A Dual‐Protective MXene/COF Artificial Interface for Dendrite‐Free and Stable Lithium Metal Anodes

Abstract It is still challengeable to inhibit the uncontrollable growth of lithium dendrites and large lithium volume expansion during cycling for high‐energy lithium metal batteries (LMBs). To simultaneously address such issues, herein, for the first time, a novel dual‐protective artificial solid electrolyte interface (SEI) combining “soft” covalent–organic framework (COF) spheres grown on a “rigid” MXene nanosheets (MXene/COF) via a facile and mild method is presented. The MXene nanosheets can provide abundant lithium‐ion diffusion channels promote rapid and uniform lithium‐ion deposition. The unique rigid‐soft MXene/COF composite has outstanding mechanical flexibility to mitigate SEI cracking, limit the volume expansion and prevent lithium dendrite puncture during cycling. As a result, the Li||Li symmetrical cell, Li||LFP full cell and Li||NCM811 full cell with dual protective MXene/COF interlayers demonstrate much better electrochemical performances, compared to those without MXene/COF interfaces. The performance enhancement mechanism is revealed by X‐ray photoelectron spectroscopy depth profiling and in situ optical microscopy and can be attributed to form lithiophilic layer, fast Li ⁺ transport, and uniform lithium deposition caused by MXene/COF artificial interface. This work provides new insight into the rational design, facile fabrication, and performance enhancement mechanisms of dual‐protective, soft‐rigid artificial interface for high‐performance LMBs.