Process for preparing mixed metal oxides

A process for preparing a mixed metal oxide having the formula LiCoO.sub.2, which comprises

• preparing a mixed aqueous solution containing equimolar amounts of lithium nitrate and cobalt nitrate;
• concentrating the mixed solution by evaporating it;
• co-crystallizing an equimolar mixed lithium cobalt nitrate salt from the concentrated mixed solution by rapidly freeze drying the concentrated mixed solution;
• and
• calcining the co-crystallized mixed salt at a low temperature of from about 400.degree. C. to about 500.degree. C. for a short period of time of from about 1 hour to about 4 hours in a stream of air to form the mixed metal oxide.

A process for preparing a mixed metal oxide having the formula Li(Co.sub.0.5 Ni.sub.0.5)O.sub.2 which comprises

• preparing a mixed aqueous solution containing one mole of lithium nitrate and one-half mole each of cobalt nitrate and nickel nitrate;
• concentrating the mixed solution by evaporating it;
• co-crystallizing a mixed lithium cobalt-nickel nitrate salt from the concentrated mixed solution by rapidly freeze drying the concentrated mixed solution;
• and
• calcining the co-crystallized mixed salt at a low temperature of from about 400.degree. C. to about 500.degree. C. for a short period of time of from about 1 hour to about 4 hours in a stream of air to form the mixed metal oxide.