Non-aqueous electrolyte solution for lithium ion battery and lithium ion battery adopting non-aqueous electrolyte solution

Abstract

The invention provides a non-aqueous electrolyte solution for a lithium ion battery and a lithium ion battery adopting the non-aqueous electrolyte solution. The non-aqueous electrolyte solution comprises a non-aqueous solvent, lithium salt dissolved into the non-aqueous solvent and an additive, wherein the additive is prepared from fluoroethylene carbonate (FEC), a dinitrile compound and a fumarate type compound. 1 to 6 percent of FEC in the additive can form good SEI at a cathode, to make sure that the battery is high in cycle performance; 1 to 6 percent of the dinitrile compound in the additive can be complexed with metal ions to reduce decomposition of the electrolyte solution and suppress dissolving out of the metal ions as well as protect an anode and improve the battery performance; 0.1 to 2 percent of the fumarate type compound in the additive can form good SEI at the cathode, to improve the low-temperature discharging performance of the battery.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery preparation, in particular to a non-aqueous electrolyte solution for lithium ion batteries and a lithium ion battery using the electrolyte solution. Background technique [0002] Lithium-ion battery is the most competitive battery of the new generation, known as "green energy", and is the preferred technology to solve contemporary environmental pollution and energy problems. In recent years, lithium-ion batteries have achieved great success in the field of high-energy batteries, but consumers still expect batteries with higher overall performance, which depends on the research and development of new electrode materials and electrolyte systems. [0003] At present, electronic digital products such as smart phones and tablet computers have higher and higher requirements on the energy density of batteries, making it difficult for commercial lithium-ion batteries to meet the requirements. ...

AI Technical Summary

Problems solved by technology

Among them, HF will corrode the positive electrode, resulting in the dissolution of metal ions, thereby destroying the structure of the positive electrode material, resulting in capacity loss; Dissolved into the electrolyte, thereby destroying the structure of the positive electrode material, resulting in capacity loss

At the same time, the metal ions dissolved into the electrolyte can easily pass through the SEI to the negative electrode to obtain electrons and be reduced to simple metals, thereby destroying the structure of the SEI, resulting in a continuous increase in the negative electrode impedance, increased battery self-discharge, and increased irreversible capacity. deterioration

[0005] U.S. Patent No. 5,471,862 replaces the ethers in the electrolyte with chain carboxylate to form an electrolyte containing a mixed solvent of chain carboxylate, cyclic carbonate and chain carbonate, avoiding side reactions between ethers and the negative electrode , significantly improved the low-temperature cycle performance and high-temperature storage performance of lithium-ion batteries, but carboxylate solvents will have unavoidable side reactions with the negative electrode

Images