Effect of mesoporosity on specific capacitance of carbons

The study compares the structural and electrochemical properties of 12 porous carbons based on phenolic resins, using both aqueous (H₂SO₄) and aprotic ((C₂H₅)₄NBF₄ in acetonitrile) electrolytes. It appears that they fit into the general pattern observed for other carbons. The present carbons have micropore volumes varying between 0.29 and 0.66 cm³ g⁻¹ and average pore widths L_o between 0.62 and 1.23 nm. Five samples are exclusively microporous, whereas seven also display a relatively important mesoporosity. This allows a direct comparison between pairs of carbons with similar micropore systems, with and without mesopores, in order to assess the role of mesoporosity in the electrochemical properties. It appears that mesopores have only a limited influence on the decrease in capacitance at high current density as opposed to earlier assumptions.