超级电容器用马尾藻基超级活性炭的制备及其电化学性能

Preparation and Electrochemical Property of Gulfweed-based Super Activated Carbon for Supercapacitor

以马尾藻为原料,采用KOH活化法制备用于超级电容器的生物质基超级活性炭。制备的超级活性炭不仅比表面积巨大,孔隙结构丰富,而且以海藻作为前驱体原料明显降低了活性炭的生产成本。采用单因素实验法分析了浸渍比、活化温度和活化时间对马尾藻基活性炭孔隙结构(比表面积、孔容及孔径分布等)的影响,探索了制备马尾藻基超级活性炭的最佳工艺条件,并研究了所制活性炭用于制备超级电容器时的电化学性能。采用N2吸附-解吸附、SEM、XRD,恒电流充放电以及循环伏安法等表征手段考察超级活性炭样品的比表面积,孔结构以及电化学性能。实验结果表明,制备马尾藻基超级活性炭的最佳工艺条件为:浸渍比4∶1,活化时间120min,活化温度800℃。在该实验条件下制得的活性炭比表面积高达2926m2/g,孔容高达1.536cm3/g,且所有活性炭的孔径大小几乎全部分布在4nm以内,孔径分布均匀。制备的超级电容器以6mol/L的KOH为电解液时,其比电容高达358.5F/g,表现出良好的电化学性能。

Gulfweed was used as raw material,and KOH activation method was adopted for producing activated carbons with high specific surface area.The prepared super activated carbon not only has large specific surface area,rich pore structure,but also reduces the production cost of activated carbon by using algae as precursor material.In order to explore the experimental approaches and technological conditions,single factor method was used to analyze the influence of impregnation ratio,activation time and activation temperature on specific surface area,pore structure and surface properties,and the electrochemical performance of super-capacitor based on the prepared activated carbon was studied.Measurements such as N2 adsorption,XRD,SEM,constant current charge-discharge techniques,and the cyclic voltammetry were carried out to investigate specific surface area,pore structure and electrochemical performance.The results show：the best preparation condition is concluded as：impregnation ratio at 4∶1,activation time for 120 min and activation temperature at 800℃,on the occasion,the largest specific surface area is 2926 m^2/g,and the biggest pore volume is 1.536 cm^3/g with all the pore diameters almost under 4 nm evenly.The super-capacitor has a large specific capacitance as 358.5 F/g in the 6 mol/L KOH electrolyte,which means a very good performance.