β-Cyclodextrin Anchor NiCo2S4 on Graphene to Enhance Electrochemical Performance of Supercapacitor

To construct high-energy-density supercapacitors, an electrode material with high conductivity needs to be compounded with an electrode material with high capacitive properties. Herein, NiCo2S4-beta-cyclodextrin graphene (CDG) composite material formed by growing NiCo2S4 nanoparticles on graphene oxide (GO) modified with beta-Cyclodextrin (beta-CD) is reported. The modification of beta-CD can tackle the problem of agglomeration of GO and acts as a bridge to increase the binding force between NiCo2S4 nanoparticles and substrates. Combining the benefits of the modified GO and NiCo2S4, the synthesized composite electrode exhibits excellent electrochemical properties of 1325.9 F g(-1) at 1 A g(-1 )and rate capability of 55.5% as current density increases from 1 to 7 A g(-1). Moreover, the asymmetric device, fabricated with NiCo2S4-beta-CDG as the positive electrode and active carbon as the negative electrode, exhibits a maximum energy of 30.72 Wh kg(-1) at 1.28 kW kg(-1) power density.