Lithium-garnet solid electrolyte composite, tape articles, and methods thereof

Patent metadata

Field	Value
Publication number	US-12074282-B2
Application number	US-202318225927-A
Country	US
Kind code	B2
Filing date	Jul 25, 2023
Priority date	Apr 17, 2017
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

A composite ceramic including: a lithium garnet major phase; and a grain growth inhibitor minor phase, as defined herein. Also disclosed is a method of making composite ceramic, pellets and tapes thereof, a solid electrolyte, and an electrochemical device including the solid electrolyte, as defined herein.

First claim

What is claimed:

1. A composite ceramic comprising:
a lithium garnet major phase; and
a grain growth inhibitor minor phase positioned between grains of the lithium garnet major phase, wherein the grain growth inhibitor minor phase is present from 3 wt % to 9 wt % based on a total weight of the composite ceramic, and the lithium garnet major phase has a cubic garnet crystal structure.

2. The composite ceramic of claim 1 , wherein the lithium garnet major phase has a formula of Li 7-x La 3 (Zr 2-x , M x )O 12 , where M is selected from a group consisting of V, Nb, Ta, or a mixture thereof, and x is greater than 0 and less than 1.

3. The composite ceramic of claim 1 , wherein the lithium garnet major phase has a formula of Li 6.5 La 3 Zr 1.5 Ta 0.5 O 12 .

4. The composite ceramic of claim 1 , wherein the lithium garnet major phase is present from 91 wt % to 97 wt % of the total weight of the composite ceramic.

5. The composite ceramic of claim 1 , wherein the composite ceramic has a formula of Li 7-x La 3 (Zr 2-x , M x )O 12 -SA, where:
M is selected from a group consisting of V, Nb, Ta, or a mixture thereof;
x is greater than 0 and less than 1; and
“SA” comprises a second additive oxide, present in from 3 to 9 wt % based on the total weight of the composite ceramic, and the second additive oxide comprising MgO, CaO, ZrO 2 , HfO 2 , or a mixture thereof.

6. The composite ceramic of claim 1 , wherein an average grain size of the lithium garnet major phase is under 10 micrometers.

7. The composite ceramic of claim 1 , wherein the composite ceramic has a mechanical strength of greater than or equal to 100 MPa.

8. The composite ceramic of claim 1 , wherein the composite ceramic has an ion conductivity greater than or equal to 1×10 −4 S/cm.

9. The composite ceramic of claim 1 , wherein a density of the composite ceramic is at least 95% of a theoretical maximum density of the composite ceramic.

10. A ceramic electrolyte comprising the composite ceramic of claim 1 , wherein a thickness of the ceramic electrolyte is from 20 micrometers to 300 micrometers.

11. An electrochemical device comprising: a negative electrode; a positive electrode; and an interposed solid electrolyte material, wherein the interposed solid electrolyte material comprises the composite ceramic of claim 1 .

12. A method of making the composite ceramic of claim 1 , comprising:
a first mixing of inorganic source materials to form a mixture, including a lithium source compound, and other suitable inorganic source materials to make a desired garnet composition;
a first milling of the mixture to reduce a particle size of the inorganic source materials in the mixture to form a milled mixture;
calcining the milled mixture to form a garnet oxide at from 800° C. to 1200° ° C. to form a milled and calcined garnet oxide;
a second mixing of the milled and calcined garnet oxide and a second additive to provide a second mixture;
a second milling of the second mixture to reduce a particle size of constituents of the second mixture to form a second milled second mixture;
tape casting the second milled second mixture to form a green tape; and
sintering the green tape at from 600° C. to 1300° C. to form a tape of the composite electrolyte, wherein the composite electrolyte has a cubic garnet crystal structure.

13. The method of claim 12 , wherein the lithium source compound is present in a stoichiometric excess.

14. The method of claim 12 , wherein the sintering is accomplished in air, in an inert atmosphere, or first in air then in an inert atmosphere.

15. The method of claim 12 , wherein the sintering is accomplished in air at from 1000° ° C. to 1300° C.

16. The method of claim 12 , wherein the particle size of the first milling is from 0.3 micrometers to 4 micrometers, and the particle size of the second milling is from 0.15 micrometers to 2 micrometers.

17. The composite ceramic of claim 1 , wherein the composite ceramic is a zirconia-containing lithium garnet.

18. The composite ceramic of claim 1 , wherein the grain growth inhibitor comprises ZrO 2 .

19. The composite ceramic of claim 1 , wherein the grain growth inhibitor comprises HfO 2 .

20. The composite ceramic of claim 1 , wherein the grain growth inhibitor comprises CaO.

Assignees

• Corning Inc
• Shanghai Inst Ceramics Cas
• Shanghai Inst Of Ceramic Chinese Academy Of Sciences

Inventors

• Badding Michael Edward
• Chen Yinghong
• Huang Xiao
• Liu Cai
• Liu Xinyuan
• Lu Yanxia Ann
• Song Zhen
• Wen Zhaoyin
• Xiu Tongping
• Zink Nathan Michael

Classifications

• C04B2235/85

  Intergranular or grain boundary phases · CPC title

• C04B2235/3203

  Lithium oxide or oxide-forming salts thereof · CPC title

• C04B2235/3208

  Calcium oxide or oxide-forming salts thereof, e.g. lime · CPC title

• C04B2235/77

  Density · CPC title

• C04B2235/3217

  Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina · CPC title