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

• Published in: iScience Vol. 23; no. 1; p. 100797
• Main Authors: Han, Mingming, Huang, Jiwu, Liang, Shuquan, Shan, Lutong, Xie, Xuesong, Yi, Zhenyu, Wang, Yiren, Guo, Shan, Zhou, Jiang
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 24.01.2020; Elsevier
• Subjects: Energy Materials; Energy Storage; Nanomaterials; Nanomaterials; Energy Materials; Energy Storage
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.100797

Rechargeable aqueous Zn/manganese dioxide (Zn/MnO2) batteries are attractive energy storage technology owing to their merits of low cost, high safety, and environmental friendliness. However, the β-MnO2 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-MnO2 cathode with enhanced ion insertion kinetics is introduced by the efficient oxygen defect engineering strategy. Density functional theory computations show that the β-MnO2 host structure is more likely for H+ insertion rather than Zn2+, and the introduction of oxygen defects will facilitate the insertion of H+ into β-MnO2. 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-MnO2 cell. These results highlight the potentials of defect engineering as a strategy of improving the electrochemical performance of β-MnO2 in aqueous rechargeable batteries. [Display omitted] •A conversion reaction mechanism is observed for Zn/β-MnO2 system•The binding energy of H+ insertion is reduced by introducing oxygen defects•The introduction of oxygen defects increases ion insertion channels•Zn/D-β-MnO2 battery delivers good performance even at high mass loading Energy Storage; Nanomaterials; Energy Materials