A semi-solid battery and a method of manufacturing the same

Abstract

The application provides a semi-solid battery and a preparation method thereof. The semi-solid battery comprises a positive electrode sheet, a negative electrode sheet, a separator and a semi-solid electrolyte. The positive electrode sheet comprises a positive electrode material layer, and the positive electrode material layer comprises a positive electrode active material. The semi-solid electrolyte comprises a gel polymer and an electrolyte solution. The gel polymer comprises monomer units from a polymerization monomer and a crosslinking agent, wherein the polymerization monomer is selected from at least one of the compounds shown in formula I. The semi-solid battery satisfies: A / B / C > 1, wherein A is the area density of the positive electrode active material, mg / cm 2 ; B is the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, %; and C is the residual amount of the polymerization monomer in the semi-solid electrolyte, %. The semi-solid battery has high room temperature cycle performance and high temperature cycle performance.

Description

Technical Field

[0001] This application relates to the field of electrochemical technology, and in particular to a semi-solid battery and its preparation method. Background Technology

[0002] Secondary batteries have advantages such as high energy density, high open-circuit voltage, low self-discharge rate, long cycle life, and good safety, and are widely used in portable energy storage, electronic devices, electric vehicles, and other fields. Currently, traditional commercial secondary batteries mainly use liquid organic electrolytes as lithium-ion transport media for energy storage and conversion. Liquid electrolytes are prone to leakage and abnormal thermal behavior caused by internal short circuits, such as battery overheating, or even malignant combustion or explosion, posing safety hazards.

[0003] Semi-solid polymer electrolytes utilize polymer networks to adsorb liquid electrolytes, addressing potential safety issues such as leakage and combustion associated with liquid electrolytes. They also inherit the excellent compatibility between liquid electrolytes and positive and negative electrode materials, making them a key area of ​​focus for both industry and academia. However, the reported conductivity of semi-solid polymer electrolytes is generally lower than that of liquid electrolytes, posing challenges when matched with high-area-density active materials in positive and negative electrode sheets, resulting in difficulties in achieving optimal battery performance at both room temperature and high temperature. Summary of the Invention

[0004] The purpose of this application is to provide a semi-solid-state battery and its preparation method, so as to improve the room temperature cycling performance and high temperature cycling performance of the semi-solid-state battery. The specific technical solution is as follows:

[0005] The first aspect of this application provides a semi-solid battery comprising a positive electrode, a negative electrode, a separator, and a semi-solid electrolyte, wherein the positive electrode comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode active material; the semi-solid electrolyte comprises a gel polymer and an electrolyte, the gel polymer comprises monomer units derived from a polymeric monomer and a crosslinking agent, wherein the polymeric monomer is selected from at least one compound shown in Formula I;

[0006]

[0007] In Formula I, R1 is H or methyl; x is 1 to 10 and x is an integer; y ≥ 0, z ≥ 0 and y and z are integers, y + z ≤ 22;

[0008] The semi-solid-state battery satisfies:

[0009] Where A is the areal density of the positive electrode active material, in mg / cm³. 2B represents the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, in %; C represents the residual amount of polymeric monomers in the semi-solid electrolyte, in %.

[0010] In one embodiment of this application, 10 < A < 40.

[0011] In one embodiment of this application, 7.5% < B < 30%.

[0012] In one embodiment of this application, C ≤ 0.2%.

[0013] In one embodiment of this application, the mass percentage of the polymeric monomer is M1, based on the mass of the gel polymer, where 90% ≤ M1 ≤ 99%.

[0014] In one embodiment of this application, the compound represented by Formula I is selected from at least one of the following compounds;

[0015]

[0016] In one embodiment of this application, the crosslinking agent is selected from the compound represented by Formula II or the compound represented by Formula III; the compound represented by Formula II is: C3H5C(O)(OCH2CH2) n OC(O)C3H5, n=1~10;

[0017] And / or, based on the mass of the gel polymer, the mass percentage of the crosslinking agent is M2, where 1% ≤ M2 ≤ 10%.

[0018] In one embodiment of this application, the electrolyte comprises an electrolyte selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonyl)imide, lithium bis(oxalate)borate, lithium difluorobis(oxalate)borate, lithium difluorobis(oxalate)phosphate, lithium tetrafluorooxalate phosphate, and lithium 4,5-dicyano-2-trifluoromethyl-imidazolium; and / or, based on the mass of the electrolyte, the mass percentage of the electrolyte is M3, where 10% ≤ M3 ≤ 20%.

[0019] In one embodiment of this application, the electrolyte includes an additive selected from at least one of vinylene carbonate, 1,3-propanesulfonate lactone, 1,3-propenesulfonate lactone, vinyl sulfate, lithium difluorophosphate, tri(trimethylsilane)borate, and tri(trimethylsilane)phosphate; and / or, based on the mass of the electrolyte, the mass percentage of the additive is M4, 0.1% ≤ M4 ≤ 5%.

[0020] In one embodiment of this application, the positive electrode active material is selected from at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium nickel cobalt manganese, lithium cobalt oxide, lithium nickel manganese oxide, and lithium-rich manganese materials; and / or, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a negative electrode active material, and the negative electrode active material is selected from at least one of silicon-based materials and carbon-based materials.

[0021] The second aspect of this application provides a method for preparing a semi-solid-state battery according to the first aspect of this application, comprising: preparing a precursor solution containing the polymeric monomer, the crosslinking agent, the electrolyte and the initiator; injecting the precursor solution into the casing of the semi-solid-state battery, encapsulating it, allowing it to stand at room temperature for 12 to 36 hours, and then performing a thermal polymerization treatment at 40 to 80°C for 6 to 24 hours to obtain a semi-solid-state battery.

[0022] In one embodiment of this application, the initiator is selected from at least one of azobisisobutyronitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, and N,N-dimethylaniline; and / or, based on the mass of the gel polymer, the mass percentage of the initiator is M5, 0.01% ≤ M5 ≤ 0.5%.

[0023] The beneficial effects of this application are:

[0024] This application provides a semi-solid-state battery and its preparation method. The semi-solid-state battery includes a positive electrode, a negative electrode, a separator, and a semi-solid electrolyte. The positive electrode includes a positive electrode material layer, which comprises a positive electrode active material. The semi-solid electrolyte includes a gel polymer and an electrolyte solution. The gel polymer includes monomer units derived from a polymerizing monomer and a crosslinking agent, wherein the polymerizing monomer is selected from at least one compound shown in Formula I. The semi-solid-state battery satisfies the following conditions: Where A is the areal density of the positive electrode active material, in mg / cm³. 2 B represents the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, in %; C represents the residual amount of polymeric monomers in the semi-solid electrolyte, in %. The semi-solid battery of this application satisfies: This method can improve the room temperature and high temperature cycling performance of semi-solid-state batteries. Furthermore, the semi-solid-state battery prepared using the method described in this application exhibits high room temperature and high temperature cycling performance.

[0025] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Detailed Implementation

[0026] The technical solutions of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0027] The first aspect of this application provides a semi-solid battery comprising a positive electrode, a negative electrode, a separator, and a semi-solid electrolyte, wherein the positive electrode comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode active material; the semi-solid electrolyte comprises a gel polymer and an electrolyte, the gel polymer comprises monomer units derived from a polymeric monomer and a crosslinking agent, wherein the polymeric monomer is selected from at least one compound shown in Formula I;

[0028]

[0029] In Formula I, R1 is H or methyl; x is 1 to 10 and x is an integer; y ≥ 0, z ≥ 0 and y and z are integers, y + z ≤ 22; for example, x can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or any two of these values, and y + z can be 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22 or any two of these values.

[0030] The semi-solid-state battery satisfies:

[0031] Where A is the areal density of the positive electrode active material, in mg / cm³. 2 B represents the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, in %; C represents the residual amount of polymeric monomers in the semi-solid electrolyte, in %.

[0032] The content of gel polymers in semi-solid electrolytes has a significant impact on battery performance. Insufficient gel polymer content prevents gel formation, leaving the battery at risk of leakage. Higher gel polymer content reduces the compatibility between the electrolyte and the positive electrode, especially for high areal density positive electrodes. Gelation leads to a decrease in electrolyte conductivity, and this decrease becomes more pronounced with increasing polymer content. The reduced conductivity of gel polymer electrolytes lowers Li-N's performance. +The conductivity of ions and the severe electrochemical polarization of the battery significantly affect its capacity and cycle stability. The negative effects are even more pronounced when matched with high areal density electrodes. Therefore, it is necessary to reduce the areal density of the active material in the positive electrode to ensure good matching between the gel electrolyte and the positive electrode, thereby guaranteeing high capacity and good cycle stability. The areal density of the active material in the positive electrode affects the battery's energy density and cycle life; higher areal density usually means higher energy density, but may increase the battery's internal resistance and reduce cycle life. Furthermore, in-situ solidification is used to prepare semi-solid batteries. In-situ solidification is mainly achieved through free radical initiation. Incomplete free radical initiation inevitably results in monomer residues in the semi-solid polymer electrolyte, and excessive monomer residues degrade battery performance. This application uses acrylate monomers containing double bonds. If the residue level is high, severe side reactions will occur with the positive and negative electrodes, resulting in a significant increase in battery impedance, which is detrimental to battery cycle performance. The inventors discovered in their research that the semi-solid battery of this application satisfies: This invention addresses the aforementioned issues and improves the cycle performance of semi-solid-state batteries. The polymer monomers used in this application are selected from compounds shown in Formula I. The resulting gel polymer exhibits high dielectric constant and ionic conductivity, demonstrating good compatibility with different positive and negative electrode materials, which is beneficial for lithium-ion transport in the semi-solid electrolyte. Preferably, introducing fluorine-containing groups can further enhance the oxidation potential of the gel polymer, improving its compatibility with high-voltage positive electrode materials, thereby improving the room-temperature and high-temperature cycle performance of the semi-solid-state battery.

[0033] In one embodiment of this application, 10 < A < 40. For example, A can be 11, 15, 20, 25, 30, 35, 39, or a range of any two of these values. Within the above range, A shows a better relationship with the content of gel polymer in the semi-solid electrolyte, thereby improving the cycle stability of the semi-solid battery.

[0034] In one embodiment of this application, 7.5% < B < 30%. For example, B can be 8%, 10%, 20%, 29%, or a range of any two of these values. Within the above range, B can better improve the matching with the positive electrode, thereby improving the cycle stability of the semi-solid-state battery.

[0035] In one embodiment of this application, C ≤ 0.2%. For example, C can be 0, 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, or a range consisting of any two of these values. When C is within the above range, the residual amount of polymeric monomers in the semi-solid electrolyte is low, and serious side reactions with the positive and negative electrodes will not occur, thereby improving the cycle stability of the semi-solid battery.

[0036] In one embodiment of this application, the mass percentage content of the polymeric monomer is M1, where 90% ≤ M1 ≤ 99%, based on the mass of the gel polymer. For example, the mass percentage content of the polymeric monomer can be 90%, 93%, 96%, 99%, or a range consisting of any two of these values, based on the mass of the gel polymer. The content of the polymeric monomer within the range specified in this application is beneficial for the bonding of the polymeric monomer units and the crosslinking agent monomer units, forming a three-dimensional network structure in the gel polymer, thereby improving the mechanical strength and ionic conductivity of the gel electrolyte and enhancing the cycle performance of the lithium-ion battery.

[0037] In one embodiment of this application, the compound represented by Formula I is selected from at least one of the following compounds;

[0038]

[0039] The compound shown in Formula I is selected from the above compounds. The resulting gel polymer has a higher dielectric constant and ionic conductivity, which is more conducive to the transport of lithium ions in the semi-solid electrolyte, thereby better improving the room temperature cycle performance and high temperature cycle performance of the semi-solid battery.

[0040] In one embodiment of this application, the crosslinking agent is selected from the compound represented by Formula II or the compound represented by Formula III; the compound represented by Formula II is: C3H5C(O)(OCH2CH2) n OC(O)C3H5, n=1~10;

[0041] And / or, based on the mass of the gel polymer, the mass percentage content of the crosslinking agent is M2, where 1% ≤ M2 ≤ 10%. For example, based on the mass of the gel polymer, the mass percentage content M2 of the crosslinking agent can be 1%, 3%, 5%, 7%, 10%, or a range of any two of these values. Selecting the above crosslinking agents with a mass percentage content within the above range is beneficial for combining with the polymer monomers of this application to form a three-dimensional network structure, improving the mechanical strength of the semi-solid electrolyte. Simultaneously, since the crosslinking agent segments have a large amount of oxygen, they can provide transport paths for lithium ions on and between molecular chains, increasing the transport rate of lithium ions in the semi-solid electrolyte, thereby improving the cycle performance of the semi-solid battery.

[0042] In one embodiment of this application, the electrolyte comprises an electrolyte selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bisfluorosulfonylimide, lithium bistrifluoromethanesulfonylimide, lithium bis(oxalate)borate, lithium difluorobis(oxalate)borate, lithium difluorobis(oxalate)phosphate, lithium tetrafluorooxalate phosphate, and lithium 4,5-dicyano-2-trifluoromethyl-imidazolium; and / or, based on the mass of the electrolyte, the mass percentage content of the electrolyte is M3, where 10% ≤ M3 ≤ 20%. For example, based on the mass of the electrolyte, the mass percentage content of the electrolyte can be 10%, 13%, 15%, 17%, 20%, or a range consisting of any two of these values. Selecting the above electrolytes and ensuring the electrolyte content is within the above range allows the semi-solid electrolyte to have higher ionic conductivity and better electrochemical stability, further improving the cycle performance of the semi-solid battery.

[0043] In one embodiment of this application, the electrolyte includes an additive selected from at least one of vinylene carbonate, 1,3-propanesulfonate lactone, 1,3-propenesulfonate lactone, vinyl sulfate, lithium difluorophosphate, tris(trimethylsilane)borate, and tris(trimethylsilane)phosphate; and / or, based on the mass of the electrolyte, the mass percentage of the additive is M4, where 0.1% ≤ M4 ≤ 5%. For example, based on the mass of the electrolyte, the mass percentage of the additive can be 0.1%, 1%, 2%, 3%, 4%, 5%, or a range consisting of any two of these values. Selecting the above additives and ensuring their content is within the aforementioned range can, on the one hand, enhance the stability of the positive and negative electrode interface films of the battery; on the other hand, it can generate interface film components containing sulfur, phosphorus, or boron on the positive and negative electrode interface films, which is beneficial for reducing the migration energy barrier of lithium ions at the electrode / electrolyte interface, improving the lithium ion conductivity, and further improving the cycle performance of the semi-solid-state battery.

[0044] In one embodiment of this application, the electrolyte includes an organic solvent selected from at least one of ethylene carbonate, propylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; and / or, based on the mass of the electrolyte, the mass percentage of the organic solvent is 75% to 90%. For example, based on the mass of the electrolyte, the mass percentage of the organic solvent can be 75%, 80%, 85%, 90%, or a range of any two of these values. Selecting the above-mentioned organic solvents and ensuring their content is within the above range allows the semi-solid electrolyte to possess high ionic conductivity and good electrochemical stability, further improving the cycle performance of the semi-solid battery.

[0045] In one embodiment of this application, the positive electrode active material is selected from at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium nickel cobalt manganese, lithium cobalt oxide, lithium nickel manganese oxide, and lithium-rich manganese materials; and / or, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a negative electrode active material, and the negative electrode active material is selected from at least one of silicon-based materials and carbon-based materials.

[0046] It should be noted that, in the specific embodiments of this application, lithium-ion batteries are used as an example of semi-solid-state batteries to explain this application; however, the semi-solid-state batteries in this application are not limited to lithium-ion batteries. The specific technical solution is as follows:

[0047] In this application, the positive electrode includes a positive current collector and a positive electrode material layer disposed on at least one surface of the positive current collector. The phrase "positive electrode material layer disposed on at least one surface of the positive current collector" means that the positive electrode material layer can be disposed on one surface of the positive current collector along its thickness direction, or on two surfaces of the positive current collector along its thickness direction. It should be noted that "surface" here can refer to the entire surface area of ​​the positive current collector, or only a portion thereof; this application does not impose any particular limitation, as long as the purpose of this application is achieved.

[0048] This application does not impose any particular limitation on the positive electrode current collector, as long as it can achieve the purpose of this application. For example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, aluminum foil, aluminum alloy foil, nickel foil, or nickel alloy can be used. The composite current collector can include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0049] This application does not impose any particular limitation on the thickness of the positive electrode material layer and the positive electrode current collector, as long as the purpose of this application can be achieved. For example, the thickness of the single-sided positive electrode material layer is 30 μm to 90 μm, and the thickness of the positive electrode current collector is 8 μm to 20 μm.

[0050] The positive electrode material layer may further include a conductive agent and a binder. This application does not impose any particular limitation on the types of conductive agents and binders, as long as they achieve the purpose of this application. For example, the conductive agent may include, but is not limited to, at least one of superconducting carbon black (SuperP), acetylene black, Ketjen black, carbon nanotubes, graphene, and carbon fibers. The aforementioned carbon nanotubes may include, but are not limited to, single-walled carbon nanotubes and / or multi-walled carbon nanotubes. The aforementioned carbon fibers may include, but are not limited to, vapor-grown carbon fibers (VGCF) and / or carbon nanofibers. The binder may include, but is not limited to, at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene-propylene terpolymer, ethylene-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resin. This application does not impose any particular limitation on the mass ratio of the positive electrode active material, conductive agent, and binder in the positive electrode material layer. Those skilled in the art can select according to actual needs, as long as the purpose of this application is achieved.

[0051] Optionally, the positive electrode may further include a conductive layer located between the positive current collector and the positive electrode material layer. The composition of the conductive layer is not particularly limited and can be any conductive layer commonly used in the art. The conductive layer includes a conductive agent and a binder. This application does not impose any particular limitation on the conductive agent and binder in the conductive layer; for example, it can be at least one of the aforementioned conductive agents and binders.

[0052] This application does not impose any particular limitation on the preparation method of the positive electrode sheet, as long as it achieves the purpose of this application. For example, the positive electrode active material, conductive agent, and binder are mixed in a certain proportion, and N-methylpyrrolidone (NMP) is added and stirred evenly to obtain a positive electrode slurry. The positive electrode slurry is uniformly coated on one surface of the positive electrode current collector, and after drying, a positive electrode sheet with a single-sided coating of positive electrode material layer is obtained. Then, the above coating steps are repeated on the other surface of the positive electrode current collector, and after drying, a positive electrode sheet with a double-sided coating of positive electrode material layer is obtained. Then, it is rolled, trimmed, cut, and slit, dried after slitting, and the tabs are welded to obtain the positive electrode sheet.

[0053] In this application, the negative electrode sheet includes a negative electrode current collector and a negative electrode material layer disposed on at least one surface of the negative electrode current collector. The phrase "a negative electrode material layer disposed on at least one surface of the negative electrode current collector" means that the negative electrode material layer can be disposed on one surface of the negative electrode current collector along its thickness direction, or on two surfaces of the negative electrode current collector along its thickness direction. It should be noted that the term "surface" here can refer to the entire surface of the negative electrode current collector or only a portion thereof; this application does not impose any particular limitation, as long as the purpose of this application is achieved.

[0054] This application does not impose any particular limitation on the negative electrode current collector, as long as it can achieve the purpose of this application. For example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, copper foil, copper alloy foil, nickel foil, stainless steel foil, titanium foil, foamed nickel, or foamed copper can be used. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.).

[0055] This application does not impose any particular limitation on the thickness of the negative electrode material layer and the negative electrode current collector, as long as the purpose of this application can be achieved. For example, the thickness of the single-sided negative electrode material layer is 30 μm to 80 μm, and the thickness of the negative electrode current collector is 6 μm to 15 μm.

[0056] In one embodiment of this application, the negative electrode material layer may further include a conductive agent and a binder. This application does not impose any particular limitation on the types of conductive agents and binders, as long as they achieve the purpose of this application. For example, the conductive agent may include, but is not limited to, at least one of superconducting carbon black (Super P), acetylene black, Ketjen black, carbon nanotubes, graphene, and carbon fibers. The aforementioned carbon nanotubes may include, but are not limited to, single-walled carbon nanotubes and / or multi-walled carbon nanotubes. The aforementioned carbon fibers may include, but are not limited to, vapor-grown carbon fibers (VGCF) and / or carbon nanofibers. The binder may include, but is not limited to, at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS). This application does not impose any particular limitation on the mass ratio of the negative electrode active material, conductive agent, and binder in the negative electrode material layer; those skilled in the art can select them according to actual needs, as long as the purpose of this application is achieved.

[0057] In one embodiment of this application, the negative electrode material layer may further include a conductive agent, a binder, and a thickener. This application does not particularly limit the types of conductive agents and binders, as long as they achieve the purpose of this application. For example, the conductive agent and binder may be at least one of the aforementioned conductive agents and binders. The thickener may include, but is not limited to, at least one of sodium carboxymethyl cellulose and lithium carboxymethyl cellulose. This application does not particularly limit the mass ratio of the negative electrode active material, conductive agent, binder, and thickener in the negative electrode material layer; those skilled in the art can select them according to actual needs, as long as the purpose of this application is achieved.

[0058] Optionally, the negative electrode sheet may further include a conductive layer located between the negative electrode current collector and the negative electrode material layer. This application does not impose any particular limitation on the composition of the conductive layer, which can be a conductive layer commonly used in the art. For example, the conductive layer may include a conductive agent and a binder. This application does not impose any particular limitation on the conductive agent and binder in the conductive layer; for example, it can be at least one of the aforementioned conductive agents and binders.

[0059] This application does not impose any particular limitation on the preparation method of the negative electrode sheet, as long as it achieves the purpose of this application. For example, the negative electrode active material, thickener, binder, and conductive agent can be mixed in a certain mass ratio, and deionized water can be added and stirred evenly to obtain a negative electrode slurry. The negative electrode slurry is uniformly coated on one surface of the negative electrode current collector, and after drying, a negative electrode sheet with a single-sided negative electrode material layer is obtained. Then, the above coating steps are repeated on the other surface of the negative electrode current collector, and after drying, a negative electrode sheet with a double-sided negative electrode material layer is obtained. Then, it is rolled, trimmed, cut, and slit, dried after slitting, and the tabs are welded to obtain the negative electrode sheet.

[0060] This application does not impose any particular limitation on the diaphragm, as long as it achieves the purpose of this application. For example, the diaphragm material can be selected from, but is not limited to, at least one of polyethylene (PE), polypropylene (PP), glass fiber, polyester (e.g., polyethylene terephthalate (PET) film), cellulose, polyimide (PI), and polyamide (PA). The type of diaphragm can include at least one of woven membrane, nonwoven fabric, microporous membrane, composite membrane, rolled membrane, and spun membrane. In this application, the thickness of the diaphragm is not particularly limited, as long as it achieves the purpose of this application; for example, the thickness of the diaphragm can be from 8 μm to 18 μm.

[0061] In this application, the semi-solid-state battery also includes a casing for housing the positive electrode, separator, negative electrode, and electrolyte, as well as other components known in the field of semi-solid-state batteries. This application does not limit the scope of these other components. This application does not impose any particular limitation on the casing; it can be a casing known in the art, as long as it achieves the purpose of this application. For example, the casing can be a rigid casing or a flexible casing. The material of the rigid casing can be metal; this application does not limit the type of metal and can use known metal rigid casings, as long as they achieve the purpose of this application. The flexible casing can be a metal plastic film, such as aluminum-plastic film, steel-plastic film, etc.

[0062] The semi-solid-state battery described in this application is not particularly limited and may include any device in which an electrochemical reaction occurs. In one embodiment of this application, the semi-solid-state battery may include, but is not limited to, lithium-ion semi-solid-state batteries (lithium-ion batteries), sodium-ion semi-solid-state batteries (sodium-ion batteries), etc.

[0063] The preparation process of the semi-solid battery in this application is well known to those skilled in the art, and this application does not have any particular limitations. For example, the preparation process of the semi-solid battery may include, but is not limited to, the following steps: stacking the positive electrode sheet, separator and negative electrode sheet in sequence, and winding, folding and other operations as needed to obtain a wound electrode assembly; placing the electrode assembly into the housing; injecting the gel electrolyte precursor solution into the housing and encapsulating it; allowing it to stand; performing thermal polymerization treatment; and then performing formation, degassing and other processes to obtain the semi-solid battery.

[0064] The second aspect of this application provides a method for preparing a semi-solid-state battery according to the first aspect of this application, comprising: preparing a precursor solution containing the polymeric monomer, the crosslinking agent, the electrolyte, and an initiator; injecting the precursor solution into a casing of a semi-solid-state battery; encapsulating the casing; allowing it to stand at room temperature for 12–36 hours; and then performing a thermal polymerization treatment at 40–80°C for 6–24 hours to obtain a semi-solid-state battery. For example, the standing time at room temperature can be 12, 18, 24, 30, or 36 hours; the thermal polymerization treatment temperature can be 40°C, 50°C, 60°C, 70°C, or 80°C, or a range of any two of these values; and the thermal polymerization treatment time can be 6, 10, 15, 20, or 24 hours, or a range of any two of these values. Preparing the semi-solid-state battery under the above conditions facilitates the in-situ polymerization reaction of the precursor solution within the semi-solid-state battery, forming a stable and solidified semi-solid electrolyte. In this application, room temperature refers to 20–30°C.

[0065] In one embodiment of this application, the initiator is selected from at least one of azobisisobutyronitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, and N,N-dimethylaniline; based on the mass of the gel polymer, the mass percentage of the initiator is M5, where 0.01% ≤ M5 ≤ 0.5%. For example, based on the mass of the gel polymer, the mass percentage of the initiator is 0.01%, 0.1%, 0.2%, 0.25%, 0.3%, 0.4%, 0.5%, or a range of any two of these values. Selecting the above initiators and controlling the mass percentage of the initiator within the above range is beneficial for controlling the polymerization rate and polymer crosslinking density, controlling the molecular weight of the polymer, and avoiding problems such as burst polymerization or decreased conductivity due to increased viscosity.

[0066] Example

[0067] The embodiments and comparative examples provided below illustrate the implementation of this application in more detail. Various tests and evaluations were conducted according to the methods described below. Furthermore, unless otherwise specified, "parts" and "%" are quality standards.

[0068] Test methods and equipment:

[0069] Test for residual polymer monomers in semi-solid electrolytes

[0070] The residual amount of polymer monomers in semi-solid electrolytes was detected by gas chromatography (GC). The specific operation method is as follows: (1) Standard solutions containing different monomers and different concentrations were prepared using toluene. The solutions were tested using GC (Agilent 7890B gas chromatograph, FID detector). The column model was DB-WAXETR (60mm×0.32mm×1.0μm). A standard curve of monomer concentration was plotted with peak area as the abscissa and solution concentration as the ordinate. The linear correlation coefficient of the curve was greater than 0.995. (2) A small amount of semi-solid electrolyte sample was placed in a 10mL volumetric flask, toluene was added to make up to 10mL, and the sample was ultrasonically cleaned for 1.5h. Then, the sample was filtered with a 0.22μm organic filter head for GC testing. The peak area corresponding to the monomer retention time was recorded. The concentration of residual monomers was obtained according to the standard curve. The residual content of monomers was finally obtained by calculation. The specific instruments and measurement steps are as follows:

[0071] 1. Instruments and equipment: Electronic balance: accurate to 0.0001g; Agilent 7890B gas chromatograph, FID detector; ultrasonic cleaner; organic filter head: pore size 0.22μm; volumetric flasks: 100mL, 10mL;

[0072] 2. Measurement Procedure

[0073] 2.1 Detection conditions: Column: DB-WAXETR (60mm×0.32mm×1.0μm); Injector temperature: 280℃; Detector temperature: 300℃; Injection volume: 2μL; Injection mode: split injection, split ratio: 50:1; Column flow rate: 1mL / min; Carrier gas: N2; Eluent: acetone; Temperature program:

[0074] type Heating rate (°C / min) Temperature (°C) Hold time (min) initial temperature -- 100 2 Phase 1 15 160 2 Phase 2 6 240 6

[0075] 2.2 Preparation of Standard Solutions

[0076] Standard solution 1: Accurately weigh 0.5 g (accurate to 0.1 mg) of monomer into a 100 mL volumetric flask, add toluene to dilute to 100 mL, shake well, and prepare a 5000 ppm monomer standard solution;

[0077] Standard solution 2: Accurately transfer 4.00 mL of standard solution 1 into a 10 mL volumetric flask, add toluene to dilute to 10 mL, shake well, and prepare a 2000 ppm monomer standard solution;

[0078] Standard solution 3: Accurately transfer 2.00 mL of standard solution 1 into a 10 mL volumetric flask, add toluene to dilute to 10 mL, shake well, and prepare a 1000 ppm monomer standard solution;

[0079] Standard solution 4: Accurately transfer 1.00 mL of standard solution 1 into a 10 mL volumetric flask, add toluene to dilute to 10 mL, shake well, and prepare a 500 ppm monomer standard solution;

[0080] Standard solution 5: Accurately transfer 1.00 mL of standard solution 3 into a 10 mL volumetric flask, add toluene to dilute to 10 mL, shake well, and prepare a 100 ppm monomer standard solution;

[0081] 2.2 Sample preparation: Accurately weigh 0.3 g of sample into a 10 mL volumetric flask, add toluene to dilute to 10 mL, place in an ultrasonic cleaner and sonicate for 1.5 h, then filter with a 0.22 μm organic filter for GC testing.

[0082] 2.3 Determination of working curve: Based on the series of standard solutions of different concentrations prepared in 2.2, set the gas chromatography conditions in 2.1. After the instrument is running stably, perform tests respectively. Plot the standard curve with peak area as the abscissa and solution concentration as the ordinate. The linear correlation coefficient of the curve should be greater than 0.995.

[0083] 2.4 Sample determination: After the instrument is running stably, prepare the sample according to step 2.2 and test it on the instrument. Record the peak area corresponding to the monomer retention time.

[0084] 2.5 Calculation: The content of each component is expressed as w, and the value is expressed as mg / kg (ppm), calculated according to the following formula:

[0085] w = (Ci × V) / m; where: Ci is the concentration of the monomer found from the standard curve, in mg / L; V is the sample dilution volume, in mL; and m is the sample amount, in g.

[0086] Initial room temperature capacity test

[0087] Place the lithium-ion battery in a 25°C constant temperature test chamber and let it stand for 30 minutes to allow it to reach a constant temperature. Charge it at a constant current of 0.1C to 4.2V, then charge it at a constant voltage of 4.2V until the cutoff current is 0.05C. Let it stand for 5 minutes, then discharge it at a constant current of 0.1C to 2.75V. Repeat this process for 3 weeks, and record the charging capacity in the 4th week as the initial room temperature capacity.

[0088] Room temperature cycling performance test

[0089] The lithium-ion battery was placed in a 25°C constant temperature test chamber and left to stand for 30 minutes to allow it to reach a constant temperature. It was then charged at a constant current of 1.0C to 4.2V, followed by constant voltage charging at 4.2V until the cutoff current reached 0.05C. After standing for 5 minutes, it was discharged at a constant current of 1.0C to 2.75V, and this discharge capacity was recorded as C1. This process was repeated for 500 cycles, and the discharge capacity C2 after 500 cycles was recorded. The room temperature cycle capacity retention rate of the lithium-ion battery was calculated as C2 / C1 × 100%.

[0090] High-temperature cycling performance test

[0091] The lithium-ion battery was placed in a 45°C constant temperature test chamber and left to stand for 60 minutes to allow it to reach a constant temperature. It was then charged at a constant current of 1.0C to 4.2V, followed by constant voltage charging at 4.2V until the cutoff current reached 0.05C. After standing for 5 minutes, it was discharged at a constant current of 1.0C to 2.75V, and this discharge capacity was recorded as C3. This process was repeated for 500 cycles, and the discharge capacity C4 after 500 cycles was recorded. The high-temperature cycle capacity retention rate of the lithium-ion battery was calculated as C4 / C3 × 100%.

[0092] Example 1-1

[0093] <Preparation of Gel Electrolyte Precursor Solution>

[0094] In an argon-filled glove box (moisture content <10ppm, oxygen content <1ppm), ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed evenly at a mass ratio of 3:7 to obtain the base solvent. Then, 1,3-propanesulfonate lactone (PS) was added and mixed evenly. Next, lithium hexafluorophosphate (LiPF6) was added, dissolved, and mixed evenly to obtain the electrolyte. The electrolyte content was 12.5% ​​by mass, the additive content was 1% by mass, and the remainder was the base solvent.

[0095] The monomer methyl acrylate (Formula 1-1), the crosslinking agent polyethylene glycol dimethacrylate (PEGDMA, average molecular weight 750), and the initiator azobisisobutyronitrile (AIBN) were mixed and homogeneous to obtain a polymer precursor solution. The polymer precursor solution contained 94.9% by mass, 5% by mass, and 0.1% by mass.

[0096] The polymer precursor solution and the electrolyte are mixed and homogeneously to obtain a gel electrolyte precursor solution; wherein, based on the mass of the gel electrolyte precursor solution, the mass percentage of the polymer precursor solution is 10% and the mass percentage of the electrolyte is 90%.

[0097] <Preparation of the positive electrode>

[0098] The positive electrode active material is lithium nickel cobalt manganese oxide ternary material (LiNi 0.8 Co 0.1 Mn 0.1 O2), conductive superconducting carbon black (Super P), conductive carbon nanotubes, and binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 96.2:2:0.6:1.2. N-methylpyrrolidone (NMP) was added to prepare a slurry with a solid content of 69 wt%. After vacuum stirring, a positive electrode slurry was obtained. The positive electrode slurry was uniformly coated onto one surface of a 16 μm thick aluminum foil current collector and dried at 80°C to obtain a single-sided coated positive electrode sheet. The above steps were repeated on the other surface of the aluminum foil to obtain a double-sided coated positive electrode sheet. The sheet was then rolled, trimmed, cut, and slit. After slitting, it was dried at 85°C under vacuum for 5 hours, and tabs were welded to obtain a 540 mm × 55 mm positive electrode sheet for later use. The thickness of the single-sided positive electrode layer was 50 μm, and the areal density of the positive electrode active material was 32 mg / cm³. 2 .

[0099] <Preparation of Negative Electrode Sheets>

[0100] The negative electrode active material is silicon carbide (model: SiC550, manufacturer: Liyang Tianmu Pilot Battery Materials Technology Co., Ltd.), and the conductive agent is superconducting carbon black. P), styrene-butadiene rubber (SBR) as binder, and sodium carboxymethyl cellulose (CMC-Na) as thickener were mixed in a mass ratio of 95:2:1.5:1.5, with deionized water added as a solvent to prepare a slurry with a solid content of 49 wt%. After vacuum stirring, a negative electrode slurry was obtained. The negative electrode slurry was uniformly coated onto one surface of a 9 μm thick copper foil current collector and dried at 85°C to obtain a negative electrode sheet with a single-sided negative electrode material layer. The above steps were repeated on the other surface of the copper foil to obtain a negative electrode sheet with a double-sided negative electrode material layer. After rolling, the sheet was trimmed, cut, and slit. After slitting, it was dried at 85°C under vacuum for 5 hours and then the tabs were welded to obtain a negative electrode sheet with a size of 660 mm × 59 mm. The thickness of the single-sided negative electrode material layer was 63 μm, and the areal density of the negative electrode active material was 20.1 mg / cm³. 2 .

[0101] <Preparation of the diaphragm>

[0102] A 12μm thick polyethylene (provided by Shenzhen Xingyuan Material Technology Co., Ltd.) was used as the diaphragm.

[0103] <Preparation of Lithium-ion Batteries>

[0104] The prepared positive electrode, separator, and negative electrode are stacked sequentially, with the separator positioned between the positive and negative electrodes to act as a separator. They are then wound, with the positive tab connected to the positive electrode and the negative tab connected to the negative electrode, resulting in an electrode assembly. The electrode assembly is placed in an aluminum-plastic film packaging bag and vacuum-baked at 85°C for 48 hours. The prepared gel electrolyte precursor solution is then injected at an injection rate of 3 g / Ah. After vacuum sealing, the assembly is allowed to stand at room temperature for 12 hours to allow the electrode, separator, and gel polymer electrolyte precursor solution to fully impregnate. Subsequently, a polymer jig formation machine (model: NP-5AFF, manufacturer: Shenzhen Xinpu Automation Equipment Co., Ltd.) is used for thermal polymerization at 60°C for 12 hours. Formation and degassing processes are then performed to obtain a formed lithium-ion battery. The formation current is 0.1C, the upper limit voltage is 4.2V, and the formation temperature is 25°C.

[0105] Test the residual amount of polymer monomers: Disassemble the molded lithium-ion battery in an argon-filled glove box (moisture <10ppm, oxygen <1ppm), take the polymerized semi-solid electrolyte from the separator, and then use GC to measure the residual amount of polymer monomers in the semi-solid electrolyte according to the method described above. The residual amount of polymer monomers is 0.01%.

[0106] Examples 1-2 to Examples 1-12

[0107] Except for the change in the type of polymeric monomer in Table 1 in the <Preparation of Gel Electrolyte Precursor Solution>, which alters the residual amount C of polymeric monomer in the semi-solid electrolyte, the rest is the same as in Example 1-1.

[0108] Examples 1-13 to Examples 1-21

[0109] Except for the following changes: in the preparation of the positive electrode sheet, the areal density A of the positive active material is changed according to Table 1; in the preparation of the gel electrolyte precursor solution, the type of polymeric monomer is changed according to Table 1, and the content of the polymeric precursor solution is adjusted, the content of the electrolyte is changed accordingly, and the residual amount C of polymeric monomer in the semi-solid electrolyte is changed accordingly; otherwise, the rest is the same as in Examples 1-1.

[0110] Examples 2-1 to 2-3

[0111] Except for the changes in the type and content of the crosslinking agent in <Preparation of Gel Electrolyte Precursor Solution> according to Table 2, which altered the content of the polymeric monomer and the residual amount C of the polymeric monomer in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0112] Examples 3-1 to 3-2

[0113] Except for the change of electrolyte type according to Table 3 in <Preparation of Gel Electrolyte Precursor Solution>, which alters the residual amount C of polymeric monomers in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0114] Examples 4-1 to 4-5

[0115] Except for the changes in the types and contents of additives, the contents of the base solvent, and the residual amount C of the polymerized monomer in the semi-solid electrolyte in the <Preparation of Gel Electrolyte Precursor Solution> according to Table 4, the rest are the same as in Examples 1-2.

[0116] Examples 5-1 to 5-3

[0117] Except for the change in the type of positive electrode active material according to Table 5 in the <Preparation of Positive Electrode Sheet>, which alters the residual amount C of polymeric monomers in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0118] Examples 6-1 to 6-4

[0119] Except for the change in the thermal polymerization temperature and time according to Table 6 in the <Preparation of Lithium-ion Batteries>, which alters the residual amount C of polymeric monomers in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0120] Examples 7-1 to 7-4

[0121] Except for the changes in the type and content of the initiator in the <Preparation of Lithium-ion Batteries> according to Table 7, which altered the content of the polymeric monomers and the residual amount C of the polymeric monomers in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0122] Comparative Example 1

[0123] Except for the change in the thermal polymerization temperature and time to 60°C and 5 hours respectively in the <Preparation of Lithium-ion Batteries>, which altered the residual amount C of the polymerized monomer in the semi-solid electrolyte, the rest is the same as in Examples 1-20.

[0124] Comparative Example 2

[0125] Except for the change in the thermal polymerization temperature and time (60°C and 4 hours respectively) in the <Preparation of Lithium-ion Batteries>, which altered the residual amount C of the polymerized monomer in the semi-solid electrolyte, the rest of the results were the same as in Examples 1-2.

[0126] Comparative Example 3

[0127] Except for the change in the thermal polymerization temperature and time to 30°C and 12 hours respectively in the <Preparation of Lithium-ion Batteries>, which altered the residual amount C of the polymerized monomer in the semi-solid electrolyte, the rest is the same as in Examples 1-21.

[0128] Comparative Example 4

[0129] Except for the change in the thermal polymerization temperature and time (30°C and 24 hours respectively) in the <Preparation of Lithium-ion Batteries>, which altered the residual amount C of the polymerized monomer in the semi-solid electrolyte, the rest is the same as in Examples 1-2.

[0130] Comparative Example 5

[0131] Except for adjusting the content of the polymer precursor solution according to Table 1 in <Preparation of Gel Electrolyte Precursor Solution>, and changing the thermal polymerization temperature and time to 30°C and 72 hours respectively in <Preparation of Lithium-ion Battery>, the residual amount C of polymeric monomers in the semi-solid electrolyte is changed accordingly, the rest is the same as in Examples 1-2.

[0132] Comparative Examples 6 to 8

[0133] Except for the following changes: in the preparation of the positive electrode sheet, the areal density A of the positive active material is changed according to Table 1; in the preparation of the gel electrolyte precursor solution, the type of polymeric monomer is changed according to Table 1, and the content of the polymeric precursor solution is adjusted, the content of the electrolyte is changed accordingly, and the residual amount C of polymeric monomer in the semi-solid electrolyte is changed accordingly; otherwise, the rest is the same as in Examples 1-1.

[0134] Table 1

[0135]

[0136]

[0137] As can be seen from Table 1, the semi-solid-state batteries of Examples 1-1 to 1-21 Within the scope of this application, the semi-solid-state battery exhibits high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance. The semi-solid-state batteries of Comparative Examples 1 to 8... Outside the scope of this application, the semi-solid-state battery exhibits lower initial room temperature capacity, room temperature cycling performance, and high-temperature cycling performance. These results demonstrate the advantages of the semi-solid-state battery described in this application. Within the scope of this application, the room temperature cycling performance and high temperature cycling performance of semi-solid-state batteries can be improved.

[0138] Table 2

[0139]

[0140] Table 3

[0141]

[0142] Table 4

[0143]

[0144] Table 5

[0145]

[0146]

[0147] As can be seen from Tables 2 to 5, selecting the crosslinking agent of this application and limiting its content within the scope of this application results in the semi-solid-state battery exhibiting high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance; selecting the electrolyte of this application and limiting its content within the scope of this application also results in the semi-solid-state battery exhibiting high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance; selecting the additives of this application and limiting their content within the scope of this application also results in the semi-solid-state battery exhibiting high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance; selecting the positive electrode active material of this application, and Within the scope of this application, semi-solid-state batteries are made to have high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance.

[0148] Table 6

[0149]

[0150] Table 7

[0151]

[0152] As can be seen from Tables 6 and 7, the thermal polymerization temperature and time for preparing semi-solid-state batteries are within the range of this application, and the resulting semi-solid-state batteries have high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance. By selecting the initiator of this application and limiting the content of the initiator within the range of this application, the resulting semi-solid-state batteries have high initial room temperature capacity, room temperature cycling performance, and high temperature cycling performance.

[0153] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A semi-solid-state battery, comprising a positive electrode, a negative electrode, a separator, and a semi-solid electrolyte, wherein, The positive electrode includes a positive electrode material layer, which includes a positive electrode active material; the semi-solid electrolyte includes a gel polymer and an electrolyte, wherein the gel polymer includes monomer units derived from a polymerizing monomer and a crosslinking agent, and wherein the polymerizing monomer is selected from at least one of the compounds shown in Formula I; In Formula I, R1 is H or methyl; x is 1 to 10 and x is an integer; y ≥ 0, z ≥ 0 and y and z are integers, y + z ≤ 22; The semi-solid-state battery satisfies: Where A is the areal density of the positive electrode active material, in mg / cm³. 2 B represents the mass percentage of the gel polymer based on the mass of the semi-solid electrolyte, in %; C represents the residual amount of polymeric monomers in the semi-solid electrolyte, in %.

2. The semi-solid-state battery according to claim 1, wherein it satisfies at least one of the following characteristics: (1)10＜A＜40； (2)7.5％＜B＜30％； (3)C≤0.2％。 3. The semi-solid-state battery according to claim 1, wherein, Based on the mass of the gel polymer, the mass percentage of the polymeric monomer is M1, where 90% ≤ M1 ≤ 99%.

4. The semi-solid-state battery according to claim 1, wherein, The compound represented by Formula I is selected from at least one of the following compounds; 5. The semi-solid-state battery according to claim 1, wherein, The crosslinking agent is selected from the compound shown in Formula II or the compound shown in Formula III; the compound shown in Formula II is: C3H5C(O)(OCH2CH2) n OC(O)C3H5, n=1~10; And / or, Based on the mass of the gel polymer, the mass percentage of the crosslinking agent is M2, where 1% ≤ M2 ≤ 10%.

6. The semi-solid-state battery according to claim 1, wherein, The electrolyte comprises an electrolyte selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethyl)sulfonyl)imide, lithium bis(oxalate)borate, lithium difluorobis(oxalate)borate, lithium difluorobis(oxalate)phosphate, lithium tetrafluorooxalate phosphate, and lithium 4,5-dicyano-2-trifluoromethyl-imidazolium; and / or, Based on the mass of the electrolyte, the mass percentage of the electrolyte is M3, where 10% ≤ M3 ≤ 20%.

7. The semi-solid-state battery according to claim 1, wherein, The electrolyte includes an additive selected from at least one of vinylene carbonate, 1,3-propanesulfonate lactone, 1,3-propenesulfonate lactone, vinyl sulfate, lithium difluorophosphate, tri(trimethylsilane)borate, and tri(trimethylsilane)phosphate; and / or, Based on the mass of the electrolyte, the mass percentage of the additive is M4, where 0.1% ≤ M4 ≤ 5%.

8. The semi-solid-state battery according to claim 1, wherein, The positive electrode active material is selected from at least one of lithium iron phosphate material, lithium manganese iron phosphate material, lithium nickel cobalt manganese material, lithium cobalt oxide material, lithium nickel manganese oxide material, and lithium-rich manganese material; And / or, the negative electrode sheet includes a negative electrode material layer, the negative electrode material layer includes a negative electrode active material, the negative electrode active material being selected from at least one of silicon-based materials and carbon-based materials.

9. A method for preparing a semi-solid-state battery according to any one of claims 1 to 8, comprising: Prepare a precursor solution comprising the polymerizable monomer, the crosslinking agent, the electrolyte, and the initiator; The precursor solution is injected into the casing of the semi-solid battery, encapsulated, and left to stand at room temperature for 12 to 36 hours. Then, it is subjected to thermal polymerization treatment at 40 to 80°C for 6 to 24 hours to obtain the semi-solid battery.

10. The preparation method according to claim 9, wherein, The initiator is selected from at least one of azobisisobutyronitrile, dimethyl azobisisobutyrate, benzoyl peroxide, tert-butyl peroxide, methyl ethyl ketone peroxide, and N,N-dimethylaniline; and / or, Based on the mass of the gel polymer, the mass percentage of the initiator is M5, where 0.01% ≤ M5 ≤ 0.5%.

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