JP2012014858A - Cylindrical solid oxide type fuel battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical solid oxide type fuel battery that has superior thermal stress and a superior power generation amount per unit volume since a flat plate type solid oxide fuel battery has uneven thermal stress due to a temperature difference between electrodes resulting from heat generation accompanying power generation, and a circular cylinder type solid oxide type fuel battery and a rectangular solid oxide type fuel battery are inferior in output per area to the flat plate type battery cell.SOLUTION: The cylindrical solid oxide type fuel battery constituted by connecting many cylindrical battery cells each comprising of a laminate wall body formed by stacking an air electrode layer, an electrolyte layer and a fuel electrode layer in order comprises a center part cylindrical battery cell arranged at a center-part and a plurality of side-part cylindrical battery cells joined in parallel along a longitudinal surface of the cylindrical battery cell, the side-part cylindrical battery cells each having only one place joined to the longitudinal side face of the center-part cylindrical battery cell in a line contact state.

Description

  The present invention relates to a solid oxide fuel cell, and more particularly to a compact cylindrical solid oxide fuel cell that can be rapidly started from a cold state, has excellent durability, and has a high specific output.

As a mechanism to convert fossil fuel into power, the 19th century is changing to solid fuel coal and steam engine, the 20th century is liquid fuel oil and internal combustion engine, and the 21st century is changing to gas fuel and fuel cell. is there.
Among them, solid oxide fuel cells (hereinafter referred to as SOFC) have no fuel selectivity, hydrogen and carbon monoxide can be used as fuel at the same time, no precious metals are used, and exhaust heat temperature is high. There are many advantages over battery systems, and development is progressing around the world for practical use.
SOFC is composed of an electrolyte layer that does not allow gas to pass through, and a porous fuel electrode layer and an air electrode layer disposed on both sides of the electrolyte layer (hereinafter referred to as a bipolar layer when both are shown). Oxygen moves in the electrolyte as oxygen ions and reacts with fuel in the fuel electrode layer to generate electricity.

  The operating temperature of the SOFC is set high in order to increase the oxygen ion conductivity in the electrolyte layer and increase the reaction rate in each electrode layer. In order to cope with this high temperature, a ceramic material is used for main components including the electrolyte layer.

In view of thermodynamics, it is impossible to convert the energy generated by the oxidation reaction of fuel to 100% electricity, and heat is generated on the fuel electrode layer side by power generation even in a constant load operation state. And non-uniform distribution of the heat capacity, heat transfer coefficient, mass, etc. around the bipolar layers brings about non-uniform temperature distribution in the battery cells, and causes thermal stress.
In particular, due to rapid start-up and sudden load fluctuations during operation, the uneven distribution of temperature around the bipolar layers is further increased, and higher thermal stress is generated than during steady operation.
On the other hand, the critical stress coefficient of the ceramic material is as small as about 1/100 that of metal, and the reduction of thermal stress and thermal deformation applied to the ceramic member is a major issue in realizing SOFC.

Furthermore, if the fuel electrode layer and the air electrode layer have a macroporous structure for allowing a gas to pass therethrough, an electrolyte layer having vacancies in the lattice for allowing oxygen ions to pass through may have a microscopic structure at the molecular level. It can be said that it has a porous structure.
Combined with the low critical stress coefficient described above, it can be said that the correspondence to micro and macro porous structures is a challenge for the practical application of SOFC formed of ceramics.

The SOFC can be said to be a system for generating electricity by dividing a space by a solid oxide electrolyte membrane and providing an electrode on each side of the electrolyte membrane to flow different gases.
The currently developed SOFC that divides the space into two is roughly divided into two layers: the electrolyte layer on both sides of the plate-like electrolyte layer shown in FIG. 9 and the inner and outer surfaces of the cylindrical electrolyte layer shown in FIG. There are a flat plate type SOFC and a cylindrical type SOFC that generate electric power by arranging a fuel electrode layer and an air electrode layer between them.

The flat SOFC cell 100 has an example as shown in FIG.
Two interconnectors 101 each having an electrolyte layer 102, a fuel electrode or an air electrode in contact with both surfaces of the electrolyte layer 102, and sealing the periphery of both electrodes from the outside; the electrolyte layer 102 and the interconnector 101; And two gaskets 103 which are sandwiched between and seal the periphery of both electrodes. Then, fuel or air passages are formed by two holes on the diagonal of the four holes provided in the battery cell, and power is generated by the reaction between the fuel and air supplied from the respective passages.

  The flat plate SOFC cell 100 has significant manufacturing advantages because the components are mainly flat.

FIG. 10 shows a cylindrical SOFC cell 150 as an example of a cylindrical SOFC cell.
As shown in FIG. 10, the cylindrical SOFC cell 150 includes a battery cell in which an air electrode layer 154 is disposed on the outer peripheral surface of a cylindrical electrolyte layer 152 and a fuel electrode layer 153 is disposed on the inner peripheral surface. In addition, the electrolyte layer 152 and the air electrode layer 154 disposed on the outer peripheral surface thereof are provided with slits along the axis, and the fuel electrode layer 153 disposed on the inner peripheral surface of the electrolyte layer from the slit. An interconnector connected to the battery cell protrudes from the battery cell.
Electric power is generated by allowing fuel to flow through the hollow portion of the cylindrical SOFC 150 and air to the outer peripheral portion.

Unlike the flat plate SOFC cell 100, the cylindrical SOFC cell 150 is formed of a closed wall, and the same temperature difference as the flat plate SOFC cell 100 between the fuel electrode layer 153 and the air electrode layer 154 of the battery cell. Even in the case of the occurrence of thermal stress, the thermal stress is smaller than that of the flat plate SOFC cell.
Furthermore, the cylindrical SOFC cell 150 does not have the large interconnector found in the flat SOFC cell, and therefore the heat capacity distribution of the power generation unit is almost constant throughout the region except for the gas seals at both ends. The stress is smaller than that of a flat plate SOFC cell.

The invention disclosed in Patent Document 1 is shown as an example of a rectangular tube type SOFC cell.
In paragraph [0022] of Patent Document 1, a solid electrolyte 212 of YSZ (yttria-stabilized zirconia) is laminated on the three side surfaces of the outer peripheral surface of a lanthanum manganate-based porous rectangular tube-shaped air electrode support tube 211, Further, a porous fuel electrode 213 made of cermet made of nickel or a nickel alloy and YSZ is laminated on the outer peripheral surface of the solid electrolyte 212, and a lanthanum chromite oxide (LaCrOn) oxide is formed on the remaining one side of the air electrode support tube 211. A solid electrolyte fuel cell assembly having a structure shown in FIG. 11 in which a connector 214 is laminated is disclosed.

  In addition, in [Claim 1] of Patent Document 1, as a manufacturing method of the solid electrolyte fuel cell assembly, “a plurality of prismatic electrode support tubes that serve both as an air electrode or a fuel electrode and a shape-retaining body are provided. An electrode layer having a polarity opposite to that of the electrode support tube is arranged on the outer periphery of the solid electrolyte, and is arranged on the separator at equal intervals, and then, a solid electrolyte is laminated on the open outer peripheral surface of each of the plurality of electrode support tubes. Is manufactured to produce a solid electrolyte fuel cell assembly unit in which a plurality of rectangular cylindrical solid electrolyte fuel cells are arranged at equal intervals on the separator.

  Further, in [Claim 2] of Patent Document 1, “a plurality of solid electrolyte fuel cell assembly units manufactured by the manufacturing method of claim 1 are stacked in a plurality of stages, and each of the electrode support tubes is disposed inside each of the electrode support tubes. The solid electrolytic fuel cell assembly in which either one of the oxidizing gas and the fuel gas is allowed to flow, and either the oxidizing gas or the fuel gas is allowed to flow in the gap between the columns of the rectangular tube solid electrolyte fuel cells. A method for supplying fuel gas and oxidizing gas to the solid electrolytic fuel cell is shown.

Japanese Patent No. 3722927

  However, in the flat SOFC cell 100, as described above, the interconnector 101 and the electrolyte layer 102 are fixed or semi-fixed via the gasket 103 for gas sealing around the fuel electrode and the air electrode. The peripheral deformation is limited. Therefore, the thermal stress resulting from the temperature difference between the fuel electrode and the air electrode due to heat generated by power generation is expanded.

In addition, the peripheral portion of the electrolyte layer 102 of the flat plate type SOFC cell is in contact with the interconnector and gasket having a large heat capacity. Therefore, the heat capacity distribution between the portion related to power generation of the electrolyte layer 102 and the peripheral portion becomes non-uniform. When the temporal temperature change such as in the middle is large, a large temperature difference is generated inside, and high thermal stress is generated.
In recent years, examples of flat plate SOFC cells that can provide stable output in steady operation have increased, but there are still examples in which deterioration occurs due to repeated starting and stopping. One of the causes is considered to be the thermal stress during the warm-up.

  Furthermore, since the interconnector 101 and the gasket 103 of the flat plate type SOFC cell seal the periphery of the fuel electrode and the air electrode, a region that does not contribute to power generation is formed around the battery cell. If this increase is required, the presence of this region is likely to be a drawback of the flat battery cell.

In the cylindrical SOFC cell 150, the ratio of the area related to power generation around the cylinder and the volume of the cylinder is smaller than that of the flat plate SOFC cell, and the output per volume is inferior to that of the flat plate SOFC cell.
In addition, the serial connection of the cylindrical SOFC cells 150 is more complicated than the flat plate SOFC cells that can be connected via a plane.

Further, as described in paragraphs “0029” and “0030” of the specification, the solid electrolyte fuel cell assembly disclosed in Patent Document 1 having the structure shown in FIG. 11 is interconnected on a separator 221 forming a current collector. A solid electrolyte fuel cell (hereinafter referred to as a rectangular tube type SOFC cell) 200A is stacked in a matrix arrangement of a plurality of stages and a plurality of columns so that 214 faces the same direction, and a lower separator 221 and a rectangular tube type SOFC cell 200A are stacked. Between the upper and lower rectangular tube type SOFC cells 200A and 200A, and between the rectangular tube type SOFC cell A and the upper separator 221, a nickel or nickel alloy felt 222 that performs a fuel reforming action and a conductive action is interposed. I am letting. An obturator plug (not shown) is attached to the end of each rectangular tube type SOFC cell 200A in the length direction, and air is supplied so that air as an oxidizing gas flows through the air electrode support pipe 211 from the outside. A tube is connected to the plugging body, and fuel gas is allowed to flow through gaps 223 between rows of the rectangular tube type SOFC cells 200A stacked in a plurality of stages to generate electric power.
Therefore, the upper surface of the rectangular tube type SOFC cells stacked up and down is connected to the upper separator 221 or the rectangular tube type SOFC cell by the interconnector 214, and there is no fuel electrode on this surface, and the surface does not contribute to power generation. Become.
Therefore, although there is a point to be seen in the manufacturing method that can form an interconnector-less solid electrolyte assembly unit in which the separator and the solid electrolyte fuel cell thereabove are integrated, the ratio between the power generation area and the volume of the rectangular tube, There exists a subject that an output is inferior to a cylindrical battery cell.

As a result of intensive studies in view of the above, the present inventor has solved this problem by the following means.
(1) In a solid oxide fuel cell formed by connecting a large number of cylindrical battery cells formed of a laminated wall formed by sequentially laminating an air electrode layer, an electrolyte layer, and a fuel electrode layer,
It consists of a central cylindrical battery cell arranged in the central part and a plurality of side cylindrical battery cells that are joined in parallel along the longitudinal side surface of the cylindrical battery cell and do not cross each other. And each said side part cylindrical battery cell is a thing of the structure formed by joining only one place by the line contact state to the vertical side surface of the said center part cylindrical battery cell, The cylindrical solid oxide characterized by the above-mentioned Fuel cell.
(2) The cylindrical solid oxide fuel cell as described in (1) above, wherein the cylindrical battery cell has a polygonal cylindrical shape.
(3) The cylindrical solid oxide fuel cell as described in (1) above, wherein the cylindrical battery cell is cylindrical.
(4) The plurality of side cylindrical battery cells are radially arranged on the side surface of the central cylindrical battery cell at equal intervals, and the central cylindrical battery cell and the plurality of side cylindrical battery cells are arranged. The inner wall surface is a fuel electrode layer, the outer wall surface is an air electrode layer, or the outer wall surface is a fuel electrode layer, the inner wall surface is an air electrode layer, and the air electrode layer constituting the outer wall surface of each cylindrical battery cell. Alternatively, the cylindrical solid oxide fuel cell as described in any one of (1) to (3) above, wherein the fuel electrode layer is formed on one continuous surface.
(5) In the cylindrical battery cell, a hollow portion inside the inner wall surface is used as an inner passage, a space outside the outer wall surface is used as an outer passage, and a fuel electrode layer or an air electrode constituting the wall surface of the passage is formed in each passage. 6. The cylindrical solid oxide fuel cell as set forth in any one of (1) to (4), wherein fuel or air corresponding to the layer is supplied.

(6) A battery cell stack is formed by stacking a plurality of cylindrical solid oxide fuel cells according to any one of (1) to (5) above and below, and each upper battery cell. The fuel electrode layer and the lower battery cell air electrode layer, or the upper battery cell air electrode layer and the lower battery cell fuel electrode layer are connected in series with an interconnector having the functions of a conductive and gas seal, respectively. A cylindrical solid oxide fuel cell characterized by the above.
(7) In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from contacting each other, the base portion (structure body) of the laminated wall body of each battery cell In the case where the layer to be) is an electrolyte, an annular blank portion in which the respective polar layers are not provided on the upper wall surface on the outer wall surface and on the lower wall surface surface on the inner wall surface is provided. The cylindrical solid oxide fuel cell according to item (6).
(8) In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from contacting each other, the base portion (structure body) of the laminated wall body of each battery cell ) Is a fuel electrode layer or an air electrode layer, an electrode layer serving as a base portion is provided as an inner wall surface of the laminated wall body, an electrolyte layer is laminated on the outer surface thereof, and the electrolyte layer is further attached to the substrate. It is continuously stretched so as to be formed as a folded portion with a minute height at the lower end surface and the lower end portion of the inner wall surface of the polar layer, and the outer wall surface of the electrolyte layer is different from that used as the base portion. The air electrode layer or fuel electrode layer to be an electrode layer is provided, and an annular blank portion not provided with the electrode layer is provided on the outer surface of the electrolyte layer. A cylindrical solid oxide fuel cell.
(9) In the case where the battery cell stack has an inner wall surface of the constituent battery cell as a fuel electrode, each inner passage is provided with a columnar spacer similar to the shape of the inner passage to narrow the inner passage space, The cylindrical solid oxide fuel cell as set forth in any one of (6) to (8), wherein only the fuel of an amount contributing to the reaction of (1) is allowed to flow.
(10) When the battery cell stack has a fuel electrode on the inner wall surface of the constituent battery cell, a chamber for supplying fuel to one end of the battery cell stack, and a cylinder similar to the shape of the inner passage in each inner passage With shape spacer,
After the fuel supplied from the chamber flows through the in-cylinder gas passage of the cylindrical spacer, the fuel is inverted at the other end of the cylindrical spacer, and the inverted fuel is the outer peripheral surface of the cylindrical spacer and the configuration. (6) to (6), wherein the fuel cell is configured to be discharged after passing only an amount of fuel that contributes to the reaction with the fuel electrode in the narrowed space between the inner wall surfaces of the battery cells. 8. The cylindrical solid oxide fuel cell according to any one of 8).

(11) A plurality of battery cell stacks according to any one of (6) to (10) are juxtaposed on the same plane, and each of them is connected in parallel, connected in series, or connected in a series-parallel combination. A cylindrical solid oxide fuel cell comprising a battery cell module.
(12) The cylindrical solid oxidation according to (10), wherein the battery cell module is formed by juxtaposing a plurality of the battery cell stacks in parallel grids or staggered grids on the same plane. Physical fuel cell.
(13) A plurality of the battery cell modules are juxtaposed in the same plane or stacked up and down and electrically connected, or a plurality of the battery cell modules juxtaposed in the same plane and electrically connected are stacked up and down. The cylindrical solid oxide fuel cell as described in (11) or (12) above, which is electrically connected.

According to the present invention, the following effects are exhibited.
1. According to the invention of claim 1 of the present invention,
In a solid oxide fuel cell formed by connecting a large number of cylindrical battery cells formed of a laminated wall body formed by sequentially laminating an air electrode layer, a fuel electrode layer, and an electrolyte layer,
The central cylindrical battery cell disposed in the central part, and a plurality of side cylindrical battery cells joined in parallel along the vertical side surface of the cylindrical battery cell, and each side cylindrical battery Since the battery cell has a configuration in which only one place is joined in a line contact state to the vertical side surface of the central cylindrical battery cell,
The central cylindrical battery cell and the side cylindrical battery cell constituting the cylindrical solid oxide fuel cell do not require a sealing function except for the upper and lower end surfaces, and the central cylindrical battery Since the battery cell and the plurality of side cylindrical battery cells are joined at one point in a line contact state, almost the entire inner and outer side surfaces can be used as the fuel electrode and the air electrode, and both the inner and outer sides Since almost the entire surface can be in contact with fuel or air, the power generation area can be increased as compared with other types of battery cells, and thus the amount of power generation per volume can be expected to increase.

Since each battery cell has a cylindrical shape with high structural rigidity, deformation of the battery cell due to heat generation due to power generation between the fuel electrode layer and the air electrode layer arranged to face each other with the electrolyte layer interposed therebetween can be greatly reduced.
In addition, since the membrane battery cell is made cylindrical, members such as interconnectors and gaskets as seen in flat SOFC cells are not required, and thermal stress due to nonuniform temperature distribution generated between this member and the electrolyte layer is eliminated. Generation can be greatly reduced.
For this reason, the temperature of a cylindrical solid oxide fuel cell during rapid warm-up or during load fluctuations during startup can be kept uniform, and deformation due to thermal stress can be greatly reduced, thus enabling high-temperature operation. High power density and high power generation efficiency can be obtained.

Since the central cylindrical battery cell and the plurality of side cylindrical battery cells are joined to the vertical side surface of the central cylindrical electronic cell only in one place in a line contact state,
It is less susceptible to the thermal stresses of the other cylindrical battery cells, so that the temperature of each battery cell cylinder during rapid warm-up during startup or load fluctuations can be kept uniform to further reduce deformation due to thermal stress. Can do.

  Since the solid oxide fuel cell of the present invention is composed of a central cylindrical battery cell and a plurality of side cylindrical battery cells arranged in the periphery thereof, the solid oxide fuel cell is stacked. The support span for the structure can be made larger than that of the conventional single cylindrical battery cell, and a solid oxide fuel cell having a stable and highly laminated structure can be obtained.

  Since a solid oxide fuel cell can be composed of a plurality of cylindrical battery cells having the same shape and the same structure, the fuel electrode layer, the electrolyte layer, or the air electrode layer can be generated by a spray coating method or a slurry coating method, Moreover, because of its cylindrical shape, access to the outer wall surface from the outside is easy and suitable for mass production, and the same manufacturing equipment can be used to generate each layer, contributing to the cost reduction of the manufacturing equipment. .

2. According to the invention of claim 2 of the present invention,
In addition to the effect of claim 1,
Since the cylindrical battery cell is polygonal, the shape of the battery cell can be selected as a fuel cell to be incorporated in another device according to the storage space, the design flexibility as the device is widened, and the integration density is increased. be able to.

3. According to the invention of claim 3 of the present invention,
In addition to the effect of claim 1,
Since the cylindrical battery cell has a cylindrical shape, the battery cell can be constituted by a cylindrical cylinder having the same shape and the same structure. Therefore, the battery is extremely easy to manufacture, is compact and low in cost, and has a high output. A cell can be realized. Furthermore, deformation due to an exothermic reaction during power generation can be greatly reduced.

4). According to the invention of claim 4 of the present invention,
In addition to the effects of claims 1 to 3,
The plurality of side cylindrical battery cells are arranged radially at equal intervals on the side surface of the central cylindrical battery cell, and any of the central cylindrical battery cell and the multiple side cylindrical battery cells Because the inner wall surface is the fuel electrode layer, the outer wall surface is the air electrode layer, or the outer wall surface is the fuel electrode layer, and the inner wall surface is the air electrode layer,
Cylindrical battery cells with the same shape and the same structure are arranged symmetrically, especially due to the temperature difference between the fuel electrode layer and the air electrode layer that face each other across the battery cell electrolyte layer due to the exothermic reaction during power generation. Since the deformation due to the generated thermal stress occurs uniformly in each cylindrical battery cell, the deformation and breakage of the battery cell due to the thermal stress can be prevented.

  In addition, since the air electrode layer or the fuel electrode layer constituting the outer wall surface of each cylindrical body is formed by one continuous surface, there is no need for an interelectrode connection structure for connecting the outer surface of each cylindrical battery cell. Thus, it is possible to realize a battery cell with high output while being compact and low cost.

5. According to the invention of claim 5 of the present invention,
In addition to the effects of the first to fourth aspects,
The cylindrical battery cell has a hollow portion inside the inner wall surface as an inner passage, a space outside the outer wall surface as an outer passage, and a fuel electrode layer or an air electrode layer constituting a wall surface of the passage in each passage. Can be supplied with fuel or air corresponding to
Coupled with the cylindrical battery cells having the same shape and the same structure being arranged symmetrically, the fuel or air supply passage is simplified, and therefore the fuel or air distribution / supply device has a symmetrical configuration. Deformation due to thermal stress generated by the temperature difference between the fuel electrode layer and the air electrode layer, including the distribution / supply device, can occur evenly in the cylindrical structure, distribution / supply device, so deformation due to thermal stress・ Can prevent damage.

6). According to the invention of claim 6 of the present invention,
A plurality of cylindrical solid oxide fuel cells according to any one of claims 1 to 5 are stacked one above the other, and a fuel electrode layer of each upper battery cell and an air electrode layer of a lower battery cell, or The battery cell stack is configured by connecting the air electrode layer of the upper battery cell and the fuel electrode layer of the lower battery cell in series with an interconnector having functions of conductivity and gas seal, respectively.
In addition to the effects of the first to fifth aspects,
The cylindrical solid oxide fuel cells can be easily connected to the required power supply voltage by stacking multiple stages in series. Therefore, the internal resistance is reduced by high temperature operation and the current loss is reduced by high voltage operation. A highly efficient battery cell stack can be realized.

7). According to the invention of claim 7 of the present invention,
In addition to the effect of claim 6,
In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from coming into contact with each other, it becomes a base portion (structure) of the laminated wall body of each battery cell. In the case where the layer is an electrolyte, since the outer wall surface is provided with a blank portion in which the respective polar layers are not provided on the upper wall surface on the outer wall surface and the lower wall surface surface on the inner wall surface,
Even when battery cells are stacked in multiple stages by using a conductive adhesive, there is no contact between the electrodes, electric leakage can be easily prevented, and other components such as gaskets are not required, and the cost is low due to a simple configuration. Battery cell stacks can be produced.
8). According to the invention of claim 8 of the present invention,
In addition to the effect of claim 6,
In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from coming into contact with each other, it becomes a base portion (structure) of the laminated wall body of each battery cell. When the layer is a fuel electrode layer or an air electrode layer, an electrode layer serving as a base part is disposed as an inner wall surface of the laminated wall body, an electrolyte layer is stacked on the outer side surface, and the electrolyte layer is used as a base part. The electrode layer is continuously stretched so as to be formed as a folded portion having a minute height at the lower end surface and the lower end portion of the inner wall surface, and on the outer wall surface of the electrolyte layer, an electrode layer different from that used as the base portion and Since an air electrode layer or a fuel electrode layer is provided, and an annular blank portion in which the electrode layer is not provided is provided on the upper surface of the electrolyte layer,
Even when battery cells are stacked in multiple stages by using a conductive adhesive, there is no contact between the electrodes, electric leakage can be easily prevented, and other components such as gaskets are not required, and the cost is low due to a simple configuration. Battery cell stacks can be produced.

9. According to the invention of claim 9 of the present invention,
In addition to the effects of claims 6 and 7,
When the inner wall surface of the battery cell stack is a fuel electrode, the battery cell stack is provided with a columnar spacer similar to the shape of the inner passage in each inner passage to narrow the inner passage space and react with the fuel electrode layer. Because it is configured to allow only the amount of fuel that contributes to the
The columnar spacer eliminates wasted fuel flowing through the center of the inner passage without coming into contact with the fuel electrode layer, which increases as the shape of the cylindrical battery cell increases and the inner passage expands. A good fuel cell can be constructed.

10. According to the invention of claim 10 of the present invention,
In addition to the effects of claims 6 and 7,
When the battery cell stack has a fuel electrode on the inner wall surface of the battery cell stack, a chamber for supplying fuel to one end of the battery cell stack, and a cylindrical spacer similar to the shape of the inner passage in each inner passage Prepared,
After the fuel supplied from the chamber flows through the in-cylinder gas passage of the cylindrical spacer, the fuel is inverted at the other end of the cylindrical spacer, and the inverted fuel is the outer peripheral surface of the cylindrical spacer and the configuration. Since it is configured to be discharged after flowing only the amount of fuel that contributes to the reaction with the fuel electrode in the narrowed space between the inner wall surfaces of the battery cells,
The fuel flowing through the central portion of the inner passage without contacting the fuel electrode layer, which increases as the shape of the cylindrical battery cell increases and the inner passage expands, is first introduced into the in-cylinder gas passage of the cylindrical spacer. After passing through, it was reversed at the other end of the cylindrical spacer and supplied to the inner passage by passing through a space narrowed between the outer peripheral surface of the cylindrical spacer and the inner wall surface of the constituent battery cell. A fuel can contact the fuel electrode layer without waste, and a fuel cell with good fuel efficiency can be configured.

  In addition, if the chamber for supplying the fuel is disposed in the lower part of the battery cell stack, the fuel supplied from the chamber flows through the in-cylinder gas passage of the cylindrical spacer, and then the The fuel is inverted at the other end, and the inverted fuel is discharged after flowing through the inner passage space narrowed between the outer peripheral surface of the cylindrical spacer and the wall surfaces of the plurality of battery cells, so that fuel such as light hydrogen is retained. It is possible to extend the time, expedite the discharge of heavy reaction gas such as carbon dioxide, and further improve the fuel efficiency.

11. According to the invention of claim 11 of the present invention,
A plurality of the battery cell stacks according to any one of claims 6 to 10 are juxtaposed on the same plane, and each of them is connected in parallel, connected in series, or connected in a series-parallel combination to form a battery cell module. Because
In addition to the effects of claims 6 to 10,
A battery cell module that supports large current capacity by connecting battery cell stacks in parallel, a module that supports high voltage batteries by connecting in series, and a battery cell module that supports large current capacity and high voltage by combining both Can be easily formed.

12 According to the invention of claim 12 of the present invention,
In addition to the effect of claim 11,
Since the battery cell modules are juxtaposed in a parallel grid pattern or a staggered grid pattern on the same plane,
Fuel passages and air passages are easy to form. Especially when battery cell stacks are arranged side by side in a staggered pattern, each outer passage space formed by the outer wall surface of each constituent cylindrical battery cell has a substantially uniform cross-sectional area. Therefore, the fuel or air flowing through the outer passage will be supplied uniformly to each constituent tubular battery cell, and the fuel or air will be in uniform contact with each polar layer of each tubular electric cell, Highly efficient and stable power generation is performed.

13. According to the invention of claim 13 of the present invention,
In addition to the effects of claims 11 and 12,
A plurality of the battery cell modules are juxtaposed in the same plane, or stacked up and down and electrically connected, or a plurality of the battery cell modules juxtaposed in the same plane and electrically connected are stacked up and down to be electrically connected. Connected to
As described above, it is possible to easily cope with the required power supply voltage by stacking a plurality of battery cells. Therefore, high efficiency is achieved by reducing internal resistance by high temperature operation and current loss by high voltage operation. Multiple battery cell stacks are made into battery cell modules, so that high current capacity compatible SOFCs with large current capacity connected by connecting battery cell modules in parallel, high voltage compatible with series connection, or a combination of them are easy. Can be formed.

The battery cell perspective view in case the layer used as the base | substrate part of the laminated wall body of the cylindrical solid oxide fuel cell of an Example of this invention is an electrolyte layer. The perspective view of the battery cell in case the layer used as the base | substrate part of the laminated wall body of the cylindrical solid oxide fuel cell of an Example of this invention is a fuel electrode layer or an air electrode layer. The perspective view of the battery cell stack of the cylindrical solid oxide fuel cell of the Example of the invention. The interconnector perspective view for connecting each battery cell which comprises the battery cell stack of the Example of the invention in series. Explanatory drawing of the cylindrical spacer arrange | positioned in the battery cell cylinder of the battery cell stack of the Example of the invention. The perspective view of the battery cell module of the parallel grid | lattice-like arrangement | positioning of the Example of the invention. The perspective view of the battery cell module of the staggered arrangement of the invention embodiment. The perspective view of the battery module system which has a minimum required function as a fuel cell of the Example of the invention. FIG. 7 is a structural diagram of a conventional flat plate type SOFC cell. FIG. 6 is a structural diagram of a conventional cylindrical SOFC cell. FIG. 6 is a structural diagram of a conventional rectangular tube type SOFC cell.

The cylindrical solid oxide fuel cell according to the present invention integrates a large number of cylindrical battery cells formed of a laminated wall formed by sequentially laminating an air electrode layer, an electrolyte layer, and a fuel electrode layer. The SOFC battery cell is formed, and in particular, the central cylindrical battery cell arranged in the central part is joined in parallel along the longitudinal side surface of the central cylindrical battery cell and intersects each other. Each side cylindrical battery cell is formed by joining only one portion in a line contact state with the vertical side surface of the central cylindrical battery cell. is there.
The laminated wall constituting each cylindrical battery cell has an electrolyte layer as a base part, and a fuel electrode layer and an air electrode layer facing each other with the electrolyte layer serving as the base part interposed therebetween, or a fuel electrode layer (or Any one in which an air electrode layer) is a base portion and an electrolyte layer and an air electrode layer (or a fuel electrode layer) are sequentially arranged on the outer surface thereof is selectively used.

  Further, the plurality of side cylindrical battery cells are arranged radially at equal intervals on a side surface of the central cylindrical battery cell, and any one of the central cylindrical battery cell and the plurality of side cylindrical battery cells is disposed. The inner wall surface is a fuel electrode layer, the outer wall surface is an air electrode layer, or the outer wall surface is a fuel electrode layer, the inner wall surface is an air electrode layer, and the air electrode layer or fuel that constitutes the outer wall surface of each cylindrical battery cell. The polar layer is formed by one continuous surface.

  Further, the hollow portion inside the inner wall surface of each cylindrical battery cell is used as an inner passage, and the space outside the outer wall surface is used as an outer passage. In each passage, a fuel electrode layer or an air electrode layer constituting the wall surface of the passage is provided. Corresponding fuel or air is supplied.

DESCRIPTION OF EMBODIMENTS Embodiments for carrying out the present invention will be described in detail with reference to the drawings.
Each cylindrical battery cell constituting the cylindrical SOFC battery cell 1 of the present invention may be any of a square, a rectangle, a rhombus, a polygon, a circle, or an ellipse, but has a typical regular quadrangular cross-sectional shape. A cylindrical SOFC formed of five cylindrical battery cells will be described with reference to the drawings of the embodiments.

  As shown in FIG. 1, a laminated wall in which the fuel electrode layer 2 and the air electrode layer 3 are arranged to face each other with the base portion of the electrolyte layer 4a interposed therebetween, or as shown in FIG. 2, a fuel electrode layer (or air electrode layer). A cylindrical battery cell formed by a laminated wall in which 3 is a base portion and an electrolyte layer 4a and an air electrode layer (or fuel electrode layer) 2 are sequentially arranged on the outer surface thereof is arranged at the central portion. Four sides of the same shape, the same size, and the same structure as the central cylindrical body 5 in which the cell 5 and the central cylindrical battery cell 5 are joined to the longitudinal side surface of the central cylindrical battery cell 5 in a line contact state. The part-cylinder battery cell 6 is integrated to form one battery cell. Hereinafter, the battery cell having this structure is referred to as a cylindrical SOFC battery cell 1.

Side cylindrical battery cells 6 of the cylindrical SOFC battery cell 1 are symmetrically arranged on the side surface of the central cylindrical body 5 radially at equal intervals both vertically and horizontally. Constitute.
In each of the one central cylindrical battery cell 5 and the four side cylindrical battery cells 6, the inner wall surface is the fuel electrode layer 2, the outer wall surface is the air electrode layer 3, and each of the cylindrical batteries. The air electrode layer 3 constituting the outer wall surface of the cell is formed by one continuous surface.

  The cylindrical SOFC battery cell 1 has a hollow portion inside the inner wall surface of each cylindrical battery cell as an inner passage 7, a space outside the outer wall surface as an outer passage 8, fuel in each inner passage 7, Air is passed through the outer passage 8.

In consideration of the case where the cylindrical SOFC battery cells 1 are connected in series in the vertical direction, in order to prevent the fuel electrode layers 2 and the air electrode layers 3 of the cylindrical SOFC battery cells 1 that are vertically stacked from contacting each other. 1, when the layer serving as the base portion of the laminated wall body of each cylindrical battery cell shown in FIG. 1 is the electrolyte layer 4a, the outer wall surface of each cylindrical battery cell is at the upper end portion, and the inner wall surface is at the lower end portion. A blank portion 9 in which no polar layer is provided is provided.
2 is a fuel electrode layer or an air electrode layer, the polar layer serving as the base portion as the inner wall surface of the multilayer wall body (in FIG. 2). A fuel electrode layer 2) is disposed, an electrolyte layer 4a is laminated on the outer side surface thereof, and the electrolyte layer 4 is further folded to a lower end surface 4c and a lower end portion of the inner wall surface of the electrode layer 2 serving as a base portion. 4b, and the electrode layer 4a is provided with an electrode layer (air electrode layer 3 in FIG. 2) different from that used as the base portion on the outer wall surface of the electrolyte layer 4a. An annular blank portion 9 not provided with the polar layer is provided on the outer surface upper portion.

The power generation amount of the cylindrical SOFC battery cell 1 of the present invention and the power generation amount of the flat plate SOFC cell are compared with the power generation area of the fuel electrode of the battery cell of the same volume.
If the inner side of the square cylinder of the cylindrical SOFC battery cell 1 of this embodiment is 6 mm, the height is 10 mm, the laminated wall thickness is 0.5 mm, and the inner wall surface is a fuel electrode layer, the power generation area is ,
(6 mm × 10 mm × 4 surfaces) × 5 = 1200 mm ²
It becomes.
On the other hand, the length of one side of the cylindrical SOFC battery cell 1 of the present invention made of five cylindrical battery cells is 20 mm including the thickness of the laminated wall, and the thickness of a square plate-type SOFC cell having a side of 20 mm is 3 mm. If the peripheral seal width is 6 mm in total, the power generation area of one flat plate SOFC cell is (20 mm−6 mm) ² , and the height of the cylindrical SOFC battery cell 1 of this embodiment is 10 mm. Since it corresponds to the thickness of three SOFC cells,
(20mm-6mm) ² × 3 = 588mm ²
It becomes. Therefore, the power generation area of the cylindrical SOFC battery cell 1 of the present invention is slightly more than twice that of the flat plate type SOFC cell.

FIG. 3 shows a perspective view of an embodiment of a battery cell stack 10 in which 12 cylindrical SOFC battery cells 1 composed of the five cylindrical battery cells are vertically stacked.
As shown in FIG. 3, an interconnector 11 is disposed between 12 battery cells 1 stacked one above the other, and the interconnector 11 causes the fuel electrode layer 2 of the upper battery cell 1 and the lower electrode layer 1 to The air electrode layers 3 of the battery cells 1 are electrically connected to each other (see FIG. 5B).

  In addition, the uppermost battery cell 1 and the lowermost battery cell 1 of the battery cell stack 10 are provided with current collecting plates 12 and 12 for taking out electric power. A chamber 14 for distributing fuel to the five inner passages of the stack 10 and a fuel that has moved up the gas passage inside the cylindrical spacer 18 in the battery cell stack 10 provided with a cylindrical spacer 18 described later at the upper end. Is placed in contact with the fuel electrode layer of each cylindrical SOFC battery cell 1 constituting the battery cell stack, and a stack upper 13 having a function of reversing the battery cell stack is provided.

The interconnector 11 shown in FIG. 4 has connector bent portions 16a and 16b. When the outer side surface of the constituent battery cell 1 is the air electrode layer 3 and the inner side surface is the fuel electrode layer 2, the upper cylindrical SOFC battery The air electrode layer 3 of the cell 1 and the fuel electrode layer 2 of the lower cylindrical SOFC battery cell 1 are connected, and the upper and lower battery cells are electrically connected in series.
In order to ensure the electrical continuity of the upper and lower battery cells 1 and the gas sealability at the joint surface between each cylindrical SOFC battery cell 1 and the interconnector 11, a conductive adhesive is applied to the entire surface of the interconnector 11. If necessary, it is applied before the battery cell stack 10 is formed.
In this case, when the battery cell stack 10 is produced, the leakage of electric current at the joint portion of each battery cell 1 with the interconnector 11 due to the protrusion of the unsolidified conductive adhesive from the adhesive portion is the blank shown in FIGS. It is completely prevented by the part 9 and the electrolyte layers 4c, 4b of FIG.

  Further, the interconnector 11 communicates the inner passages 7 of the central cylindrical body 5 and the side cylindrical body 6 of the cylindrical SOFC battery cell 1 stacked one above the other so as to allow gas to flow. The mouth 17 is provided in five places.

The action of the cylindrical spacer 18 disposed in each inner passage 7 of the battery cell stack 10 is based on the external view (a) and the XX ′ cross-sectional views (b) and (c) of the embodiment shown in FIG. I will explain.
The inner passage 7 of the battery cell stack 10 has a cylindrical spacer 18 similar to the shape of the inner passage 7, and the upper end of the battery cell stack 10 has an inner passage 7 of the uppermost tubular SOFC battery cell 1. A stack upper 13 is disposed to cover.

  The fuel indicated by the arrow supplied from the chamber 14 provided at the lower part of the battery cell stack 10 passes through the gas passage 19 of the cylindrical spacer 18 and reaches the stack upper 13 where it is reversed to constitute the battery cell stack 10. The fuel flows through the inner passage portion 7 narrowed between the inner wall surface of the central cylindrical body 5 and the four side cylindrical bodies 6 of each cylindrical SOFC battery cell 1 and the outer peripheral surface of the cylindrical spacer 18. While reacting with the polar layer 2 without waste, it reaches the lower part of the battery cell stack 10 again and is discharged.

  Here, instead of the cylindrical spacer 18, as shown in FIG. 5C, a columnar spacer 18 ′ similar to the shape of the inner passage is provided to narrow the inner passage space, and the fuel supplied from the chamber 14 is supplied. The fuel electrode 2 of each cylindrical SOFC battery cell 1 constituting the battery cell stack 10 is allowed to react without waste and discharged from the opening 13a of the stack upper 13 ′ disposed at the upper end of the battery cell stack 10. Also good.

  As shown in FIG. 6 or FIG. 7, a plurality of the battery cell stacks 10 are juxtaposed on the same plane, and each of them is connected in parallel or in series, or a battery cell module 20 is formed by serial / parallel combination connection. it can.

  Each cylindrical battery cell of the cylindrical SOFC battery cell 1 can be selected from any one of square, rectangular, rhombus, circular, or elliptical cross section, and a plurality of the battery cell stacks 10 are parallel to the same plane. Since the battery cell module 20 can be formed by arranging in a grid (FIG. 6) or in a staggered pattern (FIG. 7), the degree of freedom in design is high and the fuel cell of the device in which the fuel cell is incorporated is acceptable. The shape of the cylindrical battery cell can be selected according to the space to be formed, and the integration density can be increased.

Further, in this example, the battery cell 1 is configured with five square cylinder SOFCs, but is not limited to this, and is a polygonal cylindrical battery such as a pentagonal battery with six batteries or a hexagonal battery with seven batteries. It is good also as a cell.
In the above description, the inner wall surface of the cylindrical body is the fuel electrode layer 2 and the outer wall surface is the air electrode layer 3, but the inner wall surface may be the air electrode layer 3 and the outer wall surface may be the fuel electrode layer 2. .

In FIG. 8, the external view of the battery cell module system 21 as an example of a fuel cell was shown.
The battery cell module system 21 has a battery cell module 20 accommodated in an outer housing 22, and the fuel supplied from the lowermost fuel inlet 23 passes through the chamber 14 of the battery cell module 20 and is cylindrical. The gas 18 passes through the gas passage 19 of the spacer 18, is supplied to the upper part of the fuel electrode layer 2 of the battery cell stack 10, is inverted by the stack upper 13, and descends while performing a power generation reaction in the fuel electrode layer 2, and is oxidized from the fuel outlet 24. It is discharged as a thing.

  On the other hand, the air that reacts with the air electrode layer is supplied to the air inlet 25 provided at the upper part of the outer housing 22 and flows through the outer passage 8 of each battery cell stack 10 constituting the battery cell module 20 to react with the fuel. Thereafter, the air is discharged from the air outlet 26 opened at the lower portion of the outer housing 22.

1: Cylindrical SOFC battery cell 2: Fuel electrode layer 3: Air electrode layer 4: Electrolyte layer 4a: Electrolyte 1
4b: Electrolyte 2
4c: Electrolyte 3
5: Central cylindrical battery cell 6: Side cylindrical battery cell 7: Inner passage 8: Outer passage 9: Annular blank portion 10: Battery cell stack 11: Interconnector 12: Current collecting plates 13, 13 ′: Stack Upper 13a: Opening portion 14: Chamber 16a, 16b: Bending portion 17: Ventilation port 18: Cylindrical spacer 18 ': Columnar spacer 19: Gas passage 20: Battery cell module 21: Battery cell module system 22: Outer cover 23: Fuel inlet 24: Fuel outlet 25: Air inlet 26: Air outlet 100: Flat plate SOFC cell 101: Interconnector 102: Electrolyte 103: Gasket 150: Cylindrical SOFC cell 151: Interconnector 152: Electrolyte layer 153: Fuel electrode Layer 154: Air electrode layer 200A: Square SOFC cell 211: Air electrode support tube 212: Solid Kaishitsu 213: anode 214: interconnector 221: Separator 222: Felt 223: void

Claims (13)

In a solid oxide fuel cell formed by connecting a large number of cylindrical battery cells formed of a laminated wall formed by sequentially laminating an air electrode layer, an electrolyte layer, and a fuel electrode layer,
It consists of a central cylindrical battery cell arranged in the central part and a plurality of side cylindrical battery cells that are joined in parallel along the longitudinal side surface of the cylindrical battery cell and do not cross each other. And each said side part cylindrical battery cell is a thing of the structure formed by joining only one place by the line contact state to the vertical side surface of the said center part cylindrical battery cell, The cylindrical solid oxide characterized by the above-mentioned Fuel cell.   2. The cylindrical solid oxide fuel cell according to claim 1, wherein the cylindrical battery cell has a polygonal cylindrical shape.   2. The cylindrical solid oxide fuel cell according to claim 1, wherein the cylindrical battery cell is cylindrical.   The plurality of side cylindrical battery cells are arranged radially at equal intervals on the side surface of the central cylindrical battery cell, and any of the central cylindrical battery cell and the multiple side cylindrical battery cells An air electrode layer or fuel electrode in which the inner wall surface is a fuel electrode layer, the outer wall surface is an air electrode layer, or the outer wall surface is a fuel electrode layer, the inner wall surface is an air electrode layer, and constitutes the outer wall surface of each cylindrical battery cell. The cylindrical solid oxide fuel cell according to any one of claims 1 to 3, wherein the layers are formed on one continuous surface.   The cylindrical battery cell has a hollow portion inside the inner wall surface as an inner passage and a space outside the outer wall surface as an outer passage, and each passage corresponds to a fuel electrode layer or an air electrode layer constituting the wall surface of the passage. The cylindrical solid oxide fuel cell according to any one of claims 1 to 4, wherein fuel or air is supplied.   A plurality of cylindrical solid oxide fuel cells according to any one of claims 1 to 5 are stacked one above the other to form a battery cell stack, and a fuel electrode layer and a lower portion of each upper battery cell A battery-type air electrode layer, or an upper battery cell air electrode layer and a lower battery cell fuel electrode layer, each of which is connected in series with an interconnector having a conductive and gas seal function. Solid oxide fuel cell.   In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from coming into contact with each other, it becomes a base portion (structure) of the laminated wall body of each battery cell. 7. When the layer is an electrolyte, each of the outer wall surfaces is provided with an annular blank portion that is not provided with the respective polar layers on the upper end portion side wall surface, and the inner wall surface is provided on the lower end portion side wall surface. A cylindrical solid oxide fuel cell as described in 1.   In the battery cell stack, in order to prevent the fuel electrode layers and the air electrode layers of the upper and lower battery cells connected in series from coming into contact with each other, it becomes a base portion (structure) of the laminated wall body of each battery cell. When the layer is a fuel electrode layer or an air electrode layer, an electrode layer serving as a base part is disposed as an inner wall surface of the laminated wall body, an electrolyte layer is stacked on the outer side surface, and the electrolyte layer is used as a base part. The electrode layer is continuously stretched so as to be formed as a folded portion having a minute height at the lower end surface and the lower end portion of the inner wall surface, and on the outer wall surface of the electrolyte layer, an electrode layer different from that used as the base portion and The cylindrical solid body according to claim 6, wherein an air blank layer or fuel electrode layer is provided, and an annular blank portion not provided with the electrode layer is provided on the outer surface of the electrolyte layer. Oxide fuel cell.   In the case where the battery cell stack has an inner wall surface of the constituent battery cell as a fuel electrode, each inner passage is provided with a columnar spacer similar to the shape of the inner passage to narrow the inner passage space for reaction with the fuel electrode. 9. The cylindrical solid oxide fuel cell according to claim 6, wherein only a contributing amount of fuel is allowed to flow. When the battery cell stack has a fuel electrode on the inner wall surface of the battery cell stack, a chamber for supplying fuel to one end of the battery cell stack, and a cylindrical spacer similar to the shape of the inner passage in each inner passage Prepared,
After the fuel supplied from the chamber flows through the in-cylinder gas passage of the cylindrical spacer, the fuel is inverted at the other end of the cylindrical spacer, and the inverted fuel is the outer peripheral surface of the cylindrical spacer and the configuration. 9. The fuel cell according to claim 6, wherein only a quantity of fuel that contributes to a reaction with the fuel electrode is circulated in a narrow space between the inner wall surfaces of the battery cells and then discharged. A cylindrical solid oxide fuel cell according to any one of the preceding claims.   A plurality of the battery cell stacks according to any one of claims 6 to 10 are juxtaposed on the same plane, and each of them is connected in parallel, connected in series, or connected in a series-parallel combination to form a battery cell module. A cylindrical solid oxide fuel cell comprising:   12. The cylindrical solid oxide fuel cell according to claim 11, wherein the battery cell module is formed by arranging a plurality of the battery cell stacks side by side in a parallel grid pattern or a staggered grid pattern on the same plane. . A plurality of the battery cell modules are juxtaposed in the same plane or stacked up and down to be electrically connected, or a plurality of battery cell modules juxtaposed in the same plane and electrically connected are stacked up and down to be electrically connected. The cylindrical solid oxide fuel cell according to claim 11 or 12, wherein the cylindrical solid oxide fuel cell is connected to.

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