A Cost-Effective Silica Fume Coating Layer for Stable Zn Metal Anodes

Aqueous zinc-ion batteries have emerged as a research hotspot due to their advantages of safety, environmental friendliness, low cost, and high capacity. At the same time, there are some problems with anode materials, such as zinc dendrite growth and corrosion reactions. In this work, silica fume, a byproduct of industrial silicon smelting, was selected as a coating material for the Zn anode (SF@Zn). This material is not only cost-effective and widely available but also exhibits superior hydrophilicity, enhancing the electrolyte's wettability on the anode. Additionally, it serves as an ion shunt, preventing uneven deposition of Zn²⁺, and it was demonstrated that the symmetrical cell achieved a cycle life of up to 1800 h at 0.5 mA·cm^-2. The full cell delivered a capacity of 246.2 mAh·g^-1 at 1 mA·cm^-2 and retained a capacity of 100.4 mAh·g^-1 after 1800 cycles.