JP2023169737A - Fuel battery stack - Google Patents

Abstract

To provide a fuel battery stack capable of improving drainage.SOLUTION: A fuel battery stack has a plurality of laminated fuel battery cells each including a generation element, a frame member 20, and a pair of separators. The frame member has an opening portion for storing the generation element, and a plurality of frame member side reaction gas manifolds in which reaction gas circulate. The separator has a reaction gas channel for flowing the reaction gas in a surface direction of the separator, and a plurality of separator side reaction gas manifolds in which the reaction gas circulate. In the adjacent fuel battery cells, the frame member side reaction gas manifold of one of the fuel battery cells has an abutting portion 25 that extends in a laminating direction so as to cover a part of a side surface inside the separator side reaction gas manifold and abuts on the frame member of the other fuel battery cell.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD This application relates to fuel cell stacks.

A fuel cell (FC) consists of one single cell or a fuel cell stack in which single cells are stacked. A fuel cell is a power generation device that extracts electrical energy through an electrochemical reaction that occurs when a fuel gas such as hydrogen and an oxidant gas such as oxygen or air are supplied.

In general, a fuel cell uses a membrane electrode assembly (MEA), in which a catalyst layer is arranged on both sides of an electrolyte membrane, or a membrane electrode assembly, in which a gas diffusion layer is further formed on both sides of an MEA, as a power generation element. It is equipped with an electrode gas diffusion layer assembly (MEGA).

Further, the fuel cell has a frame member disposed around the power generation element, and a pair of separators are disposed to sandwich the frame member. The separator usually has a structure in which grooves, which are reaction gas flow paths, are formed on the surface in contact with the gas diffusion layer. Furthermore, the separator has conductivity and also functions as a current collector for the generated electricity.

At the fuel electrode (anode) of a fuel cell, fuel gas such as hydrogen supplied from the gas flow path and gas diffusion layer is protonated by the catalytic action of the catalyst layer, passes through the electrolyte membrane, and is transferred to the oxidizer electrode (cathode). Moving. At the same time, the generated electrons pass through an external circuit, perform work, and move to the cathode. Oxidizing gas such as oxygen and air supplied to the cathode reacts with protons and electrons on the cathode to generate water. The generated water provides appropriate humidity to the electrolyte membrane, and excess water passes through the gas diffusion layer and is discharged to the outside of the system.

Water produced by the electrochemical reaction is normally discharged from the system together with the reaction gas through a manifold formed in the fuel cell, but if it is not properly discharged, it remains inside. Retention of generated water causes flooding, which poses a problem of making the operation of the fuel cell unstable. In addition, due to freezing of the generated water, the flow path is blocked, and the supply of reaction gas to the fuel cell is delayed, resulting in problems such as performance deterioration and start-up time due to gas shortage. Furthermore, depending on the power generation state of the fuel cell, the catalyst layer may deteriorate due to partial gas shortage, resulting in a problem of reduced power generation durability.

In order to suppress such problems, techniques aimed at improving the drainage performance of fuel cells are known.

Patent Document 1 discloses that an electrolyte/electrode assembly in which a pair of electrodes are disposed on both sides of an electrolyte and a separator are stacked, a reaction gas flow path for flowing a reaction gas in the surface direction of the separator, and a reaction gas flow path for flowing the reaction gas. A fuel cell stack in which a plurality of power generating cells are stacked in the direction of gravity, comprising a power generation cell in which a reaction gas supply communication hole and a reaction gas discharge communication hole are formed to flow in the stacking direction, and at least the reaction gas discharge communication hole is formed. A fuel cell stack is disclosed in which a water guide member is disposed in the hole to cause the condensed water to fall directly in the direction of gravity along the reaction gas discharge communication hole. According to Patent Document 1, the water drainage performance of the fuel cell stack is improved by the guiding action of the water guide member.

Japanese Patent Application Publication No. 2010-192291

As described above, the water generated by the electrochemical reaction is discharged to the outside of the system through the manifold, but there is a predetermined step on the inside side of the manifold. The present inventor found that water generated by an electrochemical reaction adheres to such a step and is difficult to be properly discharged. In particular, generated water tends to move along the side surfaces of the manifold and therefore tends to adhere to the steps. Since the generated water that adheres to the steps tends to stay, there is a risk of causing the above-mentioned problems due to flooding and freezing.

In view of the above circumstances, the main purpose of the present disclosure is to provide a fuel cell stack that can improve drainage performance.

The present disclosure provides, as one aspect for solving the above problems, a power generation element, a frame member disposed around the power generation element, and a pair of separators laminated on the frame member so as to sandwich the power generation element and the frame member. A fuel cell stack in which a plurality of fuel cells are stacked, the frame member having an opening for accommodating a power generation element, and a plurality of frame member side reaction gas manifolds through which a reaction gas flows; The separator has a reaction gas passage through which the reaction gas flows in the surface direction of the separator, and a plurality of separator-side reaction gas manifolds through which the reaction gas flows, and includes a plurality of frame member-side reaction gas manifolds and a plurality of separator-side reaction gas manifolds. The gas manifolds are arranged in alignment with each other, thereby forming a plurality of reaction gas manifolds, and in adjacent fuel cells, the reaction gas manifold on the frame member side of one fuel cell is placed on the separator side. A fuel cell stack is provided that has a contact portion that extends in the stacking direction so as to cover a part of the inner side surface of a reaction gas manifold and that contacts a frame member of the other fuel cell.

According to the present disclosure, the level difference that occurs in the reaction gas manifold is suppressed by the predetermined contact portion, so that the drainage performance of the fuel cell stack can be improved.

1 is a perspective view of a fuel cell stack 100. FIG. FIG. 5 is an exploded perspective view of a fuel cell 50. FIG. FIG. 2 is a schematic view of the frame member 20 observed from the stacking direction. FIG. 3 is a schematic view of the surface of the anode-side separator 30a in contact with the power generation element 10, observed from the stacking direction. FIG. 3 is a schematic view of the surface of the cathode-side separator 30b in contact with the power generation element 10, observed from the stacking direction. (a) It is a top view which expanded and showed the frame member side reaction gas manifold of the frame member 20. (b) A sectional view taken along line bb in (a), showing a state in which the separator is sandwiched between two frame members 20. FIG. 6(b) is a diagram of a conventional fuel cell stack in which the frame member does not have an abutting portion, corresponding to FIG. 6(b). 6A and 6B are diagrams corresponding to FIGS. 6A and 6B, and are diagrams showing a form in which the frame member 120 has a contact portion 125. FIG. (a) and (b) are diagrams corresponding to FIGS. 6 (a) and (b), and are diagrams showing a form in which the frame member 220 has a contact portion 225 that is a separate member.

[Fuel cell stack 100]
A fuel cell stack of the present disclosure will be described using a fuel cell stack 100 that is one embodiment. FIG. 1 shows a perspective view of a fuel cell stack 100. FIG. 2 shows an exploded perspective view of the fuel cell 50.

As shown in FIG. 1, the fuel cell stack 100 is formed by stacking a plurality of fuel cells 50. In the fuel cell stack 100, the number of stacked cells 50 is not particularly limited, but is typically 2 to 200. The fuel cell stack 100 may include end plates at both ends in the stacking direction. In the fuel cell stack 100, a gasket may be arranged between adjacent fuel cells 50. Examples of the gasket material include silicone rubber.

<Fuel cell cell 50>
As shown in FIG. 2, the fuel cell 50 includes a power generation element 10, a frame member 20 disposed around the power generation element 10, and a stacked structure on the frame member 20 so as to sandwich the power generation element 10 and the frame member 20. A pair of separators (an anode side separator 30a, a cathode side separator 30b) are provided.

(Power generation element 10)
The power generation element 10 is a power generation device that extracts electrical energy through an electrochemical reaction that occurs when fuel gas is supplied to the anode and oxidant gas is supplied to the cathode. The fuel gas is hydrogen, reformed gas, or the like. The oxidant gas is oxygen, air, or the like.

The power generation element 10 is a membrane electrode assembly (MEA) or a membrane electrode gas diffusion layer assembly (MEGA).

The MEA has catalyst layers (cathode catalyst layer, anode catalyst layer) arranged on both sides of an electrolyte membrane. Examples of the electrolyte membrane include solid polymer electrolyte membranes made of fluororesin and the like. The catalyst layer contains a catalytic metal that promotes electrochemical reactions. The catalyst layer may further include an electrolyte having proton conductivity, carbon particles having electron conductivity, and the like. As the catalyst metal, for example, platinum (Pt) and an alloy of Pt and another metal (for example, a Pt alloy mixed with cobalt, nickel, etc.) can be used.

MEGA has gas diffusion layers (cathode gas diffusion layer, anode gas diffusion layer) formed on both sides of MEA. The gas diffusion layer may be a conductive member or the like having gas permeability. Examples of the conductive member include carbon porous bodies such as carbon cloth and carbon paper, and metal porous bodies such as metal mesh and foamed metal.

Note that in the case of MEA, the anode catalyst layer functions as an anode, and the cathode catalyst layer functions as a cathode. In the case of MEGA, an anode catalyst layer and an anode gas diffusion layer function as an anode, and a cathode catalyst layer and a cathode gas diffusion layer function as a cathode.

(Frame member 20)
The frame member 20 is a member disposed around the power generation element 10, and is a member for preventing cross leakage of the reaction gas supplied to the power generation element 10 and electrical short circuit between the catalyst layers of the power generation element. . FIG. 3 shows a schematic diagram of the frame member 20 observed from the stacking direction.

The frame member 20 has an opening 21 that accommodates the power generation element 10 and a plurality of frame member side reaction gas manifolds through which reaction gas flows. Further, the frame member 20 may include a plurality of frame member side refrigerant manifolds through which refrigerant flows. Here, the term "reactive gas" refers to a combination of fuel gas and oxidizing gas. The refrigerant is cooling water, cooling air, or the like.

The opening 21 is a through hole for accommodating the power generation element 10, and is formed to surround the power generation element 10. The size of the opening 21 is appropriately set according to the size of the power generation element 10.

The frame member side reaction gas manifold is a through hole through which the reaction gas flows in the stacking direction. As shown in FIG. 3, the frame member side reaction gas manifold includes a frame member side fuel gas supply manifold 22a, a frame member side fuel gas discharge manifold 22b, a frame member side oxidizing gas supply manifold 23a, and a frame member side oxidizing gas manifold. It has a discharge manifold 23b.

Fuel gas flows through the frame member side fuel gas supply manifold 22a and the frame member side fuel gas discharge manifold 22b. The frame member-side fuel gas supply manifold 22a is the one through which the fuel gas is supplied from the outside, and the frame member-side fuel gas discharge manifold 22b is the one through which the fuel gas is discharged to the outside.

Oxidizing gas flows through the frame member side oxidizing gas supply manifold 23a and the frame member side oxidizing gas discharge manifold 23b. The side through which the oxidant gas flows in the direction in which it is supplied from the outside is referred to as the frame member side oxidant gas supply manifold 23a, and the side through which the oxidant gas flows in the direction in which it is discharged to the outside is referred to as the frame member side oxidant gas discharge manifold 23b. shall be.

The frame member side refrigerant manifold is a through hole through which refrigerant flows in the stacking direction. As shown in FIG. 3, the frame member side refrigerant manifold includes a frame member side refrigerant supply manifold 24a and a frame member side refrigerant discharge manifold 24b. The side through which the refrigerant flows in the direction in which the refrigerant is supplied from the outside is referred to as the frame member side refrigerant supply manifold 24a, and the side through which the refrigerant flows in the direction in which the refrigerant is discharged to the outside is referred to as the frame member side refrigerant discharge manifold 24b.

The frame member 20 may be any member that has gas-sealing properties and insulation properties, and may be made of a resin whose structure does not change even under the temperature conditions during thermocompression bonding in the fuel cell manufacturing process. For example, polyethylene, polypropylene, PC (polycarbonate), PPS (polyphenylene sulfide), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), PA (polyamide), PI (polyimide), PS (polystyrene), PPE (polyphenylene) ether), PEEK (polyether ether ketone), cycloolefin, PES (polyether sulfone), PPSU (polyphenylsulfone), LCP (liquid crystal polymer), epoxy resin, or an alloy resin thereof. Alternatively, it may be a rubber material such as EPDM (ethylene propylene diene rubber), fluorine rubber, or silicone rubber.

The thickness of the frame member 20 may be 5 μm or more, 30 μm or more from the viewpoint of ensuring insulation, and may be 100 μm or less, 90 μm or less from the viewpoint of reducing the cell thickness. It may be the following.

The frame member 20 may include an adhesive layer for adhering to the separator. The adhesive layer may be disposed on only one surface of the frame member 20, or may be disposed on both surfaces. The adhesive layer may be provided only in the portion that contacts the separator. Typically, the adhesive layer is provided along the outer frame of the frame member 20.

In order to adhere the frame member 20 and the separator to ensure sealing properties, the adhesive layer has high adhesiveness with other substances, softens under the temperature conditions during thermocompression bonding, and has a higher viscosity and lower viscosity than the frame member 20. It may have a property of having a low melting point. For example, the adhesive layer may be made of thermoplastic resin such as polyester-based and modified olefin-based resin, or may be made of thermosetting resin such as modified epoxy resin. Specific examples include maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, epoxy-modified polyethylene, epoxy-modified polypropylene, acid-modified polyethylene, and acid-modified polypropylene.

The thickness of the adhesive layer may be 5 μm or more, or 30 μm or more, from the viewpoint of ensuring adhesiveness, and may be 100 μm or less, or 40 μm or less, from the viewpoint of reducing the cell thickness. It may be.

<Separator>
The separator is a pair of members laminated on the frame member 20 so as to sandwich the power generation element 10 and the frame member 20. As shown in FIG. 2, the separator includes an anode separator 30a and a cathode separator 30b. Each of the pair of separators has a groove (reactive gas flow path) that is a flow path for the reactive gas formed on the surface in contact with the power generation element 10, and has a structure that can supply the reactive gas to the power generation element 10. There is. Further, the pair of separators has conductivity and functions as a current collector that collects electricity generated by the power generation element.

The separator has a reaction gas flow path through which the reaction gas flows in a surface direction of the separator, and a plurality of separator-side reaction gas manifolds through which the reaction gas flows. The reaction gas flow path and the separator side reaction gas manifold are in communication with each other, and are configured to allow the reaction gas to flow therethrough. That is, the separator has a communication portion that communicates the reaction gas flow path with the separator side reaction gas manifold. Further, the separator may include a refrigerant flow path through which the refrigerant flows in a surface direction of the separator, and a plurality of separator-side refrigerant manifolds through which the refrigerant flows.

FIG. 4 shows a schematic view of the surface of the anode side separator 30a in contact with the power generation element 20, observed from the stacking direction. Further, FIG. 5 shows a schematic view of the surface of the cathode side separator 30b in contact with the power generating element 10, observed from the stacking direction.

The reaction gas flow path is provided on the surface of the separator that is in contact with the power generation element 10. The reaction gas passes through the reaction gas flow path and flows between the power generation element 10 or the frame member 20 and the separator. This causes an electrochemical reaction in the power generation element 10. A fuel gas flow path 31a is provided in the anode side separator 30a, and an oxidizing gas flow path 31b is provided in the cathode side separator 30b.

The separator side reaction gas manifold is a through hole through which the reaction gas flows in the stacking direction, and the side where the reaction gas flows in the direction in which it is supplied from the outside is called the separator side reaction gas supply manifold, and the direction in which the reaction gas is discharged to the outside. The side through which it flows is the separator side reaction gas exhaust manifold. The separator-side reaction gas supply manifold includes a separator-side fuel gas supply manifold 32a through which fuel gas flows, and a separator-side oxidant gas supply manifold 33a through which oxidant gas flows. The separator-side reaction gas discharge manifold includes a separator-side fuel gas discharge manifold 32b through which fuel gas flows, and a separator-side oxidant gas discharge manifold 33b through which oxidant gas flows. These manifolds are formed on both the anode side separator 30a and the cathode side separator 30b.

The plurality of frame member side reaction gas manifolds and the plurality of separator side reaction gas manifolds are arranged in alignment with each other. Thereby, the frame member side reaction gas manifold and the separator side reaction gas manifold are arranged so as to communicate in the stacking direction, and a plurality of reaction gas manifolds are formed.

Specifically, as can be seen from FIGS. 1 to 5, the fuel gas supply manifold 102a is formed from the frame member side fuel gas supply manifold 22a and the separator side fuel gas supply manifolds 32a, 32a. A fuel gas exhaust manifold 102b is formed from the frame member side fuel gas exhaust manifold 22b and the separator side fuel gas exhaust manifolds 32b, 32b. An oxidant gas supply manifold 103a is formed from the frame member side oxidant gas supply manifold 23a and the separator side oxidant gas supply manifolds 33a, 33a. An oxidant gas discharge manifold 103b is formed from the frame member side oxidant gas discharge manifold 23b and the separator side oxidant gas discharge manifolds 33b, 33b.

The refrigerant flow path is provided on the surface of the separator opposite to the surface in contact with the power generation element 10, that is, the surface on the side where the reaction gas flow path is not provided. As an example, FIG. 2 shows a refrigerant flow path 31c provided in the anode side separator 30a. Although not shown, the cathode side separator 30b also has a refrigerant flow path. The coolant passes through the coolant flow path and flows between adjacent fuel cells 50 . Thereby, the power generation element 10 is cooled.

The separator side refrigerant manifold is a through hole through which refrigerant flows, and the side through which the refrigerant flows in the direction in which the refrigerant is supplied from the outside is referred to as the separator side refrigerant supply manifold 34a, and the side through which the refrigerant flows in the direction in which the refrigerant is discharged to the outside is the separator side. It is referred to as a refrigerant discharge manifold 34b. These manifolds are formed on both the anode side separator 30a and the cathode side separator 30b.

The plurality of frame member side refrigerant manifolds and the plurality of separator side refrigerant manifolds are arranged in alignment with each other. Thereby, the frame member side refrigerant manifold and the separator side refrigerant manifold are arranged so as to communicate in the stacking direction, and a plurality of refrigerant manifolds are formed.

Specifically, as can be seen from FIGS. 1 to 5, a refrigerant supply manifold 104a is formed from the frame member side refrigerant supply manifold 24a and the separator side refrigerant supply manifolds 34a, 34a. A refrigerant discharge manifold 104b is formed from the frame member side refrigerant discharge manifold 24b and the separator side refrigerant discharge manifolds 34b, 34b.

The reaction gas flow path and the separator side reaction gas manifold are in communication with each other, and are configured to allow the reaction gas to flow therethrough. That is, the separator has a communication portion that communicates the reaction gas flow path with the separator side reaction gas manifold. For example, in the anode side separator 30a, there is a communication section 35a between the separator side fuel gas supply manifold 32a and the fuel gas flow path 31a, and a communication section between the fuel gas flow path 31a and the separator side fuel gas discharge manifold 32a. 35b is formed. In the cathode side separator 30b, there is a communication part 35c between the separator side oxidant gas supply manifold 33a and the oxidant gas flow path 31b, and between the oxidant gas flow path 31b and the separator side oxidant gas discharge manifold 33b. A communication portion 35d is formed.

In this manner, the communication portion is arranged to flow a specific reaction gas from the reaction gas manifold to the reaction gas flow path. Therefore, measures may be taken to prevent unintended reaction gas or refrigerant from flowing from the reaction gas manifold or refrigerant manifold to the reaction gas flow path. For example, each separator may have a predetermined partition wall.

In the anode side separator 30a, there are partition walls 36a and 36b that prevent the oxidant gas from flowing from the separator side oxidant gas supply manifold 33a and the separator side oxidant gas discharge manifold 33b to the fuel gas flow path 31a and other manifolds. You may be prepared. Further, partition walls 36c and 36d may be provided to prevent the refrigerant from flowing from the separator-side refrigerant supply manifold 34a and the separator-side refrigerant discharge manifold 34b to the fuel gas flow path 31a and other manifolds.

The cathode side separator 30b includes partition walls 36e and 36f that prevent fuel gas from flowing from the separator side fuel gas supply manifold 32a and the separator side fuel gas discharge manifold 32b to the oxidizing gas flow path 31b and other manifolds. You can. Further, partition walls 36g and 36h may be provided to prevent the refrigerant from flowing from the separator-side refrigerant supply manifold 34a and the separator-side refrigerant discharge manifold 34b to the oxidizing gas flow path 31b and other manifolds.

The separator may have an outer periphery formed to surround the outer periphery of the separator. The outer peripheral portion is a member for preventing reaction gas from leaking to the outside. An outer peripheral portion 37a is arranged in the anode side separator 30a. An outer peripheral portion 37b is arranged in the cathode side separator 30b. Further, the outer peripheral portion may also be provided on the side where the refrigerant flow path is arranged. By adhering the frame member 20 to the outer periphery of the separator and/or the partition wall, leakage of the reaction gas can be prevented. Therefore, an adhesive layer may be provided on the outer periphery of the separator and/or on the partition wall. The material of the adhesive layer is as described above.

The separator is made of a gas-impermeable electrically conductive member. Examples of the conductive member include dense carbon that is made gas-impermeable by compressing carbon, a press-formed metal plate (eg, iron, aluminum, titanium, stainless steel, etc.), and the like.

<Contact part 25>
The frame member 20 includes a predetermined contact portion 25 on the frame member side reaction gas manifold. FIG. 6(a) is an enlarged plan view of the frame member side reaction gas manifold of the frame member 20, and FIG. 6(b) is a sectional view taken along line bb in FIG. 6(a), in which two separators are shown. The figure shows a state in which it is sandwiched between frame members 20. Arrows and G indicate the flow of reactant gas. G indicates the flow of reaction gas from the back of the paper toward the front. W indicates produced water. FIG. 7 corresponds to FIG. 6(b) and is a diagram of a conventional fuel cell stack in which the frame member does not have an abutting portion.

The reaction gas manifold has a predetermined level difference due to the difference in size between the frame member side reaction gas manifold and the separator side reaction gas manifold, gaskets arranged between the fuel cells, and the like.

As shown in FIG. 7, in the conventional fuel cell stack, the inner diameter of the separator side reaction gas manifold is smaller than the frame member side reaction gas manifold, and the separator side reaction gas manifold is located inside the frame member side reaction gas manifold. ing. Therefore, a predetermined level difference exists in the reaction gas manifold. In such a case, water generated by an electrochemical reaction adheres to the step. Adhering water is difficult to drain properly. In particular, generated water tends to move along the inner side surface of the manifold and therefore tends to adhere to the level difference. The generated water that adheres to the steps tends to stay, which may cause problems due to flooding or freezing.

Therefore, in the fuel cell stack 100, a contact portion 25 is provided on the frame member side reaction gas manifold of the frame member 20 in order to suppress such a level difference. As a result, the contact portion 25 suppresses the level difference that occurs in the reaction gas manifold, so that the drainage performance of the fuel cell stack 100 can be improved. This will be explained in detail below.

The contact portion 25 has the following configuration. That is, in adjacent fuel cells 50, the frame member side reaction gas manifold of one fuel cell 50 extends in the stacking direction so as to cover a part of the inner side surface of the separator side reaction gas manifold, and It has a contact portion 25 that contacts the frame member 20 of the cell 50. In FIG. 6A, the portion where the contact portion 25 is present is shown by a transparent dotted line.

From the viewpoint of further improving drainage performance, the contact portion 25 may have a larger area covering the inner side surface of the separator side reaction gas manifold. On the other hand, if the contact portion 25 completely covers the inner side surface of the separator-side reaction gas manifold, the reaction gas cannot flow between the reaction gas flow path and the separator-side reaction gas manifold. Therefore, the contact portion 25 must not cover the entire inner side surface of the separator-side reaction gas manifold so that the flow of the reaction gas is not completely obstructed. From the viewpoint of smoothing the flow of the reaction gas, the contact portion 25 may not cover the communication portion side of the inner side surface of the separator side reaction gas manifold. This means that the contact portion 25 does not need to cover at least a portion of the communication portion side. That is, the contact portion 25 may cover a part of the communication portion side, but does not need to cover the entire communication portion side. In FIG. 6(a), the contact part 25 covers only a part of the inner side surface of the separator side reaction gas manifold other than the communication part side (only a part of the inner side surface of the separator side reaction gas manifold on the communication part side). (form that does not cover) is shown.

As shown in FIG. 6(b), the contact portion 25 is in contact with the frame member 20 of the other fuel cell 50. Since the contact portion 25 is provided on each frame member 20, it comes into contact with the contact portion 25 of the frame member 20 of the other fuel cell 50. Thereby, the level difference in the reaction gas manifold is suppressed, and the generated water W is appropriately discharged.

Here, in FIGS. 6(a) and 6(b), the type of the frame member side reaction gas manifold in which the abutment part 25 is provided is not specified, but this is because the abutment part 25 is attached to which frame member side reaction gas manifold. This means that it may be provided in For example, the contact portion 25 may be disposed on the frame member side fuel gas supply manifold 22a, may be disposed on the frame member side fuel gas discharge manifold 22b, or may be disposed on the frame member side oxidant gas supply manifold 23a. or may be arranged in the frame member side oxidant gas discharge manifold 23b. From the viewpoint of improving drainage performance, the contact portion 25 is arranged on the frame member side reaction gas discharge manifold (frame member side fuel gas discharge manifold 22b and/or frame member side oxidant gas discharge manifold 23b) from which generated water is discharged. may have been done.

The abutting portion 25 can be made of the same material as the frame member 20.

(Other form 1 of contact part)
A frame member 120 having another form has an abutting portion 125 instead of the abutting portion 25 . In addition to the structure of the abutting part 25, the abutting part 125 may further include a protruding part 125a toward the inside of the separator side reaction gas manifold. FIGS. 8A and 8B are diagrams corresponding to FIGS. 6A and 6B, and show a form in which the frame member 120 has a contact portion 125.

The contact portion 125 only needs to include at least one protrusion 125a. FIG. 8 shows a configuration having two protrusions 125a. Although the arrangement position of the protrusion 26 is not particularly limited, the protrusion 125a may be arranged in a portion other than the communication part side of the separator side reaction gas manifold from the viewpoint of improving drainage performance. This is because produced water tends to move along the inner side of the manifold. Although the direction in which the protruding portion 125a protrudes is not particularly limited, it may be set in a direction toward the center of the separator side reaction gas manifold from the viewpoint of improving drainage performance. Although the shape of the protrusion 125a is not particularly limited, it may be polygonal in plan view from the viewpoint of improving drainage performance.

As shown in FIG. 8(b), the protruding portion 125a extends in the stacking direction and abuts on the adjacent frame member 120, similarly to the abutting portion 125. That is, when viewed in the stacking direction of the fuel cell stack 100, a portion of the reactant gas manifold protrudes. Furthermore, the protruding portions 125a are provided continuously in the stacking direction. Thereby, it is possible to suppress a decrease in the flow rate of the reaction gas flowing through the reaction gas manifold due to the protruding portion 125a, and thus it is possible to improve drainage performance.
(Other form 2 of contact part)
Although the embodiment in which the contact portion is provided on the frame member has been described above, the present disclosure is not limited thereto. For example, the contact portion and the frame member may be separate members. FIGS. 9A and 9B are views corresponding to FIGS. 6A and 6B, and show an embodiment in which the frame member 220 includes a contact portion 225 that is a separate member. The dotted line in FIG. 9(a) shows the frame member side reaction gas manifold passing through it.

As shown in FIGS. 9(a) and 9(b), the contact portion 225 extends from the peripheral portion 225a in the stacking direction from the peripheral portion 225a disposed on the peripheral edge of the separator-side reaction gas manifold on the separator surface, and It has an extending portion 225b that covers a part of the inner side surface of the side reaction gas manifold and comes into contact with the frame member 220 of the other fuel cell 50.

The peripheral portion 225a is a member for arranging the contact portion 225 at the peripheral edge of the separator side reaction gas manifold. As shown in FIGS. 9(a) and 9(b), the peripheral portion 225a may be in close contact with the frame member 220 and may be integral with it. The configuration and function of the extending portion 225b are the same as those of the contact portion 25, so a description thereof will be omitted here.

The fuel cell stack of the present disclosure has been described above using one embodiment. The fuel cell stack of the present disclosure includes a predetermined contact portion, which can improve drainage performance.

10 Power generation element 20 Frame member 21 Opening 22a Frame member side fuel gas supply manifold 22b Frame member side fuel gas discharge manifold 23a Frame member side oxidant gas supply manifold 23b Frame member side oxidant gas discharge manifold 24a Frame member side refrigerant supply manifold 24b Frame member side refrigerant discharge manifold 25 Contact portion 30a Anode side separator 30b Cathode side separator 31a Fuel gas passage 31b Oxidizing gas passage 31c Refrigerant passage 32a Separator side fuel gas supply manifold 32b Separator side fuel gas discharge manifold 33a Separator Side oxidant gas supply manifold 33b Separator side oxidant gas discharge manifold 34a Separator side refrigerant supply manifold 34b Separator side refrigerant discharge manifold 35a to 35d Communication portions 36a to 36h Partition walls 37a, 37b Outer peripheral portion 50 Fuel cell 100 Fuel cell stack 102a Fuel Gas supply manifold 102b Fuel gas discharge manifold 103a Oxidizing gas supply manifold 103b Oxidizing gas discharge manifold 104a Refrigerant supply manifold 104b Refrigerant discharge manifold 120 Frame member 125 Contact portion 125a Projecting portion 220 Frame member 225 Contact portion 225a Peripheral portion 225b Extension Debe

Claims (1)

A plurality of stacked fuel cells each including a power generation element, a frame member disposed around the power generation element, and a pair of separators stacked on the frame member so as to sandwich the power generation element and the frame member. A fuel cell stack,
The frame member has an opening that accommodates the power generation element, and a plurality of frame member side reaction gas manifolds through which reaction gas flows,
The separator has a reaction gas flow path through which the reaction gas flows in a surface direction of the separator, and a plurality of separator-side reaction gas manifolds through which the reaction gas flows,
The plurality of frame member side reaction gas manifolds and the plurality of separator side reaction gas manifolds are aligned and arranged, thereby forming a plurality of reaction gas manifolds,
In the adjacent fuel cells, the frame member side reaction gas manifold of one of the fuel cells extends in the stacking direction so as to cover a part of the inner side surface of the separator side reaction gas manifold, and having a contact portion that contacts the frame member of the battery cell;
fuel cell stack.