XPS spectra of CSAC and HCSAC;Electrochemical performance data of samples prepared under different time and power from Enhancement on the electrochemical properties of commercial coconut shell-based activated carbon by H2O dielectric barrier discharge plasma

The relative proportion of surface oxygen, nitrogen and carbon elements;(a-b) CV curves of CSAC and CSAC modified with DBD H2O plasma in a three-system with 6 M KOH aqueous electrolyte at the scan rate of 10 mV/s. (c-d) GCD curves of CSAC and CSAC modified with DBD H2O plasma in a three-electrode system with 6 M KOH aqueous electrolyte at the current density of 1 A/g. (e) Nyquist plots of CSAC and CSAC modified at different power electrodes. The inset is the detail with enlarged scale (f) Rate capability of CSAC and CSAC modified at different power at the current density from 0.5 to 10 A/g.