WO2016093604A1

WO2016093604A1 - Polymer electrolyte-type fuel cell, fuel cell stack and end plate

Info

Publication number: WO2016093604A1
Application number: PCT/KR2015/013411
Authority: WO
Inventors: 오병수; 권오정; 조병현; 진성현; 이대근
Original assignee: 전남대학교산학협력단
Priority date: 2014-12-12
Filing date: 2015-12-09
Publication date: 2016-06-16
Also published as: KR101759652B1; KR20160071654A

Abstract

The present invention relates to a fuel cell, a fuel cell stack and an end plate and, more particularly, to a polymer electrolyte-type fuel cell, a fuel cell stack and an end plate, which can ensure gas sealability and reduce contact resistance, without bending or damaging a polymer electrolyte membrane and a separator when the end plate is assembled by being pressed in the stack direction of a fuel cell module, thereby improving the energy efficiency of the fuel cell module.

Description

Polymer electrolyte fuel cells, fuel cell stacks and end plates

The present invention relates to a fuel cell, a fuel cell stack, and an end plate, and more particularly, when the end plate is pressurized and assembled in a stacking direction of a fuel cell module, the polymer electrolyte membrane and the separator are not bent or damaged. The present invention relates to a polymer electrolyte fuel cell, a fuel cell stack, and an end plate capable of reducing contact resistance to improve energy efficiency of a fuel cell module.

A fuel cell is a device that generates electrical energy by electrochemically reacting fuel and an oxidant. This chemical reaction is performed by a catalyst in a catalyst layer, and in general, continuous power generation is possible as long as fuel is continuously supplied.

In addition, fuel cells can be classified into alkali type (AFC), polymer electrolyte type (PEMFC), phosphoric acid type (PAFC), molten carbonate (MCFC), and solid oxide (SOFC) fuel cells according to the type of electrolyte and operating temperature. In addition, polymer electrolyte fuel cells can be classified into hydrogen fuel cells and direct methanol fuel cells (DMFC).

Among these, the polymer electrolyte fuel cell has a form in which a porous anode and a cathode are attached to both sides of the polymer electrolyte membrane, with the electrical oxidation of hydrogen as fuel at the anode and oxygen as an oxidant at the cathode. The electrochemical reduction of occurs to generate electrical energy.

Recently, there is an effort to improve energy yield by effectively stacking polymer electrolyte membranes.

At this time, a separator (separator) is inserted between the polymer electrolyte membranes to supply the reaction gas to each of the polymer electrolyte membranes. When gas tightness between the polymer electrolyte membranes and the separator is not secured, fuel is leaked to the outside to yield energy. The lower the fuel is wasted, the contact resistance is larger, there is a problem that the efficiency of the fuel cell is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a fuel cell, a fuel cell stack, and an end plate capable of improving gas yield by securing gas tightness of a fuel cell module.

In addition, the present invention provides a fuel cell, a fuel cell stack and an end plate that are light in weight and can be mass-produced at a low cost and can easily constitute a fuel cell stack without a separate insulator.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a fuel cell module including a plurality of polymer electrolyte membranes (PEM) and electrode plates for collecting electricity generated in the polymer electrolyte membranes with separators interposed therebetween; And a pair of end plates coupled to both side surfaces of the fuel cell module in a stacking direction, the pair of end plates being fastened to each other so that the distances thereof are varied, and varying the separation distance between the end plates. Provided is a fuel cell capable of controlling the degree of adhesion between an electrolyte membrane and the electrode plate.

In a preferred embodiment, at least one of the end plates of the end plate is formed with a recess in which a portion of the fuel cell module can be seated on the inner surface in contact with the fuel cell module.

In a preferred embodiment, each of the end plates may be provided with a seating groove in which a part of the fuel cell module can be seated inward on one surface of the end plate.

In a preferred embodiment, the end plates are assembled such that the edges of the seating grooves are spaced apart from each other by a predetermined distance, and the side surfaces of the fuel cell module are exposed to the outside, so that the fuel cell module can be cooled by air cooling.

In a preferred embodiment, the end plates may be assembled such that the seating edge edges abut each other.

In a preferred embodiment, it further comprises a heat dissipation plate provided in the seating grooves of the end plates, and capable of dissipating heat generated from the fuel cell module to the outside.

In a preferred embodiment, a channel through which the cooling fluid can move is formed in the heat sink, and cooling fluid inlets and outlets are formed at both ends of the channel to extend outside the end plates to allow the cooling fluid to flow in and out. It is provided.

In a preferred embodiment, a predetermined portion of the end plate is formed with a reactor inlet for supplying an external reactor to the fuel cell module and a reactor for discharging the reactor through the fuel cell module to the outside.

In a preferred embodiment, the inner surface of the seating groove of the end plate penetrates through the reactor inlet and passes through the reactor inlet and the reactor outlet for supplying the reactor to the internal flow path of the fuel cell module. A reactive gas discharge groove for discharging the reactive gas that has passed through the module to the reactive gas outlet is formed.

In a preferred embodiment, an electrode exposure groove is formed in a predetermined portion of the seating groove edge of each end plate to expose the electrode protruding from the fuel cell module to the outside.

In a preferred embodiment, each end plate is further formed with a wire connecting groove is formed on the extension line of the electrode exposure groove and the wire and the bottom surface of the end plate does not interfere with each other when the wire is connected to the electrode.

In a preferred embodiment, each end plate is made of soft plastic.

In a preferred embodiment, the plastic may be a heat insulating plastic.

In addition, the present invention further provides a fuel cell stack in which a plurality of fuel cells are coupled, and electrodes of each fuel cell module are connected in series or in parallel.

In addition, the present invention may further provide only an end plate separately from the fuel cell.

The present invention has the following excellent effects.

First, according to the fuel cell, the fuel cell stack, and the end plate of the present invention, both sides of the fuel cell module can be assembled by pressing the end plate seating grooves. Since it can be in close contact with or without being damaged, it is possible to secure gas tightness and improve energy yield.

In addition, according to the fuel cell, the fuel cell stack, and the end plate of the present invention, since the end plate is made of an insulating plastic material, insulation is not required separately from the electrode plate, and the operating temperature of the fuel cell module is increased to an operating temperature without a separate heater. This is easy and there is an advantage in the fuel cell stack configuration.

1 is a view showing a fuel cell according to a first embodiment of the present invention;

2 is a front view of a fuel cell according to a first embodiment of the present invention;

3 is a side view of a fuel cell according to a first embodiment of the present invention;

4 is a plan view of a fuel cell according to a first embodiment of the present invention;

5 is a bottom view of a fuel cell according to a first embodiment of the present invention;

6 is a cross-sectional view of a fuel cell according to a first embodiment of the present invention;

7 is an exploded perspective view of a fuel cell according to a first embodiment of the present invention;

8 is a view showing an end plate of a fuel cell according to a first embodiment of the present invention;

9 is a view showing a fuel cell stack composed of a fuel cell according to a first embodiment of the present invention;

10 is a side view of the fuel cell stack of FIG. 9;

11 is a plan view of the fuel cell stack of FIG. 9;

12 is a bottom view of the fuel cell stack of FIG. 9;

13 is a view showing a fuel cell according to a second embodiment of the present invention;

14 is a front view of a fuel cell according to a second embodiment of the present invention;

15 is a side view of a fuel cell according to a second embodiment of the present invention;

16 is a plan view of a fuel cell according to a second embodiment of the present invention;

17 is a bottom view of a fuel cell according to a second embodiment of the present invention;

18 is a cross-sectional view of a fuel cell according to a second embodiment of the present invention;

19 is an exploded perspective view of a fuel cell according to a second embodiment of the present invention;

20 is a view showing an end plate of a fuel cell according to a second embodiment of the present invention;

21 is a view showing a fuel cell stack constructed of a fuel cell according to a second embodiment of the present invention;

FIG. 22 is a side view of the fuel cell stack of FIG. 21;

FIG. 23 is a plan view of the fuel cell stack of FIG. 21;

24 is a bottom view of the fuel cell stack of FIG. 21.

[Description of the code]

100,200:

fuel cell

100a, 200a: fuel cell stack

110: fuel cell module 111: separator

112: electrode plate 113: polymer electrolyte membrane

114: gasket 120,121,122: end plate

121a: Seating

groove

121b, 121c: Reactor gas inlet

121d, 121e: Reaction gas outlet 130: End plate connection bar

131: end plate connecting bar seating groove 140: fuel cell connecting bar

141: fuel cell connecting bar seating groove 150: screw

160: electrode connecting rod

The terms used in the present invention were selected as general terms as widely used as possible, but in some cases, the terms arbitrarily selected by the applicant are included. In this case, the meanings described or used in the detailed description of the present invention are considered, rather than simply the names of the terms. The meaning should be grasped.

Hereinafter, with reference to the preferred embodiments shown in the accompanying drawings will be described in detail the technical configuration of the present invention.

However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like numbers refer to like elements throughout the specification.

[First Embodiment]

1 to 6, the fuel cell 100 according to the first embodiment of the present invention includes a fuel cell module 110 and an end plate 120.

The fuel cell module 110 receives the hydrogen as the fuel and the oxygen as the oxidant to produce electrical energy through the electrochemical panel.

However, the reactor body of the fuel cell module 110 is not limited to hydrogen and oxygen. For example, methanol or the like may be used.

Referring to FIG. 7, the fuel cell module 110 includes a separator 111, an electrode plate 112, and a polymer electrolyte membrane 113.

In addition, the separator 111 is stacked between each of the polymer electrolyte membranes 113 and on both outer sides thereof, and supplies hydrogen to one surface of the polymer electrolyte membrane 113 and supplies air, that is, oxygen to the other surface. The polymer electrolyte membrane 113 serves to generate electricity.

In addition, the separator 111 further performs a function of supporting the shapes of the polymer electrolyte membranes 113.

In addition, the separator 111 is divided into three types of separators, and the separator 111b positioned between each of the polymer electrolyte membranes 113 has an oxygen flow path and a hydrogen flow path for discharging oxygen and hydrogen, respectively, and the polymer electrolyte The separator 111c positioned outside the polymer electrolyte membrane at the outermost side of the membrane 113 has only a hydrogen flow path, and the separator 111a positioned outside the polymer electrolyte membrane at the outermost side has only an oxygen flow path.

That is, the separators 111 are membrane separation plates for supplying hydrogen as fuel to one surface of each of the polymer electrolyte membranes 113 and for supplying oxygen to the other surface.

In addition, the electrode plate 112 is a plate for collecting electrical energy generated in the polymer electrolyte membrane 113 and is provided on the outside of the oxygen flow path separator 111a and the outside of the hydrogen flow path separator 111c, respectively.

In addition, among the electrode plates 112, the electrode plate 112a positioned outside the oxygen flow path separator 111a is a cathode electrode plate, and the electrode plate 112b located outside the hydrogen flow path separator 111c. ) Is composed of an anode electrode plate.

In addition, a gasket 114 is inserted between the electrode plate 112 and the separator 111 and between the electrode plate 112 and the end plate 120 to be described below. Can be.

In addition, the electrode plate 112 is provided with protruding electrodes 112ba and 112aa, which are connected to an external wire to output electrical energy.

In addition, the polymer electrolyte membrane 113 is a membrane that produces electrical energy by transferring hydrogen ions and blocking electron movement, and is a polyester sulfone, polyether ketone, polyimide, polyphenylene sulfide-based, sulfonated hydrocarbon-based polymer membrane Can be.

That is, the fuel cell module 110 is a module for producing electrical energy by receiving oxygen and hydrogen, which are reactive bodies.

The end plate 120 is coupled to both side surfaces of the polymer electrolyte membrane 113 of the fuel cell module 110 in the stacking direction, that is, the outer side of the electrode plate 112.

That is, the end plate 120 is composed of a pair of

end plates

121 and 122.

In addition, the

end plates

121 and 122 may be fastened to each other by screws 150, and the pressure applied to the fuel cell module 110 may be adjusted by varying the distance from each other depending on the tightness of the screws.

That is, the

end plates

121 and 122 press and fix the fuel cell module 110 to maintain the shape of the fuel cell module 110 and serve as a case for protecting the fuel cell module 110 from the outside.

Referring to FIG. 8, the at least one end plate 121 of the

end plates

121 and 122 may include a seating groove 121a in which a portion of the side surface of the fuel cell module 110 may be seated inward. Is formed and the shape and size of the seating groove 121a correspond to the shape and size of the electrode plate 112.

That is, a part of the side surface of the fuel cell module 110 may be inserted into the mounting groove 121a.

In addition, the seating grooves 121a may be formed in the

end plates

121 and 122, and the

end plates

121 and 122 may have the same shape.

However, the seating groove 121a may be formed in only one end plate 121, and in this case, the other end plate 122 may have a flat surface in contact with the fuel cell module 110. .

However, when the mounting groove 121a is formed in each of the

end plates

121 and 122 to be pressed and assembled to the fuel cell module 110, the stack structure of the fuel cell module 110 is maintained without being twisted. desirable.

In addition, the height of the mounting grooves 121a of the

end plates

121 and 122 is such that the edge edges 121aa of the mounting grooves 121a of the

end plates

121 and 122 do not meet each other when fastened to the fuel cell module 110. It consists of the height of.

This is to allow air to flow into the fuel cell module 110 through a space between the

end plates

121 and 122 so that the fuel cell module 110 can be cooled by air cooling.

In addition, each of the

end plates

121 and 122 includes a

reactor body inlet

121b and 121c for supplying a reaction gas into the seating groove 121a and a reactor body for discharging the reaction gas from the seating groove 121a to the outside.

Outlets

121d and 121e are formed.

However, the reactant inlet and outlet of only one end plate 121 allows the reaction gas to be introduced only, and the reactant inlet and outlet of the other end plate 122 allows only the reaction gas to be discharged. The location of the inlet and outlet of the reaction gas can be changed according to the designer's request.

In addition, the reactor inlet (121b, 121c) and the reactor outlet (121d, 121e) may be provided with a nozzle 123 that can be connected to the outer tube.

In addition, the inside of the mounting groove 121a of each of the

end plates

121 and 122 penetrates the

reactor inlets

121b and 121c, and contacts the internal flow path of the separator of the fuel cell module 110 to supply the reactor. A reactor body that penetrates the reactor inlet grooves 121ba and 121ca and the

reactor outlet outlets

121d and 121e and discharges the reactor body discharged in contact with the internal flow path of the separator to the

reactor outlet outlets

121d and 121e. Discharge grooves 121da and 121ea may be further formed.

This serves to keep the reactor body airtight and enter and exit the fuel cell module 110.

In addition, an electrode exposed groove 121ab is formed at a predetermined portion of the seating groove edge 121aa of each of the

end plates

121 and 122 to expose the electrodes 112aa and 112ba of the electrode plate 112 to the outside. .

In addition, the wire connecting groove 121ac may be further formed on the cutout extension line of the electrode exposure groove 121ab so as not to interfere with the bottom surface of the end plate when the wire is connected to the electrode 112ba.

Therefore, the electrodes 112aa and 112ba have an advantage of being easily protected from the outside at the inside of the electrode exposure groove 121ab and easily connecting wires.

In addition, after the

end plates

121 and 122 are fastened with screws 150, the

end plates

121 and 122 may be strongly fixed to each other by the end plate connection bars 130, and the end plate connection bars may be formed on the outer surfaces of the

end plates

121 and 122. End plate connecting bar seating groove 131 that can be fixed by mounting the 130 may be formed.

In addition, a plurality of screw insertion holes 121f through which the screw 150 is inserted and fastened may be drilled into the

end plates

121 and 122.

In addition, each of the

end plates

121 and 122 is made of a soft plastic material capable of injection molding. When the

end plates

121 and 122 are fastened with the fuel cell module 110, the

end plates

121 and 122 may be softly pressed without damaging the fuel cell module 110. It is possible to reduce the production cost through mass production.

In addition, the

end plates

121 and 122 may be made of a heat insulating plastic so that the

end plates

121 and 122 can be quickly heated without a separate heater during the initial operation of the fuel cell module 110.

For example, the heat insulating plastic may be a bubble plastic in which a blowing agent is added to the resin.

Therefore, according to the fuel cell 100 according to the first embodiment of the present invention, since the fuel cell module 110 can be pressed in a state in which it is seated in the seating groove 121a of the end plate 120, the shape is stacked without distortion. It is possible to assemble and maintain the same, and the electrode, the separator and the polymer electrolyte membrane can be strongly adhered to each other depending on the degree of pressurization, there is an advantage to ensure the gas tightness inside the fuel cell module 110.

In addition, since a separate insulation means for insulation between the electrode plate 112 and the

end plates

121 and 122 is not required, manufacturing cost can be reduced.

In addition, the fuel cell 100 may be provided as a fuel cell stack 100a by connecting a plurality of fuel cells 100 to each other, as shown in FIGS. 9 to 12.

In addition, the electrodes of the fuel cells 100 are connected in series or in parallel through the electrode connecting rod 160.

In addition, the fuel cells 100 are fixed to each other by a fuel cell connection bar 140, in this case, the fuel cell connection bar 140 is seated on the outer surface of the end plate 120 is fixed position A fuel cell connection bar seating groove 141 may be formed.

In addition, since the fuel cell stack 100a of the present invention is insulated by the end plate 120 without a separate insulating device, the stack configuration is very easy.

Second Embodiment

13 to 18, the fuel cell 200 according to the second embodiment of the present invention includes a fuel cell module 110 and an end plate 210.

The fuel cell module 110 is a module that receives electric reactant to produce electrical energy, and has the same structure and function as the fuel cell module of the first embodiment of the present invention. Therefore, detailed description is omitted.

The end plate 210 is assembled to both sides of the fuel cell module 110 to pressurize the fuel cell module 110 to maintain gas tightness and protect the fuel cell module 110 from the outside. It consists of a pair of

end plates

211, 212, the function of which is substantially the same as the end plate 120 according to the first embodiment of the present invention.

However, in the end plate 210 according to the second embodiment of the present invention, the height h of the mounting groove of the fuel cell module 110 is the height of the mounting groove of the end plate 120 according to the first embodiment. It is higher and when assembled to the fuel cell module 110, the upper edges of the edges of the seating grooves meet each other to surround the four sides and the bottom of the fuel cell module 110 so as not to be exposed to the outside.

That is, the end plate 210 according to the second embodiment of the present invention can be assembled by mounting almost both sides of the fuel cell module 110 in the mounting grooves of each end plate (211,212), the fuel cell module 110 Maintaining the stacking form of the maximum), there is an advantage that can be assembled by pressure, there is an advantageous effect to protect the fuel cell module (110).

However, since the fuel cell 200 according to the second embodiment of the present invention may open only a portion of the upper portion of the fuel cell module 110 to the outside, it is difficult to expose heat generated during operation to the outside.

Therefore, the fuel cell 200 according to the second embodiment of the present invention is a heat sink 220 that can discharge the heat generated by the fuel cell module 110 to the inside of the seating groove of the end plate 210 to the outside. This was further equipped.

In addition, the heat dissipation plate 220 has a fluid movement channel through which cooling fluid can move, and a cooling fluid inlet and outlet for extending or extending out of the end plate 210 at both ends of the channel to allow the cooling fluid to flow in or out. 221 is provided.

In addition, the end plate 210 is provided with a cooling fluid inlet and outlet exposure groove 221a to allow the cooling fluid inlet and outlet 221 to be exposed to the outside.

In addition, the cooling fluid inlet and outlet exposure groove 221a is shown in a semicircular shape to form a circular shape when the bond plate 210 abuts each other, but the shape is not limited, for example, seating of the end plate It may be formed by drilling into a circular groove on the side of the groove.

21 to 24, in the fuel cell 200 according to the second embodiment of the present invention, a plurality of fuel cells 200 may be connected to each other and provided as one fuel cell stack 200a. .

In addition, the fuel cell stack 200a according to the second embodiment of the present invention has a fuel cell connection bar 140a and a fuel cell connection bar seating recess compared with the fuel cell stack 100a according to the first embodiment of the present invention. Although shown as a difference in the position of (141a) is not limited to this position difference.

Therefore, according to the fuel cell 200 according to the second embodiment of the present invention, the end plate 120 can be press-assembled while maintaining the laminated structure of the fuel cell module 110 to the maximum, and the fuel cell module 110 from the outside ) Has the advantage of protecting.

As described above, the present invention has been illustrated and described with reference to preferred embodiments, but is not limited to the above-described embodiments, and is provided to those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

Industrial Applicability The present invention can be used industrially for fuel cells and fuel cell stacks.

Claims

A fuel cell module having a separator interposed therebetween and having a plurality of polymer electrolyte membranes (PEMs) stacked thereon and electrode plates for collecting electricity generated in the polymer electrolyte membranes; And

And a pair of end plates respectively coupled to both sides of the fuel cell module in a stacking direction and fastened to each other so that the distances of the fuel cell modules can be varied.

A fuel cell that varies the separation distance of the end plates and can adjust the adhesion of the separator, the polymer electrolyte membrane and the electrode plate.
The method of claim 1,

At least one of the end plates, the fuel cell, characterized in that the mounting groove in which a portion of the fuel cell module is seated on the inner surface in contact with the fuel cell module is formed.
The method of claim 1,

Each of the end plates has a seating groove in which a portion of the fuel cell module is seated on an inner surface of the end plate in contact with the fuel cell module.
The method of claim 3, wherein

The end plates are assembled such that the edges of the seating grooves are spaced apart from each other by a predetermined distance, and a portion of the side surface of the fuel cell module is exposed to the outside so that the fuel cell module can be cooled by air cooling.
The method of claim 3, wherein

And the end plates are assembled such that the edges of seating groove edges abut each other.
The method of claim 5, wherein

And a heat sink provided in the seating grooves of the end plates, the heat sink configured to discharge heat generated from the fuel cell module to the outside.
The method of claim 6,

A channel through which cooling fluid may move is formed in the heat sink, and both ends of the channel are provided with cooling fluid inlets and outlets extending out of the end plates to allow the cooling fluid to flow in and out. Fuel cell.
The method according to any one of claims 2 to 7,

The fuel cell, characterized in that the predetermined portion of the end plate is formed with a reactor inlet for supplying an external reactor to the fuel cell module and a reactor for discharging the reactor through the fuel cell module to the outside.
The method of claim 8,

The inner surface of the seating groove of the end plate penetrates through the reactor inlet and passes through the fuel cell module and passes through the reactor cell inlet groove for supplying the reactor body to the internal flow path of the fuel cell module. A fuel cell, characterized in that the reactor body discharge groove for discharging to the reactor outlet.
The method of claim 8,

A fuel cell, characterized in that the electrode exposed grooves are formed in a predetermined portion of the seating groove edge of each end plate to expose the electrodes protruding from the fuel cell module to the outside.
The method of claim 10,

Each end plate is formed on an extension line of the electrode exposure groove, the fuel cell, characterized in that the wire connection groove is further formed so that the wire and the bottom surface of the end plate does not interfere with each other when the wire is connected to the electrode.
The method according to any one of claims 1 to 7,

Each end plate is made of soft plastic fuel cell.
The method of claim 12,

The plastic is a fuel cell, characterized in that the insulating plastic.
The fuel cell stack of claim 1, wherein a plurality of fuel cells of any one of claims 1 to 7 are coupled, and electrodes of each fuel cell module are connected in series or in parallel.
End plates that are respectively coupled to both sides of the fuel cell module in the stacking direction,

End plate, characterized in that the mounting groove is formed on one surface in contact with the fuel cell module is a portion of the fuel cell module is seated inwardly coupled.
The method of claim 1,

An end plate, characterized in that the predetermined portion of the end plate is formed with a reactor inlet for supplying an external reactor to the fuel cell module and a reactor for discharging the reactor through the fuel cell module to the outside.
The method of claim 16,

Reacting the inner surface of the seating groove with the reactor inlet groove penetrating the reactor inlet and supplying the reactor body to the internal flow path of the fuel cell module and the reactor body penetrating the reactor cell outlet and passed through the fuel cell module End plate characterized in that the reactive gas discharge groove for discharging to the gas outlet.
The method according to any one of claims 15 to 17,

An end plate, characterized in that the electrode exposed groove is formed in a predetermined portion of the edge of the seating groove to expose the electrode protruding from the fuel cell module to the outside.
The method of claim 18,

End wires are formed on the extension line of the electrode exposure groove and the wire connecting groove is formed so as not to interfere with the bottom surface of the wire and the end plate when connecting the wire to the electrode.
The method according to any one of claims 15 to 17,

The end plate is characterized in that the end plate is formed with a screw insertion hole that can be coupled through the end plate and the screw coupled to the other surface of the fuel cell module.