煤抽提物基炭材料的制备及其电化学性能

PREPARATION AND ELECTROCHEMICAL PROPERTIES OF THE COAL EXTRACT-BASED CARBON MATERIALS

以某煤抽提物为前驱体,在N_2保护下,分别在600℃,700℃,800℃和900℃炭化制备四种电化学电容器用炭材料,分别记作:FKC600,FKC700,FKC800和FKC900.采用低温N_2吸附法对各炭材料的孔结构进行表征,并通过恒流充放电和循环伏安测试研究其电化学性能.结果表明:随着炭化温度的升高,四种炭材料的比表面积和总孔容逐渐增大,但孔结构总体上发育不完善,FKC600和FKC700的比表面积仅为14 m^2·g^(-1)左右.四种炭材料在3 mo1/L KOH电解液中具有良好的充放电可逆性和典型的双电层电容特性;其体积比电容和面积比电容随炭化温度的升高呈现先增大后减小的趋势,FKC700的体积比电容高达112.4 F·cm^(-3),FKC600和FKC700的面积比电容大于800μF·cm^(-2),远远高于炭材料的理论储能极限.

With a coal extract as precursor,four kinds of carbon materials （named FKC600,FKC700,FKC800,FKC900） used for supercapacitor electrode were successfully prepared by using carbonization method at 600 ℃,700 ℃,800 ℃,900 ℃ under the protection of nitrogen,respectively.The pore structure of as-obtained carbon materials were characterized by hypothermia nitrogen adsorption.The electrochemical properties of supercapacitors with carbon materials as electrodes were studied by using galvanostatic charge-discharge and cyclic voltammetry techniques.The results showed that,with carbonization temperature increasing,the specific surface area and total pore volume of the four carbon materials increased gradually,but the overall pore structures were underdeveloped.The specific surface area of the FKC600 and FKC700 only reached about 14 m2·g-1.Four carbon materials in 3 mol/L KOH electrolyte had a good charge-discharge reversibility,behaved a typical double layer capacitance.The volumetric specific capacitance and area capacitance first increased and then decreased with carbonization temperature increasing.The volumetric specific capacitance of FKC700 reached up to 112.4 F·cm-3,the area specific capacitance of FKC600 and FKC700 were more than 800 μF/cm2 much higher than the theoretical storage limit of carbon materials.