Enhancing the Cycling Stability of Vanadium Oxide Electrodes in Zinc-Ion Hybrid Supercapacitors: A Review

This work primarily investigates the cycling stability performance of vanadium-based oxide materials used as electrodes in zinc-ion hybrid capacitors. Distinct from previous reviews, this review systematically categorizes recent modification strategies for vanadium oxide electrodes in zinc-ion hybrid capacitors and highlights their underlying common principles─such as suppressing volume expansion, alleviating phase-transition-induced structural degradation, and enhancing ion–electron transport coupling─thus providing a more unified understanding of structure–stability relationships compared with previous reviews. By analyzing the reasons for the poor cycling stability of vanadium oxide electrodes, this work summarizes several modification strategies for vanadium oxide electrodes, including metal cation doping modification, nanostructure control modification, surface coating modification, and three-dimensional porous architecture design modification. These modification strategies mainly suppress or alleviate the volume expansion and contraction of the electrode during repeated charge and discharge processes by regulating the lattice structure, nanoscale, and porous structure of the electrode, thereby improving the cycling stability of vanadium oxide-based electrodes. The mechanism of various modification strategies to improve cycle stability was also analyzed, and the development prospects of vanadium oxide electrodes were discussed. Shortcomings in the performance research of vanadium-based oxide electrodes applied to zinc-ion hybrid capacitors were identified, and suggestions were put forward to address these issues.