Method for producing dense lithium lanthanum tantalate lithium-ion conducting ceramics

Patent metadata

Field	Value
Publication number	US-9963394-B2
Application number	US-201615010875-A
Country	US
Kind code	B2
Filing date	Jan 29, 2016
Priority date	Feb 2, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A method to produce high density, uniform lithium lanthanum tantalate lithium-ion conducting ceramics uses small particles that are sintered in a pressureless crucible that limits loss of Li 2 O.

First claim

We claim:

1. A method for producing a lithium lanthanum tantalate ceramic, comprising:
dissolving lithium nitrate in an alcohol solvent;
dissolving lanthanum acetate in an acid solvent;
suspending tantalum oxide in an alcohol;
blending the lithium nitrate solution, the lanthanum acetate solution, and the tantalum oxide suspension and evaporating the solvents to provide a stoichiometric mixture;
combusting the stoichiometric mixture at a sufficiently high temperature to remove organics, thereby providing an inorganic mixture;
calcining the inorganic mixture at a sufficiently high temperature to remove carbonates, thereby providing a mixed oxide powder; and
sintering the mixed oxide powder in a closed and non-reactive crucible at a sufficiently high temperature and pressure to provide a dense lithium lanthanum tantalate ceramic.

2. The method of claim 1 , wherein the alcohol solvent for dissolving lithium nitrate comprises ethanol.

3. The method of claim 1 , wherein the acid solvent for dissolving lanthanum acetate comprises propionic acid.

4. The method of claim 1 , wherein the alcohol for suspending tantalum oxide comprises ethanol.

5. The method of claim 1 , wherein the sufficiently high temperature for combusting is greater than 500° C.

6. The method of claim 1 , wherein the sufficiently high temperature for calcining is greater than 800° C.

7. The method of claim 1 , wherein the sufficiently high temperature for sintering is greater than 1000° C.

8. The method of claim 1 , wherein the sufficiently high pressure for sintering is ambient pressure.

9. The method of claim 1 , wherein the closed and non-reactive crucible comprises a platinum crucible.

10. The method of claim 1 , wherein the closed and non-reactive crucible comprises a transition metal crucible.

11. The method of claim 10 , wherein the transition metal comprises nickel, platinum, palladium, iridium, or alloys thereof.

Assignees

• Sandia Corp
• Nat Tech & Eng Solutions Sandia Llc

Inventors

• Brown-Shaklee Harlan James
• Ihlefeld Jon
• Spoerke Erik David
• Blea-Kirby Mia Angelica

Classifications

• C04B35/495 Primary

  based on vanadium, niobium, tantalum, molybdenum or tungsten oxides or solid solutions thereof with other oxides, e.g. vanadates, niobates, tantalates, molybdates or tungstates · CPC title

• C04B35/62645

  Thermal treatment of powders or mixtures thereof other than sintering · CPC title

• C04B2235/3203

  Lithium oxide or oxide-forming salts thereof · CPC title

• C04B2235/668

  Pressureless sintering · CPC title

• C04B2235/449

  Organic acids, e.g. EDTA, citrate, acetate, oxalate · CPC title