Fabrication of 3D micro-flower structure of ternary Ni-Co-Cu hydroxide based on Co-MOF for advanced asymmetric supercapacitors

The materials possessing electrochemical activity and good structural stability become a candidate for electrode materials of energy storage device. For supercapacitors, building an electrode with electrochemical activity and good structural stability can efficiently enhance specific capacity and energy density. However, their broad utility is constrained by the expensive synthesis route. Using the zeolitic imidazolate framework-67 as a sacrificial template, we devise a low-cost and straightforward synthetic route of nickel-cobalt-copper trimetallic hydroxides derived from MOFs. A micro-flower-like structure made of various metallic hydroxides can facilitate electron/ion transfer while maintaining structural integrity. The as-prepared sample displayed superior electrochemical properties (1122.97 F/g at 1 A/g) and excellent rate performance (92.69% retention at 20 A/g) for use in supercapacitors. The asymmetric supercapacitor (Ni1CoCu0.5-OH//AC) was also created and synthesized, showing exceptional capacitance of 168.5 F/g at 0.5 A/g, excellent energy density of 52.66 Wh/kg, and maximum power density of 7500 W/kg. This research offers new opportunities for creating more desirable electrode materials as well as insight into the synthesis of various metallic hydroxides.