经混酸HNO3/H2 SO4氧化后,煅前针状焦( GNC)转化为两种中间体,根据中间体在水中的分散能力区分为水可分散部分和水不可分散部分。这两种中间体均可经KOH活化后制得纳米多孔炭材料。通过XPS、XRD、低温N2吸脱附和TEM表征表明,在相同的KOH用量下,所得纳米多孔炭的孔结构不同,主要是由于两种中间体在表面性质和微结构方面的差异所致。以6 mol/L KOH为电解液,从水可分散中间体制得的多孔炭GNC-A10-3在40 A/g下的质量比容量为248 F/g,且倍率性能优异,C40/0.05为76%；而同样为3倍碱炭比时从水不可分散中间体制备的多孔炭GNC-R10-3在体积比电容上的电化学表现优于GNC-A10-3。
Green needle coke was oxidized by a mixture of HNO3 and H2SO4(3:7 vol/vol) acids. The resultant oxidized coke was separated into water dispersible and non-dispersible fractions, which were then activated by KOH using the same KOH/coke weight ratio to obtain two kinds of nanoporous carbons with different pore structures. The oxidized coke and the nanoporous carbons were characterized by XPS, XRD, TEM, N2 adsorption and electrochemical tests. Results indicate that, at the same KOH/coke ra-tios, the nanoporous carbons derived from the water-dispersible oxidized coke have higher mass specific capacitances and capacitance retention ratios, and lower resistances than those from the non-dispersible ones when used as an electric double layer capacitor elec-trode in 6 mol/L KOH, but the former have a lower volumetric specific capacitance than the latter.
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