Design of the 1D/2D Bi₂S₃/Bi₂O₂S Heterojunction as Battery-Type Cathode Materials for Hybrid Supercapacitors

This research accomplished the controlled fabrication of a 1D/2D Bi₂S₃/Bi₂O₂S heterostructure for hybrid supercapacitor applications, where Bi₂S₃ nanorods were grown on Bi₂O₂S nanosheets to form the composite material. When the ratio of Bi₂S₃ to Bi₂O₂S is controlled at 5:3, the composite material demonstrates outstanding electrochemical properties. This is due to the appropriate content of Bi₂O₂S, which helps construct a good interface and enhance ion diffusion capability, thereby improving the electrochemical kinetics. The strategic combination of Bi₂S₃’s theoretical capacity and Bi₂O₂S’s structural stability yields a composite material with remarkable electrochemical properties, including enhanced reversible capacity and minimized polarization during cycling. Specifically, the Bi₂S₃/Bi₂O₂S-60 electrode delivers outstanding specific capacities of 1076.6 C g^–1 at 1 A g^–1 and maintains 730.3 C g^–1 at 10 A g^–1, demonstrating excellent rate capability. Notably, the composite exhibits significantly improved cycling stability (82.8% capacity retention after 10,000 cycles at 10 A g^–1) compared to pure Bi₂S₃(67.4%) and Bi₂O₂S (73.6%). When configured as a hybrid supercapacitor (Bi₂S₃/Bi₂O₂S-60//AC), the device achieves an impressive energy density of 68.28 Wh kg^–1 (810.73 W kg^–1) with exceptional long-term stability (93.5% capacity retention after 10,000 cycles). The coherent interface studied in this paper brings a new perspective to the field of supercapacitors.