Hybrid Materials Based on Conducting Organic Polymers and Electroactive Inorganic Molecules and Oxides. Application as Lithium-Insertion Electrodes

ABSTRACTThe synthesis, spectroscopic and electrochemical characterization of a series of hybrid organic-inorganic materials are reported. The hybrids are formed by conducting organic polymers (polyaniline, polypyrrole) and electroactive inorganic species. The latter can be either molecular anions (polyoxometalates, hexacyanoferrates) or extended oxide (V205), leading to different host-guest combinations. We have carried out a systematic study of the synthesis of the hybrids and determined key parameters for the reproducibility of the materials obtained. We have determined under what conditions the molecular species stay anchored in the polymer contributing to the overall electrochemical activity of these materials and turning the polymers from anion-insertion electrodes into cation-insertion electrodes. In the PAni/V2O5 system we have established the existence of two phases corresponding to the intercalation of one and two monolayers of PAni into V2O5 and have carried out their electrochemical characterization and their optimization as insertion cathodes in reversible lithium cells.