Fuel cell

Patent metadata

Field	Value
Publication number	US-11450864-B2
Application number	US-201916296168-A
Country	US
Kind code	B2
Filing date	Mar 7, 2019
Priority date	Apr 3, 2018
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

The fuel cell of the present disclosure includes: a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes; a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and a sealing portion for hermetically bonding between the separator and the electrolyte, wherein the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator; the electrolyte includes a proton conductor; and the proton conductor is represented by a compositional formula: BaZr 1-x M x O 3 , where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and/or Gd.

First claim

What is claimed is:

1. A fuel cell comprising:
a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes;
a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and
a sealing portion for hermetically bonding between the separator and the electrolyte, wherein:
the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator,
the sealing portion has a first surface and a second surface opposite to the first surface,
the first surface is bonded to the electrolyte and the second surface is bonded to the separator,
only a lower surface of the separator facing the electrolyte contacts the sealing portion,
the electrolyte includes a proton conductor,
the proton conductor is represented by a compositional formula: BaZr 1-x M x O 3 , where 0.05≤x≤0.5; and M is at least one selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and Gd,
the separator contains Al and Si, and
the sealing portion contains Al, Ba, and Si.

2. The fuel cell according to claim 1 , wherein the separator includes a metal composition having an Al 2 O 3 film as a surface layer.

3. The fuel cell according to claim 2 , wherein the metal composition is ferrite stainless steel containing Al.

4. The fuel cell according to claim 3 , wherein the ferrite stainless steel includes a base material, and Al is contained in the base material in a proportion of 0.5 wt % or more and 5 wt % or less with respect to weight of the base material.

5. The fuel cell according to claim 4 , wherein the base material further contains Si, and Si is contained in the base material in a proportion of 0.1 wt % or more and 1 wt % or less with respect to the weight of the base material.

6. The fuel cell according to claim 5 , wherein
the proportions of Al, Ba, and Si in the sealing portion are, in terms of oxides,
SiO 2 in a proportion of 5 wt % or more and 95 wt % or less;
Al 2 O 3 in a proportion of 4.9 wt % or more and 35 wt % or less; and
BaO in a proportion of 0.1 wt % or more and 90 wt % or less.

7. The fuel cell according to claim 6 , wherein:
the sealing portion includes an electrolyte-side interface portion being an interface with the electrolyte and a separator-side interface portion being an interface with the separator,
the electrolyte-side interface portion includes a first electrolyte-side interface portion that is a region on the side coming into contact with the air, and a first electrolyte-side periphery that is a predetermined range from the first electrolyte-side interface portion in the thickness direction of the sealing portion,
the separator-side interface portion includes a first separator-side interface portion that is a region on the side coming into contact with the air, and a first separator-side periphery that is a predetermined range from the first separator-side interface portion in the thickness direction of the sealing portion,
the electrolyte-side interface portion includes a second electrolyte-side interface portion that is a region on the side coming into contact with the fuel gas, and a second electrolyte-side periphery that is a predetermined range from the second electrolyte-side interface portion in the thickness direction of the sealing portion,
the separator-side interface portion includes a second separator-side interface portion that is a region on the side coming into contact with the fuel gas, and a second separator-side periphery that is a predetermined range from the second separator-side interface portion in the thickness direction of the sealing portion, and
under temperature conditions of 600° C. that is the operating temperature of the fuel cell,
the first electrolyte-side interface portion contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 ,
the first electrolyte-side periphery contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 ,
the first separator-side interface portion contains a mixture including BaSi 2 O 5 and Al 2 SiO 5 , in the mixture, the molar fraction of Al 2 SiO 5 being higher than the molar fraction of BaSi 2 O 5 ,
the first separator-side periphery contains a mixture including BaSi 2 O 5 and Al 2 SiO 5 ,
the second electrolyte-side interface portion contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 ,
the second electrolyte-side periphery contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 ,
the second separator-side interface portion contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 , in the mixture, the molar fraction of BaAl 2 O 4 being higher than the molar fraction of Ba 2 SiO 4 , and
the second separator-side periphery contains a mixture including BaAl 2 O 4 and Ba 2 SiO 4 .

8. The fuel cell according to claim 5 , wherein the sealing portion further includes Zr or M.

9. The fuel cell according to claim 8 , wherein
the proportions of Al, Ba, Si, and Zr or M contained in the sealing portion are, in terms of oxides,
SiO 2 in a proportion of 5 wt % or more and 95 wt % or less;
Al 2 O 3 in a proportion of 4.7 wt % or more and 35 wt % or less;
BaO in a proportion of 0.1 wt % or more and 90 wt % or less; and
ZrO 2 in a proportion of 0.1 w % or more and 5 wt % or less, or an oxide of M in a proportion of 0.1 wt % or more and 5 wt % or less.

10. The fuel cell according to claim 7 , wherein the sealing portion includes Ba such that the concentrations of Ba contained in the electrolyte-side interface portion and the separator-side interface portion are higher than the concentration of Ba in the middle region between the electrolyte-side interface portion and the separator-side interface portion.

11. The fuel cell according to claim 7 , wherein
the sealing portion is composed of a first sealing layer having a surface coming into contact with the air and a second sealing layer having a surface coming into contact with the fuel gas, where the sealing layers are stacked; and
the concentration of Ba contained in the first sealing layer is higher than the concentration of Ba contained in the second sealing layer.

12. The fuel cell according to claim 11 , wherein
the first sealing layer is composed of a third sealing layer including the first electrolyte-side interface portion and a fourth sealing layer including the first separator-side interface portion stacked in the thickness direction of the sealing portion; and
the concentration of Ba contained in the third sealing layer is higher than the concentration of Ba contained in the fourth sealing layer.

13. The fuel cell according to claim 12 , wherein
the second sealing layer includes BaO in a proportion of 0.1 wt %;
the third sealing layer includes BaO in a proportion of 78 wt %; and
the fourth sealing layer includes BaO in a proportion of 30 wt %.

14. The fuel cell according to claim 1 , wherein: A fuel cell comprising:
a fuel single cell comprising a fuel electrode, an air electrode, and an electrolyte disposed between the electrodes;
a separator for separating a fuel gas flowing through the fuel electrode and air flowing through the air electrode; and
a sealing portion for hermetically bonding between the separator and the electrolyte, wherein:
the sealing portion is constituted of a glass composition containing at least two of metallic or metalloid elements contained in the electrolyte and at least two of metallic or metalloid elements contained in the separator,
the sealing portion has a first surface and

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Onuma Shigenori
• Kuroha Tomohiro
• Goto Takehito

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M2300/0074

  Ion conductive at high temperature · CPC title

• H01M8/242

  comprising framed electrodes or intermediary frame-like gaskets (H01M8/2425, H01M8/244 take precedence) · CPC title

• H01M8/1253

  the electrolyte containing zirconium oxide · CPC title

• H01M8/1246 Primary

  the electrolyte consisting of oxides · CPC title