Improving Supercapacitance of Electrospun Carbon Nanofibers through Increasing Micropores and Microporous Surface Area

Abstract

Abstract Previous papers about electrospun carbon nanofibers do not provide systemic understandings about how in situ activation agents affect the porous structure of carbon nanofibers. In this study, poly(vinylpyrrolidone), poly(methyl methacrylate), and high‐amylose starch (HAS) are used as activation agent to separately prepare porous carbon nanofibers from electrospun polyacrylonitrile nanofibers, and the effects of the polymer activation agents on the porous structure and supercapacitive properties of the resulting carbon nanofibers are examined. The studies indicate that melting point and decomposition temperature are two important parameters deciding the pore size profile. The one with high melting point and low decomposition temperature, such as HAS, allows to form micropore‐dominant porous structure with large specific surface area. The HAS‐activated carbon nanofibers have a micropore specific surface area as high as ≈809 m 2 g −1 , total pore volume of ≈0.42 cm 3 g −1 , and micropore content as high as ≈59%. The corresponding electrodes have a capacitance of 282 F g −1 at the current density of 1.0 A g −1 with excellent cycling durability. These novel understandings may be useful for the development of effective carbon nanofibers for high‐performance supercapacitor and other applications.