Hierarchically Developed Ni(OH) 2 @MgCo 2 O 4 Nanosheet Composites for Boosting Supercapacitor Performance.

MgCo 2 O 4 nanomaterial is thought to be a promising candidate for renewable energy storage and conversions. Nevertheless, the poor stability performances and small specific areas of transition-metal oxides remain a challenge for supercapacitor (SC) device applications. In this study, sheet-like Ni(OH) 2 @MgCo 2 O 4 composites were hierarchically developed on nickel foam (NF) using the facile hydrothermal process with calcination technology, under carbonization reactions. The combination of the carbon-amorphous layer and porous Ni(OH) 2 nanoparticles was anticipated to enhance the stability performances and energy kinetics. The Ni(OH) 2 @MgCo 2 O 4 nanosheet composite achieved a superior specific capacitance of 1287 F g -1 at a current value of 1 A g -1 , which is higher than that of pure Ni(OH) 2 nanoparticles and MgCo 2 O 4 nanoflake samples. At a current density of 5 A g -1 , the Ni(OH) 2 @MgCo 2 O 4 nanosheet composite delivered an outstanding cycling stability of 85.6%, which it retained over 3500 long cycles with an excellent rate of capacity of 74.5% at 20 A g -1 . These outcomes indicate that such a Ni(OH) 2 @MgCo 2 O 4 nanosheet composite is a good contender as a novel battery-type electrode material for high-performance SCs.