1 research outputs found
Intercalation and Conversion Reactions of Nanosized β‑MnO<sub>2</sub> Cathode in the Secondary Zn/MnO<sub>2</sub> Alkaline Battery
This
work reports rechargeable Zn/β-MnO<sub>2</sub> alkaline
batteries as promising stationary energy storage. Unlike commercial
alkaline batteries with poor cyclic performance, the nanosized β-MnO<sub>2</sub> cathode in the mixture of LiOH and KOH electrolyte enables
rechargeable reactions with high capacity. To unveil the underlying
reaction mechanisms of nanosized β-MnO<sub>2</sub>, we combine
thermodynamic frameworks with experimental characterization, including
electrochemistry, X-ray diffraction, and X-ray photoelectron spectroscopy.
The results demonstrate a series of proton intercalation reaction
(β-MnO<sub>2</sub> → γ-MnOOH) and two-phase conversion
reactions (γ-MnOOH → MnÂ(OH)<sub>2</sub> → λ-MnO<sub>2</sub>) during the first cycle and Li and H cointercalation in the
host structure of λ-MnO<sub>2</sub> spinel during the 100<sup>th</sup> cycle. It is remarkable that the addition of Bi<sub>2</sub>O<sub>3</sub> in the nanosized β-MnO<sub>2</sub> cathode exhibits
outstanding capacity. After 100 dischargings, the battery demonstrates
a capacity of 316 mA h g<sup>–1</sup>. Our findings can serve
in the tailored cathode design in high capacity and rechargeable Zn/β-MnO<sub>2</sub> alkaline batteries