Mn-doped ZnO microspheres as cathode materials for aqueous zinc ion batteries with ultrastability up to 10 000 cycles at a large current density

Abstract

Recently, aqueous zinc-ion batteries (ZIBs) are highly attractive due to high specific capacity of Zn, low-cost and safety, but the weak reaction kinetics and fast capacity attenuation still remain challenging. Herein, we adopt a temperature-regulation method to prepare rough Mn-doped zinc oxide microspheres. Such microsphere structure is rich in superfine nanoparticles and internal mesopores, which offers more Zn2+ diffusion channels and alleviates the stress and strain in the electrochemical process. Meanwhile, the doping of Mn into the ZnO structure can not only adjust the electronic structure, but also enhance the electrical conductivity, thereby upraising the reaction kinetics. Applied to ZIBs cathode, Mn-doped ZnO material presents appreciable rate performance, which obtains 268.1 mA h g−1 at 1 A g−1 and retains 163.8 mA h g−1 at 5 A g−1. Most importantly, high energy density (206.9 Wh kg−1), power density (6896.7 W kg−1) and superior cycle durability (~146.7% after 10 000 cycles relative to the first cycle) endow this material with more potential in energy storage.