JPS61147472A - Unit structure of fuel cell - Google Patents

Abstract

PURPOSE:To enable a cell to be subjected to required surface pressure even if its end plate is made of carbon with low rigidity, by arranging rigid restrainers on the end plate. CONSTITUTION:In an unit cell, cooling plates 2 are interposed every time a plurality of elementary cells are piled in a block and both end plates 3, 4 are made of carbon material. The face of end plate 3 is provided 4 pairs of two grooves 3e, 3f running through along said face and the face of end plate 4 is provided with two grooves 4e, 4f in the similar configuration respectively. Then, clamping bars 13, 14 are inserted in the coupling parts 15e of a clamping crew 15 serving as a clamping member, clamping bars and clamping screws are coupled together by setting pins 15p to pass through respective pin holes 13h, 14h of clamping bars 13, 14 and holes 15h of coupling parts 15e, the clamping screw 15 is clamped by a turn buckle 15t, thus an assigned surface pressure being applied to the unit cell via clamping bars 13, 14.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention consists of stacking a plurality of unit cells between end plates. The present invention relates to a unit structure of a fuel cell that includes the following.

[Prior art and its problems]

Generally, the unit cell of a fuel cell is a matrix that holds the electrolytic charge.
The gas layer and the porous fuel electrode and oxidizer that hold it in place! It consists of electrodes and means (for example, plates with grooves) for supplying different reaction gases to these electrodes, and the unit cells are tightened in the stacking direction by a tightening member to form a cell stack of a fuel cell.

In this case, conventionally, a structure has been adopted in which several to several tens of unit cells are stacked in advance to form a unit cell, and a plurality of these unit cells are stacked to form a cell stack. By configuring a unit battery with unit cells in advance and performing a characteristic test on the unit cells before stacking them into a cell stack, only unit cells with good characteristics can be assembled into a cell stack, and cells with defective unit batteries can be avoided. Inclusion in the stack can be avoided.

However, since characteristic tests on unit cells are performed with the unit cells tightened at a predetermined pressure, when the tested unit cells are assembled into a cell stack, if the pressure is released, the battery matrix, matrix, etc. There were problems such as damage to the sealing material and increased electrical and thermal resistance, so it was desired to assemble the unit cells into a cell stack with the unit cells tightened even after the test was completed.

In response to this request, the inventor of the present application previously applied for the
19, by arranging end plates at both ends of the unit cell and connecting these end plates with a tightening member, a structure is created in which the unit cell can be assembled into a cell stack while applying a predetermined surface pressure to the unit cell. is proposed.

However, when a metal such as amber is used as the end plate of the unit cell, there is a problem in that the weight of the end plate makes the entire cell stack heavy, and the surface pressure changes between the upper and lower parts of the star. Additionally, amber has a drawback of poor corrosion resistance to phosphoric acid. For this reason, it was considered to use polished, corrosion-resistant carbon fiber as a 1GS board, but carbon has low rigidity and is easily bent, so it was
If the unit cell is tightened by pressing only both ends of the end plate as in -1519, the end plate will warp and pressure cannot be applied to the cells evenly. When testing a cell, it is necessary to apply a surface pressure of 3 sand 9 to the cell in order to obtain the same condition as during operation, but if you try to obtain such a surface pressure from the configuration proposed earlier, the cell When tightening, the pressure may be uneven and the matrices and boxes may be damaged.

[Purpose of the invention]

In view of the above-mentioned points, the present invention provides a fuel cell that can apply a required surface pressure to the cell even if carbon with low rigidity is used as the end plates disposed on both end surfaces of the uni- and tri-laminate. The purpose is to provide a unit and structure of the system.

[Summary of the invention]

In order to achieve the above object, the inventor of the present application has conducted various studies and found that during operation and testing, it is necessary to apply a surface pressure of 3 (-) to the cell in order to reduce contact resistance. , or when replacing, add 0.5 to 4 to the cell.
It was found that the performance of the battery does not deteriorate as long as a uniform surface pressure of /cI/l is applied. It was also discovered that even if the end plate is made of carbon, if the clamping pressure is uniformly applied, a uniform surface pressure of 0.5 (-) can be obtained, and the matrices and boxes will not be damaged.

Therefore, according to the present invention, the above object is achieved in a cell stack in which a plurality of unit cells are interposed between end plates of carbon material, and a plurality of unit cells are stacked, and a predetermined tightening pressure is applied. a groove or hole uniformly provided in the surface direction of the end plate; a rigid holding member detachably disposed in the groove or hole; and a rigid holding member disposed on both end plates of the unit cell. This is achieved by including a tightening member that connects the ends of the holding member, respectively.

[Embodiments of the invention]

The present invention will be described in detail below based on the drawings.

FIG. 1 is a partially exploded perspective view of a unit structure according to an embodiment of the present invention. In FIG. 1, an end plate 3 and an end plate 4 are arranged at both ends of a stacked body formed by stacking a plurality of unit cells 1 to capture the unit cells and form a tail. The unit cell has a cooling plate 2 inserted between each stack of unit cells.
Both end plates 3 and 4 are made of carbon material. On the surface of the end plate 3, four sets of two grooves 3e and 3f are arranged uniformly along the periphery of the end plate, and the grooves 3e and 3f are arranged in the X direction in the surface direction of the end plate 3. Similarly, four sets of two grooves 4e and 4f are provided at positions corresponding to the grooves 3e and 3f of the upper end plate 3.

Tightening bars 13 as holding members are removably provided in the four holes 3e, and tightening bars 14 are respectively provided in the four grooves 4e. Then, the tightening bars 13 and 14 are inserted into the connections 1i1s15e of the tightening screws 15 as tightening members, and the bolt holes 13h and 14h of the tightening bars 13 and 14 are connected to the connecting portion 1.
Connect the tightening bar and the tightening screw by passing the pin 15p through the hole 15h of 5e, tighten the tightening screw 15 with the turnbuckle 15t, and apply a predetermined surface pressure to the unit cell via the tightening bars 13 and 14. I try to add

FIG. 2 is a front view showing a stacked state of the unit cells shown in FIG. 1, and FIG. 3 is a partial side view thereof. Second
In the figure, four tightening bars 13 are fitted into the four grooves 3e of the end plate 3 of the unit cell, and four tightening bars 14 are fitted into the four grooves 4e of the end plate 4. The unit cell is tightened using tightening screws 15 connected to both ends. Similarly, the other unit cells below this unit cell have four tightening bars 13 in the four grooves 31f of the end plate 31.
a, and four tightening bars 1 to four 1k41f of the end plate 41.
4a and is tightened by tightening screws 15g connected to both ends of the tightening bar. In this example,
The tightening screws 15 and 15a are #J, as shown in Figure 3.
It is arranged on the outside of the manifold 16 for supplying and discharging the reaction gas attached to each unit cell, but if the manifold is provided only on a pair of opposing sides of the unit cell, it will be tightened in the unit without this manifold. It is desirable to consider the alignment of the end plate grooves so that the mounting screws can be placed.

As mentioned above, in this embodiment, the grooves into which the holding members are fitted are uniformly provided in the end plate, and the unit cells are tightened by a plurality of holding members and tightening members, so that almost uniform surface pressure is applied to the cells. can be added. Therefore, although the end plates are made of carbon material with a low elastic modulus, the highly rigid holding members are uniformly distributed, eliminating warping of the end plates.
Uni.

As long as a uniform surface pressure of 0.5 wcd is applied to the tossel, there is no risk of damage to the matrices or camphors.

Next, unit cell testing will be explained.

FIG. 4 is a partial sectional view showing a state in which a single unit cell is housed in a test container. In FIG. 4, corresponding to the end plates 3 and 4 of the unit cell, a dummy end plate 40 is provided on the outside thereof. And the dummy end plate (9),
40 also have four sets of grooves 30e.

30f, 40e, and 40f are the grooves 3e of the end plates 3 and 4, respectively.

They are provided at positions corresponding to 3f, 4e, and 4f. As a result, when installing the unit cell in the test container or removing the unit cell from the test container, the tightening bar can be attached to the hole formed by the grooves 3e and 30e and the grooves 4e and 40.
It can be inserted into the hole consisting of 8 and uni.

The clamping pressure of the tosel can be maintained at at least 0.5 wcrjI.

When conducting a test, first, a dummy one end plate 40. Current collector plate 52. It is arranged via an insulating plate 8. 'Also, there is a dummy at one end of the upper current collector plate 52. A rigid end play 1-51a is installed via an insulating plate. The upper end plate 51a is passed through the lower end plate 51, and tightening studs are provided at the four corners of the end plate. Tighten.

As mentioned above, in the present invention in which carbon is used for the end plate, the uniform surface pressure <3 Np, , ', > required for the test is obtained by the pressurizing means, which also includes the tightening bar 13 and the tightening screw 15. However, according to this configuration, the end plate is rigid, so the surface pressure of about 30 mm required during operation can be applied evenly to the unit cell, and the end plate will not warp or cause damage. A good test can be performed without causing any damage.

After the test is completed, the force of the test vessel is separated from the flange part, and the tightening bar is inserted into the hole formed by the dummy end plate and the end plate with the tightening bar being tightened by the end plate, and the tightening screw is tightened at least. Attach the pouch so that the surface pressure is 0.5 (-).After this, loosen the tightening star and do & and remove the upper end plate 51a.

Before and after the unit cell test, in either case, the unit cell can be balanced with the surface pressure necessary to maintain the integrity of the unit cell by means of a tightening bar and a tightening screw.

After the test is completed, multiple unit cells are stacked as described above to form a cell stack, and a cell star is formed.

After tightening with a tightening surface pressure of approximately 3 (-) using the additional tightening plate, the tightening bar and tightening screw are removed.

If a unit cell becomes defective during operation of the fuel cell, after stopping the fuel cell, tighten each unit cell with a tightening bar and tightening screw, remove the defective unit and unit cell, and replace or repair. Let's do it.

Note that after the unit cells are tightened as a cell stack, the holding member and the tightening member of the unit cell are removed, but as in this example, the holding member is intersected by the overlapping end plate. If a groove is formed, if a dummy bar is inserted into this groove after the cell stack is assembled, this bar will function to prevent the unit cells from shifting.

Furthermore, the holding member is not limited to the above embodiment, and the state in which the holding member is inserted into the end plate may be through a plurality of holes provided uniformly across both ends of the end plate, but these holes are used for inserting the bar material. It is desirable to have a diameter that allows some leeway when doing so.

Next, a stacking method for stacking five unit cells into a cell stack will be explained.

When carbon is used as the end plate, carbon has low rigidity, so it is advantageous to lift the units using a rigid holding member that extends through the end plate in the surface direction.

An embodiment using a pressing member will be described below based on the drawings.

In FIGS. 5 and 6, the reference symbol indicates a cell assembly consisting of several stacked unit cells, and a cooling plate 6 with cooling pipes 61 arranged thereon.
2 is interposed in each cell assembly, and dozens of laminated unit bodies consisting of the unit cell assembly ω and the cooling plate 62 are stacked, and an upper end plate is placed on the upper end and a lower end plate is placed on the lower end. B
are provided to constitute the unit cell 6. In the grooves of the upper end plate B and the groove 67 of the lower end plate 64 marked with the unit cell mark, a part group for upper tightening and a bar ω for lower tightening are inserted respectively, and they are tightened with tightening screws 70 to form the unit cell. The tightening holds the pressure. For lower tightening, a connecting hole 71 provided at both ends of the par 69 is connected by a connecting fitting 73 to a through hole 72 provided at the lower end of a tightening screw 70 serving as a hanging fitting. A connecting portion 74 having a groove provided therein is connected to a connecting portion 76 of a rigid frame 75 by a pin 77 . This results in
For tightening, the unit cells to which the means is attached are lifted up, and the unit cells can be laminated.

In addition, by adjusting the turnbuckle 78 of the tightening screw 70, the unit cell that is tilted during lifting can be made vertical. Furthermore, after the lamination work is finished, the tightening screws 70 and the rigid frame 75 are removed.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, even if the end plates disposed at both ends of the unit cell are made of carbon material, a plurality of rigid pressing members are arranged on the end plates to hold the unit cell in place. , sKf, and H, so there is no risk of warping the end plate. Therefore, gas leakage due to peeling of seals between unit cells, separation and damage of matrices and boxes, and electrical and thermal resistance do not increase. Furthermore, since the end plates are made of carbon material, they are resistant to corrosion against electrolytes such as matrices and carbon dioxide, such as phosphoric acid, and have the effect of enabling long-term operation. In addition, even if one of the unit cells is defective after being stacked in the cell stack, there will be no problem.

Since a predetermined tightening surface pressure can be applied to the laminate alone, only the laminate having a defective unit cell can be replaced, which has the effect of facilitating maintenance and management of the battery.

[Brief explanation of drawings]

Fig. 1 is a partially exploded perspective view of a unit and unit stacked body to which a tightening member according to an embodiment of the present invention is attached, and Fig. 2 is a front view of a unit and unit stacked body 1iA unit to which the tightening member of Fig. 1 is attached. , FIG. 3 is a partial side view of FIG. 2, FIG. 4 is a partial cross-sectional view showing a test state of a uni- and tri-laminate according to an embodiment of the present invention, and FIGS. 5 and 6 are a partial side view of FIG. FIG. 6 is a front view and a side view showing a state in which units and units are stacked using members. l: unit cell, 3.4.63.64: end plate, 13.14
．． 68.69: Tightening par, 15,70: Tightening screw. Sai 1 (3) Shi 2 Figure p3q f'4 Figure Sai 5 Sen Proceedings Amendment (Speech: January 2'1, 1985, 4, Agent address: 1-1 Tanabeshinden, Kawasaki-ku, Kawasaki City, Amended) Contents 1. Delete the phrase "during the test, or" on page 4, line 16 of the specification. 2. Delete the following sentence after "during the test," written on page 6, line 14 of the specification. ``Furthermore, in the grooves 3e, 3f, 4e, and 4f of the end plate 3.4, relief grooves 3g, which are deep enough so that the tightening member does not reach in the stacking direction of the cells, are provided.
3h, 4g, 4h are provided, and the tightening bar 13.1
4 transmits the tightening force through convex portions 13f and 14f provided on its side surfaces. In other words, the tightening bar 13
．． 14 pieces 1'3g and 14g increase the rigidity of the tightening bar, and have a gap from the bottom of the relief groove. This makes it possible to increase the rigidity of the tightening bar without increasing the thickness of the end plate, and also prevents local force from being applied to the end plate made of carbon material.'' 3. Fig. 2 , Figure 3 is corrected as shown in the attached sheet.

Claims (1)

[Claims] In a cell stack formed by laminating a plurality of unit cells in which a plurality of unit cells are interposed between carbon material end plates and applying a predetermined tightening pressure, the cell stack is formed by uniformly penetrating the end plates in the surface direction. A groove or hole provided, a rigid holding member removably disposed in the groove or hole, and a tightening member connecting the ends of the holding member arranged on both end plates of the unit cell, respectively. A unit structure of a fuel cell characterized by having.