Method for forming a nanoporous grain boundary structure

Patent metadata

Field	Value
Publication number	US-2017244126-A1
Application number	US-201715489310-A
Country	US
Kind code	A1
Filing date	Apr 17, 2017
Priority date	Jan 22, 2014
Publication date	Aug 24, 2017
Grant date	—

Abstract

Gadolinium-doped cerium oxide slurries used to form a patchwork type surface structure with nanoporous grain boundary prepared by mixing gadolinium-doped cerium oxide and a polymer binder to form a first mixture; wet-atomizing the first mixture under a pressure of at least 100 MPa to obtain a second mixture; coating the second mixture to a substrate to form in a coated substrate; and sintering the coated substrate. The patchwork type structure is a polygonal or honeycomb structure having a size of from 0.1 μm to 3 μm.

First claim

1 . A method for preparing a gadolinium-doped cerium oxide slurry having a patchwork surface structure with a nanoporous grain boundary, the method comprising:
mixing a gadolinium-doped cerium oxide and a polymer binder, thereby forming a first mixture having 12 to 20% by weight of the polymer binder; wet-atomizing the first mixture thereby obtaining a second mixture; coating the second mixture on a substrate, thereby forming a coated substrate; and sintering the coated substrate, wherein the patchwork structure has polygonal grains having a size of from 0.1 μm to 3 μm; and wherein the nanoporous grain boundary is present on the surroundings of the polygonal grains.

2 . The method of claim 1 , wherein the pressure during the wet atomizing is about 150 MPa.

3 . The method of claim 1 , wherein the pressure during the wet atomizing is from 130 to 170 MPa.

4 . The method of claim 1 , wherein the wet-atomizing is repeated up to 5 times.

5 . The method of claim 1 , wherein the wet-atomizing is repeated 3 times.

6 . (canceled)

7 . The method of claim 1 , wherein the polymer binder is polyvinyl butyral.

8 . (canceled)

9 . The method of claim 1 , wherein the polymer binder is not polyvinyl pyrrolidinone.

10 . The method of claim 1 , wherein the polymer binder is not polytetrafluoroethylene.

11 . The method of claim 1 , wherein the first mixture further comprises ethanol and toluene as a solvent or suspension medium.

12 . The method of claim 1 , wherein the first mixture further comprises an amine as a dispersant.

13 . A gadolinium doped cerium oxide electrolyte prepared by the method of claim 1 .

14 . (canceled)

15 . (canceled)

16 . The method of claim 1 , wherein the nanoporous grain boundary has nanopores with a diameter of from 0.01 μm to 0.7 μm.

17 . The method of claim 1 , wherein the sintering is sintering at a temperature of from 1350 to 1425° C.

18 . The method of claim 1 , wherein the first mixture has 14 to 18% by weight of the polymer binder.

19 . The method of claim 1 , wherein the first mixture has about 16% by weight of the polymer binder.

20 . The method of claim 1 , wherein the polygonal grains have a size of from 0.5 μm to 2 μm.

21 . The method of claim 1 , wherein the coated substrate is sintered at a temperature of 1,300 to 1,450° C.

22 . The method of claim 1 , wherein the nanoporous grain boundary is present on all of the surroundings of all of the polygonal grains.

23 . The method of claim 1 , wherein the first mixture is wet-atomized at a pressure of 100 to 200 MPa.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Zahir Md Hasan
• Bahaidarah Haitham M

Classifications

• H01M8/126 Primary

  the electrolyte containing cerium oxide · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/1226

  characterised by the supporting layer · CPC title

• C04B35/62218

  obtaining ceramic films, e.g. by using temporary supports · CPC title

• C04B2235/5445

  submicron sized, i.e. from 0,1 to 1 micron · CPC title