Influences of nonsolvent on the morphologies and electrochemical properties of carbon nanofibres from electrospun polyacrylonitrile nanofibres

摘要

The influences of nonsolvent on the morphologies and electrochemical properties of carbon nanofibres (CNFs) obtained via pre-oxidation and carbonization of electrospun polyacrylonitrile (PAN) nanofibres were mainly studied. Volatile methanol (MeOH) and acetonitrile (MeCN) were introduced into PAN solutions as the nonsolvent for PAN, which may produce porous structures via inducement of phase separation. The morphologies of the prepared nanofibres were observed via scanning electron microscopy. It was found that PAN nanofibres possessed corrugated and rough surfaces. PAN fibres obtained in the presence of nonsolvent showed larger diameters and wider distributions than those obtained without nonsolvent. After thermal treatments, inter-bonded CNFs were prepared. The structures of CNFs were confirmed by X-ray diffraction and Raman spectrometry. Then the electrochemical properties of CNFs were examined by an electrochemical method in a three-electrode system. Based on chronopotentiometry, CNFs exhibited the highest capacity up to 198 F g(-1) at current density of 3 A g(-1). The influence rule of nonsolvents on the morphology and capacities of CNFs was summarized and interpreted.