Chen Hao, Dai Chunlong, Xiao Fangyuan, Yang Qiuju, Cai Shinan, Xu Maowen, Fan Hong Jin, Bao Shu-Juan
Institute for Clean Energy & Advanced Materials, School of Materials and Energy, Southwest University, Chongqing, 400715, P. R. China.
Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, P. R. China.
Adv Mater. 2022 Apr;34(15):e2109092. doi: 10.1002/adma.202109092. Epub 2022 Feb 27.
Rechargeable aqueous Zn-Mn batteries have garnered extensive attention for next-generation high-safety energy storage. However, the charge-storage chemistry of Zn-Mn batteries remains controversial. Prevailing mechanisms include conversion reaction and cation (de)intercalation in mild acid or neutral electrolytes, and a MnO /Mn dissolution-deposition reaction in strong acidic electrolytes. Herein, a Zn SO ·(OH) ·xH O (ZSH)-assisted deposition-dissolution model is proposed to elucidate the reaction mechanism and capacity origin in Zn-Mn batteries based on mild acidic sulfate electrolytes. In this new model, the reversible capacity originates from a reversible conversion reaction between ZSH and Zn MnO(OH) nanosheets in which the MnO initiates the formation of ZSH but contributes negligibly to the apparent capacity. The role of ZSH in this new model is confirmed by a series of operando characterizations and by constructing Zn batteries using other cathode materials (including ZSH, ZnO, MgO, and CaO). This research may refresh the understanding of the most promising Zn-Mn batteries and guide the design of high-capacity aqueous Zn batteries.
可充电水系锌锰电池因其下一代高安全性储能特性而备受广泛关注。然而，锌锰电池的电荷存储化学机制仍存在争议。常见的机制包括在弱酸或中性电解质中的转化反应和阳离子（脱）嵌入，以及在强酸性电解质中的MnO/Mn溶解-沉积反应。在此，基于弱酸性硫酸盐电解质，提出了一种ZnSO·(OH)·xH₂O（ZSH）辅助的沉积-溶解模型，以阐明锌锰电池的反应机理和容量来源。在这个新模型中，可逆容量源于ZSH与ZnMnO(OH)纳米片之间的可逆转化反应，其中MnO引发了ZSH的形成，但对表观容量的贡献可忽略不计。通过一系列原位表征以及使用其他阴极材料（包括ZSH、ZnO、MgO和CaO）构建锌电池，证实了ZSH在这个新模型中的作用。这项研究可能会刷新对最具潜力的锌锰电池的理解，并指导高容量水系锌电池的设计。
