1. Transition metal hydroxides@conducting MOFs on carbon nanotube yarns for ultra-stable quasi-solid-state supercapacitors with a ship-in-a-bottle architecture.
- Author
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Qingli Xu, Xia Liu, Juan Zhang, Yifei Xu, Mi Zhou, Jiaxin Li, Minzhi Du, Kun Zhang, Xiangyu Qian, Bo Xu, Xinhou Wang, and Bingjie Wang
- Abstract
Yarn-shaped supercapacitors (SCs) functionalized with pseudocapacitive materials show promise in wearable electronics. However, their development was hindered by poor electrochemical properties, especially long-term cycling stability, owing to the volumetric change during charging/discharging. Herein, we report a ship-in-a-bottle architecture on carbon nanotube yarn (CNTY) based SCs, in which transition metal hydroxide (TMH) nanoparticles (Ni(OH)
2 or Co(OH)2 ) are confined in conducting nanoporous metal-organic frameworks (MOFs, Ni3 (HITP)2 ) which anchor onto CNTY, involves the synergy of nanoconfinement and hydrogen bonding (H-bonding) network to mutually support each phase toward improved electrochemical performance. The Ni(OH)2 @Ni3 (HITP)2 @CNTY electrode possesses an areal specific capacitance of 496 mF cm-2 at 0.4 mA cm-2 due to the hierarchical structure which led to facilitated charge transport and enhanced ion storage. Moreover, the ternary CNTY-based SCs demonstrate exceptional cycle performance (90.9-92.3% capacitance retention after 10 000 cycles at 5 mA cm-2 ). Importantly, the nanoconfinement is confirmed by field emission scanning electron microscopy, transmission electron microscopy-energy dispersive spectroscopy, and energy dispersive spectroscopy, and Brunauer-Emmett-Teller and cryogenic-TEM characterization studies. The H-bonding (O/H-N) network between Ni(OH)2 and Ni3 (HITP)2 is confirmed by Fourier transform infrared spectroscopy and density functional theory calculations. Both nanoconfinement and the Hbonding network contribute to an ultra-stable Ni(OH)2 @Ni3 (HITP)2 structure due to its high durability to volumetric change caused by phase separation and structural collapse during charging/discharging. [ABSTRACT FROM AUTHOR]- Published
- 2023
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