Highly Reversible Lithium Metal Anode Enabled by 3D Lithiophilic–Lithiophobic Dual‐Skeletons

Lithium metal is a promising anode for high‐energy‐density lithium batteries, but its practical application is still hindered by intrinsic defects such as infinite volume expansion and uncontrollable dendrite growth. Herein, a dendrite‐free 3D composite Li anode (Li‐B@SSM) is prepared by mechanical rolling of lithiophilic LiB nanofibers supported by Li–B composite and lithiophobic stainless‐steel mesh (SSM). Featuring hierarchical lithiophilic–lithiophobic dual‐skeletons, the Li‐B@SSM anode shows an ultrahigh Coulombic efficiency of 99.95% and a long lifespan of 900 h under 2 mA cm−2/1 mAh cm−2. It is demonstrated that the abnormally reversible Li stripping/plating processes should be closely related to the site‐selective plating behavior and spatial confinement effect induced by the robust lithiophilic–lithiophobic dual‐skeletons, which alleviates the volume changes, suppresses the growth of Li dendrites, and reduces the accumulation of “dead” Li. More importantly, the application feasibility of the Li‐B@SSM anode is also confirmed in full batteries, of which the Li‐B@SSM|LiFePO4 full cell shows a high capacity retention of 97.5% after 400 cycles while the Li‐B@SSM|S pouch battery exhibits good cycle stability even under practically harsh conditions. This work paves the way for the facile and efficient fabrication of high‐efficiency Li metal anodes toward practical applications. A free‐standing composite Li metal anode (Li‐B@SSM) with hierarchical 3D lithiophilic–lithiophobic dual‐skeletons is developed via a facile roll‐to‐roll mechanical pressing of stainless‐steel mesh (SSM) and Li‐B alloy. The coupling of micro‐gridding SSM framework and LiB nanofibers enables site‐selective Li stripping/plating processes, achieving excellent cycle performance and practically feasible Li metal anodes.