JP2008218153A - Hydrogen separation membrane type fuel cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain degradation of a hydrogen separation membrane type fuel cell due to exfoliation of a hydrogen separation membrane and an electrolyte membrane. <P>SOLUTION: A hydrogen separation membrane base material 11f is made curved in a convex shape toward a polished face side PS by polishing that side alone. An electrolyte membrane 10 and a cathode electrode layer 12 are film-formed at a convex face side of the hydrogen separation membrane base material 11f. As a membrane electrode assembly 14A is pinched by non-curved flat separators 20, 21, a curvature of the membrane electrode assembly 14A is reduced to have tensile stress generated at the electrolyte membrane 10 in a membrane face direction. Therefore, compression stress toward a membrane face direction is restrained from occurring at the electrolyte membrane 10, and exfoliation of the electrolyte membrane 10 from the hydrogen separation membrane base material 11f can be restrained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a hydrogen separation membrane fuel cell.

  Among fuel cells, there is a hydrogen separation membrane fuel cell in which only hydrogen from a hydrogen-containing gas is supplied to an electrolyte by disposing a hydrogen separation membrane that selectively permeates hydrogen on the anode electrode layer side. As a method for manufacturing a hydrogen separation membrane fuel cell, a method of forming an electrolyte membrane on the surface of a hydrogen separation membrane substrate is known (Patent Document 1, etc.).

JP2006-12467

  By the way, in the manufacturing process of such a hydrogen separation membrane type fuel cell, the curvature of the hydrogen separation membrane substrate may change in the assembly process to the fuel cell after the formation of the electrolyte membrane. In this case, the present invention shows that the compressive stress is generated in the electrolyte membrane, and the fuel cell is more likely to be deteriorated due to the compressive stress, such as peeling of the electrolyte membrane from the hydrogen separation membrane substrate. Found. However, the reality is that until now there has not been enough contrivance for these problems.

  An object of this invention is to provide the technique which suppresses deterioration of the hydrogen separation membrane type fuel cell by peeling of a hydrogen separation membrane and an electrolyte membrane.

A method according to an aspect of the present invention is a method for manufacturing a fuel cell, the method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) curving the hydrogen separation membrane substrate;
(C) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the concave surface of the hydrogen separation membrane substrate;
(D) A step of assembling the hydrogen separation membrane / electrolyte membrane assembly to a fuel cell.

  According to this method, since the possibility that compressive stress is generated in the electrolyte membrane due to deformation of the hydrogen separation membrane / electrolyte membrane assembly can be reduced in the step after the formation of the electrolyte membrane, the hydrogen separation membrane substrate and the electrolyte membrane The possibility of peeling with can be reduced. Therefore, deterioration of the hydrogen separation membrane fuel cell due to the separation of the hydrogen separation membrane and the electrolyte membrane can be suppressed.

  The step (b) may include a step of bending the surface of the hydrogen separation membrane by polishing.

  According to this method, the hydrogen separation membrane substrate can be easily bent so that the hydrogen separation membrane material has a concave surface by polishing. Therefore, the possibility of peeling between the hydrogen separation membrane substrate and the electrolyte membrane can be further reduced.

  The step (d) may include a step of assembling the fuel cell with the hydrogen separation membrane / electrolyte membrane assembly deformed so as to reduce the curvature of the hydrogen separation membrane / electrolyte membrane assembly.

  According to this method, the compressive stress generated in the surface direction of the electrolyte membrane can be reduced by reducing the curvature of the hydrogen separation membrane / electrolyte membrane assembly. Therefore, the possibility of peeling between the hydrogen separation membrane substrate and the electrolyte membrane can be further reduced.

  The step (d) may include a step of assembling the hydrogen separation membrane / electrolyte membrane assembly in a fuel cell in a curved state without changing the curvature of the hydrogen separation membrane / electrolyte membrane assembly. good.

  According to this method, it is possible to reduce the possibility that compressive stress is generated in the direction of the membrane surface of the electrolyte membrane in the assembly process of the fuel cell. Further, when the hydrogen separation membrane is thermally expanded during the power generation of the fuel cell, the curved hydrogen separation membrane / electrolyte membrane assembly is further curved in the deflection direction. Therefore, the tensile stress acting in the film forming surface direction generated in the electrolyte membrane due to the thermal expansion of the hydrogen separation membrane is reduced by the force acting in the deflection direction. Therefore, the possibility of peeling between the hydrogen separation membrane substrate and the electrolyte membrane can be further reduced.

A method according to another aspect of the present invention is a method of manufacturing a fuel cell, the method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) curving the hydrogen separation membrane substrate;
(C) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the convex surface of the hydrogen separation membrane substrate;
(D) a step of assembling the hydrogen separation membrane / electrolyte membrane assembly in a fuel cell in a curved state without changing the curvature of the hydrogen separation membrane / electrolyte membrane assembly.

  According to this method, it is possible to reduce the possibility that compressive stress is generated in the direction of the membrane surface of the electrolyte membrane in the assembly process of the fuel cell. Therefore, the possibility of peeling between the hydrogen separation membrane substrate and the electrolyte membrane can be reduced.

  In the above method, the step (b) may include a step of bending the surface of the hydrogen separation membrane by polishing.

  According to this method, since the hydrogen separation membrane substrate can be easily curved so that the hydrogen separation membrane material has a convex surface, the possibility of separation from the electrolyte membrane can be easily reduced. In addition, since the electrolyte membrane is formed on the surface whose surface smoothness has been improved by polishing, the electrolyte membrane can be satisfactorily formed. Therefore, it is possible to reduce the possibility of a short circuit occurring during power generation.

A method according to still another aspect of the present invention is a method for manufacturing a fuel cell, the method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) polishing one surface of the hydrogen separation membrane substrate;
(C) curving the hydrogen separation membrane substrate to reduce the curvature of the hydrogen separation membrane substrate;
(D) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the hydrogen separation membrane substrate;
(E) a step of assembling the hydrogen separation membrane / electrolyte membrane assembly to a fuel cell.

  According to this method, even when the hydrogen separation membrane substrate is curved by the polishing process, the curvature of the hydrogen separation membrane substrate can be reduced before the electrolyte membrane is formed. Therefore, it is possible to reduce the compressive stress generated in the direction of the membrane surface of the electrolyte membrane due to deformation processing of the hydrogen separation membrane substrate in the process after the formation of the electrolyte membrane, thereby reducing the possibility of separation of the hydrogen separation membrane substrate and the electrolyte membrane. it can.

  The step (c) may include a step of reducing the curvature of the hydrogen separation membrane substrate by polishing the surface of the hydrogen separation membrane substrate that has not been polished in the step (b).

  According to this method, the curvature of the hydrogen separation membrane substrate can be easily reduced by two polishing steps. Therefore, the possibility of peeling between the hydrogen separation membrane substrate and the electrolyte membrane can be reduced. Moreover, since the surface smoothness of both surfaces of the hydrogen separation membrane substrate is improved by the polishing process, the electrolyte membrane can be formed satisfactorily, and the possibility that a short circuit occurs during power generation can be reduced.

  The present invention can be realized in various forms, for example, in the form of a fuel cell, a fuel cell system including the fuel cell, a vehicle equipped with the fuel cell system, and the like. .

A. Overall configuration of hydrogen separation membrane:
FIG. 1 is a schematic cross-sectional view for explaining the outline of a hydrogen separation membrane fuel cell. The hydrogen separation membrane fuel cell 100 includes a membrane electrode assembly 14 and two separators 20 and 21 sandwiching the membrane electrode assembly 14. The membrane electrode assembly 14 includes an electrolyte membrane 10 and a hydrogen separation anode electrode layer 11 and a cathode electrode layer 12 that sandwich the electrolyte membrane 10. Normally, a hydrogen separation membrane fuel cell stack in which the hydrogen separation membrane fuel cells 100 are stacked is configured.

The electrolyte membrane 10 is a thin film that exhibits good proton conductivity in a wet state. As the material of the electrolyte membrane 10, for example, “SrZr _0.8 In _0.2 O ₃ ”, “SrZrO ₃ ”, “BaCeO ₃ ”, and “SrCeO ₃ ” ceramic proton conductors can be used.

  The hydrogen separation anode electrode layer 11 includes a hydrogen separation membrane 11f that is a thin film that can selectively permeate hydrogen. The hydrogen separation membrane 11f is made of, for example, palladium (Pd) or a Pd alloy. The hydrogen separation membrane 11f may be provided with a plate-like support member (for example, stainless steel) provided with a plurality of through holes through which the supplied hydrogen-containing gas passes, on the outer surface not in contact with the electrolyte membrane. . In the present specification, among the constituent elements included in the membrane electrode assembly 14, the one in which the hydrogen separation membrane 11 f and the electrolyte membrane 10 are joined is particularly referred to as a “hydrogen separation membrane / electrolyte membrane assembly 13”.

The cathode electrode layer 12 is a layer formed on the electrolyte membrane 10 by a metal or ceramic material. As a material of the cathode electrode layer 12, for example, “LaSrCoO ₃ ” can be adopted. The cathode electrode layer 12 may be provided with an electrode catalyst layer that supports platinum (Pt) or the like.

  The cathode separator 20 is disposed in contact with the cathode electrode layer 12. A plurality of grooves (cathode gas flow paths CP) for supplying an oxygen-containing gas to the cathode electrode layer 12 are provided on the surface of the cathode separator 20 on the cathode electrode layer 12 side. The anode separator 21 is disposed in contact with the hydrogen separation membrane 11f. A plurality of grooves (anode gas flow paths AP) for supplying a hydrogen-containing gas to the hydrogen separation membrane 11f are provided on the surface of the anode separator 21 on the side in contact with the hydrogen separation membrane 11f.

  The two separators 20 and 21 have a function of collecting electricity generated by an electrochemical reaction between hydrogen and oxygen in the hydrogen separation membrane fuel cell 100. The two separators 20 and 21 can be formed of a conductive material such as carbon or metal. The separator may have other configurations. For example, the separator may be a multilayer separator in which a plurality of plates are combined, or may be a separator provided with a refrigerant flow path for cooling the fuel cell.

B. Comparative example:
2 to 3 are explanatory diagrams for explaining a manufacturing process of a hydrogen separation membrane fuel cell as a comparative example, and will be described in the order of the processes with reference to these drawings. The configuration and materials of the hydrogen separation membrane fuel cell are substantially the same as those of the hydrogen separation membrane fuel cell 100 described above, and differences will be described as appropriate.

  FIG. 2A is a schematic cross-sectional view showing a cross section of the hydrogen separation membrane substrate 11f. As the first step, the hydrogen separation membrane substrate 11f constituting the hydrogen separation type anode electrode layer described above is prepared. In this comparative example, a substantially square palladium plate (purity 99.95%) having a thickness of about 1 μm and a vertical and horizontal dimension of about 17 mm is prepared as the hydrogen separation membrane substrate 11f.

  FIG. 2B is an explanatory diagram for explaining a polishing process of the hydrogen separation membrane substrate 11f as the second process. In general, when the surface of the hydrogen separation membrane substrate has a low smoothness, an electrolyte membrane having an undesirable film formation state, such as having micro holes, may be formed in the electrolyte membrane formation step described later. In a fuel cell having such an electrolyte membrane, there is a tendency that a short circuit is likely to occur during power generation. Therefore, in this comparative example, the smoothness of the polished surface is improved by polishing one surface of the hydrogen separation membrane substrate 11f.

  In this comparative example, polishing is performed using a diamond slurry. In addition, after the polishing step, it is preferable to clean the surface of the hydrogen separation membrane substrate 11f by sequentially performing electrolytic cleaning, alkaline detergent ultrasonic cleaning, isopropyl alcohol (IPA) cleaning, and water cleaning. The polishing method and the cleaning method may be other methods.

  In this polishing step, only the polishing surface PS shown in the drawing is extended in the polishing direction (the arrow direction in the drawing), so that the hydrogen separation membrane substrate 11f is curved. For example, the hydrogen separation membrane substrate 11f may be curved until the deflection margin fd is about 0.5 μm to 1 mm.

  FIG. 2C is an explanatory diagram for explaining a step of forming the electrolyte membrane 10 and the cathode electrode layer 12 on the polishing surface PS of the hydrogen separation membrane substrate 11f as the third step. In this third step, the electrolyte membrane 10 is formed so as to uniformly cover the polishing surface PS of the hydrogen separation membrane substrate 11f. As a result, a hydrogen separation membrane / electrolyte membrane assembly 13a is formed. Further, after the electrolyte membrane 10 is formed, the cathode electrode layer 12 is formed on the surface of the electrolyte membrane 10. Thereby, the membrane electrode assembly 14a is formed. As can be understood from the above description, the membrane electrode assembly 14a of this comparative example has a shape curved convexly toward the cathode electrode layer 12 side.

  As a method for forming the electrolyte membrane 10 and the cathode electrode layer 12, a pulsed laser deposition (PLD) method can be employed. In this comparative example, after the hydrogen separation membrane substrate 11f is placed in a vacuum and heated up to 600 degrees, film formation is performed in an environment where the partial pressure of oxygen is about 0.01 torr. In this comparative example, the electrolyte membrane 10 is formed with a thickness of about 1 μm, and the cathode electrode layer 12 is formed with a thickness of about 25 nm.

  FIGS. 3A and 3B are explanatory views for explaining a process of assembling the hydrogen separation membrane fuel cell 100a by sandwiching the membrane electrode assembly 14a between the two separators 20 and 21 as the fourth process. is there. The two separators 20, 21 are flat members that are not curved. Therefore, when the curved membrane electrode assembly 14a is sandwiched between the separators 20 and 21 from both sides (FIG. 3A), the membrane electrode assembly 14a is pressed by the separators 20 and 21 to reduce its curvature (FIG. 3 (B)). Then, a compressive stress is generated in the electrolyte membrane 10 in the direction of arrow C in the figure due to the reduced curvature.

  As described above, in the hydrogen separation membrane fuel cell 100a according to the manufacturing process of the comparative example, a compressive stress is generated inside the electrolyte membrane 10. Below, based on the manufacturing method of this comparative example, the manufacturing method of the hydrogen separation membrane type fuel cell as an Example which applied the present invention is explained.

C. First embodiment:
4-5 is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane type fuel cell as a 1st Example of this invention. 4 to 5 are substantially the same as FIGS. 2 to 3 described in the comparative example except for the points described below.

  FIG. 4A is a schematic cross-sectional view showing a cross section of the hydrogen separation membrane substrate 11f, which is the same as FIG. 2A. A flat hydrogen separation membrane substrate 11f is prepared as the first step of this embodiment. The surface of the hydrogen separation membrane substrate 11f preferably has a predetermined smoothness.

  FIG. 4B is an explanatory diagram for explaining a step of bending the hydrogen separation membrane substrate 11f as the second step of the present embodiment, and is substantially the same as FIG. 2B. Here, “curving” refers to processing and deforming a flat plate-like member into a substantially tile shape or a substantially mortar shape so as to have a curvature. In addition, the bending step includes a step in which the hydrogen separation membrane substrate 11f is bent in a step that is not intended to bend the hydrogen separation membrane substrate 11f as in the polishing step of the comparative example. In the present embodiment, the hydrogen separation membrane substrate 11f is bent by the same polishing process as in the comparative example. In addition, this curve process is good also as what curves 11 f of hydrogen separation membrane base materials by press work etc.

  FIG. 4C is an explanatory diagram for explaining a step of forming the electrolyte membrane 10 and the cathode electrode layer 12 on the polishing surface PS of the hydrogen separation membrane substrate 11f as the third step of the present embodiment. FIG. 4C is the same as FIG. 2C except that the surface on which the film is formed is different. That is, in this embodiment, the electrolyte membrane 10 and the cathode electrode layer 12 are formed on the concave surface DS (surface opposite to the polishing surface PS) of the hydrogen separation membrane substrate 11f. Therefore, the hydrogen separation membrane / electrolyte membrane assembly 13A and the membrane electrode assembly 14A of the present example have a shape curved convexly toward the hydrogen separation membrane substrate 11f.

  5 (A) and 5 (B) are explanatory views for explaining a process of assembling the hydrogen separation membrane fuel cell 100A by sandwiching the membrane electrode assembly 14a between the separators 20 and 21 as the fourth process of this embodiment. FIG. FIGS. 5A and 5B are the same as FIGS. 3A and 3B except that the membrane electrode assembly 14A of this example is used instead of the membrane electrode assembly 14a of the comparative example. It is almost the same.

  In this embodiment, as in the comparative example, the separators 20 and 21 are flat members that are not curved. Therefore, when the curved membrane electrode assembly 14A is sandwiched between the separators 20 and 21 (FIG. 5A), Similar to the comparative example, the curvature of the membrane electrode assembly 14A is reduced (FIG. 5B). However, unlike the membrane electrode assembly 14a of the comparative example, the membrane electrode assembly 14A of this example is curved so that the cathode electrode layer 12 side is concave. Therefore, a tensile stress in the direction of arrow T in the figure is generated inside the electrolyte membrane 10 of the hydrogen separation membrane fuel cell 100A of the present embodiment due to the reduced curvature of the membrane electrode assembly 14A.

  FIG. 6 is a table showing results of power generation evaluation of the hydrogen separation membrane fuel cell 100a manufactured by the manufacturing method of the comparative example and the hydrogen separation membrane fuel cell 100A manufactured by the manufacturing method of the present embodiment. . Specifically, in the power generation evaluation, hydrogen and air humidified with 40 ° C. water were supplied to the hydrogen separation membrane fuel cells 100a and 100A of the comparative example and this example, respectively, on the anode electrode side and the cathode electrode side. This was done by generating electricity. In addition, the evaluation result of the hydrogen separation membrane fuel cell 100A of this example is an average value of the results of performing power generation evaluation three times for the same lot. On the other hand, the evaluation result of the hydrogen separation membrane fuel cell 100a of the comparative example is an average value of the results of the power generation evaluation for each of the five lots.

As shown in this table, the average current amount of the hydrogen separation membrane fuel cell 100A of this embodiment is 0.75 A / cm ² , and the average current amount of the hydrogen separation membrane fuel cell 100a of the comparative example is 0.67 A. / Cm ² . The standard deviation of the evaluation result of the hydrogen separation membrane fuel cell 100A of the present example is 0.04 A / cm ² , and the standard deviation of the evaluation result of the hydrogen separation membrane fuel cell 100a of the comparative example is 0.38 A / cm ^2. cm ² . That is, the hydrogen separation membrane fuel cell 100A of this example has improved power generation efficiency and reduced variations in power generation performance compared to the hydrogen separation membrane fuel cell 100a of the comparative example.

  After power generation under the above conditions, the state of the hydrogen separation membrane / electrolyte membrane assembly 13A, 13a of each of the hydrogen separation membrane fuel cells 100A, 100a of this example and the comparative example was examined. In the hydrogen separation membrane fuel cell 100a, it was found that the hydrogen separation membrane substrate 11f and the electrolyte membrane 10 were separated at a probability of 20%.

  Considering these results, in the hydrogen separation membrane fuel cell 100a of the comparative example, since the compressive stress is generated in the electrolyte membrane 10 as described above, the separation between the electrolyte membrane 10 and the hydrogen separation membrane substrate 11f occurs. It can be inferred that it occurred. Further, it can be presumed that the hydrogen separation membrane fuel cell 100a of the comparative example has a decrease in power generation efficiency and a variation in power generation performance due to the compressive stress.

  In the manufacturing method of the comparative example, compressive stress acting in the film surface direction was generated on the electrolyte membrane 10 in the step after the formation of the electrolyte membrane 10, but in this example, the tensile stress was applied to the electrolyte membrane 10. Is generated. Therefore, according to the manufacturing method of the present embodiment, the possibility of separation between the hydrogen separation membrane substrate and the electrolyte membrane is reduced, and the power generation efficiency of the hydrogen separation membrane fuel cell is improved and the variation in power generation performance is reduced. Can be reduced.

D. Second embodiment:
A method for producing a hydrogen separation membrane fuel cell will be described as a second embodiment of the present invention. Since the first to third steps of the second embodiment are the same as the first to third steps (FIGS. 4A to 4C) of the first embodiment, description thereof will be omitted. That is, in the second embodiment, the same membrane electrode assembly 14A as in the first embodiment is manufactured and used.

  7A and 7B are diagrams for explaining a process of assembling the membrane electrode assembly 14A as a hydrogen separation membrane fuel cell 100B by sandwiching the membrane electrode assembly 14A between the separators 20a and 21a as a fourth process of the second embodiment. It is explanatory drawing. FIGS. 7A and 7B are the same as FIGS. 5A and 5B described in the first embodiment except that separators 20a and 21a having different shapes are used instead of the separators 20 and 21. FIG. Is almost the same.

  The separators 20a and 21a of the second embodiment are curved flat plate members. Specifically, the cathode separator 20a is curved in a convex shape on the side where the cathode gas channel CP is provided. The anode separator 21a is curved in a concave shape on the side where the anode gas flow path AP is provided. The two separators 20a and 21a preferably have substantially the same curvature as the membrane electrode assembly 14A, that is, have approximately the same deflection margin.

  With such a configuration, the membrane electrode assembly 14A in which the cathode electrode layer 12 side is curved in a concave shape is sandwiched between the similarly curved separators 20a and 21a (FIG. 7A). The change in curvature is suppressed (FIG. 7B). That is, in the electrolyte membrane 10 of the hydrogen separation membrane fuel cell 100A of the second embodiment, the generation of internal stress due to the change in the curvature of the membrane electrode assembly 14A is suppressed. Therefore, the hydrogen separation membrane fuel cell 100B manufactured by the manufacturing method of the second embodiment is separated from the hydrogen separation membrane substrate 11f and the electrolyte membrane 10 as compared with the hydrogen separation membrane fuel cell 100a of the comparative example. Is suppressed, power generation efficiency is improved, and variation in power generation performance is also reduced.

  Further, according to the configuration of the second embodiment, the following effects can be obtained. In general, in a fuel cell, during power generation, the temperature closer to the center of the power generation unit tends to be higher due to the reaction heat. In addition, the hydrogen separation membrane substrate 11 f has a higher thermal expansion coefficient than the electrolyte membrane 10. That is, in the hydrogen separation membrane fuel cell, it can be said that stress is more likely to be generated in the electrolyte membrane at a site closer to the center of the power generation unit during power generation. However, as in the second embodiment, if the hydrogen separation membrane fuel cell itself bends due to its curvature, even if the hydrogen separation membrane substrate is thermally expanded by power generation, hydrogen separation is performed in the direction of the deflection. The membrane fuel cell itself will bend further. Therefore, especially in the vicinity of the center of the power generation unit, the tensile stress acting in the surface direction of the electrolyte membrane is dispersed and reduced. Therefore, the possibility of peeling between the electrolyte membrane and the hydrogen separation membrane substrate is further reduced.

  This effect is also obtained when the hydrogen separation membrane expands due to hydrogen elongation. Here, “hydrogen elongation” refers to a phenomenon in which the hydrogen separation membrane expands in a direction perpendicular to the direction of hydrogen movement when the hydrogen separation membrane fuel cell is used.

E. Third embodiment:
FIG. 8 is an explanatory diagram for explaining a manufacturing process of a hydrogen separation membrane fuel cell as a third embodiment of the present invention. Since the 1st process-the 3rd process of the 3rd example are the same as the 1st process-the 3rd process (Drawing 2 (A)-(C)) of a comparative example, explanation is omitted. That is, in the third embodiment, the same membrane electrode assembly 14a as in the comparative example is manufactured and used.

  8A and 8B are diagrams for explaining a process of assembling the hydrogen separation membrane fuel cell 100B by sandwiching the membrane electrode assembly 14a between the separators 20b and 21b as the fourth process of the third embodiment. It is explanatory drawing. 8A and 8B are substantially the same as FIGS. 3A and 3B described in the comparative example except that separators 20b and 21b having different shapes are used instead of the separators 20 and 21. The same.

  As can be understood by comparing FIG. 8 and FIG. 7, the third embodiment is obtained by reversing the direction of the curve from the second embodiment. Also in the third embodiment, the generation of internal stress due to the change in the curvature of the membrane electrode assembly 14B is suppressed, and the same effect as in the second embodiment described above can be obtained. Further, in the third embodiment, the electrolyte membrane 10 is formed on the surface whose surface smoothness has been improved by the polishing process. Therefore, since the film formation state of the electrolyte membrane 10 is better than that of the second embodiment, the possibility of a short circuit occurring during power generation is reduced.

F. Fourth embodiment:
FIGS. 9A to 9D are explanatory views for explaining the manufacturing process of the hydrogen separation membrane fuel cell as the fourth embodiment of the present invention. Since the first step (FIG. 9A) of the fourth embodiment is the same as the first step (FIG. 2A) of the first embodiment, description thereof is omitted. In the fourth embodiment, two bending processes shown in FIGS. 9B and 9C are performed as the bending process of the hydrogen separation membrane substrate 11f.

  In the first bending step shown in FIG. 9B, a polishing step similar to that in the first embodiment is executed (first polishing step). The surface polished by the first polishing step is referred to as “first polished surface PS1”. In the second bending step shown in FIG. 9C, the hydrogen separation membrane substrate 11f is bent in the first step (FIG. 9) by bending the hydrogen separation membrane substrate 11f contrary to the first bending step. The plate is returned to the uncurved plate shape similar to (A)). Specifically, for example, a polishing step similar to the first polishing step may be performed on the surface opposite to the first polishing surface PS1 (second polishing step). The surface polished by the second polishing step is referred to as “second polishing surface PS2”. As the second bending step, in addition to the second polishing step, for example, a step of returning the hydrogen separation membrane substrate 11f to a non-curved state by rolling or the like may be executed.

  FIG. 9D is an explanation for explaining a step of forming the electrolyte membrane 10 and the cathode electrode layer 12 on the first polishing surface PS1 of the hydrogen separation membrane substrate 11f as the third step of the fourth embodiment. FIG. The electrolyte membrane 10 is formed on the first polishing surface PS1 of the hydrogen separation membrane substrate 11f to form a hydrogen separation membrane / electrolyte membrane assembly 13C. A cathode electrode layer 12 is further formed on the outer surface of the electrolyte membrane 10 of the hydrogen separation membrane / electrolyte membrane assembly 13C to form a membrane electrode assembly 14C. When the second bending process is performed by the second polishing process, the electrolyte membrane 10 and the cathode electrode layer 12 may be formed on the second polishing surface PS2.

  The membrane electrode assembly 14C manufactured in this way is bent by being sandwiched by the non-curved flat separators 20 and 21 (FIGS. 5A and 5B) described in the first embodiment. It is assembled as a fuel cell in a state where it is not.

  According to the manufacturing method of the fourth embodiment, since the hydrogen separation membrane substrate 11f is processed into a flat plate shape that is not curved before the film formation step, it is compressed into the electrolyte membrane 10 in the step after the film formation. The generation of stress can be suppressed. Therefore, the possibility of peeling between the hydrogen separation membrane substrate 11f and the electrolyte membrane 10 can be reduced. In addition, since the electrolyte membrane 10 is formed on the surface that has undergone the polishing process, the possibility of a short circuit occurring during power generation can be reduced as in the third embodiment.

G. Variation:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

G1. Modification 1:
In the first embodiment, the curvature is reduced by sandwiching the membrane electrode assembly 14A with the separators 20 and 21, but the curvature may be reduced by other methods. For example, the curvature of the membrane electrode assembly 14A may be reduced by pressing.

G2. Modification 2:
In the fourth step of the first embodiment, the membrane electrode assembly 14A is assembled to the fuel cell in a flat plate state that is not curved by reducing its curvature, but the curvature is reduced until it is flat. It is good also as what is assembled | attached to a fuel cell in the curved state, without doing. Alternatively, the membrane electrode assembly 14A may be assembled to the fuel cell with the curvature changed until the membrane electrode assembly 14A curves convexly toward the cathode electrode layer 12 side.

G3. Modification 3:
In the second and third embodiments, the membrane electrode assemblies 14a and 14A are sandwiched between the curved separators 20a, 21a, 20b, and 21b. However, the membrane electrode assemblies 14a and 14A may not be sandwiched between members such as separators. For example, the membrane electrode assembly 14a, 14A may be configured to generate power as a power generation module having a configuration in which the membrane electrode assembly 14a, 14A is simply arranged in a curved state on a curved plate-like member.

G4. Modification 4:
In the fourth embodiment, the hydrogen separation membrane substrate 11f is returned to the uncurved plate shape by the second bending step, but the hydrogen separation membrane substrate 11f is somewhat curved after the second bending step. It may be in the state. However, it is preferable that the curvature of the hydrogen separation membrane substrate 11f after the first bending step is reduced by the second bending step. In this case, it may be sandwiched between the curved separators 20a, 21a, 20b, 21b described in the second and third embodiments.

It is a schematic sectional drawing for demonstrating the structure of a hydrogen separation membrane type fuel cell. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane fuel cell as a comparative example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane fuel cell as a comparative example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane type fuel cell as 1st Example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane type fuel cell as 1st Example. It is a table | surface which shows the result of the electric power generation evaluation of the hydrogen separation membrane fuel cell of a comparative example and 1st Example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane fuel cell as 2nd Example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane fuel cell as 3rd Example. It is explanatory drawing for demonstrating the manufacturing process of a hydrogen separation membrane fuel cell as 4th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane 11 ... Hydrogen separation type anode electrode layer 11f ... Hydrogen separation membrane base material 12 ... Cathode electrode layer 13, 13a, 13A, 13C ... Hydrogen separation membrane / electrolyte membrane assembly 14, 14a, 14A, 14B, 14C ... Membrane electrode assembly 14A ... Membrane electrode assembly 20, 20a, 20b ... Cathode separator 21, 21a, 21b ... Anode separator 100, 100a, 100A, 100B, 100C ... Hydrogen separation membrane fuel cell AP ... Anode gas channel CP ... Cathode gas flow path DS ... concave surface PS ... polishing surface PS1 ... first polishing surface PS2 ... second polishing surface

Claims (8)

A fuel cell manufacturing method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) curving the hydrogen separation membrane substrate;
(C) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the concave surface of the hydrogen separation membrane substrate;
(D) assembling the hydrogen separation membrane / electrolyte membrane assembly into a fuel cell;
A method of manufacturing a fuel cell comprising: A method of manufacturing a fuel cell according to claim 1,
The step (b) includes a step of bending the surface of the hydrogen separation membrane by polishing to produce a fuel cell. A method of manufacturing a fuel cell according to claim 1 or 2,
The step (d) includes a step of assembling the fuel cell in a state where the hydrogen separation membrane / electrolyte membrane assembly is deformed so as to reduce the curvature of the hydrogen separation membrane / electrolyte membrane assembly. Method. A method of manufacturing a fuel cell according to claim 1 or 2,
The step (d) includes a step of assembling the hydrogen separation membrane / electrolyte membrane assembly into a fuel cell in a curved state without changing the curvature of the hydrogen separation membrane / electrolyte membrane assembly. Manufacturing method. A fuel cell manufacturing method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) curving the hydrogen separation membrane substrate;
(C) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the convex surface of the hydrogen separation membrane substrate;
(D) a process of assembling the hydrogen separation membrane / electrolyte membrane assembly in a fuel cell in a curved state without changing the curvature of the hydrogen separation membrane / electrolyte membrane assembly;
A method of manufacturing a fuel cell comprising: It is a manufacturing method of the fuel cell according to claim 6,
The step (b) includes a step of bending the surface of the hydrogen separation membrane by polishing to produce a fuel cell. A fuel cell manufacturing method comprising:
(A) preparing a hydrogen separation membrane substrate that permeates hydrogen;
(B) polishing one surface of the hydrogen separation membrane substrate;
(C) curving the hydrogen separation membrane substrate to reduce the curvature of the hydrogen separation membrane substrate;
(D) forming a hydrogen separation membrane / electrolyte membrane assembly in which an electrolyte membrane is formed on the hydrogen separation membrane substrate;
(E) assembling the hydrogen separation membrane / electrolyte membrane assembly into a fuel cell;
A method for producing a fuel cell, comprising: It is a manufacturing method of Claim 7, Comprising:
The step (c) includes a step of reducing the curvature of the hydrogen separation membrane substrate by polishing the surface of the hydrogen separation membrane substrate that has not been polished in the step (b). .

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