A three-dimensional Co5-cluster-based MOF as a high-performance electrode material for supercapacitor

• Published in: Ionics Vol. 26; no. 10; pp. 5189 - 5197
• Main Authors: Gao, Gexiang, Wang, Xianmei, Ma, Yanwei, Rong, Hongren, Lai, Lifang, Liu, Qi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-10-2020; Springer Nature B.V
• Subjects: Capacitance; Chemistry; Chemistry and Materials Science; Clusters; Condensed Matter Physics; Electrochemistry; Electrode materials; Electrodes; Energy Storage; Flux density; Infrared analysis; Metal-organic frameworks; Optical and Electronic Materials; Original Paper; Photoelectrons; Porosity; Renewable and Green Energy; Spectrum analysis; Supercapacitors; Thermogravimetric analysis; X ray photoelectron spectroscopy; X ray powder diffraction; Supercapacitors; Electrode materials; MOFs; Cobalt compound
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-020-03649-8

Searching for new metal–organic frameworks with excellent electrochemical performances is considerably important to advance their application in supercapacitors. Herein, a Co
5
-cluster-based three-dimensional (3D) metal–organic framework (Co
5
(OH)
2
(O
2
CCH
3
)
8
·2H
2
O, Co
5
-MOF) was synthesized and characterized by X-ray powder diffraction, infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, and nitrogen adsorption–desorption. The Co
5
-MOF as an electrode material of supercapacitors was investigated for the first time. In a three-electrode system, the highest specific capacitance for the Co
5
-MOF electrode is 867 F g
−1
at 1 A g
−1
, and the specific capacitance still remains 90.3% of the original specific capacitance after 3000 cycles, displaying its good long-term cycle stability. The asymmetric supercapacitor based on the Co
5
-MOF as the positive electrode and the rGO as the negative electrode presented a high energy density of 18 W h kg
−1
at a power density of 0.7 kW kg
−1
. The high supercapacitive properties may be attributed to the nano-sized Co
5
-MOF particles with larger specific surface area and pore structure.
Graphical abstract
Co
5
-cluster-based MOF was synthesized by the solvothermal reaction, which displays excellent cyclic stability, better rate capability, and higher specific capacity as an electrode material for supercapacitors.