Cattails-derived porous carbon fibers for high mass loading supercapacitors

The practical application of supercapacitors requires high mass loading electrodes to enhance the energy density, which would limit a slow electron and ion migration dynamics in a thick electrode and result in poor electrochemical capacitive properties. Here, porous carbon fibers (PCFs) were prepared from natural hollow cattail fibers by optimizing the carbonization temperature prior to KOH chemical activation. The results show that the PCF-C600 prepared by the carbonization temperature of 600 °C possesses not only high specific surface area of 1298.2 m2 g− 1 and pore volume of 0.555 cm3 g− 1, but also high gravimetric capacitance (242.7 F g− 1 at 0.05 A g− 1), excellent rate performance and cycle stability. For commerical supercapacitor applications, the effect of mass loading of the PCF-C600 electrode on electrochemical performance is in-depth investigated. The PCF-C600 electrode with a high mass loading of 16.0 mg cm− 2 exhibits a high areal capacitance of 2.79 F cm− 2 (174.3 F g− 1) at 0.1 A g− 1 and high utilization of the active material owing to its large specific surface area and uniform pore distribution. The excellent electrochemical performance indicated that the obtained porous carbon fibers could be a promising electrode material for commerical supercapacitor applications.