Electrodeposited Copper Oxide Cathode for Enhanced Flexible Zn Ion Batteries

Zinc ion batteries (ZIBs) have attracted much interest in large-scale energy storage technologies due to their low cost, intrinsic safety, environment-friendly and high energy density, becoming among the most commercialized secondary batteries after lithium ion batteries. To acquire high energy density, various cathode materials with high specific capacity have been developed, such as Prussian blue analogs, polyanionic compounds, Co, Mn and V-based oxides. Herein, we developed a type of copper oxide on flexible current collectors using an efficient electrodeposition method. The loading of the active materials could be easily controlled by the electrodeposition parameters, such as time, current and voltage. The electrodeposited cathode shows superior specific capacity compared the one synthesized by conventional methods due to the unique morphology, more electrochemical active sites, and better binding with current collector. In addition, the cathode exhibited good flexibility when electrodeposited on a flexible current collector such as graphene, carbon nanotube film, or titanium foam and can be used to build flexible ZIBs. When used in a full cell with Zn metal as anode and a hydrogel electrolyte, the batteries show excellent capacity, rate performance and cycling stability that will be discussed at the conference.