Low-concentration lithium salt electrolyte and lithium secondary battery containing same

Abstract

The invention provides electrolyte solution containing low-concentration lithium salt and a lithium secondary battery containing the electrolyte solution. The electrolyte contains lithium salt (I), lithium salt (II) and a solvent, wherein the lithium salt (I) is selected from one of lithium bis(oxalato)borate, lithium tetrafluoxalato phosphate, 2-trifluoromethyl-4,5-dicyanoimidazole lithium, lithium difluorooxalatoborate, lithium chlorotrifluoroborate, and lithium trioxalatoborate or more; the lithium salt (II) is selected from one of lithium hexafluorophosphate, lithium hexafluoroarsenate, lithium tetrafluoroborate, lithium perchlorate, LiCF3SO3 and LiN (CxF2x + 1SO2) (CyF2y + 1SO2) or more, wherein x and y are each independently an integer of 0-5, and the total concentration of the lithium salt (I) and the lithium salt (II) is 0.3-0.6 mol / L.

Description

technical field

[0001] The present invention relates to the technical field of lithium batteries, in particular to a lithium secondary battery electrolyte containing low-concentration lithium salts, and a lithium secondary battery containing the electrolyte. Background technique

[0002] Lithium-ion batteries are widely used in electric vehicles and consumer electronics due to their advantages such as high energy density, high output power, long cycle life, no memory effect and low environmental pollution. With the rapid development of the lithium-ion battery market, people hope that lithium-ion batteries have better electrochemical performance, higher energy density and power density. This is especially true for batteries used in portable devices, electric vehicles and energy storage systems in smart grids. Lithium-ion battery electrolyte, as the carrier of positive and negative ions, has an important impact on the stability of the battery. The main components of the curre...

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