Roles of pore structure and type of electrolyte on the capacitive performance of activated carbons used in electrical double-layer capacitors

Capacitive performances of the microporous activated carbon (AC) and the mesoporous AC, having a comparable BET specific surface area, were evaluated for the use in the electrodes of electrical double-layer capacitors (EDLCs). The propylene carbonate-based organic electrolytes and the ionic liquid electrolyte were used in the EDLC cells. The gravimetric specific capacitance of the microporous AC was higher than that of the mesoporous AC when the organic electrolyte was used, while the difference between those ACs diminished when the ionic liquid was used. The results obtained revealed that the capacitive performances of ACs were influenced by the affinity between the pore structure and the electrolyte, and the applied voltage.