Fuel cell

Abstract

To provide a technique for suppressing drying of an electrolyte film and a cathode catalyst layer in a fuel cell.SOLUTION: A fuel cell 100 according to the present disclosure includes an anode separator 20, a cathode separator 30, a film electrode joint body 10 including an anode 13, a cathode 16, and an electrolyte film 12 and disposed between the anode separator 20 and the cathode separator 30, an oxidant gas flow channel 50 provided between the cathode 16 and the cathode separator 30, a coolant flow channel 60 provided so as to be separated from the oxidant gas flow channel 50, an oxidant gas introduction path 51 that guides an oxidant gas to the oxidant gas flow channel 50, and a coolant introduction path 61 that guides a coolant to the coolant flow channel 60. In a projection image obtained by projecting elements of the fuel cell 100 in a direction perpendicular to a first surface 31 or a second surface 32 of the cathode separator 30, at least a part of the coolant introduction path 61 overlaps the oxidant gas introduction path 51.SELECTED DRAWING: Figure 4A

Description

[Technical Field]

[0001] The present disclosure relates to fuel cells. [Background technology]

[0002] Further improvements in fuel cell performance are required to effectively utilize hydrogen, one of the next-generation energy sources. To improve fuel cell performance, it is important to increase the power generation efficiency per unit cell. One way to increase the power generation efficiency per unit cell is to prevent the electrolyte membrane and cathode catalyst layer from drying out. If the electrolyte membrane and cathode catalyst layer can be prevented from drying out, the proton conductivity of the cathode catalyst layer will improve, thereby increasing the power generation efficiency per unit cell.

[0003] Patent Document 1 describes that the portion of the anode-side separator that comes into contact with the anode and the portion of the cathode-side separator that comes into contact with the cathode are approximately rectangular, and that the straight portions of the oxidant gas flow path are formed along the long side direction of the rectangle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2001 / 035477 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a technique for suppressing drying of an electrolyte membrane and a cathode catalyst layer in a fuel cell. [Means for solving the problem]

[0006] The present disclosure provides: an anode separator; a cathode separator; and a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane, the membrane electrode assembly being disposed between the anode separator and the cathode separator; a fuel gas flow channel provided between the anode and the anode separator; an oxidant gas flow channel provided between the cathode and the cathode separator; a coolant flow path provided so as to be separated from the oxidant gas flow path; a fuel gas introduction passage connected to the fuel gas flow passage and introducing fuel gas into the fuel gas flow passage; an oxidant gas inlet passage connected to the oxidant gas flow passage and configured to introduce oxidant gas into the oxidant gas flow passage; a refrigerant introduction passage connected to the refrigerant flow passage and guiding a refrigerant to the refrigerant flow passage; Equipped with the fuel gas flow path, the oxidant gas flow path, and the coolant flow path are located inside an electrode region defined by outer edges of the anode and the cathode, and the fuel gas inlet channel, the oxidant gas inlet channel, and the coolant inlet channel are located outside the electrode region; a projection image obtained by projecting the oxidant gas flow channel, the coolant flow channel, the oxidant gas inlet channel, and the coolant inlet channel in a direction perpendicular to the first surface or the second surface of the cathode separator, At least a portion of the coolant introduction passage overlaps with the oxidant gas introduction passage. A fuel cell is provided. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to suppress drying of the electrolyte membrane and the cathode catalyst layer in the fuel cell. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a fuel cell stack according to a first embodiment; [Figure 2A] First plan view of the anode separator [Figure 2B] IIB-IIB cross section of Figure 2A [Figure 3A] First plan view of the cathode separator [Figure 3B] IIIB-IIIB cross section of Figure 3A [Figure 4A] Second plan view of the cathode separator [Figure 4B] IVB-IVB cross section of Figure 4A [Figure 5] FIG. 2 is a second plan view of the cathode separator showing another example of a coolant inlet and a coolant outlet. [Figure 6] FIG. 2 is a second plan view of a cathode separator showing another example of a coolant flow path; DETAILED DESCRIPTION OF THE INVENTION

[0009] (Findings that formed the basis of this disclosure) At the time the inventors conceived the present disclosure, it was believed that improving the gas diffusibility of the cathode catalyst layer would lead to improved fuel cell performance from the perspective of oxygen supply. In recent years, it has been discovered that excessively improving the gas diffusibility of the cathode catalyst layer dries out the electrolyte membrane and cathode catalyst layer, resulting in reduced performance. Therefore, attempts have been made to control the moisture content of the cathode catalyst layer by providing a coolant inlet near the oxidant gas inlet, arranging a coolant channel along the oxidant gas channel, and setting the coolant temperature to maintain a high relative humidity of the oxidant gas at the oxidant gas inlet. However, with this configuration, it is difficult to suppress the increase in the temperature of the oxidant gas upstream of the oxidant gas channel. The increase in the temperature of the oxidant gas upstream of the oxidant gas channel is particularly pronounced when the oxidant gas channel is a serpentine channel. Due to heat generated by exothermic reactions during power generation, the temperatures of the oxidant gas and the coolant increase from the upstream to the downstream of the coolant channel that flows along the oxidant gas channel. If the oxidant gas flow path is a serpentine flow path, the temperature of the oxidant gas flowing in the upstream oxidant gas flow path is likely to rise due to the influence of the temperatures of the oxidant gas flowing in the downstream oxidant gas flow path adjacent to the upstream oxidant gas flow path and the refrigerant flowing in the refrigerant flow path.

[0010] Under these circumstances, the present inventors focused on the oxidant gas inlet channel, which introduces the oxidant gas into the oxidant gas channel, and the coolant inlet channel, which introduces the coolant into the coolant channel, in order to suppress a rise in the temperature of the oxidant gas upstream of the oxidant gas channel. The oxidant gas inlet channel and the coolant inlet channel are located outside the electrode region defined by the outer edges of the anode and cathode, and are clearly distinguished from the oxidant gas channel and the coolant channel. Generally, the oxidant gas channel and the oxidant gas inlet are connected over the shortest distance to minimize the temperature difference between the oxidant gas at the oxidant gas inlet and the temperature of the oxidant gas flowing into the oxidant gas channel. Similarly, the coolant channel and the coolant inlet are connected over the shortest distance to minimize the temperature difference between the temperature of the coolant at the coolant inlet and the temperature of the coolant flowing into the coolant channel. For this reason, the oxidant gas inlet channel and the coolant inlet channel are arranged at a distance from each other (for example, Patent Document 1). However, the temperature of the oxidant gas rises between the oxidant gas inlet and the oxidant gas channel, i.e., while the oxidant gas flows through the oxidant gas inlet channel. Therefore, if the oxidant gas inlet channel can be cooled, the temperature of the oxidant gas flowing into the oxidant gas flow channel can be further reduced. Based on this finding, the inventors came up with the idea of ​​suppressing the temperature rise of the oxidant gas upstream of the oxidant gas flow channel by overlapping at least a portion of the coolant inlet channel with the oxidant gas inlet channel. If the temperature rise of the oxidant gas upstream of the oxidant gas flow channel can be suppressed, the relative humidity of the oxidant gas upstream of the oxidant gas flow channel will be improved, and drying of the electrolyte membrane and the cathode catalyst layer will be suppressed.

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted.

[0012] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0013] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0014] [1-1.Configuration] 1 is a schematic cross-sectional view of a fuel cell stack 200 according to Embodiment 1. The fuel cell stack 200 includes a plurality of fuel cells 100 stacked one on top of the other.

[0015] The fuel cell 100 includes a membrane electrode assembly 10, an anode separator 20, and a cathode separator 30. The membrane electrode assembly 10 is disposed between the anode separator 20 and the cathode separator 30. The fuel cell 100 is, for example, a polymer electrolyte fuel cell.

[0016] The membrane electrode assembly 10 can also be used in other electrochemical devices, such as a hydrogen purification device for purifying hydrogen.

[0017] The membrane electrode assembly 10 includes an anode 13, an electrolyte membrane 12, and a cathode 16. The anode 13 is bonded to one surface of the electrolyte membrane 12. The cathode 16 is bonded to the other surface of the electrolyte membrane 12.

[0018] The membrane electrode assembly 10 may include a frame 19. The frame 19 is disposed around the membrane electrode assembly 10 so that the anode separator 20 and the cathode separator 30 do not come into contact with each other, and fixes the membrane electrode assembly 10 between the anode separator 20 and the cathode separator 30. The frame 19 maintains airtightness around the membrane electrode assembly 10. The frame 19 prevents the fuel gas and the oxidant gas from mixing and electrically separates the anode separator 20 and the cathode separator 30. The frame 19 is insulating, gas permeation resistant, and water vapor permeation resistant. An insulating member can be used as the frame 19. The frame 19 may be, for example, a resin member.

[0019] The electrolyte membrane 12 is disposed between the anode 13 and the cathode 16. The electrolyte membrane 12 is made of a polymer material having proton conductivity. For example, the electrolyte membrane 12 is a membrane made of a perfluorocarbon sulfonic acid-based polymer material having sulfonic acid groups, or a hydrocarbon-based polymer material.

[0020] The anode 13 includes an anode catalyst layer 14 and an anode gas diffusion layer 15. The anode catalyst layer 14 is disposed between the electrolyte membrane 12 and the anode gas diffusion layer 15. The cathode 16 includes a cathode catalyst layer 17 and a cathode gas diffusion layer 18. The cathode catalyst layer 17 is disposed between the electrolyte membrane 12 and the cathode gas diffusion layer 18.

[0021] The anode catalyst layer 14 has a function of promoting an electrochemical reaction that dissociates hydrogen molecules into protons. The anode catalyst layer 14 includes an electrode catalyst and a polymer electrolyte. The anode catalyst layer 14 may include, as the electrode catalyst, carbon particles carrying catalyst particles and a polymer electrolyte.

[0022] The anode gas diffusion layer 15 has the function of supplying fuel gas (anode gas) to the anode catalyst layer 14 and the function of receiving electrons from the anode catalyst layer 14. The anode gas diffusion layer 15 is made of a gas-permeable and electrically conductive material. The anode gas diffusion layer 15 has, as its main material, for example, an electrically conductive porous body. An example of the porous body is a carbon fiber aggregate such as carbon paper.

[0023] The cathode catalyst layer 17 has a function of promoting an electrochemical reaction that produces water from protons and oxygen. The cathode catalyst layer 17 includes an electrode catalyst and a polymer electrolyte. The cathode catalyst layer 17 may include, as the electrode catalyst, carbon particles carrying catalyst particles and a polymer electrolyte. The carbon particles may be mesoporous carbon particles. The cathode catalyst layer 17 may further include conductive fibers.

[0024] The cathode gas diffusion layer 18 has the function of supplying an oxidant gas (cathode gas) to the cathode catalyst layer 17 and the function of transferring electrons to the cathode catalyst layer 17. The cathode gas diffusion layer 18 is made of a gas-permeable and electrically conductive material. The cathode gas diffusion layer 18 contains, for example, an electrically conductive porous body as its main material. An example of the porous body is a carbon fiber aggregate such as carbon paper.

[0025] An example of the fuel gas is a hydrogen-containing gas. The hydrogen-containing gas may be a gas produced from hydrocarbons by steam reforming, or may be pure hydrogen gas with a hydrogen concentration of 99% or more. An example of the oxidant gas is air.

[0026] In this specification, the region defined by the outer edges of the anode 13 and the cathode 16 is referred to as the electrode region 101. More specifically, the electrode region 101 is the region defined by the outer edges of the anode catalyst layer 14 and the cathode catalyst layer 17. The power generation reaction occurs in the electrode region 101.

[0027] A fuel gas flow channel 40 is provided between the anode 13 and the anode separator 20. Fuel gas is supplied to the anode 13 through the fuel gas flow channel 40. In this embodiment, a groove serving as the fuel gas flow channel 40 is provided in a first surface 21 of the anode separator 20. The first surface 21 and second surface 22 of the anode separator 20 refer to the two main surfaces of the plate-like anode separator 20. In this specification, the term "main surface" refers to the surface of the plate-like member having the largest area. The surface in contact with the anode 13 is the first surface 21, and the surface in contact with the cathode separator 30 is the second surface 22.

[0028] An oxidant gas flow field 50 is provided between the cathode 16 and the cathode separator 30. An oxidant gas is supplied to the cathode 16 through the oxidant gas flow field 50. In this embodiment, a groove serving as the oxidant gas flow field 50 is provided in a first surface 31 of the cathode separator 30. The first surface 31 and the second surface 32 of the cathode separator 30 refer to the two main surfaces of the plate-shaped cathode separator 30. The surface in contact with the cathode 16 is the first surface 31, and the surface in contact with the anode separator 20 is the second surface 32.

[0029] The anode separator 20 and the cathode separator 30 are each made of a conductive material such as carbon, metal, etc. To prevent corrosion, they may be provided with a corrosion-resistant coating such as plating.

[0030] The fuel cell 100 further includes a coolant flow channel 60 that is separated from the oxidant gas flow channel 50. A coolant is supplied to the coolant flow channel 60. In this embodiment, grooves serving as the coolant flow channel 60 are formed on the second surface 32 of the cathode separator 30. An oxidant gas flow channel 50 is provided on the first surface 31 of the anode separator 30, and a refrigerant flow channel 60 is provided on the second surface 32 of the cathode separator 30. However, as long as the refrigerant flow channel 60 is provided so as to be separated from the oxidant gas flow channel 50, the position where the refrigerant flow channel 60 is formed is not limited to the second surface 32 of the cathode separator 30. For example, the grooves of the refrigerant flow channel 60 may be formed on the second surface 32 of the anode separator 20. The grooves of the refrigerant flow channel 60 may be formed so as to straddle the second surface 32 of the cathode separator 30 and the second surface 32 of the anode separator 20. The grooves of the refrigerant flow channel 60 may be formed in a separate member disposed between the second surface 32 of the cathode separator 30 and the second surface 32 of the anode separator 20. The refrigerant flow channel 60 may be disposed between the anode separator 20 and the cathode separator 30 of adjacent fuel cells 100.

[0031] Examples of refrigerants are brine, water, antifreeze, etc. The refrigerant may also be water.

[0032] FIG. 2A is a first plan view of the anode separator 20. FIG. 2B is a cross-sectional view taken along line IIB-IIB of FIG. 2A. The first plan view of FIG. 2A is a plan view of the first surface 21 of the anode separator 20 that contacts the anode 13. The first surface 21 of the anode separator 20 is further formed with a fuel gas inlet channel 41 that is connected to a fuel gas flow field 40 and introduces fuel gas to the fuel gas flow field 40, and a fuel gas outlet channel 42 that is connected to the fuel gas flow field 40 and discharges the fuel gas that has passed through the fuel gas flow field 40. As shown in FIG. 2A, the fuel gas flow field 40 is located inside the electrode region 101, and the fuel gas inlet channel 41 and the fuel gas outlet channel 42 are located outside the electrode region 101. The fuel gas inlet channel 41 is connected to a fuel gas inlet 40a that is located outside the electrode region 101. The fuel gas outlet channel 42 is connected to a fuel gas outlet 40b that is located outside the electrode region 101.

[0033] 2A, the outer edge of the electrode region 101 and the wall of the groove of the fuel gas flow field 40 are aligned, but this is not necessarily the case. As long as the wall of the groove of the fuel gas flow field 40 is located inside the electrode region 101, the outer edge of the electrode region 101 and the wall of the groove of the fuel gas flow field 40 do not have to be aligned. The same applies to the positional relationship between the other flow fields and the electrode region 101.

[0034] Fig. 3A is a first plan view of the cathode separator 30. Fig. 3B is a cross-sectional view taken along line IIIB-IIIB of Fig. 3A. The first plan view of Fig. 3A is a plan view of the first surface 31 of the cathode separator 30 that contacts the cathode 16. Fig. 3A shows the refrigerant flow path 60, the refrigerant introduction path 61, and the refrigerant discharge path 62 formed on the second surface 32 of the cathode separator 30, projected perpendicularly to the first surface 31. The first surface 31 of the cathode separator 30 is further formed with an oxidant gas introduction path 51 that is connected to the oxidant gas flow path 50 and introduces the oxidant gas to the oxidant gas flow path 50, and an oxidant gas discharge path 52 that is connected to the oxidant gas flow path 50 and discharges the oxidant gas that has passed through the oxidant gas flow path 50. 3A, the oxidant gas flow channel 50 is located inside the electrode region 101, and the oxidant gas inlet channel 51 and the oxidant gas discharge channel 52 are located outside the electrode region 101. The oxidant gas inlet channel 51 is connected to an oxidant gas inlet 50a located outside the electrode region 101. The oxidant gas discharge channel 52 is connected to an oxidant gas outlet 50b located outside the electrode region 101.

[0035] 4A is a second plan view of the cathode separator 30. FIG. 4B is a cross-sectional view taken along line IVB-IVB of FIG. 4A. The second plan view of FIG. 4A is a plan view of the second surface 32 of the cathode separator 30 that contacts the anode separator 20. In FIG. 4A, the oxidant gas flow channel 50, the oxidant gas inlet channel 51, and the oxidant gas outlet channel 52 formed on the first surface 31 of the cathode separator 30 are shown projected perpendicularly to the second surface 32. The second surface 32 of the cathode separator 30 is provided with a refrigerant inlet channel 61 that is connected to the refrigerant flow channel 60 and introduces a refrigerant into the refrigerant flow channel 60, and a refrigerant outlet channel 62 that is connected to the refrigerant flow channel 60 and discharges the refrigerant that has passed through the refrigerant flow channel 60. As shown in FIG. 4A, the refrigerant flow channel 60 is located inside the electrode region 101. The coolant inlet path 60a is located outside the electrode region 101, and the coolant inlet path 61 and the coolant outlet path 62 are located outside the electrode region 101. The coolant inlet path 61 is connected to a coolant inlet 60a located outside the electrode region 101. The coolant outlet path 62 is connected to a coolant outlet 60b located outside the electrode region 101.

[0036] 4A, the coolant inlet channel 61 and the coolant outlet channel 62 are provided on the second surface 32 of the cathode separator 30. However, as long as they are connected to the coolant flow path 60, the locations at which the coolant inlet channel 61 and the coolant outlet channel 62 are provided are not limited to the second surface 32 of the cathode separator 30. For example, the grooves of the coolant inlet channel 61 and the grooves of the coolant outlet channel 62 may be formed in a member separate from the cathode separator 30.

[0037] Hereinafter, for convenience, a projection image obtained by projecting elements of the fuel cell 100, such as the oxidant gas flow field 50, the refrigerant flow field 60, the oxidant gas inlet channel 51, and the refrigerant inlet channel 61, perpendicularly onto the first surface 31 or the second surface 32 of the cathode separator 30, as shown in FIGS. 3A and 4A, is referred to as a projection image P. As shown in FIGS. 3A and 4A, in the fuel cell 100, at least a portion of the refrigerant inlet channel 61 overlaps with the oxidant gas inlet channel 51 in the projection image P. With this configuration, the refrigerant flowing through the refrigerant inlet channel 61 can cool the oxidant gas flowing through the oxidant gas inlet channel 51, thereby suppressing an increase in the temperature of the oxidant gas upstream of the oxidant gas flow field 50. This improves the relative humidity of the oxidant gas upstream of the oxidant gas flow field 50, thereby suppressing drying of the electrolyte membrane 12 and the cathode catalyst layer 17. As a result, the proton conductivity of the cathode catalyst layer 17 is improved, suppressing a decrease in power generation performance, and increasing the power generation efficiency of the fuel cell 100.

[0038] In the projection image P, the coolant introduction channel 61 may have a first portion 61a extending in a second direction d2 different from the first direction d1 in which the oxidant gas introduction channel 51 extends, and a second portion 61b extending in the first direction d1. At least the second portion 61b may overlap with the oxidant gas introduction channel 51. The tilt angle of the second direction d2 with respect to the first direction d1 is, for example, in the range of 30° to 150°. The tilt angle of the second direction d2 with respect to the first direction d1 may be in the range of 45° to 135°, in the range of 60° to 120°, or in the range of 75° to 105°.

[0039] 4A, the inclination angle of the second direction d2 with respect to the first direction d1 may be 90°. That is, in the projection image P, the coolant introduction channel 61 may have a first portion 61a extending in the second direction d2 perpendicular to the first direction d1, and a second portion 61b extending in the first direction d1. At least the second portion 61b may overlap with the oxidant gas introduction channel 51. With this configuration, it is easy to ensure an overlapping area between the coolant introduction channel 61 and the oxidant gas introduction channel 51, thereby further suppressing an increase in the temperature of the oxidant gas upstream of the oxidant gas flow channel 50.

[0040] 3A and 4A, as long as at least a portion of the coolant introduction channel 61 overlaps with the oxidant gas introduction channel 51 in the projection image P. For example, the first portion 61a may be curved, and the second portion 61b may be straight. In this case, a portion of the curved first portion 61a and the straight second portion 61b may overlap with the oxidant gas introduction channel 51. For example, the entire coolant introduction channel 61 may be curved. In this case, a portion of the curved coolant introduction channel 61 may overlap with the oxidant gas introduction channel 51.

[0041] As shown in FIGS. 3A and 4A, in the fuel cell 100, at least a portion of the coolant discharge channel 62 may overlap with the oxidizing gas discharge channel 52 in the projection image P.

[0042] In the projection image P, the coolant discharge channel 62 may have a first portion 62a extending in a fourth direction d4 different from the third direction d3 in which the oxidant gas discharge channel 52 extends, and a second portion 62b extending in the third direction d3. At least the second portion 62b may overlap with the oxidant gas discharge channel 52. The tilt angle of the fourth direction d4 with respect to the third direction d3 is, for example, in the range of 30° to 150°. The tilt angle of the fourth direction d4 with respect to the third direction d3 may be in the range of 45° to 135°, in the range of 60° to 120°, or in the range of 75° to 105°.

[0043] 4A, the tilt angle of the fourth direction d4 with respect to the third direction d3 may be 90°. That is, in the projection image P, the coolant discharge channel 62 may have a first portion 62a extending in the fourth direction d4 perpendicular to the third direction d3 and a second portion 62b extending in the third direction d3. At least the second portion 62b may overlap with the oxygen-containing gas discharge channel 52.

[0044] When at least a portion of the coolant discharge channel 62 overlaps with the oxidant gas discharge channel 52 in the projection image P, the shape of the coolant discharge channel 62 is not limited to the shapes shown in FIGS. 3A and 4A. For example, the first portion 62a may be curved, and the second portion 62b may be straight. In this case, a portion of the curved first portion 62a and the straight second portion 62b may overlap with the oxidant gas discharge channel 52. For example, the entire coolant discharge channel 62 may be curved. In this case, a portion of the curved coolant discharge channel 62 may overlap with the oxidant gas discharge channel 52.

[0045] The first direction d1 and the third direction d3 may be the same direction, and the second direction d2 and the fourth direction d4 may be the same direction.

[0046] The oxidant gas flow channel 50 and the coolant flow channel 60 may be configured so that the oxidant gas and the coolant flow, respectively, from the first side to the second side of the membrane electrode assembly 10. Such a configuration makes it easy to configure the oxidant gas and the coolant to flow without resisting gravity. Furthermore, since it is easy to strengthen cooling on the upstream side of the oxidant gas flow channel 50, it is easy to suppress an increase in the temperature of the oxidant gas on the upstream side of the oxidant gas flow channel 50.

[0047] The fuel gas flow channel 40 may be configured so that the fuel gas flows from the second side to the first side of the membrane electrode assembly 10, or so that the fuel gas flows from the first side to the second side of the membrane electrode assembly 10. If the fuel gas flow channel 40 is configured so that the fuel gas flows from the second side to the first side of the membrane electrode assembly 10, it is easy to configure the fuel gas to flow without resisting gravity.

[0048] 2A to 4B, the oxidant gas inlet 50a, the refrigerant inlet 60a, and the fuel gas outlet 40b may be located on a first side of the membrane electrode assembly 10. The oxidant gas outlet 50b, the refrigerant outlet 60b, and the fuel gas inlet 40a may be located on a second side of the membrane electrode assembly 10. This configuration makes it easy to configure the fuel gas, oxidant gas, and refrigerant to flow without resisting gravity. In addition, moisture generated in the oxidant gas flow channel 50 can be easily discharged efficiently from the oxidant gas outlet 50b.

[0049] In this embodiment, the membrane electrode assembly 10 and the fuel cell 100 have a rectangular shape having long and short sides in a plan view. A first side of the membrane electrode assembly 10 and the fuel cell 100 is the side on which one of a pair of sides positioned in a direction perpendicular to the thickness direction of the membrane electrode assembly 10 is located. A second side of the fuel cell 100 is the side on which the other of the pair of sides positioned in a direction perpendicular to the thickness direction of the membrane electrode assembly 10 is located. In the example of FIG. 1 , the X direction is the thickness direction of the membrane electrode assembly 10. The Y direction and the Z direction are each perpendicular to the thickness direction of the membrane electrode assembly 10.

[0050] The Z direction is, for example, a direction parallel to the vertical direction. The X direction is, for example, a direction parallel to the horizontal direction. The Y direction is, for example, a direction parallel to the horizontal direction and perpendicular to the thickness direction of the membrane electrode assembly 10. The first side of the membrane electrode assembly 10 and the fuel cell 100 can be one side in the horizontal direction. The second side of the membrane electrode assembly 10 and the fuel cell 100 can be the other side in the horizontal direction. That is, the first side of the membrane electrode assembly 10 can be the side on which one of the pair of short sides of the rectangle is located, and the second side of the membrane electrode assembly 10 can be the side on which the other of the pair of short sides of the rectangle is located. This configuration makes it easy to configure the fuel gas, oxidant gas, and refrigerant to flow without resisting gravity. Furthermore, since the height of the fuel cell 100 can be reduced, the height of the space required for installation can be reduced.

[0051] 2A to 4B, the first side of the membrane electrode assembly 10 is the side on which one of the pair of short sides of the rectangle is located, and the second side of the membrane electrode assembly 10 is the side on which the other of the pair of short sides of the rectangle is located. However, the fuel cell 100 is not limited to the examples shown in FIGS. 2A to 4B. For example, the first side of the membrane electrode assembly 10 may be the side on which one of the pair of long sides of the rectangle is located, and the second side of the membrane electrode assembly 10 may be the side on which the other of the pair of long sides of the rectangle is located.

[0052] In this embodiment, a fuel gas inlet 40a is provided at one end of the fuel cell 100 in the Y direction. A fuel gas outlet 40b is provided at the other end of the fuel cell 100 in the Y direction. The fuel gas inlet 40a and the fuel gas outlet 40b penetrate the anode separator 20 and the cathode separator 30 in the thickness direction. The inlets 40a of adjacent fuel cells 100 are connected to each other. The outlets 40b of adjacent fuel cells 100 are connected to each other. This allows fuel gas to be supplied to the fuel gas flow path 40 from outside the fuel cell stack 200, and allows unconsumed fuel gas, water, and water vapor to be discharged from the fuel gas flow path 40 to outside the fuel cell stack 200.

[0053] In this embodiment, an oxidant gas inlet 50a is provided at the other end of the fuel cell 100 in the Y direction. An oxidant gas outlet 50b is provided at one end of the fuel cell 100 in the Y direction. The oxidant gas inlet 50a and the oxidant gas outlet 50b penetrate the anode separator 20 and the cathode separator 30 in the thickness direction. The inlets 50a of adjacent fuel cells 100 are connected to each other. The outlets 50b of adjacent fuel cells 100 are connected to each other. This allows oxidant gas to be supplied to the oxidant gas flow path 50 from outside the fuel cell stack 200, and allows unconsumed oxidant gas, water, and water vapor to be discharged from the oxidant gas flow path 50 to outside the fuel cell stack 200.

[0054] In this embodiment, a refrigerant outlet 60b is provided at the other end of the fuel cell 100 in the Y direction. A refrigerant inlet 60a is provided at one end of the fuel cell 100 in the Y direction. The refrigerant inlet 60a and the refrigerant outlet 60b penetrate the anode separator 20 and the cathode separator 30 in the thickness direction. The inlets 60a of adjacent fuel cells 100 are connected to each other. The outlets 60b of adjacent fuel cells 100 are connected to each other. This allows a refrigerant to be supplied to the refrigerant flow path 60 from outside the fuel cell stack 200, and allows the refrigerant to be discharged from the refrigerant flow path 60 to outside the fuel cell stack 200.

[0055] 3A and 4A, the coolant inlet 60a may be located above the oxidant gas inlet 50a. With this configuration, it is easy to ensure an overlapping area between the coolant introduction channel 61 and the oxidant gas introduction channel 51, which can further suppress the rise in temperature of the oxidant gas on the upstream side of the oxidant gas flow channel 50. In addition, a configuration in which the coolant flows without resisting gravity is also possible. Cheap.

[0056] 3A and 4A, the coolant outlet 60b may be located below the oxygen-containing gas outlet 60a. This configuration makes it easier to allow the coolant to flow without resisting gravity.

[0057] However, the positions of the refrigerant inlet 60a and the refrigerant outlet 60b are not limited to the examples shown in FIGS. 3A and 4A. FIG. 5 is a second plan view of the cathode separator 30 showing another example of the refrigerant inlet 60a and the refrigerant outlet 60b. The second plan view of FIG. 5 is a plan view of the second surface 32 of the cathode separator 30. As in FIG. 4A, FIG. 5 shows the oxidant gas flow field 50, the oxidant gas inlet channel 51, and the oxidant gas outlet channel 52 formed on the first surface 31 of the cathode separator 30, projected perpendicularly to the second surface 32. In FIG. 5, elements common to those in FIG. 4A are denoted by the same reference numerals, and their description will be omitted. As shown in FIG. 5, the refrigerant inlet 60a may be located below the oxidant gas inlet 50a. Even with this configuration, it is easy to ensure an overlapping area between the refrigerant inlet channel 61 and the oxidant gas inlet channel 51 in the projection image P, thereby further suppressing the rise in the temperature of the oxidant gas upstream of the oxidant gas flow field 50.

[0058] As shown in FIG. 5, the coolant outlet 60b may be located above the oxidant gas outlet 60a.

[0059] The coolant inlet 60a may be located above the fuel gas inlet 40a, below the fuel gas inlet 40a, or at approximately the same height as the fuel gas inlet 40a.

[0060] 3A and 4A, the flow direction of the oxidant gas in the oxidant gas flow field 50 may be the same as the flow direction of the coolant in the coolant flow field 60. With this configuration, it is easy to uniformly cool the oxidant gas.

[0061] 2A and 3A, the flow direction of the oxidant gas in the oxidant gas flow field 50 may be the same as the flow direction of the fuel gas in the fuel gas flow field 40. With this configuration, the electrochemical reaction in the membrane electrode assembly 10 can be made to proceed efficiently.

[0062] As shown in FIG. 2A , the fuel gas flow channel 40 may be a serpentine flow channel including a first portion 401 and a second portion 402. The first portion 401 may be a portion extending in the Y direction from the second side (the left side in FIG. 2A ) of the membrane electrode assembly 10 toward the first side (the right side in FIG. 2A ) of the membrane electrode assembly 10. The first portion 401 may have an arc shape in a plan view. The second portion 402 may be a portion extending in the Z direction perpendicular to the Y direction from the second side to the first side of the membrane electrode assembly 10. This configuration allows fuel gas to be supplied to every corner of the anode 13. In the example shown in FIG. 2A , the fuel gas flow channel 40 includes multiple first portions 401 and multiple second portions 402. However, the shape of the fuel gas flow channel 40 is not limited to the example shown in FIG. 2A . For example, the fuel gas flow channel 40 may be composed of two first portions 401 and one second portion 402. In this case, the fuel gas inlet 40a and the fuel gas outlet 40b can be located on either the first side or the second side of the membrane electrode assembly 10.

[0063] 2A, the direction in which the fuel gas introduction channel 41 extends may be the same as the direction in which the first portion 401 of the fuel gas flow channel 40 extends. With this configuration, the fuel gas can be easily supplied to every corner of the anode 13.

[0064] As shown in FIG. 3A, the oxidizing gas flow field 50 includes a first portion 501 and a second portion 502. The first portion 501 may be a portion extending in the Y direction from the first side (left side in FIG. 3A ) to the second side (right side in FIG. 3A ) of the membrane electrode assembly 10. The first portion 501 may have an arc shape in a plan view. The second portion 502 may be a portion extending in the Z direction perpendicular to the Y direction from the first side to the second side of the membrane electrode assembly 10. This configuration allows the oxidant gas to be supplied to every corner of the cathode 16. In the example shown in FIG. 3A , the oxidant gas flow channel 50 includes multiple first portions 501 and multiple second portions 502. However, the shape of the oxidant gas flow channel 50 is not limited to the example shown in FIG. 3A . For example, the oxidant gas flow channel 50 may be composed of two first portions 501 and one second portion 502. In this case, the oxidant gas inlet 50a and the oxidant gas outlet 50b may be located on either the first side or the second side of the membrane electrode assembly 10.

[0065] The temperature of the oxidant gas increases from the upstream side to the downstream side of the oxidant gas flow path 50. If the oxidant gas flow path 50 is a serpentine flow path, the temperature of the oxidant gas flowing through the upstream first portion 501 is likely to increase due to the influence of the temperature of the oxidant gas flowing through the downstream first portion 501 adjacent to the upstream first portion 501. However, according to the fuel cell 100 of this embodiment, it is possible to suppress the increase in the temperature of the oxidant gas upstream of the oxidant gas flow path 50. The fuel cell 100 of this embodiment is particularly effective when the oxidant gas flow path 50 is a serpentine flow path.

[0066] 3A, the first direction d1 in which the oxidant gas introduction channel 51 extends may be the same as the direction in which the first portion 501 of the oxidant gas flow field 50 extends. With this configuration, the oxidant gas can be easily supplied to every corner of the cathode 16.

[0067] As shown in FIG. 4A , the refrigerant flow path 60 may be a serpentine flow path including a first portion 601 and a second portion 602. The first portion 601 may be a portion extending in the Y direction from the first side (the right side in FIG. 4A ) of the membrane electrode assembly 10 to the second side (the left side in FIG. 4A ) of the membrane electrode assembly 10. The first portion 601 may have an arc shape in a plan view. The second portion 602 may be a portion extending in the Z direction perpendicular to the Y direction from the first side to the second side of the membrane electrode assembly 10. This configuration can uniformly cool the membrane electrode assembly 10 and improve the efficiency of exhaust heat recovery. In the example shown in FIG. 4A , the refrigerant flow path 60 includes multiple first portions 601 and multiple second portions 602. However, the shape of the refrigerant flow path 60 is not limited to the example shown in FIG. 4A . For example, the refrigerant flow path 60 may be composed of two first portions 601 and one second portion 602. In this case, the refrigerant inlet 60 a and the refrigerant outlet 60 b can be located on either the first side or the second side of the membrane electrode assembly 10 .

[0068] As described above, in this embodiment, the membrane electrode assembly 10 and the fuel cell 100 have a rectangular shape having long and short sides in a plan view. The first portion 401 of the fuel gas flow field 40 may be arranged parallel to a pair of long sides of the rectangle. In this case, the second portion 402 of the fuel gas flow field 40 may be arranged parallel to a pair of short sides of the rectangle. This configuration makes it easier to efficiently promote the electrochemical reaction in the membrane electrode assembly 10.

[0069] The first portion 501 of the oxidant gas flow field 50 may be arranged parallel to a pair of long sides of the rectangle. In this case, the second portion 502 of the oxidant gas flow field 50 may be arranged parallel to a pair of short sides of the rectangle. With this configuration, a temperature gradient can be created along the flow direction of the oxidant gas flow field 50, making it easier to achieve a uniform current density distribution. Furthermore, the length of the oxidant gas flow field 50 can be increased, making it easier to efficiently discharge moisture generated in the oxidant gas flow field 50. Furthermore, it makes it easier to efficiently promote the electrochemical reaction in the membrane electrode assembly 10.

[0070] The first portion 601 of the coolant flow path 60 may be arranged parallel to a pair of long sides of the rectangle. In this case, the second portion 602 of the coolant flow channel 60 can be arranged parallel to a pair of short sides of the rectangle. With this configuration, a temperature gradient can be easily created along the flow direction of the oxidant gas flow channel 50, making it easier to achieve a uniform current density distribution along the flow direction.

[0071] As shown in Fig. 2A, the fuel gas inlet channel 41 may be located above the fuel gas outlet channel 42. As shown in Fig. 3A, the oxidant gas inlet channel 51 may be located above the oxidant gas outlet channel 52. This configuration allows the fuel gas and oxidant gas to flow without resisting gravity. Furthermore, moisture generated in the oxidant gas flow channel 50 can be efficiently discharged from the oxidant gas outlet 50b.

[0072] 4A, the coolant introduction passage 61 may be located above the coolant discharge passage 62. With this configuration, the coolant can flow without resisting gravity.

[0073] The fuel cell stack 200 is installed such that the Z direction is parallel to the vertical direction, for example. In this case, the second portion 402 of the fuel gas flow path 40, the second portion 502 of the oxidant gas flow path 50, and the second portion 602 of the coolant flow path 60 are each parallel to the horizontal direction.

[0074] FIG. 6 is a second plan view of the cathode separator 30, showing another example of the coolant flow channel 60. The second plan view of FIG. 6 is a plan view of the second surface 32 of the cathode separator 30. As in FIG. 4A, FIG. 6 shows the oxidant gas flow channel 50, the oxidant gas inlet channel 51, and the oxidant gas outlet channel 52 formed on the first surface 31 of the cathode separator 30, projected perpendicularly to the second surface 32. In FIG. 6, elements common to FIG. 4A are denoted by the same reference numerals, and their description will be omitted. In the example shown in FIG. 6, the coolant flow channel 60 does not meander, but includes multiple portions extending in the Z direction. This configuration reduces pressure loss in the coolant flow channel 60, allowing the coolant to flow smoothly through the coolant flow channel 60. Furthermore, this configuration also ensures an overlapping area between the coolant inlet channel 61 and the oxidant gas inlet channel 51 in the projection image P, thereby suppressing an increase in the temperature of the oxidant gas upstream of the oxidant gas flow channel 50.

[0075] [1-2. Operation] The operation and function of the fuel cell stack 200 configured as above will be described below with reference to FIGS. 1 to 4B.

[0076] A fuel gas, an oxidant gas, and a coolant are supplied to the fuel gas flow passage 40, the oxidant gas flow passage 50, and the coolant flow passage 60, respectively. The oxidant gas is typically air.

[0077] At the anode 13, hydrogen (H2) is converted into protons (H + ) and electrons (e - ) The protons move from the anode 13 to the cathode 16 by conduction through the electrolyte membrane 12. The electrons move from the anode 13 to the cathode 16 through an external circuit. At the cathode 16, water (H2O) is produced by an electrochemical reaction of the protons, oxygen (O2), and electrons, as expressed by the following formula (2):

[0078] H2→2H + +2e - (1) 4H+ +O2+2e - →2H2O(2)

[0079] In this embodiment, in the projection image P, at least a portion of the coolant introduction channel 61 overlaps with the oxidant gas introduction channel 51. With this configuration, the coolant flowing through the coolant introduction channel 61 can cool the oxidant gas flowing through the oxidant gas introduction channel 51. It is possible to suppress an increase in the temperature of the oxidant gas upstream of the oxidant gas flow channel 50. This increases the relative humidity of the oxidant gas upstream of the oxidant gas flow channel 50, thereby suppressing drying of the electrolyte membrane 12 and the cathode catalyst layer 17. As a result, the proton conductivity of the cathode catalyst layer 17 improves, suppressing a decrease in power generation performance and improving the power generation efficiency of the fuel cell 100.

[0080] [1-3. Supplementary Notes] The above description of the embodiments discloses the following techniques.

[0081] (Technology 1) an anode separator; a cathode separator; and a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane, the membrane electrode assembly being disposed between the anode separator and the cathode separator; a fuel gas flow channel provided between the anode and the anode separator; an oxidant gas flow channel provided between the cathode and the cathode separator; a coolant flow path provided so as to be separated from the oxidant gas flow path; a fuel gas introduction passage connected to the fuel gas flow passage and introducing fuel gas into the fuel gas flow passage; an oxidant gas inlet passage connected to the oxidant gas flow passage and configured to introduce oxidant gas into the oxidant gas flow passage; a refrigerant introduction passage connected to the refrigerant flow passage and guiding a refrigerant to the refrigerant flow passage; Equipped with the fuel gas flow path, the oxidant gas flow path, and the coolant flow path are located inside an electrode region defined by outer edges of the anode and the cathode, and the fuel gas inlet channel, the oxidant gas inlet channel, and the coolant inlet channel are located outside the electrode region; a projection image obtained by projecting the oxidant gas flow channel, the coolant flow channel, the oxidant gas inlet channel, and the coolant inlet channel in a direction perpendicular to the first surface or the second surface of the cathode separator, At least a portion of the coolant introduction passage overlaps with the oxidant gas introduction passage. fuel cell.

[0082] This configuration can suppress the temperature rise of the oxidant gas upstream of the oxidant gas flow channel, thereby suppressing drying of the electrolyte membrane and the cathode catalyst layer, thereby improving the proton conductivity of the cathode catalyst layer, suppressing deterioration of power generation performance, and improving the power generation efficiency of the fuel cell.

[0083] (Technology 2) The fuel cell according to Technology 1, wherein the fuel gas channel is formed on a first surface of the anode separator, the oxidant gas channel is formed on the first surface of the cathode separator, and the coolant channel is formed on the second surface of the cathode separator. With this configuration, it is possible to prevent the electrolyte membrane and the cathode catalyst layer from drying out.

[0084] (Technology 3) 3. The fuel cell according to claim 1, wherein in the projection image, the coolant introduction channel has a first portion extending in a second direction perpendicular to a first direction in which the oxidant gas introduction channel extends, and a second portion extending in the first direction, and at least the second portion overlaps with the oxidant gas introduction channel. With this configuration, it is easy to ensure an overlapping area between the coolant introduction channel and the oxidant gas introduction channel, and therefore it is possible to further suppress an increase in the temperature of the oxidant gas upstream of the oxidant gas flow channel.

[0085] (Technology 4) The fuel cell according to any one of Techniques 1 to 3, wherein the oxidant gas flow path and the coolant flow path are configured so that the oxidant gas and the coolant flow, respectively, from a first side to a second side of the membrane electrode assembly, and the fuel gas flow path is configured so that the fuel gas flows from the second side to the first side of the membrane electrode assembly. Such a configuration makes it easy to configure the fuel gas, the oxidant gas, and the coolant to flow without resisting gravity.

[0086] (Technology 5) The fuel cell according to Technical Problem 4 further includes an oxidant gas inlet connected to the oxidant gas introduction channel and a coolant inlet connected to the coolant introduction channel, the coolant inlet being located above the oxidant gas inlet. This configuration makes it easy to ensure an overlapping area between the coolant introduction channel and the oxidant gas introduction channel, thereby further suppressing an increase in the temperature of the oxidant gas upstream of the oxidant gas flow channel. Furthermore, it is easy to configure the coolant to flow without resisting gravity.

[0087] (Technology 6) The fuel cell according to technique 4 or 5, wherein the flow direction of the oxidant gas in the oxidant gas channel is the same as the flow direction of the coolant in the coolant channel. With this configuration, it is easy to uniformly cool the oxidant gas.

[0088] (Technology 7) The fuel cell according to any one of techniques 4 to 6, wherein the oxidant gas flow field is a serpentine flow field including a first portion extending in a direction from the first side to the second side and a second portion extending in a direction perpendicular to the direction from the first side to the second side. With this configuration, the oxidant gas can be supplied to every corner of the cathode.

[0089] (Technology 8) The fuel cell according to Technology 7 has a rectangular shape having long and short sides in a plan view, and the first portion is arranged parallel to a pair of long sides of the rectangle. With this configuration, a uniform current density distribution can be easily achieved. Also, moisture generated in the oxidant gas flow channel can be efficiently discharged. Furthermore, the electrochemical reaction in the membrane electrode assembly can be easily promoted efficiently.

[0090] (Technology 9) The fuel cell according to any one of techniques 4 to 8, wherein the fuel cell has a rectangular shape having long and short sides in a plan view, the first side of the membrane electrode assembly being the side on which one of the pair of short sides of the rectangle is located, and the second side being the side on which the other of the pair of short sides of the rectangle is located. This configuration facilitates a configuration in which the fuel gas, oxidant gas, and coolant flow without resisting gravity. Furthermore, the height of the fuel cell can be reduced, thereby reducing the height of the space required for installation.

[0091] (Technology 10) The fuel cell according to any one of the first to ninth aspects of the present invention further includes a fuel gas discharge channel connected to the fuel gas flow channel and discharging the fuel gas that has passed through the fuel gas flow channel, and an oxidant gas discharge channel connected to the oxidant gas flow channel and discharging the oxidant gas that has passed through the oxidant gas flow channel, wherein in the projection image, the fuel gas discharge channel and the oxidant gas discharge channel are located outside the electrode region, the fuel gas inlet channel is located above the fuel gas discharge channel, and the oxidant gas inlet channel is located above the oxidant gas discharge channel. This configuration allows the fuel gas and the oxidant gas to flow without resisting gravity. Furthermore, moisture generated in the oxidant gas flow channel can be efficiently discharged from the oxidant gas outlet. [Industrial Applicability]

[0092] The technology of the present disclosure is useful for electrochemical devices such as secondary batteries, fuel cells, and hydrogen purification devices. [Explanation of symbols]

[0093] 10 Membrane electrode assembly 101 Electrode area 12 Electrolyte membrane 13 Anode 14 Anode catalyst layer 15 Anode gas diffusion layer 16 cathode 17 Cathode catalyst layer 18 Cathode gas diffusion layer 19 Frame 20 Anode separator 21 Page 1 22 Side 2 30 Cathode separator 31 Page 1 32 2nd page 40 fuel gas flow path 401 Part 1 402 Part 2 40a Fuel gas inlet 40b Fuel gas outlet 41 Fuel gas inlet 42 Fuel gas exhaust passage 50 oxidant gas flow path 501 Part 1 502 Part 2 50a Oxidant gas inlet 50b Oxidant gas outlet 51 Oxidant gas inlet 52 Oxidant gas exhaust channel 60 refrigerant flow path 601 Part 1 602 Part 2 60a Refrigerant inlet 60b Refrigerant outlet 61 Refrigerant introduction path 62 Refrigerant discharge path 100 fuel cell 200 fuel cell stack

Claims

1. an anode separator; a cathode separator; and a membrane electrode assembly including an anode, a cathode, and an electrolyte membrane, the membrane electrode assembly being disposed between the anode separator and the cathode separator; a fuel gas flow channel provided between the anode and the anode separator; an oxidant gas flow channel provided between the cathode and the cathode separator; a coolant flow path provided so as to be separated from the oxidant gas flow path; a fuel gas introduction passage connected to the fuel gas flow passage and introducing fuel gas into the fuel gas flow passage; an oxidant gas inlet passage connected to the oxidant gas flow passage and configured to introduce oxidant gas into the oxidant gas flow passage; a refrigerant introduction passage connected to the refrigerant flow passage and guiding a refrigerant to the refrigerant flow passage; Equipped with the fuel gas flow path, the oxidant gas flow path, and the coolant flow path are located inside an electrode region defined by outer edges of the anode and the cathode, and the fuel gas inlet channel, the oxidant gas inlet channel, and the coolant inlet channel are located outside the electrode region; a projection image obtained by projecting the oxidant gas flow field, the coolant flow field, the oxidant gas inlet channel, and the coolant inlet channel in a direction perpendicular to the first surface or the second surface of the cathode separator, At least a portion of the coolant introduction passage overlaps with the oxidant gas introduction passage. fuel cell.

2. the fuel gas flow channel is formed on a first surface of the anode separator, the oxidant gas flow path is formed on the first surface of the cathode separator, the coolant flow path is formed on the second surface of the cathode separator; The fuel cell according to claim 1 .

3. In the projection image, the coolant introduction channel has a first portion extending in a second direction perpendicular to a first direction in which the oxidant gas introduction channel extends, and a second portion extending in the first direction, and at least the second portion overlaps with the oxidant gas introduction channel. The fuel cell according to claim 1 .

4. the oxidant gas flow path and the coolant flow path are configured so that the oxidant gas and the coolant flow, respectively, flow from a first side to a second side of the membrane electrode assembly, the fuel gas flow channel is configured so that the fuel gas flows from the second side to the first side of the membrane electrode assembly. The fuel cell according to claim 1 .

5. an oxidant gas inlet connected to the oxidant gas introduction passage; a refrigerant inlet connected to the refrigerant introduction path; Furthermore, the coolant inlet is located above the oxidant gas inlet; 5. The fuel cell according to claim 4.

6. a flow direction of the oxidant gas in the oxidant gas flow channel is the same as a flow direction of the coolant in the coolant flow channel; 5. The fuel cell according to claim 4.

7. The oxygen-containing gas flow field includes a first portion extending in a direction from the first side toward the second side; a second portion extending in a direction perpendicular to a direction from the first side to the second side; 5. The fuel cell according to claim 4.

8. the fuel cell has a rectangular shape having long sides and short sides in a plan view, The first portion is arranged parallel to a pair of long sides of the rectangle. The fuel cell according to claim 7.

9. the fuel cell has a rectangular shape having long sides and short sides in a plan view, the first side of the membrane electrode assembly is a side on which one of the pair of short sides of the rectangle is located, and the second side is a side on which the other of the pair of short sides of the rectangle is located; 5. The fuel cell according to claim 4.

10. a fuel gas discharge passage connected to the fuel gas flow passage and discharging the fuel gas that has passed through the fuel gas flow passage; an oxidant gas discharge channel connected to the oxidant gas flow channel and discharging the oxidant gas that has passed through the oxidant gas flow channel; Furthermore, In the projection image, the fuel gas discharge channel and the oxidant gas discharge channel are located outside the electrode region, the fuel gas introduction channel is located above the fuel gas discharge channel, and the oxidant gas introduction channel is located above the oxidant gas discharge channel. The fuel cell according to claim 1 .

Images