Poly (2, 2, 6, 6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) have been intensively studied in organic radical polymer batteries over the past years owing to its fast charge storage kinetics and outstanding cycling stability.  However, conductive carbon materials are required to improve the conductivity of PTMA electrode due to the insulating nature of the polymer backbone. One way to address this issue is to design PTMA analogs bearing conductive backbones. However, conjugated polymers bearing such pendant nitroxide radicals has shown even worse capacity and cycling stability as compared with the performance of PTMA. One reason for this is that conjugated polymers and nitroxide radicals are both electroactive building blocks with different redox potentials and intra and inter-charge transfer is possible. As such, it is relevant to investigate the charge transfer pathways in such a system. In this study, we report a facile way to synthesize polythiophenes carrying pendant 2, 2, 6, 6-tetramethylpiperidinyl-1-oxyl (TEMPO) radicals via electropolymerization onto indium-tin oxide ITO glass slides in boron trifluoride diethyl etherate.  By varying the alkyl chain spacer length between the thiophene ring and TEMPO radical, we tune the electronic and electrochemical properties of these electroactive polymers. In addition, the charge storage mechanism during cycling is also interrogated. Finally, the electrode degradation pathway is also discussed.<br/>

Charge-transfer mechanism on a polymer thin-films electrode from polythiophenes bearing pendant nitroxide radicals

251st National Meeting (2016)

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