Secondary battery and electrolyte injection method

Abstract

The invention relates to the field of batteries, in particular to a secondary battery and an electrolyte injection method. The secondary battery is characterized in that a cathode active matter of a cathode pole piece comprises a high-nickel ternary cathode material; an electrolyte consists of an electrolyte S1 in the first injection process and an electrolyte S2 in the second injection process; a filming additive in the electrolyte S1 is an anode filming additive, and a filming additive in the electrolyte S2 is a cathode filming additive. The secondary battery has the advantages that by adding the anode filming additive in the first electrolyte injection process, a good SEI (solid electrolyte interface) is formed at the graphite surface through formation; by adding the cathode filming additive in the second electrolyte injection process, a dense CEI (cathode electrolyte interface) is formed; the active sites at the surface of the high-nickel material are passivated, so as to balance the high-temperature property and dynamic property of the high-nickel secondary battery; the electrolyte injection method is simple, the implementing is easy, and the secondary electrolyte injection procedure is added on the basis of existing procedure.

Description

technical field [0001] The present application relates to the field of batteries, and in particular, to a secondary battery and a liquid injection method. Background technique [0002] Compared with lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, etc., lithium-ion batteries have the advantages of high operating voltage, large specific energy, small self-discharge, long cycle life, no memory effect, environmental friendliness and good safety. It quickly occupied the consumer electronics market and expanded rapidly in the field of power storage. With the improvement of consumers' requirements for lightness and durability of electronic products and the application of lithium-ion batteries in new fields such as electric vehicles, hybrid electric vehicles, large-scale energy storage power stations and mobile energy storage devices, the energy density and safety of lithium-ion batteries will be improved. Performance is imminent. [0003] The positi...

AI Technical Summary

Problems solved by technology

Common additives in high-nickel systems such as propylene sulfite (PS) and 1,3-propene sultone (PES) can effectively form a film to stabilize the positive electrode interface, but at the same time greatly increase the negative electrode interface impedance, resulting in a full-cell battery. Impedance increases, severely deteriorating dynamic performance such as cycling

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