Vanadium Nitride@nitrogen-Doped Graphene as Zinc Ion Battery Cathode with High Rate Capability and Long Cycle Stability

Vanadium nitride (VN), as a cathode material for aqueous zinc ion batteries (ZIBs), has the advantage of high stability and theoretical specific capacity. Here, we aim at the disadvantages of the poor conductivity of VN and NH3 as a nitrogen source, and prepare vanadium nitride@nitrogen-doped graphene (VN@NGr) in N2 atmosphere, using dicyandiamide (DCDA) as the nitrogen source and glucose as the carbon source. The VN@NGr electrode shows excellent reversible rate performance, and, after that, the electrode maintained ∼100% capacity retention to 1000 cycles at 1 A g–1 current density. In addition, at the current densities of 0.1 and 20 A g–1, the electrode maintained 96% and 70% capacity retention after 75 and 26 000 cycles. VN@NGr material has the advantages of simple preparation, low cost, and good electrochemical stability, so we believe it will be competitive in future large-scale energy storage fields.