JP2003051332A - Fuel cell and fuel cell power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell improved in startability or restartability by reducing a rising time or a thawing time, and to provide a fuel cell power generating system and a heating method for the fuel cell. SOLUTION: In this fuel cell, a plurality of single cells are connected two- dimensionally in a direction nearly perpendicular to a stacking direction and an extension direction for the integration, a solid electrolyte layer includes a dielectric, and AC voltage can be applied to an air electrode layer or a fuel electrode layer. The fuel cell power generating system uses the fuel cell and has a temperature detection means detecting temperature of a power generating portion. In the power generating system, an AC application means applying the AC voltage according to the detection temperature is connected to the fuel electrode layer or the air electrode layer. In the heating method for the fuel cell, the AC application means applies the AC voltage to the fuel electrode layer or the air electrode layer, and allows the heat generation of the dielectric included in the solid electrolyte layer to heat the power generating portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell, a fuel cell power generation system, and a method for heating a fuel cell, and more specifically, an AC voltage can be applied to electrodes to improve startability and restartability. The present invention relates to a fuel cell, a fuel cell power generation system, and a fuel cell heating method.

[0002]

2. Description of the Related Art A solid oxide fuel cell which is one of fuel cells (hereinafter referred to as "SOFC (Solid Oxide Fuel)"
abbreviated as “l Cell)” is configured to sandwich a solid electrolyte having ionic conductivity such as oxygen ions or protons between a porous air electrode and a fuel electrode, and an oxidizing gas containing oxygen gas on the air electrode side. Is a battery in which a reducing gas containing hydrogen or a hydrocarbon gas is supplied to the fuel electrode side, and these gases electrochemically react through the solid electrolyte to generate electromotive force.

SOFCs usually have an operating temperature of 1000 ° C.
When used as a household power supply or automobile power supply, if the temperature becomes lower than the operating temperature (normal temperature, etc.),
Again, it takes time to heat to operating temperature. Therefore, efficient heating is required in order to shorten the rising time at the time of starting or restarting. In response to this, as a conventional technique, for example, Japanese Patent Laid-Open No. 5-8990
As shown in Japanese Patent Publication No. 0 (FIG. 8), PTC (Positive Temperature) is provided above and below the fuel cell.
A method of sandwiching a PTC type heater having a re-coefficient characteristic with an insulating plate is proposed.

However, in the prior art, the fuel cells are sandwiched by the insulating plates having a large heat capacity and a low thermal conductivity to heat the entire fuel cell, so that the power generation section of the fuel cell is locally And since it cannot be heated efficiently, S
The OFC has a problem that it is difficult to shorten the rising time at the time of starting or restarting.

On the other hand, a polymer electrolyte fuel cell (hereinafter referred to as "PEFC (Polymer Ele)" which is one of the fuel cells.
abbreviated as “ctrolyte Fuel Cell)”)
Although it operates at room temperature, when it is used as a power source for automobiles, when the outside air temperature is below freezing, the water inside the PEFC freezes and does not operate, so it is difficult to reduce the thawing time with PEFC. It was

[0006]

Thus, when the fuel cell is used as a household power source or an automobile power source, in particular,
In the case of a power supply for automobiles, there are many start-stop cycles, and how to shorten the rise time at the time of starting or restarting is a major problem. That is, in the case of an automobile, if the rise time of the fuel cell is long, it is necessary to supply electric power from a secondary battery or the like as a power source within the startup time of the fuel cell, and a large capacity secondary battery is mounted on the vehicle. I have to do it. As a result, the weight of the vehicle increases, which in turn lowers fuel efficiency.

The present invention has been made in view of the above-mentioned problems of the prior art. The object of the present invention is to shorten the start-up time and the thawing time and improve the startability and restartability. A fuel cell, a fuel cell power generation system, and a fuel cell heating method.

[0008]

As a result of intensive studies to solve the above problems, the present inventors applied an AC voltage to the power generation site of a fuel cell to locally and efficiently heat a solid electrolyte. By doing so, they have found that the above problems can be solved, and completed the present invention.

That is, in the fuel cell of the present invention, a plurality of unit cells each having a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer are two-dimensionally arranged in a direction substantially perpendicular to the extending direction and the stacking direction. In the fuel cell, which is connected and integrated, the solid electrolyte layer includes a dielectric having a dielectric loss coefficient larger than that of the solid electrolyte that is a matrix, and an alternating voltage is applied between the air electrode layer and the fuel electrode layer. It is characterized by being possible.

A preferred form of the fuel cell of the present invention is characterized in that the dielectric is dispersed in the solid electrolyte layer.

Furthermore, another preferred embodiment of the fuel cell of the present invention is characterized in that the dielectric is disposed on the solid electrolyte layer.

Furthermore, the fuel cell power generation system of the present invention is a fuel cell power generation system using the above-mentioned fuel cell, and has temperature detection means for detecting the temperature of the power generation portion, and the alternating current is detected according to the detected temperature. An alternating current application means for applying a voltage is connected to the fuel electrode layer and the air electrode layer.

A method of heating a fuel cell according to the present invention is a method of heating a fuel cell by the fuel cell power generation system, wherein the AC applying means applies an AC voltage between the fuel electrode layer and the air electrode layer. Then, the dielectric contained in the solid electrolyte layer is heated to heat the power generation portion.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The fuel cell of the present invention will be described in detail below. In the present specification, “%” indicates a mass percentage unless otherwise specified. Further, in the present specification, the “solid electrolyte” is used to indicate both a solid oxide electrolyte used in SOFC and a solid polymer electrolyte used in PEFC. Furthermore, for convenience of explanation, one side of the substrate or electrode is the “front side” and the other side is the “back side”.
However, it is needless to say that these are equivalent elements, and configurations that are mutually replaced are also included in the scope of the present invention.

In such a fuel cell, a plurality of single cells each having a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer are two-dimensionally connected and integrated in a direction substantially perpendicular to the extending direction and the stacking direction. Consists of For example, a fuel cell having a stack structure as shown in FIG. 1 can be mentioned.

The solid electrolyte layer contains a dielectric having a dielectric loss coefficient (tan δ) larger than that of the solid electrolyte as a matrix. Therefore, when an AC voltage is applied to the electrode layers (air electrode layer, fuel electrode layer), the solid electrolyte layer is heated by the heat generated by the dielectric loss of the dielectric. Therefore, the structure can be simplified, the heat capacity of the fuel cell can be reduced, and the output density can be improved, as compared with the case where an insulating plate in which a known heater (PTC type heater or the like) is arranged is inserted. Further, the fuel loss can be locally and uniformly heated by the dielectric loss of the solid electrolyte layer, which is effective.

Further, the matrix of the solid electrolyte layer
As the solid electrolyte, a solid oxide or a solid polymer is used.
Can be used. Specifically, known Nd_TwoO_Three,
Sm _TwoO_Three, Y_TwoO_Three, Gd_TwoO_ThreeAnd Sc_TwoO_ThreeSuch
Stabilized zirconia (ZrO_Two), And Ce
O_Two, Bi_TwoO_ThreeAnd LaGaO_ThreeIs the main component
Solid oxide, also Nafion®, Fle
mion (registered trademark) and Aciplex (registered trademark)
Perfluorosulfonic acid ion conductive polymer such as
Can be used alone or as a mixture of solid polymers containing
It The solid electrolyte is not particularly limited to these.
And can be used as appropriate as long as it has similar properties.
It

Further, it is preferable that the solid electrolyte layer contains the dielectric in a proportion of 0.1 to 50% with respect to the total volume of the solid electrolyte layer. The dielectric content is 0.1
%, It is possible to increase the efficiency of heat generation due to dielectric loss. On the other hand, if it is 50% or less, a rapid decrease in ionic conductivity of the solid electrolyte layer is suppressed, and a marked decrease in output of the fuel cell is suppressed. be able to. As such a dielectric, for example, alumina (Al ₂ O ₃ ), forsterite porcelain (2MgO · SiO ₂ ), barium strontium titanate [(Ba, Sr) TiO ₃ ], rutile (TiO ₂ ) and the like are main components. However, the substance is not particularly limited thereto.

Further, the dielectric can be contained in the solid electrolyte layer by being dispersed or arranged in the solid electrolyte layer. Specifically, as an example of dispersing the dielectric, as shown in FIG. 3, the dielectric can be dispersed throughout the solid electrolyte layer. Further, a laminated body of dielectric dispersion films in which the above-mentioned dielectric is dispersed in a solid electrolyte can be used as the solid electrolyte layer. Further, as shown in FIG. 4, the dielectric dispersion film and the film made of a solid electrolyte can be alternately laminated to form a solid electrolyte layer. On the other hand, as an example of disposing the dielectric, as shown in FIG. 5, the dielectric can be disposed in the solid electrolyte. Further, a laminated body of the dielectric-arranged film in which the above-mentioned dielectric is arranged in the solid electrolyte can be used as the solid electrolyte layer. Further, as shown in FIG.
The dielectric-arranged film and the film made of a solid electrolyte can be alternately laminated to form a solid electrolyte layer.

The dielectric dispersion film, the dielectric-arranged film, and the solid electrolyte film can be dispersed / arranged according to an arbitrary shape and layout, and these can be appropriately selected and laminated in a desired order. it can. For example, an SOFC or the like using the dielectric dispersion film and the dielectric-arranged film in combination can be manufactured. Further, the dielectric dispersion film or the dielectric-arranged film may be dispersed and arranged in a part of the solid electrolyte layer. Further, it is preferable to dispose the dielectric dispersion film or the dielectric-arranged film on the front surface and / or the back surface of the solid electrolyte layer from the viewpoint of heating the fuel cell locally and uniformly. Further, the solid electrolyte layer and each electrode layer are coated by various film forming methods such as PVD method, CVD method, thermal spraying method, screen printing method, spray coating method, plating method, electrophoresis method and sol-gel method. it can.

The fuel cell of the present invention can apply an alternating voltage between the air electrode layer and the fuel electrode layer. As a result, the above-mentioned dielectric efficiently generates heat, and the start-up of the SOFC and the thawing process of the frozen portion generated in the PEFC are shortened. In particular, when it is used as a power source for automobiles having many start-stop cycles, it is effective because the convenience and economy of the automobile can be secured.

In the solid oxide fuel cell,
As a support for a single cell or a cell plate, a porous metal material or inorganic material can be coated with a solid electrolyte layer and an electrode layer, and the like, and is not particularly limited to the above-mentioned configuration.

Next, the fuel cell power generation system of the present invention will be described in detail. Such a fuel cell power generation system uses the above-mentioned fuel cell and has a temperature detection means for detecting the temperature of the power generation portion. The fuel electrode layer and the air electrode are provided with an AC application means for applying an AC voltage according to the detected temperature. Composed of connecting layers. As a result, the power generation part can be controlled to a desired temperature at startup, and the startability of power generation by the fuel cell is improved. Further, compared with the case of inserting an insulating plate in which a heater or the like is arranged, the configuration of the fuel cell power generation system can be simplified, which is effective. Here, the above-mentioned "power generation part" mainly refers to a sandwiching body between the solid electrolyte and the electrode.

Next, the method for heating the fuel cell of the present invention will be described in detail. In such a heating method, in the fuel cell power generation system, the AC applying means applies an AC voltage between the fuel electrode layer and the air electrode layer to heat the dielectric contained in the solid electrolyte layer to generate power. Is a method of heating. As a result, only the desired portion can be uniformly heated to the temperature required for the fuel cell to generate electricity. In addition, typically, in the case of SOFC, it is desirable to apply an alternating voltage of about 10 to 100 V to heat at 300 to 800 ° C., and in the case of PEFC, an alternating voltage of about 0.5 to 1.5 V is used. It is desirable to apply and heat between 0-90 degreeC. Alternatively, an AC voltage can be applied using the fuel cell.

[0025]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Embodiment 1) FIG. 1 shows a configuration of a fuel cell stack 1 and an AC power source 2 of a fuel cell power generation system according to this embodiment. 2 shows the configurations of the cell plate (single cell plate) and the AC power supply 2 of the fuel cell stack shown in FIG. This fuel cell power generation system uses a 100 mm square Si substrate 3
10 single cells with 2 mm square openings 7 in each
This is a view showing two adjacent cells among the individually formed cells. An opening 7 is formed in the substrate 3 on which the electric insulating layer is formed, and a fuel electrode layer 4, a solid electrolyte layer 5, and an air electrode layer 6 are formed so as to cover the opening, and an AC voltage can be applied. As described above, the fuel electrode layer 4 and the air electrode layer 6 of the adjacent cells are electrically connected.

As a method for manufacturing a unit cell plate, first, a silicon nitride film is formed on both surfaces of the Si substrate 3 as an electrically insulating layer under reduced pressure C.
It was formed to a thickness of about 200 nm by the VD method. Next, this S
A desired region of the silicon nitride film on the back surface of the i substrate was removed by photolithography and chemical dry etching using CF ₄ gas to form a silicon etching port. Further, hydrazine, which is a silicon etching solution, was used to perform etching at a temperature of about 80 ° C. to form an opening 7 on the surface of the Si substrate 3 and a diaphragm of a silicon nitride film.

Next, a Ni fuel electrode layer 4 is formed by an electron beam evaporation method using an evaporation mask to a thickness of about 500 nm so as to cover the diaphragm, and a solid electrolyte layer 5 of yttria-stabilized zirconia (YSZ) is subjected to high frequency sputtering. By a vapor deposition mask so that a part of the fuel electrode layer 4 is exposed, and further, an air cathode layer of La _1-x Sr _x MnO ₃ is formed by an RF mask using a vapor deposition mask to form an electrolyte layer. 5 was formed so that the connection portion with the fuel electrode layer 4 overlaps. Then, etching was performed again from the back surface of the Si substrate by chemical dry etching using CF ₄ gas to remove the silicon nitride film diaphragm on the back surface of the fuel electrode layer 4 to expose the fuel electrode layer 4.

Since the unit cell plates produced from the cells formed as described above are stacked as the fuel cell stack 1,
As shown in FIG. 1, a separator 8 was separately prepared. In this separator 8, gas channels were processed and formed using a dicing saw on both sides of a 100 mm square Si substrate. A separator 8 is laminated on both sides of the unit cell plate by a known method, and a fuel cell stack composed of two separators 8 and unit cell plates laminated between them is covered with a heat insulating material to form a fuel cell power generation system of this example. Got

When a voltage was applied from the AC power source 2 through the fuel electrode layer 4 and the air electrode layer 6 by the above fuel cell power generation system, the fuel cell stack was heated to 300 ° C. In addition, air was passed through a separator channel formed on the upper surface of the unit cell plate and hydrogen gas was passed through a separator channel formed on the lower side of the unit cell plate to evaluate the power generation characteristics. As a result, 100
An output of 75 V as an open circuit voltage was obtained from the fuel cell in which the cells were connected in series.

As described above, the fuel cell power generation system having the means for applying an AC voltage to the air electrode layer and the fuel electrode layer of the fuel cell makes it possible to heat the fuel cell stack and generate power. Was confirmed.

(Embodiment 2) FIG. 3 shows the structure of a unit cell of the fuel cell power generation system of this embodiment and the solid electrolyte layer 5 used in this unit cell. This fuel cell power generation system has substantially the same configuration as that of the first embodiment except that the solid electrolyte layer 5 is a layer in which a dielectric material having a larger dielectric loss coefficient than the solid electrolyte is dispersed.

In the same manner as in Example 1, a diaphragm of a silicon nitride film was formed, and a Ni fuel electrode layer was formed by an electron beam evaporation method using an evaporation mask to a thickness of about 500 nm so as to cover the diaphragm. And a layer made of (Ba, Sr) TiO _{3 having} a larger dielectric loss coefficient than YSZ were simultaneously formed by a high frequency sputtering method using a vapor deposition mask so that a part of the fuel electrode layer was exposed. At this time,
By controlling the high frequency power applied to the YSZ target and the (Ba, Sr) TiO ₃ target,
As a volume fraction, 10% (Ba, Sr) TiO ₃ -90
% YSZ. Further, an air electrode layer of La _1-x Sr _x MnO ₃ was formed by a high frequency sputtering method using a vapor deposition mask,
It was formed so as to cover the electrolyte layer and overlap the connection portion with the fuel electrode layer. Then, etching is performed again from the back surface of the Si substrate by chemical dry etching using CF ₄ gas to remove the silicon nitride film diaphragm on the back surface of the fuel electrode layer to form a unit cell plate exposing the fuel electrode layer. After that, this was stacked to obtain a fuel cell power generation system of this example.

With the obtained fuel cell power generation system, a voltage was applied from an AC power source through the air electrode layer and the fuel electrode layer, the fuel cell stack was heated to 300 ° C., and then the power generation characteristics were evaluated. An output voltage of 75 V was obtained from a fuel cell in which 100 cells were connected in series.

(Embodiment 3) FIG. 4 shows the structure of the unit cell of the fuel cell power generation system of this embodiment and the solid electrolyte layer 5 used in this unit cell. This fuel cell power generation system is substantially the same as Example 1 except that the solid electrolyte layer 5 has a plurality of laminated layers of a membrane A and a solid electrolyte membrane C in which a substance having a dielectric loss coefficient larger than that of the solid electrolyte is dispersed. Have a configuration.

In the same manner as in Example 1, single cell plates were prepared and then stacked to obtain a fuel cell power generation system of this example. At this time, the solid electrolyte layer is formed of YSZ and (B
A layer of a, Sr) TiO ₃ and a YSZ layer were alternately formed by a high frequency sputtering method using a vapor deposition mask.

With the obtained fuel cell power generation system, a voltage was applied from an AC power source through the air electrode layer and the fuel electrode layer, and the fuel cell stack was heated to 300 ° C., and then the power generation characteristics were evaluated. An output voltage of 75 V was obtained from a fuel cell in which 100 cells were connected in series.

(Embodiment 4) FIG. 5 shows the structure of a unit cell of the fuel cell power generation system of this embodiment and the solid electrolyte layer 5 used in this unit cell. This fuel cell power generation system has substantially the same configuration as that of the first embodiment except that the solid electrolyte layer 5 is formed by disposing a dielectric material having a larger dielectric loss coefficient than the solid electrolyte in the solid electrolyte.

In the same manner as in Example 1, a diaphragm of a silicon nitride film was formed, and a fuel electrode layer of Ni or the like was formed by an electron beam evaporation method using an evaporation mask to a thickness of about 500 nm.
It was formed so as to cover the diaphragm, and YSZ was simultaneously formed by a high frequency sputtering method using a vapor deposition mask so that a part of the fuel electrode layer was exposed. Further, the YSZ layer is patterned by using a known photolithography technique, YSZ is removed, and (Ba, Sr) TiO ₃ is formed on the exposed portion of the fuel electrode layer by high-frequency sputtering to form YSZ. It was formed so as to have the same film thickness. Here, the pattern was formed such that the volume fraction of (Ba, Sr) TiO ₃ with respect to YSZ was 10%. The pattern shape does not have to be the lattice shape shown in FIG. 5, and may be any shape. Next, La _1-x Sr _x Mn
The air electrode layer of O ₃ was formed by a high frequency sputtering method using a vapor deposition mask so as to cover the electrolyte layer and overlap the connection portion with the fuel electrode layer. Then, the dry etching is performed again from the back surface of the Si substrate by chemical dry etching using CF ₄ gas to remove the silicon nitride film diaphragm on the back surface of the fuel electrode layer and expose the fuel electrode layer to form a unit cell plate. Later, this was stacked to obtain a fuel cell power generation system of this example.

With the obtained fuel cell power generation system, a voltage was applied from an AC power source through the air electrode layer and the fuel electrode layer to heat the fuel cell stack to 300 ° C., and then the power generation property was evaluated. An output voltage of 75 V was obtained from a fuel cell in which 100 cells were connected in series.

(Embodiment 5) FIG. 6 shows the structure of a unit cell of a fuel cell power generation system and a solid electrolyte layer 5 used in this unit cell. This fuel cell power generation system is the same as that of Example 1 except that the solid electrolyte layer 5 is formed by laminating a plurality of layers of a film in which a dielectric having a dielectric loss coefficient larger than that of the solid electrolyte is arranged in the solid electrolyte and a solid electrolyte film. It has almost the same configuration.

In the same manner as in Example 1, single cell plates were prepared and then stacked to obtain a fuel cell power generation system of this example. At this time, as the solid electrolyte layer, layers of YSZ and (Ba, Sr) TiO ₃ formed by the method of Example 5 and layers in which the YSZ layers were arranged, and YSZ layers were alternately formed.

With the obtained fuel cell power generation system, a voltage was applied from an AC power source through the air electrode layer and the fuel electrode layer, the fuel cell stack was heated to 300 ° C., and then the power generation characteristics were evaluated. An output voltage of 75 V was obtained from a fuel cell in which 100 cells were connected in series.

(Embodiment 6) FIG. 7 shows the structure of a single cell of a fuel cell power generation system in this embodiment. This single cell is an enlarged view of the cross section of one cell of the PEFC stack. Here, by sandwiching the electrolyte-electrode assembly produced by forming the fuel electrode layer 4 and the air electrode layer 6 in the solid electrolyte layer 5 with the carbon separator 8, the unit cell was constructed.

As a solid electrolyte layer, commercially available 5 wt% Na
fion solution (manufactured by Aldrich) and (Ba, Sr) T
The volume fraction of (Ba, Sr) TiO ₃ particles of DMF (NN-dimethylformamide) in which iO ₃ particles were dispersed was 1%.
Stir and mix so that the solvent is evaporated in stages,
A Nafion film having (Ba, Sr) TiO ₃ particles dispersed therein was formed to a film thickness of 100 mm. Next, 50w for the fuel electrode layer
50% t% Pt-Ru supported carbon catalyst in the fuel electrode layer
Using a t% Pt-supported carbon catalyst, the mixture was treated with a hot press at 125 ° C. and 10 MPa for 2 minutes to prepare an electrolyte-electrode assembly.

The above electrolyte-electrode assembly was sandwiched between known carbon separators to form a fuel cell stack, which was covered with a heat insulating material to form the fuel cell power generation system of this example. Further, this system was installed in a constant temperature bath maintained at -20 ° C.

When a voltage was applied to the obtained fuel cell power generation system from an AC power source through a carbon separator, that is, a fuel electrode layer and an air electrode layer, the temperature of the fuel cell stack exceeded 0 ° C. Then, hydrogen was introduced to the fuel electrode side and air was introduced to the air electrode side to evaluate the power generation characteristics. The output per fuel cell is 0.4 W / cm ² (0.5
An output of V-0.8 A / cm ² ) was obtained.

As described above, by using the fuel cell power generation system having means for applying an AC voltage to the fuel electrode layer and the air electrode layer of the fuel cell, the PEFC can be used even at a freezing point.
It was confirmed that the stack could be efficiently heated and that power was generated.

(Example 7) In a fuel cell having the same structure as in Example 6, polytetramethylene oxide as a polymer component, which was reported at the 67th lecture meeting (lecture number 2J22) of the Institute of Electrochemistry, was used as an electrolyte. Using a mixture having silica crosslinks as an oxide component by a sol-gel reaction, (Ba, Sr) TiO ₃ particles were dispersed in the same manner as in Example 6, and 50 wt% Pt-Ru-supported carbon catalyst was added to the fuel electrode and the air electrode. 50 wt% Pt-supported carbon catalyst was used and treated with a hot press machine at 125 ° C. and 10 MPa for 2 minutes to prepare an electrolyte-electrode assembly. Using this electrolyte-electrode assembly, a fuel cell stack was formed in the same manner as in Example 6, and then the fuel cell power generation system of this example was formed.

With the obtained fuel cell power generation system,
When evaluated in the same manner as in Example 6, in an atmosphere below freezing
Also, by applying an AC voltage, the temperature of the fuel cell
When the temperature exceeds 0 ° C, hydrogen is introduced to the fuel electrode side and air is introduced to the air electrode side.
Then, the power generation characteristics were evaluated. Output per fuel cell and
And then 0.1 W / cm^Two(0.5V-0.2A / c
m ^Two) Output was obtained.

Although the present invention has been described in detail with reference to the embodiments, the present invention is not limited to these and various modifications can be made within the scope of the gist of the present invention. For example, in the present invention, the shape and the like of the fuel cell can be arbitrarily selected, and the fuel cell can be manufactured according to the target output. In addition, the dielectric dispersion film and the dielectric-arranged film are, depending on the output of the fuel cell,
You can adjust the amount used and place it in the desired position.

[0052]

As described above, according to the present invention, since the alternating voltage is applied to the power generation portion of the fuel cell to locally and efficiently heat the solid electrolyte, the rising time and the thawing time are increased. It is possible to provide a fuel cell, a fuel cell power generation system, and a fuel cell heating method, in which the fuel cell power consumption is shortened and the startability and restartability are improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a stack configuration of a fuel cell power generation system and an AC power supply connection.

FIG. 2 is a schematic diagram showing an example of connection of a cell plate structure and an AC power source.

FIG. 3 is a schematic diagram showing an example of the configuration of a single cell and a solid electrolyte layer.

FIG. 4 is a schematic diagram showing another example of the configuration of a single cell and a solid electrolyte layer.

FIG. 5 is a schematic view showing still another example of the configurations of the single cell and the solid electrolyte layer.

FIG. 6 is a schematic diagram showing another example of the configuration of a single cell and a solid electrolyte layer.

FIG. 7 is a cross-sectional view showing an example of a single cell.

FIG. 8 is a schematic view showing an example of a conventional fuel cell.

[Explanation of symbols]

1 Fuel cell stack 2 AC power supply 3 substrates 4 Fuel pole layer 5 Solid electrolyte layer 5A dispersion layer (dielectric dispersion film) 5B disposition layer (dielectric disposition film) 5C solid electrolyte 6 Air electrode layer 7 openings 8 separator 9 end plates 10 seals 20 fuel cells 21 Insulation plate 21a PTC heater 21b terminal 22 Cooling plate 23 carbon sheet 24 separator 25 Air electrode side electrode 26 Fuel electrode side 27 separator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 8/24 H01M 8/24 E (72) Inventor Naoki Hara 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. Incorporated (72) Inventor Tatsuhiro Fukuzawa 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Takashi Shibata 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa (72) Inventor Song East 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Keiko Nishitani 2nd Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Fumiki Sato Kanagawa-ku, Yokohama, Kanagawa No. 2 Takaramachi Nissan Motor Co., Ltd. (72) Inventor Makoto Uchiyama 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Earth Nissan Automobile Co., Ltd. in the (72) inventor Keiko Kushibiki, Kanagawa Prefecture, Kanagawa-ku, Yokohama-shi Takaracho address 2 Nissan Automobile Co., Ltd. in the F-term (reference) 5H026 AA06 CC03 CV06 EE12 EE18 HH05 5H027 AA06 KK46 MM16

Claims (13)

[Claims] 1. A fuel comprising a plurality of unit cells each having a solid electrolyte layer sandwiched between an air electrode layer and a fuel electrode layer, which are two-dimensionally connected and integrated in a direction substantially perpendicular to the extending direction and the stacking direction. A battery, wherein the solid electrolyte layer includes a dielectric material having a larger dielectric loss coefficient than the solid electrolyte that is a matrix, and an alternating voltage can be applied between the air electrode layer and the fuel electrode layer. Fuel cell to do. 2. The solid electrolyte layer is a solid oxide and / or
Alternatively, the fuel cell according to claim 1, wherein the solid polymer is used as a matrix. 3. The fuel cell according to claim 1 or 2, wherein the dielectric is contained in a proportion of 0.1 to 50% with respect to the total volume of the solid electrolyte layer. 4. The fuel cell according to claim 1, wherein the dielectric is dispersed in the solid electrolyte layer. 5. The fuel cell according to claim 4, wherein the solid electrolyte layer is a laminated body of dielectric dispersion films in which the dielectric is dispersed in a solid electrolyte. 6. The fuel cell according to claim 4, wherein the solid electrolyte layer is formed by alternately stacking a dielectric dispersion film in which a dielectric is dispersed in a solid electrolyte and a solid electrolyte film. 7. The fuel cell according to claim 5, wherein the dielectric dispersion film is arranged on the front surface and / or the back surface of the solid electrolyte layer. 8. The fuel cell according to any one of claims 1 to 3, wherein the solid electrolyte layer is provided with the dielectric. 9. The fuel cell according to claim 8, wherein the solid electrolyte layer is a laminate of dielectric-arranged films in which the dielectric is arranged in a solid electrolyte. 10. The solid electrolyte layer according to claim 8, wherein the solid electrolyte membrane is formed by alternately stacking a dielectric-arranged film in which the dielectric is arranged in a solid electrolyte. Fuel cell. 11. The fuel cell according to claim 9, wherein the dielectric-arranged film is arranged on the front surface and / or the back surface of the solid electrolyte layer. 12. A fuel cell power generation system using the fuel cell according to any one of claims 1 to 11, further comprising temperature detection means for detecting a temperature of a power generation portion, wherein the detected temperature is A fuel cell power generation system, characterized in that an AC applying means for applying an AC voltage is connected to the fuel electrode layer and the air electrode layer. 13. The method for heating a fuel cell by the fuel cell power generation system according to claim 12, wherein the alternating current applying means applies an alternating current voltage between the fuel electrode layer and the air electrode layer to obtain the solid electrolyte. A method for heating a fuel cell, comprising: heating a power generation portion by causing a dielectric contained in the layer to generate heat.