The performance study of nanosheet-like VO2@MnCO3@Mn3N2 composite material as the cathode material for aqueous zinc-ion batteries

Manganese-based and vanadium-based compounds possess abundant valence states, making them highly promising for application in aqueous zinc-ion batteries. In this work, the manganese and vanadium-based composite material VO₂@MnCO₃@Mn₃N₂ was synthesized via the hydrothermal method. Through electrochemical performance testing, the optimal vanadium-to-manganese ratio and urea addition amount were selected. The study also compared the differences in electrochemical performance of the composite materials synthesized under various hydrothermal conditions and calcination conditions. The material with the best electrochemical performance delivered a maximum capacity of 436.6 mAh/g at the current density of 50 mA/g, and a maximum capacity of 325.4 mAh/g at the current density of 100 mA/g. Physical property characterization reveals that the composite material synthesized under optimal conditions consists of cube shapes with protrusions and nanoparticles, both of which are uniformly distributed within the composite. The nanoparticles are composed of both vanadium-based and manganese-based compounds. The Infrared spectroscopy, Raman spectroscopy and XPS analysis confirm that the valence states of the elements are consistent with those of VO₂ and MnCO₃. Refined XRD fitting shows that the main components of the composite material are VO₂, MnCO₃, and Mn₃N₂, with a molar ratio of vanadium to manganese at 1:1 and VO₂ accounting for 50% of the composition.