JPH09129249A - Fused carbonate fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fused carbonate fuel cell substantially durable and stably operable by preventing the occurrence of a critical gas crossover due to a thermal cycle under the restraint of a functional drop through the reduction of the outflow of an electrolyte. SOLUTION: This fuel cell has an electrolyte plate 12 made of a porous material including a holder and a reinforcement impregnated with an electrolyte formed out of mixed alkaline carbonate, and a positive electrode 10 and a negative electrode 12 positioned so as to sandwich both principal planes of the electrolyte plate 12. In this case, the electrolyte plate 12 has a structure with at least three layers of porous materials 12a, 12c and 12b stacked, and the porous material layers 12a and 12b respectively in contact with both electrodes 10 and 11 contain an inorganic fiber material. In this case, at least one of lithium aluminate and alumina should preferably be selected as the inorganic fiber material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molten carbonate fuel cell, and more specifically to improving the contact interface between an electrolyte plate and an electrode arranged between a pair of electrodes to improve the performance. And a molten carbonate fuel cell.

[0002]

2. Description of the Related Art Molten carbonate fuel cells have received much attention from the viewpoint of rational utilization of resources, and their development has been advanced. FIG. 4 is a cross-sectional view showing the basic structure of this kind of molten carbonate fuel cell, showing conductivity-between the anode 1 and the cathode 2 which are paired electrodes,
The configuration is such that an electrolyte plate 3 holding an electrolyte made of an alkali carbonate is sandwiched and arranged. In FIG. 4, 4a and 4b denote a pair of electrodes, an anode (positive electrode) 1 and a cathode (negative electrode) 2, which are pressed against the surface of the electrolyte plate 3.
Corrugated plates functioning as current collectors for the housings 5a and 5b, 6 is a fuel gas supply port, 7 is a gas discharge port on the anode 1 side, 8 is an oxidant gas supply port, and 9 is a gas discharge on the cathode 2 side. It is the exit.

The molten carbonate fuel cell is operated as follows to generate the required electric power. First, while the electrolyte plate 3 is melted at a high temperature (eg, about 650 ° C.), a required fuel gas (eg, H ₂ , CO ₂ ) is supplied to the anode 1 side through the fuel gas supply port 6 of the housing 4a.
Is supplied to the cathode 2 side through the oxidant gas supply port 8 of the housing 4b, respectively (eg, air, CO ₂ ). By supplying this fuel gas and oxidant gas, the reaction of the following formula (1) is caused on the anode 1 side and the reaction of the following formula (2) is caused on the cathode 2 side to generate the required power. ing.

[0004] ^{_{H 2 + CO 3 2- → H}} 2 O + CO 2 + 2e - (1) 1/2 O 2 + CO 2 + 2e - → CO 3 2- (2) By the way, the electrolyte used in the molten carbonate fuel cell The plate is basically an electrolyte consisting of mixed alkali carbonates,
It is composed of a holding material for preventing the outflow of electrolyte that becomes liquid during high-temperature operation (for example, about 650 ° C), and a reinforcing material for preventing the occurrence of cracks during temperature rise. Here, the mixed alkali carbonates are Li ₂ CO ₃ , K ₂ CO _{3 and} Na ₂ CO _3.
It is used in the form of a mixed salt of at least two of ₃ . Also, as the holding material, γ-LiA with a particle size of 0.05 to 2.0 μm was used.
fine powder of lO ₂ and beta-LiAlO ₂ is, as a reinforcing material is used the particle size 10 to 100 [mu] m LiAlO _2, respectively.

Further, the electrolyte plate 3 not only uses the movement of carbonate ions (CO ₃ ²⁻ ) as a medium, but also the anode 1
And also functions as a gas permeation barrier layer for preventing the direct mixing (gas crossover) of the reaction gas between the cathodes 2. In order to perform such a function, it is required that the electrolyte plate 3 sufficiently holds the electrolyte and that the electrolyte plate 3 does not generate or generate cracks. That is,
This is because the outflow of electrolyte (electrolyte loss) causes an increase in internal resistance and causes gas crossover, and cracks in the electrolyte plate 3 cause fatal gas crossover. Based on such a request,
Manufactured by matrix method in which a porous body is formed in advance from a fine particle mixture of γ-LiAlO ₂ (retaining material) and β-LiAlO ₂ (reinforcing material), and then this porous body is impregnated with an electrolyte composed of mixed alkali carbonates. The electrolyte plate 3 is used. Further, in order to prevent cracks, a method of dispersing an inorganic fiber material such as alumina throughout the electrolyte plate 3 to improve the strength is also known.

[0006]

However, in the case of the molten carbonate fuel cell which has been subjected to the above-mentioned improvements and improvements, there are the following practical problems in the operation of the fuel cell for a long time. That is, even when the electrolyte plate 3 is manufactured by the matrix method, coarse holes that cannot hold the electrolyte are generated in the manufactured electrolyte plate 3. In addition, in order to reinforce the electrolyte plate 3, when the structure in which the inorganic fiber body is added / dispersed as a whole is adopted, there is a tendency that minute cracks are generated due to the added / dispersed inorganic fiber body. As a result, the temperature rise / fall (thermal cycle) associated with the start / stop of the molten carbonate fuel cell causes the coarse pores and minute cracks to be connected to form a crack, which is a deadly gas in a few thermal cycles. There is a disadvantage that crossover is caused and sufficient battery characteristics cannot be maintained.

The present invention has been made in order to solve the above-mentioned problems, and prevents the fatal gas crossover due to the thermal cycle while substantially suppressing the outflow of the electrolyte and suppressing the deterioration of the performance. An object of the present invention is to provide a molten carbonate fuel cell which has a long life and operates stably.

[0008]

According to a first aspect of the invention, an electrolyte plate in which a porous body containing a holding material and a reinforcing material is impregnated with an electrolyte composed of a mixed alkali carbonate, and the electrolyte plate is provided on both main surfaces. In a molten carbonate fuel cell having a positive electrode and a negative electrode sandwiched between the electrolyte plates, the electrolyte plate has a structure in which at least three layers of porous bodies are laminated, and the porous body layers in contact with both electrodes contain an inorganic fiber body. The molten carbonate fuel cell is characterized in that

The invention of claim 2 is the molten carbonate fuel cell according to claim 1, wherein the inorganic fiber body is at least one of lithium aluminate and alumina.

The present invention relates to a molten carbonate fuel cell provided with an electrolyte plate obtained by impregnating a porous body containing a holding material and a reinforcing material with an electrolyte composed of a mixed alkali carbonate, and between the anode and cathode electrodes. The electrolyte plates arranged so as to be sandwiched are formed of at least three layers of a porous body in a laminated type, and only the outer layer of the porous body layer in contact with both electrodes contains the inorganic fiber body in a dispersed manner. It is a molten carbonate fuel cell as the essence. That is, the porous plate forming the electrolyte plate is a laminated type having three or more layers, and the porous layer mainly prevents outflow of the molten electrolyte and the porous layer mainly prevents crack generation. The betting is divided into two parts and arranged in a stacking type considering their functionality.

In the present invention, the positive electrode (anode) and the negative electrode (cathode) are formed of, for example, a nickel base alloy or a sintered body of a porous nickel base alloy,
Further, the corrugated plate which also serves as a separator, an edge seal, a perforated plate, a current collector, etc., which is used in the construction of the power generation unit composed of the positive electrode, the electrolyte plate and the negative electrode, is made of, for example, stainless steel.

In the present invention, the electrolyte plate is a laminated body of three layers of porous material (for example, porosity of 40 to 65%), and a holding material for preventing the outflow of the electrolyte that becomes a liquid during high temperature operation, A particle reinforcing material for preventing the occurrence of cracks at the time of temperature rise is contained, and a mixed alkali carbonate is impregnated in a molten state. FIG. 1 is a cross-sectional view showing the main part of this laminated electrolyte plate. In the outer layers 12a and 12b in contact with both electrodes 10 and 11, inorganic fiber bodies functioning as a second reinforcing material are provided. In addition, the central layer 12c has no added inorganic fiber body functioning as a second reinforcing material.

That is, it is preferable that the porous body constituting the electrolyte plate specifically has the following form.

(A) Particles having a particle size of about 0.05 to 0.5 μm (holding material) and particles having a particle size of about 10 to 100 μm (reinforcing material)
And a porous body composed of an inorganic fiber body having a length of about 50 to 3000 μm.

(B) A porous body composed of particles (holding material) having a particle size of about 0.05 to 0.5 μm and an inorganic fiber body having a length of about 50 to 3000 μm.

(C) A porous body composed of particles (holding material) having a particle size of about 0.05 to 0.5 μm.

(D) A porous body composed of particles (holding material) having a particle size of about 0.05 to 0.5 μm and particles (reinforcing material) having a particle size of about 10 to 100 μm.

(E) A porous body composed of particles (holding material) having a particle size of about 0.05 to 0.5 μm and inorganic short fiber bodies (reinforcing material) having a length of 20 to 200 μm.

The form of (a) or (b) is selected as the outer layer in contact with both electrodes, and the intermediate layer not in contact with the electrodes is (c), (d) or (e). Is selected.

In the porous body (a), the amount of the inorganic fiber body added / content is 5 to 18% by weight, more preferably 8 to
It is preferably 15% by weight. The reason is that it is difficult to prevent the occurrence of cracks when the content of the inorganic fiber body is less than 5% by weight, and when it exceeds 18% by weight, the initial porosity of the porous body is high and the loss of the electrolyte is suppressed. It tends to be difficult. Further, the total amount of particles (reinforcing material) having a particle size of 10 to 100 μm is preferably 30% by weight or less in total with the inorganic fiber body. When it exceeds 30% by weight, the particle size is 0.05.
This is because the particle (holding material) component of about 0.5 μm becomes too small and the holding power of the electrolytic solution decreases.

In the porous body (b), the amount of the inorganic fiber body added and contained is 10 to 25% by weight, more preferably 12 to 20%.
% By weight. The reason is that if the content of the inorganic fiber body is less than 10% by weight, it becomes difficult to prevent cracking, and if it exceeds 25% by weight, the porosity of the porous body becomes high and it is difficult to suppress electrolyte loss. Becomes Further, in the porous body (d), 10 to 30% by weight of particles (reinforcing material) having a particle size of 10 to 100 μm, more preferably 12 to 20%
% By weight. The reason is that if it is less than 10% by weight, it is difficult to prevent the generation of cracks, and if it exceeds 30% by weight, the porosity of the porous body increases and it becomes difficult to suppress electrolyte loss.

Further, in the porous body (e), it is desirable that the content of the short fiber body is 10 to 25% by weight, more preferably 12 to 20% by weight. The reason is that it is difficult to prevent cracking when the content of the short fiber body (reinforcing material) is less than 10% by weight, and when it exceeds 5% by weight, the porosity of the porous body increases and the electrolyte loss is suppressed. It will be difficult.

In the present invention, the porous bodies (a) to (e)
The particles (supporting material, reinforcing material) contained in are lithium aluminate (α, β, γ-LiAlO ₂ ), lithium zirconate (Li ₂ ZrO ₃ ), zirconia (ZrO ₂ ), lithium tantalate (LiTaO ₃ ) And potassium tantalate include compounds represented by (KTaO ₃ ). On the other hand, as inorganic fiber bodies and short fiber bodies, alumina (Al ₂ O ₃ ), lithium aluminate (α, β, γ-LiA
lO ₂ ), zirconia (ZrO ₂ ), lithium zirconate (Li ₂ ZrO ₃ ) and the like, and these may be used in a mixture of two or more kinds. Further, the inorganic fiber body and the short fiber body may be not only so-called pure fibers but also a crystal type rod-shaped body, and further, in the operation process of a battery incorporated as an electrolyte plate, it may be affected by the electrolyte. It may be in a lithiated form.

In the present invention, examples of the electrolyte (mixed alkali carbonate) to be impregnated in the laminated multi-hard body include lithium carbonate (Li ₂ CO ₃ ) and potassium carbonate (K ₂ C).
O ₃ ) mixture, Li ₂ CO ₃ and sodium carbonate (Na ₂ CO ₃ )
And a mixture of Li ₂ CO ₃ , K ₂ CO ₃ and Na ₂ CO ₃ , and the addition of an alkaline earth metal carbonate is also possible.

The electrolyte plate according to the present invention is manufactured, for example, by the following method.

First, the holding material particles, the inorganic fiber body, the short fiber body and the reinforcing material particles which are blended as necessary are mixed with an organic binder under the mixing of an organic solvent. Examples of the organic binder used here include polyvinyl butyral, dibutyl phthalate, and acrylic resin. Examples of the organic solvent include toluene, xylene, methyl ethyl ketone and the like. continue,
A green sheet is formed from the mixture by a usual sheet forming method (for example, doctor blade method, calendar roll method, slip casting method or cold extrusion method), and then degreased to obtain a porous body having a predetermined porosity. create.

On the other hand, an electrolyte composed of mixed alkali carbonates is formed into a sheet by the same method as in the case of the porous body to prepare a sheet-like material. Then, a sheet-shaped material is stacked on the porous body, and the sheet-shaped material is melted and impregnated into the porous body to manufacture an electrolyte plate. In addition,
Specifically, the above-prepared electrolyte plate is impregnated with a mixed alkali carbonate serving as an electrolyte, and is placed as a unit cell between anode and non-impregnated cathode, and a plurality of unit cells are sandwiched by separators. After stacking to form a stack power generation element, a manifold is attached to four side surfaces of the power generation element to assemble a fuel cell. Then raise the temperature to the operating temperature,
Molten mixed alkali carbonate in the anode is diffused and filled in the pores of the electrolyte plate to function as a required electrolyte plate.

According to the first and second aspects of the present invention, a molten carbonate type having an electrolyte plate formed by impregnating a porous body containing a particulate holding material and a reinforcing material with an electrolyte composed of a mixed alkali carbonate In the fuel cell, the electrolyte plate is a laminated type of a porous body having at least three layers, and the inorganic fiber body is added and contained only in the porous body layer in contact with the electrode. In other words, by suppressing the generation of cracks in the electrolyte plate and simultaneously maintaining stable retention of the electrolytic solution, a fatal gas cross caused by crack generation due to thermal cycle, coarsening due to long time operation, etc. The occurrence of over is completely prevented. Therefore, it functions as a molten carbonate fuel cell capable of operating at high power density for a long time.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to FIGS.

FIG. 1 is an exploded perspective view showing a structural example of a main part of a molten carbonate fuel cell of the present invention, and FIG. 2 is an enlarged perspective view showing a part of a stack power generation element. The molten carbonate fuel cell includes an anode (fuel electrode) 10, a cathode (air electrode) 11, and an electrolyte plate 12 which holds an electrolyte and is arranged between the electrodes 10 and 11. Here, the anode 10, the cathode 11 and the electrolyte plate 12 form a unit cell, and a plurality of unit cells are stacked via the separator 13 to form a stack power generation element.

More specifically, the unit cell is formed as follows. That is, the electrolyte plate is provided on the pair of facing edges of the anode 10 arranged on the upper surface of the electrolyte plate 12.
Both edges and a separator of the electrolyte plate 12 which is located inside at a desired distance from the edges of 12 and in which the anode 10 does not exist.
An edge seal plate 14a for sealing the space between 13 is arranged. In addition, the cathode 11 disposed on the lower surface of the electrolyte plate 12 is orthogonal to the edge seal plate 14a-a pair of edges is provided with an electrolyte plate.
Both edges of the electrolyte plate 12 and the separator which are located inside at a desired distance from the edges of 12 and in which the cathode 11 does not exist.
An edge seal plate 14b for sealing the space between 13 is arranged. Further, the empty space (fuel gas distribution space) partitioned by the anode 10, the separator 13 and the edge seal plate 14a has a perforated plate 15 having conductivity as a current collector plate.
a and corrugated plate 16a are sequentially laminated from the anode 10 side.
On the other hand, cathode 11, separator 13 and edge seal plate
A perforated plate 16b having conductivity and a corrugated plate 16b as a current collector are sequentially stacked from the cathode 11 side in the space defined by 14b (oxidant gas circulation space). Here, the anode 10 and the cathode 11 are made of nickel base alloy, for example, and the separator 13, the edge seal plates 14a and 14b, the perforated plates 15a and 15b, and the corrugated plates 16a and 16b are made of stainless steel, for example.

A plurality of unit cells having such a structure are stacked with a separator 13 sandwiched therebetween to form a stack power generating element, and a manifold having frame-shaped flanges 17 on four side surfaces of the stack power generating element. 18 are arranged respectively. In addition, a frame-shaped manifold seal plate 19 is interposed between each side surface of the stack power generation element and the flange 17 of the manifold 18.

A fuel gas supply pipe 20 for supplying fuel gas is attached to a manifold (not shown) corresponding to the side surface of the power generation element where the fuel gas distribution space is exposed. A gas exhaust pipe 21 is attached to the manifold 18 on the opposite side of the supply pipe 20. Further, an oxidant gas supply pipe 22 for supplying an oxidant gas is attached to a manifold (not shown) corresponding to the side surface of the power generation element where the oxidant gas distribution area is exposed. A gas discharge pipe 23 is attached to the opposite side of the agent gas supply pipe 22.

Examples 1 to 6 and Comparative Examples 1 to 6 Fine powder of α-lithium aluminate (α-LiAlO ₃ ) having a specific surface area of 5 to 15 m ² / g (holding material) and particle diameter of 20 to 60 μm
Alumina (Al ₂ O ₃ ) powder (reinforcing material particles) was placed in an alumina pot at the weight ratio shown in Table 1, and wet mixed with toluene, polyvinyl butyral, and dibutyl phthalate for 72 hours to prepare a slurry. Next, Al ₂ O ₃ (inorganic fiber body) having a short diameter of about 1 μm and a long diameter of about 3 mm dispersed by a sieve at a weight ratio shown in Table 1 was added to each of the slurries, and then spread on a carrier sheet, 0.5 each
A matrix green sheet of about mm was used. As shown in Table 1, as shown in Table 1, two sheets on the electrode side and one sheet in the center sandwiched between the two sheets, a total of three sheets, were combined into a laminated type to form an electrolyte plate.

[0035]

[Table 1] Next, mixed alkali carbonate (Li ₂ C
_{O 3: 62 mol%, K} 2 CO 3: 8 the mol%), wherein a sheet Joka optionally the same method of the porous body, heating the sheet to 550 ° C. overlaid on the porous body Then, the sheet-like material was put into a molten state to impregnate the porous body with the mixed alkali carbonate, thereby preparing an electrolyte plate.

Examples 7 to 13 and Comparative Examples 7 to 11 Fine powder (holding material) of α-lithium aluminate (α-LiAlO ₃ ) having a specific surface area of 5 to 15 m ² / g and a particle size of 20 to 60 μm.
Alumina (Al ₂ O ₃ ) powder (reinforcing material particles) was placed in an alumina pot at a weight ratio shown in Table 2 and wet-mixed with toluene, polyvinyl butyral, and dibutyl phthalate for 72 hours to prepare a slurry. Then, Al ₂ O ₃ (inorganic fiber body) having a short diameter of about 1 μm and a long diameter of about 3 mm dispersed by a sieve at a weight ratio shown in Table 2 was added to each of the above-mentioned slurries, and then spread on a carrier sheet, 0.5 each
A matrix green sheet of about mm was used. As shown in Table 2, two sheets on the electrode side and a total of three sheets of the central portion sandwiched between the two sheets were combined into a laminated type to form an electrolyte plate.

[0037]

[Table 2] Next, mixed alkali carbonate (Li ₂ C
_{O 3: 62 mol%, K} 2 CO 3: 8 the mol%), wherein a sheet Joka optionally the same method of the porous body, heating the sheet to 550 ° C. overlaid on the porous body Then, the sheet-like material was put into a molten state to impregnate the porous body with the mixed alkali carbonate, thereby preparing an electrolyte plate.

Examples 14-20, Comparative Examples 12-16 α-Lithium aluminate (α-LiAlO ₃ ) fine powder (holding material) having a specific surface area of 5-15 m ² / g and a particle size of 20-60 μm
Alumina (Al ₂ O ₃ ) powder (reinforcement material particles) or Al ₂ O ₃ (mineral fiber body) having a short diameter of about 1 μm and a long diameter of about 100 μm was placed in an alumina pot at the weight ratio shown in Table 3, and toluene and polyvinyl butyral were added. , And dibutyl phthalate were wet mixed for 72 hours to prepare a slurry. Then
Al ₂ O with a short diameter of about 1 μm and a long diameter of about 3 mm dispersed by a sieve
₃ (inorganic fibrous body) was added to each of the above-mentioned slurries in a weight ratio shown in Table 3, and then spread on a carrier sheet to form matrix green sheets each having a thickness of about 0.5 mm. As shown in Table 3, two sheets on the electrode side and one sheet in the central portion sandwiched between the two sheets, a total of three sheets, were combined in a laminated type to form an electrolyte plate.

[0039]

[Table 3] Next, mixed alkali carbonate (Li ₂ C
_{O 3: 62 mol%, K} 2 CO 3: 8 the mol%), wherein a sheet Joka optionally the same method of the porous body, heating the sheet to 550 ° C. overlaid on the porous body Then, the sheet-like material was put into a molten state to impregnate the porous body with the mixed alkali carbonate, thereby preparing an electrolyte plate.

Using the electrolyte plates of Examples 1 to 20 and Comparative Examples 1 to 16, a molten carbonate fuel cell having the structure shown in FIGS. 1 and 2 was assembled, and 8000 at 650 ° C.
The battery performance after each continuous operation was examined. Further, after the battery was operated, the battery was disassembled, the electrolyte plate was taken out, the carbonate portion was dissolved by acetic acid, and the amount of carbonate loss before and after the operation was examined. These results are also shown in Tables 1, 2 and 3 respectively. Furthermore, on the anode 10 side, a volume ratio of 80% by volume of H ₂ + 20% by volume of CO ₂ in fuel gas
He gas of 10% mixed gas, the cathode 11 side flowing air 70 volume% + CO ₂ 30 volume% of the mixed gas, repeated starting and stopping of the battery every 200 hours, the cathode 11 side outlet gas He
The concentration was measured. The number of times that the He concentration exceeds 2% is also shown in Tables 1, 2 and 3 above.

As is clear from the above tables, Examples 1 to 1
Add the fibrous body only to the two layers of porous plate in contact with 20 electrodes.
In the molten carbonate fuel cell equipped with the electrolyte plate containing it, the amount of cross leak is larger than that of the fuel cell of the comparative example.
It can be seen that the number of thermal cycles until reaching 2% is extended, and the operating potential drop after 8000 hours of continuous operation is small, which is stable over the long term.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. That is, the composition of each porous body that constitutes the electrolyte plate 12, the number of stacked porous bodies, the electrolyte, and the like may take a configuration other than the configuration given as a specific example.

[0043]

As described in detail above, according to the present invention,
Cracking of the electrolyte plate is suppressed and the outflow of the electrolyte in the electrolyte plate is also suppressed without impairing the power generation characteristics. In other words, even in a thermal cycle, since the electrolyte plate that it has operates stably, the problem of fatal reduction of the operating potential due to gas crossover is completely avoided and suppressed, resulting in long-term operation. A molten carbonate fuel cell is provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a main part of an electrolyte plate included in a molten carbonate fuel cell according to the present invention.

FIG. 2 is a perspective view showing an expanded configuration example of a main part of a molten carbonate fuel cell according to the present invention.

FIG. 3 is an enlarged perspective view showing a part of FIG.

FIG. 4 is a schematic diagram showing the basic configuration of a molten carbonate fuel cell.

[Explanation of symbols]

 1, 10 …… Anode 2, 11 …… Cathode 3, 12 …… Electrolyte plate 4a, 4b, 16a, 16b …… Corrugated plate 5a, 5b …… Housing 6 …… Fuel gas supply port 7 …… Fuel gas side exhaust Outlet 8 ... Oxidant gas supply port 9 ... Oxidant gas side discharge port 12a, 12b ... Porous body of outer layer forming electrolyte plate 12c ... Porous body of inner layer (center part) forming electrolyte plate 13 …… Separator 14a, 14b …… Edge seal plate 15a, 15b …… Perforated plate 17 …… Flange 18 …… Manifold 19 …… Manifold shield plate 20 …… Fuel gas supply pipe 21, 23 …… Gas discharge pipe 22 ...... Oxidant gas supply pipe

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor: Toshimatsu Toshihiro 1 Kosuka Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa Inside Toshiba R & D Center Co., Ltd.

Claims (2)

[Claims] 1. An electrolyte comprising a mixed alkali carbonate,
In a molten carbonate fuel cell comprising an electrolyte plate impregnated in a porous body including a holding material and a reinforcing material, and a positive electrode and a negative electrode sandwiching the electrolyte plate on both main surfaces, the electrolyte plate has at least three layers of porous material. A molten carbonate fuel cell, characterized in that a porous body layer having a structure in which porous bodies are laminated and each of which is in contact with both electrodes contains an inorganic fiber body. 2. The molten carbonate fuel cell according to claim 1, wherein the inorganic fiber body is at least one of lithium aluminate and alumina.