活化温度对酚醛基活性炭纤维的孔结构和电化学性能的影响

INFLUENCES OF ACTIVATION TEMPERATURE ON PORE STRUCTURE AND ELECTROCHEMICAL PERFORMANCES OF PHONEMIC RESIN BASED ACTIVATED CARBON FIBERS

从酚醛纤维出发，经过炭化和KOH活化制备了酚醛基活性炭纤维（PACF），并对不同温度下活化样品的比表面积、孔结构以及所制备的双电层电容器（EDLC）的电化学性能之间的关系进行了探讨。氮气（77K）吸附法测定PACF活性炭纤维的孔结构和比表面积；采用循环伏安、交流阻抗、恒流充放电等测试对超级电容器的电化学性能进行了测试。结果表明：900℃是KOH活化酚醛纤维制备用于EDLC电极材料的最佳活化温度，该温度下活化样品具有最佳的循环性，稳定性和较小的内阻，比表面积为2311m^2·g^-1和比电容264．IF·g^-1（充放电电流为1000mA·g^-1）。PACF系列样品均呈现出典型的微孔炭的特征，不同活化温度下制备的PACF，虽然表现出不同的比表面积和比电容，但是其整体孔径分布范围基本相同，都在0.5nm～3．0nm之间。随活化温度的升高，样品的电容性能和功率特性越来越好，内阻也随活化温度的升高而降低。

Phonemic resin based activated carbon fibers （PACF） were prepared by treating phonemic resin based fibers with KOH at different temperatures. The relationship between specific surface areas and pore structures of PACF with the corresponding electric double layer capacitors EDLCs electrochemical performances were discussed in detail. The BET specific surface areas and pore structure parameters of all PACF samples were determined by the low temperature gas adsorption isotherm method. The electrochemical propertics of EDLCs using PACF as electrodes and the capacitive behavior were systematically studiedusing by cyclic voltammetry. AC impedance and constant current charge/discharge test. It was found that the PACF activated at 900℃ exhibits appropriate specific surface area （2 311m^2 · g^-1）and specific capacitance （264.1F · g^-1. All samples are typically microporous structure. Although the PACFs activated at different temperatures show different specific surface areas and specific capacitances, the pore size distributions are similar for all samples. Within the rauge of 0. 5nm to 3.0nm. With the increase of activation temperature,the resulting PACFs show the decrease in terms of resistance expressed by AC impedance as well as increasing specific capacitance and power capability.