Summary:

This invention belongs to the field of high-energy-density secondary battery technology, specifically disclosing a local high-concentration electrolyte additive for lithium metal secondary batteries and its application. The additive is an aromatic compound composed of a benzene ring and substituent groups, with at least two hydrogen atoms on the benzene ring being replaced by fluorine atoms, while the remaining hydrogen atoms are retained or substituted by alkyl, halogenated alkyl, or halogen atoms. The additive is used to be added to the local high-concentration electrolyte of lithium metal secondary batteries, which can be highly miscible with the local high-concentration electrolyte without changing its original solvent structure. It can also weaken the interactions between lithium ions and organic solvents or anions, thereby increasing the ionic conductivity of the local high-concentration electrolyte. By adding this additive to the existing local high-concentration electrolyte, not only does it exhibit excellent thermal stability, but it can also form stable interface components at the positive and negative electrodes of the battery, greatly improving the Coulombic efficiency and cycle life of the battery under high voltage conditions.

Link: http://epub.cnipa.gov.cn/patent/CN114361587A?8kt2YOWWXQBD=1704271276077