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

Abstract

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 V2O3 and VN composite promotes charge carrier transport and enhances cathode reaction kinetics. Additionally, the dual energy storage mechanism in VOVN composites facilitates highly reversible Zn2+ 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 cm2 s−1). This study provides a straightforward and effective approach to developing high-performance cathodes for AZIBs.