Patent ID: 8377412

Claim:
A method of preparing a compound having a substantially single phase, hexagonal layered crystal structure and being substantially free of localized cubic spinel-like structural phases, the method comprising the steps of providing a lithium metal oxide having the formula Li x Ni a Co b Mn c O 2 , wherein a and c are independently of each other a number from 0.05 to 0.8, b is a number between 0.05 and 0.50, 0.95≦(a+b+c)≦1.02, and x being a number from 0.98-1.05 while x+a+b+c=2, at a temperature of at least about 600° C.; and cooling the lithium metal oxide at a cooling rate in which temperature is a function of time and is determined by a formula of T=f*EXP(−R*t), wherein T is the temperature in degrees centigrade, and t is the cooling time in minutes, wherein f is from 600° C. to 1000° C. and R is from 0.0009 to 0.01, and the function is non linear.