1. Oxalate-derived porous C-doped NiO with amorphous-crystalline heterophase for supercapacitors.
- Author
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Yue, Hong-Li, Zeng, Hong-Yan, Peng, Jin-Feng, Yan, Wei, Zhang, Kai, Luo, Chao-Wei, and Tian, Zi-Feng
- Subjects
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ENERGY density , *ENERGY storage , *CRYSTAL structure , *DENSITY functional theory , *NICKEL oxide - Abstract
The NiC 2 O 4 -derived porous C-doped NiO (C-NiO) with amorphous/crystalline heterophase was prepared via a hydrothermal route followed by calcination treatment, and the assembled hybrid supercapacitor gave a high energy density and cycle stability. [Display omitted] • Porous C-NiO with amorphous/crystalline heterophase was constructed via self-sacrificing template method. • C-doping and amorphous/crystalline heterophase had a significant effect on the electrochemical performance of the C-NiO. • Porous C-NiO calcined at a suitable temperature showed a notable electrochemical property than the NiO counterpart. • C-NiO//AC device achieved a high energy density of 49.0 Wh kg−1 at 800 W kg−1. Constructing amorphous/crystalline heterophase structure with high porosity is a promising strategy to effectively tailor the physicochemical properties of electrode materials and further improve the electrochemical performance of supercapacitors. Here, the porous C-doped NiO (C-NiO) with amorphous/crystalline heterophase grown on NF was prepared using NF as Ni source via a self-sacrificial template method. Calcining the self-sacrificial NiC 2 O 4 template at a suitable temperature (400 °C) was beneficial to the formation of porous heterophase structure with abundant cavities and cracks, resulting in high electrical conductivity and rich ion/electron-transport channels. The density functional theory (DFT) calculations further verified that in-situ C-doping could modulate the electronic structure and enhance the OH− adsorption capability. The unique porous amorphous/crystalline heterophase structure greatly accelerated electrons/ions transfer and Faradaic reaction kinetic, which effectively improved the charge storage. The C-NiO calcined at 400 °C (C-NiO (4 0 0)) displayed a markedly enhanced specific charge, outstanding rate property and excellent cycling stability. Furthermore, the hybrid supercapacitor assembled by C-NiO (4 0 0) and active carbon achieved a high energy density of 49.0 Wh kg−1 at 800 W kg−1 and excellent cycle stability (90.9 % retention at 5 A/g after 10 000 cycles). This work provided a new strategy for designing amorphous/crystalline heterophase electrode materials in high-performance energy storage. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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