Redox-induced engineering of Cu-Zn foils: Nanosheet construction and Zn enrichment for stabilizing lithium metal anodes

Uncontrolled Li dendrite growth is the critical bottleneck limiting practical application of Li-metal batteries (LMBs). Copper-based metal foils are the most widely used current collectors in LMBs, but they often perform poorly mainly due to low specific surface area and poor lithiophilicity. A solution-based redox-induction modification strategy is proposed for commercial Cu-Zn foils. The results show that a porous nanosheet structure is successfully fabricated on foil surfaces via a simple treatment, greatly increasing their specific surface area. Moreover, Zn in the Cu-Zn alloy spontaneously enriches on the surface during the redox process, thus significantly boosting the material’s lithiophilicity. The obtained results demonstrate that the constructed Zn-rich nanosheet surface structure can effectively suppress the growth of lithium dendrites, and the half-cell using based on the optimized Cu-Zn current collector achieves stable cycling for 370 cycles with a coulombic efficiency of 99%. For the LiFePO 4 ||Cu-Zn NS 1 h full battery, its capacity can retain 80% after 400 cycles at a 1 C discharge rate. Notably, this one-step facile redox-induced modification for Cu-Zn alloys simultaneously achieves the construction of a nanosheet structure and the regulated enrichment of Zn elements, exhibiting substantial commercial potential for the industrial-scale processing of high-performance Cu-based current collectors.