context: Among the many proposed applications of graphene-based materials, supercapacitors, also known as electrochemical capacitors, have been an active area of research for the past decade. Compared with secondary batteries, graphene-based supercapacitors are electrochemical energy storage devices that promise outstanding power density, charge/discharge rate, cycling stability, and operational safety. Supercapacitors are often utilized individually or in tandem with batteries for energy storage and supply (Scheme 1a(i)). They can be classified into two types: the electric double-layer capacitor (EDLC) (Scheme 1a(ii)) and the pseudocapacitor (Scheme 1a(iii)). The energy storage mechanism of the EDLC involves a simple charge separation at the interface between the conductive electrode and the electrolyte. Because there is no chemical transformation at the EDLC electrodes, the system is quite stable, although the specific capacitance is relatively low. In comparison, charge storage in a pseudocapacitor is predominantly achieved via the redox or faradic transformation of capacitive electrode materials, such as metal oxides and conductive polymers. The specific capacitance of the pseudocapacitor is generally high, but gradually decays because of structural collapse and degradation. A composite of a conductive substance and a pseudocapacitive material is desirable to enhance the overall capacitance, charge/discharge rate, and cycling lifetime. Graphene is a promising conductive component because it has a large surface area, and excellent electronic and mechanical properties. To develop a high-performance pseudocapacitor, we focused on developing a conductive polymer as an electrode counterpart to graphene. Various graphene–polymer composites with non-covalent and covalent interactions have been synthesized, and high capacitive performances have been achieved. The non-covalent interaction between graphene and polymers limits charge transfer at their interface, and hence constrains the cycling stability (Scheme 1b(i)). To address this issue, we propose the formation of the covalent bond between graphene and redox-active polymers.