Gradient solid electrolyte interphase induced by bisfluoroacetamide for stable lithium metal batteries

With continuous development of portable electronics and electric vehicles,the conventional lithium-ion batteries (LIBs) could not meet the demand for higher energy density.Instead,the lithium metal batteries (LMBs) are regarded as the most promising candidate for next generation energy storage systems due to the highest specific capacity (3860 mAh g~(-1)) and lowest redox potential (~3.04 V vs.standard hydrogen electrode) of Li metal.However,the practical application of LMBs is hindered by several drawbacks,such as the uncontrollable formation and growth of Li dendrites the unstable solid electrolyte interphase (SEI) layer due to the reaction between Li metal and organic electrolytes,leading to severe safety problem and undesirable consumption of electrolyte and low Coulombic efficiency (CE).On the other hand,the cathode materials in high-voltage conditions always show structural degradation,leading to unstable performance and capacity decay.Up to now,numerous strategies have been made to solve these problems.Among these,exploring suitable electrolyte additives to regulate the structure and composition of SEI layer is simple and feasible way.