Fuel cell stack

Abstract

A fuel cell stack includes single cells stacked in a first direction. Each single cell includes a power generation unit, a first separator, and a second separator. The first separator and the second separator hold the power generation unit between the first separator and the second separator. The first separator of each single cell includes a first protrusion protruding toward the second separator of another single cell adjacent in the first direction. The first protrusion is in contact with the second separator. Each first protrusion includes a top wall portion and two side wall portions. At least one of the two side wall portions includes a stepped portion having a stepped shape in the first direction.

Description

Technical Field

[0001] This disclosure relates to a fuel cell stack. Background Technology

[0002] Japanese National Phase Patent 2020-522089 discloses a fuel cell stack. The fuel cell stack includes multiple individual cells stacked together. Each individual cell includes two spacers. A membrane electrode assembly and two gas diffusion layers sandwiching the membrane electrode assembly in the stacking direction of the individual cells are arranged between the two spacers.

[0003] Each separator includes an opposing surface facing the gas diffusion layer. This opposing surface has a groove-shaped channel for guiding the reaction medium. Each separator also includes a groove-shaped channel in an opposite surface located on the opposite side of the opposing surface. The channels in the opposite surfaces of adjacent single cells form a cavity between the separators. The cavity guides the cooling medium.

[0004] Each partition includes protruding ribs and recesses on its opposite surface. The recesses are arranged between the ribs and the channels.

[0005] Ribs are set on the entire outer periphery of the channel.

[0006] The bottom walls of the recesses formed in each of the partitions are in contact with each other (see Figure 6A of Japanese National Phase Special Table 2020-522089).

[0007] In fuel cell stacks that include such separators, recesses that come into contact with each other prevent the cooling medium flowing through the cavities from flowing toward the ribs. In other words, the recesses prevent so-called sideflow.

[0008] In this type of fuel cell stack, the depth of the recesses in the separators varies. That is, the recesses include relatively deep recesses and relatively shallow recesses. Gaps are likely to form between the bottom walls of the relatively shallow recesses. As a result, the cooling medium flowing laterally from the cavity leaks through the gaps, thereby reducing the lateral flow confinement effect of the recesses. This reduces the cooling efficiency of the cooling medium, and thus reduces the power generation efficiency of the fuel cell. Summary of the Invention

[0009] Accordingly, the purpose of this disclosure is to provide a fuel cell stack capable of limiting the side flow of the cooling medium.

[0010] This summary is provided to introduce some concepts in a simplified form, which will be further explained in the detailed description below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help determine the scope of the claimed subject matter.

[0011] In one general aspect, a fuel cell stack is provided, comprising single cells stacked in a first direction. Each single cell includes a power generation unit, a first separator, and a second separator. The first separator and the second separator hold the power generation unit between the first separator and the second separator. Both the first separator and the second separator include an opposing surface facing the power generation unit and an opposing surface located on the opposite side of the opposing surface. The opposing surfaces of the first separator and the second separator are each provided with a channel extending in a second direction for a cooling medium to flow through. The first separator of each single cell includes a first protrusion projecting toward a second separator of an adjacent single cell in the first direction. The first protrusion contacts the second separator. The channel includes a channel located at the outermost position in a third direction. The third direction intersects both the first and second directions. The first protrusion is disposed outside at least one of the channel located at the outermost position in the third direction. The first protrusions are arranged side by side in the second direction. Each first protrusion includes a top wall portion and two side wall portions located on opposite sides of the top wall portion in the second direction. At least one of the two side wall portions includes a stepped portion having a stepped shape in the first direction.

[0012] Other features and aspects will become apparent from the following detailed description, drawings and claims. Attached Figure Description

[0013] Figure 1 This is an exploded perspective view of a single cell for a fuel cell stack according to various embodiments.

[0014] Figure 2 This is a cross-sectional view showing a fuel cell stack according to the first embodiment.

[0015] Figure 3 It is along Figure 2 The cross-sectional view taken from line 3-3.

[0016] Figure 4 It corresponds to Figure 3 The cross-sectional view shows the fuel cell stack according to the second embodiment.

[0017] Throughout the accompanying drawings and the full description, the same reference numerals refer to the same elements. The drawings may not be drawn to scale, and for clarity, illustration, and convenience, the relative dimensions, scale, and depiction of elements in the drawings may be exaggerated. Detailed Implementation

[0018] This specification provides a comprehensive understanding of the described methods, apparatus, and / or systems. Improvements and equivalents to the described methods, apparatus, and / or systems will be apparent to those skilled in the art. The sequence of operations is exemplary, and except for operations that must occur in a specific order, it will be apparent to those skilled in the art that they can be modified. Descriptions of functions and constructions well-known to those skilled in the art may be omitted.

[0019] Exemplary implementations may take different forms and are not limited to the illustrated embodiments. However, the illustrated embodiments are thorough and complete and convey the full scope of this disclosure to those skilled in the art.

[0020] In this specification, "at least one of A and B" should be understood to mean "only A, only B, or both A and B".

[0021] Now refer to Figures 1 to 4 This section describes fuel cell stacks according to various embodiments. For illustrative purposes, some parts of the structures in the figures are exaggerated or simplified, and the dimensional ratios of the structures may differ from the actual ratios. The term "orthogonal" is not necessarily used in a strict sense, but can be used whereby the elements are generally orthogonal to each other to the extent that this construction achieves the operational advantages of the respective embodiments.

[0022] <First Implementation Method>

[0023] First, refer to Figures 1 to 3 This describes a fuel cell stack according to the first embodiment.

[0024] like Figure 1 and Figure 2 As shown, a fuel cell stack is formed by stacking multiple individual cells 90, each of which has an overall rectangular plate shape.

[0025] In the following description, the direction in which the individual cells 90 are stacked will be referred to as the first direction X. The longitudinal direction of the individual cells 90, orthogonal to the first direction X, will be referred to as the second direction Y. Furthermore, the direction orthogonal to both the first direction X and the second direction Y will be referred to as the third direction Z.

[0026] The single cell 90 has inlet manifolds 91, 93, and 95 for introducing reactant gases or cooling media into the single cell 90, and outlet manifolds 92, 94, and 96 for discharging reactant gases and cooling media from the single cell 90 to the outside. In this embodiment, inlet manifold 91 and outlet manifold 92 are manifolds through which fuel gas flows. The fuel gas is, for example, hydrogen. Inlet manifold 93 and outlet manifold 94 are manifolds through which cooling media flows. The cooling medium is, for example, a coolant. Inlet manifold 95 and outlet manifold 96 are manifolds through which oxidant gas flows. The oxidant gas is, for example, air.

[0027] Inlet manifolds 91, 93, 95 and outlet manifolds 92, 94, 96 are all rectangular in shape in the plan view and extend through the single cell 90 along the first direction X.

[0028] Inlet manifold 91 and outlet manifolds 94, 96 are located on the first side of the second direction Y of the single cell 90 (in Figure 1 The left side in the left-right direction). Inlet manifold 91 and outlet manifolds 94, 96 are located on the first side of the Z-axis from the third side ( Figure 1 The back side of the sheet) faces the second side of the Z-axis towards the third side ( Figure 1 The front side of the sheet is arranged in sequence.

[0029] The outlet manifold 92 and the inlet manifolds 93 and 95 are located on the second side of the second direction Y of the single cell 90. Figure 1 (Right side of the middle). Outlet manifold 92 and inlet manifolds 93, 95 are directed from the third side to the second side of Z ( Figure 1 The front side of the sheet faces the first side of the Z-axis towards the third side. Figure 1 The sequential arrangement of the back side of the sheet.

[0030] The single cell 90 includes a membrane electrode assembly 10 (hereinafter referred to as MEA10), a frame member 20 for holding the MEA10, a first separator 30, and a second separator 40. The separators 30 and 40 hold the MEA10 and the frame member 20 between them.

[0031] The components will now be explained.

[0032] <mea10>

[0033] like Figure 1 As shown, MEA10 includes a solid polymer electrolyte membrane (not shown; hereinafter referred to as the electrolyte membrane) and electrodes 11 and 12 respectively disposed on opposite sides of the electrolyte membrane. In this embodiment, the first side ( ) is bonded to the electrolyte membrane in the first direction X. Figure 1 The electrode on the upper side (in the vertical direction) is the cathode 11. Additionally, the second side (in the first direction X) is bonded to the electrolyte membrane. Figure 1 The electrode on the lower side of the middle is the anode 12.

[0034] Electrodes 11 and 12 both include a catalyst layer (not shown) bonded to the electrolyte membrane and a gas diffusion layer (not shown) bonded to the catalyst layer.

[0035] MEA10 corresponds to the power generation unit of the fuel cell according to this disclosure.

[0036] <Frame Component 20>

[0037] like Figure 1 and Figure 2 As shown, the frame member 20 has a rectangular shape that is longer in the second direction Y, and is made of, for example, plastic.

[0038] The frame member 20 includes through holes 21, 22, 23, 24, 25, and 26, which are corresponding parts of manifolds 91, 92, 93, 94, 95, and 96.

[0039] Frame member 20 includes a centrally located opening 27. MEA10 extends from a first side in the first direction X (e.g., Figure 1 The upper side shown) is joined to the outer periphery of the opening 27.

[0040] <First separator 30>

[0041] like Figure 1 and Figure 2 As shown, the first separator 30 is formed by pressing a metal component, for example, made of titanium or stainless steel and having a rectangular shape in the plan view.

[0042] The first separator 30 includes through holes 31, 32, 33, 34, 35, and 36, which are corresponding portions of manifolds 91, 92, 93, 94, 95, and 96.

[0043] The first separator 30 includes a first surface 30A and a second surface 30B. The first surface 30A includes an opposing surface 30a facing the anode 12 of the MEA10 in a first direction X. The second surface 30B includes an opposing surface 30b located on the opposite side of the opposing surface 30a.

[0044] The first surface 30A is provided with a channel 37A for fuel gas to flow through and two connecting parts 37B. Figure 1 The slot channel 37A and the connecting part 37B are shown in a simplified manner in the image.

[0045] The slot channel 37A is disposed in the opposing surface 30a. Each slot channel 37A extends linearly along the second direction Y (see Figure 1 Slot channels 37A are arranged side-by-side in the third direction Z, while being spaced apart from each other (see...). Figure 2 ).

[0046] like Figure 1 As shown, two connecting portions 37B extend from opposite sides of the channel 37A in the second direction Y toward the through holes 31 and 32, respectively. Fuel gas is introduced into the channel 37A from the inlet manifold 91 via one connecting portion 37B. The fuel gas flowing through the channel 37A is discharged to the outlet manifold 92 via the other connecting portion 37B.

[0047] like Figure 1 and Figure 2 As shown, the second surface 30B is provided with a channel 38A for the cooling medium to flow through, two connecting portions 38B, and a first protrusion 50. Figure 1 The slot channel 38A and the connecting part 38B are shown in a simplified manner. Figure 1 and Figure 2 The first protrusion 50 is shown in a simplified manner in the middle.

[0048] The slot channel 38A is disposed in the opposite surface 30b. Each slot channel 38A extends linearly along the second direction Y (see...). Figure 1 Slot channels 38A are arranged side-by-side in the third direction Z, while being spaced apart from each other (see...). Figure 2 ).

[0049] like Figure 2 As shown, each slot channel 37A is formed on the back side of a protrusion located between two adjacent slot channels 38A in the third direction Z. Furthermore, each slot channel 38A is formed on the back side of a protrusion located between two adjacent slot channels 37A in the third direction Z.

[0050] like Figure 1 As shown by the dashed lines, two connecting portions 38B extend from opposite sides of the channel 38A in the second direction Y toward the through holes 33 and 34, respectively. Cooling medium is introduced into the channel 38A from the inlet manifold 93 via one connecting portion 38B. Cooling medium flowing through the channel 38A is discharged to the outlet manifold 94 via the other connecting portion 38B.

[0051] <First Protrusion 50>

[0052] like Figure 1 and Figure 2 As shown, the first protrusion 50 is disposed on the outside of the two outer slot channels 38a, which are the outermost slot channels 38A in the third direction Z. In this embodiment, the first protrusion 50 is disposed on the outside of the corresponding outer slot channel 38a (see...). Figure 1 The outer side in the third direction Z refers to the side in the third direction Z that is 90 degrees away from the center of the single cell. Figure 2 The first side of the third direction Z is shown in the two outer slot channels 38a. Figure 1 The outer groove channel 38a on the rear side of the sheet and the first protrusion 50 located on the outer side of the outer groove channel 38a.

[0053] The first protrusion 50 protrudes from each individual cell 90 toward the second separator 40 of the adjacent individual cell 90 in the first direction X (see [link]). Figure 2 ).

[0054] The first protrusion 50 extends along the third direction Z.

[0055] like Figure 1 As shown, the first protrusions 50 are arranged side by side in the second direction Y, while being spaced apart from each other. The first protrusions 50 are provided over the entire range in the second direction Y that forms the outer groove channel 38a.

[0056] like Figure 3 As shown, each of the first protrusions 50 includes a first top wall portion 51 and two first side wall portions 52 located on opposite sides of the first top wall portion 51 in the second direction Y.

[0057] The first top wall portion 51 of each single cell 90 contacts the second surface 40B of the second separator 40 of the adjacent single cell 90 in the first direction X.

[0058] Each first sidewall portion 52 includes a first step portion 53 having a stepped shape in the first direction X. In this embodiment, both first sidewall portions 52 include the first step portion 53.

[0059] The first step portion 53 is located at the center of the first sidewall portion 52 in the first direction X. Each first sidewall portion 52 includes a portion in the first direction X that is closer to the first top wall portion 51 than the first step portion 53 (hereinafter referred to as the distal portion 52a), and a portion in the first direction X that is closer to the proximal end of the first protrusion 50 than the first step portion 53 (hereinafter referred to as the proximal portion 52b).

[0060] The distal portion 52a is closer to the center of the first protrusion 50 in the second direction Y than the proximal portion 52b.

[0061] <Second separator 40>

[0062] like Figure 1 and Figure 2 As shown, the second separator 40 is formed by pressing a metal component, for example, made of titanium or stainless steel and having a rectangular shape in the plan view.

[0063] The second partition 40 includes through holes 41, 42, 43, 44, 45, and 46, which are corresponding portions of manifolds 91, 92, 93, 94, 95, and 96.

[0064] The second separator 40 includes a first surface 40A and a second surface 40B. The first surface 40A includes an opposing surface 40a facing the cathode 11 of the MEA10 in a first direction X. The second surface 40B includes an opposing surface 40b located on the opposite side of the opposing surface 40a.

[0065] The first surface 40A is provided with a channel 47A for the flow of oxidant gas and two connecting portions 47B. Figure 1 The slot channel 47A and the connecting part 47B are shown in a simplified manner.

[0066] Slot channels 47A are disposed in the opposing surface 40a. Each slot channel 47A extends linearly along the second direction Y (see...). Figure 1 Slot channels 47A are arranged side-by-side in the third direction Z, while being spaced apart from each other (see...). Figure 2 ).

[0067] like Figure 1 As shown by the dashed lines, two connecting portions 47B extend from opposite sides of the channel 47A in the second direction Y toward the through holes 45 and 46, respectively. Oxidant gas is introduced into the channel 47A from the inlet manifold 95 via one connecting portion 47B. The oxidant gas flowing through the channel 47A is discharged to the outlet manifold 96 via the other connecting portion 47B.

[0068] like Figure 1 and Figure 2 As shown, the second surface 40B is provided with a channel 48A for the cooling medium to flow through and two connecting portions 48B. Figure 1 The slot channel 48A and the connecting part 48B are shown in a simplified manner in the image.

[0069] Slot channels 48A are disposed in the opposite surface 40b. Each slot channel 48A extends linearly along the second direction Y (see [reference]). Figure 1 Slot channels 48A are arranged side-by-side in the third direction Z, while being spaced apart from each other (see...). Figure 2 ).

[0070] The slot channel 48A includes two outer slot channels 48a, which are the outermost slot channels 48A in the third direction Z.

[0071] like Figure 2 As shown, each slot channel 47A is formed on the back side of a protrusion located between two adjacent slot channels 48A in the third direction Z. Furthermore, each slot channel 48A is formed on the back side of a protrusion located between two adjacent slot channels 47A in the third direction Z.

[0072] like Figure 1 As shown, two connecting portions 48B extend from opposite sides of the channel 48A in the second direction Y toward the through holes 43 and 44, respectively. Cooling medium is introduced into the channel 48A from the inlet manifold 93 via one connecting portion 48B. Cooling medium flowing through the channel 48A is discharged to the outlet manifold 94 via the other connecting portion 48B.

[0073] like Figure 2 As shown, a gasket 70 is disposed on the outer side of the first protrusion 50 in the third direction Z. The gasket 70 provides a seal between the separator 30 of the single cell 90 and the second separator 40 of another single cell 90 adjacent in the first direction X. The first protrusion 50 is configured to partially fill the space S formed between the gasket 70 and the outer groove channels 38a, 48a in the third direction Z.

[0074] The operation of the first embodiment will now be described.

[0075] The fuel cell stack comprises individual cells 90 fastened together in a first direction X. If the length of the first protrusion 50 changes in the first direction X, i.e., if the height H of the first protrusion 50 (see...) Figure 3 If the first protrusions 50 vary, then they will include relatively high protrusions and relatively low protrusions. A gap may be generated between the relatively low first protrusions 50 of each individual cell 90 and the second separator 40 of another individual cell 90 adjacent in the first direction X.

[0076] In this respect, in this embodiment, when the first protrusion 50 presses against the second partition 40, the first stepped portion 53 of the first sidewall portion 52 of the relatively high first protrusion 50 smoothly deforms to bend in the first direction X. As a result, the height H of the relatively high first protrusion 50 decreases. Therefore, it is unlikely that a gap will form between the relatively low first protrusion 50 and the second partition 40. Accordingly, it is unlikely that the cooling medium will flow through the gap to the outside of the first protrusion 50. This limits the lateral flow of the cooling medium.

[0077] The first embodiment has the following advantages.

[0078] (1-1) Each single cell 90's first separator 30 includes a plurality of first protrusions 50. The first protrusions 50 protrude toward and abut against the second separator 40 of the adjacent single cell 90 in the first direction X. The first protrusions 50 are disposed outside two outer groove channels 38a, which are located at the outermost position in the third direction Z. The first protrusions 50 are arranged side-by-side in the second direction Y. Each first protrusion 50 includes a first top wall portion 51 and two first side wall portions 52 located on opposite sides of the first top wall portion 51 in the second direction Y. Both first side wall portions 52 include a first step portion 53 having a stepped shape in the first direction X.

[0079] The structure operates as described above. This restricts the lateral flow of the cooling medium.

[0080] (1-2) The first protrusion 50 is disposed over the entire range of the second direction Y in which the outer groove channel 38a is formed.

[0081] This configuration achieves the aforementioned advantages over the entire range in the second direction Y, where the outer groove channel 38a is formed. Consequently, the lateral flow of the cooling medium is further restricted.

[0082] <Second Implementation Method>

[0083] Now refer to Figure 1 and Figure 4 A fuel cell stack according to the second embodiment will be described. The main differences from the first embodiment will be discussed. Components in the fuel cell stack according to the second embodiment that are identical or equivalent to corresponding components in the fuel cell stack according to the first embodiment are given the same reference numerals, and repeated descriptions are omitted.

[0084] <Second protrusion 60>

[0085] like Figure 1 and Figure 4 As shown, the second partition 40 includes a second protrusion 60 that protrudes toward the first protrusion 50 in the first direction X.

[0086] Depend on Figure 1 The second protrusion 60, indicated by the double-dotted line, is disposed on the outer side of the two outer groove channels 48a. In this embodiment, the second protrusion 60 is disposed on the outer side of the corresponding outer groove channel 48a.

[0087] The second protrusion 60 extends along the third direction Z.

[0088] The second protrusions 60 are arranged side-by-side in the second direction Y, while being spaced apart from each other. The second protrusions 60 are provided over the entire range in the second direction Y that forms the outer groove channel 48a. In this embodiment, the second protrusions 60 are provided at positions corresponding to one of the first protrusions 50 in the first direction X.

[0089] like Figure 4 As shown, each of the second protrusions 60 includes a second top wall portion 61 and two second side wall portions 62 located on opposite sides of the second top wall portion 61 in the second direction Y.

[0090] The second top wall portion 61 contacts the first top wall portion 51 of the corresponding first protrusion 50.

[0091] Each second sidewall portion 62 includes a second stepped portion 63 having a stepped shape in the first direction X. In this embodiment, both second sidewall portions 62 include the second stepped portion 63.

[0092] The second step portion 63 is located at the center of the second sidewall portion 62 in the first direction X. Each second sidewall portion 62 includes a portion closer to the second top wall portion 61 than the second step portion 63 (hereinafter referred to as the distal portion 62a), and a portion closer to the proximal end of the second protrusion 60 than the second step portion 63 in the first direction X (hereinafter referred to as the proximal portion 62b).

[0093] The distal portion 62a is closer to the center of the second protrusion 60 in the second direction Y than the proximal portion 62b.

[0094] The operation of the second embodiment will now be described.

[0095] When the first protrusion 50 presses against the second protrusion 60, the first step portion 53 of the first sidewall portion 52 of the relatively high first protrusion 50 and the second step portion 63 of the second sidewall portion 62 of the relatively high second protrusion 60 smoothly deform to bend in the first direction X.

[0096] The second embodiment has the following advantages.

[0097] (2-1) The second separator 40 of each single cell 90 includes a plurality of second protrusions 60 that abut against the first protrusion 50 of the adjacent single cell 90. The second protrusions 60 all protrude toward the first protrusion 50 in a first direction X.

[0098] Using this configuration, compared to the case where the second partition 40 does not include the second protrusion 60, the height H of the first protrusion 50 can be reduced (see...). Figure 3 and 4 Therefore, the first protrusion 50 is easily formed. Correspondingly, the first separator 30 is easily manufactured.

[0099] (2-2) Each of the second protrusions 60 includes a second top wall portion 61 and two second side wall portions 62 located on opposite sides of the second top wall portion 61 in the second direction Y. Both second side wall portions 62 include a second step portion 63 having a stepped shape in the first direction X.

[0100] The structure is operated in the manner described above. Accordingly, it is possible to prevent the formation of a gap between the first protrusion 50 and the second protrusion 60, while limiting the amount of bending deformation of the first step portion 53 of the first sidewall portion 52 of the first protrusion 50 and the second step portion 63 of the second sidewall portion 62 of the second protrusion 60.

[0101] (2-3) The second protrusion 60 is provided over the entire range of the second direction Y in which the outer groove channel 48a is formed.

[0102] This configuration achieves the aforementioned advantages over the entire range in the second direction Y, where the outer groove channel 48a is formed. This further restricts the lateral flow of the cooling medium.

[0103] <Variant Example>

[0104] The above embodiments can be modified in the following ways. The above embodiments and the following modifications can be combined, as long as the combined modifications remain technically consistent with each other.

[0105] The shapes of the inlet manifolds 91, 93, 95 and the outlet manifolds 92, 94, 96 in the plan view are not limited to the rectangular shape as described in the above embodiments, but can be, for example, the shape of a stadium in the plan view.

[0106] The flow of reactant gas and cooling medium through manifolds 91, 92, 93, 94, 95, and 96 is not limited to those described in the above embodiments. For example, manifold 96 can be used as an inlet manifold for oxidant gas, and manifold 95 can be used as an outlet manifold for oxidant gas. Correspondingly, manifold 94 can be used as an inlet manifold for cooling medium, and manifold 93 can be used as an outlet manifold for cooling medium. That is, the oxidant gas flowing through tank passage 47A and the cooling medium flowing through tank passages 38A and 48A can flow in the same direction as the fuel gas flowing through tank passage 37A.

[0107] The slot channel 37A (38A) is not limited to extending linearly in the second direction Y as in the above embodiment. For example, the slot channel 37A (38A) may extend in a wavy shape in the planar direction of the opposing surface 30a (opposite surface 30b).

[0108] The slot channel 47A (48A) is not limited to extending linearly in the second direction Y as in the above embodiment. For example, the slot channel 47A (48A) may extend in a wavy shape in the planar direction of the opposing surface 40a (opposite surface 40b).

[0109] The shape of the first protrusion 50 is not limited to the shape described in the above embodiments. For example, each first sidewall portion 52 may be provided with two or more first step portions 53. Furthermore, the first protrusion 50 is not limited to the configuration in which the first step portions 53 are provided on both first sidewall portions 52. The first step portion 53 may be provided on only one of the first sidewall portions 52.

[0110] The shape of the second protrusion 60 is not limited to the shape described in the second embodiment. For example, each second sidewall portion 62 may be provided with two or more second step portions 63. Furthermore, the second protrusion 60 is not limited to the configuration in which the second step portions 63 are provided on both second sidewall portions 62. The second step portions 63 may be provided on only one of the second sidewall portions 62.

[0111] The second step 63 can be omitted from the second protrusion 60.

[0112] The first protrusion 50 is not necessarily located on the outside of the corresponding outer groove channel 38a as in the above embodiment. The first protrusion 50 may be located on the outside of one of the outer groove channels 38a. In this case, the second protrusion 60 is not limited to being located on the outside of both outer groove channels 48a, and its configuration may be changed according to the first protrusion 50.

[0113] The fuel cell stack is not limited to the type of fuel cell stack described in the second embodiment, where a second protrusion 60 is provided at the position corresponding to each first protrusion 50 in the first direction X. Some of the second protrusions 60 may be omitted. In this case, the separator 30 includes first protrusions 50 that do not face the second protrusions 60 in the first direction X. The first protrusions 50 that do not face the second protrusions 60 can be any protrusion, as long as they contact the second surface 40B of the separator 40.

[0114] The separators 30 and 40 do not necessarily have to be formed by pressing metal plates, but can be formed by cutting or etching.

[0115] The materials used for separators 30 and 40 are not limited to titanium or stainless steel, but can be aluminum or carbon.

[0116] The first separator according to this disclosure is not limited to the anode-side separator in the above embodiments, but can be used as a cathode-side separator. In this case, the second separator according to this disclosure is used as an anode-side separator.

[0117] Various changes in form and detail may be made to the above embodiments without departing from the spirit and scope of the claims and their equivalents. These embodiments are for illustrative purposes only and not for limiting purposes. The description of features in each embodiment is considered applicable to similar features or aspects in other embodiments. Suitable results may be achieved if the sequences are performed in a different order, and / or if the components in the illustrated system, architecture, device, or circuit are combined in a different manner, and / or replaced or supplemented by other components or their equivalents. The scope of this disclosure is not limited by the detailed description but by the claims and their equivalents. All changes within the scope of the claims and their equivalents are included in this disclosure.

Claims

1. A fuel cell stack comprising single cells stacked in a first direction, wherein, Each individual battery includes: Power generation unit; and A first partition and a second partition, wherein the first partition and the second partition hold the power generation unit between the first partition and the second partition. Both the first separator and the second separator include: Facing the opposing surface of the power generation unit; and The opposite surface located on the opposite side of the opposing surface. The opposite surfaces of the first partition and the second partition are both provided with grooves extending in the second direction for the cooling medium to flow through. The first separator of each of the single cells includes a first protrusion protruding toward the second separator of another single cell adjacent in the first direction, the first protrusion contacting the second separator. The slot channel includes a slot channel located at the outermost position in a third direction, which intersects both the first direction and the second direction. The first protrusion is disposed on the outer side of at least one of the slot channels located at the outermost position in the third direction, and the first protrusions are arranged side by side in the second direction. Each of the first protrusions includes a top wall portion and two side wall portions located on opposite sides of the top wall portion in the second direction, and At least one of the two sidewall portions includes a stepped portion having a stepped shape in the first direction.

2. The fuel cell stack according to claim 1, characterized in that, The first protrusion is disposed over the entire range in the second direction forming the groove channel.

3. The fuel cell stack according to claim 1, characterized in that, The second separator of each of the single cells includes a second protrusion that contacts the first protrusion of an adjacent single cell, and The second protrusions all protrude toward a corresponding first protrusion among the first protrusions in the first direction.

4. The fuel cell stack according to claim 3, characterized in that, The top wall portion, the side wall portion, and the step portion of each of the first protrusions are respectively defined as the first top wall portion, the first side wall portion, and the first step portion. Each of the second protrusions includes a second top wall portion and two second side wall portions located on opposite sides of the second top wall portion in the second direction, and At least one of the two second sidewall portions includes a second step portion having a step shape in the first direction.

5. The fuel cell stack according to claim 3 or 4, characterized in that, The second protrusion is disposed over the entire range in the second direction forming the groove channel.

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