Fuel cell stack, fuel cell module, power generation system, and method of producing fuel cell stack

1. A fuel cell stack, comprising:

a substrate;

a first fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the first fuel cell being a single fuel cell;

a second fuel cell including a fuel side electrode, an electrolyte, and an oxygen side electrode on the substrate, the second fuel cell being a single fuel cell;

an interconnector film electrically connecting the fuel side electrode of the first fuel cell and the oxygen side electrode of the second fuel cell; and

a porous ceramic film covering at least the interconnector film in a region between the fuel side electrode of the first fuel cell and the fuel side electrode of the second fuel cell,

wherein the interconnector film extends from the fuel side electrode of the first fuel cell toward the fuel side electrode of the second fuel cell such that the interconnector film overlaps with the fuel side electrode of the second fuel cell.

2. The fuel cell stack according to claim 1 ,

wherein the fuel side electrode of the second fuel cell has a slope portion with a thickness which decreases toward the fuel side electrode of the first fuel cell, and the interconnector film extends to a point above a slope region middle portion of the slope portion.

3. The fuel cell stack according to claim 2 ,

wherein the point is above a region of 30% or more and 70% or less of a length of the slope portion in a slope direction.

4. The fuel cell stack according to claim 1 ,

wherein the porous ceramic film extends from a first point above the fuel side electrode of the first fuel cell toward the fuel side electrode of the second fuel cell such that the porous ceramic film overlaps with the fuel side electrode of the second fuel cell, and

wherein the fuel side electrode of the second fuel cell has a slope portion with a thickness which decreases toward the fuel side electrode of the first fuel cell, and the porous ceramic film extends to a second point above at least a partial region of the slope portion.

5. The fuel cell stack according to claim 4 ,

wherein the second point is above a region ½ or less of a length of the slope portion in a slope direction.

6. The fuel cell stack according to claim 1 ,

wherein the electrolyte of the second fuel cell is on a substrate side of the interconnector film, and extends from the fuel side electrode of the second fuel cell to the fuel side electrode of the first fuel cell.

7. The fuel cell stack according to claim 1 ,

wherein the porous ceramic film is composed of a material with a porosity of 10% or more and 60% or less.

8. The fuel cell stack according to claim 1 ,

wherein the interconnector film is composed of a material with a porosity of 0.1% or more and 5% or less.

9. The fuel cell stack according to claim 1 ,

wherein the electrolyte of the first fuel cell or the electrolyte of the second fuel cell is composed of a film with a thickness of 5 μm or more and 20 μm or less.

10. The fuel cell stack according to claim 1 ,

wherein the porous ceramic film and the interconnector film are made of a same material.

11. A fuel cell module comprising

a plurality of fuel cell stacks according to claim 1 .

12. A power generation system, comprising:

the fuel cell module according to claim 11 ; and

a rotatable device configured to generate a rotational power using an exhaust fuel gas and an exhaust oxidation gas discharged from the fuel cell module,

wherein the fuel cell module is configured to be supplied with the exhaust oxidation gas which is compressed using the rotational power, and the fuel cell module is configured to generate power using the exhaust fuel gas and the exhaust oxidation gas which has been compressed.

13. The power generation system according to claim 12 ,

wherein the rotatable device comprises a gas turbine or a turbocharger.