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

Abstract 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||MnO 2 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.