JPH02278662A - Solid electrolyte type fuel cell - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a solid fuel tank, and particularly to a fuel cell that is free from thermal damage and gas contact.

[Conventional technology]

Fuel tM, which uses an oxide solid electrolyte such as zirconia, has a high operating temperature of 800 to 1100°C, so it has high power generation efficiency, does not require a catalyst, and is easy to handle because it is an electrolyte or solid. Due to its unique characteristics, it is expected to become a third-generation fuel cell.

However, solid oxide fuel cells have been difficult to realize because their main constituent material is ceramics, which makes them susceptible to thermal damage, and there is no suitable gas sealing method. Therefore, a cylindrical fuel cell with a special shape was devised, and the above two problems were solved, and the battery was successfully tested, but the emission per unit volume of the battery was
There is still no prospect of obtaining an economically advantageous material with a low L density.

In order to increase the power generation density, it is necessary to use a flat plate type. For example, a flat plate type fuel cell having a structure shown in an exploded perspective view of FIG. 4 is known.

In this type of fuel cell, single cells 18 (consisting of a solid electrolyte plate 18A and electrodes 18B and 18C) and separate plates 17 are alternately stacked, and the three-dimensional ζ
Different reaction residues are flowed into the grooves that intersect at right angles.

[Problem to be solved by the invention]

Reactant gases are introduced separately into the fuel tank using an external gas manifold (not shown). At this time, in order to separate and sufficiently supply the reactant gas into the fuel cell (this is the single cell I
8 and the separate plate 17 need to be gas-sealed.

To perform Kassealing, ζ single cell 18 separate plate 1
It is conceivable to sinter the 7 and 7 together and join them together, but in this method, the single cell and the separate plate are made of different materials, so there may be slight differences in thermal expansion coefficients or uneven temperature distribution. (Thus, cracks occur in the integrally sintered bale.Also, it is possible to form a single cell and a separate plate separately and laminate them with a sealing material, but in this case, use a suitable high temperature gas seal. I don't have the materials.

The present invention has been made in view of the above-mentioned points, and its purpose is to provide a solid oxide fuel cell that is free from thermal damage due to bonding and has excellent reliability by using a fuel cell structure that eliminates the need for gas seals as much as possible. It is in.

[Means to solve the problem]

According to the present invention, the above-mentioned object is to provide a solid oxide fuel cell comprising a flat type single cell and a substrate which individually supplies and exhausts both reaction gases, oxidizing gas and fuel gas, on both main surfaces of the single cell. (1) Reaction gas channels 6 and 11 provided in the center of the substrate to guide the reaction gas in the stacking direction of the single cell and the substrate, and the necessary reaction gas flow paths 6 and 11 provided in the center of the substrate to guide the reaction gas in the stacking direction of the single cell and the substrate, question j-shaped guide feather 1
3, 14, and (2) a dense ceramic fitted into the reactive gas flow path 6.11 provided in the porous substrate 5, 10 and guiding the counter gas of the required reactive gas. This is achieved by comprising a ring 7.12.

One of the reaction gas channels 6 and 11 corresponds to the oxidant residue,
Others correspond to fuel gas. Ribbed guide feather 1: 1.

14 guides the reaction gas from the center toward the periphery.

A single cell 1 and a separator 9 are supported on the substrates 5 and 11, respectively. The single cell 1 is a membrane formed of a porous anode 2, a dense solid electrolyte 3, and a porous cathode 4. Separator 9 is formed into a dense film shape. The substrate 5 on which the single cell 1 is supported is formed porous. This is to enable the reaction gas to diffuse through the pores of the substrate and reach the electrodes of the single cell 1. The substrate 10 on which the separator 9 is supported is formed porous or dense. In the case of a dense substrate, a ceramic ring is not necessary.

A predetermined residue of either the oxidant gas or the fuel gas is guided along the main surface of the substrate from the central portion to the peripheral portion. The ceramic ring is provided on the porous substrate and fitted into the reaction gas channel through which the pair of the above-mentioned predetermined gases flows, at the same height as the substrate. alumina! Zirconia and Magisia rings can be used.

[Effect]

Since the reaction gas is guided from the center of the substrate toward the riverside, there is no need for a gas seal between the single cell and the substrate, and between the separator and the substrate. The #, solid ceramic ring inserted into the reaction gas flow path reduces mutual contact between the oxidant gas and the fuel gas.

[Example] Embodiments of the present invention will be briefly described based on the drawings.

In FIG. 1, a porous substrate 51 according to an embodiment of the present invention is prepared, and rib-shaped guide wings 14 are provided on the main surface. The anode 2 is fitted with an N+/ZrO2 cermet, solid or luminescent ring 7.

FIG. 2 shows a porous substrate 10 according to an embodiment of the present invention, which is provided with rib-like guide wings 13 on its main surface. Separator 9 is densely formed using LaCrO3.

An alumina ring 12 is fitted into the fuel gas supply channel 11 .

FIG. 3 shows a porous substrate 5°10 according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a stacked state of a single cell 1 and a separator 9. FIG. The fuel gas is supplied to the fuel gas supply flow path 11.
is supplied to the main surface of the porous base &5 where the rib-like guide vanes 14 are located. At this time, since the alumina ring 7 fitted into the porous substrate 51 is dense, it is possible to prevent the oxidizing gas from diffusing through the side wall pores of the oxidizing gas supply channel 6.

The oxidant gas is supplied to the main surface of the rib-shaped guide blade 1 of the porous substrate 10 through the slit 6A of the oxidant scum supply channel 6. At this time, since the alumina ring 12 fitted into the porous substrate 10 is dense, it is possible to prevent the fuel gas from diffusing through the side wall pores of the fuel gas supply channel 11. As described above, both the fuel gas and the oxidizing gas are distributed in the rib-like guide wings 13, 1 from the center of the substrate toward the periphery.
4, the gas seal between the single cell 1 and the porous substrate 10 and the gas seal between the separator 9 and the porous substrate 5 are no longer required, and the solid electrolyte can thermally expand and contract freely with respect to each other without thermal damage. type fuel cell is obtained. In addition, the alumina ring 7.12 prevents the oxidizing gas or fuel gas from forming pores in the wall of the flow path fIII, thereby reducing the mutual contact of the reactant gases, resulting in a high-performance solid oxide fuel cell. .

〔Effect of the invention〕

According to the present invention, in a solid oxide fuel cell in which a flat & type single cell and a substrate for individually supplying and exhausting both reaction gases, oxidizing gas and fuel gas, are laminated on both main surfaces of the single cell, ( 1) A passage for the reaction gas is provided in the center of the substrate to guide the reaction residue in the stacking direction of the single cell and the substrate, and a rib-shaped guide vane is provided to guide the required reaction gas between the center and the periphery of the substrate. and (2) a dense ceramic ring fitted into the reaction gas flow path that guides the counter gas of the required reaction gas provided on the porous substrate. Gas seals and gas seals for the separator and porous substrates are no longer required, and free expansion and contraction occur relative to each other, resulting in a solid oxide fuel cell without thermal damage. In addition, the dense ceramic ring prevents reaction scum from diffusing through the pores of the side wall of the flow path, thereby reducing mutual contact between the reaction gases and providing a high-performance solid oxide fuel cell.

[Brief explanation of drawings]

A cross-sectional view showing the @ layer state of the porous substrate, single cell, and separate lake, Figure 4 is a conventional fuel! FIG. 2 is a perspective view showing the configuration of a pond.

Claims (1)

[Scope of Claims] 1) In a solid oxide fuel cell formed by laminating a flat plate type single cell and a substrate for individually supplying and exhausting both reaction gases, oxidizing gas and fuel gas, on both main surfaces of the single cell. (1) A reaction gas flow path provided in the center of the substrate and guiding the reaction gas in the stacking direction of the single cell and the substrate, and a rib-shaped guide vane guiding the required reaction gas between the center and the periphery of the substrate. and (2) a dense ceramic ring fitted into the reaction gas flow path provided in the porous substrate to guide the counter gas of the required reaction gas. Fuel cell.