Electrolyte for storage battery

Abstract

The invention provides electrolyte for a storage battery. The electrolyte comprises lithium salt, a solvent and an additive. The additive is one of or the combination of many kinds of vinylene carbonate, 1,3-propanesulfonate, 1,3-propanesultone, glycol sulfite, dimethyl sulfite and lithium bis(oxalate)borate. The usage amount of the additive is 0.5%-5% of the total mass of the lithium salt and the organic solvent. According to the electrolyte, the additive forms a passivation layer on the surface of a graphene-based lithium titanate electrode when the battery is charged for the first time. The passivation layer coats on the surface of an electrode material stably. The solvent molecules are effectively prevented from passing through and prolapsing from the material through adoption of the formed passivation film, therefore, the flatulence phenomenon resulting from side reaction of the electrolyte and the graphene-based lithium titanate is prevented, while the Li<+> can freely intercalate and prolapse through the passivation layer. Through adoption of the method, the stability of the graphene-based lithium titanate battery in the circulation and high temperature storage processes can be greatly improved, and the performance of the battery can be greatly improved.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to an electrolyte solution for secondary batteries. Background technique [0002] With the development of technology, social progress and increasingly severe environmental problems, the use of green and renewable energy in various industries is becoming more and more extensive, and the market for pure electric vehicles and hybrid electric vehicles is also growing at a high speed. As one of the most important components in the field of energy storage, lithium-ion batteries, while meeting performance indicators such as high energy density, long cycle life, safety and stability, how to significantly improve their high-current charge-discharge performance and rate performance have become increasingly academic It is a research topic of great concern to the world and industry. [0003] Graphite anode materials and lithium titanate are the two most common anode materials for lit...

AI Technical Summary

Problems solved by technology

[0004] The graphene-modified lithium titanate material is densely coated with graphene to isolate the direct contact between the lithium titanate material and the electrolyte, which solves the problem of lithium titanate gas production, but due to the high electrochemical platform potential of the lithium titanate material , about 1.55V (vs Li + / Li), it is not easy to form a firm SEI film on the surface of graphene, which makes the battery flat due to the side reaction between graphene and electrolyte during the charging, discharging and storage of the material, thus affecting the battery life.

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