Pendant thioether polymer for redox capacitor cathodes

While numerous organic molecules have promising oxidation potentials and theoretical energy densities for use as redox capacitor cathode materials, practical application requires that the molecules remain in contact with the electrode during cycling. In this report, a hybrid molecule was synthesized and electrochemically polymerized to prepare a conducting polymer backbone of poly(3,4-ethylenedioxythiophene) with pendant thioether functionalities as redox (and charge-storing) sites. The choice of an electron deficient aromatic solvent was critical to form a conducting polymer film from the hybrid monomer, as well as to achieve stable charge/discharge cycling of the pendant-type polymer. In nitrobenzene, 86% of the charge was retained after 100 charge/discharge cycles.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of a hybrid conducting polymer for electrochemical energy storage. ► PEDOT backbone with pendant thioether groups for charge storage. ► Choice of electron deficient aromatic solvent critical for electrochemistry. ► 86% charge retained after 100 charge/discharge cycles.