Activated carbon materials were prepared through physical activation(CO2activation)and chemical activation(KOH activation)of sweet potato starch,respectively.The effects of the CO2/KOH activation temperature and time on the porous structures of activated carbon obtained were investigated by means of scanning electron microscopy,X-ray diffraction,and specific surface area measurement.For the KO H activation method,the optimized carbon prepared at the carbon/alkali ratio of 1:3,carbonization temperature of 800℃,and activated time of 5h possesses the highest specific surface area of 1590m2/g and mesoporosity of 20.3%.For the CO2activation method,the optimal carbon obtained at the carbonization temperature of 800℃and activated time of 2h exhibits a specific surface area of 1054m2/g and mesoporosity of 62.0%.The as-prepared two activated carbon exhibit the typical electrochemical double layer capacitive behavior in 6M KOH electrolyte and their specific capacitance at the current density of 5A/g are 143F/g and 187F/g,respectively.%以红薯为原料分别采用物理活化(CO2活化)和化学活化(KO H活化)法制备活性炭.研究了不同活化温度和时间所得活性炭的比表面积和孔结构特征,并结合扫描电子显微镜、X射线衍射仪、比表面积分析仪等对其进行测试和表征.结果表明,KOH 活化法在碳碱比为1:3、活化温度为800℃、活化时间为5h时比表面积最高,达到1590m2/g,介孔率为20.3%;CO2活化法在800℃、活化2h时比表面积较高,为1054m2/g,介孔率可达62.0%.将该两组活性炭用作超级电容器电极材料时,以6M KOH作电解质表现出了典型的双电层电容器的特征,在5A/g的电流密度下,两者的比电容量分别为143F/g和187F/g.
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