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

The hybrid organic-inorganic material formed by polyaniline and the hexacya noferrate anion (PAni/HCF) constitutes a molecular hybrid where the anchori ng of the electroactive anion within the polymer leads to its application a s a functional material that harnesses the activity of the molecular specie s. Transport measurements of the hybrid have been carried out, both by cycl ic voltammetry at different scan rates and ac impedance spectroscopy. An ap parent 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 cathode s 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, u nprecedented for this type of hybrid materials.