Coral-like cobalt-nickel sulfide/cobalt-nickel silicate composite with core-shell structure for hybrid supercapacitors

Transition metal silicates (TMSs) have demonstrated significant potential in the realm of electrochemical energy storage. Despite this promise, the practical utilization of TMSs has not met anticipated benchmarks. A viable approach to enhance the electrochemical performance of composite electrode materials is through the integration of diverse Faradic components. Herein, a coral-like cobalt–nickel sulfide/cobalt–nickel silicate composite (CHOAMCN-S) with core–shell structure was designed by in-situ cladding of cobalt nickel sulfide on the outside of the cobalt nickel silicate material. The synergistic interaction between these two components significantly enhanced the overall charge storage capacity of the CHOAMCN-S composite by facilitating efficient charge redistribution. As expected, CHOAMCN-S displayed considerable specific capacity of 2390 F·g −1 at 0.5 A·g −1 and excellent cycling stability of 93 % after 20,000 cycles at 20 A·g −1 . Further, the hybrid supercapacitor (HSC) assembled with CHOAMCN-S and activated carbon (AC) achieved 64.7 Wh·kg −1 at 403 W·kg −1 . Simultaneously, the hybrid supercapacitor (HSC) demonstrated remarkable performance metrics, as evidenced by its ability to effectively power light bulbs and diodes. This exceptional performance underscores the promising potential for achieving high energy density through the synergistic integration of diverse Faradic components.