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

Abstract

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.