JP3991102B2 - Fuel cell - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention simplifies the fuel cell gas supply method, and has a gas flow path for supplying gas directly from the manifold to the gas diffusion layer without carving serpentine or a parallel flow gas flow path groove in the separator plate. The present invention relates to a gas diffusion electrode and a fuel cell using the same.
[0002]
[Prior art]
There are various types of fuel cells, such as solid electrolyte type, molten carbonate type, solid polymer type, alkali type, phosphoric acid type, direct type methanol fuel cell, etc., but fuel or air gas is used as an electrolyte plate or membrane. The principle of generating electricity by supplying the catalyst layers arranged on one side is common. In either case, a fuel cell stack is assembled by stacking a number of power generation units called single cells to achieve the required power. In the fuel cell stack, these single cells are each divided by a material called a separator.
In low temperature fuel cells such as solid polymer type, alkaline type, phosphoric acid type, and direct type methanol fuel cells, the separator is a plate made of carbon or a metal material, and these are anode cell electrodes of adjacent single cells. In addition to preventing air and air from mixing, it also serves as an electronic conductor for connecting the two cells in series. There is a unit of a single cell between the separator and the next separator, and the single cell includes a fuel gas diffusion layer, a fuel electrode catalyst layer, an electrolyte, an air electrode catalyst layer, and an air diffusion layer.
[0003]
FIG. 2 shows a gas flow path and a gas diffusion layer portion in a general conventional fuel cell. (A) is a bottom view of the separator of the fuel cell, (B) is a sectional view of the gas diffusion layer portion, and (C) is an exploded view of the main part of the gas diffusion layer portion. As shown in FIGS. 2 (A) and 2 (B), the separator 1 has a groove 2 through which gas flows, and the fuel gas or air supplied as shown in FIG. The fuel flows into the gas diffusion layer 3 while flowing through the gas, reaches each catalyst layer 4 provided between the gas diffusion layer 3 and the electrolyte layer 5 (for example, polymer electrolyte), and reacts. Battery reaction occurs. In addition, although the groove | channel of the separator meandered in (A), in (C), it simplified and showed with the straight line. Reference numeral 5 denotes an electrolyte layer, and a similar catalyst layer, gas diffusion layer, groove, and separator exist on the opposite side. In such a flow path configuration, a groove provided with a gas supplied to the separator and a gas diffusion layer (carbon paper, carbon cloth, etc.) in which the gas naturally diffuses toward the catalyst layer are arranged adjacent to each other. Since each of them is provided separately, the space of the fuel cell stack is bulky, which causes a decrease in energy density (the number of kW per unit volume or unit weight).
[0004]
Furthermore, in order to process and engrave the groove 2 in which gas flows (the serpentine-shaped groove called serpentine or the one-sided groove called parallel flow path) is formed on the surface of the plate 1 serving as a separator. One separator requires a thickness of at least about 3 mm. For this reason, not only the space of the fuel cell stack is increased, but also the cost of materials and the poor yield required for processing have become main causes of high fuel cell costs.
[0005]
In the prior art in which a serpentine channel or a parallel channel is cut into a separator, the gas is diffused into the gas diffusion layer while gas passes through the channel from the inlet to the outlet, so that the catalyst layer is replenished. However, in this case, for example, when water vapor generated in the air electrode is condensed in the gas diffusion layer, the diffusion of oxygen gas is inhibited in that portion, and a portion where current does not flow is generated, leading to a decrease in the output of the fuel cell. . In order to improve this, a new flow channel method called Interdigitated flow field has been proposed in which the flow channel cut into the separator is stopped and the gas is forcibly sent to the adjacent flow channel through the diffusion layer (for example, non-patent literature) 1).
[0006]
[Non-Patent Document 1]
W. He, J. S. Yi, and T. V. Nguyen, AIChE
Journal, 46, No. 10, 2053-2064 (2000)
[0007]
[Problems to be solved by the invention]
An object of the present invention is to overcome such problems of an increase in the space of a conventional fuel cell stack, an increase in cost due to processing work, and a poor yield.
[0008]
[Means for Solving the Problems]
The present invention intends to fundamentally change the configuration method of such a fuel cell. That is, the gas supply method is not performed via the gas flow path 2 carved in the separator 1, but is directly supplied to the gas diffusion layer from the lateral direction (thickness direction). Therefore, the fuel cell space can be made smaller and more compact by stopping the separator to the minimum thickness. In addition, it has the merit of reducing the processing cost and greatly reducing the cost of the fuel cell. As a further important effect, improvement in gas diffusivity can be expected. In the present invention, since gas is supplied into the gas diffusion layer from the beginning, it has a great effect in preventing gas retention due to the water vapor condensation.
[0009]
As a result of examining various possibilities for the gas flow path configuration method of the fuel cell, the present inventors have provided a structure for supplying gas directly to the gas diffusion layer, and when the fuel electrode and the air electrode are respectively used, the battery is made compact. It was found that can be realized. Here, in order to supply gas to the gas diffusion layer, the gas diffusion layer is formed by combining a number of similar figures on a plane. By dividing the gas diffusion layer in this way and providing each of the divided gas diffusion layers with a gas supply port and a gas discharge port in the thickness direction (from the side surface), the fuel electrode and the air electrode reaction layer of the fuel cell are planarized. Is to be divided. Since the figure divided in this way is a similar shape, the size can be designed finely in any number of steps (hereinafter, the flow channel according to the present invention may be called a fractal flow channel). In addition, the present inventors have found that if the figure is large, non-uniformity may occur in the current density and the like, but it is possible to achieve uniformity by making it fine. The present invention has been made based on these findings.
[0010]
  That is, the present invention
(1) Separator sheet that does not cut through the serpentine or parallel flow gas flow path and does not supply gas via the gas flow path carved into the separatorA fuel cell and an air electrode by disposing a fuel gas diffusion layer, a fuel electrode catalyst layer, an electrolyte membrane, an air electrode catalyst layer, and an air diffusion layer between the separator sheet and the same separator sheet In a fuel cell consisting of
A porous material layer is provided as the fuel gas diffusion layer and the air diffusion layer constituting the fuel electrode and the air electrode, respectively, and the porous material layer is divided and separated into units of similar shapes. In addition, there is a gap as a gas outflow groove between the similar shapes, and each similar shape unit has a gas supply port and a gas discharge port for fuel or air, respectively. Gas introduced from the gas flow path of fuel or air in the vertical direction with respect to the layerLateralFrom the gas supply portIn the porous material layerDirectly from the sideSupply・Inflow into the porous material layerPhaseIn units of similar shapeSaidgasThediffusionLetFrom the similar unitleakgasTheThe gapWhatOutflowDischarge from the gas outlet,Gas diffusion electrodeUsedA fuel cell, characterized by
(2) The fuel cell according to (1), wherein the shape of the similar shape is a triangle, a quadrangle, a rhombus, or a trapezoid.
(3) The fuel cell according to (1) or (2), wherein the fuel cell is a polymer electrolyte fuel cell,
(4) The fuel cell according to any one of (1) to (3), wherein the porous material layer is a carbon material or a metal felt.
(5) The fuel cell according to any one of (1) to (4), wherein the porosity of the porous material of the porous material layer is 50 to 95%,
(6) The fuel cell according to any one of (1) to (5), wherein liquid fuel is supplied instead of fuel gas.
(7) Separator sheet that does not cut through the serpentine or parallel flow gas flow path and does not supply gas via the gas flow path carved into the separatorA fuel cell and an air electrode by disposing a fuel gas diffusion layer, a fuel electrode catalyst layer, an electrolyte membrane, an air electrode catalyst layer, and an air diffusion layer between the separator sheet and the same separator sheet A porous material layer is provided as the fuel gas diffusion layer and the air diffusion layer that constitute the fuel electrode and the air electrode, respectively. The planar shape is divided / separated into similar shape units, and there is a gap as a gas outflow groove from the porous material layer between the similar shapes, and the fuel supply or air gas supply port for each similar shape unit. And gas introduced from a gas flow path of fuel or air in the vertical direction to the fuel or air gas diffusion layer.LateralFrom the gas supply portIn the porous material layerDirectly from the sideSupply・Inflow into the porous material layerPhaseIn units of similar shapeSaidgasThediffusionLetFrom the similar unitleakgasTheThe gapWhatOutflowAnd discharge from the gas outletA gas diffusion electrode, characterized by
(8) The gas diffusion electrode according to (7), wherein the shape of the similar shape is a triangle, a quadrangle, a rhombus, or a trapezoid, and
(9) The porosity of the porous material of the porous material layer is 50 to 95% as described in (7) or (8)gasDiffusion electrode
Is to provide.
  In the present invention, preferably, a gas supply port and an exhaust port penetrating through the fuel cell stack in which single cells are stacked are provided for each of the similar shapes, and the fuel gas diffusion layer and air diffusion of the single cell which is a unit of the stack. The fuel cell according to any one of (1) to (6), wherein the gas supply port and the discharge port are separately connected to a layer.I will provide a.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In a preferred embodiment of the present invention, a specific configuration of the fuel cell gas flow path will be described with reference to the drawings.
FIG. 1 illustrates a gas flow path (fractal flow path) in a fuel cell employing the present invention, and is a configuration example in the case where the similar shape is an isosceles right triangle.
In FIG. 1, reference numeral 11 denotes a separator, and it is sufficient to simply separate the gas (fuel gas and air) in contact with each other. Therefore, the separator 11 may be composed of a sheet of carbon, metal, or conductive material having a thickness of 1 mm or less. Is possible. Reference numeral 13 denotes a porous carbon material (carbon paper, carbon cloth, etc.) or a metal felt which becomes a gas diffusion layer. Gas flows into this portion from the lateral inlet inlet portion 13a and flows out from the outlet outlet 13b. To do. In addition, this portion can constitute the electrode surface of the entire fuel cell unit cell by combining similar figures (in this case, triangles 13c and 13d) that divide the plane, with the gaps 16 provided one after another. 14 is a catalyst layer, 15 is an electrolyte (plate or membrane), and the opposite side is similarly composed of a catalyst layer, a gas diffusion layer, and a separator. Gas supply to the gas diffusion layer 13 is performed from a gas flow path 17 (see FIG. 1B) provided on the side surface.
[0012]
Here, the 13 gas diffusion layers do not need to overlap each other on the opposite side of the electrolyte. In some cases, it may be desirable to configure similar figures so that the current density on the single cell electrode surface is uniform. In addition, it is also desirable that the size of the similar shape is successively fined as shown in FIG. 3 so that the current density becomes uniform. In that case, it is necessary to arrange the gas supply port and the exhaust port for each of these similar shapes. This is because the gas supply port and the exhaust port penetrating the fuel cell stack are provided for each similar shape, and the unit of the stack is used. This can be solved by separately connecting to the fuel gas diffusion layer and the air diffusion layer of a single cell. In FIG. 3, (A) and (B) are examples in which the gas diffusion layer is divided into 8 parts, and (C) and (D) are examples in which the gas diffusion layer is divided into 32 parts. (A) and (C) are fuel gas diffusion layers, and (B) and (D) are air diffusion layers as viewed from above. Actually, they are three-dimensionally overlapping, but they are drawn side by side for convenience of explanation. In (A) to (D), the white circle 21 indicates a gas inlet, and the black circle 22 indicates a gas outlet. Reference numeral 23 denotes a gap provided in the dividing portion, which forms a gas outflow groove. In the figure, arrows indicate the inflow of gas. The black line portion 24 is a boundary that separates the similar shapes.
[0013]
  FIG. 4 shows a configuration example in the case where the similar shape is a quadrangle in a similar gas flow path. It is expected that the uniformity of the current density is improved as compared with the case of the triangle. 4A to 4D show an example in which the fractal channel is divided into quadrangles, where (A) and (B) are divided into two, and (C) and (D) are divided into four. In the figure, gas flows from 31 to the gas diffusion layer, and gas flows out from 32. Reference numeral 33 denotes a partition.
  FIG. 5 is an explanatory view of a gas diffusion layer having further different division modes. As shown in this figure, the similar shape is a hexagon.Formed by dividing, Regular triangles (FIG. 5A), diamonds (FIG. 5B), and trapezoids (FIG. 5C).
  The size of the similar figure is preferably 0.5 cm to 10 cm on a side, but in order to facilitate the creation and maintain the uniformity of the current density, it may be composed of 1 cm to 3 cm. More preferred.
[0014]
Specific examples of the porous material used as the material for the gas diffusion layer include carbon materials such as carbon paper and carbon cloth, preferably those having a porosity of 50% to 95% and a thickness of 50 μm to 1 mm. More preferably, a porous metal felt having a porosity of 70% to 90% and a thickness of 90 μm to 500 μm is used as long as it satisfies the object of the present invention. Can also be used.
[0015]
The size of the gas supply port and exhaust port that penetrates the fuel cell stack connected to the gas supply unit or the discharge unit can be selected as appropriate, but minimizes the unused electrode area while minimizing the gas pressure loss. In order to suppress it, it is preferably designed to be 1 mm to 15 mm, more preferably 2 mm to 5 mm.
As the separator material, a carbon sheet having a thickness of 0.05 mm to 5 mm, more preferably 0.2 mm to 1 mm, or a metal foil or plate having no electrical conductivity but having electrical conductivity can be used. .
The direction in which the fuel gas and air flow is preferably determined as appropriate while looking at the temperature distribution, reactant and product distribution, and current density distribution.
[0016]
The boundary for separating the divided similar shapes is that a frame made of polymer material, rubber, carbon or metal material that can block gas is used, and then a similar shape made of carbon paper or carbon cloth is used between the frames. By embedding, one gas diffusion layer can be formed. Alternatively, after making a gas diffusion layer with carbon paper or carbon cloth first, leave similar parts while embedding adhesive or thermosetting resin at the boundary, and finally solidify By doing so, the target gas diffusion layer can be formed.
[0017]
Next, the structure of the manifold for guiding the fuel gas or air to each single cell when manufacturing the fuel cell stack will be described. For example, as shown in an enlarged view in FIG. 6, a gas supply method that penetrates the stack in a direction perpendicular to the surface of the stacked unit cell electrodes and distributes in the plane direction of the gas diffusion layer at the position of the fuel electrode or the air electrode. Can be adopted as appropriate. At that time, it is desirable to provide a gas supply port and a discharge port for each of the divided similar shapes, but they may be made common at the adjacent portions. FIG. 6 schematically shows an embodiment of this fuel cell, in which 41 is a separator, 42 is a fuel electrode gas diffusion layer, 43 is an electrolyte, 44 is an air electrode gas diffusion layer, 45 is a fuel electrode catalyst layer, 46 is It is an air electrode catalyst layer. A predetermined number of combination units are stacked in the fuel cell. 47 is a flow pipe for the fuel gas 48, and allows the fuel gas 48a to flow into the fuel electrode gas diffusion layer through a through hole (not shown) provided in the side portion. On the other hand, 49 is a flow tube for the air electrode gas 50, and air 50a is supplied into the air electrode gas diffusion layer from a through hole (not shown) provided in the side portion. In FIG. 6, the fuel electrode gas diffusion layer 42 and the air electrode gas diffusion layer 44 exist for the explanation of the gas flow, but are only indicated by a one-dot chain line.
[0018]
In the fuel cell stack shown in FIG. 6, the manifold is first attached to each of the separator, the gas diffusion layer, and the membrane electrode assembly (one in which the electrolyte membrane, the fuel electrode, and the air electrode catalyst layer are integrated) in each single cell. After the fabrication, it can be completed by stacking the stacks one by one so that the holes are aligned.
Alternatively, without providing holes from the beginning, the separator, gas diffusion layer, and membrane electrode assembly in each single cell are stacked to form a stack, and then a manifold is formed by penetrating the holes perpendicular to the electrode surface. can do.
[0019]
【Example】
Next, embodiments of the present invention will be described in more detail with reference to the drawings.
Example 1
According to the design shown in FIG. 3, an isosceles right triangle unit that is formed when a white porous body having a side of 33 mm (Millipore membrane filter) is divided into 2 parts, 4 parts, and 8 parts in a similar shape with an isosceles right triangle. The colored liquid was infiltrated from one apex to the bottom on the opposite side, and the time when the liquid reached the bottom was measured. At that time, there are two types of cases, namely, the case of penetration from the apex of 45 ° and the case of penetration from the apex of 90 °, and they will be referred to as 45 ° mode and 90 ° mode, respectively.
[0020]
FIG. 7 shows the time required for fluid diffusion according to the inflow direction of the fluid such as gas and the number of divisions obtained by visualization with the white porous body and the colored liquid. The permeation was uniform and the diffusion was not biased anywhere. In addition, as for the 45 ° mode and the 90 ° mode, as the number of divisions increases, the time required for diffusion naturally decreases, but the reciprocal of the number of divisions and the time required for diffusion have a substantially proportional relationship. That is, when the area is doubled, the time required for diffusion is also doubled. On the other hand, looking at the diffusion time in the inflow mode, it can be seen that the time required for diffusion is shorter in the 90 ° mode than in the 45 ° mode.
[0021]
Example 2
Using the apparatus shown in FIG. 8, oxygen gas from the 45 ° apex of the unit made of carbon paper 81 (made by Toray International Co., Ltd.) cut into an isosceles right triangle with a side of 25 mm toward the bottom on the opposite side 82 was passed at a constant flow rate, and the pressure loss generated between the gas inlet and outlet at that time was measured using a differential pressure gauge. In the figure, (A) is a front view, and (B) is a diagram for explaining the gas flow in the oxygen gas diffusion layer corresponding to (A). In FIG. 8B, 81a is a gas inlet and 81b is a gas outlet, and gas is introduced from the side of the oxygen gas diffusion layer 81 as shown in FIG. 8A.
[0022]
Thickness 0.35mm, bulk density 0.49g / cm^ThreeFIG. 9 shows the relationship between pressure loss and gas flow rate measured when the length of one side of an isosceles right triangle is variously changed in Toray carbon paper TPG-H-120 (trade name) having a porosity of 76%. Show. If the length of one side is 12.5 mm and the single cell is divided into two, the case where the length of one side is 6.25 mm corresponds to eight divisions. When the same current is taken out, the oxygen gas flow rate per unit is 1/4 in 8 divisions compared to the case of 2 divisions. However, if integrated into the same area, the gas flow rate will be the same.
[0023]
Example 3
Similarly to Example 2, using the apparatus shown in FIG. 8, carbon paper (TPG-H-120 (trade name, manufactured by Toray International Co., Ltd.) cut into a rectangle having a width of 40 mm, a gas passage distance of 50 mm, 30 mm, and 10 mm. )), Oxygen gas was passed at a constant flow rate from one side to the bottom of the opposite side, and the pressure loss generated between the gas inlet and outlet at that time was measured using a differential pressure system.
The results are shown in FIG. 10 as the relationship between pressure loss and gas flow rate. In the case of the rectangle, the relationship of the pressure loss almost proportional to the gas passing distance was obtained. Compared to the 45 ° mode triangle of Example 2, it can be seen that the difference in pressure loss due to the gas passage distance is more apparent. This is shown in FIG. 11 as the relationship between gas passage distance and pressure loss.
[0024]
Example 4
Using the apparatus shown in FIG. 8, 45 ° mode and 90 ° mode for a unit composed of carbon paper (made by Toray International, thickness 0.37 mm) cut into an isosceles right triangle with a side of 50 mm Then, oxygen gas was passed at a constant flow rate from the top of the triangle toward the bottom of the opposite side, and the pressure loss generated between the gas inlet and outlet at that time was measured using a differential pressure system.
At that time, the bulk density and porosity of the carbon paper are 0.45 g / cm.^ThreeAnd 78% and 0.32 g / cm^Three12A and 12B show the relationship between the pressure loss and the gas flow rate measured at 84% and 84%. As a result, it was found that the pressure loss in the 45 ° mode was approximately twice that of the 90 ° mode. In the case of triangular carbon paper, the resistance at the introduction portion to the gas diffusion layer is the largest, but the cross-sectional area of that portion is half that of the 90 ° mode in the 45 ° mode. The loss is thought to have increased.
[0025]
Example 5
Carbon paper with a thickness of 0.38 mm is used to form fractal channels consisting of two 90 ° -mode isosceles right triangles as shown in FIG. 1 on both sides of the Nafion 115 membrane (thickness: about 130 μm). A 25 mm square membrane / electrode assembly was constructed. At this time, 20 wt% Pt / C Vulcan XC-72 (manufactured by ElectroChem Co., Ltd., trade name) catalyst is used for the catalyst layer on the fuel electrode side and the air electrode side, respectively, with a platinum amount of 1 mg / cm.²It carried so that it might become. Using this membrane / electrode assembly, a single cell power generation test was conducted at 50 ° C., and current / voltage and output density were measured. In addition, hydrogen gas humidified at 70 ° C. is used as the fuel gas, and oxygen gas humidified at 70 ° C. is used as the air electrode gas.^Three/ Min.
Power density per electrode area obtained in the fractal flow path 0.067W / cm²Is converted to per unit cell volume with a separator thickness of 0.2 mm, 0.067 W / cm²÷ 0.11cm = 0.61W / cm^Threewas gotten.
[0026]
On the other hand, for comparison, carbon paper having a thickness of 0.19 mm is used so that a normal gas flow path (serpentine flow path) as shown in FIG. 2 is formed on both sides of the Nafion 115 film (thickness: about 130 μm). A 23 mm square membrane / electrode assembly was constructed. At this time, 20 wt% Pt / C Vulcan XC-72 catalyst was added to the catalyst layer on the fuel electrode side and the air electrode side, respectively, with a platinum amount of 1 mg / cm.²It carried so that it might become. Using this membrane / electrode assembly, a single cell power generation test was performed under the same conditions as described above, and current / voltage and output density were tested.
Power density per electrode area obtained in the serpentine channel 0.1 W / cm²Is converted into per unit cell volume with a separator thickness of 3 mm, 0.1 W / cm²÷ 0.35cm = 0.29W / cm^Threewas gotten. Thus, compared with Example 5 of the present invention using the fractal flow path, the output density per unit cell of the fuel cell is lower than half in the normal flow path, so the fractal flow path is only the material cost of the fuel cell. It was also shown that energy density has an advantage.
[0027]
【The invention's effect】
As described above, the present invention is intended to fundamentally change the configuration method of the fuel cell, and as a gas supply method, it is not performed through the gas flow path engraved in the separator as in the prior art. The gas diffusion layer is directly supplied from the lateral direction (thickness direction).
That is, the fuel cell of the present invention can be designed compactly, and has an excellent effect of reducing the processing cost and greatly reducing the cost of the fuel cell. Furthermore, since the fuel cell of the present invention is forcibly supplied to the gas diffusion layer, it has an excellent effect of preventing gas retention due to water vapor condensation occurring at the air electrode and improving the output.
Further, the gas diffusion electrode of the present invention is divided into a structure in which a number of similar figures are combined on a plane, and uniformity can be realized by supplying gas directly to each of the divided shapes. The output of the fuel cell can be improved. Moreover, since it is divided into similar shapes, it is possible to design the fuel cell in a small size in steps and to design a compact fuel cell.
[Brief description of the drawings]
1A is a plan view of a gas diffusion layer, FIG. 1B is a front view of a main part of a constituent unit of a fuel cell, and FIG. 1C is a constituent unit of a fuel cell. It is an exploded view of the principal part.
2A is a plan view of a separator, FIG. 2B is a front view of a main part of a constituent unit of a fuel cell, and FIG. 2C is a main part of a constituent unit of the fuel cell. FIG.
FIGS. 3A and 3B are explanatory diagrams showing fractal channel division, in which FIGS. 3A and 3B are examples of 8 divisions, and FIGS. 3C and 3D are examples of 32 divisions. FIGS.
FIGS. 4A and 4B are explanatory diagrams showing rectangular fractal channel division, in which FIGS. 4A and 4B are examples of two divisions, and FIGS. 4C and 4D are examples of four divisions. FIGS.
FIG. 5 shows a configuration of a fractal channel derived from a hexagon, in which (A) is an equilateral triangle, (B) is a rhombus, and (C) is a trapezoid.
FIG. 6 is a perspective view showing the flow of a fuel cell stack and fuel gas or air.
FIG. 7 is a graph showing the relationship between the number of divisions of the fractal flow path and the diffusion speed of the colored fluid into the white porous body.
8A and 8B are schematic views of a pressure loss measuring device, in which FIG. 8A is a front view and FIG. 8B is an explanatory diagram showing a state of gas diffusion in a gas diffusion layer in this device.
FIG. 9 is a graph showing the relationship between the pressure loss in TGP-H-120 45 ° mode and the length of one side of the carbon paper.
FIG. 10 is a graph showing a relationship between pressure loss and gas flow rate of a TGP-H-120 rectangular type.
FIG. 11 is a graph showing the relationship between gas passage distance and pressure loss (TGP-H-120, 150 sccm).
FIG. 12 shows the result of a comparison test between 45 ° mode and 90 ° mode in pressure loss-gas flow rate, (A) TGP-H-120 (porosity 78%), paper area 12.5 cm²(B) TGP-H-120 gas permeability improved product (void ratio 84%), paper area 12.5 cm²It is.
[Explanation of symbols]
11 Separator
13 Gas diffusion layer (porous carbon material)
13a Inlet
13b outlet
14 Catalyst layer
15 Electrolyte (plate or membrane)
16, 23 Air gap
17 Gas flow path
21, 31 Gas inlet
22, 32 Gas outlet
24, 33 border
41 separator
42 Fuel electrode gas diffusion layer
43 electrolyte
44 Air electrode gas diffusion layer
45 Fuel electrode catalyst layer
46 Air electrode catalyst layer
47 Fuel gas distribution pipe
48 Fuel gas
49 Air electrode gas distribution pipe
50 cathode gas

Claims (9)

A fuel gas diffusion layer between a separator sheet that does not cut through a serpentine or parallel flow gas passage, and that does not supply gas via a gas passage engraved in the separator, and a separator sheet similar to this separator sheet In a fuel cell comprising a unit of a single cell in which a fuel electrode catalyst layer, an electrolyte membrane, an air electrode catalyst layer, an air diffusion layer are arranged to form a fuel electrode and an air electrode,
A porous material layer is provided as the fuel gas diffusion layer and the air diffusion layer constituting the fuel electrode and the air electrode, respectively, and the porous material layer is divided and separated into units of similar shapes. In addition, there is a gap as a gas outflow groove between the similar shapes, and each similar shape unit has a gas supply port and a gas discharge port for fuel or air, respectively. to the layer, the gas introduced from the vertical direction of the fuel or the gas flow path of the air, by directly supplying and flowing from the lateral side to the porous material layer from the gas supply port of the lateral side of the gas diffusion layer wherein the porous material layer at the phase Nigata unit by diffusing the gas, the gas flowing out of said phase Nigata units, drained into the gap, is discharged from the gas discharge port, for using the gas diffusion electrode A fuel cell.   2. The fuel cell according to claim 1, wherein the shape of the similar shape is a triangle, a quadrangle, a rhombus, or a trapezoid.   The fuel cell according to claim 1 or 2, wherein the fuel cell is a polymer electrolyte fuel cell.   The fuel cell according to any one of claims 1 to 3, wherein the porous material layer is a carbon material or a metal felt.   The fuel cell according to any one of claims 1 to 4, wherein a porosity of the porous material of the porous material layer is 50 to 95%.   6. The fuel cell according to claim 1, wherein liquid fuel is supplied instead of the fuel gas. A fuel gas diffusion layer between a separator sheet that does not cut through a serpentine or parallel flow gas passage, and that does not supply gas via a gas passage engraved in the separator, and a separator sheet similar to this separator sheet A fuel electrode catalyst layer, an electrolyte membrane, an air electrode catalyst layer, and an air diffusion layer, which are used for a fuel cell comprising a single cell unit in which a fuel electrode and an air electrode are formed. A porous material layer is provided as the fuel gas diffusion layer and the air diffusion layer constituting each of the poles, and the porous material layer is divided and separated into units of similar shapes. Each of which has a gas supply port and a gas discharge port for each of the similar units, and each of the similar shape units has a gap as a gas outflow groove from the porous material layer. Respect of the gas diffusion layer, the gas introduced from the vertical direction of the fuel or the gas flow path of the air, directly supply and from the lateral side to the porous material layer from the gas supply port of the lateral side of the gas diffusion layer allowed to flow by diffusing said gas porous material layer in the phase Nigata units, the gas flowing out of said phase Nigata units, drained into the gap, characterized in that it discharged from the gas outlet gas Diffusion electrode.   The gas diffusion electrode according to claim 7, wherein the shape of the similar shape is a triangle, a quadrangle, a rhombus, or a trapezoid. The gas diffusion electrode according to claim 7 or 8, wherein the porosity of the porous material in the porous material layer is 50 to 95%.

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