JP2551986B2 - 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 by connecting a plurality of cells in series or in parallel.

For example, as shown in FIG. 6 and FIG. 7, the plurality of unit cells are connected to the plate-shaped anode terminal 22 located on the outer peripheral portion on one end face of the unit cell 21 (upper face of FIG. 7). By vertically arranging the cathode terminals 23 located in the central direction and connecting the anode terminals 22 and the cathode terminals 23 upright with the plate-shaped connecting pieces 24 bent at two points at right angles, Has been done.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional sodium-sulfur battery, the plate-shaped anode terminal 22 and the cathode terminal 23 are connected by the connecting piece 24 in an upright state without being particularly supported. Therefore, if the anode terminal 22 or the cathode terminal 23 is bent, the insulation between them becomes uncertain, and a connection piece 24 of a specific shape bent at two right angles must be used. There is a problem that it is not easy to attach the connecting piece 24 to the upright anode terminal 22 and the cathode terminal 23.

An object of the present invention is to provide a sodium-sulfur battery in which insulation between an anode part and a cathode part provided on one end surface of a single cell of a sodium-sulfur battery is reliable, and other objects are plural. Another object of the present invention is to provide a sodium-sulfur battery in which connection pieces can be easily attached to the anode part and the cathode part when connecting the unit cells.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention arranges both an anode terminal and a cathode terminal on one end surface of a single cell of a sodium-sulfur battery, and An electric insulating member that insulates between the anode terminal and the cathode terminal is placed, and the anode terminal and the cathode terminal are supported by the electric insulating member.

Further, it is preferable to adopt a means of forming through holes through which the anode terminal and the cathode terminal can be inserted in the electric insulating member, and inserting the anode terminal and the cathode terminal into the through holes and bending them. .

Further, a square hole, for example, a hexagonal hole is provided in the electrical insulating member, a nut is inserted into the hexagonal hole, and a connecting piece for connecting the anode terminal or the cathode terminal of each unit cell to each other is bolted to the nut. It is possible to adopt a means of fixing by screwing.

[Operation] By adopting the above configuration, both the anode terminal and the cathode terminal arranged on one end face of the single cell of the sodium-sulfur battery are electrically insulated from each other, which are also mounted on the one end face of the sodium-sulfur battery. Since each member is supported at a predetermined position, the anode terminal and the cathode terminal are prevented from contacting each other, and reliable insulation is exhibited.

In addition, the through hole through which the anode terminal and the cathode terminal can be inserted is provided in the electrical insulating member, and the anode terminal and the cathode terminal are inserted into the through holes and bent to form a predetermined anode terminal and cathode terminal. It is positioned at the position of and is more reliably insulated.

Further, the electrical insulating member is provided with an angled hole, a nut is inserted into the angled hole, and a connecting piece for connecting the anode terminal or the cathode terminal between the unit cells to each other is bolted to the nut. By fixing the connection piece by screwing it in, the connection piece can be easily and reliably attached to the anode terminal or the cathode terminal.

[Examples] Examples in which the present invention is embodied 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. 5, a cylindrical anode container 2 is arranged in the lower part, and an anode collector piece 3a is fixed to the side surface of the anode container 2, and the anode collector piece 3a is a unit cell 1a. An anode terminal 3b is formed extending upward from the outer peripheral portion of the. An annular insulating plate 4 made of α-alumina is provided on the upper end of the anode container 2.
Is stuck. Inside the anode container 2, a solid electrolyte tube 5 made of β-alumina and having a cylindrical shape with a bottom is arranged.
The upper end of the solid electrolyte tube 5 is fixed to the insulating plate 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 lid 7 is fixed to the upper portion of the insulating plate 4. Inside the cathode lid 7 and the solid electrolyte tube 5, a slender cylindrical cathode tube 8a made of aluminum is fixed to the cathode lid 7. The solid electrolyte tube 5 is filled with a stainless steel wick 9 impregnated with molten sodium which is a cathode acting substance.

Now, as shown in FIG. 1, on the upper end surface of the unit cell 1a, a plate-shaped anode terminal 3b connected to the anode current collector piece 3a is provided.
And the same plate-shaped cathode terminal 8b connected to the cathode tube 8a.
Is protruding upward. An insertion hole 10 through which a bolt can be inserted is provided at the center of the upper part of the anode terminal 3b and the cathode terminal 8b.
a and 10b are provided.

The disk-shaped ceramic electrical insulating member 11 having an outer diameter substantially the same as the upper surface of the unit cell 1a is provided with through holes 11a and 11b through which the anode terminal 3b and the cathode terminal 8b can be inserted, respectively. , Bottomed hexagonal holes 13a, 13b into which the nuts 12a, 12b can be inserted are provided at two positions adjacent to the two through holes 11a, 11b.

The electrical insulating member 11 has a high temperature limit of 350 because the operating temperature of the sodium-sulfur battery is usually as high as 300 to 350 ° C or higher.
It is preferable to have a strength that can sufficiently withstand at a temperature of not less than 0 ° C. and at such a high temperature. Ceramic is mentioned as the suitable material.

Then, the hexagonal holes 13a and 13b of the electric insulating member 11 are previously formed.
The nuts 12a and 12b are inserted into the through holes 11a and 11b of the electric insulating member 11 and the anode terminal 3b and the cathode terminal 8b, respectively, and then the anode terminal 3b and the cathode terminal 8b are bent. There is.

On the upper part of the anode terminal 3b, a connecting piece 15a having a through hole 14a connected to the cathode terminal of an adjacent unit cell is placed, and by tightening the bolt 16a to the nut 12a from above. The connection piece 15a is fixed to the electric insulating member 11. Similarly, on the upper part of the cathode terminal 8b, a connecting piece 15b having a through hole 14b connected to the positive electrode terminal of another adjacent unit cell different from the above is placed, and the nut with the bolt 16b is mounted thereon. The connection piece 15b is fixed to the electrical insulating member 11 by being tightened with respect to 12b.

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

As shown in FIG. 1, first, a plate-shaped anode terminal 3b and a cathode terminal 8b extending upward from the upper surface of the unit cell 1a are inserted into the two through holes 11a and 11b of the disk-shaped electric insulating member 11 from the bottom. The electrical insulating member 11 is inserted and brought into close contact with the upper surface of the unit cell 1a.
After inserting the nuts 12a and 12b into the two hexagonal holes 13a and 13b of the electric insulating member 11 in this state, the anode terminal 3b and the cathode terminal 8b protruding above the electric insulating member 11 are respectively oriented in the same direction (the right side of FIG. 1). It is bent backward by 90 degrees and the tips of both terminals 3b and 8b are fixed to the upper surface of the electric insulating member 11.

Next, apply the connection piece 15a connected to the cathode terminal of an unillustrated unit cell adjacent to the upper surface of the anode terminal 3b, and to the anode terminal of an unillustrated unit cell adjacent to the opposite side on the upper surface of the cathode terminal 8b. Apply the connected connection piece 15b. Then, the bolt 16a is passed through the through hole 14a of the connecting piece 15a, through the through hole 10a of the anode terminal 3b, and tightened to the nut 12a. Similarly, pass the bolt 16b through the through hole 14b of the connection piece 15b, and connect the cathode terminal 8b.
Through the insertion hole 10b and tightened to the nut 12b.

In this way, the electrical insulating member 11 and the connecting pieces 15a, 15b
2 is attached to the unit cell, as shown in FIG. 2, the anode terminal 3b is fixed on the electric insulating member 11 at the left position in FIG. 2 and the cathode terminal 8b is fixed at the right position at a predetermined interval. The terminals 3b and 8b are surely insulated, and the connection pieces 15a and 15b are tightly fixed on the terminals 3b and 8b, so that the anode terminal 3b and the connection piece 15a and the cathode terminal 8b and the connection piece 15b are electrically connected.

Thus, as shown in FIGS. 3 and 4, the cathode terminal 8b of the unit cell 1a is connected to the anode terminal 3b of the unit cell 1b adjacent on the right side thereof, and the cathode terminal 8b of the unit cell 1b is It is connected to the anode terminal 3b of the unit cell 1c adjacent to the right side thereof, and the unit cells 1a, 1b, 1c are connected in series. Thereafter, a predetermined number of unit cells are connected in series in the same manner.

In addition, each unit cell 1a, 1b, 1c of the sodium-sulfur battery,
Operates at a high temperature of 300-350 ℃, and solid electrolyte tube 5 during discharge
The sodium inside becomes sodium ions, permeates through the solid electrolyte tube 5 having the same sodium ion permeability, and moves into the anode container 2. 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 1.8 to 2.0 V is obtained.

When 2Na + xS → Na ₂ Sx discharge is continued, the amount of sodium in the solid electrolyte tube 5 decreases.

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. The applied voltage during charging requires approximately 1.9 to 2.3V.

As described above, according to the present embodiment, the electrical insulating member 11 provided on the upper surface of the sodium-sulfur battery as the unit cell.
Since the anode terminal 3b and the cathode terminal 8b are inserted into the through holes 11a and 11b and bent and formed and fixed at a predetermined position, the insulation between the anode terminal 3b and the cathode terminal 8b is ensured. . Further, when connecting the plurality of cells 1a, 1b, 1c, insert nuts 12a, 12b into the hexagonal holes 13a, 13b of the electric insulating member 11, a connection piece for connecting the anode terminal 3b or the cathode terminal 8b between the cells. 15
Since a and 15b are fixed by screwing bolts 16a and 16b into the nuts 12a and 12b, the anode terminal
Attachment of the connection pieces 15a, 15b to the 3b and the cathode terminal 8b is easy and reliable.

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) In the above embodiment, the anode terminal 3b and the cathode terminal 8b are provided on the upper surface of the unit cells 1a, 1b, 1c.
Provided on the lower surface of 1c, each connection piece 15a, in the same manner as the above embodiment.
15b can be connected to the anode terminal 3b and the cathode terminal 8b.

(2) In the above embodiment, the anode terminal 3b and the cathode terminal
8b protruding position, shape of electrical insulating member 11, thickness, connecting piece 15
The shapes and the like of a and 15b can be appropriately set so that the anode side and the cathode side are surely insulated.

[Effect of the Invention] The sodium-sulfur battery of the present invention has an effect of ensuring sufficient insulation between the anode terminal and the cathode terminal.

Further, by providing through holes through which the anode terminal and the cathode terminal can be inserted respectively in the electrical insulating member, and by bending the anode terminal and the cathode terminal by inserting through the through holes, the anode terminal and the cathode terminal can be formed. A more reliable insulating property is secured.

Further, a hexagonal hole as a hole having an angle is provided in the electrical insulating member, a nut is inserted into the hexagonal hole, and a connecting piece for connecting an anode terminal or a cathode terminal between the unit cells to each other is attached to the nut. By fixing the connection piece by screwing it in, the connection piece can be easily and reliably attached to the anode terminal or the cathode terminal.

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention, FIG. 1 is an exploded perspective view showing a mounting state of an electrically insulating member and a connecting piece, and FIG. 2 is a connecting piece for an anode terminal and a cathode terminal. FIG. 3 is a sectional view showing a connected state, FIG. 3 is a plan view showing a state in which connecting pieces are connected to an anode terminal and a cathode terminal, FIG. 4 is a front view of FIG. 3, and FIG. FIG. 6 is a cross-sectional view showing a battery, FIGS. 6 and 7 are views showing a conventional example, FIG. 6 is a plan view showing a state where connecting pieces are connected to an anode terminal and a cathode terminal, and FIG. It is a front view of a figure. 1a, 1b, 1c …… single cell, 3b …… anode terminal, 8b …… cathode terminal, 11 …… electrical insulating member, 11a, 11b …… through hole, 12a, 12b
...... Nuts, 13a, 13b ...... Hexagonal holes as square holes, 15a, 15b ...... Connecting pieces, 16a, 16b ...... Bolts

Claims (3)

(57) [Claims] 1. A single cell of a sodium-sulfur battery (1a, 1b, 1
Both the anode terminal (3b) and the cathode terminal (8b) are arranged on one end surface of c), and the anode terminal (3b) and the cathode terminal (8b) are arranged on one end surface of the unit cell (1a, 1b, 1c). A sodium-sulfur battery, characterized in that an electric insulating member (11) for insulating between them is placed, and the anode terminal (3b) and the cathode terminal (8b) are supported by the electric insulating member (11). 2. A through hole (11a, 11) through which the anode terminal (3b) and the cathode terminal (8b) can be inserted into the electrically insulating member (11).
b) are provided respectively, and the anode terminal (3b) and the cathode terminal (8
The sodium-sulfur battery according to claim 1, wherein b) is inserted into each through hole (11a, 11b) and is bent. 3. The electrical insulation member (11) is provided with angular holes (13a, 13b), and nuts (12a, 12b) are inserted into the angular holes (13a, 13b), respectively. Connect the nuts (12a, 12b) to the nuts (12a, 12b) with the connecting pieces (15a, 15b) connecting the anode terminals (3b) or the cathode terminals (8b) of the unit cells (1a, 1b, 1c) to each other. The sodium-sulfur battery according to claim 1, wherein the sodium-sulfur battery is fixed by being screwed.