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.