CN-122025443-A - Electrolyte and hybrid supercapacitor

Abstract

The embodiment of the application provides an electrolyte and a hybrid supercapacitor. The electrolyte comprises a solvent, lithium salt and an additive, wherein the solvent comprises dimethyl 2, 5-dioxane carboxylate and tetraethoxysilane. The electrolyte is used for achieving the effect of high temperature resistance.

Inventors

• ZHONG ZHENXIN
• LI CHONG
• CHEN YIGE
• DI HUIFANG
• SU FANGYUAN
• CHEN KAIFENG
• LIN JIEHUAN
• ZHANG HUIRONG
• LIU YE
• WEN ZHENXING

Assignees

• 广东电网有限责任公司惠州供电局

Dates

Publication Date

20260512

Application Date

20260115

Claims (11)

1. 1. An electrolyte solution, which is used for the electrolytic solution, characterized by comprising the following steps: the electrolyte comprises a solvent, lithium salt and an additive; The solvent comprises dimethyl 2, 5-dioxane carboxylate and tetraethoxysilane.
2. 2. The electrolyte of claim 1, wherein the 2, 5-dioxane carboxylic acid dimethyl ester is 60% -90% of the solvent, and the tetraethoxysilane is 10% -30% of the solvent.
3. 3. The electrolyte according to claim 1, wherein the concentration of the lithium salt is 0.5 to 1.5mol/L.
4. 4. The electrolyte of claim 3 wherein the lithium salt comprises lithium difluorosulfonimide salt and lithium difluorooxalato borate.
5. 5. The electrolyte according to claim 4, wherein the molar mass ratio of the lithium difluorosulfonimide salt to the lithium difluorooxalato borate salt is (3-5): 1.
6. 6. The electrolyte according to any one of claims 1 to 5, wherein the additive is present in an amount of 0.1% to 5% of the electrolyte.
7. 7. The electrolyte according to claim 6, wherein, the additive includes vinylene carbonate and fluoroethylene carbonate.
8. 8. The electrolyte of claim 7, wherein the volume ratio of vinylene carbonate to fluoroethylene carbonate in the additive is (1-3): 1.
9. 9. A hybrid supercapacitor comprising a positive electrode material, a negative electrode material, a separator, and the electrolyte according to any one of claims 1 to 8.
10. 10. The hybrid supercapacitor of claim 9, comprising: The positive electrode material comprises a first positive electrode material and a second positive electrode material, wherein the content of the first positive electrode material is 20% -95%, and the content of the second positive electrode material is 5% -80%; The first positive electrode material contains one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium vanadium oxide and lithium iron silicate; the second positive electrode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of active carbon, carbon aerogel, carbon nanotube and pyrolytic carbon, and the oxide comprises one or more of ruthenium oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide.
11. 11. The hybrid supercapacitor of claim 9, comprising: the anode material comprises a first anode material and a second anode material, wherein the content of the first anode material is 20% -95%, and the content of the second anode material is 5% -80%; The first negative electrode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of natural graphite, artificial graphite mesophase carbon microspheres, carbon fibers, carbon nanotubes, coke and pyrolytic carbon, and the oxide comprises one or more of tin oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide; The second anode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of active carbon, carbon aerogel, carbon nano-tube and pyrolytic carbon, and the oxide comprises one or more of ruthenium oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide.

Description

Electrolyte and hybrid supercapacitor Technical Field The application relates to the technical field of electrolyte, in particular to electrolyte and a hybrid supercapacitor. Background The hybrid capacitor is a novel energy storage device between a secondary battery and a super capacitor, and has very wide application in the field of electrochemical energy storage. However, the problems of gas expansion, internal resistance increase, rapid capacity decay and the like can occur in the high-temperature application of the hybrid supercapacitor, and the main problem is that electrolyte is rapidly decomposed at high temperature, and more side reactions occur, so that the cell is invalid. Therefore, there is a need for an electrolyte that is resistant to high temperatures. Disclosure of Invention The embodiment of the application provides electrolyte and a hybrid supercapacitor, which are used for achieving a high temperature resistant effect. In a first aspect, an embodiment of the present application provides an electrolyte comprising a solvent, a lithium salt, and an additive. The solvent comprises dimethyl 2, 5-dioxane carboxylate and tetraethoxysilane. In one possible embodiment, the ratio of the dimethyl 2, 5-dioxane carboxylate to the solvent is 60% -90%, and the ratio of the tetraethoxysilane to the solvent is 10% -30%. In one possible embodiment, the concentration of the lithium salt is 0.5 to 1.5mol/L. In one possible embodiment, the lithium salt includes lithium difluorosulfonimide salt and lithium difluorooxalato borate. In one possible embodiment, the molar mass ratio of the lithium bisfluorosulfonyl imide salt to the lithium bisfluoro oxalato borate salt is (3-5): 1. In one possible embodiment, the additive accounts for 0.1% -5% of the electrolyte. In one possible embodiment, the additives include vinylene carbonate and fluoroethylene carbonate. In one possible embodiment, the volume ratio of vinylene carbonate to fluoroethylene carbonate in the additive is (1-3): 1. In a second aspect, the embodiment of the application provides a hybrid supercapacitor, which comprises a positive electrode material, a negative electrode material, a diaphragm and the electrolyte. In one possible implementation mode, the positive electrode material comprises a first positive electrode material and a second positive electrode material, wherein the content of the first positive electrode material is 20% -95%, and the content of the second positive electrode material is 5% -80%; The first positive electrode material contains one or more of lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium cobalt oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium vanadium oxide and lithium iron silicate; the second positive electrode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of active carbon, carbon aerogel, carbon nanotube and pyrolytic carbon, and the oxide comprises one or more of ruthenium oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide. In one possible implementation mode, the anode material comprises a first anode material and a second anode material, wherein the content of the first anode material is 20% -95%, and the content of the second anode material is 5% -80%; The first negative electrode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of natural graphite, artificial graphite mesophase carbon microspheres, carbon fibers, carbon nanotubes, coke and pyrolytic carbon, and the oxide comprises one or more of tin oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide; The second anode material contains a carbon material and/or an oxide, wherein the carbon material comprises one or more of active carbon, carbon aerogel, carbon nano-tube and pyrolytic carbon, and the oxide comprises one or more of ruthenium oxide, manganese oxide, cobalt oxide, nickel oxide and vanadium oxide. According to the electrolyte and the hybrid supercapacitor provided by the embodiment of the application, the 2, 5-dioxane carboxylic acid dimethyl ester and tetraethoxysilane are selected as solvents, and the lithium salt and the additive are matched, so that the battery performance can be remarkably improved. The 2, 5-dioxane carboxylic acid dimethyl ester is favorable for improving the stability and structural integrity of the battery under a high-temperature environment, and tetraethoxysilane is used as a film forming solvent, so that a stable solid electrolyte interface film (Solid Electrolyte Interface, SEI) can be formed on the surface of an electrode, the co-intercalation of the solvent is reduced, and the electrochemical stability and the cycle life of the electrode are improved. In addition, the proper lithium salt and the additive can further optimize the conductivity, chemical stability and thermal stability of the electrolyte, enhance the safety of the batter