A New Approach towards Improving the Specific Energy and Specific Power of a Carbon-Based Supercapacitor using Platinum-Nanoparticles on Etched Stainless Steel Current Collector

We report an improved performance of a carbon-based supercapacitor using etched stainless steel (SS) current collector deposited with platinum nanoparticles (PtNs) over bare SS current collector/un-etched SS current collector deposited with PtNs. The PtNs grown on the etched surface of the current collectors provides a better contact with the surface of activated carbon monoliths electrode prepared from pre-carbonized fibres of oil palm empty fruit bunches. X-ray diffraction, field-emission scanning electron microscopy, the energy dispersive X-ray analysis, and X-ray photoelectron spectroscopy were employed to investigate the different properties of bare SS current collector and the modified current collector. Electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge results consistently suggest that the deposition of PtNs on the etched surface of the current collector causes an increase in specific capacitance of 10% (from 105 to 115 F g−1), 4% (from 141 to 146 F g−1) and 6% (from 142 to 150 F g−1) respectively. Correspondingly, the specific energy increases from 4.12 to 4.51 Wh kg−1 and specific power from 173 to 196 W kg−1. Also EIS and GCD results respectively show a decrease of 47% (from 1.332 to 0.710 Ω) and 44% (from 1.75 to 0.974 Ω) in equivalent series resistance.