Lithium Battery Electrodes with Ultra-thin Alumina Coatings

• US 20120077082A1
• Filed: 06/13/2011
• Published: 03/29/2012
• Est. Priority Date: 06/14/2010
• Status: Active Grant

• Current Assignee: Alliance For Sustainable Energy LLC
• Original Assignee: Alliance For Sustainable Energy LLC
• Inventors: George, Steven M., Dillon, Anne C., Se-Hee, Lee, Cavanagh, Andrew S., Seok, Jung Yoon
• Granted Patent: US 9,196,901 B2
• Time in Patent Office: Days
• US Class Current: 429/209
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/628 Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Electrodes for lithium batteries are coated via an atomic layer deposition process. The coatings can be applied to the assembled electrodes, or in some cases to particles of electrode material prior to assembling the particles into an electrode. The coatings can be as thin as 2 Ångstroms thick. The coating provides for a stable electrode. Batteries containing the electrodes tend to exhibit high cycling capacities.

Claims

1. A process for preparing a lithium ion battery electrode, comprising shaping a mixture of particles of a cathode or anode material and a binder to form a shaped lithium ion battery electrode in which the particles are held together by the binder, and applying a coating to the shaped lithium ion battery electrode via an atomic layer deposition process.

2. The process of claim 1, wherein the coating has a thickness from 2 to 20 Å

ngstroms.

3. The process of claim 2, wherein the coating is an oxide of a metal or a semi-metal.

4. The process of claim 3, wherein the particles have a longest dimension of up to 5 μ

m.

5. The process of claim 1, wherein during the atomic layer deposition process, the reactants diffuse through the binder and react at the surface of the particles to coat particles in the electrode.

6. The process of claim 4, wherein the coating is alumina.

7. The process of claim 1, wherein the particles are of a cathode material.

8. The process of claim 7, wherein the cathode material is CoO₂, MnO, V₂O₅, V₆O₁₃ a lithium/cobalt composite oxide, a lithium/nickel composite oxide, lithium/manganese composite oxides whose basic composition is approximately LiMn₂O₄ or LiMnO₂, a lithium iron phosphate, a lithium iron phosphate fluoride, a lithium manganese phosphate, a lithium cobalt phosphates, a lithium iron manganese phosphate, SnO₂, SiO₂, lithium iron orthosilicate or a mixture of two or more thereof.

9. The process of claim 1, wherein the particles are of an anode material.

10. The process of claim 9 wherein the anode material is natural or artificial graphite, carbonized pitch, a carbon fiber, porous glass carbon, a graphitized mesophase microsphere, furnace black, acetylene black, lithium, silicon, germanium, molybdenum oxide or a mixture of two or more thereof.

11. A process for preparing a lithium ion battery cathode, comprising applying an coating having a thickness of about 2 to about 100 Å

ngstroms onto the surfaces of particles of a cathode material via an atomic layer deposition process, and then mixing the coated particles with a binder and shaping the mixture into an electrode in which the coated particles are held together by the binder.

12. The process of claim 11, wherein the coating has a thickness from 2 to 20 Å

ngstroms.

13. The process of claim 12, wherein the coating is an oxide of a metal or a semi-metal.

14. The process of claim 13, wherein the coating is alumina.

15. The process of claim 11 wherein the cathode material is CoO₂, MnO, V₂O₅, V₆O₁₃ a lithium/cobalt composite oxide, a lithium/nickel composite oxide, lithium/manganese composite oxides whose basic composition is approximately LiMn₂O₄ or LiMnO₂, a lithium iron phosphate, a lithium iron phosphate fluoride, a lithium manganese phosphate, a lithium cobalt phosphates, a lithium iron manganese phosphate, SnO₂, SiO₂, lithium iron orthosilicate or a mixture of two or more thereof.

16. A lithium ion battery cathode comprising particles of a cathode material bound together with a binder, wherein at least a portion of the particles are at least partially coated with a protective layer of from about 2 to about 100 Å

ngstroms in thickness.

17. A lithium ion battery electrode which is coated with a protective layer having a thickness of from 2 to about 100 Å

ngstroms.