Effects of electrode layer composition/thickness and electrolyte concentration on both specific capacitance and energy density of supercapacitor

In this paper, the effects of several experimental conditions, such as electrode layer binder content, conducting carbon content, electrode layer thickness, as well as electrolyte concentration, on both the specific capacitance and energy density of a BP2000 carbon-based supercapacitor are investigated using both cyclic voltammetry and a galvanic charging–discharging curve. The electrode layer studied contains Super C45 carbon as the conducting additive, PTFE as the binder, and Na2SO4 as the aqueous electrolyte, respectively. With the purpose of optimizing the electrode layer structure, 15 wt% of Super C45 and 5 wt% of PTFE in the electrode layer with a thickness of 100 μm, are found to be the best composition in terms of improving both specific capacitance and energy density. Regarding the effect of electrolyte concentration in the range of 0.1–1.0 M, 0.5 M of Na2SO4 gives the best performance.

► The effects of carbon electrode layer and electrolyte concentration on both the specific capacitance and energy density are investigated.
► Cyclic voltammetry and a galvanic charging–discharging curve are used in the investigation.
► 15 wt% of Super C45 and 5 wt% of PTFE in the electrode layer with a thickness of 100 μm, are found to be the best composition.
► The electrolyte concentration in the range of 0.1–1.0 M, 0.5 M of Na2SO4 gives the best performance.