Lithium ion battery electrolyte

Abstract

The invention relates to a pyrazole compound electrolyte additive. The structural formula of the additive is 1R<1>,3R<2>,4R<3>-pyrazole or 1R<1>,4R<2>,5R<3>-pyrazole, wherein each of R<1>, R<2> and R<3> is a linear or branched C1-4 structure. A lithium ion battery electrolyte includes a lithium salt, an organic solvent, the pyrazole compound and other functional additives, and the mass of the pyrazole compound is 0.1-10% of the mass of the lithium battery electrolyte. The pyrazole compound is beneficial for forming an interface film having a certain conductivity on the surface of a positive electrode, and can be used together with other positive electrode film forming additives to reduce the impedance of the surface of a positive electrode, so the safety performance of the lithium ion battery and the cycle performances under a high voltage are improved.

Description

technical field [0001] The invention relates to a pyrazole compound electrolyte additive and a high-voltage electrolyte containing the additive, belonging to the field of lithium ion batteries. Background technique [0002] Lithium-ion batteries have a series of advantages such as high working voltage, high energy and power density, long cycle life, small self-discharge, and environmental friendliness. It is currently widely used in mobile electronic devices and has been widely used in electric vehicles. As the functions of smartphones continue to be upgraded and the market requires an increase in the mileage of electric vehicles, the requirements for batteries are greatly increased. It is increasingly important and urgent to increase the energy density of lithium batteries. In addition to the improvement of existing materials and battery manufacturing processes, high-voltage cathode materials have always been one of the more popular research directions. It achieves high en...

AI Technical Summary

Problems solved by technology

At present, the ester electrolyte of conventional lithium-ion batteries is easy to decompose under high voltage, resulting in relatively low charge and discharge efficiency and poor cycle performance of lithium-ion batteries; however, high-voltage additives are used to form a film on the surface of the positive electrode to prevent the positive electrode and electrolyte. Direct contact will lead to large polarization of the battery and faster cycle attenuation

Images