Polymer gel electrolyte membrane, method for preparing the same, and battery

Abstract

This invention relates to the field of new energy batteries, specifically to a polymer gel electrolyte membrane, its preparation method, and a battery thereof. The polymer gel electrolyte membrane comprises a cross-linked polymer with a three-dimensional network structure; the cross-linked polymer includes a polymer backbone material and a lithium salt, with at least a portion of the lithium salt located within the pores of the polymer backbone material; the polymer backbone material includes a first segment, a second segment, and a third segment; the first segment includes a first free radical and a first group; the second segment includes a polymeric monomer and a second free radical; and the third segment includes a third free radical and a third group. The three-dimensional network structure of the cross-linked polymer in this invention exhibits good toughness and tensile strength, enabling the polymer gel electrolyte membrane to demonstrate high tensile strength and elongation at break.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy batteries, in particular to a polymer gel electrolyte film, a preparation method thereof and a battery. BACKGROUND

[0002] In the field of lithium ion batteries and solid-state batteries, polymer gel electrolytes have become a research hotspot due to their characteristics of ion conductivity and mechanical strength. Polymer gel electrolytes encapsulate liquid electrolytes in a three-dimensional polymer network, which can overcome the leakage risk of traditional liquid electrolytes and avoid the interface impedance problem of all-solid-state electrolytes. However, the existing technology still faces multiple challenges: (1) the balance between ion conductivity and mechanical strength - high ion conductivity often depends on flexible matrix and high lithium salt concentration, but it will lead to mechanical performance decline; on the contrary, rigid matrix can improve strength, but it inhibits ion transmission efficiency; (2) poor interface compatibility - poor interface contact between polymer matrix and electrode material can easily cause lithium dendrite growth; (3) environmental adaptability limitation - the influence of temperature change on ion migration number has not been effectively solved.

[0003] The research progress of multifunctional fillers shows a polarization trend: on the one hand, nano-oxides (such as SiO2, Al2O3) and carbon-based materials (such as graphene, carbon nanotubes) are widely studied due to their high specific surface area and ion transmission channel effect, but their agglomeration problem leads to uneven dispersion and poor interface compatibility with the polymer matrix; on the other hand, organic-inorganic hybrid fillers (such as SiO2 / PEO composite materials) can partially improve the interface problem, but they are difficult to mass produce due to complex preparation process. The latest research attempts to introduce porous structure fillers (such as mesoporous carbon, zeolite), which can improve the liquid retention rate of electrolyte, but the pore size distribution regulation and ion selective permeation mechanism are not clear. In addition, the trade-off between the increase in electrolyte thermal stability and the increase in cost still lacks systematic research, which is a key bottleneck restricting the practical application of multifunctional fillers. SUMMARY

[0004] Therefore, the present application is devoted to providing a polymer gel electrolyte film, a preparation method thereof and a battery, to solve the problems of ion conductivity, mechanical strength and poor environmental adaptability of the electrolyte film in the prior art.

[0005] To solve the above technical problems, the present application is implemented as follows:

[0006] The first aspect of the present application provides a polymer gel electrolyte film, which comprises a cross-linked polymer with a three-dimensional network structure; the cross-linked polymer comprises a polymer skeleton material and a lithium salt, and at least part of the lithium salt is located in the pores of the polymer skeleton material.

[0007] The polymer backbone material includes a first segment, a second segment, and a third segment;

[0008] The first chain segment comprises a first free radical and a first group; the first free radical comprises [-CH2-CH2-O-]. m - Wherein, 1≤m≤3; the first group includes hydroxyl and / or ether bonds;

[0009] The second segment comprises a polymeric monomer and a second free radical, wherein the polymeric monomer comprises at least one selected from vinylidene chloride, methyl acrylate, and ethyl acrylate, and the second free radical comprises [-CH2-CHCl-]. n - Where 1 ≤ n ≤ 3;

[0010] The third segment comprises a third free radical and a third group; the third free radical comprises [-CH2-C(CH3)(COOR)-]. p - Wherein, 1≤p≤3, and R is a fluorosulfonamide or carbonate group; the third group includes a carbon-carbon double bond and / or an ester group.

[0011] Optionally, the specific surface area of ​​the polymer gel electrolyte membrane is 150~300m². 2 / g; and / or, the average pore size of the polymer gel electrolyte membrane is 0.5~2μm; and / or, the porosity of the polymer gel electrolyte membrane is 30~60%.

[0012] Optionally, the polymer gel electrolyte membrane further includes nanofillers, at least a portion of which are located within the pores of the cross-linked polymer; optionally, the nanofillers include at least one of nanoporous diatomaceous earth particles, nano-SiO2, and kaolin.

[0013] Optionally, the nanofiller is nanoporous diatomaceous earth particles; optionally, the purity of the nanoporous diatomaceous earth particles is 98.5~99.5%; and / or, the Dv50 of the nanoporous diatomaceous earth particles is 1~5μm; and / or, the pore size of the nanoporous diatomaceous earth particles is 10~50nm, and the porosity is 50~70%.

[0014] A second aspect of the present invention provides a method for preparing a polymer gel electrolyte membrane, the method comprising the following steps:

[0015] S1. The polymer monomer, plasticizer, lithium salt, interface additive, crosslinking agent, visible light initiator, thermal initiator, redox initiation aid and solvent are mixed and treated to obtain the first material;

[0016] S2. The first material is coated on the surface of the substrate, and after standing, it is dried to obtain a pre-condensed film.

[0017] S3. The initial coagulated film is subjected to photo-initiated polymerization, gradient temperature treatment and microwave cross-linking curing reaction to obtain a cured gel film.

[0018] S4. The cured gel film is dried.

[0019] The polymer monomers include at least one of vinylidene chloride, methyl acrylate and ethyl acrylate;

[0020] The plasticizer includes at least one of polyethylene glycol, polypropylene glycol, and polyethylene oxide;

[0021] The crosslinking agent includes at least one of methylpropane triacrylate, 1,1-dimethylvinyl glycol and pentaerythritol tetraacrylate;

[0022] The visible light initiator includes at least one of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzophenone, and 4-phenyldibenzofuranone;

[0023] The thermal initiator includes at least one of di-tert-butyl peroxide, benzoyl peroxide, and tert-butyl peroxide.

[0024] Optionally, the mass ratio of the polymerizing monomer, the plasticizer, the lithium salt, the interface additive, the crosslinking agent, the visible light initiator, and the redox initiation aid is 1:(3~5):(0.2~0.4):(0.05~0.15):(0.1~0.3):(0.01~0.03):(0.005~0.015); and / or, the amount of solvent used is 8~12 mL relative to each g of polymerizing monomer.

[0025] Optionally, the lithium salt includes at least one of lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate, and lithium bis(trifluoromethanesulfonyl)imide; and / or, the interface additive includes at least one of fluoroethylene carbonate, trimethyl phosphate, and lithium difluorophosphate; and / or, the redox initiator includes at least one of ascorbic acid, sodium isoascorbate, and vitamin C palmitate; and / or, the solvent includes at least one of acetonitrile, N-methylpyrrolidone, and dimethylacetamide.

[0026] Optionally, in step S2, the thickness of the coating on the substrate surface is 100~150μm; and / or, the drying conditions include: a temperature of 20~25℃ and a time of 30~60min; and / or, in step S3, the conditions for the photoinitiated polymerization reaction include: a visible light wavelength of 420~500nm and a light intensity of 50~150mW / cm². 2 The irradiation time is 5-10 min; and / or, the gradient heating treatment includes a first stage heating, a second stage heating, and a third stage heating; the temperature of the first stage heating is 50-60℃, and the time is 10-30 min; the temperature of the second stage heating is 80-100℃, and the time is 30-50 min; the temperature of the third stage heating is 110-140℃, and the time is 10-30 min; the heating rate of the gradient heating treatment is 2-10℃ / min; and / or, the conditions of the microwave crosslinking curing reaction include: microwave frequency 2-3 GHz, microwave power 300-700 W, curing temperature 120-140℃, and curing time 0.5-1.5 h; and / or, in step S4, the drying treatment is supercritical drying; optionally, the conditions of the supercritical drying treatment include: pressure 8-12 MPa, and temperature 30-50℃.

[0027] Optionally, the first material further contains nanofillers; optionally, the content of the nanofillers is 8-12 wt% based on the total mass of the first material.

[0028] A third aspect of the present invention provides a battery comprising an electrolyte membrane, the electrolyte membrane comprising the polymer gel electrolyte membrane described above and / or a polymer gel electrolyte membrane prepared according to the method described above.

[0029] The beneficial technical effects of the present invention through the above technical solution are as follows:

[0030] (1) The polymer gel electrolyte membrane of the present invention comprises a cross-linked polymer having a three-dimensional network structure, wherein the three-dimensional network structure of the cross-linked polymer has good toughness and tensile strength, so that the polymer gel electrolyte membrane exhibits high tensile strength and elongation at break.

[0031] (2) The preparation method of the present invention, through photothermal dual thermal initiation, microwave synergistic regulation, drying and other methods, synthesizes a polymer gel electrolyte with the following advantages: First, the preparation process of the present invention is more efficient. The photothermal dual initiation process significantly shortens the polymerization reaction time. Microwave dynamic crosslinking and other steps can be automated, greatly reducing the time and cost of manual operation; Second, through the design of the ion transport network and the crosslinking curing process, the migration rate and electrochemical stability of the battery are significantly improved; Third, the visible light initiation system and microwave-assisted crosslinking process reduce energy consumption and environmental pollution; Fourth, through the synergistic effect of multiple functional components such as lithium salt, interface additives, and plasticizers, a polymer gel electrolyte with excellent comprehensive performance is prepared.

[0032] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof.

[0034] Figure 1 The image shown is a scanned image (SEM) of the polymer gel electrolyte membrane prepared in Example 1.

[0035] Figure 2 The Fourier transform infrared (FTIR) spectrum of the polymer gel electrolyte membrane prepared in Example 1 is shown. Detailed Implementation

[0036] This invention discloses a polymer gel electrolyte membrane, its preparation method, and a battery. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It is particularly important to note that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0037] In the description of this invention, the list of items connected by the term "at least one of" or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0038] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0039] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0040] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0041] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0042] To address the shortcomings of existing electrolyte membranes in terms of ionic conductivity, mechanical strength, and environmental adaptability, the present invention employs the following technical solution:

[0043] A first aspect of the present invention provides a polymer gel electrolyte membrane comprising a cross-linked polymer having a three-dimensional network structure; the cross-linked polymer comprising a polymer backbone material and a lithium salt, wherein at least a portion of the lithium salt is located within the pores of the polymer backbone material;

[0044] The polymer backbone material includes a first segment, a second segment, and a third segment;

[0045] The first chain segment comprises a first free radical and a first group; the first free radical comprises [-CH2-CH2-O-]. m -Wherein, 1≤m≤3; the first group includes hydroxyl and / or ether bonds;

[0046] The second segment comprises a polymeric monomer and a second free radical, wherein the polymeric monomer comprises at least one selected from vinylidene chloride, methyl acrylate, and ethyl acrylate, and the second free radical comprises [-CH2-CHCl-]. n - Where 1 ≤ n ≤ 3;

[0047] The third segment comprises a third free radical and a third group; the third free radical comprises [-CH2-C(CH3)(COOR)-]. p - Wherein, 1≤p≤3, and R is a fluorosulfonamide or carbonate group; the third group includes a carbon-carbon double bond and / or an ester group.

[0048] The polymer gel electrolyte membrane of the present invention comprises a cross-linked polymer with a three-dimensional network structure, wherein the three-dimensional network structure has good toughness and tensile strength, enabling the polymer gel electrolyte membrane to exhibit high tensile strength and elongation at break. The polymer backbone material of the present invention comprises a first segment, a second segment, and a third segment, wherein the ether bond oxygen atom of the first segment is bonded to Li… + Coordination can lower the migration activation energy, increase the transference number and ionic conductivity. At the same time, the ether bond in the first segment has a large degree of freedom in bond angle, which improves the molecular chain ductility and increases the elongation at break. The C-Cl bond in the second segment has high polarity, which can induce inter-chain dipole interactions, increase the molecular chain slip energy barrier, and increase tensile strength. The ester group in the third segment forms a hydrogen bond network with the -OH on the surface of the cathode material, which can reduce interfacial phase transition. The CF bond energy in the third segment is much higher than that of CH, which can delay thermal oxidation and improve the thermal stability of the product.

[0049] According to the present invention, a suitable specific surface area of ​​the polymer gel electrolyte membrane can improve ion transport efficiency. In this invention, the specific surface area of ​​the polymer gel electrolyte membrane can be 150~300 m² / g. 2 / g. Exemplarily, the specific surface area of ​​the polymer gel electrolyte membrane can be 150 m². 2 / g、175 m 2 / g、200 m 2 / g、225 m 2 / g、250 m 2 / g、275m 2 / g and 300 m 2 Any value in / g or any value within the range formed by any two of the above values.

[0050] In this invention, if the pore size of the polymer gel electrolyte membrane is too large, it may lead to insufficient cross-linking of the polymer network and a loose structure, resulting in poor mechanical reliability and easy failure. It will also affect the transport capacity, causing a decrease in battery coulombic efficiency. A larger pore size weakens the membrane's ability to sieve impurity ions, accelerating the decay rate. If the pore size of the polymer gel electrolyte membrane is too small, it may limit the ion migration rate and quantity, reducing ionic conductivity and power density. Furthermore, a small pore size will hinder ion transport, increasing the ion concentration gradient near the electrode / electrolyte interface, making lithium deposition more likely at high rates and triggering irreversible side reactions. According to this invention, the pore size of the polymer gel electrolyte membrane can be 0.5~2μm; exemplaryly, the pore size of the polymer gel electrolyte membrane can be any value selected from 0.5μm, 0.75μm, 1μm, 1.5μm, and 2μm, or any value within the range formed by any two of the above values.

[0051] According to the present invention, a suitable porosity of the polymer gel electrolyte membrane can improve ion transport efficiency. In this invention, the porosity of the polymer gel electrolyte membrane can be 30-60%. Exemplarily, the porosity of the polymer gel electrolyte membrane can be any value selected from 30%, 35%, 40%, 45%, 50%, 55%, and 60%, or any value within a range formed by any pair of the above values.

[0052] In some embodiments, the polymer gel electrolyte membrane further includes nanofillers, at least a portion of which are located within the pores of the cross-linked polymer. As functional fillers, the porous structure of the nanofillers not only provides more lithium-ion transport channels and improves ionic conductivity, but their high specific surface area also allows for the adsorption of more lithium salts, thereby increasing ion concentration and transport number. The addition of nanofillers enables the formation of physical cross-linking points within the gel network, further significantly enhancing the overall strength and toughness of the material.

[0053] For example, the nanofiller includes at least one of nanoporous diatomaceous earth particles, nano-SiO2, and kaolin.

[0054] In a preferred embodiment of the present invention, the nanofiller is nanoporous diatomaceous earth particles, and the chemical stability of the porous diatomaceous earth particles can delay the decomposition of the gel electrolyte at high temperature.

[0055] Optionally, the purity of the nanoporous diatomite particles is 98.5-99.5%, taking into account cost and reducing impurity interference.

[0056] The Dv50 of the nanoporous diatomite particles described in this invention can be 1~5μm. This particle size ensures that the particles have a sufficiently high specific surface area, while avoiding the serious agglomeration problem caused by strong van der Waals forces.

[0057] In some embodiments of the present invention, the pore size of the nanoporous diatomaceous earth particles is 10-50 nm, and the porosity is 50-70%. The pore size of 10-50 nm in the nanoporous diatomaceous earth particles ensures sufficient electrolyte wetting of the pores, providing a stable formation space for the SEI film and preventing excessive SEI thickness. Too small a pore size leads to difficulty in wetting due to excessive capillary forces, while too large a pore size reduces the mechanical strength of the material and weakens the constraint on silicon expansion. A porosity of 50-70% in the nanoporous diatomaceous earth particles maximizes the utilization rate of active materials and mechanical stability. It provides sufficient space to accommodate the huge volume expansion of lithium intercalation, preventing structural collapse, forming continuous ion channels, and improving reaction kinetics.

[0058] A second aspect of the present invention provides a method for preparing a polymer gel electrolyte membrane, the method comprising the following steps:

[0059] S1. The polymer monomer, plasticizer, lithium salt, interface additive, crosslinking agent, visible light initiator, thermal initiator, redox initiation aid and solvent are mixed and treated to obtain the first material;

[0060] S2. The first material is coated on the surface of the substrate, and after standing, it is dried to obtain a pre-condensed film.

[0061] S3. The initial coagulated film is subjected to photo-initiated polymerization, gradient temperature treatment and microwave cross-linking curing reaction to obtain a cured gel film.

[0062] S4. The cured gel film is dried.

[0063] The polymer monomers include at least one of vinylidene chloride, methyl acrylate and ethyl acrylate;

[0064] The plasticizer includes at least one of polyethylene glycol (PEG), polypropylene glycol (PPG), and polyethylene oxide (PEO, molecular weight 2000);

[0065] The crosslinking agent includes at least one of trimethylolpropane triacrylate (TMPTA), 1,1-dimethylvinyl glycol (ACVA), and pentaerythritol tetraacrylate (PETA);

[0066] The visible light initiator includes at least one of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure819), benzophenone (BP), and 4-phenyldibenzofuranone (DCL);

[0067] The thermal initiator includes at least one of di-tert-butyl peroxide (DTBP), benzoyl peroxide (BPO), and tert-butyl peroxide (TBPB).

[0068] The preparation method of this invention, through photothermal dual initiation, microwave synergistic regulation, and drying, synthesizes a polymer gel electrolyte with the following advantages: First, the preparation process of this invention is more efficient; the photothermal dual initiation process significantly shortens the polymerization reaction time. Steps such as microwave dynamic crosslinking can be automated, greatly reducing the time and cost of manual operation. Second, the design of the ion transport network and the crosslinking curing process significantly improve the battery's migration rate and electrochemical stability. Third, the visible light initiation system and microwave-assisted crosslinking process reduce energy consumption and environmental pollution. Fourth, through the synergistic effect of multiple functional components such as lithium salts, interface additives, and plasticizers, a polymer gel electrolyte with excellent comprehensive performance is prepared.

[0069] For example, in this invention, the molecular weight of polyethylene glycol can be 2000, and the molecular weight of polyethylene oxide can be 2000.

[0070] According to the present invention, the addition of lithium salt, interfacial additive, crosslinking agent, visible light initiator, and redox initiation aid is beneficial to the formation of an ion transport network. In the present invention, the mass ratio of the polymeric monomer, the plasticizer, the lithium salt, the interfacial additive, the crosslinking agent, the visible light initiator, and the redox initiation aid can be 1:(3~5):(0.2~0.4):(0.05~0.15):(0.1~0.3):(0.01~0.03):(0.005~0.015).

[0071] In this invention, the amount of solvent used is 8 to 12 mL per gram of polymerizable monomer. Exemplarily, the amount of solvent used per gram of polymerizable monomer can be any value from 8 mL, 9 mL, 10 mL, 11 mL, and 12 mL, or any value within the range of any two of the above values.

[0072] In a preferred embodiment of the present invention, the polymerizable monomer may be vinylidene chloride, wherein the chlorine atoms in the vinylidene chloride molecule have high electronegativity and can form a weak coordination with lithium ions in lithium salts (such as LiFSI), thereby promoting the dissociation of lithium salts and improving the ionic conductivity of the electrolyte.

[0073] For example, the lithium salt includes at least one of lithium bis(fluorosulfonyl)imide (LiFSI), lithium hexafluorophosphate (LiPF6), and lithium bis(trifluoromethanesulfonyl)imide (LiTFSi).

[0074] For example, the interface additive includes at least one selected from fluoroethylene carbonate (FEC), trimethyl phosphate (TMP), and lithium difluorophosphate (LiPO2F2). FEC contains strongly electron-withdrawing Cl atoms, which can form weak bonds with Li+, promoting the dissociation of LiFSi. Trimethyl phosphate contains a polar PO group, which can adsorb and passivate the transition metal on the positive electrode surface. Lithium difluorophosphate contains mixed F and O functional groups, which can form a gradient SEI film at both the positive and negative electrodes.

[0075] For example, the redox initiator includes at least one of ascorbic acid, sodium isoascorbate, and vitamin C palmitate.

[0076] For example, the solvent includes at least one of acetonitrile, N-methylpyrrolidone (NMP), and dimethylacetamide (DMAC).

[0077] In some embodiments of the present invention, in step S2, the thickness of the coating on the substrate surface is 100~150μm; and / or, the drying conditions include: a temperature of 20~25℃ and a time of 30~60min.

[0078] In some embodiments of the present invention, in step S3, the conditions for the photo-initiated polymerization reaction include: visible light wavelength of 420~500nm and light intensity of 50~150mW / cm². 2 The irradiation time is 5-10 min; and / or, the gradient heating treatment includes a first stage heating, a second stage heating, and a third stage heating; the temperature of the first stage heating is 50-60℃, and the time is 10-30 min; the temperature of the second stage heating is 80-100℃, and the time is 30-50 min; the temperature of the third stage heating is 110-140℃, and the time is 10-30 min; the heating rate of the gradient heating treatment is 2-10℃ / min; and / or, the conditions of the microwave crosslinking curing reaction include: microwave frequency 2-3 GHz, microwave power 300-700 W, curing temperature 120-140℃, and curing time 0.5-1.5 h.

[0079] In some embodiments of the present invention, in step S4, the drying process can be supercritical drying or vacuum drying. In a preferred embodiment, the drying process is supercritical drying; optionally, the conditions for the supercritical drying process include: pressure 8~12MPa and temperature 30~50℃. The supercritical drying process in the present invention helps to remove residual solvents and eliminate microporous structural defects.

[0080] In a preferred embodiment of the present invention, the first material further contains nanofillers.

[0081] In some embodiments, the preparation method of the present invention further includes a pretreatment process for the nanofiller. Exemplarily, the pretreatment process may include calcining the commercially available nanofiller at 600-1000°C for 2-4 hours under the protection of an inert gas. The combination of the calcined nanofiller and the three-dimensional network structure significantly enhances the mechanical strength and flexibility of the material.

[0082] According to the present invention, the content of the nanofiller can be 8-12 wt%, based on the total mass of the first material. If the content of the nanofiller is too low, it may result in the inability to form an effective network structure and insufficient active sites, making it impossible to effectively reduce the activation energy of ion migration or form a through-hole ion conduction network. The restrictive effect of the filler on the movement of polymer chain segments is weakened, and its crystallization cannot be effectively inhibited, leading to Li+ transport obstruction. Too low a content will also lead to a decrease in the mechanical strength and dimensional stability of the product. If the content of the nanofiller is too high, uncontrolled agglomeration may occur in the polymer matrix, hindering lithium-ion transport. Agglomerates are prone to become stress concentration points under stress, inducing microcracks. Exemplarily, based on the total mass of the first material, the content of the nanofiller can be any value from 8 wt%, 9 wt%, 10 wt%, 11 wt%, and 12 wt%, or any value within the range of any two of the above values.

[0083] A third aspect of the present invention provides a battery comprising an electrolyte membrane, the electrolyte membrane comprising the polymer gel electrolyte membrane described above and / or a polymer gel electrolyte membrane prepared according to the method described above.

[0084] The present invention will be further described in detail below through examples. All raw materials used in the examples are commercially available.

[0085] Example 1

[0086] High-purity porous nano-diatomite particles were obtained by calcining nanoporous diatomite in a tube furnace at 800℃ for 3 hours under nitrogen protection and then cooling.

[0087] Mix 50g vinylidene chloride (VC) and 20g polyethylene glycol (PEG) in a certain proportion, add 10g LiFSI, 0.1g trimethylpropane triacrylate (TMPTA) and 5g fluoroethylene carbonate (FEC), dissolve in 200ml acetonitrile solvent, add 10g porous nano-diatomaceous earth filler, disperse for 30 min using an ultrasonic disperser (300 W power, 40 kHz frequency) to ensure uniform dispersion of nano-filler, then add 0.2g di-tert-butyl peroxide (DTBP) and 0.2g bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819) and 0.04g ascorbic acid, stir until uniform to form the first material.

[0088] Fix the aluminum foil on the platform of the coating machine, start the coating program, and use a scraper to evenly coat the first material onto the aluminum foil. The thickness is controlled at 125μm. After coating, place the sample in natural air and let it stand for 30 minutes to allow the solvent to evaporate naturally and form a preliminary film.

[0089] The pre-condensed membrane was placed under visible light irradiation for 7 minutes to initiate photopolymerization. The irradiated membrane was then transferred to a gradient heating furnace for asymmetric gradient thermal initiation polymerization at 55℃→90℃→125℃, with a heating rate of 5℃ / min and holding times of 20min, 40min, and 20min at each temperature. During the heating process, the monomers gradually activated and underwent chain polymerization, forming a preliminary three-dimensional network structure. The pre-polymerized membrane was then transferred to a dynamic crosslinking reactor. The reaction temperature was set to 130℃, the reaction time to 1 hour, and microwave-assisted crosslinking was introduced. During dynamic crosslinking, the polymer network was crosslinked and cured under dynamic conditions by controlling the temperature and microwave power. This further controlled the density of the polymer network structure and the distribution of ion transport channels, resulting in a cured gel membrane.

[0090] The cured gel membrane is peeled off from the substrate material. A precision cutter is then used to cut the membrane to the desired size. The cut gel electrolyte membrane is then placed in a supercritical CO2 drying apparatus to remove residual solvent, yielding the final polymer gel electrolyte membrane.

[0091] Example 2

[0092] High-purity porous nano-diatomite particles were obtained by calcining nanoporous diatomite in a tube furnace at 600℃ for 1 hour under nitrogen protection and then cooling.

[0093] Mix 40g vinylidene chloride (VC) and 15g polyethylene glycol (PEG) in a certain proportion, add 8g LiFSI, 0.05g trimethylpropane triacrylate (TMPTA) and 2g fluoroethylene carbonate (FEC), dissolve in 100ml acetonitrile solvent, add 4g porous nano-diatomaceous earth filler, disperse for 30 min using an ultrasonic disperser (power 300 W, frequency 40 kHz) to ensure uniform dispersion of nano-filler, then add 0.04g di-tert-butyl peroxide (DTBP) and 0.04g bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819) and 0.008g ascorbic acid, stir until uniform to form the first material.

[0094] Fix the aluminum foil on the platform of the coating machine, start the coating program, and use a scraper to evenly coat the first material onto the aluminum foil. The thickness is controlled at 100μm. After coating, place the sample in natural air and let it stand for 30 minutes to allow the solvent to evaporate naturally and form a preliminary film.

[0095] The pre-condensed membrane was placed under visible light irradiation for 5 minutes to initiate photopolymerization. The irradiated membrane was then transferred to a gradient heating furnace for asymmetric gradient thermal initiation polymerization at 50℃→80℃→110℃, with a heating rate of 2℃ / min and holding times of 10 min, 30 min, and 10 min at each temperature. During the heating process, the monomers gradually activated and underwent chain polymerization, forming a preliminary three-dimensional network structure. The pre-polymerized membrane was then transferred to a dynamic crosslinking reactor. The reaction temperature was set to 120℃, the reaction time to 0.5 h, and microwave-assisted crosslinking was introduced. During dynamic crosslinking, the polymer network was crosslinked and cured under dynamic conditions by controlling the temperature and microwave power, further regulating the density of the polymer network structure and the distribution of ion transport channels to obtain the cured gel membrane.

[0096] The cured gel membrane is peeled off from the substrate material. A precision cutter is then used to cut the membrane to the desired size. The cut gel electrolyte membrane is then placed in a supercritical CO2 drying apparatus to remove residual solvent, yielding the final polymer gel electrolyte membrane.

[0097] Example 3

[0098] High-purity porous nano-diatomite particles were obtained by calcining nanoporous diatomite in a tube furnace at 1000℃ for 3 hours under nitrogen protection and then cooling.

[0099] Mix 60g vinylidene chloride (VC) and 25g polyethylene glycol (PEG) in a certain proportion, add 12g LiFSI, 0.15g trimethylpropane triacrylate (TMPTA) and 8g fluoroethylene carbonate (FEC), dissolve in 300ml acetonitrile solvent, add 16g porous nano-diatomaceous earth filler, disperse for 30min using an ultrasonic disperser (300W power, 40kHz frequency) to ensure uniform dispersion of nano-filler, then add 0.3g di-tert-butyl peroxide (DTBP) and 0.3g bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Irgacure 819) and 0.06g ascorbic acid, stir until uniform to form the first material.

[0100] Fix the aluminum foil on the platform of the coating machine, start the coating program, and use a scraper to evenly coat the first material onto the aluminum foil. The thickness is controlled at 150μm. After coating, place the sample in natural air and let it stand for 30 minutes to allow the solvent to evaporate naturally and form a preliminary film.

[0101] The pre-condensed membrane was placed under visible light irradiation for 10 minutes to initiate photopolymerization. The irradiated membrane was then transferred to a gradient heating furnace for asymmetric gradient thermal polymerization at 60℃→100℃→140℃, with a heating rate of 10℃ / min and holding times of 30min, 50min, and 30min at each temperature. During the heating process, the monomers gradually activated and underwent chain polymerization, forming a preliminary three-dimensional network structure. The pre-polymerized membrane was then transferred to a dynamic crosslinking reactor. The reaction temperature was set at 140℃, the reaction time was 1.5h, and microwave-assisted crosslinking was introduced. During dynamic crosslinking, the polymer network was crosslinked and cured under dynamic conditions by controlling the temperature and microwave power. This further controlled the density of the polymer network structure and the distribution of ion transport channels, resulting in a cured gel membrane.

[0102] The cured gel membrane is peeled off from the substrate material. A precision cutter is then used to cut the membrane to the desired size. The cut gel electrolyte membrane is then placed in a supercritical CO2 drying apparatus to remove residual solvent, yielding the final polymer gel electrolyte membrane.

[0103] Example 4

[0104] The difference between this embodiment and Example 1 is that the monomer used is methyl acrylate (MA), while the rest is the same as in Example 1.

[0105] Example 5

[0106] The difference between this embodiment and Embodiment 1 is that the thermal initiator is benzoyl peroxide (BPO), and the photoinitiator is BP (replaced with ultraviolet light initiation). Everything else is the same as in Embodiment 1.

[0107] Example 6

[0108] The difference between this embodiment and Example 1 is that the crosslinking agent used is 1,1-dimethylvinyl glycol (ACVA), otherwise it is the same as Example 1.

[0109] Example 7

[0110] The difference between this embodiment and Embodiment 1 is that the lithium salt used is LiPF6, while the rest is the same as in Embodiment 1.

[0111] Example 8

[0112] Example 8: Replacement material for interface additives

[0113] The difference between this embodiment and Embodiment 1 is that the interface additive used is trimethyl phosphate (TMP), while the rest is the same as in Embodiment 1.

[0114] Example 9: Drying process replacement

[0115] The difference between this embodiment and Embodiment 1 is that vacuum drying (60°C, 12h) is used instead of supercritical drying; otherwise, they are the same as in Embodiment 1.

[0116] Example 10: Non-functional packing

[0117] The difference between this embodiment and Embodiment 1 is that there is no functional filler, that is, no porous nano-diatomaceous earth is added; otherwise, it is the same as Embodiment 1.

[0118] Comparative Example 1: Photoinitiated polymerization process

[0119] The difference between this comparative example and Example 1 is that it does not use the photoinitiator Irgacure 819, the redox agent ascorbic acid, or the photoinitiated polymerization process; otherwise, it is the same as Example 1.

[0120] Comparative Example 2: Thermally Initiated Polymerization Process

[0121] The difference between this embodiment and Embodiment 1 is that there is no thermal initiator DTBP and no thermally initiated polymerization process; otherwise, it is the same as Embodiment 1.

[0122] Comparative Example 3: Microwave-free dynamic cross-linking curing process

[0123] The difference between this embodiment and Embodiment 1 is that there is no microwave dynamic crosslinking process; otherwise, it is the same as Embodiment 1.

[0124] Test Example 1

[0125] Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were performed on the polymer gel electrolyte membrane prepared in Example 1, as shown in the figure.Figure 1 and Figure 2 As shown.

[0126] in, Figure 1 SEM images of polymer gel electrolyte membranes. Figure 2 The image shows the FTIR spectrum of the polymer gel electrolyte membrane.

[0127] pass Figure 1 As can be seen, the left side shows a cut circular gel electrolyte membrane, and the right side shows the SEM image after sampling. The membrane exhibits a three-dimensional internet-like structure, formed by the copolymerization of PEG and VC, possessing high connectivity and flexibility. Numerous micron-sized pores exist within the network, permeating the entire membrane material and providing efficient channels for lithium-ion migration. The cross-linked structure of the three-dimensional network endows the material with excellent elasticity and toughness, maintaining structural integrity during repeated bending or stretching. The calcined nano-sized diatomaceous earth is uniformly distributed in the pores and surface of the three-dimensional network, effectively dispersing applied stress, preventing material failure caused by localized stress concentration, and improving the overall tensile strength and fracture toughness of the material. Furthermore, it provides more transport channels for lithium-ion migration.

[0128] pass Figure 2 It can be seen that: 1245cm -1 The CO bond at this point directly corresponds to the ether bond in PEG. This peak is strong and stable, demonstrating that PEG has been successfully integrated into the framework of the three-dimensional network, enhancing ion transport channels. (890 cm⁻¹) -1 The C-Cl stretching vibration at this point originates from the chlorine atom in the vinylidene chloride monomer of the second segment. The weak peak intensity indicates that VC participates in the photothermal polymerization reaction, and the final product contains relatively little residual C-Cl, confirming that the second segment is a rigid component of the cross-linked structure through unit embedding within the network. The characteristic peak corresponding to the third segment, the acrylic acid derivative chain (containing functionalized R groups, LiFSi / FEC), is 680 cm⁻¹. -1 Corresponding to the -CF3 / CF2 group (carbonate group R) in FEC, 1375 cm -1 This corresponds to the -SO2F group (fluorosulfonamide R) in LiFSI. The stable peak position proves that both FEC and LiFSI are inserted into the third segment (R-group connection) through chemical bonding, rather than physical doping. 1737 cm⁻¹ -1 The C=O double bond originates from the carbonyl group of fluorosulfonamide (-SO2N-CO-) in LiFSI and the carbonyl group of carbonate (-OC=O) in FEC. The broad peak superposition reflects the coexistence and bonding of multiple carbonyl-containing functional groups in the third segment. 1642 cm⁻¹ -1 The presence of fewer C=C double bonds and weaker peak intensity indicates that acrylates consume C=C bonds through free radical polymerization to form [-CH2-C(CH3)(COOR)-]p segments.

[0129] Test Example 2

[0130] The electrolyte membranes prepared in Examples 1-10 and Comparative Examples 1-3 were used to prepare batteries, and the performance of the electrolyte membranes and batteries was tested. The test results are shown in Table 1.

[0131] The battery manufacturing methods include:

[0132] (1) Mix lithium iron phosphate cathode material, conductive carbon black and PVDF in a mass ratio of 8:1:1, add NMP solvent and grind into a slurry. Coat the slurry onto aluminum foil (load 1-3 mg / cm2), vacuum dry at 80℃ for 12 h, and press into tablets to make them uniform.

[0133] (2) Mix 90 wt% of the negative electrode active material (artificial graphite) and 10 wt% of styrene-butadiene rubber (SBR), add deionized water, and stir until viscous. Coat the mixture onto copper foil (loading 2~5 mg / cm²). 2 Dry at 80℃ for 12 hours, compress into tablets, and cut to the same size as the positive electrode for later use.

[0134] (3) Cut the electrolyte membrane to a diameter 1-2 mm larger than the electrode to ensure that it covers the electrode edge. Wipe the surface of the electrolyte membrane with acetonitrile to remove residual solvent and impurities.

[0135] (4) Assemble the battery in the following order: “shell → negative electrode → gel electrolyte membrane → trace electrolyte → positive electrode → gasket → spring”, and finally seal the clasp with a press machine.

[0136] Performance testing:

[0137] (1) Ionic conductivity: The conductivity was obtained by testing with a digital source meter manufactured by Tektronix, USA. The device model was Keithley 2400 SourceMeter.

[0138] (2) Tensile strength and elongation at break: measured by a universal testing machine manufactured by Instron 3365 in the United States.

[0139] (3) Thermal decomposition temperature at 5% mass loss: measured using a thermogravimetric analyzer manufactured by a Swiss company, model Mettler Toledo TGA.

[0140] (4) Interface impedance: The electrochemical workstation manufactured by Shanghai Chenhua Company, model CHI660E, was used.

[0141] Table 1

[0142]

[0143] As can be seen from Table 1, compared with Comparative Examples 1-3, Examples 1-10 showed significantly improved ionic conductivity, tensile strength, elongation at break, and thermal decomposition temperature with a 5% mass loss, significantly reduced interfacial impedance, significantly increased specific surface area and porosity, and significantly reduced pore size.

[0144] Specifically, Example 1 represents the optimal parameter combination, achieving an ionic conductivity as high as 3.6 × 10⁻⁶. -3 Tensile strength 14.8 MPa, elongation at break 180%, interfacial resistance 17.5 Ω cm 2 The thermal decomposition temperature is 275℃ when the mass loss is 5%, and the specific surface area is 300m². 2 / g, pore size 1μm, porosity 60%. The above-mentioned excellent electrochemical performance is mainly due to the following factors: ① Calcination of porous nano-diatomite at 800℃ for 3h under nitrogen protection effectively removes organic impurities and moisture from the diatomite, improving its purity; the calcination process activates the pore structure of the diatomite, increases the specific surface area, and enhances the material's adsorption capacity and mechanical strength. ② The dense three-dimensional network structure and microwave dynamic cross-linking curing enhance the material's tensile strength and elongation at break. ③ Gradient thermally initiated polymerization and microwave dynamic cross-linking curing increase the material's thermal decomposition temperature. ④ Uniformly dispersed functional additives and supercritical drying process reduce interfacial impedance and improve electrochemical stability.

[0145] Example 2 adjusted the proportions of various parameters, resulting in a decrease in electrical conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss compared to Example 1. The main reasons were insufficient filler leading to partial breakage of ion channels, low-temperature calcination retaining some impurities that blocked some pores, and low-temperature polymerization resulting in insufficient network cross-linking. Insufficient calcination prevented the diatomaceous earth pores from fully opening, leading to a decrease in specific surface area. Thinning the coating reduced the filler loading, thus decreasing porosity. Insufficient light and a too-gradient heating gradient resulted in incomplete monomer activation, a loose network structure, and increased pore size.

[0146] Example 3: Adjusting the proportions of various parameters resulted in a decrease in thermal decomposition temperature compared to Example 1 when conductivity, tensile strength, and mass loss were reduced by 5%. The main reasons were: excessive filler agglomeration hindered ion transport; excessively high calcination temperature damaged part of the porous structure of diatomaceous earth; and aggressive polymerization triggered internal stress cracks. Over-calcination caused partial collapse of the diatomaceous earth's pore structure, reducing specific surface area. Thickening the coating increased filler accumulation, reducing porosity. Excessive light exposure and rapid gradient heating may cause localized overheating, leading to pore size reduction. Excessive microwave curing caused excessive cross-linking of polymer chains, further reducing porosity.

[0147] Example 4: Using MA as the polymerization monomer resulted in a decrease in electrical conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss compared to Example 1. The main reason is that MA has a fast polymerization rate but low chain segment rigidity, resulting in a loose crosslinking network and increased resistance to ion migration. MA also has low reactivity, slow polymer chain growth, and decreased porosity.

[0148] Example 5: Using BPO as a thermal initiator and BP (ultraviolet light) as a photoinitiator resulted in a significant decrease in thermal decomposition temperature when conductivity, tensile strength, and mass loss were reduced by 5%. The main reasons were that BPO's high thermal decomposition temperature delayed initiation, and the weak penetration of ultraviolet light led to incomplete deep polymerization and increased network defects. The high decomposition temperature of BPO may have resulted in incomplete polymerization; BP requires ultraviolet light, but the lighting conditions were not optimized, leading to an uneven network structure.

[0149] Example 6: Using ACVA as a crosslinking agent resulted in a decrease in electrical conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss compared to Example 1. The main reason is that ACVA induces a low concentration of free radicals, resulting in sparse crosslinking points and decreased mechanical strength. BPO has a high decomposition temperature, which may indicate incomplete polymerization. BP requires ultraviolet light, but the light conditions were not optimized, leading to an uneven network structure.

[0150] Example 7: Using LiPF6 as the lithium salt LiFSI resulted in a decrease in conductivity and thermal decomposition temperature at a 5% mass loss compared to Example 1. The main reason is that PF6... - The small molecular structure and strong Lewis acidity of LiPF6 result in weak interactions with polymer chains, leading to a less dense network structure and affecting ion conduction efficiency. Its high reactivity also makes it prone to side reactions at interfaces. Furthermore, LiPF6 has low solubility, which may clog pores and reduce porosity.

[0151] Example 8: Using TMP as an interface additive resulted in a decrease in conductivity and thermal decomposition temperature at 5% mass loss compared to Example 1, while the interfacial impedance increased. The main reason is that TMP preferentially adsorbs onto the electrode but has poor thermal stability, and the SEI film contains more organic components, making it prone to decomposition at high temperatures. TMP may reduce surface shrinkage during solvent evaporation and slightly increase porosity.

[0152] Example 9: Using vacuum drying instead of supercritical drying resulted in a decrease in conductivity and thermal decomposition temperature at a 5% mass loss compared to Example 1, while the interfacial impedance increased. The main reason is that vacuum drying caused micropore collapse, and solvent residue triggered interfacial side reactions. Vacuum drying led to slow solvent evaporation, severe pore structure collapse, and increased pore size.

[0153] Example 10: Without diatomaceous earth filler, the electrical conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss decreased compared to Example 1. This was mainly due to the loss of the reinforcing and ion channel-building effects of the nanofiller, resulting in a slightly looser polymer network and a more singular transport path. The absence of diatomaceous earth as a template agent led to the collapse of the pore structure and a significant decrease in performance.

[0154] Comparative Example 1: Photoinitiated polymerization without a photoinitiator resulted in a significant decrease in conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss compared to Example 1. The main reason is that thermal initiation alone led to surface over-crosslinking and internal loosening, causing gradient breakage of ion channels and accelerating thermal decomposition of residual monomers. Photoinitiation is a necessary step for the initial network formation; without it, monomers cannot be activated, and the pore structure completely collapses.

[0155] Comparative Example 2: The absence of a thermal initiator and thermal polymerization resulted in a significant decrease in electrical conductivity, tensile strength, and thermal decomposition temperature at 5% mass loss compared to Example 1. This was primarily because photoinitiation alone limited polymerization to the surface layer, leaving unreacted monomers in the deeper layers forming soft regions, leading to simultaneous deterioration of mechanical and thermal stability. Thermal initiation completes subsequent polymerization; without it, the network is not fully cross-linked, resulting in abnormally enlarged pore sizes.

[0156] Comparative Example 3: Without microwave dynamic crosslinking, the thermal decomposition temperature at 5% mass loss was significantly lower than in Example 1, while the interfacial impedance was significantly higher. This was mainly due to the uneven chain segment distribution caused by static crosslinking, the unreacted initiator catalyzing electrolyte decomposition, and a surge in interfacial side reactions. Microwave crosslinking regulates network density; its absence resulted in a significant decrease in porosity and specific surface area.

[0157] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polymer gel electrolyte membrane, characterized in that, The polymer gel electrolyte membrane comprises a cross-linked polymer having a three-dimensional network structure; the cross-linked polymer comprises a polymer backbone material and a lithium salt, with at least a portion of the lithium salt located within the pores of the polymer backbone material; The polymer backbone material includes a first segment, a second segment, and a third segment; The first chain segment comprises a first free radical and a first group; the first free radical comprises [-CH2-CH2-O-]. m - Wherein, 1≤m≤3; the first group includes hydroxyl and / or ether bonds; The second segment comprises a polymeric monomer and a second free radical, wherein the polymeric monomer comprises at least one selected from vinylidene chloride, methyl acrylate, and ethyl acrylate, and the second free radical comprises [-CH2-CHCl-]. n - Where 1 ≤ n ≤ 3; The third segment comprises a third free radical and a third group; the third free radical comprises [-CH2-C(CH3)(COOR)-]. p - Wherein, 1≤p≤3, and R is a fluorosulfonamide or carbonate group; the third group includes a carbon-carbon double bond and / or an ester group.

2. The polymer gel electrolyte membrane according to claim 1, characterized in that, The specific surface area of ​​the polymer gel electrolyte membrane is 150~300m². 2 / g; and / or, The polymer gel electrolyte membrane has an average pore size of 0.5~2μm; and / or, The porosity of the polymer gel electrolyte membrane is 30-60%.

3. The polymer gel electrolyte membrane according to claim 1, characterized in that, The polymer gel electrolyte membrane further includes nanofillers, at least a portion of which are located within the pores of the cross-linked polymer; The nanofiller includes at least one of nanoporous diatomaceous earth particles, nano-SiO2, and kaolin.

4. The polymer gel electrolyte membrane according to claim 3, characterized in that, The nanofiller is nanoporous diatomaceous earth particles; The purity of the nanoporous diatomite particles is 98.5-99.5%; and / or, the Dv50 of the nanoporous diatomite particles is 1-5 μm; and / or, the pore size of the nanoporous diatomite particles is 10-50 nm and the porosity is 50-70%.

5. A method for preparing a polymer gel electrolyte membrane, characterized in that, The preparation method includes the following steps: S1. The polymer monomer, plasticizer, lithium salt, interface additive, crosslinking agent, visible light initiator, thermal initiator, redox initiation aid and solvent are mixed and treated to obtain the first material; S2. The first material is coated on the surface of the substrate, and after standing, it is dried to obtain a pre-condensed film. S3. The initial coagulated film is subjected to photo-initiated polymerization, gradient temperature treatment and microwave cross-linking curing reaction to obtain a cured gel film. S4. The cured gel film is dried. The polymeric monomers include at least one of vinylidene chloride, methyl acrylate, and ethyl acrylate; The plasticizer includes at least one of polyethylene glycol, polypropylene glycol, and polyethylene oxide; The crosslinking agent includes at least one of methylpropane triacrylate, 1,1-dimethylvinyl glycol and pentaerythritol tetraacrylate; The visible light initiator includes at least one of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, benzophenone, and 4-phenyldibenzofuranone; The thermal initiator includes at least one of di-tert-butyl peroxide, benzoyl peroxide, and tert-butyl peroxide.

6. The preparation method according to claim 5, characterized in that, The mass ratio of the polymeric monomer, the plasticizer, the lithium salt, the interfacial additive, the crosslinking agent, the visible light initiator, and the redox initiation aid is 1:(3~5):(0.2~0.4):(0.05~0.15):(0.1~0.3):(0.01~0.03):(0.005~0.015); and / or, The amount of solvent used is 8 to 12 mL per gram of monomer.

7. The preparation method according to claim 5, characterized in that, The lithium salt comprises at least one of lithium bis(fluorosulfonyl)imide, lithium hexafluorophosphate, and lithium bis(trifluoromethanesulfonyl)imide; and / or, The interface additive includes at least one selected from fluoroethylene carbonate, trimethyl phosphate, and lithium difluorophosphate; and / or, The redox initiator includes at least one of ascorbic acid, sodium isoascorbate, and vitamin C palmitate; and / or, The solvent includes at least one of acetonitrile, N-methylpyrrolidone, and dimethylacetamide.

8. The preparation method according to claim 5, characterized in that, In step S2, the thickness of the coating on the substrate surface is 100~150μm; And / or, the drying conditions include: a temperature of 20~25℃ and a time of 30~60 min; and / or; In step S3, the conditions for the photo-initiated polymerization reaction include: visible light wavelength of 420~500nm and light intensity of 50~150mW / cm². 2 Irradiation time 5-10 min; and / or, The gradient heating process includes a first stage of heating, a second stage of heating, and a third stage of heating; the temperature of the first stage of heating is 50~60℃, and the time is 10~30 min; the temperature of the second stage of heating is 80~100℃, and the time is 30~50 min; the temperature of the third stage of heating is 110~140℃, and the time is 10~30 min; the heating rate of the gradient heating process is 2~10℃ / min; and / or, The conditions for the microwave crosslinking and curing reaction include: microwave frequency 2~3GHz, microwave power 300~700W, curing temperature 120~140℃, and curing time 0.5~1.5h; and / or, In step S4, the drying process is supercritical drying; the conditions for the supercritical drying process include: pressure 8~12MPa and temperature 30~50℃.

9. The preparation method according to claim 5, characterized in that, The first material also contains nanofillers; Based on the total mass of the first material, the content of the nanofiller is 8~12wt%.

10. A battery, characterized in that, The battery includes an electrolyte membrane, which includes the polymer gel electrolyte membrane according to any one of claims 1 to 4 and / or the polymer gel electrolyte membrane prepared by the method according to any one of claims 5 to 9.

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