Discharging Behavior of Hollandite α-MnO2 in a Hydrated Zinc-Ion Battery
Department
Chemistry and Biochemistry
Document Type
Article
Publication Date
12-22-2021
Abstract
Hollandite, α-MnO2, is of interest as a prospective cathode material for hydrated zinc-ion batteries (ZIBs); however, the mechanistic understanding of the discharge process remains limited. Herein, a systematic study on the initial discharge of an α-MnO2 cathode under a hydrated environment was reported using density functional theory (DFT) in combination with complementary experiments, where the DFT predictions well described the experimental measurements on discharge voltages and manganese oxidation states. According to the DFT calculations, both protons (H+) and zinc ions (Zn2+) contribute to the discharging potentials of α-MnO2 observed experimentally, where the presence of water plays an essential role during the process. This study provides valuable insights into the mechanistic understanding of the discharge of α-MnO2 in hydrated ZIBs, emphasizing the crucial interplay among the H2O molecules, the intercalated Zn2+ or H+ ions, and the Mn4+ ions on the tunnel wall to enhance the stability of discharged states and, thus, the electrochemical performances in hydrated ZIBs.
Journal Title
ACS Applied Materials and Interfaces
Journal ISSN
19448244
Volume
13
Issue
50
First Page
59937
Last Page
59949
Digital Object Identifier (DOI)
10.1021/acsami.1c18849