Fuel cell

Abstract

To provide a fuel cell capable of measuring a state quantity in the fuel cell with ease and with accuracy.SOLUTION: A fuel cell 10 comprises a sensor 40, 42, 44, 46 that has a sensor part 50 provided on at least one of separators 14 and 16, a frame member 24, and an electrolyte film 18, and a wiring part 55 connected with the sensor part 50 and extended to an outer peripheral part of the separators 14 and 16 or an MEA (Membrane Electrode Assembly) 12. The sensor 40, 42, 44, 46 has: a foundation insulating film 56 that covers a sensor arrangement region 48, 48A, 48B, 48C; wiring patterns 52 and 54 laminated on the foundation insulating film 56; and a coating insulating film 58 that covers the wiring patterns 52 and 54 and the foundation insulating film 56 of a portion not covered with the wiring patterns 52 and 54.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fuel cell equipped with a sensor for detecting an internal state quantity. [Background technology]

[0002] A fuel cell has a membrane electrode assembly and a pair of separators that sandwich the membrane electrode assembly. The membrane electrode assembly is a configuration in which an electrolyte membrane that conducts ions such as hydrogen ions and oxygen ions, and an anode electrode and a cathode electrode are laminated on one side and the other side of the electrolyte membrane, respectively. One separator is disposed opposite the anode electrode, and a fuel gas flow path through which a fuel gas flows is formed between the separator and the anode electrode. In addition, an oxidant gas flow path through which an oxidant gas flows is formed between the other separator and the cathode electrode. A plurality of such fuel cells are laminated in the thickness direction to form a fuel cell stack, which is mounted, for example, on a fuel cell electric vehicle or the like.

[0003] In a fuel cell, measuring the internal environment such as the temperature and conductivity of various components such as the electrolyte membrane and electrodes during power generation is useful for understanding the operation of the fuel cell. For this reason, the internal environment of the fuel cell is measured by a method such as placing a temperature sensor such as a thermocouple between the separator and the electrolyte membrane-electrode assembly.

[0004] For example, Patent Document 1 discloses a technology for measuring the temperature inside a fuel cell by placing a cover body with a groove for placing a sensor on the cathode electrode side of an electrolyte membrane-electrode structure having an electrolyte membrane sandwiched between an anode electrode and a cathode electrode. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-135270 A Summary of the Invention [Problem to be solved by the invention]

[0006] In general, measurements are performed by placing a sensor such as a thermocouple between the separator and the membrane electrode assembly in a fuel cell with a normal structure. This requires the sensor to be placed inside the fuel cell, which is a complicated process. In such cases, the thin metal wire for the thermocouple may be damaged during the process, or the sensor may be misaligned during assembly, making it impossible to accurately measure the condition of the target area.

[0007] Furthermore, in the case of the technology of Patent Document 1, it is necessary to provide space for arranging a cover body, etc., which requires significant modification to the structure of the fuel cell and increases the thickness of the fuel cell.

[0008] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a fuel cell that allows easy and accurate measurement of the internal state quantities of the fuel cell. [Means for solving the problem]

[0009] One aspect of the following disclosure resides in a fuel cell comprising: an electrolyte membrane, an electrolyte membrane-electrode assembly having an anode electrode provided on one side of the electrolyte membrane, and a cathode electrode provided on the other side of the electrolyte membrane; a frame member surrounding an outer periphery of the electrolyte membrane-electrode assembly, a pair of separators sandwiching the electrolyte membrane-electrode assembly, and a sensor having a sensor portion provided on at least one of the separators, the frame member, and the electrolyte membrane, and a wiring portion connected to the sensor portion and extending to the outer periphery of the separator or the electrolyte membrane-electrode assembly, the sensor having an underlying insulating film covering a surface of a sensor arrangement region in which the sensor is arranged, a wiring pattern laminated on the underlying insulating film, and a covering insulating film covering the wiring pattern and a portion of the underlying insulating film not covered by the wiring pattern. Effect of the Invention

[0010] According to the fuel cell of the above aspect, the internal state quantities of the fuel cell can be measured easily and accurately. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view of a fuel cell according to an embodiment; [Diagram 2] 2 is a plan view of a first surface of the second separator of FIG. 1. FIG. [Diagram 3] 3 is a cross-sectional view of the fuel cell taken along the line III-III in FIG. 2. [Figure 4] FIG. 2 is a plan view of the membrane electrode assembly of FIG. [Diagram 5] 3 is a cross-sectional view of the fuel cell taken along a portion corresponding to line VV in FIG. 2. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 3 is a cross-sectional view of the fuel cell taken along the line VII-VII in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to preferred embodiments thereof and accompanying drawings.

[0013] As shown in FIG. 1, a fuel cell 10 (power generating cell) includes a framed membrane electrode assembly 12 (hereinafter referred to as "framed MEA 12"), and a first separator 14 and a second separator 16 arranged on either side of the framed MEA 12. The fuel cell 10 is formed, for example, in a horizontally (or vertically) long rectangular shape. A plurality of fuel cells 10 are stacked, for example, in the direction of arrow A to form a fuel cell stack (not shown). The fuel cell stack is mounted, for example, in a fuel cell electric vehicle (not shown) as an on-vehicle fuel cell stack with the stacking direction oriented horizontally or vertically.

[0014] In the fuel cell 10, a framed MEA 12 is sandwiched between a first separator 14 and a second separator 16. The first separator 14 and the second separator 16 have a horizontally (or vertically) long rectangular shape. The first separator 14 and the second separator 16 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, a titanium plate, or a metal plate whose metal surface has been subjected to a corrosion-resistant surface treatment, a carbon member, or the like.

[0015] The rectangular framed MEA 12 includes a membrane electrode assembly 12a (hereinafter referred to as "MEA 12a"). The MEA 12a includes an electrolyte membrane 18, an anode electrode 20 (first electrode) provided on a first surface 18a of the electrolyte membrane 18 (the surface facing the viewer in the figure), and a cathode electrode 22 (second electrode) provided on a second surface 18b of the electrolyte membrane 18 (the surface facing the viewer in the figure).

[0016] The electrolyte membrane 18 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). The solid polymer electrolyte membrane is, for example, a thin film of perfluorosulfonic acid containing moisture, and is made of a material that allows hydrogen ions to pass through. In addition to a fluorine-based electrolyte, a HC (hydrocarbon)-based electrolyte can be used as the material for the electrolyte membrane 18. The electrolyte membrane 18 is sandwiched between an anode electrode 20 and a cathode electrode 22.

[0017] The electrolyte membrane 18 is not limited to a solid polymer electrolyte membrane, but may be made of an oxide ceramic having oxygen ion conductivity, or a porous material impregnated with various molten salts having proton or carbonate ion conductivity.

[0018] The framed MEA 12 further includes a frame member 24 that wraps around the entire periphery of the electrolyte membrane 18 and is joined to the anode electrode 20 and the cathode electrode 22. The frame member 24 is disposed so as to be sandwiched between the outer periphery of the anode electrode 20 and the outer periphery of the cathode electrode 22, and is joined to the anode electrode 20 and the cathode electrode 22 with an adhesive or the like. The frame-shaped sheet that constitutes the frame member 24 is not particularly limited, and may be made of, for example, a resin material. Depending on the design of the fuel cell 10, the fuel cell 10 may be composed of only the MEA 12a without providing the frame member 24.

[0019] 1, an oxidant gas inlet manifold 30a and a fuel gas outlet manifold 32b are provided at one end edge of the fuel cell 10 in the direction of arrow B (horizontal direction), and communicate with each other in the direction of arrow A, which is the stacking direction. The oxidant gas inlet manifold 30a supplies air as an oxidant gas. The fuel gas outlet manifold 32b discharges a hydrogen-containing gas as a fuel gas. The oxidant gas inlet manifold 30a and the fuel gas outlet manifold 32b are arranged in the direction of arrow C.

[0020] A fuel gas inlet manifold 32a for supplying fuel gas and an oxidant gas outlet manifold 30b for discharging oxidant gas are provided at the other end edge of the fuel cell 10 in the direction of arrow B, and these are connected to each other in the direction of arrow A. The fuel gas inlet manifold 32a and the oxidant gas outlet manifold 30b are arranged in the direction of arrow C.

[0021] A fuel gas flow path 34 communicating with the fuel gas inlet manifold 32a and the fuel gas outlet manifold 32b is provided on an inner surface 14a of the first separator 14 facing the framed MEA 12. The fuel gas flow path 34 is formed between the first separator 14 and the framed MEA 12. The fuel gas flow path 34 has a plurality of protrusions 34a and flow path grooves 34b formed between the protrusions 34a. The protrusions 34a bulge toward the anode electrode 20 and abut against the anode electrode 20. The protrusions 34a are formed in a straight or wavy shape and extend in the direction of arrow B. The flow path grooves 34b are formed between the plurality of protrusions 34a. The protrusions 34a and the flow path grooves 34b are alternately arranged in the flow path width direction (direction of arrow C).

[0022] An oxidant gas flow path 38 communicating with the oxidant gas inlet manifold 30a and the oxidant gas outlet manifold 30b is provided on the inner surface 16a of the second separator 16 facing the framed MEA 12. The oxidant gas flow path 38 is formed between the second separator 16 and the framed MEA 12. The oxidant gas flow path 38 has a plurality of protrusions 38a and flow path grooves 38b formed between the protrusions 38a. The protrusions 38a bulge toward the cathode electrode 22 and abut against the cathode electrode 22. The protrusions 38a are formed in a straight or wavy shape and extend in the direction of arrow B. The flow path grooves 38b are formed between the plurality of protrusions 38a. The protrusions 38a and the flow path grooves 38b are alternately arranged in the flow path width direction (direction of arrow C).

[0023] The protrusion 34a of the first separator 14 and the protrusion 38a of the second separator 16 are formed in positions facing each other, and the MEA 12a is sandwiched and held between the protrusions 34a and 38a.

[0024] Next, the sensors 40, 42, 44, 46 of the fuel cell 10 of this embodiment will be described. As shown in Figures 2 and 4, the fuel cell 10 includes a first sensor 40 that detects the temperature of the second separator 16, a second sensor 42 that detects the temperature of the electrolyte membrane 18, a third sensor 44 that detects the temperature of the frame member 24, and a fourth sensor 46 that detects the impedance of the MEA 12a.

[0025] 2, the first sensor 40 is a temperature sensor formed in a sensor placement area 48 provided on the inner surface 16a of the second separator 16. The first sensor 40 has a sensor unit 50 provided in a portion of the second separator 16 corresponding to the measurement target site 16c, and a wiring unit 55 including a first wiring pattern 52 and a second wiring pattern 54 connected to the sensor unit 50. The sensor unit 50, the first wiring pattern 52, and the second wiring pattern 54 are formed of conductors formed in a thin film shape.

[0026] Of these, the sensor section 50 is formed from a conductive material such as a metal or a semiconductor whose resistance value changes with temperature, and is formed in a zigzag pattern as shown in the figure when viewed from above. A first wiring pattern 52 is connected to one end of the sensor section 50, and a second wiring pattern 54 is connected to the other end of the sensor section 50. The first wiring pattern 52 and the second wiring pattern 54 are formed in straight lines and extend parallel to each other toward the outer periphery of the second separator 16.

[0027] The sensor portion 50, the first wiring pattern 52 and the second wiring pattern 54 are covered with an insulating film to prevent short-circuiting with the second separator 16 made of a conductive material such as metal and to prevent influences such as the power generation potential of the MEA 12a.

[0028] 3, the insulating film of the first sensor 40 includes a base insulating film 56 and a covering insulating film 58. The base insulating film 56 is an insulating film formed on the inner surface 16a of the second separator 16, and is made of an insulating resin such as a polyimide resin or a parylene resin. When the fuel cell 10 is configured as a solid oxide fuel cell, the base insulating film 56 may be made of a heat-resistant insulator such as an oxide. The base insulating film 56 is formed so as to cover the entire sensor arrangement region 48 in FIG. 2.

[0029] 3, the first wiring pattern 52 and the second wiring pattern 54 of the first sensor 40 have a convex-crossing portion 60 that crosses the convex portion 38a of the second separator 16. The base insulating film 56 is formed in the convex-crossing portion 60 so as to cover the side wall 38a1 and upper end portion 38a2 of the convex portion 38a.

[0030] A conductive film constituting the above-mentioned sensor portion 50, the first wiring pattern 52 and the second wiring pattern 54 is formed on the base insulating film 56. The method of forming the conductive film will be described later.

[0031] The insulating coating film 58 is formed so as to cover the sensor section 50, the first wiring pattern 52, the second wiring pattern 54, and the base insulating film 56 in a portion not covered by the sensor section 50, the first wiring pattern 52, and the second wiring pattern 54. The insulating coating film 58 can be formed using an insulating resin material such as polyimide resin or parylene resin. In this embodiment, the insulating coating film 58 is formed so that the thickness of the portion filling the gap between the first wiring pattern 52 and the second wiring pattern 54 (see FIG. 2) is thicker than the thickness of the portion covering the first wiring pattern 52 and the second wiring pattern 54, and is formed with a uniform height so that no step is generated between the first wiring pattern 52 and the second wiring pattern 54 and the other portions. This allows the surface pressure to be distributed over a wider portion in the convex portion crossing portion 60, and damage to the wiring patterns 52 and 54 due to concentration of load can be suppressed.

[0032] Furthermore, the insulating cover 58 may be formed so that the portion above the convex crossing portion 60 is thicker than the other portions. By forming it in this manner, deterioration due to wear of the insulating cover 58 can be suppressed even if the second separator 16 and the framed MEA 12 are misaligned in the planar direction due to vibration or thermal cycles.

[0033] 3, for ease of explanation, the thicknesses of the base insulating film 56, the first wiring pattern 52, and the covering insulating film 58 are exaggerated, but these members are actually thinner than the thickness of the cathode electrode 22 of the MEA 12a. In addition, in the convex portion crossing portion 60, the thicknesses of the base insulating film 56, the first wiring pattern 52, and the covering insulating film 58 can be supported by the deformation of each member constituting the MEA 12a.

[0034] As shown in Fig. 2, a first connection pad 52a and a second connection pad 54a are formed on the outer peripheral ends of the first wiring pattern 52 and the second wiring pattern 54, respectively. As shown at the right end of Fig. 3, the first connection pad 52a is provided in an opening 58a of a covering insulating film 58 that covers the first wiring pattern 52. In the first connection pad 52a, the first wiring pattern 52 is exposed from the covering insulating film 58. The second connection pad 54a (see Fig. 2) has a structure similar to that of the first connection pad 52a, and the second wiring pattern 54 is exposed.

[0035] The first sensor 40 is configured as described above, but the present embodiment is not limited to this, and the first sensor 40 may be provided on the first separator 14 side.

[0036] The first sensor 40 is not limited to a resistance thermometer, and may be configured as, for example, a thermocouple. In this case, the first wiring pattern 52 and the second wiring pattern 54 are formed from different types of metals. The sensor unit 50 can be configured as a junction between the first wiring pattern 52 and the second wiring pattern 54.

[0037] In addition, the first wiring pattern 52 and the second wiring pattern 54 may be disposed along the flow channel 38b. In this case, the number of the convex portion crossing portions 60 can be reduced. No. 1 This makes it possible to more effectively suppress the deterioration of the sensor 40.

[0038] Next, a method for manufacturing the fuel cell 10 having the first sensor 40 will be described.

[0039] First, the second separator 16 is prepared as shown in Fig. 1. Next, a base insulating film 56 (see Fig. 3) is formed over the entire sensor arrangement region 48 on the inner surface 16a of the second separator 16 shown in Fig. 2. The base insulating film 56 can be formed by applying a polyimide resin by an inkjet method. Alternatively, the base insulating film 56 may be formed by depositing a parylene resin by a vacuum deposition method.

[0040] 3, a mask having an opening of a predetermined shape is placed on the base insulating film 56, and a conductor film is formed on the base insulating film 56 exposed through the opening of the mask by various film forming methods such as vapor deposition, sputtering, plating, etc. As a result, the sensor section 50, the first wiring pattern 52, and the second wiring pattern 54 are formed on the base insulating film 56.

[0041] Next, after removing the mask, a covering insulating film 58 is formed on the sensor portion 50, the first wiring pattern 52, the second wiring pattern 54, and the exposed base insulating film 56. The covering insulating film 58 is formed by the same method as the base insulating film 56. Through the above steps, the second separator 16 on which the first sensor 40 is formed is completed.

[0042] Thereafter, in the same manner as in the manufacture of a normal fuel cell 10, a second separator 16 is abutted against the cathode electrode 22 side of the framed MEA 12, and a first separator 14 is abutted against the anode electrode 20 side of the framed MEA 12, thereby obtaining the cross-sectional structure shown in FIG. 3.

[0043] Next, the second sensor 42 will be described with reference to FIGS.

[0044] As shown in Fig. 4, the second sensor 42 is a temperature sensor provided on the surface of the electrolyte membrane 18 of the MEA 12a and detects the temperature of the electrolyte membrane 18. In order to measure the accurate temperature of the electrolyte membrane 18, the second sensor 42 is formed between the second surface 18b of the electrolyte membrane 18 and the cathode electrode 22 as shown in Fig. 5. Although not particularly shown, the second sensor 42 may be provided on the first surface 18a side of the electrolyte membrane 18, in which case the second sensor 42 may be disposed between the first surface 18a and the anode electrode 20.

[0045] In order for the second sensor 42 to measure the temperature of the electrolyte membrane 18 more accurately, the sensor unit 50 is provided at a portion corresponding to the protrusion 34a of the first separator 14 and the protrusion 38a of the second separator 16. With this configuration, the sensor unit 50 is pressed by the protrusions 34a, 38a, improving the thermal connection between the sensor unit 50 and the electrolyte membrane 18.

[0046] The second sensor 42 has a structure basically similar to that of the first sensor 40 described with reference to Figures 2 and 3, except that it is formed on the electrolyte membrane 18, and has a similar sensor portion 50, first wiring pattern 52, and second wiring pattern 54. Therefore, in the second sensor 42 shown in Figures 4 and 5, the same components as those of the first sensor 40 in Figures 2 and 3 are denoted by the same reference numerals and detailed description thereof will be omitted. However, the outer periphery of the framed MEA 12 does not protrude to the outside, making it difficult to provide a connection terminal for connection to external wiring.

[0047] Therefore, the second sensor 42 has a wiring portion 55 including the first wiring pattern 52 and the second wiring pattern 54 divided into a first wiring portion 62 formed in a sensor arrangement area 48A1 on the second surface 18b of the electrolyte membrane 18 shown in Fig. 4, and a second wiring portion 64 formed in a sensor arrangement area 48A2 on the inner surface 16a of the second separator 16 shown in Fig. 2. The first wiring pattern 52 and the second wiring pattern 54 formed in the second wiring portion 64 are extended to the outer periphery of the second separator 16, and a first connection pad 52a and a second connection pad 54a are provided at the ends on the outer periphery.

[0048] The first wiring portion 62 and the second wiring portion 64 are electrically connected via a first terminal portion 62a (FIG. 4) provided on the first wiring portion 62 side and a second terminal portion 64a (FIG. 2) provided on the second wiring portion 64. That is, as shown in FIG. 4, the first wiring pattern 52 and the second wiring pattern 54 of the first wiring portion 62 are each provided with a first terminal portion 62a. As shown in FIG. 5, an opening 58b is formed in the covering insulating film 58 in the first terminal portion 62a, and the first wiring pattern 52 (or the second wiring pattern 54) is exposed from the opening 58b. The first terminal portion 62a is provided in a portion corresponding to the protrusion 34a of the first separator 14 and the protrusion 38a of the second separator 16.

[0049] The second terminal portion 64a is formed on the inner surface 16a of the second separator 16 in a portion facing the first terminal portion 62a. The second terminal portion 64a is formed in a portion riding on the protruding portion 38a of the second separator 16. In the second terminal portion 64a, an opening 58c is formed in the covering insulating film 58 that covers the second wiring portion 64, and the first wiring pattern 52 (or the second wiring pattern 54) of the second wiring portion 64 is exposed.

[0050] An opening 22c is formed in the cathode electrode 22 in the portion where the first terminal portion 62a and the second terminal portion 64a are formed. The first wiring pattern 52 of the first wiring portion 62 and the first wiring pattern 52 of the second wiring portion 64 are pressed by the protrusions 34a and 38a, so that they come into contact with each other via the opening 22c and the openings 58b and 58c, and the first wiring pattern 52 of the first wiring portion 62 and the first wiring pattern 52 of the second wiring portion 64 are electrically connected to each other. Similarly, the first wiring portion 62 and the second wiring portion 64 are connected to each other via the first terminal portion 62a and the second terminal portion 64a for the second wiring pattern 54.

[0051] Next, a method for manufacturing the fuel cell 10 including the second sensor 42 will be described.

[0052] First, the second wiring portion 64 of the second sensor 42 is formed on the inner surface 16a of the second separator 16 by the same process as in the manufacturing method of the first sensor 40. Since the manufacturing process of the second wiring portion 64 is the same as that of the first sensor 40, it can be formed at the same time as the first sensor 40.

[0053] Next, a framed MEA 12 having the first wiring portion 62 of the second sensor 42 is formed. First, a base insulating film 56, a sensor portion 50, a first wiring pattern 52, a second wiring pattern 54, and a covering insulating film 58 are formed in this order on the electrolyte membrane 18 shown in Fig. 5. These steps are similar to the manufacturing steps of the first sensor 40, so detailed explanations will be omitted.

[0054] Next, the cathode electrode 22, in which the opening hole 22c is formed in the portion corresponding to the first terminal portion 62a and the second terminal portion 64a, is joined onto the second surface 18b of the electrolyte membrane 18 on which the first portion of the second sensor 42 is formed. In addition, the anode electrode 20 is joined onto the first surface 18a of the electrolyte membrane 18.

[0055] Thereafter, the frame member 24 is joined to the outer periphery of the electrolyte membrane 18, the anode electrode 20, and the cathode electrode 22. The frame member 24 is joined so as to be sandwiched between the electrolyte membrane 18 and the cathode electrode 22, and the anode electrode 20. Through the above steps, the framed MEA 12 on which the first wiring portion 62 of the second sensor 42 is formed is completed.

[0056] 1, the second separator 16 is abutted against the cathode electrode 22 side of the framed MEA 12, and the first separator 14 is abutted against the anode electrode 20 side of the framed MEA 12. As a result, the first terminal 62a and the second terminal 64a are pressed by the protrusions 34a, 38a and electrically connected, as shown in FIG. 5, completing the fuel cell 10 in which the second sensor 42 is formed.

[0057] Next, the third sensor 44 will be described.

[0058] 4, the third sensor 44 is a temperature sensor that detects the temperature of the frame member 24, and its entire area is formed in a sensor arrangement area 48B provided in the frame member 24. The third sensor 44 is configured to include a sensor unit 50 similar to the first sensor 40, and a wiring unit 55 having a first wiring pattern 52 and a second wiring pattern 54.

[0059] However, as shown in FIG. of When the sensor section 50 is made of an insulating resin material, the base insulating film 56 does not need to be provided under the sensor section 50, the first wiring pattern 52, and the second wiring pattern 54. In this case, the frame member 24 also serves as the base insulating film 56. The sensor section 50, the first wiring pattern 52, the second wiring pattern 54, and the sensor arrangement region 48B around them are covered with a covering insulating film 58 to prevent a short circuit with the second separator 16. An opening 58d is formed in the covering insulating film 58 on the outer periphery of the third sensor 44, and a first connection pad 52a and a second connection pad 54a (see FIG. 4) are formed with the first wiring pattern 52 and the second wiring pattern 54 exposed from the opening 58d.

[0060] The third sensor 44 can be produced by preparing a frame member 24, and sequentially forming on its surface a sensor portion 50, a first wiring pattern 52, a second wiring pattern 54, and a covering insulating film 58. These steps are similar to the manufacturing steps of the first sensor 40.

[0061] Next, the fourth sensor 46 will be described.

[0062] 7, the fourth sensor 46 has a first wiring pattern 52A formed along the upper end 34a2 of the protrusion 34a of the first separator 14, and a second wiring pattern 54A formed along the upper end 38a2 of the protrusion 38a of the second separator 16. The first wiring pattern 52A and the second wiring pattern 54A are provided in portions facing each other, and are formed to have the same shape in a plan view (see FIG. 2).

[0063] The first wiring pattern 52A is formed on the base insulating film 56 and is insulated from the first separator 14 via the base insulating film 56. The second wiring pattern 54A is also formed on the base insulating film 56 and is insulated from the second separator 16 via the base insulating film 56. The base insulating film 56 of the second separator 16 is formed over the entire sensor arrangement region 48C formed in an elongated shape as shown in FIG. 2. The sensor arrangement region 48C and the base insulating film 56 of the first separator 14 are also formed in the same shape. The first wiring pattern 52A and the second wiring pattern 54A are each covered with a covering insulating film 58 and insulated from the anode electrode 20 or the cathode electrode 22.

[0064] figure 7 2, a first sensor unit 50A is formed at the tip of the first wiring pattern 52A, with the first wiring pattern 52A exposed from the insulating coating film 58. Moreover, a second sensor unit 50B is formed at the tip of the second wiring pattern 54A, with the second wiring pattern 54A exposed from the insulating coating film 58. The first sensor unit 50A and the second sensor unit 50B are provided at positions overlapping each other in a plan view, and face each other via the MEA 12a.

[0065] The first sensor unit 50A and the second sensor unit 50B are pressed toward the MEA 12a via the protrusions 34a, 38a, and the first sensor unit 50A is in contact with the anode electrode 20 so as to be embedded therein. The second sensor unit 50B is in contact with the cathode electrode 22 so as to be embedded therein. The fourth sensor 46 can detect the local impedance of the MEA 12a by applying an AC voltage between the first sensor unit 50A and the second sensor unit 50B.

[0066] The fuel cell 10 having the fourth sensor 46 is produced by the steps of producing a first separator 14 having a first wiring pattern 52A, producing a second separator 16 having a second wiring pattern 54A, and stacking the first separator 14, the framed MEA 12, and the second separator 16.

[0067] Of these, the first separator 14 provided with the first wiring pattern 52A is produced by a process of forming, in order, a base insulating film 56, the first wiring pattern 52A, and a covering insulating film 58 on its inner surface 14a. Meanwhile, the second separator 16 provided with the second wiring pattern 54A is produced by a process of forming, in order, a base insulating film 56, the second wiring pattern 54A, and a covering insulating film 58 on its inner surface 16a. The process of producing the first wiring pattern 52A and the second wiring pattern 54A can be performed in the same manner as the process of forming the first sensor 40 on the second separator 16. Through the above processes, the fuel cell 10 having the fourth sensor 46 is obtained.

[0068] The fuel cell 10 of this embodiment provides the following advantages.

[0069] The fuel cell 10 of this embodiment includes an MEA 12a (membrane electrode assembly) having an electrolyte membrane 18, an anode electrode 20 provided on a first surface 18a of the electrolyte membrane 18, and a cathode electrode 22 provided on a second surface 18b of the electrolyte membrane 18, a frame member 24 surrounding the outer periphery of the MEA 12a, a pair of separators 14, 16 sandwiching the MEA 12a, sensor units 50, 50A, 50B provided on at least one of the separators 14, 16, the frame member 24, and the electrolyte membrane 18, and a sensor unit 50, 50A, 50B connected to the sensor units 50, 50A, 50B and connected to the separator 14. , 16 or the outer periphery of MEA 12a, and sensors 40, 42, 44, 46 have an underlying insulating film 56 covering sensor arrangement regions 48, 48A, 48B, 48C in which sensors 40, 42, 44, 46 are arranged, wiring patterns 52, 52A, 54, 54A stacked on the underlying insulating film 56, and a covering insulating film 58 covering the underlying insulating film 56 in portions not covered by the wiring patterns 52, 52A, 54, 54A.

[0070] According to the above configuration, the sensors 40, 42, 44, 46 can be made thin-film shaped and integrated with the fuel cell 10, eliminating the need for complicated arrangement of the sensors 40, 42, 44, 46 and allowing easy and accurate detection of state quantities. In addition, the positional deviation of the sensors 40, 42, 44, 46 can be prevented, making this suitable for detecting local state quantities at desired locations.

[0071] In the above fuel cell 10, the separators 14, 16 may have protrusions 34a, 38a that protrude toward the MEA 12a and press against the MEA 12a, and the sensor units 50, 50A, 50B may be provided at positions corresponding to the protrusions 34a, 38a of the separators 14, 16. With this configuration, the sensor units 50, 50A, 50B can be brought into close contact with the object to be measured, thereby enabling more accurate measurement.

[0072] In the above fuel cell 10, the sensor section 50 is formed on a base insulating film 56, and may be covered by a covering insulating film 58 together with the wiring patterns 52, 54. With this configuration, the sensor section 50 can be electrically insulated from the separators 14, 16, the MEA 12a, etc., and therefore measurements can be performed with high accuracy.

[0073] In the above fuel cell 10, the sensor unit 50 is provided on the surface of the electrolyte membrane 18, and the wiring unit 55 includes a first wiring unit 62 extending along the surface of the electrolyte membrane 18 and connected to the sensor unit 50, and a second wiring unit 64 extending along the surfaces of the separators 14, 16, and the first wiring unit 62 and the second wiring unit 64 are electrically connected by abutting a first terminal unit 62a where the wiring patterns 52, 54 of the first wiring unit 62 are exposed from the insulating coating film 58 against a second terminal unit 64a where the wiring patterns 52, 54 of the second wiring unit 64 are exposed from the insulating coating film 58. According to this configuration, the wiring unit 55 of the sensor unit 50 can be provided on the electrolyte membrane 18 and the separators 14, 16, which increases the degree of freedom in the arrangement position of the sensor unit 50.

[0074] In the above fuel cell 10, the separators 14, 16 may have a plurality of protrusions 34a, 38a protruding toward the MEA 12a and extending along the flow direction of the reactant gas, and flow grooves 34b, 38b formed between the protrusions 34a, 38a, and the wiring 55 may be provided along the flow grooves 34b, 38b. This configuration can prevent wear of the wiring 55 due to friction with the protrusions 34a, 38a.

[0075] In the above fuel cell 10, the covering insulating film 58 may be formed so that the portion covering the wiring patterns 52, 54 and the portion covering the portions other than the wiring patterns 52, 54 have the same height.

[0076] In the above fuel cell 10, the wiring portion 55 may have a convexity crossing portion 60 that crosses the convexities 34a, 38a from which the separators 14, 16 protrude and press against the MEA 12a, and the insulating coating film 58 of the convexity crossing portion 60 may be formed thicker than the insulating coating film 58 of other portions. With this configuration, damage due to wear of the insulating coating film 58 at the convexity crossing portion 60 can be suppressed.

[0077] In the above fuel cell 10, the convex portions 34a, 38a of the separators 14, 16 have flat surfaces at least in the portions corresponding to the convex-crossing portions 60. With this configuration, the load can be distributed within the convex-crossing portions 60, and damage to the wiring patterns 52, 54 due to concentrated load can be prevented.

[0078] In the above fuel cell 10, the wiring patterns 52, 54 include a first wiring pattern 52 formed from a first metal and a second wiring pattern 54 formed from a second metal of a different type from the first metal, and the sensor section 50 may be a thermocouple junction where the tip of the first wiring pattern 52 and the tip of the second wiring pattern 54 are in contact with each other.

[0079] In the above fuel cell 10, the sensor 44 is formed on the frame member 24, and the frame member 24 may also serve as the base insulating film 56. With this configuration, the process of forming an independent base insulating film 56 is not necessary, and the manufacturing process can be simplified.

[0080] In the above fuel cell 10, the wiring section 55 has a first wiring section 62 formed on the surface of one separator 14 and including a first wiring pattern 52A, and a second wiring section 64 formed on the surface of the other separator 16 and including a second wiring pattern 54A, and the sensor section 50 has a first wiring Department At the end of No. 1 Wiring Pattern 52A The first sensor section 50A is exposed, and the second wiring Department At the end of Second Wiring Pattern 54A The first sensor unit 50A and the second sensor unit 50B may be disposed opposite to each other with the MEA 12a in between and electrically connected to the MEA 12a. With this configuration, the local impedance of the MEA 12a can be detected by applying an AC voltage between the first sensor unit 50A and the second sensor unit 50B.

[0081] Although the present invention has been described above with reference to preferred embodiments, it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0082] 10…Fuel cell 12a…MEA 14, 16...Separator 18...Electrolyte membrane 20...anode electrode 22...cathode electrode 34a, 38a... protruding portion 34b, 38b... flow path groove 40, 42, 44, 46…Sensor 48, 48A, 48B, 48C…Sensor placement area 50, 50A, 50B...sensor section 52, 52A...first wiring pattern 54, 54A... second wiring pattern 55... wiring section 56: Undercoat insulating film 58: Covering insulating film 60: convex crossing portion 62: first wiring portion 62a...First terminal section 64...Second wiring section 64a…Second terminal part

Claims

1. an electrolyte membrane electrode assembly including an electrolyte membrane, an anode electrode provided on one surface of the electrolyte membrane, and a cathode electrode provided on the other surface of the electrolyte membrane; a frame member surrounding an outer periphery of the membrane electrode assembly; a pair of separators sandwiching the membrane electrode assembly; a sensor including a sensor portion provided on at least one of the separator, the frame member, and the electrolyte membrane, and a wiring portion connected to the sensor portion and extending to an outer periphery of the separator or the membrane electrode assembly, the sensor including: a base insulating film covering a surface of a sensor arrangement region in which the sensor is arranged; A wiring pattern laminated on the base insulating film; The wiring pattern and a covering insulating film that covers a portion of the base insulating film that is not covered by the wiring pattern, A fuel cell, wherein the separator has a convex portion that protrudes toward the electrolyte membrane / electrode assembly and presses the electrolyte membrane / electrode assembly, and the sensor portion is provided at a position corresponding to the convex portion of the separator.

2. 2. The fuel cell according to claim 1, wherein the sensor section is formed on the base insulating film and is covered, together with the wiring pattern, by the covering insulating film.

3. An electrolyte membrane-electrode structure having an electrolyte membrane, an anode electrode provided on one surface of the electrolyte membrane, and a cathode electrode provided on the other surface of the electrolyte membrane; a frame member surrounding an outer periphery of the membrane electrode assembly; a pair of separators sandwiching the membrane electrode assembly; a sensor including a sensor portion provided on at least one of the separator, the frame member, and the electrolyte membrane, and a wiring portion connected to the sensor portion and extending to an outer periphery of the separator or the membrane electrode assembly, the sensor including: a base insulating film covering a surface of a sensor arrangement region in which the sensor is arranged; A wiring pattern laminated on the base insulating film; The wiring pattern and a covering insulating film that covers a portion of the base insulating film that is not covered by the wiring pattern, The sensor unit is provided on a surface of the electrolyte membrane, and the wiring unit is a first wiring portion extending along a surface of the electrolyte membrane and connected to the sensor portion; A second wiring portion extending along a surface of the separator, A fuel cell, wherein the first wiring portion and the second wiring portion are electrically connected by abutting a first terminal portion, where the wiring pattern of the first wiring portion is exposed from the covering insulating film, and a second terminal portion, where the wiring pattern of the second wiring portion is exposed from the covering insulating film, face to face.

4. 4. The fuel cell according to claim 1, wherein the separator has a plurality of protruding portions protruding toward the membrane electrode assembly and extending along a flow direction of a reactant gas, and a flow channel formed between the protruding portions; The wiring portion is provided along the flow channel.

5. 5. The fuel cell according to claim 1, wherein the insulating coating film is formed so that a portion covering the wiring pattern and a portion covering a portion other than the wiring pattern have the same height.

6. An electrolyte membrane-electrode structure having an electrolyte membrane, an anode electrode provided on one surface of the electrolyte membrane, and a cathode electrode provided on the other surface of the electrolyte membrane; a frame member surrounding an outer periphery of the membrane electrode assembly; a pair of separators sandwiching the membrane electrode assembly; a sensor including a sensor portion provided on at least one of the separator, the frame member, and the electrolyte membrane, and a wiring portion connected to the sensor portion and extending to an outer periphery of the separator or the membrane electrode assembly, the sensor including: a base insulating film covering a surface of a sensor arrangement region in which the sensor is arranged; A wiring pattern laminated on the base insulating film; The wiring pattern and a covering insulating film that covers a portion of the base insulating film that is not covered by the wiring pattern, a wiring portion having a convex portion crossing portion that crosses a convex portion through which the separator protrudes and presses the electrolyte membrane / electrode assembly, and the covering insulating film at the convex portion crossing portion is formed thicker than the covering insulating film in other portions.

7. 7. The fuel cell according to claim 6, wherein at least a portion of said convex portion of said separator that corresponds to said convex portion crossing portion is made of a flat surface.

8. An electrolyte membrane-electrode structure having an electrolyte membrane, an anode electrode provided on one surface of the electrolyte membrane, and a cathode electrode provided on the other surface of the electrolyte membrane; a frame member surrounding an outer periphery of the membrane electrode assembly; a pair of separators sandwiching the membrane electrode assembly; a sensor including a sensor portion provided on at least one of the separator, the frame member, and the electrolyte membrane, and a wiring portion connected to the sensor portion and extending to an outer periphery of the separator or the membrane electrode assembly, the sensor including: a base insulating film covering a surface of a sensor arrangement region in which the sensor is arranged; A wiring pattern laminated on the base insulating film; The wiring pattern and a covering insulating film that covers a portion of the base insulating film that is not covered by the wiring pattern, the wiring section includes a first wiring section formed on a surface of one of the separators and including a first wiring pattern, and a second wiring section formed on a surface of the other of the separators and including a second wiring pattern, the sensor unit has a first sensor unit formed by exposing the first wiring pattern at an end of the first wiring unit, and a second sensor unit formed by exposing the second wiring pattern at an end of the second wiring unit, a fuel cell, the first sensor unit and the second sensor unit being disposed opposite each other with the membrane electrode assembly therebetween, and being electrically connected to the membrane electrode assembly;

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