| abstract |
Composite lithium oxide is produced by co-precipitating a composite Ni-Co hydroxide from a mixed salt solution using aqueous ammonia solution as complexing agent, adding lithium hydroxide and heat treating. A composite lithium oxide of formula LiaNi1-xCoxO2 (I), where a = 0.97 to 1.05 and x = 0.1 to 0.3, is produced by: (a) co-precipitating a composite Ni-Co hydroxide by adding an aqueous ammonia complexing solution and an alkaline pH adjusting solution to an aqueous cobalt and nickel salt solution; (b) adding lithium hydroxide and heat treating at 280-420 deg C; and (c) heat treating the product at 650-750 deg C. Independent claims are also included for the following: (i) a composite lithium oxide having the formula LiaNi1-x-yCoxMyO2 (II), (where M = one or more of Al, Ca, Mg and B, a = 0.97 to 1.05, x = 0.1 to 0.3 and y = 0 to 0.05), and comprising primary particles of rectangular or square structure which are agglomerated to form either spherical secondary particles with a vibrated density of 2.4-3.2 g/cm<3> or irregular secondary particles; and (ii) a secondary lithium ion cell containing a non-aqueous electrolyte, a carbonaceous material-containing cathode and an anode which contains the above composite lithium oxide as active material. |