COATED LITHIUM MIXED OXIDE PARTICLES

摘要

The invention relates to lithium-mixed oxide particles coated with metal- oxide. Said particles are used to improve the characteristics of electrochemical cells. The invention relates to undoped and doped mixed oxid es which are selected from the group Li(MnMez)2O4, Li(CoMez)O2, Li(Ni1-x- yCoxMey)O2 as cathode material. Me means at least one metal cation from the groups IIa, IIIa, IVa, IIb, IIIb, IVb, VIb, VIIb, VIII of the periodic table . Copper, silver, nickel, magnesium, zinc, aluminium, iron, cobalt, chromium, titanium and zircon are especially useful cations. Lithium is especially useful for the spinel compositions. The present invention also relates to lithium intercalations and insertion compounds that can be used for 4V- cathodes and have improved high temperature characteristics, especially at temperatures above room temperature. The invention further relates to the production and utilisation thereof, especially as cathode material in electrochemical cells. Various metal-oxides, especially oxides or mixed oxid es of Zr, Al, Zn, Y, Ce, Sn, Ca, Si, Sr, Mg and Ti and the mixtures thereof, su ch as ZnO, CaO, SrO, SiO2, CaTiO3, MgAl2O4, ZrO2, Al2O3, Ce2O3, Y2O3, SnO2, TiO 2 and MgO for instance, can be used as coating materials. It has been found th at the undesired reactions of the electrolyte with the electrode materials can be significantly hindered by means of the coating with said metal-oxides.