AUTHOR=Wang Nengze , Yang Gaochen , Gan Yi , Wan Houzhao , Chen Xu , Wang Cong , Tan Qiuyang , Ji Jie , Zhao Xiaojuan , Liu Pengcheng , Zhang Jun , Peng Xiaoniu , Wang Hanbin , Wang Yi , Ma Guokun , van Aken Peter A. , Wang Hao TITLE=Contribution of Cation Addition to MnO2 Nanosheets on Stable Co3O4 Nanowires for Aqueous Zinc-Ion Battery JOURNAL=Frontiers in Chemistry VOLUME=8 YEAR=2020 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00793 DOI=10.3389/fchem.2020.00793 ISSN=2296-2646 ABSTRACT=

Zinc-based electrochemistry attracts significant attention for practical energy storage owing to its uniqueness in terms of low cost and high safety. In this work, we propose a 2.0-V high-voltage Zn–MnO₂ battery with core@shell Co₃O₄@MnO₂ on carbon cloth as a cathode, an optimized aqueous ZnSO₄ electrolyte with Mn²⁺ additive, and a Zn metal anode. Benefitting from the architecture engineering of growing Co₃O₄ nanorods on carbon cloth and subsequently deposited MnO₂ on Co₃O₄ with a two-step hydrothermal method, the binder-free zinc-ion battery delivers a high power of 2384.7 W kg⁻¹, a high capacity of 245.6 mAh g⁻¹ at 0.5 A g⁻¹, and a high energy density of 212.8 Wh kg⁻¹. It is found that the Mn²⁺ cations are in situ converted to Mn₃O₄ during electrochemical operations followed by a phase transition into electroactive MnO₂ in our battery system. The charge-storage mechanism of the MnO₂-based cathode is Zn²⁺/Zn and H⁺ insertion/extraction. This work shines light on designing multivalent cation-based battery devices with high output voltage, safety, and remarkable electrochemical performances.