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Abstract

This invention discloses compounds of lithium nickel cobalt metal oxide and the methods of their fabrication. The formula for said compounds of lithium nickel metal of oxide is Li.sub.aNi.sub.1-b-cCo.sub.bM.sub.cO.sub-.2 where 0.97.ltoreq.a.ltoreq.1.05 , 0.01.ltoreq.b.ltoreq.0.30 , 0.ltoreq.c.ltoreq.0.10, and M is one or more or the following: manganese, aluminum, titanium, chromium, magnesium, calcium, vanadium, iron, and zirconium. The method for the fabrication of said compounds of lithium nickel cobalt metal oxide includes: (a) fabricating a cobalt nickel hydroxy compound; (b) ballgrinding to evenly mix said cobalt nickel hydroxy compound; a lithium compound and compound of said metal M; (c) calcining said mixture in oxygen at between 600.degree. C. and 720.degree. C. for 1 hour to 10 hours; (d) calcining a second time in oxygen at between 750.degree. C. and 900.degree. C. for 8 hours to 10 hours; (e) cooling the twice calcined compound rapidly; (f) ballgrinding and then sifting the cooled compound to obtain said compound of lithium nickel cobalt metal oxide. The fabrication method of this invention produces said compound containing a high percentage of secondary granules that are formed by the aggregation of crystalline granules. These granules are spherically or elliptically shaped with no halite magnetic domains resulting in a material that has excellent electrochemical properties. Using these materials in the positive electrodes of rechargeable batteries produce batteries with high capacity and good cycle characteristics.

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First Claim