Quinone-based imide conjugated microporous polymer-reductive graphene oxide composite as an efficient electrode for hybrid supercapacitors

Abstract

Conjugated microporous polymers (CMPs) are emerging as an important class of energy storage material owing to their inherent pores and structural diversity. However, the low conductivity of CMPs limits their specific capacity. Herein, a novel quinone-based imide conjugated microporous polymer-reductive graphene oxide (PIBQ-1%rGO) composite was designed and successfully prepared by the in situ formation of quinone-based imide conjugated microporous on the reductive monolayer graphene oxide, resulting in the formation of a unique sandwich structure. The PIBQ-1%rGO composite exhibits a high specific capacity of 340 C g⁻¹ at 1 A g⁻¹ in a sulfuric acid electrolyte, which is significantly higher than the corresponding PIBQ polymer, rGO and the reference benzene-based imide conjugated microporous polymer-reductive graphene oxide (PIBT-1%rGO) composite (50 C g⁻¹ at 1 A g⁻¹). The high energy storage capacity for the PIBQ-1%rGO composite could be attributed to the effective utilization of rGO and adequate quinone and imide redox units of the PIBQ polymer, which may be owing to the synergistic effect between PIBQ and rGO. Moreover, a symmetric device was successfully constructed with PIBQ-1%rGO composites as the negative and positive electrodes, and the device yielded an energy density of 9.03 W h kg⁻¹ with a power density of 500.12 W kg⁻¹.