Abstract VO 2 (B) has attracted tremendous attention as a cathode for aqueous zinc‐ion batteries (AZIBs), but its low intrinsic electronic conductivity and uncontrolled vanadium dissolution hinder further practical applications. Herein, Zn 0.03 VO 2 , with guest zinc ions preinserted into the tunnel sites, is demonstrated to enhance the conductivity and cyclability of VO 2 (B). The tailored structure, featuring a modulated electronic configuration, offers enlarged ion diffusion tunnels, improved electronic conductivity, and enhanced electrochemical activity, thereby facilitating the reversible de‐intercalation of Zn 2+ /H + ions, as confirmed by both experimental results and theoretical calculations. Notably, vanadium dissolution is significantly suppressed due to the chemical pre‐insertion of guest zinc, which weakens the interaction between Zn 2+ and host lattice, as well as the homologous ion effect. As a result, Zn 0.03 VO 2 cathode delivers a high capacity of 358 mAh g −1 , particularly at low current density of 0.1 A g −1 , with 85% capacity retention after 300 cycles, excellent rate capability of 175 mAh g −1 at 5 A g −1 , and long cycling stability over 2000 cycles at 20 A g −1 . Moreover, a pseudocapacitive‐dominated Zn 2+ /H + co‐insertion mechanism is conclusively identified through electrochemical and spectroscopic analyses. This work provides valuable insights into ion‐preinserted structural modulation of vanadium oxides for the development of high‐performance AZIBs.
Wang et al. (Thu,) studied this question.