Umicore

Thomas Lau

Jens M Paulsen

JiHye Kim

HeonPyo Hong

Jens Martin Paulsen

Disclosed is a cathode active material and a method to produce the same at low cost. The cathode powder comprises modified LiCoO, and possibly a second phase which is LiM'Owhere M&#x2032; is Mn, Ni, Co with a stoichiometric ratio Ni:Mn&#x2267;1. The modified LiCoOis Ni and Mn bearing and has regions of low and high manganese content, where regions with high manganese content are located in islands on the surface. The cathode material has high cycling stability, a very high rate performance and good high temperature storage properties.

Island-covered lithium cobaltite oxides

A powderous lithium transition metal oxide having a layered crystal structure LiMOM'Swith &#x2212;0.03&#x3c;a&#x3c;0.06, b&#x2245;0, 0&#x2266;m&#x2266;0.6, m being expressed in mol %, M being a transition metal compound, consisting of at least 95% of either one or more elements of the group Ni, Mn, Co and Ti; M&#x2032; being present on the surface of the powderous oxide, and consisting of either one or more elements of the group Ca, Sr, Y, La, Ce and Zr, wherein: either k=0 and M=NiMnCO, with 0&#x3c;c&#x3c;1, and 0&#x3c;d&#x3c;1; or 0.015&#x3c;k&#x3c;0.15, k being expressed in wt % of said lithium transition metal oxide; characterized in that for said powderous oxide, the X-ray diffraction peak at 44.5&#xb1;0.3 degree, having as index 104, measured with K alpha radiation, has a FWHM value of &#x2266;0.1 degree. By optimizing the sintering temperature of the metal oxide the FWHM value can be minimized.

Highly Crystalline lithium transition metal oxides

The invention covers a powderous lithium transition metal oxide having a layered crystal structure LiMOM'Sm with &#x2212;0.03&#x3c;a&#x3c;0.06, b&#x2245;0, M being a transition metal compound, consisting of at least 95% of either one or more elements of the group Ni, Mn, Co and Ti; M&#x2032; being present on the surface of the powderous oxide, and consisting of either one or more elements from (IUPAC) of the Periodic Table, each of said Group 2, 3, or 4 elements having an ionic radius between 0.7 and 1.2 Angstrom, M&#x2032; however not comprising Ti, with 0.015&#x3c;k&#x3c;0.15, k being expressed in wt %, and 0.15&#x3c;m&#x2266;0.6, m being expressed in mol %. The addition M&#x2032; (like Y, Sr, Ca, Zr, . . . ) improves the performance as cathode in rechargeable lithium batteries. In a preferred embodiment a content of 250-400 ppm calcium and 0.2-0.6 mol % of sulfur is used. Particularly, a significantly lower content of soluble base and a dramatically reduced content of fine particles are achieved. Especially preferred performance is achieved if 11.5-13.5% of the metal atoms of the cathodes are divalent nickel.

Growing community of inventors

Edmonton, Canada

Thomas Lau