JPS6059306B2 - Ion-conductive crystalline solid separator with honeycomb structure and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to solid separators made from ionically conductive crystalline sintered bodies, and more particularly to solid separators made from ionically conductive crystalline sintered bodies, most commonly β-
A1.

O. A sodium-sulfur storage battery with a large storage capacity per unit weight produced by a cation conductor used in the diaphragm between the cathode cell and the anode cell of a sodium chloride molten salt electrolyzer for producing chlorine and sodium hydroxide. The present invention relates to an oxygen ion conductive crystalline solid separator made of a conductive crystalline solid separator, a stabilized zirconia, or the like. In recent years, electric vehicles that do not use internal combustion engines have been attracting attention because the exhaust gas of vehicles running on internal combustion engines releases CO and HC gases that are harmful to the human body. When using a storage battery, there was a problem that the amount of electricity stored per single position was small and the travel distance was short. To compensate for this, sodium-sulfur storage batteries have been developed, but the tubular solid separators made of β-alumina used in these batteries are fragile, which has been an obstacle to their practical application. For this reason, there has been a demand for a solid separator that is lightweight, has a large surface area, and is strong, satisfying the contradictory requirements at the same time. β- used as a solid separator in these applications
Al2OJ can efficiently react by using a large number of thin-walled bottomed cylinders or plate-like bodies in parallel, but these cylinders or plate-like bodies should be thin in order to reduce electrical resistance. It was necessary to increase the number of cylinders or plates. However, there was a limit to the ability to reduce the electrical resistance and increase the surface area by making the wall thinner and increasing the number of cylinders or plates. That is, β-AI2O used for these applications
3 is fragile not only when it is a green molded body but also when it is a sintered body, and when producing a bottomed cylindrical body or a plate-shaped body, it is important to make the wall thinner at each stage of molding drying, firing, transportation, and assembly. Yield. This had the disadvantage of requiring extreme care in handling to prevent damage. On the other hand, fuel cells that generate electricity by reacting hydrogen and oxygen are being developed on a large scale as energy-saving power generation devices, but the stabilizing diode used for this is being developed on a large scale. Solid separators mainly made of luconia use thin-walled cylinders or plates to increase the surface area, but it is important that these be thin-walled and wide-area in order to reduce electrical resistance, similar to sodium-sulfur storage batteries. It is. However, such a shape inevitably reduces the strength and poses a major obstacle in handling and maintenance. The present invention has been made to improve this problem, and the ion conductive crystalline sintered body is formed into an integral structure consisting of a large number of passages, also known as a honeycomb structure, thereby reducing the wall thickness of the cylinder. To provide an ion-conductive crystalline solid separator that is stronger than a body, has a container or passage divided into a large number of thin plates, and is easy to produce and handle.

Here, the reason why the honeycomb type solid separator of the present invention is strong even though it is thin is because it is an integral structure that is interconnected and reinforces each other, so it has sufficient strength even if it is extremely thin. In addition, since it has a one-piece honeycomb structure, several hundred tubes can be extruded at once and manufactured and assembled as one unit. Furthermore, by using every other tube as a cathode cell and an anode cell, a solid separator can be produced at once with an efficiency comparable to hundreds of cylinders or several dozen thin plates. Details of the saw layer will be clearly understood from the examples described below.

Example 1 To 99 w't% of fine α-alumina powder with an average particle size of 1 μm (maximum particle size of 3 μm), 1 wt% of MgO powder (7) with an average particle size of 1 μm was added and mixed in a trommel. A honeycomb structure was formed by a conventional method using a clay prepared by adding 5 parts of a non-aqueous solvent hydrocurable polyurethane resin as a binder and kneading it as a raw material.

This honeycomb has appropriate flexibility, but does not deform and is easy to handle. After drying and curing this, 50'C
After heating to 800'C in a reducing atmosphere to remove organic matter at a rate of 900'C/hour, the temperature was gradually changed to an oxidizing atmosphere and heated to 900'C.
C. for 5 hours to oxidize residual carbon and obtain an unglazed body. This was embedded inside a mixed powder of "-Al2O3 coarse particles passed through a 60 mesh sieve and 5 wt% of Na2cO3 added, and also in each tube of the honeycomb.
Filled with mixed powder of O3 and Na2cO, the temperature was raised at a rate of 100°C/hour in a magnesia pod, and the temperature was raised to 1500°C for 1. After holding for a period of time, the mixture was cooled at a rate of 500° C./hour to obtain a honeycomb structure made of β-Al2O3. A perspective view thereof is shown in FIG. 1 is a honeycomb structure, 2 is a partition wall (web), and 3 is a tube, the dimensions of which are the thickness of the partition wall: 0.4
m, the cross section of each tube is a square with an inner diameter of 9.6rfgIi,
The external shape is a square with an end face of approximately 100 wrIt, and a length of 15".
It is a four-sided prism.

It was confirmed by X-ray diffraction that this honeycomb structure had a specific gravity of the web part excluding the hollow part of 3.20 and was completely made of β-Al2O3 porcelain, and when the conductivity of Na+ ions was measured, At 300°C, it exhibited a conductivity of 20mh0/C7l, which is comparable to the conventional one. This means that when each partition wall (also called a web) is used as a separator,
Since it has a honeycomb structure in which the tubes interconnect and reinforce each other, it is smaller, more robust, and of higher practical value than the conventional case where a large number of bottomed cylinders or plate-shaped bodies are used. Note that β″-Al
When manufacturing a honeycomb structure made of a mixture of 2O3 and β-Al2O3, Japanese Patent Application No. 51-5 filed by the present applicant
As stated in No. 7598 (Special Publication No. 57-59227), Na salt is added to 87 to 95% of Al2O3 by weight.
The ratio of β-Al2O3 and β″-Al2O3 is 5% to 13% in terms of the amount of β-Al2O3 and β″-Al2O3.
269A0 (017) plane β-Al2O3 peak intensity Iβα = 260 to 0 (01,11) plane β2-AI2
The ratio of intensity values 1β:I expressed by the peak intensity 1β'' of O3
Synthesized so that f3'' is within the range of 1.0 to 0.25, and 10 parts by weight of this synthetic powder contains 3 parts by weight or less of monovalent and/or divalent metal ions in terms of oxides based on the total amount. A honeycomb structure may be formed and fired using a well-known method by mixing the powders in different proportions and using this as a raw material powder.

According to the conventional method, a method of manufacturing and assembling a large number of tubes was adopted, but the manufacturing cost was high due to the large number of steps, whereas the method of the present invention reduces the manufacturing cost of manufacturing the pipes all at once. Significantly decreased. Example 2 After molding a green honeycomb structure in the same manner as in Example 1, a thin plate with a thickness of 1wn was extruded using the same clay. Although not shown, dimethylformamide was added to the extruded clay to lower the viscosity. The thin plate was adhered tightly to one end of the green honeycomb using an adhesive, dried, and then carried out in the same manner as in Example 1 to obtain a honeycomb structure made of β-alumina with one end open and one end closed.

This material property is the same as the honeycomb structure of Example 1, and since each tube has a honeycomb structure that interconnects and reinforces each other, it has high strength and is compatible with the conventional method of manufacturing and assembling a large number of tubes. In contrast, it is a cation-conducting crystalline solid separator that is easy to manufacture, compact and robust, and has extremely high practical value. Example 3 The same extruded clay as in Example 1 was prepared, and a part of it was used in Example 1.
A similar molding method is used to form a honeycomb-shaped single layer A in which a large number of tubes 3'' are provided in one direction by partition walls 2'' as shown in Fig. 2, and another part of the clay as shown in Fig. 3. A corrugated plate B having a large number of bent portions 4 having a sinusoidal cross section is extruded in the same manner.

These are stacked alternately so that the axes of the tube and the bent part are perpendicular to each other, and the contact area is coated with a slurry prepared with dimethyl formamide to reduce the viscosity of the clay, and a thickness of 1. The plates in the order of 5 were glued to the bottom of the final corrugated plate B, dried, and fired in the same manner as in Example 1.
- A honeycomb structure 1'' made of Al2O3 was obtained. The axes of the tubes in even-numbered stages are perpendicular to each other.A perspective view of this is shown in FIG.

The honeycomb structure shown in FIG. 4 can perform electrolysis continuously by using one opening as an electrolyte supply hole and the other as an electrolyte discharge hole. Since the tubes of this honeycomb structure are perpendicular to each other, even if the catholyte or anolyte is supplied from each side, it is easy to perform continuous electrolysis without mixing with each other. It is also easy to make devices for attaching electrodes and other aspects.

Example 4 91m01% of zirconia fine powder and 9rr101% of ittria fine powder were pulverized and mixed in a trommel,
This was extruded in the same manner as in Example 1, first heated to 800°C in a reducing atmosphere at a rate of 100°C/hour, and then gradually heated to 1600°C at a rate of 100°C/hour in an oxidizing atmosphere. After raising the temperature to 100° C. and holding it for 2 hours, the temperature was lowered at a rate of 100° C./hour to complete firing.

This is the sintered density of the web excluding the hollow part: 5.50g/C
Tl, and the volume specific electrical resistance is 4 at 350'C.
0K・Ωα or less, and a porous platinum electrode is formed by applying platinum paste to each web except for the end face and baking it. By using this honeycomb structured oxygen ion conductive crystalline solid separator, the thickness of the partition wall is thinner than that of a conventional flat plate or vibrator assembly, and the number of tubes can be increased, making it easy to handle large voltages. In addition, each tube has a honeycomb structure that connects and reinforces each other, making it stronger compared to the conventional method of manufacturing and assembling multiple tubes.
It provides an element that is easy to manufacture, efficient and highly practical as a battery, and has good sensitivity as an oxygen concentration meter.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the ion-conductive crystalline solid separator of the present invention, FIGS. 2 and 3 are perspective views of a single layer and a corrugated plate constituting the present invention, and FIG. Figures 2 and 3
FIG. 7 is a perspective view of a separator showing another embodiment using the single layer and corrugated sheet shown in the figure. 1,1''...Ion-conducting crystalline solid separator, 2,2''...Partition wall, 3,3''...
Pipe, 4... Bent part of corrugated plate, 5... Bottom plate.

Claims (1)

[Claims] 1. It has a continuous honeycomb structure in which triangular, square, hexagonal, wavy, or other desired unit shapes are arranged in an appropriate adjoining relationship, and comprises β-alumina+ or β-Al_2O_3 and β″-A.
β-Al_2O_ where the ratio of l_2O_3 is (017) plane
3 peak intensity and β″-Al_2O of (01,11) plane
Ion-conducting crystalline material made of a material impermeable to a fluid mainly composed of a mixture of β-Al_2O_3 and β''-Al_2O_3 or stabilized zirconia with a ratio of peak intensities of _3 of 1.0 to 0.25 A solid separator. 2. The ion-conductive crystalline solid separator according to claim 1, wherein the axes of the tubes of the honeycomb structure are substantially parallel to each other. 3. A honeycomb-shaped unit provided with partition walls in one direction. Claim 1 is a block comprising a layer and a honeycomb-shaped single layer formed on the main surface of the layer and a honeycomb-shaped single layer provided with partition walls in a perpendicular direction to the single layer formed on the main surface of the layer. 4. The tubes of the honeycomb structure are open at both ends,
Claims 1 to 3 form an inlet and an outlet for fluid.
The ion conductive crystalline solid separator according to item 3. 5. The ion conductive crystalline solid separator according to claim 1, wherein the tubes of the honeycomb structure are closed at one end and open at the other end. 6 Add 5% or less of a solvent to alumina powder to form a honeycomb structure, and fire it in an oxidizing atmosphere to make a porous unglazed body,
This was embedded inside a mixed powder to which 2 to 10 wt% of β-Al_2O_3 coarse particles of Na_2CO_3 had been passed through a 60-mesh sieve, and the β-
Packed with mixed powder of Al_2O_3 and Na_2CO_3,
β-Al is fired at over 1300℃ in a refractory sheath.
A method for producing an ion-conductive crystalline solid separator having a honeycomb structure of _2O_3. 7 Al_2O_387-95% by weight ratio and Na_2O
They were mixed to a ratio of 5 to 13% in terms of 017) Surface β-Al_2O_
Peak intensity of 3 I βα = 260A゜ (01,11) plane β″-peak intensity of Al_2O_3 Ratio of intensity values expressed by I β″ I β: I β″ = range of 1.0 to 0.25 100 parts by weight of this synthetic powder is mixed with monovalent and/or divalent metal ions at a ratio of 3% by weight or less of the total amount in terms of oxide, and a temporary binder of organic matter is added. In addition, β-Al_2O is formed into a honeycomb structure and fired.
A method for producing an ion-conductive crystalline solid separator made of _3 and β″-Al_2O_3.