Fuel cell

Abstract

The present invention relates to a fuel cell. The fuel cell (10) includes sensors (40, 42, 44, 46), and the sensors (40, 42, 44, 46) have a sensor portion (50) and a wiring portion (55). The sensor portion (50) is provided on at least one of separators (14, 16), a frame member (24), and an electrolyte membrane (18). The wiring portion (55) is connected to the sensor portion (50) and extends to the outer peripheral portion of the separator (14, 16) or the MEA (12). The sensors (40, 42, 44, 46) have a base insulating film (56), wiring patterns (52, 54), and a covering insulating film (58). The base insulating film (56) covers sensor arrangement regions (48, 48A, 48B, 48C). The wiring patterns (52, 54) are laminated on the base insulating film (56). The covering insulating film (58) covers the wiring patterns (52, 54) and the portion of the base insulating film (56) not covered by the wiring patterns (52, 54).

Description

Technical Field

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

[0002] A fuel cell has an electrolyte membrane - electrode structure body and a pair of separators sandwiching the electrolyte membrane - electrode structure body. The electrolyte membrane - electrode structure body is a structure in which an electrolyte membrane, an anode electrode, and a cathode electrode are laminated. The electrolyte membrane conducts ions such as hydrogen ions and oxygen ions, and the anode electrode and the cathode electrode are laminated on one surface and the other surface of the electrolyte membrane, respectively. One separator is disposed adjacent to the anode electrode. A fuel gas flow path for allowing a fuel gas to flow is provided between one separator of the fuel cell and the anode electrode. In addition, an oxidant gas flow path for allowing an oxidant gas to flow is provided between the other separator of the fuel cell 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 on, for example, a fuel cell electric vehicle.

[0003] In a fuel cell, it is beneficial to measure the internal environment such as the temperature and conductivity of various structural components such as the electrolyte membrane and the electrode during power generation to grasp the operation of the fuel cell. Therefore, a method of disposing a temperature sensor such as a thermocouple between the separator and the electrolyte membrane - electrode structure body is used to measure the internal environment of the fuel cell.

[0004] For example, Patent Document 1 discloses a technique for measuring the internal temperature of a fuel cell having an electrolyte membrane - electrode structure body in which an electrolyte membrane is sandwiched between an anode electrode and a cathode electrode. This document discloses a technique of disposing a lid provided with a groove for disposing a sensor on the cathode electrode side.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010 - 135270. Summary of the Invention

[0008] Conventional measurement techniques measure by disposing a sensor such as a thermocouple between a separator having a normal structure and an electrolyte membrane - electrode structure body. Therefore, an operator needs to perform an operation of disposing the sensor inside the fuel cell, and the operator is required to perform a complicated operation. At this time, the operator sometimes damages the thin metal wire for the thermocouple during the operation. In addition, due to the displacement of the position of the sensor during the assembly of the fuel cell, the state of the target part sometimes cannot be accurately measured.

[0009] In addition, in the case of the technology of Patent Document 1, a configuration space for the lid body is required, and a significant change to the structure of the fuel cell is needed. In addition, due to the configuration of the lid body, there is a problem of increasing the thickness of the fuel cell.

[0010] Therefore, an object of the present invention is to provide a fuel cell capable of simply and accurately measuring the state quantity inside the fuel cell.

[0011] One aspect disclosed below relates to a fuel cell, comprising: 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 the outer peripheral portion of the electrolyte membrane-electrode structure; a pair of separators sandwiching the electrolyte membrane-electrode structure; and a sensor having a sensor portion and a wiring portion, the sensor portion being provided on at least one of the separator, the frame member, and the electrolyte membrane, the wiring portion being connected to the sensor portion and extending to the outer peripheral portion of the separator or the electrolyte membrane-electrode structure, the sensor having: a base insulating film covering the surface of the sensor configuration area for configuring the sensor; a wiring pattern laminated on the base insulating film; and a covering insulating film covering the wiring pattern and the portion of the base insulating film not covered by the wiring pattern.

[0012] The fuel cell according to the above aspect can simply and accurately measure the state quantity inside the fuel cell.

[0013] From the description of the following embodiments with reference to the drawings, the above objects, features, and advantages can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is an exploded perspective view of the fuel cell according to the embodiment.

[0015] Figure 2 is Figure 1 a top view of the first surface of the second separator.

[0016] Figure 3 is Figure 2 a cross-sectional view of the fuel cell corresponding to line III-III of

[0017] Figure 4 is Figure 1 a top view of the electrolyte membrane-electrode structure of

[0018] Figure 5 is Figure 2 a cross-sectional view of the fuel cell corresponding to line V-V of

[0019] Figure 6 is Figure 4 a cross-sectional view of the VI-VI line.

[0020] Figure 7 is the part corresponding to the VII-VII line of Figure 2 a cross-sectional view of the fuel cell. Detailed Embodiments

[0021] Hereinafter, preferred embodiments will be listed, and the present invention will be described in detail with reference to the accompanying drawings.

[0022] As Figure 1 shown, the fuel cell 10 (power generation single cell) has a framed electrolyte membrane-electrode structure 12 (hereinafter referred to as "framed MEA 12"), a first separator 14, and a second separator 16. The first separator 14 and the second separator 16 are disposed on both sides of the framed MEA 12. The fuel cell 10 is formed, for example, in a horizontally long (or vertically long) rectangular shape. A plurality of fuel cells 10 are stacked, for example, in the direction of the arrow symbol A to form a fuel cell stack (not shown). The fuel cell stack is mounted, for example, as a vehicle-mounted fuel cell stack on a fuel cell electric vehicle (not shown) in a state where the stacking direction faces the horizontal direction or the vertical direction.

[0023] The fuel cell 10 has a structure in which the framed MEA 12 is sandwiched between the first separator 14 and the second separator 16. The first separator 14 and the second separator 16 have a horizontally long (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 obtained by performing a surface treatment for corrosion prevention on the metal surface, a carbon member, or the like.

[0024] The rectangular-shaped framed MEA 12 includes an electrolyte membrane-electrode structure 12a (hereinafter referred to as "MEA 12a"). The MEA 12a includes an electrolyte membrane 18, an anode electrode 20 (first electrode) provided on the first surface 18a of the electrolyte membrane 18, and a cathode electrode 22 (second electrode) provided on the second surface 18b of the electrolyte membrane 18.

[0025] 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 containing perfluorosulfonic acid with moisture and is formed of a material that allows hydrogen ions to pass through. In addition to fluorine-based electrolytes, materials such as HC (hydrocarbon) electrolytes can be used for the electrolyte membrane 18. The electrolyte membrane 18 is sandwiched between the anode electrode 20 and the cathode electrode 22.

[0026] In addition, the electrolyte membrane 18 is not limited to a solid polymer electrolyte membrane, and may also be composed of an oxide ceramic having oxygen ion conductivity, or a porous material impregnated with various molten salts having proton conductivity or carbonate ion conductivity.

[0027] The framed MEA 12 further includes a frame member 24 that extends throughout the entire circumference of the outer 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 peripheral portion of the anode electrode 20 and the outer peripheral portion of the cathode electrode 22. The frame member 24 is joined to the anode electrode 20 and the cathode electrode 22 by an adhesive or the like. The frame member 24 is composed of a frame-shaped sheet. Although not particularly limited, for example, it may be made of a resin material. Depending on the design of the fuel cell 10, the MEA 12 may not have the frame member 24 and may be composed only of the MEA 12a.

[0028] As Figure 1 shown, the fuel cell 10 has an oxidant gas inlet communication hole 30a and a fuel gas outlet communication hole 32b at one end edge portion in the direction of arrow B (horizontal direction). The oxidant gas inlet communication hole 30a communicates with other oxidant gas inlet communication holes 30a in the stacking direction, i.e., the direction of arrow A. The fuel gas outlet communication hole 32b also communicates in the stacking direction. The oxidant gas inlet communication hole 30a supplies an oxidant gas, such as air. The fuel gas outlet communication hole 32b discharges a fuel gas, such as a hydrogen-containing gas. The oxidant gas inlet communication hole 30a and the fuel gas outlet communication hole 32b are arranged in the direction of arrow C.

[0029] At the other end edge portion of the fuel cell 10 in the direction of arrow B, there are provided a fuel gas inlet communication hole 32a for supplying a fuel gas and an oxidant gas outlet communication hole 30b for discharging an oxidant gas. The fuel gas inlet communication hole 32a communicates in the direction of arrow A. The oxidant gas outlet communication hole 30b communicates in the direction of arrow A. The fuel gas inlet communication hole 32a and the oxidant gas outlet communication hole 30b are arranged in the direction of arrow C.

[0030] On the inner surface 14a of the first separator 14 facing the framed MEA 12, there is a fuel gas flow path 34. The fuel gas flow path 34 communicates with the fuel gas inlet communication hole 32a and the fuel gas outlet communication hole 32b. 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 convex portions 34a and flow path grooves 34b formed between the convex portions 34a. The convex portions 34a bulge toward the anode electrode 20 and abut against the anode electrode 20. The convex portions 34a are formed in a straight line or a wavy line and extend in the direction of arrow B. The flow path grooves 34b are formed between the plurality of convex portions 34a. The convex portions 34a and the flow path grooves 34b are alternately arranged in the flow path width direction (the direction of arrow C).

[0031] On the inner surface 16a of the second separator 16 facing the framed MEA 12, there is an oxidant gas flow path 38. The oxidant gas flow path 38 communicates with the oxidant gas inlet communication hole 30a and the oxidant gas outlet communication hole 30b. 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 convex portions 38a and flow path grooves 38b formed between the convex portions 38a. The convex portions 38a bulge toward the cathode electrode 22 and abut against the cathode electrode 22. The convex portions 38a are formed in a straight line or a wavy line and extend in the direction of arrow B. The flow path grooves 38b are formed between the plurality of convex portions 38a. The convex portions 38a and the flow path grooves 38b are alternately arranged in the flow path width direction (the direction of arrow C).

[0032] The convex portions 34a of the first separator 14 and the convex portions 38a of the second separator 16 are formed at positions facing each other. The MEA 12a is sandwiched and held by the convex portions 34a and the convex portions 38a.

[0033] Next, the sensors 40, 42, 44, and 46 of the fuel cell 10 of the present embodiment will be described. As Figure 2 and Figure 4 shown, the fuel cell 10 includes a first sensor 40, a second sensor 42, a third sensor 44, and a fourth sensor 46. The first sensor 40 is a sensor for detecting the temperature of the second separator 16. The second sensor 42 is a sensor for detecting the temperature of the electrolyte membrane 18. The third sensor 44 is a sensor for detecting the temperature of the frame member 24. The fourth sensor 46 is a sensor for detecting the impedance of the MEA 12a.

[0034] As Figure 2As shown, the first sensor 40 is a temperature sensor formed in the sensor arrangement area 48 provided on the inner surface 16a of the second partition 16. The first sensor 40 includes: a sensor section 50 provided at a portion of the second partition 16 corresponding to the measurement target section 16c; and a wiring section 55 including a first wiring pattern 52 and a second wiring pattern 54 connected to the sensor section 50. The sensor section 50, the first wiring pattern 52, and the second wiring pattern 54 are formed of a conductor formed in a thin film shape.

[0035] Among them, the sensor section 50 is formed of a conductive material whose impedance value changes according to the temperature of a metal or semiconductor or the like. The sensor section 50 has a sawtooth pattern as shown in a plan view. The first wiring pattern 52 is connected to one end of the sensor section 50, and the 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 a straight line shape. The first wiring pattern 52 and the second wiring pattern 54 extend parallel to each other toward the outer peripheral portion of the second partition 16.

[0036] The sensor section 50, the first wiring pattern 52, and the second wiring pattern 54 are covered with an insulating film. The insulating film prevents a short circuit from occurring between the sensor section 50, the first wiring pattern 52, or the second wiring pattern 54 and the second partition 16 formed of a conductive material such as metal. In addition, the insulating film prevents the power generation potential of the MEA 12a or the like from affecting the signal of the sensor section 50.

[0037] As Figure 3 shown, 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 partition 16. The base insulating film 56 is composed of an insulating resin such as polyimide resin or parylene resin, for example. Alternatively, in the case where the fuel cell 10 is configured as a solid oxide fuel cell, the base insulating film 56 is composed of a heat-resistant insulator such as an oxide. The base insulating film 56 is formed so as to cover the entire area of the sensor arrangement area 48. Figure 2 of

[0038] As Figure 3 shown, the first wiring pattern 52 and the second wiring pattern 54 of the first sensor 40 have a convex portion crossing section 60 that crosses the convex portion 38a of the second partition 16. The base insulating film 56 covers the side wall 38a1 and the upper end portion 38a2 of the convex portion 38a at the convex portion crossing section 60.

[0039] A conductor film is formed on the base insulating film 56, and the conductor film constitutes the above-described sensor section 50, first wiring pattern 52, and second wiring pattern 54. A method for forming the conductor film will be described later.

[0040] The covering insulating film 58 covers the sensor portion 50, the first wiring pattern 52, the second wiring pattern 54, and the base insulating film 56 of the portion not covered by the sensor portion 50, the first wiring pattern 52, and the second wiring pattern 54. For example, an insulating resin material such as polyimide resin or parylene resin can be used to form the covering insulating film 58. In the present embodiment, the covering insulating film 58 is formed with a uniform height. That is, the covering insulating film 58 of the portion filling the gap between the first wiring pattern 52 and the second wiring pattern 54 (refer to Figure 2 ) is formed thicker than the thickness of the covering insulating film 58 of the portion covering the first wiring pattern 52 and the second wiring pattern 54. Thus, the covering insulating film 58 has a uniform height such that no step is generated between the first wiring pattern 52, the second wiring pattern 54, and the other portions. Thus, the covering insulating film 58 can disperse the surface pressure to a wider portion at the convex portion crossing portion 60, and can suppress damage to the wiring patterns 52, 54 due to the concentration of the load.

[0041] Alternatively, the thickness of the portion of the covering insulating film 58 on the convex portion crossing portion 60 may be formed thicker than the thickness of the other portions. By forming in this way, even when the second separator 16 and the framed MEA 12 are displaced in the plane direction due to vibration or thermal cycling, deterioration of the covering insulating film 58 due to abrasion can be suppressed.

[0042] In addition, in Figure 3 , for convenience of explanation, the thicknesses of the base insulating film 56, the first wiring pattern 52, and the covering insulating film 58 are exaggeratedly illustrated. However, in reality, these members are thinner than the thickness of the cathode electrode 22 of the MEA 12a. In addition, at the convex portion crossing portion 60, each member constituting the MEA 12a can be deformed to withstand the thicknesses of the base insulating film 56, the first wiring pattern 52, and the covering insulating film 58.

[0043] As Figure 2 shown, the first wiring pattern 52 has an end portion disposed at the outer peripheral portion of the second separator 16, and has a first connection pad 52a at this end portion. The second wiring pattern 54 has an end portion disposed at the outer peripheral portion of the second separator 16, and has a second connection pad 54a at this end portion. As Figure 3 shown at the right end of Figure 2 , the first connection pad 52a is formed in the opening 58a of the covering insulating film 58 covering the first wiring pattern 52. The first connection pad 52a exposes the first wiring pattern 52 from the covering insulating film 58. The second connection pad 54a (refer to

[0044] The first sensor 40 is configured as described above, but the present embodiment is not limited thereto, and the first sensor 40 may be provided on the first partition 14.

[0045] In addition, the first sensor 40 is not limited to a resistance thermometer, and may be configured as a thermocouple, for example. In this case, the first wiring pattern 52 and the second wiring pattern 54 are formed of different kinds of metals. In addition, the sensor portion 50 can be configured as the contact point between the first wiring pattern 52 and the second wiring pattern 54.

[0046] Alternatively, the first wiring pattern 52 and the second wiring pattern 54 may be arranged along the flow path groove 38b. In this case, the sensor portion 50 can reduce the number of convex portion crossing portions 60, and can more effectively suppress the deterioration of the first sensor 40.

[0047] Next, a method for manufacturing the fuel cell 10 having the first sensor 40 will be described.

[0048] First, as Figure 1 shown, the second partition 16 is prepared. Then, on Figure 2 the entire area of the sensor arrangement region 48 on the inner surface 16a of the second partition 16 shown, a base insulating film 56 is formed (see Figure 3 ). The base insulating film 56 is formed by spraying a polyimide resin. Alternatively, the base insulating film 56 may be formed by depositing a parylene resin by vacuum evaporation.

[0049] Then, as Figure 3 shown, a mask having an opening hole with a predetermined shape is arranged on the base insulating film 56. Then, on the base insulating film 56 exposed through the opening hole of the mask, a conductor film is formed by various film forming methods such as evaporation, sputtering, or electroplating. Thus, the sensor portion 50, the first wiring pattern 52, and the second wiring pattern 54 are formed on the base insulating film 56.

[0050] Then, the mask is removed. Then, 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 partition 16 having the first sensor 40 is completed.

[0051] After that, in the same manner as the manufacture of the ordinary fuel cell 10, the second partition 16 is brought into contact with the cathode electrode 22 of the framed MEA 12. In addition, the first partition 14 is brought into contact with the anode electrode 20 of the framed MEA 12. Through the above steps, the Figure 3 shown cross-sectional structure is obtained.

[0052] Then, referring to Figure 2, Figure 4 and Figure 5 to illustrate the second sensor 42.

[0053] As Figure 4 shown, the second sensor 42 is disposed on the surface of the electrolyte membrane 18 of the MEA 12a and is a temperature sensor for detecting the temperature of the electrolyte membrane 18. To achieve the accurate temperature of the electrolyte membrane 18, as Figure 5 shown, the second sensor 42 is formed between the second surface 18b of the electrolyte membrane 18 and the cathode electrode 22. Additionally, although not particularly illustrated, the second sensor 42 may be disposed on the first surface 18a of the electrolyte membrane 18. In this case, the second sensor 42 may be disposed between the first surface 18a and the anode electrode 20.

[0054] To enable the second sensor 42 to more accurately measure the temperature of the electrolyte membrane 18, the sensor portion 50 is disposed at a portion corresponding to the convex portion 34a of the first separator 14 and the convex portion 38a of the second separator 16. According to this structure, the sensor portion 50 is pressed by the convex portions 34a and 38a, and the heat transfer state between the sensor portion 50 and the electrolyte membrane 18 is improved.

[0055] Except for being formed on the electrolyte membrane 18, the second sensor 42 has substantially the same structure as the first sensor 40 described with reference to Figure 2 and Figure 3 . The sensor portion 50, the first wiring pattern 52, and the second wiring pattern 54 of the second sensor 42 have the same structure as the sensor portion 50, the first wiring pattern 52, and the second wiring pattern 54 of the first sensor 40. Thus, in the second sensor 42 shown in Figure 4 and Figure 5 , the same reference numerals are assigned to the same structure as the first sensor 40 shown in Figure 2 and Figure 3 , and its detailed description is omitted. However, since the outer peripheral portion of the framed MEA 12 does not protrude outward, it is difficult for the second sensor 42 to provide connection terminals for wiring connection with the outside in the first wiring pattern 52 and the second wiring pattern 54.

[0056] Therefore, the second sensor 42 has a wiring portion 55. The wiring portion 55 includes the first wiring pattern 52 and the second wiring pattern 54. The wiring portion 55 has: a first wiring portion 62, which is formed in the sensor arrangement region 48A1 on the second surface 18b of the electrolyte membrane 18 shown in Figure 4 ; and a second wiring portion 64, which is formed in Figure 2The sensor configuration area 48A2 on the inner surface 16a of the second partition plate 16 shown. The second wiring portion 64 has a first wiring pattern 52 and a second wiring pattern 54 that extend to the outer peripheral portion of the second partition plate 16. At the end of the first wiring pattern 52 at the position of the outer peripheral portion of the second partition plate 16, there is a first connection pad 52a, and at the end of the second wiring pattern 54 at the position of the outer peripheral portion of the second partition plate 16, there is a second connection pad 54a.

[0057] The wiring pattern of the first wiring portion 62 and the wiring pattern of the second wiring portion 64 are electrically connected to each other via a first terminal portion 62a ( Figure 4 ) provided on the first wiring portion 62 side and a second terminal portion 64a ( Figure 2 ) provided on the second wiring portion 64. That is, as Figure 4 shown, the first wiring pattern 52 and the second wiring pattern 54 of the first wiring portion 62 each have a first terminal portion 62a. As Figure 5 shown, an opening 58b for covering the insulating film 58 is formed at the first terminal portion 62a. Therefore, the first terminal portion 62a has a structure that exposes the first wiring pattern 52 (or the second wiring pattern 54) from the opening 58b. The first terminal portion 62a is disposed at a portion corresponding to the convex portion 34a of the first partition plate 14 and the convex portion 38a of the second partition plate 16.

[0058] The second terminal portion 64a is formed on the inner surface 16a of the portion of the second partition plate 16 facing the first terminal portion 62a. The second terminal portion 64a is formed at a portion straddling the convex portion 38a of the second partition plate 16. At the second terminal portion 64a, an opening 58c is formed in the covering insulating film 58 covering the second wiring portion 64. At the opening 58c, the first wiring pattern 52 (or the second wiring pattern 54) of the second wiring portion 64 is exposed.

[0059] An opening hole 22c is formed at the portion of the cathode electrode 22 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 convex portions 34a, 38a. The first wiring pattern 52 of the first wiring portion 62 and the first wiring pattern 52 of the second wiring portion 64 are in contact with each other and electrically connected via the opening hole 22c and the openings 58b, 58c. The same applies to the second wiring pattern 54. The second wiring pattern 54 of the first wiring portion 62 and the second wiring pattern 54 of the second wiring portion 64 are electrically connected to each other via the first terminal portion 62a and the second terminal portion 64a.

[0060] Next, a manufacturing method of the fuel cell 10 including the second sensor 42 will be described.

[0061] First, a second wiring portion 64 of the second sensor 42 is formed on the inner surface 16a of the second separator 16. The second wiring portion 64 can be formed by the same process as the manufacturing method of the first sensor 40. The second wiring portion 64 is formed simultaneously with the manufacturing process of the first sensor 40.

[0062] Then, a framed MEA 12 having the first wiring portion 62 of the second sensor 42 is formed. First, on Figure 5 the electrolyte membrane 18 shown, 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 sequentially formed. The above processes are the same as the manufacturing process of the first sensor 40, so detailed description is omitted.

[0063] Then, the cathode electrode 22 having an opening hole 22c formed in a portion corresponding to the first terminal portion 62a and the second terminal portion 64a is joined to the second surface 18b of the electrolyte membrane 18 where the first portion of the second sensor 42 is formed. In addition, the anode electrode 20 is joined to the first surface 18a of the electrolyte membrane 18.

[0064] After that, the frame member 24 is joined to the outer peripheral portions of the electrolyte membrane 18, the anode electrode 20, and the cathode electrode 22. The frame member 24 is joined in such a manner that the electrolyte membrane 18 is sandwiched between the cathode electrode 22 and the anode electrode 20. Through the above processes, the framed MEA 12 having the first wiring portion 62 of the second sensor 42 is completed.

[0065] After that, as Figure 1 shown, the second separator 16 is brought into contact with the cathode electrode 22 of the framed MEA 12, and the first separator 14 is brought into contact with the anode electrode 20 of the framed MEA 12. As a result, as Figure 5 shown, the first terminal portion 62a and the second terminal portion 64a are pressed by the convex portions 34a, 38a and electrically connected, and the fuel cell 10 having the second sensor 42 is completed.

[0066] Then, the third sensor 44 will be described.

[0067] As Figure 4 shown, the third sensor 44 is a temperature sensor that detects the temperature of the frame member 24. The third sensor 44 is formed in the entire area of the sensor arrangement area 48B provided in the frame member 24. The third sensor 44 includes a sensor portion 50 similar to the first sensor 40 and a wiring portion 55 having a first wiring pattern 52 and a second wiring pattern 54.

[0068] However, as Figure 6As shown, in the case where the frame member 24 is made of an insulating resin material, the base insulating film 56 may not be provided under the sensor portion 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 portion 50, the first wiring pattern 52, the second wiring pattern 54, and the sensor configuration area 48B around them are covered with a cover insulating film 58 to prevent a short circuit with the second partition plate 16. An opening 58d of the cover insulating film 58 is formed on the outer periphery of the third sensor 44. A first connection pad 52a and a second connection pad 54a are formed so that the first wiring pattern 52 and the second wiring pattern 54 are exposed from the opening 58d, respectively (see Figure 4 ).

[0069] The third sensor 44 can be manufactured by preparing the frame member 24 and sequentially forming the sensor portion 50 , the first wiring pattern 52 , the second wiring pattern 54 , and the cover insulating film 58 on the surface of the frame member 24 . These steps are the same as the manufacturing steps of the first sensor 40 .

[0070] Next, the fourth sensor 46 will be described.

[0071] like Figure 7 As shown, the fourth sensor 46 has: a first wiring pattern 52A formed along the upper end 34a2 of the protrusion 34a of the first partition 14; and a second wiring pattern 54A formed along the upper end 38a2 of the protrusion 38a of the second partition 16. The first wiring pattern 52A and the second wiring pattern 54A are provided at portions facing each other, and when viewed from above (refer to Figure 2 ) have the same shape.

[0072] The first wiring pattern 52A is formed on the base insulating film 56 and is insulated from the first spacer 14 via the base insulating film 56. The second wiring pattern 54A is also formed on the base insulating film 56. The second wiring pattern 54A is insulated from the second spacer 16 via the base insulating film 56. Figure 2 The entire area of ​​the sensor arrangement region 48C is formed to be elongated and extended as shown. The sensor arrangement region 48C of the first spacer 14 and the base insulating film 56 are also formed in the same shape. The first wiring pattern 52A and the second wiring pattern 54A are respectively covered by the cover insulating film 58 and insulated from the anode electrode 20 or the cathode electrode 22.

[0073] like Figure 7As shown, a first sensor portion 50A is formed at the front end of the first wiring pattern 52A by exposing the first wiring pattern 52A from the covering insulating film 58. In addition, a second sensor portion 50B is formed at the front end of the second wiring pattern 54A by exposing the second wiring pattern 54A from the covering insulating film 58. The first sensor portion 50A and the second sensor portion 50B are disposed at overlapping positions in a plan view and face each other with the MEA 12a therebetween.

[0074] The first sensor portion 50A and the second sensor portion 50B are pressed toward the MEA 12a by the convex portions 34a and 38a, and the first sensor portion 50A abuts against the anode electrode 20 in a manner of being press-fitted into the anode electrode 20. In addition, the second sensor portion 50B abuts against the cathode electrode 22 in a manner of being press-fitted into the cathode electrode 22. An AC voltage is applied between the first sensor portion 50A and the second sensor portion 50B, whereby the fourth sensor 46 can detect the local impedance of the MEA 12a.

[0075] The fuel cell 10 having the fourth sensor 46 is manufactured by the following processes, which include: a process of manufacturing the first separator 14 provided with the first wiring pattern 52A; a process of manufacturing the second separator 16 provided with the second wiring pattern 54A; and a process of laminating the first separator 14, the framed MEA 12, and the second separator 16.

[0076] Among them, the first separator 14 provided with the first wiring pattern 52A is manufactured by a process of sequentially forming a base insulating film 56, the first wiring pattern 52A, and the covering insulating film 58 on the inner surface 14a of the first separator 14. In addition, the second separator 16 provided with the second wiring pattern 54A is manufactured by a process of sequentially forming a base insulating film 56, the second wiring pattern 54A, and the covering insulating film 58 on the inner surface 16a of the second separator 16. The processes of manufacturing 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.

[0077] The fuel cell 10 of the present embodiment achieves the following effects.

[0078] The fuel cell 10 of the present embodiment includes: an MEA 12a (electrolyte 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 peripheral portion of the MEA 12a; a pair of separators 14, 16 sandwiching the MEA 12a; and sensors 40, 42, 44, 46 having sensor portions 50, 50A, 50B and wiring portions 55. The sensor portions 50, 50A, 50B are provided on at least one of the separators 14, 16, the frame member 24, and the electrolyte membrane 18. The wiring portions 55 are connected to the sensor portions 50, 50A, 50B and extend to the outer peripheral portion of the separators 14, 16 or the MEA 12a. The sensors 40, 42, 44, 46 include: a base insulating film 56 covering sensor arrangement regions 48, 48A, 48B, 48C for arranging the sensors 40, 42, 44, 46; wiring patterns 52, 52A, 54, 54A laminated on the base insulating film 56; and a covering insulating film 58 covering the wiring patterns 52, 52A, 54, 54A and the portion of the base insulating film 56 not covered by the wiring patterns 52, 52A, 54, 54A.

[0079] According to the above fuel cell 10, the sensors 40, 42, 44, 46 can be formed in a thin film shape and integrated with the fuel cell 10. Therefore, complicated sensor configuration operations for the sensors 40, 42, 44, 46 are not required, and the state quantity can be detected simply and accurately. In addition, the fuel cell 10 can prevent the sensors 40, 42, 44, 46 from shifting in position, so it is suitable for detecting local state quantities of desired parts.

[0080] In the above fuel cell 10, the separators 14, 16 may have convex portions 34a, 38a that project toward the MEA 12a and press the MEA 12a, and the sensor portions 50, 50A, 50B are provided at positions corresponding to the convex portions 34a, 38a of the separators 14, 16. According to this fuel cell 10, the sensor portions 50, 50A, 50B can be brought into close contact with the measurement object, so the measurement can be performed with better accuracy.

[0081] In the above fuel cell 10, the sensor portion 50 may be formed on the base insulating film 56 and covered by the covering insulating film 58 together with the wiring patterns 52, 54. According to this fuel cell 10, the separators 14, 16, the MEA 12a, etc. can be electrically insulated from the sensor portion 50, so the measurement can be performed with good accuracy.

[0082] In the above-described 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 that extends along the surface of the electrolyte membrane 18 and is connected to the sensor unit 50; and a second wiring unit 64 that extends along the surfaces of the separators 14 and 16, and the first terminal portion 62a where the wiring patterns 52 and 54 of the first wiring unit 62 are exposed from the covering insulating film 58 faces and abuts against the second terminal portion 64a where the wiring patterns 52 and 54 of the second wiring unit 64 are exposed from the covering insulating film 58, thereby electrically connecting the first wiring unit 62 and the second wiring unit 64. According to this fuel cell 10, the wiring unit 55 of the sensor unit 50 can be provided on the electrolyte membrane 18 and the separators 14 and 16, so the degree of freedom in the arrangement position of the sensor unit 50 is increased.

[0083] In the above-described fuel cell 10, alternatively, the separators 14 and 16 may have: a plurality of convex portions 34a and 38a that project toward the MEA 12a and extend along the flow direction of the reaction gas; and flow path grooves 34b and 38b formed between the convex portions 34a and 38a, and the wiring unit 55 is provided along the flow path grooves 34b and 38b. According to this fuel cell 10, abrasion of the wiring unit 55 due to friction with the convex portions 34a and 38a can be prevented.

[0084] In the above-described fuel cell 10, alternatively, the portions of the covering insulating film 58 that cover the wiring patterns 52 and 54 and the portions that cover the portions other than the wiring patterns 52 and 54 may be formed to have an equal height.

[0085] In the above-described fuel cell 10, alternatively, the wiring unit 55 may have a convex portion crossing portion 60 that crosses the convex portions 34a and 38a that project from the separators 14 and 16 and press the MEA 12a, and the covering insulating film 58 at the convex portion crossing portion 60 is formed thicker than the covering insulating film 58 at other portions. According to this fuel cell 10, damage caused by abrasion of the covering insulating film 58 at the convex portion crossing portion 60 can be suppressed.

[0086] In the above-described fuel cell 10, at least the portions of the convex portions 34a and 38a of the separators 14 and 16 that correspond to the convex portion crossing portion 60 are formed of flat surfaces. According to this fuel cell 10, the load within the convex portion crossing portion 60 can be dispersed, and breakage of the wiring patterns 52 and 54 due to load concentration can be prevented.

[0087] In the above-described fuel cell 10, alternatively, the wiring patterns 52 and 54 may include a first wiring pattern 52 formed of a first metal and a second wiring pattern 54 formed of a second metal different from the first metal, and the sensor unit 50 is a thermocouple contact formed by bringing the front end portions of the first wiring pattern 52 and the second wiring pattern 54 into contact with each other.

[0088] In the above-described fuel cell 10, it is also possible that the sensor 44 is formed on the frame member 24, and the frame member 24 also serves as the base insulating film 56. According to this fuel cell 10, there is no need for a process of forming an independent base insulating film 56, so the manufacturing process can be simplified.

[0089] In the above-described fuel cell 10, it is also possible that the wiring portion 55 has: a first wiring portion 62 formed on the surface of one separator 14 and including a first wiring pattern 52A; and a second wiring portion 64 formed on the surface of the other separator 16 and including a second wiring pattern 54A. The sensor portion 50 has: a first sensor portion 50A formed by exposing the first wiring pattern 52A at the end of the first wiring portion; and a second sensor portion 50B formed by exposing the second wiring pattern 54A at the end of the second wiring portion. The first sensor portion 50A and the second sensor portion 50B are arranged to sandwich the MEA 12a and are electrically connected to the MEA 12a. According to this fuel cell 10, by applying an alternating voltage between the first sensor portion 50A and the second sensor portion 50B, it is possible to detect the local impedance of the MEA 12a.

[0090] In the above, preferred embodiments of the present invention have been described, but the present invention is not limited to the above embodiments, and various modifications can of course be made without departing from the gist of the present invention.

Claims

1. A fuel cell, in which the fuel cell includes: An electrolyte membrane - electrode structure, which has 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, which surrounds the outer peripheral portion of the electrolyte membrane - electrode structure; A pair of separators, which sandwich the electrolyte membrane - electrode structure; And A sensor, which has a sensor portion and a wiring portion, the sensor portion is provided on the surface of the electrolyte membrane, the wiring portion is connected to the sensor portion and extends to the separator or the outer peripheral portion of the electrolyte membrane - electrode structure, The sensor has: A base insulating film, which covers the surface of the sensor configuration area for configuring the sensor; A wiring pattern, which is laminated on the base insulating film; And A covering insulating film, which covers the wiring pattern and the portion of the base insulating film not covered by the wiring pattern, The sensor portion is provided on the surface of the electrolyte membrane, and the wiring portion includes: A first wiring portion, which extends along the surface of the electrolyte membrane and is connected to the sensor portion; and A second wiring portion, which extends along the surface of the separator, The first terminal portion formed by exposing the wiring pattern of the first wiring portion from the covering insulating film faces and abuts against the second terminal portion formed by exposing the wiring pattern of the second wiring portion from the covering insulating film, thereby electrically connecting the first wiring portion and the second wiring portion.

2. The fuel cell according to claim 1, wherein The separator has: a plurality of convex portions, which protrude toward the electrolyte membrane - electrode structure and extend along the flow direction of the reaction gas; and flow channels, which are formed between the convex portions, The wiring portion is provided along the flow channels.

3. The fuel cell according to claim 1 or 2, wherein The portion of the covering insulating film covering the wiring pattern and the portion covering the portion other than the wiring pattern are formed to have an equal height.

4. A fuel cell, in which the fuel cell includes: An electrolyte membrane - electrode structure, which has 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, which surrounds the outer peripheral portion of the electrolyte membrane - electrode structure; A pair of separators, which sandwich the electrolyte membrane - electrode structure; And A sensor, which has a sensor portion and a wiring portion, the sensor portion is provided on at least one of the separator, the frame member, and the electrolyte membrane, the wiring portion is connected to the sensor portion and extends to the separator or the outer peripheral portion of the electrolyte membrane - electrode structure, The sensor has: A base insulating film, which covers the surface of the sensor configuration area for configuring the sensor; A wiring pattern, which is laminated on the base insulating film; And A covering insulating film, which covers the wiring pattern and the portion of the base insulating film not covered by the wiring pattern, The wiring portion has a convex portion crossing part that crosses a convex portion protruding from the separator and pressing the electrolyte membrane - electrode structure. The covering insulating film at the convex portion crossing part is formed thicker than the covering insulating film at other parts, and the thickness of the covering insulating film at parts other than the convex portion crossing part is thinner than the thickness of the covering insulating film at the convex portion crossing part.

5. The fuel cell according to claim 4, wherein: At least a portion of the convex portion of the separator corresponding to the convex portion crossing part is formed of a flat surface.

6. A fuel cell, comprising: 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 the outer peripheral portion of the electrolyte membrane - electrode structure; A pair of separators sandwiching the electrolyte membrane - electrode structure; And A sensor having a sensor portion and a wiring portion, the sensor portion being provided to sandwich the electrolyte membrane, the wiring portion being connected to the sensor portion and extending to the outer peripheral portion of the separator or the electrolyte membrane - electrode structure, The sensor has: A base insulating film covering the surface of a sensor configuration area for configuring the sensor; A wiring pattern laminated on the base insulating film; And A covering insulating film covering the wiring pattern and the base insulating film at portions not covered by the wiring pattern, The wiring portion has: a first wiring portion formed on the surface of one of the separators and including a first wiring pattern; and a second wiring portion formed on the surface of the other separator and including a second wiring pattern, The sensor portion has: a first sensor portion formed by exposing the first wiring pattern at the end of the first wiring portion; and a second sensor portion formed by exposing the second wiring pattern at the end of the second wiring portion, The first sensor portion and the second sensor portion are arranged to face each other with the electrolyte membrane - electrode structure therebetween and are electrically connected to the electrolyte membrane - electrode structure.

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