Copper oxide-modified highly reversible Zn powder anode for aqueous Zn metal batteries

With the advantages of mature preparation technology,structural adjustability and suitability for large-scale application,Zn powder anode is considered to be an ideal electrode for realizing low-cost,high-energy-density aqueous Zn metal batteries.However,the high specific surface of Zn powders leads to severe side reactions such as hydrogen evolution and corrosion,thus limiting their widespread use Here,this work develops a novel CuO@Zn powder anode with a synergy effect of surface wrapping and compositing.Zn powders are uniformly wrapped by small CuO particles due to the strong adsorption between Zn and CuO.The wrapped CuO particles build a good conductive framework to inhibit the structural collapse of the Zn powder caused by corrosion and non-uniform deposition.Meanwhile,CuO can also be used as a seed to guide the uniform deposition of Zn ions through its strong binding energy with Zn.As a result,the Cu O@Zn anode can maintain a long cyclic life of 900 h at current density of 1 mA·cm-2and capacity of 1 mAh·cm-2,as well as contribute to an excellent capacity retention of 92%after 800cycles for CuO@Zn||NH4V4O10full cell.Even at high current density of 5 A·g-1,the full cell exhibits a specific capacity of more than 200 mAh·g-1after 800 cycles,with a good capacity retention of 89%.This work provides a new idea for developing high-performance Zn powder-based anodes.