Electrolyte of lithium ion battery taking lithium titanate as cathode

Abstract

The invention discloses electrolyte of a lithium ion battery taking lithium titanate as cathode. The electrolyte comprises the organic solvent, lithium salt and additive dissolved in the organic solvent; the additive comprises one or the combination of the adiponitrile, butanedinitrile, 1,3-propane sultone, wherein the additive further comprises one or the combination of the cyclic acid anhydride and / or the derivate thereof, the total weight of the additive is 1-10% of the weight of the electrolyte, the weight of the cyclic acid anhydride and / or the derivate thereof, is 0.01-1% of the weight of the electrolyte. The additive comprises the cyclic acid anhydride and / or the derivate which have chemical reaction with the water in the battery, the combination water in the lithium titanate material, the water, the hydroxy and other groups for generating one component of the electrolyte, the defect that the water cannot be removed totally in the conventional vacuum baking process is compensated. The catalytic reaction for the hydroxy can be effectively avoided while having reaction with the Ti-OH bond on the surface of the lithium titanate particle, and the high temperature storage performance and the high temperature circulation performance of the lithium titanate battery are improved.

Description

Technical field: [0001] The invention relates to the technical field of electrolytes for lithium ion batteries, in particular to an electrolyte for lithium ion batteries with lithium titanate as the negative electrode. Background technique: [0002] With the development of science and technology and the improvement of people's living standards, people have put forward higher requirements on the specific capacity, cycle life and safety of lithium-ion batteries that provide electrical energy. The currently widely used anode materials for lithium-ion batteries are mainly graphite materials. Since the graphite-based negative electrode material has a potential close to that of lithium metal, there are potential safety hazards such as short circuit and thermal runaway caused by the precipitation of lithium metal dendrites on the electrode surface during overcharging. Moreover, lithium ions inside the battery undergo multiple intercalation and deintercalation processes during char...

AI Technical Summary

Problems solved by technology

[0004] However, the disadvantage is that due to the strong hygroscopicity of the lithium titanate material, the moisture forms Ti-OH hydroxyl structural groups on the surface of the lithium titanate particles, and these structural groups are difficult to be completely removed by conventional vacuum heating and baking methods. On the one hand, it increases the moisture content inside the battery, and on the other hand, it also has a catalytic effect on the electrolyte, resulting in more gas generated during the charge and discharge process and high temperature storage process of lithium titanate batteries.

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