Lithium ion gel battery and preparation method thereof

Abstract

The invention discloses a lithium ion gel battery and a preparation method thereof. The preparation method of the lithium ion gel battery comprises the following steps: (1) assembling a dry battery cell; (2) primary liquid injection: injecting a first precursor liquid into the dry cell, wherein the first precursor liquid comprises a polymer monomer, an electrolyte salt, an additive and a first non-aqueous organic solvent; (3) performing formation and exhaust on the battery cell treated in the step (2); (4) secondary liquid injection: injecting second precursor liquid into the battery cell treated in the step (3), wherein the second precursor liquid comprises an initiator and a second non-aqueous organic solvent; and (5) polymerizing, exhausting and sealing the battery cell treated in the step (4). The lithium ion gel battery prepared by the invention has relatively low internal resistance and good high-temperature performance and safety performance.

Description

Technical Field

[0001] This invention relates to the field of gel battery technology, and in particular to a lithium-ion gel battery and its preparation method. Background Technology

[0002] High-nickel ternary cathodes (such as NCM811) and silicon-based or lithium metal anodes are widely used in the core of high-energy-density lithium-ion batteries. NCM811 material (LiNi) 0.8 Co 0.1 Mn 0.1 The energy density of O2 can reach over 300 Wh / kg. However, high-nickel cathodes are prone to structural distortion and lattice oxygen release under high voltage (>4.3 V), leading to transition metal dissolution and electrolyte decomposition, resulting in capacity decay and thermal runaway risks. Liquid electrolytes (especially carbonates) are flammable and can undergo chain reactions with oxygen free radicals released from the cathode at high temperatures, posing a risk of thermal runaway. Traditional flame retardant additives (such as phosphate esters) can inhibit combustion, but they often have poor compatibility with graphite anodes, leading to anode peeling and capacity loss.

[0003] In-situ gel polymer electrolytes (GPEs) are considered an important strategy for simultaneously improving battery safety and cycle life due to their high flexibility, leak-proof properties, interfacial compatibility, high ionic conductivity, scalable processing, and intrinsic safety. For example, the flame-retardant GPE developed by the University of Science and Technology of China remained safe even after thermal runaway in NCM811 batteries. Furthermore, ultra-thin high-strength GPEs (such as the 1 µm thick HCGPE-PE developed by the Hong Kong University of Science and Technology team) combine high mechanical strength with uniform lithium-ion flux, enhancing battery safety.

[0004] However, the aforementioned methods do not pay much attention to the actual process when manufacturing gel electrolyte lithium-ion batteries, such as the electrolyte injection process, severe gas generation, and uneven polymer interfaces. These problems can lead to increased impedance and decreased cycle stability in lithium-ion batteries. For example, in existing methods for preparing lithium-ion gel batteries, a conventional electrolyte is first injected, followed by aging and formation, and then polymer monomers and initiators are injected a second time. Because the components of the first and second injections have certain differences in properties, this results in significant differences in wettability, leading to poor gel uniformity and consequently deteriorating the internal resistance and cycle performance of the lithium-ion gel battery.

[0005] Therefore, there is an urgent need for a lithium-ion gel battery and its preparation method to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] In view of the above problems, the purpose of this invention is to provide a lithium-ion gel battery and a method for preparing the same, wherein the prepared lithium-ion gel battery has low internal resistance and good high-temperature performance and safety performance.

[0007] To achieve the above objectives, the present invention provides a method for preparing a lithium-ion gel battery, comprising the following steps: (1) Assemble dry cell batteries; (2) First injection: A first precursor solution is injected into the dry cell. The first precursor solution includes a polymer monomer, an electrolyte salt, an additive, and a first non-aqueous organic solvent. The polymer monomer is selected from at least one of 1,3-dioxolane and 1,4-dioxane. The electrolyte salt is selected from at least one of lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorophosphate, lithium difluorooxalate borate, lithium lower aliphatic carboxylic acid, lithium difluorodioxalate phosphate, lithium bis(fluorosulfonyl)imide, lithium chloroborane, and lithium tetraphenylborate. (3) The battery cells processed in step (2) are subjected to formation and degassing; (4) Secondary injection: A second precursor liquid is injected into the cell after the treatment in step (3). The second precursor liquid includes an initiator and a second non-aqueous organic solvent. The initiator is selected from lithium hexafluorophosphate. (5) The battery cells processed in step (4) are polymerized, degassed, and sealed.

[0008] Compared with existing technologies, this invention first injects polymer monomers, a first non-aqueous organic solvent, an electrolyte salt, and additives as a first precursor liquid into a dry cell for formation and degassing. Then, an initiator and a second non-aqueous organic solvent are injected into the cell for polymerization and degassing. This two-stage injection process helps to expel gases generated during formation and polymerization, while also improving the uniformity of the lithium-ion gel electrolyte-electrode interface. This, in turn, enhances the high-temperature performance and safety of the lithium-ion gel battery and reduces its internal resistance. This invention uses at least one of 1,3-dioxolane and 1,4-dioxane as the polymer monomer, and further combines it with an electrolyte salt selected from at least one of lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium bis(trifluoromethanesulfonyl)imide, lithium difluorophosphate, lithium difluorooxalateborate, lithium lower aliphatic carboxylic acids, lithium difluorodioxalate phosphate, lithium bis(fluorosulfonyl)imide, lithium chloroborane, and lithium tetraphenylborate. This further effectively reduces the battery's internal resistance and improves its high-temperature performance.

[0009] Furthermore, the first precursor fluid of the present invention accounts for 75% to 97% of the sum of the mass of the first precursor fluid and the second precursor fluid.

[0010] Furthermore, the polymer monomer of the present invention accounts for 5% to 50% of the total mass of the first precursor fluid.

[0011] Furthermore, the additive of the present invention accounts for 0.05% to 5% of the total mass of the first precursor fluid.

[0012] Furthermore, the electrolyte salt of the present invention accounts for 5% to 25% of the total mass of the first precursor fluid.

[0013] Furthermore, the initiator of the present invention accounts for 0.5% to 50% of the total mass of the second precursor fluid.

[0014] Furthermore, step (1) of the present invention includes preparing a positive electrode sheet and a negative electrode sheet respectively, and then assembling the positive electrode sheet, the negative electrode sheet and the separator into a shell to form a dry cell.

[0015] Furthermore, the polymerization temperature of the present invention is 30℃~75℃, and the polymerization time is 8h~96h.

[0016] Furthermore, the electrolyte salt of the present invention is selected from lithium difluorosulfonylimide.

[0017] Furthermore, the first non-aqueous organic solvent and the second non-aqueous organic solvent of the present invention are each independently selected from at least one of γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate, ethyl propionate, butyl acetate, propyl propionate, butyl propionate, ethylene carbonate, propylene carbonate, butyl carbonate, methyl pentyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, propylene carbonate, crown ether, tetrahydrofuran, 2-methyltetrahydrofuran, 2-trifluoromethyltetrahydrofuran, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

[0018] Furthermore, the additives of the present invention include at least one selected from fluoroethylene carbonate, vinylene carbonate, vinyl sulfite, 1,3-propanesulfonate lactone, 1,3-propenesulfonate lactone, 1,4-butanesulfonate lactone, vinyl sulfate, and succinic anhydride.

[0019] In another aspect, the present invention provides a lithium-ion gel battery, which is prepared by the aforementioned method for preparing lithium-ion gel batteries. Detailed Implementation

[0020] The lithium-ion gel battery of the present invention has low internal resistance and good cycle performance and safety performance. Specifically, the preparation method of the lithium-ion gel battery of the present invention includes the following steps: (1) assembling dry cells; (2) primary liquid injection: injecting a first precursor liquid into the dry cells; (3) forming and venting the cells after step (2); (4) secondary liquid injection: injecting a second precursor liquid into the cells after step (3); (5) polymerizing, venting and sealing the cells after step (4).

[0021] The first precursor fluid accounts for 75% to 97% of the sum of the masses of the first precursor fluid and the second precursor fluid. As an example, the first precursor fluid accounts for 75%, 78%, 80%, 82%, 84%, 85%, 86%, 88%, 90%, 92%, 94%, 95%, 97% of the sum of the masses of the first precursor fluid and the second precursor fluid, but is not limited thereto. Other values not listed within the scope of the present invention are equally applicable.

[0022] In step (1), assembling the dry battery cell includes preparing the positive electrode sheet and the negative electrode sheet, and then assembling the positive electrode sheet, the negative electrode sheet and the separator into the shell to make the dry battery cell.

[0023] Specifically, the positive electrode sheet is obtained by coating the positive electrode paste on the current collector. The positive electrode paste includes a positive electrode active material, and the positive electrode active material includes at least one of a metal oxide and a polyanionic compound. Specifically, the metal oxide includes a lithium cobalt oxide material, a lithium iron phosphate material, a nickel cobalt manganese oxide or a nickel cobalt aluminum oxide. The lithium cobalt oxide material is lithium cobalt oxide or lithium cobalt oxide doped and coated and modified, the lithium iron phosphate material is lithium iron phosphate or lithium iron phosphate doped and coated and modified, and the chemical formula of the nickel cobalt manganese oxide is LiNi x Co y Mn z M (1-x-y-z) O2, and the chemical formula of the nickel cobalt aluminum oxide is LiNi x Co y Al z N (1-x-y-z) O2, where M is at least one of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, N is at least one of Mn, Mg, Cu, Zn, Sn, B, Ga, Cr, Sr, V and Ti, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z ≤ 1. The chemical formula of the polyanionic compound is Li x N y (XO z ) n , where N is independently selected from at least one of Fe, Mn, Ni, Cu and V, X is independently selected from one of S, P, Si, Mo and As, 1 ≤ x ≤ 4, 1 ≤ y ≤ 3, 1 ≤ n ≤ 3, 1 ≤ z ≤ 4. As an example, the positive electrode active material of the present invention is nickel cobalt manganese oxide, and its chemical formula is LiNi 0.8 Co 0.1 Mn 0.1 O2.

[0024] The negative electrode sheet is obtained by coating the negative electrode paste on the current collector, and the negative electrode paste includes a negative electrode active material, and the negative electrode active material is selected from at least one of artificial graphite, natural graphite, lithium titanate, silicon carbon composite material and silicon monoxide. As an example, the negative electrode material of the present invention is artificial graphite.

[0025] The diaphragm of the present invention may be a PP diaphragm, but is not limited thereto.

[0026] In step (2), the first precursor liquid includes polymer monomers, electrolyte salts, additives, and a first non-aqueous organic solvent. The first injection of the present invention specifically includes mixing the polymer monomers, electrolyte salts, additives, and the first non-aqueous organic solvent evenly to obtain the first precursor liquid, controlling the water content to be ≤10ppm, injecting the first precursor liquid into the storage area of ​​the dry cell, and then sealing the cell.

[0027] Specifically, the polymer monomer accounts for 5% to 50% of the total mass of the first precursor fluid. For example, the polymer monomer accounts for 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% of the total mass of the first precursor fluid, but is not limited thereto; other values ​​not listed within the scope of this invention are also applicable. The polymer monomer is selected from at least one of 1,3-dioxolane and 1,4-dioxane.

[0028] The electrolyte salt accounts for 5% to 25% of the total mass of the first precursor body fluid. More preferably, the electrolyte salt accounts for 8% to 20% of the total mass of the first precursor body fluid. For example, the electrolyte salt accounts for 5%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 20%, and 25% of the total mass of the first precursor body fluid, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The electrolyte salt is selected from at least one of lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium difluorophosphate (LiPO2F2), lithium difluorooxalate borate (LiDFOB), lower aliphatic carboxylic acids, lithium difluorodioxalate phosphate (LiDFBP), lithium bis(fluorosulfonyl)imide (LiFSI), lithium chloroborane, and lithium tetraphenylborate. Lithium hexafluorophosphate (LiPF6) readily reacts prematurely with 1,3-dioxolane and 1,4-dioxane, making it unsuitable for existing lithium-ion battery manufacturing processes. In this invention, the electrolyte salt is preferably lithium bis(fluorosulfonyl)imide (LiFSI). Using lithium bis(fluorosulfonyl)imide as the electrolyte salt in combination with the polymer monomers 1,3-dioxolane and 1,4-dioxane prevents premature curing of the polymer monomers and effectively reduces the battery's internal resistance and improves high-temperature performance.

[0029] The additive comprises 0.05% to 5% of the total mass of the first precursor fluid, preferably 0.1% to 4% of the total mass of the first precursor fluid, and more preferably 0.5% to 3% of the total mass of the first precursor fluid. As examples, the additive comprises 0.05%, 0.1%, 0.2%, 0.4%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, and 5% of the total mass of the first precursor fluid, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The additive includes at least one of fluoroethylene carbonate (FEC), vinyl sulfite (ES), 1,3-propanesulfonate lactone (PS), 1,3-propenesulfonate lactone (PST), 1,4-butanesulfonate lactone (1,4-BS), vinyl sulfate (DTD), and succinic anhydride (SA).

[0030] The first non-aqueous organic solvent is selected from γ-butyrolactone (GBL), γ-valerolactone (GVL), δ-valerolactone (DVL), methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), butyl acetate (BAC), propyl propionate (PP), butyl propionate (PRB), ethylene carbonate (EC), propylene carbonate (PCA), butyl carbonate (BC), methyl amyl carbonate (MPC), vinylene carbonate (VEC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). At least one of methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC), propylene carbonate (PC), crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH3-THF), 2-trifluoromethyltetrahydrofuran (2-CF3-THF), dimethoxymethane (DMM), diethoxymethane (DEM), ethoxymethoxymethane (DCE), ethylene glycol di-n-propyl ether (EDP), ethylene glycol di-n-butyl ether (EDB), and diethylene glycol dimethyl ether (DEGME).

[0031] In step (4), the second precursor liquid includes an initiator and a second non-aqueous organic solvent. The secondary injection specifically includes mixing the initiator and the second non-aqueous organic solvent evenly to obtain the second precursor liquid, controlling the water content to be ≤10ppm, injecting the second precursor liquid into the storage area of ​​the battery cell after being treated in step (3), and then sealing the battery cell.

[0032] Specifically, the initiator accounts for 0.5% to 50% of the total mass of the second precursor liquid, preferably 1% to 45%, and more preferably 3% to 40%. As examples, the initiator accounts for 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 45%, and 50% of the sum of the organic solvent and the initiator mass, but is not limited to the listed values; other unlisted values ​​within this range are also applicable. The initiator is selected from lithium hexafluorophosphate. Using lithium hexafluorophosphate as the initiator of this invention can further improve the compatibility between the second and first precursor liquids, improve the uniformity of the gel electrolyte obtained after polymerization and curing, thereby more effectively reducing internal resistance and improving high-temperature performance and safety performance.

[0033] The second non-aqueous organic solvent is selected from γ-butyrolactone (GBL), γ-valerolactone (GVL), δ-valerolactone (DVL), methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), butyl acetate (BAC), propyl propionate (PP), butyl propionate (PRB), ethylene carbonate (EC), propylene carbonate (PCA), butyl carbonate (BC), methyl amyl carbonate (MPC), vinylene carbonate (VEC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). At least one of the following: ethyl methyl carbonate (EMC), methyl propyl carbonate (MPC), propylene carbonate (PC), crown ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-CH3-THF), 2-trifluoromethyltetrahydrofuran (2-CF3-THF), dimethoxymethane (DMM), diethoxymethane (DEM), ethoxymethoxymethane (DCE), ethylene glycol di-n-propyl ether (EDP), ethylene glycol di-n-butyl ether (EDB), and diethylene glycol dimethyl ether (DEGME). The second non-aqueous organic solvent may be the same as or different from the first non-aqueous organic solvent.

[0034] In step (5), the polymerization temperature is 30℃~75℃. For example, the polymerization temperature is 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, or 75℃, but is not limited to these. Other values ​​not listed within the scope of this invention are also applicable. The polymerization time is 8h~96h. For example, the polymerization time can be, but is not limited to, 8h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, 95h, or 96h, but is not limited to these. Other values ​​not listed within the scope of this invention are also applicable.

[0035] To better illustrate the purpose, technical solution, and beneficial effects of this invention, the invention will be further described below with reference to specific embodiments. It should be noted that the methods described below are further explanations of this invention and should not be construed as limiting it.

[0036] Example 1 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0037] Example 2 (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,4-dioxane (DX) were mixed in a weight ratio of EC:EMC:DX = 2:5:2 (89.0 g). Then, 3.0 g of vinylene carbonate was added, dissolved, and stirred thoroughly. Then, 8.0 g of LiFSI was added and mixed evenly to obtain the first precursor liquid. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand.

[0038] (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0039] Example 3 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:4 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0040] Example 4 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 85% of the total mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0041] Example 5 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl acetate (EA), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EA:DOL = 2:5:2 (89.0 g). Then, 3.0 g of vinylene carbonate was added, dissolved, and stirred thoroughly. Then, 8.0 g of LiFSI was added and mixed evenly to obtain the first precursor liquid. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0042] Example 6 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then, 3.0 g of fluoroethylene carbonate was added, dissolved, and stirred thoroughly. Then, 8.0 g of LiFSI was added and mixed evenly to obtain the first precursor liquid. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0043] Example 7 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 4.0 g of lithium hexafluorophosphate was added to 96.0 g of ethylene carbonate (EC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0044] Comparative Example 1 This comparative example provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) The cells processed in step (2) are formed (charged at a constant current of 0.05C for 60 minutes, then charged at a constant current of 0.1C for 60 minutes, and then the current is adjusted to a constant current of 0.2C until 3.6V is cut off), the air is vented, and the cells are stamped and sealed to obtain lithium-ion batteries.

[0045] Comparative Example 2 This comparative example provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,4-dioxane (DX) were mixed in a weight ratio of EC:EMC:DX = 2:5:2 (89.0 g). Then, 3.0 g of vinylene carbonate was added, dissolved, and stirred thoroughly. Then, 8.0 g of LiFSI was added and mixed evenly to obtain the first precursor liquid. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) The cells processed in step (2) are formed (charged at a constant current of 0.05C for 60 minutes, then charged at a constant current of 0.1C for 60 minutes, and then the current is adjusted to a constant current of 0.2C until 3.6V is cut off), the air is vented, and the cells are stamped and sealed to obtain lithium-ion batteries.

[0046] Comparative Example 3 This comparative example provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then, 3.0 g of vinylene carbonate was added, dissolved, and stirred thoroughly. Then, 8.0 g of LiPF6 was added and mixed evenly to obtain the first precursor liquid. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0047] Comparative Example 4 This comparative example provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiBOB was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of lithium hexafluorophosphate was added to 94.0 g of methyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0048] Comparative Example 5 This comparative example provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of azobisisobutyronitrile was added to 94.0 g of ethyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0049] Comparative Example 6 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co0.1 Mn 0.1 O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of benzoyl peroxide was added to 94.0 g of ethyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the total mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0050] Comparative Example 7 This embodiment provides a method for preparing a lithium-ion gel battery, including the following steps: (1) Assemble dry cell: use nickel-cobalt-manganese ternary material LiNi 0.8 Co 0.1 Mn 0.1O2, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 95:1:4 to prepare a positive electrode slurry of a certain viscosity. This slurry is then coated onto both sides of an aluminum foil, dried, and rolled to obtain the positive electrode sheet. Similarly, artificial graphite material, PVDF binder, and SuperP conductive agent are mixed evenly at a mass ratio of 90:2:8 to prepare a negative electrode slurry of a certain viscosity. This slurry is then coated onto both sides of a copper foil, dried, and rolled to obtain the negative electrode sheet. The positive electrode sheet, separator, and negative electrode sheet are stacked in sequence, and the tabs are welded together before being placed in the aluminum-plastic film of the battery packaging to obtain a dry cell. (2) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and 1,3-dioxolane (DOL) were mixed in a weight ratio of EC:EMC:DOL = 2:5:2 (89.0 g). Then 3.0 g of vinylene carbonate was added, dissolved and stirred thoroughly, and then 8.0 g of LiFSI was added. After mixing evenly, the first precursor liquid was obtained. The first precursor liquid was injected into the dry cell, vacuum sealed, and left to stand. (3) Form the battery cell after step (2) (charge it with a constant current of 0.05C for 60 minutes, then charge it with a constant current of 0.1C for 60 minutes, then adjust the current to a constant current of 0.2C and charge it to 3.6V to cut off), and exhaust the gas; (4) In a glove box filled with argon (O2 < 1 ppm, H2O < 1 ppm), 6.0 g of aluminum trifluoromethanesulfonate was added to 94.0 g of ethyl methyl carbonate (EMC), dissolved and stirred thoroughly to obtain a second precursor liquid. The second precursor liquid was injected into the battery cell after formation and venting, and then stamped and sealed. The first precursor liquid accounted for 97% of the sum of the mass of the first and second precursor liquids. (5) The cell treated in step (4) is polymerized in situ at 40°C for 24 hours, the air is vented, and the cell is stamped and sealed to obtain a lithium-ion gel battery.

[0051] The lithium-ion gel batteries prepared in Examples 1-7 and the lithium-ion batteries prepared in Comparative Examples 1-7 were subjected to tests for first-efficiency performance, discharge capacity, internal resistance, high-temperature storage, high-temperature cycling, and safety performance. The test conditions are as follows, and the test results are shown in Table 1. First-cycle efficiency and discharge capacity: Under high temperature (45℃) conditions, the lithium-ion battery was charged at 0.1C to 95% of its design capacity, and the charging capacity was recorded as C0; Under normal temperature (25℃) conditions, the lithium-ion battery was subjected to three 0.33C / 0.33C charge and discharge cycles, with an upper limit voltage of 3.6V and a lower limit voltage of 2.5V. The first cycle charging capacity was recorded as C1, the first cycle discharging capacity as C2, and the third cycle discharging capacity as C3.

[0052] First-efficacy = ((C0+C1) / C2)×100% Discharge capacity = C3 Internal resistance: Under normal temperature (25℃) conditions, the lithium-ion battery was charged and discharged at 0.33C / 0.33C, with an upper limit voltage of 3.6V and a lower limit voltage of 2.5V, and the discharge capacity was recorded as C0; under normal temperature (25℃) conditions, the lithium-ion battery was charged at 0.33C, with an upper limit voltage of 3.6V, and then discharged at 0.33C to C0 / 2, and left to stand for 1 hour, and the end voltage was recorded as V0; the lithium-ion battery was discharged at a current of 1C0 for 30 seconds, and the end voltage was recorded as V1.

[0053] Internal resistance = (V0 - V1) / C0 High-temperature storage: Under normal temperature (25℃) conditions, the lithium-ion battery is charged and discharged once at 0.5C / 0.5C (the battery discharge capacity is recorded as C0), with an upper limit voltage of 3.6V and a lower limit voltage of 2.5V. Then, the battery is charged to 3.6V under constant current and constant voltage conditions at 0.5C. The battery is placed in a 60℃ oven for 15 days, removed and the battery thickness is measured. The battery is placed in a 25℃ environment and discharged at 0.5C to the lower limit voltage of 2.5V (the discharge capacity is recorded as C1). The capacity retention rate is calculated.

[0054] Capacity retention rate = (C1 / C0) × 100% High-temperature cycling: Under high-temperature (50°C) conditions, the lithium-ion battery is subjected to one 1.0C / 1.0C charge and discharge cycle (battery discharge capacity is C0), with an upper limit voltage of 3.6V and a lower limit voltage of 2.5V. Then, under high-temperature (50°C) conditions, it is subjected to 400 cycles of 1.0C / 1.0C charge and discharge (battery discharge capacity is C1), and the capacity retention rate is calculated.

[0055] Capacity retention rate = (C1 / C0) × 100% Needle penetration test: The lithium-ion battery is charged to the upper limit voltage of 3.6V at a constant current of 0.5C; a high-temperature resistant steel needle with a diameter of φ5 mm to φ8 mm (the cone angle of the needle tip is 45° to 60°, and the surface of the needle is smooth, free of rust, oxide layer and oil) is used to penetrate the battery from a direction perpendicular to the lithium-ion battery plate at a speed of (25±5) mm / s. The penetration position should be close to the geometric center of the pierced surface, and the steel needle should remain in the battery; observe for 1 hour. It should not explode or catch fire.

[0056] Table 1 Performance test results of Examples 1-7 and Comparative Examples 1-7

[0057] Please refer to Table 1 for the test results. As can be seen from Examples 1-7 and Comparative Examples 1-7, the lithium-ion gel battery prepared by the method of this invention has lower internal resistance, better high-temperature storage, high-temperature cycling, and safety performance. Further comparison of Examples 1 and Comparative Examples 4-7 shows that when DOL is used as the polymer monomer, LiFSI is used as the lithium salt, and lithium hexafluorophosphate is used as the initiator, its performance is optimal. LiBOB is prone to decomposition and gas generation under high temperature conditions in lithium-ion batteries, affecting the performance of lithium-ion batteries. Free radical initiators such as azobisisobutyronitrile / benzoyl peroxide cannot effectively initiate DOL polymerization, and the improvement on lithium-ion safety performance is not significant. Aluminum trifluoromethanesulfonate can initiate DOL polymerization, but it introduces exogenous aluminum ions. As a strong Lewis acid, aluminum ions will simultaneously activate the nucleophilic reaction of solvent molecules in the electrolyte (such as the breaking of CO bonds in carbonates), accelerating solvent polymerization or degradation, and producing gases such as methane, ethane, and CO2, which may lead to bulging or leakage risks.

[0058] As can be seen from the comparison between Example 1 and Comparative Example 1, and between Example 2 and Comparative Example 2, the five-membered ring structure of DOL is more stable than that of DX. In contrast, DX is easily oxidized in lithium-ion batteries and consumes lithium ions to generate organic SEI / CEI, which leads to an increase in the internal resistance of lithium-ion batteries and a decrease in cycle retention.

[0059] As can be seen from the comparison between Example 1 and Comparative Example 3, when both the electrolyte salt and the initiator are lithium hexafluorophosphate, the performance deteriorates. This may be because lithium hexafluorophosphate can directly initiate DOL polymerization under weakly acidic conditions. When the electrolyte contains a high content of lithium hexafluorophosphate, it continues to react with DOL, resulting in a significant increase in the battery's internal resistance, a sharp deterioration in performance, and significant gas production in the battery.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method of making a lithium ion gel battery, characterized by, The method comprises the steps of: (1) assembling a dry battery cell; (2) first liquid injection: injecting a first precursor liquid into the dry battery cell, the first precursor liquid comprising a polymer monomer, an electrolyte salt, an additive, and a first non-aqueous organic solvent, the polymer monomer being selected from at least one of 1,3-dioxolane and 1,4-dioxane, the electrolyte salt being selected from at least one of lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethylsulfonate, lithium bis-trifluoromethylsulfonimide, lithium difluorophosphate, lithium difluoro oxalate borate, lithium lower aliphatic carboxylate, lithium difluoro dioxalate phosphate, lithium bis-fluorosulfonylimide, lithium chloroborane, and lithium tetraphenylborate; (3) performing formation and degassing on the battery cell after the step (2); (4) second liquid injection: injecting a second precursor liquid into the battery cell after the step (3), the second precursor liquid comprising an initiator and a second non-aqueous organic solvent, the initiator being selected from lithium hexafluorophosphate; (5) performing polymerization, degassing, and sealing on the battery cell after the step (4).

2. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The first precursor liquid accounts for 75% to 97% of the total mass of the first precursor liquid and the second precursor liquid.

3. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The polymer monomer accounts for 5% to 50% of the total mass of the first precursor liquid, the additive accounts for 0.05% to 5% of the total mass of the first precursor liquid, and the electrolyte salt accounts for 5% to 25% of the total mass of the first precursor liquid.

4. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The step (1) comprises separately preparing a positive electrode sheet and a negative electrode sheet, and assembling the positive electrode sheet, the negative electrode sheet, and a separator into a shell to form the dry battery cell.

5. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The polymerization temperature is 30°C to 75°C, and the polymerization time is 8h to 96h.

6. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The electrolyte salt is selected from lithium bis-fluorosulfonylimide.

7. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The initiator accounts for 0.5% to 50% of the total mass of the second precursor liquid.

8. The method for preparing a lithium-ion gel battery according to claim 1, characterized in that, The first non-aqueous organic solvent and the second non-aqueous organic solvent are each independently selected from at least one of γ-butyrolactone, γ-valerolactone, δ-valerolactone, methyl acetate, ethyl acetate, ethyl propionate, butyl acetate, propyl propionate, butyl propionate, ethylene carbonate, propylene carbonate, butylene carbonate, methyl-pentyl carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, methyl propyl carbonate, propylene carbonate, crown ether, tetrahydrofuran, 2-methyl tetrahydrofuran, 2-trifluoromethyl tetrahydrofuran, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether.

9. The method of claim 1, wherein the gelation of the electrolyte is performed by adding a gelation agent to the electrolyte. The additive comprises at least one of fluoroethylene carbonate, vinylene carbonate, vinyl sulfite, 1,3-propane sultone, 1,3-propene sultone, 1,4-butane sultone, vinyl sulfate, and succinic anhydride.

10. A lithium-ion gel battery, characterized by, The lithium ion gel battery is prepared by the method of any one of claims 1 to 9.

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