Work

Oxygen Defects in β-MnO2 Enabling High-Performance Rechargeable Aqueous Zinc/Manganese Dioxide Battery

Year: 2019

Type: article

Abstract: Rechargeable aqueous Zn/manganese dioxide (Zn/MnO 2 ) batteries are attractive energy storage technology owing to their merits of low cost, high safety, and environmental friendliness. However, the β -MnO 2 cathode is still plagued by the sluggish ion insertion kinetics due to the relatively narrow tunneled pathway. Furthermore, the energy storage mechanism is under debate as well. Here, β -MnO 2 cathode with enhanced ion insertion kinetics is introduced by the efficient oxygen defect engineering strategy. Density functional theory computations show that the β -MnO 2 host structure is more likely for H + insertion rather than Zn 2+ , and the introduction of oxygen defects will facilitate the insertion of H + into β -MnO 2 . This theoretical conjecture is confirmed by the capacity of 302 mA h g −1 and capacity retention of 94% after 300 cycles in the assembled aqueous Zn/ β -MnO 2 cell. These results highlight the potentials of defect engineering as a strategy of improving the electrochemical performance of β -MnO 2 in aqueous rechargeable batteries.

Source: iScience

DOI: 10.1016/j.isci.2019.100797