High Energy Density Cathode Materials for Lithium Ion Batteries

Example 1

[0081]Sol solutions were prepared from stoichiometric mixtures of Li(CH3COO).2H2O, Ni(CH3COO)).4H2O, and Mn(CH3COO)2.4H2O in distilled water. The solution was then added dropwise to a continuously stirred aqueous solution of citric acid. The pH of the mixed solution was adjusted by adding ammonium hydroxide solution. The solution was then heated at a temperature of about 75° C. overnight. A transparent gel was obtained. The resulting gel precursors were decomposed at a temperature of about 400° C. for about 10 hours in air and then calcined at a temperature of about 800° C. for about 10 hours.

Example 2

[0082]Sol solutions were prepared from stoichiometric mixtures of Li(CH3COO).2H2O, Ni(CH3COO)2.4H2O, and Mn(CH3COO)2.4H2O in distilled water. Chromium acetate was added to the distilled water according to the stoichiometry. The solution was then added dropwise to a continuously stirred aqueous solution of citric acid. The pH of the mixed solution was adjusted by adding ammonium hydroxide solution. The solution was then heated at a temperature of about 75° C. overnight. A transparent gel was obtained. The resulting gel precursors were decomposed at a temperature of about 400° C. for about 10 hours in air and then calcined at a temperature of about 800° C. for about 10 hours to produce a compound of the form Li2CrxNi0.5-x-yMn1.5+yO4.

Example 3

[0083]Sol solutions were prepared from stoichiometric mixtures of Li(CH3COO).2H2O, Ni(CH3COO)2.4H2O, and Mn(CH3COO)2.4H2O in distilled water. Copper acetate was added to the distilled water according to the stoichiometry. The solution was then added dropwise to a continuously stirred aqueous solution of citric acid. The pH of the mixed solution was adjusted by adding ammonium hydroxide solution. The solution was then heated at a temperature of about 75° C. overnight. A transparent gel was obtained. The resulting gel precursors were decomposed at a temperature of about 400° C. for about 10 hours in air and then calcined at a temperature of about 800° C. for about 10 hours to produce a compound of the form Li2CuxNi0.5-x-yMn1.5+yO4.