Electrolyte solution for lithium metal batteries

Abstract

The invention discloses electrolyte solution for lithium metal batteries. Esters, ethers or ether ester blend solution is used as an organic solvent for the electrolyte solution. The electrolyte solution comprises lithium salt with the molar concentration of 1.0-5.0 mol / L and additives with lithium nitrate and metal halide. The electrolyte solution has the advantages that electrolyte solution systems with the additives can be used for the lithium metal batteries, accordingly, stable mixed ionic conductor interface layers can be formed on the surfaces of lithium negative electrodes, direct contact between the electrolyte solution and metal lithium can be prevented to the greatest extent, lithium dentrite growth and irreversible loss of lithium sources can be reduced, lithium ions can be quickly migrated on the interface layers and can be uniformly deposited on electrodes, the coulombic efficiency of the metal lithium can be obviously improved by the electrolyte solution with the additives, the service lives of the total batteries can be obviously prolonged by the electrolyte solution with the additives, and the electrolyte solution has an excellent application prospect.

Description

technical field [0001] The invention relates to an electrolyte solution for a lithium metal battery, belonging to the technical field of lithium metal batteries. Background technique [0002] In the new era of demand for high specific energy batteries, lithium metal has a low electrode potential (-3.04V vs standard hydrogen electrode) and an ultra-high theoretical specific capacity (3860mAh g -1 ) has become a promising anode material. In the process of practical application of lithium metal, there are urgent technical problems that need to be solved; first, the thermodynamic instability of lithium metal and electrolyte can easily lead to the formation of an unstable solid-liquid interface layer on the surface of lithium metal; secondly, with the charging and discharging The unstable solid-liquid interface will induce uneven deposition of lithium ions, resulting in the generation of lithium dendrites and dead lithium; the existence of lithium dendrites may pierce the batter...

AI Technical Summary

Problems solved by technology

Lithium metal is facing technical problems that need to be solved urgently in the process of practical application; firstly, the thermodynamic instability between lithium metal and electrolyte can easily lead to the formation of an unstable solid-liquid interface layer on the surface of lithium metal; secondly, with the charging and discharging The unstable solid-liquid interface will induce uneven deposition of lithium ions, resulting in the generation of lithium dendrites and dead lithium; the existence of lithium dendrites may pierce the battery separator, causing contact and short circuit of the positive and negative electrodes, which has a potential explosion hazard ; The existence of the dead lithium layer leads to an increase in the polarization of the battery and a decrease in Coulombic efficiency