(中南大学 冶金科学与工程学院，长沙 410083)
摘 要: 以煤焦油沥青为原料，在500 ℃下调制得到炭质微晶结构的中间相沥青。以不同粒径的中间相沥青为原料，以KOH和CO2为活化剂，采用物理−化学联合活化法制得超级电容器用高比表面积活性炭。以制备的活性炭作电极材料，以1 mol/L Et4NBF4/PC为有机电解液，考察活性炭材料的电容行为。结果表明：随着中间相沥青粒径的减小，活性炭比表面积先增大后减小；在中间相沥青粒径为150~250 µm时制备的活性炭的BET比表面积达最大值2 476 m2/g，质量比电容量最大，达到103.5 F/g。以粒径75~96 µm中间相沥青制备的活性炭表现出良好的功率特性，在1 mA充放电时，质量比电容量为87 F/g；在20 mA充放电时，质量比电容量也达到83 F/g。
关键字: 活性炭；超级电容器；中间相沥青；粒径；物理−化学联合活化
（School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:Using coal-tar pitch as raw material, the mesophase pitches with carbonaceous crystallites were produced at 500 ℃. With mesophase pitches of different particle sizes, the ultra-high surface area activated carbons of supercapacitors were prepared by chem-physical activation. Using the prepared activated carbons as electrode materials and Et4NBF4/PC solution as electrolyte, the coin type cells were assembled. The effects of distribution of particle size of mesophase pitches on the electrochemical behaviors of activated carbons were investigated. The results show that the specific surface area of activated carbons increases and then decreases with decreasing particle size of mesophase pitches, and the activated carbons prepared by mesophase pitch of 150−250 µm show the largest BET specific surface area of 2 476 m2/g. When the particle size decreases, the tep density decreases. The activated carbons prepared by mesophase pitch of 150−250 µm show the highest specific capacitance of 103.5 F/g. The activited carbons prepared by mesophase pitch of 75−96 µm show good power discharge behavior, and the specific capacitance is 87 F/g at the current of 1 mA and 83 F/g at the current of 20 mA.
Key words: activated carbon; supercapacitor; mesophase pitch; particle size; chem-physical activation
