Lv Fei, Wu Jiazhe, Liu Xuan, Zheng Zhihao, Pan Lixia, Zheng Xuewen, Guo Liejin, Chen Yubin
International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
Nat Commun. 2024 Feb 13;15(1):1339. doi: 10.1038/s41467-024-45321-z.
Decoupled electrolysis for hydrogen production with the aid of a redox mediator enables two half-reactions operating at different rates, time, and spaces, which offers great flexibility in operation. Herein, a pre-protonated vanadium hexacyanoferrate (p-VHCF) redox mediator is synthesized. It offers a high reversible specific capacity up to 128 mAh g and long cycling performance of 6000 cycles with capacity retention about 100% at a current density of 10 A g due to the enhanced hydrogen bonding network. By using this mediator, a membrane-free water electrolytic cell is built to achieve decoupled hydrogen and oxygen production. More importantly, a decoupled electrolysis system for hydrogen production and hydrazine oxidation is constructed, which realizes not only separate hydrogen generation but electricity generation through the p-VHCF-NH liquid battery. Therefore, this work enables the flexible energy conversion and storage with hydrogen production driven by solar cell at day-time and electricity output at night-time.
借助氧化还原介质的解耦电解制氢能够使两个半反应在不同的速率、时间和空间下进行，这在操作上提供了极大的灵活性。在此，合成了一种预质子化的六氰合铁酸钒（p-VHCF）氧化还原介质。由于氢键网络增强，它具有高达128 mAh g的高可逆比容量以及6000次循环的长循环性能，在10 A g的电流密度下容量保持率约为100%。通过使用这种介质，构建了一个无膜水电解槽以实现氢氧解耦生产。更重要的是，构建了一个用于制氢和肼氧化的解耦电解系统，该系统不仅实现了单独制氢，还通过p-VHCF-NH液流电池实现了发电。因此，这项工作实现了在白天由太阳能电池驱动制氢、夜间输出电力的灵活能量转换和存储。
