Lithium ion battery electrolyte and lithium ion battery

Abstract

The invention belongs to the technical field of lithium ion batteries, and particularly relates to lithium ion battery electrolyte and a lithium ion battery. Four types of additives, i.e., type A, type B, type C and type D are added into the electrolyte, the additive A is used as a cathode film forming additive and is a premise for ensuring the long cycling performance of the electrolyte; the additive B can improve the output performance of the battery and reduce the impedance in the cycling process; a synergistic effect is formed between the additive C and the additive B, so that a low-temperature discharging level of the battery can be improved, and the temperature rise in the large-current discharging process can be reduced; and the additive D can play a role in regulating and controlling an SEI film, the type-B additive and the type-C additive can be prevented from excessively anticipating in the formation of the SEI film, and the discharging efficiency is high while the battery isensured to have high discharging level, and the additive D enables the battery to have higher charge retention in the high-temperature storage and large-current discharging process, and the increaseof the battery impedance can be inhibited; and in addition, the electrolyte has overcharging prevention performance in the case of not adding the overcharge preventing additive.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery electrolyte and a power type cylindrical lithium ion battery. Background technique [0002] Power-type lithium-ion batteries require lithium batteries to be able to meet the instantaneous and continuous high-current charge and discharge capabilities, have a low temperature rise and a wide operating temperature range during use, and have high safety performance. [0003] For the power battery electrolyte, it is necessary to quickly realize the diffusion of lithium ions to reduce polarization during the high-current discharge process, reduce the impedance of the SEI film, and improve the electrolyte to have a higher conductivity in a wide temperature range. High-rate discharge capability can still be achieved at a low temperature of -20°C; at the same time, the electrolyte is required to work normally at a high temperature of 60-80°C ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to: the film-forming impedance of the electrolyte negative electrode of the existing power type battery is relatively high, although the discharge platform is improved, the discharge efficiency is not ideal, and at the same time, the high-temperature long-term storage performance, especially the capacity retention and recovery ability is low, and the high rate High temperature rise in the discharge process, poor safety performance such as anti-overcharge, etc., the present invention provides a power type lithium-ion battery electrolyte that can solve the above problems without adding anti-overcharge additives, which satisfies The requirements of power type battery electrolyte for high current charge and discharge capacity in wide temperature range, temperature rise control, high temperature storage and anti-overcharge performance

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