Marigold micro-flower like NiCo 2 O 4 grown on flexible stainless-steel mesh as an electrode for supercapacitors.

Nanostructured NiCo 2 O 4 is a promising material for energy storage systems. Herein, we report the binder-free deposition of porous marigold micro-flower like NiCo 2 O 4 (PNCO) on the flexible stainless-steel mesh (FSSM) as (PNCO@FSSM) electrode by simple chemical bath deposition. The SEM and EDS analysis revealed the marigold micro-flowers like morphology of NiCo 2 O 4 and its elemental composition. The porous nature of the electrode is supported by the BET surface area (100.47 m 2 g -1 ) and BJH pore size diameter (∼1.8 nm) analysis. This PNCO@FSSM electrode demonstrated a specific capacitance of 530 F g -1 at a high current density of 6 mA cm -2 and revealed 90.5% retention of specific capacitance after 3000 cycles. The asymmetric supercapacitor device NiCo 2 O 4 //rGO within a voltage window of 1.4 V delivered a maximum energy density of 41.66 W h kg -1 at a power density of 3000 W kg -1 . The cyclic stability study of this device revealed 73.33% capacitance retention after 2000 cycles. These results indicate that the porous NiCo 2 O 4 micro-flowers electrode is a promising functional material for the energy storage device.