Bimodal Lithium Transition Metal Based Oxide Powder for Use in a Rechargeable Battery

A bimodal lithium transition metal oxide based powder for a rechargeable battery, comprising:

• a first lithium transition metal oxide based powder having an average particle size (D50) of at least 15 μm and comprising either:
• a material A, having a layered crystal structure comprising the elements Li, a metal M and oxygen, wherein the Li content is stoichiometrically controlled, wherein the metal M has a formula M=Co1-a M′a, with 0≦a≦0.05, wherein M′ is one or more metals selected from the group consisting of Al, Ga and B, and wherein the material A has an electrical conductivity of less than 10−3 S/cm;
• or
• a material B, having a core and a surface layer, wherein the core comprises a layered crystal structure comprising the elements Li, a metal M and oxygen, wherein the Li content is stoichiometrically controlled, wherein the metal M has a formula M=Co1-a M′a, with 0≦a≦0.05, and wherein M′ is one or more metals selected from the group consisting of Al, Ga and B;
• wherein the surface layer comprises a mixture of the elements of the core and inorganic N-based oxides, wherein N comprises one or more metals selected from the group consisting of Mg, Ti, Fe, Cu, Ca, Ba, Y, Sn, Sb, Na, Zn, Zr, Si, Nb, Mo, Ru, Rh, Pd, Ag, Cd, Sc, Ce, Pr, Nd, Gd, Dy, and Er;
• and
• a second lithium transition metal oxide based powder having the formula Li1+bN′1−bO2, wherein −0.03≦b≦0.25, and N′═NixMnyCozAd, wherein 0.10≦x≦0.60, 0.30≦y≦0.80, 0.05≦z≦0.20 and 0≦d≦0.10, and wherein A is a dopant;
• wherein the second powder has an average particle size (D50) of less than 5 μm and wherein the ratio of the D50 value of the first powder to the D50 value of the second powder is at least 5:1 when the first powder comprises material A.