A kind of electrolytic solution containing silicon solvent and thiophene additive and lithium ion battery using the electrolytic solution

Abstract

The invention discloses an electrolyte containing a silicon solvent and thiophene additives and a lithium ion battery using the same. The electrolyte containing the silicon solvent and the thiophene additives comprises lithium salt, an organic solvent and an additive, wherein the organic solvent comprises a silicon organic solvent, the additive comprises thiophene compounds, the organic solvent further comprises one or more organic solvents of chain-type carbonates, cyclic carbonates and carboxylic esters. According to the electrolyte and the lithium ion battery in the invention, the silicon solvent is matched with the thiophene compounds supplemented by other organic solvents and additives, the proportion is reasonable, the conductivity of the lithium ion in the electrolyte can be effectively improved through the prepared lithium ion battery high-voltage electrolyte, impedance increase caused by film forming is inhibited, and the cycling performance and the low-temperature performanceof the battery are effectively improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to an electrolyte solution containing a silicon solvent and a thiophene additive and a lithium ion battery using the electrolyte solution. Background technique [0002] Electronic equipment is developing towards miniaturization and portability, and electric vehicles also require higher mileage. Improving the energy density of batteries is the current focus of battery companies and scientific research institutions. The most common way to increase the energy density of batteries is to increase the working voltage of batteries. At present, a variety of high-voltage cathode materials have been developed, such as LiNiMn with spinel structure. (2-x) o 4 and LiMPO with olivine structure 4 Wait. However, under high voltage conditions, metal ions in a high oxidation state tend to migrate to the negative electrode under the action of an electric field, and get electrons at the negative...

AI Technical Summary

Problems solved by technology

However, under high voltage conditions, metal ions in a high oxidation state tend to migrate to the negative electrode under the action of an electric field, and get electrons at the negative electrode and become metal precipitation, resulting in irreversible loss of positive electrode materials, loss of battery capacity, and reduced battery cycle life.

In addition, under high voltage conditions, the active sites on the surface of the positive electrode are highly oxidizable, causing the traditional carbonate electrolyte materials to be oxidized and decomposed to produce gas, which eventually poses a safety hazard

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