Marigold micro-flower like NiCo2O4 grown on flexible stainless-steel mesh as an electrode for supercapacitors

Nanostructured NiCo2O4 is a promising material for energy storage systems. Herein, we report the binder-free deposition of porous marigold micro-flower like NiCo2O4 (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 NiCo2O4 and its elemental composition. The porous nature of the electrode is supported by the BET surface area (100.47 m2 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 NiCo2O4//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 NiCo2O4 micro-flowers electrode is a promising functional material for the energy storage device.