Thin film lithium conducting powder material deposition from flux
The present invention is directed to battery technologies and processing techniques thereof. In various embodiments, ceramic electrolyte powder material (or component thereof) is mixed with two or more flux to form a fluxed powder material. The fluxed powder material is shaped and heated again at a temperature less than 1100° C. to form a dense lithium conducting material. There are other variations and embodiments as well.
1. A method for making an electrolyte, the method comprising:
providing a lithium conducting garnet electrolyte powder at a first quantity, the lithium conducting garnet electrolyte powder being characterized by a first density and a median particle size of about 100 nm to 10 μm;
providing a first flux material at a second quantity, the first flux material comprising inorganic salts of lithium, the first flux material being characterized by a melting temperature of about 500-1000° C.;
providing a second flux material at a third quantity, the second flux material being characterized by a melting temperature of about 500-1000° C.;
mixing the first flux material and the second flux material with the lithium conducting garnet electrolyte powder to form a fluxed electrolyte powder;
shaping the fluxed electrolyte powder in to a predetermined shape;
flux sintering the shaped electrolyte powder at a temperature of greater than 100° C. and less than 800° C. to form a dense lithium conducting electrolyte, the dense lithium conducting electrolyte being characterized by a second density, the second density is at least 20% higher than the first density; and
removing the first and second flux materials from the dense lithium conducting electrolyte.
2. The method of claim 1 wherein the mixing step comprises mixing at least the first flux material and the second flux material to form a eutectic mixture, the eutectic mixture being characterized by a melting point of less than 800° C.; and subjecting the eutectic mixture to a temperature of about 100 to 1000° C.
3. The method of claim 1 , wherein the first quantity is more than 100% of the second quantity.
4. The method of claim 1 wherein the lithium conducting garnet electrolyte powder is Li A La B M′ C M″ D Zr E O F , where 4<A<8.5, 1.5<B<4, 0≤C≤2, 0≤D≤2, 0≤E<2, 10<F<14; and M′ is selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, and Ta; and M″ is selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, and Ta.
5. The method of claim 3 wherein the lithium conducting garnet electrolyte powder is Li A La B M′ C M″ D Zr E O F , where 4<A<8.5, 1.5<B<4, 0≤C≤2, 0≤D≤2, 0≤E<2, 10<F<14; and M′ is selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, and Ta; and M″ is selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, and Ta.
6. The method of claim 1 , wherein the lithium conducting garnet electrolyte powder comprises a garnet material with the formula Li 7 LaZr 2 O 12 .
7. The method of claim 1 , wherein the lithium conducting garnet electrolyte powder comprises a garnet material with the formula Li 7-x Al y La 3-y Zr 2 O 12 , wherein 0≤x≤2 and 0≤y≤3.
8. The method of claim 1 , wherein the lithium conducting garnet electrolyte powder comprises a garnet material with the formula Li 7-x La 3 Zr 2-x M x O 12 , wherein 0≤x≤2 and M is selected from Nb and Ta.