Iron doped lithium cobalt oxides as lithium intercalating cathode materials

Abstract

Layered transition metal oxides of the formula LiMO2 have good lithium insertion properties for which reason LiCoO2 and LiNiO 2 have been exploited in practical lithium rocking chair batteries. Another member of the LiMO2 series, LiFeO2, should be an attractive cathode material considering the cheapness and environment- friendliness of iron compounds. Its rock-salt structure, however, does not allow significant amounts of lithium to be reversibly intercalated in its structure. Synthesis of layered LiFeO2 and study of its lithium intercalating properties have been of limited success. Therefore, an attempt has been made here to study LiCo1-yFeyO2 solid solutions (0 ≤ y ≤ 0.4) as prospective cathode materials. XRD, FTIR, Atomic absorption spectroscopy, Particle size and Surface area analysis were carried out in this regard towards the physical characterization of the entire series of LiCo 1-yFeyO2 compounds. The electrochemical discharge capacity of these materials is explained as a function of the iron content.