A Surface Chemistry Approach to Tailoring the Hydrophilicity and Lithiophilicity of Carbon Films for Hosting High‐Performance Lithium Metal Anodes

Porous carbon scaffolds can host lithium (Li) metal anodes to potentially enable stable Li metal batteries. However, the poor Li metal wettability on the carbon surface has inhibited the uniform distribution of metallic Li on most carbon scaffolds. Herein, this work reports a lithiophilic top layer through mild surface ozonolysis and ammoniation methods can universally facilitate the infiltration of liquid Li metal into most carbon matrices. Based on this finding, thin, a lightweight Li@carbon film (CF) composite anode with a high practical capacity of 3222 mAh g−1 and suppressed volume expansion and dendrite formation is reported. It is observed that the deep stripping/plating pre-cycling yields dense, trunky Li metal in the Li@CF composite, which allows for favorable long-term cycling performance. The full cell combining the thin Li@CF composite anode and a high-mass-loading, cobalt-free cathode can deliver high reversible capacity, good cycle stability, and good rate capability in the conventional carbonate electrolyte. The present study further establishes the relationship between lithiophilicity and hydrophilicity for carbon materials as well as provides insights into improving the liquid Li metal infiltration into other carbon scaffolds.