Constructing a uniform lithium iodide layer for stabilizing lithium metal anode

摘要

The metallic lithium(Li)is the ultimate option in the development of anodes for high-energy secondary batteries.Unfortunately,inferior cycling reversibility and Li dendrites growth of Li metal as anode enormously impede its commercialization.Here,a uniform Li I protective layer is constructed on Li metal anode via a facile and direct solid-gas reaction of Li metal with iodine vapor.The pre-constructed Li I layer possesses more steadily and faster Li ion transport than the conventional SEI layer and contributes to a steady interface for the Li metal anode,which affords a smooth Li deposition morphology without Li dendrites formation.The symmetrical cell with the Li metal anode protected by Li I layer exhibits a longer cycling lifetime of over 700 h at a current density of 1 m A cm^(-2) with Li plating capacity of 1 m Ah cm^(-2).Moreover,the Li I layer protected Li metal anode can still remain high capacity retention of 74.6%after 500 cycles in the full cell paired with NCM523 cathode.The work proposes an easy and effective method to fabricate a uniform and stable protective layer on the Li metal anode and offers a practicable thinking for the commercial implementation of Li metal batteries.