Electrochemical Redox Properties of Polypyrrole/Nafion Composite Film in a Solid Polymer Electrolyte Battery

Nafion® was introduced into a polypyrrole (PPy) matrix, and the redox performance of the PPy/Nafion electrode was investigated in a poly(ethylene oxide) (PEO)-LiC1O₄ electrolyte. A rougher interface between polymer cathode and polymer electrolyte is usually needed for an all-solid battery, however, the PPy/Nafion cathode works well regardless of the flat surface of the PPy/Nafion film. When compared to a PPy film doped with _ClO4 anions with a similar morphology, the PPy/Nafion film showed better redox performance. The results of ac impedance spectroscopy and potential-step chronoamperometry confirmed that the improvement in the redox reaction of the PPy/Nafion film was due to the enhancement of the ion diffusion rate in the film. Thus, the PPy/Nafion film showed good charging-discharging properties in a rechargeable Li/PEO-LiC1O₄/(PPy/Nafion) battery.