Fig. 4

Analysis of the reaction mechanism during the electrochemical process. a FTIR spectra of the PTCDA electrode recorded at different SOC: OCV (black), the initial discharged (red), the charged state (blue), and FTIR spectra of methyl viologen dichloride powder (green) and its reduced form of MV⁰ (orange); b XPS O 1s spectrum of PTCDA electrodes recorded at different SOC; c Schematic illustration showing the possible reversible electrochemical redox mechanism of PTCDA electrode