Regulating zinc storage and transport characteristics of VO2(B) cathodes via cobalt introduction

Abstract

The VO₂(B) cathode materials maintain high stability during the zinc ion embedding/removal process, making it a research hotspot in positive electrode materials for water-based zinc ion batteries. However, its poor ion diffusion kinetics and intrinsic semiconductor properties have become the main reasons limiting the enhancement of the specific capacity and rate performance. Herein, the function of Co-doping on the microstructure, morphological characteristics, transport characteristics and electrochemical performances of the Co_xV_1-xO₂(B) nanorods were comparatively investigated. The Co_0.05V_0.95O₂(B) cathode has the highest specific capacity and unmatched cycle stability. The optimized electrochemical performance was mainly due to the synergistic optimization of grain distortion, grain size and oxygen vacancy inside the lattice. The electrochemical kinetics results show that the Co_0.05V_0.95O₂(B) cathodes were capacitor and battery hybrid characteristics. The above conclusions provide a good idea and experimental verification for applying VO₂(B) cathode in the water-based zinc ion batteries market.