JP3004593B2 - Molten carbonate fuel cell - Google Patents

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 particularly to a molten carbonate fuel cell having a function of supplying an electrolyte to a specific cell.

[0002]

2. Description of the Related Art Hydrogen and oxygen are produced by an electrochemical reaction.
Fuel cells that can convert electric energy with high efficiency are classified into phosphoric acid type, molten carbonate type, solid electrolyte type, and solid polymer type depending on the type of electrolyte. And 650 ° C
A fuel cell using an alkali metal carbonate, which becomes liquid at a high temperature in the vicinity, as an electrolyte is called a molten carbonate fuel cell, and generally comprises a fuel electrode, an electrolyte matrix, and an oxidant electrode.

FIG. 6 is a schematic diagram showing a conventional molten carbonate fuel cell. A fuel electrode 1 and an oxidant electrode 4 are provided above and below an electrolyte matrix 7 made of a carbonate ion conductor so as to sandwich the electrolyte matrix 7,
A unit battery 10 is configured. A fuel electrode current collector plate 2 and a fuel gas flow channel plate 3 are stacked on the upper side of the fuel electrode 1, and an oxidizer electrode current collector plate 5 and an oxidizer gas flow channel plate below the oxidizer electrode 4. 6, a plurality of unit batteries 10 are sequentially stacked in series via a metal separator 8 made of a stainless steel / nickel thin plate, and holding plates (not shown) are arranged above and below the stacked body. A molten carbonate fuel cell is configured. In addition to electronically connecting the unit cells 10, the metal separator 8 also has a function of isolating the reaction gas from the outside air such as air or nitrogen. In particular, a portion in contact with the electrolyte matrix 7 is called a wet seal portion 9. Although not shown, a heat insulating material is provided so as to surround the outer periphery of the laminate. In some cases, the fuel electrode 1 and the oxidant electrode 4 may be upside down.

In such a molten carbonate fuel cell, a porous sintered body of a transition metal such as nickel is used for the fuel electrode 1, and a high electron conductivity is used for the oxidant electrode 4 as in the case of the fuel electrode. An oxide porous material such as nickel having a property is used. The electrolyte matrix 7 is made of a sintered body of lithium aluminate particles impregnated with an electrolyte. Further, a binary system of lithium and potassium carbonates is mainly used for the electrolyte, and the composition ratio thereof makes the ionic conductivity high and the melting point is lower than the operating temperature (for example, 650 ° C.) of the battery. If necessary, a eutectic salt composition or a carbonate close to that composition is used. The fuel electrode current collector 2 and the oxidant electrode current collector 5 are made of the same material as the fuel electrode 1 and the oxidant electrode 4, respectively. The fuel gas flow path plate 3 is formed, for example, by forming a nickel plate into a corrugated shape. The oxidant gas flow path plate 6
For example, a stainless steel plate formed into a corrugated shape is used.

In a molten carbonate fuel cell, generally, 65
Since the battery is operated at a high temperature of around 0 ° C., there is a problem that the electrolyte inside the battery is consumed with time due to a corrosion reaction with a metal member of the battery and evaporation of a carbonate, that is, the amount of the electrolyte gradually decreases. . The consumption of the electrolyte induces a decrease in gas sealing performance, an increase in polarization in an electrode reaction, and an increase in battery resistance, and is a major factor in lowering battery performance.

As a remedy, various electrolyte replenishment methods for replenishing the electrolyte matrix with the exhausted electrolyte have been proposed. For example, Japanese Unexamined Patent Publication No. Hei 1-211861 discloses a structure made of a metal having a higher electric resistance than an electrolyte matrix, and has a thickness of 2 mm in the thickness direction of the electrolyte matrix.
An electrolyte reservoir formed in a shape capable of sandwiching the surface and storing the electrolyte is disposed so as to surround the periphery of the electrolyte matrix end, and the electrolyte stored in the electrolyte reservoir in the battery is caused by a pressure difference in the battery. A structure has been proposed for replenishment. However, Japanese Patent Application Laid-Open No.
The electrolyte replenishing structure described in JP-A-861 has a problem that it is difficult to replenish a predetermined amount only to a specific battery of the battery stack because the electrolyte is easily moved mainly by capillary attraction. Also, Japanese Patent Application Laid-Open No. 1-19556
No. 69, the electrolyte reservoir is disposed so as to surround the periphery of the electrolyte matrix, and a cooling gas flow path for cooling the electrolyte reservoir is provided, the flow rate of the cooling gas flowing through the cooling gas flow path A structure has been proposed in which the amount of electrolyte supplied to the battery is adjusted by adjusting the temperature of the electrolyte to melt or solidify the electrolyte stored in the electrolyte reservoir in advance. However, Japanese Patent Application Laid-Open No.
In the electrolyte replenishing structure described in Japanese Patent Application Laid-Open Publication No. H10-157, there is a problem that it is difficult to replenish a predetermined amount only to a specific battery of the battery stack.

[0007] Further, in the structures described in JP-A-62-98568 and JP-A-61-26986, an electrolyte replenishing structure has been proposed in which electrolyte can be supplied to all batteries from an electrolyte replenishing tube. I have. In this case, a predetermined amount cannot be replenished only to a specific battery of the battery stack, and a hole must be made in a thin metal separator, and an electrolyte replenishing tube must be welded, which complicates the battery structure. I will.
Also, JP-A-2-61063, JP-A-62-23
No. 7671 discloses a method of replenishing the electrolyte from the electrolyte reservoir during the operation of the battery to compensate for the consumption of the electrolyte. In this method, the electrolyte is independently supplied to each battery. There is no thought.

[0008]

Since the conventional molten carbonate fuel cell is configured as described above, when replenishing the electrolyte, it is not possible to replenish the electrolyte only to a specific cell, and the electrolyte is not replenished. The electrolyte is replenished to a battery that is sufficient and does not need replenishment. Accordingly, there has been a problem that an electrolyte overflow phenomenon occurs, a reaction gas cannot be sufficiently supplied to the electrodes, and a decrease in battery performance due to an increase in polarization occurs. Further, since the molten carbonate fuel cell is operated at a high temperature of 650 ° C., it is difficult to replenish the individual cells with electrolyte during the operation. Therefore, it is conceivable to lower the battery temperature to normal temperature and replenish the electrolyte with depleted battery, but the operation must be stopped every time the electrolyte is replenished, resulting in a significant decrease in operating efficiency. This is an operationally undesirable method.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it has been made possible to selectively supply electrolyte to each battery in a high-temperature operation state, and to eliminate a battery in which electrolyte is excessively supplied. It is an object of the present invention to provide a molten carbonate fuel cell capable of suppressing a decrease in cell characteristics due to an increase in polarization.

[0010]

According to the first aspect of the present invention, there is provided a molten carbonate fuel cell comprising a unit cell having an electrolyte matrix sandwiched between a fuel electrode and an oxidant electrode, and a separator plate alternately arranged vertically. A plurality of fuel gas passages and an oxidant gas passage are provided between the fuel electrode and the oxidant electrode of the unit cell and the separator plate, respectively, and an alkali metal carbonate electrolyte is held in the electrolyte matrix. In the molten carbonate fuel cell thus prepared, an electrolyte reservoir provided around the outer periphery of each unit cell so as to surround the wet seal portion, and the electrolyte supplied to the electrolyte reservoir is supplied to the electrolyte matrix. comprising an electrolyte replenishing portion, and an electrolyte guide portion guiding the electrolyte from the outside so as to extend outward in the electrolyte reservoir from the electrolyte reservoir, the separator It is sandwiched between the unit cell
Separator part and the entire circumference from the separator part
It is constituted by a metal plate having an extension part extended outward,
The base portion of the extension of the metal plate wraps the separator.
Constituted concave so as to surround the electrolyte reservoir
And from the root to the tip over the entire circumference.
The electrolyte guiding section is formed on an uphill slope.
It has been achieved .

[0011]

The molten carbonate fuel cell according to the second aspect of the present invention is the molten carbonate fuel cell according to the first aspect , wherein an electrically insulating ceramic plate is interposed between the extension portions of the adjacent metal plates each having the inclined surface. A through-hole that is mounted and through which an electrolyte is inserted is provided in the ceramic plate so as to connect the electrolyte reservoir side to the outside.

In the molten carbonate fuel cell according to the third aspect of the present invention, in the first aspect, the end of the electrolyte matrix is extended from the wet seal portion to the inside of the electrolyte reservoir to form the electrolyte supply portion. It is composed.

According to a fourth aspect of the present invention, there is provided a molten carbonate fuel cell according to the third aspect , wherein a reinforcing material is buried inside an extended portion of the electrolyte matrix constituting the electrolyte replenishing portion from the wet seal portion. Is what it is.

According to a fifth aspect of the present invention, in the molten carbonate fuel cell according to the third or fourth aspect , the extended portion of the electrolyte matrix from the wet seal portion is located at the wet seal portion of the electrolyte matrix. Is formed to have an average pore diameter larger than the average pore diameter of the portion where the gas flows.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a plan view showing a molten carbonate fuel cell according to Embodiment 1 of the present invention, and FIG.
3 is a plan view showing a separator plate used in the molten carbonate fuel cell according to Embodiment 1 of the present invention, FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3, and FIG. FIG. 7 is a perspective view showing an electrolyte matrix used in the molten carbonate fuel cell according to Embodiment 1 of the present invention. In the figure, the same or corresponding portions as those of the conventional molten carbonate fuel cell shown in FIG. The same reference numerals are given and the description is omitted.

3 and 4, reference numeral 20 denotes a metal plate;
For example, it is a metal separator plate made of a stainless steel / nickel thin plate (cladding material). The metal separator plate 20 has a rectangular separator portion 2 sandwiched between unit batteries.
1 and an extension portion 22 extending outwardly from the separator portion 21 over the entire circumference to form an electrolyte reservoir and an electrolyte guiding portion. And the separator part 21
A rectangular frame-shaped stainless steel frame 21b having an L-shaped cross section on each side is joined to a stainless steel surface side of a flat base 21a made of a stainless steel / nickel thin plate,
A nickel frame 21c molded in the same shape as the frame 21b is joined to the nickel surface side of the flat base a in opposition to the frame 21b. The extension 22 is made of a stainless steel / nickel thin plate.
It extends outward from the first part over the entire circumference by a predetermined length (extending part 22a), and is then bent toward the stainless steel surface side to form an inclined surface 22b. Therefore, on the base portion side of the extension portion 22, a concave portion including the frame 21b, the extension portion 22a, and the inclined surface 22b is formed so as to surround the separator portion 21a, and constitutes an electrolyte reservoir. And
The inclined surface 22b of the extension portion 22 is formed with an upward slope from the electrolyte reservoir, and constitutes an electrolyte guiding portion.

In FIG. 5, reference numeral 25 denotes a rectangular electrolyte matrix made of, for example, a sintered body of lithium aluminate particles, and reference numeral 26 denotes an electrolyte supply portion extending outward from the center of each side of the electrolyte matrix 25. The electrolyte communication matrix 26 is, for example, a sintered body of lithium aluminate particles.
And are integrally formed. The electrolyte connection matrix 26 is formed such that the average pore diameter is larger than the average pore diameter of the electrolyte matrix 25. The electrolyte communication matrix 26 is formed into a shape along the outer peripheral surfaces of the frame 21b and the extension 22a of the metal separator plate 20 when assembled as a fuel cell.
Further, as shown in FIG. 2, a reinforcing material 27 made of an aluminum alloy plate or a nickel plate is embedded in the electrolyte communication matrix 26.

Next, the overall structure of the molten carbonate fuel cell according to Embodiment 1 will be described with reference to FIGS. A fuel cell 1 and an oxidant electrode 4 are provided above and below an electrolyte matrix 25 holding an electrolyte so as to sandwich the electrolyte matrix 25, thereby constituting a unit cell 10. A fuel electrode current collector plate 2 and a fuel gas flow channel plate 3 are stacked on the upper side of the fuel electrode 1, and an oxidizer electrode current collector plate 5 and an oxidizer gas flow channel plate below the oxidizer electrode 4. 6 are stacked, and a plurality of unit batteries 10 are sequentially stacked in series via the metal separator plate 25. Further, the laminated body is integrally fastened via pressing plates (not shown) arranged vertically. Next, an electrically insulating ceramic plate 30 is interposed between the extension portions 22 of the adjacent metal separator plates 25 on which the inclined surfaces 22b are formed. Thereafter, a heat insulating material 31 made of an electrically insulating ceramic material is placed outside the four sides of the laminate so as to surround the laminate, and a molten carbonate fuel cell is formed. On the inner peripheral surface of the heat insulating material 31, projecting pieces 32 are provided at predetermined intervals in the vertical direction.
2 is the inclined surface 2 of the adjacent metal separator plate 25
The projecting piece 32 has the same function as that of the ceramic plate 30. The heat insulating material 31 is provided with a through hole 33 that communicates between the outer peripheral surface side and the inner peripheral surface side so as to penetrate each protruding piece 32. Although not shown, the supply flow path and the discharge flow path of each reaction gas communicate with each reaction gas flow path composed of the fuel gas flow path plate 3 and the oxidizing gas flow path plate 6, respectively. It is provided so as to penetrate the laminate vertically, avoiding the battery reaction part.

Here, the metal separator plate 20 is disposed so that the stainless steel surface side faces upward, and its inclined surface 22
b has an upward slope toward the outside. Then, the side turned back toward the inside of the frame 21b is inserted into a step provided over the entire periphery of the surface of the oxidant electrode 4 on the side of the electrolyte matrix 25, and is inserted between the oxidant electrode 4 and the electrolyte matrix 25. It is pinched. Also, frame 2
The inner side of the fuel electrode 1 c is inserted into a step provided over the entire periphery of the surface of the fuel electrode 1 on the electrolyte matrix 25 side, and is sandwiched between the fuel electrode 1 and the electrolyte matrix 25. Further, the base 21a is sandwiched between the fuel gas flow path plate 3 and the oxidizing gas flow path plate 6 to isolate the flow paths of both reaction gases. Thus, the metal separator plate 20 electrically connects the unit batteries 10 and isolates the reaction gas from the outside air such as air or nitrogen. The portion that comes into contact with the electrolyte matrix 25 forms the wet seal portion 9. The electrolyte communication matrix 26 extends from the electrolyte matrix 25 along the outer peripheral surfaces of the frame 21b and the extension 22a of the metal separator plate 20.
a and the inclined surface 22b is located in a concave portion as an electrolyte reservoir. The protruding pieces 32 of the ceramic plate 30 and the heat insulating material 31 are connected to the adjacent metal separator plates 25.
Is formed to have the same thickness as the gap between the extended portions 22 where the inclined surfaces 22b are formed.

In the molten carbonate fuel cell configured as described above, when electrolyte consumption occurs in a certain unit cell 10, the intervening portion 22 extends between the extension portions 22 of the metal separator plate 20 sandwiching the corresponding unit cell 10. At room temperature, a carbonate electrolyte solid at room temperature, which is formed into a spherical shape, is inserted from the outside of the heat insulating material 31 into a through hole 33 penetrating the mounted protruding side 32. The spherical electrolyte inserted into the through-hole 33 rolls inside the through-hole 33 having a downward slope and moves inward. Then, on the way, it is melted by the temperature of the fuel cell,
It becomes a liquid electrolyte and is guided into a recess formed by the frame 21b, the extension 22a, and the inclined surface 22b. The electrolyte stored in the concave portion is guided to the electrolyte matrix 25 through the electrolyte communication matrix 26 by capillary action, and the electrolyte is supplied to the electrolyte matrix 25. Further, the amount of electrolyte supplied to the electrolyte matrix 25 can be adjusted by the amount of electrolyte inserted into the through holes 33.

As described above, according to the first embodiment,
Since the electrolyte can be supplied to each unit battery, the electrolyte can be reliably supplied only to the unit battery whose electrolyte has been consumed. Therefore, it is possible to avoid electrolyte overflow to unit batteries that do not need to be replenished and to cause electrolyte overflow, as in the conventional technique of replenishing electrolyte for all unit batteries at once. As a result, the reaction gas can be sufficiently supplied, and a decrease in battery characteristics due to an increase in polarization can be suppressed. In addition, since the metal separator plate 20 is formed of a metal plate, the electrolyte reservoir and the electrolyte guide can be easily formed integrally by bending or welding, thereby reducing the number of components and reducing cost. And the workability of assembling can be improved. Further, the interval between the extending portions 22 of the metal ceramic plate 20 is only about several millimeters, and an electronic short circuit accident is likely to occur due to thermal deformation.
Since the electrically insulating ceramic plate 30 and the protruding piece 32 are interposed between the extension portions 22 of the "0", an electronic short-circuit accident between the metal separator plates 20 can be reliably prevented, and the operation reliability is improved. Can be.

A protruding piece 32 projecting from the inner peripheral surface of the heat insulating material 31 is interposed between the extended portions 22 of the metal separator plate 20 to communicate the outer peripheral surface and the inner peripheral surface of the heat insulating material 31. Since the through holes 33 are provided through the respective projecting pieces 32,
The electrolyte can be replenished from the outside of the heat insulating material 31 through the through-hole 33, and it is not necessary to stop the operation of the battery every time the electrolyte is replenished. The decline can be prevented. Also,
By adjusting the insertion amount of the electrolyte into the through hole 33,
The supply amount can be adjusted, and the occurrence of electrolyte overflow due to excessive supply of electrolyte can also be suppressed.

Further, since the electrolyte communication matrix 26 is formed integrally with the end of the electrolyte matrix 25,
There is no need to provide a separate member as an electrolyte replenishing unit,
Accordingly, the number of components can be reduced, and assembling workability can be improved. Further, since the electrolyte communication matrix 26 is provided on each side of the electrolyte matrix 25, the electrolyte can be supplied from the entire circumference of the electrolyte matrix 25, and the electrolyte can be supplied uniformly. Further, since the average pore diameter of the electrolyte communication matrix 26 is formed larger than the average pore diameter of the portion of the electrolyte matrix 25 located at the wet seal portion 9, the difference in pore suction force causes the frame 21b, the extension 22a, The electrolyte stored in the recess formed by the inclined surface 22b is quickly guided to the electrolyte matrix 25 through the electrolyte communication matrix 26. Further, since the electrolyte contact matrix 26 is not subjected to surface pressure from above and below, it is easily damaged when an external force is applied during assembly. However, in the first embodiment, the electrolyte contact matrix 2
Since the reinforcing member 27 is buried inside 6, the strength of the electrolyte communication matrix 26 is increased, and it is possible to prevent the electrolyte communication matrix 26 from being damaged during assembly.

In the first embodiment, the metal separator plate 20 and the fuel gas flow path plate 3 and the oxidizing gas flow path plate 6 are formed separately. Even if the oxidizing gas flow path plate 3 and the oxidizing gas flow path plate 6 are formed integrally with the separator plate, the same effect can be obtained. In the first embodiment, the frame 21 of the metal separator plate 20
b, a concave portion composed of the extending portion 22a and the inclined surface 22b is formed so as to surround the separator portion 21a, and constitutes an electrolyte reservoir. However, the electrolyte reservoir is not limited to this. What is necessary is just to be formed in the concave shape surrounding the part 21. Further, in the first embodiment, the electrolyte communication matrix 26 is provided one by one at the center of each side of the electrolyte matrix 25. However, the extension position and the number of the electrolyte communication matrix 26 are It is not limited to one at the center of the side. For example, two may be provided symmetrically with respect to the center at each side, and further, the entire length may be extended from each side of the electrolyte matrix 25. You may make it.

In the first embodiment, the ceramic plate 30 and the projecting piece 32 of the heat insulating material 31 are interposed between the extension portions 22 of the metal separator plate 20 without any gap. There is no need to interpose without any gap between them, and in some cases, even if only the protruding piece 32 is interposed, the same effect can be obtained. Also, in some cases,
Only the ceramic plate 30 may be interposed. In this case, if a gap is provided between the ceramic plates 30 and a solid electrolyte is inserted between the extension portions 22 from the outside, the electrolyte will be inclined 22b.
It rolls over and is guided to the electrolyte reservoir. Further, in the first embodiment, the projecting piece 32 is formed integrally with the heat insulating material 31, but the same effect can be obtained even if the projecting piece 32 is formed separately. Further, in the first embodiment, the through hole 33 is provided in the heat insulating material 31. However, when the through hole 33 impairs the heat insulating effect, the through hole 3 is formed.
A cover may be attached to close the heat insulating material 3 or a heat insulating material may be further provided around the heat insulating material 31.

[0027]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, a plurality of unit cells each having an electrolyte matrix sandwiched between a fuel electrode and an oxidant electrode and a plurality of separator plates are alternately stacked in the up-down direction to form a fuel gas flow path and an oxidizing agent. In a molten carbonate fuel cell in which an agent gas flow path is provided between the fuel electrode and the oxidant electrode of the unit cell and the separator plate, and an alkali metal carbonate electrolyte is held in the electrolyte matrix, An electrolyte reservoir provided on the outer periphery of the unit battery so as to surround the wet seal portion; an electrolyte replenishing portion for replenishing the electrolyte replenished in the electrolyte reservoir with the electrolyte matrix; An electrolyte guide portion extending from the outside to guide the electrolyte from the outside to the electrolyte reservoir portion, wherein the separator plate includes
From the separator part sandwiched between and the separator part
Metal plate having an extension extending outward all around
The extended portion of the metal plate has a base portion at the base side.
It is formed in a concave shape so as to surround the
Constitutes a reservoir,
Is formed on an upward slope toward the tip
Since the decomposition induction section is configured, it is possible to reliably supply the electrolyte only to the unit battery with the exhausted electrolyte , and furthermore,
Electrolyte reservoir and electrolyte by bending or welding
Ru can be formed integrally with the quality guide portion in a simple manner. Therefore, it is possible to avoid electrolyte overflow to unit batteries that do not need to be replenished and to cause electrolyte overflow, as in the conventional technique of replenishing electrolyte for all unit batteries at once. reaction gas Te becomes to be sufficiently supplied, it is possible to suppress a decrease in battery characteristics due to increase in polarization, further electrolytic
The reservoir and electrolyte guide can be easily integrated
As a result, the number of components can be reduced, and cost reduction can be achieved.
To improve assembly workability.
DOO molten carbonate fuel cells that can be obtained.

[0029]

According to the second aspect , in the first aspect , an electrically insulating ceramic plate is interposed between the extension portions of the adjacent metal plates each having the inclined surface,
In addition, since a through hole through which the electrolyte is inserted is provided in the ceramic plate so as to connect the electrolyte reservoir side to the outside, an electronic short circuit between the metal separator plates can be prevented, and operation reliability can be improved. Can be enhanced.

According to the third aspect , in the first aspect, the electrolyte replenishing portion is formed by extending the end of the electrolyte matrix from the wet seal portion to the inside of the electrolyte reservoir. The part is integrally formed with the electrolyte matrix, so that the number of components can be reduced by that amount, and the assembling workability can be improved.

According to the fourth aspect , in the third aspect , the reinforcing material is buried inside the extending portion of the electrolyte matrix constituting the electrolyte replenishing portion from the wet seal portion. Although the strength of the portion is increased and the extension portion is not subjected to surface pressure from above and below, damage to the extension portion during assembly can be suppressed, and the yield can be improved.

According to the fifth aspect , in the third or fourth aspect , the portion of the electrolyte matrix extending from the wet seal portion is the average pore diameter of the portion of the electrolyte matrix located at the wet seal portion. Since the pores are formed to have a larger average pore diameter, the electrolyte is quickly guided to the electrolyte matrix through the extension due to the pore suction force difference.

[Brief description of the drawings]

FIG. 1 is a plan view showing a molten carbonate fuel cell according to Embodiment 1 of the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a plan view showing a separator plate used in the molten carbonate fuel cell according to Embodiment 1 of the present invention.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is a perspective view showing an electrolyte matrix used in the molten carbonate fuel cell according to Embodiment 1 of the present invention.

FIG. 6 is a schematic configuration diagram showing a conventional molten carbonate fuel cell.

[Explanation of symbols]

1 fuel electrode, 3 fuel gas channel plate, 4 oxidizer electrode,
6 oxidant gas flow path plate, 9 wet seal part, 10
Unit battery, 20 metal separator plate, 21 separator, 21b frame (electrolyte reservoir), 22 extension, 22a extension (electrolyte reservoir), 22b inclined surface (electrolyte induction), 25 electrolyte matrix, 26 electrolyte connection Matrix (electrolyte replenishing unit), 27 reinforcing materials,
32 projecting piece (ceramic plate), 33 through hole.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norio Mitsuda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Corporation (72) Inventor Yoji Fujita 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Inside Electric Corporation (72) Inventor Takashi Nishimura 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (56) References JP-A-62-188177 (JP, A) JP-A-62-237671 ( JP, A) JP-A-62-98568 (JP, A) JP-A-42-19165 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (5)

(57) [Claims] 1. A unit cell comprising an electrolyte matrix sandwiched between a fuel electrode and an oxidant electrode, and a plurality of separator plates are alternately stacked in the vertical direction, and the fuel gas flow path and the oxidant gas flow path are formed in the unit cell. In a molten carbonate fuel cell provided between a fuel electrode and an oxidizer electrode of a battery and the separator plate, and an alkali metal carbonate electrolyte is held in the electrolyte matrix, a wet part is provided on an outer peripheral portion of each unit cell. An electrolyte reservoir provided to surround the seal portion, an electrolyte replenishing portion for replenishing the electrolyte replenished in the electrolyte reservoir with the electrolyte matrix, and an externally extending externally extending from the electrolyte reservoir. An electrolyte guiding portion for guiding an electrolyte to the electrolyte reservoir portion, wherein the separator plate includes a separator portion sandwiched between the unit cells and the separator. A metal plate having an extended portion extending outwardly over the entire periphery from the separator portion. The extended portion of the metal plate is formed in a concave shape so that the base portion side surrounds the separator portion, and the electrolyte reservoir is formed. Make up the department,
A molten carbonate fuel cell, characterized in that the electrolyte guiding portion is formed on an inclined surface that is formed on the entire surface from the base portion side to the front end and has an upward slope. 2. An electrically insulating ceramic plate is interposed between extension portions of adjacent metal plates each having an inclined surface, and a through hole through which an electrolyte is inserted is formed in the ceramic plate by an electrolyte reservoir. 2. The molten carbonate fuel cell according to claim 1, wherein the molten carbonate fuel cell is provided so as to communicate between the side and the outside. 3. The molten carbonate fuel cell according to claim 1, wherein an end portion of the electrolyte matrix is extended from the wet seal portion to the inside of the electrolyte reservoir to constitute an electrolyte replenishing portion. 4. The molten carbonate fuel cell according to claim 3, wherein a reinforcing material is buried inside an extension of the electrolyte matrix constituting the electrolyte replenishing portion from the wet seal portion. 5. The electrolyte matrix according to claim 1, wherein a portion of the electrolyte matrix extending from the wet seal portion is formed to have a larger average pore diameter than a portion of the electrolyte matrix located at the wet seal portion. 3 or claim 4
2. The molten carbonate fuel cell according to item 1.