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. 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. Disclosed herein are novel electrochemical devices which incorporate these garnet catholytes, electrolytes and/or anolytes. Set forth herein are methods for preparing novel structures, including dense thin 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. The methods set forth herein disclose novel sintering techniques, for solid state energy storage devices and the components thereof.
1. A thin unsintered film, comprising
lithium-stuffed garnet precursor powders or calcined lithium-stuffed garnet powder;
at least one member selected from the group consisting of a binder, a solvent, a dispersant, and combinations thereof;
wherein the solid loading of the lithium-stuffed garnet precursor powders or the calcined lithium-stuffed garnet powder is at least 65% by volume (v/v); and
wherein the film thickness is less than 100 μm; and wherein the median grain size of the lithium-stuffed garnet precursor powders or the calcined lithium-stuffed garnet powder is between 0.1 μm and 10 μm.
2. The thin unsintered film of claim 1 , wherein the lithium-stuffed garnet is characterized by the empirical formula Li A La B M' c M″ D Zr E O F , wherein 5<A<8, 1.5<B<4, 0.1≤C≤2, 0 <D≤2; 1≤E≤2, 10<F≤13, and
M′ is A1; and
M″ is selected from the group consisting of Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, and Rb.
3. The thin unsintered film of claim 1 , wherein the lithium-stuffed garnet is characterized by the empirical formula
Li A La B M′ c M″ D Zr E O F , wherein 6.5<A<8, 1.5<B<4, 0.1≤C≤2, 0<D≤2; 1≤E≤2, 10<F≤13,
M′ is A1; and
M″ is Ta.
4. The thin unsintered film of claim 1 , wherein the thin unsintered garnet film is adhered to a substrate.
5. The thin unsintered film of claim 4 , wherein the substrate is selected from the group consisting of a polymer, a metal foil, a metal powder, a metal powder film, or a metal coating.
6. The thin unsintered film of claim 5 , wherein the metal is selected from the group consisting of Ni, Cu, Al, steel, alloys, and combinations thereof.
7. The thin unsintered film of claim 1 , wherein the solid loading is at least 65 v/v to 80% v/v.
8. The thin unsintered film of claim 1 , wherein the thin unsintered garnet film thickness is less than 50 μm and greater than 10 nm.
9. The thin unsintered film of claim 1 , wherein the thin unsintered garnet film is free standing.
10. The thin unsintered film of claim 8 , wherein:
the thin unsintered garnet film is bonded to a current collector (CC) film on at least one side of the thin unsintered garnet film; and
the CC film comprises a metal or metal powder, wherein the metal is selected from the group consisting of Nickel (Ni), Copper (Cu), combinations thereof, and alloys thereof.
11. The thin unsintered film of claim 10 , wherein the thin unsintered garnet film is bonded to a CC film on one side of the film.
12. The thin unsintered film of claim 10 , wherein the thin unsintered garnet film is bonded to a CC film on two sides of the film.
13. A bilayer comprising a metal foil or metal powder positioned in contact with a thin unsintered film according to claim 2 .
14. A trilayer comprising a metal foil or metal powder and two unsintered films according to claim 2 , wherein the metal foil or metal powder is positioned between and in contact with the two thin unsintered films according to claim 2 .
15. The thin unsintered film 2 , wherein the film thickness is 10 μm to 100 μm.