Redox-active polymers as organic electrode materials for sustainable supercapacitors

Redox polymers in light of electrochemical activity, mechanical flexibility, molecular diversity, good processability, and low cost, in sharp contrast to conventional inorganic materials like carbons or metal oxides, are promising electrode candidates for fabricating affordable, sustainable, and high-performance supercapacitors. Representative conducting polymers thus far have made great progress in the field of electrochemical energy storage, but their capacitive performance in particular lifespan still fall short of demand, resulted from their volume expansion and shrinkage during charge/discharge process. Concurrently, other types of electrochemically-active polymers with diverse molecular structures and redox centers, have been extensively explored and designed for efficient energy harvesting and storage. This article gives a broad overview of recent advancements of those emerging redox polymers as well as conventional conducting polymers in supercapacitor application including synthetic strategy, structure manipulation, and electrochemical behavior, to shed light on the future direction of further optimization and extension for advanced organic supercapacitor technologies.