Rapid ceramic processing techniques and equipment
Provided herein are rapid, high quality film sintering processes that include high-throughput continuous sintering of lithium-lanthanum zirconium oxide (lithium-stuffed garnet). The instant disclosure sets forth equipment and processes for making high quality, rapidly-processed ceramic electrolyte films. These processes include high-throughput continuous sintering of lithium-lanthanum zirconium oxide for use as electrolyte films. In certain processes, the film is not in contact with any surface as it sinters (i.e., during the sintering phase).
1. A process for sintering a bilayer, the process comprising:
unwinding a bilayer roll to provide a bilayer;
heating the bilayer comprising a green body layer disposed on a metal layer in a furnace at about 1100° C. to about 1300° C. for about 5 seconds to about 3 minutes at a heating rate of higher than 300° C./min;
thereby providing a sintered bilayer comprising a lithium-stuffed garnet layer on the metal layer;
wherein the bilayer has a thickness, after sintering, of between about 10 μm and about 50 μm;
wherein the bilayer moves through the furnace at a rate between about 2 centimeters/minute and 100 centimeters/min; and
wherein the furnace comprises an atmospheric controller that maintains an atmosphere in the furnace that comprises argon (Ar) gas; nitrogen (N 2 ) gas; hydrogen gas; or a mixture thereof.
2. The process of claim 1 , further comprising a binder burn-out step prior to heating the bilayer at about 1100° C. to about 1300° C. for about 5 seconds to about 3 minutes.
3. The process of claim 2 , wherein the binder burn-out step occurs in a binder burn-out furnace.
4. The process of claim 2 , wherein the bilayer, prior to the binder burn-out step, comprises at least one member selected from a solvent, a binder, a dispersant, a plasticizer, a surfactant, or a combination thereof.
5. The process of claim 1 , wherein the lithium-stuffed garnet layer comprises compounds having the formula Li A La B Zr C O F , Li A La B M′ C M″ D Ta E O F , or Li A La B M′ C M″ D Nb E O F , wherein 4<A<8.5, 1.5<B<4, 0<C≤2, 0<D<2; 0<E<2.5, 10<F<13, and M′ and M″ are each, independently in each instance selected from Al, Mo, W, Nb, Ga, Sb, Ca, Ba, Sr, Ce, Hf, Rb, and Ta; or Li a La b Zr c Al d Me″ e O f , wherein 5<a<7.7; 2<b<4; 0<c≤2.5; 0<d<2; 0<e<2, 10<f<13 and Me″ is a metal selected from Nb, V, W, Mo, Ta, Ga, and Sb.
6. The process of claim 1 , wherein the metal layer comprises a metal selected from the group consisting of nickel, copper, iron, alloys thereof, and combinations thereof.
7. The process of claim 1 , wherein the bilayer has a thickness, after sintering, of between about 20 μm and about 40 μm.
8. The process of claim 1 , wherein the metal layer has a thickness of about 1 μm to about 20 μm.
9. The process of claim 1 , wherein the bilayer has a width, after sintering, of between about 0.8 mm to about 5 m.
10. The process of claim 1 , wherein the atmospheric controller maintains an atmosphere in the furnace comprising less than 500 ppm O 2 .
11. The process of claim 1 , further comprising rolling up the sintered bilayer.
12. The process of claim 1 , wherein the sintered lithium-stuffed garnet layer has a porosity of less than 5%.
13. The process of claim 1 , wherein the lithium stuffed garnet layer comprises 70-99% cubic garnet.