CATHODE MATERIALS FOR LITHIUM ION ACCUMULATORS BASED ON LITHIATED VANADIUM OXIDE COMPOUNDS

摘要

The invention relates to novel active cathode materials, to their use, and to a process for the manufacture of active electrode materials in the field of lithium ion accumulators based on lithium vanadium oxide stabilized with titanium or aluminum, exhibiting a layered structure. The active electrode materials are represented by the general chemical formula LixVMO4, wherein typically x=2, and M stands preferably for titanium or aluminum. The invention describes the useful electrochemical activity of Li2VTiO4 and Li2VAIO4, which are compounds having a layered structure, as cathode material in lithium ion accumulators, enabling the reversible exploitation of the electrochemical energy stored in the said compounds within the potential window 1 - 4.6V with respect to metallic lithium. The invention relates to the process for the manufacture of the said compounds based on the homogenization of the lithium, vanadium, titanium, and aluminum precursors, respectively, in an aqueous medium or in a non-aqueous medium, in the presence of organic acids and/or nonionic dispergators. The obtained dispersion of the precursors is after homogenization dried and thermally treated in an inert atmosphere or in a reductive atmosphere. The products are particles having a chemical composition LixVMO4, and are preferably coated with an electron conductive phase wherein the X-ray powder diffraction analysis corresponds to the layered structure.