Fuel cell stack

Abstract

A fuel cell stack is provided with: a cell stack (10) configured by stacking power generation cells; a guide section (50) that protrudes from the inner wall of a case (30) toward the cell stack (10); and a positioning section that is provided at the edge of the power generation cells so as to correspond to the guide section (50) and positions the power generation cells with respect to the case (30). The positioning part is provided with a first protruding part (331, 351) and a second protruding part (332, 352) which protrude from a first edge part (101) and a second edge part (102) of the power generation battery facing the inner wall of the housing (30) to the inner wall. The guide portion (50) includes a first guide portion provided on one side of the first direction and the second direction of the first protruding portion (331, 351), and a second guide portion provided on the other side of the first direction and the second direction of the second protruding portion (332, 352).

Description

Technical Field

[0001] The present invention relates to a fuel cell stack including a stack of a plurality of power generation cells. Background Art

[0002] In recent years, to ensure that more people have access to cost-effective, reliable, sustainable, and advanced energy, technological development has been underway for fuel cells that contribute to improved energy efficiency. A previously known technology for fuel cell stacks for such fuel cells is to erect guide rods on a mounting platform, engage recessed portions provided on the edges of power generation cells with the guide rods, and stack the power generation cells on the mounting platform to form a stack. This technology is described, for example, in Patent Document 1. In the stack described in Patent Document 1, a coating is applied to the guide rods to reduce frictional resistance between the power generation cells and the guide rods when the cells are stacked.

[0003] However, when a coating is provided on the surface of the guide rods as in the laminate described in Patent Document 1, the number of steps required to assemble the fuel cell stack increases, leading to an increase in cost.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-132847 (JP 2022-132847 A). Summary of the Invention

[0007] A fuel cell stack according to one embodiment of the present invention comprises: a cell stack formed by stacking power generation cells including membrane electrode structures (MEAs) comprising electrolyte membranes and electrodes, and separators; a housing surrounding the cell stack; a guide portion protruding from the inner wall of the housing toward the cell stack and extending in the direction in which the cell stack is stacked; and a positioning portion provided at the edge of the power generation cells in correspondence with the guide portion, for positioning the power generation cells relative to the housing. The positioning portion comprises a protrusion protruding from the edge of the power generation cell toward the inner wall. The protrusion includes a first protrusion and a second protrusion protruding from a first edge of the power generation cell facing the inner wall of the housing and a second edge opposite the first edge, respectively. The first protrusion and the second protrusion each have a first end surface extending substantially perpendicularly from the first edge and a second end surface extending substantially perpendicularly from the second edge, respectively. When mutually opposite directions within a surface perpendicular to the stacking direction are defined as a first direction and a second direction, the guide portion includes: a first guide portion, which is arranged on either side of the first direction and the second direction of the first protrusion, and has a first abutting surface abutting the first end surface; and a second guide portion, which is arranged on either the other side of the first direction and the second direction of the second protrusion, and has a second abutting surface abutting the second end surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The objects, features and advantages of the present invention will be further clarified through the following description of the embodiments in conjunction with the accompanying drawings.

[0009] Figure 1 is a perspective view schematically showing the overall structure of a fuel cell stack according to an embodiment of the present invention;

[0010] Figure 2 is included in Figure 1 A cross-sectional view of a main portion of a cell stack of a fuel cell stack;

[0011] Figure 3 The structure of the integrated electrode assembly is shown Figure 1 Cross-sectional view of the main parts;

[0012] Figure 4A The structure of the first separator is shown Figure 1 Cross-sectional view of the main parts;

[0013] Figure 4B The structure of the second separator is shown Figure 1 Cross-sectional view of the main parts;

[0014] Figure 5A 1 is a diagram showing an example of steps of a method for assembling a fuel cell stack according to an embodiment of the present invention;

[0015] Figure 5B It is a successor Figure 5A A diagram of an example of the steps of

[0016] Figure 5C It is a successor Figure 5B A diagram of an example of the steps of

[0017] Figure 5D It is a successor Figure 5C A diagram of an example of the steps of

[0018] Figure 5E It shows the following Figure 5D FIG. 1 is a diagram showing an example of the steps of FIG. DETAILED DESCRIPTION

[0019] Below, refer to Figures 1 to 5E The present invention will now be described in its embodiments. The fuel cell stack according to the embodiments of the present invention is a key component of a fuel cell and is included in the fuel cell. The fuel cell can be installed in, for example, a vehicle to generate electricity to drive the vehicle. Fuel cells can also be installed in mobile objects other than vehicles, such as aircraft and ships, as well as robots and various industrial machinery.

[0020] First, the overall structure of a fuel cell stack will be briefly described. Figure 1This is a perspective view schematically showing the overall structure of a fuel cell stack 100 according to an embodiment of the present invention. For convenience, the following diagram defines three mutually orthogonal axial directions as the front-to-back direction, the left-to-right direction, and the up-to-down direction, and describes the structure of each part according to these definitions. These directions are not necessarily the same as the front-to-back direction, the left-to-right direction, and the up-to-down direction of the vehicle. For example, Figure 1 The front-to-back direction may be the front-to-back direction of the vehicle, may be the left-to-right direction, and may be the up-down direction. Figure 1 The front-to-back direction is the stacking direction of the fuel cell stack 100 , and the stacking direction is aligned with the direction of gravity when assembling the fuel cell stack 100 .

[0021] like Figure 1 As shown, the fuel cell stack 100 includes a cell stack 10 , end units 40 disposed at both front and rear ends of the cell stack 10 , and a housing 30 surrounding the cell stack 10 . The fuel cell stack 100 is generally in the shape of a rectangular parallelepiped.

[0022] The outer casing 30 has four generally rectangular side walls 300 that face the top, right, bottom, and left surfaces of the battery stack 10. These four side walls 300 define a generally box-shaped housing space SP0 with open front and rear surfaces. The outer casing 30 is made of a metal such as aluminum or iron.

[0023] Although not shown, the end unit 40 includes a plurality of plates stacked in the front-to-back direction. More specifically, the end unit 40 includes a terminal plate disposed inward in the front-to-back direction, an insulating plate disposed outward in the front-to-back direction of the terminal plate, and an end plate disposed outward in the front-to-back direction of the insulating plate.

[0024] The terminal plate is a generally rectangular plate-shaped member made of metal and has terminals for extracting electricity generated by the electrochemical reaction in the battery stack 10. The insulating plate is a generally rectangular plate-shaped member made of non-conductive resin or rubber and electrically insulates the terminal plate from the end plate. The end plate is a plate-shaped member made of metal or a high-strength resin.

[0025] A guide member 50 ( Figure 3 The guide member 50 is a rod-shaped or plate-shaped member extending in the front-rear direction. The guide members 50 are pre-installed on the inner surfaces of the four side walls 300 (the inner walls of the outer casing 30), and the battery stack 10 is assembled in this state.

[0026] exist Figure 1 A portion of the side wall 300 of the housing 30 is cut away. Figure 1As shown in section A of FIG. , the battery stack 10 is a stack of a plurality of power generation cells 1 (for convenience, only a single cell 1 is shown). The battery stack 10 is stacked in the front-to-back direction while being guided by a guide member 50 .

[0027] The power generation cell 1 includes a Unitized Electrode Assembly (UEA) 2 and separators 3 positioned on the front and rear sides of the UEA 2, sandwiching the UEA 2. The UEA 2 and separators 3 are arranged alternately in the front-to-back direction. Separators 3 facing the front of the UEA 2 are sometimes referred to as first separators 31, while those facing the rear are sometimes referred to as second separators 32. Depending on the UEA 2 used as a reference, the same separator 3 may function as either the first separator 31 or the second separator 32.

[0028] Figure 2 1 is a cross-sectional view of the main parts of the battery stack 10. Figure 2 As shown, the partition 3 comprises a pair of front and rear thin metal plates with a corrugated cross-section, namely a front plate 3F and a rear plate 3R. The front plate 3F extends in the vertical and horizontal directions and has a front surface 3Fa and a rear surface 3Fb. The rear plate 3R extends in the vertical and horizontal directions and has a front surface 3Ra and a rear surface 3Rb. The rear surface 3Fb of the front plate 3F and the front surface 3Ra of the rear plate 3R, which face each other, are joined at their outer peripheries by welding or the like. Thus, the front plate 3F and the rear plate 3R are integrated into one body, forming the partition 3. The partition 3 is made of a material with good corrosion resistance and electrical conductivity, such as stainless steel, titanium, or a titanium alloy.

[0029] A cooling channel PAw for the flow of a cooling medium is formed inside the partition 3, which is surrounded by the front plate 3F and the rear plate 3R, that is, between the rear surface 3Fb of the front plate 3F and the front surface 3Ra of the rear plate 3R. The power generation surface of the power generation cell 1 is cooled by the flow of the cooling medium. For example, water can be used as the cooling medium. The surface of the partition 3 facing the UEA2 (the front surface 3Fa and the rear surface 3Rb) is formed into a concave and convex shape by stamping, etc., so that a gas flow channel is formed between the UEA2. More specifically, the partition 3 has a pair of front and rear ribs 3A protruding toward the UEA2 and a pair of front and rear recesses 3B connected to the front and rear ribs 3A and formed into a concave shape.

[0030] The front and rear pair of ribs 3A abut against the front and rear surfaces 2a and 2b of the UEA 2. During assembly of the fuel cell stack 100, a compressive load F is applied to the cell stack 10 in the front-to-back direction. After assembly of the fuel cell stack 100 is complete, this compressive load F is maintained. Consequently, a predetermined surface pressure due to the compressive load F acts on the UEA 2 in the front-to-back direction via the ribs 3A.

[0031] Between the front surface 2a of the UEA 2 and the rear plate 3R of the separator 3 facing the front surface 2a, an anode flow channel PAa for the flow of fuel gas containing hydrogen (anode gas) is formed by a recess 3B. Between the rear surface 2b of the UEA 2 and the front plate 3F of the separator 3 facing the rear surface 2b, a cathode flow channel PAc for the flow of oxidant gas containing oxygen (cathode gas) is formed by a recess 3B. For example, hydrogen can be used as the fuel gas, and air can be used as the oxidant gas. Fuel gas and oxidant gas are sometimes not distinguished and are referred to as reactant gases.

[0032] Figure 3 This shows the schematic structure of UEA2 Figure 1 The main part of the cross-sectional view (cross-sectional view taken along line III-III). UEA2 is sometimes called membrane electrode structure or membrane electrode assembly. Figure 3 As shown, the UEA 2 includes a substantially rectangular membrane electrode assembly 20 (hereinafter referred to as MEA) and a frame 21 supporting the MEA 20. Figure 2 As shown in the detailed view of part A of FIG, the MEA 20 includes an electrolyte membrane 23 , an anode electrode 24 provided on a front surface 231 of the electrolyte membrane 23 , and a cathode electrode 25 provided on a rear surface 232 of the electrolyte membrane 23 .

[0033] The electrolyte membrane 23 is, for example, a solid polymer electrolyte membrane, and a thin film of a perfluorosulfonic acid polymer containing water can be used. The electrolyte membrane is not limited to a fluorine-based electrolyte membrane, and a hydrocarbon-based electrolyte membrane can also be used.

[0034] The anode electrode 24 includes an electrode catalyst layer 241 formed on the front surface 231 of the electrolyte membrane 23 and serving as a reaction field for the electrode reaction, and a gas diffusion layer 242 provided on the front surface of the electrode catalyst layer 241 and configured to diffuse and supply the fuel gas. An intermediate layer (base layer) may be provided between the electrode catalyst layer 241 and the gas diffusion layer 242. The cathode electrode 25 includes an electrode catalyst layer 251 formed on the rear surface 232 of the electrolyte membrane 23 and serving as a reaction field for the electrode reaction, and a gas diffusion layer 252 provided on the rear surface of the electrode catalyst layer 251 and configured to diffuse and supply the oxidant gas. An intermediate layer (base layer) may be provided between the electrode catalyst layer 251 and the gas diffusion layer 252.

[0035] The electrode catalyst layers 241 and 251 include a catalyst metal that promotes the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidant gas, a proton-conductive electrolyte (such as an ionomer), and electron-conductive carbon particles. The gas diffusion layers 242 and 252 are composed of a gas-permeable conductive member, such as a porous carbon body.

[0036] At the anode electrode 24, the fuel gas (hydrogen) supplied via the anode flow channel PAa is ionized by the catalyst and moves through the electrolyte membrane 23 toward the cathode electrode. The electrons generated at this time are extracted as electrical energy through an external circuit. At the cathode electrode 25, the oxidant gas (oxygen) supplied via the cathode flow channel PAc reacts with the hydrogen ions introduced from the anode electrode 24 and the electrons transferred from the anode electrode 24 to produce water. The generated water provides appropriate humidity to the electrolyte membrane 23, and the excess water is discharged to the outside of the UEA2 along with the flow of gas.

[0037] like Figure 3 As shown, frame 21 is a thin, roughly rectangular plate made of insulating resin, rubber, or the like. A roughly rectangular opening 21a is provided in the center of frame 21. MEA 20 is positioned so as to cover the entire opening 21a, with the periphery of MEA 20 supported by frame 21. To the left of opening 21a in frame 21, three through-holes 211 to 213 are arranged in the vertical direction and extend through frame 21 in the front-to-back direction. To the right of opening 21a, three through-holes 214 to 216 are arranged in the vertical direction and extend through frame 21 in the front-to-back direction. For convenience, through-holes 211 to 216 are shown as roughly rectangular, but the shape of through-holes 211 to 216 is not limited to this. Figure 3 The point P is the middle point of the battery stack 10 in the vertical direction and the left-right direction, and is called the center point.

[0038] Figure 4A The structure of the rear surface of the first partition plate 31 (the rear surface 3Rb of the rear plate 3R) arranged in front of the UEA2 is shown. Figure 1 Cross-sectional view of the main parts, Figure 4B The structure of the rear surface of the second partition plate 32 (the rear surface 3Fb of the front plate 3F) arranged behind the UEA2 is shown. Figure 1 A cross-sectional view of the main portion of the rear surface 3Rb is shown. Although partially omitted from the illustration, multiple ribs 3A extending in the horizontal direction are provided in the vertical direction at the center portion of the rear surface 3Rb facing the MEA 20 of the UEA 2. Although omitted from the illustration, the ribs 3A extend in a serpentine manner in the horizontal direction.

[0039] like Figure 4A 、 4B As shown, the partition 3 (the first partition 31 and the second partition 32) is connected to the through holes 211 to 216 ( Figure 3) are respectively provided with through holes 311 to 316 that pass through the partition 3 in the front-to-back direction at corresponding positions. For convenience, the through holes 311 to 316 are shown as being roughly rectangular, but the shape of the through holes 311 to 316 is not limited thereto. The through holes 311 to 316 are respectively connected to the through holes 211 to 216 of the frame 21. A plurality of flow channels that pass through the battery stack 10 and extend in the front-to-back direction are formed by the collection of these mutually connected through holes 211 to 216, 311 to 316. Although not shown in the figure, a plurality of protrusions for sealing that protrude toward the frame 21, i.e., metal protrusion seals, are provided around the through holes 311 to 316 of the partition 3 and on the peripheral edge of the partition 3.

[0040] like Figure 1 As shown, the rear end unit 40 has multiple through-holes 401-406 extending through the end unit 40 in the front-to-back direction at positions corresponding to through-holes 211-216 and 311-316. The front end unit 40 does not have through-holes 401-406. The front end unit 40 is sometimes referred to as the dry-side end unit, and the rear end unit 40 as the wet-side end unit. For convenience, through-holes 401-406 are shown as generally rectangular, but the shapes of through-holes 401-406 are not limited to this.

[0041] A fuel gas tank storing high-pressure fuel gas is connected to through-hole 401 via an ejector, injector, or the like. As indicated by the solid arrow, fuel gas is supplied to the fuel cell stack 100 via through-hole 401. This fuel gas is introduced into the anode flow channel PAa between the UEA 2 and the rear plate 3R of the separator 3 via through-holes 211 and 311. The fuel gas (fuel off-gas) that has passed through the anode flow channel PAa is discharged from through-hole 406 via through-holes 216 and 316, as indicated by the solid arrow.

[0042] A compressor for supplying oxidant gas is connected to the through-hole 404. As indicated by the dotted arrow, the oxidant gas compressed by the compressor is supplied to the fuel cell stack 100 via the through-hole 404. The oxidant gas is introduced into the cathode flow channel PAc between the UEA 2 and the front plate 3F of the separator 3 via the through-holes 214 and 314. The oxidant gas (oxidant off-gas) after passing through the cathode flow channel PAc is discharged from the through-hole 403 via the through-holes 213 and 313 as indicated by the dotted arrow.

[0043] A pump for supplying a cooling medium is connected to through-hole 405. As indicated by the dashed line, the cooling medium is supplied to the fuel cell stack 100 via through-hole 405. This cooling medium is introduced into the cooling flow channel PAw between the front plate 3F and the rear plate 3R of the separator 3 via through-holes 215 and 315. After passing through the cooling flow channel PAw, the cooling medium is discharged from through-hole 402 via through-holes 212 and 312, as indicated by the dashed line. The discharged cooling medium is cooled by heat exchange at the radiator and then supplied again to the fuel cell stack 100 via through-hole 405.

[0044] The above is a schematic structure of the fuel cell stack 100. The fuel cell stack 100 of this embodiment is characterized by the support structure of the cell stack 10 supported from the inner wall of the housing 30. The cell stack 10 is constructed by positioning and stacking the power generation cells 1 (UEA2, separators 3) via guide members 50 in the storage space SP0 within the housing 30. Therefore, the fuel cell stack 100 needs to be constructed so that the power generation cells 1 can be positioned with high precision and can also be easily stacked. Taking this into consideration, the fuel cell stack 100 of this embodiment is constructed as follows.

[0045] Figure 3 、 Figure 4A 、 Figure 4B This is a diagram viewed from the stacking direction of the battery stack 10. Figure 3 、 Figure 4A 、 Figure 4B As shown, guide members 50 of the same shape are interposed between the four side walls 300 of the housing 30 and the four side surfaces (upper side 101, lower side 102, left side 103, and right side 104) of the battery stack 10. The battery stack 10 has a generally rectangular shape with the upper side 101 and lower side 102 as long sides and the left side 103 and right side 104 as short sides.

[0046] The guide member 50 has an elongated base 51 extending along the side wall 300 and a protrusion 52 extending approximately perpendicularly from the base 51, resulting in a generally T-shaped cross-section. More specifically, the protrusion 52 projects not from the center of the base 51 but rather from a position offset from the center toward one end. The four guide members 50 may have different shapes rather than the same shape. For example, the upper and lower guide members 50 may have the same shape, while the guide members 50 on the right and left sides may have different shapes.

[0047] The guide member 50 is formed by extrusion molding using resin as a constituent material, and has a constant cross-sectional shape in the front-to-back direction. The guide member 50 extends in the entire front-to-back direction of the fuel cell stack 100. The front end portion of the guide member 50 is supported on Figure 1The front end unit 40 is supported by the rear end unit 40. For example, a recess or a through hole is provided in the end unit 40, and the front and rear ends of the guide member 50 are fitted or inserted into the recess or through hole, thereby supporting the guide member 50.

[0048] Support portions 301 are provided on each of the four side walls 300 of the housing 30, facing the storage space SP0. The support portions 301 have engagement grooves 302 extending generally parallel to the side surfaces 101 to 104 of the battery stack 10, and entrance portions 303 serving as the entrances to the engagement grooves 302. When viewed in the stacking direction, with the direction extending along the side surfaces 101 to 104 defined as the longitudinal direction and the direction perpendicular to the longitudinal direction defined as the width direction, the entrance portions 303 have a pair of protrusions 303a that protrude inward from the longitudinal ends of the engagement grooves 302, thereby narrowing the entrance to the engagement grooves 302.

[0049] The length and width of the engagement groove 302 are the same or substantially the same as those of the base 51 of the guide member 50, and the base 51 fits into the engagement groove 302. Thus, the base 51 is positioned by the protrusion 303a and is supported integrally with the side wall 300. At this point, the tip of the protrusion 52 protrudes beyond the inlet 303 toward the center point P.

[0050] like Figure 4A 、 4B As shown, the protrusion 52 has a pair of end surfaces 50a and 50b extending toward the center point P. When the guide member 50 is supported by the support portion 301, the protrusion 52 of the upper guide member 50, which faces the upper side surface 101 of the battery stack 10, is located to the right of the center point P, and the protrusion 52 of the lower guide member 50, which faces the lower side surface 102, is located to the left of the center point P. More specifically, the upper and lower protrusions 52 are symmetrically arranged with respect to the center point P. Therefore, the distance from the center point P to the left end surface 50a of the upper protrusion 52 is the same as the distance from the center point P to the right end surface 50a of the lower protrusion 52. Furthermore, the distance from the center point P to the right end surface 50b of the upper protrusion 52 is the same as the distance from the center point P to the left end surface 50b of the lower protrusion 52.

[0051] When the guide member 50 is supported by the support portion 301, the protrusion 52 of the left guide member 50 facing the left side 103 of the battery stack 10 is located above the center point P, and the protrusion 52 of the right guide member 50 facing the right side 104 is located below the center point P. More specifically, the left and right protrusions 52 are symmetrically arranged with respect to the center point P. Therefore, the distance from the center point P to the upper end face 50b of the left protrusion 52 is the same as the distance from the center point P to the lower end face 50b of the right protrusion 52. Furthermore, the distance from the center point P to the lower end face 50a of the left protrusion 52 is the same as the distance from the center point P to the upper end face 50a of the right protrusion 52.

[0052] Positioning portions PT11 to PT14, PT21 to PT24, and PT31 to PT34 are provided on the upper side 101, lower side 102, left side 103, and right side 104 of the UEA2, first partition 31, and second partition 32, respectively, corresponding to the guide member 50. The UEA2, first partition 31, and second partition 32 are positioned relative to the housing 30 by the guide member 50 and the positioning portions PT11 to 14, PT21 to 24, and PT31 to 34.

[0053] like Figure 4A As shown, a recessed portion 101a is provided in the left-right center portion of the upper side surface 101 of the first separator 31. A substantially rectangular protrusion 331 is provided in the center of the recessed portion 101a, protruding upward from the bottom surface SF21 of the recessed portion 101a, serving as a positioning portion PT21. The upper end surface of the protrusion 331 is positioned approximately in the same vertical direction as the upper side surfaces 101 on the left and right sides of the recessed portion 101a. The right end surface 331a of the protrusion 331 extends vertically, abutting against the end surface 50a of the guide member 50, extending perpendicularly to the upper side surface 101.

[0054] Similarly, a recessed portion 102a is provided in the left-right center of the lower side surface 102 of the first partition plate 31. A substantially rectangular protrusion 332 is provided in the center of the recessed portion 102a, protruding downward from the bottom surface SF22 of the recessed portion 102a, serving as a positioning portion PT22. The lower end surface of the protrusion 332 is positioned approximately in the same vertical direction as the lower side surfaces 102 on the left and right sides of the recessed portion 102a. The left end surface 332a of the protrusion 332 extends vertically so as to abut against the end surface 50a of the guide member 50, that is, it extends perpendicularly to the lower side surface 102.

[0055] The convex portion 331 and the convex portion 332 are symmetrically arranged with respect to the center point P. Therefore, the distance from the center point P to the right end surface 331 a of the convex portion 331 and the distance from the center point P to the left end surface 332 a of the convex portion 332 are equal to each other.

[0056] The left side 103 and right side 104 of the first separator 31 are provided with substantially rectangular recesses 341 and 342, respectively, serving as positioning portions PT23 and PT24. The widths (vertical lengths) of recesses 341 and 342 are greater than the width of the protrusion 52 of the guide member 50. The protrusion 52 of the left guide member 50 is inserted into recess 341, while the protrusion 52 of the right guide member 50 is inserted into recess 342. Recesses 341 and 342 are symmetrically arranged about a center point P.

[0057] More specifically, the left recess 341 is arranged so that its upper end surface 341a contacts the end surface 50b of the guide member 50 above the center point P, and its lower end surface 341b is spaced apart from the end surface 50a of the guide member 50. The right recess 342 is arranged so that its lower end surface 342b contacts the end surface 50b of the guide member 50 below the center point P, and its upper end surface 342a is spaced apart from the end surface 50a of the guide member 50.

[0058] Thus, in this embodiment, the right end surface 331a of the upper convex portion 331 and the left end surface 332a of the lower convex portion 332 of the first partition plate 31 abut against the left end surface 50a of the upper guide member 50 and the right end surface 50a of the lower guide member 50, respectively, thereby preventing the first partition plate 31 from moving in the left-right direction. Furthermore, the upper end surface 341a of the left concave portion 341 and the lower end surface 342b of the right concave portion 342 of the first partition plate 31 abut against the upper end surface 50b of the left guide member 50 and the lower end surface 50b of the right guide member 50, respectively, thereby preventing the first partition plate 31 from moving in the vertical direction.

[0059] Furthermore, the right end surface 331a of the convex portion 331 and the left end surface 332a of the convex portion 332 respectively abut against the guide member 50, thereby preventing clockwise rotation (in the direction of arrow R1) of the first partition plate 31 about the center point P. Furthermore, the upper end surface 341a of the concave portion 341 and the lower end surface 342b of the concave portion 342 respectively abut against the guide member 50, thereby preventing counterclockwise rotation (in the direction of arrow R2) of the first partition plate 31 about the center point P. As a result, movement and rotation of the first partition plate 31 relative to the housing 30 are prevented, allowing the first partition plate 31 to be precisely positioned and retained within the housing space SP0 of the housing 30 while separated from the inner wall (side wall 300) of the housing 30.

[0060] like Figure 4BAs shown, a recessed portion 101b is provided in the left-right center portion of the upper side surface 101 of the second partition plate 32. A substantially rectangular protrusion 351 is provided in the center of the recessed portion 101b, protruding upward from the bottom surface SF31 of the recessed portion 101b, serving as a positioning portion PT31. The upper end surface of the protrusion 351 is positioned approximately in the same vertical direction as the upper side surfaces 101 on the left and right sides of the recessed portion 101b. The left end surface 351a of the protrusion 351 extends vertically, abutting against the end surface 50b of the guide member 50, thereby extending perpendicularly to the upper side surface 101.

[0061] Similarly, a recessed portion 102b is provided in the left-right center of the lower side surface 102 of the second partition plate 32. A substantially rectangular protrusion 352 is provided in the center of the recessed portion 102b, protruding downward from the bottom surface SF32 of the recessed portion 102b, serving as a positioning portion PT32. The lower end surface of the protrusion 352 is positioned approximately in the same vertical direction as the lower side surfaces 102 on the left and right sides of the recessed portion 102b. The right end surface 352a of the protrusion 352 extends vertically, abutting against the end surface 50b of the guide member 50, that is, extending perpendicularly to the lower side surface 102.

[0062] The convex portion 351 and the convex portion 352 are symmetrically arranged with respect to the center point P. Therefore, the distance from the center point P to the left end surface 351 a of the convex portion 351 and the distance from the center point P to the right end surface 352 a of the convex portion 352 are equal to each other.

[0063] The left side 103 and right side 104 of the second partition plate 32 are provided with substantially rectangular recesses 361 and 362, respectively, serving as positioning portions PT33 and PT34. The widths (vertical lengths) of recesses 361 and 362 are greater than the width of the protrusion 52 of the guide member 50. The protrusion 52 of the left guide member 50 is inserted into recess 361, while the protrusion 52 of the right guide member 50 is inserted into recess 362. Recesses 361 and 362 are symmetrically positioned about a center point P.

[0064] More specifically, the left recess 361 is arranged so that its lower end surface 361b contacts the end surface 50a of the guide member 50 above the center point P, and its upper end surface 361a is spaced apart from the end surface 50b of the guide member 50. The right recess 362 is arranged so that its upper end surface 362a contacts the end surface 50a of the guide member 50 below the center point P, and its lower end surface 362b is spaced apart from the end surface 50b of the guide member 50.

[0065] Thus, in this embodiment, the left end surface 351a of the upper convex portion 351 and the right end surface 352a of the lower convex portion 352 of the second partition plate 32 abut against the right end surface 50b of the upper guide member 50 and the left end surface 50b of the lower guide member 50, respectively, thereby preventing the second partition plate 32 from moving in the left-right direction. Furthermore, the lower end surface 361b of the left concave portion 361 and the upper end surface 362a of the right concave portion 362 of the second partition plate 32 abut against the lower end surface 50a of the left guide member 50 and the lower end surface 50a of the right guide member 50, respectively, thereby preventing the second partition plate 32 from moving in the vertical direction.

[0066] Furthermore, the left end surface 351a of the convex portion 351 and the right end surface 352a of the convex portion 352 respectively abut against the guide member 50, thereby preventing the second partition plate 32 from rotating counterclockwise (in the direction of arrow R2) about the center point P. Furthermore, the lower end surface 361b of the concave portion 361 and the upper end surface 362a of the concave portion 362 respectively abut against the guide member 50, thereby preventing the second partition plate 32 from rotating clockwise (in the direction of arrow R1) about the center point P. As a result, movement and rotation of the second partition plate 32 relative to the housing 30 are prevented, allowing the second partition plate 32 to be precisely positioned and retained within the housing space SP0 of the housing 30 while separated from the inner wall (side wall 300) of the housing 30.

[0067] like Figure 4A 、 4B As shown, the protrusions 331, 332 of the first separator 31 and the protrusions 351, 352 of the second separator 32 are arranged on opposite sides of each other in the left-right direction, with the guide member 50 interposed therebetween. Therefore, when viewed in the stacking direction (front-to-back direction), the protrusions 331, 332 of the first separator 31 and the protrusions 351, 352 of the second separator 32 do not overlap but are offset in the left-right direction. Specifically, the right end surface 331a of the protrusion 331 is located to the left of the left end surface 351a of the protrusion 351, and the left end surface 332a of the protrusion 332 is located to the right of the right end surface 352a of the protrusion 352. This increases the insulation distance between the protrusions 331, 332 and the protrusions 351, 352.

[0068] like Figure 3As shown, a recess 101c is provided in the left-right center of the upper side 101 of the frame 21 of the UEA 2. A generally rectangular protrusion 261 is provided in the center of recess 101c, protruding upward from the bottom surface SF11 of recess 101c. The upper end surface of protrusion 261 is positioned approximately at the same vertical position as the upper side surfaces 101 on the left and right sides of recess 101c. Similarly, a recess 102c is provided in the left-right center of the lower side 102 of the frame 21 of the UEA 2. A generally rectangular protrusion 262 is provided in the center of recess 102c, protruding downward from the bottom surface SF12 of recess 102c. The lower end surface of protrusion 262 is positioned approximately at the same vertical position as the lower side surfaces 102 on the left and right sides of recess 102c.

[0069] The protrusion 261 is positioned to the right of the protrusion 262. Recesses 271 and 272 are provided at the left-right center of the protrusion 261 and the left-right center of the protrusion 262, respectively, to serve as positioning portions PT11 and PT12. Concave portions 271 and 272 are symmetrically positioned about the center point P. The width (left-right length) of recesses 271 and 272 is approximately the same as the width of the protrusion 52 of the guide member 50. The protrusion 52 of the upper guide member 50 fits into recess 271, and the protrusion 52 of the lower guide member 50 fits into recess 272. This prevents the UEA 2 from moving in the left-right direction.

[0070] The left side 103 and right side 104 of the frame 21 of the UEA 2 are provided with roughly rectangular recesses 273 and 274, respectively, serving as positioning portions PT13 and PT14. Recesses 273 and 274 are symmetrically arranged about a center point P. The width (vertical length) of recesses 273 and 274 is approximately the same as the width of the protrusion 52 of the guide member 50. The protrusion 52 of the left guide member 50 fits into recess 273, and the protrusion 52 of the right guide member 50 fits into recess 274. This prevents vertical movement of the UEA 2.

[0071] The partition 3 is made of metal, while the frame 21 is made of resin or rubber. Therefore, the frame 21 has a lower rigidity than the partition 3 and is easily deformed. Therefore, the protrusion 52 can be easily fitted into the recesses 271 to 274. Instead of providing the recesses 271 to 274 in the frame 21, Figure 4A 、 4B The partition plate 3 is similarly provided with a recessed portion that is wider than the convex portion or recessed portion 271 to 274 , and only one end surface of the protrusion 52 abuts against one end surface of the convex portion or the wide recessed portion.

[0072] The protrusions 261 and 262 of the frame 21 are interposed between the protrusions 331 and 332 of the first separator 31 and the protrusions 351 and 352 of the second separator 32. Furthermore, because the recesses 273 and 274 of the frame 21 are narrow, portions of the frame 21 other than the recesses 273 and 274 are interposed between the recesses 341 and 342 of the first separator 31 and the recesses 361 and 362 of the second separator 32. This ensures good insulation between the separators.

[0073] Although not shown in the figure, in this embodiment, the UEA 2 is longer in both the vertical and horizontal directions than the partitions 3. Therefore, when viewed in the stacking direction, the partitions are entirely covered by the UEA 2. Consequently, the upper and lower ends of the frame 21 are positioned above and below those of the partitions 3, and the left and right ends of the frame 21 are positioned to the left and right of those of the partitions 3. This ensures reliable insulation between the partitions.

[0074] A method of assembling the fuel cell stack 100 of this embodiment will be described. Figures 5A to 5E 1 is a diagram showing an example of the assembly steps of the fuel cell stack 100. When assembling the fuel cell stack 100, the guide member 50 is manufactured in advance by extrusion molding or the like, and the guide member 50 of a predetermined length is prepared (preparation step). Figure 5A As shown, on the wet side ( Figure 1 The end plate 41 of the end unit 40 (on the front side) is fixed to the housing 30 using bolts (housing mounting step). A recess 41a is provided on the upper surface of the end plate 41 corresponding to the position of the guide member 50.

[0075] Then, if Figure 5B As shown, the guide member 50 is inserted from above the housing 30 along the engagement groove 302 provided on the inner surface of the side wall 300 of the housing 30. The lower end of the guide member 50 is then engaged with the recess 41a on the upper surface of the end plate 41 (guide insertion step). At this time, before or after the guide member 50 is engaged, an extended guide member 55 having the same cross-sectional shape as the guide member 50 is attached to the upper end surface of the guide member 50 (extended guide installation step). For example, a pin is provided protruding from the lower end surface of the extended guide member 55, and a bottomed recess is provided on the upper end surface of the guide member 50. The pin is engaged with the bottomed recess, thereby removably attaching the extended guide member 55 to the guide member 50.

[0076] Next, the wet side insulation plate and terminal plate are inserted into the housing 30 along the extension guide member 55 and the guide member 50, and stacked in sequence. Figure 5CAs shown, a predetermined number of UEAs 2 and separators 3 are housed in the housing 30 from above along the extension guide member 55 and the guide member 50 and stacked (stacking step).

[0077] In this case, the end faces 50a and 50b of the protrusion 52 of the guide member 50 abut against the end faces 331a, 332a, 351a, and 352a of the protrusions 331, 332, 351, and 352 of the separator 3, and the end faces 50a and 50b of the protrusion 52 of the guide member 50 abut against the end faces 341a, 342b, 361b, and 362a of the recesses 341, 342, 361, and 362 of the separator 3, thereby positioning the separator 3 relative to the outer casing 30 and stacking the separator 3 within the outer casing 30. Furthermore, the protrusion 52 of the guide member 50 fits into the recesses 271 to 274 of the UEA 2, thereby positioning the UEA 2 relative to the outer casing 30 and stacking the separator 3 within the outer casing 30. Thus, the battery stack 10 can be constructed with the UEA 2 and separator 3 positioned with high precision.

[0078] In particular, one of the pair of end faces 50a, 50b of the protrusion 52 of the guide member 50 abuts against the protrusions 331, 332, 351, 352 and recesses 341, 342, 361, 362 of the separator 3. Consequently, frictional resistance is reduced when the separator 3 is lowered along the guide member 50, making it easier to stack the separators 3. Alternatively, a single UEA 2 and a single separator 3 (e.g., the second separator 32) can be pre-bonded to form a single set of unit cells, and a predetermined number of these units can be lowered along the extended guide member 55 and guide member 50 within the housing 30 to form the battery stack 10.

[0079] Next, the dry side ( Figure 1 The terminal plate and the insulating plate on the rear side of the terminal plate are lowered along the extended guide member 55, and after being stacked in sequence, as shown in FIG. Figure 5D As shown, the dry-side end plate 41 is lowered along the extended guide member 55. More specifically, a through hole 41b is opened in the dry-side end plate 41 at a position corresponding to the guide member 50, and the extended guide member 55 is passed through the through hole 41b of the end plate 41, while the end plate 41 is placed on top of the battery stack 10 (strictly speaking, the insulating plate) (the final stacking process). After that, a press machine (not shown) is used to apply pressure from above the end plate 41, and while the height of the dry-side end plate 41 is maintained at a predetermined height, the dry-side end plate 41 is fixed to the housing 30 using bolts (fixing process). In this state, the extended guide member 55 protrudes upward from the dry-side end plate 41.

[0080] Then, if Figure 5EAs shown, the extended guide member 55 is removed from the guide member 50 via the through-hole 41b (extraction step). Finally, the through-hole 41b of the end plate 41 is covered with a cover (not shown) using a sealing material to seal the through-hole 41b (sealing step). The cover is fastened to the end plate 41 using bolts, for example. The above steps complete the assembly of the fuel cell stack 100.

[0081] The present embodiment can achieve the following effects.

[0082] (1) The fuel cell stack 100 comprises: a cell stack 10, which is formed by stacking a power generation cell 1 having a UEA 2 including an electrolyte membrane 23, an anode electrode 24, and a cathode electrode 25, and a separator 3; a housing 30, which surrounds the cell stack 10; a guide member 50, which protrudes from the inner wall of the housing 30 toward the cell stack 10 and extends along the stacking direction of the cell stack 10; and positioning portions PT11 to PT14, PT21 to PT24, PT31 to PT34, which are provided at the edge portions (upper side 101, lower side 102, left side 103, and right side 104) of the power generation cell 1 corresponding to the guide member 50, and position the power generation cell 1 relative to the housing 30 ( Figures 1 to 4B The positioning parts PT21, PT22, PT31, and PT32 have convex parts (first convex parts) 331, 351 and convex parts (second convex parts) 332, 352 ( respectively) protruding from the upper side surface 101 and the lower side surface 102 of the power generation cell 1 facing the inner wall of the housing 30 toward the inner wall. Figure 4A 、 Figure 4B The convex portions 331, 351 and the convex portions 332, 352 respectively have end surfaces 331a, 351a extending substantially perpendicularly from the upper side surface 101 and end surfaces 332a, 352a extending substantially perpendicularly from the lower side surface 102 ( Figure 4A 、 Figure 4B The guide member 50 includes: an upper guide member 50, which is provided on the right side of the protrusion 331 and on the left side of the protrusion 351, and has end faces 50a and 50b that abut against the end faces 331a and 351a; and a lower guide member 50, which is provided on the left side of the protrusion 332 and on the right side of the protrusion 352, and has end faces 50a and 50b that abut against the end faces 332a and 352a. Figure 4A 、 Figure 4B ).

[0083] With this structure, only one of the left-right end faces 50a, 50b of the protrusion 52 of the guide member 50 contacts the end faces 331a, 332a, 351a, 352a of the convex portions 331, 332, 351, 352 of the power generation cells 1 (separator 3). Consequently, frictional resistance between the power generation cells 1 and the guide member 50 is reduced when the power generation cells 1 are stacked. Consequently, there is no need to coat the guide member 50, making it easy to stack the power generation cells 1 and enabling the fuel cell stack 100 to be constructed at a low cost. Furthermore, the end faces 331a, 332a and end faces 351a, 352a of the upper convex portions 331, 351 and the lower convex portions 332, 352 of the power generation cells 1, respectively, contact the guide member 50 on different left-right directions (sides). Consequently, the power generation cells 1 can be stacked while being positioned within the casing.

[0084] (2) The convex portions 331, 351 and the convex portions 332, 352 are symmetrically arranged with respect to the center point P located in the center of the power generation cell 1 when the power generation cell 1 is viewed from the stacking direction ( Figure 4A 、 Figure 4B Thus, the positioning portions PT21, PT22, PT31, and PT32 are symmetrically provided on the upper side surface 101 and the lower side surface 102 of the power generation cell 1, so that the power generation cell 1 can be well positioned.

[0085] (3) The housing 30 has a plurality of inner wall surfaces facing the upper side surface 101, the lower side surface 102, the left side surface 103, and the right side surface 104 of the power generation cell 1 ( Figure 4A 4B). Guide members 50 are provided on multiple inner wall surfaces, and positioning portions PT11 to PT14, PT21 to PT24, and PT31 to PT34 are provided on upper side 101, lower side 102, left side 103, and right side 104 of power generation cell 1, respectively. This allows for highly accurate positioning of power generation cell 1 in both the horizontal and vertical directions.

[0086] (4) The partition 3 includes a first partition 31 disposed facing the front surface 2a (first surface) of the UEA 2 and a second partition 32 disposed facing the rear surface 2b (second surface) of the UEA 2. Figure 1 The convex portion (first convex portion) 331 and the convex portion (second convex portion) 332 of the first partition plate 31 are provided so as to be located on the left side (first direction side) of the upper guide member 50 and on the right side (second direction side) of the lower guide member 50, respectively ( Figure 4A The convex portion (first convex portion) 351 and the convex portion (second convex portion) 352 of the second partition plate 32 are provided so as to be located on the right side (second direction side) of the upper guide member 50 and on the left side (first direction side) of the lower guide member 50, respectively ( Figure 4BThus, the guide member 50 is sandwiched between the convex portions 331 , 332 of the first separator 31 and the convex portions 351 , 352 of the second separator 32 , so that the pair of separators 31 , 32 can be firmly positioned and held by the guide member 50 .

[0087] (5) The power generation cell 1 has four sides (a first side, a second side, a third side, and a fourth side) that constitute the edge and are located on opposite sides of each other, namely, the upper side surface 101 and the lower side surface 102 on the opposite side of the upper side surface 101, the left side surface 103 and the right side surface 104 on the opposite side of the left side surface 103 ( Figure 4A 、 Figure 4B ). The convex parts (first convex parts) 331, 351 and the convex parts (second convex parts) 332, 352 are respectively provided on the upper side surface 101 and the lower side surface 102 ( Figure 4A 、 Figure 4B Thus, by providing the protrusions 331 and 351 and the protrusions 332 and 352 on the upper side surface 101 and the lower side surface 102 on opposite sides, the power generation cell 1 can be well positioned in the left-right direction.

[0088] (6) In the power generation cell 1, near the left side 103 and the right side 104, through holes 211 to 216 and 311 to 316 for the flow of gas and cooling medium are provided. Figure 3 、 Figure 4A 、 Figure 4B The positioning parts PT23, PT24, PT33, and PT34 have recesses (first recesses) 341 and 361 and recesses (second recesses) 342 and 362 ( Figure 4A 、 Figure 4B The guide member 50 further includes: a left guide member 50 inserted into the inner side of the recesses 341 and 361, having end faces 50a and 50b that abut against the upper end face 341a of the recess 341 and the lower end face 361b of the recess 361; and a right guide member 50 inserted into the inner side of the recesses 342 and 362, having end faces 50a and 50b that abut against the lower end face 342b of the recess 342 and the upper end face 362a of the recess 362. Figure 4A 、 Figure 4B Thus, by providing recessed portions 341, 361 and recessed portions 342, 362 on the left side 103 and right side 104 on opposite sides, the power generation cell 1 can be well positioned in the vertical direction. By providing recessed portions 341, 361, 342, 362 as positioning portions PT23, PT24, PT33, PT34 on the left side 103 and right side 104 instead of protruding portions, the power generation cell 1 can be prevented from becoming larger in the horizontal direction.

[0089] (7) The recesses 341, 361 and the recesses 342, 362 are symmetrically arranged with respect to the center point P located at the center of the power generation cell 1 when the power generation cell 1 is viewed from the stacking direction. Figure 4A , 4B). Thus, the positioning parts PT23, PT24, PT33, and PT34 are symmetrically provided on the left side 103 and the right side 104 of the power generation cell 1, so that the power generation cell 1 can be well positioned.

[0090] (8) The UEA 2 includes an MEA 20 composed of an electrolyte membrane 23, an anode electrode 24, and a cathode electrode 25, and a frame 21 having an opening 21a for arranging the MEA 20. Figure 3 ). The protrusions 331, 332, 351, 352 are provided on the upper side 101 and the lower side 102 of the partition 3 ( Figure 4A 、 Figure 4B The frame 21 has recesses 271 to 274 on the upper side 101 , the lower side 102 , the left side 103 , and the right side 104 , into which the guide member 50 engages. Figure 3 ). This allows the UEA 2 to be well positioned relative to the housing 30, thereby forming the battery stack 10. The frame 21, which serves as a frame member, has lower rigidity than the separator 3 and is easily deformed, making it easier for the guide member 50 to engage with the recesses 271 to 274 when stacking the power generation cells 1.

[0091] (9) The size of the frame 21 in a plane perpendicular to the stacking direction (lateral length and vertical length) is larger than the size of the partition 3 (lateral length and vertical length). Thus, the frame 21 is interposed between the protrusions 331, 332 of the first partition 31 and the protrusions 351, 352 of the second partition 32, thereby ensuring sufficient insulation between the first partition 31 and the second partition 32.

[0092] The above-mentioned embodiment can be modified in various ways. Several modified examples are described below. In the above-mentioned embodiment, the battery stack 10 is surrounded by a shell 30 having a substantially rectangular shape, but the structure of the shell is not limited to the above. In the above-mentioned embodiment, as a guide portion protruding from the inner wall of the shell 30 toward the battery stack 10, a guide member 50 that is a component separate from the shell 30 is provided, but a guide portion may also be formed on the inner wall of the shell 30. In the above-mentioned embodiment, the first protrusions 331, 351 and the second protrusions 332, 352 are provided on the upper side 101 (first edge) and the lower side 102 (second edge) of the power generation cell 1, but these protrusions may also be provided on the left side 103 and the right side 104.

[0093] In the above embodiment, the end faces 50a, 50b (first abutting faces) of the upper guide member 50 (first guide portion) abut against the end faces 331a, 351a (first end faces) of the upper convex portions 331, 351 of the power generation cell 1, and the end faces 50a, 50b (second abutting faces) of the lower guide member 50 (second guide portion) abut against the end faces 332a, 352a (second end faces) of the lower convex portions 332, 352 of the power generation cell 1. Furthermore, the end faces 50a and 50b (third abutting surface) of the left guide member 50 (third guide portion) abut against the end faces 341a and 361b (third end face) of the left recesses 341 and 361 (first recesses) of the power generation cell 1, and the end faces 50a and 50b (fourth abutting surface) of the right guide member 50 (fourth guide portion) abut against the end faces 342b and 362a (fourth end face) of the right recesses 342 and 362 (second recesses) of the power generation cell 1. Furthermore, the first and second end faces are positioned on one side (the first direction side) and the other side (the second direction side) of the convex portions 331 and 351 and convex portions 332 and 352 in the left-right direction, while the third and fourth end faces are positioned on one side (the third direction side) and the other side (the fourth direction side) of the top-bottom directions of the concave portions 341 and 361 and concave portions 342 and 362. However, the configuration of the power generation cell may be any configuration as long as the first and second convex portions are provided on at least the first edge and the second edge opposite thereto, and the first and second convex portions have first and second end faces facing oppositely. The recesses 341, 361 and 342, 362 on the third and fourth side surfaces may also be omitted. Similarly to the first and second side surfaces, the third and fourth side surfaces may also have convex portions.

[0094] One or more of the above-described embodiments and modifications may be arbitrarily combined, and modifications may be combined with each other.

[0095] According to the present invention, there is no need to provide a coating on the guide member, and the power generation cells can be positioned and stacked simultaneously, so that a fuel cell stack can be constructed at a low cost.

[0096] The present invention has been described above with reference to preferred embodiments. However, it should be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the claims.

Claims

1. A fuel cell stack, characterized in that: have: A battery stack (10) is constructed by stacking a power generation cell (1) having a membrane electrode structure (2) including an electrolyte membrane (23) and electrodes (24, 25) and a separator (3); a housing (30) surrounding the battery stack (10); a guide portion (50) protruding from the inner wall of the housing (30) toward the battery stack (10) and extending along the stacking direction of the battery stack (10); and A positioning portion is provided at the edge of the power generation cell (1) corresponding to the guide portion (50) and positions the power generation cell (1) relative to the housing (30). The positioning portion has a convex portion protruding from the edge of the power generation cell (1) toward the inner wall. The convex portion includes a first convex portion (331, 351) and a second convex portion (332, 352) respectively projecting toward the inner wall from a first edge portion (101) of the power generation cell (1) facing the inner wall and a second edge portion (102) on the opposite side of the first edge portion (101). The first convex portion (331, 351) and the second convex portion (332, 352) respectively have a first end surface (331a, 351a) extending substantially perpendicularly from the first edge portion (101) and a second end surface (332a, 352a) extending substantially perpendicularly from the second edge portion (102). When mutually opposite directions in a plane perpendicular to the stacking direction are defined as a first direction and a second direction, the guide portion (50) includes: a first guide portion provided on either side of the first direction or the second direction of the first convex portion (331, 351) and having a first abutting surface abutting against the first end surface (331a, 351a); and A second guide portion is provided on the other side of the second convex portion (332, 352) in the first direction and the second direction, and has a second contact surface that contacts the second end surface (332a, 352a).

2. The fuel cell stack according to claim 1, wherein: The first convex portion (331, 351) and the second convex portion (332, 352) are symmetrically arranged with reference to a center point located in the center of the power generation cell (1) when the power generation cell (1) is viewed from the stacking direction.

3. The fuel cell stack according to claim 1, wherein: The housing (30) has a plurality of inner wall surfaces facing the plurality of edge portions (101 to 104) of the power generation cell (1). The guide portions (50) are respectively arranged on the plurality of inner wall surfaces, and the positioning portions are respectively arranged on the plurality of edge portions (101 to 104).

4. The fuel cell stack according to any one of claims 1 to 3, characterized in that The separator (3) includes a first separator (31) arranged facing a first surface (2a) of the membrane electrode structure (2) and a second separator (32) arranged facing a second surface (2b) of the membrane electrode structure (2) opposite to the first surface (2a). The first convex portion (331) and the second convex portion (332) of the first partition plate (31) are arranged to be located on the first direction side of the first guide portion and the second direction side of the second guide portion, respectively. The first convex portion (351) and the second convex portion (352) of the second partition plate (32) are arranged to be located on the second direction side of the first guide portion and the first direction side of the second guide portion, respectively.

5. The fuel cell stack according to claim 1, wherein: The power generation cell (1) comprises a first side (101) constituting the edge portion, a second side (102) on the opposite side of the first side (101), a third side (103), and a fourth side (104) on the opposite side of the third side (103), The first convex portion (331, 351) and the second convex portion (332, 352) are respectively arranged on the first side (101) and the second side (102).

6. The fuel cell stack according to claim 5, characterized in that In the power generation cell (1), through holes (211-216, 311-316) for allowing gas and cooling medium to flow are provided near the third side (103) and the fourth side (104). The positioning portion comprises a first recess (341, 361) and a second recess (342, 362) respectively arranged on the third side (103) and the fourth side (104). When directions opposite to each other in a plane perpendicular to the stacking direction and perpendicular to the first direction and the second direction are defined as a third direction and a fourth direction, the guide portion (50) further includes: a third guide portion inserted into the inner side of the first recess (341, 361) and having a third abutting surface abutting against a third end surface (341a, 361b) of the first recess (341, 361) in either the third direction or the fourth direction; and The fourth guide portion is inserted into the inner side of the second recess (342, 362) and has a fourth abutting surface abutting against a fourth end surface (342b, 362a) on either the other side of the third direction and the fourth direction of the second recess (342, 362).

7. The fuel cell stack according to claim 6, characterized in that The first recess (341, 361) and the second recess (342, 362) are symmetrically arranged with reference to a center point located in the center of the power generation cell (1) when the power generation cell (1) is viewed from the stacking direction.

8. The fuel cell stack according to claim 1, wherein: The membrane electrode structure (2) includes a membrane electrode assembly (20) composed of the electrolyte membrane (23) and the electrodes (24, 25), and a frame member (21) having an opening for arranging the membrane electrode assembly (20). The protrusion is provided at the edge of the partition (3), The frame member (20) has recessed portions (271 to 274) at its edge for engagement with the guide portion (50).

9. The fuel cell stack according to claim 8, characterized in that The size of the frame member (21) in a plane perpendicular to the stacking direction is larger than the size of the partition (3).

10. The fuel cell stack according to claim 1, wherein: The first edge portion (101) and the second edge portion (102) respectively have recessed portions (101a, 101b, 102a, 102b), The first convex portion (331, 351) and the second convex portion (332, 352) are respectively protruded from the bottom surface (SF21, SF31) of the concave portion (101a, 101b) of the first edge portion (101) and the bottom surface (SF22, SF32) of the concave portion (102a, 102b) of the second edge portion (102).

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