Zn/MnO2 Battery Chemistry With H+ and Zn2+ Coinsertion
By Sun, Wei; Wang, Fei; Hou, Singyuk; Yang, Chongyin; Fan, Xiulin; Ma, Zhaohui; Gao, Tao; Han, Fudong; Hu, Renzong; Zhu, Min; Wang, Chunsheng
Published in Journal of the American Chemical Society
2017
Abstract
Rechargeable aqueous Zn/MnO2 battery chemistry in a neutral or mildly acidic electrolyte has attracted extensive attention recently because all the components (anode, cathode, and electrolyte) in a Zn/MnO2 battery are safe, abundant, and sustainable. However, the reaction mechanism of the MnO2 cathode remains a topic of discussion. Herein, we design a highly reversible aqueous Zn/MnO2 battery where the binder-free MnO2 cathode was fabricated by in situ electrodeposition of MnO2 on carbon fiber paper in mild acidic ZnSO4+MnSO4 electrolyte. Electrochemical and structural analysis identify that the MnO2 cathode experience a consequent H+ and Zn2+ insertion/extraction process with high reversibility and cycling stability. To our best knowledge, it is the first report on rechargeable aqueous batteries with a consequent ion-insertion reaction mechanism.