A Cu4 cluster-based MOF as a supercapacitor electrode material with ultrahigh capacitance

Abstract

Developing new pristine metal-organic framework (MOF)-based electrode material for high-performance supercapacitors is a considerable attractive task. Herein, a Cu4 cluster-based three-dimensional (3D) MOF ([Cu4(μ3-OH)2(atrz)2(1,3-BDC)3]·2H2O, Cu-atrz-BDC; atrz, 4-amino-1,2,4-triazole; 1,3-H2BDC, 1,3-benzenedicarboxylic acid) was synthesized and characterized by infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, nitrogen adsorption-desorption, scanning electron microscopy, and X-ray photoelectron spectroscopy. The Cu-atrz-BDC firstly was used as an electrode material for supercapacitor. In a three-electrode system, the Cu-atrz-BDC electrode exhibited ultrahigh specific capacitance of 5525 F g−1 at 1 A g−1 and its specific capacitance can also keep about 886 F g−1 after 1000 cycles at 3 A g−1. Importantly, the Cu-atrz-BDC as the positive electrode and the rGO as the negative electrode were assembled into an asymmetric supercapacitor with excellent cycling stability, displaying the maximum energy density of 9.96 Wh kg−1 at a power density of 0.81 kW kg−1. The high supercapacitive performance might be ascribed to its porous three-dimensional structure, the nanosized particles, and better conductivity.