High-Energy Li Metal Battery with Lithiated Host

Lithium metal batteries (LMB) are promising energy storage systems due to the highest capacity of Li (3,860 mAh/g). However, the low Coulombic efficiency of Li plating/stripping and safety concern due to uncontrolled Li dendrite and dead Li prevent its applications. Here, we report that Li plating on a prelithiated LixSi anode can effectively suppress the formation of dead Li on LixSi when the total lithiation/delithiation capacity in each cycle is higher than the Li plating/stripping capacity on LixSi because the slight delithiation from LixSi at a higher delithiation potential than the stripping potential of deposited Li on LixSi will ensure the complete stripping of the plated Li before delithiation of LixSi, the root of deposited Li, thus dramatically enhancing the Coulombic efficiency of Li plating/stripping to the highest recorded (>99.7%) even at a high Li plating/stripping capacity of 1.0 mAh cm−2.