CN-121507083-B - Gel electrolyte precursor and application thereof

Abstract

The application relates to the technical field of electrochemistry, in particular to a gel electrolyte precursor and application thereof. The gel skeleton monomer of the gel electrolyte precursor is bicycloheptadiene, the gel electrolyte precursor further comprises an additive, a cross-linking agent, a polymerization initiator and fluorine-containing lithium salt, and the content ratio of the bicycloheptadiene relative to the total mass of the gel electrolyte precursor is 1% -10%. The application designs and constructs a novel crosslinked gel polymer electrolyte by regulating and controlling the contents of bicycloheptadiene and acrylic ester in a precursor solution. According to the application, by introducing the bicycloheptadiene, not only is the transmission channel of lithium ions improved, but also the dissociation and transmission capacity of the gel electrolyte on lithium ions is enhanced. Therefore, the crosslinked copolymer gel electrolyte of the present application exhibits excellent lithium ion transport properties at room temperature, and its full cell performance is also significantly improved.

Inventors

• ZHU XINGBAO
• LIU TAO
• ZHANG WENQIANG
• LI XIAOLONG

Assignees

• 合肥国轩高科动力能源有限公司

Dates

Publication Date

20260505

Application Date

20260112

Claims (9)

1. 1. The gel electrolyte precursor is characterized in that a gel skeleton monomer of the gel electrolyte precursor is bicycloheptadiene, the gel electrolyte precursor further comprises an additive, a cross-linking agent, a polymerization initiator and fluorine-containing lithium salt, the content ratio of bicycloheptadiene relative to the total mass of the gel electrolyte precursor is 1% -10%, the additive is fluorine-containing carbonic ester, and the cross-linking agent is acrylic ester.
2. 2. The precursor of claim 1, wherein the fluorine-containing lithium salt is at least one of lithium bis (trifluoromethanesulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium hexafluorophosphate, lithium tetrafluoroborate.
3. 3. The precursor according to claim 1, wherein the content of the fluorine-containing lithium salt relative to the total mass of the gel electrolyte precursor is 5% -20%.
4. 4. The precursor according to claim 1, wherein the content of the crosslinking agent relative to the total mass of the gel electrolyte precursor is 5% -10%.
5. 5. The precursor according to any one of claims 1 to 4, wherein the content of the polymerization initiator with respect to the total mass of the gel electrolyte precursor is 0.075 to 0.15%.
6. 6. A method for preparing a gel electrolyte, characterized in that the precursor according to any one of claims 1-5 is treated according to the following method, namely, fluorine-containing lithium salt is dissolved into an additive, then bicycloheptadiene and a cross-linking agent are added after the mixture is uniformly mixed, a polymerization initiator is added and uniformly mixed to obtain a solution for preparing the gel electrolyte, and the solution for preparing the gel electrolyte is heated and solidified after polymerization gelation.
7. 7. A gel electrolyte prepared by the method of claim 6.
8. 8. A battery comprising the gel electrolyte of claim 7 and a positive electrode, a separator, and a negative electrode; The membrane is any one of a cellulose membrane, a polyethylene battery membrane, a polypropylene battery membrane and a polyethylene/polypropylene composite battery membrane; The positive electrode comprises a positive electrode current collector which is carbon-coated aluminum foil; the positive electrode comprises a positive electrode active material, wherein the positive electrode active material is any one of a lithium iron phosphate positive electrode, a lithium manganese iron phosphate positive electrode, a lithium cobalt oxide positive electrode and a nickel cobalt manganese 811 positive electrode.
9. 9. An electronic device, which is characterized in that, the electronic device comprising the battery of claim 8.

Description

Gel electrolyte precursor and application thereof Technical Field The application relates to the technical field of electrochemistry, in particular to a gel electrolyte precursor and application thereof. Background With the rapid development of new energy technology and electric automobiles, energy storage equipment has increasingly stringent performance requirements, in particular to the aspects of safety, charge and discharge platforms, energy density and the like. The lithium ion battery is one of batteries with wider application range, but the common graphite negative electrode of the current lithium ion battery has limited capacity on lithium ions and limits the energy density, and the high voltage of the positive electrode material of the current lithium ion secondary battery is easy to decompose electrolyte. In order to meet the requirements, the high-voltage lithium metal battery is a potential solution for solving the problems of the lithium ion battery, and adopts metal lithium as a negative electrode, so that the high-voltage lithium metal battery has extremely high theoretical specific capacity and lowest electrochemical potential, and simultaneously is matched with a high-voltage positive electrode material so as to realize breakthrough increase of energy density. The high-voltage positive electrode material stands out by virtue of higher charge-discharge voltage and energy density, while the lithium metal negative electrode material is paid attention to by virtue of the ultrahigh specific capacity and the extremely low electrochemical potential, and although the two materials are excellent in performance, electrolyte materials designed for the high-voltage lithium metal battery are rarely available in practical application. The liquid electrolyte has poor performance of high pressure resistance and lithium dendrite growth inhibition, and is easy to cause fire, and the all-solid electrolyte is difficult to popularize and apply due to the problems of high cost, non-environment-friendly preparation process, poor electrode wettability, narrow electrochemical window and the like. Disclosure of Invention The application aims to provide a gel electrolyte precursor and application thereof. According to the first aspect of the application, the application provides a gel electrolyte precursor, wherein a gel skeleton monomer of the gel electrolyte precursor is bicycloheptadiene, the gel electrolyte precursor further comprises an additive, a cross-linking agent, a polymerization initiator and fluorine-containing lithium salt, and the content of the bicycloheptadiene relative to the total mass of the gel electrolyte precursor is 1% -10%. In some embodiments of the application, the fluorine-containing lithium salt is at least one of lithium bis (trifluoromethanesulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium hexafluorophosphate, lithium tetrafluoroborate. In some embodiments of the application, the content of the fluorine-containing lithium salt relative to the total mass of the gel electrolyte precursor is 5% -20%. In some embodiments of the application, the crosslinker is an acrylate; In some embodiments of the application, the crosslinker is an acrylate containing two or more carbon-carbon double bonds; In some embodiments of the application, the crosslinker is at least one of polyethylene glycol diacrylate, 1, 3-butanediol diacrylate, vinyl diacrylate, triethylene glycol dimethacrylate, trimethylolpropane ethoxylated triacrylate, pentaerythritol tetraacrylate. In some embodiments of the application, the content of the cross-linking agent relative to the total mass of the gel electrolyte precursor is 5% -10%. In some embodiments of the application, the additive is a fluorocarbonate; In some embodiments of the application, the additive is at least one of fluoroethylene carbonate, difluoroethylene carbonate, trifluoropropylene carbonate. In some embodiments of the application, the polymerization initiator is an azo-based initiator; in some embodiments of the present application, the polymerization initiator is at least one of dimethyl azodiisobutyrate, azodiisoheptonitrile, azodiisobutyronitrile; In some embodiments of the application, the polymerization initiator is present in an amount of 0.075% to 0.15% relative to the total mass of the gel electrolyte precursor. According to a second aspect of the application, a preparation method of the gel electrolyte is provided, the precursor according to the first aspect is treated according to the following method, namely, fluorine-containing lithium salt is dissolved in an additive, then bicycloheptadiene and a cross-linking agent are added after the fluorine-containing lithium salt is mixed uniformly, a polymerization initiator is added and mixed uniformly to obtain a solution for preparing the gel electrolyte, and the solution for preparing the gel electrolyte is heated and solidified after polymerization gelation. In a third aspect, the present a