Nafion doped polyaniline/graphene oxide composites as electrode materials for high performance flexible supercapacitors based on Nafion membrane

Nafion membrane possesses good ionic conductivity and excellent mechanical stability, which can be used as electrolyte and separator of flexible supercapacitor. However, due to its solid-state structure, it is difficult for the Nafion membrane to permeate in solid-state electrode, which reduces electrochemical surface area, and increases interface resistance. The electrode materials need to be carefully designed to solve the above issues. In this study, Nafion doped polyaniline/graphene oxide composites were designed and synthesized as electrode materials to fabricate flexible supercapacitors based on Nafion membrane. The polyaniline utilization rate and the electrochemical surface area are improved by Nafion doping. In addition, the electrostatic interaction between polyaniline and Nafion can reduce the interface resistance. Graphene oxide can enhance the polyaniline electrochemical stability. The specific capacitances of flexible supercapacitor are 309 and 300F g-1 under flat and bent conditions (at 1 A/g), respectively, which are the maximum values among reported Nafion membranebased supercapacitors. After 1000 cycles, the capacitance retention rate of supercapacitor with Nafion membrane is 87.2%, which is higher than that with H2SO4 electrolyte (83.0%). Therefore, the Nafion membrane-based flexible supercapacitor has widespread applications in electronic products because of its high performance and good cycling stability.