PFPT/CF复合材料及其在电化学电容器中的应用

PFPT/carbon foam composite electrodes used for electrochemical capacitors

为提高电容器电极的比能量,在乙腈溶液中,用电化学聚合方法直接制备了聚3-(4-氟苯基)噻吩/泡沫碳(PF-PT/CF)复合电极,用电子扫描电镜(SEM)观察了复合电极的微孔结构,研究了该复合电极的循环伏安特性。发现在0.2 mol/L Et4NBF4乙腈溶液或0.2 mol/L Me4NSO3CF3乙腈溶液中,该复合电极既能以法拉第准电容机制储能,又能以双电层电容机制储能,这与泡沫碳所具有的多孔结构有关。还用该复合电极组装了聚合物III型模拟电化学电容器,以整体电极的质量计,其比能量可达4.2 Wh/kg,比功率可达683 W/kg。

Composite electrodes used for electrochemical capacitors were fabricated by electrochemical polymerization of 3-(4-fluorophenyl)-thiophene onto carbon foam in 0.2 mol/L tetraethylammonium tetrafluoroborate (Et4NBF4) acetonitrile solutions or in 0.2 mol/L tetramethylammonium trifluoromethanesulfonate (Me4NSO3CF3 ) acetonitrile solutions. Cyclic voltammetry (CV), FTIR and SEM were used to characterize the composite electrodes. There are two mechanisms of storing electrical energy for the composite electrodes: one is pseudocapacitance resulted from PFPT, and the other is double layer capacitance resulted from porous structure of the composite electrodes. The prototype electrochemical capacitor was assembled with two pieces of composite electrodes with electrolyte of 0.2 mol/L Et4NBF4 acetonitrile solutions or 0.2 mol/L Me4NSO3CF3 acetonitrile solutions, and tested by chronopotentiometry. Calculated on total mass of the electrodes, energy density of the electrochemical capacitor can reach 4.2 Wh/kg, and power density can reach 683 W/kg in 0.2 mol/L Me4NSO3CF3 acetonitrile solutions.