Facile hydrothermal synthesis of NiCo2O4- decorated filter carbon as electrodes for high performance asymmetric supercapacitors.

Abstract A simple hydrothermal method is developed for the growth of NiCo 2 O 4 nano-needle arrays on a filter paper carbon (FC) substrate for use as a high performance electrode for supercapacitors. The as-synthesized NiCo 2 O 4 /C composites exhibited high specific capacitance (995.2 F g−1 at a current density of 10 A g−1) and excellent cycling performance (no capacitance loss after 3000 cycles). The 3D framework of the FC substrate not only prevents the aggregation of NiCo 2 O 4 nanoparticles, but also improves its electrical conductivity, thus leading to excellent electrochemical performance. Moreover, an asymmetric supercapacitor was assembled by using the NiCo 2 O 4 /C composites and activated carbon as the positive and negative electrode, respectively, and provided a maximum energy density of 20.87 Wh kg−1 at a power density of 374.6 W kg−1 and a maximum power density of 7.48 kW kg−1 at an energy density of 11.43 Wh kg−1 within a potential window of 0–1.5 V, demonstrating the potential of the composites for use in high performance energy storage systems. Highlights • Filter paper derived carbon (FC)/NiCo 2 O 4 was prepared by hydrothermal method. • The FC with open channels increased the electron and ion transport rates. • The FC-based supercapacitor exhibited good capacity and cycling stability. [ABSTRACT FROM AUTHOR]