A high-voltage rechargeable alkaline Zn–MnO4− battery with enhanced stability achieved by highly reversible MnO4−/MnO42− redox pair. (June 2021)

• Record Type: Journal Article
• Authors: Liu, C.; Chi, X.; Huang, J.; Liu, Y.
• Is Part Of: Materials today energy. Volume 20(2021)
• Publication Date: 2021-06
• Subjects: High voltage -- Rechargeable alkaline Zn–Mn battery -- MnO4−/MnO42− redox reaction -- Flow battery; Energy development -- Periodicals; Energy industries -- Periodicals; Power resources -- Periodicals; Energy policy -- Periodicals; Energy development; Energy industries; Energy policy; Power resources; Electronic journals; Periodicals; 621.042
• DOI: 10.1016/j.mtener.2021.100680
• Languages: English
• ISSNs: 2468-6069

Abstract

Abstract: Development of rechargeable alkaline Zn–Mn batteries has been facing big challenges for low working voltage and poor cycling stability, although they have advantages of low cost, high safety, and simple maintenance. For the first time, this work demonstrates a record high voltage (1.78 V) for rechargeable alkaline Zn–MnO4 − battery achieved by a high reversible redox pair of MnO4 − /MnO4 2−, which shows excellent cycling stability up to 1, 500 cycles at a high current density of 20 mA cm −2 without obvious capacity attenuation. The MnO4 − /MnO4 2− redox reaction investigated by ex-situ scanning electron microscope as well as ultraviolet and visible absorption spectrum indicates high reversibility of the MnO4 − /MnO4 2− redox couple after the activation during the first discharge process. Furthermore, benefiting from the liquid-phase reaction nature of MnO4 − /MnO4 2−, a flow battery is further prototyped to show highly stable cycles with 95.8% of discharge capacity retention for 600 cycles at the current density of 40 mA cm −2 . Graphical abstract: Image 1 Highlights: The MnO4 − /MnO4 2− pair with a good reversibility is investigated by ex-situ SEM and UV–visible absorption spectrum. A record high-voltage (1.78 V) for rechargeable alkaline Zn–Mn battery was achieved by the redox reaction of MnO4 − /MnO4 2− . The full battery can cycle stably for 1500 cycles at a high current density of 20 mA cm −2 without capacity attenuation. The flow battery shows discharge capacity retention of 95.8% after 600 cycles at the current density of 40 mA cm −2 .