Evolution of cellulose into flexible conductive green electronics: a smart strategy to fabricate sustainable electrodes for supercapacitors

The integration of native polymers with electronic elements to form green electronics will be the subject of intense scientific research. In this work, conductive cellulose composite films have been prepared by in situ polymerization of aniline monomers in the cellulose scaffolds. The effects of reaction time, different dopants and the concentration of aniline monomer on the structure and properties of the composite films have been investigated. With the optimized reaction protocols, the structurally defined polyaniline (PANI)/cellulose composite films with PANI content of only about 24.6% exhibited electrical conductivity as high as 0.06 S cm(-1), which could be compared with that of pure PANI. The PANI/cellulose films integrated the merits of cellulose and conductive polyaniline. The composite films with electrical conductivity performance were foldable and could be used as flexible electrode materials for supercapacitors. The specific capacitance of the films was about 120-160 F g(-1) at current densities ranging from 0.1 to 0.5 A g(-1) in the supercapacitor, and it maintained at least 81% after 1000 cycles at a current density of 0.5 A g(-1). The straightforward fabrication of the cellulose-based conductive films represented not only a novel scientific approach for supercapacitor-based energy storage materials, but also an emerging area of research aimed at identifying compounds of natural origin and establishing economically efficient routes for the production of environmentally safe (biodegradable) and/or biocompatible devices.