Co doped-CuS as cathode for high-voltage aqueous Cu-Al hybrid-ion batteries

Aqueous hybrid-ion batteries (AHBs) offered various advantages, including low cost, high energy density, high operation voltage, safety, and durability. These characteristics made them an attractive choice for energy storage devices. CuS was a high-capacity cathode material for Al storage. However, the rate performance of CuS under high-voltages conditions was not satisfying. Here, we prepared Co-doped CuS (Co-CuS) nanosheet material with the small band gap by using the ball milling method as the cathode material of aqueous Cu-Al hybrid-ion battery. Co doping can improve the electron transport capacity and provide more active sites. At high current density, Co doping enhances the electrochemical kinetics, operating voltage and electrochemical performance of the materials. The battery exhibits a capacity of 175 mAh g -1 at 2000 mA g -1 and 108 mAh g -1 at 4000 mA g -1 . After 200 cycles of charge and discharge tests, a capacity of 93 mAh g -1 remains. This offers a valuable approach to the development of aqueous Cu-Al hybrid-ion battery electrode materials with good electrochemical performance under high operating voltage and high current conditions.