Surface Adsorption and Proton Chemistry of Ultra‐Stabilized Aqueous Zinc‐Manganese Dioxide BatteriesQiang Chen, Xuan Lou, Yifei Yuan, Kun You, Chenghang Li, Chenhao Jiang, Yuquan Zeng, Sheng Zhou, Jianli Zhang, Guangya Hou, Jun Lu, Yiping Tang
- Mechanical Engineering
- Mechanics of Materials
- General Materials Science
Aqueous rechargeable Zn batteries incorporating MnO2 cathodes possess favourable sustainability properties and are being considered for low‐cost, high‐safety energy storage. However, unstable electrode structures and unclear charge storage mechanisms limit their development. Here, we utilize advanced transmission electron microscopy, electrochemical analysis, and theoretical calculations to study the working mechanisms of a Zn/MnO2 battery with a Co2+‐stabilized, tunnel‐structured α‐MnO2 cathode (CoxMnO2). We show that Co2+ can be pre‐intercalated into α‐MnO2 and occupy the [2 × 2] tunnel structure, which improves the structural stability of MnO2, facilitate the proton diffusion and Zn2+ adsorption on the MnO2 surface upon battery cycling. We further reveal that for the MnO2 cathode, the charge storage reaction proceeds mainly by proton intercalation with the formation of α‐HyCoxMnO2, and that the anode design (with or without Zn metal) affects the surface adsorption of by‐product Zn4SO4(OH)6·nH2O on MnO2 surface. Our work advances the fundamental understanding of rechargeable Zn batteries and also sheds light on efficient electrode modifications toward performance enhancement.
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