Cerium oxide as cathode material for aqueous zinc-ion battery

Abstract

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.