JPH0215578A - Solid electrolytic pipe for sodium-sulfur battery - Google Patents

Abstract

PURPOSE:To enhance the mechanical strength of a solid electrolytic pipe made from beta-alumina and formed in a single construction so as to enhance reliability in its durability, by integrally sintering onto the outer surface of its main body an outer covering layer made from beta-alumina the shrinkage rate of which is higher than that of the main body during burning and cooling thereof. CONSTITUTION:On the inner and outer surfaces, particularly on the outer surface, of the main body 4 (a) of a solid electrolytic pipe made from beta-alumina and formed in a single construction is integrally sintered an outer covering layer 4b made from beta-alumina the shrinkage rate of which is higher than that of the beta-alumina of the main body 4 (a) during burning and cooling thereof. The main body 4 (a) of the solid electrolytic pipe may thus be compressed by shrinkage force of the outer covering layer 4 (b) without deteriorating ion conduction resistance thereof, so that its mechanical strength can be enhanced to control breakage of the solid electrolytic pipe during assembly of a battery and/or during rise and fall of temperature under operation of the battery for enhancing reliability on its durability.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a solid electrolyte tube for a sodium-sulfur battery, and more specifically, it improves the mechanical strength of the solid electrolyte tube to improve battery assembly and battery operation. This article relates to the structure of a solid electrolyte tube that can improve durability during temperature increases and decreases (δ stability), reduce ionic conduction resistance, and improve battery capacity.

(Prior art) Recently, as a secondary battery for electric vehicles and nighttime power storage, it has been developed to be excellent in both performance and economical aspects.
Research and development is progressing on high-temperature sodium-sulfur batteries that operate at ℃.

As shown in FIG. 7, this sodium-sulfur battery conventionally includes a cylindrical anode container 1 that houses a conductive material M for the anode, such as a carbon mat impregnated with molten sulfur S, which is an anode active material, and A cathode container 3 which is connected to the upper end of 2"i1 via an insulating ring 2 made of α-alumina and stores molten metal Na, and the insulating ring 2
A solid electrolyte tube 4 made of polycrystalline β-alumina is fixed to the inner periphery of the tube and has a cylindrical shape with a bottom and a function of selectively transmitting sodium ions (Na''), which is a cathode active material. .

Further, an elongated cathode tube 5 extending through the cathode container 3 to the bottom of the solid electrolyte tube 4 is supported through the center of the upper lid of the cathode container 3 .

During discharge, sodium ions pass through the solid electrolyte tube 4 and react with the sulfur S in the anode container 1 to produce sodium polysulfide through the following reaction.

2Na+XS→Na2Sx Also, during charging, a reaction opposite to that during discharging occurs, and sodium Na and sulfur S are generated.

The solid electrolyte tube 4 of the sodium-sulfur battery configured as described above is formed by rubber press molding a mixture of aluminum oxide, sodium oxide, lithium oxide, or magnesium oxide, etc., and then heated in an electric furnace. It is sintered and formed. As described above, this solid electrolyte tube 4 is used by fitting into the insulating ring 2 and also fitting into the conductive material M for the anode, so it is required to have high mechanical strength and has low transmission resistance for sodium ions. required to decrease.

(Problems to be Solved by the Invention) The conventional solid electrolyte tube 4 having a single structure as described above has different mixing ratios of lithium oxide (LizO) or magnesium oxide (MgO) as a stabilizer, firing temperature, etc. This allows the mechanical strength and ionic conduction resistance to be adjusted. However, when the mechanical strength is increased, the ion conduction resistance increases, and when the ion conduction resistance is decreased, the mechanical strength also tends to decrease. Therefore, it is extremely difficult to satisfy both characteristics, and if there is an assembly error between the insulating ring 2 and the solid electrolyte tube 4 or a manufacturing error in the conductive material M for the anode, the solid electrolyte tube may be damaged during the assembly of the sodium-sulfur battery. When inserting the solid electrolyte tube 4 into the conductive material M for the anode, stress was concentrated on the base end of the solid electrolyte tube 4 and the tube broke. In addition, even if the above-mentioned manufacturing errors are not a problem, the solid electrolyte may be damaged due to thermal distortion due to melting or solidification of the sulfur impregnated in the conductive material M for the anode, or thermal distortion of the conductive material M for the anode, etc. There was a problem in that the tube 4 received stress and was damaged. On the other hand, if the thickness of the solid electrolyte g4 is increased to prevent damage, there is a problem in that the ionic conduction resistance increases and the battery capacity decreases.

A first object of the present invention is to provide a solid electrolyte tube for a sodium-sulfur battery that can improve mechanical strength and durability and reliability.

A second object of the present invention is to provide a solid electrolyte tube for a sodium-sulfur battery that can increase mechanical strength and reduce ion conduction resistance.

Furthermore, in addition to the second object, a third object of the present invention is to provide a solid electrolyte tube for a sodium-sulfur battery that can omit the work of joining the solid electrolyte tube and the insulating ring.

(Means for Solving the Problems) In order to achieve the first object, the solid electrolyte tube according to claim 1 has a solid electrolyte tube body having a single structure made of β-alumina, both the inner and outer surfaces, especially the outer surface. On top of this, a method is taken in which a jacket layer made of β-alumina, which has a higher shrinkage rate during firing and cooling than the main body, is integrally sintered.

In order to achieve the second object, the solid electrolyte In tube according to claim 2 has a solid electrolyte tube body made of β-
The proximal tube part, which is made of alumina and fitted into the insulating ring, is made of high-strength β-alumina, and the solid electrolyte tube body and the proximal tube part are integrally sintered. There is.

In order to achieve the second object, the solid electrolyte tube according to claim 3 has intermediate physical properties between the solid electrolyte tube main body and the base end cylinder portion in the solid electrolyte tube according to claim 2. A method of integrally sintering the intermediate cylindrical portion made of β-alumina is adopted.

The solid electrolyte tube according to claim 4 has a third purpose.

In order to achieve this, the solid electrolyte tube body is made of β-alumina with low ionic conduction resistance, the proximal tube portion and the insulating ring are made of α-alumina, and the solid electrolyte tube body is made of β-alumina and α-alumina. The proximal end tube portion and the insulating ring are integrally sintered.

In the solid electrolyte tube according to claim 5, in order to achieve the third object, in the solid electrolyte tube according to claim 4, alumina made of a mixture of the two is provided between the solid electrolyte tube main body and the base end cylindrical portion. The method is to integrally sinter the intermediate cylindrical portion.

(Function) In the solid electrolyte tube according to claim 1, since the outer coating layer having a large firing shrinkage rate is integrally adhered and sintered on the surface of the solid electrolyte tube body, the solid electrolyte is heated by the shrinkage force of the outer coating layer. The tube body is compressed, which improves its mechanical strength, and when used in a sodium-sulfur battery by fitting and fixing it into an insulating ring, even if stress is applied to the proximal end tube, it will not break due to the stress. Never.

Moreover, since the solid electrolyte tube according to claim 2 also improves the mechanical strength of the proximal tube portion, when it is fitted and fixed to an insulating ring and used in a sodium-sulfur battery, stress is not applied to the proximal tube portion. Even if it is applied, it will not be destroyed by the stress. Furthermore, since the solid electrolyte tube body is made of β-alumina, which has low ionic conduction resistance, the battery capacity increases.

In addition to the effects of the solid electrolyte tube according to claim 2, the solid electrolyte tube according to claim 3 suppresses rapid compositional changes in the connection between the solid electrolyte tube main body and the proximal end cylindrical portion, thereby preventing thermal expansion of both members. Differences in ratio, thermal strain, etc. are absorbed by the intermediate cylinder, improving mechanical strength.

In the solid electrolyte tube according to claim 4, since the base end cylinder portion and the insulating ring are integrally formed of α-alumina, in addition to the function of the solid electrolyte tube according to claim 2, the insulating ring and the solid electrolyte There is no need for a separate process to connect the pipes.

In addition to the effects of the solid electrolyte tube according to claim 3, the solid electrolyte tube according to claim 5 eliminates the need for a separate step of connecting the insulating ring and the solid electrolyte tube body.

(Example) Examples 1 to 4 each embody the method for manufacturing a solid electrolyte tube according to claim 1, Examples 5 and 6 embody the method for manufacturing a solid electrolyte tube according to claim 2, and Example 7. 8 is claim 3
The solid electrolyte tube manufacturing method described in Example 9 embodies the solid electrolyte tube manufacturing method described in claim 4, and Example 10 embodies the solid electrolyte tube manufacturing method described in claim 5.

Each example will be explained in sequence below.

(Example 1) First, 90.2 parts by weight of aluminum oxide (Aj!z
03), 9. O parts by weight of sodium oxide (Na2
0) and 0.8 parts by weight of lithium oxide (LizO) was wet-processed using a 1001 ball mill for $51.
A β-alumina-containing powder having a specific surface area of 5 rrr/g is prepared by crushing, mixing, and calcining.

Thereafter, the β-alumina-containing powder is granulated to a predetermined particle size (average particle size of 40 to 120 μm) using a spray dryer.

Next, using a rubber press molding device (isostatic press machine), the outer diameter is 15 m5 and the wall thickness is 1.5 m at a pressure of 1.5 ton/ad. On, a solid electrolyte tube body body 4a (see FIG. 2) having a single structure in the shape of a bag tube with a length of 150 mm is molded.

Furthermore, the molded body is immersed in a slurry of β-alumina-containing powder having a specific surface area of 9 rd/g and having the same composition as the solid electrolyte tube body base material 4a''.
4b' (second layer) with a thickness of 0.2 mm
(see the dashed line in the figure). Next, after drying, surface finishing and degreasing, baking was performed at 1610°C for 5 minutes to coat the outer surface of the solid electrolyte tube body 4a with a jacket Jl.
A solid electrolyte tube 4 having the ff14b integrally attached thereto is obtained.

The thickness of the outer covering layer 4b is about 1/10 of the thickness of the main body 4a.
It is set between 0 and 1/2.

The solid electrolyte tube 4 thus obtained has an outer covering layer 4
Since the specific surface area of b is larger than that of the main body 4a, the contraction rate of the outer sheath J54b becomes larger than that of the main body 4a during firing and cooling, and therefore, the solid electrolyte tube main body 4a is compressed by the outer sheath 14b. The strength of the solid electrolyte tube 4 increases. Incidentally, even if the specific surface area of the outer covering layer 4b is increased, there is no problem because the ionic rolling resistance does not increase to the extent that it affects the battery function.

(Example 2) A preparation consisting of 89.3 parts by weight of aluminum oxide, 10 parts by weight of sodium oxide and 0.7 parts by weight of lithium oxide was ground, mixed and calcined in the same manner as in Example 1. A β-alumina-containing powder with a specific surface area of 5 rrr/g was prepared, and it was dried to a predetermined particle size (
Granulate to an average particle size of 40 to 120 μm.

Next, using a rubber press molding device, pressure 1, 5
ton/cIa, for example, the outer diameter is 15 Tsuru, the wall thickness is 2,
A solid electrolyte tube body base 4a (see FIG. 2) having a single structure in the shape of a bag tube with a length of 1501 mm and a length of 1501 mm is formed.

This solid electrolyte tube body base 4a' is degreased at about 1000°C for 2 hours, and the surface of the body base 4a' after degreasing has a specific surface area of 9 cd /
A slurry of β-alumina-containing powder (g) was applied by spraying to form an outer covering layer base 4b'' having a thickness of 0.5 mm on the surface of the main body base 4a''. After that, after drying, surface finishing and degreasing, it was baked at 1600°C for 10 minutes.
A solid electrolyte tube 4 shown in FIG. 1 is obtained in which a jacket layer 4b is integrally formed on the outer surface of a solid electrolyte tube body 4a.

(Example 3) A preparation consisting of 89.0 parts by weight of aluminum oxide, 9.0 parts by weight of sodium oxide and 2.0 parts by weight of magnesium oxide was crushed, mixed and calcined in the same manner as in Example 1. to prepare β-alumina-containing powder with a specific surface area of 5nf/g,
Same as in Example 1, the particles are granulated to a predetermined particle size (average particle size of 40 to 120 μm) using a spray dryer.

Next, using a rubber press molding device, the pressure was 2.5Lo.
n/a! Then, a solid electrolyte tube main body base 4a' having a single structure shown in FIG. 2 is formed, for example, in the shape of a bag tube with an outer diameter of 15 mm, a wall thickness of 2.0 mm, and a length of 150 mm. A slurry of β-alumina-containing powder having the same composition as that of the solid electrolyte tube body 4a' and having a specific surface area of 9 rrr/g is applied by spraying onto the surface of the solid electrolyte tube body body 4a' to a thickness of 0.2 rrr/g. After that, after drying, surface finishing and degreasing, the first coated body 4b was baked at 1630°C for 30 minutes to integrally form the outer coated layer 4b on the surface of the solid electrolyte tube body 4a. A solid electrolyte tube 4 shown in the figure is obtained.

(Example 4) A preparation consisting of 87.0 parts by weight of aluminum oxide, 10 parts by weight of sodium oxide, and 3.0 parts by weight of magnesium oxide was ground, mixed, and calcined in the same manner as in Example 1. A β-alumina-containing powder with a specific surface area of 5 rd/g was prepared and dried to a predetermined particle size (average particle size of 4
0 to 120 μm).

Next, using a rubber press molding device, a pressure of 2,0
For example, the outer diameter of ton/cTA is 15 mm and the wall thickness is 1 mm.
A solid electrolyte tube main body base 4a having a single structure shown in FIG. 2 and having a bag tube shape with a diameter of 0 mm and a length of 150 mm is molded. This substrate 4a'' is degreased at approximately 1 ooo'c for 2 hours, and the substrate 4a' after degreasing has a specific surface area of 9 having the same composition as that of the substrate.
n? /g of β-alumina-containing powder into a slurry,
On the surface of the substrate 4a' is an outer covering layer substrate 4b' having a thickness of 0.3 mm.
Form the adhesion. Thereafter, after drying, surface finishing and degreasing, the solid electrolyte tube shown in FIG. 1 is baked at 1000° C. for 10 minutes to integrally form an outer covering layer 4b on the outer surface of the solid electrolyte tube body 4a. Get 4.

(Example 5) A preparation consisting of 90.5 parts by weight of aluminum oxide, 9 parts by weight of sodium oxide, and 0.5 parts by weight of lithium oxide was ground, mixed, and calcined in the same manner as in Example 1. While adjusting to β-alumina-containing powder 8, 90.2 parts by weight of aluminum oxide, 9 parts by weight of sodium oxide and 0.
A preparation containing 8 parts by weight of lithium oxide is similarly ground and mixed to prepare β-alumina-containing powder B. Thereafter, the β-alumina-containing powder Yatsunin B was dried in a spray dryer in the same manner as in Example 1 to a predetermined particle size (average particle size of 40 to
120 μm).

Next, approximately 85% of the β-alumina-containing powder B is applied to the part other than the open end of the mold of the rubber press molding device, that is, the space where the main body 4a of the solid electrolyte tube 4 is to be molded, and the other part is That is, approximately 15% of the β-alumina-containing powder A is filled into the space in which the base end cylinder portion 4c of the solid electrolyte tube 4 shown in FIG. 3 is to be formed, and the pressure is 2. 5 tons/ctA
A solid electrolyte tube base with a composite composition is formed using the following steps. Thereafter, after drying, surface finishing and degreasing, the tube was fired at 1600° C. for 5 minutes to obtain the solid electrolyte tube 4 shown in FIG. 3.

The solid electrolyte tube 4 thus obtained has a proximal tube portion 4
Since c has excellent strength, it can sufficiently withstand the stress that is applied during battery assembly and during temperature rise and fall during battery operation, and on the other hand,
Since the solid electrolyte tube body 4a has low ionic conduction resistance,
Battery capacity can be improved.

(Example 6) In this Example 6, 89.5 parts by weight of α-alumina, 9.
Similarly to Example 5, β-
In addition to preparing alumina-containing powder C, β-alumina was prepared in the same manner as in Example 5 using a formulation consisting of 89.0 parts by weight of α-alumina, 9.0 parts by weight of sodium oxide, and 3.0 parts by weight of magnesium oxide. Prepare the containing powder.

With this β-alumina-containing powder C, the base end cylinder portion 4c is
The solid electrolyte tube body 4a is formed by the steps shown in FIG. 3, and the solid electrolyte tube 4 shown in FIG.
The manufacturing process is the same as Example 5 except that it is baked at ℃ for about 40 minutes, so a detailed explanation of the manufacturing process will be omitted. The solid electrolyte tube 4 thus obtained has the same effects as the solid electrolyte tube of Example 5.

(Example 7) In this Example 7, in addition to the β-alumina-containing powder HachiheB prepared in Example 5, 90.3 parts by weight of α-alumina,
A preparation consisting of 9.0 parts by weight of sodium oxide and 0.7 parts by weight of lithium oxide was pulverized, mixed and calcined by the above-mentioned wet pulverization to prepare β-alumina-containing powder E with medium IuI physical properties. do.

Thereafter, the β-alumina-containing powders A, B, and E were each dried using a spray dryer to a predetermined particle size (average particle size of 4
0 to 120 μm).

Next, as shown in FIG.
Approximately 75% of the β-alumina-containing powder B is placed in the space where the
The powder E is filled into the upper cylindrical portion 4d at approximately 10%.
Fill and finally open the opening part, that is, 40 solid electrolyte tubes @
Approximately 15% of the β-alumina-containing powder A is filled into the space where the box part 4c is to be formed, and the pressure is set to 2. A solid electrolyte tube base having a composite composition is molded at 5 tons/cd. Then dry,
After surface finishing and degreasing, the tube is fired at 1590° C. for 10 minutes to produce a solid electrolyte tube 4 as shown in FIG. 4, which has a strong upper mechanical strength.

The solid electrolyte tube 4 of Example 7 has a cylindrical portion 4d with intermediate physical properties.
As a result, the bonding strength between the main body 4a and the proximal tube portion 4c is improved, and the stress due to the difference in coefficient of thermal expansion is alleviated (Example 8) In this Example 8, the β-alumina-containing powder C of Example 6 described above, D and 88.7 parts by weight of α-alumina; 9.
Using a β-alumina-containing powder F having a composition of 0 parts by weight of sodium oxide and 2.3 parts by weight of magnesium oxide, the main body 4a is prepared using a powder mill as shown in FIG.
The cylindrical portion 4d is formed with powder C, and the cylindrical portion 4c is formed with powder C, thereby producing a solid electrolyte tube 4 with strong mechanical strength in the upper part.

This Example 8 differs from Example 7 in that baking is performed at 1630° C. for about 30 minutes, and other manufacturing steps are the same, so a detailed explanation will be omitted.

(Example 9) A preparation consisting of 88.0 parts by weight of α-alumina, 9.0 parts by weight of sodium oxide, and 3.0 parts by weight of magnesium oxide was pulverized, mixed, and calcined by the wet pulverization described above. β-alumina-containing powder G is prepared.

On the other hand, α-alumina powder H is prepared by crushing and mixing α-alumina in the same manner.

Thereafter, the β-alumina-containing powder G and α-alumina powder H are each dried to a predetermined particle size (
Granulate to an average particle size of 40 to 120 μm.

Next, approximately 85% of the volume of the β-alumina-containing powder G is applied to a portion of the mold of the rubber press molding device other than the open end, that is, the space where the main body 4a of the solid electrolyte tube 4 shown in FIG. 5 is to be molded. The remaining portions, that is, the space where the proximal end cylinder portion 4c of the solid electrolyte tube 4 and the insulating ring 2 are to be formed, are filled with approximately 15% α-alumina powder 14, and the pressure is 2. 5t
A solid electrolyte tube base having a composite composition is formed using on/c+a. After that, after drying, surface finishing and degreasing,
A solid electrolyte tube 4 as shown in FIG. 5 is obtained by baking at 1630°C for 60 minutes to integrally form the base end and flange of a solid electrolyte tube made of β-alumina with α-alumina.
Manufacture.

The thus obtained solid electrolyte M,'ii tube 4 not only has the effect of the fifth embodiment, but also allows the operation of connecting the insulating ring 2 and the solid electrolyte tube 4 to be omitted.

(Example 10) Alumina powder I having a mixed composition of β-alumina-containing powder G of Example 9, α-alumina powder H1, and both powders G and H is prepared. These powders G.

H and I were dried by a spray dryer to 40 to 12
Granulate to 0 μm.

Next, approximately 75% of the volume of β-alumina powder G is filled into the part other than the open end of the mold of the bar press molding apparatus, that is, the space where the solid electrolyte tube body 4a shown in FIG. 6 is to be molded. Approximately 10% of alumina powder I of intermediate composition is placed above it.
After filling the solid electrolyte tube 4 with approximately 15% of α-alumina powder H into the space where the proximal end cylindrical portion 4c and the insulating ring 2 are to be formed.
% filling, and the solid electrolyte tube bases with these three types of composite compositions are rubber press molded. Thereafter, after drying, surface finishing and degreasing, the tube was fired at 1630° C. for 60 minutes to obtain a solid electrolyte tube 4 as shown in FIG.

In addition to the effects of Example 9, the thus obtained solid electrolyte tube 4 has a stronger connection between the main body 4a and the proximal tube portion 4c, which is due to the difference in coefficient of thermal expansion between the two members. Stress can be alleviated.

Note that the present invention can also be embodied as follows.

In the embodiment shown in FIG. 1, an inner sheath 1 (not shown) having the same composition as the outer sheath 154b is formed on the inner peripheral surface of the solid electrolyte tube 4, and In the embodiments, it is also possible to change the structure arbitrarily and embody it within the scope of the claims of the present invention, such as by continuously changing the composition of the boundary part.

(Effect of the invention) As detailed above, the solid electrolyte tube according to claim 1 has the following features:
Since the outer covering layer is sintered on the surface, the solid electrolyte tube body is compressed by the contraction force of the outer covering layer without reducing the ion rolling resistance, thus improving the mechanical strength.
This has the effect of improving durability and reliability by suppressing damage to the solid electrolyte tubes during battery assembly and temperature rise and fall during battery operation.

In addition, in the solid electrolyte 'i-tube according to claim 2, since the proximal cylindrical part of the solid electrolyte In tube has excellent mechanical strength, the stress of the solid electrolyte tube is reduced during battery assembly and during temperature rise and fall during battery operation. In addition to improving durability and reliability by preventing damage due to
-Since it is made of alumina, it also has the effect of increasing battery capacity.

In addition to the effects of the solid electrolyte tube according to claim 2, the solid electrolyte tube according to claim 3 has a strong connection between the solid electrolyte tube main body and the base end cylinder portion, and furthermore, the solid electrolyte tube has a strong connection between the solid electrolyte tube body and the base end cylinder portion, and furthermore, stress generation due to a difference in coefficient of thermal expansion is achieved. This has the effect of improving the durability of the solid electrolyte tube by alleviating it.

In the solid electrolyte tube according to claim 4, the base end cylinder portion and the insulating ring are integrally formed of α-alumina, and the whole is integrally formed. In addition to the effects, it is possible to form a solid electrolyte tube with an integral structure up to the flange portion, and it also eliminates the need for a separate step of connecting the insulating ring and the solid electrolyte tube, making manufacturing easier and reducing costs.

The solid electrolyte tube according to the fifth aspect has the effects of the solid electrolyte tube according to the third and fourth aspects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the central part of a solid electrolyte tube showing an embodiment of the present invention, with a portion omitted, and FIG. 3 is a vertical sectional view of the central portion of the solid electrolyte tube according to claim 2, FIG. 4 is a vertical sectional view of the central portion of the solid electrolyte tube according to claim 3, and FIG. FIG. 6 is a vertical sectional view of the central portion of the solid electrolyte tube according to claim 4, FIG. 6 is a longitudinal sectional view of the central portion of the solid electrolyte tube according to claim 5, and FIG. 7 is a vertical sectional view of the central portion of a conventional sodium-sulfur battery. It is. 2... Insulating ring, 4... Solid electrolyte tube, 4a...
・Solid electrolyte tube body, 4a...Solid electrolyte tube body base, 4b...Outer cover layer, 4b'...Outer cover layer base, 4c
... Proximal tube portion, 4c... Proximal tube portion base material, 4d...
Intermediate cylindrical part, 4d"...Intermediate cylindrical part base material.

Claims (1)

[Claims] 1. The outer surface of the solid electrolyte tube main body (4a), which has a single structure made of β-alumina, is made of β-alumina which has a higher shrinkage rate during firing and cooling than the main body (4a). Outer layer (4
b) characterized by being integrally sintered.
Solid electrolyte tube for sulfur batteries. 2. The solid electrolyte tube body (4a) is made of β-alumina with low ionic conduction resistance, and the base end cylinder portion (4c) fitted to the insulating ring (2) is made of β-alumina with high strength. , the solid electrolyte tube body (4a) and the proximal tube portion (
A solid electrolyte tube for a sodium-sulfur battery, characterized in that 4c) is integrally sintered. 3. In the solid electrolyte tube according to claim 2, an intermediate tube portion (4) made of β-alumina having intermediate physical properties between the solid electrolyte tube body (4a) and the proximal tube portion (4c) is provided between the solid electrolyte tube body (4a) and the proximal tube portion (4c).
d) characterized by being integrally sintered.
Solid electrolyte tube for sulfur batteries. 4. The solid electrolyte tube body (4a) is made of β-alumina with low ionic conduction resistance, the proximal tube portion (4c) and the insulating ring (2) are made of α-alumina, and the solid electrolyte tube body (4a) is made of α-alumina. ), a base end cylinder part (4c), and an insulating ring (2) are integrally sintered. A solid electrolyte tube for a sodium-sulfur battery. 5. In the solid electrolyte tube according to claim 4, an intermediate tube portion (4d) made of alumina made of a mixture of the solid electrolyte tube body (4a) and the proximal tube portion (4c) is integrally provided between the solid electrolyte tube body (4a) and the proximal tube portion (4c). A solid electrolyte tube for a sodium-sulfur battery characterized by being sintered.