WO1998032186A1

WO1998032186A1 - Sodium-sulfur battery module

Info

Publication number: WO1998032186A1
Application number: PCT/JP1997/000061
Authority: WO
Inventors: Takeshi Hiranuma; Hiromi Tokoi; Naohisa Watahiki
Original assignee: Hitachi, Ltd.
Priority date: 1997-01-16
Filing date: 1997-01-16
Publication date: 1998-07-23

Abstract

A sodium-sulfur battery module comprising batteries (1) separated by spaces filled up with an insulating liquid (3) which does not react with sodium and sulfur, wherein a recovering device (5) prevents the short circuit between adjacent batteries by removing an active material, such as the sodium or sulfur leaking into the liquid or sodium polysulfide, etc., and removes heat from the batteries or equalizes the temperatures of adjacent batteries by circulating the liquid. Therefore, the module can be continuously operated even when some of the batteries are out of order and, at the same time, the batteries are protected from damage by stabilizing their characteristics and temperature.

Description

Specification

[Sulfuric acid] battery module Technical field

The present study relates to a module battery made up of a series of sulfur batteries. Background art

As shown in Fig. 13, a conventional natural sulfur battery module battery is composed of a plurality of unit cells 1 assembled in an insulated container 4, and sand or ceramic particles are interposed between the unit cells 1. There is a space for filling or circulating gas, and a ceramic or metal partition is placed in the space. Some are filled with non-combustible shanto besides sand.

In the above prior art, when a unit cell is damaged and an active material such as sodium or sodium polysulfide having electrical conductivity leaks, the adjacent unit cell is short-circuited, the balance of series-parallel voltage is lost, and sufficient Battery output cannot be obtained. In addition, adjacent cells may be damaged by overcurrent or overdischarge, or may be damaged by temperature rise caused by reaction heat. The entire module, including the battery, will need to be replaced. In general, a module battery is composed of several hundred cells or more, and the damage of one battery greatly affects the output and shuts down. For this reason, there is a demand for a highly reliable module that can continue battery operation, and it is necessary to provide a structure in which damage to the cells is difficult and even if damage occurs, the damage does not spread . Also, as an emergency power supply or peak demand power supply, when discharging in a shorter time and higher power is required, In a cell, the heating value of the joule increases in proportion to the square of the current value, so the temperature of the cell rises, promoting thermal stress, internal pressure rise and uneven temperature, which may cause damage. Increase. In this case, conventional heat transfer by sand or non-combustible oil or heat transfer by gas cannot prevent them.

The thirteenth goal of this study is to provide a highly reliable and safe module for sodium sulfur batteries.

¾ l j) Disclosure of J

The i! JJ module is filled with a liquid that is non-reactive with sodium and sulfur and electrically insulating between cells, and leaks sodium, sulfur, and polysulfide in the liquid. Riumu is provided with a device for collecting the active material, such as _c further, the module, which was provided with a control device for sensors and control them for detecting damage a pump for circulating the liquid Confuse.

ADVANTAGE OF THE INVENTION According to this invention, since the active material leaked from the cell and released into the surrounding liquid can be removed, and a short circuit of the adjacent battery can be prevented, the operation of the module can be continued. In addition, the leaked active material can be effectively collected in the recovery device by flowing the liquid by the pump, and the damaged portion can be gradually heated to suppress the temperature change of the adjacent battery. In addition, since the uniformity between the batteries can be achieved, the characteristics and temperature of the batteries are stabilized, and the cells are less likely to be damaged. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram showing a main part structure of a first embodiment of the present invention, FIG. 2 is a diagram showing a main part structure of a second embodiment of the present invention, and FIG. Implementation of FIG. 4 is a view showing a main part structure of an example, FIG. 4 is a view showing a main part structure of a fourth embodiment of the present invention, FIG. 5 is a view showing one embodiment of the active material recovery apparatus of the present invention, FIG. The figure shows the battery operation control method based on the damage detection of the present invention. FIG. 7 shows the first embodiment of the unit cell of the present invention and the position of the damage detection sensor. FIG. 8 shows the unit of the present invention. FIG. 9 is a diagram showing a second embodiment of the battery and the position of the damage detection sensor, FIG. 9 is a diagram showing the main structure of the first embodiment of the power storage system according to the present invention, and FIG. FIG. 11 is a diagram showing a main part of the second embodiment of the power storage system according to the present invention, FIG. 11 is a diagram showing an embodiment of the active material recovery device of the present invention, FIG. FIG. 13 is a view showing a transportation method, and FIG. 13 is a view showing a structure of a conventional example.

Best mode for implementing% Ming

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of the present invention. As in the conventional module shown in FIG. 13, the cells 1 are collectively arranged in a heat insulating container 4. Around this, an electrically insulating liquid 3 that does not react with sodium and sulfur (for example, a perfluoropolyether-based heating medium, an alkylbiphenyl-based heating medium, a dibenzyltoluene-based heating medium, etc.) The space is filled with inert gas 4 at the top to alleviate the expansion of the liquid. An active material recovery device 5 for removing sodium, sulfur and sodium polysulfide from the liquid 3 is provided in a pipe 7 to which a pump 8 is connected. The installation position of the active material recovery device 5 is not limited to the piping, but may be in an insulated container or the like as long as the active material leaked from the unit cell can be captured. In the liquid 3, a leak sensor 6 for detecting the active material leaked from the cell is installed, and the active material recovery device 5 and the pump 8 are controlled by the control device 10 based on a leak signal of the leak sensor 16. Ko Control. The active material recovery device 5, the pump 8, the leak sensor 6, and the control device 10 are connected by a signal line 9. The leakage sensor 6 changes the electrical resistance when sodium or sodium polysulfide leaks into the liquid 3. Another method that detects battery damage from the electrical changes in the sodium-conducting solid conductive solid electrolyte is _c. Another method is to detect leakage from the rise in temperature of the liquid 3 due to the heat of reaction at the time of breakage and the acoustic change associated with the damage. Detect. When detecting a leakage, the active material is activated the pump 8 at that time _t to remove the active material leads to the active material recovery device 5, by forced convection of the liquid 3, the reaction heat at failure is also removed. As described above, since the damage is prevented from spreading, the module of the present invention can continue to operate. In addition, the pump 8 is always operated at the base to be used as an emergency power supply or as a power demand peak cut power supply, so that the inside of the battery is evenly heated and damage is prevented.

FIG. 2 is a diagram showing a second embodiment of the present invention. A heating or cooling device 10 is provided in the embodiment of FIG. 1 to actively control the temperature of the liquid 3. In this embodiment, since the temperature of the unit cell is kept constant, the battery performance is further stabilized, and damage is less likely to occur.

FIG. 3 is a view showing a third embodiment of the present invention. The embodiment shown in Fig. 1 is provided with a heat storage tank 11 (which also reduces the expansion of liquid in this example), and supplies heat to an external heat load 12 or an adjacent module. is there. Joule heat generated during discharging and charging can be stored and used effectively, such as maintaining the temperature during standby and supplying heat to adjacent modules and external heat loads.Figure 4 shows a fourth embodiment of the present invention. FIG. The liquid 3 in the insulated container 2 is directly heated or cooled by the heating device or cooling device 1 1, and the liquid 4 is circulated using the natural convection of the liquid, eliminating the need for a pump. Become. If 11 is a cooling device, a downward flow of the liquid 3 occurs between the heat insulating container 2 and the partition plate 14 and an upward flow occurs between the cells, so that the cells can be cooled. When 11 is a heating device, an ascending flow of the liquid 3 occurs between the heat insulating container 2 and the partition plate 14, and a descending flow occurs between the cells, so that the cells can be heated.

FIG. 5 is a view showing a fifth embodiment of the present invention. When battery damage is detected, the liquid 3 in the heat insulating container 2 is replaced with the liquid 3 in the heat storage tank 12. This prevents the damage from spreading and allows the battery to continue operating, as in Example 1.

FIG. 6 is a diagram showing a specific example of a control method of the present invention. If damage is detected, activate the active material recovery device and pump. However, if the damage is still widespread, for example when the temperature continues to rise or the electrical resistance of the liquid continues to drop, the battery output is temporarily reduced to prevent the damage from spreading.

FIG. 7 is a view showing a specific example of the arrangement of the unit cell and the leak sensor of the present invention. Sodium is lighter than liquid, and the temperature rises due to the heat generated due to breakage, and the density becomes lighter and the liquid rises, so the leak sensor that detects electrical resistance, Na leak, and temperature is installed above the cell. By doing so, leakage can be detected with a small number of sensors. In addition, the separators 14 between the collections of the cells 1 connected to the terminals 15 in series are connected in parallel to the collection of batteries including the damaged batteries in series. This prevents the active material from leaking and accumulates in the collection of batteries, and reduces the effect of reduced output due to damaged batteries to only the stains of series batteries including damaged batteries.

FIG. 8 is a view showing a second specific example of the arrangement of the unit cell and the leak sensor according to the present invention. If a liquid is flowing during power generation, a leak sensor that detects electrical resistance, Na leak, and temperature is installed downstream. Liquid flows Therefore, if damage occurs on the upstream side, an increase in electrical resistance, temperature, Na leakage, etc. can be detected on the downstream side, so the number of upstream leakage sensors can be reduced.

FIG. 9 is a diagram showing a specific example of the power storage system of the present invention. By connecting multiple modules with pipes and sharing the active material recovery tank, materials can be reduced. If damage is detected in module 16, turn on flow control valve 17, start pump 8, and pump the liquid in the module into the active material recovery tank.

Introduce to 5.

笫1 0 Figure has two pipes for circulating liquid in a pipe and a pump connected to the _c active material collecting device is a diagram showing a second specific example of the power storage system of the present ¾叨. If one module recovers the active material and reduces the output of that module to prevent damage from spreading, the other module compensates for the loss of power due to the short-term high-power output. FIG. 11 is a view showing a specific example of the active material recovery device of the present invention. Sodium 18, sulfur 19, and sodium polysulfide 20 leaked from the pipe 7 are mixed with the liquid 3 and flow. When sodium 18 and sodium polysulfide 20 are applied with a voltage to the porous electrode 22 provided on the solid electrolyte 21, the sodium conducts the solid electrolyte 21 in the form of ions, and the solid electrolyte 1 7 It is taken into the sodium recovery tank 19 inside. On the other hand, if liquid 3 is, for example, a perfluoropolyether-based heating medium, the density at the battery operating temperature is about 1.3 g, and the density of sulfur 15 is about 1.7 g. 5 precipitates and accumulates in the sulfur recovery tank 24 at the bottom of the active material recovery device. Sodium 14 and sulfur 15 can be discharged from the drain valve 22.

FIG. 12 is a view showing a transportation method of the present invention. After transporting the battery from the battery manufacturing site to the battery installation location, filling it with liquid reduces the volume required for transportation. Can be

The present invention can provide a highly reliable and safe module of one sodium sulfur pond as in the above embodiment. Industrial applicability

According to Kizaki, the active material leaked from the cell and released into the surrounding liquid can be removed, a short circuit between adjacent cells can be prevented, and the module can be operated continuously. In addition, the leaked material can be effectively collected in the recovery device by flowing the liquid by the pump, and the temperature of the adjacent battery can be suppressed by gradually heating the damaged portion. In addition, since the temperature between the batteries can be made uniform or constant by applying liquid heat or gradual heating, the characteristics and temperature of the entire battery are stabilized, and the battery is less likely to be damaged.

Claims

The scope of the claims

1. In a sodium-sulfur battery module consisting of a number of cells connected in series or in parallel, the surroundings of the cells are filled with liquid that is non-reactive with sodium and sulfur and is electrically insulating. A sodium-sulfur battery module characterized by providing active material recovery means for recovering active materials such as sodium, sulfuric acid and sodium polysulfide from liquid.

2. The module for a sulfur battery according to claim 1, wherein said electrically insulating liquid driving means is provided.

3. The module for a sodium-sulfur battery according to claim 2, wherein: a leakage sensor for detecting that an active material has leaked from a cell into the electrically insulating liquid; and the driving means. And a control device for controlling the active material recovery device from the signal of the leak sensor (1).

4. The module according to claim 3, wherein the leak sensor is provided above a single S pond. Le.

5. The module according to claim 3, wherein the leak sensor is provided on the downstream side when the electrically insulating liquid is caused to flow. A module for a natural sulfur battery.

6. The sodium-sulfur battery according to claim 1, wherein the partition plate is provided between the battery clusters in which the cells are connected in series. Module.

7. The module for a sulfur battery according to claim 1, wherein the electrically insulating liquid having a different density from an active material is used, A sodium sulfur battery module characterized by recovering the active material by precipitating or suspending the active material.

8. The sodium sulfur battery module according to claim 1, wherein sodium is recovered from the electrically insulating liquid by using a sodium-conductive solid electrolyte. A module for a sulfur sulfur battery.

9. In a module of a sulfur battery with a number of cells connected in series or in parallel, the cell is filled with a liquid that is non-reactive with the sulfur and sulfur and is electrically insulating. A module for a sodium sulfur battery characterized by having means for exchanging the liquid at the battery operating temperature <