Li+, Na+ co-stabilized vanadium oxide nanobelts with a bilayer structure for boosted zinc-ion storage performance

Abstract

Addressing the structural instability and torpid kinetic limitation has been a pressing while challenging issue for vanadium oxide cathode materials to realize their outstanding performance in rechargeable aqueous zinc-ion batteries (ZIBs). Herein, vanadium oxide nanobelts with a bilayer structure (LiV₃O₈@NaV₃O₈, LVO@NVO) have been prepared successfully via a quick one-pot eutectic oxidation process. When evaluated as a cathode for ZIBs, the LVO@NVO shows an amazing capacity of 476 mA h g⁻¹ at 0.05 A g⁻¹, superior rate properties (236 mA h g⁻¹ @ 5 A g⁻¹), and excellent cycling capability over 2000 cycles with a capacity-retention of 93.4%. Owing to the pre-intercalated Li⁺ and Na⁺ cations and the resulting bilayer structure, higher pseudocapacitance, faster charge-transfer/ion-diffusion kinetics, and a robust architecture have been achieved in the LVO@NVO cathode, which are responsible for the superior zinc-ion storage performance. Furthermore, the energy storage mechanism based on Zn²⁺ and H⁺ co-intercalation/extraction has been proved.