V2O3/VO2@S/N-C nanofibers with excellent cycling stability and superior rate capability in aqueous zinc ion batteries

Abstract

The development of aqueous zinc-ion batteries (AZIBs) marks a significant advancement in the field of sustainable and environmentally friendly energy storage. To address the challenges faced by single-phase vanadium-based oxides, such as poor conductivity and dissolution in electrolytes, this study introduces vacuum S/N doping to fabricate V2O3/VO2@S/N-C nanofibers, improving the cycling stability and enhancing the capacity. The V2O3/VO2@S/N-C electrode exhibits exceptional cyclic stability, retaining a capacity of 133.3 mA h g−1 after 30,000 cycles at a high current density of 100 A g−1 and a capacity retention of 81.8% after 150,000 cycles at 200 A g−1. Characterizations using ex-situ X-ray diffraction and ex-situ X-ray photoelectron spectroscopy reveal co-intercalation of H+ and Zn2+ in the V2O3/VO2@S/N-C electrode. Due to the presence of S22-, more phases changed to V10O24·12H2O, making the V2O3/VO2@S/N-C electrode better reversible. By elucidating the zinc storage mechanism and demonstrating the stable performance of the doped electrode, this work contributes valuable insights into the optimization of the electrode materials for future energy storage solutions.