Composite metal oxide particles

Abstract

A powder of lithiated manganese oxide has an average particle diameter preferably less than about 250 nm. The particles have a high degree of uniformity and preferably a very narrow particle size distribution. The lithiated manganese oxide can be produce by the reaction of an aerosol where the aerosol comprises both a first metal (lithium) precursor and a second metal (manganese) precursor. Preferably, the reaction involves laser pyrolysis where the reaction is driven by heat absorbed from an intense laser beam.

What is claimed is:  
     
         1 . A method of producing composite metal oxide particles, the method comprising reacting a reactant stream to form, within the flow of the reactant stream, a powder of composite metal oxide particles with an average diameter less than about 500 nanometers, the reactant stream comprising a first metal compound precursor and a second metal compound precursor, wherein the reaction is driven by heat from a light beam and wherein the light beam intersects the reactant stream at a reaction zone.  
     
     
         2 . The method of  claim 1  wherein the composite metal oxide comprises lithiated manganese oxide.  
     
     
         3 . The method of  claim 1  wherein the composite metal oxide comprises lithiated vanadium oxide.  
     
     
         4 . The method of  claim 1  wherein a metal precursor comprises a compound selected from the group consisting of MnCl 2  and MnNO 3 .  
     
     
         5 . The method of  claim 1  wherein a metal precursor comprises a compound selected from the group consisting of LiCl and Li 2 NO 3 .  
     
     
         6 . The method of  claim 1  wherein a metal precursor comprises VOCl 2 .  
     
     
         7 . The method of  claim 7  wherein the light beam is generated by an infrared laser.  
     
     
         8 . The method of  claim 1  wherein the reaction is performed in a reaction chamber, the chamber having a cross section along a direction perpendicular to a reactant stream with a dimension along a major axis greater than a factor of about two larger than a dimension along a minor axis.  
     
     
         9 . The method of  claim 1  wherein the precursor comprises a third metal precursor.  
     
     
         10 . The method of  claim 1  wherein the reactant stream comprises an aerosol of the first metal precurosr and a vapor of the second metal precursor.  
     
     
         11 . The method of  claim 1  wherein the reactant stream comprises an aerosol.  
     
     
         12 . The method of  claim 11  wherein the aerosol is generated by a mechanical atomization aerosol generator.  
     
     
         13 . The method of  claim 1  wherein the reaction stream further comprises O 2 .  
     
     
         14 . The method of  claim 1  wherein the composite metal oxide particles have an average diameter less than about 250 nm.  
     
     
         15 . The method of  claim 1  wherein the composite metal oxide particles have an average diameter less than about 100 nm.  
     
     
         16 . The method of  claim 1  wherein the composite metal oxide particles have essentially no particles with a diameter greater than about 4 times the average diameter.  
     
     
         17 . A method of producing composite metal oxide particles, the method comprising reacting a reactant stream to form, within the flow of the reactant stream, a powder of composite metal oxide particles with an average diameter less than about 500 nanometers, the reactant stream comprising a first metal compound precursor, a second metal compound precursor and a third metal compound percursor.  
     
     
         18 . The method of  claim 17  wherein the reaction is driven by heat from a light beam and wherein the light beam intersects the reactant stream at a reaction zone.  
     
     
         19 . The method of  claim 17  wherein the reactant stream comprises an aerosol.  
     
     
         20 . The method of  claim 17  wherein the first metal precursor comprises lithium, the second metal precursor comprises manganese.