JP4222008B2 - Performance evaluation method and apparatus based on air permeability of fuel cell diffusion layer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a performance evaluation method and apparatus for evaluating the performance of a diffusion layer sandwiched between an electrode and a separator in various types of fuel cells.
[0002]
[Prior art]
For example, in a solid polymer electrolyte fuel cell, as shown in FIG. 8, an electrode (MEA: Membrane-Electrode Assembly) 3 comprising an electrolyte membrane 1 and electrode catalyst layers 2 and 2 applied to the front and back surfaces thereof is used. The electrode 3 is sandwiched by a separator 6 that forms a fluid flow path 5 for supplying a fuel gas (hydrogen) and an oxidizing gas (oxygen, usually air) through the diffusion layers 4 and 4 and is unit cell A. It is said. The electrolyte membrane 1 uses an ion exchange membrane such as a perfluorosulfonic acid membrane or a hydrocarbon-based membrane, in which a carbon powder carrying a catalyst substance (for example, Pt) and an electrolyte powder (fluorine functional resin, perfluorocarbon) are used. A mixture of sulfonic acid amide and the like is applied and formed as the electrode catalyst layer 2. The diffusion layer 4 is for efficiently diffusing the fuel gas and the oxidizing gas, and carbon cloth, carbon paper, or the like is used. Similar diffusion layers are formed not only in solid polymer electrolyte fuel cells but also in other forms of fuel cells.
[0003]
The mode in which the fuel gas or oxygen gas supplied to the fluid flow path 5 permeates through the diffusion layer 4 is roughly divided into a mode in which the region that is not pressed by the separator 6 of the diffusion layer 4 reaches the electrode catalyst layer 2 ( 8 (shown as F1), a mode of passing through the region pressed by the separator 6 of the diffusion layer 4 and reaching the electrode catalyst layer 2 (shown as F2 in FIG. 8), and pressing by the separator 6 of the diffusion layer 4 The mode is divided into three modes (shown as F3 in FIG. 8) that permeate the region that has been transmitted in the plane direction and flow out to the adjacent fluid passage 5.
[0004]
By the way, in order to increase the power generation efficiency of the fuel cell, it is necessary to objectively evaluate the performance of the electrodes and the like. For example, in Japanese Patent Laid-Open No. 2000-283951, as an evaluation test method for a gas diffusion electrode, an electrode test piece is held in a partially immersed state in an electrolyte solution, and the immersion part of the electrode test piece is changed over time. Describes a method for realizing a gas diffusion electrode simulated environment in such a manner that the electrode forms a three-phase interface at the boundary between the gas phase portion and the liquid layer portion. Japanese Patent Application Laid-Open No. 5-205762 discloses a characteristic evaluation apparatus that can press-clamp a unit cell of a phosphoric acid fuel cell, and evaluates the power generation characteristics and gas seal characteristics of the unit cell using the apparatus. Thus, defective unit cells are discriminated early.
[0005]
[Problems to be solved by the invention]
As described above, a fuel cell or a unit cell thereof is configured by organically combining a plurality of members such as an electrolyte membrane, an electrode catalyst layer, a diffusion layer, and a separator, and whether the discharge (power generation) performance is good or bad. In some cases, it may be caused by a combination state thereof, or may be caused by individual component members themselves. Conventionally performed fuel cell performance evaluation, as described in each of the above-mentioned publications, is usually performed on the basis of the unit cell after assembly, and whether the performance obtained as a test result is good or bad, It is not possible to clearly grasp which component causes the problem. If objective performance evaluation can be performed individually for each component member, the obtained data will be extremely effective for designing an efficient fuel cell (unit cell).
[0006]
The present invention has been made in view of the circumstances as described above, and attention is paid particularly to the diffusion layer among the individual members constituting the fuel cell so that the performance evaluation of the diffusion layer can be performed by the diffusion layer alone. An object of the present invention is to provide a performance evaluation method and an apparatus therefor.
[0007]
[Means for Solving the Problems]
By conducting many experiments and researches to solve the above problems, the present inventors have found that the ventilation performance of the fuel cell diffusion layer has a great influence on the quality of the discharge performance of the fuel cell (unit cell). Perceived. If the air permeability of each diffusion layer is objectively grasped, the data is extremely effective for assembling an efficient fuel cell (unit cell).
[0008]
The present invention is based on such perception, and the fuel cell diffusion layer performance evaluation method according to the present invention is a method in which the fuel cell diffusion layer is airtightly sandwiched by a measurement jig partially equipped with a deaeration hole. The gas diffusion performance of the diffusion layer is measured by supplying a constant flow of gas to the diffusion layer and measuring the change in the back pressure that occurs when a part of the supplied gas passes through the diffusion layer and escapes from the deaeration holes to the atmosphere. It is characterized by evaluating.
[0009]
Various materials such as carbon cloth and carbon paper are used for the diffusion layer, and the thickness varies depending on the power generation capacity. For many types of diffusion layers, if the ventilation performance is prepared as objective data under the same conditions by the above method, the data can be used very effectively when an actual unit cell is assembled.
[0010]
As described above, when the diffusion layer is incorporated in the unit cell, the fuel gas or the oxidant gas escapes from the one surface to the other surface (F1 and F2 in FIG. 8) and from one surface. A mode (F3 in FIG. 8) of moving in the entrance surface direction and exiting from the same surface may occur. The former mode is related to power generation, and the latter mode is not directly related to power generation and is counted as a loss. Obtaining three types of data for each diffusion layer is extremely effective for improving the material efficiency of the diffusion layer itself as well as improving the power generation efficiency.
[0011]
Therefore, in the method for evaluating the performance of the fuel cell diffusion layer according to the present invention, the change in the back pressure caused by the supplied gas permeating from one surface of the diffusion layer sandwiched by the measuring jig to the other surface and exiting to the atmosphere. Measure and evaluate the ventilation performance in the thickness direction of the diffusion layer (evaluation in the embodiment of F1 and F2), and in the surface direction in the diffusion layer in which the supplied gas is sandwiched by the measurement jig Measuring the change in the back pressure due to permeating through the atmosphere and evaluating the ventilation performance in the surface direction of the diffusion layer (evaluation in the aspect of F3) is a highly effective performance. It becomes an evaluation method.
[0012]
In an actual unit cell, the diffusion layer is sandwiched between the electrolyte layer having the electrode catalyst layer and the separator in a predetermined pressure state. A large number of fuel (air) channels are usually formed on the surface of the separator in contact with the diffusion layer. Therefore, it is also effective to construct an efficient fuel cell by ascertaining the ventilation performance of the diffusion layer under conditions that approximate the actual state in the unit cell.
[0013]
Therefore, in the method for evaluating the performance of the fuel cell diffusion layer according to the present invention, it is possible to evaluate the ventilation performance of the diffusion layer in a state where a predetermined pressure is applied to a part or all of the diffusion layer sandwiched by the measurement jig. This is a highly effective performance evaluation method. A concave groove corresponding to the gas flow path formed in the separator is formed on the surface of the measurement jig, and the sandwiched diffusion layer is pressurized via the measurement jig, so that a part of the diffusion layer is formed. It is possible to easily create a state in which a predetermined pressure is applied and no pressure is applied to other parts (concave grooves), and the above-described various ventilation performance tests can be performed.
[0014]
The present invention also provides, as an apparatus for carrying out the above method, a mounting means for mounting a fuel cell diffusion layer whose performance is to be evaluated, and a sandwiching mechanism for sandwiching the diffusion layer in cooperation with the mounting means. Means, an airtight holding means for airtightly holding the sandwiched diffusion layer, a gas supply means for supplying a gas of a predetermined pressure toward the airtightly sandwiched diffusion layer, and a part of the supplied gas A fuel cell diffusion layer comprising at least deaeration means for allowing passage through the sandwiched diffusion layer and allowing escape to the atmosphere, and means for measuring the back pressure of the supplied gas A performance evaluation device is also disclosed.
By using the above apparatus, it is possible to perform a uniform ventilation performance test on a diffusion layer test sample having various different physical property values.
[0015]
Preferably, in the above apparatus, either one or both of the placing means and the sandwiching means is detachable and replaceable with respect to the means for hermetically holding the sandwiched diffusion layer. In this aspect, a plurality of different forms of mounting means and / or clamping means are prepared, and these can be combined as appropriate for use in clamping the diffusion layer, so that more ventilation can be achieved using the same device. A test pattern can be implemented.
[0016]
In the above apparatus, either the mounting means or the clamping means may be provided with a gas supply means, and the other may be provided with a deaeration means. Alternatively, either the mounting means or the clamping means may be provided with a gas. You may make it provide both a supply means and a deaeration means. In the former form, it is possible to evaluate the ventilation performance in the direction from one surface of the sandwiched diffusion layer to the other surface, and in the latter aspect, the breathing performance in the surface direction of the sandwiched diffusion layer is evaluated. be able to. Which mode is adopted can be easily selected by attaching any form of mounting means and / or clamping means to the means for hermetically holding the sandwiched diffusion layer.
[0017]
In the above apparatus, preferably, a pressure applying means for applying a predetermined pressure to a part or all of the diffusion layer held between the placing means and the holding means is further provided. More preferably, a load cell is installed to measure the applied pressure. In order to apply a predetermined pressure to a part of the sandwiched diffusion layer, for example, a mounting means or a sandwiching means in which a concave groove corresponding to a gas flow path formed in the separator is formed on a surface in contact with the diffusion layer is used. Can implement it. By pressing the mounting means or the clamping means with an appropriate pressurizing means, a predetermined pressure is applied to a part of the sandwiched diffusion layer, and a pressure is applied to the other part (concave groove part). A state that is not done is created.
[0018]
In the present invention, the change in the back pressure may be measured over time while continuously supplying the gas. First, a constant flow rate of gas is supplied to make the gas pressurized. The supply may be stopped and subsequent changes in back pressure may be measured over time.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of an apparatus for carrying out a performance evaluation method based on the ventilation performance of a fuel cell diffusion layer according to the present invention, and FIG. 2 is a sectional view of the apparatus of FIG. FIG. 3 is an exploded view showing an example of each member such as mounting means and clamping means, which are the main parts of the present invention, and FIG. 4 is a cross-sectional view after the members shown in FIG. 3 are assembled. Is shown.
[0020]
In this example, an apparatus 10 according to the present invention has a base 11 and a support column 12 erected on the base 11, and members such as mounting means 20 as a measuring unit are attached to the base 11 so as to be assembled and disassembled. A pressurizing means 70 is attached to the column 12 so as to be movable in the vertical direction.
[0021]
The mounting means 20 includes a base block 21, a lower measurement block 30, and a hollow cylinder 40. The base block 21 has a bottomed hole 22 having a predetermined depth in the center, and the bottomed hole 22 is provided with a through hole 23 functioning as a gas introduction hole and a device (not shown) for measuring back pressure. One end of each through hole 24 is open. A concentric wall 25 is integrally formed so as to surround the bottomed hole 22, an O-ring 26 is mounted on the inner peripheral wall, and a screw 27 is cut on the outer peripheral surface. Further, a positioning projection 28 that enters the hole 12 provided in the base 11 is formed at the bottom.
[0022]
The lower measurement block 30 has a cylindrical shape as a whole, and a cylindrical hole 31 having a lower end opened is formed inside. The ceiling surface 32 of the cylindrical hole 31 and the upper end surface 33 of the lower measurement block 30 are communicated with each other by a plurality of holes 34 and an annular groove 35 connecting the upper ends of the holes 34. The outer diameter of the lower measurement block 30 is substantially the same as the inner diameter of the bottomed hole 22 of the base block 21, and a bulge placed on the top surface of the concentric wall 25 formed in the base block 21 in the vicinity of the lower end thereof. A portion 36 is formed.
[0023]
The hollow cylinder 40 is provided with a bottomed hole 41 whose upper side is open, and a positioning projection 42 is formed on the bottom portion so as to enter the hole 29 formed on the inner bottom surface of the base block 21. The outer diameter dimension of the hollow cylinder 40 is smaller than the inner diameter dimension of the cylindrical hole 31 of the lower measurement block 30, and a number of notches 43 are formed along the upper edge.
[0024]
In assembling, first, the base block 21 is placed on the base 11, and the hollow cylinder 40 is attached to the base block 21. From there, the lower measurement block 30 is placed. Thereby, the lower measurement block 30 is positioned in a state where the lower surface of the bulging portion 36 is placed on the upper end surface of the concentric wall 25 formed in the base block 21. In this state, the upper end surface of the hollow cylinder 40 is in contact with the outside of the plurality of holes 34 in the ceiling surface 32 of the lower measurement block 30.
[0025]
A mounting ring 45 is used to stably hold the state. The mounting ring 45 includes a cylindrical wall 47 formed with an internal thread 46 that meshes with a screw 27 formed on the outer peripheral surface of the concentric wall 25 formed in the base block 21, and an inward flange 48 formed integrally with the upper portion of the cylindrical wall 47. The upper surface of the bulging portion 36 is pressed against the inward flange 48 by screwing the screw 27 and the inner screw 46 together and screwing the mounting ring 45, so that the lower measurement block 30 is stable. Positioning is performed. Each member can be easily disassembled by releasing the screw engagement.
[0026]
The upper measurement block 50 is placed on the upper end surface 33 of the lower measurement block 30. The upper measurement block 50 is a cylindrical body having the same outer diameter as the lower measurement block 30. In the example shown in FIGS. 1 to 4, an annular concave groove 51 (51a) is formed on the bottom surface of the upper measurement block 50. Has been. The concave groove 51 (51 a) is concentric with the annular concave groove 35 formed on the upper end surface 33 of the lower measurement block 30 when the upper measurement block 50 is placed on the lower measurement block 30. Are formed so as not to overlap each other. In the illustrated example, the groove 51 (51a) is positioned outside the groove 35. The separation distance between the concave groove 51 (51a) and the concave groove 35, that is, the distance h between the outer peripheral line of the concave groove 35 and the inner peripheral line of the concave groove 51 (51a) is arbitrarily set. In the example shown in FIG. 4, two modes are shown in the same drawing, when the distance h is h1 (concave groove 51) and when it is h2 (> h1) (concave groove 51a).
[0027]
A plurality of vertical holes 52 (52a) are formed so as to communicate with the annular concave groove 51 (51a), and the upper ends of the vertical holes 52 (52a) are connected to the atmosphere via the horizontal holes 53 (53a). It is open to. Further, in the illustrated example, a concave portion 55 having a size in which the outer peripheral edge is positioned in the region of the concave groove 35 when formed on the lower measurement block 30 is formed on the bottom surface of the upper measurement block 50, Uniform circulation is ensured. Such a recessed portion 55 may be omitted.
[0028]
In order to prevent gas from flowing out from the contact surface between the lower measurement block 30 and the upper measurement block 50 arranged above and below, an airtight holding means 60 is used. The airtight holding means 60 has a cylindrical shape, and the inner peripheral diameter thereof is substantially the same as the outer peripheral diameters of the lower measurement block 30 and the upper measurement block 50. The inner circumferential surface is formed with concave grooves 61 and 61 in two upper and lower stages, and O-rings 62 and 62 are inserted therein. When the lower end surface of the cylindrical body is placed on the inward flange 48 of the mounting ring 45, the airtight holding means 60 is positioned, and in this state, the lower measurement block 30 and the upper measurement block are positioned between the upper and lower O-rings 62 and 62. An abutting surface with the block 50 is located. As a result, since the upper measurement block 50 is positioned with respect to the lower measurement block 30 by the cylindrical airtight holding means 60, an external guide or the like for the upper measurement block 50 is not required, and the structure is also improved. The advantage is that it can be simplified. In addition, assembly and disassembly becomes easy.
[0029]
The pressurizing means 70 attached to the column 12 may be any means as long as it can apply pressure to the upper measurement block 50 during the test, but here, in synchronization with the rotation of the handle 70a. A coil spring 73 is interposed between the first machine casing 71 that moves up and down and the second machine casing 72 that can move up and down regardless of the rotation of the handle 70a. The second machine casing 72 can move freely. A load cell 74 is attached to the lower end of the second machine casing 72.
[0030]
The usage mode of said apparatus 10 is demonstrated. As described above, the base block 21 is placed on the base 11, the hollow cylinder 40 is mounted in the base block 21, the lower measurement block 30 is covered from above, and then the mounting ring 45 is used. Integrate the whole. Then, a pressurized gas supply source (not shown) is connected to the through hole 23 formed in the base block 21, and a back pressure measuring device (not shown) is attached to the other through hole 24. A diffusion layer 100 whose performance is to be evaluated is disposed on the upper end surface 33 of the assembled lower measurement block 30. Preferably, the diffusion layer 100 is cut so as to match the shape of the upper end surface 33 of the lower measurement block 30.
[0031]
Before and after the arrangement of the diffusion layer 100, the airtight holding means 60 is press-fitted from above the lower measurement block 30 in an externally fitted state, and further, the upper measurement block 50 is placed in a state of being fitted inside the airtight holding means 60. It press-fits until it hits the diffused layer 100. Thereafter, the handle 70 a is operated to lower the pressurizing means 70, and the tip of the load cell 74 is brought into contact with the upper surface of the upper measurement block 50. Further, the upper measurement block 50 is gradually pushed down by operating the handle 70a. As a result, a required load is applied to the annular plane portion which is the distance (width) h (h1 or h2) between the outer peripheral line of the concave groove 35 and the inner peripheral line of the concave groove 51 (51a) of the diffusion layer 100. Will be applied. Although not shown, a desired surface pressure can be applied to the annular plane portion (evaluation region) of the diffusion layer 100 by displaying the load related to the diffusion layer 100 on an appropriate external monitor.
[0032]
A gas having a predetermined pressure is supplied from a pressurized gas supply source to a space S surrounded by the lower measurement block 30 and the upper measurement block 50. The space S is hermetically closed with the O-ring 26 and the O-rings 62 and 62, and has an annular groove 51 (51a), a vertical hole 52 (52a), and a horizontal hole 53 (53a) formed in the upper measurement block 50. ) Is merely communicated with the outside air as a deaeration hole. Between the annular groove 51 (51a) and the space S, there is an annular plane portion having the aforementioned width h (h1 or h2) of the diffusion layer 100 to be evaluated. Has a predetermined resistance. Only the gas that has permeated the annular flat portion against the resistance is released to the atmosphere.
[0033]
Accordingly, by supplying a certain amount of gas having a predetermined pressure from the pressurized gas supply source, a predetermined pressure is established in the space S, and the pressure is measured by the back pressure measuring instrument described above. And since a part of supplied gas permeate | transmits the said annular plane part of the diffusion layer 100, and is discharge | released to air | atmosphere, a back pressure changes according to permeation | transmission amount. By measuring the change in the back pressure, the ventilation performance of the diffusion layer 100 can be uniformly evaluated. 2 and 4, the annular groove 35 on the lower measurement block 30 side can be compared with the fluid passage 5 of the separator 6 in the actual cell, and the upper portion that presses the diffusion layer 100. The area portion having the width h of the measurement block 50 can be compared with the pressure contact portion between the fluid passages 5 and 5. Therefore, the embodiment shown in FIGS. 2 and 4 is equivalent to evaluating the gas permeation performance in the region corresponding to F2 shown in FIG. In addition, the width h1 is extremely narrow compared with the width h2, and in this case, the width h1 approximates the ventilation performance in the boundary region between the fluid passage 5 and the pressing portion (circled in FIG. 8). You can evaluate things.
[0034]
In the above apparatus and evaluation method, the hollow cylinder 40 is not necessarily required. It is possible to omit the evaluation. However, the diffusion layer 100 is often made of cloth, paper, or the like, and minute lint is likely to occur in the evaluation process. If lint or the like accumulates in the gas flow path, it adversely affects the measurement result of the back pressure measuring device. By disposing the hollow cylinder 40 as described above, lint and the like are housed therein, and it is possible to avoid affecting the gas flow path.
[0035]
FIG. 5 is a sectional view corresponding to FIG. 4 showing another embodiment of the present invention. Here, the upper measurement block 50A is different from those shown in FIGS. That is, in this upper measurement block 50A, an annular groove 51A formed on the bottom surface is formed on the upper end surface 33 of the lower measurement block 30 when the upper measurement block 50A is placed on the lower measurement block 30. It is formed so as to overlap with the annular groove 35. The annular concave groove 51A is open to the atmosphere through the vertical hole 52A and the horizontal hole 53A, and this aspect is the same as that shown in FIGS.
[0036]
In this embodiment, the gas in the annular groove 35 on the lower measurement block 30 side passes through the portion not receiving pressure by the upper measurement block 50A and flows into the annular groove 51A located on the opposite side, and the atmosphere To be released. This gas permeation performance is equivalent to the evaluation of the gas permeation performance in the region corresponding to F1 shown in FIG. In addition, the width h1 is extremely narrow compared with the width h2, and in this case, the width h1 approximates the ventilation performance in the boundary region between the fluid passage 5 and the pressing portion (circled in FIG. 8). You can evaluate things.
[0037]
FIG. 6 is a sectional view corresponding to FIG. 4 showing still another embodiment of the present invention. Here, both the lower measurement block 30B and the upper measurement block 50B are partially different from those shown in FIGS. That is, it is the same as that shown in FIGS. 2 and 4 in that a plurality of holes 34 and an annular groove 35 that connects the upper ends of the holes 34 are formed. A second annular concave groove 37 is formed concentrically on the outer side of the first annular concave groove 37, and the second annular concave groove 37 is open to the atmosphere through a hole 38. The second annular groove 37 and the hole 38 form a deaeration hole in the present invention. In the figure, reference numeral 69 denotes a notch formed in the airtight holding means 60 in order to open the hole 38 to the atmosphere. The upper measurement block 50B is only formed with the recess 55 in the upper measurement block 50 shown in FIGS. 2 and 4, and is not formed with a hole communicating with the outside.
[0038]
In this embodiment, when the upper measurement block 50B is placed and pushed down, in the region of the width h3 between the annular groove 35 and the second annular groove 37 formed concentrically on the outside thereof. The diffusion layer 100 to be evaluated is in a state of receiving a predetermined load. Then, the pressurized gas in the space S permeates through the concavely pressed region of the diffusion layer 100 from the concave groove 35 in the surface direction, reaches the second concave groove 37, and is released to the outside through the hole 38. . This gas permeation performance is equivalent to evaluating the gas permeation performance in the region corresponding to F3 shown in FIG. 8, and the gas leakage to the adjacent flow path can be evaluated.
[0039]
In the apparatus of the present invention, when the airtightness due to the two O-rings 62, 62 of the airtight holding means 60 is broken, the gas in the space S flows from the contact surface between the lower measurement block 30 and the upper measurement block 50. It will be released to the atmosphere and cannot be properly evaluated. FIG. 7 shows a mode of use when the airtightness of the airtight holding means 60 is checked. Here, as an alternative to the lower measurement block 30 and the upper measurement block 50, a tall test cylinder 90 having the same outer diameter as the lower measurement block 30 and the upper measurement block 50 is used. The cylindrical body 90 has a bulging portion 91 in the vicinity of the bottom portion, and has a void 92 having an open lower end inside. A large number of through holes 93 are formed in the peripheral wall portion to communicate the space 92 with the outside air. The test cylinder 90 is attached to the base block 21 using the attachment ring 45 in the same manner as the lower measurement block 30 described above. Then, the airtight holding means 60 is mounted so that the through hole 93 is positioned between the two O-rings 62 and 62. The state is shown in FIG. 7. In this state, the pressurized gas is poured into the void 92 in the same manner as in the evaluation of the diffusion film, and the change in the back pressure is observed. The airtight performance of 62 can be confirmed.
[0040]
【The invention's effect】
As described above, according to the present invention, the performance evaluation of the diffusion layer constituting the fuel cell, particularly the performance evaluation based on the ventilation performance can be performed by the diffusion layer alone. Further, the performance evaluation can be performed for the gas permeability in different modes generated in the actual diffusion layer in a state in which the performance evaluation is simulated in the actual operation state of the fuel cell.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of an apparatus for carrying out a performance evaluation method based on aeration performance of a fuel cell diffusion layer according to the present invention.
2 is a cross-sectional view of the apparatus of FIG.
FIG. 3 is an exploded view showing an example of each member such as mounting means and clamping means, which are the main part of the present invention.
4 is a cross-sectional view showing a state after the members shown in FIG. 3 are assembled. FIG.
FIG. 5 is a cross-sectional view corresponding to FIG. 4 showing another embodiment of the present invention.
6 is a cross-sectional view corresponding to FIG. 4, showing still another embodiment of the present invention.
FIG. 7 is a cross-sectional view showing a use mode when checking the airtightness of the airtight holding means.
FIG. 8 is a view for explaining an electrode composed of an electrolyte membrane and an electrode catalyst layer applied to the front and back surfaces thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Apparatus for enforcing the performance evaluation method by the ventilation | gas_flowing performance of the fuel cell diffusion layer by this invention, 11 ... Base, 12 ... Support | pillar, 20 ... Mounting means which is a measurement part, 70 ... Pressurizing means, 21 ... Base block, 22 ... bottomed hole, 23 ... through-hole functioning as a gas introduction hole, 24 ... through-hole for attaching a device for measuring back pressure, 25 ... concentric wall, 26 ... O-ring, 27 ... screw, 28 ... Positioning projections, 30 ... Lower measurement block, 31 ... Cylindrical hole, 32 ... Ceiling surface, 33 ... Upper end surface of the lower measurement block, 34 ... Multiple holes, 35 ... Annular groove, 36 ... Concentric wall A bulging portion placed on the top surface, 40 ... hollow cylinder, 41 ... bottomed hole, 42 ... positioning projection, 43 ... notch, 45 ... mounting ring, 46 ... internal thread, 47 ... cylindrical wall, 48 ... Inward flange, 50 ... Upper measurement block, 51 ... Circle Concave groove 52, multiple vertical holes, 53 horizontal holes, 55 concave portions, 60 airtight holding means, 61 concave grooves, 62 O-ring, 70 pressurizing means, 70a handle, 71 ... 1st machine casing, 72 ... 2nd machine casing, 73 ... Coil spring, 74 ... Load cell

Claims (9)

  The fuel cell diffusion layer is hermetically sandwiched by a measurement jig partially equipped with a deaeration hole, a constant flow of gas is supplied to the sandwiched diffusion layer, and part of the supplied gas passes through the diffusion layer. A method for evaluating the performance of a fuel cell diffusion layer, characterized in that the ventilation performance of the diffusion layer is evaluated by measuring a change in back pressure caused by escape from the deaeration hole to the atmosphere.   The change in back pressure caused by the supplied gas permeating from one surface of the diffusion layer sandwiched by the measurement jig to the other surface and exiting to the atmosphere is measured, and the ventilation performance in the thickness direction of the diffusion layer is measured. 2. The method for evaluating the performance of a fuel cell diffusion layer according to claim 1, wherein the evaluation is performed.   Measuring the back pressure change caused by the gas supplied through the diffusion layer sandwiched by the measurement jig in the surface direction and passing through the atmosphere, and evaluating the ventilation performance in the surface direction of the diffusion layer. The method for evaluating the performance of a fuel cell diffusion layer according to claim 1, wherein: 4. The ventilation performance of the diffusion layer is evaluated in a state where a predetermined clamping pressure by the measurement jig is applied to a part or all of the diffusion layer held by the measurement jig . The fuel cell diffusion layer performance evaluation method described.   Mounting means for mounting a fuel cell diffusion layer whose performance is to be evaluated, clamping means for clamping the diffusion layer in cooperation with the mounting means, airtight holding means for holding the sandwiched diffusion layer in an airtight manner, and airtightness Gas supply means for supplying a gas at a predetermined pressure toward the sandwiched diffusion layer, deaeration means for allowing a part of the supplied gas to pass through the sandwiched diffusion layer and escape to the atmosphere, and And a means for measuring the back pressure of the supplied gas, and a fuel cell diffusion layer performance evaluation apparatus.   6. The fuel cell diffusion according to claim 5, wherein either or both of the mounting means and the clamping means are detachable and replaceable with respect to the means for holding the sandwiched diffusion layer in an airtight manner. Layer performance evaluation device.   7. The fuel cell diffusion layer performance evaluation apparatus according to claim 5, wherein a gas supply means is provided in one of the mounting means and the clamping means, and a deaeration means is provided in the other.   7. The fuel cell diffusion layer performance evaluation apparatus according to claim 5, wherein either the mounting means or the clamping means is provided with both a gas supply means and a deaeration means. 6. A pressure applying means for applying a pressure of clamping by the mounting means and the clamping means to a part or all of the diffusion layer sandwiched between the mounting means and the clamping means. 8. The fuel cell diffusion layer performance evaluation apparatus according to any one of 8 above.

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