Synthesis of NiCl2-enhanced carbon electrodes from oil palm fronds (Elaeis Guinness Jacq) for high-performance supercapacitor

The performance of supercapacitors can be enhanced by adding catalysts that improve graphitization and electrical conductivity. This study uses NiCl2 as a catalyst in carbon electrodes from oil palm fronds (OPF) to evaluate its effect on supercapacitor performance. The OPF was converted into activated carbon through pre-carbonization, chemical activation with KOH, and physical activation with CO2. NiCl2 catalysts at 0.1 M and 0.2 M concentrations were added during the chemical activation, enhancing nanofibril formation. OPF-01 achieved the best graphitization with a specific surface area of 688.80 m2g- 1. The OPF-01 demonstrated the highest specific capacitance at 359 Fg- 1 and maintained strong performance at a 10 mVs- 1 scan rate (221 Fg- 1), outperforming OPF and OPF-02 electrodes. However, at a NiCl2 concentration of 0.2 M, OPF-02 faced aggregation issues, causing pore blockage and reduced electrochemical performance. These results suggest that NiCl2 is an effective catalyst for enhancing carbon-based electrodes in supercapacitors, with optimal performance at a 0.1 M concentration.