Fabrication of a synergistic dual-functional layer-modified Cu current collector using a Co-FCVA apparatus for high-performance anode-free lithium metal batteries

Abstract

Anode-free lithium metal batteries (AFLMBs) show great promise for application in high-performance energy storage devices owing 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 the improved performance of AFLMBs. A lithiophilic Zn layer promotes stable lithium nucleation and growth, while an exquisite AlN layer induces SEI formation rich in Li₃N during cycling, thus enhancing stability and rapid Li⁺ diffusion. The synergistic effects result in the superior lithium plating morphology of 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 mA h cm⁻², and the symmetric cell maintains stability for 1600 hours at 0.5 mA cm⁻² and 1 mA h cm⁻². Even for 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 AFLMB anode CCs, offering new avenues for performance enhancement.