Micro-crystallite carbon ( CC) was synthesized by KOH activation of carbonized petroleum coke precursors. The porous properties structure and crystallite structure were characterized by N2 adsorption-desorption, X-ray diffraction ( XRD) measurements. The capacitive behavior of CC was investigated in the electrolyte of Et4NBF4 /PC,Et4NBF4 /AN,Bu4NBF4 /PC and Bu4NBF4 /AN,respectively. Results showed that the lower potential of electric field activation ( EFA) was obtained in the solvent of AN than in PC,which was ascribed to the fact that smaller solvated ions dimension in AN facilitating the intercalation of the solvated ions into micro-crystallite interlayer. The extent of EFA was more remarkable in AN under the same operating voltage due to its lower EFA potential; and consequently,produced the higher specific capacitance. With regarding to the Bu4NBF4 and Et4NBF4,little effect of cations size on the EFA process was observed,compared with that of solvent. After charge-discharged,micro-crystallite interlayer of CC swelled,indicating that the ion intercalation occurred during the EFA. And the interlayer expansion increased to a greater extent when the dimension of intercalated-ion was larger.


micro-crystallite carbon, electric field activation, organic electrolyte

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