Dissolvable conducting polymer supercapacitor for transient electronics

Abstract

This work explores the use of a conducting polymer that can dissolve in mild aqueous conditions as a supercapacitor material for applications in transient electronics, biomedical devices, and biodegradable energy storage. A repeating polymer of methyl 1H-pyrrole-3-carboxylate monomer (“MPC polymer”) is prepared via electrochemical and chemical polymerization methods, and tested for the first time as a supercapacitor energy storage material. The MPC polymer exhibits charge storage performance comparable to pseudocapacitive conducting polymer polypyrrole (PPY), both as a planar electrode and as a composite porous electrode with poly (l-lactic acid) (PLLA). Chronoamperometry charge-discharge results indicate that the MPC polymer stores energy as a pseudocapacitive material following a faradaic current model. Electrochemical impedance spectroscopy (EIS) measurements demonstrate that MPC polymer electrodes have lower equivalent series and charge transfer resistance compared to PPY electrodes. Cycle life testing of MPC polymer and PPY electrodes shows equal capacitance loss for both electrodes over 1100 cycles. After use as a supercapacitor electrode with an organic electrolyte, MPC polymer-based electrodes showed visible signs of degradation in a mild aqueous environment (37 °C, pH 8.2) in 8 h.