Boosting Electrolytic MnO2-Zn Batteries by a Bromine Mediator

Xinhua Zheng; Yongchao Wang; Yan Xu; Touqeer Ahmad; Yuan Yuan; Jifei Sun; Ruihao Luo; Mingming Wang; Mingyan Chuai; Na Chen; Taoli Jiang; Shuang Liu; Wei Chen

doi:10.1021/acs.nanolett.1c03319

Boosting Electrolytic MnO₂-Zn Batteries by a Bromine Mediator

Nano Lett. 2021 Oct 27;21(20):8863-8871. doi: 10.1021/acs.nanolett.1c03319. Epub 2021 Oct 11.

Authors

Xinhua Zheng¹, Yongchao Wang², Yan Xu¹, Touqeer Ahmad¹, Yuan Yuan¹, Jifei Sun¹, Ruihao Luo¹, Mingming Wang¹, Mingyan Chuai¹, Na Chen¹, Taoli Jiang¹, Shuang Liu¹, Wei Chen¹

Affiliations

¹ Department of Applied Chemistry, School of Chemistry and Materials Science, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
² National Center for Material Service Safety, University of Science and Technology Beijing, Beijing 100083, People's Republic of China.

PMID: 34633819
DOI: 10.1021/acs.nanolett.1c03319

Abstract

An aqueous electrolytic MnO₂-Zn battery with eye-catching Mn²⁺/MnO₂ cathode chemistry has been attracting immense interest for next-generation energy storage devices due to its irreplaceable advantages. However, the limited MnO₂ conductivity restricts its long service life at high areal capacities. Here, we report a high-performance electrolytic MnO₂-Zn battery via a bromine redox mediator, to enhance its electrochemical performance. The MnO₂/Br₂-Zn battery displays a high discharge voltage of 1.98 V with a capacity of ∼5.8 mAh cm^-2. It also shows an excellent rate performance of 20 C with a long-term stability of over 600 cycles. Furthermore, the scaled-up MnO₂/Br₂-Zn battery with a capacity of ∼950 mAh exhibits a stable 100 cycles with a practical cell energy density of ∼32.4 Wh kg^-1 and an attractively low energy cost of below 15 US$ kWh^-1. The design approach can be generalized to other electrodes and battery systems, thus opening up new possibilities for large-scale energy storage.

Keywords: Bromine; Large-scale energy storage; MnO2−Zn battery; Redox mediator.