JP2001118598A - Sodium-sulfur cell system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide enhancement of energy density, while arranging many cylindrical bodies in the same space as in prior art. SOLUTION: This sodium-sulfur cell system comprises a plural of cylindrical bodies 14 having bottom 13 for charging solution, Na and arranged in a module 12 in a matrix form, a sulfur charging hollow part 18 having a sulfur feeding hole for charging solution, sulfur in its bottom, where the interval being formed between its upper, a Na-storing tank 27 for storing Na supplied into the can bodies, a sulfur-storing tank 29 for storing supplied into the sulfur charging hollow part, and a force feeding means for inflowing Na, sulfur into the can bodies 14 and the sulfur charging hollow part 18 from each of the tanks 27, 29 and discharging Na, sulfur into each of the tanks 27, 29 from the cylindrical bodies 14 and the sulfur charging hollow part 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sodium-sulfur battery system, and more particularly to a sodium-sulfur battery system used for power storage.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 6A and 6B, a module composed of a unit cell is known. Here, FIG. 6A is a schematic diagram of the module, and FIG.
FIG. 2 shows a cross-sectional view of a unit cell constituting the module of FIG.

As shown in FIG. 6A, a module 1 includes a plurality of cells 3 arranged in a matrix in a housing 2. As shown in FIG. 6B, the single cell 3 includes a protective container 4 and β ″ disposed in the protective container 4.
A bottomed cylindrical body 5 made of alumina, sodium (Na) 6 as an active material housed in the cylindrical body 5, a cathode 7 arranged in the cylindrical body 5, the protective container 4, and a cylindrical body. And sulfur (S) 8 contained between the bodies 5.

In the cell having such a structure, the cylindrical body 5 is
The negative electrode side is Na → Na in the discharge state through⁺+ E⁻, Na⁺
Moves to the positive electrode side through the cylinder 5, and the negative electrode side
Na ⁺+ E⁻→ Na, positive electrode Na⁺Is negative through the cylinder 5
The battery is configured using a mechanism that moves to the pole side.
You. By the way, when the module 1 is increased in size,
The number of cells 3 is increased to cope with an increase in capacity. example
For example, for a 210 kW delivery, one module can be created from 480 cells.
Joule is configured. In this case, the energy density
Is 145 kw / m³It is.

[0005]

However, the conventional single cell has a problem that a large space is required because the thick protective container 4 is a component of the single cell 3. In addition, N is added to the sulfur side (positive electrode side) by discharging.
There is a possibility that the product of a ₂ S _x accumulates and the concentration increases, and the performance of the unit cell is deteriorated. Further, when the performance is deteriorated due to repeated charging and discharging, the unit cell whose performance has deteriorated in the conventional method is disposed of.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a sodium-sulfur battery system in which a large number of cylinders can be installed in the same space as in the related art, so that the energy density can be increased.

[0007]

Means for Solving the Problems A first invention of the present application comprises a plurality of bottomed cylinders arranged in a matrix in a module and filled with molten Na as a cathode active material, and an upper part of the cylinders. A sulfur filling cavity having a sulfur supply hole at the bottom formed therein and filled with molten sulfur as an anode active material, a Na storage tank for storing Na to be sent into the cylinder, and the sulfur filling A sulfur storage tank for storing sulfur to be sent into the cavity, and Na and sulfur from the respective tanks respectively flow into the cylindrical body and the sulfur filling cavity, and Na and sulfur respectively from the cylindrical body and the sulfur filling cavity. A sodium-sulfur battery system comprising:

According to a second aspect of the present invention, a plurality of bottomed cylinders which are arranged in a matrix in a module and are filled with molten sulfur as an anode active material are formed in a gap between upper portions of the cylinders. A Na filling cavity having a Na supply hole at the bottom, filled with molten sodium as a cathode active material, a sulfur storage tank for storing sulfur to be sent into the cylinder, and a Na sending into the Na filling cavity. Na that stores
A storage tank, and a pumping means for allowing sulfur and Na to flow into the cylindrical body and the Na filling cavity from each of the tanks, and for discharging sulfur and Na from the cylindrical body and the Na filling cavity to the respective tanks. And a sodium-sulfur battery system.

[0009]

Next, the present invention will be described in detail. In the present invention, the cylinders are arranged in a matrix (in a matrix) in the module, and it is preferable to provide an insulating partition between these cylinders. Thereby, when a cylinder is damaged, damage to other cylinders can be prevented.

In the present invention, the module is generally stored in a module protection container (module), and the module protection container is stored in a storage container. In this case, the storage container and the module protection container can be electrically insulated by an insulating material.

In the present invention, the material of the cylindrical body is, for example, β ″ alumina.

In the present invention, the sulfur filling cavity is disposed, for example, as shown in FIGS. 1 and 2 to be described later, at the top of a cylindrical body and having a sulfur supply hole at the bottom; It is composed of an insulating material formed on the outer periphery of the upper part of the cylindrical body, but is not limited to this. For example, by disposing a tubular body having a sulfur supply hole at the bottom in the upper end gap of the tubular body,
It may be a cavity for sulfur filling. The same applies to the case of the Na filling cavity.

In the present invention, examples of the pressure feeding means include, for example, a pipe through which molten sulfur or molten Na flows, and a pump interposed in the pipe. Further, the pumping means may be a gas pressure supply control system for pumping sulfur and Na in the sulfur storage tank or the Na storage tank in the direction of the module or the like by the pressure of a gas such as Ar gas.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) Reference is made to FIGS. Here, FIG. 1 is a conceptual diagram of the configuration of a loop-type Na-S battery system, and FIG. 2 is an enlarged view of a main part of FIG. Reference numeral 11 in the figure indicates an external container. In the outer container 11, a plurality of modules 12
Is arranged. In the module 12, a plurality of bottomed cylinders 14 filled with molten Na13 as a cathode active material are arranged in a matrix.

Here, the cylindrical body 14 is made of, for example, β ″ alumina.

In the module 12, a first partition plate 15 having a plurality of sulfur supply holes 15a is disposed above the cylindrical body 14. Here, the sulfur supply hole 15
a is for supplying a fixed amount of sulfur to the gap between the cylinders 14. An insulating material 16 made of, for example, α-alumina is wound around the cylindrical body 14 located above the partition plate 15. The insulating material 16 and the first partition plate 15 around the cylindrical body 14 form a sulfur filling cavity 18 for filling molten sulfur 17 as an anode active material. A carbon felt 19 is arranged at the bottom of the cylindrical body 14 in the module 12 in order to enhance current collection.

At the upper end of the cylinder 14, a module 1
The 2nd partition board 21 which constitutes Na storage tank 20 which stores molten Na with 2 upper walls is provided. A positive electrode 22 is connected to an outer wall of the module 12.
Further, the positive electrode 22 is formed of molten Na1 in the Na storage tank 20.
3 is connected to a liquid detection sensor 23 for detecting the number 3 of the liquid. The sensor 23 is turned off during discharging and turned on during charging. One end of the second partition plate 21 is connected to the cylindrical body 1.
A pipe 24 is installed, which reaches near the bottom of N4.
The molten Na 13 in the a storage tank 20 is supplied into the cylindrical body 14 through the pipe 24. The pipe 24
Is electrically connected to a negative electrode 25.

A Na storage tank 27 is connected to the Na storage tank 20 via a pipe 26a. In the sulfur filling cavity 18, a pipe 26b with a pump 28 interposed
Through a sulfur tank 29, a sodium polysulfide tank 30
Are connected respectively. The sulfur tank 29 and the sodium polysulfide tank 30 are connected to a drain pipe 32 at the bottom of the outer container 11 via a pipe 26c having a pump 31 interposed. Here, the drain tube 32 is used when extracting Na ₂ Sx generated at the time of discharging and extracting molten sulfur at the time of charging.

The operation of the Na-S battery system having such a configuration is as follows. First, after evacuating the inside of the module 12 and the like, Ar gas is sent from the pipe 26d and purged. Next, the molten Na13 is sent from the Na storage tank 27 to the Na storage tank 20 via the pipe 26a to accumulate the molten Na13. Next, the molten sulfur 17 is sent from the sulfur storage tank 29 to the sulfur filling cavity 18 via the pipe 26b to accumulate the molten sulfur 17. After that, the molten Na18 is stored in the Na storage tank 2.
On the other hand, the molten sulfur 17 is fed into the cylindrical body 14 through the pipe 24 from the pipe 0, and the molten sulfur 17 is sent from the sulfur filling cavity 18 to the gap between the cylindrical bodies 14 through the sulfur supply hole 15a provided in the partition plate 15. When a voltage is applied between the positive electrode 22 and the negative electrode 25 in this state, a discharge reaction occurs, and Na
⁺ → Na + e ⁻ , and Na ⁺ moves to the positive electrode side through the cylinder 14.

Conversely, when a charging reaction occurs, sodium polysulfide is treated from sodium polysulfide tank 30 instead of sulfur tank 29 in the same manner as in the case of sulfur. In this case, the negative electrode side ^Na + + e ^- → ^Na, and the positive electrode of the Na ⁺ moves through the tubular body 14 to the negative electrode side.

According to the first embodiment, the conventionally used protective container is removed, and the cylindrical bodies 14 containing Na are arranged in a matrix in the module 12.
Is filled with molten Na13, so that the space for the conventional protective container can be used effectively, and the divided cylinders 14 can be densely arranged in the same area as the conventional case. Specifically, the volume was reduced to about half that of the conventional one, and the energy density was increased to about 290 kw / m ³ . In other words, about twice as many cylinders can be installed with the same spacer as before, and the energy density can be increased.

In the case of a storage type Na-S battery, the NaSx concentration increases with the discharge, and there is a possibility that the performance may deteriorate. However, in the first embodiment, by flowing molten Na and molten sulfur using the Na storage tank 27 and the sulfur storage tank 29, high purity Na / sulfur can always be ensured, and a long life can be realized.

Further, in the first embodiment, since it is only necessary to supply a fixed amount of molten sulfur from the sulfur supply hole 15a of the first partition plate 15 (to the extent that dielectric breakdown is not caused), it is possible to stabilize the power. Can be.

Further, in the conventional system, the unit cell whose performance has deteriorated is disposed of. In the loop-type Na-sulfur battery system as in the second embodiment, each of the Na storage tank 27 and the sulfur storage tank 29 drained from the module may be purified by a purifier (not shown). An eco-friendly system can be realized by reduction.

(Embodiment 2) Referring to FIGS. 3A and 3B. Here, FIG. 3A shows a conceptual diagram of the configuration of the sodium-sulfur battery system according to the second embodiment, and FIG.
Shows a plan view of the module of FIG. However, FIG.
2 and the same members as those in FIG.

The system according to the second embodiment is different from the system according to the first embodiment in that the molten sulfur 17 is accommodated inside the cylinder 14 and the gap between the cylinders 14 is filled with molten Na 13. Are completely different, and the other basic configurations are the same. As shown in FIG. 3, a Na storage tank 27, a sulfur storage tank 29, and a Na ₂ Sx storage tank 44 are arranged. The tank 27 and the module 12 are connected by a pipe 26a with a pump 41 interposed therebetween. 29, 44
And the module 12 are connected by a pipe 26b with a pump 42 interposed. In the case of FIG. 3, for example, 24 × 36 cylinders 14 are arranged. Reference numeral 43a in the figure denotes a Na purifier, and reference numeral 43b denotes a sulfur purifier.

According to the second embodiment, the conventionally used protective container is removed, and the cylindrical body 14 containing the molten sulfur 17 is removed.
Are arranged in a matrix in the module 12, and the space between the cylinders 14 is filled with the molten sulfur 17, so that the space for the conventional protective container can be effectively used. It can be densely arranged in the same area as the conventional one. Specifically, 900 cylinders could be installed, and the energy density could be increased to 272 kw / m ^3, which is about 1.9 times.

In the case of a storage type Na-S battery, the Na ₂ Sx concentration increases with discharge, and there is a possibility that the performance may deteriorate. However, in the second embodiment, the molten Na and the molten sulfur can be made to flow using the Na storage tank 27 and the sulfuric acid tank 29. Therefore, high purity Na / sulfur can always be ensured inside and outside the cylindrical body 14, and a long life can be realized.

Furthermore, when there is no flow, the amount of Na and the amount of sulfur required for the specified electric power capacity are required in the container, so that at least the volume of the amount is required as a module. However, as described above, by fluidizing Na / S, only the contact area of the cylindrical body 14 is secured in the battery portion,
/ Be to flow from the storage tank for the S, Na ₂ S produced by reaction between Na ⁺ and sulfur through the cylindrical body 14
Deterioration of performance due to accumulation of x can be prevented, and the capacity as a module can be reduced.

Further, in the conventional method, the unit cell whose performance has deteriorated is disposed of. In the loop-type Na-sulfur battery system as in the second embodiment, each of the Na storage tank 27 and the sulfur storage tank 29 drained from the module may be purified by the purifiers 43a and 43b. By reducing the cost, an environment-friendly system can be realized.

(Embodiment 3) Referring to FIGS. 4A and 4B. Here, FIG. 4A shows a conceptual diagram of the configuration of the sodium-sulfur battery system according to the third embodiment, and FIG.
Shows a plan view of the module of FIG. However, the same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and description thereof will be omitted.

In the third embodiment, similarly to the system of the second embodiment, the molten sulfur 17 is contained inside the cylinder 14 and the cylinder 1
The gap between the four is filled with molten Na13. And
On the molten Na side, the cylindrical body 14 is divided by an insulating partition 45 every several lines (10 lines in FIG. 4).

In FIG. 4, the Na side is pumped by a pump 41, and the sulfur side is pumped by controlling the gas pressure in the tank. Since Na in the module has a gas space at a free liquid level, a system (gas pressure supply control system) 46 for supplying an inert gas to the gas space is provided.

According to the third embodiment, in addition to having the same effect as the second embodiment, by providing the insulating partition wall 45 and dividing the Na side, a voltage of 2 V of the battery is taken out for each.
There is an advantage that damage to another cylinder due to damage to the cylinder 14 can be prevented.

(Embodiment 4) Referring to FIG. Here, FIG. 5 shows a conceptual diagram of a configuration of the sodium-sulfur battery system according to the fourth embodiment. However, the same members as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals, and description thereof will be omitted.

The fourth embodiment is similar to the second embodiment, except that
Molten sulfur 17 is accommodated inside 4, and molten Na 13 is filled in gaps between the cylindrical bodies 14. In FIG. 5, the module 12 is housed inside the module protection container 51, and the module protection container 51 is housed inside the storage container 52.
1 is electrically insulated by an insulating material 53. Also, a pipe 5 is provided between the sulfur storage tank 29 and the module 12.
4a and a pumping system (not shown) (gas pumping or pumping) to allow sulfur to circulate. On the other hand, the Na storage tank 27 and the storage container 51 are connected by a pipe 54b, but are a non-circulating system. Piping 54
b is used when initially filling the module protection container 51 with Na and when recovering Na. Further, the module 12 and the pipe 54 in contact with the molten Na13
Leads 55 and 56 are taken out from a, so that a power source can be connected during charging and a load can be connected during discharging (broken line in FIG. 5).

Next, the operation of the system shown in FIG. 5 will be described. First, the molten Na13 is stored in a Na storage tank 27 containing Na purified by the Na purifier 43a.
The container 52 is filled by pressure feeding. When the liquid level of the molten Na 13 in the storage container 52 rises and reaches the upper end of the module protection container 51, the molten Na 13 flows into the protection container 51 and is finally filled. Then, the molten N in the storage container 52 is
a13 is collected in the Na storage tank 27. On the other hand, the molten sulfur 17 is the molten sulfur 1 purified by the sulfur purifier 43b.
7 is pressure-fed from the sulfur storage tank 29 into the cylinder 14 in the module, and the molten sulfur 17 is filled.

From this state, the charge / discharge operation is started.
Here, at the time of discharging, an external load is connected while the molten sulfur 17 is fed into the cylinder 14 under pressure. When charging, Na
_An external power supply is connected while the Na ₂ Sx in the ₂ Sx storage tank 44 is pressure-fed into the cylinder 14.

According to the fourth embodiment, the conventionally used protection container is removed, and a plurality of module protection containers 51 are disposed in the storage container 51 via the insulating material 53 so as to be electrically insulated from the storage container 52. At the same time, the cylinders 14 containing the molten sulfur 17 are arranged in a matrix in the module protection container 51, and the gaps between the cylinders 14 are filled with molten Na13. Therefore, the space for the conventional protective container can be effectively used, and the divided cylinders 14 can be densely arranged in the same area as the conventional case.

In a storage type Na—S battery, the product of Na ₂ Sx is accumulated on the sulfur side (positive electrode side) by discharging,
Performance may be degraded. However, in the fourth embodiment, the molten sulfur 17 can be made to flow using the sulfur storage tank 29 or the like. Therefore, high-purity sulfur can always be ensured inside and outside the cylinder 14, and the initial performance can be maintained.

Further, the performance of a single cell deteriorates due to repeated charging and discharging. For this reason, in the conventional method, a unit cell whose performance has deteriorated is disposed of. However, according to the fourth embodiment, the Na purification device 43a recovered from the module,
What is necessary is just to purify with the sulfur purifier 43b, and to save resources.
An environmentally friendly system can be realized by reducing waste.

[0042]

As described above in detail, according to the present invention, it is possible to provide a sodium-sulfur battery system in which a large number of cylinders can be installed in the same space as in the prior art and the energy density can be increased.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a configuration of a sodium-sulfur battery system according to Embodiment 1 of the present invention.

FIG. 2 is an enlarged view of a main part of the system of FIG. 1;

FIG. 3 is an explanatory diagram of a sodium-sulfur battery system according to Embodiment 2 of the present invention.

FIG. 4 is an explanatory diagram of a sodium-sulfur battery system according to Embodiment 3 of the present invention.

FIG. 5 is an explanatory diagram of a sodium-sulfur battery system according to Embodiment 4 of the present invention.

FIG. 6 is an explanatory diagram of a conventional sodium-sulfur battery system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... External container, 12 ... Module, 13 ... Molten Na, 14 ... Cylindrical body, 15, 21 ... Partition plate, 15a ... Sulfur supply hole, 16 ... Insulation material, 17 ... Molten sulfur, 18 ... Sulfur filling cavity, 19 ... Carbon felt, 20 ... Na storage tank, 22 ... Positive electrode, 23 ... Liquid detection sensor, 24 ... Pipe, 25 ... Negative electrode, 27 ... Na storage tank, 28, 31 ... Pump, 29 ... Sulfur tank, 30 ... Polysulfide Sodium tank, 31: drain pipe, 45: insulating partition wall, 46: Na ₂ Sx storage tank, 51: module protection container, 52: storage container, 53: insulating material.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kikuo Nakamura 2-1-1 Shinama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Kazuhisa Tanaka 2-1-1, Araimachi, Takarai City, Hyogo Prefecture No. 1 Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Harusuke Utsumi 2-1-1, Araimachi Shinhama, Takasago City, Hyogo Prefecture Inside the Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Masao Kado, Araimachi Shinhama, Takasago City, Hyogo Prefecture 2-1-1 1-1 Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory F-term (reference) 5H029 AJ03 AJ14 AK05 AL13 AM15 BJ02 BJ21 BJ24 DJ02

Claims (4)

[Claims] 1. A plurality of cylinders having a bottom and filled with molten Na as a cathode active material, which are arranged in a matrix in a module, and formed in a gap between upper portions of the cylinders, and serve as an anode active material. And a sulfur filling cavity having a hole for supplying sulfur at the bottom filled with molten sulfur of
a, a Na storage tank for storing a, a sulfur storage tank for storing sulfur to be sent into the sulfur filling cavity, Na and sulfur from the respective tanks respectively flowing into the cylindrical body, the sulfur filling cavity, and the cylindrical body. And a pumping means for discharging Na and sulfur from the sulfur filling cavity to the respective tanks. 2. A plurality of bottomed cylinders which are arranged in a matrix in a module and are filled with molten sulfur as an anode active material, and are formed in gaps between upper portions of the cylinders, and serve as a cathode active material. Filled with molten sodium at the bottom
a Na-filling cavity having a supply hole, a sulfur storage tank for storing sulfur to be sent into the cylinder, a Na storage tank for storing Na to be sent into the Na-filling cavity, sulfur from each tank, Na is caused to flow into the cylindrical body and the cavity for filling Na, respectively, and sulfur and N are introduced from the cylindrical body and the cavity for filling Na.
a-sulfur battery system comprising: 3. The sodium-sulfur battery system according to claim 1, wherein an insulating partition is provided between the cylinders in the module. 4. The module is stored in a module protection container, and the module protection container is stored in a storage container, and the storage container and the module protection container are electrically insulated by an insulating material. The sodium-sulfur battery system according to claim 1 or claim 2, wherein