fig8

Figure 8. (A) Schematic diagram of the action mechanism of the pore structure of the MPDC electrode material in the double-layer supercapacitor; (B) CV curve at a scanning rate of 400 mV·s^-1; (C) Galvanostatic charge/discharge curve at a current density of 20 A·g^-1; (D) specific capacitance at a scanning rate of 400 mV·s^-1; (E) the corresponding capacitance reduction rate in organic electrolyte at a charge/discharge current density from 0.05 to 20 A·g^-1; (F) electrochemical impedance spectrum; and (G) energy and power density curves at different current densities for different electrode. This figure is quoted with permission from Guo et al.^[60]. MCN1: Micro-/small mesopores; MCN2: meso-/micropores; MCN3: mesopore channels-micropores; HMC: hierarchical macro-/meso-/micropores; MPDC: mesoporous polydopamine and its derived carbon; CV: cyclic voltammetry.