High‐Performance 3D Li‐B‐C‐Al Alloy Anode and its Twofold Li Electrostripping and Plating Mechanism Revealed by Synchrotron X‐Ray Tomography

The uncontrollable Li electrostripping and plating process that results in dendritic Li growth and huge volume change of Li anode limits the practicality of Li metal batteries (LMBs). To simultaneously address these issues, designing three‐dimensional (3D), lithiophilic and mechanically robust electrodes seems to be one of the cost‐effective strategies. Herein, a new 3D Li‐B‐C‐Al alloy anode is designed and fabricated. The prepared 3D alloy anode exhibits not only superior lithiophilicity that facilitates uniform Li nucleation and growth but also sufficient mechanical stability that maintains its structural integrity. Superior performance of the prepared 3D alloy is demonstrated through comprehensive electrochemical tests. In addition, non‐destructive and 3D synchrotron X‐ray computed tomography (SX‐CT) technique is employed to investigate the underlying working mechanisms of the prepared alloy anode. A unique twofold Li electrostripping and plating mechanism under different electrochemical cycling conditions is revealed. Lastly, improved performance of the full cells built with the 3D alloy anode and LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode corroborate its potential application capability. Overall, the current work not only showcases the superiority of the 3D alloy as potential anode material for LMBs but also provides fundamental insights into its underlying working mechanisms that may further propel its research and development.