Lithium-sulfur battery electrolyte capable of improving battery capacity and preparation method thereof

Abstract

The invention relates to lithium-sulfur battery electrolyte capable of improving battery capacity and a preparation method thereof. The electrolyte is prepared from organic solvents, a lithium salt and an additive and is characterized in that the organic solvents include a first solvent, a second solvent and a third solvent; the first solvent is one or more of 1,3-dioxolane, 1,4-dioxane and 1,1-dimethoxyethane; the second solvent is one or more of glycol dimethyl ether and diglyme; the third solvent is one or more of dimethyl sulfide organics; the volume ratio of the first solvent to the second solvent is (0.5 to 2) : 1, and the volume fraction of the third solvent in the organic solvents is 10 to 40%. Dimethyl ether organics are reduced into methyl lithium sulfur and can contribute capacity except positive active materials. By means of the unique work principle, lithium sulfur batteries prepared from the electrolyte have the characteristics of achieving and even exceeding the theoretical capacity of the lithium sulfur batteries.

Description

technical field [0001] The invention belongs to the field of battery electrolyte materials, and relates to a lithium-sulfur battery electrolyte, in particular to a lithium-sulfur battery electrolyte with improved battery capacity and a preparation method thereof. Background technique [0002] Since the third industrial revolution in the 1940s, the scientific and technological civilization of human society has made rapid progress. Especially since the rapid development of pure electric and hybrid vehicles in the 1990s, the demand for energy has continued to increase, followed by energy and environmental problems caused by excessive dependence on natural resources. Therefore, it is imminent to continuously improve lithium-sulfur battery technology, which has important practical significance for alleviating and even solving energy and environmental problems that endanger the world. [0003] A lithium-sulfur battery is a type of lithium battery in which elemental sulfur or sulf...

AI Technical Summary

Problems solved by technology

However, despite accounting for 90% of the total electrolyte mass, the organic solvent of the traditional lithium-sulfur electrolyte only maintains lithium ion transport, and does not play a substantial role in further improving the capacity of lithium-sulfur batteries.

At the same time, in the cycle process of lithium-sulfur batteries with traditional electrolytes, soluble polysulfides "shuttle" between the positive and negative electrodes, so the basic problem of poor long-term cycle of lithium-sulfur batteries cannot be well solved.

Images