POSITIVE ELECTRODE MATERIALS COMBINING HIGH SAFETY AND HIGH POWER IN A LI RECHARGEABLE BATTERY

摘要

The invention relates to a Li a Ni x Co y Mn y,M'z O 2 composite oxide for use as a cathode material in a rechargeable battery, with a non-homogenous Ni/M' ratio in the particles, allowing excellent power and safety properties when used as positive electrode material in Li battery. More particularly, in the formula 0.9a1.1, 0.3=x=0.9, 0y=0.4, 0y'=0.4, 0z=0.35, e0.02, 0=f=0.05 and 0.9 (x+y+y'+z+f) 1.1; M' consists of either one or more elements from the group Al, Mg, Ti, Cr, V, Fe, Mn and Ga; N consists of either one or more elements from the group F, Cl, S, Zr, Ba, Y, Ca, B, Sn, Sb, Na and Zn. The powder has a particle size distribution defining a D10, D50 and D90; and the x and z parameters varying with the particles size of the powder, and is characterized in that either one or both of: x1 - x2 = 0.005 and z2 - z1 = 0.005; x1 and z1 being the parameters corresponding to particles having a particle size D90; and x2 and z2 being the parameters corresponding to particles having a particle size D10.