JP5118827B2 - Proton conduction fuel cell and method for producing the same, hydrogen sensor and method for producing the same - Google Patents

Description

  The present invention relates to a proton conductive fuel cell and a method for manufacturing the same, a hydrogen sensor and a method for manufacturing the same, and more particularly to an improvement in the air electrode of the proton conductive fuel cell and the measurement electrode of the hydrogen sensor.

There are the following documents regarding electrode materials exhibiting high proton conductivity. In the research results by KDKreuer et al., An example in which Zr is replaced with Y in the basic form of BaZrO ₃ is introduced.

When Y is less than 0.1, the crystal system is cubic. However, when Y is from 0.1 to 0.25, the crystal system changes to tetragonal system and 0.25 to become cubic system again. The ion conductivity of LaSrGaMgO ₃ and Zr _1-x Y _x O ₂ systems is 10 ⁻⁶ S / cm at 300 ° C. or lower, whereas proton conductivity (PH ₂ O ₃ ) by the BaZr _0.8 Y _0.2 O ₃ vehicle mechanism. = 23 hPa) is 10 ⁻² S / cm at 200 ° C., which is 10,000 times as effective. (See Non-Patent Document 1)
According to the report of Bohn and Schober, BaZr _0.9 Y _0.1 O _2.95 shows the result of measuring the conductivity in the particles by changing the temperature and the amount of water vapor, and 1.7 × 10 ⁻³ S / s in a humid atmosphere of 300 ° C. cm, about 1.7 × 10 ⁻⁶ S / cm at a dry atmosphere of 300 ° C., which is a result that the conductivity is improved 1000 times by the wet atmosphere. In the comparison of the normalized conductivity of the inside of the grain and the grain boundary, the influence of the atmospheric humidity was small between 100 and 300 ° C. within the grain, but the wet atmosphere was one order larger at the grain boundary. (See Non-Patent Document 2)
Schneller and Schober reported that the conductivity of thin film BaZr _0.8 Y _0.2 O _2.9 on a silicon substrate was compared between 200 and 400 ° C. using dry air and wet hydrogen. It was a value ten times higher. (See Non-Patent Document 3)
In the BaCeO ₃ system, many reports have been made by KDKreuer in which Ce is replaced with a rare earth. With (Ba _0.97 Y _0.03 ) (Ce _0.84 Y _0.16 ) O _2.983 and (Ba _0.97 Nd _0.03 ) (Ce _0.84 Nd _0.16 ) O _2.983 , 3 × H ₂ O is changed from 1.7 × 10 ⁻³ S / cm to 0. 01 S / cm. (See Non-Patent Document 4)
Similarly, in the review by KDKreuer et al., There is a report on single crystal Y: BaCeO _3, which is 1.7 × 10 ⁻³ S / cm. In this system, hydration enthalpy increases due to substitution of the B site element with Gd or Y, and thus a high proton concentration is exhibited at high temperatures. (See Non-Patent Documents 5 and 6)
Regarding the BaCeO ₃ -based electrode, Patent Document 1 discloses one using Pd and a Pd alloy, and Patent Document 2 discloses Ba (Zr _1-x Ce) _{1- y My} Al _z O _{3 -a.} A system (500 ° C.) is disclosed.
Solid State Ionics 145 (2001) 295-306 Journal of American Ceramic Society 83 [4] 768-72 (2000) Solid State Ionics 164 (2003) 131-136 Solid State Ionics 86-88 (1996) 613-620 Solid State Ionics 97 (1997) 1-15 Solid State Ionics 125 (1997) 285-302 JP 2004-146337 A JP 2004-063460 A

  In general, in such a conventional electrode material, when the noble metal is baked, the number of the three-phase interfaces of the proton conductor is reduced, the gas reaction cannot be sufficiently caused, and the proton conductivity is lowered. A phenomenon occurs in which the rate increases. In addition, there is a problem that the cost increases because an expensive noble metal is used as the electrode material.

  The present invention has been made paying attention to such a conventional problem, and an object of the present invention is to provide a fuel cell with high proton conductivity or a highly sensitive hydrogen sensor at low cost.

  The present invention is a fuel cell or a hydrogen sensor having the following characteristics.

That is, the present invention includes a proton conductor made of tetravalent barium metal acid to which yttria is added, and a noble metal electrode, the noble metal electrode is made of Ag, has an average particle diameter of less than 10 μm, and the surface of the electrode 90% or more denseness der in two dimensions observed from is, the proton conductor is a proton-conducting fuel cell or the hydrogen sensor having a composition represented by the following formula (1).
BaM _1-x Y _x O ₃ (1)
(However, M is a Ce or Zr element, x = 0.15 to 0.25.)

  The present invention also provides a method for manufacturing a fuel cell or a hydrogen sensor having the following characteristics.

That is, the present invention includes a step of obtaining a slurry by mixing Ag powder and an organic vehicle, a step of applying the slurry to a proton conductor made of tetravalent barium metal oxide to which yttria is added, and the slurry as the proton. possess a step of forming an electrode by baking the conductor, wherein the a Ag powder particle size 0.003～1.5Myuemu, average particle size and wherein 0.005~1.0μm der Rukoto A method for producing a proton conducting fuel cell or a hydrogen sensor.

  According to the present invention, a highly efficient proton conductive fuel cell or a highly sensitive hydrogen sensor can be obtained at low cost.

[First embodiment]
The first embodiment of the present invention is a proton conducting fuel cell in which an air electrode and an oxygen electrode made of silver (Ag) are provided on a proton conductor made of tetravalent barium metal acid to which yttria is added.

  The composition of the proton conductor is as shown in the following formula (1).

BaM _1-x Y _x O ₃ (1)
(However, M is Ce or Zr element, x = 0.06 to 0.25, and a better composition is x = 0.15 to 0.25.)
In the proton conducting fuel cell having the above configuration, the basic material constituting the proton conductor is yttria-added barium ceria or yttria-added barium zirconate. As for the crystal, BaCe _1-x Y _x O ₃ is orthorhombic when x is 0.06 to 0.10, and is rhombohedral when 0.10 or more, but BaZr _1-x Y _x O ₃ is in the above range. It is orthorhombic. There is no phase transition in the temperature range of about 400 to 800 ° C. at which proton conductivity is measured, and the crystal structure is stable.

Hydrogen is supplied to the fuel electrode on the surface of the proton conductor, and hydrogen (H ₂ ) emits electrons to become hydrogen ions (H ⁺ ). Hydrogen ions move through the solid electrolyte and reach the air electrode. In parallel, protons (H ⁺ ) conducted from the fuel electrode react with oxygen in the air to produce water. In the fuel electrode, the reaction proceeds according to the fuel gas supplied to the fuel electrode, and electrons are generated. When hydrogen is supplied to the fuel electrode, water (H ₂ O) is generated by a reaction between hydrogen (H ₂ ) and oxygen ions (O ²⁻ ).

  In the proton conductor, an air electrode and a fuel electrode using Ag powder having an Ag powder particle diameter of 0.003 to 1.5 μm and an average particle diameter of 0.005 to 1.0 μm are formed. The Ag powder is mixed with an organic vehicle to form a paste-like slurry, and the organic content burns during baking, leaving pores in the Ag. The porosity at this time is less than 10%. The silver electrode particles after sintering have an average particle size of 10 μm or less and a density of 90% or more. Porous Ag has good adhesion to the proton conductor and has hydrogen and air permeability. By applying the porous body Ag as the fuel electrode material, the hydrogen ion conductivity in the proton conductor can be improved, and the output as the proton conduction fuel cell can be improved.

  The shapes and forms of the fuel electrode and air electrode made of Ag are not particularly limited as long as they function as a fuel electrode and an air electrode, such as catalytic activity for sending gas to the proton conductor. For example, mesh shape, particle network shape, honeycomb shape, etc. The process of fixing the electrode to the proton conductor can be varied, such as baking of thick film paste formed by vapor deposition, ion plating, paste printing, ink jet printing, etc. It is.

The proton conductive fuel cell according to the present invention is not particularly limited in size and configuration. If the composition (BaM _1-x Y _x O ₃ ) shown in the above formula (1) is applied as a proton conductor and a porous noble metal, particularly Ag, is applied as a fuel electrode, any proton conductive fuel cell can be used. It is possible to exhibit excellent performance. In addition, the proton conducting fuel cell according to the present invention can be operated at a low temperature because excellent ion conductivity is obtained even at a relatively low temperature. For this reason, it is possible to apply metal parts, such as a ferritic stainless steel, to containers, such as a combustor main body. In other words, the present invention not only improves the output of the proton conducting fuel cell, but also expands the range of selection of members constituting the proton conducting fuel cell, which also contributes to a reduction in manufacturing cost.
[Second Embodiment]
The second embodiment of the present invention is a hydrogen sensor in which an air electrode and an oxidation electrode made of silver (Ag) are provided on a proton conductor made of tetravalent barium metal acid to which yttria is added.

  The composition of the proton conductor is as shown in the following formula (2).

BaM _1-x Y _x O ₃ (2)
(However, M is Ce or Zr element, x = 0.06 to 0.25, and a better composition is x = 0.15 to 0.25.)
The hydrogen sensor is used to measure the hydrogen concentration in the gas. Thereby, for example, the concentration of unburned hydrogen gas contained in the exhaust gas in the fuel cell can be measured. The hydrogen sensor includes a proton conductor, a measurement electrode, and a reference electrode. The hydrogen sensor is arranged in the order of the measurement electrode, the proton conductor, and the reference electrode. The measurement electrode is arranged on the measured gas side. Depending on the concentration of hydrogen contained in the gas to be measured, an ion current using hydrogen ions as carriers flows. Then, the hydrogen concentration in the measured gas is detected based on the measured current value.

  The hydrogen sensor according to the present invention has a measurement electrode made of porous Ag. Porous Ag has good adhesion to the proton conductor and has hydrogen permeability. By applying porous Ag as a measurement electrode material of a hydrogen sensor having a proton conductor having the above composition, the hydrogen ion conductivity in the hydrogen sensor can be improved and the responsiveness can be improved.

  The reference electrode used in the hydrogen sensor according to the present invention is not particularly limited. A known material may be used, or a newly developed material may be used. Or you may use 2 or more types of materials together. The reference electrode can be formed by plating, paste printing, ink jet printing, or the like. Other means may be used to make the reference electrode.

  The shape and form of the reference electrode are not particularly limited as long as it functions as a reference electrode. The shape of the porous body Ag is determined according to the applied hydrogen sensor. For example, the reference electrode has a plate shape, a coin shape, a fan shape, or the like.

The hydrogen sensor according to the present invention has a proton conductor having the above composition and a measurement electrode made of porous Ag. For this reason, the responsiveness of the hydrogen sensor is improved, and the fluctuation of the hydrogen concentration can be dealt with quickly. For example, when a hydrogen sensor is used in a fuel cell, release of unburned hydrogen into the atmosphere can be better suppressed. Other effects and configurations are the same as those of the proton conduction fuel cell according to the first embodiment.
[Third embodiment]
The third embodiment of the present invention is a method for manufacturing a proton conductive fuel cell having the following steps. That is, the method for producing a proton conducting fuel cell according to this embodiment is:
(A) a step of obtaining a slurry by mixing an Ag powder having an average particle size of 0.003 to 1.5 μm and an average particle size of 0.005 to 1.0 μm and an organic vehicle;
(B) applying the slurry to a proton conductor having the composition shown in (1) above;
(C) baking the slurry onto a solid electrolyte to create an air electrode;
Have

  With this manufacturing method, the proton conduction fuel cell shown as the first embodiment of the present invention can be manufactured. However, it goes without saying that the proton conducting fuel cell according to the present invention may be manufactured using other methods. You may improve the said manufacturing method as needed.

  Hereinafter, the details of the method for producing a proton conducting fuel cell will be described. In addition, since the material to be used is as described in the first embodiment, it will be omitted in the following description.

  The proton conductor having the composition (1) is formed by temporary sintering using citrate. A solid electrolyte having the above composition is formed by a series of processes such as a pulverization process, a molding process, and a sintering process for a predetermined metal produced by a citrate method. The powder produced by the citric acid method is uniformly mixed at the atomic stage and becomes a powder having a uniform particle size. For this reason, the produced solid electrolyte becomes a porous body having appropriate pores. The pulverization method, molding method, and sintering method are not particularly limited. For example, a ball mill can be used for pulverization and an isostatic press can be used for molding.

  The powder is sintered within a temperature range of 1300 to 1650 ° C. within a time range of 2 to 6 hours. Preferably, the sintered density is 98% or more of the true density. If the sintering time is shorter than the above or the temperature is lower than 1400 ° C., open pores remain in the sintered body, which may cause a decrease in ion conductivity. On the other hand, if the sintering time is too long or the temperature exceeds 1650 ° C., there is a risk that cracks will enter the grain boundary and the ionic conductivity will decrease.

  Separately, an Ag powder having a powder particle size of 0.003 to 1.5 μm and an average particle size of 0.005 to 1.0 μm is prepared. When Ag powder in the particle size range is used, Ag and the organic vehicle are suitably mixed, and the porosity of the sintered body to be produced becomes appropriate. In the present specification, the particle diameter means a particle diameter defined by “sphere equivalent diameter”, and the average particle diameter is an average value of the particle diameters. The particle diameter can be measured using, for example, a laser diffraction scattering method.

  Next, the Ag powder and the organic vehicle are mixed to prepare a slurry. As the organic vehicle, one obtained by dissolving ethyl cellulose in terpineol and dibutyl phthalate can be used. The density of the samarium cobalt oxide in the slurry and the viscosity of the slurry are not particularly limited. Based on the obtained knowledge, it may be determined in consideration of the device used and work efficiency. For example, if priority is given to work efficiency, the concentration of Ag may be increased.

  The slurry containing Ag is preferably applied onto a proton conductor (solid electrolyte) having the above composition by a screen printing method or an ink jet printing method. The application thickness of the slurry is not particularly limited.

  The slurry is applied on the proton conductor and then baked to dry the air electrode. In order to produce an air electrode excellent in proton conductivity, the baking conditions are preferably controlled as follows. That is, the baking temperature is 450 to 900 ° C., and the baking time is within a range of 30 to 90 minutes. If it is out of the range, the hydrogen ion conductivity may be lowered. The silver electrode particles after sintering have an average particle size of 10 μm or less and a density of 90% or more.

The slurry is preferably baked in an air atmosphere. If baking is performed in an atmosphere with insufficient oxygen concentration, such as in an inert gas atmosphere or in a vacuum, oxygen in the air electrode is deficient, and battery performance may be degraded.
[Fourth embodiment]
The fourth embodiment of the present invention is a method for manufacturing a hydrogen sensor having the following steps. That is, the manufacturing method of the hydrogen sensor according to this embodiment is:
(A) a step of obtaining a slurry by mixing an Ag powder having an average particle size of 0.003 to 1.5 μm and an average particle size of 0.005 to 1.0 μm and an organic vehicle;
(B) applying the slurry to the proton conductor having the composition shown in (2) above;
(C) baking the slurry onto a solid electrolyte to create an air electrode;
Have

  By this manufacturing method, the hydrogen sensor shown as the second embodiment of the present invention can be manufactured. However, it goes without saying that the hydrogen sensor according to the present invention may be manufactured using other methods. You may improve the said manufacturing method as needed.

  A method for producing a hydrogen sensor using a proton conductor having the above composition and Ag powder is in accordance with the third embodiment of the present invention, and preferred production conditions such as processing temperature or time are substantially the same. is there. That is, the particle diameter of the Ag powder is preferably such that the Ag powder particle diameter is 0.003 to 1.5 μm and the average particle diameter is in the range of 0.005 to 1.0 μm. The slurry is preferably applied to the proton conductor by screen printing, ink jet printing, or the like. At this time, the porosity of the slurry is preferably in the range of 40 to 70%. The baking temperature of the slurry is preferably 450 to 900 ° C., and the baking time is preferably in the range of 30 to 90 minutes. Further, the baking of the slurry is preferably performed in an air atmosphere. The silver electrode particles after sintering have an average particle size of 10 μm or less and a density of 90% or more. The description of the other manufacturing conditions is the same as that of the third embodiment, and the description is omitted. What is necessary is just to select the application | coating thickness etc. of a slurry so that the function as a hydrogen sensor may express suitably.

  In the hydrogen sensor according to the present invention, measurement electrodes are formed as necessary, and other wirings are provided. Various designs can be applied to the configuration for practical use as a hydrogen sensor, and means and materials for the design are not particularly limited.

  Next, several examples and comparative examples that demonstrate the effects of the present invention will be described. Needless to say, the technical scope of the present invention is not limited to the following examples.

<Examples 1-5>
BaCO ₃ , CeO ₂ , Y ₂ O ₃ are weighed at a predetermined composition ratio, mixed using a ball mill and molded into a powder sample, solid phase synthesis is performed at 1300 ° C. for 12 hours, further pulverized, and mesh classification The grain was adjusted to 500 μm or less. As the chemically synthesized powder, a commercially available powder of citrate compensation was used. The powder was molded with a biaxial press at a pressure of 8 MPa, then molded with a hydrostatic pressure press (CIP) at a pressure of 196 MPa, and then sintered in an electric furnace. The heating rate during sintering was 100 ° C./Hr, and the cooling rate was 50 ° C./Hr. The sintering temperature was 1600 ° C. and the time was 12 to 24 hours in the air or with the same powder embedded.

IV measurement was performed in a hydrogen atmosphere of BaCe _0.8 Y _0.2 O ₃ (solid phase synthesis, sintering temperature 1600 ° C., same powder embedded, d = 6.14 g / cm ³ (99.3% TD)). . Commercially available Ag paste (Tanaka Kikinzoku (registered trademark) MH406A, Shoei Chemical (registered trademark) ML4013 (specific surface area 1.0 m ² / g)) on both sides of a disk-shaped sample having a diameter of 14 mm and a thickness of 1 mm so as to have a diameter of 5 mm. Was baked at 500 to 800 ° C. for 30 minutes, and then set in an SOFC single cell evaluation apparatus. The temperature was raised to a predetermined temperature in an argon atmosphere, and the anode side was replaced with gas with humidified hydrogen (H ₂ + H ₂ O (25 ° C.)), followed by measurement. I-V characteristics were measured by passing a current between the anode and cathode using a current pulse generator and measuring the potential (CCV) between the anode and cathode from a multimeter. FIG. 1 shows the measurement results of the maximum power density at temperatures of 600 ° C., 500 ° C., and 450 ° C. for each sample. Which maximum output at 600 ° C. This result is 1.1mW / cm ^2, 500 ℃ at maximum output 0.12mW / cm ² or more, fulfill the function as a hydrogen concentration cell becomes at 450 ℃ 0.018mW / cm ² or more It is.

<Examples 6 and 7>
BaCO ₃ , CeO ₂ , Y ₂ O ₃ are weighed at a predetermined composition ratio, mixed using a ball mill and molded into a powder sample, solid phase synthesis is performed at 1300 ° C. for 12 hours, further pulverized, and mesh classification The grain was adjusted to 500 μm or less. After forming with a biaxial press at a pressure of 8 MPa, forming with a hydrostatic press (CIP) at a pressure of 196 MPa, sintering was performed in an electric furnace. The heating rate during sintering was 100 ° C./Hr, and the cooling rate was 50 ° C./Hr. The sintering temperature was 1600 ° C. and the time was 12 to 24 hours in the air or with the same powder embedded.

IV measurement was performed in a hydrogen atmosphere of BaCe _0.8 Y _0.2 O ₃ (solid phase synthesis, sintering temperature 1600 ° C., same powder embedded, d = 6.14 g / cm ³ (99.3% TD)). . Commercially available Ag powder (Tanaka Kikinoki (registered trademark) 6080 (average particle size 0.3 to 0.9 μm, specific surface area 1.5 to 3 mm) on both sides of a disk-shaped sample having a diameter of 14 mm and a thickness of 1 mm so as to have a diameter of 5 mm. 0.0 m ² / g)) and Bake Harima Kasei (registered trademark) NSP paste (particle size 0.003 to 0.007 μm, average particle size 0.005 μm) at 600 and 700 ° C. for 30 minutes The SOFC single cell evaluation apparatus was set. The temperature was raised to a predetermined temperature in an argon atmosphere, and the anode side was replaced with gas with humidified hydrogen (H ₂ + H ₂ O (25 ° C.)), followed by measurement. I-V characteristics were measured by passing a current between the anode and cathode using a current pulse generator and measuring the potential (CCV) between the anode and cathode from a multimeter. FIG. 1 shows the measurement results of the maximum power density at temperatures of 600 ° C., 500 ° C., and 450 ° C. for each sample. Maximum power 1mW / cm ^2, 500 ℃ at maximum output 0.1 mW / cm ² or more, and that fulfill the function as a hydrogen concentration cell becomes at 450 ℃ 0.02mW / cm ² or more at 600 ° C. This results .

<Examples 8 and 9>
BaCO ₃ , CeO ₂ , Y ₂ O ₃ are weighed at a predetermined composition ratio, mixed using a ball mill and molded into a powder sample, solid phase synthesis is performed at 1300 ° C. for 12 hours, further pulverized, and mesh classification The grain was adjusted to 500 μm or less. After forming with a biaxial press at a pressure of 8 MPa, forming with a hydrostatic press (CIP) at a pressure of 196 MPa, sintering was performed in an electric furnace. The heating rate during sintering was 100 ° C./Hr, and the cooling rate was 50 ° C./Hr. The sintering temperature was 1600 ° C. and the time was 12 to 24 hours in the air or with the same powder embedded.

IV measurement in a hydrogen atmosphere of BaCe _0.8 Y _0.2 O ₃ (solid phase synthesis, sintering temperature 1600 ° C., 24 hours, same powder embedded, d = 6.14 g / cm ³ (99.3% TD)) Went. Commercially available platinum paste was baked on the anode at 700 ° C. on both sides of a disk-shaped sample having a diameter of 14 mm and a thickness of 1 mm at 700 ° C., and commercially available Ag paste (Tanaka Kikinzoku (registered trademark) MH406A and Harima Kasei (registered trademark)) NSP paste) was applied only to the cathode and baked at 500 for 30 minutes, and then set in a SOFC single cell evaluation apparatus. The temperature was raised to a predetermined temperature in an argon atmosphere, and the anode side was replaced with gas with humidified hydrogen (H ₂ + H ₂ O (25 ° C.)), followed by measurement. The current was passed between the anode and cathode using a current pulse generator, and the potential (CCV) between the anode and cathode was measured by a multimeter to measure the IV characteristics and calculate the output. The measurement results of the maximum power density at temperatures of 500 ° C. and 400 ° C. for each sample are shown in FIG. As a result, the maximum output is 10 mW / cm ² or more at 500 ° C. and 1 mW / cm ² or more at 400 ° C., so that the function as a hydrogen concentration cell can be achieved.

<Comparative Examples 1-5>
BaCO ₃ , CeO ₂ , Y ₂ O ₃ are weighed at a predetermined composition ratio, mixed using a ball mill and molded into a powder sample, solid phase synthesis is performed at 1300 ° C. for 12 hours, further pulverized, and mesh classification The grain was adjusted to 500 μm or less. As the chemically synthesized powder, a commercially available powder of citrate compensation was used. The powder was molded with a biaxial press at a pressure of 8 MPa, then molded with a hydrostatic pressure press (CIP) at a pressure of 196 MPa, and then sintered in an electric furnace. The heating rate during sintering was 100 ° C./Hr, and the cooling rate was 50 ° C./Hr. The sintering temperature was 1600 ° C. and the time was 12 to 24 hours in the air or with the same powder embedded.

I in a hydrogen atmosphere of BaCe _0.8 Y _0.2 O ₃ (solid phase synthesis and chemical synthesis, sintering temperature 1600 ° C., 24 hours, same powder embedded, d = 6.14 g / cm ³ (99.3% TD)) -V measurement was performed. Commercially available Ag powder (Tanaka Kikinoki (registered trademark) 6010 (average particle size 6 to 13 μm, specific surface area 1.0 to ^2.5 m 2/2) on both sides of a disk-shaped sample having a diameter of 14 mm and a thickness of 1 mm so as to have a diameter of 5 mm. g)) and a commercially available Ag paste (Tanaka Kikinzoku (registered trademark) TR6182 (average particle size 4 to 8 μm, specific surface area 0.2 to 0.4 m ² / g)) at 600 to 800 ° C. for 30 minutes. After baking, it was set in a SOFC single cell evaluation apparatus. The temperature was raised to a predetermined temperature in an argon atmosphere, and the anode side was replaced with gas with humidified hydrogen (H ₂ + H ₂ O (25 ° C.)), followed by measurement. I-V characteristics were measured by passing a current between the anode and cathode using a current pulse generator and measuring the potential (CCV) between the anode and cathode from a multimeter. FIG. 3 shows the measurement results of the maximum power density at temperatures of 600 ° C., 500 ° C., and 450 ° C. for each sample. As a result the maximum output at 600 ° C. in the 0.53mW / cm ² or less, 500 ° C. at maximum output 0.05 mW / cm ² or less, perform its function as a hydrogen concentration cell becomes less than 0.02 mW / cm ² at 450 ° C. It is not considered.

<Comparative Examples 6 and 7>
In a hydrogen atmosphere of BaCe _0.9 Y _0.1 O ₃ (solid phase synthesis 1600 ° C., 24 hours, same powder embedded, d = 6.14 g / cm ³ (99.3% TD)) made by the same method as in the examples I-V measurement was performed. A paste made from a commercially available Ag powder (Tanaka Kikinzoku (registered trademark) 6080) and a commercially available Ag paste (Shoei Chemical (registered trademark) ML4013) on both sides of a disk-shaped sample having a diameter of 14 mm and a thickness of 1 mm and having a diameter of 5 mm. Was baked at 700 ° C. for 30 minutes, and then set in an SOFC single cell evaluation apparatus. The temperature was raised to a predetermined temperature in an argon atmosphere, and the anode side was replaced with gas with humidified hydrogen (H ₂ + H ₂ O (25 ° C.)), followed by measurement. I-V characteristics were measured by passing a current between the anode and cathode using a current pulse generator and measuring the potential (CCV) between the anode and cathode from a multimeter. FIG. 4 shows the measurement results of the maximum power density at temperatures of 600 ° C., 500 ° C., and 450 ° C. for each sample. The output is the same as in Comparative Examples 1 to 5, and the output performance is not improved.

It is a figure which shows the measurement result of the IV characteristic of the fuel cell which concerns on Examples 1-7. It is a figure which shows the measurement result of the IV characteristic of the fuel cell which concerns on Example 8 and 9. FIG. It is a figure which shows the measurement result of the IV characteristic of the fuel cell which concerns on Comparative Examples 1-5. It is a figure which shows the measurement result of the IV characteristic of the fuel cell which concerns on the comparative examples 6 and 7. FIG.

Claims (10)

A proton conductor made of tetravalent barium metal acid to which yttria is added, and a noble metal electrode;
The noble metal electrode is made of Ag, less than 10μm in average particle size, and Ri 90% or more denseness der in two dimensions observed from the surface of the electrode,
The proton conductor has the following formula (1)
BaM _1-x Y _x O ₃ (1)
(However, M is a Ce or Zr element, x = 0.15 to 0.25.)
A proton conductive fuel cell, characterized by having a composition represented by: A proton conductor made of tetravalent barium metal acid to which yttria is added, and a noble metal electrode;
The noble metal electrode is made of Ag, has an average particle diameter of less than 10 μm, and has a density of 90% or more by two-dimensional observation from the surface of the electrode,
The proton conductor has the following formula (2)
BaM _1-x Y _x O ₃ (2)
(However, M is a Ce or Zr element, and x = 0.15 to 0.25.)
The hydrogen sensor characterized by having the composition represented by these . Mixing Ag powder and organic beagle to obtain a slurry;
Applying the slurry to a proton conductor made of tetravalent barium metalate with added yttria;
Baking the slurry onto the proton conductor to form an electrode;
Have
Said Ag powder particle diameter is 0.003-1.5 micrometer, and average particle diameter is 0.005-1.0 micrometer , The manufacturing method of the proton conduction fuel cell characterized by the above-mentioned . 4. The method for producing a proton conductive fuel cell according to claim 3, wherein the slurry is applied by screen printing or ink jet printing, and the porosity thereof is less than 10% . 5. The method for producing a proton conductive fuel cell according to claim 3 , wherein the baking of the slurry is performed within a baking temperature of 450 to 900 ° C. and a baking time of 30 to 90 minutes . The method for producing a proton conductive fuel cell according to any one of claims 3 to 5, wherein the slurry is baked in an air atmosphere . Mixing Ag powder and organic beagle to obtain a slurry;
Applying the slurry to a proton conductor made of tetravalent barium metalate with added yttria;
Baking the slurry onto the proton conductor to form an electrode;
I have a,
Said Ag powder particle diameter is 0.003-1.5 micrometer, and average particle diameter is 0.005-1.0 micrometer, The manufacturing method of the hydrogen sensor characterized by the above-mentioned . The method for producing a hydrogen sensor according to claim 7, wherein the slurry is applied by screen printing, and a porosity thereof is in a range of 40 to 70% . The baking of the slurry, the baking temperature is 450 to 900 ° C., the method of manufacturing the hydrogen sensor according to claim 7 or claim 8 baking time and performing within a 30 to 90 minutes. The method for manufacturing a hydrogen sensor according to any one of claims 7 to 9, wherein baking of the slurry is performed in an air atmosphere .

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