微波处理时间对电化学电容器用活性炭性能的影响

摘要

采用微波对氢氧化钾活化石油焦制备的活性炭进行处理,考察了微波处理时间对活性炭的孔结构、表面(官能团)性质和电化学电容器中活性炭电化学性能的影响.结果表明:微波处理后活性炭的比容和内阻随着其比表面积和总孔容的降低而变小.和采用常规加热方式在1073K下处理1h所得活性炭相比,在700w功率下仅处理7 min所得活性炭的孔结构就具有较高的大/中孔的孔容比和较高的羰基含量；该活性炭用作电化学电容器的电极时,具有较高的能量密度和较高的能量保持率.显然,微波处理是制备电化学电容器用活性炭的一种简单而有效的方法.%Activated carbons (ACs) made from petroleum coke by KOH activation were further treated by microwaves to investigate the effect of microwave-treatment time on the pore structure,the surface properties ( functional groups)and the electrochemical properties of the as-made ACs for electrochemical capacitors (ECs).Results show that the specific capacitance and the equivalent series resistance of microwave-treated ACs become smaller with a decrease in the Brunauer-Emmett-Teller surface area and the total pore volume (vt) of the treated ACs.Compared with the AC sample heated at 1073K for lh by a conventional heating method,the AC sample treated by microwaves at 700W for only 7min has a pore size distribution with a high ( meso- and macropore volume)/vt ratio and a high carbonyl content,and exhibits a high energy density and powder density as an electrode of ECs.This has clearly shown that the microwave-treatment is a simple and efficient atproach to obtain high-tperformance ACs for ECs.