Garnet materials for Li secondary batteries and methods of making and using garnet materials
Set forth herein are garnet material compositions, e.g., lithium-stuffed garnets and lithium-stuffed garnets doped with alumina, which are suitable for use as electrolytes and catholytes in solid state battery applications. Also set forth herein are lithium-stuffed garnet thin films having fine grains therein. Disclosed herein are novel and inventive methods of making and using lithium-stuffed garnets as catholytes, electrolytes and/or anolytes for all solid state lithium rechargeable batteries. Also disclosed herein are novel electrochemical devices which incorporate these garnet catholytes, electrolytes and/or anolytes. Also set forth herein are methods for preparing novel structures, including dense thin (<50 um) free standing membranes of an ionically conducting material for use as a catholyte, electrolyte, and, or, anolyte, in an electrochemical device, a battery component (positive or negative electrode materials), or a complete solid state electrochemical energy storage device. Also, the methods set forth herein disclose novel sintering techniques, e.g., for heating and/or field assisted (FAST) sintering, for solid state energy storage devices and the components thereof.
1. A method for making a lithium (Li) ion conducting thin film, the method comprising:
providing a reaction mixture comprising lithium-stuffed garnet or lithium-stuffed garnet chemical precursors;
milling the mixture;
providing a slurry comprising the mixture and a solvent;
depositing the slurry onto a substrate to form a thin film; and
sintering the thin film between and in direct contact with setter plates to form a sintered lithium-stuffed garnet thin film.
2. The method of claim 1 , wherein the precursors comprise one or more members selected from the group consisting of LiOH, Li 2 O, ZrO 2 , La 2 O 3 , Al 2 O 3 , AlNO 3 , Nb 2 O 5 , Ta 2 O 5 , Li 2 C 2 O 5 , AlN 2 O 5 -hydrate, AlN 2 O 5 .9H 2 O, and combinations thereof.
3. The method of claim 1 , further comprising depositing an additional layer of the mixture or the slurry onto the thin film to form a multilayer thin film before sintering the thin film between setter plates to form a sintered lithium-stuffed garnet thin film.
4. The method of claim 1 , wherein the milling step results in precursor particle sizes that have a d 50 of 1 μm or less.
5. The method of claim 4 , wherein the particle sizes have a d 50 of about 50 -200 nm.
6. The method of claim 1 , wherein the milling comprises solvent milling and wherein the solvent is a polar solvent.
7. The method of claim 6 , wherein the solvent is selected from the group consisting of toluene, isopropanol, ethanol, acetic acid, diacetone alcohol, acetonitrile, ethyl acetate, methyl ethyl ketone, and combinations thereof.
8. The method of claim 1 , wherein the substrate comprises a metal selected from the group consisting of Al, Ni, Cu, Au, Ag, Fe, steel, stainless steel, Li, alloys thereof, and combinations thereof.
9. The method of claim 1 , comprising calcining the film prior to sintering the thin film and at a temperature from about 300° C. to about 1000° C.
10. The method of claim 1 , comprising the step of depositing the slurry onto a substrate to form a thin film and subsequently evaporating the solvent prior to sintering the thin film.
11. The method of claim 1 , wherein the reaction mixture further comprises a member selected from the group consisting of NASICON, LISICON, and a tungsten bronze.
12. The method of claim 1 , wherein the reaction mixture further comprises a binder selected from the group consisting of polypropylene (PP), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), atactic polypropylene (aPP), isotactive polypropylene, ethylene propylene rubber (EPR), ethylene pentene copolymer (EPC), polyisobutylene (PIB), ZEON™, styrene butadiene rubber (SBR), polyolefins, polyethylene-co-poly-1-octene (PE-co-PO), PE-co-poly(methylene cyclopentane) (PE-co-PMCP), stereoblock polypropylenes, polypropylene polymethylpentene copolymer and silicone.
13. The method of claim 1 , wherein depositing comprises tape casting or slot-die coating.
14. The method of claim 1 , comprising sintering the thin film at about 1100° C. for about 15 minutes to about 2 hours.
15. The method of claim 1 , wherein the sintered lithium-stuffed garnet thin film is a free standing film.
16. The method of claim 1 , further comprising providing a rechargeable battery comprising the sintered lithium-stuffed garnet thin film.
17. The method of claim 1 , comprising:
sintering the thin film by applying pressure to the thin film with a setter plate.
18. The method of claim 17 , wherein applying pressure comprises applying the pressure applied by the weight of the setter plate resting on top of the thin film.
19. The method of claim 17 , comprising calcining the film prior to sintering the thin film and at a temperature from about 300° C. to about 1000° C.
20. The method of claim 17 , wherein the reaction mixture further comprises a binder selected from the group consisting of polypropylene (PP), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), atactic polypropylene (aPP), isotactive polypropylene ethylene propylene rubber (EPR), ethylene pentene copolymer (EPC), polyisobutylene (PIB), ZEON™, styrene butadiene rubber (SBR), polyolefins, polyethylene-co-poly-1-octene (PE-co-PO), PE-co-poly(methylene cyclopentane) (PE-co-PMCP), stereoblock polypropylenes, polypropylene polymethylpentene copolymer and silicone.
21. The method of claim 17 , comprising sintering the thin film at about 1100° C. for about 15 minutes to about 2 hours.
22. The method of claim 17 , further comprising providing a rechargeable battery comprising the sintered lithium-stuffed garnet thin film.
23. The method of claim 1 , further comprising depositing an additional layer of the mixture or the slurry onto the thin film to form a multilayer thin film before sintering the thin film between setter plates to form a sintered lithium-stuffed garnet thin film.