JP2008066173A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell which exhibits superior electrical characteristics, without the use a forcible oxygen supply means, such as a blower. <P>SOLUTION: The fuel cell comprises a plurality of electrode/electrolyte integrated structures (MEA: membrane electrode assembly) that are arranged flatly in serial connection. On the positive/negative electrode sides of each MEA, current collecting plates, insulating plates, and panel plates, each having an oxygen introduction hole are arranged, in this order, and the oxygen introduction holes form an opening extending from the positive electrodes panel plates to the MEA. In a plan view from the positive electrode panel plates, an open-area percentage determined from a ratio between the total area of the opening and the area of the positive electrodes is 10 to 60%, the shortest distance between two parallel lines that is in contact with the opening is 0.2 to 3 mm, and the shortest distance from any point at a place other than the opening to the opening is 2 mm or smaller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell in which a plurality of integrated electrodes and electrolytes are arranged in a planar shape.

  In recent years, with the widespread use of cordless devices such as personal computers and mobile phones, there has been a demand for further miniaturization and higher capacity of batteries as power sources. Currently, lithium ion secondary batteries have been put into practical use as batteries that have high energy density and can be reduced in size and weight, and demand for portable power sources is increasing. However, this lithium ion secondary battery has a problem that it cannot guarantee a sufficient continuous use time for some cordless devices.

  In order to solve the above problems, for example, development of fuel cells such as polymer electrolyte fuel cells (PEFC) is underway. The fuel cell can be used continuously if fuel and oxygen are supplied. A PEFC that uses a solid polymer electrolyte as an electrolyte, oxygen in the air as a positive electrode active material, and fuel as a negative electrode active material has attracted attention as a battery having a higher energy density than a lithium ion secondary battery.

  However, since the conventional fuel cell is formed by stacking a plurality of single cells (single cells), the entire battery becomes bulky. In addition, oxygen must be circulated and supplied to the positive electrode and fuel to the negative electrode, respectively, and an auxiliary device for that purpose is required. For this reason, the fuel cell is much larger than a small secondary battery such as a lithium ion battery, and there is a problem in using it as a small portable power source.

  Under such circumstances, there has been proposed a planar fuel cell having a configuration in which single cells are arranged on a plane and the air supply to the air electrode (positive electrode) uses the diffusion of the atmosphere (see Patent Document 1). With such a configuration, it is not necessary to use forced air supply means such as a blower, and the fuel cell can be made compact.

  However, with the technology disclosed in Patent Document 1, it is difficult to say that the functions of individual cells constituting the fuel cell can be sufficiently extracted.

JP 2002-56855 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fuel cell that can exhibit excellent battery characteristics without using a forced oxygen supply means such as a blower.

  The fuel cell according to the present invention that has achieved the above object includes a plurality of electrode / electrolyte integrated products in which a positive electrode, a solid electrolyte membrane, and a negative electrode are sequentially laminated, and a plurality of the electrode / electrolyte integrated products. Are connected in series, and a positive electrode current collecting plate, a positive electrode insulating plate, and a metal positive electrode panel plate are sequentially arranged on the positive electrode side of each electrode / electrolyte integrated body. On the negative electrode side of the electrode / electrolyte integrated product, a negative electrode current collecting plate, a negative electrode insulating plate, and a metal negative electrode panel plate are sequentially arranged. All the electrode / electrolyte integrated product is composed of the positive electrode panel plate and the negative electrode panel. The positive electrode current collecting plate, the positive electrode insulating plate, and the positive electrode panel plate are oxygenated outside the fuel cell. The positive electrode panel plate has an oxygen introduction hole for introduction into the positive electrode, and the oxygen introduction hole of the positive electrode current collecting plate, the oxygen introduction hole of the positive electrode insulating plate, and the oxygen introduction hole of the positive electrode panel plate. An opening reaching the electrode / electrolyte integrated body from the outer surface of the fuel cell is formed, and the following (A), (B) and (C) are satisfied in a plan view from the positive electrode panel plate of the fuel cell It is a feature.

(A) The aperture ratio calculated | required from the ratio of the total area of the said opening part and the area of a positive electrode is 10 to 60%.
(B) The shortest distance is 0.2 to 3 mm when two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn.
(C) The shortest distance from any point other than the opening to the nearest opening is 2 mm or less.

  That is, in the present invention, attention is paid to the configuration of the opening for supplying oxygen to the positive electrode of the electrode / electrolyte integrated product (hereinafter referred to as “MEA”), and this is referred to as the above (A), (B) and (C ) So that the supply of oxygen to the positive electrode and the collection of the current generated from the MEA are good, and without using a forced oxygen supply means such as a blower, It is possible to provide a fuel cell having excellent battery characteristics.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell which has the outstanding battery characteristic can be provided, without using the forced oxygen supply means by a blower etc. Therefore, the fuel cell of the present invention can be easily downsized and can be preferably used as a small portable power source.

  The details of the fuel cell of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the fuel cell of the present invention. Although FIG. 1 is a cross-sectional view, in order to facilitate understanding of each component, some components are not hatched to indicate a cross section.

  In the fuel cell of FIG. 1, 3 MEAs 100 in which a positive electrode composed of a positive electrode diffusion layer 13 and a positive electrode catalyst layer 14, a solid electrolyte membrane 15, and a negative electrode composed of a negative electrode diffusion layer 17 and a negative electrode catalyst layer 16 are sequentially laminated. These MEAs 100 are arranged in a plane.

  On the positive electrode side of each MEA 100, positive electrode current collecting plates 5 and 6, a positive electrode insulating plate 3, and a positive electrode panel plate 1 are sequentially arranged. Further, negative electrode current collector plates 7 and 8, negative electrode insulating plate 4, and negative electrode panel plate 2 are sequentially arranged on the negative electrode side of each MEA 100.

  All the MEAs 100 are sandwiched and integrated by the positive electrode panel plate 1 and the negative electrode panel plate 2. Although not clearly shown in FIG. 1, adjacent MEAs 100 are connected in series by electrical connection between the positive current collector plates 5 and 6 and the negative current collector plates 7 and 8.

  The positive electrode current collecting plates 5 and 6, the positive electrode insulating plate 3 and the positive electrode panel plate 1 are provided with a plurality of oxygen introduction holes for introducing oxygen outside the fuel cell into the positive electrode as air. Then, from the outer surface of the positive electrode panel plate 1 to the positive electrode diffusion layer 13 of the MEA 100 by the oxygen introduction holes of the positive electrode current collecting plates 5 and 6, the oxygen introduction hole of the positive electrode insulating plate 3, and the oxygen introduction hole of the positive electrode panel plate 1. A plurality of reaching openings 11 are formed, and oxygen (air) outside the fuel cell is supplied from the openings 11 to the positive electrode diffusion layer 13 by diffusion.

  Further, in the fuel cell of FIG. 1, the negative electrode current collecting plates 7 and 8, the negative electrode insulating plate 4 and the negative electrode panel plate 2 are provided with a plurality of fuel introduction holes for introducing the fuel in the fuel tank portion 10 into the negative electrode. ing. Then, the negative electrode diffusion of the MEA 100 from the surface of the negative electrode panel plate 2 on the fuel tank 10 side is performed by the fuel introduction holes of the negative electrode current collecting plates 7 and 8, the fuel introduction hole of the negative electrode insulating plate 4, and the fuel introduction hole of the negative electrode panel plate 2. A plurality of openings 12 reaching the layer 17 are formed, and the fuel in the fuel tank 10 is supplied to the negative electrode diffusion layer 17 from these openings 12.

  In the fuel cell of FIG. 1, the positive electrode panel plate 1 and the negative electrode panel plate 2 (and the fuel tank portion 10) are fixed by fixing portions arranged at intervals, and in the fixing portion, bolts 18 and nuts are fixed. The fixing by 19 is made. In FIG. 1, 9a and 9b are seals.

  In the fuel cell of the present invention, the total area of the positive electrode side opening 11 in plan view is divided by the area of the positive electrode in plan view, and the aperture ratio (A) expressed as a percentage is 10% or more and 60%. It is as follows. By making the aperture ratio on the positive electrode side as described above, it is possible to improve the supply of oxygen to the positive electrode and the current collection from the MEA. That is, if the aperture ratio (A) is too small, the supply of oxygen to the positive electrode may be insufficient. On the other hand, when the aperture ratio (A) is too large, the current collecting property of the current generated from the MEA is reduced, and when the fuel is a gas, drying is promoted, so that the output of the battery is reduced. The aperture ratio (A) is more preferably 15% or more, and more preferably 50% or less.

  The opening 11 on the positive electrode side and the opening 12 on the negative electrode side can have various shapes such as a square (rectangle, square, etc.) and a circle (true circle, ellipse, etc.). The opening 11 on the positive electrode side is in contact with the opening 11 in a plan view on the positive electrode side, and when the two parallel lines with the shortest shortest distance between the lines are drawn, the shortest distance (B ) Is 0.2 mm or more and 3 mm or less.

  FIG. 2 shows an enlarged view of one of the openings 11 on the positive electrode side. FIG. 2A shows a case where the opening 11 is rectangular. When the opening 11 is rectangular, two parallel lines I and II and i and ii in the figure can be drawn as two parallel lines in contact with the opening 11. Among these, the shortest distance between the two lines is the shortest between the lines I and II in the figure, and the shortest distance between the lines I and II is 0.2 mm or more. 3 mm or less.

  2B shows a case where the opening 11 is a perfect circle. If the opening 11 is a perfect circle, two parallel lines in contact with the opening 11 are Two lines sandwiching the diameter of the opening 11 can be drawn like I and II in the middle, and even if the two lines are drawn at any position of the opening 11, the distance between these lines Is equal to the diameter of the opening 11. Therefore, when the opening 11 is a perfect circle, the shortest distance between the line I and the line II, that is, the diameter of the opening 11 is 0.2 mm or more and 3 mm or less.

  By setting the shortest distance (B) between the two wires in the opening on the positive electrode side as described above, it is possible to improve the supply of oxygen to the positive electrode and the current collection from the MEA. That is, if the shortest distance (B) between the two lines is too small, it becomes difficult to take in oxygen from the atmosphere outside the fuel cell. On the other hand, if the shortest distance (B) between the two lines is too large, current collection at the portion where the opening 11 is located becomes insufficient, and the output of the battery decreases. The shortest distance (B) between the two lines is more preferably 0.5 mm or more, and more preferably 2 mm or less.

  Furthermore, in the fuel cell of the present invention, in a plan view on the positive electrode side, a portion other than the opening 11 (that is, the opening 11 reaching the positive electrode diffusion layer 13 is not formed, and the positive electrode panel plate 1 and the like are present. The shortest distance (C) from an arbitrary point in the position) to the opening 11 located closest to the arbitrary point is 2 mm or less. By setting the shortest distance (C) to be equal to or less than the upper limit value, it is possible to improve the uniformity of supply of oxygen to the MEA 100 and improve the output of the battery.

  That is, if the above shortest distance (C) is too short, a portion where the upper portion of the positive electrode diffusion layer 13 is not opened becomes large due to the presence of the positive electrode panel plate 1 and the like, and the portion outside the fuel cell is located in the portion. It becomes difficult to supply oxygen. Therefore, a location where the supply of oxygen is insufficient in MEA 100 occurs, and the output of the battery decreases. The shortest distance (C) is more preferably 1.5 mm or less. In addition, there is no restriction | limiting in particular about the lower limit of said shortest distance (C), and it determines suitably in balance with the said aperture ratio (A).

  As for the opening portion 12 on the negative electrode side, the total area of the negative electrode side opening portion 12 in plan view is divided by the area of the negative electrode in plan view, and the opening ratio expressed as a percentage is 10% or more, More preferably, it is 15% or more, and it is 60% or less, more preferably 50% or less.

  Further, in the negative electrode side opening 12, when the two parallel lines that are in contact with the opening 12 and have the shortest shortest distance between the lines are drawn in the plan view on the negative electrode side, the shortest distance is 0.2 mm or more, more preferably 0.5 mm or more, and 3 mm or less, more preferably 2 mm or less.

  In addition, in a plan view on the negative electrode side, an arbitrary position other than the opening 12 (that is, a position where the opening 12 reaching the negative electrode diffusion layer 17 is not formed and the negative electrode panel plate 2 or the like is present). The shortest distance from the point to the opening 12 located closest to the arbitrary point is preferably 2 mm or less, more preferably 1.5 mm or less.

Each area of the opening 11 on the positive electrode side is preferably 0.1 mm ² or more, more preferably 0.2 mm ² or more, from the viewpoint of better taking in oxygen outside the fuel cell. On the other hand, if the individual areas of the openings 11 are too large, the strength of the positive electrode panel plate 1 and the like may be reduced. Therefore, the area is preferably 40 mm ² or less, and more preferably 30 mm ² or less. preferable.

Note that the individual area of the opening on the negative electrode side is also preferably 0.1 mm ² or more, more preferably 0.2 mm ² or more, and 40 mm ² or less, more preferably 30 mm ² or less. .

  The total thickness of the positive electrode panel plate 1, the positive electrode insulating plate 3, and the positive electrode current collecting plates 5 and 6 is preferably 1 mm or more. In order to reduce the internal resistance of the fuel cell, the MEA 100 is preferably suppressed with a certain degree of uniformity by the positive electrode panel plate 1 and the negative electrode panel plate 2. For example, as shown in FIG. 1, in the case where the positive electrode panel plate 1 and the negative electrode panel plate 2 are fixed by using bolts 18 and nuts 19 or the like at fixed portions arranged at intervals, the positive electrode panel plate 1 If the total thickness of the positive electrode insulating plate 3 and the positive electrode current collecting plates 5 and 6 is too small, the MEA 100 may be bent when the MEA 100 is suppressed, and the uniformity of the MEA 100 may be impaired.

  On the other hand, if the total thickness of the positive electrode panel plate 1, the positive electrode insulating plate 3, and the positive electrode current collecting plates 5 and 6 is too large, the amount of oxygen supplied from the opening 11 to the positive electrode diffusion layer 13 tends to decrease. The total thickness is preferably 4 mm or less.

  The total thickness of the negative electrode panel plate 2, the negative electrode insulating plate 4, and the negative electrode current collector plates 7 and 8 is the same as that of the positive electrode panel plate 1, the positive electrode insulating plate 3 and the positive electrode current collector plates 5 and 6. Is preferably 1 mm or more from the viewpoint of increasing the uniformity of the suppression of the battery and lowering the internal resistance of the battery, and is further 4 mm or less from the viewpoint of increasing the amount of fuel supplied from the opening 12 to the negative electrode diffusion layer 17. It is preferable.

  FIG. 3 is a schematic plan view of the positive electrode panel plate 1. The positive electrode panel plate 1 is provided with an oxygen introduction hole 11a in accordance with the position of the positive electrode diffusion layer of each MEA, and the oxygen introduction hole 11a is formed by the oxygen introduction hole of the positive electrode insulating plate and the oxygen introduction hole of the positive electrode current collecting plate. The opening is formed together with the hole. 20, 20 a, 20 b, 20 c, 20 d, and 20 e are screw holes through which bolts for fixing the positive electrode panel plate 1 and the negative electrode panel plate are passed, and fixing portions for fixing the positive electrode panel plate 1 and the negative electrode panel plate It becomes.

  The positive electrode panel plate 1 is made of metal. In the positive electrode panel plate 1 made of a material other than metal, bending occurs when the MEA is suppressed. Further, from the viewpoint of reducing the deflection at the time of suppressing the MEA, the metal constituting the positive electrode panel plate 1 preferably has a Young's modulus required by a bending test of 50000 MPa or more. Specific examples of the metal include carbon steel, alloy steel, stainless steel, superalloy, aluminum alloy, magnesium alloy, titanium alloy, and nickel alloy. In addition, the Young's modulus calculated | required by the bending test as used in this specification is a value calculated | required by measuring the amount of deflection | deviation especially produced when a load was applied to the center part of the plate-shaped sample which supported both ends.

  Moreover, it is preferable that the thickness of the positive electrode panel plate 1 is 0.5-3.5 mm. If the positive electrode panel plate 1 is too thin, the deflection when the MEA is suppressed increases, and the uniformity of the MEA suppression may be impaired. On the other hand, if the positive electrode panel plate 1 is too thick, the total thickness of the positive electrode panel plate 1, the positive electrode insulating plate, and the positive electrode current collector plate increases, and the amount of oxygen supplied to the positive electrode may decrease.

  In addition, the thing of the same structure as said positive electrode panel plate can be used for a negative electrode panel plate.

  4 and 5 are schematic plan views of the positive electrode current collecting plates 5 and 6. The positive electrode current collecting plate 5 of FIG. 4 and the positive electrode current collector plate 6 of FIG. 5 are provided with oxygen introducing holes 11b in accordance with the position of the positive electrode diffusion layer of the MEA and in accordance with the position of the oxygen introducing hole of the positive electrode panel plate. The oxygen introduction hole 11b forms the opening together with the oxygen introduction hole of the positive electrode panel plate and the oxygen introduction hole of the positive electrode insulating plate. Further, the positive current collecting plate 5 in FIG. 4 and the positive current collecting plate 6 in FIG. 5 are provided with a fixing portion 20 (screw hole) in accordance with the position of the fixing portion (screw hole) of the positive electrode panel plate. .

  The positive electrode current collecting plate 5 in FIG. 4 is a current collecting plate (positive electrode end current collecting plate) for disposing on the positive electrode of the leftmost MEA 100 in the fuel cell in FIG. A positive electrode current collecting terminal portion 21 is provided. Although there is no restriction | limiting in particular as the positive electrode current collection terminal part 21, For example, as shown in FIG. 4, the hole etc. for connecting the external terminal drawn out from the apparatus etc. which connect with a fuel cell are mentioned.

  The positive electrode current collecting plate 6 in FIG. 5 is a current collecting plate for disposing on the positive electrode of the center and right MEA 100 in the fuel cell in FIG. 1, and the positive electrode series connection tab 22 is located at a position corresponding to the outer peripheral portion of the fuel cell. Is provided. The positive electrode series connection tab 22 is brought into contact with a negative electrode current collecting plate disposed on the negative electrode of the adjacent MEA (for example, brought into contact with a negative electrode series connection tab provided on the negative electrode current collector plate). By connecting each other, each MEA is connected in series.

  Although only one positive electrode series connection tab 22 may be provided at a position corresponding to the outer peripheral portion of the fuel cell, it is preferable to provide two at the position corresponding to the outer peripheral portion of the fuel cell as shown in FIG. Since the resistance between the current collecting plates is reduced by connecting from two tabs rather than connecting from one positive electrode series connection tab, the output of the battery can be further improved.

  The material of the positive electrode current collecting plates 5 and 6 may be any material having electronic conductivity, but is preferably a material having high acid resistance. Alternatively, the positive electrode current collecting plates 5 and 6 may be configured by coating a low acid resistance material with a high acid resistance material. Specifically, for example, stainless steel, nickel, copper, graphite, titanium and the like, and those materials plated with a noble metal such as gold or platinum can be used.

  The thickness of the positive electrode current collecting plates 5 and 6 is preferably 0.2 to 3.2 mm. If the positive electrode current collecting plates 5 and 6 are too thin, the electronic resistance may increase and the output of the battery may decrease. On the other hand, if the positive current collecting plates 5 and 6 are too thick, the total thickness of the positive electrode panel plate, the positive electrode insulating plate and the positive current collecting plate is increased, and the supply amount of oxygen to the positive electrode may be reduced.

  Note that the negative electrode current collecting plate (the negative electrode end current collecting plate 7 and the negative electrode current collecting plate 8 in FIG. 1) includes the positive electrode current collecting plate (the positive electrode end current collecting plate 5 shown in FIG. 4 and FIG. 5). The positive electrode current collecting plate 6) shown in FIG.

  FIG. 6 shows a schematic diagram of the positive electrode insulating plate 3. In FIG. 6, (a) is a plan view. Further, (b) is a cross-sectional view taken along the line AA in (a), but the arrangement of the fixing portion 20 (screw hole) is indicated by a dotted line, and is a cross section for easy understanding of this arrangement. The hatched lines indicating that are omitted. The positive electrode insulating plate 3 is disposed between the metal positive electrode panel plate and the positive electrode current collecting plate, and plays a role of insulating between these plates.

  The positive electrode insulating plate 3 is provided with an oxygen introduction hole 11c in accordance with the position of the positive electrode diffusion layer of each MEA and in accordance with the position of the oxygen introduction hole of the positive electrode panel plate and the oxygen introduction hole of the positive electrode current collector plate, The oxygen introduction hole 11c forms the opening together with the oxygen introduction hole of the positive electrode panel plate and the oxygen introduction hole of the positive electrode current collecting plate. Further, the positive insulating plate 3 is provided with a fixing portion 20 (screw hole) in accordance with the position of the fixing portion (screw hole) of the positive electrode panel plate and the positive electrode current collecting plate.

  The positive electrode insulating plate 3 is preferably provided with a recess 23 for receiving the positive electrode current collecting plate. Since the step can be eliminated when the positive electrode insulating plate 3 and the positive electrode current collecting plate are laminated by the concave portion 23, it is possible to suppress the occurrence of gas leakage and uneven MEA suppression due to the step.

  The material of the positive electrode insulating plate 3 is not particularly limited as long as it is electronically insulating. For example, a glass epoxy resin, a polycarbonate resin, an acrylic resin, a polyimide resin, a fluororesin [polytetrafluoroethylene (PTFE), etc.], etc. Plastic is preferred.

  Of the positive electrode insulating plate 3, the thickness of the recess 23 in which the positive electrode current collecting plate is accommodated is preferably 0.3 to 3.3 mm. If the recess 23 is too thin, there is a risk of cracking due to insufficient strength. Moreover, when the recessed part 23 is too thick, the total thickness of a positive electrode panel plate, a positive electrode insulating plate, and a positive electrode current collecting plate will become large, and the supply amount of oxygen to a positive electrode may fall.

  In addition, the thing of the same structure as said positive electrode insulating plate can be used for a negative electrode insulating plate.

  FIG. 7 is a schematic diagram of the fuel tank unit 10 according to the fuel cell of FIG. In FIG. 7, (a) is a plan view. (B) is a cross-sectional view taken along line AA in (a), and (c) is a cross-sectional view taken along line BB in (a). In these cross-sectional views, the arrangement of the fixing portion 20 (screw hole) is shown. Since it is indicated by a dotted line, in order to facilitate understanding of this arrangement, a diagonal line indicating a cross section is omitted.

  The fuel tank unit 10 is provided to supply fuel to the negative electrode of the MEA or to hold the fuel. The fuel tank unit 10 is provided with a fuel supply port 24 for supplying fuel and a fuel discharge port 25 for discharging fuel in order to supply and discharge fuel. Further, a fuel flow guide portion 26 is provided so that the fuel is uniformly supplied to each MEA. Reference numeral 27 denotes an inside of a tank for holding fuel. Although the fuel tank unit 10 shown in FIG. 7 (the fuel tank unit 10 according to the fuel cell of FIG. 1) is independent, for example, the fuel tank unit may be integrated with the negative panel plate.

  The material of the fuel tank unit 10 is not required to be corroded or changed in shape by the fuel. Specifically, for example, glass epoxy resin; polycarbonate resin, acrylic resin, polyimide resin, fluororesin (PTFE, etc.) plastic; metal such as stainless steel, nickel, copper, graphite, titanium, etc. are suitable.

  FIG. 8 shows a schematic diagram of the MEA 100. In FIG. 8, (a) is a plan view and (b) is a cross-sectional view of (a). In (b), in order to facilitate understanding of each component, a hatched line indicating a cross-section is shown. Is omitted.

  The MEA 100 includes a positive electrode catalyst layer 14 that reduces oxygen and a negative electrode catalyst layer 16 that oxidizes hydrogen, and further includes a solid electrolyte membrane 15 between the positive electrode catalyst layer 14 and the negative electrode catalyst layer 16. Yes. The positive electrode diffusion layer 13 is laminated on the surface of the positive electrode catalyst layer 14 opposite to the surface on the solid electrolyte membrane 15 side, and the negative electrode diffusion layer is formed on the surface opposite to the surface of the negative electrode catalyst layer 16 on the solid electrolyte membrane 15 side. Layer 17 is laminated.

  The solid electrolyte membrane 15 has a larger area than the electrodes (positive electrode and negative electrode) in plan view. This is because sealing is performed using a portion protruding from the electrode. If sealing is not performed, the fuel and oxygen in the air will be mixed, and the function of the fuel cell may not be achieved. The width of the portion of the solid electrolyte membrane 15 that is larger than the electrode is preferably 1 mm or more from the viewpoint of securing a sufficient width for sealing. If the width of the portion that is larger than the electrode in the solid electrolyte membrane 15 is made too large, the ratio of the area to be sealed in the limited area of the solid electrolyte membrane 15 becomes large, so the area of the electrode is sacrificed. Therefore, the width is preferably 5 mm or less.

  The width of the electrode is preferably 3 to 35 mm. This is because it is restricted by the relationship between the size of the solid electrolyte membrane 15 and the distance between the fixed portions described later. There is no restriction | limiting in particular in the length of an electrode, It can set in view of the output requested | required of a fuel cell.

  Further, as shown in FIG. 9, the MEA 100 may have a structure in which the solid electrolyte membrane 15 is shared by a plurality of MEAs 100. 9A is a plan view, and FIG. 9B is a cross-sectional view of FIG. 9A. Also in FIG. 9B, in order to facilitate understanding of each component, the cross-section is shown. The diagonal lines are omitted.

  In FIG. 9, reference numeral 28 denotes a series connection tab contact area. In this portion, the positive electrode series connection tab of the positive electrode current collector plate and the negative electrode series connection tab of the negative electrode current collector plate are electrically contacted to connect each MEA in series. can do. Further, the MEA 100 of FIG. 9 is also provided with a fixing portion 20 (screw hole).

  The positive electrode diffusion layer 13 and the negative electrode diffusion layer 17 are made of a porous electron conductive material or the like, for example, a porous carbon sheet subjected to a water repellent treatment. In addition, on the catalyst layer side of the positive electrode diffusion layer 13 and the negative electrode diffusion layer 17, a carbon powder paste containing fluororesin particles (such as PTFE resin particles) is provided for the purpose of further improving water repellency and improving contact with the catalyst layer. It may be applied.

  The positive electrode catalyst layer 14 has a function of reducing oxygen diffused through the positive electrode diffusion layer 13. The positive electrode catalyst layer 14 contains, for example, a carbon powder carrying a catalyst (catalyst carrying carbon powder) and a proton conductive material. Moreover, you may further contain the resin binder as needed.

  The catalyst contained in the positive electrode catalyst layer 14 is not particularly limited as long as it can reduce oxygen, and examples thereof include platinum fine particles. The catalyst may be fine particles composed of an alloy of platinum and at least one metal element selected from the group consisting of iron, nickel, cobalt, tin, ruthenium and gold.

As the carbon powder as the catalyst carrier, for example, carbon black having a BET specific surface area of 10 to 2000 m ² / g and an average particle diameter of 20 to 100 nm is used. The catalyst can be supported on the carbon powder by, for example, a colloid method.

  As a content ratio of the carbon powder and the catalyst, for example, the catalyst is preferably 5 to 400 parts by mass with respect to 100 parts by mass of the carbon powder. This is because such a content ratio can constitute a positive electrode catalyst layer having sufficient catalytic activity. In addition, for example, when the catalyst-supported carbon powder is produced by a method of depositing the catalyst on the carbon powder (for example, a colloid method), the catalyst diameter is as long as the carbon powder and the catalyst have the above content ratio. This is because it does not become too large and sufficient catalytic activity is obtained.

  The proton conductive material contained in the positive electrode catalyst layer 14 is not particularly limited. For example, a resin having a sulfonic acid group such as a polyperfluorosulfonic acid resin, a sulfonated polyether sulfonic acid resin, or a sulfonated polyimide resin is used. Can be used. Specific examples of the polyperfluorosulfonic acid resin include “Nafion (registered trademark)” manufactured by DuPont, “Flemion (registered trademark)” manufactured by Asahi Glass, and “Aciplex (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. Or the like.

  The content of the proton conductive material in the positive electrode catalyst layer 14 is preferably 2 to 200 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. If the proton conductive material is contained in the above amount, sufficient proton conductivity is obtained in the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained. It is.

  The binder for the positive electrode catalyst layer 14 is not particularly limited. For example, PTFE, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetra Fluoropolymers such as fluoroethylene-ethylene copolymer (E / TFE), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE), polyethylene, polypropylene, nylon, polystyrene, polyester, ionomer, butyl rubber, ethylene -Non-fluorinated resins such as vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, and ethylene / acrylic acid copolymer can be used.

  The binder content in the positive electrode catalyst layer 14 is preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. This is because if the binder is contained in the above-mentioned amount, sufficient binding properties can be obtained for the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained.

  The negative electrode catalyst layer 16 has a function of oxidizing a fuel such as hydrogen or methanol that has diffused through the negative electrode diffusion layer. The negative electrode catalyst layer contains, for example, a carbon powder carrying a catalyst (catalyst-carrying carbon powder) and a proton conductive material. If necessary, a binder such as a resin may be further contained.

  The catalyst related to the negative electrode catalyst layer 16 is not particularly limited as long as it can oxidize a fuel such as hydrogen or methanol. For example, each of the catalysts exemplified as the catalyst related to the positive electrode catalyst layer can be used. As for the carbon powder, proton conductive material, and binder related to the negative electrode catalyst layer, the above-described materials exemplified as the carbon powder, proton conductive material, and binder related to the positive electrode catalyst layer can be used.

  The solid electrolyte membrane 15 is not particularly limited as long as it is made of a material that can transport protons and does not exhibit electron conductivity. As a material that can constitute the solid electrolyte membrane 15, for example, polyperfluorosulfonic acid resin, specifically, "Nafion (registered trademark)" manufactured by DuPont, "Flemion (registered trademark)" manufactured by Asahi Glass, Examples include “Aciplex (trade name)” manufactured by Asahi Kasei Corporation. In addition, sulfonated polyether sulfonic acid resin, sulfonated polyimide resin, sulfuric acid-doped polybenzimidazole, and the like can also be used as the material of the solid electrolyte membrane 15.

  FIG. 10 is a schematic plan view of the seals 9a and 9b. The seals 9a and 9b are arranged above and below the MEA. At that time, the MEA electrode fits in the hole 29 provided in the seal, and the portion of the solid electrolyte membrane that protrudes from the electrode portion is sandwiched between the seals 9a and 9b. With such a configuration, the fuel cell can be made to function well by separating the fuel and oxygen in the air. The seals 9a and 9b shown in FIG. 10 are provided with a series connection tab contact area 28, in which the positive electrode series connection tab of the positive electrode current collector plate and the negative electrode series connection tab of the negative electrode current collector plate are electrically contacted. Each MEA can be connected in series. In addition, a fixing portion 20 (screw hole) is also provided in the seals 9a and 9b in FIG.

  As a material for the seal, various materials known as a seal material in the field of fuel cells, for example, silicon rubber, ethylene-propylene-diene rubber, PTFE film, polyimide film, and the like can be used.

  The positive panel plate and the negative panel plate for integrating all the MEAs are not particularly limited as long as each MEA can be suppressed with a certain degree of uniformity. For example, a positive electrode panel plate, a positive electrode insulating plate, a positive electrode current collecting plate, a seal, a negative electrode current collecting plate, a portion corresponding to the negative electrode insulating plate and the negative electrode panel plate other than the MEA electrode portion, and an electrode portion of the MEA solid electrolyte membrane The whole protruding part may be fixed by bonding or the like.

  However, since the MEA can be more easily suppressed, as shown in FIG. 1, it is preferable to fix the positive electrode panel plate and the negative electrode panel plate by the mechanical clamping means in the fixing portions arranged at intervals. In this case, as the mechanical clamping means in the fixing portion, for example, screwing using a bolt and nut shown in FIG. 1 or riveting can be preferably employed.

  In addition, as described above, when the positive electrode panel plate and the negative electrode panel plate are fixed by the fixing portions that are positioned with a space therebetween, the shorter fixing portion between the adjacent fixing portions with the MEA interposed therebetween. The distance between them is preferably 10 mm or more and 40 mm or less. By disposing the fixing portions so that the distance between the fixing portions is as described above, the battery characteristics can be further improved.

  The distance between the fixed parts will be described with reference to FIG. 3. As fixed parts adjacent to the fixed part 20a and the MEA, there are 20b, 20c, and 20d. It is 20c that the distance becomes shorter. “The distance between the shorter fixed parts among the adjacent fixed parts across the MEA is 10 mm or more and 40 mm or less” means that the distance between the fixed part 20a and the fixed part 20c is 10 mm or more and 40 mm or less. I mean.

  If the distance between the fixed parts is too short, the area of the electrode portion of the MEA becomes small. If it is too long, the deflection of the panel plate when tightened by the mechanical clamping means becomes large and the MEA is uniformly suppressed. The internal resistance of the battery may increase, or current concentration may occur in a relatively restrained portion, causing deterioration of the electrode. The distance between the fixed parts is more preferably 15 mm or more, and more preferably 30 mm or less.

  Further, the distance between the adjacent fixed parts without sandwiching the MEA (for example, the distance between the fixed part 20a and the fixed part 20e in FIG. For the same reason as “the shorter distance between the fixed portions”, it is desirable that the distance is 10 mm or more, more preferably 15 mm or more, and 40 mm or less, more preferably 30 mm or less.

  Although the fuel cell of the present invention has been described with reference to FIGS. 1 to 10, what is shown in these drawings is only an example of the present invention, and the fuel cell of the present invention is shown in these drawings. The structure is not limited to the above.

  As described above, the fuel cell of the present invention is a planar fuel cell in which a plurality of MEAs are arranged in a planar shape. By adopting the above configuration, a forced oxygen supply means such as a blower is not used. Excellent battery characteristics can be ensured. Therefore, the fuel cell of the present invention can be easily reduced in size and is suitable for a small portable power source, and can be preferably used for various applications to which a known fuel cell is applied.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

Example 1
A fuel cell having the structure shown in FIG. 1 was produced. The MEA 100 having the configuration shown in FIG. 8 was used (the planar shape is different from that shown in FIG. 8). As the positive electrode and the negative electrode of MEA 100, electrodes (“LT140E-W” manufactured by E-TEK, Pt amount: 0.5 mg / cm ² ) coated with Pt-supported carbon on carbon cloth were used. Further, “Nafion 112” manufactured by DuPont was used for the solid electrolyte membrane 15. Each electrode was 45 mm × 51 mm, and the solid electrolyte membrane was 49 mm × 55 mm.

  As the positive electrode panel plate 1, the one shown in FIG. 11 having a thickness of 4 mm made of stainless steel 304 was used. As shown in FIG. 11, the oxygen introduction holes 11a for forming the openings are rectangular holes of 1 mm × 11 mm over the entire area corresponding to the upper part of the positive electrode diffusion layer of each MEA, and four oxygen holes vertically and 22 holes left and right. A total of 88 pieces were arranged. Thereby, the said shortest distance when drawing the two parallel line | wires which contact | connect an opening part and the shortest distance between lines becomes the shortest will be 1 mm. The oxygen introduction holes 11a are arranged with a distance of 1 mm on the left and right and 2 mm on the top and bottom. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. The ratio (opening ratio) of the opening on the positive electrode side to the electrode area is 42%. As shown in FIG. 11, a hole of φ3 mm was provided in the fixing portion 20 at a position corresponding to the outer peripheral portion of the MEA. Among the fixed parts adjacent to each other with the MEA interposed therebetween, the distance between the shorter fixed parts is 51 mm, and the distance between the adjacent fixed parts without sandwiching the MEA is 15 mm.

  The negative electrode panel plate 2 was prepared with the same material and shape as the positive electrode panel plate 1.

  As the positive electrode current collecting plates 5 and 6, the ones having a structure shown in FIG. 12 (positive electrode end current collecting plate) and FIG. The shape and arrangement of the oxygen introduction holes 11b and the fixing portions 20 of the positive electrode current collecting plates 5 and 6 are the same as those of the positive electrode panel plate. Moreover, the positive electrode current collector plate 5 was provided with a positive electrode current collector terminal portion 21. Furthermore, the positive electrode current collecting plate 6 was provided with one positive electrode series connection tab 22 at a position corresponding to the outer peripheral portion of the fuel cell.

  The negative electrode end current collecting plate 7 and the negative electrode current collecting plate 8 were prepared in the same material and shape as the positive electrode end current collecting plate 5 and the positive electrode current collecting plate 6.

  A positive electrode insulating plate 3 having a structure shown in FIG. 14 and made of glass epoxy resin and having a thickness of 0.5 mm was used. The shape and arrangement of the oxygen introduction hole 11c and the fixing portion 20 of the positive electrode insulating plate 3 are the same as those of the positive electrode panel plate. The negative electrode insulating plate 4 was prepared with the same material and shape as the positive electrode insulating plate 3.

  As the fuel tank 10, a fuel tank having a structure shown in FIG. 15 and made of glass epoxy resin and having a thickness of 3 mm was used. The depth of the central tank interior 27 is 2 mm.

  As the seals 9a and 9b, those having the structure shown in FIG. 16 and made of silicon rubber and having a thickness of 0.2 mm were used. The size of the hole 29 for accommodating the electrode was 46 m × 52 mm.

  The above members were stacked in the order shown in FIG. 1 and tightened with bolts 18 and nuts 19 to produce a fuel cell.

Example 2
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has the structure shown in FIG. 17, and the oxygen introduction holes 11 a have rectangular holes of 2 mm × 11 mm in the whole area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. 11 in total, 44 in total. As a result, when the two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn, the shortest distance is 2 mm. The oxygen introduction holes 11a are arranged with a distance of 2 mm vertically and horizontally. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. The ratio (opening ratio) of the opening on the positive electrode side to the electrode area is 42%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Example 3
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has the structure shown in FIG. 18, and the oxygen introduction hole 11 a has a rectangular hole of 1 mm × 11 mm in the whole area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. A total of 60 pieces were arranged in 15 pieces. Thereby, the said shortest distance when drawing the two parallel line | wires which contact | connect an opening part and the shortest distance between lines becomes the shortest will be 1 mm. The oxygen introduction holes 11a are arranged with a distance of 2 mm vertically and horizontally. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. The ratio (opening ratio) of the opening on the positive electrode side to the electrode area is 29%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Example 4
A fuel cell was produced in the same manner as in Example 1 except that the thickness of the positive electrode panel plate 1 and the negative electrode panel plate 2 was 2 mm.

Example 5
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, each electrode of the MEA 100 was 25 mm × 92 mm, and the solid electrolyte membrane 15 was 29 mm × 96 mm.

  Further, the positive electrode panel plate 1 has the structure shown in FIG. 3, and the oxygen introduction hole 11 a has a 1 mm × 13 mm rectangular hole in the whole area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. 12 in total, 72 in total. Thereby, the said shortest distance when drawing the two parallel line | wires which contact | connect an opening part and the shortest distance between lines becomes the shortest will be 1 mm. The oxygen introduction holes 11a are arranged with a distance of 1 mm on the left and right and 2 mm on the top and bottom. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. Moreover, the ratio (opening ratio) with respect to the electrode area of the opening part on the positive electrode side is 41%. As shown in FIG. 3, a hole of φ3 mm was provided in the fixing portion 20 at a position corresponding to the outer peripheral portion of the MEA. Among the fixed parts adjacent to each other with the MEA interposed therebetween, the shorter distance between the fixed parts (for example, the distance between the fixed part 20a and the fixed part 20c in FIG. 3) is 31 mm. The distance between the fixed parts to fit (for example, the distance between the fixed part 20a and the fixed part 20e in FIG. 3) is 15 mm. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Further, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, those oxygen introduction holes and screw holes are provided. The arrangement and shape of were changed to match the positive panel plate 1 and the negative panel plate 2. Moreover, about the seal | stickers 9a and 9b (FIG. 10), the hole 29 was changed according to the shape of MEA100, and arrangement | positioning of the screw hole was changed according to the positive electrode panel plate 1 grade | etc.,. Further, the fuel tank unit 10 is changed to the structure shown in FIG.

Example 6
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, as shown in FIG. 19, the positive electrode end current collecting plate 5 was shaped to surround the positive electrode current collecting terminal portion 21 from both ends of the plate. Further, the positive electrode current collecting plate 6 was provided with two positive electrode series connection tabs 22 as shown in FIG. The negative electrode end current collecting plate 7 and the negative electrode current collecting plate 8 have the same shape as the positive electrode current collecting plate 5 and the positive electrode current collecting plate 6, respectively.

  Further, in the positive electrode insulating plate 3, as shown in FIG. 21, the shape of the concave portion 23 was made to match the positive electrode end current collecting plate 5 (FIG. 19) and the positive electrode current collecting plate 6 (FIG. 20). The negative electrode insulating plate 4 has the same shape as the positive electrode insulating plate 3.

Example 7
A fuel cell was fabricated in the same manner as in Example 5 except that the following points were changed. First, the thickness of the positive electrode panel plate 1 and the negative electrode panel plate 2 was set to 2 mm. Further, as shown in FIG. 4, the positive electrode end current collecting plate 5 was shaped to surround the positive electrode current collecting terminal portion 21 from both ends of the plate. Furthermore, in the positive electrode current collecting plate 6, two positive electrode series connection tabs 22 were provided as shown in FIG. The negative electrode end current collecting plate 7 and the negative electrode current collecting plate 8 have the same shape as the positive electrode current collecting plate 5 and the positive electrode current collecting plate 6, respectively.

  Further, in the positive electrode insulating plate 3, as shown in FIG. 6, the shape of the recess 23 is made to match the shape of the positive electrode end current collecting plate 5 (FIG. 4) and the positive electrode current collecting plate 6 (FIG. 5). The negative electrode insulating plate 4 has the same shape as the positive electrode insulating plate 3.

Example 8
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has the structure shown in FIG. 22, and the oxygen introduction hole 11a has circular holes of φ2 mm in the whole area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100, each vertically 18 288 in total. As a result, when the two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn, the shortest distance is 2 mm. The oxygen introduction holes 11a are arranged with a distance of 0.8 mm vertically and horizontally. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. The ratio (opening ratio) of the opening on the positive electrode side to the electrode area is 40%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Comparative Example 1
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has the structure shown in FIG. 23, and the oxygen introduction hole 11a has four rectangular holes of 4 mm × 9.5 mm in the upper and lower portions in the entire area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. , 6 on the left and right, 24 in total. As a result, when the two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn, the shortest distance is 4 mm. The oxygen introduction holes 11a are arranged with a distance of 4 mm vertically and horizontally. Thereby, there exists a point where the shortest distance to the nearest opening exceeds 2 mm among arbitrary points other than the oxygen introduction hole 11a (that is, the opening). Moreover, the ratio (opening ratio) with respect to the electrode area of the opening part on the positive electrode side is 41%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Comparative Example 2
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has a structure shown in FIG. 24, and a 0.5 mm × 0.5 mm square hole is formed in the oxygen introduction hole 11 a over the entire area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. 25 pieces, 22 pieces on the left and right, a total of 550 pieces were arranged. As a result, when the two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn, the shortest distance is 0.5 mm. The oxygen introduction holes 11a are arranged with a distance of 1.5 mm vertically and horizontally. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. Moreover, the ratio (opening ratio) with respect to the electrode area of the opening part on the positive electrode side is 6%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Comparative Example 3
A fuel cell was fabricated in the same manner as in Example 1 except that the following points were changed. First, the positive electrode panel plate 1 has a structure shown in FIG. 25, and the oxygen introduction hole 11a has a rectangular hole of 2 mm × 12 mm in the whole area corresponding to the upper part of the positive electrode diffusion layer 13 of each MEA 100. 17 were arranged in total, 68 in total. As a result, when the two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn, the shortest distance is 2 mm. The oxygen introduction holes 11a are arranged with a distance of 0.6 mm vertically and horizontally. Thereby, the shortest distance from the arbitrary point in places other than the oxygen introduction hole 11a (namely, opening part) to the nearest opening part will be 2 mm or less. The ratio (opening ratio) of the opening on the positive electrode side to the electrode area is 71%. The negative electrode panel plate 2 has the same configuration as the positive electrode panel plate 1.

  Furthermore, with respect to the positive electrode end current collecting plate 5, the positive electrode current collecting plate 6, the positive electrode insulating plate 3, the negative electrode end current collecting plate 7, the negative electrode current collecting plate 8, and the negative electrode insulating plate 4, The shape was changed to match the positive panel plate 1 and the negative panel plate 2.

Comparative Example 4
A fuel cell was produced in the same manner as in Example 1 except that the material of the positive electrode panel plate 1 and the negative electrode panel plate 2 was changed to polycarbonate.

  Hydrogen was supplied as a fuel from the fuel supply port 24 to the fuel cells of Examples 1 to 8 and Comparative Examples 1 to 4, and a power generation test was performed at a constant voltage of 2 V to obtain the output of the fuel cell. The test was performed at room temperature of 25 ° C. The results are shown in Table 1.

  As is clear from Table 1, in the fuel cells of Examples 1 to 8, the outputs at the time of 2V constant voltage power generation were all 5.0 W or more and had excellent battery characteristics. On the other hand, in the fuel cells of Comparative Examples 1 to 4, the output during 2V constant voltage power generation was inferior.

  Among these, in the battery of Comparative Example 1, the shortest distance when drawing two parallel lines in contact with the opening and the shortest distance between the lines being the shortest is long, and the portion corresponding to the opening The MEA has insufficient current collection, and there is a point where the shortest distance to the nearest opening is long among arbitrary points other than the opening, and in the MEA corresponding to such a point, oxygen The supply is insufficient, and it is considered that the output of the battery is reduced by these.

  Further, in the battery of Comparative Example 2, it is considered that the output of the battery was lowered because the opening ratio of the opening was too small and oxygen supply to the positive electrode was insufficient.

  Furthermore, in the battery of Comparative Example 3, since the opening ratio of the opening is too large and the contact area between the MEA and the current collecting plate is small, the current collecting performance is reduced and the internal resistance of the battery is increased. The battery output is considered to have decreased.

  Further, in the battery of Comparative Example 4, since the material of the positive electrode panel plate 1 and the negative electrode panel plate 2 is not metal but polycarbonate, the strength is insufficient, and bending occurs when the MEA is tightened, so that the MEA cannot be suppressed. It is considered that the internal resistance of the battery is increased and the output of the battery is thereby reduced.

It is a cross-sectional schematic diagram which shows an example of the fuel cell of this invention. It is explanatory drawing of the shape of an opening part. It is a plane schematic diagram which shows an example of the positive electrode panel plate which concerns on the fuel cell of this invention. It is a plane schematic diagram which shows an example of the positive electrode current collection plate (positive electrode edge part current collection plate) which concerns on the fuel cell of this invention. It is a plane schematic diagram which shows an example of the positive electrode current collecting plate which concerns on the fuel cell of this invention. It is a schematic diagram which shows an example of the positive electrode insulating plate which concerns on the fuel cell of this invention. It is a schematic diagram which shows an example of the fuel tank part which concerns on the fuel cell of this invention. It is a schematic diagram which shows an example of the electrode and electrolyte integrated material which concerns on the fuel cell of this invention. It is a schematic diagram which shows the other example of the electrode and electrolyte integrated material which concerns on the fuel cell of this invention. It is a plane schematic diagram which shows an example of the seal | sticker which concerns on the fuel cell of this invention. 3 is a schematic plan view showing a positive electrode panel plate according to the fuel cell of Example 1. FIG. 3 is a schematic plan view showing a positive electrode end current collecting plate according to the fuel cell of Example 1. FIG. 3 is a schematic plan view showing a positive electrode current collecting plate according to a fuel cell of Example 1. FIG. 3 is a schematic plan view showing a positive electrode insulating plate according to the fuel cell of Example 1. FIG. 2 is a schematic plan view showing a fuel tank part according to the fuel cell of Example 1. FIG. 2 is a schematic plan view showing a seal according to the fuel cell of Example 1. FIG. 6 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Example 2. FIG. 6 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Example 3. FIG. 10 is a schematic plan view showing a positive electrode end current collecting plate according to a fuel cell of Example 6. FIG. 10 is a schematic plan view showing a positive electrode current collecting plate according to a fuel cell of Example 6. FIG. 10 is a schematic plan view showing a positive electrode insulating plate according to a fuel cell of Example 6. FIG. 10 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Example 8. FIG. 6 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Comparative Example 1. FIG. 6 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Comparative Example 2. FIG. 10 is a schematic plan view showing a positive electrode panel plate according to a fuel cell of Comparative Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positive electrode panel plate 2 Negative electrode panel plate 3 Positive electrode insulating plate 4 Negative electrode insulating plate 5, 6 Positive electrode current collecting plate 7, 8 Negative electrode current collecting plate 9a, 9b Seal 11 Opening part 20 Fixed part 100 Electrode / electrolyte integrated object

Claims (5)

A fuel cell in which a plurality of electrode / electrolyte integrated products in which a positive electrode, a solid electrolyte membrane, and a negative electrode are sequentially stacked are arranged in a plane, and the plurality of electrode / electrolyte integrated products are connected in series,
A positive electrode current collector plate, a positive electrode insulating plate, and a metal positive electrode panel plate are sequentially arranged on the positive electrode side of each electrode / electrolyte integrated product, and the negative electrode collector is disposed on the negative electrode side of each electrode / electrolyte integrated product. Electric plate, negative electrode insulation plate and metal negative electrode panel plate are arranged in sequence,
All electrode / electrolyte integrated products are sandwiched and integrated between the positive electrode panel plate and the negative electrode panel plate,
The positive electrode current collecting plate, the positive electrode insulating plate, and the positive electrode panel plate have oxygen introducing holes for introducing oxygen outside the fuel cell to the positive electrode, and oxygen introducing holes of the positive electrode collecting plate, Through the oxygen introduction hole of the positive electrode insulating plate and the oxygen introduction hole of the positive electrode panel plate, an opening reaching the electrode / electrolyte integrated body from the outer surface of the positive electrode panel plate is formed,
A fuel cell satisfying the following (A), (B), and (C) in a plan view of the fuel cell from the positive electrode panel plate.
(A) The aperture ratio calculated | required from the ratio of the total area of the said opening part and the area of a positive electrode is 10 to 60%.
(B) The shortest distance is 0.2 to 3 mm when two parallel lines that are in contact with the opening and have the shortest shortest distance between the lines are drawn.
(C) The shortest distance from any point other than the opening to the nearest opening is 2 mm or less.   The fuel cell according to claim 1, wherein the total thickness of the positive electrode panel plate, the positive electrode insulating plate, and the positive electrode current collecting plate is 1 to 4 mm.   The positive panel plate and the negative panel plate are fixed by mechanical clamping means at fixed portions arranged at intervals, and the shorter fixed portion between adjacent fixed portions sandwiching the electrode / electrolyte integrated product. The fuel cell according to claim 1 or 2, wherein the distance between them is 10 to 40 mm.   The positive electrode current collecting plate and / or the negative electrode current collecting plate has two tabs for electrically connecting the electrode / electrolyte integrated materials at positions corresponding to the outer peripheral portion of the fuel cell. 4. The fuel cell according to any one of 3.   The fuel cell according to any one of claims 1 to 4, wherein the metal constituting the positive electrode panel plate and / or the negative electrode panel plate has a Young's modulus determined by a bending test of 50000 MPa or more.

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