Abstract
Aqueous Zn ion batteries (ZIBs) are promising in energy storage due to the low cost, high safety, and material abundance. The development of metal oxides as the cathode for ZIBs is limited by the strong electrostatic forces between O(2-) and Zn(2+) which leads to poor cyclic stability. Herein, Bi(2)S(3) is proposed as a promising cathode material for rechargeable aqueous ZIBs. Improved cyclic stability and fast diffusion of Zn(2+) is observed. Also, the layered structure of Bi(2)S(3) with the weak van der Waals interaction between layers offers paths for diffusion and occupancy of Zn(2+). As a result, the Zn/Bi(2)S(3) battery delivers high capacity of 161 mAh g(-1) at 0.2 A g(-1) and good cycling stability up to 100 cycles with ca. 100% retention. The battery also demonstrates good cyclic performance of ca. 80.3% over 2000 cycles at 1 A g(-1). The storage mechanism in the Bi(2)S(3) cathode is related to the reversible Zn ion intercalation/extraction reactions and the capacitive contribution. This work indicates that Bi(2)S(3) shows great potential as the cathode of ZIBs with good performance and stability.