Micro-meso porous structured carbon nanofibers with ultra-high surface area and large supercapacitor electrode capacitance

Carbon nanofibers from electrospun polymer nanofibers have received considerable attention. However, most of the carbon nanofibers with a surface area above 1000 m(2)/g were reported to have a supercapacitor electrode capacitance far below 350 F g(-1). Herein, we report a novel carbon nanofibrous material that has a supercapacitor electrode capacitance as high as 394 F g(-1) (1.0 A g(-1)). We used a polymer blend of polyacrylonitrile (PAN) and novolac (NOC) as materials, to electrospin them into precursor nanofibers and subsequently carbonize the nanofibers into carbon nanofibers. The carbon nanofibers prepared had a specific surface area as high as 1468 m(2) g(-1) with a meso-micro pores (average pore size 2.2 nm) predominated porous structure. The carbon nanofiber electrodes after 10,000 cycles of charging and discharging at 1.0 A g(-1) maintained the capacitance almost unchanged. At the optimal condition, the supercapacitor device made of the electrodes had an energy density as high as 13.6 Wh.kg(-1) (at 0.5 kW kg(-1)). The high capacitance value comes from the carbon nanofibers with a large surface area and a unique porous structure. The high inter-fiber interconnection contributes to high capacitance. This super-high surface area carbon may be useful for the development of high-performance supercapacitors and other energy devices.