Solvent-free processing of lithium lanthanum zirconium oxide coated-cathodes
A dry process for coating Ni-rich cathode powder with cubic LLZO powder prepared by flame spray pyrolysis.
1. A method, comprising:
dry mixing, by ball-milling, a nickel rich lithium metal oxide cathode material with a doped LLZO powder until the nickel rich lithium metal oxide cathode material has a particle size of at least 6 microns and equal to or less than 15 microns, wherein the LLZO consisting of primary particles between 200 nanometers to 1 micrometer in size, forming a LLZO-cathode material mixture of 90-99.9 wt % nickel rich lithium metal oxide cathode material and 0.1 to 10 wt % doped LLZO powder; and
calcining the dry LLZO-cathode material mixture between 300° C. and 700° C. for 1-10 hours under a flowing oxygen atmosphere.
2. The method of claim 1 , wherein the doped LLZO powder comprises aluminum, tantalum, yttrium, iron, tellurium, tungsten, niobium, barium, cerium, titanium, boron, antimony, or gallium as a dopant which replaces 3-50 mol % of Li or Zr in Li 7 La 3 Zr 2 O 12 .
3. The method of claim 1 , wherein the nickel rich lithium metal oxide cathode material comprises LiNi x Co y Mn z O 2 material, where x+y+z=1, further wherein x≥0.6.
4. The method of claim 1 , wherein mixing is at 50-300 RPM for 5-90 minutes.
5. An electrochemical cell comprising the LLZO coated lithium nickel oxide of claim 1 as the cathode material.
6. A method, comprising:
forming a doped cubic LLZO powder by flame spray pyrolysis;
dry ball-milling a nickel rich lithium metal oxide cathode material until the nickel rich lithium metal oxide cathode material has a particle size of at least 6 microns and equal to or less than 15 microns with the doped LLZO powder comprising Li 7 La 3 Zr 2 O 12 with 3-50 mol % of one or both of Li and Zr replaced with an aluminum dopant, wherein the LLZO consisting of primary particles between 200 nanometers to 1 micrometer in size;
forming a dry LLZO-cathode material mixture of 90-99.9 wt % nickel rich lithium metal oxide cathode material and 0.1 to 10 wt % doped LLZO powder; and
calcining the dry LLZO-cathode material mixture between 300° C. and 700° C. for 1-10 hours under a flowing oxygen atmosphere.
7. The method of claim 6 , wherein the nickel rich lithium metal oxide cathode material comprises LiNi x Co y Mn z O 2 material, further wherein x+y+z=1.
8. The method of claim 7 , wherein x≥0.6.
9. The method of claim 6 , wherein mixing is by a ball milling process at 50-300 RPM for 5-90 minutes.
10. The method of claim 2 , wherein the dopant is aluminum.