Anode‐Free Lithium Metal Battery Enabled by Oxygen‐Functionalized MWCNT and TiN Interlayer for Uniform Lithium Deposition

Anode‐free lithium metal batteries (AFLMBs), with high energy density, low cost, and enhanced safety, are regarded as the next‐generation high‐energy‐density batteries. However, capacity decay and uncontrollable dendritic Li growth hinder its practical adoption. Hence, a Cu@TiN‐MWCNT interfacial layer was rationally designed on Cu foil to enable highly reversible Li deposition/stripping. TiN nanoparticles provide abundant lithiophilic sites to reduce the Li nucleation overpotential, while COOH‐functionalized multi‐walled carbon nanotubes construct a conductive network to decrease local current density and improve interfacial stability. Moreover, oxygen‐containing carboxyl groups promote lithium salt dissociation and facilitate the formation of a LiF‐rich solid electrolyte interphase, further stabilizing the electrode/electrolyte interface and suppressing dendritic Li growth. Benefiting from these synergistic effects, compact and uniform Li deposition is achieved. As a result, the Li/Cu@TiN‐MWCNT||LFP cell with a low N/P ratio of 2.1 maintains a specific capacity of 144.15 mAh g −1 after 150 cycles at 3 C. Additionally, the AFLMB exhibits a high‐capacity retention of 51.41% and coulombic efficiency of 98.67% after 80 cycles, which points out a new direction for the development of current collectors toward high‐performance AFLMBs.