Long‐Life Anode‐Free Lithium Metal Battery Enabled by Synergistic Electrodes Design

Abstract Anode‐free lithium metal batteries (AFLMBs) have been emerging for energy‐dense practical applications, but they encounter a major issue of cycling instability due to the poor lithium plating/stripping reversibility on the copper (Cu) current collector during electrochemical cycling. A synergistic electrodes design is reported to ameliorate long‐term cycling performance for AFLMBs. In the cathode, the Li‐rich Li 22 Sn 5 ‐Li 2 O‐LiF (LSOF) shell is fabricated on core LiFePO 4 (LFP) particles to provide excessive active lithium ion (Li + ) during the initial charging as the lithium compensator. Concurrently in the anode, the Cu foil is coated with a conformal and uniform Al 2 O 3 layer through atomic layer deposition (ALD) to obtain the composite current collector. The enhanced lithiophilic property of Cu@ALD‐Al 2 O 3 is conclusively proved by electrochemical measurements, in situ optical microscopy, and theoretical simulations, resulting in improved reversibility and kinetics of the lithium plating/stripping on its surface. The LFP@LSOF||Cu@ALD‐Al 2 O 3 pouch cell with a capacity of 26 mAh achieves a desirable 79.3% capacity retention after 200 cycles, demonstrating significantly enhanced cycling stability for AFLMBs. This work provides a breakthrough solution for lengthening the cycle life of anode‐free lithium metal batteries for their promising practical deployment.