Figure 4.

(a) Schematic illustration for the preparation of hierarchically porous nitrogen doped carbon (HPC)/PANI composites; (b) SEM image of HPC; (c,d) SEM images of HPC/PANI hybrids; (e) Cyclic voltammetry (CV) curves at a scan rate of 50 mV s⁻¹ of HPC and HPC/PANI electrodes measured in a three-electrode system; (f) schematic diagram of the structure of the asymmetrical supercapacitor (ASC) device based on HPC and HPC/PANI electrodes; (g) specific capacitance of HPC/PANI//HPC based on the total mass of the two electrodes versus current density. Reproduced with permission from Reference [17], copyright Wiley, 2016.