JP2022069404A - Electrolyte membrane for fuel cell and fuel cell - Google Patents

Abstract

To provide an electrolyte membrane for a fuel cell which is effective in suppressing a decrease in output.SOLUTION: An electrolyte membrane 4 includes a membrane body portion 42 and a first resin layer 41. The membrane body 42 includes an ionic conductor 421 and a support 422. The ion conductor 421 is made of ceramics. The support 422 is made of resin. The first resin layer 41 is arranged on one surface of the film body portion 42.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electrolyte membrane for a fuel cell and a fuel cell.

A fuel cell generally has an electrolyte membrane and a pair of electrodes. The electrolyte membrane is arranged between the pair of electrodes. Patent Document 1 proposes an electrolyte membrane in which an ionic conductor made of ceramics and a support made of resin are composited.

Japanese Unexamined Patent Publication No. 2010-232158 International Publication No. 2019/12431

In a fuel cell having the above-described configuration, it is required to suppress a decrease in the output thereof. Therefore, it is an object of the present invention to provide an electrolyte membrane for a fuel cell which is effective in suppressing a decrease in output.

The electrolyte membrane for a fuel cell according to the first aspect of the present invention is used for a fuel cell. This electrolyte membrane includes a membrane main body portion and a first resin layer. The membrane body portion has an ionic conductor and a support. The ionic conductor is composed of ceramics. The support is made of resin. The first resin layer is arranged on one surface of the film body.

The present inventors have stated that when the ionic conductor in the electrolyte membrane is exposed to water or water vapor, the ionic conductor grows or elutes, which causes a decrease in the output of the fuel cell. I found. Therefore, in the electrolyte membrane for a fuel cell according to the present invention, the first resin layer is formed on one surface of the membrane main body. According to this configuration, the ionic conductor is suppressed from being exposed to external water or water vapor at least on one surface of the membrane body. As a result, the grain growth and elution of the ionic conductor can be suppressed, and eventually the output decrease of the fuel cell can be suppressed.

Preferably, the first resin layer is made of a material different from the support.

Preferably, the first resin layer has a higher ionic conductivity than the support.

Preferably, the first resin layer has a lower water absorption rate than the support.

Preferably, the first resin layer is made of the same material as the support.

Preferably, the first resin layer is thinner than the film body portion.

Preferably, the first resin layer is thicker than the film body portion.

Preferably, the fuel cell electrolyte membrane further comprises a resin second resin layer disposed on the other side of the membrane body. According to this configuration, it is possible to suppress the exposure of the ionic conductor to external water or water vapor also on the other surface of the main body of the membrane.

Preferably, the second resin layer is made of a material different from the support.

Preferably, the second resin layer has a higher ionic conductivity than the support.

Preferably, the second resin layer has a lower water absorption rate than the support.

Preferably, the second resin layer is made of the same material as the support.

Preferably, the second resin layer is thinner than the film body portion.

Preferably, the first resin layer is thicker than the second resin layer.

Preferably, the first resin layer is thinner than the second resin layer.

Preferably, the first resin layer has a higher ionic conductivity than the second resin layer.

Preferably, the first resin layer has a lower ionic conductivity than the second resin layer.

The fuel cell according to the second aspect of the present invention includes any of the above-mentioned electrolyte membranes for a fuel cell, a first electrode, and a second electrode. The first electrode is arranged on one surface of the electrolyte membrane. The second electrode is arranged on the other side of the electrolyte membrane.

According to the present invention, it is possible to provide an electrolyte membrane for a fuel cell which is effective in suppressing a decrease in output.

Sectional view of the fuel cell. Enlarged sectional view of the electrolyte membrane. Sectional drawing of the fuel cell which concerns on the modification.

Hereinafter, the solid alkaline fuel cell 100, which is an example of the fuel cell according to the present embodiment, will be described with reference to the drawings. The solid alkaline fuel cell 100 is a kind of alkaline fuel cell (AFC) having a hydroxide ion as a carrier.

(Solid alkaline fuel cell 100)
FIG. 1 is a cross-sectional view showing the configuration of the solid alkaline fuel cell 100 according to the embodiment. The solid alkaline fuel cell 100 includes a cathode 2 (an example of a first electrode), an anode 3 (an example of a second electrode), and an electrolyte membrane 4. Further, the solid alkaline fuel cell 100 includes a first separator 11 and a second separator 12. The cathode 2, the anode 3, and the electrolyte membrane 4 constitute the fuel cell junction 10. When actually used, a plurality of solid alkaline fuel cells 100 are stacked. Specifically, a plurality of fuel cell joints 10 are stacked via the first and second separators 11 and 12.

(1st and 2nd separators 11 and 12)
The first and second separators 11 and 12 are arranged so as to sandwich the fuel cell joint 10 from both sides in the thickness direction (z-axis direction). The first separator 11 is configured to supply an oxidizing agent containing oxygen (O ₂ ) to the cathode 2. The first separator 11 has a first flow path 111. The first flow path 111 faces the cathode 2. An oxidizing agent containing oxygen (O ₂ ) is supplied to the first flow path 111.

The second separator 12 is configured to supply fuel containing a hydrogen atom (H) to the anode 3. The second separator 12 has a second flow path 121. The second flow path 121 faces the anode 3. Fuel containing a hydrogen atom (H) is supplied to the second flow path 121. For example, methanol is supplied to the second flow path 121.

When a plurality of fuel cell joints 10 are stacked via the first and second separators 11 and 12, the first separator 11 is a surface opposite to the surface on which the first flow path 111 is formed. A second flow path is formed in. Further, in the second separator 12, the first flow path is formed on the surface opposite to the surface on which the second flow path 121 is formed.

(Fuel cell junction 10)
The fuel cell junction 10 includes a cathode 2, an anode 3, and an electrolyte membrane 4. The fuel cell junction 10 generates electricity at a relatively low temperature (for example, 50 ° C. to 250 ° C.) based on the following electrochemical reaction formula. However, in the following electrochemical reaction formula, methanol is used as an example of fuel.

・ Cathode 2: 3 / 2O ₂ + 3H ₂ O + 6e ^－ → 6OH ^－
・ Anode 3: CH ₃ OH + ^6OH- → ^6e- + CO ₂ + 5H ₂ O
・ Overall: CH ₃ OH + 3 / 2O ₂ → CO ₂ + 2H ₂ O

(Cathode 2)
The cathode 2 is arranged on the first surface 401 side (upper surface side in FIG. 1) of the electrolyte membrane 4. Specifically, the cathode 2 is arranged on the first resin layer 41 of the electrolyte membrane 4. The cathode 2 is an anode generally called an air electrode.

During power generation of the solid alkaline fuel cell 100, an oxidizing agent containing oxygen (O ₂ ) is supplied to the cathode 2 via the first flow path 111 of the first separator 11. As the oxidizing agent, it is preferable to use air, and it is more preferable that the air is humidified. The cathode 2 is a porous body capable of diffusing an oxidizing agent inside. The porosity of the cathode 2 is not particularly limited. The thickness of the cathode 2 is not particularly limited, but may be, for example, 10 to 200 μm.

The cathode 2 is not particularly limited as long as it contains a known air electrode catalyst used for AFC. Examples of cathode catalysts include group 8-10 elements (IUPAC format periodic table) such as platinum group elements (Ru, Rh, Pd, Os, Ir, Pt) and iron group elements (Fe, Co, Ni). Elements belonging to Group 8-10), Group 11 elements such as Cu, Ag, and Au (elements belonging to Group 11 in the periodic table in the IUPAC format), rhodium phthalocyanine, tetraphenylporphyrin, Co-salen, Ni-salen (elements belonging to Group 11), Cu, Ag, Au, etc. Salen = N, N'-bis (salicylidene) ethylenediamine), silver nitrate, and any combination thereof. The amount of the catalyst supported on the cathode 2 is not particularly limited, but is preferably 0.1 to 10 mg / cm ² , more preferably 0.1 to 5 mg / cm ² . The cathode catalyst is preferably supported on carbon. Preferred examples of the cathode 2 or the catalyst constituting the cathode 2 are platinum-supported carbon (Pt / C), palladium-supported carbon (Pd / C), rhodium-supported carbon (Rh / C), nickel-supported carbon (Ni / C), and the like. Examples thereof include copper-supported carbon (Cu / C) and silver-supported carbon (Ag / C).

The method for producing the cathode 2 is not particularly limited, but for example, the cathode catalyst and, if desired, the carrier are mixed with a binder to form a paste. Then, the cathode 2 can be formed by applying this paste-like mixture on the electrolyte membrane 4 and drying it.

(Anode 3)
The anode 3 is arranged on the second surface 402 side (lower surface side in FIG. 1) of the electrolyte membrane 4. Specifically, the anode 3 is arranged on the second resin layer 43 of the electrolyte membrane 4. The anode 3 is a cathode generally called a fuel electrode.

During power generation of the solid alkaline fuel cell 100, fuel containing a hydrogen atom (H) is supplied to the anode 3 via the second flow path 121 of the second separator 12. As the fuel, it is preferable to use methanol. The anode 3 is a porous body capable of diffusing fuel inside. The porosity of the anode 3 is not particularly limited. The thickness of the anode 3 is not particularly limited, but may be, for example, 10 to 500 μm.

The fuel may contain a fuel compound capable of reacting with hydroxide ions (OH ⁻ ) at the anode 3, and may be in the form of either liquid fuel or gaseous fuel.

Examples of the fuel compound include (i) hydrazine (NH ₂ NH ₂ ), hydrated hydrazine (NH ₂ NH ₂ · H ₂ O), hydrazine carbonate ((NH ₂ NH ₂ ) ₂ CO ₂ ), and hydrazine sulfate (NH). ₂ NH ₂ · H ₂ SO ₄ ), monomethyl hydrazine (CH ₃ NHNH ₂ ), dimethyl hydrazine ((CH ₃ ) ₂ NNH ₂ , CH ₃ NHNHCH ₃ ), and hydrazines such as carboxylic hydrazine ((NHNH ₂ ) ₂ CO). Class, (ii) urea (NH ₂ CONH ₂ ), (iii) ammonia (NH ₃ ), (iv) imidazole, 1,3,5-triazine, 3-amino-1,2,4-triazole and other heterocycles. Examples thereof include (v) hydroxylamines such as hydroxylamine (NH ₂ OH) and hydroxylamine sulfate (NH ₂ OH · H ₂ SO ₄ ), and combinations thereof. Of these fuel compounds, carbon-free compounds (ie, hydrazine, hydrated hydrazine, hydrazine sulfate, ammonia, hydroxylamine, hydroxylamine sulfate, etc.) are particularly suitable because they do not have the problem of catalytic poisoning by carbon monoxide. be.

The fuel compound may be used as a fuel as it is, or may be used as a solution dissolved in water and / or an alcohol (for example, a lower alcohol such as methanol, ethanol, propanol or isopropanol). For example, among the above fuel compounds, hydrazine, hydrated hydrazine, monomethylhydrazine and dimethylhydrazine are liquids and can be used as they are as liquid fuels. In addition, hydrazine carbonate, hydrazine sulfate, carboxylic hydrazine, urea, imidazole, and 3-amino-1,2,4-triazole, and hydroxylamine sulfate are solid but soluble in water. 1,3,5-triazine and hydroxylamine are solid but soluble in alcohol. Ammonia is a gas but is soluble in water. As described above, the solid fuel compound can be dissolved in water or alcohol and used as a liquid fuel. When the fuel compound is dissolved in water and / or alcohol and used, the concentration of the fuel compound in the solution is, for example, 1 to 90% by weight, preferably 1 to 30% by weight.

Further, a hydrocarbon-based liquid fuel containing alcohols such as methanol and ethanol and ethers, a hydrocarbon-based gas such as methane, or pure hydrogen can be used as it is as a fuel. In particular, methanol is suitable as the fuel used in the solid alkaline fuel cell 100 according to the present embodiment. Methanol may be in a gaseous state, a liquid state, or a gas-liquid mixed state.

The anode 3 is not particularly limited as long as it contains a known anode catalyst used for AFC. Examples of anode catalysts include metal catalysts such as Pt, Ni, Co, Fe, Ru, Sn, and Pd. The metal catalyst is preferably supported on a carrier such as carbon, but may be in the form of an organic metal complex having a metal atom of the metal catalyst as a central metal, or the organic metal complex may be supported as a carrier. Further, a diffusion layer made of a porous material or the like may be arranged on the surface of the anode catalyst. Preferred examples of the anode 3 and the catalysts constituting the anode 3 are nickel, cobalt, silver, platinum-supported carbon (Pt / C), palladium-supported carbon (Pd / C), rhodium-supported carbon (Rh / C), and nickel-supported carbon. (Ni / C), copper-supported carbon (Cu / C), and silver-supported carbon (Ag / C) can be mentioned.

The method for producing the anode 3 is not particularly limited, but for example, the anode catalyst and, if desired, the carrier are mixed with a binder to form a paste. Then, the anode 3 can be formed by applying this paste-like mixture on the electrolyte membrane 4 and drying it.

(Electrolyte membrane 4)
The electrolyte membrane 4 is arranged between the cathode 2 and the anode 3. The electrolyte membrane 4 is connected to each of the cathode 2 and the anode 3. The electrolyte membrane 4 has ionic conductivity. In this embodiment, the electrolyte membrane 4 has hydroxide ion conductivity. The electrolyte membrane 4 has a first resin layer 41, a membrane body 42, and a second resin layer 43.

The first resin layer 41 is formed on one surface (upper surface) of the film body portion 42. The second resin layer 43 is formed on the other surface (lower surface) of the film body portion 42. That is, the film body portion 42 is arranged between the first resin layer 41 and the second resin layer 43. The first resin layer 41, the film body portion 42, and the second resin layer 43 are laminated in this order.

The thickness t of the electrolyte membrane 4 is, for example, about 5 to 100 μm. Among them, the thickness t1 of the first resin layer 41 and the thickness t3 of the second resin layer 43 are, for example, about 0.1 to 50 μm, respectively. The thickness t2 of the film body portion 42 is, for example, about 5 to 80 μm.

The method for measuring the thicknesses t1 to t3 of the first resin layer 41, the film main body portion 42, and the second resin layer 43 is as follows. First, a cut surface (xz surface) passing through the vicinity of the center of the electrolyte membrane 4 as shown in FIG. 1 is created. Then, the cut surface is photographed by SEM, the thickness of the first resin layer 41 is measured at an arbitrary point at both ends of the electrolyte membrane 4 and an arbitrary point at the central portion, and the average value thereof is the first. The thickness of the resin layer 41 can be t1. By the same method, the thickness t2 of the membrane body 42, the thickness t3 of the second resin layer 43, and the thickness t of the electrolyte membrane 4 can also be calculated.

The thickness t1 of the first resin layer 41 is smaller than the thickness t2 of the film body portion 42. The thickness t3 of the second resin layer 43 is smaller than the thickness t2 of the film body portion 42. The thickness t1 of the first resin layer 41 is the same as the thickness t3 of the second resin layer 43.

For example, the ratio (t1 / t2) of the thickness t1 of the first resin layer 41 to the thickness t2 of the film body portion 42 can be 0.001 to 0.9. Similarly, the ratio (t3 / t2) of the thickness t3 of the second resin layer 43 to the thickness t2 of the film body portion 42 can be 0.001 to 0.9.

FIG. 2 is a schematic view showing an enlarged cross section of the electrolyte membrane 4. As shown in FIG. 2, the membrane body 42 has an ion conductor 421 and a support 422. The ion conductor 421 is dispersed in the support 422. The ion conductor 421 is supported by the support 422.

The content of the ionic conductor 421 in the membrane body 42 can be 30 to 70 vol%, preferably 50 to 70 vol% in consideration of ionic conductivity. The membrane body 42 is substantially composed of only the ionic conductor 421 and the support 422, and other substances are negligible.

The ionic conductor 421 has ionic conductivity. The ion conductor 421 has, for example, hydroxide ion conductivity. During the power generation of the solid alkaline fuel cell 100, the electrolyte membrane 4 conducts hydroxide ions (OH ⁻ ) from the cathode 2 side to the anode 3 side mainly by the ion conductor 421.

The hydroxide ion conductivity of the ion conductor 421 is not particularly limited, but is preferably 0.1 mS / cm or more, more preferably 0.5 mS / cm or more, still more preferably 1.0 mS / cm or more. The higher the hydroxide ion conductivity of the ion conductor 421 is, the more preferable it is, and the upper limit thereof is not particularly limited, but is, for example, 10 mS / cm.

The ion conductor 421 is made of ceramics. Specifically, the ion conductor 421 can be made of a ceramic having hydroxide ion conductivity. For example, the ionic conductor 421 can be composed of a layered double hydroxide (LDH).

LDH is M ²⁺ _1-x M ³⁺ _x (OH) ₂ A ^n- x / n · mH ₂ O (in the formula, M ²⁺ is a divalent cation, M ³⁺ is a trivalent cation, and A ^n- is an n-valent anion, n is an integer of 1 or more, x is 0.1 to 0.4, and m is an arbitrary integer meaning the number of moles of water). Have. Examples of M ²⁺ include Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ni ²⁺ , Co ²⁺ , Fe ²⁺ , Mn ²⁺ , and Zn ²⁺ , and examples of M ³⁺ include Al ³⁺ , Fe ³⁺ , Ti ³⁺ , Examples include Y ³⁺ , Ce ³⁺ , Mo ³⁺ , and Cr ³⁺ , and examples of ^An − include CO ₃ ^2- and OH ⁻ . As M ²⁺ and M ³⁺ , one type may be used alone or two or more types may be used in combination.

LDH is composed of a plurality of hydroxide basic layers and an intermediate layer interposed between the plurality of hydroxide basic layers. The middle layer is composed of anions and _H2O . The hydroxide basic layer contains, for example, Ni, Al, Ti and OH groups when the metal M is Ni, Al, Ti. Hereinafter, the case where the hydroxide basic layer of LDH contains Ni, Al, Ti and OH groups will be described.

Ni in LDH can take the form of nickel ions. Nickel ions in LDH are typically considered to be Ni ²⁺ , but are not particularly limited as other valences such as Ni ³⁺ are possible. Al in LDH can take the form of aluminum ions. Aluminum ions in LDH are typically considered to be Al ³⁺ , but are not particularly limited as other valences are possible. Ti in LDH can take the form of titanium ions. Titanium ions in LDH are typically considered to be Ti ⁴⁺ , but are not particularly limited as other valences such as Ti ³⁺ are possible. The hydroxide basic layer preferably contains Ni, Al, Ti and OH groups as main components, but may contain other elements or ions, or may contain unavoidable impurities. The unavoidable impurity is an arbitrary element that can be unavoidably mixed in the production method, and can be mixed in LDH, for example, derived from a raw material or a base material.

The middle layer of LDH is composed of anions and _H2O . The anion is a monovalent or higher anion, preferably a monovalent or divalent ion. Preferably, the anions in ^LDH contain OH ^- and / or CO _3-2- .

As mentioned above, since the valences of Ni, Al and Ti are not always fixed, it is impractical or impossible to specify LDH strictly by a general formula. Assuming that the hydroxide basic layer is mainly composed of Ni ²⁺ , Al ³⁺ , Ti ⁴⁺ and OH groups, LDH is expressed by the general formula: Ni ²⁺ _1-xy Al ³⁺ _x Ti ⁴⁺ _y (OH). ) 2A ^n- _{(x + 2y) / n} · mH ₂ O ( _In the formula, Ann- is an n-valent anion, ⁿ is an integer of 1 or more, preferably 1 or 2, and 0 <x <1, preferably. 0.01 ≦ x ≦ 0.5, 0 <y <1, preferably 0.01 ≦ y ≦ 0.5, 0 <x + y <1, m is 0 or more, typically more than 0 or 1 or more It can be expressed by the basic composition (which is a real number of). However, the above general formula should be understood as "basic composition" to the extent that elements such as Ni ²⁺ , Al ³⁺ , and Ti ⁴⁺ do not impair the basic characteristics of LDH, and other elements or ions (of the same element). It should be understood as replaceable with elements or ions of other valences or elements or ions that can be unavoidably mixed in the process.

The support 422 is configured to support the ionic conductor 421. Specifically, the support 422 is a binder. The support 422 is arranged between the constituent particles constituting the ion conductor 421. The support 422 supports the ionic conductor 421 by fastening the constituent particles of the ionic conductor 421 to each other. In this way, the support 422 supports the ion conductor 421 to maintain the shape of the membrane body 42.

The support 422 is made of resin. For example, the support 422 is made of a well-known organic polymer material having insulating properties. That is, the support 422 is made of a well-known organic polymer material having no ionic conductivity. In this embodiment, the support 422 is made of a well-known organic polymer material having no hydroxide ion conductivity. Specifically, the ionic conductivity of the support 422 is 0.01 mS / cm or less.

Examples of the material constituting the support 422 include polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyether sulfone, polyphenylene sulfide, polyamideimide, polyether ether ketone, and polyimide. Can be mentioned.

The first resin layer 41 is made of resin. The first resin layer 41 is made of a material different from that of the support 422. Examples of the material constituting the first resin layer 41 include nafion, sulfonated polyetheretherketone (S-PEEK), and alkyl sulfonated polybenzimidazole. The first resin layer 41 has ionic conductivity. The first resin layer 41 has a higher ionic conductivity than the support 422. That is, the resin constituting the first resin layer 41 has a higher ionic conductivity than the resin constituting the support 422. Further, the first resin layer 41 has a higher ionic conductivity than the second resin layer 43.

The first resin layer 41 has a lower water absorption rate than the support 422. That is, the resin constituting the first resin layer 41 has a lower water absorption rate than the resin constituting the support 422. The water absorption rate of the first resin layer 41 can be, for example, 0.9% or less, preferably 0.4% or less. The water absorption rate can be measured at room temperature as follows. First, the weight of the resin containing water is measured, then the resin is placed in a constant temperature bath to evaporate the water, and then the weight is measured again. The amount of change in weight is defined as the amount of water, and the ratio of the amount of water to the weight of the resin is defined as the water absorption rate.

The second resin layer 43 is made of resin. As the material constituting the second resin layer 43, the materials listed as the constituent materials of the first resin layer 41 can be used. The second resin layer 43 can be made of the same material as the first resin layer 41. The second resin layer 43 has ionic conductivity. The second resin layer 43 has a higher ionic conductivity than the support 422. The second resin layer 43 has a lower ionic conductivity than the first resin layer 41.

The second resin layer 43 has a lower water absorption rate than the support 422. The water absorption rate of the second resin layer 43 can be, for example, 0.9% or less.

The electrolyte membrane 4 can be formed, for example, as follows. First, the film body portion 42 is formed. Specifically, the material constituting the support 422 as described above is dissolved with an organic solvent to prepare a solution for the support 422. Then, the material constituting the above-mentioned ion conductor 421 is put into this solution to prepare a paste for the membrane body 42. Then, this paste is formed on a release film, the paste is dried, and then the release film is peeled off to form the film main body portion 42.

Next, the material constituting the first resin layer 41 is dissolved with an organic solvent to prepare a paste for the first resin layer 41. Then, the paste of the first resin layer 41 is applied on one surface of the film body portion 42 and dried. As a result, the first resin layer 41 is formed. In the same manner, the second resin layer 43 is formed on the other surface of the film body portion 42. As described above, the electrolyte membrane 4 having the first resin layer 41, the membrane body portion 42, and the second resin layer 43 can be formed.

(Modified example of the embodiment)
Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made without departing from the spirit of the present invention.

Modification 1
In the above embodiment, the cathode 2 is arranged on the first resin layer 41 and the anode 3 is arranged on the second resin layer 43, but the configuration of the fuel cell is not limited to this. That is, the cathode 2 may be arranged on the second resin layer 43, and the anode 3 may be arranged on the first resin layer 41.

Modification 2
In the above embodiment, the first resin layer 41 has the same thickness as the second resin layer 43, but the configuration of the electrolyte membrane 4 is not limited to this. For example, the first resin layer 41 can be made thicker than the second resin layer 43. Although not particularly limited, for example, the first resin layer 41 can be made thicker than the second resin layer 43 by about 1 to 10 μm. The first resin layer 41 may be thinner than the second resin layer 43.

Modification 3
In the above embodiment, the electrolyte membrane 4 has a first resin layer 41, a membrane body portion 42, and a second resin layer 43, but the configuration of the electrolyte membrane 4 is not limited to this. For example, as shown in FIG. 3, the electrolyte membrane 4 does not have to have the second resin layer 43. That is, the electrolyte membrane 4 can be composed of the first resin layer 41 and the membrane body portion 42. In this case, the cathode 2 may be formed on the first resin layer 41 and the anode 3 may be formed on the film body 42, or the anode 3 may be formed on the first resin layer 41 and the cathode 2 may be formed on the film body. It may be formed on the portion 42.

Modification 4
In the above embodiment, the first resin layer 41 is made of a material different from that of the support 422, but the structure of the first resin layer 41 is not limited to this. For example, the first resin layer 41 may be composed of the materials listed as the constituent materials of the support 422. Further, the first resin layer 41 can be made of the same material as the support 422. In this case, the first resin layer 41 may have an ionic conductor. The volume content of the ionic conductor in the first resin layer 41 is smaller than the volume content of the ionic conductor 421 in the membrane body 42. Similarly, the second resin layer 43 may also be composed of the materials listed as the constituent materials of the support 422.

Modification 5
In the above embodiment, the first resin layer 41 has a lower water absorption rate than the support 422, but the first resin layer 41 is not limited to this. For example, the first resin layer 41 may have a higher water absorption rate than the support 422. That is. The resin constituting the first resin layer 41 may have a higher water absorption rate than the resin constituting the support 422.

Modification 6
In the above embodiment, the thickness t1 of the first resin layer 41 and the thickness t3 of the second resin layer 43 are smaller than the thickness t2 of the film body portion 42, but the configuration of the electrolyte 4 is not limited to this. For example, the thickness t1 of the first resin layer 41 may be larger than the thickness t2 of the film body portion 42. Further, the thickness t3 of the second resin layer 43 may be larger than the thickness t2 of the film body portion 42.

In this case, the ratio (t1 / t2) of the thickness t1 of the first resin layer 41 to the thickness t2 of the film main body portion 42 can be set to 1.1 to 2.0. Similarly, the ratio (t3 / t2) of the thickness t3 of the second resin layer 43 to the thickness t2 of the film main body portion 42 can be set to 1.1 to 2.0.

Modification 7
In the above embodiment, the first resin layer 41 has a higher ionic conductivity than the second resin layer 43, but the first resin layer 41 can have a lower ionic conductivity than the second resin layer 43.

Modification 8
In the above embodiment, the membrane body 42 has hydroxide ion conductivity, but the ion conductivity of the membrane body 42 is not limited to this. For example, the membrane body portion 42 may have proton conductivity or oxygen ion conductivity.

Modification 9
In the above embodiment, the embodiment in which the fuel cell electrolyte membrane according to the present invention is applied to a solid alkaline fuel cell has been described, but the object to which the fuel cell electrolyte according to the present invention is applied is a solid alkaline fuel cell. It is not limited, and can be applied to other fuel cells such as a solid polymer fuel cell.

Modification 10
Further, in the above embodiment, as an example of the fuel cell, the solid alkaline fuel cell 100 having a hydroxide ion as a carrier has been described, but a fuel cell having a proton as a carrier may be used. In this case, the ionic conductor 421 can be made of a ceramic material having proton conductivity.

As the ceramic material having proton conductivity, a metal oxide hydrate having proton conductivity or the like can be used. Examples of such metal oxide hydrates include zirconium oxide hydrate, tungsten oxide hydrate, tin oxide hydrate, niobium-doped tungsten oxide, silicon oxide hydrate, and phosphoric acid oxide hydrate. Zirconium-doped silicon oxide hydrate, tonguestronic acid, molybdrine acid and the like can be used.

2 Cathode 3 Anode 4 Electrolyte film 41 1st resin layer 42 Membrane body 43 2nd resin layer

Claims (18)

An electrolyte membrane used in fuel cells
A membrane body having an ionic conductor made of ceramics and a support made of resin,
The first resin layer arranged on one surface of the film body and
To prepare
Electrolyte membrane for fuel cells.
The first resin layer is made of a material different from that of the support.
The electrolyte membrane for a fuel cell according to claim 1.
The first resin layer has a higher ionic conductivity than the support.
The electrolyte membrane for a fuel cell according to claim 1 or 2.
The first resin layer has a lower water absorption rate than the support.
The electrolyte membrane for a fuel cell according to any one of claims 1 to 3.
The first resin layer is made of the same material as the support.
The electrolyte membrane for a fuel cell according to claim 1.
The first resin layer is thinner than the film body.
The electrolyte membrane for a fuel cell according to any one of claims 1 to 5.
The first resin layer is thicker than the film body.
The electrolyte membrane for a fuel cell according to any one of claims 1 to 5.
A second resin layer made of resin, which is arranged on the other surface of the film body, is further provided.
The electrolyte membrane for a fuel cell according to any one of claims 1 to 7.
The second resin layer is made of a material different from that of the support.
The electrolyte membrane for a fuel cell according to claim 8.
The second resin layer has a higher ionic conductivity than the support.
The electrolyte membrane for a fuel cell according to claim 8 or 9.
The second resin layer has a lower water absorption rate than the support.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 10.
The second resin layer is made of the same material as the support.
The electrolyte membrane for a fuel cell according to claim 8.
The second resin layer is thinner than the film body.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 12.
The first resin layer is thicker than the second resin layer.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 13.
The first resin layer is thinner than the second resin layer.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 13.
The first resin layer has a higher ionic conductivity than the second resin layer.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 15.
The first resin layer has a lower ionic conductivity than the second resin layer.
The electrolyte membrane for a fuel cell according to any one of claims 8 to 15.
The electrolyte membrane for a fuel cell according to any one of claims 1 to 17.
The first electrode arranged on one surface of the electrolyte membrane and
A second electrode arranged on the other surface of the electrolyte membrane and
Equipped with a fuel cell.

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