Molecular organic-inorganic hybrid materials: Synthesis and application aselectrodes in lithium rechargeable batteries

A novel family of molecular hybrid materials based on electroactive inorgan ic species dispersed in conducting organic polymers is reported as electrod es for energy storage or conversion. Polyaniline and polypyrrole are effect ively doped with electroactive polyoxometalates ([PMo12O40](3-)) or ferricy anide ([(FeCN)(6)](3-)) anions as the only doping species. The high charge and size of these anions prevents their deintercalation during reduction in most cases. The synthesis of these hybrids can be made by chemical (bulk p owders) and electrochemical (films) methods. For [PMo12O40](3-), nine anili ne/pyrrole rings by anion are found in each case and the anion stays in the polymer matrix even after reduction at -0.4V (vs Ag/AgCl, 2.6V vs Li). In the case of Polypyrrole-FeCN6 hybrid the pyrrole-ring/Fe(CN)(6) ratio was a round 10-12 depending on the temperature of synthesis. Temperature also aff ects the electrical conductivity, with the best values around 60Scm(-1) (sa mple prepared at 0 degrees C). Fe(CN)(6) stays in the polymer matrix when t he hybrid material is reduced in organic media. PMo12 hybrids intercalate u p to 5.3 h(+) during discharge (52 Ah/Kg) whereas the hybrid with Fe(CN)(6) intercalates 2.7 lithium ions per formula unit (69 Ah/Kg).