Chitosan-induced NHVO hierarchical hybrids as high-capacity cathode for aqueous zinc ion batteries.

Aqueous zinc ion batteries (AZIBs) have been widely investigated due to their characteristics of convenient operation and intrinsic safety. However, there are several issues to be addressed in AZIBs, such as slow diffusion kinetics of Zn, cathode material dissolution and the dendrite formation of zinc anodes. Thus, it is challenging to prepare a high-performance cathode material. In this work, we prepare NHVO flower-like structures by a facile hydrothermal route. The introduction of chitosan significantly enlarges the layer spacing of the (001) crystal plane. The assembled Zn//NVO-0.15C batteries deliver a specific capacity of 520.54 mA h g at a current density of 0.2 A g. Furthermore, they maintain 91% of the retention rate at 5.0 A g after 1000 times cycling. It demonstrates the excellent zinc ion storage behavior of ammonium vanadate electrode materials for AZIBs.