Process for making nano-sized and sub-micron-sized lithium-transition metal oxides

Abstract

A process is provided for making nano-sized or sub-micron sized oxides of lithium and a transition metal. The desired size is generally in the range 10 nm to 1000 nm and preferably in the range 10 nm to 100 nm. The particles have a narrow size distribution. The process includes milling and re-firing under controlled conditions so that crystallites of the desired particle size are grown.

1 . A process for producing a nano-sized or sub-micron oxide of lithium and a transition metal comprising: 
 a. milling a coarse lithium transition-metal oxide; and,    b. re-firing the lithium transition-metal oxide    
     
     
         2 . The process of  claim 1  wherein the lithium transition-metal oxide is tetra lithium titanate spinel  
     
     
         3 . The process of  claim 1  wherein the lithium transition-metal oxide is LiCoO 2 .  
     
     
         4 . The process of  claim 1  wherein the lithium transition-metal oxide is LiMn 2 O 4 .  
     
     
         5 . The process of  claim 1  wherein the milling is accomplished by wet-milling in a bead mill.  
     
     
         6 . The process of  claim 1  further comprising: 
 a. dispersing the product resulting from re-firing to liberate crystallites; and,    b. slurrying the crystallites to form a suspension.    
     
     
         7 . The process of  claim 1  further comprising milling the product resulting from re-firing to form a dispersed powder.  
     
     
         8 . The process of  claim 6  further comprising spray-drying the suspension.  
     
     
         9 . The process of  claim 8  further comprising milling the spray-dried product to form a dispersed powder.  
     
     
         10 . A lithium-transition metal oxide with a particle size between 10 nm and 1000 nm and a standard deviation of no more than 20%.  
     
     
         11 . A lithium-transition metal oxide with a particle size between 10 nm and 1000 nm and a standard deviation of no more than 20% made according to the process of  claim 1.