Binder free Ni-foam bolstered NiCo2S4/NiCo-MOF composite for enhanced supercapacitor applications

Priyanka Wadhwa¹Pratap Singh²Robin Saini²Karuna Jain³Neeraj Dilbhaghi¹Rahul Kumar Dhaka³Neelam S Sangwan²Manoj Kumar Singh²Sandeep Kumar^4*

• ¹Guru Jambheshwar University of Science and Technology, Hisar, Haryana, India
• ²Central University of Haryana, Haryana, Haryana, India
• ³Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana, India
• ⁴Punjab engineering college (Deemed to be University), Chandigarh, India

The efficient electrode materials for energy storage devices fabrication are in demand to address the revitalizing global energy needs. In this research work, novel binder free electrodes based on NiCo2S4 (NCS) and Ni-Co-Metal-Organic Framework (MOF).Electrodes were engineered using a convenient dual-step solvothermal method employing Nickel (Ni) foam as a current collector. The electrode material was characterized for crystallinity and crystal phase purity (pXRD), morphology (FESEM), and surface elemental profiling (XPS). Cyclic Voltammetry (CV) for redox behavior analysis, Galvanostatic Charge Discharge (GCD) for capacitance evaluation, and Electrochemical Impedance Spectroscopy (EIS) for charge transfer resistance were employed to investigate the electrochemical performance. The composite active electrode materials NCS/NCM@NF exhibited high specific capacitance (2150.3 F g -1 ) at a scan rate of 2mVs -1 with KOH (6M) as electrolyte.The fabricated electrode was highly reusable; approximately 89 % of capacitance retained even after 10000 cycles of usage (charge-discharge). The composite material has high energy density, Ed (199.6 W h Kg -1 ) and power density, Pd (1500.2 W kg -1 ). The charge transfer resistance (Rct, 790 mΩ) and solution resistance (Rs, 1.52 Ω), computed through EIS, being low show a quick charge transfer at the interface making the composite material suitable for supercapacitor application.