JPS58129775A - Fuel battery - Google Patents

Abstract

PURPOSE:To obtain an electrolytic body higher in its ability to support an electrolyte and excellent in its mechanical strength by providing an electrolyte supporting layer, on at least one face of the electrolytic body, differing in its pore properties. CONSTITUTION:A multilayer electrolytic body obtained by providing an electrolyte supporting layer comprising nonconducting impalpable powder differing in its pore properties on the at least one face, preferably on the both faces of an electrolytic body constructed by supporting an electrolyte on a long fiber structural body having a self supporting property or a porous sintered body, and supporting an electrolyte on said electrolyte supporting layer. For the particle diameter of the nonconducting impalpable powder used for said electrolytic body, particles fine to the utmost, less than at least 1mum, are preferred in order to raise the electrolyte supporting property thereof. Further, for the electrolyte supporting layer formed by said palpable powder either will do between a paste type electrolyte structure and a matrix type electrolytic body structure. Moreover, it is also proper to form the electrolyte layer in a state where the electrolyte is previously mixed with the nonconducting palpable powder, or to form the same by allowing the former to soak into the latter.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fuel cells, and more particularly to a fuel cell having an improved electrolyte structure containing an electrolyte.

The electrolyte body includes an electrolyte body that holds an electrolyte in a porous ceramic sintered body (hereinafter referred to as a matrix type electrolyte body) and an electrolyte body that is a mixture of non-conductive particles and electrolyte (hereinafter referred to as a paste type electrolyte body). There are both formulas.

The electrolyte body of the prior art cannot be said to be fully satisfactory in the following points.

1) Occurrence of cracks during the manufacturing process 2) Occurrence of cracks due to thermal cycles during operation 3) Thermal deformation during operation (% paste-type electrolyte body) 4) Low electrolyte retention capacity The present invention is different from the above-mentioned conventional technology. The purpose of this invention is to provide a fuel cell that uses an electrolyte body that has high electrolyte holding capacity and excellent mechanical strength.

The main point of the present invention is to use an electrolyte body formed by holding an electrolyte in a multi-N electrolyte holding body as an electrolyte body for a fuel cell.

That is, the electrolyte body is arranged between an anode and a cathode and both electrodes and holds all the electrolyte, and the fuel and oxidizer are arranged in a fuel chamber arranged on the anode side and on the cathode side, respectively. A fuel cell capable of electrochemically generating electricity by supplying an oxidizing agent to an oxidizer chamber, which has an electrolyte holding layer of gold film with different pore characteristics on at least one surface of the electrolyte body, and holds an electrolyte therein. In order to efficiently obtain the full output of the fuel cell, the electrolyte must be an ionic conductor with as low internal resistance as possible.

To this end, the electrolyte body must have fine pores to prevent the electrolyte from flowing into the electrode pores, have the ability to sufficiently retain the electrolyte through capillary action, and be thin and mechanically strong. It is desired that it is an electrolyte body.

As an electrolyte body having such functions, the present inventors provide the following electrolyte body.

One of them is a non-conductive electrolyte body with different pore characteristics on at least one surface, preferably both surfaces, of an electrolyte body that is made by holding the entire electrolyte in a self-supporting long fiber structure or a porous sintered body. An electrolyte retention layer made of fine powder is provided.
It is a multi-M electrolyte body that holds an electrolyte in it. The particle size of the non-conductive fine powder used in this electrolyte body is preferably as fine as possible in order to enhance electrolyte retention, and is preferably at least 1 micron or less.

The electrolyte retainer 1- formed from the fine powder may have either a paste-type vehicle disintegrate structure or a matrix-type vehicle disintegrate structure. As for the case, the entire layer can be formed by mixing the electrolyte with non-conductive fine powder in advance, or it can be soaked in afterwards.

The above-mentioned self-supporting long fiber structure refers to any structure in which long fibers are intertwined with each other in a self-supporting state, vapor-like, felt-like, mat-like, woven fabric-like. It can be used in the form of

By using this multilayer electrolyte body, the following effects can be expected.

1) Improved smoothness.

2) The gas-tightness of the contact area between the electrolyte body and other battery components (eg, gas separator) is improved.

3) A large amount of electrolytes can be retained.

4) Increased electrolyte retention ability.

5) High mechanical strength and high durability against heat cycles.

Non-conductive fine powder is not particularly limited, but
Especially preferred are magnesia, zirconia, lithium aluminate, lithium titanate, and the like.

Another M material body according to the present invention is a paste-type electrolyte body having a reinforcing gold film on at least one surface, preferably on both surfaces.

The reinforcing material includes a self-supporting long fiber structure made of metal or ceramic, a two-dimensional or three-dimensional network structure, a non-nicam structure, and the like. Expanded metal made by stretching wire mesh or perforated metal plates also falls into this category.

By using this multilayer electrolyte body, mechanical strength is high and resistance to heat cycles is high.

Still other electrolyte bodies are matrix type electrolyte bodies provided with reinforcing layers on at least one surface, preferably on both surfaces.

As the reinforcing material, the above-mentioned materials can be used, but particularly preferred are long fiber structures made of metal or ceramics having self-supporting properties, wire mesh, expanded metal, and the like.

By using this multilayer electrolyte body, mechanical strength is large and durability against heat cycles is increased.

Further, according to the present invention, an electrolyte body is obtained in which the average pore diameter of the portion of the surface electrolyte holding layer where the electrolyte can exist is smaller than that of the interior.

The electrolyte body formed inside the electrolyte body is of a paste type or matrix type, and the electrolyte body is even more preferable if a self-supporting long fiber structure is used as a reinforcing core material. In other words, it is an electrolyte in which non-conductive fine powder with different particle sizes is introduced and filled into the inside of a long fiber structure in multiple stages, so that the particles existing on the surface layer are finer than those inside. It is the body.

By using this multilayer electrolyte body, the following effects can be expected.

1) Improved smoothness.

2) The gas-tightness of the contact area between the electrolyte body and other battery components is improved.

3) Can hold a large amount of electrolytes.

4) Increased electrolyte retention ability.

5) High mechanical strength and high durability against heat cycles.

Although the fuel cell using the electrolyte body of the present invention is not particularly limited, the following specific examples will be more specifically explained using a molten carbonate fuel cell as an example.

Example 1 Felt-like alumina long fiber structure (100ran×1
00 mm, thickness 3 tan, fiber diameter 1-5 microns.

Fiber length: 0.3 to 3 days) After press-forming at a total pressure of 10 tons, the lithium aluminate long fiber structure was obtained by processing at 480C for 10 hours with lithium hydroxide. The mixture (62:38 molar ratio) was impregnated in a heated and molten state at 5,200 ml, and cooled to form an electrolyte holding layer using the long fiber structure as an electrolyte holding body. Next, using a mold, 5 g of each mixture with lithium aluminate powder having an average particle size of 0.8 microns containing 50 wt% of the electrolyte having the above mixed composition was placed above and below the electrolyte plate, The final electrolyte body was obtained by press molding at 480 tT and a total pressure of 10 tons. The thickness of the layer in which the long fiber structure of the electrolyte body is used as an electrolyte holding layer is approximately 0.5 mm, and the thickness of the layer in which the fine powder provided on both sides thereof is used as an electrolyte holding layer is approximately 0.2 mm. It was easy.

Example 2 200wnX 200wonX2.5 obtained using lithium titanate with an average particle size of about 3 microns as a base material
A mixture of lithium carbonate and potassium carbonate (6
2:38. molar ratio) was melted and impregnated in the same manner as in Example 1 to obtain an electrolytic plate. Furthermore, in the same manner as in Example 1,
A multilayer electrolyte body was obtained in which electrolyte layers made of a mixture of electrolyte and tium aluminate and having a thickness of about 0.2 rtrm were provided on both sides of the electrolyte plate.

(10) Example 3 33 g of a mixture of lithium carbonate and potassium carbonate (62:38, molar ratio), 8 g of lithium hydroxide monohydrate, and 20 $ll of lithium aluminate with an average particle size of 0.5 microns.
The mixed slurry containing R was poured onto a felt-like alumina long fiber structure having the same dimensions as in Example 1, and another felt-like alumina long fiber JfIt structure having the same dimensions was placed on top of the felt-like alumina long fiber structure and filter-pressed.

This was dried at 50'C for 5 hours and at 150 tl:' for 3 hours, and then heated at 500C for 10 hours to obtain the final electrolyte body.

The thickness of the paste-type electrolyte body portion (inside) of this electrolyte body was approximately 2 m, and the thickness of each reinforced portion by the long fiber structure of the coating layer was approximately 0.5 m.

Example 4 Lithium aluminate 20 with an average particle size of 0.5 microns
A mixed slurry containing 8 gk of lithium hydroxide monohydrate and 8 gk of lithium hydroxide monohydrate was sandwiched between two felt-like alumina fiber structures having the same dimensions as in Example 1, and then pressed into a filter (11). This was dried at 50 r for 5 hours and at 150 tT for 3 hours, and then treated at 1300 tT for 5 hours to obtain a sintered body. This is combined with a mixture of lithium carbonate and potassium carbonate (
62:38. molar ratio) in the same manner as in Example 1,
Cool and finally '111. M, obtained a substance.

Example 5 Using the electrolyte body obtained in Examples 1 to 4, a porous nickel sintered plate and a lithiated nickel oxide sintered plate were used for the anode and cathode to form a single cell,
Battery performance was measured.

50% Ht as fuel in the fuel chamber on the anode side.

A mixed gas of 0.15%, 30% Co2, and 55% N was completely supplied to the oxidizer chamber on the cathode side as an oxidizer, and the battery was fully operated at a temperature of 650 tll'.

As a result of measuring the cell voltage during discharge at a current density of 100 mA/cm2, in the battery using the electrolyte body of Example 4, the voltages were 0, 78 V, 0.78 V, and 0.0 V, respectively.
75V, 0.76VTi1+7'n.

Even after 100 hours, the battery performance has deteriorated (12
) I used it. In the meantime, 650tr to 300? The entire shutdown was repeated 7 times, with the mixture dropping to T and rising again to 6501T, but no gas cross phenomenon or gas leakage from the wet seal was observed (13)

Claims (1)

[Claims] 1. An electrolyte body comprising an anode, a cathode, and an electrolyte disposed between the two electrodes, and a fuel chamber and a cathode side in which a fuel and an oxidizing agent are respectively disposed on the anode side. In a fuel cell that electrochemically generates electricity by supplying an oxidizer to an oxidizer chamber arranged in It has all the characteristics of a fuel cell. 2. In the fuel cell according to claim 1, the electrolyte body has an electrolyte held in a self-supporting long fiber structure or a porous sintered body, and at least one of the electrolyte bodies A fuel cell characterized in that an electrolyte holding layer made of non-conductive fine powder with different pore characteristics is provided on the surface, and an electrolyte is held in the electrolyte holding layer. 3.% Permissible In the fuel cell according to claim 1, the electrolyte body is a mixture of non-conductive fine powder and electrolyte, and at least one surface of the electrolyte body has a reinforcing material. A fuel cell characterized by: 4. In the fuel cell according to claim 3, it is provided that the reinforcing material is a self-supporting long fiber structure, a network structure, or a honeycomb structure made of metal or Hiramix. ! Features fuel cells and ponds. 5. In the fuel cell according to claim 1, the electrolyte body is a porous sintered body holding an electrolyte,
A fuel cell characterized in that a reinforcing material is provided on at least one surface of the electrolyte body. 6. The fuel cell according to claim 5, wherein the reinforcing material is a self-supporting long-fiber structure such as a metal or ceramic ring. 7. The fuel cell according to claim 5, wherein the reinforcing material is a wire mesh or an extracted bumped metal. 8. The fuel cell according to claim 1, wherein the average pore diameter of the surface electrolyte retaining layer of the electrolyte body is smaller than that of the inside. 9. The fuel cell according to claim 1, wherein the electrolyte body is a paste type. 10.% In the fuel cell according to claim 1,
A fuel cell in which the electrolyte body is of Madox type. 11.% Allowance In the fuel cell according to claim 1,
A fuel cell that uses a self-supporting long fiber structure as a reinforcing core material.