Direct spinning of high-performance graphene fiber supercapacitor with a three-ply core-sheath structure

Abstract The emerging fiber-shaped supercapacitors have motivated tremendous research interest in energy storage devices. However, obtaining thin gel electrolyte interlayers with small thickness and large contact interface area of electrodes, which are crucial for the high-performance realization, still remains challenging. Here, we demonstrate the facile and direct spinning of three-ply core-sheath graphene fiber supercapacitors with thin and continuous wrinkling gel electrolyte interlayer by a wet spinning approach through coaxial three-channel spinneret. The architectural feature of gel electrolyte interlayer can remarkably increase electrode/electrolyte contact interface area and facilitate transport of charges and ions. The resulting flexible core-sheath graphene fiber supercapacitors exhibit a high specific capacitance of 249 mF cm −2 , perfect cycling stability (96% retentions after 10000 cycles), and almost unaltered capacitance performance during repeated bending to 180°. The maximum power and energy densities are estimated to be 4.81 mW cm −2 and 44 μWh cm −2 , respectively. The energy density was further improved to 59 μWh cm −2 , when polyaniline was used.