Strategy to Enhance the Cycling Stability of the Metallic Lithium Anode in Li-Metal Batteries

Based on the analysis of systematic research (density functional theory calculations, physical characterizations, and electrochemical performances), here, we report a novel mixture surface modification layer of LiC6&LiF, which can enhance the lithium-ion diffusion and decrease the local current density. This is beneficial to the improvement of cycling stability. As a result, the Li@LiC6&LiF-5/NCM half-cell possesses an excellent capacity retention of 94% after 100 cycles at 0.1C, with a capacity decay of only 0.06% per cycle. For comparison, the capacity retention of a pristine Li/NCM cell is only 9.3% after 100 cycles. Our study confirms that compositing the high ionic conductivity layer (e.g., LiC6&LiF for the first time) is a promising avenue to stabilize lithium-metal anodes. From this perspective, we concisely review recent discoveries in this field and suggest possible new research directions for further development of Li-metal batteries.