Lithium/Graphene Composite Anode with 3D Structural LiF Protection Layer for High-Performance Lithium Metal Batteries.

Lithium metal batteries (LMBs) are a promising candidate for next-generation energy storage devices. However, the high irreversibility and dead Li accumulation of the lithium metal anode caused by its fragile original solid electrolyte interface (SEI) seriously hinder the practical application of LMBs. Herein, a facile slurry-coating and one-step thermal fluorination reaction method is proposed to construct the 3D structural LiF-protected Li/G composite anode. The existence of a 3D LiF protection layer is convincingly confirmed and the function of the Li/G skeleton is discussed in detail. The 3D structural LiF protection layer results in superior electrochemical performance by improving the utilization of Li and suppressing the accumulation of dead Li in symmetric and full coin cells. Moreover, a 0.85 Ah pouch cell strictly following the parameters of the practical battery industry can work stably for 140 cycles with a gradual internal resistance increase. This novel Li/G composite anode indicates a promising strategy in lithium/carbon composite anodes for LMBs, and the facile thermal fluorination reaction method presented in this paper offers a new method for the construction of a 3D structural protection layer for lithium metal anodes.