Method of tuning the conversion temperature of cubic phase of aluminum-doped lithium lanthanum zirconium oxide
A process for forming cubic LLZO through the use of atomic mixing of metal salts used in an aerosol process. The cubic LLZO is formed at temperatures below 1000° C.
1. A method, comprising:
mixing metal nitrate salts comprising lanthanum nitrate, lithium nitrate, aluminum nitrate, and zirconium nitrate;
forming a feed solution comprising a dopant with the metal nitrate salts in a solvent;
generating a droplet from the feed solution;
converting the droplet to an atomically mixed powder; and
calcining the atomically mixed powder at a temperature less than 1000° C., forming cubic LLZO.
2. The method of claim 1 , wherein the solvent is flammable and converting the droplet to a powder comprises flame spray pyrolysis.
3. The method of claim 1 , wherein the dopant comprises aluminum, the dopant being different a different composition than the aluminum nitrate.
4. The method of claim 1 , wherein the calcining is at a calcination temperature is below 800° C.
5. The method of claim 1 , wherein the calcining is at a calcination temperature is 650° C. to 900° C.
6. The method of claim 1 , wherein converting the droplet to a powder comprises converting at least a portion of the droplets to particles without combusting the portion of the droplets.
7. The method of claim 1 , converting the droplet to a powder comprises combusting a second portion of the droplets a flame forming a gas and further converting the gas into particles.
8. The method of claim 1 , where converting the droplet comprises drying the droplets via a spray drying process.
9. The method of claim 1 , wherein converting the droplet comprises pyrolysis via a spray pyrolysis process.
10. A method, comprising:
forming a feed solution comprising an aluminum dopant, lanthanum precursor, lithium precursor, and zirconium precursor dissolved in a solvent comprising xylene and ethylhexanoic acid;
generating a plurality of droplets 2-10 microns in diameter;
exposing the plurality of droplets to a flame;
converting at least a portion of the plurality of droplets to particles, forming a powder comprising atomically mixed aluminum, lanthanum, lithium, and zirconium; and
calcinating powder at a calcine temperature of 650° C. to 1000° C. to form a cubic LLZO.
11. The method of claim 10 , wherein the aluminum dopant is alumatrane.
12. The method of claim 10 , wherein the feed solution comprises 3-9% ceramic loading.
13. The method of claim 10 , wherein exposing the plurality of droplets to the flame comprise directing the flame with a flame guide.
14. The method of claim 10 , wherein the cubic LLZO has a formula of Li (7-3x) La 2 Zr 3 O 7 Al x where x is 0.19 to 0.389.
15. The method of claim 10 , wherein the cubic LLZO has a formula of Li (7-3x) La 2 Zr 3 O 7 Al x where x is 0.25.