Synthesis of three-dimensional graphene aerogel-supported NiCo2O4 nanowires for supercapacitor application

In the present work, the NiCo2O4 (NCO) nanowires were grown on three-dimensional (3D) porous graphene aerogel (GA) through a facile two-step hydrothermal method, labeled as NCO/GA. NCO/GA obtained exhibited a high specific capacitance of 720 F g(-1) at the current density of 1 A g(-1) and good cycling performance with 84% capacitance retention after 1000 cycles. Additionally, an asymmetric supercapacitor device was fabricated by using NCO/GA as the positive electrode and activated carbon (AC) as the negative electrode. The as-prepared NCO/GA//AC device delivered a high energy density of 25.41 Wh kg(-1) at a power density of 658 W kg(-1) and good cycling stability (78% of the initial capacitance retention after 3000 cycles).