Formation of hierarchical core-shell hollow Co3S4@NiCo2S4 nanocages with enhanced performance for supercapacitor

Metal-organic frameworks (MOFs) have sparked considerable interest as prospective metal precursors or sacrificial templates to design high-performance supercapacitor electrode materials. Here Co 3 S 4 @NiCo 2 S 4 nanocages supercapacitor electrode material with a dual-core layer hollow structure was successfully constructed through an appropriate ion-exchange strategy of MOFs and the subsequent vulcanization treatment. The specific capacitance of the Co 3 S 4 @NiCo 2 S 4 electrode was up to 1202 F g −1 at 1 A g −1 and could still attain 80% initial capacity at 10 A g −1 . The integrated Co 3 S 4 @NiCo 2 S 4 //AC asymmetric supercapacitor achieved 58 Wh kg −1 of energy density at 750 W kg −1 of power density. The asymmetric supercapacitor retained 81.8% of its capacitance after 10,000 galvanostatic charge-discharge cycles. In this study, the individual nanostructure and excellent electrochemical properties of Co 3 S 4 @NiCo 2 S 4 nanocages provide a rational strategy for developing high-energy-density supercapacitor electrode materials based on MOFs derivatives.