Electrochemical Properties of Pillared Carbons for the Electrode of Electric Double Layer Capacitor

Microporous pillared carbon prepared from graphite oxide silylated with methyltrichlorosilane for three times was tested for the electrode of electric double layer capacitor. The capacitance gradually increased as the applied potential increased and reached 74 F/g at an initial stage of cycling in 1 M triethylmethylammonium tetrafuluor-oborate (TEMABF 4 ) -propylene carbonate (PC) when it is used as a positive electrode, independent of the counter cations or existence of solvent molecules. This value indicated that two BF4- ions were accommodated in a micropore of it. On the other hand, only one ion per micropore was stored when larger ions such as TEMA(+), bis(trifluoromethanesulfone) imide (TFSI-) and ethylmethylimmidazorium (EMI+) ions were used. These results indicated that two larger ions can not be accommodated in a micropore of pillared carbon. (C) The Electrochemical Society of Japan, All rights reserved.