JP2010086893A - Stack structure of fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack structure capable of reducing internal temperature variations without complicating the shape of a flow passage. <P>SOLUTION: A unit module 100 including a cooling water passage 41, a cooling side heat generating unit cell 10 in which an electrode 112b on the cooling water passage side of electrolyte membranes 111 generates heat by catalyst reaction, and a rear side heat generating unit cell 20 in which the electrode 212b on the rear face of face on the cooling water passage side of the electrolyte membrane 211 generates heat by catalyst reaction, and a heat resistance of membrane-electrode assembly 21 is smaller compared with that of the membrane-electrode assembly 11 of the cooling side heat generating unit cell 10 is laminated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stack structure of a fuel cell.

  A fuel cell is configured by stacking hundreds of membrane electrode assemblies (MEA) each having an anode electrode catalyst layer and a cathode electrode catalyst layer formed on both surfaces of an electrolyte membrane. Each membrane electrode assembly (MEA) generates power through the following reaction in the anode electrode catalyst layer and the cathode electrode catalyst layer.

  At this time, moisture is generated and heat is generated in the cathode electrode catalyst layer. If the calorific value is excessive, the electrolyte membrane is dried to a dry-out state, and the power generation efficiency is deteriorated.

  The fuel cell is formed by stacking a large number of MEAs as described above. If the electrolyte membrane of a specific MEA among those MEAs is in a dry-out state, efficient power generation cannot be performed, so it is desirable that the temperature state inside the stack be uniform.

Therefore, in Patent Document 1, the temperature inside the stack is made uniform by adjusting the amount of reaction gas by forming protrusions in the reaction gas flow path for distributing the reaction gas to each MEA.
JP 2000-251913 A

  However, even if the protrusion is formed as in Patent Document 1, the flow rate cannot be adjusted well when liquid water is present in the flow path. Under conditions where liquid water is present, the behavior of liquid water cannot be predicted. Therefore, it is difficult to optimally design the protrusion. Further, if the protrusion is formed, the flow path becomes a complicated shape.

  The present invention has been made paying attention to such a conventional problem, and provides a fuel cell stack structure capable of reducing internal temperature variations without complicating the shape of the flow path. Objective.

  The present invention solves the above problems by the following means.

  In the present invention, the cooling water channel, the cooling side heating unit cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat by the catalytic reaction, and the electrode on the back surface of the cooling water channel side of the electrolyte membrane generate heat by the catalytic reaction. A unit module including a back-side heat generating unit cell, in which the thermal resistance of the membrane electrode assembly is smaller than that of the membrane electrode assembly of the cooling-side heat generating unit cell, is laminated.

  According to the present invention, compared with the thermal resistance of the membrane electrode assembly of the cooling side heating unit cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat, the back side heat generation in which the electrode on the back side of the cooling water channel of the electrolyte membrane generates heat. A unit cell module having a low thermal resistance of a single cell membrane electrode assembly was stacked to form a fuel cell stack. Since it comprised in this way, the temperature variation in a unit module was able to be reduced.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
(Basic form)
1A and 1B are views showing the appearance of a fuel cell according to the present invention. FIG. 1A is a perspective view and FIG. 1B is a side view.

  First, the basic configuration of the fuel cell will be described. The fuel cell stack 1 includes a plurality of stacked unit modules 100, a current collecting plate 200, an insulating plate 300, an end plate 400, and four tension rods 500.

  The unit module 100 includes a single cell. Hundreds of unit modules 100 are arranged in series. Details of the configuration of the unit module 100 will be described later.

The current collecting plate 200 is disposed outside each of the stacked unit modules 100. The current collecting plate 200 is formed of a gas impermeable conductive member, for example, dense carbon. The current collecting plate 200 includes an output terminal 201 on a part of the upper side. The fuel cell stack 1, the output terminal 201, electrons e generated in the respective unit modules 100 ^- to the removed output.

  The insulating plates 300 are respectively disposed outside the current collecting plate 200. The insulating plate 300 is formed of an insulating member such as rubber.

  The end plate 400 is disposed outside the insulating plate 300, respectively. The end plate 400 is made of a rigid metal material such as steel.

  One end plate 400 (the left front end plate 400 in FIG. 1A) is provided with an anode supply port, an anode discharge port, a cathode supply port, a cathode discharge port, a cooling water supply port, and a cooling water discharge port. It has been. Note that in FIG. 1A, these are shown as circular, but the shape may be changed as appropriate.

  As a method of supplying hydrogen as anode gas to the anode supply port, for example, a method of supplying hydrogen gas directly from a hydrogen storage device, or a method of supplying a hydrogen-containing gas reformed by reforming a fuel containing hydrogen and so on. Examples of the hydrogen storage device include a high-pressure gas tank, a liquefied hydrogen tank, and a hydrogen storage alloy tank. Examples of the fuel containing hydrogen include natural gas, methanol, and gasoline. Air is generally used as the cathode gas supplied to the cathode supply port.

  The tension rods 500 are disposed near the four corners of the end plate 400, respectively. The fuel cell stack 1 has a hole (not shown) penetrating therethrough. The tension rod 500 is inserted into the through hole (see FIG. 1B). The tension rod 500 is made of a rigid metal material such as steel. The tension rod 500 is insulated on its surface in order to prevent an electrical short circuit inside the fuel cell stack. A nut 501 is screwed into the tension rod 500 (see FIG. 1B). A stacking pressure is generated by the tension rod 500 and the nut 501 tightening the fuel cell stack 1 in the stacking direction.

  As shown in FIG. 1B, the fuel cell stack 1 has a current collecting plate 200, an insulating plate 300, and an end plate 400 disposed on both sides of a plurality of unit modules 100 stacked.

  In addition, a sub-end plate 401 is disposed outside the insulating plate 300 on one side of the fuel cell stack 1, and a fluctuation absorbing member 402 made of, for example, a disc spring is disposed outside the sub-end plate 401. An end plate 400 is provided. The fuel cell stack having such a stacked structure is fastened in the stacking direction by four tension rods 500. Thus, since the fluctuation | variation absorption member 402 is provided, the fluctuation | variation of the surface pressure which acts on a fuel cell stack can be absorbed.

(Unit Module; First Embodiment)
FIG. 2 is an enlarged cross-sectional view showing a first embodiment of a unit module used in a fuel cell stack structure according to the present invention.

  The unit module 100 includes a first unit cell 10, a second unit cell 20, and a cooling plate 40.

  Here, for convenience of explanation, the cooling plate 40 will be described prior to the first unit cell 10 and the second unit cell 20. The cooling plate 40 is disposed between the first unit cell 10 and the second unit cell 20. A cooling water channel 41 through which cooling water flows is formed in the cooling plate 40. The cooling plate 40 is formed by resin molding using conductive carbon powder such as carbon black.

  Next, the first unit cell 10 and the second unit cell 20 will be described.

  The first single cell 10 is a unit cell of a fuel cell. The first single cell 10 generates an electromotive voltage of about 1 volt (V). The first unit cell 10 includes a membrane electrode assembly (MEA) 11, an anode separator 12a, and a cathode separator 12b.

  The MEA 11 includes an electrolyte membrane 111, an anode electrode catalyst layer 112a and a cathode electrode catalyst layer 112b, an anode gas diffusion layer (GDL) 113a, and a cathode GDL 113b.

  The electrolyte membrane 111 is formed of an ion exchange membrane.

  The anode electrode catalyst layer 112a and the cathode electrode catalyst layer 112b generate power by the above-described catalytic reaction. The anode electrode catalyst layer 112a and the cathode electrode catalyst layer 112b include, for example, a mixed layer composed of a catalyst in which platinum Pt or a platinum-based alloy is supported on a carbon carrier powder, an electrolyte particle (ionomer), and a water repellent agent on the electrolyte membrane. It is formed by hot pressing or direct spraying. The anode electrode catalyst layer 112a is formed on one surface of the electrolyte membrane 111, and the cathode electrode catalyst layer 112b is formed on the opposite surface. In the present embodiment, the anode electrode catalyst layer 112 a is formed on the left surface of the electrolyte membrane 111, and the cathode electrode catalyst layer 112 b is formed on the right surface of the electrolyte membrane 111. In the cathode electrode catalyst layer 112b, moisture is generated and heat is generated by the catalytic reaction described above. That is, in the first unit cell 10, the cathode electrode catalyst layer 112b, which is an electrode on the surface of the electrolyte membrane 111 on the cooling water channel side, generates heat due to a catalytic reaction.

  The anode GDL 113a and the cathode GDL 113b diffuse the reaction gas and supply it to the electrode catalyst layer 112 (112a, 112b). The anode GDL 113a and the cathode GDL 113b are formed of a member having sufficient gas diffusibility and conductivity, such as carbon fiber. The anode GDL 113a is formed on the anode electrode catalyst layer 112a. The cathode GDL 113b is formed on the cathode electrode catalyst layer 112b.

  The anode separator 12a and the cathode separator 12b are gas impermeable and electrically conductive. The anode separator 12a and the cathode separator 12b are formed by resin molding using conductive carbon powder such as carbon black. The anode separator 12a overlaps the anode GDL 113a. In the anode separator 12a, an anode gas flow path 121a through which anode gas flows is formed on the surface facing the anode GDL 113a. The cathode separator 12b overlaps the cathode GDL 113b. In the cathode separator 12b, a cathode gas flow path 121b through which cathode gas flows is formed on the surface facing the cathode GDL 113b.

  The second unit cell 20 has the same basic configuration as the first unit cell 10. Therefore, the description of the same function as that of the first unit cell 10 is omitted by changing the initial code to 2. In the second unit cell 20 as well, moisture is generated and heat is generated in the cathode electrode catalyst layer 212b by the above-described catalytic reaction. That is, in the second single cell 20, the cathode electrode catalyst layer 212b, which is the back electrode of the surface on the cooling water channel side of the electrolyte membrane 211, generates heat due to the catalytic reaction.

  The thermal resistance from the cathode electrode catalyst layer 212b to the cooling water channel 41 is adjusted to be substantially equal to the thermal resistance from the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41. Specifically, for example, the plate thickness of the anode separator 22a of the second single cell 20 may be made thinner than the plate thickness of the cathode separator 12b of the first single cell 10. Moreover, you may adjust a thermal resistance by changing content of the composition component of the anode separator 22a and the cathode separator 12b. Furthermore, the cooling water channel 41 formed in the cooling plate 40 may be formed close to the anode separator 22 a of the second single cell 20. The thermal resistance is an index indicating the difficulty of conducting heat in a substance. Heat is more difficult to conduct as the thermal resistance is higher, and heat is easier to conduct as the thermal resistance is smaller.

  According to this embodiment, the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41 and the cathode electrode catalyst layer 212b of the second single cell 20 to the cooling water channel 41 have substantially the same thermal resistance. is there.

  The heat generated in the cathode electrode catalyst layer 112b of the first single cell 10 is conducted to the cooling plate 40 through the cathode GDL 113b and the cathode separator 12b, and is cooled.

  The heat generated in the cathode electrode catalyst layer 212b of the second single cell 20 is conducted to the cooling plate 40 through the electrolyte membrane 211, the anode electrode catalyst layer 212a, the anode GDL 213a, and the anode separator 22a, and is cooled.

  Here, since the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41 and the cathode electrode catalyst layer 212b of the second single cell 20 to the cooling water channel 41 have substantially the same thermal resistance, the first The cathode electrode catalyst layer 112 b of the single cell 10 to the cathode electrode catalyst layer 212 b of the second single cell 20 are cooled substantially uniformly by the cooling water channel 41. Therefore, the temperature distribution from the cathode electrode catalyst layer 112b of the first unit cell 10 to the cathode electrode catalyst layer 212b of the second unit cell 20 becomes substantially uniform. Therefore, the temperature variation of each MEA can be reduced, and there is no situation where the specific MEA generates a large amount of heat and the electrolyte membrane becomes dry out.

(Second Embodiment)
FIG. 3 is an enlarged cross-sectional view showing a second embodiment of the unit module used in the fuel cell stack structure according to the present invention.

  In the following description, parts having the same functions as those described above are denoted by the same reference numerals, and redundant description is omitted as appropriate.

  In the present embodiment, the thermal resistance of the MEA 21 of the second single cell 20 is made smaller than the thermal resistance of the MEA 11 of the first single cell 10. Specifically, for example, the electrolyte membrane 211 of the MEA 21 is made thinner than the electrolyte membrane 111 of the MEA 11.

  As a result, heat generated in the cathode electrode catalyst layer 212b of the second single cell 20 is easily conducted to the cooling plate 40 through the electrolyte membrane 211, the anode electrode catalyst layer 212a, the anode GDL 213a, and the anode separator 22a. It becomes easy to be cooled. In particular, if the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41 and the cathode electrode catalyst layer 212b of the second single cell 20 to the cooling water channel 41 are adjusted to have substantially the same thermal resistance, The cathode electrode catalyst layer 112b of the first unit cell 10 to the cathode electrode catalyst layer 212b of the second unit cell 20 are cooled substantially uniformly by the cooling water channel 41. Therefore, the temperature distribution from the cathode electrode catalyst layer 112b of the first unit cell 10 to the cathode electrode catalyst layer 212b of the second unit cell 20 becomes substantially uniform. Therefore, the temperature variation of each MEA can be reduced.

(Third embodiment)
FIG. 4 is an enlarged cross-sectional view showing a third embodiment of a unit module used in the fuel cell stack structure according to the present invention.

  In the present embodiment, the thermal resistance of the MEA 11 of the first single cell 10 is made larger than the thermal resistance of the MEA 21 of the second single cell 20. Specifically, for example, a microporous layer (MPL) 114 (114a, 114b) may be formed between the electrode catalyst layer 112 (112a, 112b) and the GDL 113 (113a, 113b). The MPL 114 is a mixed layer of a binder / water repellent composed mainly of conductive carbon powder such as carbon black and polytetrafluoroethylene (PTFE). The MPL 114 prevents the GDL 113 fibers from penetrating the electrolyte membrane 111 and short-circuiting. Further, the MPL 114 increases the contact area between the electrode catalyst layer 112 and the GDL 113. Further, the MPL 114 adjusts the drainage of the electrode catalyst layer 112 to optimize the wet environment of the electrode catalyst layer 112 during power generation and prevent flooding and dryout. Furthermore, the MPL 114 promotes the distribution of the reaction gas and improves the power generation performance of the fuel cell. And since such MPL114 is provided in MEA11 of the 1st single cell 10, and not in MEA21 of the 2nd single cell 20, the thermal resistance of MEA11 of the 1st single cell 10 is the heat of MEA21 of the 2nd single cell 20. Greater than resistance.

  Since it did in this way, the heat generated in the cathode electrode catalyst layer 112b of the first single cell 10 becomes difficult to conduct to the cooling plate 40. In particular, if the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41 and the cathode electrode catalyst layer 212b of the second single cell 20 to the cooling water channel 41 are adjusted to have substantially the same thermal resistance, The cathode electrode catalyst layer 112b of the first unit cell 10 to the cathode electrode catalyst layer 212b of the second unit cell 20 are cooled substantially uniformly by the cooling water channel 41. Therefore, the temperature distribution from the cathode electrode catalyst layer 112b of the first unit cell 10 to the cathode electrode catalyst layer 212b of the second unit cell 20 becomes substantially uniform. Therefore, the temperature variation of each MEA can be reduced.

(Fourth embodiment)
FIG. 5 is an enlarged cross-sectional view showing a fourth embodiment of the unit module used in the fuel cell stack structure according to the present invention.

  In the unit module 100 of the present embodiment, the third unit cell 30 is further arranged next to the second unit cell 20.

  The third unit cell 30 has the same basic configuration as the first unit cell 10 and the second unit cell 20. In view of this, the same reference numerals as those in the first unit cell 10 and the second unit cell 20 are changed to 3 to omit redundant description. In the third unit cell 30 as well, moisture is generated and heat is generated by the above-described catalytic reaction in the cathode electrode catalyst layer 312b. That is, in the third unit cell 30, the cathode electrode catalyst layer 312b, which is the back electrode of the surface of the electrolyte membrane 311 on the cooling water channel side, generates heat due to the catalytic reaction.

  The thermal resistance from the cathode electrode catalyst layer 112b of the first single cell 10 to the cooling water channel 41, the thermal resistance from the cathode electrode catalyst layer 212b of the second single cell 20 to the cooling water channel 41, and the cathode of the third single cell 30. The thermal resistance from the electrode catalyst layer 312b to the cooling water channel 41 is adjusted to be substantially equal.

  The thermal resistance may be adjusted by changing the thickness of the separator as in the first embodiment. For example, the thickness of the anode separator 32a of the third unit cell 30 farthest from the cooling water channel 41 may be made the thinnest, and the thickness of the cathode separator 12b of the first unit cell 10 may be made the thickest. Further, the separator material is changed as in the first embodiment, the formation position of the cooling water channel 41 is adjusted, the thickness of the electrolyte membrane is adjusted as in the second embodiment, or the third embodiment is changed. MPL may be provided in the above, or they may be combined.

  By configuring in this way, the cathode electrode catalyst layer 112 b of the first single cell 10 to the cathode electrode catalyst layer 312 b of the third single cell 30 are cooled substantially uniformly by the cooling water channel 41. Therefore, even if the number of unit cells constituting the unit module 100 increases, the temperature distribution in the unit module becomes substantially uniform. Therefore, the temperature variation of each MEA can be reduced.

  Without being limited to the embodiments described above, various modifications and changes are possible within the scope of the technical idea, and it is obvious that these are also included in the technical scope of the present invention.

  For example, the number of single cells constituting the unit module may be increased to four or more.

  Moreover, in the said embodiment, although the cooling water channel was formed in the cooling plate, it is not restricted to such a structure. For example, a channel is formed in the back surface of the cathode separator 12b of the first single cell 10 and the back surface of the anode separator 22a of the second single cell 20, and a cooling water channel is formed by combining the recesses on the back surfaces of both separators. May be.

  Further, in the second embodiment, in order to make the thermal resistance of the MEA 21 of the second single cell 20 smaller than the thermal resistance of the MEA 11 of the first single cell 10, the electrolyte membrane 211 of the MEA 21 is changed to the electrolyte of the MEA 11. Although it is exemplified that the thickness is smaller than that of the membrane 111, the anode electrode catalyst layer 212a and the anode GDL 213a may be thinner than the cathode electrode catalyst layer 112b and the cathode GDL 113b.

  Furthermore, in the first embodiment, the thermal resistance from the cathode electrode catalyst layer 212b to the cooling water channel 41 is substantially equal to the thermal resistance from the cathode electrode catalyst layer 112b to the cooling water channel 41 of the first single cell 10. It is adjusted. In this case, if the thermal resistance of the anode electrode catalyst layer 212a and the anode GDL 213a of the second single cell 20 is a standard resistance, the thermal resistance of the cathode electrode catalyst layer 112b and the cathode GDL 113b of the first single cell 10 is The heat resistance of the anode electrode catalyst layer 212a and the anode GDL 213a of the two unit cell 20 is set to be larger. The thermal resistance of the anode electrode catalyst layer 112a and the anode GDL 113a of the first single cell 10 may be equal to the thermal resistance of the anode electrode catalyst layer 212a and the anode GDL 213a of the second single cell 20. In this way, the specifications of the front and back surfaces of the MEA 11 of the first single cell 10 may be different. However, when configured in this way, there is a possibility that the water transfer characteristic between the electrodes via the MEA is not uniform in a single cell. And the amount of liquid water which exists in either one pole of a single cell may vary. And the amount of liquid water may be generated by a single cell. In a single cell having a relatively large amount of liquid water, flooding may occur and power generation may become unstable. In order to avoid such a problem, even if the specifications of the MEA are changed, the water transfer characteristics between the electrodes via the electrolyte membrane should not be uneven. For that purpose, the water movement characteristics between the poles of all the MEAs may be set within a predetermined range. The certain predetermined value refers to a threshold value of a difference in water movement characteristics that is a limit at which flooding, which is relatively generated by a single cell, does not remarkably occur in a designed operating condition. In order to adjust the water transfer characteristics, the thickness of the electrolyte membrane, the material, the GDL material, the material, the pore diameter, the porosity, the hydrophilicity of the surface, the hydrophobicity, etc. may be adjusted.

It is a figure which shows the external appearance of the fuel cell by this invention. 1 is an enlarged cross-sectional view showing a first embodiment of a unit module used in a fuel cell stack structure according to the present invention. FIG. 4 is an enlarged cross-sectional view showing a second embodiment of a unit module used in a fuel cell stack structure according to the present invention. FIG. 5 is an enlarged cross-sectional view showing a third embodiment of a unit module used in a fuel cell stack structure according to the present invention. It is a cross-sectional enlarged view which shows 4th Embodiment of the unit module used for the stack structure of the fuel cell by this invention.

Explanation of symbols

100 Unit module 10 1st single cell (cooling side heat generating single cell)
11 Membrane electrode assembly (MEA)
111 Electrolyte membrane 112a Anode electrode catalyst layer 112b Cathode electrode catalyst layer (power generation electrode)
113a Anode gas diffusion layer (anode GDL)
113b Cathode gas diffusion layer (cathode GDL)
20 2nd single cell (backside exothermic single cell)
21 Membrane electrode assembly (MEA)
211 Electrolyte membrane 212a Anode electrode catalyst layer 212b Cathode electrode catalyst layer (power generation electrode)
213a Anode gas diffusion layer (anode GDL)
213b Cathode gas diffusion layer (cathode GDL)
30 3rd single cell (backside heating single cell)
31 Membrane electrode assembly (MEA)
311 Electrolyte membrane 312a Anode electrode catalyst layer 312b Cathode electrode catalyst layer (power generation electrode)
313a Anode gas diffusion layer (anode GDL)
313b Cathode gas diffusion layer (cathode GDL)
40 Cooling plate 41 Cooling channel

Claims (11)

A cooling channel,
A cooling-side exothermic single cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction;
The electrode on the back side of the cooling water channel side of the electrolyte membrane generates heat by catalytic reaction, and the heat resistance of the membrane electrode assembly is smaller than the heat resistance of the membrane electrode assembly of the cooling side heating unit cell. A single cell,
Stack structure of a fuel cell in which unit modules including a stack are stacked. A cooling channel,
A cooling-side exothermic single cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction;
The electrode on the back surface of the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction, and the thermal resistance from the heating electrode to the cooling water channel is the thermal resistance from the heating electrode of the cooling side heating unit cell to the cooling water channel. A backside exothermic single cell that is substantially equivalent to
Stack structure of a fuel cell in which unit modules including a stack are stacked. The electrolyte membrane of the membrane electrode assembly of the back side exothermic single cell is thinner than the electrolyte membrane of the membrane electrode assembly of the cooling side exothermic single cell,
3. The fuel cell stack structure according to claim 1, wherein the stack structure is a fuel cell stack. The component on the cooling water channel side of the electrolyte membrane of the back side heat generating single cell is thinner than the component on the cooling water channel side of the electrolyte membrane of the cooling side heat generating single cell,
The fuel cell stack structure according to any one of claims 1 to 3, wherein the fuel cell stack structure is provided. A cooling channel,
A cooling-side exothermic single cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction;
The electrode on the back surface of the cooling water channel side of the electrolyte membrane generates heat by catalytic reaction, and the thermal resistance of the membrane electrode assembly is smaller than the thermal resistance of the membrane electrode assembly of the cooling side heating unit cell, and A plurality of back side heat generating single cells having a smaller thermal resistance as they move away from the cooling water channel,
Stack structure of a fuel cell in which unit modules including a stack are stacked. A cooling channel,
A cooling-side exothermic single cell in which the electrode on the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction;
The electrode on the back side of the cooling water channel side of the electrolyte membrane generates heat by a catalytic reaction, and the thermal resistance from each heating electrode to the cooling water channel is the thermal resistance from the heating electrode of the cooling side heating unit cell to the cooling water channel. A plurality of backside heating unit cells that are substantially equivalent to
Stack structure of a fuel cell in which unit modules including a stack are stacked. The electrolyte membrane of the membrane electrode assembly of each backside exothermic single cell is thinner than the electrolyte membrane of the membrane electrode assembly of the cooling side exothermic single cell, and is thin enough to move away from the cooling water channel.
7. The fuel cell stack structure according to claim 5, wherein the fuel cell stack structure is a fuel cell stack structure. The components on the cooling water channel side of the electrolyte membrane of each backside heat generating unit cell are thinner than the components on the cooling water channel side of the electrolyte membrane of the cooling side heat generating unit cell, and are separated from the cooling water channel. It ’s so thin,
The fuel cell stack structure according to any one of claims 5 to 7, wherein the fuel cell stack structure is provided. The membrane electrode assembly of the cooling side exothermic single cell includes a microporous layer, and thermal resistance is increased by the microporous layer.
The fuel cell stack structure according to any one of claims 1 to 8, wherein the stack structure is a fuel cell. All single-cell membrane electrode assemblies have equivalent inter-electrode water transfer characteristics,
10. The fuel cell stack structure according to claim 1, wherein the stack structure is a fuel cell stack structure. The electrode that generates heat by the catalytic reaction is a cathode electrode.
11. The fuel cell stack structure according to claim 1, wherein the stack structure is a fuel cell stack structure.

Images