Polyaniline/reduced graphene oxide hydrogel film with attached graphite current collector for flexible supercapacitors

Reduced graphene oxide (RGO) hydrogel films possess a low specific capacitance and have no flexible current collectors, which limit their use in flexible supercapacitors. To solve these problems, a novel polyaniline (PANI) modified RGO hydrogel film with an attached graphite current collector (PANI/RGO/G) was prepared. Based on this film, a flexible supercapacitor device was fabricated and characterized. PANI/RGO/G film demonstrates good flexibility and electron transport. The graphite current collector highly reduces the internal resistance of the device. It shows a high specific capacitance of 478 F g−1 at a current density of 2 mA cm−2 based on the mass of one electrode and a good cycling stability (86.5% retention after 5000 cycles). Moreover, during the fabrication of the device, a modified design was adopted to solve the problem of low extension of PANI/RGO/G hydrogel film. The obtained device also exhibits a good flexibility; its capacitance hardly changes after 500 cycles of bending at an angle of 90°.