JP2010113926A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell for reducing an effect of a force working in the direction to cross the lamination direction of the cells. <P>SOLUTION: The fuel cell includes a plurality of battery cells having a membrane electrode assembly and a pair of separators to pinch at least the membrane electrode assembly, and a plurality of passages in which reaction gas flows are installed on the surface on the membrane electrode assembly side of the pair of separators. On the plurality of passages, a first passage of which the depth becomes shallower from one side to the other end, and a second passage of which the depth becomes deeper from one side to the other end are provided. When the two battery cells of which the separators are in contact are made a first battery cell and a second battery cell, and the separator of the first battery cell in contact with the separator of the second battery cell is made a first separator and the separator of the second battery cell in contact with the first separator is made a second separator, the inclined bottom part of the first passage of the first separator and the inclined bottom part of the second passage of the second separator are in contact, and the inclined bottom part of the second passage of the first separator and the inclined bottom part of the first passage of the second separator are in contact. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly, to a fuel cell having a channel whose depth is not constant.

  A fuel cell includes a membrane electrode structure (hereinafter referred to as an “electrolyte membrane”) and electrodes (an anode catalyst layer and a cathode catalyst layer) disposed on both sides of the electrolyte membrane. , And may be referred to as “MEA”), and an electric energy generated by the electrochemical reaction is taken out to the outside. Among fuel cells, a polymer electrolyte fuel cell (hereinafter sometimes referred to as “PEFC”) used in a home cogeneration system, an automobile, or the like can be operated in a low temperature region. This PEFC has been attracting attention as a power source and portable power source for electric vehicles because of its high energy conversion efficiency, short start-up time, and small and light system.

  The PEFC cell includes an MEA and a pair of current collectors (separators) that sandwich the MEA, and has a theoretical electromotive force of 1.23V. However, since such a low electromotive force is insufficient as a power source for an electric vehicle or the like, it is usually a stack type fuel cell configured by disposing end plates or the like at both ends in a stacking direction of a cell stack in which cells are stacked. Is used.

  On the other hand, the PEFC MEA contains a proton conducting polymer that exhibits proton conducting performance by being kept in a water-containing state. During operation of PEFC, a hydrogen-containing gas (hereinafter referred to as “hydrogen”) is supplied to the anode, and an oxygen-containing gas (hereinafter referred to as “air”) is supplied to the cathode. The hydrogen supplied to the anode is separated into protons and electrons under the action of the catalyst contained in the anode catalyst layer, and the protons generated from the hydrogen reach the cathode catalyst layer through the anode catalyst layer and the electrolyte membrane. On the other hand, electrons reach the cathode catalyst layer through an external circuit, and through such a process, electric energy can be extracted. Then, protons and electrons that have reached the cathode catalyst layer react with oxygen contained in the air supplied to the cathode catalyst layer, thereby generating water.

  As a technique related to such PEFC, for example, Patent Document 1 discloses that a channel whose cross-sectional area continuously increases from one to the other in the length direction of the groove-shaped channel, and a continuous decrease. A fuel cell having a separator arranged so that a flow path to be adjacent to each other is disclosed. Patent Document 1 discloses a technique for increasing or decreasing the cross-sectional area of the flow path by changing the width of the flow path or the depth of the flow path. Further, Patent Document 2 discloses a fuel cell that has a plurality of closed passages in which the inlets or outlets of the passages are closed, and the flow passage width of the closed passage is wider in the downstream region than in the upstream region. ing.

JP 2006-114387 A JP 2005-85626 A

  According to the technique disclosed in Patent Document 1, even if the concentration decreases toward the downstream side of the flow channel due to consumption of hydrogen or air in the reaction, the cross-sectional area increases toward the downstream side of the flow channel. By continuously reducing the flow rate, it becomes possible to increase the flow velocity of hydrogen or air that flows through the downstream side of the flow path, so that power generation in the fuel cell can be performed efficiently. However, in the technique disclosed in Patent Document 1, when stacking a plurality of cells, if the stacking direction is the vertical direction, the cells are brought into contact with each other by contacting the horizontal surfaces of the separators constituting the adjacent cells. A laminate is constructed. Therefore, for example, when a force is applied from the outside of the fuel cell in a direction crossing the cell stacking direction, one or a plurality of cells are easily pushed out from the cell stack. When the cell is pushed out in this manner, the performance of the fuel cell is likely to deteriorate due to tearing of the MEA, wrinkling of the MEA, reduction of the contact area between the contacting separators, and the like. That is, since the technique disclosed in Patent Document 1 does not have a configuration that reduces the influence of the force in the direction intersecting the cell stacking direction, a force in the direction intersecting the cell stacking direction is applied. There was a problem that the performance was likely to deteriorate. Such a problem cannot be solved even if the technique disclosed in Patent Document 1 and the technique disclosed in Patent Document 2 are simply combined.

  Then, this invention makes it a subject to provide the fuel cell which can reduce the influence of the force which acts on the direction which cross | intersects the lamination direction of a cell.

In order to solve the above problems, the present invention takes the following means. That is,
The present invention includes a plurality of cells each including a membrane electrode structure and a pair of separators that sandwich at least a laminate including the membrane electrode structure, and the membrane on the surface of the pair of separators on the membrane electrode structure side is provided. Each of the plurality of flow paths through which the reaction gas supplied to the electrode structure flows is provided. The plurality of flow paths have a first flow path whose depth decreases from one to the other, and from one to the other. And a second flow path whose depth increases toward the surface, and among the plurality of cells, two cells that are in contact with each other are defined as a first cell and a second cell, and are in contact with the separator of the second cell. When the separator of the first cell is the first separator and the separator of the second cell that is in contact with the first separator is the second separator, the second separator is provided with the inclined bottom portion of the first flow path provided in the first separator. Be The inclined bottom part of the two flow paths is in contact, and the inclined bottom part of the second flow path provided in the first separator and the inclined bottom part of the first flow path provided in the second separator are in contact with each other. And a fuel cell.

  Here, in the present invention, the “membrane electrode structure” means an electrolyte membrane, an anode catalyst layer disposed on one surface of the electrolyte membrane, and a surface opposite to the one surface of the electrolyte membrane. An MEA having a cathode catalyst layer disposed thereon. Furthermore, in the present invention, “a laminate comprising at least the membrane electrode structure” includes both a laminate comprising a membrane electrode structure and a laminate comprising the membrane electrode structure and other components. It is a concept. Examples of the “other components” include known components that can constitute a PEFC cell, such as a gas diffusion layer and a water repellent layer disposed on one or both sides of the MEA. Furthermore, in the present invention, the “first flow path” refers to a flow path whose depth becomes shallower from the outlet toward the inlet when viewed from the inlet of the fluid flowing through the flow path. Furthermore, in the present invention, the “second flow path” means, in other words, a flow path whose depth increases from the outlet toward the inlet when viewed from the inlet of the fluid flowing through the first flow path. Say.

  In the present invention, it is preferable that a plurality of first flow paths and second flow paths are provided, and the first flow paths and the second flow paths are alternately and continuously arranged.

  Here, in the present invention, "the first flow path and the second flow path are alternately and continuously disposed" means, for example, that the second flow path is disposed on the right side of any first flow path, A first channel is disposed on the right side of the second channel, a second channel is disposed on the right side of the first channel, and so on. The plurality of first channels and the plurality of second channels are arranged so that the second channel is arranged and one first channel is arranged between any two second channels. It means that

  Moreover, in the said invention, it is preferable that the inclined bottom part of the 1st flow path with which a 1st separator is equipped and the inclined bottom part of the 2nd flow path with which a 2nd separator is equipped are in surface contact.

  Moreover, in the said invention, it is preferable that the inclined bottom part of the 2nd flow path with which a 1st separator is equipped and the inclined bottom part of the 1st flow path with which a 2nd separator is equipped are in surface contact.

  In the present invention, the first flow path and the second flow path are preferably closed at the inlet or outlet of the flowing reaction gas.

  In the present invention, the inclined bottom portion of the first flow path provided in the first separator is in contact with the inclined bottom portion of the second flow path provided in the second separator, and the second flow path provided in the first separator. And the inclined bottom of the first flow path provided in the second separator are in contact with each other. Here, the first flow channel is inclined so that the depth becomes shallower from one side to the other, while the second flow channel has a depth that becomes deeper from one side to the other. It is inclined to. Therefore, by adopting such a configuration, even when a force acting in a direction crossing the cell stacking direction is applied to the cell stack, the influence can be reduced. Therefore, according to the present invention, it is possible to provide a fuel cell capable of reducing the influence of the force acting in the direction intersecting the cell stacking direction.

  Further, in the present invention, the influence of the force acting in the direction intersecting the cell stacking direction can be easily reduced by alternately arranging the plurality of first and second flow paths that are provided. be able to.

  In the present invention, in addition to the above effect, the contact resistance is obtained by bringing the inclined bottom portion of the first flow path provided in the first separator into contact with the inclined bottom portion of the second flow path provided in the second separator. It is possible to suppress the increase of.

  In the present invention, the contact resistance is further increased by bringing the inclined bottom portion of the second flow path provided in the first separator into contact with the inclined bottom portion of the first flow path provided in the second separator. It becomes possible to suppress.

  Further, in the present invention, a flow path in which the inlet or outlet of the flowing reaction gas is closed (hereinafter, the flow path may be referred to as a “closed flow path”. In the “closed flow path”, the outlet is closed. In such a flow path, the inlet is open, and the flow path that closes the inlet is the outlet, so that the gas flowing in from the inlet cannot flow out from the outlet of the closed flow path, In addition to the above effects, in addition to the above effect, the separator in the MEA can control the flow velocity distribution of the reaction gas flowing through the closed channel. It becomes possible to increase the frequency of occurrence of electrochemical reactions. Therefore, the fuel cell performance can be improved by adopting such a configuration.

  The present invention will be described below with reference to the drawings. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below.

  FIG. 1 is a sectional view showing an example of a fuel cell according to the present invention. FIG. 1 shows a cell 10 provided in the fuel cell of the present invention and separators (separator 7 ′ and separator 8 ′) provided in a cell adjacent to the cell 10. 1 is the stacking direction of the cells 10 and the depth direction of the flow path through which the reaction gas flows, and the back / front direction of FIG. 1 is the reaction gas flow direction. FIG. 2 is a view showing only the separator 7, the separator 8, the separator 7 ', and the separator 8' extracted from FIG. The arrows shown in FIG. 2 are the direction of hydrogen flow and the direction of air flow. In FIG. 1 and FIG. 2, the description of the separator 7, the separator 8, the separator 7 ', and the inlets and outlets of the channels provided in the separator 8' are omitted.

  As shown in FIG. 1, the fuel cell of the present invention includes a plurality of cells configured similarly to the cell 10. The cell 10 includes the electrolyte membrane 1, the anode catalyst layer 2 formed on one surface of the electrolyte membrane 1, and the other surface of the electrolyte membrane 1 (the surface opposite to the surface on which the anode catalyst layer 2 is formed). The formed MEA 4 having the cathode catalyst layer 3, the gas diffusion layer 5 disposed on the anode catalyst layer 2 side, the gas diffusion layer 6 disposed on the cathode catalyst layer 3 side, and the gas diffusion layer 5 side And a separator 8 disposed on the gas diffusion layer 6 side.

  The separator 7 includes a plurality of first flow paths 7x, 7x,... Formed so as to increase in depth from the front side to the back side in FIG. 1 and FIG. Has a plurality of second flow paths 7y, 7y,... Formed so as to become shallower from the near side to the back side, and the first flow paths 7x, 7x,. In the space (flow paths 9, 9,...) Between 7y, 7y,..., Cooling water is circulated. The inclined bottoms of the first flow paths 7x, 7x,... Provided in the separator 7 and the inclined bottoms of the second flow paths 7y, 7y,. The inclined bottom portion of the flow path provided is in surface contact. The flow path of the separator 8 ′ that is in surface contact with the inclined bottoms of the first flow paths 7x, 7x,... (Hereinafter may be referred to as “second flow paths 8y ′, 8y ′,...)” The flow of the separator 8 'is configured such that the depth becomes shallower from the front side to the back side in FIG. 1 and FIG. 2, and is in surface contact with the inclined bottoms of the second flow paths 7y, 7y,. The path (hereinafter, sometimes referred to as “first flow paths 8x ′, 8x ′,...)” Is configured so that the depth becomes deeper from the front side to the back side in FIG. 1 and FIG. Has been.

  On the other hand, the separator 8 has a plurality of first flow paths 8x, 8x,... Formed so as to increase in depth from the front side to the back side in FIGS. 1 and 2, and FIGS. , And a plurality of second flow paths 8y, 8y,... Formed so as to decrease in depth from the front side to the back side of the paper, and the first flow paths 8x, 8x,. In the space between the flow paths 8y, 8y,... (Flow paths 9, 9,...), Cooling water is circulated. The inclined bottom portions of the first flow paths 8x, 8x,... Provided in the separator 8 and the inclined bottom portions of the second flow paths 8y, 8y,... And the cell separator 7 ′ disposed below the cell 10 The inclined bottom portion of the flow path provided is in surface contact. The flow path of the separator 7 ′ that is in surface contact with the inclined bottoms of the first flow paths 8x, 8x,... (Hereinafter, may be referred to as “second flow paths 7y ′, 7y ′,...”). The flow of the separator 7 ′ is configured such that the depth becomes shallower from the front side to the back side in FIG. 1 and FIG. 2, and is in surface contact with the inclined bottoms of the second flow paths 8y, 8y,. The path (hereinafter, sometimes referred to as “first flow paths 7x ′, 7x ′,...)” Is configured such that the depth becomes deeper from the front side to the back side in FIG. 1 and FIG. Has been.

  As described above, in the fuel cell of the present invention, the inclined bottom portions of the second flow paths 8y′8y ′ and the inclined bottom portions of the first flow paths 7x, 7x,. The cell having the separator 8 'and the cell 10 are laminated so that the inclined bottoms of', 8x ', ... and the inclined bottoms of the second flow paths 7y, 7y, ... are in surface contact. Further, the inclined bottom portions of the first flow paths 8x, 8x,... And the inclined bottom portions of the second flow paths 7y ′, 7y ′,. The cell 10 and the cell having the separator 7 ′ are stacked so that the inclined bottom portions of the first flow paths 7x ′, 7x ′,. Therefore, when a stress (force acting in a direction crossing the cell stacking direction) from the outside of the fuel cell toward the back side in FIG. 1 and FIG. Friction force acting between the inclined bottoms of the channels 7x, 7x,... And the inclined bottoms of the second channels 8y ′, 8y ′,... And the inclined bottoms of the second channels 8y, 8y,. The stress can be reduced by the frictional force acting between the first and the first flow paths 7x ′, 7x ′,. In addition, when a stress (force acting in a direction crossing the cell stacking direction) from the outside of the fuel cell toward the front side of FIG. 1 and FIG. Friction force acting between the inclined bottoms of the channels 7y, 7y,... And the inclined bottoms of the first channels 8x ′, 8x ′,... And the inclined bottoms of the first channels 8x, 8x,. The stress can be reduced by the frictional force acting between the second flow paths 7y ′, 7y ′,. Therefore, according to this invention, the fuel cell which can reduce the influence of the force which acts on the direction which cross | intersects the lamination direction of a cell can be provided. According to the present invention, the influence of the force acting in the direction intersecting the cell stacking direction can be reduced, so that one or a plurality of cells are prevented from being pushed out from the cell stack constituting the fuel cell. It is also possible to do.

  Further, in the fuel cell of the present invention, the depth of the end portion (entrance) of the first flow paths 7x, 7x,... On the front side in FIG. The depth of the end portion (exit) at X2 is X2 (> X1), and the depth of the end portion (inlet) at the front side of the drawing of FIGS. 1 and 2 of the second flow paths 7y, 7y,. When the depth of the end (exit) on the back side of the paper surface of FIG. 1 and FIG. 2 is Y2 (<Y1), it is easy to achieve the effect of reducing the effect of the force acting in the direction intersecting the cell stacking direction. From the standpoint of, for example, X2-X1 = Y1-Y2. Similarly, in the fuel cell of the present invention, the depth of the end (exit) of the first flow paths 8x, 8x,... On the front side in FIG. The depth of the end (inlet) on the side is X4 (> X3), and the depth of the end (outlet) on the front side of the paper in FIGS. 1 and 2 of the second flow paths 8y, 8y,. 1 and 2, when the depth of the end (inlet) on the back side of the paper surface is Y4 (<Y3), a configuration that easily exerts an effect of reducing the influence of the force acting in the direction intersecting the cell stacking direction. From the standpoint of, for example, X4-X3 = Y3-Y4 is preferable.

  Further, in the fuel cell of the present invention, the depth of the end (exit) of the first flow paths 8x ′, 8x ′,... On the front side in FIG. The depth of the end (inlet) on the back side is X6 (> X5), and the depth of the end (outlet) of the second flow paths 8y ′, 8y ′,. Where Y5 is the depth of the end (entrance) on the back side of the paper in FIGS. 1 and 2 is Y6 (<Y5), and the MEA 4, the gas diffusion layer 5 and the gas diffusion layer 6 are more difficult to wrinkle. From the viewpoint of making the fuel cell performance easy to improve, it is preferable to set X1 + Y5 = X2 + Y6 = Y1 + X5 = Y2 + X6. Similarly, in the fuel cell of the present invention, the depth of the end (inlet) of the first flow paths 7x ′, 7x ′,... The depth of the end (exit) on the back side of the paper is X8 (> X7), and the depth of the end (inlet) of the second flow paths 7y ′, 7y ′,. When the depth is Y7 and the depth of the end (exit) on the back side in FIG. 1 and FIG. 2 is Y8 (<Y7), the MEA 4, the gas diffusion layer 5, and the gas diffusion layer 6 are more difficult to wrinkle. From the viewpoint of making the fuel cell performance easier to improve by adopting the form, it is preferable to set X3 + Y7 = X4 + Y8 = Y3 + X7 = Y4 + X8.

  In the fuel cell of the present invention, the first flow paths 7x, 7x, ..., the second flow paths 7y, 7y, ..., the first flow paths 8x, 8x, ..., the second flow paths 8y, 8y, ... 1 channel 7x ', 7x', ..., 2nd channel 7y ', 7y', ..., 1st channel 8x ', 8x', ..., and 2nd channel 8y ', 8y', ... The flow path may be a flow path in which both ends (inlet and outlet) of the flow path are not closed, or may be a closed flow path in which one end (inlet or outlet) of the flow path is closed. However, in addition to the effect of reducing the influence of the force acting in the direction crossing the cell stacking direction, hydrogen is evenly supplied to the entire surface of the anode catalyst layer 2 and air is supplied to the entire surface of the cathode catalyst layer 3. From the standpoint of providing a form in which the performance of the fuel cell is easily improved by supplying it evenly, these flow paths are preferably closed flow paths.

  In FIG. 3, the second flow path 7 y that is a closed flow path by closing the outlet by the closing member 11 and the first flow path 7 x that is closed by closing the inlet by the closing member 11 are alternately arranged. It is a top view which shows the example of a form of the separator 7 arrange | positioned. 3 corresponds to the rear side / front side direction of FIG. 2, and the front / back direction of FIG. 3 corresponds to the vertical direction of FIG. Further, FIG. 4 shows a first flow path 8x that is made a closed flow path by closing the outlet with the closing member 11, and a second flow path 8y that is made the closed flow path by closing the inlet with the closing member 11. It is a top view which shows the example of a form of the separator 8 arrange | positioned alternately. 4 corresponds to the rear side / front side direction of FIG. 2, and the front / back direction of FIG. 4 corresponds to the vertical direction of FIG.

  As shown in FIG. 1 to FIG. 3, the depth of the second flow paths 7y, 7y,..., Whose inlet is open and whose outlet is closed, is configured so that the depth becomes shallower from the inlet toward the outlet. Thus, it is possible to suppress a decrease in the flow rate of hydrogen in the vicinity of the outlets of the closed second flow paths 7y, 7y,. In addition, the depth of the first flow paths 7x, 7x,..., Where the inlet is closed and the outlet is open, is configured so that the depth becomes deeper from the inlet toward the outlet. It is possible to suppress a decrease in the flow rate of hydrogen in the vicinity of the inlet of one flow path 7x, 7x,. Therefore, according to the present invention, hydrogen is supplied to the entire surface of the anode catalyst layer 2 by providing the first flow paths 7x, 7x,... And the second flow paths 7y, 7y,. It is possible to provide a fuel cell capable of improving performance by supplying evenly.

  In addition, as shown in FIG. 1, FIG. 2, and FIG. 4, the depth of the first flow paths 8x, 8x,. Is made shallower, it is possible to suppress a decrease in the air flow velocity in the vicinity of the outlet of the closed first flow paths 8x, 8x,. In addition, the depth of the second flow paths 8y, 8y,..., Where the inlet is closed and the outlet is open, is configured so that the depth becomes deeper from the inlet toward the outlet. It is possible to suppress a decrease in the air flow velocity in the vicinity of the inlets of the two flow paths 8y, 8y,. Therefore, according to the present invention, air is supplied to the entire surface of the cathode catalyst layer 3 by providing the first flow paths 8x, 8x,... And the second flow paths 8y, 8y,. It is possible to provide a fuel cell capable of improving performance by supplying evenly.

  In the above description regarding the fuel cell of the present invention, a plurality of first flow paths and second flow paths are provided, and the first flow path and the second flow path are alternately and continuously disposed. The fuel cell of the present invention is not limited to this form. In the fuel cell of the present invention, one separator is provided with one first flow path and one second flow path, and the other flow paths provided in the one separator have a depth that covers the entire length of the flow path. And may be configured to be substantially constant. However, from the viewpoint of easily reducing the force acting in the direction intersecting the cell stacking direction, a plurality of first flow paths and second flow paths are provided, and the first flow path and the second flow path are provided. It is preferable that the paths are arranged alternately and continuously.

  In the above description of the fuel cell of the present invention, the inclined bottom portions of the flow paths of the two separators that are in contact with each other are in surface contact with each other (the inclined bottom portion of the first flow paths 7x, 7x,. Are in surface contact with the inclined bottoms of the second channels 7y, 7y,... And the inclined bottoms of the first channels 8x ′, 8x ′,. Are in surface contact, and the inclined bottom portions of the first flow paths 8x, 8x,... And the inclined bottom portions of the second flow paths 7y ′, 7y ′,... Are in surface contact, and the second flow paths 8y, 8y,. However, the fuel cell of the present invention is not limited to the above-described embodiment. In the embodiment, the bottom portion and the inclined bottom portions of the first flow paths 7x ′, 7x ′,. In the fuel cell of the present invention, of the two separators to be contacted, the inclined bottom portion of the flow path formed in one separator and the inclined bottom portion of the flow path formed in the other separator have a plurality of points. It is also possible to use a form of contact through a wire. However, the inclined bottoms of the flow paths provided in each of the two separators that are in contact with each other are in surface contact with each other from the standpoint of, for example, a mode in which performance is easily improved by suppressing an increase in contact resistance. The form is preferred.

  In the above description regarding the fuel cell of the present invention, the first flow paths 7x, 7x,..., The second flow paths 7y, 7y,..., The first flow paths 8x, 8x,. ..., first flow paths 7x ', 7x', ..., second flow paths 7y ', 7y', ..., first flow paths 8x ', 8x', ..., and second flow paths 8y ', 8y', Although the embodiment in which the bottom portion is configured by an inclined plane is illustrated, the fuel cell of the present invention is not limited to the embodiment. The fuel cell of the present invention can also be formed in a curved surface shape or stepped shape in which the bottom of the first flow path and / or the second flow path provided in the separator is inclined.

  Further, in the above description regarding the fuel cell of the present invention, the mode in which hydrogen and air are circulated is exemplified so that the flow direction of hydrogen and the flow direction of air are opposite to each other. It is not limited to the said form. The fuel cell of the present invention can also circulate hydrogen and air so that the flow direction of hydrogen and the flow direction of air are the same.

  Further, in the fuel cell of the present invention, the flow direction of the cooling water flowing through the flow passages 9, 9,... Is not particularly limited, but from the viewpoint of facilitating the temperature control of the cell 10, etc. It is preferable to distribute the cooling water, air, and hydrogen so that the water flow direction and the air flow direction are opposite to each other, and the cooling water flow direction and the hydrogen flow direction are the same. .

  Further, in the above description regarding the fuel cell of the present invention, an example in which X2−X1 = Y1−Y2 and X4−X3 = Y3−Y4 is illustrated. However, the fuel cell of the present invention is limited to this mode. It is not a thing. The first flow paths 7x, 7x,..., The second flow paths 7y, 7y,..., The first flow paths 8x, 8x,. 8y,... Is provided, the flow rate distribution of hydrogen supplied to the anode catalyst layer 2 and the cathode catalyst layer 3 are reduced while reducing the influence of the force acting in the direction crossing the cell stacking direction. From the standpoint of making the flow velocity distribution of the air easy to control, “X2-X1” and “Y1-Y2” are not equal, and “X4-X3” and “Y3-Y4” are equal. It is preferable to have no form.

  In the fuel cell of the present invention, the separator 7, the separator 8, the separator 7 ', and the separator 8' can be manufactured by, for example, press molding or cutting a metal plate, a carbon plate, or the like. The constituent material of the separator provided in the fuel cell of the present invention is not particularly limited as long as it is a constituent material that can be used as a PEFC separator. From the standpoint of making it easier to improve the production efficiency, it is preferable to use a press-molded separator.

  In addition, when the fuel cell of the present invention is mounted on a vehicle, the relationship between the vehicle front-rear direction and the left-right direction and the cell stacking direction is not particularly limited. From the standpoint of making it easy to express the effect of the present invention that the influence of the force can be reduced even when the vehicle is applied, the vehicle front-rear direction and the cell stacking direction are matched. It is preferable.

It is sectional drawing which shows the example of a form of the fuel cell of this invention. It is a figure which shows the form example of the separator with which the fuel cell of this invention is equipped. It is a figure which shows the example of a form of the separator which has the 1st flow path made into the obstruction | occlusion flow path, and a 2nd flow path. It is a figure which shows the example of a form of the separator which has the 1st flow path made into the obstruction | occlusion flow path, and a 2nd flow path.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 2 ... Anode catalyst layer 3 ... Cathode catalyst layer 4 ... MEA
5 ... Gas diffusion layer 6 ... Gas diffusion layer 7 ... Separator (first separator)
7 '... Separator (first separator)
7x ... 1st flow path 7y ... 2nd flow path 8 ... Separator (2nd separator)
8 '... Separator (second separator)
8x ... 1st flow path 8y ... 2nd flow path 9 ... Flow path 10 ... Cell 11 ... Closure member

Claims (5)

A plurality of cells each including a membrane electrode structure and a pair of separators sandwiching a laminate including at least the membrane electrode structure;
A plurality of flow paths through which a reaction gas supplied to the membrane electrode structure circulates are provided on the surfaces of the pair of separators on the membrane electrode structure side. A first flow path that decreases in depth toward the second side, and a second flow path that increases in depth from the one side toward the other,
Among the plurality of cells, the two cells that are in contact with each other are the first cell and the second cell, and the separator of the first cell that is in contact with the separator of the second cell is the first separator, When the separator of the second cell that contacts the first separator is the second separator,
The inclined bottom of the first flow path provided in the first separator and the inclined bottom of the second flow path provided in the second separator are in contact with each other, and the second provided in the first separator. The fuel cell according to claim 1, wherein the inclined bottom portion of the channel and the inclined bottom portion of the first channel provided in the second separator are in contact with each other. The first flow path and the second flow path are respectively provided in plural, and the first flow path and the second flow path are alternately and continuously arranged. Fuel cell. The inclined bottom portion of the first flow path provided in the first separator and the inclined bottom portion of the second flow path provided in the second separator are in surface contact with each other. 3. The fuel cell according to 1 or 2. The inclined bottom portion of the second flow path provided in the first separator and the inclined bottom portion of the first flow path provided in the second separator are in surface contact with each other. The fuel cell according to any one of 1 to 3. 5. The fuel cell according to claim 1, wherein the first flow path and the second flow path are closed at an inlet or an outlet of the reaction gas flowing therethrough.

Images