Lithium Lanthanum Zirconium Oxide (LLZO) Powder

Abstract

Disclosed herein are embodiments of doped and undoped spherical or spheroidal lithium lanthanum zirconium oxide (LLZO) powder products, and methods of production using microwave plasma processing, which can be incorporated into solid state lithium ion batteries. Advantageously, embodiments of the disclosed LLZO powder display a high quality, high purity stoichiometry, small particle size, narrow size distribution, spherical morphology, and customizable crystalline structure.

What is claimed is: 
     
         1 . A method of processing a material in a microwave plasma having a selected length to produce particular characteristics of the material, the method comprising:
 flowing at least one gas into a reaction chamber of a microwave plasma apparatus, the reaction chamber having a length;   igniting the at least one gas to form a microwave plasma by providing microwave radiation to the reaction chamber;   tuning a length of the microwave plasma and a reactor temperature within the length of the reaction chamber by adjusting at least microwave power, gas flow rate and gas flow characteristics so that the length of the microwave plasma is at least 15 feet and up to 30 feet; and   injecting a feedstock material at one or more locations surrounding the microwave plasma and at a selected position along the length of the microwave plasma so that the feedstock material is exposed to a desired temperature and provided with a desired residence time in order to impart the desired characteristics to the material.   
     
     
         2 . The method of  claim 1 , wherein the microwave power is between 2 kW and 120 kW. 
     
     
         3 . The method of  claim 1 , wherein the length of the plasma is at least half of the length of the reaction chamber length. 
     
     
         4 . The method of  claim 1 , wherein the gas flow rate is between 1 CFM and 20 CFM. 
     
     
         5 . The method of  claim 1 , wherein the length of the microwave plasma is further tuned based on a microwave plasma torch type. 
     
     
         6 . The method of  claim 1 , wherein the length of the microwave plasma is further tuned based on a pressure in the reaction chamber. 
     
     
         7 . The method of  claim 1 , wherein increasing the length of the plasma increases the crystallinity of the material. 
     
     
         8 . The method of  claim 1 , wherein the length of the microwave plasma is further tuned based on a plasma torch diameter. 
     
     
         9 . The method of  claim 8 , wherein the plasma torch diameter is between 0.5 inches and 4 inches. 
     
     
         10 . The method of  claim 1 , wherein the length of the microwave plasma is tuned to produce an at least 99% crystalline material. 
     
     
         11 . A microwave plasma processing system comprising:
 a reaction chamber having a reaction chamber length;   a gas supply configured to flow at least one gas into the reaction chamber;   a microwave radiation source configured to provide microwave radiation to the reaction chamber to ignite the at least one gas to form a microwave plasma having a plasma length, the plasma length configurable within the length of the reaction chamber by adjusting at least microwave power, gas flow rate and gas flow characteristics so that the length of the microwave plasma is at least 15 feet and up to 30 feet; and   one or more locations surrounding the microwave plasma configured to allow injection of feedstock material at a selected position along the length of the microwave plasma so that the feedstock material is exposed to a desired temperature and provided with a desired residence time in order to impart the desired characteristics to the material.   
     
     
         12 . The microwave plasma system of  claim 11 , wherein the microwave power is configurable between 2 kW and 120 kW. 
     
     
         13 . The microwave plasma system of  claim 11 , wherein the plasma length is configurable to at least half of the length of the reaction chamber. 
     
     
         14 . The microwave plasma system of  claim 11 , wherein the gas flow rate is configurable between 1 CFM and 20 CFM. 
     
     
         15 . The microwave plasma system of  claim 11 , wherein the plasma length is further configurable by adjusting a plasma torch diameter between 0.5 inches and 4 inches. 
     
     
         16 . The microwave plasma system of  claim 11 , wherein the plasma length is further configurable by adjusting the gas flow to be laminar or turbulent. 
     
     
         17 . A method of processing a material in a microwave plasma having a selected length to produce particular characteristics of the material, the method comprising:
 flowing at least one gas into a reaction chamber of a microwave plasma apparatus, the reaction chamber having a length;   igniting the at least one gas to form a microwave plasma by providing microwave radiation to the reaction chamber;   tuning a length of the microwave plasma and a reactor temperature within the length of the reaction chamber by adjusting at least microwave power, gas flow rate and gas flow characteristics; and   injecting a feedstock material at one or more locations surrounding the microwave plasma and at a selected position along the length of the microwave plasma so that the feedstock material is exposed to a desired temperature and provided with a desired residence time in order to impart the desired characteristics to the material.   
     
     
         18 . The method of  claim 17 , wherein the reaction chamber has a length between 8 feet and 30 feet. 
     
     
         19 . The method of  claim 17 , wherein the length of the reaction chamber is between a lower end value selected from the group consisting of 5 feet, 8 feet, 10 feet, 15 feet, 20 feet, and an upper end value of 30 feet. 
     
     
         20 . The method of  claim 19 , wherein the length of the microwave plasma is tuned to occupy a majority of the length of the reaction chamber.