▎ 摘　　要

This work states the preparation of ternary composites of reduced graphene oxide/polyaniline/iron oxide as free-standing and flexible thin films using a simple doctor blade technique. We optimized the properties of the films for further studies as an electrode in a symmetric all-solid supercapacitor. Adding polyaniline into the composites is imperative to produce free-standing films with no binder and conductive additive, besides improving the energy storage performance along with iron oxide. The ternary free-standing film exhibited a specific capacitance of 281 F g(-1) in the three-electrode system and a specific capacitance of 24 F g(-1) in the all-solid supercapacitor, including a good long-term stability of 76% and excellent Coulombic efficiency ranging from 92 to 166% after 3000 cycles at 3 A g(-1). The performance of these free-standing ternary composites prepared using the same method applied in commercial supercapacitors may offer a perspective to its large-scale application in energy storage systems.