Thermal conversion engineering of vanadium nitride-oxide cathode for high-rate aqueous Zn-ion battery

Vanadium-based materials are promising cathodes for high electrochemical performance aqueous Zn-ion batteries (AZIBs) due to their high specific capacity and multielectron redox reactions. However, vanadium-based materials suffer from low intrinsic conductivities and slow reaction kinetics, leading to poor rate performance. Here, we introduce vanadium nitride-oxide (VOVN) composites fabricated through a thermal conversion strategy, which exhibit high capacity and superior rate performance. The interface regulation of V 2 O 3 and VN composite promotes charge carrier transport and enhances cathode reaction kinetics. Additionally, the dual energy storage mechanism in VOVN composites facilitates highly reversible Zn 2+ storage processes. Consequently, the VOVN cathode demonstrates high discharge capacity (445.3 mAh g −1 at 0.1 A g −1 ), excellent rate performance (151.4 mAh g −1 at 30 A g −1 ), and fast diffusion coefficient (10 −9 –10 −10  cm 2  s −1 ). This study provides a straightforward and effective approach to developing high-performance cathodes for AZIBs.