JP2007188745A - Hydrogen separation membrane fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a leak of glass electrolyte when thin layerization of the glass electrolyte is worked. <P>SOLUTION: The hydrogen separation membrane fuel cell comprises an electrolyte membrane 200, a cathode 120, and an anode 140. Oxidizer gas including oxygen is supplied to the cathode 120 arranged on one of sides of the electrolyte membrane 200, and fuel gas including hydrogen is supplied to the anode 140 arranged on another side of the electrolyte membrane 200. The electrolyte membrane 200 of the fuel cell comprises: a hydrogen permeable base 220 with hydrogen permeability which has a non-porous layer on its cathode side surface; and a glass electrolyte layer 210 with proton conductivity which is so formed that it contacts to the non-porous layer of the hydrogen permeable base 200. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for thinning a glass electrolyte of a fuel cell using a glass electrolyte.

  The use of a vitreous electrolyte (glass electrolyte) as an electrolyte of a fuel cell that can operate in a medium temperature range has been performed. Since this glass electrolyte is a brittle material, it may be damaged if made thin in order to reduce the membrane resistance of the electrolyte. In view of this, it has been proposed to reduce the thickness of the glass electrolyte by forming a glass electrolyte on a porous support and applying mechanical strength to the support (see, for example, Patent Document 1).

JP 2003-331862 A JP 2003-331867 A JP 2004-146337 A

  However, when a glass electrolyte is formed on a porous support, if the glass electrolyte is thinned, pinholes may be generated in the glass electrolyte due to irregularities on the surface of the support. Further, depending on the thickness of the glass electrolyte and the pore diameter of the support, the glass electrolyte may be broken and cracks may occur. Thus, when pinholes or cracks occur in the glass electrolyte, there is a risk that the power generation characteristics and power generation efficiency of the fuel cell may be reduced due to leakage of gas or the like.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to suppress the leakage of the glass electrolyte when the glass electrolyte is thinned.

  In order to achieve at least a part of the above object, a fuel cell of the present invention includes an electrolyte membrane, a cathode disposed on one surface of the electrolyte membrane and supplied with an oxidant gas containing oxygen, and the electrolyte membrane. And an anode to which a hydrogen-containing fuel gas is supplied, wherein the electrolyte membrane is hydrogen permeable and includes a non-porous layer on the cathode side surface. It is characterized by comprising a hydrogen permeable base material and a glass electrolyte layer formed so as to be in contact with the non-porous layer of the hydrogen permeable base material and having proton conductivity.

  According to this configuration, since the glass electrolyte is formed on the non-porous layer of the hydrogen permeable substrate, the occurrence of pinholes and cracks in the glass electrolyte due to the unevenness of the substrate surface is suppressed. Therefore, it becomes possible to make the glass electrolyte thinner while suppressing the leakage of the glass electrolyte.

  The hydrogen permeable substrate may include a hydrogen permeable metal layer having hydrogen selective permeability.

  The hydrogen permeable metal layer having hydrogen selective permeability is a non-porous layer. Therefore, by using a hydrogen permeable metal layer, the cathode side surface of the hydrogen permeable substrate can be made more non-porous.

  The hydrogen-permeable base material may include a main component having hydrogen permeability and a proton converting substance having a higher ability to convert atomic hydrogen into protons and electrons than the main component.

  According to this configuration, protons converted from atomic hydrogen by the proton conversion substance are supplied to the glass electrolyte. Therefore, since the amount of protons that permeate the glass electrolyte can be increased, the power generation characteristics of the fuel cell are further improved.

  The hydrogen permeable base material may include a proton conversion layer containing the proton conversion material on the cathode side surface of the hydrogen permeable base material.

  According to this configuration, protons are generated by the proton conversion layer in contact with the glass electrolyte forming surface of the hydrogen permeable substrate, so that it is possible to increase the amount of protons supplied to the glass electrolyte.

  The present invention can be realized in various modes. For example, a fuel cell and a fuel cell system using the fuel cell, and a power generation device using the fuel cell system and the fuel cell system are provided. It can be realized in the form of a mounted electric vehicle or the like.

Next, 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. Fourth embodiment:
E. Variation:

A. First embodiment:
FIG. 1 is a schematic cross-sectional view showing the structure of a cell 100 constituting the fuel cell in the first embodiment. The fuel cell has a fuel cell stack in which the cells 100 are stacked. The cell 100 includes an electrolyte membrane 200, two electrode layers 120 and 140 provided on both surfaces of the electrolyte membrane 200, a cathode-side separator 110 and an anode-side separator 130 that sandwich the electrolyte membrane 200 and the electrode layers 120 and 140 from both sides. It is equipped with. These two separators 110 and 130 are formed of a material having gas impermeability and conductivity, such as press-molded stainless steel.

The first electrode layer 120 (hereinafter also referred to as “cathode side electrode layer 120”) is formed by supporting a catalyst that promotes an oxidation reaction on the cathode side on a metal porous body. As the catalyst supported on the cathode side electrode layer 120, a noble metal such as platinum (Pt) or a conductive ceramic such as LaSrMnO ₃ can be used. In the first embodiment, the catalyst is supported on the metal porous body. However, the catalyst may be directly supported on the cathode side surface of the electrolyte membrane 200, or the cathode side surface of the electrolyte membrane 200. Alternatively, a layer having hydrogen permeability and catalytic activity such as a thin film of palladium (Pd) may be formed. In this case, the cathode side electrode layer 120 can be omitted.

  The second electrode layer 140 (hereinafter also referred to as “anode side electrode layer 140”) is formed of a metal porous body in the same manner as the cathode side electrode layer 120. No catalyst is supported on the anode-side electrode layer 140 of the first embodiment. However, a catalyst such as platinum or an alloy containing platinum as a main component may be supported. The anode side electrode layer 140 can also be omitted.

  The electrolyte membrane 200 includes a hydrogen permeable metal layer 220 and a glass electrolyte layer 210 formed on one surface of the hydrogen permeable metal layer 220. The glass electrolyte layer 210 is a glass thin film in which functional groups (ion exchange groups) that impart proton conductivity to glass are immobilized in a glass skeleton. The glass electrolyte layer 210 may be any glass as long as it is proton conductive, such as a phosphate glass electrolyte layer having a phosphate group as an ion exchange group, or a sulfuric acid glass electrolyte layer having a sulfate group as an ion exchange group. It is possible to use an electrolyte layer.

  The hydrogen permeable metal layer 220 is a member formed of an alloy of palladium and platinum (palladium / platinum alloy) and having a sufficient thickness (for example, 40 μm) to maintain the mechanical strength of the electrolyte membrane 200. The hydrogen permeable metal layer 220 is formed so dense (non-porous) that gas gas does not permeate so as to have selective hydrogen permeability. The hydrogen permeable metal layer 220 can be said to be a hydrogen permeable substrate on which a glass electrolyte layer is formed and a non-porous layer on the surface of the hydrogen permeable substrate cathode.

  In the first embodiment, the composition ratio of palladium to platinum of the palladium-platinum alloy used for the hydrogen permeable metal layer 220 is set to 5 parts by weight of platinum with respect to 95 parts by weight of palladium. This composition ratio can be appropriately set in consideration of hydrogen permeability and the like. Specifically, the weight of platinum relative to the weight of the palladium / platinum alloy (hereinafter also referred to as “platinum content”) is preferably 20% by weight or less. Further, in order to sufficiently increase the hydrogen permeability of the hydrogen permeable metal layer 220, the platinum content is more preferably 10% by weight or less.

  The hydrogen permeable metal layer 220 can be formed of high-purity palladium containing almost no platinum (hereinafter also referred to as “single palladium”), but as described later, an alloy of palladium and platinum is used to form hydrogen. The permeable metal layer 220 is preferably formed. In this case, the platinum content of the palladium-platinum alloy is more preferably 1% by weight or more, and further preferably 2% by weight or more.

  The cathode side separator 110 and the anode side separator 130 are each provided with a recess on the side facing the electrolyte membrane 200. Air is supplied as an oxidant gas containing oxygen to a space (cathode side flow path) 112 formed by the concave portion provided in the cathode side separator 110 and the cathode side electrode layer 120. Further, a fuel gas containing hydrogen is supplied to a space (anode-side flow path) 132 formed by the recess provided in the anode-side separator 130 and the anode-side electrode layer 140. In addition, the shape of the separators 110 and 130, the shape of the flow paths 112 and 132, and these structures can be changed suitably. For example, it is possible to form the separators 110 and 130 on the side of the electrolyte membrane 200 and form the channels 112 and 132 with porous gas diffusion layers.

  FIG. 2 is an explanatory view showing main steps for manufacturing the electrolyte membrane 200. First, in the process of FIG. 2A, a hydrogen permeable metal layer 220 formed of palladium / platinum alloy is prepared. The flat hydrogen-permeable metal layer 220 is formed, for example, by rolling an ingot of palladium / platinum alloy (hereinafter also referred to as “alloy lump”). The hydrogen permeable metal layer 220 formed by rolling the alloy lump becomes a non-porous member from which voids, pinholes and the like are removed.

  The hydrogen permeable metal layer 220 is preferably formed with a smooth surface in order to improve the adhesion between the hydrogen permeable metal layer 220 and the glass electrolyte layer 210. In this case, in the hydrogen permeable metal layer 220, the ratio of the arithmetic surface roughness (Ra) of the hydrogen permeable metal layer 220 to the thickness of the glass electrolyte layer 210 is a predetermined value (for example, 1/100 to 1/200). It is formed to be as follows.

In the step of FIG. 2B, liquid glass is applied to one side of the hydrogen permeable metal layer 220. The liquid glass to be applied is prepared, for example, by forming a phosphoric acid (H ₃ PO ₄ ) and tetraethylorthosilicate (TEOS) mixed liquid when forming the phosphoric acid-based glass electrolyte layer 210. It can be produced by hydrolyzing acid and TEOS.

  Application of liquid glass to the hydrogen permeable metal layer 220 can be performed by a known method such as a spin coating method or a doctor blade method. Thus, by applying liquid glass, a thin glass electrolyte gel 212 is formed on the hydrogen permeable metal layer 220.

  In the step of FIG. 2C, the glass electrolyte layer 210 is fired by heat-treating the hydrogen permeable metal layer 220 coated with liquid glass. Thus, even when the glass electrolyte layer 210 is thinned by forming the glass electrolyte layer 210 on the surface of the hydrogen permeable metal layer 220, the occurrence of pinholes in the glass electrolyte layer 210 and the glass electrolyte Damage to the layer 210 is suppressed. Therefore, even if the thin glass electrolyte layer 210 is used for the electrolyte membrane 200, it is possible to suppress the occurrence of leakage in which hydrogen leaks to the cathode side through the electrolyte membrane 200 due to pinholes or breakage.

  FIG. 3 is an explanatory diagram showing main chemical reactions that proceed in the electrolyte membrane 200 and the electrode layers 120 and 140. FIG. 3 shows main components (reaction components) that exist in each layer and participate in the electrochemical reaction in the fuel cell.

As described above, the fuel gas containing hydrogen is supplied to the anode side electrode layer 140 from the anode side flow path 132 (FIG. 1). Hydrogen molecules (H ₂ ) in the fuel gas are dissociated into atomic hydrogen (H) at the interface between the hydrogen permeable metal layer 220 and the anode-side electrode layer 140 by the catalytic action of palladium. The dissociated atomic hydrogen moves from the anode side electrode layer 140 side into the hydrogen permeable metal layer 220 which is a hydrogen permeable metal.

Atomic hydrogen in the hydrogen permeable metal layer 220 is converted into protons (H ⁺ ) by the catalytic action of platinum. Therefore, the hydrogen in the hydrogen permeable metal layer 220 is in a state where atomic hydrogen and protons are mixed. Electrons (e ⁻ ) generated along with the conversion of atomic hydrogen to protons are supplied to an external conductor via the anode side electrode layer 140 and the anode side separator 130 (FIG. 1).

Protons in the hydrogen permeable metal layer 220 move to the cathode side electrode layer 120 through the proton conductive glass electrolyte layer 210. In the cathode-side electrode layer 120, protons supplied from the glass electrolyte layer 210, electrons supplied from an external conductor via the cathode-side separator 110 (FIG. 1), and supply from the cathode-side channel 112 (FIG. 1). Oxygen molecules (O ₂ ) in the generated oxidant gas react to produce water (H ₂ O). Power generation in the cell 100 (FIG. 1) is performed by electrons moving from the anode side separator 130 to the cathode side separator 110 through an external conductor.

  In general, the glass electrolyte layer 210 that supplies protons from the anode side to the cathode side has a low action of a catalyst that converts atomic hydrogen into protons (hereinafter also referred to as “proton conversion ability”). Therefore, when the proton concentration on the glass electrolyte layer 210 side of the hydrogen permeable metal layer 220 is low, the amount of protons moving to the cathode side electrode layer 120 through the glass electrolyte layer 210 decreases, and the power generation characteristics of the fuel cell decrease. There is a risk.

  Therefore, in the first embodiment, the hydrogen permeable metal layer 220 is formed of palladium / platinum alloy containing platinum having a high proton conversion capacity, thereby increasing the amount of protons in the hydrogen permeable metal layer 220, and the fuel. The power generation characteristics of the battery are improved. In addition, although elemental palladium also has proton conversion ability, since platinum has higher proton conversion ability than palladium, the hydrogen permeable metal layer 220 is formed of a hydrogen permeable alloy containing platinum such as palladium / platinum alloy. Is more preferable. Note that palladium / platinum alloy has a smaller expansion amount due to occlusion of hydrogen, lower thermal expansion coefficient, and higher hardness than simple palladium. Therefore, as a material for forming the hydrogen permeable metal layer 220, palladium / platinum alloy is preferable to elemental palladium.

  As described above, in the first embodiment, the glass electrolyte layer 210 is formed on the non-porous hydrogen permeable metal layer 220, so that pinholes in the glass electrolyte layer 210 are generated and the glass electrolyte layer 210 is damaged. It is suppressed. Therefore, it is possible to suppress the occurrence of leakage due to the thin glass electrolyte layer 210.

  In the first embodiment, the hydrogen permeable metal layer 220 is formed of palladium / platinum alloy containing platinum having high proton conversion ability. Therefore, sufficient protons can be supplied from the hydrogen permeable metal layer 220 to the glass electrolyte layer 210, and the power generation characteristics of the fuel cell can be improved.

  In general, glass electrolytes have higher proton conductivity at low temperatures than ceramic electrolytes. Therefore, in the first embodiment, by using the glass electrolyte layer 210, the operating temperature of the fuel cell is reduced as compared with a hydrogen separation membrane fuel cell using an electrolyte membrane in which a ceramic electrolyte layer is formed on a hydrogen permeable metal substrate. It becomes possible to do.

B. Second embodiment:
FIG. 4 is a schematic cross-sectional view showing the structure of the cell 100a in the second embodiment. The cell 100a of the second embodiment is different from the cell 100 of the first embodiment in that the configuration of the electrolyte membrane 200a is different from the electrolyte membrane 200 (FIG. 1) of the first embodiment. Specifically, in the electrolyte membrane 200a, the proton-permeable layer 230a having a high proton-conversion capability is sandwiched between the hydrogen-permeable metal layer 220a and the glass electrolyte layer 210a, and the hydrogen-permeable metal layer 220a is It is different from the electrolyte membrane 200 of the first embodiment in that it is made of simple palladium. The other points are the same as in the first embodiment.

  FIG. 5 is an explanatory view showing main steps for manufacturing the electrolyte membrane 200a. In the manufacturing process of the electrolyte membrane 200a of the second embodiment, proton conversion is performed between the step of preparing the hydrogen permeable metal layer 220a (FIG. 5A) and the step of applying liquid glass (FIG. 5C). This is different from the manufacturing process of the electrolyte membrane 200 of the first embodiment shown in FIG. 2 in that a step of forming the layer 230a (FIG. 5B) is added. The other points are the same as those of the first embodiment, and thus the description thereof is omitted here. The step of preparing the hydrogen permeable metal layer of FIG. 5A corresponds to the step of FIG. 2A in the first embodiment, and the steps of the glass electrolytes of FIG. 5C and FIG. The forming process corresponds to each of the processes of FIGS. 2B and 2C in the first embodiment.

  In the process of FIG. 5B, the proton conversion layer 230a is formed on one side of the hydrogen permeable metal layer 220a. The proton conversion layer 230a is formed by, for example, forming a proton conversion material having a higher proton conversion capacity than the material constituting the hydrogen permeable metal layer 220a by physical vapor deposition (PVD) or chemical vapor deposition (CVD). The proton conversion ability of a substance can be evaluated by, for example, forming a thin layer of the substance to be evaluated on a glass electrolyte plate and measuring the hydrogen permeability of the glass electrolyte plate.

  In order to maintain the proton conductivity of the electrolyte membrane 200a, the proton converting material is preferably formed to have an island structure as shown in FIG. Therefore, the proton conversion layer 230a is preferably formed so that the average film thickness is 10 nm or less, and more preferably formed so that the average film thickness is 5 nm or less. However, when the proton conductivity of the proton converting substance is sufficiently high, a dense film impermeable to gas molecules may be formed.

As the proton converting substance to be formed, proton conductive ceramic electrolyte, platinum or the like can be used. Examples of ceramic electrolytes include barium serate (BaCeO ₃ ), strontium serate (SrCeO ₃ ), barium zirconate (BaZrO ₃ ), and strontium zirconate (BaZrO ₃ ) perovskite type proton conduction. A negative electrolyte can be used. Specifically, a part of the B site of these perovskite ceramics represented by the general formula of ABO ₃ is yttrium (Y), neodymium (Nd), gadolinium (Gd), ytterbium (Yb), etc. It is possible to use a ceramic electrolyte or the like replaced with a transition metal. As the proton conversion substance, for example, ceramic electrolytes shown in Table 1 below can be used.

  Even when the above ceramic electrolyte is used as the proton converting substance, the proton conductivity of the ceramic electrolyte is the proton of the glass electrolyte at the operating temperature (150 to 200 ° C.) of the fuel cell using the glass electrolyte. It becomes lower than the conductivity. Therefore, even when a ceramic electrolyte is used, the proton conversion layer 230a is preferably formed so as to have an island structure.

  FIG. 6 is an explanatory diagram showing main chemical reactions that proceed in the electrolyte membrane 200a and the electrode layers 120 and 140. FIG. Similar to FIG. 3, FIG. 6 also shows reaction components present in each layer. As shown in FIG. 6, in the electrolyte membrane 200a of the second embodiment, almost no conversion from atomic hydrogen to proton is performed in the hydrogen permeable metal layer 220a. Therefore, most of the hydrogen exists as atomic hydrogen in the hydrogen permeable metal layer 220a. The atomic hydrogen moves from the hydrogen permeable metal layer 220a to the proton conversion layer 230a.

  The atomic hydrogen moved from the hydrogen permeable metal layer 220a to the proton conversion layer 230a is converted into protons in the proton conversion layer 230a. Protons converted from atomic hydrogen move to the cathode electrode layer 120 through the glass electrolyte layer 210a and react. Note that the layer in which the hydrogen permeable metal layer 220a and the proton conversion layer 230a are stacked has hydrogen permeability, and thus can be referred to as a “hydrogen permeable substrate”. In this case, the main component of the hydrogen permeable base material is palladium which is the main component of the hydrogen permeable metal layer 220a. In addition, when the proton conversion layer 230a is formed so as to have an island-like structure, the hydrogen permeable metal layer 220a exposed on the surface of the hydrogen permeable substrate is not porous on the hydrogen permeable substrate cathode side surface. It can also be called a layer.

  Thus, in the electrolyte membrane 200a of the second embodiment, the proton conversion layer 230a is sandwiched between the hydrogen permeable metal layer 220a and the glass electrolyte layer 210a. By the proton conversion layer 230a, atomic hydrogen in the hydrogen permeable metal layer 220a is converted into protons. Therefore, it is possible to supply sufficient protons to the glass electrolyte layer 210a, so that the power generation characteristics of the fuel cell can be improved.

C. Third embodiment:
FIG. 7 is an explanatory diagram illustrating main chemical reactions that proceed in the electrolyte membrane 200b and the electrode layers 120 and 140. FIG. FIG. 7 also shows the reaction components present in each layer. The third embodiment differs from the proton conversion layer 230a of the second embodiment shown in FIG. 6 in that the proton conversion layer 230b is formed as a layer (mixed layer) in which a glass electrolyte and a proton conversion substance are mixed. ing. The other points are the same as in the second embodiment.

  FIG. 8 is an explanatory diagram showing the main steps for manufacturing the electrolyte membrane 200b. Of the manufacturing steps of the electrolyte membrane 200a of the third embodiment, the step of preparing the hydrogen permeable metal layer 220b (FIG. 8A) is the step of preparing the hydrogen permeable metal layer 220a in the second embodiment (FIG. 5). Same as (a)).

  8B and 8C, glass electrolyte fine particles and proton converting substance fine particles are sprayed on one surface of the hydrogen permeable metal layer 220b prepared in FIG. 8A. It is done. Specifically, fine particles of a glass electrolyte and a proton conversion substance are mixed with gas to form an aerosol, and the aerosol is sprayed onto the hydrogen permeable metal layer 220b at a high pressure. By the film formation by the aerosol deposition method, a mixed layer 230b containing a glass electrolyte and a proton converting substance and a glass electrolyte layer 210b are formed on the hydrogen permeable metal layer 220b. According to the aerosol deposition method, a dense film that is impermeable to gas molecules is formed.

  FIG. 8D and FIG. 8E show temporal changes in the spraying amounts of the glass electrolyte and the proton conversion material when the mixed layer 230b and the glass electrolyte layer 210b are formed. The horizontal axis of FIG.8 (d) and FIG.8 (e) represents time. Moreover, the vertical axis | shaft of FIG.8 (d) and FIG.8 (e) has each shown the spraying quantity of the glass electrolyte, and the spraying quantity of the proton conversion substance.

  In the example of FIGS. 8D and 8E, spraying is started at time t0. The spray amount of the glass electrolyte and the spray amount of the proton conversion substance are kept constant until time t1. At time t1, the proton conversion substance spraying is stopped. The amount of glass electrolyte sprayed during the period from time t1 to time t2 is greater than that during the period from time t0 to time t1. At time t2, the glass electrolyte spraying is stopped. Thus, by controlling the spraying amounts of the glass electrolyte and the proton conversion material, the mixed layer 230b as the proton conversion layer and the glass electrolyte layer 210b are formed.

  In the third embodiment, the spray amount of the glass electrolyte per unit time is increased after stopping the spraying of the proton conversion material, but the glass electrolyte layer 210b is formed without increasing the spray amount of the glass electrolyte. It is good as a thing. Since the glass electrolyte layer 210b can be formed if the proton conversion substance spraying is stopped, the glass electrolyte spraying amount per unit time can be set to an arbitrary value after the proton conversion substance spraying is stopped. Is possible.

  Also in the electrolyte membrane 200b of the third embodiment, a mixed layer 230b that is a proton conversion layer is sandwiched between the hydrogen permeable metal layer 220b and the glass electrolyte layer 210b. Therefore, as in the second embodiment, the atomic hydrogen in the hydrogen permeable metal layer 220b is converted into protons by the proton conversion layer 230b, and sufficient protons can be supplied to the glass electrolyte layer 210b. The power generation characteristics of the fuel cell can be improved.

D. Fourth embodiment:
FIG. 9 is an explanatory view showing main chemical reactions that proceed in the electrolyte membrane 200c and the electrode layers 120 and 140. FIG. FIG. 9 also shows the reaction components present in each layer. The fourth embodiment is different from the third embodiment shown in FIG. 7 in that the proton conversion layer 230c is formed as an inclined layer in which the composition ratio between the glass electrolyte and the proton conversion substance changes in the film thickness direction. . The other points are the same as in the third embodiment.

  FIG. 10 is an explanatory diagram showing the main steps for manufacturing the electrolyte membrane 200c. FIG. 10D shows the time change of the spray amount of the glass electrolyte when forming the inclined layer 230c and the glass electrolyte layer 210c, and FIG. 10E shows the time change of the spray amount of the proton converting substance. ) Is different from FIG. The other steps are the same as those of the third embodiment shown in FIG. 8, and the description thereof is omitted here.

  In the example of FIGS. 10D and 10E, spraying is started at time t0. In the period from time t0 to time t1, the amount of proton conversion substance sprayed linearly decreases with the passage of time. On the other hand, the spray amount of the glass electrolyte increases linearly with the passage of time in the period from time t0 to time t1. Then, after only the glass electrolyte is sprayed during the period from the time t1 to the time t2, the spraying of the glass electrolyte is stopped at the time t2. In this way, by controlling the spraying amounts of the glass electrolyte and the proton conversion substance, the composition of the proton conversion substance changes from 100% to 0% from the hydrogen permeable metal layer 220c side to the glass electrolyte layer 210c side. An inclined layer 230c and a glass electrolyte layer 210c are formed.

  In the fourth embodiment, the gradient layer 230c and the glass electrolyte layer 210c in which the composition ratio between the proton conversion substance and the glass electrolyte layer continuously changes are formed in this way. Since the composition ratio changes continuously, there is no clear interface between the gradient layer 230c containing the proton conversion material and the glass electrolyte layer 210c not containing the proton conversion material. Therefore, the peel strength between the inclined layer 230c and the glass electrolyte layer 210c is increased, and the strength of the electrolyte membrane 200c is further increased.

  In the electrolyte membrane 200c of the fourth embodiment, an inclined layer 230c that is a proton conversion layer is sandwiched between the hydrogen permeable metal layer 220c and the glass electrolyte layer 210c. Therefore, as in the third embodiment, sufficient protons can be supplied to the glass electrolyte layer 210c, and the power generation characteristics of the fuel cell can be improved.

  Thus, the fourth embodiment is preferable to the third embodiment in that the peel strength between the inclined layer 230c and the glass electrolyte layer 210c is increased, and the strength of the electrolyte membrane 200c can be further increased. . On the other hand, the third embodiment is preferable to the fourth embodiment in that the spray amount of the proton conversion substance and the glass electrolyte can be controlled more easily.

E. Variation:
In addition, this invention is not restricted to the said Example and embodiment, It can implement in a various aspect in the range which does not deviate from the summary, For example, the following deformation | transformation is also possible.

E1. Modification 1:
In each of the above embodiments, a palladium / platinum alloy or a single palladium single layer is used as the hydrogen permeable metal layer. However, if the hydrogen permeable metal layer has a selective hydrogen permeability, a different hydrogen permeable metal layer may be used. It is also possible to use it. As the hydrogen permeable metal layer, for example, a single layer of hydrogen permeable metal containing vanadium (V), titanium (Ti), zirconium (Zr) or the like, or these single layers are made of hydrogen permeable such as palladium. A composite layer coated with a thin film can be used.

E2. Modification 2:
In each of the above embodiments, the electrolyte membrane is formed using a hydrogen permeable substrate having a hydrogen permeable metal layer, but the electrolyte membrane is formed using a hydrogen permeable substrate having no hydrogen permeable metal layer. It is also possible to do. Generally, the hydrogen permeable substrate may be a member having a non-porous layer on the cathode side surface on which the glass electrolyte is formed and having hydrogen permeability. As the hydrogen-permeable base material, for example, a porous body in which the cathode-side pores are filled with a hydrogen-permeable metal such as palladium and the electrolyte forming surface is made non-porous can be used. In this case, the region filled with the pores of the porous body is a non-porous layer. As the porous body used for the hydrogen permeable substrate, porous ceramics, porous metals, and the like can be used.

The cross-sectional schematic diagram which shows the structure of the cell 100 which comprises the fuel cell in 1st Example. Explanatory drawing which shows the main processes which manufacture the electrolyte membrane 200. FIG. Explanatory drawing which shows the main chemical reactions which advance in the electrolyte membrane 200 and the electrode layers 120 and 140. It is a cross-sectional schematic diagram which shows the structure of the cell 100a in 2nd Example. Explanatory drawing which shows the main processes which manufacture the electrolyte membrane 200a. Explanatory drawing which shows the main chemical reactions which advance in the electrolyte membrane 200a and the electrode layers 120 and 140. Explanatory drawing which shows the main chemical reactions which advance in the electrolyte membrane 200b and the electrode layers 120 and 140. Explanatory drawing which shows the main processes which manufacture the electrolyte membrane 200b. Explanatory drawing which shows the main chemical reactions which advance in the electrolyte membrane 200c and the electrode layers 120 and 140. Explanatory drawing which shows the main processes which manufacture the electrolyte membrane 200c.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,100a ... Cell 110 ... Cathode side separator 112 ... Cathode side channel 120 ... Cathode side electrode layer 130 ... Anode side separator 132 ... Anode side channel 140 ... Anode side electrode layer 200, 200a, 200b, 200c ... Electrolyte membrane 210 , 210a, 210b, 210c ... glass electrolyte layer 212 ... gel 220, 220a, 220b, 220c ... hydrogen permeable metal layer 230a, 230b, 230c ... proton conversion layer

Claims (6)

An electrolyte membrane; a cathode disposed on one surface of the electrolyte membrane and supplied with an oxidant gas containing oxygen; and an anode disposed on the other surface of the electrolyte membrane and supplied with a fuel gas containing hydrogen. A fuel cell comprising:
The electrolyte membrane is
A hydrogen permeable substrate having hydrogen permeability and comprising a non-porous layer on the cathode side surface;
A glass electrolyte layer formed to be in contact with the non-porous layer of the hydrogen permeable substrate and having proton conductivity;
A fuel cell comprising: The fuel cell according to claim 1, wherein
The hydrogen permeable substrate includes a hydrogen permeable metal layer having hydrogen selective permeability. The fuel cell according to claim 1, wherein
The hydrogen permeable base material includes a main component having hydrogen permeability and a proton converting substance having a higher ability to convert atomic hydrogen into protons and electrons than the main component. The fuel cell according to claim 3, wherein
The hydrogen permeable substrate includes a proton conversion layer containing the proton conversion substance on a cathode side surface of the hydrogen permeable substrate. The fuel cell according to claim 3 or 4, wherein
The fuel cell, wherein the proton converting substance is a perovskite proton conductive electrolyte. The fuel cell according to claim 3 or 4, wherein
The fuel cell, wherein the proton converting material is platinum.

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