Synthesis of long chain-like nickel cobalt oxide nanoneedles-reduced graphene oxide composite material for high-performance supercapacitors

Long chain-like nickel cobalt oxide nanoneedle-reduced graphene oxide (NiCo2O4-rGO) composite materials were synthesized via a one-step hydrothermal method. The optimized mass ratio (NiCo2O4 to rGO) was defined. The electrochemical results showed NiCo2O4-rGO to possess remarkable electrochemical performance, i.e. high specific capacitance of 882 F g−1 at a current density of 1 A g−1 and good rate capability 610 F g−1 at 10 A g−1. It is noteworthy that the specific capacitance increased instead of decreasing up to 800 cycles, and only 6.2% was lost after 3000 cycles compared to the highest specific capacitance at 800 cycles. For their high specific capacitance, remarkable rate capability and excellent cycle stability, NiCo2O4-rGO composite materials show great potential in the application of supercapacitors.