KR20080090861A - Modular fuel cell stack and method of modularizing fuel cell stack - Google Patents

Abstract

The present invention relates to a modular fuel cell stack and a method of modularizing a fuel cell stack. The modular fuel cell stack of the present invention includes a membrane-electrode assembly formed by bonding an anode of a cathode and an anode of an air electrode to both sides of an electrolyte membrane, and a plate installed on both sides of the membrane-electrode assembly to perform bipolar and inner wall functions. A plurality of unit stacks to be provided; A current collecting plate disposed on an outer surface of the outermost unit stack of the plurality of unit stacks for collecting current; An outer wall supporting the unit stack so that the surface pressure of the unit stack is constant; Fastening holes formed in the plurality of unit stacks and current collector plates and outer walls, respectively; And a fastening member inserted into the fastening hole and simultaneously fastening each unit stack.

Description

Fuel cell stack for module and module method of fuel cell stack

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a side view schematically showing a stack of a conventional fuel cell;

2 is a perspective view illustrating a unit stack of a modular fuel cell stack according to a preferred embodiment of the present invention.

3 is a side view showing a modular fuel cell stack in accordance with a preferred embodiment of the present invention.

4 is a perspective view briefly showing a fastening member of a modular fuel cell stack according to a preferred embodiment of the present invention.

5 is a flowchart illustrating a method of assembling a fuel cell stack according to another exemplary embodiment of the present invention.

6 is an assembly cross-sectional view illustrating a method of assembling a fuel cell stack according to another exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: fuel cell stack 110: unit stack

111 electrolyte membrane 112 positive electrode

113 negative electrode 114 membrane-cell assembly

115: plate 120: current collector

130: outer wall 140: fastening hole

150: fastening member 156: hollow bolt

157: Rod Bolt

The present invention relates to a modular fuel cell stack and a method of modularizing a fuel cell stack, and more particularly, a modular fuel cell stack capable of easily repairing and stacking fuel cell stacks and making surface pressure in a stack uniform. A method of modularizing a fuel cell stack.

In general, a fuel cell is known as a device for directly changing the energy of a fuel into electrical energy. Here, the fuel cells are classified according to the type of electrolyte. If the fuel cells are classified according to the type of electrolyte, the phosphoric acid fuel cell operates at around 200 ° C., the alkaline electrolyte fuel cell operates at 60 to 110 ° C., and the room temperature. Polymer electrolyte fuel cells operating at 80 ℃, molten carbonate electrolyte fuel cells operating at a high temperature of about 500 ~ 700 ℃, and solid oxide fuel cells operating at a high temperature of 1000 ℃ or more.

Such a conventional fuel cell will be briefly described with reference to FIG. The fuel cell 10 has a single cell 16 or a stacked stack of single cells 16. The stacked stack fuel cell 10 includes a membrane-electrode assembly 14 (MEA: Membrane electrode assembly) formed by bonding the anode 12 and the cathode 13 to diffuse gas on both sides of the electrolyte membrane 11, A bipolar plate 15 and an outermost bipolar plate 15 which are assembled to be in close contact with both sides of the membrane-electrode assembly 14 to form a flow path of fuel gas and oxygen-containing gas at the anode 12 and the cathode 13. And a current collector plate 20 arranged on both sides of the current collector plate 20 to serve as collector electrodes of the anode 12 and the cathode 13. Here, the electrochemical oxidation of hydrogen as a fuel occurs at the anode 12 (anode or anode), and the electrochemical reduction of oxygen as an oxidant occurs at the cathode 13 (reduction electrode or cathode), and the movement of electrons generated at this time occurs. As a result, electricity is generated, and the generated electricity is collected at the current collector plate 20 to be used as an energy source.

In a fuel cell using this principle, a stack of fuel cells is used in which many single cells are stacked. Here, when stacking a single cell in a fuel cell stack so that the surface pressure distribution of a single cell is uniform depends on the performance of the stack, it should be stacked so that the surface pressure distribution of a single cell is uniform.

However, in the case of a stack stacked once, if a single cell fails, all the stacks must be released and stacked again. In addition, as the number of single cells stacked is increased, it is difficult to maintain a constant surface pressure.

The present invention was devised to solve the above problems, and can be divided into a plurality of unit stacks, and can be easily repaired and repaired by stacking unit stacks using bolts, and uniform surface pressure for each unit stack. It is an object of the present invention to provide a modular fuel cell stack and a method for modularizing a fuel cell stack that can be distributed in a smooth manner.

In order to achieve the above object, the modular fuel cell stack according to the present invention has a membrane-electrode assembly formed by bonding an anode and a cathode to both sides of an electrolyte membrane, and is installed on both sides of the membrane-electrode assembly to provide bipolar and inner wall functions. A plurality of unit stacks having a plate to perform; A current collecting plate disposed on an outer surface of the outermost unit stack of the plurality of unit stacks for collecting current; An outer wall supporting the unit stack so that the surface pressure of the unit stack is constant; Fastening holes formed in the plurality of unit stacks and current collector plates and outer walls, respectively; And a fastening member inserted into the fastening hole to fasten each unit stack simultaneously.

Preferably, the fastening member, the hollow bolt formed with a thread on the inner peripheral surface; And a rod bolt having a thread formed on an outer circumferential surface thereof so as to be engaged with the hollow bolt.

Here, the plate is preferably formed by applying a strong conductive epoxy resin.

According to another aspect of the present invention, (a) a step of manufacturing a plurality of unit stack by adhering a plate for performing the bipolar and inner wall functions on both sides of the membrane-electrode assembly formed by bonding the electrolyte membrane between the positive electrode and the negative electrode; (b) forming fastening holes in the plurality of unit stacks, respectively; (c) inserting and fastening hollow bolts into the fastening holes of the plurality of unit stacks; And (d) inserting a rod bolt into the hollow bolt and fastening the rod bolt to provide the modularization method of the fuel cell stack.

A current collector plate for collecting electricity is disposed on an outer surface of the outermost unit stack of the plurality of unit stacks, and an outer wall that supports the unit pressure so that the surface pressure of each unit stack is constant is disposed on the bolts. It is preferable to be fastened together with the unit stacks.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

2 is a perspective view showing a unit stack of a modular fuel cell stack according to a preferred embodiment of the present invention, Figure 3 is a side view showing a modular fuel cell stack according to the present invention.

2 and 3, the modular fuel cell stack 100 includes a plurality of units including a membrane-electrode assembly 114 and a plate 115 formed on both sides of the membrane-electrode assembly 114. The stack 110, a current collector plate 120 and an outer wall 130 sequentially disposed on the outermost outer surface of the unit stack 110, and a fastening member 150 for fastening them.

Each unit stack 110 is formed by adhering the plates 115 to both sides of the membrane-electrode assembly 114.

The membrane-electrode assembly 114 is formed by bonding the anode 112 and the cathode 113 to both sides of the electrolyte membrane 111. Here, the membrane-electrode assembly 114 may be composed of a single or a plurality.

The plate 115 has the same function as that of the conventional bipolar plate, and serves as an inner wall for dividing into each unit stack 110. That is, the plate 115 is bonded to both sides of the membrane-electrode assembly 114 to form one unit stack 110. A plurality of such unit stacks 110 are stacked to form one fuel cell stack 100. On the other hand, the plate 115 is preferably formed by applying a strong epoxy resin or the like.

The current collector plate 120 is disposed on the outermost surfaces of the outermost units of the plurality of unit stacks 110. That is, the current collector plate 120 is disposed at the upper end of the plate 115 of the unit stack 110 of the uppermost layer and the lower end of the plate 115 of the unit stack 110 of the lowermost layer. Since the role and function of the current collector plate 120 have been described above, a detailed description thereof will be omitted.

The outer wall 130 is disposed on the outer surface of the current collector plate 120, respectively. On the other hand, the outer wall 130 is preferably molded of a light plastic material.

Here, each of the unit stack 110, the current collector plate 120 and the outer wall 130 is formed with a fastening hole 140 is fastened by a fastening member 150 to be described later. Preferably, the fastening hole 140 may be formed at each corner, but if the unit stack 110, the current collector plate 120 and the outer wall 130 can be fastened so as not to move the position of the fastening hole 140 and its It can be formed regardless of the number.

The fastening member 150 is inserted into the fastening hole 140 to fasten the plurality of unit stacks 110, the current collector plate 120, and the outer wall 130. The fastening member 150 is composed of a hollow bolt 156 and a rod bolt 157 (see FIG. 4).

A thread 156a is formed on the inner circumferential surface of the hollow bolt 156 and is formed to have a predetermined length. The rod bolt 157 is formed with a thread 157a on its outer circumferential surface so as to be inserted into and fastened to the inner circumferential surface of the hollow bolt 156. The rod bolt 157 is preferably formed to correspond to or shorten the length of the hollow bolt 156.

One complete fuel cell stack 100 is manufactured by coupling the plurality of unit stacks 110, the current collector plate 120, and the outer wall 130 using the bolts 156 and 157 as described above.

5 is a flowchart illustrating a method of assembling a fuel cell stack according to another exemplary embodiment of the present invention, and FIG. 6 is an assembly cross-sectional view illustrating a method of assembling a fuel cell stack according to another exemplary embodiment of the present invention. .

5 and 6, the method of modularizing the fuel cell stack may include attaching the plates 115 to both sides of the membrane-electrode assembly 114 to manufacture a plurality of unit stacks 110 (S10); In step S20, the current collector plate 120 and the outer wall 130 are sequentially disposed at the top and the bottom of the unit stack 110, and the plurality of unit stacks 110, the current collector plate 120, and the outer wall 130 are disposed. Forming a fastening hole 140 in the step S30, and inserting the hollow bolt 156 into the fastening hole 140 and fastening the bar bolt 157 to the fastening bolt 140 and the hollow bolt 156. Inserting and fastening (S50).

First, in operation S10 of manufacturing the plurality of unit stacks 110, the plate 115 is attached to the membrane-electrode assembly 114 formed by adhering the anode 112 and the cathode 113 to both sides of the electrolyte membrane 111. It is prepared by adhering. The membrane-electrode assembly 114 may be formed in plural, and the plate 115 is adhered to both sides of the membrane-electrode assembly 114. Here, the plate 115 is formed to have the function of the bipolar plate and the inner wall of the commonly used. That is, the unit stack 110 includes a plate 115 formed on both sides of the membrane-electrode assembly 114. A plurality of such unit stack 110 is manufactured.

Next, the current collector plate 120 and the outer wall 130 are sequentially disposed on the uppermost layer and the lowermost layer of the unit stack 110 (S20). More specifically, the collector plate 120 is disposed on the outer surface of the plate 115 of the uppermost layer and the lower layer on which the plurality of unit stacks 110 are stacked, and the outer wall 130 is disposed with the collector plate 120 interposed therebetween. do. Here, the outer wall 130 is preferably molded of a plastic material.

Subsequently, a fastening hole 140 is formed in the plurality of unit stacks 110, the current collector plate 120, and the outer wall 130 (S30). The fastening hole 140 may be formed on the unit stack 110, the current collector plate 120, and the outer wall 130 in the same line. The fastening hole 140 may be pre-formed and manufactured at the time of manufacturing the unit stack 110, and the collecting plate 120 and the outer wall 130 may also be pre-formed and molded in each process. That is, the plurality of unit stacks 110, the collector plate 120, and the outer wall 130 having the fastening holes 140 may be disposed in the same structure as in the step S20.

When the fastening hole 140 is formed, the hollow bolt 156 is inserted into the fastening hole 140 (S40). The hollow bolt 156 has a thread 156a formed on an inner circumferential surface thereof, and preferably has a diameter corresponding to the diameter of the fastening hole 140 to be crimped to the fastening hole 140.

Finally, the bar bolt 157 is inserted into the hollow bolt 156 and fastened (S50). The rod bolt 157 is finally fastened by threaded thread 157a formed on the outer circumferential surface thereof and screwed with the threaded thread 156a of the hollow bolt 156.

The fuel cell stack 100 having the structure as described above may determine the abnormality by measuring the voltage at the end of the unit stack 110. In this case, when an abnormality occurs in any one of the unit stacks 110 of the plurality of unit stacks 110, the bolts 157 are released to repair, remove or replace the unit stacks 110 in which the abnormality occurs. As a result, there is no need to unload and re-stack all the stacks in order to remove, repair, and replace the faulty stack, thereby maintaining the density of the membrane-cell assembly 114.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

As described above, the modular fuel cell stack and the method of modularizing the fuel cell stack according to the present invention are easier to repair and replace than the conventional fuel cell stack. In other words, when the abnormal voltage is measured in the conventional fuel cell stack, all the stacks must be released to remove or repair the single cell in which the abnormality is generated, and then stacked again, whereas the fuel cell stack of the present invention is composed of unit stacks. Loosen to repair or replace only the faulty unit stack. In addition, while the conventional fuel cell stack must maintain the density to have a uniform surface pressure when the membrane-cell assembly and the bipolar plate are laminated, the fuel cell stack of the present invention does not lower the density and contacts the membrane-cell assembly in the stack. It can be maintained.

Claims (5)

A plurality of unit stacks including a membrane-electrode assembly formed by bonding an anode and a cathode to both sides of the electrolyte membrane, and plates provided on both sides of the membrane-electrode assembly to perform bipolar and inner wall functions; A current collecting plate disposed on an outer surface of the outermost unit stack of the plurality of unit stacks for collecting current; An outer wall supporting the unit stack so that the surface pressure of the unit stack is constant; Fastening holes formed in the plurality of unit stacks and current collector plates and outer walls, respectively; And And a fastening member inserted into the fastening hole to fasten the respective unit stacks at the same time. The method of claim 1, The fastening member, A hollow bolt having a thread formed on an inner circumferential surface thereof; And And a rod bolt having a screw thread formed on an outer circumferential surface thereof so as to be engaged with the hollow bolt. The method according to claim 1 or 2, The plate is a modular fuel cell stack, characterized in that formed by coating a strong epoxy resin. (a) bonding a plate performing a bipolar and inner wall function to both sides of a membrane-electrode assembly formed by bonding an electrolyte membrane between an anode and a cathode to produce a plurality of unit stacks; (b) forming fastening holes in the plurality of unit stacks, respectively; (c) inserting and fastening hollow bolts into the fastening holes of the plurality of unit stacks; And and (d) inserting a rod bolt into the hollow bolt and fastening the rod bolt to the hollow bolt. The method of claim 4, wherein A current collector plate for collecting electricity is disposed on an outer surface of the outermost unit stack of the plurality of unit stacks, and an outer wall that supports the unit pressure so that the surface pressure of each unit stack is constant is disposed on the bolts. The method of modularizing the fuel cell stack, characterized in that coupled with the unit stack by.

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