Improving the multifunctionality of structural supercapacitors by interleaving graphene nanoplatelets between carbon fibers and solid polymer electrolyte

Novel structural supercapacitors, containing graphene nanoplatelets incorporated carbon fiber mats as electrodes, crosslinked diglycidylether of bisphenol-A epoxy polymer electrolyte and filter paper separator, have been manufactured for the first time by vacuum-assisted resin transfer molding process. These supercapacitors can bear structural loads and store electrochemical energy at the same time. Loading of high surface area graphene nanoplatelets on carbon fiber mats is an effective process to improve the charge storage capacity of the electrodes. Electrochemical and structural properties of the structural supercapacitors are explored through in-plane shear testing, dynamic mechanical thermal analysis, chronoamperometry and impedance spectroscopy, respectively. As graphene nanoplatelet loadings on carbon fiber mat electrodes increase from 0 to 10 wt.%, the structural supercapacitors exhibit significant improvements in specific capacitance (8.9–118.7？mF·cm？3), energy density (19.7–263.8？Wh·m？3) and normalized in-plane shear modulus (1.7–3.1？GPa). Thus, this study has revealed that using the graphene nanoplatelet loaded carbon fiber mats as structural supercapacitor electrodes is a relatively novel and easy approach to enhance the multifunctionality of structural supercapacitors