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 thin unsintered film, comprising:
lithium-stuffed garnet precursor powders or calcined lithium-stuffed garnet powder; and
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 30% by volume (v/v);
wherein the unsintered film thickness is less than 100 μm; and
wherein the unsintered film is in contact with a second film comprising a metal powder.
2. The thin unsintered film of claim 1 , wherein the solid loading of the lithium-stuffed garnet precursor powders or the calcined lithium-stuffed garnet powder is at least 40% by volume (v/v).
3. The thin unsintered film of claim 1 , wherein the solid loading of the lithium-stuffed garnet precursor powders or the calcined lithium-stuffed garnet powder is at least 45% by volume (v/v).
4. The thin unsintered film of claim 1 , wherein the solid loading of the lithium-stuffed garnet precursor powders or the calcined lithium-stuffed garnet powder is from 40% to 80% by volume (v/v).
5. 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;
M′ is Al; and
M″ is selected from the group consisting of Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, and Rb.
6. 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 Al; and
M″ is Ta.
7. The thin unsintered film of claim 1 , wherein the metal powder comprises a metal selected from the group consisting of Ni, Cu, Al, steel, and alloys and combinations thereof.
8. The thin unsintered film of claim 1 , wherein the thin unsintered film thickness is less than 50 μm and greater than 10 nm.
9. The thin unsintered film of claim 1 , wherein the thin unsintered film has a thickness from 10 μm to 100 μm.