JPH07230821A - Layer-built fuel cell - Google Patents

Abstract

PURPOSE:To improve adhesion of electromotive parts of a cell layered body for increasing electric conductivity between cells, and provide a layer-built fuel cell having end part structural bodies having tightening functions which satisfy gas seal properties both at wet seal parts and manifold parts. CONSTITUTION:A layer-built fuel cell comprises unit cells 1 comprising electrolyte matrix held by an anode and a cathode, which are laminated alternately. with separators to introduce fuel gas to the anodes and oxidizer gas to the cathodes respectively and separately, and holes provided at circumferential edge parts of the separators having manifolds penetrating a layered body for supplying/discharging both gases. Manifold parts and electromotive parts 23 on which the unit cells 1 are positioned are integrally covered with plate-shaped structural bodies 21, 22 to be tightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a unit cell in which an electrolyte matrix is sandwiched between an anode (fuel electrode) and a cathode (air electrode), and a fuel gas is led to the anode and an oxidant gas is led to the cathode. The present invention relates to a stacked fuel cell in which separators are stacked alternately.

[0002]

2. Description of the Related Art A fuel cell is a power generation system in which an electrochemical reaction occurring on an electrode is directly converted into an electric output. In order to carry out this reaction, a fuel gas and an oxidant gas face each other with an electrolyte matrix in between. The anode and the cathode are separately supplied. Then, the separator that guides the gas to the anode and the cathode and the electrolyte matrix, and the unit cell composed of the anode and the cathode are alternately laminated, and the current extraction at the upper and lower ends, tightening, gas supply and discharge,
A laminated fuel cell is constituted by sandwiching the end structure having an electrical insulating function.

FIG. 19 is a view showing an example of a repeating structure of a stacked fuel cell, in which a unit cell 1 is an electrolyte matrix 2
And an anode 3 and a cathode 4 which are arranged in close contact with both surfaces thereof. The separator 5 is interposed between the interconnector 6, the anode edge plate 7, the cathode edge plate 8, the anode current collector plate 9, the cathode current collector plate 10, and the anode edge plate 7, the cathode edge plate 8 and the interconnector 6. It is composed of an edge spring (not shown) mounted, and is arranged in close contact with the unit cell 1,
Fuel gas 11 for anode 3 and oxidant gas 1 for cathode 4
Guide 2 A single cell is composed of these components shown in this figure, and a plurality of these cells are stacked to form a battery stack that constitutes a basic unit of a fuel cell power generation facility. When stacking
The separator 5 is handled by sandwiching the interconnector 6 from both sides with the anode edge plate 7 and the cathode edge plate 8 and joining the peripheral edges together. Fuel gas is flown into the space formed between the interconnector 6 and the anode edge plate 7, and oxidant gas is flowed into the space formed between the interconnector 6 and the cathode edge plate 8. To secure these spaces, an anode current collector 9 and a cathode current collector 10 are provided in the edge plates 7 and 8.

The separator has a role of forming a gas flow path and electrically connecting adjacent cells to each other. The electricity is mainly collected by the anode current collector 9 and the cathode current collector 9 which are in close contact with the anode 3 and the cathode 4. Flow through the electrical plate 10.

The fuel gas and the oxidant gas are supplied and discharged from the holes penetrating the stack at the periphery of the separator. The holes of the separators that are stacked one above the other are connected by an electrically insulating manifold ring 13. This gas supply / discharge gas passage is called an internal manifold, and a fuel cell having this internal manifold is called an internal manifold type fuel cell.

The peripheral portion of the unit cell 1 is in close contact with the separator to seal the gas passage in the separator and the battery atmosphere. Since the unit cell 1 contains the electrolyte solution, the contact surface can be wet and sealed. This seal is called a wet seal.

As described above, since the close contact between the parts is required, the stack is clamped by the clamp plates constituting the upper and lower end structures and is used for the power generation operation.

[0008]

As described above, the unit cell is formed by stacking a plurality of constituent elements, and the battery stack is formed by stacking a plurality of unit cells. If the variation is uneven, the adhesion may be impaired. If the wet seal portion has poor adhesion, not only gas may leak and the power generation performance and power generation efficiency may be impaired, but also the fuel gas and the oxidant gas may cause a combustion reaction. In addition, poor adhesion at the electromotive portion causes an increase in electrical resistance, and some of the generated power is lost.

In particular, since the components to be laminated are different between the electromotive portion and the manifold portion, the difference in height between them is
This may impair the adhesion of the electromotive part and cause the above-mentioned performance deterioration.

On the other hand, the laminated end structure has a tightening function to secure the adhesion and electric conductivity of the electromotive portion and the gas sealability of the wet seal portion and the manifold portion, and also to take out the direct current and the reaction gas. Supply and discharge, electrical insulation,
Desirably, a heat insulation function is required.

Therefore, the present invention improves the adhesion of the electromotive portion of the battery stack consisting of the constituent elements having dimensional variations within the manufacturing dimensional tolerance, and increases the electrical conductivity between the cells. Provide a laminated fuel cell having an end structure that has a tightening function that achieves both gas sealability between the cell's wet seal part and manifold part, and that also has the functions of direct current extraction, electrical insulation, and reaction gas supply / discharge. The purpose is to do.

[0012]

According to the present invention, a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode, and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated. In a laminated fuel cell in which a manifold that supplies and discharges both gases has a manifold that is formed by holes that are provided in the peripheral portion of each separator and that penetrates through the laminated body, in the stack fuel cell It is characterized in that it is fastened by a plate-like structure integrally covering the electric part.

A second aspect of the invention is characterized in that an elastic body is provided between the tightening plate and the battery stack or between the battery units to eliminate the height variation.

Furthermore, a third aspect of the present invention is to divide a cell stack into a plurality of units and stack the units, and to arrange a gas of a unit to be stacked on the downstream side of a fuel gas or an oxidant gas of an arbitrary unit. It is characterized by being located on the upstream side.

According to a fourth aspect of the invention, the battery stack is divided into a plurality of battery units and stacked, and an intermediate header for supplying and discharging gas is provided in the manifold of each battery unit to maintain the adhesion of the battery stack. The pipe connecting the intermediate headers to each other was configured using expansion joints.

A fifth aspect of the present invention is characterized in that the battery stack is once tightened in advance with a higher tightening pressure before the power generation operation is performed with a predetermined tightening pressure.

A sixth aspect of the invention is characterized in that the tightening plate for tightening the battery stack from above and below has a rib structure in which the central part is thicker than the peripheral part.

[0018]

In the internal manifold type fuel cell, since the separator is composed of a central portion that performs a current collecting function and a manifold portion that is an outer edge that performs a gas supply / discharge function, the separator is tightened with independent displacement. Will be deformed, and the adhesion of the components will be impaired, which is not preferable. Therefore, by tightening the battery laminated body by using a clamp plate having high rigidity that integrates both parts, the displacement amount of both parts can be made equal, the deformation of the separator can be suppressed, and the adhesion of both parts can be improved. .

When the battery stack is pressed from above and below by the flat plate-shaped tightening plate, the elements constituting the electromotive portion are usually required to have a particularly accurate thickness. If the sum of the heights of the respective constituent elements integrated in the stacking direction of the battery stack is different in the plane of the separator, the tightening pressure may not be locally applied. Further, even if the constituent element locally shrinks due to high temperature creep, the sum of the heights of the constituent elements changes with time. Therefore, by providing an elastic body between the tightening plate and the battery stack or between the battery units,
Height variations can be eliminated.

The temperature inside the cell stack is generally high downstream of the fuel gas and the oxidant gas, and the degree of high temperature creep is affected by the temperature distribution.
By distributing the downstream side of the gas in which the constituent elements are exposed to higher temperature and easily creeps and contracts in different directions of the battery stack, it is possible to keep the amount of change in the height of the battery stack uniform.

In order to distribute the gas flow direction, the battery stack was divided into a plurality of battery units and stacked, and an intermediate header for supplying and discharging gas was provided in the manifold of each battery unit. Further, the space between the intermediate headers is contracted due to the creep contraction of the battery units or the elastic body provided between the battery units. Even in that case, the adhesion of the battery stack can be maintained by using the expansion joint for the pipe connecting the intermediate headers.

As described above, the laminated fuel cell is clamped with a predetermined pressure in order to maintain good gas sealing and electrical contact. The higher the tightening pressure, the better the adhesion, but since the amount of shrinkage of the components due to high temperature creep increases, it is preferable to tighten the tightening pressure as low as possible during the power generation operation. As one method of reducing the tightening pressure, the constituent elements of the battery stack can be made to fit together by previously tightening the battery stack at a higher tightening pressure before the power generation operation at a predetermined tightening pressure.

The tightening plate needs to have sufficient rigidity in order to tighten the battery stack with a uniform surface pressure. However,
In raising the temperature of the battery related to the start of battery power generation operation,
In order to minimize the amount of energy supplied from the outside of the battery, the heat capacity of the end structure of the battery stack is preferably small, and the amount of heat transfer from the end structure to the container that houses the stacked battery is small. It is preferable. Therefore, the tightening plate has a rib structure in which the central portion is thicker than the peripheral portion, so that the heat capacity of the end structure can be reduced and the heat conductivity can be reduced.

[0024]

Embodiments of the present invention will be described with reference to the drawings. Figure 1
Shows a conceptual diagram of the battery stack in a state where it is clamped from above and below, and the middle of stacking is omitted by broken lines. In the present invention, the upper clamping plate 21 and the lower clamping plate 22 are extended to the manifold portion in order to equalize the displacement amounts of the electromotive portion and the manifold portion. In the conventional example, the size of the tightening plate required to obtain a stacked fuel cell with good performance, that is, the size of the tightening plate required to bring the electromotive portions into close contact with each other was generally limited to the size of the electrolyte matrix 2. . in this case,
Since the components of the electromotive part and the manifold part are different and the bending rigidity of the separator 5 is small, the difference in the manufacturing dimensions of each component and the creep contraction during power generation operation result in a difference in the height of both parts. Occurs and the separator is bent and deformed. This deformation impairs the adhesiveness of the electromotive portion. In this example shown in FIG. 1, the upper and lower tightening plates 2 have a bending rigidity sufficiently higher than that of the separator.
1 and 22, the electromotive portion 23 and the manifold portion 24
By pressing both of them, bending deformation of the separator can be suppressed. Therefore, the adhesiveness of the electromotive portion is improved, and thus the gas sealing property and the electrical contact property can be improved.

In this example, the tightening bellows 25, which expands and contracts by air pressure, is used as a means for tightening it with a predetermined pressure by following the change in the height of the entire laminated body, but other tightening methods may be used. Also has the same effect. Further, the size of the tightening bellows may be increased to a size equivalent to the tightening plate in consideration of the space efficiency and the gas pressure in the bellows. Between the upper and lower tightening plates and the uppermost and lowermost unit cells, an electron conductive current collecting end plate 26 that is in contact with the cell and an electric insulating plate 27 that electrically cuts off the tightening plates are interposed. ing. A reaction gas supply / discharge pipe connected to a manifold for supplying / discharging gas to / from each cell is connected to the lower tightening plate, and a second electrical insulation is provided between the upper tightening plate 21 and the tightening bellows 25. A plate 28 is interposed so that the bellows has the same potential as the ground potential as does the container. The tightening pressure is controlled by the gas pressure filled in the bellows.

Further, an improved example of the present invention will be described. Since the electromotive portion is joined only to the contact of each component with respect to the manifold portion that mechanically joins the separators to each other, the adhesiveness directly affects the power generation performance. As described above, connect the manifold part and the electromotive part to the upper and lower tightening plates 21, 2.
When pressed by 2, both parts are tightened with the same amount of displacement, so the elasticity of both parts with respect to tightening affects the controllability of the tightening pressure applied to the electromotive part. In order to improve the controllability, the elastic modulus of the manifold portion against the compression is made smaller than that of the electromotive portion. That is,
By making the reaction force of the manifold part against tightening sufficiently smaller than the reaction force of the electromotive part, the tightening pressure applied to the electromotive part is well controlled and the adhesion of the electromotive part is made more reliable. . Thereby, the electrical contact property and the wet seal property of the electromotive portion can be improved.

Next, a second embodiment for eliminating the variation in height within the electromotive surface will be described. As described above, by sufficiently reducing the reaction force of the manifold portion, the difference in height between the manifold portion and the electromotive portion can be absorbed, but the variation in height within the electromotive portion cannot be eliminated. If there is a large height locally in the electromotive part,
A part where the tightening pressure is not applied occurs in the peripheral part. Therefore, the elastic body 29 is interposed between the current collecting end plate 26 and the electric insulating plate 27. The conceptual diagram is shown in FIG. The difference from FIG. 1 is the presence of the interposed elastic body 29. This elastic body can be freely deformed according to the unevenness of the contacting separator. By interposing such an elastic body, the elastic body is more contracted and deformed at a locally large height in the electromotive portion, and a uniform tightening pressure can be applied to the entire electromotive portion. . Thereby, the adhesion of the electromotive portion can be improved.

In this example, the current collecting end plate 26 is sandwiched between the elastic body 29 and the battery stack, but the current collecting end plate 26 is sufficiently flexible so that it can be deformed following the irregularities of the separator. Must be rich. If the elastic body has a high electric conductivity, the current collecting end plate 26 may be sandwiched between the elastic body 29 and the electric insulating plate 27.

Further, in this example, the elastic body 29 is interposed between the battery stack and the upper tightening plate 21, but the position of the elastic body is not limited to this, and may be between the separators or the middle. Between the header and the battery unit, or the lower clamp plate 2
The same effect can be obtained regardless of where it is interposed, such as between 2 and the battery stack. Also, a plurality of elastic bodies may be interposed at the same time.

Next, a structural example of the elastic body interposed between the battery laminate and the tightening plate will be described. FIG. 3 shows an example of an elastic body used for tightening the battery stack. Spring 3 in which projections 31 are provided at equal intervals by pressing a thin metal plate
2 is a laminate of two with the protrusions being out of phase. The flat portion of the spring 32 is bent by the protrusion of the spring immediately below, so that the entire spring 32 exhibits elastic characteristics. Actually, as shown in FIG. 5, ten springs 32 are used in a stacked manner. In order to eliminate the variation in the entire surface of the separator, it is effective to stack the springs 32 having a width sufficiently narrower than the width of the separator and to arrange them in parallel.

A spacer may be arranged between the narrow springs to limit the maximum contraction amount of the springs. An example thereof is shown in FIG. This spring 3
3, the spacers 34 whose thickness does not change are arranged between the springs 32 of FIG. Further, springs of such a combination may be stacked and used with thin plates. In this case, the total amount of contraction can be increased while suppressing the amount of contraction of each spring and keeping the stress applied to the springs small.

Since such an elastic body has a small heat transfer area in the stacking direction, it is possible to suppress the heat loss that flows out from the cell stack through the tightening structure to the outside, and to improve the system efficiency of the fuel cell. it can. Furthermore, when the temperature of the battery stack is raised or lowered, thermal stress is generated due to the difference in thermal expansion between the battery stack and the tightening structure, but this elastic body expands and contracts in the plane direction to relax the thermal stress. There is also.

Further, another elastic body is shown in FIG. This elastic body is obtained by accommodating the laminated body of the springs 32 shown in FIG. 3 inside the bellows 35 which contracts by gas pressure. With the elastic body shown in FIG. 3, the entire surface of the separator cannot be clamped with a uniform pressure. This is because the spring that locally contacts the location where the height of the battery stack is large flexes greatly,
This is because the reaction force at that point is large. Therefore, the improvement of this example is that a more uniform tightening pressure can be obtained over the entire surface of the separator. A more uniform tightening pressure can be obtained by using the bellows to supplement a portion where the amount of bending is small and the tightening pressure is small only with the spring. A thin plate is used on the surface of the bellows that comes into contact with the separator so that the unevenness of the separator is sufficiently followed. This can improve the adhesion of the electromotive portion. The gas pipe for controlling the gas pressure in the bellows is electrically insulated, so that the gas pipe is provided later through a lower tightening plate shown in FIG. Further, by bringing the gas pressure inside the bellows close to vacuum, it is possible to reduce the amount of heat transfer in the stacking direction of the elastic body.

The invention described above works effectively even when the constituent elements shrink due to high temperature creep, but when the amount of shrinkage due to high temperature creep is large, the following construction is effective. In cells that operate at high temperatures, such as molten carbonate fuel cells, the separator and individual cell components creep when exposed to high temperatures, shrinking in thickness and height. Generally, in a fuel cell, the temperature is higher on the downstream side of the fuel gas and the oxidant gas, and the components located on the downstream side are more likely to creep at high temperature. Therefore, when the gas flows in one direction in the battery stack, there is a possibility that the gas may shrink more on the downstream side and the adhesion of the electromotive portion may be impaired.

Therefore, in the present invention, the battery units in which the gas flow directions are distributed are stacked to keep the shrinkage amount of the entire battery stack uniform. FIG. 6 shows a conceptual diagram of the laminated fuel cell. The battery laminated body was divided into two battery units 41 and laminated via the intermediate header 42. In the figure, the direction of the fuel gas 43 flowing inside the cell stack is indicated by an arrow.
The fuel gas 43 supplied from the intermediate header 42 is distributed to each separator in the manifold, and after a cell reaction occurs in the electromotive portion, the fuel gas 43 is discharged through the intermediate header. The upper and lower cell units are arranged so that the fuel gas 43 flows in opposite directions. The downstream side of the fuel gas, that is, the upper battery unit is on the right side in the figure, and the lower battery unit is on the left side in the figure.The contraction amount becomes larger during power generation operation, but the overall contraction amount can be kept uniform. it can. As a result, the above-mentioned tightening plate and elastic body were easy to function, and the adhesion of the electromotive portion was improved. Although only the direction of the fuel gas is shown in the figure, the oxidizing gas also flows in the opposite direction.

Distributing the gas to the battery unit by the intermediate header causes another factor that hinders the adhesion. That is, when the stacked intermediate headers are connected by pipes, the length of the pipes limits the distance between the headers. If this space does not shrink, the adhesion of the electromotive portion is impaired.
Therefore, the intermediate headers are connected to each other by expansion piping. An example thereof is shown in FIG. The battery units 41 that are stacked in the same manner as in FIG. 6 are stacked via the intermediate header 42, and the pipe 4 for the fuel gas 43 that connects the intermediate headers 4 together.
4 are connected via a telescopic pipe 45. Therefore, as the battery unit 31 contracts, the expansion pipe 4
5 also contracts. This figure shows an example in which the fuel gas is made to flow in the same direction in the upper and lower cell units, but of course the same effect can be obtained by making it flow in the opposite direction. The same applies to the oxidant gas piping.

When an elastic body is interposed between the intermediate header and the battery unit, the reaction gas pipe connecting the intermediate header and the battery unit must expand and contract as the elastic body expands and contracts. Therefore, as shown in FIG. 8, the expansion tube 46 is used for the pipe of the fuel gas 43 that connects the intermediate header 42 to the manifold of the battery unit 41.

Next, a method for tightening the battery stack will be described. Since excessive clamping pressure promotes high temperature creep of the separator and cell components, it is preferred that the clamping pressure of the stack be sufficient and minimal to provide electrical contact and wet sealing. Therefore, we attempted a method to reduce the tightening pressure during power generation operation. When a high tightening pressure is temporarily applied to the battery stack, warpage of the separator and the unit cell is eliminated, and the adhesion of the electromotive part can be improved with a relatively low tightening pressure. FIG. 9 is a graph showing the relationship between the pressure difference between the gas inside and outside the wet seal and the flow rate of the gas leaking from the wet seal portion. The tightening pressure during power generation is 1
Although it was set to kgf / cm ² , it was once 3 kgf / cm before operation.
^{When the} laminate was tightened at ² , the amount of gas leakage was significantly reduced even after returning to the tightening pressure of 1 kgf / cm ² . 3k
The gf / cm ² tightening time was within 10 hours, but the effect was due to the fact that each element constituting the stack became familiar with the tightening. As a result, the adhesion of the electromotive section was improved.
Here, “before operation” refers to a state in which the laminated battery is kept at a temperature at which the oxidation reaction of the cathode separator material is not so large and the high temperature creep of the single cell material is not large. This temperature is about 450 ° C. or lower. This temporary tightening is not limited to before power generation, and it is of course possible to obtain the same effect after power generation operation is started, but the tightening time is set to prevent the material from shrinking due to high temperature creep. It is desirable to make it shorter.

Next, a tightening plate having a small heat capacity will be described. FIG. 10 shows a battery stack 52 that is tightened from above and below using a tightening plate 51 composed of ribs. At the four corners of the battery stack, the upper and lower tightening structures are fixed to each other with through rods (not shown). Since the tightening structure has a space between the ribs, the heat capacity is sufficiently small. Further, since the rib is made high in the central portion where the bending stress applied to the rib is large and is made low in the peripheral portion, the heat capacity can be suppressed by using the minimum number of members necessary to satisfy the strength of the tightening structure. . The space between the ribs is preferably filled with a material having a low heat radiation ability and a heat insulating property.

FIG. 11 shows another embodiment of the tightening plate. The tightening plate 53 has a rib joined to a thin plate to secure the strength while suppressing the heat capacity. An embodiment in which the battery stack is assembled in a horizontal cylindrical container 54 by using this tightening plate 53 is shown in FIG.
2 shows. The central cylindrical rib of the tightening plate is held by the expandable expandable tightening bellows 25. An electric insulating layer is formed by plasma spraying of alumina on the surface where the cylindrical rib and the tightening bellows are in contact with each other. Reference numeral 57 in the figure is a current extracting member. By thickening the central portion of the tightening plate, uniform tightening is possible with the tightening bellows having a cross section smaller than the cross section of the battery stack. Further, it is possible to increase the volumetric efficiency when it is housed in a horizontally placed cylindrical container. In addition, since the tightening plate has a rib structure, the heat transfer passage that is transmitted from the battery stack to the container can be made small, and heat loss can be suppressed. In FIG. 10, the provisional tightening bar that tightens the laminated battery in FIG. 10 is omitted, and the battery laminated body is tightened by the tightening bellows attached to the container. Further, the heat insulating material (heat insulating material) in the container is not shown.

FIG. 13 shows an embodiment in which the battery laminated body is similarly housed in a vertical cylindrical container 56. This figure is seen from the diagonal position of the quadrilateral battery stack.

The current collecting end plate 26 shown in FIGS. 12 and 13 is connected to the current extracting member 57 so that the electric output of the laminated battery is taken out of the container. However, the battery laminated body is incorporated in the container. Figure 1 to make the connection easier sometimes
As shown in FIG. 4, a current extraction member 57 is arranged on the container wall 58 via the glass 59 and the expansion bellows 60, and the current extraction member 57 and the current collecting end plate 26 are in contact with each other by the expansion bellows 60. Is configured. Then,
When the battery stack is assembled in a container, the current collecting end plate 2 is produced by its own weight.
6 presses the expandable bellows 60 with the current extracting member 57 interposed therebetween, and the expandable bellows 60 presses the current extracting member 57 against the current collecting end plate 26 by the pressure of the gas supplied from the gas supply pipe 61.

Next, FIG. 15 shows an example in which a plurality of laminated bodies are incorporated in a horizontally placed cylindrical container. The lower tightening plate 62 is common to all the laminated bodies and also serves as a gas header for supplying a reaction gas to each laminated body. FIG. 16 shows the state of connection between the laminated body and the lower tightening plate 62, and FIG. 17 shows the AA cross-section detail thereof. The structure is such that the header of the reaction gas and the manifold are connected by simply placing the laminated body on the lower tightening plate.
The reaction gas 72 flowing through the connecting portion is indicated by an arrow in the figure. That is, the lower tightening plate 62 is provided with a gas supply port 63 at a position corresponding to the manifold of each laminated body, and the first connector 64 is attached to each gas supply port 63 via the bellows 65. There is. On the other hand, a second connector 66 is provided on each manifold of the stack. Therefore, when the laminated body is placed on the lower clamping plate, the second connector 66 mounted on the manifold of the laminated body is engaged with the first connector 64 mounted on the bellows 73 of the lower clamping plate 71 by fitting. To meet. At this time, the bellows 65 contracts, and the reaction force of the bellows 65 airtightly connects the pipes at the connecting portion. That is,
If the thermal expansion coefficients of the two are different, the two mesh with each other during the temperature rise before the power generation operation, and the airtightness is maintained. By simply installing the laminated body in this way, the airtightness is automatically obtained, and the pipe connecting work is unnecessary. Further, in order to improve the electric insulation between the laminated body and the container, the lower tightening plate is preferably made of an electric insulating material such as ceramics.

Next, the electrical insulation of the high voltage portion of the laminate will be described. FIG. 18 shows an example in which a plurality of laminated bodies are connected in series. In order to reduce the power loss of power transmission, it is preferable to connect the stacked bodies in series and increase the voltage value without increasing the current value, but at this time, depending on the method of electrical connection, electrical insulation of high voltage difference may be performed. Will be required. The connecting method shown in the figure is a connecting method of the laminated body in which the voltage difference of electrical insulation is suppressed to a small level.
Each of the laminated bodies is housed in a container, and the container is kept at the same potential as the ground. The electric potential of the laminated body was set to the ground electric potential of the central electric lead 71 connected in series. Therefore, the highest potential of the connected batteries is distributed such that the leftmost laminate L is negative and the rightmost laminate R is positive with respect to the ground potential, and the maximum potential difference between the laminate and the container is determined. Was minimized. As described above, the electrical insulation between the laminated body and the container is performed by the electrical insulating plate interposed between the tightening plate and the current collecting end plate. Are overlapped at a position where the temperature is low and the electrical insulation is high. The electric insulating plate 28 shown in FIGS. 1 and 2 is used in the upper portion of the laminated body, and the electrically insulating lower clamping plate 62 shown in FIGS. 15 and 16 is used in the lower portion of the laminated body.

Needless to say, various changes can be made without departing from the scope of the present invention.

[0046]

Since the present invention is constructed as described above, by improving the adhesion of the electromotive portion, it is possible to reduce the electrical contact resistance and also improve the sealing performance of the wet seal. As a result, the performance of the stacked fuel cell can be improved.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a laminated fuel cell in which a fastening plate is extended to an electromotive portion according to the present invention.

FIG. 2 is a conceptual diagram of a laminated fuel cell in which an elastic body is interposed between a cell laminated body and a fastening plate according to the present invention.

FIG. 3 is a perspective view of a spring interposed between a battery stack and a tightening plate according to the present invention.

FIG. 4 is a perspective view of another embodiment of the spring interposed between the battery stack and the fastening plate according to the present invention.

FIG. 5 is a cross-sectional view of a bellows interposed between a laminated body and a fastening plate according to the present invention.

FIG. 6 is a conceptual diagram of a laminated fuel cell according to the present invention, in which cell units having gas flow directions opposite to each other are laminated.

FIG. 7 is a conceptual diagram of a laminated fuel cell in which an intermediate header according to the present invention is connected by expansion pipes.

FIG. 8 is a partial view of a laminated fuel cell in which an elastic body is interposed between an intermediate header and a cell unit according to the present invention.

FIG. 9 is an explanatory diagram showing a change in leak amount with respect to a gas differential pressure.

FIG. 10 is a perspective view of a battery stack tightened using a tightening plate having a rib structure.

FIG. 11 is a perspective view of another embodiment of the tightening plate having a rib structure.

FIG. 12 is a cross-sectional view of a battery laminated body incorporated in a horizontal container.

FIG. 13 is a cross-sectional view of a battery laminated body incorporated in a vertically placed cylindrical container.

FIG. 14 is a connection partial view of a current collecting end plate and a current extracting member.

FIG. 15 is a perspective view of a fuel cell in which a plurality of stacks are assembled in a horizontal container.

FIG. 16 is a detailed view of a connecting portion between the laminated body and the lower tightening plate.

FIG. 17 is a sectional view of a connecting portion between the laminated body and the lower tightening plate.

FIG. 18 is a connection conceptual diagram of a fuel cell in which a plurality of laminated bodies are connected in series.

FIG. 19 is an exploded perspective view illustrating the configuration of a general molten carbonate fuel cell.

[Explanation of symbols]

 1 Single Cell 3 Anode 4 Cathode 5 Separator 9 Anode Current Collector Plate 10 Cathode Current Collector Plate 13 Manifold Ring 21 Upper Tightening Plate 22,62 Lower Tightening Plate 23 Electromotive Portion 24 Manifold Portion 26 Current Collector End Plate 27, 28 Electricity Insulation plate 29 Elastic body 32 Spring 35 Bellows 42 Intermediate header 45 Expansion pipe 46 Expansion pipe 51,53 Tightening plate 57 Current extraction member 64,66 Connector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Murata 1 Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Research & Development Center

Claims (10)

[Claims] 1. A single cell in which an electrolyte matrix is sandwiched between an anode and a cathode, and a separator for introducing a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated to supply and exhaust both gases. In a laminated fuel cell having an internal manifold formed of holes formed in the peripheral portion of each separator, the manifold penetrating the laminated body, and integrally covering the manifold portion and the electromotive portion where the unit cell is located. A laminated fuel cell characterized by being fastened with a plate-shaped structure. 2. The laminated fuel cell according to claim 1, wherein the elastic modulus of the cell stack against compression is smaller than that of the electromotive part. 3. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated, A laminated fuel cell, wherein the laminated body is fastened via an elastic body. 4. The stacked fuel cell according to claim 3, wherein the elastic body is composed of a plate-shaped spring which expands and contracts by utilizing elasticity of the plate. 5. An elastic body for tightening a battery stack, comprising a plate-shaped spring that expands and contracts by utilizing the elasticity of the plate in a gas bellows that keeps gas tight inside and expands and contracts by the pressure of the gas. 4. The stacked fuel cell according to claim 3, wherein the stacked fuel cell is configured by including the. 6. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated. A laminated body characterized in that the laminated body is divided into a plurality of units and laminated, and a downstream side of a fuel gas or an oxidant gas of an arbitrary unit is positioned on a gas upstream side of a unit laminated on the unit. Type fuel cell. 7. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated. A laminated fuel cell, wherein a laminated body is divided into a plurality of units and laminated, and gas pipes connecting intermediate headers for supplying and exhausting gas to and from each unit are connected via expansion joint pipes. 8. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated, wherein: A laminated fuel cell, wherein a laminated body is divided into a plurality of units and laminated, and an elastic body is interposed between an intermediate header for supplying and discharging gas to each unit and a cell laminated body unit. 9. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated, With a pressure higher than the predetermined tightening pressure during operation,
A laminated fuel cell characterized by temporarily tightening a cell stack. 10. A laminated fuel cell in which a unit cell in which an electrolyte matrix is sandwiched between an anode and a cathode, and a separator for guiding a fuel gas to the anode and a separator for guiding an oxidant gas to the cathode are alternately laminated. A laminated fuel cell, wherein a tightening plate for tightening the laminated body from above and below has a rib structure and a central portion is thicker than a peripheral portion.