Abstract
Nanofiber fabric is firstly introduced to replace common microfiber fabrics as the platform for flexible supercapacitors. Nanofiber and microfiber electrodes can be simply fabricated using a dipping process that impregnates reduced graphene oxide (RGO) nanosheets into electrospun polyamide-66 (PA66) nanofiber and microfiber fabrics. RGO nanosheets are tailored to various sizes and only RGO with a medium diameter of 250-450 nm (denoted as M-RGO) can effectively penetrate the pores of nanofiber fabrics for constructing smooth conductive paths within PA66 nanofiber fabrics. The synergistic effect between suitable sizes of RGO nanosheets and nanofiber fabrics with a high specific area provides a symmetric supercapacitor composed of M-RGO/PA66 nanofiber fabric electrodes with high-volume and high-area specific capacitance (C S,V and C S,A , equal to 38.79 F cm -3 and 0.931 F cm -2 at 0.5 A g -1 , respectively), which are much larger than that of a symmetric supercapacitor composed of RGO/PA66 microfiber fabric electrodes (8.52 F cm -3 and 0.213 F cm -2 at 0.5 A g -1 ). The effect of impregnating nanofiber fabrics with suitably sized RGO to promote C S,V and C S,A of flexible supercapacitors has been demonstrated. © 2014 Elsevier Ltd. All rights reserved.