JP2009076211A - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably operate a fuel cell stack by suppressing temperature decrease of a unit cell at the end while reducing cost. <P>SOLUTION: The fuel cell stack 50 is equipped with a stack 51 formed by stacking a plurality of cells in which a solid polymer membrane is arranged between an anode and a cathode; a pair of current collectors 53a, 53b coming in contact with cells positioned at both end parts of the stack 51 in order to guide current generated by the cells; a pair of end plates 110a, 110b to which fastening force for fastening the stack 51 is applied; and an insulator 55a arranged between at least one current collector 53a out of the pair of current collectors 53a, 53b, and the end plate 110a and insulating the current collector 53a from the end plate 11a. A heat insulating material 190 fills a space 180 formed between the end plate 110a and the insulator 55a, and a heat insulating material 192 fills a space 182 formed between the current collector 53a and the insulator 55a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel cell stack. More specifically, the present invention relates to a technique for stably operating a fuel cell stack.

  Generally, a polymer electrolyte fuel cell stack is configured as follows. First, a membrane electrode assembly (hereinafter referred to as “MEA”) is constructed by joining an anode to one surface of a solid polymer membrane and a cathode to the other surface. Next, a cell is configured by sandwiching the MEA between an anode side plate provided with a fuel flow path facing the anode of the MEA and a cathode side plate provided with an oxidant flow path facing the cathode of the MEA. Further, a stacked body is formed by stacking a plurality of cooling plates with the cooling plates interposed between the cells, and an end plate is attached to both ends of the stacked body and tightened to constitute a polymer electrolyte fuel cell stack.

  In the polymer electrolyte fuel cell stack, fuel gas such as reformed gas is circulated through the anode side plate, and oxidant gas such as air is circulated through the cathode side plate to cause an electrochemical reaction through the electrolyte membrane. To generate DC power. Since the electrochemical reaction is an exothermic reaction, the normal operating temperature of the polymer electrolyte fuel cell stack (for example, about 70 to 80 [° C.]) is obtained by circulating cooling water through the cooling plate and cooling each cell. Is maintained.

  In the polymer electrolyte fuel cell stack, the cells at both ends adjacent to the end plate are easily affected by outside air. For this reason, the temperature of the cells at both ends tends to be lower than the cells at other portions. When the temperature of the cell decreases, the water vapor in the reaction gas flowing through the flow path of the anode side plate or the cathode side plate may condense in the flow path, and the condensed water formed by condensing the water vapor is the flow of the reaction gas. This causes a decrease in battery performance.

In view of such a current situation, a technology for suppressing a temperature drop of cells at both ends in a polymer electrolyte fuel cell stack is desired. In Patent Document 1, a flow path for flowing cooling water is provided to the end plates at both ends, the temperature is raised to a temperature close to the operating temperature, and the cooling water discharged after power generation is supplied to the flow path provided on the entire end plate. A technique for heating and heating the cells at both ends is disclosed. Patent Document 2 discloses a technique for suppressing a temperature drop of cells at both ends.
JP 2001-68141 A JP 2002-184449 A

  As described in Patent Document 1 and Patent Document 2, it is a factor of an increase in manufacturing cost that the end plate or the conductive plate has a special structure, or that a part dedicated to heat insulation or heating is installed in the vicinity of the end plate.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a technique for stably operating the fuel cell stack while suppressing the temperature drop of the end unit cell while reducing the cost. .

  One embodiment of the present invention is a fuel cell stack. The fuel cell stack includes a stacked body in which a plurality of unit cells each provided with an electrolyte membrane between a fuel electrode and an oxidant electrode are stacked, and both ends of the stacked body in order to guide the current generated by the unit cell to the outside. A pair of current collectors that are in contact with the single cells located in the section, a pair of end plates that are subjected to a tightening force for tightening the stacked body, and at least one of the pair of current collectors between the current collector and the end plate And an insulator that insulates between the current collector and the end plate, and the insulator is provided on at least one of a side facing the end plate and a side facing the current collector It has a recessed part, and the recessed part is filled with the heat insulation member, It is characterized by the above-mentioned.

  According to this aspect, due to an inexpensive structure, heat is hardly transmitted from the current collector to the end plate, and heat can be prevented from escaping to the outside via the end plate or the insulator. Therefore, it is possible to suppress the temperature drop of the cell located at the end of the stacked body with which the current collector is in contact, and to operate the fuel cell stack stably.

  In the above aspect, the recess may be provided on both the side facing the end plate and the side facing the current collector.

  Moreover, when an insulator has a recessed part in the side which faces an end plate, the said recessed part may be divided | segmented into a some division, and the heat insulation member may be filled into each division. In this case, a communication groove that connects adjacent partitions to a partition member that partitions the adjacent partitions may be formed, and the communication groove may be filled with a heat insulating member. Moreover, the support part which supports an end plate may be provided in the recessed part provided in the side which faces an end plate.

  Moreover, when an insulator has a recessed part in the side which faces a collector, the said recessed part may be divided | segmented into a some division, and the heat insulation member may be filled into each division. A communication groove that allows communication between the partitions adjacent to the partition member that partitions the adjacent partitions may be formed, and the heat insulating member may be filled in the communication groove.

Moreover, the heat insulating member has rigidity, and the heat insulating member provided on the side facing the end plate may also serve as a structure that supports the end plate. The heat insulating member may have rigidity, and the heat insulating member provided on the side facing the current collector may also serve as a structure that supports the current collector.
In any of the above embodiments, the heat insulating member may be a foam. The heat insulating member may be an independent foam.

  A combination of the above-described elements as appropriate can also be included in the scope of the invention for which patent protection is sought by this patent application.

  According to the present invention, it is possible to stably operate the fuel cell stack while suppressing the temperature reduction of the cell at the end while reducing the cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, an example of a fuel cell system that can suitably use the fuel cell stack according to the present embodiment will be described.

(Embodiment 1)
FIG. 1 is a schematic diagram showing the overall configuration of a fuel cell system 10 according to the first embodiment. Note that the schematic diagram of FIG. 1 is a diagram schematically showing mainly the functions and connections of each component, and does not limit the positional relationship or arrangement of each component.

  The fuel cell system 10 includes a power supply unit 20. The power supply unit 20 includes a reforming device 40, a fuel cell stack 50, a fuel wet heat exchanger 60, an oxidant wet heat exchanger 70, a converter 90, an inverter 92, and a control device 100. The fuel moist heat exchanger 60 and the oxidant moist heat exchanger 70 of the present embodiment humidify the gas to be humidified to a predetermined humidity by bubbling the gas to be humidified using the water stored in the tank. can do.

  The reformer 40 is supplied with clean water that has been subjected to water treatment by the water treatment device 42 as reforming water. The water treatment device 42 treats water from the clean water using a reverse osmosis membrane and an ion exchange resin. The water subjected to the water treatment by the water treatment device 42 is used for steam reforming of the reformer included in the reforming device 40.

  The battery off-gas, which is the reformed gas that is discharged unreacted in the fuel cell stack 50, is sent to the reformer 40 via the gas-liquid separator 44. In the gas-liquid separator 44, only the gas component of the battery off gas is taken out and sent to the reformer 40, where it is used as fuel for the burner. The gas-liquid separator 44 also has a heat exchange function that allows the battery off gas and the reforming water to exchange heat, and the reforming water is heated by the heat of the battery off gas.

  The DC power generated in the fuel cell stack 50 is converted into DC power having a predetermined voltage (for example, 24V) by the converter 90, and then converted to AC power (for example, 100V) by the inverter 92. The AC power converted by the inverter 92 is output to the system 94. Further, the DC power of a predetermined voltage converted by the converter 90 is used as a power source for the control device 100 or the like.

  The control device 100 controls the amount of power generated by the fuel cell stack 50 by adjusting the amount of fuel supplied from the reformer 40 and the amount of air supplied from the outside. In addition, the control device 100 controls the amount of cooling water by adjusting the opening of a control valve provided in the piping for cooling water and the circulation pump. Further, the control device 100 transmits and receives electrical signals to and from the converter 90 and the inverter 92 and controls these various devices. The control device 100 can perform infrared communication with the remote controller 96. The user can set the operation of the fuel cell system 10 using the remote controller 96.

(Fuel cell stack)
Next, the fuel cell stack 50 will be described in detail. FIG. 2 is a perspective view showing an overview of the fuel cell stack 50. FIG. 3 is a side view of the fuel cell stack 50 of FIG. 2 as viewed from the A1 direction. FIG. 4 is a side view of the fuel cell stack 50 of FIG. 2 as viewed from the A2 direction. FIG. 5 is a side view of the fuel cell stack 50 of FIG. 2 as viewed from the A3 direction.

  The fuel cell stack 50 includes a stacked body 51 in which a plurality of cells are stacked, and a pair of current collectors 53a and 53b (hereinafter referred to as current collectors 53 as appropriate) provided with connection terminals 80 for electrical connection to the outside. And a pair of end plates 110a and 110b (hereinafter referred to as end plate 110 as appropriate), and between the current collector 53 and the end plate 110 to insulate the current collector 53 and the end plate 110 from each other. Insulators 55a and 55b (hereinafter referred to as insulator 55 as appropriate).

  The laminated body 51 is formed by laminating a plurality of cells each provided with a solid polymer film 52 as an electrolyte film between an anode 54 as a fuel electrode and a cathode 56 as an oxidant electrode shown in FIG. The current collectors 53 are in contact with the cells located at both ends of the stacked body 51 in order to guide the current generated by the cells to the outside. The end plate 110 is fastened by a fastening mechanism so that a fastening force for fastening the laminated body 51 is applied to both ends of the laminated body 51 via the current collector 53 and the insulator 55.

  The fuel cell stack 50 is fastened by a fastening mechanism including a plurality of spring members 108 having a W-shaped cross section for applying a compression load in the cell stacking direction to the bolts 104, nuts 106, and the stacked body 51.

  The fuel cell stack 50 generates power using hydrogen gas as a fuel and air as an oxidant. Specifically, in each cell (unit cell) constituting the fuel cell stack 50, an electrode reaction represented by the formula (1) occurs at the anode 54 in contact with one surface of the solid polymer film 52. On the other hand, at the cathode 56 in contact with one surface of the solid polymer film 52, an electrode reaction represented by the formula (2) occurs. Each cell is cooled by cooling water flowing through the cooling water plate 58 and adjusted to an appropriate temperature of about 70 to 80 ° C.

(Insulator)
Further, the insulator 55a will be described. FIG. 6 is a front view of the insulator 55a according to the present embodiment as viewed from the side where the current collector is disposed. 7 is a cross-sectional view taken along the line BB ′ of FIG. FIG. 8 is a side view of the insulator 55a according to the present embodiment. FIG. 9 is a rear view of the insulator 55a according to the present embodiment as viewed from the side in contact with the end plate 110a. FIG. 10 is a perspective view of the insulator 55a according to the present embodiment as viewed from the side in contact with the end plate 110a. FIG. 11 is a perspective view of a main part of the insulator 55a according to the present embodiment as viewed from the side in contact with the end plate 110a. FIG. 12 is a schematic diagram showing that a space formed between the insulator 55 and the current collector plate according to the present embodiment is filled with a heat insulating member.

  As shown in FIG. 4 and FIG. 6, the insulator 55 a includes an oxidant inlet 120 through which air flows, a cooling water air vent 122 for venting cooling water, A fuel inlet 124 through which hydrogen gas flows in and a cooling water outlet 126 through which cooling water is discharged are formed. The insulator 55a and the end plate 110a are overlapped and tightened so that each flow path formed in the insulator 55a protrudes from a through hole provided in the end plate 110a.

  Further, as shown in FIG. 5, the insulator 55b has an oxidant drain outlet 128 that discharges excess components contained in air and a cooling water inlet 130 into which cooling water flows, on a surface facing the end plate 110b. A fuel drain outlet 132 for discharging excess components contained in the hydrogen gas, a fuel outlet 134 for discharging unreacted hydrogen gas in the cell, and an oxidant exhaust for discharging unreacted air in the cell. An outlet 136 is formed. The insulator 55b and the end plate 110b are overlapped and tightened so that each flow path formed in the insulator 55b protrudes from a through hole provided in the end plate 110b.

  As shown in FIG. 6 and FIG. 10, the insulator 55 a intersects with the longitudinal ribs 240 provided in the longitudinal direction of the insulator 55 a on the surface where the insulator 55 a is in contact with the end plate 110 a. A plurality of horizontal ribs 242 are provided. The vertical ribs 240 and the horizontal ribs 242 function as pressed parts that are pressed against the end plate 110a. Moreover, it has the recessed part 244 used as the space closed when the end plate 110a pressed the vertical rib 240 and the horizontal rib 242. FIG.

  The lateral rib 242 is provided with a communication groove 250 that communicates with a recess 244 adjacent in the longitudinal direction of the insulator 55a. The longitudinal rib 240 forming the row of recesses 244a aligned in the short direction of the insulator 55a is provided with a communication groove 260 that communicates with the recess 244a adjacent to the insulator 55a in the short direction. Further, as shown in FIG. 6, a gate 270 is provided at the center of the side surface of the insulator 55a. The position where the gate 270 is provided corresponds to the height of the row of recesses 244a, and preferably coincides with the center of the row of recesses 244a in the longitudinal direction of the insulator 55a. In addition, the installation positions of the communication grooves 250 and 260 in the vertical rib 240 and the horizontal rib 242 of each concave portion 244 are not limited to the present embodiment, and can communicate with any concave portion 244 from the gate 270 through an arbitrary path. As long as it is provided.

  The insulator according to the present embodiment is a resin member, and can be easily formed in a shape such as a recess and a rib by integral molding, and the manufacturing cost and material cost of the fuel cell stack can be reduced. . As the resin material, PPS (polyphenylene sulfide) containing glass fiber is preferable. This material is thermally stable, has very few eluents that increase electrical conductivity, and has high steam resistance, so that the fuel cell stack can maintain stable power generation over a long period of time.

  Further, as shown in FIG. 9, a plurality of vertical ribs 140 provided in the longitudinal direction of the insulator 55 a and a plurality of crossing the vertical ribs 140 are provided on the surface of the insulator 55 a on the side where the current collector 53 a is disposed. Horizontal ribs 142 are provided.

  The vertical rib 140 and the horizontal rib 142 formed on the insulator 55a function as a pressing portion that presses the current collector 53a when the stacked body 51 is sandwiched. In addition, a concave portion 144 that is a closed space when the insulator 55 a presses the current collector 53 a is formed as a region surrounded by the vertical rib 140 and the horizontal rib 142.

  The lateral rib 142 is provided with a communication groove 150 that communicates with a recess 144 adjacent in the longitudinal direction of the insulator 55a. In addition, a communication groove 160 that communicates with the recess 144a adjacent in the short direction of the insulator 55a is provided in the vertical rib 140 that forms a row of the recesses 144a aligned in the short direction of the insulator 55a. A gate 170 is provided at the center of the side surface of the insulator 55a. The position where the gate 170 is provided corresponds to the height of the row of recesses 144a, and preferably coincides with the center of the row of recesses 144a in the longitudinal direction of the insulator 55a. In addition, the installation positions of the communication grooves 150 and 160 in the vertical rib 140 and the horizontal rib 142 of each concave portion 144 are not limited to the present embodiment, and can communicate with any concave portion 144 from the gate 170 through an arbitrary path. As long as it is provided.

  Note that the vertical rib 140 and the horizontal rib 142 formed on the insulator 55a have regions 140a and 142a in contact with the current collector 53a than regions 140b and 142b in contact with the stacked body 51 without the current collector 53a. It is recessed. As a result, as shown in FIG. 9, the current collector 53a can be disposed in a region recessed from a region where the insulator 55a does not contact the current collector 53a, so that the fuel cell stack 50 can be made compact. it can.

  When such an insulator 55a is arranged between the end plate 110a and the current collector 53a, as shown in FIG. 12, when the laminated body 51 is sandwiched, the end plate 110 and the insulator 55 are interposed. A space 180 is formed, and a space 182 is formed between the insulator 55 and the current collector 53. In the present embodiment, spaces 180 and 182 are filled with heat insulating members 190 and 192, respectively. As the heat insulating member, a foam, more preferably an independent foam can be used. An independent foam is a foam having innumerable cells independent from each other. Since the closed foam is made of closed cells of the resin, the air flow is blocked and high heat insulation performance is exhibited. The foam has such closed cells and open cells composed of bubbles communicated with each other through pores. As the foam or the independent foam, for example, a resin foam such as a foamed polystyrene resin or a foamed polyethylene resin can be used. The thermal conductivity of the heat insulating member is preferably 0.04 W / m · K or less, and more preferably 0.03 W / m · K or less. According to this, the temperature fall of the cell located in the edge part of the laminated body 51 can be suppressed more reliably.

  In addition, in the state which assembled | attached the fuel cell stack 50, the heat insulation member 190, such as a polystyrene foam resin, is inject | poured from the gate 270, and the resin can be solidified, The space 180 can be filled with the heat insulation member 190. As a result, the heat insulating member 190 is injected from the gate 270 to each recess 244 via the arbitrary communication groove 250, and the heat insulating member 190 is filled in each recess 244 at once. In addition, before assembling the fuel cell stack 50, the heat insulating member 190 may be injected in a state in which the insulator 55a presses the flat plate against the surface in contact with the end plate 110a.

  Similarly, a heat insulating member 192 such as expanded polystyrene resin is injected from the gate 170 in a state where the fuel cell stack 50 is assembled, or in a state where the insulator 55a presses a flat plate against the surface in contact with the current collector 53a. Is solidified, the space 182 can be filled with the heat insulating member 192. As a result, the heat insulating member 192 is injected from the gate 270 to each concave portion 244 via the arbitrary communication groove 250, and the respective heat insulating members 192 are filled in the respective concave portions 244 at once. In addition, before assembling the fuel cell stack 50, the heat insulating member 192 may be injected in a state in which the insulator 55a presses the flat plate against the surface in contact with the current collector 53a.

  As described above, by filling the spaces 180 and 182 with the heat insulating members 190 and 192, respectively, it becomes difficult for heat to be transferred from the current collector 53a to the end plate 110a, and externally through the end plate 110a and the insulator 55a. It is possible to suppress the escape of heat. Therefore, the temperature drop of the cell located at the end of the stacked body 51 with which the current collector 53a is in contact can be suppressed, and the fuel cell stack 50 can be stably operated. In addition, like the insulator 55a according to the present embodiment, the strength of the insulator 55a itself can be improved and the current collector 53a can be pressed uniformly by configuring the pressing portion with a rib. it can. Further, since the heat insulating members 190 and 192 can be made of an inexpensive material, the heat insulating performance at the end of the fuel cell stack 50 can be realized at low cost.

  Further, a plurality of recesses 244 provided in insulator 55a according to the present embodiment are formed by a plurality of intersecting vertical ribs 240 and horizontal ribs 242, and vertical ribs 240 and horizontal ribs 242 press end plate 110a. It becomes a plurality of spaces closed to each other. Therefore, since the plurality of spaces are closed and not in communication with each other, the heat generated by the current collector 53a is not easily transmitted to the adjacent space, and the diffusion of the heat of the cell at the end can be suppressed.

  Similarly, a plurality of recesses 144 provided in insulator 55a according to the present embodiment are formed by a plurality of intersecting vertical ribs 140 and horizontal ribs 142, and vertical ribs 140 and horizontal ribs 142 are formed as current collector 53a. When the is pressed, a plurality of spaces are closed. Therefore, since the plurality of spaces are closed and not in communication with each other, the heat generated by the current collector 53a is not easily transmitted to the adjacent space, and the diffusion of the heat of the cell at the end can be suppressed.

  The insulator 55a is provided with a cooling water discharge port 126 as a flow path through which a fluid for making the temperature of the stacked body 51 appropriate.

  Note that the structure of the surface of the insulator 55b on the side in contact with the end plate 110b is formed in the same manner as the structure of the surface of the insulator 55a on the side in contact with the end plate 110a. The structure of the surface of the insulator 55b on the side in contact with the current collector 53b is formed in the same manner as the structure of the surface of the insulator 55b on the side in contact with the current collector 53b.

(Heat insulation effect of end cell by heat insulation member)
FIG. 13 is a graph showing the heat retention effect of the end cells in the fuel cell stack of the above embodiment. Specifically, each of the configurations of the fuel cell stack according to the above-described embodiment (the configuration in which the insulator has the heat insulating member in the recess of the insulator) and the configuration in which the heat insulating member is removed from the fuel cell stack are collected. Simulation calculations were performed for the temperature near the body and the temperature at the outermost part of the end plate (the part in contact with air). In the simulation calculation, conditions were set such that the outside air temperature was room temperature (25 ° C.) and there was a certain amount of heat generation (5 W) from the end cells. As a result, as shown in FIG. 13, the configuration in which the heat insulating member is provided in the concave portion of the insulator has a higher temperature near the current collector and the end plate than the configuration in which the heat insulating member is not provided in the concave portion of the insulator. It can be seen that there is a large difference from the external temperature. That is, it was confirmed that by providing a heat insulating member in the recess of the insulator, the temperature drop of the end cell of the fuel cell stack is further suppressed, and the end cell of the fuel cell stack is held at a higher temperature.

  Here, a modified example of the communication groove provided in the insulator 55a according to the present embodiment will be described.

(Modification 1)
FIG. 14 is a perspective view of an essential part of the insulator 55a according to Modification 1 as viewed from the side in contact with the end plate 110a. In the first modification, a communication groove 250a is provided at a portion where the vertical rib 240 and the horizontal rib 242 intersect. Thereby, since the four recessed parts 244 can be connected through the communication groove 250a, when injecting a heat insulation member, the flow of a heat insulation member can be made easy. In addition, since the number of communication grooves can be reduced as compared with the first embodiment, it is possible to further easily mold the insulator 55a. A similar communication groove can also be provided in the structure of the surface of the insulator 55a on the side in contact with the current collector 53a.

(Modification 2)
FIG. 15 is a perspective view of a main part of the insulator 55a according to the second modification viewed from the side in contact with the end plate 110a. In the second modification, a communication hole 252 that penetrates the side surfaces of the vertical rib 240 and the horizontal rib 242 is provided instead of the communication groove. The shape of the communication hole 252 may be circular or rectangular. A similar communication hole can be provided in the structure of the surface of the insulator 55a on the side in contact with the current collector 53a.

(Modification 3)
FIG. 16 is a perspective view of a main part of an insulator 55a according to Modification 3 as viewed from the side in contact with the end plate 110a. In the third modification, a communication hole 254 that communicates the recess 244 and the recess 144 is provided. Thereby, by injecting the heat insulating member from the gate 270, not only the concave portion 244 but also the concave portion 144 can be filled at once, and the manufacturing process can be simplified. Further, since the gate 170 is unnecessary, the structure of the insulator 55a can be further simplified.

(Embodiment 2)
The basic configuration of the fuel cell stack of the present embodiment is the same as that of the first embodiment. Hereinafter, a configuration of the present embodiment that is different from the first embodiment will be described. FIG. 17 is a main part perspective view of the insulator 55a according to the present embodiment as viewed from the side in contact with the end plate 110a. In the present embodiment, a columnar boss 300 is used instead of the vertical rib and the horizontal rib. The bosses 300 are provided on both surfaces of the insulator 55a at a predetermined interval. By filling the gap between the bosses 300 with the above-described insulating member, it is possible to suppress the temperature drop of the cell located at the end of the fuel cell stack at low cost and stably operate the fuel cell stack. A similar boss can be provided on the structure of the surface of the insulator 55a on the side in contact with the current collector 53a.

(Embodiment 3)
The basic configuration of the fuel cell stack of the present embodiment is the same as that of the first embodiment. Hereinafter, a configuration of the present embodiment that is different from the first embodiment will be described. FIG. 18 is a main part perspective view of the insulator 55a according to the present embodiment as viewed from the side in contact with the end plate 110a. In the present embodiment, the ribs and the bosses are omitted, and are provided on both surfaces of the insulator 55a. As the heat insulating members 190 and 192 used in the present embodiment, a rigid foam or an independent foam is used. Accordingly, the heat insulating members 190 and 192 also serve as structures that support the end plate 110a and the current collector 53a, respectively. Thereby, the insulator 55a can have a simpler structure and can be easily processed.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The form can also be included in the scope of the present invention.

  For example, in the above-described embodiments,

1 is a schematic diagram showing an overall configuration of a fuel cell system according to a first embodiment. It is a perspective view which shows the general view of a fuel cell stack. FIG. 3 is a side view of the fuel cell stack of FIG. 2 when viewed from the A1 direction. FIG. 3 is a side view of the fuel cell stack of FIG. 2 when viewed from the A2 direction. FIG. 3 is a side view when the fuel cell stack of FIG. 2 is viewed from the A3 direction. It is the front view which looked at the insulator which concerns on 1st Embodiment from the side by which a collector is arrange | positioned. FIG. 7 is a B-B ′ sectional view of FIG. 6. It is a side view of the insulator which concerns on 1st Embodiment. It is the rear view which looked at the insulator which concerns on 1st Embodiment from the side which contact | connects an end plate. It is the perspective view which looked at the insulator which concerns on 1st Embodiment from the side which contact | connects an end plate. It is the principal part perspective view which looked at the insulator which concerns on 1st Embodiment from the side which contact | connects an end plate. It is a schematic diagram which shows that the heat insulation member is filled in the space formed between the insulator and current collector plate which concern on 1st Embodiment. It is a graph which shows the heat retention effect of the edge part cell in the fuel cell stack of 1st Embodiment. It is the principal part perspective view which looked at the insulator which concerns on the modification 1 from the side which contact | connects an end plate. It is the principal part perspective view which looked at the insulator which concerns on the modification 2 from the side which contact | connects an end plate. It is the principal part perspective view which looked at the insulator which concerns on the modification 3 from the side which contact | connects an end plate. It is the principal part perspective view which looked at the insulator which concerns on 2nd Embodiment from the side which contact | connects an end plate. It is the principal part perspective view which looked at the insulator which concerns on 3rd Embodiment from the side which contact | connects an end plate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Fuel cell system, 20 Power supply unit, 50 Fuel cell stack, 51 Laminated body, 52 Solid polymer film, 53 Current collector, 54 Anode, 55 Insulator, 56 Cathode, 110 End plate, 140 Vertical rib, 142 Horizontal rib 144 Recess, 240 Vertical rib, 242 Horizontal rib, 244 Recess

Claims (13)

A laminate in which a plurality of single cells each provided with an electrolyte membrane are laminated between a fuel electrode and an oxidant electrode;
A pair of current collectors respectively in contact with the unit cells located at both ends of the laminated body in order to guide the current generated by the unit cells to the outside;
A pair of end plates to which a tightening force for tightening the laminate is applied;
An insulator disposed between at least one of the pair of current collectors and the end plate, and insulating between the current collector and the end plate;
With
The insulator has a recess provided on at least one of the side facing the end plate and the side facing the current collector,
A fuel cell stack, wherein the recess is filled with a heat insulating member.   2. The fuel cell stack according to claim 1, wherein the recess is provided on both the side facing the end plate and the side facing the current collector. 3.   When the said insulator has a recessed part in the side which faces the said end plate, the said recessed part is divided | segmented into several division, The said heat insulation member is filled into each division, The Claim 1 or 2 characterized by the above-mentioned. The fuel cell stack described.   4. The fuel cell stack according to claim 3, wherein a communication groove that communicates between adjacent sections to a partition member that partitions adjacent sections is formed, and the heat insulating member is filled in the communication groove. 5.   3. The fuel cell stack according to claim 1, wherein a support portion that supports the end plate is provided in a concave portion provided on a side facing the end plate. 4.   When the said insulator has a recessed part in the side which faces the said electrical power collector, the said recessed part is divided | segmented into several division, The said heat insulation member is filled with each division, The said heat insulation member is filled. The fuel cell stack described in 1.   7. The fuel cell stack according to claim 6, wherein a communication groove that communicates between adjacent partitions to a partition member that partitions adjacent partitions is formed, and the heat insulating member is filled in the communication groove.   3. The fuel cell stack according to claim 1 or 2, wherein a support portion for supporting the current collector is provided in a concave portion provided on the side facing the current collector.   The concave portion provided on the side facing the end plate is divided into a plurality of sections, each of the sections is filled with the heat insulating member, and the concave section provided on the side facing the current collector is a plurality of sections. The fuel cell stack according to claim 2, wherein the fuel cell stack is divided into two parts.   In the recess provided on the side facing the end plate, a communication groove is formed for communicating adjacent sections to a partition member that partitions the adjacent sections, and the heat insulating member is filled in the communication groove, In the recess provided on the side facing the current collector, a communication groove that connects adjacent sections to a partition member that partitions adjacent sections is formed, and the communication groove is filled with the heat insulating member. The fuel cell stack according to claim 9. The heat insulating member has rigidity;
2. The fuel cell stack according to claim 1, wherein the heat insulating member provided on the side facing the end plate also serves as a structure that supports the end plate. The heat insulating member has rigidity;
The fuel cell stack according to claim 1, wherein the heat insulating member provided on the side facing the current collector also serves as a structure that supports the current collector.   The fuel cell stack according to any one of claims 1 to 12, wherein the heat insulating member is made of a foam.

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