Adjustment of Nickel Cobalt Sulfide morphology with double solvents for its excellent charge-discharge performance

Abstract The double solvothermal method is used for the preparation of Nickel Cobalt Sulfide and its composite for good-performance supercapacitors. Their morphologies are adjusted by changing ratio of isopropanol and ethylene glycol in mixed solvents. It is found that honeycomb-like morphology of NiCo 2 S 4 can be prepared. And after addition of graphene, the honeycomb-like NiCo 2 S 4 /rGO composite are obtained, which delivered an high capacity of 1244 F/g at 1 A/g and 960 F/g even at 20 A/g. Its capacitance retention reaches 90.91% at 5 A/g after 1000 cycles, exhibiting an excellent charge-discharge performance.