High-performance hybrid supercapacitors based on MOF-derived hollow ternary chalcogenides

In-situ growth of hybrid nanostructures composed of hollow transition metal chalcogenides has attracted increasing attention for the fabrication of high-performance hybrid supercapacitors (HSCs). Herein, we report the binder-free design of hierarchical ternary Cu(Co-Ni)2S4 nanotubes on nickel foam (Cu(Co-Ni)2S4 NTs/Ni foam) using synchronous etching and multi-ion doping enabled metal-organic framework (MOF) precursors. The MOF-derived hollow structured Cu(Co-Ni)2S4 NTs/Ni foam electrode unveils an excellent battery-type redox kinetics with highest areal and specific capacities of Qac: 382.1 µAh/cm2 and Qsc:181.9 mAh/g, respectively at a current density of 2 mA/cm2 with good cycling stability in 1 M KOH electrolyte. With the large electroactive area and superior electrochemical conductivity, the hierarchical composite electrode offers much space to grasp huge volume of charges, thus enabling an excellent energy storage performance. By integrating battery-type Cu(Co-Ni)2S4 NTs/Ni foam as a positive electrode with porous carbon as a capacitive-type electrode, a prototype HSC device is assembled. Along with high energy and power densities of 0.27 mWh/cm2 and 21.75 mW/cm2, the fabricated prototype device retains excellent cyclability with an energy efficiency of 95.8%. Capitalizing high energy storage properties of HSC, an assembled self-powered station consisting of HSC and solar cell further illustrates its practical applicability for renewable energy applications.