High-energy density lithium ion battery and electrolyte thereof

Abstract

The invention belongs to the technical field of lithium ion batteries, and specifically relates to a high-energy density lithium ion battery and electrolyte thereof. According to the high-energy density lithium ion battery and the electrolyte thereof, additive A, additive B, additive C and additive D are added in the electrolyte; the additive A is a negative electrode film formation additive for guaranteeing circulating performance, the additive B is the additive for improving high temperature performance, the additive C is modification additive of solid electrolyte membrane, and the additiveD is the additive for restraining electrolyte decomposition. Compared with the existing technology, for the electrolyte provided by the invention, by combined utilization of four types of additive A+B+C+D, a high-energy-density battery system can be guaranteed to have long circulation performance under premise of relatively lower electrolyte retention capacity in a limited space range and have excellent high temperature and low temperature performance at the same time.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a high energy density lithium ion battery and an electrolyte thereof. Background technique [0002] Lithium-ion batteries are widely used in 3C digital products, electric vehicles and other fields because of their advantages such as high working voltage, high energy density, long cycle life, and environmental friendliness. With the development of smart wearables, smart phones, portable mobile office and other equipment, high energy density lithium-ion batteries are currently a hot spot in the industry. [0003] Improving the volume energy density of batteries in a limited volume space is the common pursuit of many products at present, and the main methods used to increase the energy density of batteries in a certain space are: 1) Increase the working voltage of the positive electrode material so that the gram capacity of the active material Maximize; 2)...

AI Technical Summary

Problems solved by technology

However, after the compaction density of the positive and negative electrode materials of the battery is increased, on the one hand, the adsorption of the electrolyte will be reduced, and the liquid retention of the electrolyte will be reduced; on the other hand, under the premise of ensuring that the battery has a good shape and hardness, the lithium ion The battery technology does not allow the electrolyte retention to be too high; the advantage of low electrolyte retention is that the proportion of the electrolyte is reduced, the volume specific energy density and weight specific energy density of the battery will be directly improved, and the battery is not easy to become soft and Deformation, but the problem is that the cycle performance of the traditional electrolyte is not guaranteed when the liquid retention coefficient is low, the phenomenon of diving often occurs in the later stage of the cycle, and it is difficult to balance high and low temperature performance

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