Three electrochemical double layer capacitor (EDLC) cells (Cell X, Y and Z) made from an electrode of 90 wt. % of the multiwalled commercial carbon nanotubes, 10 wt. % of poly (vinylidene fluoride-co-hexafluoropropylene) and three different samples of electrolytes polymer electrolyte made up of a compositions of 50:50, 60:40 and 70:30 wt.% of H3PO4/PVA (in ratio) soaked in a filter paper was characterized in this study. The aim is to ascertain the disparities in performances of the cells in relation to their respective scan rates. Cyclic voltammetry (CV) measurement of cells shows a high specific capacitance of 313 Fg−1 for the scan rates 10 mV was recorded from the cell with the highest composition H3PO4/PVA ratio (i.e. 70:30 wt.%). However, when the CV of the cell was measured with different scan rates, disparities in the performance occurred, as only 94 and 174 Fg−1 was recorded at the scan rates 100 and 50 mV respectively for cell-X. The result was not different when the two other cells (60:40 and 70:30 wt. % of H3PO4/PVA) were measured at the same scan rates.
Graphenated carbon nanotubes for enhanced electrochemical double layer capacitor performance