高比表面积竹炭基活性炭的孔结构对电容性能的影响

Influence of Pore Structure on the Electrochemical Performance of High-specific-surface-area Bamboo Char-based Activated Carbon

以毛竹为炭前驱体,KOH作活化剂,制备具有高比表面积的活性炭(HSAAC)材料,考察了KOH与竹炭的质量比(碱炭比)对活性炭孔结构、吸附性能和电容性能的影响。结果表明:随着碱炭比值的增加,活性炭的比表面积、中孔容积和总孔容增大,微孔孔容先增大后减小;碘吸附值、亚甲基蓝吸附值均呈现先增大后减小的趋势,碱炭比值为4时达到最大,分别为2 168和569 mg/g。当碱炭比值为4时,可制得比表面积为2 610 m2/g、总孔容为1.24 cm3/g(其中微孔孔容0.81 cm3/g,中孔孔容0.382 cm3/g)的活性炭材料。以其为电极材料组装的电容器在30%H2SO4电解液中的比电容为206 F/g。

High-specific-surface-area activated carbon（HSAAC） was prepared from bamboo char by activation with KOH.The specific surface area and pore structure of activated carbon were characterized by nitrogen adsorption isotherm at 77K.The specific surface area,mesopore volume and total pore volume increased with the ratio of KOH to carbon.The iodine and methylene blue adsorption values of the HSAAC increased with the increased ratio of KOH to carbon at first and then decreased,at the ratio value of 4,the values reached the maximum,or 2168 and 569 mg/g respectively.Moreover the performance in charge and discharge of electric double-layer capacitor EDLC using HSAAC as electrodes and relation between specific capacitance and different factors were discussed.The results show that HSAAC sample from the ratio of KOH to carbon of 4 presented a high specific surface area（2610m2/g） and total pore volume（1.24cm3/g） and its specific capacitance reached 206F/g in 30% H2SO4 aqueous electrolytes.