In situ construction of high lithiophilic lithium phosphide protective layer for stable lithium metal anode

Abstract

To suppress dendrites and avoid side reactions that hinder the practical application of Li metal anode, a homogeneous lithiophilic Li3P layer is cast on the Li metal anode surface (Li3P@Li) via a simple impregnation process. The low Li+ diffusion barrier of the obtained Li3P layer facilitates the dendrite-free Li deposition. A prolonged cycle life of 2740 h with low overpotential (∼10 mV) is thus achieved by the Li3P@Li electrode. The cycle performance of Li3P@Li || LiFePO4 full cell is also improved, which remains an 85 % capacity retention after 1200 cycles at 3C. This work provides new ideas for Li metal anode surface engineering and promotes Li metal anode's practical application.