Binary nanosheet frameworks of graphene/polyaniline composite for high-areal flexible supercapacitors

Graphene/polyaniline composites with a unique structure serve as a crucial class of materials for supercapacitor (SC) electrodes. In this work, we design and construct binary nanosheet frameworks of graphene/polyaniline composite for high-capacity flexible all-solid-state SCs. Novel morphological PANI nanosheets are synthesized by a self-assembly process at −20 °C without using additional template material. The as-prepared PANI nanosheets are 1–5 μm lateral dimension and 40–50 nm thickness. The PANI nanosheets exhibit excellent pseudocapacitance properties and are potential supercapacitor materials. The sacked framework based on PANI nanosheets and reduced graphene oxide (rGO) are successfully constructed, even the weight content of PANI is as high as 82%. The rGO/PANI-82% electrode in aqueous symmetric SCs presents a high specific areal capacitance (Ca) of 684 mF cm−2 at 1 mA cm−2. Furthermore, the resulting rGO/PANI-67% electrode-based all-solid-state SC device is fabricated. The device exhibits an energy density of 21 μWh cm−2 (or 4.2 Wh L−1 or 10.2 Wh kg−1) at a power density of 252 μWcm−2 (or 50.4 W L−1 or 121 W kg−1). Overall, the new method of synthesizing polyaniline nanosheets reported here and as-designed structures pave the way to advancements in high-capacity flexible electrodes.