(中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 以煤焦油瀝青為原料，在500 ℃下調(diào)制得到炭質(zhì)微晶結(jié)構(gòu)的中間相瀝青。以不同粒徑的中間相瀝青為原料，以KOH和CO2為活化劑，采用物理−化學(xué)聯(lián)合活化法制得超級電容器用高比表面積活性炭。以制備的活性炭作電極材料，以1 mol/L Et4NBF4/PC為有機(jī)電解液，考察活性炭材料的電容行為。結(jié)果表明：隨著中間相瀝青粒徑的減小，活性炭比表面積先增大后減小；在中間相瀝青粒徑為150~250 µm時制備的活性炭的BET比表面積達(dá)最大值2 476 m2/g，質(zhì)量比電容量最大，達(dá)到103.5 F/g。以粒徑75~96 µm中間相瀝青制備的活性炭表現(xiàn)出良好的功率特性，在1 mA充放電時，質(zhì)量比電容量為87 F/g；在20 mA充放電時，質(zhì)量比電容量也達(dá)到83 F/g。
關(guān)鍵字: 活性炭；超級電容器；中間相瀝青；粒徑；物理−化學(xué)聯(lián)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
