Preparation of LiCoPO4 powders and films via sol–gel

Abstract

Lithium intercalation materials are of special interest as cathodes in rechargeable batteries. An uncomplicated sol–gel process has been used for the synthesis of Li–Co phosphates powders and, for the first time, of LiCoPO4 films. The powders were prepared from aqueous solutions, containing Li, Co and phosphate precursors to which acid citric and ethylene glycol was added, during the drying process at 75 °C. The X-ray diffraction patterns of the prepared powders confirmed the presence of LiCoPO4 with an olivine-like structure as main phase. The morphological investigations of the powder showed a platelet-like structure with an average grain size of 0.75 μm. The films of LiCoPO4 were deposited onto ITO glass substrates with the combination of the dip-coating process under the same conditions. Finally, the films were annealed in inert atmosphere at 300 °C. The morphological investigations reveal a smooth and homogeneous surface of the prepared Li–Co phosphate films. The preliminary electrical investigation on the prepared LiCoPO4 films showed lithium ions electrochemical activity in the range 3.0–4.5 V.