Kinetics‐Matched Electrode Design for Zn‐Metal Free Zinc Ion Batteries with High Energy Density and Stabilities

The metal‐free rocking chair type Zn‐ion batteries (ZIBs) provide a promising approach toward the promotion of the Zn‐based batteries by circumventing the challenges including dendrite growth, hydrogen evolution reaction (HER), and surface corrosion. In order to sufficiently exploit the available capacity of this metal‐free batteries, it is necessary to effectively enhance the sluggish reaction kinetics of divalent zinc ions. Equally important is to achieve a balance in the kinetics between cathode and anode. Here, hetero‐valent doping and oxygen vacancy engineering are employed to effectively enhance the reaction dynamics of V2O5 cathodes and MoO3 anodes. Moreover, to the best of the knowledge, for the first time, the strategy of kinetics matching between the two electrodes is applied to the construction of rocking‐chair zinc ion batteries, enabling the cathode and anode to share similar zinc ion migration rates, and achieving a high energy density of up to 58.7 Wh kg−1 (based on the total electrode mass) as well as excellent cycling stability (90% after 500 cycles). This work demonstrates the importance of kinetics matching in zinc‐ion full‐cell performance and pave a benefitable avenue to for the pursuit of advanced multi‐valent metal‐ion batteries. The reaction kinetics between the V2O5 cathode and MoO3 anode are improved and matched by hetero‐valent doping and oxygen vacancy engineering. This kinetics matching strategy achieves a high energy density of 58.7 Wh kg−1 and excellent cycling stability, highlighting its importance for advanced metal‐ion batteries.