Gao Mingming, Wang Zhiyong, Liu Zaichun, Huang Ying, Wang Faxing, Wang Mingchao, Yang Sheng, Li Junke, Liu Jinxin, Qi Haoyuan, Zhang Panpan, Lu Xing, Feng Xinliang
State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074, China.
Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01069, Dresden, Germany.
Adv Mater. 2023 Oct;35(41):e2305575. doi: 10.1002/adma.202305575. Epub 2023 Aug 30.
Ammonium ions (NH ) are emerging non-metallic charge carriers for advanced electrochemical energy storage devices, due to their low cost, elemental abundance, and environmental benignity. However, finding suitable electrode materials to achieve rapid diffusion kinetics for NH storage remains a great challenge. Herein, a 2D conjugated metal-organic framework (2D c-MOF) for immobilizing iodine, as a high-performance cathode material for NH hybrid supercapacitors, is reported. Cu-HHB (HHB = hexahydroxybenzene) MOF embedded with iodine (Cu-HHB/I ) features excellent electrical conductivity, highly porous structure, and rich accessible active sites of copper-bis(dihydroxy) (Cu─O ) and iodide species, resulting in a remarkable areal capacitance of 111.7 mF cm at 0.4 mA cm . Experimental results and theoretical calculations indicate that the Cu─O species in Cu-HHB play a critical role in binding polyiodide and suppressing its dissolution, as well as contributing to a large pseudocapacitance with adsorbed iodide. In combination with a porous MXene anode, the full NH hybrid supercapacitors deliver an excellent energy density of 31.5 mWh cm and long-term cycling stability with 89.5% capacitance retention after 10 000 cycles, superior to those of the state-of-the-art NH hybrid supercapacitors. This study sheds light on the material design for NH storage, enabling the development of novel high-performance energy storage devices.
铵离子（NH ）作为先进电化学储能装置中新兴的非金属电荷载体，具有成本低、元素丰度高和环境友好等优点。然而，找到合适的电极材料以实现铵存储的快速扩散动力学仍然是一个巨大的挑战。在此，报道了一种用于固定碘的二维共轭金属有机框架（2D c-MOF），作为铵混合超级电容器的高性能阴极材料。嵌入碘的Cu-HHB（HHB = 六羟基苯）MOF（Cu-HHB/I ）具有优异的导电性、高度多孔的结构以及丰富的可及活性位点，即双（二羟基）铜（Cu─O ）和碘化物物种，在0.4 mA cm 时产生了111.7 mF cm 的显著面积电容。实验结果和理论计算表明，Cu-HHB中的Cu─O 物种在结合多碘化物并抑制其溶解方面起着关键作用，同时也有助于与吸附的碘化物形成较大的赝电容。与多孔MXene阳极相结合，全铵混合超级电容器具有31.5 mWh cm 的优异能量密度和长期循环稳定性，在10000次循环后电容保持率为89.5%，优于目前最先进的铵混合超级电容器。这项研究为铵存储的材料设计提供了思路，有助于开发新型高性能储能装置。
