JP5478417B2 - Method for producing electrolyte composite layer for fuel cell - Google Patents

Description

  The present invention relates to a fuel cell.

  Some fuel cells include an electrolyte layer having an inorganic electrolyte having proton conductivity (the following Patent Document 1). In such a fuel cell, in order to improve power generation performance, it has been required to reduce the thickness of the electrolyte layer and improve its proton conductivity. However, simply reducing the thickness of the electrolyte layer does not sufficiently improve proton conductivity, and the power generation performance of the fuel cell is not sufficiently improved.

JP-A-2005-310606 International Publication WO2005 / 088749 Pamphlet JP 2007-273429 A JP 2007-250312 A JP 2007-214008 A

  An object of the present invention is to provide a technique for improving the power generation performance of a fuel cell.

  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]
An electrolyte composite layer for a fuel cell, comprising a hydrogen permeable metal membrane that selectively permeates hydrogen, and a plurality of communication holes that are stacked on the hydrogen permeable metal membrane and communicate in the thickness direction and bend. And a porous layer, wherein the porous layer includes a proton conductive inorganic electrolyte impregnated in the communication hole.
In the case of this fuel cell electrolyte composite layer, an electrolyte layer constituted by impregnating a porous layer with an electrolyte having proton conductivity is laminated on a hydrogen permeable metal film, thereby reducing cross-leakage of a reaction gas. It is possible to reduce the thickness while suppressing. Further, since the communication hole of the porous layer is bent, the contact interface between the electrolyte impregnated in the communication hole and the porous layer can be increased, and the proton conductivity in the proton conductive layer is further improved. be able to. Therefore, this fuel cell electrolyte composite layer can improve the power generation efficiency of the fuel cell.

[Application Example 2]
The electrolyte composite layer for a fuel cell according to Application Example 1, wherein the porous layer is made of phosphate silicate.
With this fuel cell electrolyte composite layer, the porous layer is composed of phosphoric silicate, so that better proton conductivity can be obtained.

[Application Example 3]
A fuel cell, comprising: the fuel cell electrolyte composite layer according to Application Example 1 or 2; and electrodes disposed on both sides of the fuel cell electrolyte composite layer.
According to this fuel cell, since the fuel cell electrolyte composite layer having good proton conductivity is used, the power generation performance is improved.

[Application Example 4]
A method for producing an electrolyte composite layer for a fuel cell, comprising:
(A) preparing a hydrogen permeable metal membrane that selectively permeates hydrogen;
(B) forming a porous layer provided with a plurality of bent communication holes communicating in the thickness direction on the surface of the hydrogen permeable metal film;
(C) impregnating an inorganic electrolyte having proton conductivity into the communication hole of the porous layer;
A manufacturing method comprising:
According to this manufacturing method, an electrolyte composite layer for a fuel cell having good proton conductivity can be obtained.

[Application Example 5]
In the manufacturing method according to Application Example 4, in the step (b), the hydrogen permeable metal is obtained by using a mixed solution obtained by mixing a material containing a constituent element of the porous layer and a solvent using an electrostatic force. The manufacturing method including the process of forming the said porous layer by spraying toward a film | membrane.
According to this manufacturing method, the thinned porous layer can be easily formed on the surface of the hydrogen permeable metal film.

  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. .

Schematic which shows the structure of a fuel cell. The schematic diagram which shows the manufacturing process of a single cell in order of a process. The schematic diagram for demonstrating in more detail the film-forming process of the porous thin film by an electrostatic spraying method. The schematic diagram for demonstrating the impregnation process of the electrolyte to a pore. Explanatory drawing which shows the process conditions when the inventor of this invention performed the electrostatic spraying method. Explanatory drawing which shows the image of the sample of the porous thin film layer which the inventor of this invention created. The graph which shows the IV characteristic of the electric power generation body of an Example and a comparative example.

A. Embodiment:
FIG. 1 is a schematic view showing the configuration of a fuel cell as one embodiment of the present invention. The fuel cell 100 has a stack structure in which a plurality of single cells 50 that are power generators are stacked, and generates power by receiving supply of hydrogen and oxygen as reaction gases. The single cell 50 includes an electrolyte composite layer 20 having proton conductivity, and first and second electrodes 31 and 32 that sandwich the electrolyte composite layer 20 from both sides. The single cell 50 also includes first and second separators 41 and 42 that sandwich a laminated body 40 in which the electrolyte composite layer 20 and the two electrodes 31 and 32 are laminated from the outside.

  The electrolyte composite layer 20 includes an electrolyte layer 10 that is a proton conductive layer and a hydrogen permeable metal membrane 15 that is also called a hydrogen separation membrane. The electrolyte layer 10 has proton conductivity obtained by impregnating the pores 11p of the porous thin film 11 formed on the outer surface of the hydrogen permeable metal film 15 with the electrolyte 12 which is an inorganic solid acid having proton conductivity. It is a layer having. The pores 11p are bent communication holes that allow both surfaces of the porous thin film 11 to communicate with each other, and are formed so as to be distributed almost uniformly over the entire porous thin film 11.

  Here, it is known that an electrolyte layer in a fuel cell is improved when a porous base material is used as a base material (matrix) and the pores are impregnated with an electrolyte, rather than being formed as a single electrolyte layer. (Refer to the reference example described later). The inventors of the present invention have inferred from the results of experiments conducted independently that the proton conductivity is further improved as the contact area between the porous substrate and the electrolyte increases. Therefore, in the fuel cell 100 of this embodiment, the contact area between the electrolyte 12 and the porous thin film 11 is increased by configuring the pores 11p of the porous thin film 11 constituting the electrolyte layer 10 as bent communication holes. ing.

The porous thin film 11 can be composed of, for example, phosphoric silicate. As the electrolyte 12, for example, cesium hydrogen sulfate (CsHSO ₄ ), cesium dihydrogen phosphate (CsH ₂ PO ₄ ), cesium pentahydrogen phosphate (CsH ₅ (PO ₄ ) ₂ ), and the like can be used. A method for manufacturing the electrolyte layer 10 will be described later.

  The hydrogen permeable metal film 15 is a dense metal thin film that selectively permeates hydrogen, and the reaction gas is transferred to the electrode on the side opposite to the electrode on which the reaction gas is supplied through the electrolyte composite layer 20. The so-called cross leak that permeates is suppressed. Further, in the fuel cell 100 of the present embodiment, the hydrogen permeable metal film 15 is made to function also as a support base material for supporting the electrolyte layer 10, so that the electrolyte layer 10 is thinned and protons in the electrolyte composite layer 20 are obtained. Improves conductivity.

  As the hydrogen permeable metal film 15, for example, palladium (Pd) or a Pd alloy can be used. In addition, a single group 5 metal such as vanadium (V), niobium (Nb), or tantalum (Ta), or an alloy containing these group 5 metals can be used. When the latter group 5 metal is used as the hydrogen permeable metal film 15, it is preferable that a coating layer of Pd or Pd alloy is formed on both surfaces of the hydrogen permeable metal film 15. This is because the coating layer formed on the surface opposite to the electrolyte membrane 10 of the hydrogen permeable metal membrane 15 functions as an anode electrode catalyst, and the coating layer formed on the surface on the electrolyte membrane 10 side is hydrogen permeable. This is because the metal film 15 can function as an antioxidant layer.

  The first electrode 31 is disposed on the hydrogen permeable metal film 15 side as an anode, and the second electrode 32 is disposed on the electrolyte layer 10 side as a cathode. These two electrodes 31 and 32 are made of a conductive member having gas diffusibility, and also function as a gas flow path for spreading the reaction gas over the entire electrolyte composite layer 20. The two electrodes 31 and 32 can be made of a fiber base material such as carbon fiber or graphite fiber, or a porous metal member such as foam metal or metal mesh.

  A catalyst layer for promoting an electrochemical reaction is formed on the surface of the electrodes 31 and 32 on the electrolyte composite layer 20 side. For example, platinum (Pt) can be used as the catalyst. However, in the fuel cell 100, since the hydrogen permeable metal film 15 that promotes protonation of hydrogen is arranged on the anode side, the catalyst layer on the first electrode 31 (anode) side may be omitted. The laminated body 40 in which the electrodes 31 and 32 are joined to the electrolyte composite layer 20 is also called MEA (Membrane Electrode Assembly).

  The first separator 41 is disposed on the anode side of the stacked body 40, and the second separator 42 is disposed on the cathode side of the stacked body 40. Each of the separators 41 and 42 is formed of a gas-impermeable conductive member such as a metal plate, and a flow channel 43 for a reaction gas is formed on the surface of each of the electrodes 31 and 32. . In addition, it is good also as what is provided with the refrigerant | coolant flow path for making a refrigerant | coolant flow in between each single cell 50 in the inside of the two separators 41 and 42, or an outer surface.

  2A to 2D are schematic views showing the manufacturing process of the single cell 50 in the order of steps. In the first step, a hydrogen permeable metal film 15 is prepared (FIG. 2A). In the second step, the porous thin film 11 having the pores 11p is formed on one surface of the hydrogen permeable metal film 15 by electrostatic spraying (ESD) (FIG. 2B). Here, the “electrostatic spraying method” is a method of forming a thin film on the surface of a substrate by spraying a solution of a material toward the substrate using an electrostatic force.

  FIG. 3 is a schematic diagram for explaining in more detail the film forming process of the porous thin film 11 by the electrostatic spraying method in the second process. FIG. 3A is a schematic diagram showing a configuration of a film forming apparatus 200 that forms the porous thin film 11 on the hydrogen permeable metal film 15. The film forming apparatus 200 includes a nozzle 210, a syringe device 212, a base 220, and a DC power source 230. The nozzle 210 is installed above the base 220 so as to open toward the base 220. The syringe device 212 is connected to the nozzle 210 via a pipe 213 and supplies a solution of the material to the nozzle 210.

  An electrode plate 221 is disposed on the base surface of the base 220 so as to face the opening 211 of the nozzle 210. At the time of film formation, a hydrogen permeable metal film 15 as a film forming base material is placed on the plate surface of the electrode plate 15. Note that the distance between the opening 211 of the nozzle 210 and the electrode plate 15 can be arbitrarily adjusted.

  Inside the base 220, a heater 222 is provided so as to heat the placed hydrogen permeable metal film 15. In addition, a thermocouple for detecting the heating temperature by the heater 222 is provided inside the base 220, but the illustration thereof is omitted. The DC power supply 230 is electrically connected to the electrode plate 221 and the nozzle 210 via a DC power supply line 231. The DC power supply 230 applies a high voltage (for example, 4 to 6 kV) between the nozzle 210 and the electrode plate 221 with the nozzle 210 as an anode and the electrode plate 221 as a cathode.

  FIG. 3B is a schematic diagram for explaining spraying of the material solution from the opening 211 of the nozzle 210. In the film forming process by the film forming apparatus 200, a material solution is supplied from the syringe device 212 to the nozzle 210 in a state where a high voltage is applied between the nozzle 210 and the electrode plate 221. In the opening 211 of the nozzle 210, the material solution is positively charged and pulled toward the cathode side (lower electrode plate 221 side), and the liquid level S hangs down in a tapered shape. When the resultant force of the attractive force from the electrode plate 221 and the repulsive force between the charges on the liquid surface S becomes larger than the surface tension of the liquid surface S, the liquid droplet of the solution starts from the tip of the liquid surface S. Are continuously discharged toward the hydrogen-permeable metal film 15 placed on the substrate.

  As the discharged droplet approaches the outer surface of the hydrogen permeable metal film 15, it is split into finer droplets by the repulsive force between the charges in the droplet and diffuses in a spray form. Further, since the solvent evaporates due to the heating of the heater 222 of the base 220, the droplets shrink as they approach the outer surface of the hydrogen permeable metal film 15. A thin film is formed on the outer surface of the hydrogen permeable metal film 15 by adhering and depositing the material that has reached the hydrogen permeable metal film 15. By baking the thin film formed on the hydrogen permeable metal film 15 for a predetermined time, the porous thin film 11 is formed (FIG. 2B).

  The structure of the porous thin film 11 such as the thickness of the porous thin film 11, the pore diameter of the pores 11 p, and the porosity varies depending on the processing conditions in the film forming apparatus 200. Specific processing conditions include a distance between the nozzle 210 and the hydrogen permeable metal film 15 (hereinafter referred to as “spraying distance”), a voltage applied by the DC power source 230, and a supply flow rate of the solution from the syringe device 212. , Processing time (also referred to as “deposition time”), heating temperature by the heater 222 (also referred to as “deposition temperature”), concentration of the material solution, and the like.

  FIG. 4 is a schematic diagram for explaining a step of impregnating the electrolyte 12 into the pores 11p of the porous thin film 11 as the third step. In this step, the electrolyte solution 301 melted by heating is stored in the solution tank 300. Then, the hydrogen permeable metal film 15 on which the porous thin film 11 is formed is immersed in the electrolyte solution 301 for a predetermined time in a state where the pressure in the tank of the solution tank 300 is reduced by the suction pump 310. Thereby, the pores 11p of the porous thin film 11 can be impregnated with the electrolyte 12, and the electrolyte composite layer 20 is formed (FIG. 2C).

  In the fourth step (FIG. 2D), the stacked body 40 is formed by disposing the electrodes 31 and 32 on both sides of the electrolyte composite layer 20. Specifically, the catalyst-supporting carbon is applied to one surface of the base material (for example, carbon paper) of the electrodes 31 and 32, and the applied surface and the electrolyte composite layer 20 are brought into contact with each other to perform hot pressing. . Next, in this 4th process, the single cell 50 is comprised by holding the laminated body 40 with the separators 41 and 42. FIG. The fuel cell 100 is completed by stacking and fastening the plurality of single cells 50 manufactured by these steps.

  As described above, in the fuel cell 100 of the present embodiment, the electrolyte composite layer 20 includes the hydrogen permeable metal film 15, thereby suppressing the cross leak of the reaction gas via the electrolyte composite layer 20 and the electrolyte layer 10. Thinning can be achieved. Further, in the electrolyte layer 10, the contact area between the electrolyte 12 and the porous thin film 11 is formed by configuring the pores 11 p of the porous thin film 11 that is a base material for holding the electrolyte 12 as bent communication holes. Has increased. Accordingly, proton conductivity in the electrolyte composite layer 20 is improved. If the fuel cell 100 uses the electrolyte composite layer 20, the power generation performance is improved.

B. Example of creating a porous thin film layer:
5 and 6 are explanatory views for explaining an example of creating the porous thin film 11 by the electrostatic spraying method performed by the inventors of the present invention. FIG. 5 shows a table in which the processing conditions when the inventor of the present invention performs the electrostatic spray method are summarized for each created sample. The inventor of the present invention created three samples S1 to S3 as preparation samples of the porous thin film 11 under the conditions described below.

The common creation conditions for the samples S1 to S3 are as follows.
<Material solution>
Any sample S1-S3 was formed using the following material solution. That is, using diethylene glycol monobutyl ether (C ₈ H ₁₈ O ₃ ; manufactured by Nacalai Tesque) as a solvent, phosphoric acid (H ₃ PO ₄ ; manufactured by Wako Pure Chemical Industries, Ltd.) and tetraethyl orthosilicate ((C ₂ H ₅ O) ₄ A mixed solution obtained by mixing Si: Wako Pure Chemical Industries, Ltd. (special grade) was used as a material solution. In addition, the density | concentration of the material solution was changed for every sample S1-S3.
<Deposition substrate>
In any of the samples S1 to S3, a Pd substrate having a thickness of 100 μm was formed as a hydrogen permeable metal film 15 on the surface thereof.
<Others>
The heating temperature of the hydrogen permeable metal film 15 by the heater 222 was detected and controlled by a thermocouple. Furthermore, the thin film formed by electrostatic spraying was baked at 400 ° C. for 6 hours.

Next, the production conditions that differ for each of the samples S1 to S3 are as follows.
<Sample S1>
For the sample S1, a mixed solution having a volume molar concentration of H ₃ PO ₄ of 0.04 mol / L and a volume molar concentration of (C ₂ H ₅ O) ₄ Si of 0.016 mol / L was used as a material. Further, the spraying distance is 40 mm, the voltage applied by the DC power supply 230 is 5.4 kV, the solution supply flow rate from the syringe device 212 is 2.0 ml / h, and the temperature of the hydrogen permeable metal film 15 is controlled to 250 ° C. The processing time was 24 hours.
<Sample S2>
For sample S2, a mixed solution having a volume molar concentration of H ₃ PO ₄ of 0.01 mol / L and a volume molar concentration of (C ₂ H ₅ O) ₄ Si of 0.004 mol / L was used as a material. Further, the spraying distance is 25 mm, the voltage applied by the DC power supply 230 is 4.5 kV, the solution supply flow rate from the syringe device 212 is 4.0 ml / h, and the temperature of the hydrogen permeable metal film 15 is controlled to 300 ° C. The processing time was 3 hours.
<Sample S3>
For sample S3, a mixed solution having a volume molar concentration of H ₃ PO ₄ of 0.04 mol / L and a volume molar concentration of (C ₂ H ₅ O) ₄ Si of 0.016 mol / L was used as a material. Further, the spray distance is 40 mm, the voltage applied by the DC power supply 230 is 4.9 kV, the solution supply flow rate from the syringe device 212 is 2.0 ml / h, and the temperature of the hydrogen permeable metal film 15 is controlled to 275 ° C. The processing time was 24 hours.

  6A to 6F are images obtained by photographing samples S1 to S3 created under the above processing conditions. 6A is an image obtained by photographing the surface of the sample S1, and FIG. 6B is an image obtained by photographing a cross section of the sample S1. FIG. 6C is an image obtained by photographing the surface of the sample S2, and FIG. 6D is an image obtained by photographing a cross section of the sample S2. 6E is an image obtained by photographing the surface of the sample S3, and FIG. 6F is an image obtained by photographing a cross section of the sample S3. Note that each image in FIGS. 6A to 6F is provided with a scale indicating the scale of the image. FIGS. 6B, 6D, and 6F show the thicknesses of the samples S1 to S3 (sample S1: 18 μm, sample S2: 11.5 μm, sample S3: 17 μm).

  Sample S1 had medium pore pore roughness among samples S1 to S3, and the thickness of the film was the thickest. Sample S2 was formed with the thinnest membrane thickness, although the pores were the coarsest among samples S1 to S3. That is, by using the sample S2, when the electrolyte composite layer 20 is formed, the distance of the proton conduction path (the thickness of the membrane) can be minimized, and the electrolyte 12 and the porous thin film 11 are formed by the bent pores. The contact area with can be increased. Sample S3 had the finest pores among samples S1 to S3. That is, when the sample S3 is used, the contact area between the electrolyte 12 and the porous thin film 11 can be maximized when the electrolyte composite layer 20 is formed.

C. Example:
FIG. 7 is a graph showing the results of an experiment by the inventors of the present invention. As an embodiment of the present invention, the inventor of the present invention forms an electrolyte layer by using the above-described sample S2, and configures a power generation body by arranging electrodes on both sides of the electrolyte layer. Was measured. Specifically, the experiment was performed as follows.

CsH ₅ (PO ₄ ) ₂ was used as the electrolyte impregnated into the porous thin film. CsH ₅ (PO ₄ ) ₂ is an aqueous solution in which H ₃ PO ₄ (manufactured by Wako Pure Chemical Industries, Ltd.) and cesium carbonate (Cs ₂ CO ₃ ; manufactured by Aldrich, 99%) are mixed at a molar ratio of 4: 1. The powder was obtained by heating and drying at 100 ° C. for about 12 hours. As a result of XRD measurement of this powder, it was confirmed that all peaks belonged to the CsH ₅ (PO ₄ ) ₂ phase (corresponding to JCPDS card 24-0252).

The sample S2 is immersed in the electrolyte solution (temperature 160 ° C.) in which the CsH ₅ (PO ₄ ) ₂ powder is melted at a pressure of 8 hPa for about 30 minutes, so that the CsH ₅ is contained in the pores of the sample S2. (PO ₄ ) ₂ was impregnated. Carbon paper coated with platinum-supporting carbon was bonded as an electrode to both sides of the electrolyte layer thus formed. The platinum loading per unit area of the electrode was 1 mg / cm ² . The power generation test was performed at a temperature of 200 ° C. by supplying hydrogen with a humidity of 30% and oxygen with a humidity of 30% to each electrode.

Here, the inventor of the present invention created a power generator as a comparative example described below, and measured its IV characteristics. The power generator of the comparative example was formed by the same configuration as the power generator of the example except that the configuration of the porous thin film impregnated with the electrolyte was different. In the power generation body of the comparative example, a porous thin film formed of eutectic-decomposed silica and formed so that pores extending substantially linearly in the thickness direction are regularly arranged is used. Specifically, the porous thin film of the comparative example was obtained by forming a film on the surface of a hydrogen permeable metal film (Pd substrate) by sputtering. As a film forming raw material (target), a mixture in which iron oxide (FeO) and silicon oxide (SiO ₂ ) were mixed at a ratio of 7: 3 was used. The Pd substrate on which the thin film was formed was fired at a temperature of 600 ° C. for about 2 hours, thereby eutecticizing the thin film FeO and SiO ₂ . Moreover, the above-mentioned pore group was formed in the thin film by etching the thin film using an aqueous hydrochloric acid solution having a concentration of 15% and removing the iron oxide portion. The IV characteristics of the power generator of the comparative example were measured under the same conditions as the power generator of the example.

  In the graph of FIG. 7, the IV characteristic of the power generator of the example is indicated by a solid line, and the IV characteristic of the power generator of the comparative example is indicated by a one-dot chain line. As these graphs show, the power generator of the example was able to generate power at a low voltage and high current density, and the power generation efficiency was improved. From this experiment, it is understood that the power generation performance of the fuel cell can be improved by forming the proton conductive layer using a porous thin film having bent pores.

D. Reference example:
As a reference example of the present invention, a change in the temperature dependence characteristic of conductivity due to a difference in the configuration of the electrolyte layer described in the following reference will be described.
[References]
Toshiaki MATSUI, Hiroki MUROYAMA, Ryuji KIKUCHI, and Koichi EGUCHI, "Development of Novel Proton Conductors Consisting of Solid Acid / pyrophosphate Composite for Intermediate-temperature Fuel Cells", Journal of the Japan Petroleum Institute, 53, (1), 1-11 (2010)
Fig. 4 of this reference shows the temperature dependence characteristics of the conductivity of the four electrolyte layers obtained by experiments. The graph shows the logarithm of conductivity on the vertical axis and the reciprocal of absolute temperature on the horizontal axis. It is shown.

Here, in FIG. 4, the graph plotted with “●” is an electrolyte layer (hereinafter referred to as “first”) in which SiP ₂ O ₇ is used as a matrix and pores thereof are impregnated with CsH ₂ PO ₄ which is an inorganic electrolyte. The electrolyte layer is referred to as “the electrolyte layer”. The first electrolyte layer has a molar ratio of CsH ₂ PO ₄ and SiP ₂ O ₇ of 1: 2. The graph plotted with “◇” is a graph for an electrolyte layer (hereinafter referred to as “second electrolyte layer”) configured as a single layer of CsH ₂ PO ₄ without providing a matrix.

The graph plotted with “▽” is a graph of an electrolyte layer (hereinafter, referred to as “third electrolyte layer”) in which pores are impregnated with CsH ₂ PO ₄ as an inorganic electrolyte using SiO ₂ as a matrix. It is. The third electrolyte layer has a molar ratio of CsH ₂ PO ₄ and SiO ₂ of 2: 1. The graph plotted with “x” is a graph for an electrolyte layer (hereinafter referred to as “fourth electrolyte layer”) configured as a single layer of SiP ₂ O ₇ without providing a matrix.

  Comparing the graph for the first electrolyte layer with the graph for the second electrolyte layer reveals the following. That is, the conductivity of the second electrolyte layer not having a matrix is significantly reduced when the temperature is lowered below a certain temperature (about 230 ° C.), whereas the first electrolyte layer having a matrix is The conductivity is relatively stable regardless of temperature changes. Further, when the graph for the first electrolyte layer is compared with the graph for the third electrolyte layer, the following can be understood. That is, even in the case of having a matrix, the first electrolyte layer containing phosphoric acid in the matrix is stably higher than the second electrolyte layer not containing phosphoric acid regardless of temperature changes. The conductivity is shown.

  Thus, as can be seen from these graphs shown in the reference, the electrolyte layer preferably has a matrix. Further, it is more preferable that the matrix is constituted by a member containing phosphoric acid such as phosphoric acid silicate.

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

E1. Modification 1:
In the said embodiment, the porous thin film 11 was formed using the electrostatic spraying method. However, the porous thin film 11 may be formed by other methods. For example, the porous thin film 11 may be formed by applying an organic solvent in which a material is dissolved substantially uniformly on the surface of the hydrogen permeable metal film 15 by a doctor blade method or the like and baking it.

E2. Modification 2:
In the above embodiment, the electrolyte composite layer 20 is formed by directly forming the porous thin film 11 on the surface of the hydrogen permeable metal film 15. However, the electrolyte composite layer 20 may be formed by laminating and bonding the porous thin film 11 and the hydrogen permeable metal film 15 separately prepared. However, since the porous thin film 11 can be made thinner by forming the porous thin film 11 directly on the surface of the hydrogen permeable metal film 15, the proton conduction in the electrolyte composite layer 20 can be reduced. It is possible to improve the property.

E3. Modification 3:
In the said Example, the porous thin film 11 was comprised with the phosphoric acid silicate. However, the porous thin film 11 may be composed of other members. For example, the porous thin film 11 may be made of silica. However, the proton conductivity in the electrolyte composite layer 20 can be further improved when the porous thin film 11 is made of phosphate silicate. The reason why the proton conductivity is improved by the phosphate silicate of the porous thin film 11 is presumed to be that the phosphoric acid constituting the phosphate silicate contributes to proton conduction.

E4. Modification 4:
In the said Example, the electrolyte 12 was impregnated to the pore 11p by immersing the porous thin film 11 in the solution which melt | dissolved the electrolyte 12. FIG. However, the impregnation of the electrolyte 12 into the pores 11p may be performed by other methods. For example, a solution in which the electrolyte 12 is melted may be injected toward the pores 11p.

DESCRIPTION OF SYMBOLS 10 ... Electrolyte layer 11 ... Porous thin film 11p ... Pore 12 ... Electrolyte 15 ... Hydrogen-permeable metal film 20 ... Electrolyte composite layer 31 ... 1st electrode 32 ... 2nd electrode 40 ... Laminate 41 ... 1st separator DESCRIPTION OF SYMBOLS 42 ... 2nd separator 43 ... Channel groove 50 ... Single cell 100 ... Fuel cell 200 ... Film-forming apparatus 210 ... Nozzle 211 ... Opening part 212 ... Syringe device 213 ... Piping 220 ... Base 221 ... Electrode plate 222 ... Heater 230 ... DC power supply 231 ... DC power supply line 300 ... Solution tank 301 ... Electrolyte solution 310 ... Suction pump S ... Liquid surface

Claims (1)

A method for producing an electrolyte composite layer for a fuel cell, comprising:
(A) preparing a hydrogen permeable metal membrane that selectively permeates hydrogen;
(B) forming a porous layer provided with a plurality of bent communication holes communicating in the thickness direction on the surface of the hydrogen permeable metal film;
(C) impregnating an inorganic electrolyte having proton conductivity into the communication hole of the porous layer;
Equipped with a,
In the step (b), the porous solution is formed by spraying a mixed solution obtained by mixing a material containing a constituent element of the porous layer and a solvent toward the hydrogen permeable metal film using an electrostatic force. The manufacturing method including the process of forming a layer .

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