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 Li22Sn5‐Li2O‐LiF (LSOF) shell is fabricated on core LiFePO4 (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 Al2O3 layer through atomic layer deposition (ALD) to obtain the composite current collector. The enhanced lithiophilic property of Cu@ALD‐Al2O3 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‐Al2O3 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.