Proton-conductive cell structure, proton-conductive material, electrochemical device, and method of manufacturing proton-conductive material

Patent metadata

Field	Value
Publication number	US-2024006642-A1
Application number	US-202117927579-A
Country	US
Kind code	A1
Filing date	May 28, 2021
Priority date	Jun 18, 2020
Publication date	Jan 4, 2024
Grant date	—

Abstract

A proton-conductive cell structure includes an air electrode, a hydrogen electrode, and a solid electrolyte layer disposed between the air electrode and the hydrogen electrode, wherein the solid electrolyte layer includes at least a first solid electrolyte layer formed of a compact material. The first solid electrolyte layer includes a metal oxide having a perovskite structure and represented by Formula 1 below, a ratio of Sr to a total amount of Ba and Sr in an air-electrode-side near-surface region of the first solid electrolyte layer is 0.4 or more, and a ratio of Sr to a total amount of Ba and Sr in a hydrogen-electrode-side near-surface region of the first solid electrolyte layer is 0.003 to 0.3.Bax1Srx2A1-yMyO3-δ  (1)

First claim

1 . A proton-conductive cell structure comprising an air electrode, a hydrogen electrode, and a solid electrolyte layer disposed between the air electrode and the hydrogen electrode,
wherein the solid electrolyte layer at least includes a first solid electrolyte layer formed of a compact material, the first solid electrolyte layer includes a metal oxide having a perovskite structure and represented by Formula (1) below:
Ba x1 Sr x2 A 1-y M y O 3-δ   (1)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x1+x2≤1.10 and 0<y≤0.5 are satisfied) in an air-electrode-side near-surface region of the first solid electrolyte layer, a ratio of Sr to a total amount of Ba and Sr (Sr/[Ba+Sr]: based on a number of atoms) is 0.4 or more, and in a hydrogen-electrode-side near-surface region of the first solid electrolyte layer, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.003 to 0.3.

2 . The proton-conductive cell structure according to claim 1 , wherein, in a central region in a thickness direction of the first solid electrolyte layer, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.005 to 0.3.

3 . The proton-conductive cell structure according to claim 1 , wherein, in the first solid electrolyte layer, in a region extending, in a thickness direction, from an air-electrode-side surface toward a hydrogen electrode side and corresponding to 6% of a total thickness, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.3 or more.

4 . The proton-conductive cell structure according to claim 1 , wherein, in Formula (1) above,
Element A includes 50 at % or more of Zr, and Element M is Y.

5 . The proton-conductive cell structure according to claim 1 , wherein the solid electrolyte layer further includes a second solid electrolyte layer disposed between the first solid electrolyte layer and the air electrode and formed of a porous material, and
the second solid electrolyte layer includes a metal oxide having a perovskite structure and represented by Formula (1) below:
Ba x1 Sr x2 A 1-y M y O 3-δ   (1)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x1+x2≤1.10 and 0<y≤0.5 are satisfied).

6 . The proton-conductive cell structure according to claim 5 , wherein, in Formula (1) above,
Element A includes 50 at % or more of Zr, and Element M is Y.

7 . A proton-conductive material used as the first solid electrolyte layer in the proton-conductive cell structure according to claim 1 ,
wherein the proton-conductive material is a layer material formed of a compact material, and includes a metal oxide having a perovskite structure and represented by Formula (1) below:
Ba x1 Sr x2 A 1-y M y O 3-δ   (1)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x1+x2≤1.10 and 0<y≤0.5 are satisfied), in a region near a first main surface, a ratio of Sr to a total amount of Ba and Sr (Sr/[Ba+Sr]: based on a number of atoms) is 0.4 or more, and in a region near a second main surface, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.003 to 0.3.

8 . The proton-conductive material according to claim 7 , wherein, in a central region in a thickness direction, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.005 to 0.3.

9 . The proton-conductive material according to claim 7 , wherein, in a region extending, in a thickness direction, from a side of the first main surface toward a side of the second main surface and corresponding to 6% of a total thickness, the ratio of Sr to the total amount of Ba and Sr (Sr/[Ba+Sr]) is 0.3 or more.

10 . The proton-conductive material according to claim 7 , wherein in Formula (1) above,
Element A includes 50 at % or more of Zr, and Element M is Y.

11 . An electrochemical device comprising the proton-conductive cell structure according to claim 1 .

12 . A method of manufacturing a proton-conductive material used as the first solid electrolyte layer of the proton-conductive cell structure according to claim 4 ,
the method comprising bringing, into contact with an air-electrode-side surface of a first solid electrolyte precursor layer including a metal oxide having a perovskite structure and represented by Formula (2) below:
Ba x1 A 1-y M y O 3-δ   (2)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x1≤1.10 and 0<y≤0.5 are satisfied), a mixture of a powder of a strontium compound and a powder of a metal oxide having a perovskite structure and represented by Formula (3) below:
Sr x2 A 1-y M y O 3-δ   (3)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x2≤1.10 and 0<y≤0.5 are satisfied), and in this state, performing heat-treatment at 1200° C. to 1400° C.

13 . A method of manufacturing a proton-conductive material used as the solid electrolyte layer of the proton-conductive cell structure according to claim 5 ,
the method comprising applying, to an air-electrode-side surface of a first solid electrolyte precursor layer including a metal oxide having a perovskite structure and represented by Formula (2) below:
Ba x1 A 1-y M y O 3-δ   (2)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x1≤1.10 and 0<y≤0.5 are satisfied), a paste including a binder, a powder of a strontium compound, and a powder of a metal oxide having a perovskite structure and represented by Formula (3) below:
Sr x2 A 1-y M y O 3-δ   (3)

(where Element A is at least one selected from the group consisting of Zr, Ce, and Hf, Element M is at least one selected from the group consisting of Y, Yb, Er, Ho, Tm, Gd, In, and Sc, δ is an oxygen deficiency, and 0.95≤x2≤1.10 and 0<y≤0.5 are satisfied), and in this state, performing heat-treatment at 1200° C. to 1400° C.

Assignees

• Sumitomo Electric Industries

Inventors

• Higashino Takahiro
• Noda Yohei
• Mizuhara Naho
• Ogawa Mitsuyasu
• Tawarayama Hiromasa
• Majima Masatoshi
• FUNAKOSHI Akiko

Classifications

• H01M8/1253 Primary

  the electrolyte containing zirconium oxide · CPC title

• H01M8/1213

  characterised by the electrode/electrolyte combination or the supporting material · CPC title

• H01M2300/0077

  based on zirconium oxide · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01B1/08 Primary

  oxides · CPC title