Synergistic dual-functional layer-modified Cu current collector by Co-FCVA apparatus for high-performance anode-free lithium metal batteries

Abstract

Anode-free lithium metal batteries (AFLMBs) show great promise for high-performance energy storage devices due to their high energy density, simple assembly, and cost-effectiveness. However, challenges such as uncontrollable dendritic Li growth and capacity decay arise from lithium's reactivity and Solid Electrolyte Interphase (SEI) instability. This study employs advanced coating techniques to enhance commercial Cu current collectors (CCs) for improved AFLMBs performance. The lithiophilic Zn layer promotes stable lithium nucleation and growth, while the exquisite AlN layer induces SEI formation rich in Li3N during cycling, enhancing stability and rapid Li+ diffusion. The synergistic effects result in superior lithium deposition morphology for Zn-AlN@Cu. The half-cell achieves an average Coulombic efficiency (CE) of 99.31% after 500 cycles at 0.5 mA cm-2 and 1 mAh cm-2, and the symmetric cell maintains stability for 1600 hours at 0.5 mA cm-2 and 1 mAh cm-2. Even in full-cell cycling with LiFePO4 cathodes at 0.5C-rate and a high cathode loading of 11.08 mg cm-2, Zn-AlN@Cu exhibits an impressive capacity retention of 57.93% after 100 cycles (bare Cu is 10.13%). This work introduces a versatile coating strategy for the optimization of AFLMBs anode CCs, offering new avenues for performance enhancement.