Stabilizing Li Plating by a Fluorinated Hybrid Protective Layer

Li metal anode is considered to be the most potential battery anode due to its high theoretical capacity and low potential. However, Li dendritic growth hinders its practical application. Here, a stable Li-metal anode with a fluorinated hybrid layer is fabricated by a simple chemical-modification strategy. The stabilization of Li metal is attributed to the formation of chemical and mechanical stability hybrid protective layer consisting of bulk alloy and Li fluoride, which can effectively minimize the side reactions and suppress Li dendrite growth. With these advantages, the LiF/Li3Mg7-protected Li electrodes enable the Li parallel to Li symmetric cell to maintain a stable overpotential of 25 mV at a capacity of 1 mAh cm(-2) over 1800 h and enable the Li parallel to LiFePO4 cell to a capacity of 134.5 mAh g(-1) at 1 C for 200 cycles; the capacity retention rate is 98.6%.