JP2564407B2 - Sodium-sulfur battery - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sodium-sulfur battery used as a secondary battery for power storage, electric vehicles and the like.

[Prior Art] In recent years, sodium-sulfur batteries have been developed as secondary batteries for applications such as nighttime power storage and electric vehicles.

The sodium-sulfur battery has characteristics that the theoretical energy density is higher than that of the lead storage battery, there is no side reaction such as generation of hydrogen and oxygen during charging and discharging, and the utilization rate of the active material is high. Such a sodium-sulfur battery is usually used as an assembled battery in which a plurality of single cells are connected in series or in parallel.

The assembled battery in which the plurality of unit cells are connected is, for example, the 10th
The unit cell 21 covered with the insulating member 22 as shown in the figure
As shown in the figure, a large number of cells are arranged in the horizontal direction and electrically connected with lead wires 23 between them, and the battery group thus connected is housed in a cell housing box 24, which is stacked in three layers above and below. It is formed by doing.

However, since the above-mentioned assembled battery has the space portion 26 and the cell housing box 24 that separate the upper and lower three stages, there is a problem that the height is high and the entire volume is increased. Therefore, as shown in FIG. 12, a plurality of single cells 21 are provided in one long ceramic insulating cylinder 25 extending in the vertical direction.
There has been proposed an assembled battery in which the layers are arranged one above the other, and as shown in FIG. This assembled battery is superior in volumetric efficiency to the polymer battery.

[Problems to be Solved by the Invention] However, sodium-
In the sulfur battery, since each unit cell 21 receives the weight load of the unit cell 21 stacked above it, the lower unit cell 21 has a larger weight load, and the unit cell 21 may be deformed. was there.

It is an object of the present invention to provide a sodium-sulfur battery that compacts the entire assembled battery without imposing a heavy load on the cells located above each of the assembled batteries when the assembled battery is stacked vertically. .

[Means for Solving the Problems] In order to achieve the above object, the first invention is to provide a single cell (1a, 1b, 1c) of a sodium-sulfur battery under an insulating member (4) at an anode container (2). ), A cathode container (7) is joined to the upper part, and a plurality of the unit cells (1a, 1b, 1c) are vertically stacked in an insulating cylinder (11) extending vertically, and the unit cells are vertically adjacent to each other ( 1a, 1b, 1c) is electrically connected to the anode part (3) and the cathode part (8), and the anode part (3) side and the cathode part (8) side of the unit cells (1a, 1b, 1c) The outer diameter of the insulating member (4) that insulates the insulating member (4) is made larger than the outer diameters of the cathode container (7) and the anode container (2) joined to the upper and lower sides of the insulating member (4). Then, the unit (1a, 1b, 1c) is supported by the insulating cylinder (11).

A second aspect of the invention is to stack a plurality of single cells (1a, 1b, 1c) of sodium-sulfur batteries vertically in a vertically extending storage cylinder (34), and to vertically stack the single cells (1a, 1b, 1c). 1
Each cell (1a, 1b, 1c) between each anode container (2) of c)
An insulating member (36) having a groove or a hole for electrically connecting the anode part (30) and the cathode part (33) is interposed, and the insulating member (36) vertically adjacent to each other is provided around the insulating member (36). Insulation member (3
The support (35) for supporting 6) is interposed, and the single cells (1a, 1b, 1c) are housed in the support (35), and the unit cell (1a, 1b, 1c) is inserted through the groove or hole of the insulating member (36). The means of electrically connecting the anode part (3) and the cathode part (8) of the batteries (1a, 1b, 1c) is adopted.

[Operation] By adopting the first means, sodium-
In the unit cell of the sulfur battery, an anode container is joined to the lower part of the insulating member and a cathode container is joined to the upper part of the insulating member to be integrated. Then, a plurality of unit cells are vertically stacked in the insulating cylinder. At this time, the outer diameter of the insulating member is formed larger than the outer diameter of the cathode container and the anode container joined to the upper and lower sides thereof, and the portion is supported by the insulating cylinder. Therefore, each unit cell is suspended and supported by the insulating cylinder. As a result, the upper unit cell does not exert a heavy load on the lower unit cell.

By adopting the second means, a plurality of single cells of sodium-sulfur batteries are vertically stacked in the housing cylinder, and the support is provided around the insulating member provided between the vertically adjacent single cells. Intervened. At this time, the support body supported by the lower insulating member supports the upper insulating member. Further, each unit cell is housed and arranged in the supporting body. Therefore, the unit cell located above does not exert a heavy load on the unit cell located below.

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

First, the structure of the unit cell 1a of the sodium-sulfur battery will be described. As shown in FIG. 3, a cylindrical anode container 2 is arranged in the lower part, and an anode part 3 is fixed to the bottom surface of the anode container 2. An insulating ring 4 made of α-alumina as an insulating member is fixed to the upper end of the anode container 2. Further, a bottomed cylindrical solid electrolyte tube 5 made of β-alumina is disposed inside the anode container 2, and an upper end portion of the solid electrolyte tube 5 is fixed to the insulating ring 4.

The solid electrolyte tube 5 selectively permeates sodium ions, which are cathode acting substances. Between the solid electrolyte tube 5 and the anode container 2, a carbon mat 6 impregnated with sulfur which is an anode acting substance is filled.

A cathode container 7 having a lower end bent inward is fixed to the upper part of the insulating ring 4. In the cathode container 7 and the solid electrolyte tube 5, a slender cylindrical cathode part 8 made of aluminum is fixed to the lid surface of the upper end part of the cathode container 7 and further upwardly from the cathode container 7. It is extended. The solid electrolyte tube 5 and the cathode container 7 are filled with a stainless steel wick 9 impregnated with molten sodium as a cathode active substance.

Now, as shown in FIG. 1, an insulating tube 11 made of ceramic and having a certain length is disposed in a vertically extending cylindrical aluminum tube 10 having good heat conductivity. The aluminum tube 10 is formed of a material having a good heat conductivity in order to eliminate the temperature difference in the vertical direction, and stainless steel or the like can be used.

In the insulating cylinder 11, the unit cells 1a, 1a as shown in FIG.
b, 1c, etc. are stacked in the vertical direction and have an outer diameter larger than the outer diameters of the anode container 2 and the cathode container 7 of each unit cell 1a, 1b, 1c, and the anode part 3 side and the cathode part 8 side are electrically connected. The insulating ring 4 that insulates the insulating cylinder 11 is arranged so as to divide the insulating cylinder 11.
The unit cells 1a, 1b, 1c are supported by mounting the insulating rings 4 on the insulating cylinder 11. in this case,
In the present embodiment, the outer diameter of each insulating ring 4 is formed to be substantially the same as the outer diameter of the insulating tube 11. However, the outer diameter of the insulating ring 4 is such that the insulating ring 4 is placed on the insulating tube 11 and the unit cells 1a, 1b are formed. , 1c insulation tube 11
Is appropriately set within a range that can support the above. Further, the insulating ring 4 may have sufficient strength to support one unit cell 1a, 1b, 1c.

As shown in FIG. 4, the anode part 3 below the unit cell 1b is formed in a cylindrical shape, and the cathode part 8 above the unit cell 1a located therebelow is slightly expanded in diameter from the above-mentioned anode part 3 to form a bellows. It is formed into a shape. Then, by fitting the anode part 3 into the cathode part 8, both are connected. At that time, welding can be performed to further secure the connection between the anode part 3 and the cathode part 8. In that case, the insulating cylinder 11 is divided, a part thereof is removed, and welding is performed. Similarly,
Further, the anode part 3 at the lower part of the unit cell 1c located above is connected to the cathode part 8 at the upper part of the unit cell 1b located below.

The operation and effect of the sodium-sulfur battery configured as described above will be described.

As shown in FIG. 1, first, one insulating cylinder of a predetermined length
Insert one unit cell 1a into 11. At this time, the same cell 1a
Since the outer diameter of the insulating ring 4 that insulates the anode container 2 and the cathode container 7 is larger than the outer diameters of the anode container 2 and the cathode container 7, the insulating ring 4 is placed on the upper surface of the insulating cylinder 11, so that the same insulation is achieved. It is supported by the cylinder 11.

Next, another insulating cylinder 11 having the same shape is placed on the insulating ring 4 of the unit cell 1a. Subsequently, another unit cell 1b is inserted into the insulating cylinder 11. At this time, since the insulating ring 4 of the unit cell 1b is placed on the insulating cylinder 11, the unit cell 1b is supported by the insulating cylinder 11 and, as shown in FIG.
The cathode part 8 on the upper part of the unit cell 1a in which the lower anode part 3 is inserted first
It is fitted inside and electrically connected. At this time, since the cathode portion 8 has a bellows shape, the upper unit cell 1b is
The load of can be absorbed to some extent.

In the same manner, the insulating cylinder 11 is placed on the insulating ring 4 of the single battery 1b in the same manner, and then the single battery 1c is inserted into the insulating cylinder 11 to stack a plurality of single batteries 1a, 1b, 1c. To be done. Then, such an operation is repeated. Finally, the outer periphery of the laminated insulating cylinder 11 is covered with a cylindrical aluminum tube 10. In this way, an assembled battery in which the upper and lower parts are connected in series is formed.

Incidentally, the unit cells 1a, 1b, 1c of the sodium-sulfur battery are 30
It operates at a high temperature of 0 to 350 ° C., and the sodium in the fixed electrolyte tube 5 becomes sodium ions at the time of discharge, and permeates the solid electrolyte tube 5 permeable to the same sodium ion to pass through the anode container 2
Move in. Then, it reacts with sulfur based on the chemical reaction represented by the following formula to produce sodium polysulfide. At this time, a discharge voltage of about 2V is obtained.

When 2Na + xS → Na ₂ Sx discharge is continued, the amount of sodium in the solid electrolyte tube 5 decreases, and sodium corresponding to the decrease is gradually replenished from the cathode container 7.

Next, when discharging is completed and charging is performed, the anode container 2
Inside, a chemical reaction opposite to the above-mentioned chemical reaction occurs, sodium polysulfide is decomposed, and sulfur and sodium ions are generated. This sodium ion permeates the solid electrolyte tube 5 again, moves into the solid electrolyte tube 5, and returns to sodium. When the charging is continued, the generated sodium fills the inside of the solid electrolyte tube 5 and further moves into the cathode container 7. The voltage applied during charging requires about 1.9 to 2.3V.

As described above, according to the present embodiment, the unit cells 1a, 1b, 1c, etc. stacked in the insulating tube 11 in the aluminum tube 10 have the insulating ring 4 for insulating the anode part 3 and the cathode part 8 from each other. Since the outer diameters are larger than the outer diameters of the anode container 2 and the cathode container 7, the insulating ring 4 is engaged with the insulating cylinder 11 so that each unit cell
The insulating cylinder 11 supports 1a, 1b, 1c and the like. Therefore, the unit cell 1b located above does not exert a heavy load on the unit cell 1a located below. Further, since each unit cell 1a, 1b, 1c, etc. is supported by the insulating cylinder 11 located on the outer periphery thereof, the insulating cylinder 11 has a length corresponding to one unit cell 1a, 1b, 1c. It becomes possible to subdivide into products, and the insulating cylinder 11 is easily manufactured.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same components as those of the first embodiment and corresponding components are designated by the same reference numerals and the description thereof will be omitted.

First, the structure of the unit cell 1a of the sodium-sulfur battery will be described. As shown in FIG. 13, a cylindrical anode container 2 is disposed in the lower portion, and an anode portion 30 bent to have an L-shaped cross section is fixed to the bottom surface of the anode container 2. The tip end side of the anode part 30 extends to the left side in FIG. Further, a cathode plate 32 insulated from the anode container 2 is fixed to the upper ends of the cells 1a, 1b, 1c, and a cathode portion 33 symmetrical with the anode portion 30 is provided on the upper surface of the cathode plate 32. It is fixed.

Now, as shown in FIG. 13, a support cylinder 35 as a stainless steel support body having a certain length is provided in an elongated cylindrical ceramic storage cylinder 34 extending in the vertical direction. . The inner diameter of the support cylinder 35 is formed to be slightly larger than the outer diameter of the unit cells 1a, 1b, 1c. The upper peripheral edge 35a of the support cylinder 35 is curved inward so as to have a semicircular shape. Also,
A lower peripheral edge 35b of the support cylinder 35 is bent inward in a perpendicular manner. Therefore, each unit cell 1a, 1b, 1c is housed inside the support tube 35, and the lower peripheral edge 35 of the support tube 35 is accommodated.
Placed on b.

The unit cells 1a, 1b, 1c, etc. are vertically stacked in the storage cylinder 34, and have the same outer diameter as the outer diameter of the anode container 2 of each unit cell 1a, 1b, 1c. An insulating member 36 that electrically insulates the bottom surface and the upper surface of the anode container 2 therebelow is disposed so as to divide the support tubes 35, and each support tube 35 is supported by each insulating member 36. .

That is, the upper surface of the insulating member 36 contacts the lower peripheral edge 35b of the support cylinder 35, and the lower surface of the insulating member 36 contacts the upper peripheral edge 35a of the support cylinder 35. Therefore, the load of each unit cell 1a, 1b, 1c is applied to the support cylinder 35 via the insulating member 36.

Further, as shown in FIG. 14, the insulating member 36 has a lateral T
A storage groove 40 formed in a V shape is formed, and the anode portion 30 and the cathode portion 33 are in contact with each other in the storage groove 40, and the tips thereof are welded to each other.

The operation and effect of the sodium-sulfur battery configured as above will be described.

As shown in FIG. 13, when used as an assembled battery,
The load of each unit cell 1a, 1b, 1c is applied to the support cylinder 35. As a result, the unit cell 1b located at the upper side is replaced with the unit cell 1a located at the lower side.
Does not exert a weight load on.

Further, since the insulating member 36 can be made to have substantially the same diameter as the outer diameter of the anode container 2, the outer diameter and the inner diameter of the storage cylinder 34 can be made smaller than in the first embodiment.

Further, since the storage cylinder 3 corresponding to the insulating cylinder 11 of the first embodiment is integrally formed, the aluminum tube 10
Is not required, which not only simplifies the manufacturing but also reduces the cost.

The present invention is not limited to the above embodiments, and can be arbitrarily modified without departing from the spirit of the invention,
For example, it can be configured as follows.

(1) Connection between the anode part 3 at the lower end of the unit cell 1b located above and the cathode part 8 at the top part of the unit cell 1a located below is performed by connecting the anode part 3 to the male screw part 12 as shown in FIG. And the male screw 12 is screwed into the female screw 13 using the cathode portion 8 as the female screw portion 13.

(2) Further, as shown in FIG. 6, the anode part 3 and the cathode part 8 can be connected by a flexible lead wire 14 such as a braided wire plated with nickel in the same manner.

(3) Further, as shown in FIG. 7, the anode part 3 and the cathode part 8
A U-shaped conductor 15 is interposed between the conductors 15 and a spring washer 16 is sandwiched between the conductors 15 and the conductor 15 is extruded to the anode part 3 and the anode part 8 to form the anode part 3 and the cathode part 8. You can also connect and.

(4) Further, as shown in FIG. 8, trapezoidal recesses 17 are provided at two locations on the outer periphery of the anode part 3, and trapezoidal projections 18 corresponding to the recesses 17 are provided at the upper end of the cathode part 8. It is possible to connect the anode part 3 and the cathode part 8 by providing the above and fitting them together. In this case, as the material of the recess 17 side,
A soft material such as aluminum is preferable, and a material such as an aluminum alloy that is harder than that is preferable as the material of the convex portion 18 side.

(5) Further, in the second embodiment, it is also possible to divide the support cylinder 35, for example, to divide it into two parts in the vertical direction.

(6) Further, a material having flexibility is used for the anode part 30 and the cathode part 33.

[Advantages of the Invention] The sodium-sulfur battery of the present invention does not have a possibility of being deformed because the weight load of the cells located above the sodium-sulfur battery is not applied to each battery when the assembled battery is stacked vertically. There is an effect.

Further, since the support member is interposed between the insulating members, the insulating member can have a diameter substantially the same as that of the unit cell, so that the storage cylinder can be made compact.

[Brief description of drawings]

1 to 4 are views showing a first embodiment of the present invention, FIG. 1 is a partial sectional view showing an assembled battery in which unit cells are stacked, FIG. 2 is a front view showing the unit cells, and FIG. FIG. 4 is a cross-sectional view showing a unit cell. FIG. 4 is a perspective view showing a connection state of an anode portion of a lower portion of a unit cell and a cathode portion of another unit cell. FIGS. 5 to 8 show another example of the present invention. FIG. 9 is a perspective view showing a connection state of the anode part of FIG. 4 and the cathode part of another unit cell, and FIGS.
FIG. 9 is a partial sectional view showing the assembled battery, FIG. 10 is a partial sectional view showing the unit cell, FIG. 11 is a schematic view showing the assembled battery, and FIG.
FIG. 13 is a partial sectional view showing a stacked assembled battery, FIGS. 13 to 14 are views showing a second embodiment of the present invention, and FIG. 13 is a partial sectional view showing a stacked battery in which unit cells are stacked. FIG. 14 is a partially enlarged side view showing a state where the electrode parts of the individual cells are connected. 1a, 1b, 1c …… single cell, 2 …… anode container, 3,30 …… anode part, 4 …… insulating ring as an insulating member, 7 …… cathode container, 8,33 …… cathode part, 11… … Insulation cylinder, 34 …… Storage cylinder, 35
...... Support tube as a support, 36 ...... Insulation member.

Front page continuation (72) Inventor Yusuke Utsumi 3-150 Omoteyama, Tenpaku-ku, Nagoya, Aichi (72) Inventor Atsumi Atsumi 2-82 Honami-cho, Chikusa-ku, Nagoya, Aichi (72) Inventor Kimura Genzo Junko Yoshimizu, 2-15 Takeda-cho, Mizuho-ku, Nagoya-shi, Aichi Prefecture

Claims (2)

(57) [Claims] 1. A single cell of a sodium-sulfur battery (1a, 1b, 1
c) is constructed by joining the anode container (2) to the lower part of the insulating member (4) and the cathode container (7) to the upper part, and the unit cells (1a, 1b, 1c) are housed in an insulating cylinder (11) extending vertically. ) Are vertically stacked to electrically connect the anode part (3) and the cathode part (8) of the unit cells (1a, 1b, 1c) vertically adjacent to each other, and the unit cells (1a, 1b, 1c) The outer diameter of the insulating member (4) that insulates the anode part (3) side and the cathode part (8) side of (1) is joined to the upper and lower sides of the insulating member (4) to form a cathode container (7) and an anode container (2). ) Of the unit cell (1a, 1)
b, 1c) is supported by the insulating cylinder (11), the sodium-sulfur battery. 2. A plurality of unit cells (1a, 1b, 1c) of sodium-sulfur batteries are vertically stacked in a vertically extending container (34), and unit cells (1a, 1b, 1c) vertically adjacent to each other. An insulating member having a groove or hole for electrically connecting the anode part (30) and the cathode part (33) of each unit cell (1a, 1b, 1c) between each anode container (2) A support (35) for supporting the insulating member (36) is interposed around the insulating members (36) vertically adjacent to each other with the (36) interposed therebetween, and also the support (35).
The unit cells (1a, 1b, 1c) are housed inside, and the insulating member (36)
Anode part (3) of unit cell (1a, 1b, 1c) through groove or hole of
A sodium-sulfur battery characterized in that the cathode and the cathode part (8) are electrically connected.