PF与PVB共混炭化制备双电层电容器用多孔炭材料的研究

STUDY ON THE PERFORMANCE OF POROUS CARBON PREPARED BY CARBONIZATION POLYMER BLENDS MADE OF PF AND PVB AND FOR THE EDLC

以酚醛树脂(PF)为原料,聚乙烯醇缩丁醛(PVB)为成孔剂,采用聚合物共混炭化法制备双电层电容器 用多孔炭材料。通过热重(TG)和差热(DTA)分析,初步探讨了单一PF、PVB和PF与PVB的共混物在炭化 过程中的热解行为。考察了炭化温度和PF／PVB质量比对所得多孔炭的收率、BET比表面积、孔径分布和比 电容的影响,并进一步探讨了以这种多孔炭材料作电极的模拟双电层电容器的充放电特性。结果表明,共混 聚合物中PF与PVB是不相容的,热解过程各自独立进行,但存在一定的协同作用。随着炭化温度的升高, 所得多孔炭的收率下降,比表面积、总孔容积和比电容先增大后减小,在800℃时达到最大值。随着PF／PVB 质量比的增加,所得多孔炭的收率增加,比表面积和总孔容减小,比电容也减小。聚合物的混合方式及状态也 是影响多孔炭性能的因素之一。以比电容为26.3F/g的多孔炭作电极的模拟双电层电容器具有良好的充放 电性能。

The polymer blend technique was proposed as a method for designing porous carbon materials used as electrodes in electric double - layer capacitance (EDLC). Phenol - formaldehyde (PF) resin and polyvinyl butyral(PVB) were used as carbon precursor polymer(CPP)and thermally decomposable polymer (TDP),which were with and without carbon residue after heating under an inert atmosphere,respectively. The pyrolytic behaviors of sigle PF resin and sigle PVB and PF/PVB blends in course of carbonization were discussed by thermogravimetric analysis (TG) and differential thermal analysis(DTA). The influences of carbonization temperature and PF/PVB mass ratio on the yield,BET specific surface area (BET - SSA), pore distribution and specific capacitance of porous carbon have been studied. And charge - discharge performance of EDLC used resultant porous carbon as simulating electrode material has also been re-seached. It showed that there was no interaction occurred between PF and PVB. With the increase of carbonization temperature,the yield of porous carbon decreased while BET - SSA,total pore volume(TPV) and specific capacitance increase firstly then decrease after reaching the maximun at 800℃. When the PF/ PVB mass ration increasing,the yield of porous carbon increase while BET-SSA,TPV and specific capacitance decrease. Moreover,hybride mode and state of polymer blends have great effect on the performance of porous carbon. The EDLC with porous carbon whose specific capacitance is 26. 3 F/g as electrodes has good performance of charge and discharge.