High temperature carbon-carbon supercapacitor using ionic liquid as electrolyte

摘要

This paper presents results about the electrochemical and cycling characterizations of a supercapacitor cell using a microporous activated carbon as the active material and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR_(14)TFSI) ionic liquid as the electrolyte. The microporous activated carbon exhibited a specific capacitance of 60 F g~(-1) measured from the three-electrode cyclic voltammetry experiments at 20 mV s~(-1) scan rate, with a maximum operating potential range of 4.5 V at 60℃. A coin cell assembled with this microporous activated carbon and PYR_(14)TFSI as the electrolyte was cycled for 40,000 cycles without any change of cell resistance (9 Ω cm~2), at a voltage up to 3.5 V at 60℃, demonstrating a high cycling stability as well as a high stable specific capacitance in this ionic liquid electrolyte. These high performances make now this type of supercapacitor suitable for high temperature applications (≥ 60℃).