Electrolyte for lithium secondary battery, secondary battery, and electric device
AssigneeContemporary Amperex Technology Co., Limited
InventorsZeli Wu, Qiao Wu, Jie Guo, Changlong Han, Cuiping Zhang, Peng Fan, Lei Huang, Yilin Deng, Wenhao Liu
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Abstract
The present application discloses an electrolyte for a lithium secondary battery, a secondary battery, and an electric device. The electrolyte for a lithium secondary battery includes a sulfate ester and difluorophosphate ions, a molar ratio of the sulfate ester to the difluorophosphate ions is (0.2 to 30):1, and a molar concentration of the sulfate ester is 0.04 mol/L to 0.16 mol/L.
Claims18
A secondary battery, wherein the secondary battery comprises a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte,
- wherein the positive electrode sheet comprises a positive electrode active material, the positive electrode active material comprises a lithium transition metal oxide, the transition metal comprises Ni, Co, and one or more selected from Mn, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn, Nb, and Zr,
- wherein the negative electrode sheet comprises a negative electrode active material, the negative electrode active material comprises artificial graphite,
- the electrolyte comprises a sulfate ester, difluorophosphate ions, a positive electrode film-forming additive, and tetrafluoroborate ions, the sulfate ester comprises at least one of 4-methyl-ethylene sulfate, 4-fluoro-ethylene sulfate, 4-n-propyl-ethylene sulfate, and 4,4′-bi(1,3,2-dioxathiolane)-2,2,2′,2′-tetraoxide, the positive electrode film-forming additive comprises fluoroethylene carbonate and 1,3-propane sultone,
- a molar ratio of the sulfate ester to the difluorophosphate ions is (0.2 to 30):1,
- a molar concentration of the sulfate ester is 0.04 mol/L to 0.16 mol/L,
- a molar concentration of the positive electrode film-forming additive is 0.01 mol/L to 0.03 mol/L,
- a molar concentration of the tetrafluoroborate ions is 0.0005 mol/L to 0.001 mol/L.
An electrolyte for a lithium secondary battery, wherein the electrolyte comprises a sulfate ester, difluorophosphate ions, a positive electrode film-forming additive, and tetrafluoroborate ions, the sulfate ester comprises at least one of 4-methyl-ethylene sulfate, 4-fluoro-ethylene sulfate, 4-n-propyl-ethylene sulfate, and 4,4′-bi(1,3,2-dioxathiolane)-2,2,2′,2′-tetraoxide, the positive electrode film-forming additive comprises fluoroethylene carbonate and 1,3-propane sultone,
- a molar ratio of the sulfate ester to the difluorophosphate ions is (0.2 to 30):1,
- a molar concentration of the sulfate ester is 0.04 mol/L to 0.16 mol/L,
- a molar concentration of the positive electrode film-forming additive is 0.01 mol/L to 0.03 mol/L,
- a molar concentration of the tetrafluoroborate ions is 0.0005 mol/L to 0.001 mol/L.
Dependencies are inferred from the claim text.