Highly\nDeformable Graphene/Poly(3,4-ethylenedioxythiophene):Poly(styrene\nSulfonate) Hydrogel Composite Film for Stretchable Supercapacitors

Abstract

Graphene\nfilms have been extensively applied in supercapacitors\nowing to their high electrical conductivity and good mechanical strength;\nhowever, their application in stretchable supercapacitors is still\nhampered by their low elastic deformation ability. Herein, hybridizing\ngraphene with the hydrogel of a conductive polymer (PEDOT:PSS) endows\ngraphene films with substantially improved ductility. The resultant\ngraphene-conductive polymer hydrogel composite film (GCPH) can be\nstretched to as long as 114.6% of its original length. Meanwhile,\nit possesses a much higher specific capacitance (28.52 F g^–1) than that of the pure graphene film, as the PEDOT:PSS hydrogel\nprevents graphene from restacking. A proof-of-concept all-gel-state\nplanar supercapacitor based on GCPH film electrodes is fabricated,\nwhich exhibits excellent electrochemical performance under a stretching\nstate. The device shows no significant capacitance decline even when\nit is stretched to 220% of its original length (20% more than the\npre-strain limit), and it maintains 98.23% of its initial capacitance\nafter repeated stretching–releasing cycles.