共聚炭化法制备多孔炭材料及其电容性能研究

采用酚醛树脂(PF)为热稳定聚合物, 端环氧基的聚合物(QS)为热不稳定聚合物, 利用聚合物共聚炭化法制备多孔炭。经红外光谱分析及热重分析证实, 在酚醛树脂与QS的共聚固化物中, QS链段上的环氧基与酚醛树脂链段上的酚羟基发生反应生成醚键, QS接枝到酚醛树脂的链段上。BET比表面积、孔结构和电化学性能分析表明: 在共聚固化物PF/QS的炭化过程中, QS的热解逸出能起到造孔作用, 并随着QS用量的增加多孔炭的比表面积先增大后减小。QS加入量为15%的多孔炭具有最大的比表面积609.0 m²/g、总孔容0.28 cm³/g和微孔孔容0.22 cm³/g, 与聚合物共混炭化法相比, 在相同热不稳定聚合物加入量条件下, 多孔炭的比表面积和孔容都有所提高。该多孔炭电极在30wt% KOH电解液中的比电容达177.5 F/g, 具有良好的电容特性。

Preparation of Porous Carbon by Copolymerization for Electric Double-layer Capacitors

Porous carbons were prepared by chemical blending using phenolic resin (PF) and epoxy-terminated prepolymer (QS) as carbon precursor and thermally decomposable polymer, respectively. Chemical reaction of PF with QS was manifested by FT-IR spectra and a higher decomposition temperature of QS in TG curves. In the curing reaction, epoxy groups of QS reacts with the phenolic hydroxyl of PF to form ether linkage. The influences of the content of QS on specific surface area, pore structure and electrochemical performance were investigated. As the content of QS increases, the specific surface area, total pore volume and micropore volume increases firstly and then decreases, reaching the maximum value of 609.0 m²/g, 0.28 cm³/g and 0.22 cm³/g, respectively when w(QS)/w(PF)=15%. The performances of prepared samples are better than that of porous carbon prepared by polymer blend method at the same condition. When the porous carbon used as the electrodes in electric double layer capacitor (EDLC), a satisfied speci?c capacitance of 177.5 F/g in 30wt% KOH aqueous electrolytes is acquired and the capacitance maintenance achieves 78% when the current density increases to 20 mA/cm².