Enhancing Zn-Ion Storage Capability of Hydrated Vanadium Pentoxide by the Strategic Introduction of La3+

Hydrated vanadium pentoxide (VO) cathodes with two-dimensional bilayer structures hold great potential for advanced aqueous Zn-ion batteries (ZIBs) construction, but their further application is impeded by the poor cycling stability. Herein, to address this issue and enhance the Zn ion storage capability, La3+ with a big radius was selected to finely tune their nanostructure. The strategic introduction of La3+ to VO led to the formation of LaVO4, which showed larger interplanar spacing, better electrical conductivity, and superior Zn-ion diffusion efficiency. These unique characteristics were beneficial in the (de)intercalation and the prevention of electrode degradation/collapse, thereby significantly strengthening the corresponding electrochemical performance. As a consequence, the cathode possessed a high specific capacity of 472.5 mAh g(-1) at a current density of 0.38 A g(-1) and displayed good rate performance, accompanied by enduring cycling stability (no decay after 2000 cycles). Besides, when equipped as an aqueous ZIB, it delivered an outstanding peak energy density of 341.9 Wh kg(-1) and a peak power density of 3.22 kW kg(-1), surpassing most VO-based energy-storage devices.