Effect of Surface Treatment of Stainless Steel Foils in High‐Performance Aqueous Zinc‐Ion Battery

Stainless steel foil, as the most commonly used current collector of aqueous zinc‐ion battery cathode, has the advantages of low cost, good conductivity, good flexibility, lightweight, and so on. However, as a current collector, stainless steel foil still faces a series of challenges, such as easy shedding of active materials and large contact resistance. In this work, the surface of stainless steel foil is modified by physical grinding and chemical etching, and the influence of surface morphology of stainless steel foil on battery performance is investigated. The results show that the stainless steel foil treated with 0.2 m FeCl 3 + 0.1 m HCl etching solution for 1 min has the best electrochemical performance, and its maximum discharge specific capacity is 2.14 times that of the original stainless steel foil. In addition, the assembled Zn–MnO 2 battery has good cycle stability and excellent rate performance, which can be attributed to the moderate roughness, effective contact area, and excellent conductivity of the modified stainless steel foil current collector.