Guo Haocheng, Wu Sicheng, Chen Wen, Su Zhen, Wang Qing, Sharma Neeraj, Rong Chengli, Fleischmann Simon, Liu Zhaoping, Zhao Chuan
School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia.
Advanced Li-ion battery lab, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo, 315200, P. R. China.
Adv Mater. 2024 Feb;36(6):e2307118. doi: 10.1002/adma.202307118. Epub 2023 Dec 6.
Rapid proton transport in solid-hosts promotes a new chemistry in achieving high-rate Faradaic electrodes. Exploring the possibility of hydronium intercalation is essential for advancing proton-based charge storage. Nevertheless, this is yet to be revealed. Herein, a new host is reported of hexagonal molybdates, (A O) ·MoO ·(H O) (A = Na , NH ), and hydronium (de)intercalation is demonstrated with experiments. Hexagonal molybdates show a battery-type initial reduction followed by intercalation pseudocapacitance. Fast rate of 200 C (40 A g ) and long lifespan of 30 000 cycles are achieved in electrodes of monocrystals even over 200 µm. Solid-state nuclear magnetic resonance confirms hydronium intercalations, and operando measurements using electrochemical quartz crystal microbalance and synchrotron X-ray diffraction disclose distinct intercalation behaviours in different electrolyte concentrations. Remarkably, characterizations of the cycled electrodes show nearly identical structures and suggest equilibrium products are minimally influenced by the extent of proton solvation. These results offer new insights into proton electrochemistry and will advance correlated high-power batteries and beyond.
固体基质中快速的质子传输促进了实现高倍率法拉第电极的新化学过程。探索水合氢离子嵌入的可能性对于推进基于质子的电荷存储至关重要。然而，这一点尚未得到揭示。在此，报道了一种新的主体材料——六方钼酸盐（(AO)·MoO·(H₂O)，A = Na⁺、NH₄⁺），并通过实验证明了水合氢离子的（去）嵌入过程。六方钼酸盐表现出电池型的初始还原过程，随后是嵌入赝电容。即使对于超过200 µm的单晶电极，也能实现200 C（40 A g⁻¹）的快速倍率和30000次循环的长寿命。固态核磁共振证实了水合氢离子的嵌入，使用电化学石英晶体微天平及同步加速器X射线衍射进行的原位测量揭示了在不同电解质浓度下不同的嵌入行为。值得注意的是，对循环电极的表征显示结构几乎相同，这表明平衡产物受质子溶剂化程度的影响极小。这些结果为质子电化学提供了新的见解，并将推动相关的高功率电池及其他领域的发展。
