Solid ceramic electrolytes

Patent metadata

Field	Value
Publication number	US-9876247-B2
Application number	US-201213677654-A
Country	US
Kind code	B2
Filing date	Nov 15, 2012
Priority date	Nov 15, 2012
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A solid ceramic electrolyte may include an ion-conducting ceramic and at least one grain growth inhibitor. The ion-conducting ceramic may be a lithium metal phosphate or a derivative thereof. The grain growth inhibitor may be magnesia, titania, or both. The solid ceramic electrolyte may have an average grain size of less than about 2 microns. The grain growth inhibitor may be between about 0.5 mol. % to about 10 mol. % of the solid ceramic electrolyte.

First claim

I claim:

1. A solid ceramic electrolyte consisting of an ion-conducting ceramic and a grain growth inhibitor, wherein:
the ion-conducting ceramic consists of a lithium metal phosphate compound;
the grain growth inhibitor is selected from the group consisting of magnesia, titania, and a mixture of magnesia and titania;
the solid ceramic electrolyte is substantially free of glass, glass-ceramic and polymer phases;
the solid ceramic electrolyte is physically stable when in contact with an aqueous solution for at least about 24 hours; and
the grain growth inhibitor comprises between about 0.5 mol. % to about 10 mol. % of the solid ceramic electrolyte.

2. The solid ceramic electrolyte of claim 1 , wherein the grain growth inhibitor consists essentially of titania.

3. The solid ceramic electrolyte of claim 1 , wherein the grain growth inhibitor consists essentially of magnesia.

4. The solid ceramic electrolyte of claim 1 , wherein the grain growth inhibitor comprises titania and magnesia.

5. The solid ceramic electrolyte of claim 4 , wherein a molar ratio of titania to magnesia (titania:magnesia) is between about 2:1 to about 8:1.

6. The solid ceramic electrolyte of claim 1 , wherein the grain growth inhibitor comprises between about 3 mol. % to about 6 mol. % of the solid ceramic electrolyte.

7. The solid ceramic electrolyte of claim 1 , wherein the solid ceramic electrolyte has an ion conductivity of at least about 1×10 −4 S/cm.

8. The solid ceramic electrolyte of claim 1 , wherein the lithium metal phosphate compound is lithium aluminum titanium phosphate (LATP).

9. The solid ceramic electrolyte of claim 1 , wherein the lithium metal phosphate compound is Li 1+x Al x Ti 2−x (PO 4 ) 3 , where x is between 0 and 0.6.

10. The solid ceramic electrolyte of claim 1 , wherein a thickness of the solid ceramic electrolyte is less than about 200 microns.

11. The solid ceramic electrolyte of claim 1 , wherein a density of the solid ceramic electrolyte is at least 95% of a theoretical maximum density of the solid ceramic electrolyte.

12. A method of forming the solid ceramic electrolyte of claim 1 , the method comprising:
combining an ion-conducting ceramic with at least one grain growth inhibitor to form a mixture, wherein the ion-conducting ceramic comprises a lithium metal phosphate compound and the grain growth inhibitor is selected from the group consisting of magnesia, titania, a magnesia precursor and a titania precursor;
casting the mixture to form a body; and
sintering the body to form the solid ceramic electrolyte.

13. The method of claim 12 , wherein a sintering temperature is equal to or less than about 950° C.

14. The method of claim 12 , wherein the casting comprises tape casting.

15. The method of claim 12 , wherein the body comprises a binder, a plasticizer, or both.

16. The method of claim 12 , wherein the ion-conducting ceramic has an average particle size of less than about 1 micron.

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

18. The electrochemical device of claim 17 , wherein a thickness of the solid ceramic electrolyte is less than about 200 microns.

19. The electrochemical device of claim 17 , wherein the electrochemical device is a lithium-air battery.

Assignees

• Brown Jacqueline Leslie
• Corning Inc

Inventors

• Brown Jacqueline Leslie

Classifications

• H01M6/16

  with organic electrolyte (H01M6/18 takes precedence) · CPC title

• H01M6/04

  Cells with aqueous electrolyte · CPC title

• C04B2235/3203

  Lithium oxide or oxide-forming salts thereof · CPC title

• H01M8/124

  characterised by the process of manufacturing or by the material of the electrolyte · CPC title

• C04B2235/786

  Micrometer sized grains, i.e. from 1 to 100 micron · CPC title