Nitrogen doped vanadium oxide (AlVO-N) as cathode for zinc ion battery with high stability and high rate performance

Abstract

• The influence of N- doping on trivalent vanadium salt is studied. • The microsphere morphology is beneficial to electrolyte penetration. • The microsphere morphology can reduce volume expansion during charging. • The electrode has high stability with 90% capacity retention after 9000 cycles. Vanadium-based aqueous zinc ion battery has a great advantage in terms of theoretical specific capacity. However, due to the poor conductivity of pure vanadium oxide and the easy damage of its structure when zinc ions are embedded, it needs to be further studied. In this work, Nitrogen doped aluminum-vanadium oxide (AlVO-N) is prepared by using ammonia (NH 3 ) as reducing agent and nitrogen source. The addition of N atom inhibits the agglomeration of AlVO-N in the reduction process and makes the electrolyte easily permeate into the electrode material, thus increasing the contact area of the electrode solid-liquid interface. Through kinetic studies, N-doping can improve the redox reaction rate of the electrode material surface, so that the electrode can obtain higher capacitance contribution, and thus has excellent rate performance. At the current density of 1 A g -1 , the specific discharge capacity of the AlVO-N electrode is 224 mA h g -1 and the capacity retention is 94.5%. Under the current density of 20 A g -1 , the capacity retention of the electrode remains above 90% after 9000 cycles. Therefore, we believe that the electrochemical performance of AlVO-N has potentially competitive in large-scale energy storage in the future.