Abstract
The performance of supercapacitors depends on the selection of electrode materials. Carbon materials are widely used in the electrode of electrochemical double-layer capacitor (EDLC), because of its availability, low cost and high surface area. Polyacrylonitrile (PAN) is the primary source used to produce carbon fibers which possess above advantages and thus has a potential to be a candidate for supercapacitors. In this study, lithium chloride (LiCl) is mixed with PAN to create porous film, followed by carbonization to form porous carbon as the electrode. Additionally, carbon nanotubes (CNTs) are added into LiCl/PAN to form additional electrode for a comparison. The morphology and structure of electrodes are characterized by X-ray diffraction (XRD), Raman measurement, field emission scanning electron microscopy (FE-SEM), fourier-transform infrared spectrometer (FTIR) and high-resolution surface area and porosimetry analyser. The electrical and electrochemical properties of electrodes, including resistivity, capacitance, rate capability, and cycle life, are studied by van der pauw method, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) in Autolab. Results indicate that the porous electrodes which are made with 50% LiCl in PAN and carbonized at 900℃show the highest surface area and capacitance. Moreover, addition of a certain amount of CNTs into electrodes may promote capacitance.