A two-electron transfer mechanism of the Zn-doped δ-MnO2 cathode toward aqueous Zn-ion batteries with ultrahigh capacity. Issue 12 (24th February 2022)

• Record Type: Journal Article
• Authors: Zhao, Wen; Fee, Jared; Khanna, Harshul; March, Seth; Nisly, Nathaniel; Rubio, Samantha Joy B.; Cui, Can; Li, Zhuo; Suib, Steven L.
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 12(2022)
• Page Start: 6762
• Page End: 6771
• Publication Date: 2022-02-24
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta10864f
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : We developed a Zn-doped δ-MnO2 material via a microwave-assisted method for the cathode in aqueous ZIBs. The successive insertion of H + and Zn 2+ and deep two-electron transfer routes mechanism is revealed systematically by ex situ experiments. Abstract : Neutral aqueous zinc-ion batteries (ZIBs) have attracted considerable attention due to their safe and green features. As one typical cathode, birnessite MnO2 (δ-MnO2 ) suffers from low conductivity and structural instability, and its energy storage mechanism is still not well established yet. Herein, we developed a Zn-doped δ-MnO2 material via a facile and effective microwave-assisted method for the cathode in aqueous ZIBs. By incorporating Zn to modify the microstructure and promote reaction kinetics, the Zn-doped δ-MnO2 electrode demonstrates significantly enhanced electrochemical performance with an ultrahigh reversible capacity of 455 mA h g −1 and excellent specific energy of 628 W h kg −1 . In addition, the successive insertion of H + and Zn 2+ and deep two-electron transfer routes are revealed systematically by ex situ experiments. The two-electron transfer route (Mn 4+ /Mn 3+ and Mn 3+ /Mn 2+ ) mechanism of Zn-doped δ-MnO2 electrodes explains the exceedingly high capacity and opens new opportunities to develop high-energy aqueous ZIBs.