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Layered hydrated vanadates have been regarded as promising cathode materials for Zn-ion batteries, while their electrochemical properties have been proved to be highly related to the species of the interlayer cations. However, because the single species of the interlayer cation can hardly endow the layered materials with comprehensively favorable properties, the introduction of multiple interlayer cations may offer an avenue to further optimization of the Zn-ion storage performance. Herein, this work introduces the codoping of Ca/Ni-ions in the structure of hydrated vanadate (Ca0.19Ni0.08V2O5·0.85H2O), which not only upgrades the specific capacities but also gives rise to high rate and cycling performances. Specifically, the interlayer Ni-ion in the structure plays a vital role in contributing to the high charge storage capability via participating in the electrochemical reactions. Meanwhile, the Ca-ion could stably act as pillars, pinning the adjacent VO x layers and thus leading to the structural stability of the layered material during operation. Moreover, the synergistic effects of the codoping result in the enlarged lattice spacing, which incurs the nearly zero-strain structural evolution processes with solid-solution-like charge storage behaviors. Accordingly, on the basis of a multiple-ion doping strategy, this study offers an effective approach to further boost the Zn-ion storage performance of hydrated vanadates.

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