▎ 摘　　要

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.