CN-122025783-A - Gel electrolyte battery and preparation method thereof

Abstract

The invention relates to the technical field of lithium ion batteries, in particular to a gel electrolyte battery and a preparation method thereof. The gel electrolyte is polymerized in situ in the battery core by adopting a constant temperature gradient pressure-increasing curing method to prepare the gel electrolyte battery, the constant temperature gradient pressure-increasing curing realizes physical adsorption and chemical bonding of an electrode-electrolyte interface, and the stability of the gel electrolyte and the electrode interface is improved. The gel electrolyte of the gel electrolyte battery contains phosphorus-containing ureido pyrimidinone monomer and ionic liquid monomer, can form a physical cross-linked network with self-repairing capability and a chemical cross-linked network double-network structure with flame retardant property, and can synchronously regulate and control the formation of the gel electrolyte double-network structure through constant temperature gradient and pressure rise solidification. The gel electrolyte battery is prepared by a constant temperature gradient pressure-increasing solidification method, and the obtained gel electrolyte battery has excellent conductivity, cycle performance and safety.

Inventors

• LUO YONG
• LI DEFU
• LUO HAO
• DING ZHITIAN
• LIAO YA
• ZHU LUFA
• SONG SHIPAI
• JIANG YAN
• XIANG YONG

Assignees

• 天府绛溪实验室

Dates

Publication Date

20260512

Application Date

20260227

Claims (10)

1. 1. The preparation method of the gel electrolyte battery is characterized by comprising the following steps of: mixing a phosphorus-containing ureido pyrimidinone monomer, an ionic liquid monomer, lithium salt and an initiator to prepare a gel electrolyte precursor solution; Assembling the cells, injecting a gel electrolyte precursor solution into the cells, and Performing constant-temperature gradient pressure-increasing solidification on the battery core to obtain a gel electrolyte battery; In the constant temperature gradient pressure-increasing curing process, the constant temperature is 40-90 ℃, gradient pressure-increasing is applied to the battery core according to the sequence of the first stage, the second stage and the third stage and is kept for a certain time, the pressure difference between the first stage and the second stage is 0.01-0.06MPa, and the pressure difference between the second stage and the third stage is 0.01-0.12MPa.
2. 2. The method for preparing a gel electrolyte battery according to claim 1, wherein the step-up pressure is applied to the battery core in the order of the first stage, the second stage and the third stage in the constant temperature gradient step-up curing process, and the step-up pressure is maintained for a certain period of time, and the step-up pressure comprises the following steps: a first stage of maintaining the pressure of 0.001-0.02 MPa for 0.5-6 hr; a second stage, maintaining for 1-5h under the pressure of 0.03-0.06 MPa; And a third stage, wherein the mixture is maintained at a pressure of 0.07-0.15 MPa for 1-4h.
3. 3. The method for preparing a gel electrolyte battery according to claim 1, wherein the structural general formula of the phosphorus-containing ureido pyrimidinone monomer is shown as formula [1 ]: [1] Wherein R 1 、R 2 in the formula [1] is C1-C4 alkyl, R 1 、R 2 can be the same, R 3 is alpha-hydroxy saturated alkyl, R 4 is an inert group, ar is phenylene or alkyl substituted derivative thereof.
4. 4. The method of preparing a gel electrolyte battery according to claim 1, wherein the ionic liquid monomer comprises one or more of 1-vinyl-3-ethylimidazolium bis (trifluoromethylsulfonyl) imide salt, 1-vinyl-3-alkylimidazolium bis (fluorosulfonyl) imide salt, N-vinyl-N-alkylpyrrolidinium bis (trifluoromethylsulfonyl) imide salt, and/or the ionic liquid monomer has a viscosity of 100 mPa. S or less at ordinary temperature.
5. 5. A method of preparing a gel electrolyte battery according to claim 1, wherein the lithium salt comprises one or more of lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide, and lithium hexafluorophosphate, and/or the initiator comprises one or more of azobisisobutyronitrile and dibenzoyl peroxide.
6. 6. The method of claim 1, wherein the gel electrolyte precursor solution further comprises a compatibilizer and a plasticizer, the gel electrolyte precursor solution is prepared by stepwise mixing, wherein The mass percentage of the phosphorus-containing ureido pyrimidinone monomer is 0.5% -5%, The mass percentage of the ionic liquid monomer is 5% -20%, The mass percentage of the lithium salt is 5% -15%, The mass percentage of the compatilizer is 0.5% -3%, The mass percentage of the initiator is 0.1% -2%, and The mass percentage of the plasticizer is 60% -85%.
7. 7. The method for producing a gel electrolyte battery according to claim 6, wherein the compatibilizing agent comprises one or more of triethyl phosphate, tributyl phosphate, polyethylene glycol dimethyl ether, diethyl 1-ethyl-3-methylimidazole phosphate, and/or, The plasticizer comprises one or more combinations of succinonitrile, polyvinyl alcohol, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and the like.
8. 8. The method for preparing a gel electrolyte battery according to claim 6, wherein the step-by-step mixing specifically comprises the steps of: firstly mixing a phosphorus-containing ureido pyrimidinone monomer, an ionic liquid monomer and a compatilizer to obtain a first premix, then adding the first premix into a plasticizer containing lithium salt, and finally adding an initiator to obtain a gel electrolyte precursor solution.
9. 9. A gel electrolyte battery, characterized in that the gel electrolyte battery is obtained by a preparation method of a gel electrolyte battery according to any one of claims 1 to 8.
10. 10. The gel electrolyte battery according to claim 9, wherein the gel electrolyte of the gel electrolyte battery has a chemical cross-linked network and a physical cross-linked network, the chemical cross-linked network is formed by covalent bond cross-linking of ionic liquid monomers and phosphorus-containing ureido pyrimidinone monomers, and the physical cross-linked network is formed by quadruple hydrogen bonding of copolymer molecules formed by the chemical cross-linked network.

Description

Gel electrolyte battery and preparation method thereof Technical Field The invention relates to the technical field of lithium batteries, in particular to a gel electrolyte battery and a preparation method thereof. Background Lithium ion batteries are widely used in consumer electronics, electric vehicles, and energy storage systems due to their high energy density. However, conventional liquid electrolytes use flammable organic carbonate solvents with serious safety hazards of leakage, volatilization, and fire explosion under thermal runaway. In situ polymerized gel electrolyte (GPE) is considered a promising solution due to its compatibility with existing coating/lamination/injection processes. The process is that the liquid precursor is injected into the battery and then polymerized into gel, which can wet the electrode pore to realize tight interface contact. However, the existing in-situ polymerization GPE technology still faces multiple challenges, namely, firstly, effective and stable interface contact cannot be formed between an electrode and an electrolyte, interface contact resistance is large, conductivity is weak, secondly, a plurality of polymer frameworks of the GPE are inflammable, safety risks are not eradicated, thirdly, the battery can generate electrode volume change, dendrite growth and microcrack in the electrolyte in long-term circulation, performance is continuously degraded, and the existing GPE lacks the capability of autonomously repairing microscopic damage. Therefore, there is a need for a gel electrolyte that combines flame retardant properties, self-healing properties and stable electrolyte-electrode interface, improving battery life, safety and conductivity. Disclosure of Invention The invention provides a gel electrolyte battery and a preparation method thereof, aiming at solving the problems of unstable interface between the electrolyte and an electrode of the lithium ion battery, flammability, irreversible damage and the like. The invention provides a preparation method of a gel electrolyte battery, which specifically comprises the steps of mixing a phosphorus-containing ureido pyrimidinone monomer, an ionic liquid monomer, lithium salt and an initiator to prepare a gel electrolyte precursor solution, assembling a battery core, injecting the gel electrolyte precursor solution into the battery core, and carrying out constant-temperature gradient pressure-increasing curing on the battery core to obtain the gel electrolyte battery, wherein in the constant-temperature gradient pressure-increasing curing process, the constant temperature is 40-90 ℃, gradient pressure increasing is applied to the battery core according to the sequence of a first stage, a second stage and a third stage and kept for a certain time, the pressure difference between the first stage and the second stage is 0.01-0.06MPa, and the pressure difference between the second stage and the third stage is 0.01-0.12MPa. Further, the step-up pressure gradient is applied to the battery core according to the sequence of the first stage, the second stage and the third stage in the constant temperature gradient step-up curing process and maintained for a certain period of time, and the step-up pressure gradient curing process specifically comprises the following steps of the first stage, wherein the first stage is maintained for 0.5-6h under the pressure of 0.001-0.02 MPa, the second stage is maintained for 1-5h under the pressure of 0.03-0.06 MPa, and the third stage is maintained for 1-4h under the pressure of 0.07-0.15 MPa. Further, the structural general formula of the phosphorus-containing ureido pyrimidinone monomer is shown as a formula [1 ]: [1] Wherein R 1、R2 in the formula [1] is C1-C4 alkyl, R 1、R2 can be the same, R 3 is alpha-hydroxy saturated alkyl, R 4 is an inert group, ar is phenylene or alkyl substituted derivative thereof. Further, the ionic liquid monomer comprises one or more of 1-vinyl-3-ethylimidazolium bis (trifluoromethylsulfonyl) imide salt, 1-vinyl-3-alkylimidazolium bis (fluorosulfonyl) imide salt, N-vinyl-N-alkylpyrrolidinium bis (trifluoromethylsulfonyl) imide salt, and/or the ionic liquid monomer has a viscosity of 100 mPa s or less at normal temperature. Further, the lithium salt comprises one or more of lithium bis (trifluoromethylsulfonyl) imide, lithium bis (fluorosulfonyl) imide and lithium hexafluorophosphate, and/or the initiator comprises one or two of azobisisobutyronitrile and dibenzoyl peroxide. Further, the compatilizer comprises one or more of triethyl phosphate, tributyl phosphate, polyethylene glycol dimethyl ether, and 1-ethyl-3-methylimidazole diethyl phosphate, and/or the plasticizer comprises one or more of succinonitrile, polyvinyl alcohol, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate, and the like. The gel electrolyte precursor solution further comprises a compatilizer and a plasticizer, wherein the gel elect