The volumetric capacitance of microporous carbons in organic electrolyte

Abstract

The study of 26 microporous carbons with average pore widths L_o between 0.7 and 1.8 nm shows that the volume-related capacitance C_mi (F cm^− 3) in the organic electrolyte (C₂H₅)₄NBF₄/acetonitrile is an inverse function of the average micropore width L_o. This means that for a given micropore volume W_o, the gravimetric capacitance C (F g^− 1) is larger for carbons with smaller pores due to the higher surface to volume ratio. Furthermore, the increase of C_mi (F cm^− 3) in smaller pores suggests that the surface-related capacitance C (F m^− 2) should be relatively constant in slit-shaped micropores. This has important technological consequences for the design of carbon-based supercapacitors.