JP2009231094A - Membrane electrode assembly and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of restraining degradation of a cell performance when a fuel cell is structured with the use of an MEA with a seal member containing silicone. <P>SOLUTION: The membrane electrode assembly includes a stack with at least an electrolyte membrane and a catalyst layer laminated, an aluminum-hydroxide-content part containing aluminum hydroxide arranged inside the stack, and a seal member containing silicone arranged so as to cover at least part of the stack. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a membrane electrode assembly including a seal part containing silicone.

  2. Description of the Related Art Conventionally, a fuel cell having a so-called stack structure in which a membrane electrode assembly (MEA) having an electrolyte membrane and a separator are stacked and fastened in a stacking direction has been developed. As such a fuel cell, there is a fuel cell in which a sealing member that contacts the separator is provided around the MEA so that a reaction gas (fuel gas or oxidant gas) does not leak from between the separator and the MEA (the following patents) Reference 1).

JP 2006-114227 A

  Silicone rubber may be used as the sealing member. However, the silicone contained in the silicone rubber can be decomposed under the operating environment of the fuel cell and exist in the electrolyte membrane or the catalyst layer (electrode) as a silicon oxide (Journal of Power Sources 127 (2004) p. 222- See page 229). In this case, the movement of protons and water in the electrolyte membrane and the catalyst layer is hindered by the silicon oxide, and the battery performance may be deteriorated.

  An object of this invention is to provide the technique which can suppress deterioration of battery performance, when a fuel cell is comprised using MEA provided with the sealing member containing silicone.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A membrane / electrode assembly, in which at least an electrolyte membrane and a catalyst layer are laminated, an aluminum hydroxide-containing portion including aluminum hydroxide disposed inside the laminate, A membrane electrode assembly comprising: a seal member including silicone disposed so as to cover at least a part of the laminate.

  Thus, since the membrane electrode assembly of Application Example 1 includes the aluminum hydroxide-containing portion, the product (silicon oxide) generated by decomposition of the silicone contained in the seal portion is converted into the aluminum hydroxide. It can adsorb | suck by a containing part, and when a fuel cell is comprised, deterioration of the battery performance by this silicon oxide can be suppressed.

  [Application Example 2] The membrane electrode assembly according to Application Example 1, wherein the aluminum hydroxide-containing portion is configured as a catalyst layer included in a covering portion covered with the seal member in the laminated body. A membrane electrode assembly.

  By doing in this way, an aluminum hydroxide containing part can be formed in the part which is easy to accelerate | stimulate decomposition | disassembly of a silicone by a catalyst among membrane electrode assemblies. Further, since the silicone is easily decomposed in the covering portion, the silicon oxide can be efficiently adsorbed by providing the aluminum hydroxide-containing portion in the covering portion.

  [Application Example 3] The membrane electrode assembly according to Application Example 1, wherein the aluminum hydroxide-containing portion is configured as an electrolyte membrane included in a covering portion covered with the seal member in the laminated body. A membrane electrode assembly.

  By doing in this way, an aluminum hydroxide content part can be formed in an electrolyte membrane. Accordingly, it is possible to suppress the movement of protons and water in the electrolyte membrane from being hindered by silicon oxide generated by the decomposition of silicone. Further, since the covering portion is likely to decompose silicone, the silicon oxide adsorption can be efficiently performed by providing the aluminum hydroxide-containing portion in the covering portion.

  [Application Example 4] The membrane electrode assembly according to Application Example 1, wherein the aluminum hydroxide-containing portion includes an electrolyte membrane and a catalyst layer included in a covering portion covered with the seal member in the laminate. A membrane electrode assembly disposed between two electrodes.

  By doing so, both the silicon oxide present in the catalyst layer in which the decomposition of the silicone is easily promoted and the silicon oxide present in the electrolyte membrane in which protons, water and the like are moved are adsorbed. Can do. Further, since the silicone is easily decomposed in the covering portion, the silicon oxide can be efficiently adsorbed by providing the aluminum hydroxide-containing portion in the covering portion.

  Application Example 5 A method for producing a membrane electrode assembly, wherein (a) a laminate in which at least an electrolyte membrane and a catalyst layer are laminated, and an aluminum hydroxide-containing portion containing aluminum hydroxide is disposed inside A method of manufacturing a membrane electrode assembly, comprising: preparing a body; and (b) covering at least a part of the laminate with a sealing member containing silicone to form a covering portion.

  In the method for producing a membrane / electrode assembly according to Application Example 5, since a laminated body in which an aluminum hydroxide-containing portion is disposed is used, a product (silicon oxide) generated by decomposition of silicone contained in the seal portion is used. ) Can be adsorbed by the aluminum hydroxide-containing part, and deterioration of battery performance due to the silicon oxide can be suppressed when a fuel cell is constructed.

  Application Example 6 In the method of manufacturing a membrane electrode assembly according to Application Example 5, the step (a) includes (c) a first catalyst ink containing aluminum hydroxide and a second ink not containing aluminum hydroxide. A step of preparing a catalyst ink; and (d) applying the first catalyst ink to a coating-corresponding portion of the electrolyte membrane that is to be included in the coating portion. And (e) forming the catalyst layer by applying the second catalyst ink to the other part of the electrolyte film excluding the coating corresponding part. Electrode assembly manufacturing method.

  By doing in this way, an aluminum hydroxide containing part can be formed by coating two types of catalyst inks separately, and an aluminum hydroxide containing part can be formed comparatively easily. Further, since the aluminum hydroxide-containing part can be formed near the catalyst layer where the decomposition of the silicone is easily promoted by the catalyst, the silicon oxide can be efficiently adsorbed. Moreover, according to this manufacturing method, the aluminum hydroxide-containing portion can be provided in the covering portion where the silicone is likely to be decomposed, and the silicon oxide can be efficiently adsorbed.

  Application Example 7 In the method of manufacturing a membrane electrode assembly according to Application Example 5, the step (a) includes (f) aluminum hydroxide in a coating corresponding part to be included in the coating part as the electrolyte film. And a process for producing a film that does not contain aluminum hydroxide in the other part excluding the coating corresponding part.

  By doing in this way, an aluminum hydroxide containing part can be formed as a part of electrolyte membrane. Accordingly, it is possible to suppress the movement of protons and water in the electrolyte membrane from being hindered by silicon oxide generated by the decomposition of silicone. Moreover, according to this manufacturing method, the aluminum hydroxide-containing portion can be provided in the covering portion where the silicone is likely to be decomposed, and the silicon oxide can be efficiently adsorbed.

  [Application Example 8] The method for manufacturing a membrane electrode assembly according to Application Example 5, wherein the step (a) includes (g) a portion sandwiched between the electrolyte membrane and the catalyst layer to be included in the covering portion The manufacturing method of a membrane electrode assembly which has the process of arrange | positioning aluminum hydroxide and forming the said aluminum hydroxide containing part.

  By doing so, it is possible to adsorb both the silicon oxide present in the catalyst layer where the decomposition of silicone is easily promoted and the silicon oxide present in the electrolyte membrane in which protons, water, and the like are moved. it can. Moreover, according to this manufacturing method, the aluminum hydroxide-containing portion can be provided in the covering portion where the silicone is likely to be decomposed, and the silicon oxide can be efficiently adsorbed.

Hereinafter, the best mode for carrying out the present invention will be described in the following order based on examples.
A. First embodiment:
B. Second embodiment:
C. Third embodiment:
D. Variations:

A. First embodiment:
FIG. 1 is a cross-sectional view showing a configuration of a fuel cell to which a membrane electrode assembly as one embodiment of the present invention is applied. This fuel cell 1000 has a configuration in which seal-integrated MEAs 100 and separators are alternately stacked. The separator has a two-layer structure in which the anode side plate 22 and the cathode side plate 23 are bonded together. For convenience of illustration, an anode side plate 22 of the upper separator and a cathode side plate 23 of the lower separator among the two separators that are in contact with the seal-integrated MEA 100 in the vertical direction are shown.

  The seal-integrated MEA 100 is configured as a so-called MEGA (Membrane-Electrode-Gas diffusion layer Assembly) including a gas diffusion layer. Specifically, the seal-integrated MEA 100 includes an electrolyte membrane 10, an anode side catalyst layer 20a formed on the anode side surface of the electrolyte membrane 10, and an anode side gas diffusion layer formed on the anode side catalyst layer 20a. 21a, a cathode side catalyst layer 20c formed on the cathode side surface of the electrolyte membrane 10, a gas diffusion layer 21c formed on the cathode side catalyst layer 20c, and a seal portion 40. As the electrolyte membrane 10, for example, Nafion (registered trademark), Flemion (registered trademark), Aciplex (registered trademark) or the like, which is a fluororesin-based ion exchange membrane, can be used.

  The seal portion 40 is formed so as to cover a peripheral portion of the laminate 110 formed by laminating the electrolyte membrane 10, the two catalyst layers 20a and 20c, and the two gas diffusion layers 21a and 21c. The seal portion 40 includes a protrusion 42, and the protrusion 42 abuts against the anode side plate 22 and the cathode side plate 23 to ensure airtightness in the seal-integrated MEA 100. The seal portion 40 is made of silicone rubber.

  The seal-integrated MEA 100, the anode side plate 22, and the cathode side plate 23 are each formed with a through-hole penetrating in the stacking direction at the same position. In the fuel cell 1000, these through holes constitute a supply manifold and a discharge manifold for reaction gas (fuel gas and oxidant gas). Specifically, the seal-integrated MEA 100 (seal part 40) includes an oxidant gas supply manifold forming part 100y that is a through hole. The anode side plate 22 includes an oxidant gas supply manifold forming part 22y, and the cathode side plate 23 includes an oxidant gas supply manifold forming part 23y. The oxidant gas supply manifold 150 is formed by the manifold forming portions 100y, 22y, and 23y. Similarly, an oxidant gas discharge manifold 152 is formed on the opposite side. In the example of FIG. 1, a cross section of the fuel cell 1000 is shown at a portion where the manifolds 150 and 152 for supplying and discharging the oxidant gas are formed. And a discharge manifold are formed.

  A hollow oxidant gas supply channel 23 a is formed inside the cathode side plate 23. One end of the oxidant gas supply channel 23 a communicates with the oxidant gas supply manifold 150, and the other end communicates with a space ARc formed between the cathode side plate 23 and the seal-integrated MEA 100. A hollow oxidant gas discharge channel 23 b is formed inside the cathode side plate 23. One end of the oxidant gas discharge channel 23 b communicates with the space ARc, and the other end communicates with the oxidant gas discharge manifold 152. Under such a configuration, the oxidant gas supplied from the oxidant gas supply manifold 150 flows into the oxidant gas supply flow path 23a in the cathode side plate 23 and is sent to the space ARc. The oxidant gas flowing into the space ARc is diffused in the gas diffusion layer 21c and used for the electrochemical reaction. Then, the oxidant gas (off-gas) that has not been used for the electrochemical reaction is discharged to the oxidant gas discharge manifold 152 through the oxidant gas discharge passage 23b. In addition, a fuel gas supply channel and a discharge channel (not shown) are also formed inside the anode side plate 22, and fuel is supplied to a space ARa formed between the anode side plate 22 and the seal-integrated MEA 100. Gas is supplied.

  Here, the anode side catalyst layer 20a includes a portion containing aluminum hydroxide (hereinafter referred to as “aluminum hydroxide containing portion”) 51a and a portion not containing aluminum hydroxide (hereinafter referred to as “aluminum hydroxide non-containing portion”). 52a). Similarly, the cathode side catalyst layer 20c includes an aluminum hydroxide-containing portion 51c and an aluminum hydroxide non-containing portion 52c. The two aluminum hydroxide-containing portions 51 a and 51 c are arranged inside a portion (hereinafter referred to as “coating portion”) 105 covered with the seal portion 40 in the stacked body 110. On the other hand, the aluminum hydroxide non-containing parts 52 a and 52 c are arranged inside the part of the laminate 110 that is not covered with the seal part 40.

  Aluminum hydroxide has the property of adsorbing silicon oxide. Therefore, in the fuel cell 1000, the silicon oxide produced by the decomposition of the seal portion 40 is adsorbed by the aluminum hydroxide contained in the aluminum hydroxide-containing portions 51a and 51c, so that the cell performance of the fuel cell 1000 is improved. Deterioration is suppressed.

  FIG. 2 is a flowchart showing a procedure of a manufacturing method of the seal-integrated MEA 100 shown in FIG. In step S105, a catalyst ink containing aluminum hydroxide (first catalyst ink) and a catalyst ink not containing aluminum hydroxide (second catalyst ink) are prepared. )

  FIG. 3 is an explanatory diagram showing the composition of the first catalyst ink and the composition example of the second catalyst ink prepared in step S105. As the first catalyst ink, for example, platinum-supported carbon (platinum-supported 50 Wt%) is 4.2 Wt%, aluminum hydroxide is 4.2 Wt%, and an electrolyte (for example, Nafion (registered trademark) 20% solution) is used. A mixed solution of 20.7 Wt%, water 29.2 Wt%, and ethanol 41.7 Wt% can be used. As the second catalyst ink, for example, a mixed solution containing 4.4 Wt% platinum-supported carbon, 21.7 Wt% electrolyte, 30.4 Wt% water, and 43.5 Wt% ethanol can be used.

  In step S110 (FIG. 2), the first catalyst ink is applied to the coating corresponding part. Here, the coating corresponding portion refers to a portion included in the coating portion 105 in the electrolyte membrane 10 (FIG. 1).

  FIG. 4A is an explanatory view showing the electrolyte membrane 10 after step S110. FIG. 4B is an explanatory diagram showing an AA cross section in FIG. As described above, the seal portion 40 is formed so as to cover the peripheral portion of the stacked body 110. Therefore, the covering corresponding portion 11 is located in the peripheral portion of the stacked body 110. Accordingly, the first catalyst ink is applied to the coating corresponding portion 11 by spraying the first catalyst ink while masking the central portion (other portions excluding the coating corresponding portion 11) of the electrolyte membrane 10. Can do. Since the applied first catalyst ink contains aluminum hydroxide, the aluminum hydroxide-containing portions 51 a and 51 c are formed in the coating corresponding portion 11. 4A and 4B, in the coating corresponding part 11, an aluminum hydroxide-containing part 51a is formed on the anode side (front side), and an aluminum hydroxide-containing part 51c is formed on the cathode side (back side). ing. In addition, as a member which masks the center part of the electrolyte membrane 10 mentioned above, a Teflon (trademark) sheet etc. can be used, for example.

  In step S115 (FIG. 2), the second catalyst ink is applied to the other part of the electrolyte membrane 10 excluding the coating corresponding part 11.

  FIG. 5A is an explanatory view showing the electrolyte membrane 10 after step S115. FIG. 5B is an explanatory diagram illustrating a cross section taken along the line AA in FIG. In the above-described step S110, the aluminum hydroxide containing portions 51a and 51c are formed in the covering corresponding portion 11. In step S115, the second catalyst ink is applied to a portion of the electrolyte membrane 10 excluding the coating corresponding portion 11, that is, the central portion of the electrolyte membrane 10. Specifically, for example, the second catalyst ink is applied by spraying after masking the aluminum hydroxide-containing portions 51a and 51c using a Teflon (registered trademark) sheet. Since the applied second catalyst ink does not contain aluminum hydroxide, the aluminum hydroxide non-containing portions 52 a and 52 c are formed in the central portion of the electrolyte membrane 10. 5A and 5B, in the central portion of the electrolyte membrane 10, an aluminum hydroxide-free portion 52a is formed on the anode side (front side), and an aluminum hydroxide-free portion on the cathode side (back side). 52c is formed. Thus, the anode side catalyst layer 20a (FIG. 1) is formed on the anode side surface of the electrolyte membrane 10, and the cathode side catalyst layer 20c is formed on the cathode side surface.

  In step S120 (FIG. 2), the anode side gas diffusion layer 21a is formed on the anode side catalyst layer 20a formed in step S115, and the gas diffusion layer 21c is formed on the cathode side catalyst layer 20c. Thus, the laminated body 110 is formed. For example, carbon paper or carbon cloth can be used as the two gas diffusion layers 21a and 21c. In step S125, the sealing part 40 is formed in the peripheral part of the laminated body 110 formed in step S120. Specifically, for example, a mold (mold) can be arranged around the laminated body 110 and silicone rubber can be injected into the mold.

  In the seal-integrated MEA 100 manufactured by the above manufacturing process, the silicone constituting the seal portion 40 is decomposed into silicon oxide in combination with oxygen under the operating environment of the fuel cell 1000. This chemical change is promoted by the platinum contained in the two catalyst layers 20a and 20c acting as a catalyst. Therefore, silicon oxide is easily generated in the two catalyst layers 20 a and 20 c and the electrolyte membrane 10, particularly in a portion included in the covering portion 105. And when this produced | generated silicon oxide moves and deposits on the aluminum hydroxide non-containing part 52a, 52c, there is a possibility that the movement of protons and water is hindered by the silicon oxide and the battery performance is deteriorated. However, as described above, the seal-integrated MEA 100 includes the aluminum hydroxide-containing portion 51a in the anode-side catalyst layer 20a, and the aluminum hydroxide-containing portion 51c in the cathode-side catalyst layer 20c. Accordingly, the silicon oxide is adsorbed by the aluminum hydroxide contained in the aluminum hydroxide-containing parts 51a and 51c, and the movement to the aluminum hydroxide non-containing parts 52a and 52c is suppressed. Therefore, in the seal-integrated MEA 100, the movement of protons and water is not hindered and deterioration of battery performance is suppressed.

B. Second embodiment:
FIG. 6 is an explanatory view showing the structure of a fuel cell to which the membrane electrode assembly in the second embodiment is applied. In the example of FIG. 6, the vicinity of the oxidizing gas supply route is shown enlarged. The fuel cell 1000a in the second embodiment is different from the fuel cell 1000 (FIG. 1) in that the aluminum hydroxide-containing portion is configured as a part of the electrolyte membrane, and other configurations are the same as those in the first embodiment. It is.

  Specifically, in electrolyte membrane 10a, a portion (aluminum hydroxide-containing portion) 10y including aluminum hydroxide is formed in a portion (covering corresponding portion) included in covering portion 105, and the other portion includes aluminum hydroxide. There is no portion (aluminum hydroxide non-containing portion) 10x. In the seal-integrated MEA 100a, the two catalyst layers 20a and 20b are not formed with an aluminum hydroxide-containing portion, unlike the first embodiment.

  FIG. 7 is a flowchart showing a manufacturing procedure of the seal-integrated MEA 100a shown in FIG. In step S205, as the electrolyte membrane 10a, a membrane containing aluminum hydroxide at the coating corresponding portion is manufactured. As a detailed procedure of step S205, for example, the following procedure can be considered.

  FIG. 8 is an explanatory diagram schematically showing the detailed procedure of step S205 shown in FIG. First, the aluminum hydroxide powder 200 is disposed on the periphery of the rotating plate 310 of the spin coater 400 (the part corresponding to the coating corresponding part). Next, an electrolyte solution (for example, Nafion (registered trademark) 20% solution) 300 is dropped while the spin coater 400 is driven to rotate the rotating plate 310. Then, an electrolyte film 210 is formed on the rotating dish 310 and the aluminum hydroxide powder 200 is coated. Thereafter, the solvent in the dropped electrolyte solution evaporates to form an aluminum hydroxide-containing portion 10y in the coating-corresponding portion, and an aluminum hydroxide-free portion 10x is formed in the other portion to complete the electrolyte membrane 10a. To do.

  In step S210 (FIG. 7), a catalyst layer is formed on the electrolyte membrane 10a manufactured in step S205. Specifically, for example, the second catalyst ink (FIG. 3) used in the first embodiment is spray-coated on both surfaces (the anode surface and the cathode surface) of the electrolyte membrane 10a to form a catalyst layer. it can. Subsequent steps S120 and S125 are the same as the procedure in the first embodiment described above (see FIG. 2), and thus the description thereof is omitted.

  As described above, the seal-integrated MEA 100a in the second embodiment has the same effect as the seal-integrated MEA 100 in the first embodiment because the electrolyte membrane 10 includes the aluminum hydroxide-containing portion 10y. .

C. Third embodiment:
FIG. 9 is an explanatory view showing the structure of a fuel cell to which the membrane electrode assembly in the third embodiment is applied. In the example of FIG. 9, the vicinity of the oxidizing gas supply route is shown enlarged. In the fuel cell 1000b according to the third embodiment, the aluminum hydroxide-containing portion is disposed between the electrolyte membrane 10 and the anode side catalyst layer 20a and between the electrolyte membrane 10 and the cathode side catalyst layer 20c. Unlike the fuel cell 1000 (FIG. 1), other configurations are the same as those of the first embodiment.

  Specifically, in the covering portion 105, an aluminum hydroxide-containing portion 30a is disposed between the electrolyte membrane 10 and the anode side catalyst layer 20a. In addition, an aluminum hydroxide-containing portion 30c is disposed between the electrolyte membrane 10 and the cathode side catalyst layer 20c. In the seal-integrated MEA 100a, the two catalyst layers 20a and 20b are not formed with an aluminum hydroxide-containing portion, unlike the first embodiment. Unlike the second embodiment, the aluminum hydroxide-containing portion is not formed in the coating corresponding portion of the electrolyte membrane 10.

  FIG. 10 is a flowchart showing a manufacturing procedure of the seal-integrated MEA 100b shown in FIG. In step S305, an aluminum hydroxide film is formed on the coating corresponding portion of the electrolyte membrane 10. As a detailed procedure of step S305, for example, the following procedure can be considered.

  FIG. 11 is an explanatory diagram schematically showing the detailed procedure of step S305 shown in FIG. First, the central portion of the electrolyte membrane 10 on the anode side (other portions excluding the coating corresponding portion 11) is masked by the mask member 500, and aluminum hydroxide is deposited. Thereafter, when the mask member 500 is removed, an aluminum hydroxide film (aluminum hydroxide-containing portion 30a) is formed on the covering corresponding portion 11. Similarly, the aluminum hydroxide containing portion 30c (FIG. 9) can be formed also on the cathode side. As the mask member 500, for example, a Teflon (registered trademark) sheet can be used.

  When step S305 (FIG. 10) is completed, the processes of steps S210, S120, and S125 described above are executed in this order, and the seal-integrated MEA 100b is completed.

  As described above, the seal-integrated MEA 100b in the third embodiment has the same effects as the seal-integrated MEA 100 in the first embodiment because the seal-integrated MEA 100b includes the aluminum hydroxide-containing portions 30a and 30c.

D. Variations:
In addition, elements other than the elements claimed in the independent claims among the constituent elements in each of the above embodiments are additional elements and can be omitted as appropriate. 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.

D1. Modification 1:
In each of the above-described embodiments, the aluminum hydroxide-containing portion is disposed inside the two catalyst layers 20a and 20b, or inside the electrolyte membrane 10a, or between the catalyst layer and the electrolyte membrane, but is not limited thereto. Alternatively, it may be disposed in another part inside the stacked body 110. For example, the anode-side gas diffusion layer 21a may be disposed on a surface (boundary surface) in contact with the catalyst layer 20a. The cathode side can be similarly configured. Such a configuration can be realized, for example, by depositing aluminum hydroxide on the surface in contact with the catalyst layer 20a in the gas diffusion layer 21a. Even in such a configuration, the silicon oxide generated in the two catalyst layers 20a and 20c is adsorbed in the aluminum hydroxide-containing portion formed on the surfaces of the gas diffusion layers 21a and 21c, thereby suppressing deterioration in battery performance. can do. As can be understood from the above examples and modifications, any configuration in which the aluminum hydroxide-containing portion is disposed inside the laminate 110 can be employed in the membrane electrode assembly of the present invention.

D2. Modification 2:
In each of the above-described embodiments, the seal-integrated MEAs 100, 100a, and 100b are configured as so-called MEGA (membrane-electrode-diffusion layer assembly). Instead, the gas diffusion layer is a separate member. It can also be configured as a so-called membrane-electrode assembly. Even in this case, as described above, the aluminum hydroxide-containing portion is disposed inside the electrolyte membrane constituting the MEA, inside the catalyst layer constituting the MEA, or between the electrolyte membrane and the catalyst layer. The same effect as each embodiment can be produced.

D3. Modification 3:
In the second embodiment described above, the spin coater 400 (FIG. 8) is used to produce the film containing aluminum hydroxide in the coating corresponding part in step S205. However, the production is performed without using the spin coater 400. You can also. Specifically, for example, the aluminum hydroxide powder 200 is disposed on an edge portion (a portion corresponding to the coating corresponding portion) of a container such as a petri dish, and then the electrolyte solution is dropped over the entire container. Even in this case, when the dropped solvent evaporates, the aluminum hydroxide-containing portion 10y is formed at the edge portion of the container, and the aluminum hydroxide-free portion 10x is formed at the other portion.

D4. Modification 4:
In each of the embodiments described above, the aluminum hydroxide-containing portions 51a, 51c, 10y, 30a, and 30c are formed over the entire horizontal surface of the covering portion 105 in the catalyst layer, the electrolyte membrane, and the like. Further, it can be formed only on a part of the covering portion 105 in the horizontal direction. For example, in the first embodiment, the aluminum hydroxide-containing portions 51a and 51c are formed in the outer half of the catalyst layer included in the covering portion 105, and the aluminum hydroxide is formed in the inner half. The non-containing parts 52a and 52c can also be formed.

D5. Modification 5:
In the first embodiment described above, the first catalyst-like ink that is the basis of the aluminum hydroxide-containing portions 51a and 51c has a composition containing platinum-supporting carbon, but instead contains platinum-supporting carbon at all. It is also possible to use inks having no composition. With such a configuration, it is not necessary to use platinum-supporting carbon containing relatively expensive platinum, and the manufacturing cost of the fuel cell 1000 can be kept relatively low. Further, since no catalyst is used in the covering portion 105, the decomposition of silicone can be suppressed.

D6. Modification 6:
Instead of implementing each of the above-described embodiments independently, each of the embodiments can be implemented in combination. For example, a part of the catalyst layer is configured as an aluminum hydroxide-containing portion (corresponding to the first embodiment), and the coating corresponding portion of the electrolyte membrane is formed as an aluminum hydroxide-containing portion (corresponding to the second embodiment). You can also Furthermore, in this configuration, an aluminum hydroxide-containing portion can be formed between the catalyst layer and the electrolyte membrane (corresponding to the third embodiment).

D7. Modification 7:
In each of the above-described embodiments, the separator has a two-layer structure of the anode side plate 22 and the cathode side plate 23. However, instead of this, it may be configured by an arbitrary number of plates. For example, a three-layer structure in which the anode side plate 22 and the cathode side plate 23 are sandwiched between intermediate plates can be used.

D8. Modification 8:
In each of the above-described embodiments, the fuel cells 1000, 1000a, 1000b, and 1000c are configured by laminating a plurality of seal-integrated MEAs and separators, but instead of this, one seal-integrated MEA and this It can also be configured as a so-called single cell comprising two separators arranged with a seal-integrated MEA interposed therebetween.

It is sectional drawing which shows the structure of the fuel cell to which the membrane electrode assembly as one Example of this invention is applied. It is a flowchart which shows the procedure of the manufacturing method of seal integrated MEA100 shown in FIG. It is explanatory drawing which shows the composition example of the 1st catalyst ink prepared in step S105, and the composition example of the 2nd catalyst ink. It is explanatory drawing which shows the electrolyte membrane 10 after step S110, and explanatory drawing which shows the AA cross section of FIG. 4 (A). It is explanatory drawing which shows the electrolyte membrane 10 after step S115, and explanatory drawing which shows the AA cross section of FIG. 5 (A). It is explanatory drawing which shows the structure of the fuel cell to which the membrane electrode assembly in a 2nd Example is applied. 7 is a flowchart showing a manufacturing procedure of the seal-integrated MEA 100a shown in FIG. It is explanatory drawing which shows typically the detailed procedure of step S205 shown in FIG. It is explanatory drawing which shows the structure of the fuel cell to which the membrane electrode assembly in a 3rd Example is applied. 10 is a flowchart showing a manufacturing procedure of the seal-integrated MEA 100b shown in FIG. It is explanatory drawing which shows typically the detailed procedure of step S305 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,10a ... Electrolyte membrane 10x ... Aluminum hydroxide non-contained part 10y ... Aluminum hydroxide containing part 11 ... Covering | corresponding part 20a ... Anode side catalyst layer 20c ... Cathode side catalyst layer 21a ... Anode side gas diffusion layer 21c ... Cathode gas diffusion layer 22 ... Anode side plate 22y ... Oxidant gas supply manifold forming part 23 ... Cathode side plate 23a ... Oxidant gas supply Flow path 23b ... Oxidant gas discharge flow path 23y ... Oxidant gas supply manifold forming part 30a, 30c ... Aluminum hydroxide-containing part 40 ... Seal part 42 ... Projection part 51a, 51c. .. Aluminum hydroxide containing part 52a, 52c ... Aluminum hydroxide non-containing part 100y ... Oxidant gas supply manifold forming part 105 ... Covering part 110 ... Laminate 150 ... Oxidant gas supply Manifold 152 ... Oxidation Gas exhaust manifold 200 ... Aluminum hydroxide powder 210 ... Membrane 310 ... Rotating dish 400 ... Spin coater 500 ... Mask member 1000, 1000a, 1000b ... Fuel cell 100, 100a, 100b, 100c ... MEA with integrated seal
ARa, ARc ... space

Claims (8)

A membrane electrode assembly,
A laminate in which at least an electrolyte membrane and a catalyst layer are laminated;
An aluminum hydroxide-containing portion containing aluminum hydroxide disposed inside the laminate;
A seal member including silicone arranged to cover at least a part of the laminate;
A membrane electrode assembly comprising: The membrane electrode assembly according to claim 1,
The said aluminum hydroxide containing part is a membrane electrode assembly comprised as a catalyst layer contained in the coating | coated part covered with the said sealing member among the said laminated bodies. The membrane electrode assembly according to claim 1,
The said aluminum hydroxide containing part is a membrane electrode assembly comprised as an electrolyte membrane contained in the coating | coated part covered with the said sealing member among the said laminated bodies. The membrane electrode assembly according to claim 1,
The said aluminum hydroxide containing part is a membrane electrode assembly arrange | positioned on both sides of the electrolyte membrane and catalyst layer contained in the coating | coated part covered with the said sealing member among the said laminated bodies. A method for producing a membrane electrode assembly, comprising:
(A) a step of preparing a laminate in which at least an electrolyte membrane and a catalyst layer are laminated and an aluminum hydroxide-containing portion containing aluminum hydroxide is disposed inside;
(B) covering at least a part of the laminate with a sealing member containing silicone to form a covering portion;
A membrane electrode assembly manufacturing method comprising: In the manufacturing method of a membrane electrode assembly according to claim 5,
The step (a)
(C) preparing a first catalyst ink containing aluminum hydroxide and a second catalyst ink not containing aluminum hydroxide;
(D) forming the aluminum hydroxide-containing portion by applying the first catalyst ink to a coating corresponding portion to be included in the coating portion of the electrolyte membrane;
(E) forming the catalyst layer by applying the second catalyst ink to other portions of the electrolyte membrane excluding the coating corresponding portion;
A method for producing a membrane electrode assembly, comprising: In the manufacturing method of a membrane electrode assembly according to claim 5,
The step (a)
(F) A step of producing a film containing aluminum hydroxide in the coating corresponding part to be included in the coating part and not including aluminum hydroxide in the other part excluding the coating corresponding part as the electrolyte film. A method for producing a membrane electrode assembly, comprising: It is a membrane electrode assembly manufacturing method according to claim 5,
The step (a)
(G) A method for producing a membrane / electrode assembly, including a step of forming aluminum hydroxide-containing portions by placing aluminum hydroxide in a portion sandwiched between an electrolyte membrane and a catalyst layer to be included in the covering portion.

Images