A Novel Sustainable Flour Derived Hierarchical Nitrogen-Doped Porous Carbon/Polyaniline Electrode for Advanced Asymmetric Supercapacitors

Hierarchically porous nitrogen-doped carbon (HPC)/polyaniline (PANI) nanowire arrays nanocomposites are synthesized by a facile in situ polymerization. 3D interconnected honeycomb-like HPC was prepared by a cost-effective route via one-step carbonization using urea and alkali-treated wheat flour as carbon precursor with a high specific surface area (1294 m(2) g(-1)). The specific capacitances of HPC and HPC/PANI (with a surface area of 923 m(2) g(-1)) electrode are 383 and 1080 F g(-1) in 1 m H2SO4, respectively. Furthermore, an asymmetric supercapacitor based on HPC/PANI as positive electrode and HPC as negative electrode is successfully assembled with a voltage window of 0-1.8 V in 1 m Na2SO4 aqueous electrolyte, exhibiting high specific capacitance (134 F g(-1)), high energy density (60.3 Wh kg(-1)) and power density (18 kW kg(-1)), and excellent cycling stability (91.6% capacitance retention after 5000 cycles).