Reactive sintering of ceramic lithium ion electrolyte membranes

• US 9,673,483 B2
• Filed: 01/19/2015
• Issued: 06/06/2017
• Est. Priority Date: 01/19/2015
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Badding, Michael Edward, Iyer, Sriram Rangarajan, Kent, Brian Alan, Lonnroth, Nadja Teresia, Dutta, Indrajit
• Primary Examiner(s): SNELTING, ERIN LYNN
• Application Number:
  US14/599,692
• Publication Number:
  US 20160211546A1
• Time in Patent Office: 869 Days
• CPC Class Codes: C01B 25/45 containing plural metal, or metal and ammonium
• CPC Class Codes: C03B 19/06 by sintering, e.g. by cold isostatic pressing of powders and subsequent sintering, by hot pressing of powders, by sintering slurries or dispersions not undergoing a liquid phase reaction
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed herein are methods for making a solid lithium ion electrolyte membrane, the methods comprising combining a first reactant chosen from amorphous, glassy, or low melting temperature solid reactants with a second reactant chosen from refractory oxides to form a mixture; heating the mixture to a first temperature to form a homogenized composite, wherein the first temperature is between a glass transition temperature of the first reactant and a crystallization onset temperature of the mixture; milling the homogenized composite to form homogenized particles; casting the homogenized particles to form a green body; and sintering the green body at a second temperature to form a solid membrane. Solid lithium ion electrolyte membranes manufactured according to these methods are also disclosed herein.

Claims

1. A method for making a solid lithium ion electrolyte membrane, comprising:

combining a first reactant chosen from lithium phosphate glasses, germanium phosphate glasses, lithium aluminum phosphate glasses, and crystallized lithium aluminum phosphate ceramics with a second reactant chosen from refractory oxides to form a mixture;

heating the mixture to a first temperature to form a homogenized composite comprising unreacted first and second reactants, wherein the first temperature is between a glass transition temperature of the first reactant and a crystallization onset temperature of the mixture;

milling the homogenized composite to form homogenized particles;

casting the homogenized particles to form a green body; and

reactively sintering the green body at a second temperature to form a solid membrane.

2. The method of claim 1, wherein the first reactant further comprises an oxide modifier.

3. The method of claim 2, wherein the oxide modifier is chosen from TiO₂, GeO₂, SiO₂, B₂O₃, Fe₂O₃, Nb₂O₅, V₂O₅, Sb₂O₃, CoO, WO₃, SnO₂, and combinations thereof.

4. The method of claim 1, wherein the first reactant is lithium aluminum phosphate.

5. The method of claim 1, wherein the second reactant is chosen from TiO₂, SnO₂, GeO₂, and combinations thereof.

6. The method of claim 1, wherein the first reactant has an average particle size of less than about 10 microns, and the second reactant has an average particle size of less than about 1 micron.

7. The method of claim 1, wherein the first temperature is at least about 350°

C.

8. The method of claim 1, wherein the first temperature ranges from about 350°

C. to about 550°

C.

9. The method of claim 1, wherein the homogenized particles have an average diameter ranging from about 1 micron to about 2 microns.

10. The method of claim 1, wherein the second temperature is less than about 1100°

C.

11. The method of claim 1, wherein casting comprises tape casting the homogenized particles to form a green tape.

12. The method of claim 1, wherein the solid membrane has a thickness of less than about 200 microns, a density of at least about 95% of a theoretical density of the solid membrane, and a conductivity of at least about 1×

10<sup>−

4</sup> S/cm.

13. The method of claim 1, wherein the solid membrane is substantially flat.

14. The method of claim 13, wherein the method does not comprise a flattening step after the sintering step.