Fuel battery block and fuel battery system

Abstract

A fuel battery block (200) comprises: a first plate member 21; a second plate member 22; a frame member 23; a plurality of first fuel battery cells 100a; and a plurality of second fuel battery cells 100b. In the first fuel battery cell 100a, a first lead-out part 14a is positioned on the first plate member 21 side, and a second lead-out part 12a is positioned on the second plate member 22 side. In the second fuel battery cell 100b, the second lead-out part 12a is positioned on the first plate member 21 side, and the first lead-out part 14a is positioned on the second plate member 22 side.

Description

Fuel cell block and fuel cell system

[0001] The present invention relates to a fuel cell block having a plurality of fuel cell units, and a fuel cell system having a plurality of fuel cell blocks.

[0002] Patent Documents 1, 2 and 3 disclose techniques using solid oxide fuel cells (SOFCs).

[0003] Patent Document 1 discloses an SOFC with a stack structure. In the SOFC with a stack structure, a fuel gas flow path and an oxidant gas flow path are formed in each layer. In the stacking direction, fuel cells, fuel gas flow paths, separators which are conductors, and oxidant gas flow paths are repeatedly stacked in this order.

[0004] The generated electricity is extracted vertically via a current collector connected to the anode electrode and a current collector connected to the cathode electrode. The fuel cell units are connected in series via separators. Electrical power is output from the fuel cell unit located at the bottom and the fuel cell unit located at the top to the outside of the stack structure.

[0005] In response to this, Patent Document 2 discloses a stack structure equipped with a thin-film SOFC. Research and development of thin-film SOFCs has been actively carried out in recent years. A feature of thin-film SOFCs is that the thickness of the solid electrolyte membrane, yttria-stabilized zirconia (YSZ), is extremely thin, at 1 μm or less. The resistance of the electrolyte membrane is reduced by thinning the membrane, so the power generation capacity can be increased to several W / cm. ２ (∝A / cm ２ ) will improve.

[0006] Usually, a thin-film SOFC is formed on some kind of support. In Patent Document 2, an anode electrode film, a YSZ film, and a cathode electrode film are formed in this order on a porous insulating substrate (anodic alumina film). The planar size of the porous insulating substrate is several cm ２Therefore, in Patent Document 2, a high output is obtained by connecting multiple fuel cell units in parallel and mounting them on an intermediate substrate, stacking these intermediate substrates vertically, and connecting the multiple parallel-connected fuel cell units in series.

[0007] In Patent Document 3, a stack structure is constructed by connecting multiple fuel cells in series or in parallel using intermediate substrates, stacking these intermediate substrates vertically, and connecting multiple fuel cells in series or in parallel, thereby further increasing the output voltage and reducing ohmic loss caused by parasitic resistance within the stack structure.

[0008] JP 2022-66744 A JP 2023-167722 A JP 2023-155085 A

[0009] For example, in a thin-film SOFC, the ２ Such a high power generation efficiency and low temperature operation at, for example, 500° C. are possible. However, there are problems inherent to thin-film SOFCs.

[0010] The first problem is the difficulty of extracting the cathode electrode using a current collector, as disclosed in Patent Document 1. An anode electrode is provided directly below the cathode electrode, with a solid electrolyte membrane interposed between them. When the current collector is pressed against the cathode electrode, the pressure is not uniform, and stress concentration causes cracks in the solid electrolyte membrane. As a result, a short circuit occurs between the anode electrode and the cathode electrode.

[0011] Even if there are no problems in the early stages immediately after manufacture, there is a problem that short-circuit defects can be induced over time due to residual stress and thermal stress caused by temperature cycles between room temperature and high temperatures during operation.

[0012] The second problem is that porous insulating substrates have structural defects at a certain density (several defects / cm ２ Therefore, from the viewpoint of yield, such as preventing short circuits between the anode and cathode electrodes, there is an upper limit to the size that can be used for the porous insulating substrate.

[0013] Therefore, as disclosed in Patent Documents 2 and 3, it is necessary to use an intermediate substrate to increase the number of small-area fuel cells, but arranging the fuel cells requires clearance between the bonding area and its surroundings, and also requires wiring areas for electrically connecting to the anode and cathode electrodes. Therefore, Patent Documents 2 and 3 have the problem of reducing the effective area available for power generation, and reducing power generation capacity.

[0014] The main objective of the present application is to provide a fuel cell block that can suppress a decrease in the effective area available for power generation and that allows multiple fuel cell units to be arranged at high density, and a fuel cell system that includes multiple fuel cell blocks, as well as fuel cell units for realizing such a fuel cell block and fuel cell system.

[0015] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0016] In one embodiment, the fuel cell block includes a first plate member, a second plate member arranged to face the first plate member, a frame member sandwiched between the first plate member and the second plate member, and a plurality of fuel cell units arranged in a gas container surrounded by the first plate member, the second plate member, and the frame member. The fuel cell units have a laminated structure including a first electrode film, a second electrode film, and a solid electrolyte film formed between the first electrode film and the second electrode film on a porous insulating substrate, the fuel cell units having a rectangular shape when viewed from above in the direction of lamination of the first electrode film, the electrolyte film, and the second electrode film, a portion of the first electrode film located on one long side of the fuel cell units forming a first lead portion for electrical conduction with the outside of the fuel cell units, and a portion of the second electrode film located on the other long side of the fuel cell units forming a second lead portion for electrical conduction with the outside of the fuel cell units, and the plurality of fuel cell units are arranged in a gas container surrounded by the first plate member, the second plate member, and the frame member. The number of fuel cell units includes a plurality of first fuel cell units in which the first draw-out portion is located on the first plate member side and the second draw-out portion is located on the second plate member side, and a plurality of second fuel cell units in which the second draw-out portion is located on the first plate member side and the first draw-out portion is located on the second plate member side, and the first fuel cell units and the second fuel cell units are repeatedly arranged side by side so that the first electrode film of the first fuel cell unit faces the first electrode film of the second fuel cell unit, and so that the porous insulating substrate of the first fuel cell unit faces the porous insulating substrate of the second fuel cell unit.

[0017] According to one embodiment, it is possible to provide a fuel cell block that can suppress a decrease in the effective area available for power generation and that can densely arrange multiple fuel cell units, and a fuel cell system that includes multiple fuel cell blocks. It is also possible to provide fuel cell units for realizing such a fuel cell block and fuel cell system.

[0018] FIG. 1 is a plan view showing a fuel cell cell in embodiment 1. FIG. 2 is a cross-sectional view showing a fuel cell cell in embodiment 1. FIG. 3 is a cross-sectional view showing a fuel cell block in embodiment 1. FIG. 4 is a cross-sectional view showing a fuel cell block in embodiment 1. FIG. 5 is a cross-sectional view showing a fuel cell block in embodiment 1. FIG. 6 is a cross-sectional view showing a fuel cell block in embodiment 1. FIG. 7 is a cross-sectional view showing a fuel cell block in embodiment 1. FIG. 8 is a plan view showing a fuel cell block in embodiment 1. FIG. 9 is a front view showing a fuel cell block in embodiment 1. FIG. 10 is a right side view showing a fuel cell block in embodiment 1. FIG. 11 is a right side view showing a fuel cell system in embodiment 1. FIG. 12 is a right side view showing a fuel cell system in embodiment 1. FIG. 13 is a plan view showing a fuel cell system in embodiment 1. FIG. 14 is a plan view showing a fuel cell system in embodiment 1.

[0019] Hereinafter, embodiments will be described in detail with reference to the drawings. In all drawings for explaining the embodiments, components having the same functions are designated by the same reference numerals, and repeated explanations thereof will be omitted. In the following embodiments, explanations of the same or similar parts will not be repeated unless particularly necessary.

[0020] Furthermore, the X direction, Y direction, and Z direction described in this application intersect with each other and are perpendicular to each other.

[0021] (Embodiment 1) <Structure of fuel cell> A fuel cell 100 in embodiment 1 will be described below with reference to Figs. 1 to 3. The fuel cell 100 is a thin-film SOFC. Fig. 1 shows a plan view of the fuel cell 100. Fig. 2 is a cross-sectional view taken along line A-A shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line B-B shown in Fig. 1.

[0022] As shown in Figures 1 to 3, the fuel cell 100 comprises a porous insulating substrate 11, a second electrode film (anode electrode) 12, a first electrode film (cathode electrode) 14, and a solid electrolyte film 13 formed between the second electrode film 12 and the first electrode film 14.

[0023] The porous insulating substrate 11 is an insulating substrate. The porous insulating substrate 11 includes, for example, anodized aluminum, and is formed by anodizing aluminum to form a porous coating. The porous insulating substrate 11 may also be a porous glass substrate or may be made of a track-etched polymer.

[0024] The second electrode film 12 is formed on the porous insulating substrate 11. The second electrode film 12 is, for example, a metal film such as a platinum (Pt) film or a nickel (Ni) film, a composite film of platinum or nickel and yttria-stabilized zirconia (YSZ), or a laminate film in which these are appropriately laminated. The thickness of the second electrode film 12 is, for example, 50 nm or more and 50 μm or less.

[0025] The electrolyte membrane 13 is formed on the second electrode film 12. The electrolyte membrane 13 is a stabilized zirconia film to which a rare earth element is added. When the rare earth element is Y, the electrolyte membrane 13 is made of yttria-stabilized zirconia (YSZ). The thickness of the electrolyte membrane 13 is, for example, 10 nm or more and 1 μm or less.

[0026] The first electrode film 14 is formed on the electrolyte film 13. The first electrode film 14 is, for example, a metal film such as a nickel film or a La film. ０．５ Sr ０．５ CoO ３－δ The first electrode film 14 may be an oxide electrode material such as a (LSC) film, or a laminated film of these materials. The thickness of the first electrode film 14 is, for example, 50 nm to 50 μm.

[0027] The porous insulating substrate 11, the second electrode film 12, and the first electrode film 14 are gas permeable. The electrolyte film 13 is not gas permeable, but is permeable to hydrogen ions (H ＋ ) or oxygen ions (O － The fuel cell 100 uses an oxidant gas and a fuel gas. The oxidant gas is, for example, air, and the fuel gas is, for example, hydrogen (H ２ )

[0028] Oxygen (O ２) enters the fuel cell 100, receives electrons at the first electrode film 14, and becomes oxygen ions. The oxygen ions move through the electrolyte membrane 13, release electrons at the second electrode film 12, and become hydrogen (H ２ ) reacts with water (H ２ O) As oxygen ions pass through the fuel cell 100, a current is generated in the fuel cell 100.

[0029] As shown in FIG. 1, the fuel cell 100 has a rectangular shape when viewed in a plan view from the stacking direction (Y direction) of the porous insulating substrate 11, the second electrode film 12, the solid electrolyte film 13, and the first electrode film 14.

[0030] As shown in FIGS. 1 and 3, the second electrode film 12 and the first electrode film 14 are not provided on either short side of the fuel cell 100, and only the electrolyte membrane 13 is provided.

[0031] 1 and 2, a portion of the first electrode film 14 located on one long side of the fuel cell 100 constitutes a first lead portion 14a for electrical conduction with the outside of the fuel cell 100. A portion of the second electrode film 12 located on the other long side of the fuel cell 100 constitutes a second lead portion 12a for electrical conduction with the outside of the fuel cell 100.

[0032] The second electrode film 12 is not provided on one long side of the fuel cell 100, and the first electrode film 14 is not provided on the other long side of the fuel cell 100. In other words, in a plan view perpendicular to the stacking direction (Y direction), the first lead portion 14a does not overlap the second electrode film 12, and the second lead portion 12a does not overlap the first electrode film 14.

[0033] In the case of a fuel cell 100 having such a structure, the generated current flows from the second lead-out portion 12a through the electrolyte membrane 13 toward the first lead-out portion 14a. The voltage drop ΔV that occurs at this time is proportional to the density α [A / cm ２ ] and the volume resistivity ρ [Ω / cm ３] and the film thickness d [cm] of the second electrode film 12 and the first electrode film 14, it is expressed by the following "Equation 1".

[0034] Formula 1: ΔV=α×(ρ / d)×L ２

[0035] Here, the voltage drop ΔV depends on the length L of the fuel cell 100 in the short side direction, not on the length W of the fuel cell 100 in the long side direction. In other words, once the allowable voltage drop ΔV and the density α of the generated current are determined, the volume resistivity ρ, film thickness d, and length L can be set so as to satisfy "Equation 1."

[0036] <Fuel Cell Block> The fuel cell block 200 according to the first embodiment will be described below with reference to Figs. 4 to 11. Fig. 4 shows a plan view of the fuel cell block 200. Fig. 5 is a cross-sectional view taken along line CC shown in Fig. 4. Fig. 6 is a cross-sectional view taken along line DD shown in Fig. 4. Fig. 7 is a cross-sectional view taken along line EE shown in Fig. 4. Fig. 8 is a cross-sectional view taken along line FF shown in Fig. 4.

[0037] 4 to 8, the fuel cell block 200 includes a plurality of fuel cell units 100, a first plate member 21, a second plate member 22, and a frame member 23. The second plate member 22 is disposed opposite the first plate member 21. The frame member 23 connects the first plate member 21 and the second plate member 22. The first plate member 21, the second plate member 22, and the frame member 23 form a panel-shaped gas container.

[0038] Note that Figure 4 is a plan view seen from the first plate member 21 side, but in order to make the structure easier to understand, Figure 4 omits the illustration of part of the first plate member 21 and illustrates only the second plate member 22, and also illustrates not only the second plate member 22 but also the collector wiring 25 provided inside the second plate member 22.

[0039] A plurality of current collecting wires 24 are provided inside the first plate member 21. A plurality of current collecting wires 25 are provided inside the second plate member 22. A plurality of fuel cell units 100 are arranged in a gas container surrounded by the first plate member 21, the second plate member 22, and the frame member 23.

[0040] The first plate member 21 and the second plate member 22 are substrates having metal wiring therein, and are made of, for example, ceramic, glass, or polymer. In particular, ceramic substrates having copper wiring with very low electrical resistance, known as green sheets, are most suitable for the first plate member 21 and the second plate member 22. Such metal wiring (copper wiring) constitutes the current collecting wiring 24 and the current collecting wiring 25. Furthermore, the frame member 23 is made of the same material as the first plate member 21 and the second plate member 22, from the viewpoint of matching the thermal expansion coefficient.

[0041] Counterbore holes are formed by machining or the like at predetermined positions on the first plate member 21, the second plate member 22, and the frame member 23 in order to fit and fix the plurality of fuel cell units 100. At the locations where the counterbore holes are formed, the current collecting wires 24 are exposed from the first plate member 21, and the current collecting wires 25 are exposed from the second plate member 22.

[0042] Frit glass or a high-heat resistant adhesive is used to join the first plate member 21, the second plate member 22, and the frame member 23. A conductive paste such as silver paste or gold paste is used for the electrical connections. These connection materials are applied to the connection points by screen printing or a dispenser before assembling the components, and then pre-baked. After assembling the components, the panel-shaped gas container is formed by main baking.

[0043] As shown in FIGS. 5 to 8, the plurality of fuel cell units 100 are connected to a gas container via an oxidizing gas flow path 27 (Air) and a fuel gas flow path 28 (H ２ The piping for supplying and discharging gas to and from the oxidizing gas flow path 27 and the fuel gas flow path 28 will be described later with reference to FIG. 9 and other figures.

[0044] 4 and 5, the plurality of fuel cells 100 includes a plurality of first fuel cells 100a and a plurality of second fuel cells 100b. The orientation in which the plurality of fuel cells 100 are arranged will be described below.

[0045] In a plan view perpendicular to the direction along the long side of the fuel cell 100 (X direction), the first fuel cell 100a and the second fuel cell 100b are arranged at 180 degrees inversion from each other. That is, in the first fuel cell 100a, the first lead-out portion 14a is located on the first plate member 21 side, and the second lead-out portion 12a is located on the second plate member 22 side. In the second fuel cell 100b, the second lead-out portion 12a is located on the first plate member 21 side, and the first lead-out portion 14a is located on the second plate member 22 side.

[0046] In addition, the first fuel cell 100a and the second fuel cell 100b are repeatedly arranged side by side so that the first electrode film 14 of the first fuel cell 100a faces the first electrode film 14 of the second fuel cell 100b, and so that the porous insulating substrate 11 of the first fuel cell 100a faces the porous insulating substrate 11 of the second fuel cell 100b.

[0047] By arranging the first fuel cell 100a and the second fuel cell 100b in this manner, an oxidant gas (air) is supplied to the opposing first electrode film 14 in the oxidant gas flow channel 27, and a fuel gas (H ２ ) is supplied.

[0048] As described above, the current collecting wires 24 are exposed in the recesses formed in the first plate member 21, and the current collecting wires 25 are exposed in the recesses formed in the second plate member 22. Therefore, the multiple current collecting wires 24 are electrically connected to the first lead-out portion 14a of the first fuel cell 100a and the second lead-out portion 12a of the second fuel cell 100b, respectively. The multiple current collecting wires 25 are electrically connected to the first lead-out portion 14a of the second fuel cell 100b and the second lead-out portion 12a of the first fuel cell 100a, respectively. In this way, the multiple fuel cell units 100 are connected in series with each other.

[0049] Some of the multiple current collecting wirings 25 pulled out to the outside of the second plate member 22 can be electrically connected to the outside of the fuel cell block 200 via the negative output terminal 25a and the positive output terminal 25b, which constitute the negative output terminal 25a and the positive output terminal 25b.

[0050] The positive output terminal and the negative output terminal may be configured by the current collecting wires 24. That is, some of the multiple current collecting wires 24 drawn out to the outside of the first plate member 21 may configure the positive output terminal and the negative output terminal.

[0051] Furthermore, the number of fuel cells 100 provided in the fuel cell block 200 is not limited to six, and can be changed as appropriate.

[0052] The piping for supplying and discharging gas will be described below with reference to Figures 9 to 11. Like Figure 4, Figure 9 is a plan view of the fuel cell block 200 as seen from the Z direction, but the first plate member 21 and the second plate member 22 are omitted to make the oxidant gas flow path 27 and the fuel gas flow path 28 easier to see. Figure 10 is a front view of the fuel cell block 200 as seen from the Y direction. Figure 11 is a right side view of the fuel cell block 200 as seen from the X direction.

[0053] As shown in FIGS. 9 to 11, the fuel cell block 200 includes an oxidizing gas supply pipe 27a, an oxidizing gas exhaust pipe 27b, a fuel gas supply pipe 28a, and a fuel gas exhaust pipe 28b.

[0054] The oxidizing gas supply pipe 27a is provided to supply oxidizing gas to the oxidizing gas flow path 27, and the oxidizing gas exhaust pipe 27b is provided to exhaust gas remaining in the oxidizing gas flow path 27. The fuel gas supply pipe 28a is provided to supply fuel gas to the fuel gas flow path 28, and the fuel gas exhaust pipe 28b is provided to exhaust gas remaining in the fuel gas flow path 28.

[0055] 10 , the negative electrode output terminal 25a is extended to the front side of the fuel cell block 200, and the positive electrode output terminal 25b is extended to the back side of the fuel cell block 200. Therefore, in order not to interfere with the negative electrode output terminal 25a and the positive electrode output terminal 25b, the oxidant gas supply pipe 27a and the fuel gas exhaust pipe 28b are provided on the right side of the fuel cell block 200, and the fuel gas supply pipe 28a and the oxidant gas exhaust pipe 27b are provided on the left side of the fuel cell block 200. Alternatively, the oxidant gas supply pipe 27a and the fuel gas exhaust pipe 28b may be provided on the left side of the fuel cell block 200, and the fuel gas supply pipe 28a and the oxidant gas exhaust pipe 27b may be provided on the right side of the fuel cell block 200.

[0056] 9 , a plurality of through holes 26 that connect the oxidant gas flow path 27 or the fuel gas flow path 28 to the respective pipes 27 a, 27 b, 28 a, and 28 b are formed in the frame member 23. Specifically, the frame member 23 is provided with a through hole 26 that connects the oxidant gas flow path 27 to the oxidant gas supply pipe 27 a, a through hole 26 that connects the oxidant gas flow path 27 to the oxidant gas exhaust pipe 27 b, a through hole 26 that connects the fuel gas flow path 28 to the fuel gas supply pipe 28 a, and a through hole 26 that connects the fuel gas flow path 28 to the fuel gas exhaust pipe 28 b.

[0057] With this configuration, the oxidant gas enters the oxidant gas flow path 27 from the oxidant gas supply pipe 27a and is discharged to the outside of the fuel cell block 200 via the oxidant gas exhaust pipe 27b extending in the Z direction from the oxidant gas flow path 27. Similarly, the fuel gas enters the fuel gas flow path 28 from the fuel gas supply pipe 28a and is discharged to the outside of the fuel cell block 200 via the fuel gas exhaust pipe 28b extending in the Z direction from the fuel gas flow path 28.

[0058] 6 and 8, the first plate member 21 has portions where the plurality of current collecting wires 24 are not provided, and the second plate member 22 has portions where the plurality of current collecting wires 25 are not provided. A plurality of through holes 26 may be formed in these portions to connect the oxidant gas flow path 27 or the fuel gas flow path 28 to the respective pipes 27a, 27b, 28a, 28b.

[0059] The pipes 27a, 27b, 28a, and 28b are preferably made of the same material as the frame member 23, from the viewpoint of matching the thermal expansion coefficients. The pipes 27a, 27b, 28a, and 28b are preferably made of the same material as the frame member 23. The pipes 27a, 27b, 28a, and 28b are joined to the frame member 23 using a frit material or a highly heat-resistant adhesive, or are mechanically fixed with a jig via a sealing material made of a ceramic or vermiculite-based material.

[0060] As described above, in the fuel cell block 200 of the first embodiment, the oxidant gas flow path 27 and the fuel gas flow path 28, which serve as gas flow paths, can be configured by using a plurality of fuel cell units 100 as partition walls. Furthermore, by arranging two first electrode films 14 opposite each other in the oxidant gas flow path 27 and two second electrode films 12 opposite each other in the fuel gas flow path 28, it is possible to extract current efficiently. Therefore, it is possible to suppress a decrease in the effective area available for power generation, and it is possible to arrange a plurality of fuel cell units 100 at high density.

[0061] Furthermore, by providing the first lead-out portion 14a and the second lead-out portion 12a to the fuel cell 100, adjusting the orientation of the plurality of fuel cell units 100, and using the current collecting wires 24 and 25, it is possible to connect the plurality of fuel cell units 100 in series. Therefore, the voltage output from the negative output terminal 25a and the positive output terminal 25b can be amplified according to the number of fuel cell units 100. Amplifying the output voltage in this manner is a very effective means for reducing power loss due to parasitic resistance (internal resistance) present in the fuel cell block 200.

[0062] <Fuel Cell System> A fuel cell system 300 according to the first embodiment will be described below with reference to Figures 12 to 15. The fuel cell system 300 includes a plurality of fuel cell blocks 200. Figures 12 to 15 show two of the plurality of fuel cell blocks 200 arranged adjacent to each other. The plurality of fuel cell blocks 200 are connected in series or in parallel.

[0063] 12 and 13 show an example in which two fuel cell blocks 200 are stacked in the Z direction. As shown in Fig. 12, the two fuel cell blocks 200 are adjacently arranged so that the first plate member 21 of one block faces the second plate member 22 of the other block. A connecting conductor is used to electrically connect the negative output terminal 25a and the positive output terminal 25b. While the connecting conductor may be a cable or the like, a bus bar 31 with sufficiently low electrical resistance is used here as the connecting conductor.

[0064] In the two fuel cell blocks 200 shown in Figure 12, the pipes 27a, 27b, 28a, and 28b are aligned, so that the negative output terminals 25a and the positive output terminals 25b are connected in the same direction. Therefore, to reduce parasitic resistance, the negative output terminals 25a are electrically connected to each other, and the positive output terminals 25b are electrically connected to each other. Thus, the example shown in Figure 12 can be advantageously used when connecting two fuel cell blocks 200 in parallel to amplify current.

[0065] When two fuel cell blocks 200 are stacked, the two fuel cell blocks 200 are mechanically fixed using a jig or the like, or are bonded using frit, a heat-resistant adhesive, etc. The pipes 27 a, 27 b, 28 a, 28 b are also bonded to each other.

[0066] In addition, from the viewpoint of suppressing temperature rise due to heat dissipation, it is preferable that the periphery of the bus bar 31, the periphery of each pipe 27a, 27b, 28a, 28b, and the surfaces of each of the first plate member 21, the second plate member 22 and the frame member 23 are covered with insulating material.

[0067] In the example of Figure 13, two fuel cell blocks 200 are arranged adjacent to each other so that one first plate member 21 faces the other first plate member 21. Because the positions of the respective pipes 27a, 27b, 28a, and 28b are aligned, the respective negative output terminals 25a are drawn in opposite directions, and the respective positive output terminals 25b are drawn in opposite directions. Therefore, to reduce power loss due to parasitic resistance, one negative output terminal 25a and the other positive output terminal 25b are electrically connected. Thus, the example of Figure 13 is suitable for use when two fuel cell blocks 200 are connected in series to amplify voltage.

[0068] Furthermore, even when one second plate member 22 and the other second plate member 22 are disposed adjacent to each other so as to face each other, the negative output terminals 25 a and the positive output terminals 25 b are also drawn in opposite directions. Therefore, this configuration is suitable for use when connecting two fuel cell blocks 200 in series.

[0069] 14 and 15 show an example of a planar arrangement of two fuel cell blocks 200. In the example of Fig. 14 and 15, the two fuel cell blocks 200 are arranged adjacent to each other so that their frame members 23 face each other.

[0070] In the two fuel cell blocks 200 shown in FIG. 14 , the frame members 23 face each other in the direction in which the negative output terminal 25 a or the positive output terminal 25 b is pulled out (Y direction). The negative output terminal 25 a of one block and the positive output terminal 25 b of the other block are integrated. Therefore, the two fuel cell blocks 200 are connected in series. There is no need to use a connecting conductor such as a bus bar 31 to electrically connect the negative output terminal 25 a and the positive output terminal 25 b. Therefore, in the example shown in FIG. 14 , the parasitic resistance between the two fuel cell blocks 200 can be reduced by the amount of the connecting conductor.

[0071] In the two fuel cell blocks 200 shown in Fig. 15, the frame members 23 face each other in the direction (X direction) in which the negative output terminal 25a or the positive output terminal 25b is not drawn out. In the example shown in Fig. 15, at least one of the pipes 27a, 27b, 28a, and 28b is shared, which is an advantage in that it promotes the miniaturization of the fuel cell system 300.

[0072] 15 are arranged 180 degrees inverted from each other in a plan view perpendicular to the Z direction. Since one of the oxidizing gas supply pipes 27a can be shared, the space required for arranging the other oxidizing gas supply pipe 27a can be reduced, thereby facilitating the miniaturization of the fuel cell system 300 in the X direction.

[0073] 15, a fuel cell block 200 that is inverted by 180 degrees can be provided to the left of the left fuel cell block 200. In this case, one of the fuel gas supply pipes 28a can be shared, and the space required for arranging the other fuel gas supply pipe 28a can be reduced, thereby further promoting the miniaturization of the fuel cell system 300 in the X direction.

[0074] 15, the negative output terminals 25a are drawn in opposite directions, and the positive output terminals 25b are drawn in opposite directions. Therefore, in order to reduce power loss due to parasitic resistance, one negative output terminal 25a and the other positive output terminal 25b are electrically connected. In this way, the example of FIG. 15 can be suitably used when two fuel cell blocks 200 are connected in series.

[0075] In the example of FIG. 15, two fuel cell blocks 200 may also be connected in parallel.

[0076] The fuel cell system 300 has been described above using Figures 12 to 15, but the arrangement of the fuel cell blocks 200 is not limited to the examples in Figures 12 to 15, and it is also possible to implement an appropriate combination of the examples in Figures 12 to 15. For example, it is also possible to arrange the first layer of fuel cell blocks 200 in a planar arrangement, and then stack the second and subsequent layers of fuel cell blocks 200 on top of the first layer of fuel cell blocks 200.

[0077] The present invention has been specifically described above based on the above embodiment, but the present invention is not limited to the above embodiment and can be modified in various ways without departing from the spirit of the present invention.

[0078] DESCRIPTION OF SYMBOLS 100 Fuel cell 100a First fuel cell 100b Second fuel cell 11 Porous insulating substrate 12 Second electrode film 12a Second lead-out portion 13 Electrolyte membrane 14 First electrode film 14a First lead-out portion 200 Fuel cell block 21 First plate member 22 Second plate member 23 Frame member 24 Current collecting wire 25 Current collecting wire 25a Negative electrode output terminal 25b Positive electrode output terminal 26 Through hole 27 Oxidant gas flow path 27a Oxidant gas supply pipe 27b Oxidant gas exhaust pipe 28 Fuel gas flow path 28a Fuel gas supply pipe 28b Fuel gas exhaust pipe 300 Fuel cell system 31 Bus bar

Claims

1. A fuel cell comprising: a first plate member; a second plate member arranged to face the first plate member; a frame member sandwiched between the first plate member and the second plate member; and a plurality of fuel cell units arranged in a gas container surrounded by the first plate member, the second plate member, and the frame member, wherein the fuel cell units have a laminated structure consisting of a first electrode film, a second electrode film, and a solid electrolyte film formed between the first electrode film and the second electrode film on a porous insulating substrate, the fuel cell units having a rectangular shape when viewed from a plane in a direction in which the first electrode film, the electrolyte film, and the second electrode film are laminated, a portion of the first electrode film located on one long side of the fuel cell units forms a first lead-out portion for electrical conduction with the outside of the fuel cell, and a portion of the second electrode film located on the other long side of the fuel cell units forms a second lead-out portion for electrical conduction with the outside of the fuel cell, the plurality of fuel cell cells include a plurality of first fuel cell cells in which the first draw-out portion is located on the first plate member side and the second draw-out portion is located on the second plate member side, and a plurality of second fuel cell cells in which the second draw-out portion is located on the first plate member side and the first draw-out portion is located on the second plate member side, and the first fuel cell cells and the second fuel cell cells are repeatedly arranged side by side so that the first electrode film of the first fuel cell cells faces the first electrode film of the second fuel cell cells, and so that the porous insulating substrate of the first fuel cell cells faces the porous insulating substrate of the second fuel cell cells.

2. A fuel cell block as described in claim 1, wherein, in a plan view seen from the stacking direction, the first draw-out portion does not overlap the second electrode film, and the second draw-out portion does not overlap the first electrode film.

3. A fuel cell block as described in claim 1, wherein the plurality of fuel cell cells function as a partition dividing the gas container into a first gas flow path for supplying oxidant gas to the opposing first electrode film and a second gas flow path for supplying fuel gas to the opposing second electrode film.

4. A fuel cell block as described in claim 3, further comprising: a plurality of first current collecting wirings provided inside the first plate member; and a plurality of second current collecting wirings provided inside the second plate member, wherein the plurality of first current collecting wirings are each electrically connected to the first draw-out portion of the first fuel cell cell and the second draw-out portion of the second fuel cell cell, and the plurality of second current collecting wirings are each electrically connected to the first draw-out portion of the second fuel cell cell and the second draw-out portion of the first fuel cell cell, and the plurality of fuel cell cells are connected in series with each other.

5. A fuel cell block as described in claim 4, wherein a portion of the plurality of first current collecting wirings drawn out to the outside of the first plate member, or a portion of the plurality of second current collecting wirings drawn out to the outside of the second plate member, constitutes a positive output terminal and a negative output terminal for electrical conduction with the outside of the fuel cell block.

6. A fuel cell block according to claim 5, further comprising: a first gas supply pipe for supplying the oxidant gas to the first gas flow path; a first gas exhaust pipe for exhausting gas remaining in the first gas flow path; a second gas supply pipe for supplying the fuel gas to the second gas flow path; and a second gas exhaust pipe for exhausting gas remaining in the second gas flow path.

7. A fuel cell block as described in claim 6, wherein the frame member is formed with a first through-hole connecting the first gas flow path to the first gas supply pipe, a second through-hole connecting the first gas flow path to the first gas exhaust pipe, a third through-hole connecting the second gas flow path to the second gas supply pipe, and a fourth through-hole connecting the second gas flow path to the second gas exhaust pipe.

8. A fuel cell block as described in claim 6, wherein a first through-hole connecting the first gas flow path to the first gas supply pipe, a second through-hole connecting the first gas flow path to the first gas exhaust pipe, a third through-hole connecting the second gas flow path to the second gas supply pipe, and a fourth through-hole connecting the second gas flow path to the second gas exhaust pipe are formed in a portion of the first plate member where the plurality of first current collecting wirings are not provided, or in a portion of the second plate member where the plurality of second current collecting wirings are not provided.

9. A fuel cell system comprising a plurality of fuel cell blocks as described in claim 6, wherein the plurality of fuel cell blocks include two fuel cell blocks arranged adjacent to each other, the plurality of fuel cell blocks are connected in series or in parallel, and the two fuel cell blocks are arranged adjacent to each other so that the first plate member of one block faces the second plate member of the other block, the first plate member of one block faces the first plate member of the other block, or the second plate member of one block faces the second plate member of the other block, or the frame members of the two fuel cell blocks are arranged adjacent to each other so that the frame members of the two fuel cell blocks face each other.

10. A fuel cell system as described in claim 9, wherein the two fuel cell blocks are arranged adjacent to each other so that the first plate member of one of the fuel cell blocks and the second plate member of the other of the fuel cell blocks face each other, and the two fuel cell blocks are connected in parallel.

11. A fuel cell system as described in claim 9, wherein the two fuel cell blocks are arranged adjacent to each other so that the one first plate member and the other first plate member, or the one second plate member and the other second plate member, face each other, and the two fuel cell blocks are connected in series.

12. A fuel cell system as claimed in claim 9, wherein the two fuel cell blocks are arranged adjacent to each other with their frame members facing each other, the positive output terminal of one and the negative output terminal of the other are integrated, and the two fuel cell blocks are connected in series.

13. A fuel cell system as described in claim 9, wherein the two fuel cell blocks are arranged adjacent to each other with their frame members facing each other, and at least one of the first gas supply pipe, the first gas exhaust pipe, the second gas supply pipe and the second gas exhaust pipe provided in the two fuel cell blocks is shared.

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