JP6062154B2 - Fuel cell and method of using the same - Google Patents

Description

  The present invention relates to a fuel cell and a method for using the same.

  Fuel cells are expected to be put to practical use as new power sources for electronic devices. Among them, polymer electrolyte fuel cells and direct alcohol fuel cells that use an ion exchange membrane that is a solid polymer as an electrolyte material are high at room temperature. Since power generation efficiency can be obtained, practical application as a small fuel cell for the purpose of application to portable electronic devices is being studied.

  Direct alcohol fuel cells that use liquid alcohol or aqueous alcohol as a fuel have a simplified fuel cell structure because the fuel tank can be designed relatively easily compared to when the fuel is gas. And space saving, and the expectation as a small fuel cell is particularly high.

When a direct alcohol fuel cell supplies a fuel such as methanol to the anode electrode and an oxidant such as oxygen to the cathode electrode, the following oxidation-reduction reaction:
Anode electrode: CH ₃ OH + H ₂ O → CO ₂ ↑ + 6H ⁺ + 6e ⁻ (1)
Cathode: 3/2 O ₂ + 6H ⁺ + 6e ⁻ → 3H ₂ O (2)
To generate electricity.

  For fuel cells that use liquid fuel, such as direct alcohol fuel cells, a liquid supply system that supplies liquid fuel to the anode electrode in a liquid state, and liquid fuel that is induced from the fuel tank into the fuel cell There is a vaporization supply system that vaporizes in the battery and supplies the vaporized component (hereinafter referred to as “vaporized fuel”) to the anode electrode. For example, Japanese Patent Application Laid-Open No. 2008-226627 (Patent Document 1) discloses a water-repellent sheet that blocks liquid fuel and allows vaporized fuel to pass between a back cover having a pipe portion (fuel flow path) and an anode electrode. A vaporization and supply type direct methanol fuel cell in which a gas-liquid separation membrane) is disposed is disclosed. By interposing the gas-liquid separation membrane, only the vaporized fuel is supplied to the anode electrode.

  The gas-liquid separation membrane may be used for other purposes. For example, in Japanese Patent Application Laid-Open No. 2006-024401 (Patent Document 2), in a direct methanol fuel cell, a gas-liquid separation membrane is arranged in a fuel chamber in a fuel cell that stores liquid fuel, so that the anode electrode A technique is disclosed in which carbon dioxide generated and reaching the fuel chamber is discharged from an exhaust gas port provided in the fuel chamber via a gas-liquid separation membrane.

JP 2008-226627 A JP 2006-244401 A

  In a fuel cell using liquid fuel, a portion serving as a chamber (space) for storing liquid fuel or a flow path for circulating liquid fuel is usually provided in the fuel cell. In the present invention, this portion is referred to as a “liquid fuel chamber”. In the above-mentioned patent document 1, “pipe part” corresponds to “fuel chamber” in the above-mentioned patent document 2.

  In the liquid fuel chamber filled with the liquid fuel, gas may be mixed or generated due to various factors, and bubbles may be generated. Examples of such factors are: 1) vaporization of dissolved gas in liquid fuel due to temperature rise, 2) vaporization of liquid fuel itself due to temperature rise, 3) air that gradually enters when the fuel cell is stopped, 4) anode due to power generation There is a mixture of product gas such as carbon dioxide generated at the pole.

  In a fuel cell of a vaporization supply system in which a gas-liquid separation membrane is arranged between the liquid fuel chamber and the anode electrode, the gas (bubbles) in the liquid fuel chamber as described above is stably supplied to the anode electrode, and consequently Since it is a factor that hinders stable power generation, it is highly desirable to discharge from the liquid fuel chamber. For example, the gas in the liquid fuel chamber is discharged by introducing the liquid fuel into the liquid fuel chamber using a pumping means such as a liquid feed pump, and permeating the gas-liquid separation membrane by the pressure, and passing the permeated gas to the fuel cell. It is realizable by the method of discharging from the gas discharge port provided in the appropriate place.

  In a vaporization supply type fuel cell having a gas-liquid separation membrane, in order to discharge gas in the liquid fuel chamber through the gas-liquid separation membrane, the pressure in the liquid fuel chamber is increased by increasing the discharge pressure of the pumping means. In order to discharge gas effectively, the higher the pressure in the liquid fuel chamber, the better.

  However, when the internal pressure of the liquid fuel chamber is increased in a conventional fuel cell of the vaporization supply system, the liquid fuel passes through the gas-liquid separation membrane in a liquid state together with gas (bubbles) (hereinafter, this phenomenon is referred to as “ There was also a problem of “liquid leakage”. On the other hand, if the internal pressure of the liquid fuel chamber is set low in order to avoid liquid leakage, the gas in the liquid fuel chamber is not sufficiently discharged.

  Accordingly, an object of the present invention is to vaporize gas (bubbles) inevitably mixed or generated in the liquid fuel chamber through the gas-liquid separation membrane, thereby enabling stable power generation. It is to provide a supply type fuel cell.

  As means for solving the above conventional problems, the present inventors first tried to increase the thickness of the gas-liquid separation membrane. As a result, by increasing the thickness of the gas-liquid separation membrane, it was possible to improve the liquid fuel barrier property of the gas-liquid separation membrane somewhat. The term “liquid fuel barrier property” as used herein means that liquid fuel that has contacted one surface of the gas-liquid separation membrane permeates the gas-liquid separation membrane and remains in a liquid state from the other surface facing the one surface. It means the ability to prevent leakage.

  However, depending on the means for increasing the thickness of the gas-liquid separation membrane, it has been found that a sufficiently improved liquid fuel barrier property cannot be obtained even if the thickness is extremely increased even at the expense of thinning the fuel cell. . Based on this point, the present inventors have further studied and have completed the present invention.

The present invention includes the following.
[1] A unit cell having an anode electrode, an electrolyte membrane, and a cathode electrode in this order;
A liquid fuel chamber that comprises a space in which the anode electrode side is open, and circulates or houses liquid fuel;
A gas-liquid separation layer disposed between the liquid fuel chamber and the anode electrode and capable of transmitting the vaporized fuel;
A first intervening layer disposed between the gas-liquid separation layer and the anode electrode and having a first through-hole penetrating in the thickness direction;
The first through hole is a fuel cell disposed in a region different from a region immediately above the liquid fuel chamber in the first intervening layer.

  [2] The fuel cell according to [1], wherein the gas-liquid separation layer has higher permeability of the liquid fuel in the thickness direction than in the in-plane direction.

  [3] The fuel cell according to [1] or [2], wherein the first intervening layer is directly laminated on a surface of the gas-liquid separation layer.

  [4] A layer disposed between the first intervening layer and the anode electrode, the second through hole penetrating in the thickness direction, provided at a peripheral portion of the layer, and the second through hole The fuel cell according to any one of [1] to [3], further including a second intervening layer having a communication path communicating with the outside of the layer.

  [5] The fuel cell according to any one of [1] to [4], wherein the fuel is methanol or a methanol aqueous solution.

[6] The method of using the fuel cell according to any one of [1] to [5], wherein the fuel is supplied to the liquid fuel chamber using a liquid feed pump to generate power.
Use method wherein the discharge pressure of the liquid feed pump is 20 kPa or more.

[7] The method of using the fuel cell according to any one of [1] to [5], wherein the fuel is supplied to the liquid fuel chamber using a liquid feed pump to generate power.
A method of use in which the fuel is continuously supplied to the liquid fuel chamber during power generation.

  According to the present invention, gas (bubbles) mixed or generated in the liquid fuel chamber can be effectively discharged through the gas-liquid separation layer and the first intervening layer, and thus stable supply of vaporized fuel to the anode electrode is possible. As a result, it is possible to provide a fuel cell of a vaporization supply system that can stably generate power.

  Further, in a conventional fuel cell having a low liquid fuel blocking property, a pump (liquid feed pump) is used to increase the internal pressure of the liquid fuel chamber, and when the gas is discharged, the pump is intermittently operated to prevent liquid leakage. Although it was necessary, according to the present invention, such a sequence control of the pump is unnecessary, and the system can be simplified.

  The fuel cell of the present invention is suitable as a small fuel cell intended for application to a portable electronic device, particularly as a small fuel cell mounted on a portable electronic device.

It is a schematic sectional drawing which shows an example of the fuel cell of this invention. It is a schematic top view which shows the 1st intervening layer which the fuel cell shown by FIG. 1 has. It is a schematic top view which shows the flow-path board which the fuel cell shown by FIG. 1 has. It is the schematic which shows the 2nd intervening layer which the fuel cell shown by FIG. 1 has. It is a schematic sectional drawing in the VV line shown by FIG. It is a schematic sectional drawing for demonstrating the positional relationship of a 1st through-hole and a liquid fuel chamber. It is a schematic top view which shows another example of a 1st intervening layer. It is the schematic which shows another example of a 2nd intervening layer.

Hereinafter, the fuel cell of the present invention will be described in detail with reference to embodiments.
1 is a schematic cross-sectional view showing an example of a fuel cell of the present invention, FIG. 2 is a schematic top view showing a first intervening layer 2, FIG. 3 is a schematic top view showing a flow path plate 40, and FIG. 2 is a schematic view showing an intervening layer 3. FIG. Moreover, the schematic sectional drawing in the VV line | wire shown by FIG. 1 is shown in FIG.

  The fuel cell 100 shown in these drawings includes a membrane electrode assembly 20 including an anode electrode 11, an electrolyte membrane 10 and a cathode electrode 12 in this order, and is laminated on the anode electrode 11 and electrically connected thereto. A unit cell 30 comprising an anode current collecting layer 21 and a cathode current collecting layer 22 laminated on the cathode electrode 12 and electrically connected thereto; a second cell laminated in contact with the surface of the anode current collecting layer 21 The intervening layer 3; the first intervening layer 2 laminated in contact with the surface of the second intervening layer 3; the gas-liquid separation layer 1 laminated in contact with the surface of the first intervening layer 2; A flow path plate 40 disposed below is basically provided. The flow path plate 40, the gas-liquid separation layer 1, the first intervening layer 2, and a fuel tank (not shown) constitute a fuel supply part (a part for supplying fuel to the anode electrode 11) of the fuel cell 100.

  The flow path plate 40 is a member disposed below the anode electrode 11, and includes a liquid fuel chamber 41, which includes a recess (groove) formed on one surface thereof, for circulating liquid fuel (liquid fuel). Have. The liquid fuel chamber 41 is composed of a space in which the anode 11 is opened, and the gas-liquid separation layer 1 capable of transmitting vaporized fuel is disposed so as to cover the opening. A fuel tank (not shown) for storing (holding) the liquid fuel is connected to the end 42 of the liquid fuel chamber 41.

  The fuel cell 100 includes a protective cover 50 that is stacked on the cathode current collecting layer 22 and has a plurality of openings 51. The left end surface of the unit battery 30, the second intervening layer 3, the first intervening layer 2 and the gas-liquid separation layer 1 in FIG. 1, and the right side of the unit battery 30, the first intervening layer 2 and the gas-liquid separation layer 1 in FIG. The end face is provided with a sealing layer 60 made of a cured product layer of an epoxy curable resin composition or the like in order to prevent external air from being mixed in, leakage of vaporized fuel or liquid fuel, and the like. The second intervening layer 3 has a communication path 3 b, and this communication path 3 b is connected to the gas discharge port 65.

  The fuel cell 100 generates power by the following operation. That is, the liquid fuel that has flowed into the liquid fuel chamber 41 is distributed throughout the liquid fuel chamber 41 and is gas-liquid separated by the gas-liquid separation layer 1, and only the vaporized fuel permeates to the first intervening layer 2 side. The vaporized fuel passes through the first through hole 2a (see FIG. 2) of the first intervening layer 2, the second through hole 3a (see FIG. 4) of the second intervening layer 3, and the opening of the anode current collecting layer 21 in order. Supplied to the pole 11. Taking the case where the liquid fuel is methanol or an aqueous methanol solution as an example, the vaporized fuel supplied to the anode electrode 11 is consumed by causing an oxidation reaction represented by the above formula (1). The vaporized fuel will be consumed according to the amount of current generated by the fuel cell 100. To compensate for this, the liquid fuel continues to evaporate from the gas-liquid separation layer 1, so that the vaporized fuel near the anode 11 is vaporized. The fuel vapor pressure is kept substantially constant.

  On the other hand, in the case where the oxidizing agent is air, for example, in the cathode electrode 12, the oxygen in the air that has reached through the opening 51 of the protective cover 50 and the opening of the cathode current collecting layer 22 and the electrolyte membrane 10 are separated. The protons transmitted from the anode electrode 11 to the cathode electrode 12 cause a reduction reaction represented by the above formula (2). Electric power is supplied to an external electronic device by electron transfer based on the above oxidation-reduction reaction.

  The carbon dioxide gas generated at the anode electrode 11 as a result of power generation passes through the opening of the anode current collecting layer 21, the second through-hole 3 a of the second intervening layer 3, the communication path 3 b and the gas outlet 65 in order. It is discharged outside.

Next, each member constituting the fuel cell 100 will be described in detail.
[Gas-liquid separation layer and first intervening layer]
The gas-liquid separation layer 1 is a layer that is disposed between the liquid fuel chamber 41 and the anode electrode 11 and is vaporized fuel permeable and does not transmit liquid fuel at least at normal pressure, that is, at least at normal pressure. It is a layer having “liquid fuel barrier property” defined in By providing the gas-liquid separation layer 1, the fuel can be vaporized and supplied to the anode 11. The gas-liquid separation layer 1 may have a function of controlling (limiting) the amount or concentration of vaporized fuel supplied to the anode electrode 11 to an appropriate amount and making it uniform. Therefore, by providing the gas-liquid separation layer 1, it is possible to suppress crossover of fuel and temperature unevenness in the power generation unit, which contributes to achieving a stable power generation state. In the fuel cell 100, the gas-liquid separation layer 1 is laminated on the surface of the flow path plate 40 on the anode electrode 11 side so as to cover the liquid fuel chamber 41.

  The 1st intervening layer 2 is a layer arrange | positioned between the gas-liquid separation layer 1 and the anode electrode 11, and has the 1st through-hole 2a penetrated in the thickness direction as FIG. 2 shows. . In the fuel cell 100, the first intervening layer 2 is directly laminated on the surface of the gas-liquid separation layer 1 on the anode electrode 11 side, but may be joined and laminated through a layer containing an adhesive component. The first through-hole 2a is disposed in a region different from the region directly above the liquid fuel chamber 41 in the first intervening layer 2 (see FIGS. 2, 3 and 5).

  Thus, the fuel cell 100 includes the gas-liquid separation layer 1 disposed on the liquid fuel chamber 41, and the first intervening layer disposed on the gas-liquid separation layer 1 and having the first through-hole 2a at the predetermined position. 2 is one feature, and with this configuration, when the internal pressure of the liquid fuel chamber 41 is increased and the gas (bubbles) in the liquid fuel chamber 41 is discharged, the liquid fuel remains in a liquid state. In addition, it is possible to effectively suppress “liquid leakage” that permeates through the laminated structure portion including the gas-liquid separation layer 1 and the first intervening layer 2. That is, the “liquid fuel blocking property” defined above can be effectively improved. However, the “liquid fuel barrier property” referred to here is a liquid fuel barrier property as a laminated structure including the gas-liquid separation layer 1 and the first intervening layer 2.

  By improving the liquid fuel blocking property, the internal pressure of the liquid fuel chamber 41 can be increased, so that the gas (bubbles) in the liquid fuel chamber 41 can be discharged more effectively. In addition, the high liquid fuel barrier property provides very high reliability in terms of preventing liquid leakage from the fuel cell. In addition to this, a high liquid fuel blocking property is utilized, and the discharge pressure of the liquid pump for feeding the liquid fuel into the liquid fuel chamber is kept constant at the maximum discharge pressure, and the fuel is continuously supplied to the liquid fuel chamber 41. Thus, the fuel cell can be continuously operated (continuous power generation). According to the fuel cell of the present invention, it is possible to generate electric power with the discharge pressure of the liquid feed pump being 20 kPa or more without causing liquid leakage. Conventionally, since the liquid fuel blocking property is low, the pump has to be intermittently operated, and it has been necessary to avoid applying high pressure continuously. When the environmental temperature is different, the amount of fuel to be supplied is different. Therefore, the intermittent operation of the liquid feeding pump requires a complicated sequence control linked with the environmental temperature. In the fuel cell of the present invention, liquid leakage does not occur even when a high pressure is continuously applied. Therefore, the fuel cell can be used without performing complicated sequence control, thereby simplifying the system.

  With reference to FIG. 6, the liquid fuel barrier property of the fuel cell 100 will be described more specifically. The laminated structure of the flow path plate 40 / gas-liquid separation layer 1 / first intervening layer 2 shown in FIG. 6A is the same as the laminated structure of the fuel cell 100, and the first through-hole 2a is a liquid fuel chamber. It is provided in an area different from the area immediately above 41. On the other hand, in the stacked structure shown in FIG. 6B, the first through hole 2 a is provided in a region immediately above the liquid fuel chamber 41. The dotted arrows in FIGS. 6A and 6B indicate that the vaporized component of the liquid fuel in the liquid fuel chamber 41 permeates the gas-liquid separation layer 1 and vaporizes the fuel from the first through-hole 2a of the first intervening layer 2. It shows the route when it is supplied as.

  In the stacked structure of FIG. 6B, when the internal pressure of the liquid fuel chamber 41 is increased to discharge the gas in the liquid fuel chamber 41 and the pressure exceeds a certain pressure, it passes through the same path as the dotted arrow. Liquid leakage occurs from the 1 through-hole 2a. The constant pressure can be increased to some extent by increasing the thickness α of the gas-liquid separation layer 1, but this has a limit.

  On the other hand, in the laminated structure of FIG. 6A, the first through hole 2a is provided in a region different from the region directly above the liquid fuel chamber 41 (at a distance from the region immediately above). When the internal pressure of the chamber 41 is increased, the liquid fuel penetrates not only in the thickness direction of the gas-liquid separation layer 1 but also in the in-plane direction, as in the dotted arrow. As described above, in order to cause liquid leakage from the first through-hole 2a, it is necessary to permeate in the in-plane direction. Therefore, the liquid fuel blocking performance is improved accordingly.

  When the permeability in the in-plane direction and the permeability in the thickness direction of the liquid fuel in the gas-liquid separation layer 1 are equal, as shown in FIG. When the linear distance to the through-hole 2a is α, the thickness of the gas-liquid separation layer 1 is α in the stacked structure of FIG. Equivalent liquid fuel barrier properties can be obtained. If the thickness of the gas-liquid separation layer 1 is α in the laminated structure of FIG. 6A, the pressure required to permeate the gas-liquid separation layer 1 in the in-plane direction is more than that of the laminated structure of FIG. High liquid fuel barrier properties can be obtained.

  It is possible to control the liquid fuel blocking performance by adjusting the distance from the region directly above the liquid fuel chamber 41 to the first through-hole 2a, and the liquid fuel blocking performance can be increased as the distance is increased. it can. The distance from the region directly above the liquid fuel chamber 41 to the first through-hole 2a is typically 0.5 mm to 50 mm.

  The gas-liquid separation layer 1 can be used without particular limitation as long as it has a gas-liquid separation ability with respect to the fuel to be used and has a liquid fuel barrier property at least at normal pressure, but its own liquid fuel barrier property is higher. It is preferable to use one having a higher permeability of the liquid fuel in the thickness direction than in the in-plane direction. As described above, the improvement of the liquid fuel blocking performance by providing the first through hole 2a in a region different from the region directly above the liquid fuel chamber 41 requires a pressure for allowing the liquid fuel to permeate in the in-plane direction. Due to By using the gas-liquid separation layer 1 having a lower permeability of the liquid fuel in the in-plane direction, it is possible to obtain a higher liquid fuel blocking effect. Further, when compared with the gas-liquid separation layer 1 in which the in-plane permeability of the liquid fuel is equal to the permeability in the thickness direction, the distance between the region directly above the liquid fuel chamber 41 and the first through-hole 2a. Even if is shorter, it is possible to obtain the same effect of improving the liquid fuel barrier property. This means that more first through holes 2 a can be formed in the first intervening layer 2, whereby a more uniform supply of vaporized fuel to the anode 11 can be achieved.

  Examples of the gas-liquid separation layer 1 in which the permeability of the liquid fuel in the thickness direction is higher than that in the in-plane direction include, for example, “Temish (registered trademark)” manufactured by Nitto Denko Corporation, “Poaflon” manufactured by Sumitomo Electric Fine Polymer Co., Ltd. Registered trademark) ”,“ all ePTFE membrane ”manufactured by Nippon Gore Co., Ltd., and other porous films made of stretched polytetrafluoroethylene or other fluororesin, or porous powder obtained by sintering molding plastic powder A film obtained by compressing a material, a film obtained by compressing a polymer porous material obtained by a foaming method, and the like can be suitably used.

  Further, as the gas-liquid separation layer 1, a fluororesin porous membrane other than the above (for example, “Fluorinert membrane” manufactured by Millipore), a porous plastic membrane (for example, “MICROVENT” manufactured by Taisei Plus Co., Ltd.), A polymer porous body obtained by a foaming method can also be used.

  The thickness of the gas-liquid separation layer 1 is not particularly limited, but is preferably 20 μm or more, and more preferably 50 μm or more in order to obtain sufficient gas-liquid separation ability and liquid fuel blocking performance. From the viewpoint of reducing the thickness of the fuel cell, the thickness of the gas-liquid separation layer 1 is preferably 500 μm or less, and more preferably 300 μm or less.

  The first intervening layer 2 is made of a material that is impermeable to liquid fuel and impermeable to vaporized fuel. More specifically, as the first intervening layer 2, a non-porous resin sheet or a non-porous metal plate having a through-hole penetrating in the thickness direction as the first through-hole 2a can be used. When a thermosetting resin or a thermoplastic resin is selected as the material for the non-porous resin sheet, the first intervening layer 2 can be joined to the gas-liquid separation layer 1 by thermal fusion or the like. From the viewpoint of reliability, it is preferable to use a material that does not undergo thermal deformation such as thermal contraction or thermal expansion. This is for suppressing an increase or decrease in the permeated amount of the vaporized fuel due to a change in the shape of the first through-hole 2a described later.

  The number of the first through holes 2a is not particularly limited, and may be only one, but is usually 2 or more. In the case of having two or more first through holes 2a, these through holes may be arranged as uniformly as possible in the plane of the first intervening layer 2 so that vaporized fuel can be supplied uniformly to the anode electrode 11. preferable. The shape of the first through-hole 2a is not particularly limited, and may be a shape other than the square shown in FIG. 2, for example, a circle shown in FIG. The opening diameter of the first through-hole 2a (the length of the longest side in the case of a square, the maximum diameter in the case of a circle or the like) can be about 0.1 to 5 mm.

  The thickness of the first intervening layer 2 is not particularly limited, but is preferably 50 μm or more from the viewpoint of ease of handling and heat insulation properties that prevent heat generated by power generation of the fuel cell from being transmitted to the liquid fuel chamber 41. More preferably, it is 100 μm or more. From the viewpoint of reducing the thickness of the fuel cell, the thickness of the first intervening layer 2 is preferably 500 μm or less, and more preferably 300 μm or less.

  Note that the first intervening layer 2 can control (limit) the amount or concentration of vaporized fuel supplied to the anode electrode 11 to an appropriate amount, and can also have a function of making it uniform.

[Channel plate]
The flow path plate 40 is a member having a liquid fuel chamber 41 for circulating or containing the liquid fuel, and is preferably disposed below the anode electrode 11. A fuel tank (not shown) for storing liquid fuel is connected to the end 42 of the liquid fuel chamber 41, and the liquid fuel is usually transferred into the liquid fuel chamber 41 using a liquid feeding means such as a liquid feed pump.

  In the fuel cell 100, as shown in FIG. 3, the fuel plate 40 includes a liquid fuel chamber 41 composed of branched comb-shaped grooves. With such a shape, the liquid fuel is uniformly diffused in the plane, so that the vaporized fuel can be uniformly supplied to the anode 11. In the fuel cell 100, the first through-hole 2a is formed between the grooves (flow paths) of two adjacent comb-tooth portions constituting the liquid fuel chamber 41 when the fuel cell 100 is viewed from above (intermediate position). Has been.

  The liquid fuel chamber 41 is not limited to a branched flow path as shown in FIG. 3, and can be a flow path having any shape (for example, a serpentine shape). The liquid fuel chamber 41 can also be one (or a plurality) of relatively large tanks (recesses) that store the liquid fuel.

  The flow path plate 40 can be made of a plastic material or a metal material. Examples of the plastic material include polyphenylene sulfide (PPS), polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS), polyvinyl chloride, polyethylene (PE), polyethylene terephthalate (PET), polyether ether ketone (PEEK). ), Polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and the like. As a metal material, alloy materials, such as stainless steel and a magnesium alloy other than titanium and aluminum, can be used, for example.

[Second intervening layer]
The second intervening layer 3 is a layer disposed between the first intervening layer 2 and the anode electrode 11. In the fuel cell 100, the second intervening layer 3 is composed of the first intervening layer 2, the anode current collecting layer 21, and the like. It is arranged between. 4 (a) is a schematic top view showing the second intervening layer 3 used in the fuel cell 100, and FIG. 4 (b) is a schematic cross-sectional view taken along the line BB shown in FIG. 4 (a). is there. The 2nd intervening layer 3 has the 2nd through-hole 3a penetrated in the thickness direction, and the communication path | route 3b which connects the 2nd through-hole 3a and the 2nd intervening layer 3 exterior. The communication path 3b includes a groove (concave portion) provided at the peripheral edge of the second intervening layer 3 and extending from the second through-hole 3a to the end surface of the peripheral edge.

  The second intervening layer 3 serves as a heat insulating layer for heat insulation between the power generation unit and the liquid fuel chamber 41 by a space (filled with air or other gas) existing in the second through-hole 3a. This is effective in suppressing crossover due to excessive rise in the temperature of the liquid fuel chamber 41. When the second intervening layer 3 having the second through-hole 3a is provided, the gas such as carbon dioxide gas generated at the anode electrode 11 can be discharged out of the fuel cell together with the heat generated by the power generation. Fuel supply hindrance due to excessive temperature rise and poor gas discharge can be suppressed. This contributes to maintaining a stable power generation state. Moreover, since the gas produced | generated by the anode pole 11 can be discharged | emitted favorably from the communication path 3b, the penetration | invasion into the liquid fuel chamber 41 of this gas can be suppressed. Further, the second intervening layer 3 provides a discharge path for the gas (bubbles) discharged from the liquid fuel chamber 41 by increasing the internal pressure of the liquid fuel chamber 41 to the outside of the fuel cell.

  Moreover, the 2nd intervening layer 3 can be utilized as a buffer for supplying vaporized fuel uniformly to a power generation part. The vaporized fuel that has passed through the first through hole 2a of the first intervening layer 2 spreads radially from the through hole and reaches the power generation unit. Since the second intervening layer 3 includes an air layer serving as a space, the vaporized fuel diffuses in the plane, so that uniform power generation is possible in the plane of the power generation unit. This function also has an anode conductive porous layer, which will be described later, and preferably includes at least one or both.

  From the viewpoint of heat insulation between the power generation unit and the liquid fuel chamber 41, it is preferable that the second through hole 3a has an opening ratio as large as possible with respect to the area of the second intervening layer 3 as shown in FIG. The ratio of the opening ratio of the second through hole 3a, that is, the ratio of the opening area of the second through hole 3a to the area of the second intervening layer 3 (the total of the opening areas in the case of having two or more second through holes 3a). Is preferably 50% or more, more preferably 60% or more. The opening ratio of the second through-hole 3a is usually 90% or less.

  The communication path 3b may be a through-hole penetrating in the thickness direction, but is preferably formed of a groove (concave portion) provided in the peripheral portion of the second intervening layer 3 from the viewpoint of the strength of the second intervening layer 3. .

  FIG. 8A is a schematic top view showing another example of the second intervening layer 3, and FIG. 8B is a schematic cross-sectional view taken along line CC shown in FIG. 8A. As shown in FIG. 8, the second intervening layer 3 may have two or more second through holes 3a. Since the second intervening layer 3 having a plurality of second through holes 3a (provided with beams) as shown in FIG. 8 has increased rigidity in the in-plane direction, it is possible to obtain a fuel cell having excellent strength against impacts and the like. This is advantageous.

  When the second intervening layer 3 has two or more second through holes 3a, the communication paths 3b may be provided in the same number as the second through holes 3a for each second through hole 3a. A smaller or larger number of communication paths 3b than the number of through-holes 3a may be provided. In the example of FIG. 8, two communication paths 3b are provided for the four second through holes 3a. The second through hole 3a (the lower two second through holes 3a in FIG. 8A) in which the communication path 3b is not provided is connected to the second through hole 3a (in FIG. 8A) in which the communication path 3b is provided by the connection path 3c. 8 (a) is spatially connected to the upper two second through holes 3a). Similarly to the communication path 3b, the connection path 3c can be a groove (concave) provided in the beam between the second through holes 3a (see FIG. 8B). By providing the connection path 3c, the gas that has entered the second through-hole 3a where the communication path 3b is not provided can be discharged to the outside through the communication path 3b. It is also preferable to provide a connection path 3d that spatially connects the second through holes 3a provided with the communication path 3b and / or the second through holes 3a not provided with the communication path 3b (FIG. 8A). reference).

The ratio S ₁ / S ₀ between the cross-sectional area of the communication path 3b (the sum of these cross-sectional areas when there are two or more communication paths 3b) S ₁ and the total area S ₀ of the side surface of the second intervening layer 3 is , Greater than 0, preferably 0.002 or more. Further, it is preferably less than 0.3, more preferably less than 0.1, and still more preferably less than 0.05. When the ratio is 0.3 or more, the vaporized fuel is liable to leak and air is likely to be mixed, and the stability of power generation may be reduced.

  The material of the second intervening layer 3 can be a plastic material or a metal material as exemplified for the flow path plate 40, a non-porous carbon material, or the like. The thickness of the 2nd intervening layer 3 can be about 100-1000 micrometers, for example. In the present invention, the second intervening layer 3 can be omitted. However, in this case, instead of the second intervening layer 3, by increasing the internal pressure of the liquid fuel chamber 41, another discharge path for discharging the gas (bubbles) discharged from the liquid fuel chamber 41 to the outside of the fuel cell is formed. .

[Electrolyte membrane]
The electrolyte membrane 10 constituting the membrane electrode assembly 20 has a function of transmitting protons from the anode electrode 11 to the cathode electrode 12, and a function of maintaining electrical insulation between these electrodes and preventing a short circuit. The material of the electrolyte membrane 10 is not particularly limited as long as it is a material having proton conductivity and electrical insulation, and a polymer membrane, an inorganic membrane, or a composite membrane can be used. As the polymer membrane, for example, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Co., Ltd.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.), which is a perfluorosulfonic acid electrolyte membrane, etc. Can be mentioned. Also, styrene-based graft polymer, trifluorostyrene derivative copolymer, sulfonated polyarylene ether, sulfonated polyetheretherketone, sulfonated polyimide, sulfonated polybenzimidazole, phosphonated polybenzimidazole, sulfonated polyphosphazene. It is also possible to use a hydrocarbon-based electrolyte membrane such as.

  Examples of the inorganic film include films made of phosphate glass, cesium hydrogen sulfate, polytungstophosphoric acid, ammonium polyphosphate, and the like. Examples of the composite film include a composite film of an inorganic material such as tungstic acid, cesium hydrogen sulfate, and polytungstophosphoric acid and an organic material such as polyimide, polyetheretherketone, and perfluorosulfonic acid.

  The thickness of the electrolyte membrane 10 is, for example, 1 to 200 μm. The EW value (dry weight per mole of proton functional groups) of the electrolyte membrane 10 is preferably about 800 to 1100. The smaller the EW value, the lower the resistance of the electrolyte membrane 10 accompanying proton transfer, and a higher output can be obtained.

[Anode and cathode]
The anode electrode 11 laminated on one surface of the electrolyte membrane 10 and the cathode electrode 12 laminated on the other surface include a catalyst layer composed of a porous layer containing a catalyst and an electrolyte. The catalyst for the anode 11 catalyzes a reaction for generating protons and electrons from the fuel, and the electrolyte has a function of conducting the generated protons to the electrolyte membrane 10. The catalyst for the cathode 12 catalyzes a reaction for generating water from protons and oxidants that have been conducted through the electrolyte.

  The catalyst for the anode electrode 11 and the cathode electrode 12 may be supported on the surface of a conductor such as carbon or titanium, and in particular, a conductive material such as carbon or titanium having a hydrophilic functional group such as a hydroxyl group or a carboxyl group. It is preferably carried on the surface of the body. Thereby, the water retention of the anode 11 and the cathode 12 can be improved. The electrolyte of the anode electrode 11 and the cathode electrode 12 is preferably made of a material having an EW value smaller than the EW value of the electrolyte membrane 10. Specifically, the electrolyte material is the same material as the electrolyte membrane 10, but has an EW value. An electrolyte material having a thickness of 400 to 800 is preferred. By using such an electrolyte material, the water retention of the anode 11 and the cathode 12 can be improved. By improving the water retention of the anode electrode 11 and the cathode electrode 12, it is possible to improve the resistance of the electrolyte membrane 10 accompanying proton transfer and the potential distribution in the anode electrode 11 and the cathode electrode 12. In addition, since the electrolyte with a low EW value has a high liquid fuel permeability, vaporized fuel can be supplied more uniformly to the catalyst layer of the anode 11 by using an electrolyte with a low EW value. .

  The anode electrode 11 and the cathode electrode 12 may each include an anode conductive porous layer and a cathode conductive porous layer laminated on the catalyst layer. These conductive porous layers have a function of diffusing gas (vaporized fuel or oxidant) supplied to the anode electrode 11 and the cathode electrode 12 in the plane, and a function of exchanging electrons with the catalyst layer. . As the anode conductive porous layer and the cathode conductive porous layer, since the specific resistance is small and the decrease in voltage is suppressed, carbon materials; conductive polymers; noble metals such as Au, Pt, Pd; Ti, Porous materials made of transition metals such as Ta, W, Nb, Ni, Al, Cu, Ag, Zn; nitrides or carbides of these metals; and alloys containing these metals typified by stainless steel Is preferably used. When using metals with poor corrosion resistance in an acidic atmosphere, such as Cu, Ag, Zn, etc., noble metals with high corrosion resistance such as Au, Pt, Pd, conductive polymers, conductive nitrides, conductive Surface treatment (film formation) may be performed with carbide or conductive oxide.

  More specifically, as the anode conductive porous layer and the cathode conductive porous layer, for example, the above-mentioned noble metal, foam metal made of transition metal or alloy, metal fabric and metal sintered body; and carbon paper, carbon cloth, An epoxy resin film containing carbon particles can be suitably used.

[Anode current collecting layer and cathode current collecting layer]
The anode current collecting layer 21 and the cathode current collecting layer 22 are laminated on the anode electrode 11 and the cathode electrode 12, respectively, and constitute a unit cell 30 together with the membrane electrode assembly 20. The anode current collecting layer 21 and the cathode current collecting layer 22 each have a function of collecting electrons at the anode electrode 11 and the cathode electrode 12 and a function of performing electrical wiring.

  The material of the current collecting layer is preferably a metal because it has a small specific resistance and suppresses a decrease in voltage even when a current is taken in the plane direction. It is more preferable that the metal has corrosion resistance. Such metals include noble metals such as Au, Pt, Pd; transition metals such as Ti, Ta, W, Nb, Ni, Al, Cu, Ag, Zn; and nitrides or carbides of these metals; and And alloys containing these metals typified by stainless steel. When using metals with poor corrosion resistance in an acidic atmosphere, such as Cu, Ag, Zn, etc., noble metals with high corrosion resistance such as Au, Pt, Pd, conductive polymers, conductive nitrides, conductive Surface treatment (film formation) may be performed with carbide or conductive oxide. When the anode conductive porous layer and the cathode conductive porous layer are made of, for example, metal and the conductivity is relatively high, the anode current collecting layer and the cathode current collecting layer may be omitted.

More specifically, the anode current collecting layer 21 is a flat plate having a mesh shape or a punching metal shape made of the above metal material or the like having a plurality of openings penetrating in the thickness direction for inducing vaporized fuel to the anode electrode 11. Can be. This opening also functions as a discharge port for guiding a gas (such as CO ₂ gas) generated in the catalyst layer of the anode electrode 11 to the second through-hole 3 a of the second intervening layer 3. Similarly, the cathode current collecting layer 22 includes a mesh made of the above-described metal material or the like having a plurality of openings penetrating in the thickness direction for supplying an oxidizing agent (for example, air outside the fuel cell) to the catalyst layer of the cathode electrode 12. It can be a flat plate having a shape or a punching metal shape.

[Protective cover]
In the fuel cell 100 shown in FIG. 1, the protective cover 50 prevents the unit cell 30 from being directly exposed. A plurality of openings 51 are formed in the protective cover 50 immediately above the cathode electrode 12 so as to be able to take in air outside the fuel cell. The number of openings 51 is not particularly limited, and may be one or more. The protective cover 50 can be manufactured by using a plastic material or a metal material as exemplified for the flow path plate 40 and molding the protective cover 50 into an appropriate shape.

  The fuel cell of the present invention can be a polymer electrolyte fuel cell, a direct alcohol fuel cell, or the like, and is particularly suitable as a direct alcohol fuel cell (in particular, a direct methanol fuel cell). Examples of the liquid fuel that can be used in the fuel cell of the present invention include alcohols such as methanol and ethanol; acetals such as dimethoxymethane; carboxylic acids such as formic acid; esters such as methyl formate; An aqueous solution can be mentioned. The liquid fuel is not limited to one type, and may be a mixture of two or more types. Methanol or an aqueous methanol solution is preferably used from the viewpoints of low cost, high energy density per volume, high power generation efficiency, and the like.

(Modification)
The fuel cell of the present invention is not limited to the above-described embodiments and modifications, and includes, for example, the following modifications. The fuel cell of the present invention may have a configuration in which the unit cells 30 are disposed on both surfaces of the liquid fuel chamber 41. In this case, since the liquid fuel chamber 41 needs to be opened on both the upper and lower surfaces in order to supply fuel to the upper and lower two anode electrodes 11, a space with the upper and lower surfaces opened as the flow path plate 40. The member which has is used. According to the fuel cell in which the unit cells 30 are arranged on both surfaces of the liquid fuel chamber 41, since one flow path plate 40 is sufficient for two unit cells, the thickness of the fuel cell can be reduced, The output per unit volume of the fuel cell can be improved.

  Further, the fuel cell of the present invention may include two or more unit cells 30 arranged on the same plane. In this case, the liquid fuel chamber 41 may be provided for each unit cell 30 or may be provided in a number smaller than that of the unit cells 30.

  The fuel cell of the present invention can be suitably used as a power source for electronic devices, in particular, small electronic devices such as mobile devices such as mobile phones, electronic notebooks, and notebook computers.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
A fuel cell having a configuration similar to that shown in FIG. 1 (however, the protective cover 50 is not provided) was manufactured by the following procedure.

(1) Production of Membrane Electrode Composite Catalyst-supported carbon particles (TEC66E50, manufactured by Tanaka Kikinzoku Co., Ltd.) having a Pt loading amount of 32.5% by weight and a Ru loading amount of 16.9% by weight, and 20% by weight of Nafion as an electrolyte ( (Registered trademark) Alcohol solution (Aldrich), n-propanol, isopropanol, and zirconia balls are put into a fluororesin container at a predetermined ratio and mixed for 50 minutes at 500 rpm using a stirrer. By performing this, a catalyst paste for the anode electrode was prepared. Also, a catalyst paste for the cathode electrode was prepared in the same manner as the catalyst paste for the anode electrode except that catalyst-supporting carbon particles (TEC10E50E, manufactured by Tanaka Kikinzoku Co., Ltd.) having a Pt loading amount of 46.8% by weight were used.

Next, after cutting carbon paper (GDL25BC, manufactured by SGL) having a water-repellent porous layer on one side into a length of 35 mm and a width of 40 mm, the above-mentioned catalyst paste for anode electrode is formed on the porous layer. Is applied using a screen printing plate having a window with a length of 30 mm and a width of 35 mm so that the amount of the catalyst supported is about 3 mg / cm ^2, and then dried, so that the anode conductive porous layer is coated on the carbon paper. Thus, an anode electrode 11 having a thickness of about 400 μm, in which an anode catalyst layer was formed at the center, was prepared. Further, a screen printing plate having a window of 30 mm length and 35 mm width on the porous layer of carbon paper of the same size so that the catalyst loading amount of the above cathode electrode is about 1 mg / cm ^2. The cathode electrode 12 having a thickness of about 270 μm in which the cathode catalyst layer was formed at the center on the carbon paper, which is the cathode conductive porous layer, was prepared by applying and drying.

  Next, a perfluorosulfonic acid ion exchange membrane having a thickness of about 175 μm (Nafion (registered trademark) 117, manufactured by DuPont) was cut into a length of 35 mm and a width of 40 mm to form the electrolyte membrane 10, and the anode electrode 11 and the electrolyte membrane 10 After superposing the cathode electrodes 12 in this order so that the respective catalyst layers face the electrolyte membrane 10, thermocompression bonding is performed at 130 ° C. for 2 minutes to join the anode electrode 11 and the cathode electrode 12 to the electrolyte membrane 10. did. The superposition was performed so that the positions of the anode electrode 11 and the cathode electrode 12 in the plane of the electrolyte membrane 10 were matched, and the centers of the anode electrode 11, the electrolyte membrane 10 and the cathode electrode 12 were matched. Subsequently, the membrane electrode assembly 20 having a length of 22 mm and a width of 26 mm was produced by cutting the outer peripheral portion of the obtained laminate.

(2) Manufacture of unit cell A stainless steel plate (NSS445M2, manufactured by Nisshin Steel Co., Ltd.) having a length of 26.5 mm, a width of 27 mm, and a thickness of 100 μm is prepared. 2 stainless steel plates having a plurality of through-holes penetrating in the thickness direction are produced by processing a hole pattern: zigzag 60 ° pitch 0.8 mm) from both sides by wet etching using a photoresist mask. The anode current collecting layer 21 and the cathode current collecting layer 22 were used.

  Next, the anode current collecting layer 21 is laminated on the anode electrode 11 via a conductive adhesive layer made of carbon particles and an epoxy resin, and the cathode current collecting layer 22 is formed on the cathode electrode 12 with carbon particles. Are stacked via a conductive adhesive layer made of epoxy resin and bonded together by thermocompression bonding to produce a unit battery 30 having a length of 22 mm and a width of 26 mm (referring to the size of the membrane electrode assembly 20). did. The anode current collecting layer 21 and the cathode current collecting layer 22 were laminated so that the regions where the holes were formed were arranged immediately above the anode electrode 11 and the cathode electrode 12, respectively.

(3) Joining of Gas-Liquid Separation Layer, First Intervening Layer, and Second Intervening Layer As the gas-liquid separation layer 1, a porous film made of polytetrafluoroethylene having a length of 25 mm, a width of 27 mm, and a thickness of 0.2 mm (Nitto Denko) "Temish [TEMISH (registered trademark)] S-NTF2122A-S06") manufactured by KK was prepared. Further, as the first intervening layer 2, a thermoplastic resin film ("FB-ML4" manufactured by Nitto Shinko Co., Ltd.) having a length of 25 mm, a width of 27 mm, and a thickness of 0.07 mm was prepared. The first intervening layer 2 has the shape shown in FIG. 2, and the width and length of the four first through holes 2a are 1 mm and 20 mm, respectively. The 1st intervening layer 2 was laminated | stacked on the gas-liquid separation layer 1, and the layer boundary part of all the side surfaces was joined with the adhesive agent.

  Next, a second intervening layer 3 made of SUS having a shape shown in FIG. 4 and having a length of 26.5 mm, a width of 27.0 mm, and a thickness of 0.2 mm was produced by etching. The opening ratio of the second through-hole 3a is 77%, and the ratio of the cross-sectional area of the communication path 3b to the total area of the side surfaces of the second intervening layer is 0.005. The first intervening layer 2 is laminated on the surface of the second intervening layer 3 opposite to the groove forming surface, and these are joined by thermocompression bonding, so that the second intervening layer 3 / the first intervening layer 2 / the gas-liquid separation. A laminate of layer 1 was obtained.

(4) Fabrication of Fuel Cell A fuel plate 40 having a shape shown in FIG. 3 and having a length of 26.5 mm, a width of 27 mm, and a thickness of 0.6 mm was prepared. The five branched flow paths constituting the liquid fuel chamber 41 have a width of 1 mm, and in order to visually check the behavior of the gas mixed in or generated in the flow path, those penetrating in the depth direction were used. Although not shown, a laminate film prepared by coating a thermoplastic resin on one side having a length of 26.5 mm, a width of 27 mm, and a thickness of 0.1 mm was prepared. Since the laminate film becomes transparent after bonding, the inside of the flow path can be observed. First, the flow path plate 40 and the laminate film were joined by thermocompression bonding. Further, the gas-liquid separation layer 1 is joined to the surface opposite to the surface facing the laminate film of the flow path plate 40 (on the groove forming surface) by thermocompression bonding, so that the second intervening layer 3 / the first intervening layer 2 are joined. A gas / liquid separation layer 1 / channel plate 40 / laminate film laminate was obtained. In the second intervening layer 3, the distance from the region immediately above the branch flow path constituting the liquid fuel chamber 41 to the first through-hole 2 a is 1.75 mm.

  Next, after the unit battery 30 is joined to the second intervening layer 3 by thermocompression bonding, a sealing layer 60 made of a cured epoxy resin is formed on the end surface of the unit battery 30 or the like as shown in FIG. A fuel cell was obtained.

<Comparative Example 1>
A fuel cell was fabricated in the same manner as in Example 1 except that the first intervening layer 2 having the first through-hole 2a was used in the region immediately above the branch flow path constituting the liquid fuel chamber 41. The first intervening layer 2 used in this comparative example is the same as that used in Example 1 in terms of the outer shape and the shape of the first through-hole 2a, but the first through-hole 2a is a region immediately above the branch channel. It has five first through-holes 2a.

(Evaluation of liquid fuel barrier properties)
Using a liquid feed pump, an aqueous methanol solution having a methanol concentration of 12M or pure methanol (corresponding to a concentration of 24.7M) is supplied to the end portion 42 of the liquid fuel chamber 41 to increase the internal pressure of the liquid fuel chamber 41. The presence or absence of liquid leakage was measured. As a result, in the fuel cell of Example 1, when a methanol aqueous solution having a methanol concentration of 12 M was supplied, the cell temperature became approximately 30 ° C., and the internal pressure of the liquid fuel chamber 41 (that is, the discharge pressure of the liquid feed pump) was 35 kPa (apparatus Liquid leakage did not occur even when held above the measurement limit. When pure methanol was supplied, the battery temperature was about 50 ° C., and no liquid leakage occurred even when the internal pressure of the liquid fuel chamber 41 was maintained at 30 kPa, but liquid leakage was observed when the pressure was maintained at 35 kPa.

  In addition, regardless of whether a methanol aqueous solution having a methanol concentration of 12M or pure methanol is supplied, gas is discharged without remaining in the flow path when the internal pressure of the liquid fuel chamber 41 is maintained at 20 kPa and power is continuously generated. It was confirmed visually. The battery output was very stable.

  On the other hand, in the fuel cell of Comparative Example 1, when a methanol aqueous solution having a methanol concentration of 12M was supplied, the cell temperature was approximately 30 ° C., and no liquid leakage occurred even when the internal pressure of the liquid fuel chamber 41 was maintained at 30 kPa. Liquid leakage was observed when held at 35 kPa. When pure methanol was supplied, the battery temperature was about 50 ° C., and no liquid leakage occurred even when the internal pressure of the liquid fuel chamber 41 was maintained at 15 kPa, but liquid leakage was observed when the pressure was maintained at 20 kPa.

  In addition, when a methanol aqueous solution having a methanol concentration of 12M was supplied and the internal pressure of the liquid fuel chamber 41 was maintained at 20 kPa to continuously generate power, it was visually confirmed that gas was discharged without remaining in the flow path. However, when pure methanol was supplied and maintained at 15 kPa, which was the maximum internal pressure at which no liquid leakage occurred, it was visually confirmed that gas pools were scattered in the flow path and remained without being discharged. When degassing was insufficient, the gas pool gradually grew and eventually became a factor that hindered the supply of liquid fuel. As a result, it was confirmed that the fuel supply was not stable and the battery output gradually decreased.

  DESCRIPTION OF SYMBOLS 1 Gas-liquid separation layer, 2 1st intervening layer, 2a 1st through-hole, 3nd 2nd intervening layer, 3a 2nd through-hole, 3b communication path, 3c, 3d connection path, 10 electrolyte membrane, 11 anode pole, 12 cathode Electrode, 20 Membrane electrode composite, 21 Anode current collecting layer, 22 Cathode current collecting layer, 30 Unit cell, 40 Channel plate, 41 Liquid fuel chamber, 42 End of liquid fuel chamber, 50 Protective cover, 51 Opening, 60 Sealing layer, 65 gas outlet, 100 fuel cell.

Claims (6)

A unit cell having an anode electrode, an electrolyte membrane and a cathode electrode in this order;
A liquid fuel chamber ing from the anode electrode side is open space, and the liquid fuel chamber for or accommodated circulating a liquid fuel,
A gas-liquid separation layer disposed between the liquid fuel chamber and the anode electrode and capable of transmitting the vaporized fuel;
A first intervening layer disposed between the gas-liquid separation layer and the anode electrode and having a first through-hole penetrating in the thickness direction;
The gas-liquid separation layer is disposed so as to cover the opening of the space where the anode electrode side is open,
The gas-liquid separation layer is made of a porous material,
The first intervening layer is directly laminated on the surface of the gas-liquid separation layer,
The first through hole is a fuel cell disposed in a region different from a region immediately above the liquid fuel chamber in the first intervening layer.   The fuel cell according to claim 1, wherein the gas-liquid separation layer has higher permeability of the liquid fuel in a thickness direction than in an in-plane direction. A layer disposed between the first intervening layer and the anode electrode, the second through-hole penetrating in the thickness direction; provided at a peripheral edge of the layer; and the second through-hole and the outside of the layer the fuel cell according to claim 1 or 2 further comprising a second intermediate layer having a communicating path, the communicating and. The fuel is a fuel cell according to any one of claims 1 to 3 which is methanol or aqueous methanol. The method of using a fuel cell according to any one of claims 1 to 4 , wherein power generation is performed by supplying the fuel to the liquid fuel chamber using a liquid feed pump.
Use method wherein the discharge pressure of the liquid feed pump is 20 kPa or more. The method of using a fuel cell according to any one of claims 1 to 4 , wherein power generation is performed by supplying the fuel to the liquid fuel chamber using a liquid feed pump.
A method of use in which the fuel is continuously supplied to the liquid fuel chamber during power generation.

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