Methods of fabricating porous ceramic electrodes for solid state battery applications

Patent metadata

Field	Value
Publication number	US-2022093904-A1
Application number	US-202117478509-A
Country	US
Kind code	A1
Filing date	Sep 17, 2021
Priority date	Sep 18, 2020
Publication date	Mar 24, 2022
Grant date	—

Abstract

Compositions and methods for the fabrication of electrode and porous lithium-garnet electrolyte scaffolds for use in solid state batteries and other devices are provided. The methods produce porous structures using phase inversion or high shear compaction processes to fabricate a solid-state battery electrode material from LLZO electrolytes. Engineered electrode structures with a porous scaffold of solid electrolyte material provide lower interfacial resistances and a mechanical support for a thin solid electrode layer improving performance.

First claim

What is claimed is:

1 . A method of forming a porous tape structure, the method comprising:
(a) forming a slurry of LLZO powder, a binder and a solvent; (b) tape casting the slurry on a base to form a LLZO tape; (c) immersing the LLZO tape in water to induce solvent/water exchange; and (d) removing the LLZO tape from the water and drying the LLZO tape; (e) wherein a LLZO tape with elongate pores with a length aligned perpendicularly to a top surface of the LLZO tape is produced.

2 . The method of claim 1 , wherein the slurry further comprises one or more selected from the group of Li 2 CO 3 , MgO, a dispersant and a wetting agent.

3 . The method of claim 1 , wherein the water for solvent/water exchange further comprises:
a lithium salt selected from the group consisting of Li 2 CO 3 , LiCl, LiOH, LiNO 3 , and Li 2 SO 4 ; wherein lithium loss during solvent exchange is inhibited.

4 . The method of claim 1 , wherein the base comprises a dense LLZO tape forming a LLZO tape with a dense/porous bilayer.

5 . The method of claim 4 , wherein a second porous layer is tape cast on the dense LLZO base forming a LLZO tape with a porous/dense/porous tri-layer.

6 . The method of claim 1 , wherein the water has a temperature between about 0° C. and about 50° C., wherein porosity of the LLZO tape increases with decreasing temperatures.

7 . The method of claim 1 , further comprising:
removing a top surface of the LLZO tape to increase size of pore openings.

8 . The method of claim 1 , further comprising:
removing binder from the dry LLZO tape; and sintering the LLZO tape after binder removal.

9 . The method of claim 8 , further comprising:
infiltrating a powdered electrode material into the porosity of the sintered LLZO tape.

10 . A method of forming a porous tape structure, the method comprising:
(a) forming a slurry of LLZO powder, a binder and a solvent; (b) tape casting the slurry on a substrate to form a LLZO tape; (c) applying a sacrificial layer on the LLZO tape to produce a bi-layered LLZO tape; (d) immersing the bi-layered LLZO tape in water to induce solvent/water exchange; (e) removing the bi-layered LLZO tape from the water and drying the bi-layered LLZO tape; and (f) heating the bi-layered LLZO tape to remove the sacrificial layer and sinter the LLZO tape to produce a sintered LLZO tape; (g) wherein a sintered LLZO tape with elongate pores with a length aligned perpendicularly to a top surface of the sintered LLZO tape is produced.

11 . The method of claim 10 , wherein the sacrificial layer is a material selected from the group of materials consisting of poly(methyl methacrylate) (PMMA), carbon, graphite, camphor, naphthalene and a polymer.

12 . The method of claim 10 , wherein the slurry further comprises one or more selected from the group of Li 2 CO 3 , MgO, a dispersant and a wetting agent.

13 . The method of claim 10 , wherein the water for solvent/water exchange further comprises:
a lithium salt selected from the group consisting of Li 2 CO 3 , LiCl, LiOH, LiNO 3 , and Li 2 SO 4 ; wherein lithium loss during solvent exchange is inhibited.

14 . The method of claim 10 , further comprising:
removing binder from the dry bi-layered LLZO tape; sintering the bi-layered LLZO tape after binder removal; and infiltrating the sintered LLZO tape with lithium nickel manganese cobalt oxide (NMC).

15 . A method of forming a porous tape structure, the method comprising:
(a) forming a LLZO mixture tape from a mixture of LLZO powder and a pore former by high shear compaction; (b) tape casting a LLZO slurry of LLZO powder and Li 2 CO 3 in a solvent on a substrate to form a dense LLZO tape; and (c) laminating the dense LLZO tape to the LLZO mixture tape.

16 . The method of claim 15 , further comprising:
forming a second LLZO mixture tape from LLZO and a pore former by high shear compaction; and laminating the second LLZO mixture tape to the dense LLZO tape to produce a trilayer laminate of LLZO mixture tape/dense LLZO tape/LLZO mixture tape.

17 . The method of claim 15 , said dense LLZO tape is formed from a slurry of a mixture of LLZO powder, Li 2 CO 3 and MgO.

18 . The method of claim 15 , wherein the pore former comprises polymethyl methacrylate (PMMA) and wherein the pore former comprises a volume % of the mixture tape in the range of 35 volume % and 85 volume % of the mixture.

19 . The method of claim 15 , further comprising:
sintering the dense LLZO tape/LLZO mixture tape laminate; and infiltrating the of LLZO mixture tape laminate with lithium nickel manganese cobalt oxide (NMC).

20 . The method of claim 16 , further comprising:
sintering the LLZO mixture tape/dense LLZO tape/LLZO mixture tape laminate to produce a sintered LLZO laminate; and infiltrating the sintered LLZO laminate with lithium nickel manganese cobalt oxide (NMC).

Assignees

• Univ California

Inventors

• Tucker Michael
• Shen Fengyu

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title