Polypyrrole/polymer electrolyte composites prepared by in situ electropolymerization of pyrrole as cathode/electrolyte material for facile electron transfer at the solid interface

Polypyrrole (PPy)/ion-conducting polymer electrolyte (PE) composites are pr epared by in situ electropolymerization of pyrrole in a solvent-free PE mat rix which is formed by photocross-linking of triacrylated poly(ethylene oxi de-ca-propylene oxide) (TA). X-ray photoelectron spectroscopy measurements reveal the gradient structure at the PPy/PE interface where PPy is formed w ith the concentration gradient. For the composite film, a facile electron t ransfer across the PPy/PE interface is demonstrated by a cyclic voltammogra m for the doping-undoping process? and a decrease in the charge-transfer re sistance at the interface is proved by an electrochemical impedance analysi s. This is in marked contrast to a combined bilayer film of PPy and TA-base d PE for which an electron transfer across the interface between two polyme r Films is not clearly observed. The composite exhibits charge-discharge pe rformance, which suggests a possibility of fabricating solid-state batterie s composed of conductive polymer electrode/ion-conductive PE/Li by one-step electrolysis. (C) 2001 The Electrochemical Society. All rights reserved.