Lithium metal oxide materials and methods of synthesis and use

Abstract

A composition having a formula Li x Mg y NiO 2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.91<x+y<1.3 can be utilized as cathode materials in electrochemical cells. A composition having a core, having a formula Li x Mg y NiO 2 wherein 0.9<x<1.3, 0.01<y<0.1, and 0.9<x+y<1.3, and a coating on the core, having a formula Li a Co b O 2 wherein 0.7<a<1.3, and 0.9<b<1.2, can also be utilized as cathode materials in electrochemical cells.

1 - 23 . (canceled) 
     
     
         24 . A method of preparing coated particles comprising steps of:
 providing a first mixture of compounds comprising a lithium source, a magnesium source, and a nickel source and heating the first mixture in an oxidizing atmosphere at a first temperature of about 350°-700° C. and for a first period sufficient to crystallize the first mixture into core particles having a formula Li x Mg y NiO 2  wherein 0.9<x<1.3, 0.01<y<0.1, and 0.91<x+y<1.3; and   coating the core particles with a second mixture comprising compounds comprising lithium and cobalt and heating the coated core particles at a second temperature of about 600°-800° C. and for a second period sufficient to crystallize a material having a formula Li a Co b O 2  wherein 0.7<a<1.3, and 0.9<b<1.2.   
     
     
         25 . The method of  claim 24  wherein 0.9<x<1.1, 0.02<y<0.05, 0.9<a<1.3, and 0.9<b<1.2. 
     
     
         26 . The method of  claim 24  wherein heating the first mixture comprises heating the first mixture at a rate of about 5° C. per minute to a first soaking temperature of between about 400° C. and 500° C. and heating the first mixture at a rate of about 2° C. per minute to a second soaking temperature of between about 650° C. and 750° C. 
     
     
         27 . The method of  claim 26  wherein heating the first mixture further comprises maintaining the first soaking temperature for about one to about six hours and maintaining the second soaking temperature for about one to about eight hours. 
     
     
         28 . The method of  claim 24  wherein heating the coated core particles comprises heating the coated core particles at a rate of about 2° C. per minute to a third soaking temperature of between about 90° C. and about 120° C. 
     
     
         29 . The method of  claim 28  wherein heating the coated core particles further comprises maintaining the third soaking temperature for about one hour. 
     
     
         30 . The method of  claim 29  wherein heating the coated core particles further comprises heating the coated core particles at a rate of about 5° C. per minute to a fourth soaking temperature in the range from about 300° C. and about 500° C. 
     
     
         31 . The method of  claim 30  wherein heating the coated core particles further comprises maintaining the fourth soaking temperature for about one hour. 
     
     
         32 . The method of  claim 24  wherein heating the coated core particles further comprises heating the coated core particles at a rate of about 2° C. per minute to a fifth soaking temperature in the range of from about 650° C. to about 750° C. 
     
     
         33 . The method of  claim 32  wherein heating the coated core particles further comprises maintaining the fifth soaking temperature for about two hours. 
     
     
         34 . The method of  claim 24  wherein the magnesium source comprises Mg(OH) 2 , the lithium source comprises LiNO 3  and LiOH, and the nickel source comprises Ni(OH) 2 . 
     
     
         35 - 38 . (canceled)