JP6090866B2 - Hydrogen peroxide concentration detection sensor for fuel cell and manufacturing method thereof - Google Patents

Description

  The present invention relates to a hydrogen peroxide concentration detection sensor for a fuel cell incorporated in a fuel cell in which an electrolyte membrane / electrode structure sandwiching an electrolyte membrane between an anode electrode and a cathode electrode and a separator are stacked, and a method for manufacturing the same About.

  For example, a solid polymer fuel cell employs a solid polymer electrolyte membrane made of a polymer ion exchange membrane. This fuel cell has an electrolyte membrane / electrode structure (MEA) in which an anode electrode and a cathode electrode each made of an electrode catalyst (electrode catalyst layer) and porous carbon (gas diffusion layer) are disposed on both sides of a solid polymer electrolyte membrane. ). The electrolyte membrane / electrode structure is sandwiched between separators (bipolar plates) to form a power generation cell. Usually, in a fuel cell, a fuel cell stack in which a predetermined number of power generation cells are stacked is mounted on a fuel cell electric vehicle as an in-vehicle fuel cell stack, for example.

  In the fuel cell, fuel gas may pass through the solid polymer electrolyte membrane from the anode side to the cathode side, while oxidant gas may pass through the solid polymer electrolyte membrane from the cathode side to the anode side.

For this reason, hydrogen and oxygen react with each other on the anode side and the cathode side to easily generate hydrogen peroxide (H ₂ O ₂ ) (H ₂ + O ₂ → H ₂ O ₂ ). This hydrogen peroxide is decomposed on the carbon support or platinum (Pt) in the electrode, and for example, an active substance such as hydroxy radical (.OH) is generated. Thereby, there exists a problem of deteriorating a solid polymer electrolyte membrane and an electrode catalyst.

  Therefore, for example, a fuel cell abnormality monitoring method and apparatus disclosed in Patent Document 1 are known. In Patent Document 1, a fuel cell in which luminol is attached to a monitoring target site such as a catalyst layer is prepared, and the fuel cell is caused to generate power. At that time, when an abnormal potential is generated in the catalyst layer or hydrogen peroxide is generated, the abnormal potential generation site and the hydrogen peroxide generation site emit light by the luminol reaction. It is said that the observer can easily identify the occurrence of an abnormal potential or the generation of hydrogen peroxide by visually observing this light emission.

JP 2005-332682 A

  However, in Patent Document 1 described above, it is difficult to accurately detect the hydrogen peroxide concentration corresponding to a plurality of locations of the electrolyte membrane / electrode structure. In addition, there is a problem that the operation of detecting the hydrogen peroxide concentration at a particularly fine position is not performed.

  The present invention solves this type of problem, and in particular, performs peroxidation for a fuel cell which can perform the detection of hydrogen peroxide concentration at a fine position well and accurately and can be manufactured economically. An object of the present invention is to provide a hydrogen concentration detection sensor and a manufacturing method thereof.

  The hydrogen peroxide concentration detection sensor for a fuel cell according to the present invention is used in a fuel cell in which an electrolyte membrane / electrode structure sandwiching an electrolyte membrane between an anode electrode and a cathode electrode and a separator are stacked. . This fuel cell hydrogen peroxide concentration detection sensor detects the hydrogen peroxide concentration in the electrolyte membrane / electrode structure.

  The hydrogen peroxide concentration detection sensor for a fuel cell is provided with a flat metal catalyst on the surface of an ion exchange membrane, and exposes one end and the other end of the metal catalyst to the outside. Is sandwiched between insulating films. And the coating layer containing an ion exchange component is formed in the one end part of a metal catalyst.

  In the fuel cell hydrogen peroxide concentration detection sensor, the first insulating film constituting the pair of insulating films and laminated on the ion exchange film exposes one end of the metal catalyst to the outside, and the metal It is preferable to cover the surface on the other end side of the catalyst. On the other hand, it is preferable that the second insulating coating that forms a pair of insulating coatings and is laminated on the metal catalyst exposes one end of the metal catalyst and the other end of the metal catalyst to the outside.

  Furthermore, in this hydrogen peroxide concentration detection sensor for a fuel cell, the first insulating coating that constitutes a pair of insulating coatings and is laminated on the ion exchange membrane is arranged from one end of the metal catalyst to the other end of the metal catalyst. It is preferable to cover the surface. On the other hand, it is preferable that the second insulating coating that forms a pair of insulating coatings and is laminated on the metal catalyst exposes one end of the metal catalyst and the other end of the metal catalyst to the outside.

  Furthermore, in the hydrogen peroxide concentration detection sensor for a fuel cell, the first insulating coating that constitutes the pair of insulating coatings and is laminated on the ion exchange membrane exposes one end of the metal catalyst to the outside, and It is preferable to cover the surface on the other end side of the metal catalyst. On the other hand, it is preferable that the second insulating coating that forms a pair of insulating coatings and is laminated on the metal catalyst covers the surface of one end of the metal catalyst and exposes the other end of the metal catalyst to the outside. .

  Further, in the hydrogen peroxide concentration detection sensor for a fuel cell, the first insulating coating that constitutes a pair of insulating coatings and is laminated on the ion exchange membrane is provided from one end of the metal catalyst to the other end of the metal catalyst. It is preferable to cover the surface. On the other hand, the second insulating film that forms a pair of insulating films and is laminated on the metal catalyst covers the surface of one end of the metal catalyst, exposes the other end of the metal catalyst to the outside, and at least It is preferable that an opening for providing a coating layer is formed in the second insulating film.

  Furthermore, in this hydrogen peroxide concentration detection sensor for fuel cells, a plurality of metal catalysts are provided in parallel with each other on the surface of the ion exchange membrane, and a pair of insulating coatings are formed and stacked on the ion exchange membrane. It is preferable that a 1st insulating film covers the surface of the other end part side of the said metal catalyst from the one end part side of the said metal catalyst. On the other hand, the second insulating coating that forms a pair of insulating coatings and is laminated on the metal catalyst covers the surface of one end of the metal catalyst, and exposes the other end of the metal catalyst to the outside. In the second insulating film, it is preferable that a plurality of openings for providing a coating layer are formed in steps along the parallel direction of the metal catalyst.

  Furthermore, the method for manufacturing a hydrogen peroxide concentration detection sensor for a fuel cell according to the present invention includes a step of providing a flat metal catalyst on the surface of the ion exchange membrane. This manufacturing method further includes a step of exposing one end and the other end of the metal catalyst to the outside and sandwiching the metal catalyst with a pair of insulating coatings; and an ion exchange component on the one end of the metal catalyst. Forming a coating layer including the same.

  According to the present invention, in the hydrogen peroxide concentration detection sensor, a flat metal catalyst is provided on the surface of the ion exchange membrane, and a coating layer containing an ion exchange component is provided at one end of the metal catalyst. . For this reason, the sensor unit for detecting the hydrogen peroxide concentration is miniaturized well and the amount of the metal catalyst used is reduced as much as possible. Therefore, the measurement of the hydrogen peroxide concentration in the minute region of the electrolyte membrane / electrode structure can be carried out satisfactorily and accurately and can be manufactured economically.

1 is a schematic configuration explanatory diagram of a fuel cell system in which a hydrogen peroxide concentration detection sensor for a fuel cell according to a first embodiment of the present invention is incorporated. It is a principal part disassembled perspective explanatory view of a fuel cell. It is principal part sectional explanatory drawing of the electrolyte membrane and electrode structure which comprises the said fuel cell. It is a partial cross-section perspective explanatory view of the hydrogen peroxide concentration detection sensor incorporated in the electrolyte membrane / electrode structure. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor. It is explanatory drawing when a metal catalyst is apply | coated to an ion exchange membrane. It is explanatory drawing at the time of providing a 1st insulating film in the said ion exchange membrane. It is explanatory drawing at the time of providing a 2nd insulating film in the said ion exchange membrane. It is explanatory drawing at the time of providing a coating layer in the one end part of the said metal catalyst. It is explanatory drawing of the relationship between an electric potential and hydrogen peroxide concentration. It is a partial cross section perspective explanatory view of the hydrogen peroxide concentration detection sensor for fuel cells concerning a 2nd embodiment of the present invention. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor. It is a partial cross section perspective explanatory view of the hydrogen peroxide concentration detection sensor for fuel cells concerning a 3rd embodiment of the present invention. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor. It is a partial cross section perspective explanatory view of the hydrogen peroxide concentration detection sensor for fuel cells concerning a 4th embodiment of the present invention. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor. It is a partial cross section perspective explanatory view of the hydrogen peroxide concentration detection sensor for fuel cells concerning a 5th embodiment of the present invention. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor. It is explanatory drawing when a metal catalyst is apply | coated to an ion exchange membrane. It is explanatory drawing at the time of providing a 1st insulating film in the said ion exchange membrane. It is explanatory drawing at the time of providing a 2nd insulating film in the said ion exchange membrane. It is explanatory drawing at the time of providing a coating layer in the one end part of the said metal catalyst. It is principal part perspective explanatory drawing of the hydrogen peroxide concentration detection sensor for fuel cells which concerns on the 6th Embodiment of this invention. It is side surface explanatory drawing of the said hydrogen peroxide concentration detection sensor.

  As shown in FIG. 1, a fuel cell system 10 incorporating a hydrogen peroxide concentration detection sensor for a fuel cell according to a first embodiment of the present invention is mounted on a fuel cell vehicle such as a fuel cell electric vehicle, for example. An in-vehicle fuel cell system is configured.

  The fuel cell system 10 includes a fuel cell stack 14 in which a plurality of fuel cells 12 are stacked. The fuel cell system 10 includes an oxidant gas supply device 16 that supplies an oxidant gas to the fuel cell stack 14, a fuel gas supply device 18 that supplies fuel gas to the fuel cell stack 14, and a cooling to the fuel cell stack 14. And a cooling medium supply device 20 for supplying a medium. Control of the entire fuel cell system 10 is performed by a control unit (ECU) 22.

  As shown in FIG. 2, the fuel cell 12 sandwiches the electrolyte membrane / electrode structure 24 between the first separator 26 and the second separator 28. The first separator 26 and the second separator 28 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, a metal plate whose surface is subjected to anticorrosion treatment, a carbon member, or the like. .

  As shown in FIGS. 2 and 3, the electrolyte membrane / electrode structure 24 includes, for example, a solid polymer electrolyte membrane 30 in which a perfluorosulfonic acid thin film is impregnated with water, and the solid polymer electrolyte membrane 30 interposed therebetween. An anode electrode 32 and a cathode electrode 34 are provided. As the solid polymer electrolyte membrane 30, an HC (hydrocarbon) electrolyte is used in addition to the fluorine electrolyte.

  For example, the outer peripheral end of the cathode electrode 34 protrudes outward from the outer peripheral end of the anode electrode 32, and the anode electrode 32 is disposed on one surface 30 a of the solid polymer electrolyte membrane 30. The anode electrode 32 exposes the outer periphery of the solid polymer electrolyte membrane 30 in a frame shape. The anode electrode 32 may be set to have the same planar dimensions as the solid polymer electrolyte membrane 30. The cathode electrode 34 is disposed on the other surface 30 b of the solid polymer electrolyte membrane 30, and the outer peripheral end portion of the solid polymer electrolyte membrane 30 protrudes outward from the outer peripheral end portion of the cathode electrode 34. The solid polymer electrolyte membrane 30 may be set to have the same planar dimensions as the cathode electrode 34.

  Although not shown, the anode electrode 32 is provided with an electrode catalyst layer bonded to one surface 30a of the solid polymer electrolyte membrane 30 and a gas diffusion layer laminated on the electrode catalyst layer. Although not shown, the cathode electrode 34 includes an electrode catalyst layer bonded to the other surface 30b of the solid polymer electrolyte membrane 30 and a gas diffusion layer laminated on the electrode catalyst layer.

  The electrolyte membrane / electrode structure 24 includes a resin frame member 36 that goes around the outer periphery of the solid polymer electrolyte membrane 30. The resin frame member 36 is made of, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), LCP, PES, PEEK, PFA, or the like. The resin frame member 36 is not necessarily used.

  As shown in FIG. 2, the oxidant gas inlet communication hole 38a and the fuel gas inlet communication communicate with each other in the arrow A direction at the upper edge of the fuel cell 12 in the arrow C direction (vertical direction in FIG. 2). A hole 40a is provided. The oxidant gas inlet communication hole 38a supplies an oxidant gas, for example, an oxygen-containing gas. The fuel gas inlet communication hole 40a supplies a fuel gas, for example, a hydrogen-containing gas. The oxidant gas inlet communication hole 38a and the fuel gas inlet communication hole 40a are arranged in the arrow B direction (horizontal direction).

  The lower end edge of the fuel cell 12 in the direction of arrow C communicates with each other in the direction of arrow A, a fuel gas outlet communication hole 40b for discharging fuel gas, and an oxidant gas outlet for discharging oxidant gas The communication holes 38b are arranged in the arrow B direction.

  A pair of (or a single) cooling medium inlet communication hole 42 a for supplying a cooling medium is provided at one end edge of the fuel cell 12 in the arrow B direction. A pair of (or a single) cooling medium outlet communication hole 42 b for discharging the cooling medium is provided at the other end edge of the fuel cell 12 in the arrow B direction.

  An oxidant gas flow path 46 communicating with the oxidant gas inlet communication hole 38a and the oxidant gas outlet communication hole 38b is provided on the surface 26a of the first separator 26 facing the electrolyte membrane / electrode structure 24. A fuel gas passage 48 communicating with the fuel gas inlet communication hole 40a and the fuel gas outlet communication hole 40b is formed on the surface 28a of the second separator 28 facing the electrolyte membrane / electrode structure 24. The oxidant gas passage 46 and the fuel gas passage 48 allow the oxidant gas and the fuel gas to flow in the vertical direction.

  The cooling medium inlet communication hole 42a and the cooling medium outlet communication hole 42b communicate with the surface 26b opposite to the surface 26a of the first separator 26 and the surface 28b opposite to the surface 28a of the second separator 28. A cooling medium flow path 50 is formed. The cooling medium channel 50 circulates the cooling medium in the horizontal direction.

  The first seal member 52 is integrated with the surfaces 26 a and 26 b of the first separator 26 around the outer peripheral end of the first separator 26. The second seal member 54 is integrated with the surfaces 28 a and 28 b of the second separator 28 around the outer peripheral end of the second separator 28.

  The first seal member 52 and the second seal member 54 are, for example, EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber or the like, cushion material, Alternatively, an elastic seal member such as a packing material is used.

  The second separator 28 includes a plurality of supply holes 56 that communicate the fuel gas inlet communication hole 40a with the fuel gas flow path 48, and a plurality of discharge holes that communicate the fuel gas flow path 48 with the fuel gas outlet communication hole 40b. Part 58 is formed.

  As shown in FIG. 3, the electrolyte membrane / electrode structure 24 is directly provided with a plurality of hydrogen peroxide concentration detection sensors 60. The hydrogen peroxide concentration detection sensor 60 is, for example, interposed between the anode electrode 32 and the solid polymer electrolyte membrane 30 in the electrode surface of the anode electrode 32 and at the outer peripheral edge of the anode electrode 32. A plurality may be provided.

  As shown in FIG. 3, the hydrogen peroxide concentration detection sensor 60 is provided between the anode electrode 32 and the solid polymer electrolyte membrane 30 in the power generation region (region where the electrode catalyst layer is applied), as well as the cathode electrode in the power generation region. 34 and the solid polymer electrolyte membrane 30, the end of the anode electrode 32, the end of the cathode electrode 34, or the exposed surface of the solid polymer electrolyte membrane 30.

  As shown in FIGS. 4 and 5, the hydrogen peroxide concentration detection sensor 60 is provided with a flat metal catalyst 64 on the surface of a rectangular ion exchange membrane 62. For the ion exchange membrane 62, for example, a membrane in which a fluorine-based membrane component (or HC membrane component) made of a fluororesin copolymer is impregnated with a sulfonate ion is used, and for the metal catalyst 64, Pt or the like is used. An electrocatalyst is used.

  The hydrogen peroxide concentration detection sensor 60 exposes one end portion 64a and the other end portion 64b of the metal catalyst 64 to the outside, and sandwiches both sides of the metal catalyst 64. The first insulating coating 66a and the second insulating coating 66b. Is provided. Here, the first insulating coating 66 a is laminated on the ion exchange membrane 62, while the second insulating coating 66 b is laminated on the metal catalyst 64. This relationship is the same in the second and subsequent embodiments.

  The first insulating coating 66a exposes the one end 64a side of the metal catalyst 64 to the outside through the ion exchange membrane 62 and covers the surface of the metal catalyst 64 on the other end 64b side. The second insulating film 66b exposes one end portion 64a of the metal catalyst 64 and the other end portion 64b side of the metal catalyst 64 to the outside. A coating layer 68 containing an ion exchange component is formed on one end portion 64 a of the metal catalyst 64. As the ion exchange component, for example, a membrane in which a fluorinated membrane component (or HC membrane component) is impregnated with sulfonate ions is used. The one end portion 64a of the metal catalyst 64 and the coating layer 68 constitute a sensor portion.

  As shown in FIG. 4, the second insulating coating 66 b and the coating layer 68 are smoothly level and continuous without any step, and the tip of the coating layer 68 contacts the ion exchange membrane 62. One end portion 64a of the metal catalyst 64 is covered between the ion exchange membrane 62 and the coating layer 68, and the one end portion 64a is not exposed to the outside. The width W of the metal catalyst 64 is smaller than the width Wa of the first insulating coating 66a and the second insulating coating 66b, and both ends in the width direction of the first insulating coating 66a and the second insulating coating 66b are in direct contact.

  The first insulating film 66a and the second insulating film 66b are sheet members that have insulating properties, are excellent in hot water resistance, acid resistance, and heat resistance, and are formed of a flexible material. The first insulating film 66a and the second insulating film 66b are, for example, a polyimide film or an insulating film (polytetrafluoroethylene), PPS (polyphenylene sulfide resin), PET (polyethylene naphthalate resin), LCP (liquid crystal polymer), PFA ( It is preferably composed of fluororesin), PPA (polyphthalamide resin), and PES (polyethersulfone resin).

  As shown in FIG. 3, the electrolyte membrane / electrode structure 24 is provided with a potential sensor 69 as necessary. Similar to the hydrogen peroxide concentration detection sensor 60, the potential sensor 69 is set at a plurality of locations and detects the potential at each location. The potential sensor 69 exposes the tip of a platinum wire having an outer periphery coated with an insulating coating and is brought into contact with a location where the potential is measured. The potential is measured with reference to the anode reference electrode.

  As shown in FIG. 1, the oxidant gas supply device 16 compresses air (oxidant gas) from the atmosphere and supplies it to the oxidant gas inlet communication hole 38a of the fuel cell stack 14, and also communicates with the oxidant gas outlet. The used oxidant gas is discharged in communication with the hole 38b. The fuel gas supply device 18 includes a high-pressure hydrogen tank (not shown) that stores high-pressure hydrogen (fuel gas), and supplies the fuel gas to the fuel gas inlet communication hole 40 a of the fuel cell stack 14. The used fuel gas is recovered from the fuel gas outlet communication hole 40b. The cooling medium supply device 20 communicates with the cooling medium inlet communication hole 42a and the cooling medium outlet communication hole 42b of the fuel cell stack 14, and circulates and supplies the cooling medium.

  Next, a manufacturing method for manufacturing the thus configured hydrogen peroxide concentration detection sensor 60 will be described.

  First, as shown in FIG. 6, a plurality of metal catalysts 64 are applied to the upper surface of the wide ion exchange membrane 62 by, for example, screen printing. Each metal catalyst 64 is arranged in parallel on the ion exchange membrane 62, the one end portion 64 a side is spaced inward from one end portion of the ion exchange membrane 62, and the other end portion 64 b side is the other end of the ion exchange membrane 62. It is arranged at the same position as the part.

  Next, as shown in FIG. 7, a first insulating coating 66 a is provided on the lower surface of the ion exchange membrane 62 (the surface opposite to the metal catalyst 64). The first insulating coating 66a exposes the one end portion 64a side of the metal catalyst 64 to the outside through the ion exchange membrane 62 (may be directly exposed), and the other end portion 64b side of the metal catalyst 64. Cover the surface. Furthermore, as shown in FIG. 8, one end portion 64 a of the metal catalyst 64 and the other end portion 64 b of the metal catalyst 64 are exposed to the outside on the upper surface (surface on the metal catalyst 64 side) of the ion exchange membrane 62. A second insulating film 66b is provided.

  As shown in FIG. 9, a coating layer 68 is formed on the upper surface of the ion exchange membrane 62 so as to cover the one end portion 64 a of the metal catalyst 64, that is, to cover the sensor portion. For this reason, a plurality of hydrogen peroxide concentration detection sensors 60 are integrally manufactured, and then each hydrogen peroxide concentration detection sensor 60 is separated by cutting.

  The operation of the fuel cell system 10 configured as described above will be described below.

  As shown in FIG. 1, oxidant gas (air) is supplied from the oxidant gas supply device 16 to the oxidant gas inlet communication hole 38 a of the fuel cell stack 14. On the other hand, fuel gas (hydrogen gas) is supplied from the fuel gas supply device 18 to the fuel gas inlet communication hole 40 a of the fuel cell stack 14. In the cooling medium supply device 20, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 42 a of the fuel cell stack 14.

  As shown in FIG. 2, the oxidant gas is introduced into the oxidant gas flow path 46 of the first separator 26 from the oxidant gas inlet communication hole 38 a and moves in the direction of arrow C to move the electrolyte membrane / electrode structure 24. It is supplied to the cathode electrode 34. On the other hand, the fuel gas is introduced into the fuel gas flow path 48 of the second separator 28 from the fuel gas inlet communication hole 40 a through the supply hole portion 56. The fuel gas moves in the direction of arrow C along the fuel gas flow path 48 and is supplied to the anode electrode 32 of the electrolyte membrane / electrode structure 24.

  Therefore, in each electrolyte membrane / electrode structure 24, the oxidant gas supplied to the cathode electrode 34 and the fuel gas supplied to the anode electrode 32 are consumed by an electrochemical reaction in the electrode catalyst layer to generate power. Done.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 34 is discharged in the direction of arrow A along the oxidant gas outlet communication hole 38b. Similarly, the fuel gas consumed by being supplied to the anode electrode 32 passes through the discharge hole 58 and is discharged in the direction of arrow A along the fuel gas outlet communication hole 40b.

  The cooling medium supplied to the cooling medium inlet communication hole 42 a is introduced into the cooling medium flow path 50 formed between the first separator 26 and the second separator 28 and then flows in the direction of arrow B. This cooling medium is discharged from the cooling medium outlet communication hole 42b after the electrolyte membrane / electrode structure 24 is cooled.

  As described above, when the power generation operation of the fuel cell system 10 is performed, the control device 22 calculates the current detected by each hydrogen peroxide concentration detection sensor 60 directly attached to the electrolyte membrane / electrode structure 24. Measure and grasp the hydrogen peroxide concentration. The hydrogen peroxide concentration detection sensor 60 is in contact with the surface for measuring the hydrogen peroxide concentration, and measures the hydrogen peroxide concentration by measuring the potential of the other end portion 64b of the metal catalyst 64.

  One or a plurality of hydrogen peroxide concentration detection sensors 60 are arranged in one MEA, and among them, the detected hydrogen peroxide concentration with the largest change is adopted. Depending on the power generation conditions, the location of the electrolyte membrane / electrode structure 24 having the largest change varies. Further, empirically, the hydrogen peroxide concentration detection sensor 60 may be arranged only in one place where the hydrogen peroxide concentration can be detected most efficiently. Note that the highest density value may be used.

Here, the hydrogen peroxide concentration (H ₂ O ₂ %) and the potential (fuel cell voltage) have the relationship shown in FIG. For example, the production of hydrogen peroxide increases in the low potential region. The control device 22 controls the fuel cell system 10 based on the detected hydrogen peroxide concentration.

  In this case, in the first embodiment, as shown in FIGS. 4 and 5, the hydrogen peroxide concentration detection sensor 60 includes a metal catalyst 64 made of a long minute thin film, a first insulating film 66a and a second insulating film. It is coated with a film 66b. A coating layer 68 containing an ion exchange component is formed at one end 64 a of the metal catalyst 64.

  For this reason, in the hydrogen peroxide concentration detection sensor 60, the sensor unit for detecting the hydrogen peroxide concentration is satisfactorily miniaturized. Therefore, the effect that it becomes possible to perform the measurement of the hydrogen peroxide concentration in a minute region of the electrolyte membrane / electrode structure 24 in a favorable and accurate manner is obtained. As a result, the entire hydrogen peroxide concentration detection sensor 60 can be easily reduced in size.

  Moreover, the metal catalyst 64 is applied to the surface of the ion exchange membrane 62. For this reason, there is an advantage that the usage amount of the metal catalyst 64 is reduced as much as possible, and the hydrogen peroxide concentration detection sensor 60 can be manufactured economically.

  As shown in FIGS. 11 and 12, the fuel cell hydrogen peroxide concentration detection sensor 70 according to the second embodiment of the present invention is incorporated in a fuel cell system (not shown). The same components as those in the hydrogen peroxide concentration detection sensor 60 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the third and subsequent embodiments described below, detailed description thereof is omitted.

  The hydrogen peroxide concentration detection sensor 70 exposes one end portion 64a and the other end portion 64b of the metal catalyst 64 from the second insulating coating 66b to the outside so that the first insulating coating 66c and the first insulating coating 66c sandwich the metal catalyst 64. Two insulating coatings 66b are provided. The first insulating coating 66 c covers the entire surface from the one end 64 a side of the metal catalyst 64 to the other end 64 b side of the metal catalyst 64. Specifically, the first insulating coating 66 c is set to have approximately the same size (outer dimensions) as the ion exchange membrane 62. The one end portion 64a of the metal catalyst 64 and the coating layer 68 constitute a sensor unit.

  As shown in FIGS. 13 and 14, the fuel cell hydrogen peroxide concentration detection sensor 80 according to the third embodiment of the present invention is incorporated in a fuel cell system (not shown).

  The hydrogen peroxide concentration detection sensor 80 exposes the other end portion 64b of the metal catalyst 64 to the outside, and is provided with a first insulating film 66a and a second insulating film 66d that sandwich the metal catalyst 64. The second insulating coating 66d covers the surface of the metal catalyst 64 on the one end portion 64a side, and exposes the other end portion 64b side of the metal catalyst 64 to the outside. The one end portion 64 a of the metal catalyst 64 and the one end portion of the ion exchange membrane 62 constitute a sensor unit.

  As shown in FIGS. 15 and 16, a hydrogen peroxide concentration detection sensor 90 for a fuel cell according to a fourth embodiment of the present invention is incorporated in a fuel cell system (not shown).

  The hydrogen peroxide concentration detection sensor 90 exposes the other end portion 64b of the metal catalyst 64 to the outside, and is provided with a first insulating film 66e and a second insulating film 66f that sandwich the metal catalyst 64.

  The first insulating coating 66e covers the entire surface from the one end 64a side of the metal catalyst 64 to the other end 64b side of the metal catalyst 64, and has a hole 92a on the one end 64a side. A coating layer 68a containing an ion exchange component is formed in the hole 92a. The second insulating coating 66f covers the surface of the metal catalyst 64 on the one end portion 64a side, exposes the other end portion 64b side of the metal catalyst 64 to the outside, and provides a hole 92b on the one end portion 64a side. . A coating layer 68b containing an ion exchange component is formed in the hole 92b. The hole shape is not limited to a square, and may be various shapes such as a round shape and an ellipse.

  The coating layer 68b is disposed at the same position as the coating layer 68a in the stacking direction. The coating layers 68 a and 68 b and the one end portion 64 a of the metal catalyst 64 constitute a sensor unit.

  As shown in FIGS. 17 and 18, the fuel cell hydrogen peroxide concentration detection sensor 100 according to the fifth embodiment of the present invention is incorporated in a fuel cell system (not shown).

  The hydrogen peroxide concentration detection sensor 100 exposes the other end portion 64b of the metal catalyst 64 to the outside, and is provided with a first insulating film 66c and a second insulating film 66f that sandwich the metal catalyst 64.

  In the hydrogen peroxide concentration detection sensor 100, the coating layer 68b containing an ion exchange component is formed in the hole 92b in which the second insulating film 66f is formed. A sensor portion is configured by the coating layer 68 b and the one end portion 64 a of the metal catalyst 64.

  A manufacturing method for manufacturing the hydrogen peroxide concentration detection sensor 100 configured as described above will be described below.

  First, as shown in FIG. 19, a plurality of metal catalysts 64 are applied to the upper surface of the ion exchange membrane 62 by, for example, screen printing. Each metal catalyst 64 is arranged in parallel on the ion exchange membrane 62, the one end portion 64 a side is arranged at the same position as one end portion of the ion exchange membrane 62, and the other end portion 64 b side is the other side of the ion exchange membrane 62. Arranged at the same position as the end.

  Next, as shown in FIG. 20, a first insulating coating 66 c is provided on the lower surface of the ion exchange membrane 62 (the surface opposite to the metal catalyst 64). The first insulating coating 66 c covers the entire surface from the one end 64 a side of the metal catalyst 64 to the other end 64 b side of the metal catalyst 64. In addition, it is preferable that the 1st insulating film 66c protrudes outward from the front-end | tip of the one end part 64a.

  Furthermore, as shown in FIG. 21, the upper surface of the ion exchange membrane 62 covers the surface of the metal catalyst 64 on the one end portion 64a side, and the other end portion 64b side of the metal catalyst 64 is exposed to the outside. Two insulating coatings 66f are provided. As shown in FIG. 22, a plurality of hole portions 92 b are formed in the second insulating film 66 f corresponding to the one end portion 64 a of the metal catalyst 64. The hole portions 92b are opened in advance before assembly, and each hole portion 92b forms a sensor portion by forming an application layer 68b. For this reason, a plurality of hydrogen peroxide concentration detection sensors 100 are integrally manufactured, and then each hydrogen peroxide concentration detection sensor 100 is separated by cutting. Note that the shape of the hole 92b is not limited to a square, and may be various shapes such as a round shape and an oval shape.

  In the second to fifth embodiments configured as described above, the same effects as those of the first embodiment can be obtained.

  As shown in FIGS. 23 and 24, the hydrogen peroxide concentration detection sensor 110 for a fuel cell according to the sixth embodiment of the present invention is incorporated in a fuel cell system (not shown).

  In the hydrogen peroxide concentration detection sensor 110, a plurality of flat metal catalysts 64A to 64E are provided in parallel to each other on the surface of a wide ion exchange membrane 62w. The metal catalysts 64A to 64E are integrally sandwiched between the wide first insulating coating 66A and the second insulating coating 66B. The first insulating coating 66A covers the surfaces of the metal catalysts 64A to 64E from the one end 64a side to the other ends 64b of the metal catalysts 64A to 64E.

  The second insulating coating 66B covers the surfaces of the metal catalysts 64A to 64E on the one end portion 64a side, exposes the other end portions 64b of the metal catalysts 64A to 64E to the outside, and the surface of the ion exchange membrane 62w. Provided. In the second insulating film 66B, a plurality of openings 112a, 112b, 112c, 112d, and 112e are formed in a step shape along the parallel direction of the metal catalysts 64A to 64E (the width direction T intersecting the length direction L). Is done.

  The openings 112a to 112e can have various shapes such as a circular opening shape as well as a rectangular opening shape. In the openings 112a, 112b, 112c, 112d and 112e, a plurality of sensor units are formed by forming coating layers 68A, 68B, 68C, 68D and 68E of ion exchange components. The first insulating coating 66A may also be provided with an opening to form a coating layer.

  In the sixth embodiment configured as described above, the application layers 68A, 68B, 68C, 68D, and 68E as the sensor units can be arranged as close as possible. Thereby, the effect that the hydrogen peroxide concentration and concentration distribution of the minute part of the electrolyte membrane / electrode structure 24 can be analyzed in detail and accurately using a plurality of sensor units is obtained. In addition, since the coating layers 68A, 68B, 68C, 68D and 68E are arranged in steps, it is possible to sufficiently secure the width of the adjacent coating layers 68A, 68B, 68C, 68D and 68E. .

DESCRIPTION OF SYMBOLS 10 ... Fuel cell system 12 ... Fuel cell 14 ... Fuel cell stack 16 ... Oxidant gas supply device 18 ... Fuel gas supply device 20 ... Cooling medium supply device 22 ... Control device 24 ... Electrolyte membrane and electrode structure 26, 28 ... Separator 30 ... Solid polymer electrolyte membrane 32 ... Anode electrode 34 ... Cathode electrode 38a ... Oxidant gas inlet communication hole 38b ... Oxidant gas outlet communication hole 40a ... Fuel gas inlet communication hole 40b ... Fuel gas outlet communication hole 42a ... Cooling medium inlet Communication hole 42b ... Cooling medium outlet communication hole 46 ... Oxidant gas flow path 48 ... Fuel gas flow path 50 ... Cooling medium flow path 60, 70, 80, 90, 100, 110 ... Hydrogen peroxide concentration detection sensor 62 ... Ion exchange Membrane 64, 64A-64E ... Metal catalyst 64a ... One end 64b ... Other end 66a-66f, 66A, 66B ... Insulating coating 68, 68a, 68b ... coating layer 92a, 92b ... hole 112a-112e ... opening

Claims (7)

A fuel cell in which an electrolyte membrane / electrode structure sandwiching an electrolyte membrane between an anode electrode and a cathode electrode and a separator are stacked, and a fuel cell for detecting a hydrogen peroxide concentration in the electrolyte membrane / electrode structure A hydrogen peroxide concentration detection sensor for
In the hydrogen peroxide concentration detection sensor for a fuel cell, a flat metal catalyst is provided on the surface of the ion exchange membrane, and one end and the other end of the metal catalyst are exposed to the outside. Sandwiched between a pair of insulating coatings,
A hydrogen peroxide concentration detection sensor for a fuel cell, wherein a coating layer containing an ion exchange component is formed at the one end of the metal catalyst. 2. The hydrogen peroxide concentration detection sensor for a fuel cell according to claim 1, wherein the first insulating coating that constitutes the pair of insulating coatings and is stacked on the ion exchange membrane exposes the one end side of the metal catalyst to the outside. And while covering the surface of the other end side of the metal catalyst,
The second insulating coating that constitutes the pair of insulating coatings and is laminated on the metal catalyst exposes the one end portion side of the metal catalyst and the other end portion side of the metal catalyst to the outside. Battery hydrogen peroxide concentration detection sensor. 2. The hydrogen peroxide concentration detection sensor for a fuel cell according to claim 1, wherein the first insulating coating that constitutes the pair of insulating coatings and is stacked on the ion exchange membrane is formed from the one end side of the metal catalyst from the one end side. While covering the surface of the other end side of
The second insulating coating that constitutes the pair of insulating coatings and is laminated on the metal catalyst exposes the one end portion side of the metal catalyst and the other end portion side of the metal catalyst to the outside. Battery hydrogen peroxide concentration detection sensor. 2. The hydrogen peroxide concentration detection sensor for a fuel cell according to claim 1, wherein the first insulating coating that constitutes the pair of insulating coatings and is stacked on the ion exchange membrane exposes the one end side of the metal catalyst to the outside. And while covering the surface of the other end side of the metal catalyst,
The second insulating coating that constitutes the pair of insulating coatings and is laminated on the metal catalyst covers the surface of the one end side of the metal catalyst, and exposes the other end side of the metal catalyst to the outside. A hydrogen peroxide concentration detection sensor for a fuel cell. 2. The hydrogen peroxide concentration detection sensor for a fuel cell according to claim 1, wherein the first insulating coating that constitutes the pair of insulating coatings and is stacked on the ion exchange membrane is formed from the one end side of the metal catalyst from the one end side. While covering the surface of the other end side of
The second insulating coating that constitutes the pair of insulating coatings and is laminated on the metal catalyst covers the surface of the one end side of the metal catalyst, and exposes the other end side of the metal catalyst to the outside. With
The hydrogen peroxide concentration detection sensor for a fuel cell, wherein an opening for providing the coating layer is formed at least in the second insulating coating. The hydrogen peroxide concentration detection sensor for a fuel cell according to claim 1, wherein a plurality of the metal catalysts are provided in parallel with each other on the surface of the ion exchange membrane,
The first insulating coating that constitutes the pair of insulating coatings and is stacked on the ion exchange membrane covers the surface of the metal catalyst from the one end side to the other end side,
The second insulating coating that constitutes the pair of insulating coatings and is laminated on the metal catalyst covers the surface of the one end side of the metal catalyst, and exposes the other end side of the metal catalyst to the outside. ,
A plurality of openings for providing the coating layer are formed at least in the second insulating film in a step shape along the parallel direction of the metal catalyst. Sensor. A fuel cell in which an electrolyte membrane / electrode structure sandwiching an electrolyte membrane between an anode electrode and a cathode electrode and a separator are stacked, and a fuel cell for detecting a hydrogen peroxide concentration in the electrolyte membrane / electrode structure A method for manufacturing a hydrogen peroxide concentration detection sensor for a vehicle,
Providing a flat metal catalyst on the surface of the ion exchange membrane;
Exposing one end and the other end of the metal catalyst to the outside and sandwiching the metal catalyst with a pair of insulating coatings;
Forming a coating layer containing an ion exchange component at the one end of the metal catalyst;
A method for producing a hydrogen peroxide concentration detection sensor for a fuel cell, comprising:

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