JP4767406B2 - Electrochemical device and integrated electrochemical device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an integrated electrochemical device including a plurality of electrochemical cells.
[0002]
[Prior art]
“Fuel cell power generation” (Electrical Society, edited by Fuel Cell Drivability Research Committee) Corona, page 77, describes forming a plurality of solid oxide fuel cell cells on a porous substrate. Has been. That is, each unit cell is formed by sequentially forming a fine air electrode, a solid electrolyte membrane, and a fuel electrode on the surface of the porous substrate. At this time, a large number of single cells are formed on the porous substrate. Then, an interconnector film is formed between the fuel electrode and the air electrode of adjacent unit cells, and the adjacent unit cells are electrically connected in series. Then, the oxidizing gas permeates through the porous substrate and diffuses in the air electrode in contact with the porous substrate. On the other hand, the fuel gas permeates the fuel electrode and contributes to power generation.
[0003]
[Problems to be solved by the invention]
Such an assembled battery is capable of accumulating a large number of power generation elements in a small volume and improving the amount of power generation per unit space, and thus has been recognized as an excellent design concept.
[0004]
However, when the inventor further studied, there were actually the following difficult problems. That is, for example, the oxidizing gas needs to pass through the porous substrate once and then diffuse in the air electrode in contact with the porous substrate. However, the porous substrate is a portion that retains the overall structural strength of the assembled battery, and for this purpose, a certain degree of thickness and density are required. However, when the porous substrate becomes thicker or the porosity is lowered, the oxidizing gas is less likely to permeate through the porous substrate. For this reason, it is difficult to diffuse into the air electrode in contact with the porous substrate. Becomes lower.
[0005]
Adjacent electrochemical cells need to be connected by an interconnector film formed on the porous substrate. Accordingly, the interconnector is exposed to the fuel gas and inevitably exposed to the oxidizing gas that diffuses through the porous substrate. The temperature at the time of this exposure is 1000 degreeC, for example. For this reason, the material of the interconnector must have three conditions: high conductivity, stability to oxidizing gas at high temperature, and stability to fuel gas at high temperature. unknown. As a result, the resistance associated with the connection between the adjacent cells increases, or the connection resistance between the cells increases due to the deterioration of the material of the interconnector when operated for a long time.
[0006]
An object of the present invention is to reduce the diffusion resistance of each gas up to each electrode of each electrochemical cell in an electrochemical device having a structure in which a plurality of electrochemical cells are electrically connected, And it is enabling it to suppress deterioration of the material of the connection part of an adjacent electrochemical cell.
[0007]
[Means for Solving the Problems]
The present invention includes a solid electrolyte layer, a plurality of first electrodes provided on the solid electrolyte layer, and a plurality of second electrodes provided on the solid electrolyte layer. A plurality of electrochemical cells, each having at least one through-hole conductor penetrating through the solid electrolyte layer, and at least two adjacent electrochemical cells. Are electrically connected through a through-hole conductor.
[0008]
The present invention will be described below with reference to the drawings as appropriate.
[0009]
1A is a cross-sectional view showing an electrochemical device 5 according to an embodiment of the present invention, and FIG. 1B is a plan view of the device 5 of FIG. 1A viewed from the first electrode 16 side. FIG.
[0010]
The apparatus 5 of FIG. 1 is provided with a plurality of, for example, four electrochemical cells 15, and each cell 15 is connected in series. In other words, the solid electrolyte layer 9 has a rectangular flat plate shape in plan view in this example. For example, four first electrodes 16 are formed on one surface 9c of the solid electrolyte layer 9, and for example, four second electrodes 17 are formed on the other surface 9d. Each first electrode 16 constitutes a corresponding second electrode 17 and electrochemical cell 15. B is a main working area of the electrochemical device 5.
[0011]
An elongated gap 23 is formed between adjacent first electrodes 16 to insulate the electrodes 16 of adjacent cells. An elongated gap 24 is formed between the adjacent second electrodes 17 to insulate the electrodes 17 of the adjacent cells. The end portion of each electrode 16 is opposed to the end portion of the electrode 17 of the adjacent cell with the solid electrolyte layer 9 interposed therebetween. A through-hole conductor 22 is provided in the solid electrolyte layer 9 in the region opposite to the end portion described above. Each through-hole conductor 22 connects the electrodes 16 and 17 of the adjacent electrochemical cell 15 in series.
[0012]
According to such an electrochemical apparatus, in an apparatus in which a plurality of electrochemical cells are provided on a single substrate, the diffusion resistance of each gas to each electrode of each electrochemical cell can be reduced. This is because the solid electrolyte layer itself is used as a substrate for supporting the whole, and a separate porous substrate is not required. Further, the side peripheral surface of the through-hole conductor 22 is covered with the solid electrolyte layer 9 and thus is not exposed to the oxidizing gas or the fuel gas, so that the material of the through-hole conductor is hardly deteriorated. Of course, only the upper end surface and the lower end surface of the through-hole conductor 22 in FIG. 1 are in contact with the external gas diffused through the electrodes 16 and 17. However, since this is a gas that has diffused and permeated through the electrodes, the concentration of oxygen and fuel in the gas is low and the absolute amount of gas is small, so the degree of deterioration of the through-hole conductor is small.
[0013]
In the example of FIG. 1, adjacent cells 15 are connected in series. In this way, by connecting a plurality of electrochemical cells in series in one solid electrolyte layer, for example, the extraction voltage can be increased, and the current value can be reduced accordingly. As the current value decreases, the current loss inside the device can be reduced accordingly.
[0014]
In a particularly preferred embodiment, adjacent cells are connected in series in the solid electrolyte layer. However, it is possible to connect adjacent cells in parallel.
[0015]
In a preferred embodiment, a plurality of first electrodes are provided on one surface of the solid electrolyte layer, and a plurality of second electrodes are provided on the other surface of the solid electrolyte layer.
[0016]
Further, in a preferred embodiment, the end of the first electrode of one electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell form a solid electrolyte layer. The end portions of the first electrode and the end portions of the second electrode are electrically connected by a through-hole conductor. Here, the fact that the end portion of the first electrode and the end portion of the second electrode are provided at positions facing each other across the solid electrolyte layer means that the direction X (FIG. 1) is perpendicular to the solid electrolyte layer. This means that they are in overlapping positions as seen from (a). In this case, the end portion of the first electrode and the end portion of the second electrode can be easily connected by providing a through-hole conductor in the overlapping region.
[0017]
The electrochemical device of the present invention can be used as an oxygen pump or a high temperature steam electrolysis cell in addition to a solid oxide fuel cell. This cell can be used in a hydrogen production apparatus and a water vapor removal apparatus. Furthermore, the apparatus of the present invention can be used as NOx, hydrocarbon, and carbon monoxide decomposition cells.
[0018]
The first gas and the second gas may be the same or different. The types include oxidizing gas, reducing gas, inert gas, and the like, and there are preferable embodiments depending on the application.
[0019]
In the case of a fuel cell, the first gas is an oxidizing gas and the second gas is a reducing gas. Examples of the oxidizing gas include air and oxygen. Moreover, as reducing gas, the gas containing hydrogen, methane, carbon monoxide, etc. can be illustrated. In the fuel cell, the first electrode has a high potential and is an anode, and the second electrode has a low potential and is a cathode. In this case, the first electrode functions as a cathode and the second electrode functions as an anode.
[0020]
Further, in the case of an oxygen pump, the first and second gases may be oxidizing or reducing gas. For example, the first gas is air or oxygen, the second gas is a process gas on the side where oxygen is injected, and examples thereof include an inert gas. In this case, the first electrode acts as a cathode at the cathode, and the second electrode acts as an anode as the anode.
[0021]
In the case of a NOx decomposition device or a water vapor removal device, the first gas is an inert gas or air. The second gas is a process gas containing NOx and water vapor, and is an inert gas, hydrogen, or methane in addition to exhaust gas from various internal combustion engines. In this case, the first electrode acts as a cathode at the cathode, and the second electrode acts as an anode as the anode.
[0022]
Examples of the material of the solid electrolyte layer include lanthanum gallate, scandia stabilized zirconia, and ytterbia stabilized zirconia in addition to yttria stabilized zirconia, yttria partially stabilized zirconia, and cerium oxide ceramics.
[0023]
The main raw material of the anode is preferably a perovskite complex oxide containing lanthanum, more preferably lanthanum manganite or lanthanum cobaltite, and even more preferably lanthanum manganite. Lanthanum manganite may be doped with strontium, calcium, chromium, cobalt, iron, nickel, aluminum or the like.
[0024]
The main cathode materials are nickel, nickel oxide, nickel-zirconia mixed powder, nickel oxide-zirconia mixed powder, palladium, platinum, palladium-zirconia mixed powder, platinum-zirconia mixed powder, nickel-ceria, nickel oxide-ceria, palladium -Ceria, platinum-ceria mixed powder, etc. are preferable.
[0025]
The material of the through-hole conductor is iron, cobalt, nickel, copper, aluminum, silicon, gold, silver, platinum, palladium, ruthenium, molybdenum, tungsten and other metals, lanthanum chromite, lanthanum cobaltite, lanthanum manganite, etc. The above-mentioned ceramics, composite materials of the above-described metals and ceramics, and composite materials of the above-mentioned conductive ceramics and ceramics are preferable.
[0026]
The present invention also provides an integrated electrochemical device constructed by laminating a plurality of the aforementioned electrochemical devices.
[0027]
In a preferred embodiment, an integrated electrochemical device comprises a plurality of the aforementioned electrochemical devices. And it is provided with the surrounding wall part which consists of ceramics, and the through-hole conductor in the surrounding wall part embed | buried in the surrounding wall part, the 1st gas passage and the 2nd gas passage are formed inside the surrounding wall part, The solid electrolyte layer is provided inside the peripheral wall portion, the first electrode faces the first gas passage, and the second electrode faces the second gas passage.
[0028]
2 to 4 relate to this embodiment. 2 is an exploded perspective view showing each layer of the integrated electrochemical device 30, FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2, and FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. .
[0029]
In the examples of FIGS. 3 and 4, for example, five rows of electrochemical devices 5A-5E are stacked and incorporated in an integrated electrochemical device. In FIG. 2, each part from the upper end of the apparatus to the solid electrolyte layer 9D is shown as an exploded perspective view due to space limitations.
[0030]
The device 30 includes a functional unit 13 including a plurality of electrochemical devices 9A-9E and a peripheral wall 12 surrounding the functional unit 13. The entire apparatus 30 is produced by, for example, a green sheet lamination method. That is, separator layers 8A, 8B, 8C, 8D, 8E, and 8F and electrochemical devices 9A, 9B, 9C, 9D, and 9E are alternately stacked between the end layer 1A and the end layer 1B. . Each separator layer 8A-8F is formed with a planar hollow portion as shown in FIG. 2, thereby forming a first gas passage 3 and a second gas passage 4.
[0031]
Each electrochemical device 9A-9E is the same as the device described with reference to FIG. However, 15A and 15B are electrochemical cells, 16A and 16B are first electrodes, and 17A and 17B are second electrodes. In FIG. 2, each electrode on the solid electrolyte layer is not shown.
[0032]
In this example, the first gas passage 3 and the second gas passage 4 are alternately provided in the device 30.
[0033]
The peripheral wall portion through-hole conductor 2A passes through the end layer 1A, the separator layer 8A, and the solid electrolyte layer 9A. The conductor 2B penetrates the solid electrolyte layer 9A and the separator layer 8B. The conductor 2C penetrates the separator layer 8C and the solid electrolyte layer 9C. The conductor 2D penetrates the solid electrolyte layer 9C and the separator layer 8D. The conductor 2E penetrates the separator layer 8E and the solid electrolyte layer 9E. The conductor 2F passes through the solid electrolyte layer 9E, the separator layer 8F, and the end layer 1B. In this example, in order to reduce the electrical resistance in the conductor, two conductors are provided in each layer as shown in FIG. However, the number and shape of each conductor are not limited.
[0034]
The electrode 17B of the cell 15A at the end of the electrochemical device 5A is connected to the peripheral wall through-hole conductor 2A. Further, the electrode 16B of the cell 15A at the other end of the electrochemical device 5A extends into the peripheral wall portion 12, and is connected to the through-hole conductor 2B. Similarly, the electrode 17B of the cell 15B at the end of the electrochemical device 5B is connected to the through-hole conductor 2B, and the electrode 16B of the cell 15B at the other end extends into the peripheral wall portion 12 so that the through-hole conduction is achieved. It is connected to the body 2C. Similarly, the electrode 17B of the cell 15A at the end of the electrochemical device 5C is connected to the through-hole conductor 2C, and the electrode 16B of the cell 15A at the other end extends to the inside of the peripheral wall portion 12 so as to conduct through-holes. It is connected to the body 2D. Similarly, the electrode 17B of the cell 15B at the end of the electrochemical device 5D is connected to the through-hole conductor 2D, and the electrode 16B of the cell 15B at the other end extends to the inside of the peripheral wall portion 12 so as to conduct through-holes. It is connected to the body 2E. Similarly, the electrode 17B of the cell 15A at the end of the electrochemical device 5E is connected to the through-hole conductor 2E, and the electrode 16B of the cell 15A at the other end extends to the inside of the peripheral wall portion 12 so as to conduct through-holes. It is connected to the body 2F. The conductors 2A and 2F are connected to external terminals (not shown).
[0035]
In FIG. 3, the gas supply routes to the first gas passage, the second gas passage, or the gas discharge routes from the passages are not shown. The normal method can be used for such gas supply route and discharge route. For example, as shown in the exploded perspective view of FIG. 2 and the cross-sectional view of FIG. 4, gas is supplied from the first gas supply passage 10A to the first gas passage 3, and then through another gas supply passage 10B. Gas can flow into the lower gas passage 3. Further, the gas is caused to flow through the gas supply path 10C, the passage 3 and the discharge path 10D to be discharged out of the apparatus.
[0036]
Similarly, gas flows in the order of the second gas supply path 11A, the second gas passage 4, the gas supply path 11B, the passage 4, the gas supply path 11C, the passage 4, and the gas discharge path 11D.
[0037]
The effect by such embodiment is described.
[0038]
Since each electrode needs to have corrosion resistance against oxidizing gas and reducing gas, usable materials such as nickel-zirconia cermet and lanthanum manganite are limited. On the other hand, the peripheral wall through-hole conductor 2A-2F does not require such corrosion resistance, and therefore, a high melting point metal that has high conductivity and does not cause melting or deformation at the operating temperature of the ceramic is preferable. However, due to such a difference in material, the contact insulation resistance increases between the through-hole conductor and the surface of each electrode.
[0039]
In addition, when the temperature of such a structure increases, each electrode deforms following the deformation of the solid electrolyte layer. On the other hand, the peripheral wall portion through-hole conductor mainly deforms following the deformation of the ceramics constituting the separator layer. For this reason, due to the difference in deformation amount between the two, stress remains in the direction of arrow A (see FIG. 3) between the peripheral wall portion through-hole conductor and each electrode. For this reason, the contact state tends to be inhomogeneous at the interface.
[0040]
For example, in a solid oxide fuel cell described in JP-A-1-128359, each electrochemical cell is connected in parallel in such a structure. This means that the voltage taken out from the electrochemical device is at most about 0.7 to 1.0 volts, and thus the current value is large. Since the extraction voltage is constant, this amount of current increases in proportion to the number of electrochemical cells. On the other hand, it can be presumed that the entire interface has a high interface resistance for the reasons described above, and a very small part of the interface is in a state where the conductor and the electrode surface are in strong contact. In such a state, if a large current flows through the interface between the peripheral wall through-hole conductor and the electrode surface, the current concentrates on a part of the interface, generating local heat generation and altering the structure near the interface. It is done.
[0041]
In the present embodiment, by connecting the electrochemical cells inside the peripheral wall portion in series, the extraction voltage is increased and the amount of current flowing through the interface between the through-hole conductor and the electrode surface is reduced. The local current concentration at the interface was reduced so that no significant local heat generation occurred.
[0042]
2 to 4, the solid electrolyte layer and the peripheral wall portion constituting the electrochemical cell are formed of the same kind of ceramic solid electrolyte material and integrated to form the same kind of solid electrolyte material. An integral structure is generated.
[0043]
When a thermal cycle is applied to such a structure, each electrode on the solid electrolyte layer deforms following the thermal expansion and contraction of the solid electrolyte layer. At the same time, the peripheral wall portion through-hole conductor is deformed following the thermal expansion and contraction of the peripheral wall portion. At this time, by forming the peripheral wall portion and each solid electrolyte layer as a skeleton made of the same kind of material as described above, the positional deviation between each electrode on the solid electrolyte layer and the end face of the peripheral wall portion through-hole conductor is reduced. Almost disappear. In particular, the positional deviation in the in-plane direction of the electrode as shown by the arrow A (see FIG. 3) can be eliminated.
[0044]
In a preferred embodiment, the ceramic structure of the separator layer and the ceramic structure of the solid electrolyte layer are continuous as viewed microscopically.
[0045]
In a preferred embodiment, each of the first electrode and the second electrode extends into the peripheral wall portion, and is in direct contact with the end face of the through-hole conductor. FIG. 3 and FIG. 4 show such a form. This can further reduce the electrical resistance inside the device.
[0046]
Preferably, the peripheral wall portion includes a plurality of separator layers that hermetically surround the first gas passage and the second gas passage, the solid electrolyte layer extends into the peripheral wall portion, and an end portion of the solid electrolyte layer is , Sandwiched between adjacent separator layers.
[0047]
In a preferred embodiment, at least one of the first gas passages 3 is sandwiched between a pair of adjacent cells 15A and 15B, and each first electrode of these cells is a first gas. Opposite across the passage 3. In addition, at least one of the second gas passages 4 is sandwiched between a pair of adjacent cells 15A and 15B, and the second electrodes of these cells face each other across the second gas passage. Yes. By adopting such a design, the first gas passage and the second gas passage are alternately positioned with the cell interposed therebetween, and no useless space is generated. For this reason, the efficiency per unit volume becomes high.
[0048]
The peripheral wall portion can be formed of an insulating ceramic or a solid electrolyte material. These are not particularly limited as long as the materials have corrosion resistance to the first gas passage and the second gas passage at the operating temperature of the electrochemical cell. Such insulating ceramics include alumina, mullite, magnesia spinel, calcia or magnesia stabilized zirconia. In addition to yttria stabilized zirconia, yttria partially stabilized zirconia, cerium oxide ceramics, lanthanum gallate, scandia stabilized zirconia, and ytterbia stabilized zirconia can be exemplified as the solid electrolyte type material.
[0049]
Note that the same type of ceramic solid electrolyte material constituting the peripheral wall portion and the material constituting the solid electrolyte layer means that the basic components are the same. In the case where there are a plurality of basic components, if the plurality of basic components are the same, it can be said that they are the same kind of ceramics even if the constituent ratios of the basic components are different. Moreover, there is no problem even if a small amount of the dope component is changed. This is because if the basic composition is the same, the ceramic structure of the peripheral wall portion and the solid electrolyte layer is continuous after integral sintering, and the seam disappears.
[0050]
When the dope component is different between the ceramic constituting the peripheral wall portion and the ceramic constituting the solid electrolyte layer, the weight ratio of the different dope components is preferably 10% by weight or less of the whole. .
[0051]
Although the manufacturing method of the assembly electrochemical apparatus of this invention is not limited, From a viewpoint of productivity, manufacturing by the green sheet lamination method is especially preferable. At this time, each layer as shown in FIGS. 1 and 2 is formed by a doctor blade method, a press method, an extrusion method, or the like to produce each green sheet, which is laminated and sintered.
[0052]
Examples of the organic binder that can be used for molding include polymethyl acrylate, nitrocellulose, polyvinyl alcohol, methyl cellulose, ethyl cellulose, starch, wax, acrylic acid polymer, and methacrylic acid polymer. Examples of the pore former include cellulose, carbon, and acrylic powder.
[0053]
In a preferred embodiment, there is a solid electrolyte layer between the end of the first electrode of one electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell. Interposes a separate insulator. This embodiment will be described below.
[0054]
FIG. 5 is an enlarged cross-sectional view of a connection portion between adjacent electrochemical cells in the electrochemical device of FIG. The end portion 31 of the first electrode 16C of one cell and the end portion 32 of the second electrode 17D of the other cell face each other with the solid electrolyte layer 9 interposed therebetween. A gap 23 is provided between the first electrodes 16C and 16D, and a gap 24 is provided between the second electrodes 17C and 17D. The end portions 31 and 32 are connected by a through-hole conductor 22.
[0055]
Oxygen ions O between the electrodes 16C and 17C and 16D and 17D belonging to the same cell₂ ^- When the e moves, the electron e is commensurate with it.^- Moves through-hole conductor 22. However, even between the electrodes 16C and 17D or 16D and 17C belonging to different cells adjacent to each other, oxygen ions O₂ ^- May move. Particularly, oxygen ions move between the end portions 31 and 32 as shown by an arrow C around the through-hole conductor 22. Also, oxygen ions move between the end of the electrode 17C and the electrode 16D as indicated by an arrow E.
[0056]
When these oxygen ions move, a closed circuit is generated around the through-hole conductor 22 and consumes a part of the electromotive force generated in each adjacent cell, which causes current loss. In addition, the current flowing through the closed circuit consumes fuel and oxidant, leading to a reduction in fuel utilization.
[0057]
In the present embodiment, the solid electrolyte layer is between the end of the first electrode of an electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell. A separate insulator is interposed. Thereby, the movement of oxygen ions between the end portions as indicated by the arrow C is at least suppressed and prevented, and current loss can be reduced.
[0058]
The position of the insulator is not limited as long as it is between the end of the first electrode of one electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell. For example, it may be on one surface 9c of the solid electrolyte layer 9 or on the other surface 9d, on the inner wall surface of the through hole 9a (that is, on the side peripheral surface 22a of the through-hole conductor 22). Further, it may be embedded in the solid electrolyte layer 9.
[0059]
An insulator separate from the solid electrolyte layer needs to have no oxygen ion permeability, but its insulation performance is a matter of design. However, for example, the volume resistivity of the insulator is preferably 1000 Ω · cm or more.
[0060]
Examples of the insulator material include alumina, silica, mullite, magnesia, and alumina-magnesia spinel.
[0061]
Although the thickness of an insulating layer does not have a restriction | limiting in particular, 10-50 micrometers is preferable.
[0062]
In a preferred embodiment, the insulator is an insulating layer provided between the end of the first electrode and the solid electrolyte layer, and the insulator is solid with the end of the second electrode. It is an insulating layer provided between the electrolyte layers. Thus, the end portions can be insulated most efficiently.
[0063]
In a preferred embodiment, a gap is provided between the first electrodes between a pair of adjacent electrochemical cells, and the insulating layer is exposed in this gap. A gap is provided between the second electrodes between a pair of adjacent electrochemical cells, and the insulating layer is exposed in this gap.
[0064]
6 to 9 show an electrochemical apparatus according to this embodiment. 6A is a cross-sectional view showing an electrochemical device 35A, and FIG. 6B is a plan view showing a state in which a through-hole conductor and an insulating layer are formed on the solid electrolyte layer 9, and FIG. (C) is a plan view of the device 35A.
[0065]
The device 35A is provided with a plurality of, for example, four electrochemical cells 15, and each cell 15 is connected in series with each other. In this example, the solid electrolyte layer 9 has a rectangular flat plate shape when viewed in plan. For example, four first electrodes 16 are formed on one surface 9c of the solid electrolyte layer 9, and for example, four second electrodes 17 are formed on the other surface 9d. B is the main working area of the electrochemical cell.
[0066]
An elongated gap 23 is formed between the adjacent first electrodes 16, and an elongated gap 24 is formed between the adjacent second electrodes 17. The end portion 31 of each electrode 16 is opposed to the end portion 32 of the electrode 17 of the adjacent cell with the solid electrolyte layer 9 interposed therebetween. A through-hole conductor 22 is provided in the solid electrolyte layer 9 in the region opposite to the end portion described above. Each through-hole conductor 22 connects the electrodes 16 and 17 of the adjacent electrochemical cell 15 in series.
[0067]
Around the through-hole conductor 22, insulating layers 25A and 25B are provided on one surface 9c of the solid electrolyte layer 9, and insulating layers 25C and 25D are provided on the other surface 9d of the solid electrolyte layer 9. Is provided. Thus, an insulating layer is interposed between the end of each electrode and the surface of the solid electrolyte layer to insulate. The insulating layer 25B is exposed in the gap 23, and the insulating layer 25D is exposed in the gap 24.
[0068]
In a preferred embodiment, an insulator is provided between the through-hole conductor and the solid electrolyte layer, or an insulator is provided inside the through-hole conductor.
[0069]
In FIG. 5, the through-hole conductor 22 itself may act as a kind of electrode with respect to the electrodes 16C and 16D or with respect to the electrodes 17C and 17D, and may consume electric power. For this reason, providing an insulator between the through-hole conductor 22 and the solid electrolyte layer 9 prevents the through-hole conductor from acting as an electrode, thereby preventing power consumption.
[0070]
7 to 9 relate to this embodiment. The electrochemical device 35B of FIGS. 7A to 7C is the same as the device 35A of FIG. 6, but an insulating layer 25E is formed on the side peripheral surface of the through-hole conductor 22, thereby The through-hole conductor 22 and the inner wall surface of the through-hole 9a are insulated.
[0071]
In a preferred embodiment, the insulating layer includes an extension portion that is not covered by the first electrode or the second electrode in a direction perpendicular to the arrangement direction in which the plurality of electrochemical cells are arranged. . 8 and 9 relate to this embodiment.
[0072]
The electrochemical device 35C shown in FIGS. 8A to 8C is substantially the same as the device 35B shown in FIG. However, the planar shape of each through-hole conductor 22A is not a circle but a rectangle. In particular, as shown in FIG. 8C, the insulating layer includes an extending portion 25F that is not covered with the electrode 16 in the direction Y perpendicular to the arrangement direction Z in which the plurality of electrochemical cells are arranged. ing.
[0073]
In this embodiment, even if the relative position between the insulating layer and the electrode deviates from a manufacturing error, there is an advantage that the end of the electrode can be reliably insulated. That is, in the configuration shown in FIGS. 6 and 7, the edge of the electrode 16 and the edges of the insulating layers 25A and 25B are substantially on the same line as viewed in the Y direction. Therefore, if the position of the insulating layers 25A and 25B and the position of the electrode 16 are displaced due to manufacturing errors, the edge of the electrode 16 and the edge of the insulating layers 25A and 25B are viewed in the Y direction. It will shift. As a result, a portion of the end portion 31 of the electrode 16 is in direct contact with the one surface 9c of the solid electrolyte layer 9 without being insulated by the insulating layer. This results in the closed circuit described above.
[0074]
On the other hand, by providing the extending portion 25F, as described above, even if a positional shift occurs in the planar position between the electrode and the insulating layer, the positional shift is absorbed by the extending portion, and the electrode Insulation at the end of the is ensured.
[0075]
The electrochemical device 35D shown in FIGS. 9A to 9C is substantially the same as the device 35C shown in FIG. However, in particular, as shown in FIG. 9B, in addition to the extending portion 25F, an extending portion 25G extending along the edge surface in the arrow Y direction in the action region B of each cell is formed.
[0076]
【The invention's effect】
As described above, according to the present invention, in an electrochemical device having a structure in which a plurality of electrochemical cells are electrically connected, the diffusion resistance of each gas to each electrode of each electrochemical cell is reduced. And the deterioration of the material of the connecting portion of the adjacent electrochemical cell can be suppressed.
[Brief description of the drawings]
1A is a cross-sectional view showing an electrochemical device 5 according to an embodiment of the present invention, and FIG. 1B is a plan view of the device 5. FIG.
FIG. 2 is an exploded perspective view showing a part of the electrochemical device 5;
FIG. 3 is a cross-sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is an enlarged cross-sectional view showing a connection portion between adjacent cells in the device 5 of FIG. 1;
6A is a cross-sectional view of the electrochemical device 35A, and FIG. 6B is a plan view showing a state in which the through-hole conductor 22 and the insulating layer are formed on the solid electrolyte layer 9, and FIG. ) Is a plan view of the device 35A.
7A is a cross-sectional view of an electrochemical device 35B, and FIG. 7B is a plan view showing a state in which a through-hole conductor 22 and an insulating layer are formed on the solid electrolyte layer 9, and FIG. ) Is a plan view of the device 35B.
8A is a cross-sectional view of an electrochemical device 35C, and FIG. 8B is a plan view showing a state in which a through-hole conductor 22 and an insulating layer are formed on the solid electrolyte layer 9, and FIG. ) Is a plan view of the device 35C.
9A is a cross-sectional view of the electrochemical device 35D, and FIG. 9B is a plan view showing a state in which the through-hole conductor 22 and the insulating layer are formed on the solid electrolyte layer 9. FIG. ) Is a plan view of the device 35D.
[Explanation of symbols]
1A, 1B End layer 2A, 2B, 2C, 2D, 2E, 2F Peripheral wall through-hole conductor 3 First gas passage 4 Second gas passage 5, 5A, 5B, 5C, 5D, 5E, 15 Electrochemical cell 17, 17A, 17B Second electrode 8A, 8B, 8C, 8D, 8E, 8F Separator layer 9A, 9B, 9C, 9D, 9E Solid electrolyte layer 9a Through-hole 9c One side 9d The other side 10A, 10B, 10C 10D 1st gas supply path 11A, 11B, 11C, 11D 2nd gas supply path 12 Perimeter wall part 13 Function part 16, 16A, 16B 1st electrode 22, 22A Through-hole conductor 23 1st of adjacent cell 24. Gap between the second electrodes of adjacent cells X direction perpendicular to the solid electrolyte layer 9 Y direction perpendicular to the arrangement direction of the plurality of cells Z arrangement direction of the plurality of cells

Claims (14)

A solid electrolyte layer, a plurality of first electrodes provided on the solid electrolyte layer, and a plurality of second electrodes provided on the solid electrolyte layer, the first electrode and the An electrochemical device in which a plurality of electrochemical cells are constituted by a second electrode,
It has at least one through-hole conductor penetrating the solid electrolyte layer, and at least two of the electrochemical cells adjacent in the solid electrolyte layer are electrically connected via the through-hole conductor. An electrochemical device characterized by The plurality of first electrodes are provided on one surface of the solid electrolyte layer, and the plurality of second electrodes are provided on the other surface of the solid electrolyte layer. The apparatus of claim 1. The end of the first electrode of an electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell are located at positions facing each other across the solid electrolyte layer. The first end of the first electrode and the end of the second electrode are electrically connected by the through-hole conductor. 2. The apparatus according to 2. The solid electrolyte layer is separated from the end of the first electrode of an electrochemical cell and the end of the second electrode of another electrochemical cell adjacent to the electrochemical cell. 4. The device according to claim 1, wherein an insulator is interposed. The apparatus according to claim 4, wherein the insulator is an insulating layer provided between an end of the first electrode and the solid electrolyte layer. The device according to claim 4, wherein the insulator is an insulating layer provided between an end of the second electrode and the solid electrolyte layer. A gap is provided between the first electrodes between a pair of adjacent electrochemical cells, and the insulator is exposed in the gap. A device according to one claim. A gap is provided between the second electrodes between a pair of adjacent electrochemical cells, and the insulator is exposed in the gap. A device according to one claim. The insulating layer includes an extending portion that is not covered with the first electrode or the second electrode in a direction perpendicular to an arrangement direction in which the plurality of electrochemical cells are arranged. A device according to any one of claims 5-8. The device according to claim 1, wherein an insulator is provided between the through-hole conductor and the solid electrolyte layer. The apparatus according to any one of claims 1 to 10, wherein the at least two adjacent electrochemical cells are connected in series via the through-hole conductor. An integrated electrochemical device comprising a plurality of the electrochemical devices according to any one of claims 2-11,
Comprising a peripheral wall portion made of ceramics and a through-hole conductor in the peripheral wall portion embedded in the peripheral wall portion, and a first gas passage and a second gas passage are formed inside the peripheral wall portion, A plurality of solid electrolyte layers are provided inside the peripheral wall portion, the first electrode faces the first gas passage, and the second electrode faces the second gas passage. An integrated electrochemical device, characterized in that 13. The apparatus according to claim 12, wherein a pair of adjacent electrochemical devices are electrically connected in series by the through-hole conductor in the peripheral wall portion. The device according to claim 12 or 13, wherein the peripheral wall portion and the solid electrolyte layer are made of the same kind of ceramic solid electrolyte material.

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