Layer-by-layer in situ growth flexible polyaniline/graphene paper wrapped by MnO2 nanoflowers for all-solid-state supercapacitor

Free-standing hierarchical polyaniline/graphene/MnO2 (PANI/G/MnO2) paper is well constructed using low-cost printing paper by a simple layer-by-layer in situ growth and vacuum filtration method. The PANI nanofiber was polymerized on cellulose fibers, and then the pristine graphene sheet was introduced to generate the polyaniline/graphene paper, whose surface was subsequently scattered with the formed MnO2 nanoflowers through oxidation of the cellulose fiber and graphene. The PANI/G/MnO2 paper possessing a mass loading of 11.75 mg cm(-2) is of high flexibility and could serve as a working electrode without using any binder and conductive additives. The electrode shows a sizeable areal capacitance of 3.5 F cm(-2) at 5 mA cm(-2) and excellent cycling stability of 90% after 1000 bending cycles. All-solid-state supercapacitor assembled with the PANI/G/MnO2 paper exhibits a high energy density of 5.2 mW h cm(-3) at 8.4 mW cm(-3). Eight supercapacitors connected in series can light a green light-emitting diode of 3 V.