Abstract
The notorious lithium dendrite growth, causing the safety concern, hinders the practical application of high-capacity Li metal anodes for rechargeable batteries. Here, a robust and highly ionic conductive solid electrolyte interphase (SEI) layer to protect Li metal anode is in-situ constructed by introducing trace additive of tetrapotassium heptaiodobismuthate (K(4)BiI(7)) into electrolyte. The K(4)BiI(7)-added electrolyte enables Li metal anode to display a stable cycling for over 600 cycles at 1.0 mA cm(-2)/1.0 mAh cm(-2) and over 400 cycles at 5.0 mA cm(-2)/5.0 mAh cm(-2). In situ optical microscopy observations also conform the suppression of Li dendrites at high current density. Moreover, the in-situ SEI layer modified Li anode exhibits an average Coulombic efficiency of 99.57% and less Li dendrite growth. The Li-S full sells with the modified electrolyte also show improved electrochemical performance. This research provides a cost-efficient method to achieve a highly ionic conductive and stable SEI layer toward advanced Li metal anodes.