JPH0574471A - Cell for fuel cell and fuel cell - Google Patents

Abstract

PURPOSE:To enhance the durability of a fuel cell against oxidation and reduction and to lower the internal resistance of the fuel cell so as to enhance the performance of the fuel cell. CONSTITUTION:An oxygen side gas passage forming portion R comprises a passage component member 4 disposed in close contact with an oxygen electrode 2 and a protecting member 5 disposed in close contact with the passage component member 4 and made of a material which is plastically deformed through heating and which has resistance in a hydrogen gas atmosphere in the heated state, and the passage component member 4 is made of a material having resistance in an oxygen-containing gas atmosphere in the heated state and comprises a plurality of passage forming portions 4a arranged in parallel to one another, the passage forming portions 4a each having a channel serving as an oxygen- containing gas passage (s). A plurality of cells C are arranged in parallel to one another along the vertical direction and at intervals so as to form fuel gas passages (f) and soft electrically conductive material 9 is disposed among the cells C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a plate-like solid electrolyte layer having an oxygen electrode on one surface and a fuel electrode on the other surface,
TECHNICAL FIELD The present invention relates to a cell of a fuel cell having an oxygen-side gas flow channel constituent portion having conductivity and arranged to form an oxygen-containing gas flow channel on the side facing the oxygen electrode, and a fuel cell configured using the cell. ..

[0002]

2. Description of the Related Art As shown in FIGS. 9 and 10, conventionally, a cell C of a fuel cell has a plate-like solid electrolyte layer 1 having an oxygen electrode 2 on one surface and a fuel electrode 3 on the other surface. And forming a plurality of grooves on the side facing the oxygen electrode 2 as the oxygen-containing gas flow channel s to form an oxygen-side gas flow channel constituting section, and the side facing the fuel electrode 3 is the fuel gas flow channel. In the state of forming the fuel-side gas flow passage by forming a plurality of grooves f, the gas flow passage forming portion 16 is integrally formed of a kind of conductive material. In addition, a plurality of cells C of the fuel cell configured as described above are connected to the oxygen electrode 2 and the fuel electrode 3 of the adjacent plate-shaped solid electrolyte layer 1 in a conductive state at the gas flow path forming portion 16. A fuel cell was constructed by arranging them side by side in a stacked state.

[0003]

The oxygen-side gas flow path forming section has excellent conductivity because it draws a current from the oxygen electrode, and also has an oxygen-containing gas atmosphere in a warmed state (hereinafter referred to as an oxidizing atmosphere). (Also referred to as) resistance is required, and as the fuel-side gas flow path constituent section, it has excellent conductivity for deriving a current from the fuel electrode, and
It is required to have resistance in a fuel gas (that is, hydrogen gas) atmosphere (hereinafter, also referred to as a reducing atmosphere) in a heated state.

However, conventionally, the oxygen-side gas flow path forming section and the fuel-side gas flow path forming section are integrally formed of a kind of material as the gas flow path forming section.
3) Resistance in oxidizing atmosphere and resistance in reducing atmosphere
Since there is no excellent material for both of them, the gas flow path configuration is made because the material is excellent in resistance in an oxidizing atmosphere and in a reducing atmosphere, but is made of a material having a slightly lower conductivity at the sacrifice of conductivity. The resistance of the department was high. Further, in the heated state, warpage occurs in the plate-like electrolyte layer,
Since the close contact between the oxygen electrode and the oxygen-side gas flow channel constituent portion and the fuel electrode and the fuel-side gas flow channel constituent portion deteriorates, the oxygen electrode and the oxygen-side gas flow channel constituent portion and the fuel electrode and the fuel-side gas flow channel The connection resistance between the components has been increased. Therefore, due to these factors, the conventional fuel cell has a problem that the internal resistance is high, and in the conventional fuel cell configured as described above using a plurality of such fuel cell cells. However, there was a problem that the internal resistance was high.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell and a fuel cell which are excellent in durability against oxidation and reduction and have low internal resistance and excellent performance. There is a point to do.

[0006]

A first characteristic structure of a cell of a fuel cell according to the present invention is a flow path forming member in which the oxygen side gas flow path forming portion is arranged in close contact with the oxygen electrode, and its flow. And a protective member which is disposed in close contact with the channel constituent member and is plastically deformed by heating and is made of a material having resistance in a hydrogen gas atmosphere in a heated state, wherein the flow channel constituent member is
The point is that a plurality of flow path forming portions made of a material having resistance in an oxygen-containing gas atmosphere in a heated state and having a groove serving as the oxygen-containing gas flow path are arranged in parallel.

A second characteristic constitution of the cell of the fuel cell according to the present invention is that the flow path forming portion is made of LaMnO ₃ .

A third characteristic constitution of the cell of the fuel cell according to the present invention is that the protective material is made of LaCrO ₃ .

The fuel cell according to the present invention is characterized in that a plurality of cells of the fuel cell having any one of the above-mentioned first to third characteristics are vertically spaced apart from each other to form a fuel gas passage. They are arranged side by side in the direction, and a flexible conductive material is arranged between the cells.

[0010]

According to the first characteristic constitution of the cell of the fuel cell according to the present invention, the oxygen-side gas flow passage forming portion is arranged in close contact with the oxygen electrode to form an oxygen-containing gas flow passage, and Since it is composed of a protective material that is closely attached to the side of the flow path constituent material facing the fuel gas flow path in order to protect the flow path constituent material from being exposed to the reducing atmosphere, the conventional oxygen side gas flow As in the case where the channel forming portion is integrally formed of a kind of material, it is not necessary to consider the conductivity, the resistance in the oxidizing atmosphere and the resistance in the reducing atmosphere. Can be formed of a material that has excellent conductivity and resistance in an oxidizing atmosphere in a heated state, and the protective material is a material that has resistance and conductivity in a reducing atmosphere in a heated state and has a reduced thickness. Can be formed with a low resistance. Further, even if the plate-shaped solid electrolyte layer is warped in the heated state, the flow path forming member is formed by arranging a plurality of flow path forming portions side by side. Can be made to follow the warp of the electrolyte layer, and
Since the protective material placed in close contact with the flow path constituent material plastically deforms in a heated state, the flow path forming parts are pressed against the oxygen electrode by the weight of the protective material, and the oxygen electrode and the flow path constituent material (that is, the oxygen side gas The close contact with the flow path forming part) can be maintained in a good state.

According to the second characteristic configuration of the fuel cell of the present invention, LaMnO ₃ has excellent conductivity and excellent resistance in an oxidizing atmosphere in a heated state, so that the flow path forming portion is made of LaMnO 3. By being formed by _3, it can function effectively as a flow path forming portion.

According to the third characteristic constitution of the cell of the fuel cell according to the present invention, LaCrO ₃ has an excellent resistance in a reducing atmosphere in a heated state and is plastically deformed by heating. By forming LaCrO _3, it can effectively function as a protective material.

According to the characteristic configuration of the fuel cell according to the present invention, even if warp occurs in each cell of the fuel cells arranged in parallel in the vertical direction with a space therebetween, the fuel cells are arranged between the cells in a heated state. Due to the flexibility of the flexible conductive material, the adhesion between the cell and the flexible conductive material can be maintained in a good state.

[0014]

According to any one of the first to third characteristic constitutions of the cell of the fuel cell according to the present invention, the oxygen side gas flow path constituting portion is excellent in resistance in an oxidizing atmosphere and a reducing atmosphere and has conductivity. Can be configured in an excellent state, and the oxygen electrode and the oxygen-side gas flow channel can be always in good contact with each other, and the oxygen electrode and the oxygen-side gas flow channel are caused by the warpage of the plate-shaped solid electrolyte layer. It is possible to effectively avoid an increase in connection resistance between the constituent parts, and thus, it has excellent durability against oxidation and reduction, and
A fuel cell having low internal resistance and excellent performance can be provided.

Further, according to the characteristic structure of the fuel cell according to the present invention, the close contact between the cell and the flexible conductive material can be always maintained in a good state, and the connection resistance is increased due to the occurrence of the warp of the cell of the fuel cell. Since it can be effectively avoided, it is possible to reduce the connection resistance between the respective cells, and thus it is possible to provide a fuel cell that has excellent durability against oxidation and reduction as well as low internal resistance and excellent performance. ..

[0016]

Embodiments Next, embodiments will be described with reference to the drawings.

1 to 5 show the structure of a cell of a fuel cell, 1 is a plate-like solid electrolyte layer having an oxygen electrode 2 on one surface and a fuel electrode 3 on the other surface. The electrolyte layer 1, the oxygen electrode 2, and the fuel electrode 3 constitute a three-layer electromotive section K. Reference character R denotes an oxygen-side gas flow path constituent part which is arranged to form an oxygen-containing gas flow path s on the side facing the oxygen electrode 2 and has conductivity, and the electromotive part K and the oxygen-side gas flow path constituent part. R and R form a cell C of the fuel cell.

The oxygen-side gas flow path forming section R is a flow path forming member 4 which is arranged in close contact with the oxygen electrode 2, and a thin plate which is arranged in close contact with the flow path forming member 4 and which is added during fuel cell operation. And a protective material 5 that plastically deforms in a warm state, and the flow path forming material 4 is
A plurality of flow path forming portions 4a in which a plurality of grooves are formed as oxygen-containing gas flow paths s are arranged side by side. The edges Ka, Ka of the electromotive section K and the edges 5a, 5a of the protective member 5 are projected from both ends of the flow path component 4 by a predetermined width. At both ends of 4,
The partition walls 6 and 6 are arranged in close contact with the end face 4b of the flow path forming member 4, the edge Ka of the electromotive portion K, and the edge 5a of the protective member 5. The partition members 6 and 6 may be arranged with a gap with respect to the end surface 4b of the flow path forming member 4.

As described above, by constructing the cell C, the groove formed in the flow path forming portion 4a is used as the oxygen-containing gas flow path s, and the circumference of the cell C is viewed in the flow direction of the oxygen-containing gas flow path s. The whole part is made to be a fuel gas channel f which is separated from the oxygen-containing gas channel s.

The oxygen-side gas flow channel forming section R forms the oxygen-containing gas flow channel s as a partition and also functions as a terminal for deriving a current from the oxygen electrode 2 facing the oxygen-containing gas flow channel s. As described above, the oxygen-side gas flow path forming section R
By configuring the above, even if the plate-shaped solid electrolyte layer 1 is warped (that is, the electromotive portion K is warped) in a heated state during fuel cell operation, the flow path constituent member 4 is Since the plurality of forming portions 4a are arranged side by side, each of the plurality of passage forming portions 4a can be arranged along the warp of the electromotive portion K, and the passage forming member 4 is closely arranged. The thin plate-shaped protective material 5 is plastically deformed in a heated state to press the flow path forming portions 4a against the oxygen electrode 2 by the weight of the protective material 5, and the oxygen electrode 2 and the flow path forming material 4 (that is, oxygen The close contact with the side gas flow path forming part R) can be maintained in a good state, and the connection resistance between the oxygen electrode 2 and the oxygen side gas flow path forming part R increases due to the occurrence of the warp of the electromotive part K. Can be effectively avoided.

Further, by forming the oxygen-side gas flow path forming portion R from the flow path forming material 4 and the protective material 5, the flow path forming material 4 forming the oxygen-containing gas flow path s is excellent in conductivity. In addition, the protective material 5 facing the fuel gas flow path f is made of a material having resistance in an oxidizing atmosphere in a heated state, and the protective material 5 has resistance in a reducing atmosphere in a heated state and has electrical conductivity and its thickness. It has become possible to form it by reducing the thickness and reducing the resistance. Therefore, the flow path forming portion 4a
Is made of LaMnO ₃ which is excellent in conductivity and resistance in an oxidizing atmosphere in a heated state, and the protective material 5 is LaCrO ₃ which has excellent resistance in a reducing atmosphere in a heated state and is plastically deformed by heating. It is formed by. The partition wall material 6 facing the fuel gas channel f is also formed of the same material as the protective material 5 or the plate-shaped solid electrolyte layer 1.

6 to 8 show an integrated structure in a fuel cell in which a plurality of the above-mentioned cells C are integrated. The oxygen-containing gas flow passage s inlet side end of the cell C is inserted into the mounting holes 7a formed in the frame member 7 at predetermined intervals, and the oxygen-containing gas flow passage s outlet side end of the cell C is inserted into the frame member 8 In the state of being inserted into the mounting holes 8a formed at predetermined intervals, a plurality of cells C are arranged in parallel in the vertical direction at the predetermined intervals so as to form the fuel gas passage f, and the cells C, A plurality of strip-shaped flexible conductive materials 9 are dispersedly arranged between C, and in adjacent cells C, C, the fuel electrode 3 of one cell C and the other cell C of the other cell C are arranged.
Is electrically connected to the oxygen-side gas flow path forming section R.

A gas flow path forming material 10 forming an oxygen-containing gas supply path S1 is arranged on the frame material 7 side, and a gas flow path forming material 11 forming an oxygen-containing gas discharge path S2 is arranged on the frame material 8 side. The gas flow path forming material 12 forming the fuel gas supply path F1 is provided at the end of the fuel gas flow path f of the cell C, and the fuel gas exhaust path is provided at the end of the fuel gas flow path f of the cell C. The gas flow path forming materials 13 that form F2 are respectively arranged, so that the cell C
In a fuel cell in which a plurality of fuel cells are integrated, an oxygen-containing gas supply passage S1, an oxygen-containing gas discharge passage S2, a fuel gas supply passage F
1 and the fuel gas discharge passage F2 are formed by partitions.

Therefore, by electrically connecting the adjacent cells C to each other by the flexible conductive material 9, the fuel cells arranged in parallel in the vertical direction at intervals in the warmed state during fuel cell operation. Even if warp occurs in each cell C of
Due to the flexibility of the flexible conductive material 9, the cell C and the flexible conductive material 9
And the flexible conductive material can be effectively prevented from increasing due to the warpage of the cell C.

Since the flexible conductive material 9 is arranged in the fuel gas flow path f, in order to ensure resistance in the reducing atmosphere,
It is formed of a felt-like material of Ni.

[Other Embodiment] Each of the flow path forming portion 4a, the protective material 5, and the partition wall material 6 can be formed by various materials other than the materials shown in the above embodiments. Also, the flexible conductive material 9
Can also be formed of various materials other than the felt-like material of Ni.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a perspective view of a cell of a fuel cell.

FIG. 2 is a front view of the same.

FIG. 3 is a partial cross-sectional side view of the same.

FIG. 4 is a partial sectional plan view of the same.

FIG. 5 is an exploded perspective view of the same.

FIG. 6 is a partially sectional front view of a fuel cell.

FIG. 7 is a partial cross-sectional side view of the same.

FIG. 8 is a partial cross-sectional plan view of the same.

FIG. 9 is a partially sectional front view of a conventional fuel cell.

FIG. 10 is a partial cross-sectional side view of the same.

[Explanation of symbols]

 1 plate-like solid electrolyte layer 2 oxygen electrode 3 fuel electrode 4 flow path constituent material 4a flow path forming portion 5 protective material 9 flexible conductive material f fuel gas flow path s oxygen-containing gas flow path C fuel cell R oxygen side gas Flow path component

Claims (4)

[Claims] 1. A plate-like solid electrolyte layer (1) having an oxygen electrode (2) on one surface and a fuel electrode (3) on the other surface.
And a conductive oxygen-side gas flow channel component (R) arranged to form an oxygen-containing gas flow channel (s) on the side facing the oxygen electrode (2). And the oxygen-side gas flow path forming section (R) is the oxygen electrode (2)
Of the flow path component (4) closely attached to the flow path component (4) and a material that is closely placed to the flow path component (4) and plastically deforms by heating and has resistance in a hydrogen gas atmosphere in a heated state. And a flow path forming material (4) made of a material having resistance in an oxygen-containing gas atmosphere in a heated state and having a groove serving as the oxygen-containing gas flow path (s). A fuel cell cell comprising a plurality of flow path forming portions (4a) arranged in parallel. 2. The flow path forming portion (4a) is LaMnO.
_The cell of the fuel cell according to claim 1, which is composed of ₃ . 3. The fuel cell according to claim 1, wherein the protective material (5) is made of LaCrO ₃ . 4. A plurality of cells (C) of the fuel cell according to claim 1, wherein a plurality of cells (C) are arranged side by side in a vertical direction at intervals to form a fuel gas flow channel (f). And a flexible conductive material (9) disposed between the cells (C) and (C).