Large areal mass, flexible and freestanding polyaniline/bacterial cellulose/graphene film for high-performance supercapacitors

Abstract

Flexible supercapacitors are promising energy storage devices for wearable and portable electronics. The key challenge for practical applications is to exploit a simple, scalable and low-cost strategy for fabricating large areal mass, high areal performance and mechanically tough flexible electrodes. Here, we describe flexible and freestanding electrodes with high mass loading in the range of 7–13 mg cm⁻² made of polyaniline (PANI)/bacterial cellulose (BC)/graphene (GN) conductive paper through a simple filtering method. This hierarchically flexible electrode exhibits an ultrahigh areal capacitance of 6.15 F cm⁻² at a large mass of 12.9 mg cm⁻², which is about two to five times higher than that of most polymer flexible electrodes. A symmetric supercapacitor using this flexible electrode is able to offer high areal capacitance (1.93 F cm⁻²) and energy density (0.17 mW h cm⁻²). Therefore, this flexible and freestanding paper electrode holds great promise for flexible energy storage devices.