A self-adapting artificial SEI layer enables superdense lithium deposition for high performance lithium anode

Metallic lithium (Li) is known to consider a critical role in next-generation rechargeable batteries. However, the uncontrolled growth of Li dendrites result in low Coulombic efficiency and safety issues in applications of Li metal batteries. High capacity and stable dense deposits of lithium metal are of great significant for high energy density battery. Herein, we propose a suitable degree of substitution for Carboxymethylcellulose Lithium (CMC-Li) as an artificial SEI layer, which has a high ionic transference number (0.66), high Young's modulus (24.6 GPa) and good lithiophilicity, then it can adapt to the volume changes of the lithium anode, enable superdense lithium deposits on Cu collector. The metallic lithium anode with CMC-Li films (CMC-Li@Li) delivers excellent cycling performance in the symmetrical cell at a large current density of 10 mA cm(-2) and an areal capacity of 10 mAh cm(-2) for almost 300 h. Moreover, the CMC-Li@Li||NCM613 full cell (N/P = 2) delivers an initial specific capacity of 165 mAh g(-1) with a high retention of 80% after 200 cycles.