fig4

Figure 4. (A) The CV curves of AC and MACs at 0.005 V/s; (B) CV curves of 140MCA24 with different sweep rates; (C) GCD curves of AC and MACs at 0.2 A/g; (D) GCD curves of 140MAC24 with different current density; (E) EIS spectra for AC and MAC electrodes; and (F) long cycling performance of 140MAC24 electrodes. CV: Cyclic voltammetry; AC: activated carbon; MACs: modified activated carbons; 140MCA24: modified activated carbon heated at 140 °C for 24 h; GCD: galvanostatic charge-discharge; EIS: electrical impedance spectroscopy.