JP2001057226A - Manufacture of fuel cell and fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a fuel cell capable of produc ing a fuel cell layered body having high assembling accuracy at a low cost with high accuracy. SOLUTION: This manufacturing method as shown below. Through-holes 45 of cells 6 and separator plates 39, 40 are sequentially fitted on a cylindrical intermediate adapter 60 (a) to form a unit block 70 (b). Next, by inserting a shaft 72 through through-holes 62 of the intermediate adapter 60, plural unit blocks 70 are stacked to form a layered body (c), then the layered body is fastened with the shaft 72 as an axis to manufacture a fuel cell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell for generating electric power by utilizing an electrochemical reaction, for example, used in an electric vehicle or the like. Hereinafter, although the present specification particularly describes a polymer electrolyte fuel cell, the present invention can also be applied to a phosphoric acid fuel cell.

[0002]

2. Description of the Related Art As is well known, a fuel cell has a pair of electrodes via an electrolyte, and supplies fuel to one of the electrodes and an oxidant to the other electrode. Is a device that directly converts chemical energy into electrical energy by causing an electrochemical reaction in the device. There are several types of fuel cells depending on the type of electrolyte. In recent years, a polymer electrolyte fuel cell using a solid polymer electrolyte membrane as an electrolyte has attracted attention as a fuel cell capable of obtaining high output. For example, when hydrogen gas is supplied to the fuel electrode and oxygen gas is supplied to the oxidant electrode, and current is taken out from an external circuit, reactions represented by the following chemical reaction formulas (1) and (2) occur. Cathodic reaction: H ₂ → 2H ⁺ + 2e ⁻ (1) Anodic reaction: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (2)

When this reaction occurs, hydrogen becomes a proton on the fuel electrode, moves with the water through the electrolyte to the oxidant electrode, and reacts with oxygen on the oxidant electrode to produce water. Therefore, the operation of the fuel cell as described above requires the supply and discharge of the reaction gas and the extraction of the current.

A separator plate for extracting current from a fuel cell and for efficiently flowing gas and water is disclosed in, for example, JP-A-58-161270 and JP-A-58-1612.
No. 69 and JP-A-3-206676. FIG. 6 is a cross-sectional view for explaining a conceptual configuration of a unit cell in the fuel cell disclosed in Japanese Patent Laid-Open Publication No. Hei 3-206763. In FIG. Is an oxidant electrode, 4 is a fuel electrode,
Reference numeral 5 denotes an electrolyte using a proton conductive solid polymer, for example, the electrolyte 5, the oxidant electrode 3, and the fuel electrode 4.
Constitutes the single cell 6.

FIG. 7 is an explanatory view showing the upper surface of the separator plate in the fuel cell shown in FIG. 6, and will be described with reference to FIG. That is, reference numeral 20 denotes a main surface of the separator plate 1, reference numeral 21 denotes an electrode supporting portion for supporting the electrode 3 in the separator plate 1, reference numeral 22 denotes an oxidant supply port formed in the separator plate 1 and supplies air as an oxidant, and reference numeral 23 denotes air. An oxidant discharge port for discharging the fuel, 24 is a fuel supply port for supplying fuel, and 25 is a fuel discharge port for discharging fuel. In the separator plates 1 and 2, the oxidant flow path 10 and the fuel flow path 11 are respectively formed by the grooves formed by cutting the main surface 20 and the space surrounded by the electrodes 3 and 4.

Hereinafter, the operation of the fuel cell will be described with reference to FIGS. 6 and 7. Oxygen gas supplied from the oxidant supply port 22 of the separator plate 1 is supplied to the oxidant electrode 3 through a plurality of oxidant passages 10 running in parallel, while hydrogen gas is supplied in the same manner as the oxidant. And the fuel gas flow path 1
1 to the fuel electrode 4. At this time, since the oxidant electrode 3 and the fuel electrode 4 are electrically connected outside,
The reaction of the chemical reaction formula (2) occurs on the oxidant electrode 3 side, and the unreacted gas and water are discharged to the oxidant discharge port 23 through the oxidant gas flow path 10. At this time, the fuel electrode 4
On the side, the reaction of the chemical reaction formula (1) occurs, and the unreacted gas is similarly discharged from the fuel outlet 25 through the fuel gas passage 11. The electrons obtained by this reaction flow from the electrodes 3 and 4 via the electrode supporting portions 21 and the separator plates 1 and 2.

In the above-mentioned conventional fuel cell, the voltage per unit cell is 1 V or less, and in order to obtain a practically useful voltage of 100 V or more, as described in JP-A-4-121914, It is necessary to stack more than one unit cell and separator plate.

[0008]

However, laminating several hundred single cells and separator plates at one time is not only inefficient in work efficiency, it is difficult to secure alignment accuracy when laminating, but also in operation. There has been a problem that the displacement may occur due to vibration or the like at the time, and the gas may be leaked due to the displacement of the gas supply port or the discharge port in the worst case.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a method of manufacturing a fuel cell capable of producing a fuel cell laminate having high assembly accuracy at low cost and high efficiency, and stability of a mechanical shape during operation. It is an object of the present invention to obtain a fuel cell having an improved performance.

[0010]

According to a first method of manufacturing a fuel cell according to the present invention, a single cell having an electrolyte membrane sandwiched between a fuel electrode and an oxidant electrode and having a first through hole in the electrode surface is provided. Step of obtaining a separator plate comprising the single cell, a fuel flow path for supplying a fuel fluid to the fuel electrode, and an oxidant flow path for supplying an oxidant fluid to the oxidant electrode, and having a second through hole in a main surface. A step of inserting an intermediate adapter having a third through-hole into which the shaft is inserted into the first and second through-holes, and sequentially stacking to obtain a unit block; In this method, a shaft is inserted into a third through-hole of the intermediate adapter, the unit blocks are stacked, a laminate is obtained, and the laminate is tightened around the shaft.

In a second method for manufacturing a fuel cell according to the present invention, in the first method for manufacturing a fuel cell, the intermediate adapter is a cylinder, and the third through hole has a dimension capable of inserting a shaft. The outer diameter is a method of a dimension that can be inserted into the first through hole and the second through hole.

A third method of manufacturing a fuel cell according to the present invention is the method of manufacturing the second fuel cell, wherein the first through hole, the second through hole, and the intermediate adapter have an elliptical cross-sectional shape. It is.

A first fuel cell according to the present invention comprises a single cell in which an electrolyte membrane is sandwiched between a fuel electrode and an oxidant electrode, a fuel flow path for supplying a fuel fluid to the fuel electrode, and an oxidant electrode oxidized by the oxidant electrode. A separator plate provided with an oxidizing agent flow path for supplying an agent fluid, an intermediate adapter having a through hole is inserted into the single cell and the separator plate, and a plurality of unit blocks are sequentially laminated. .

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 (a)-
(C) is a process drawing showing a method of manufacturing a fuel cell of the present invention in the order of steps, in which 6 is a single cell, 39 is a separator plate provided with a fuel flow path and a cooling water flow path, and 40 is an oxidant flow path. The provided separator plate, 45 is the single cell 6 and the separator plate 39,
In the through-holes (first and second through-holes) provided in the unit 40, the unit cell 6 and the separator plates 39 and 40 are provided correspondingly so that each fluid can be efficiently supplied to each electrode of the unit cell. . Reference numeral 72 denotes a shaft for tightening the laminated body, and reference numeral 60 denotes an intermediate adapter, in which a through hole (third through hole) 62 into which the shaft 72 can be inserted is provided. Reference numeral 70 denotes a unit block obtained by inserting the intermediate adapter 60 into the through hole 45 of the single cell and the separator plate, and sequentially stacking a plurality of single cells and separator plates.

That is, the single cell 6 having an effective area of 200 cm ² and the separator plates 39 and 40 have a diameter of 13 m at the same position.
m through holes 45 are provided. These have an outer diameter of 13m
M, an inner diameter of 10 mm, and a length of 40 mm are sequentially fitted to a cylindrical intermediate adapter 60 (FIG. 1A), and a unit block 70 is formed (FIG. 1B). Next, the diameter 1
A 0 mm shaft 72 is inserted into the through holes 62 of the plurality of unit blocks 70, and the plurality of unit blocks 70 are stacked to form a laminate {FIG. 1 (c)}, with the shaft 72 as an axis. The stack is tightened to produce a fuel cell. In the figure, the fasteners, current collectors, etc. of the complete laminate are not shown.

The fuel cell is manufactured by the above-described manufacturing method, so that a unit block 70 having ten stacked cells is manufactured.
Is a block of 120mm in length, 250mm in width, 30mm in thickness (excluding the protrusion of the intermediate adapter), and weighs 700g. Can be handled without damage. Furthermore, a 100-cell fuel cell stack (equivalent to 10 kW) could be formed by merely stacking ten unit blocks without using an extra positioning jig or the like.

In the present embodiment, the production efficiency can be improved because the production of the laminated body according to the power generation scale can be performed not by stacking one by one but only by stacking unit blocks of 10 cells, which are easy to store and transport. And costs were greatly reduced. Also, the intermediate adapter is used as an index for positioning,
It is possible to form a unit block every few cells where the position of each component in the laminate is fixed, and since the laminate is bound by the intermediate adapter, the displacement of the laminate does not occur, and the conventional laminate When the body was placed sideways, the deflection caused by gravity disappeared. Furthermore, in the present embodiment, since polypropylene was used for the intermediate adapter, the intermediate adapter became an insulating material, and there was no occurrence of a short circuit of current through the fastening shaft.

Embodiment 2 FIG. In the first embodiment, a fuel cell was manufactured in the same manner as the first embodiment except that the intermediate adapter 60 shown in FIG. 2 was used. FIG. 2 is a schematic diagram showing, for example, a part of an upper surface of a separator plate 39 cut away to show a state where an intermediate adapter 60 is inserted into a through hole 45 of the separator plate used in the second embodiment of the present invention. Reference numeral 63 denotes a projection provided on the outer peripheral portion of the intermediate adapter 60. The intermediate adapter had an outer diameter of 12.5 mm and a gap of 0.25 mm with respect to the through hole 45. However, projections 63 were provided in four directions, and the circumscribed circle including the projections was 13.2 mm, which was slightly larger than through-hole 45. In the first embodiment, when the unit block is formed, if the dimensional accuracy varies, it may be difficult to insert the separator plate or the single cell. However, in the present embodiment, the intermediate adapter 60 and the through hole Since there is a gap between the 45, it is possible to easily insert them. Furthermore, although the gap may be too large, the constituent material at the end may fall off from the unit block.
Because it was pressed against, it could be fixed firmly. That is, assembling was facilitated and the mechanical stability of the formed block could be improved. Note that the protrusion may be provided on the inner wall of the through hole 62 of the intermediate adapter.

Embodiment 3 A fuel cell was manufactured in the same manner as in the first embodiment except that the intermediate adapter 60 shown in FIG. 3 was used. FIG. 3 is a cross-sectional view of a side surface of the intermediate adapter 60 used in the present embodiment. Numerals 65 and 66 denote overlapping portions for overlapping with the intermediate adapters of the adjacent unit blocks. The overlap portion 66 has a diameter of 8 mm, and the overlap portion 66 has a diameter of 12 mm. It is possible to adjust the thickness and expand and contract during operation by stacking the intermediate adapters that have protruded when the unit blocks are stacked.

Embodiment 4 A fuel cell was manufactured in the same manner as in the first embodiment except that the intermediate adapter 60 shown in FIG. 4 was used. FIG. 4 is an explanatory diagram of a side surface of the intermediate adapter 60 used in the present embodiment, in which a convex portion 68 and a concave portion 67 are provided in an overlap portion at an end. The outer circumference of the convex portion 68 has the same diameter as the main body, and the circumcircle of the intermediate adapter is always constant even if the thickness of the laminate changes and the degree of overlap between the intermediate adapters changes. Or, the position of the unit cell at the overlapping (joining) portion of the intermediate manifold is not lost.

Embodiment 5 FIG. 5 shows a fifth embodiment of the present invention in which the intermediate adapter 60 is connected to the separator plate 3.
9 is a cross-sectional view showing a state of being inserted in FIG. 9, and is different from the first embodiment in that an intermediate adapter 60 having a cross-sectional shape shown in FIG. 5 and a separator plate having a through-hole 45 having a cross-sectional shape shown in FIG. A fuel cell was manufactured in the same manner as described above.
FIG. 5 is a schematic plan view of a unit block when the through hole 45 of the intermediate adapter 60 and the separator plate 39 of the present invention is an ellipse having a major axis of 15 mm and a minor axis of 12 mm and is not a perfect circle.

In the third and fourth embodiments, since the laminated body is bound by the intermediate adapter, there is no deviation in the position of the laminated body in the X and Y directions, but the deviation due to the rotation about the intermediate adapter is rare. Could occur.
However, since the cross-sectional shape is made elliptical as in the present embodiment, rotation can be prevented, and complete alignment and deviation prevention can be performed with only one through hole. In the present embodiment, the cross-sectional shape is an ellipse. However, similar effects can be expected as long as the shape deviates from a perfect circle such as a square or a triangle.

[0023]

According to the first method of manufacturing a fuel cell of the present invention,
A step of obtaining a single cell having a first through hole in the electrode surface by sandwiching an electrolyte membrane between a fuel electrode and an oxidant electrode, the single cell, a fuel flow path for supplying a fuel fluid to the fuel electrode, and the oxidation cell; A separator plate having an oxidizing agent flow path for supplying an oxidizing agent fluid to the agent electrode and having a second through hole on the main surface; and a third through hole for inserting a shaft into the first and second through holes. A step of inserting and stacking the intermediate adapters in order to obtain a unit block by sequentially stacking, and inserting a shaft into the third through hole of the intermediate adapter of the plurality of unit blocks, and stacking and stacking the unit blocks A method of obtaining a body and tightening the laminate with the shaft as an axis, thereby producing a fuel cell with high assembling accuracy at low cost and high efficiency, and improving the stability of the mechanical shape during operation. The effect is That.

According to a second method for manufacturing a fuel cell of the present invention, in the first method for manufacturing a fuel cell, the intermediate adapter is a cylinder, the third through-hole has a size capable of inserting a shaft, and has an outer shape. The diameter is a method that can be inserted into the first through hole and the second through hole. A fuel cell with high assembly accuracy can be produced at low cost and high efficiency, and the stability of the mechanical shape during operation is improved. There is an effect of doing.

According to a third method of manufacturing a fuel cell according to the present invention, there is provided the method of manufacturing the second fuel cell, wherein the first through hole, the second through hole and the intermediate adapter have an oval cross-sectional shape. Thus, a fuel cell with higher assembling accuracy can be produced at low cost and with high efficiency, and the stability of the mechanical shape during operation is improved.

The first fuel cell of the present invention comprises a single cell in which an electrolyte membrane is sandwiched between a fuel electrode and an oxidant electrode, a fuel flow path for supplying a fuel fluid to the fuel electrode, and an oxidant A separator plate provided with an oxidizing agent channel for supplying a fluid, an intermediate adapter having a through hole is inserted into the single cell and the separator plate, and a plurality of unit blocks are sequentially laminated, and the operation is performed. There is an effect that the stability of the inside mechanical shape is improved.

[Brief description of the drawings]

FIG. 1 is a process chart of a method for manufacturing a fuel cell according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a part of an upper surface of a separator plate cut away to show a state in which an intermediate adapter is inserted into a through hole of a separator plate used in a second embodiment of the present invention. .

FIG. 3 is a side sectional view of an intermediate adapter used in a third embodiment of the present invention.

FIG. 4 is an explanatory side view of an intermediate adapter used in a fourth embodiment of the present invention.

FIG. 5 is a schematic plan view of a unit block used in the fifth embodiment of the present invention as viewed from above.

FIG. 6 is a cross-sectional view for explaining a conceptual configuration of a unit cell in a conventional fuel cell.

FIG. 7 is an explanatory view showing an upper surface of a separator plate in a conventional fuel cell.

[Explanation of symbols]

6 Single cell, 39, 40 Separator plate, 45, 62
Through hole, 60 intermediate adapter, 70 unit block,
71 laminate, 72 shaft.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Koji Hamano 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Norio Mitsuda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation F-term (reference) 5H026 AA04 AA05 AA06 CC03 CC08 HH03

Claims (4)

[Claims] 1. A step of obtaining a single cell having a first through hole in the electrode surface by sandwiching an electrolyte membrane between a fuel electrode and an oxidant electrode, and a fuel for supplying a fuel fluid to the single cell and the fuel electrode. A separator plate having an oxidizing agent channel for supplying an oxidizing agent fluid to the channel and the oxidizing agent electrode and having a second through hole in the main surface is inserted into a shaft through the first and second through holes. A step of inserting an intermediate adapter having three through holes and sequentially stacking them to obtain a unit block, and inserting a shaft into a third through hole of the intermediate adapter of the plurality of unit blocks, A fuel cell manufacturing method comprising the steps of: laminating a laminate to obtain a laminate, and tightening the laminate around the shaft. 2. The intermediate adapter is a cylinder, the third through-hole has a size capable of inserting the shaft, and the outer diameter has a size capable of being inserted into the first through-hole and the second through-hole. The method for manufacturing a fuel cell according to claim 1, wherein: 3. The method according to claim 2, wherein the first through hole, the second through hole, and the intermediate adapter have an elliptical cross-sectional shape. 4. A single cell having an electrolyte membrane sandwiched between a fuel electrode and an oxidant electrode, a fuel flow path for supplying a fuel fluid to the fuel electrode, and an oxidant flow path for supplying an oxidant fluid to the oxidant electrode. A fuel cell in which a plurality of unit blocks are stacked by sequentially inserting a separator plate provided with an intermediate adapter having a through-hole into the single cell and the separator plate, and stacking the unit blocks.