Cerium oxide as cathode material for aqueous zinc-ion battery

Zinc-ion battery is regarded as one of the potential alternatives for advanced energy storage system , due to its high discharge capacity, low cost, and environmental benignity. The research and development of new electrode materials and reaction mechanism for zinc-ion battery have attracted most attention. Herein, cerium oxide is systematically investigated as a novel cathode material for aqueous zinc-ion battery. The battery charge and discharge test results show that cerium oxide has a discharge specific capacity comparable to that of manganese oxide cathode material, the discharge specific capacity is stable at 143.8 mAh g −1 after 500 cycles. The cyclic voltammetry curves and charge-discharge curves of cerium oxide are very similar to manganese oxide cathode materials. The results of X-ray diffraction and X-ray photoelectron spectroscopy demonstrate that the performance of cerium oxide as a cathode material for aqueous zinc-ion battery is related to the reaction product of zinc sulfate hydroxide hydrate and manganese ion in the electrolyte. And it is found that the discharge cut-off voltage also plays a crucial role in the discharge capacity of the aqueous zinc-ion battery with manganese ion.