2D Conjugated Metal-Organic Frameworks Embedded with Iodine for High-Performance Ammonium-Ion Hybrid Supercapacitors

Mingming Gao; Zhiyong Wang; Zaichun Liu; Ying Huang; Faxing Wang; Mingchao Wang; Sheng Yang; Junke Li; Jinxin Liu; Haoyuan Qi; Panpan Zhang; Xing Lu; Xinliang Feng

doi:10.1002/adma.202305575

2D Conjugated Metal-Organic Frameworks Embedded with Iodine for High-Performance Ammonium-Ion Hybrid Supercapacitors

Adv Mater. 2023 Oct;35(41):e2305575. doi: 10.1002/adma.202305575. Epub 2023 Aug 30.

Authors

Mingming Gao¹, Zhiyong Wang^{2

3}, Zaichun Liu⁴, Ying Huang^{1

5}, Faxing Wang², Mingchao Wang², Sheng Yang^{2

6}, Junke Li^{1

7}, Jinxin Liu², Haoyuan Qi⁸, Panpan Zhang¹, Xing Lu¹, Xinliang Feng^{2

3}

Affiliations

¹ 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.
² Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstrasse 4, 01069, Dresden, Germany.
³ Department of Synthetic Materials and Functional Devices, Max Planck Institute of Microstructure Physics, D-06120, Halle (Saale), Germany.
⁴ Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and Environment, Southeast University, Nanjing, 210096, China.
⁵ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
⁶ Frontiers Science Center for Transformative Molecules School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
⁷ School of Environmental Science and Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, 430074, China.
⁸ Central Facility of Electron Microscopy Electron Microscopy Group of Materials Science, Universität Ulm, 89081, Ulm, Germany.

PMID: 37608530
DOI: 10.1002/adma.202305575

Abstract

Ammonium ions (NH₄ ⁺ ) 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 NH₄ ⁺ 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 NH₄ ⁺ hybrid supercapacitors, is reported. Cu-HHB (HHB = hexahydroxybenzene) MOF embedded with iodine (Cu-HHB/I₂ ) features excellent electrical conductivity, highly porous structure, and rich accessible active sites of copper-bis(dihydroxy) (Cu─O₄ ) and iodide species, resulting in a remarkable areal capacitance of 111.7 mF cm^-2 at 0.4 mA cm^-2 . Experimental results and theoretical calculations indicate that the Cu─O₄ 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 NH₄ ⁺ hybrid supercapacitors deliver an excellent energy density of 31.5 mWh cm^-2 and long-term cycling stability with 89.5% capacitance retention after 10 000 cycles, superior to those of the state-of-the-art NH₄ ⁺ hybrid supercapacitors. This study sheds light on the material design for NH₄ ⁺ storage, enabling the development of novel high-performance energy storage devices.

Keywords: 2D conjugated metal-organic frameworks; I2; NH4+; cathode; hybrid supercapacitors.

Abstract

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