A sustainable route from spent hydrogenation catalysts to lamellar spherical vanadium oxide hydrates for superior low-cost aqueous Zn-ion batteries

Vanadium oxides are the promising cathode candidate for zinc ions batteries due to their fascinating structure with adjustable tunnels. Whereas, the expensive reagent-grade vanadium raw materials impede their economically-feasible production for scale-up battery applications. Herein, based on the selective recycling of vanadium and facile hydrothermal treatment, the hierarchical hydrated vanadium oxides (HVO) derived from spent hydrogenation catalysts were successfully fabricated as superior cathode materials of ZIBs. The regulating role of guest water molecules on morphology and electrochemical performance of vanadium oxides was elucidated. The lamellar spherical V10O22.8.12H(2)O achieved a specific discharge capacity of 287 mA h g(-1) at 0.2 A g (-1) and the discharge specific capacity of 238 mA h g (-1 )at 1 A g (-1). Meanwhile, it exhibited a high energy density of 106 Wh kg(- 1) at a power density of 3324 W kg(-1) and excellent capacity retention of 82% after 3000 cycles at a high density of 10 A g( -1). The storage mechanism of zinc ions were disclosed by ex situ Raman and XRD tests. This waste-to-wealth strategy may provide a promising route for the efficient utilization of hazardous spent catalysts and sustainable development of high performance vanadium-based cathode materials.

Automated summary

Vanadium oxides with adjustable tunnels are promising cathode candidates for zinc ions batteries. In this study, hierarchical hydrated vanadium oxides (HVO) were successfully fabricated from spent hydrogenation catalysts via selective recycling and facile hydrothermal treatment, exhibiting superior cathode materials for ZIBs. The regulating role of guest water molecules on the morphology and electrochemical performance of vanadium oxides was elucidated.