Work

Synergetic Effect of Mo‐Doped and Oxygen Vacancies Endows Vanadium Oxide with High‐Rate and Long‐Life for Aqueous Zinc Ion Battery

Year: 2024

Type: article

Abstract: Vanadium (V)‐based oxides have garnered significant attention as cathode materials for aqueous zinc‐ion batteries (AZIBs) due to their multiple valences and high theoretical capacity. However, their sluggish kinetics and low conductivity remain major obstacles to practical applications. In this study, Mo‐doped V2O3 with oxygen vacancies (OVs, Mo‐V2O3‐x@NC) is prepared from a Mo‐doped V‐metal organic framework. Ex situ characterizations reveal that the cathode undergoes an irreversible phase transformation from Mo‐V2O3‐x to Mo‐V2O5‐x·nH2O and serves as an active material exhibiting excellent Zn2+ storage in subsequent charge‐discharge cycles. Mo‐doped helps to further improve cycling stability and increases with increasing content. More importantly, the synergistic effect of Mo‐doped and OVs not only effectively reduces the Zn2+ migration energy barrier, but also enhances reaction kinetics, and electrochemical performance. Consequently, the cathode demonstrates ultrafast electrochemical kinetics, showing a superior rate performance (190.9 mAh g−1 at 20 A g−1) and excellent long‐term cycling stability (147.9 mAh g−1 at 20 A g−1 after 10000 cycles). Furthermore, the assembled pouch cell exhibits excellent cycling stability (313.6 mAh g−1 at 1 A g−1 after 1000 cycles), indicating promising application prospects. This work presents an effective strategy for designing and fabricating metal and OVs co‐doped cathodes for high‐performance AZIBs.

Source: Small

DOI: 10.1002/smll.202405168