Acceleration of interfacial kinetics induced by regulation of Li+ desolvation process in lithium metal-based batteries

Abstract

Lithium (Li) metal anode is the most promising anode for next-generation high-energy-density batteries due to the high theoretical specific capacity and the lowest redox potential. However, the uncontrollable growth of lithium dendrite and infinite volume expansion limit the development of Li metal-based batteries (LMBs). Introducing functional additives into electrolytes is considered as one of the efficient and economical strategies to suppress the Li dendrite growth and relieve the volume effect. Nevertheless, single-functional electrolyte additives can hardly comprehensively enhance the electrochemical performance of LMBs. Herein, boron-based anion receptor Tris(hexafluoroisopropyl) Borate (THFPB) is introduced into the electrolyte to weaken the interaction between the solvent and lithium ions, which regulates the lithium-ion desolvation process and enhance Li+ migration, resulting in the formation of smooth, dense, and rich-inorganic solid electrolyte interphase (SEI) film. Strikingly, with 2 wt % THFPB additive, the Li||Li cell shows an extremely long cycle life of 4200 h, and the Li||Cu cell affords a high Coulombic efficiency (CE) of 99.87 %. The THFPB-modified electrolyte shows superior universality, which enhances the cycling and rate performance of the Li||S and Li||LiFePO4 cells. Generally, this work provides a new perspective on the selection of new functional additives to achieve a long cycling life Li metal battery with great performance.