Song Wanxin, Zhang Jianyong, Wen Cheng, Lu Haiyan, Han Chunhua, Xu Lin, Mai Liqiang
State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China.
Hubei Longzhong Laboratory, Wuhan University of Technology (Xiangyang Demonstration Zone), Xiangyang 441000, China.
J Am Chem Soc. 2024 Feb 21;146(7):4762-4770. doi: 10.1021/jacs.3c12710. Epub 2024 Feb 7.
Proton batteries are competitive due to their merits such as high safety, low cost, and fast kinetics. However, it is generally difficult for current studies of proton batteries to combine high capacity and high stability, while the research on proton storage mechanism and redox behavior is still in its infancy. Herein, the polyanionic layered copper oxalate is proposed as the anode for a high-capacity proton battery for the first time. The copper oxalate allows for reversible proton insertion/extraction through the layered space but also achieves high capacity through synchronous redox reactions of Cu and CO. During the discharge process, the bivalent Cu-ion is reduced, whereas the C═O of the oxalate group is partially converted to C-O. This synchronous behavior presents two units of charge transfer, enabling the embedding of two units of protons in the (110) crystal face. As a result, the copper oxalate anode demonstrates a high specific capacity of 226 mAh g and maintains stable operation over 1000 cycles with a retention of 98%. This work offers new insights into the development of dual-redox electrode materials for high-capacity proton batteries.
质子电池因其高安全性、低成本和快速动力学等优点而具有竞争力。然而，目前质子电池的研究通常很难同时兼顾高容量和高稳定性，而关于质子存储机制和氧化还原行为的研究仍处于起步阶段。在此，首次提出将聚阴离子层状草酸铜用作高容量质子电池的负极。草酸铜不仅允许质子通过层间空间进行可逆嵌入/脱出，还通过铜和一氧化碳的同步氧化还原反应实现了高容量。在放电过程中，二价铜离子被还原，而草酸根基团的碳氧双键部分转化为碳氧单键。这种同步行为呈现出两个电荷转移单元，使得两个质子单元能够嵌入（110）晶面。结果，草酸铜负极展现出226 mAh g的高比容量，并在1000次循环中保持稳定运行，容量保持率为98%。这项工作为高容量质子电池双氧化还原电极材料的开发提供了新的见解。
