Assembly of highly stable aqueous dispersions and flexible films of nitrogen-doped graphene for high-performance stretchable supercapacitors

Here, we propose a route for production of highly stable nitrogen-doped graphene (NG) aqueous dispersions and flexible NG films. The NG dispersions are formed through sonication of NG hydrogels in methyl orange solution and stabilized through electrostatic repulsion without using any polymeric or surfactant stabilizer. The flexible NG films are formed by vacuum filtration of as-prepared NG dispersions and transferred onto stretchable and adhesive polyacrylate for the fabrication of stretchable supercapacitors. The supercapacitor exhibits high gravimetric specific capacitances of 315 F g(-1) under no strain and 300 F g(-1) under 30% applied strain at a current density of 1 A g(-1). The fabrication of aqueous dispersions and stretchable NG films makes NG materials attractive for a diversity of applications in stretchable electronics.