Femtosecond Laser‐Induced Nanostructured Sacrificial Layer for Stable Zinc Metal Anode

Aqueous zinc-ion batteries are a promising option for grid-scale energy storage owing to their cost-effectiveness and safety. The Zn metal anode with large gravimetric capacity and moderate redox potential can enable high-energy-density Zn batteries. However, the surface instability of commercial Zn metal foils leads to capacity degradation and limited cycle life of batteries. Here, a sacrificial layer strategy is proposed to address these issues by femtosecond laser-induced nanostructuring on the Zn metal substrate (Fs-Zn). This sacrificial layer features an orderly interface consisting of exposed aligned crystal edges after the initial stripping process. This structure induces nearly (101)-oriented epitaxial growth and offers more active sites during the Zn plating/stripping process, effectively minimizing dendrite growth and side reactions. Accordingly, compared with commercial Zn metal, the Fs-Zn symmetric cell shows prolonged operational life, operating for over 500 h at 1 mA cm^-2/1 mA h cm^-2 and 180 h at 0.5 mA cm^-2/1.5 mA h cm^-2. Moreover, the Fs-Zn||MnO₂ full cell exhibits enhanced cycling stability over 500 cycles. This femtosecond laser-induced sacrificial layer strategy offers an effective solution to the practical application of aqueous zinc-ion batteries.