claim 1, characterized in that: The concentration of the electrolyte salt is 0.1 mol / L to 3 mol / L.

3. The polymer-based solid-state battery according to claim 1, characterized in that: The settling time is 6 h-12 h.

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