用不同温度热处理腐植酸基活性炭制备超级电容器用炭电极材料,在3 mol/L的KOH电解液中研究了表面含氧官能团对电极电化学性能的影响。采用低温N2吸附、元素分析和傅里叶红外光谱(FTIR)表征活性炭孔结构和表面性质。研究结果表明,不同温度热处理后活性炭的比表面积和孔容变化不大,表面含氧量减小,且活性炭表面的含氧官能团种类含量发生了变化。由FTIR的分析结果判断,活性炭电极材料的漏电和贮存性能主要是受表面含氧官能团醛基、羧基、羰基和羟基的影响。在大电流充放电时,高温处理后炭电极比电容的衰减率明显低于处理前。
The electrodes for electric double-layer capacitors (EDLCs) supercapacitor were prepared by the heat treatment of humic acid activated carbon at different temperatures. The effects of the surface oxygen functional groups on the electrochemical performance were studied in 3 mol/L KOH electrolyte. The porous structure and surface properties of the activated carbon were investigated by low temperature nitrogen adsorption, element analysis and FTIR, respectively. The results show that the surface area and pore volume change little, surface oxygen content reduces and surface oxygen groups species change after heat treatment at different temperatures. FTIR analysis indicate that the leakage and storage performance are mainly affected by the surface oxygen functional groups such as aldehyde,carboxyl, carbonyl and hydroxyl group. In the large current charge and discharge and after high temperature treatment, the decay rate of specific capacitance of the carbon electrode is significantly lower than before treatment.