Construction of hierarchical S,C-(Cu-PBA/CuS) for enhanced rechargeable aqueous alkaline Cu-Zn batteries

A unique hierarchical S,C-(Cu-PBA/CuS) nanoarray was designed and synthesized through a simple hydrothermal and in-situ vulcanization process. By incorporating the merits of a high theoretical capacity of Cu-based sulfides, a Cu-PBA/CuS heterojunction coated with a polydopamine-derived N-doped carbon layer, homogeneous/heterogeneous surface/interface resulted from in-situ vulcanization process, the S,C-(Cu-PBA/CuS) electrode shows a high specific capacity of 668.5 mAh g- 1 at 1 A g- 1. Furthermore, the assembled S,C-(Cu-PBA/ CuS)//Zn alkaline battery delivers good reversibility for 2000 cycles (capacity retention of 81.3 %) and displays a high energy density of 944 Wh kg- 1 at a power density of 1.24 kW kg- 1. This structural design strategy provides a feasible scheme for constructing metal sulfides with homojunction/heterojunction structures for highperformance aqueous energy storage and promotes the development of alkaline Cu-Zn batteries and beyond.