Integration of hexacyanoferrate as an active species in a molecular hybrid material. transport properties and application of polyaniline/hexacyanoferrate as a cathode in rechargeable lithium batteries

The hybrid organic-inorganic material formed by polyaniline and the hexacyanoferrate anion (PAni/HCF) constitutes a molecular hybrid where the anchoring of the electroactive anion within the polymer leads to its application as a functional material that harnesses the activity of the molecular species. Transport measurements of the hybrid have been carried out, both by cyclic voltammetry at different scan rates and ac impedance spectroscopy. An apparent diffusion coefficient of 5 x 10(-8) cm(2)/s and an activation energy of 15.5 kJ/mol (0.16 eV) have been obtained. The particular application of these hybrids to energy storage is shown here through their use as cathodes in lithium rechargeable cells. In this respect, the PAni/HCF hybrids show very good cyclabilities and high specific charges of up to 140 A(.)h/kg, unprecedented for this type of hybrid materials.