JP2000030739A - Vacuum heat insulating container for sodium-sulfur battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum heat insulating container for a sodium-sulfur battery capable of preventing secondary accident caused by the break of a unit cell without use of a heat resistant plate (a carbon plate) expensive and difficult to handle. SOLUTION: This vacuum heat insulating container is used for housing a battery module formed by vertically collecting a plurality of sodium-sulfur batteries 8. The vacuum heat insulating container consists of a box-type container main body 2 having an opening at the top and a container upper cover 1 to be fit to the opening of the container main body 2. The container main body 2 and the container upper cover 1 have cavities 3, 5 between outer circumferential walls 1a, 2a and inner circumferential walls 1b, 2b, and powdery fire protecting material 6 is filled in the cavity 3 in the ceiling part of the container upper cover 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vacuum insulated container used for housing a sodium-sulfur battery module.

[0002]

2. Description of the Related Art In a sodium-sulfur battery, molten metal sodium as a cathode active material and molten sulfur as an anode active material are separated by a β-alumina solid electrolyte having selective permeability to sodium ions. , Usually 28
This is a chargeable / dischargeable high-temperature secondary battery operated at 0 to 370 ° C, and in recent years, expectations for practical use as a large-scale power storage / supply system are increasing.

[0003] In a sodium-sulfur battery, during discharge, molten sodium emits electrons to become sodium ions, which pass through the solid electrolyte and move to the anode side, reacting with sulfur and electrons supplied from an external circuit, and On the other hand, sodium polysulfide is generated, and at the time of charging, a reaction occurs in which sodium and sulfur are generated from sodium polysulfide, contrary to discharging.

[0004] Since the electromotive force of such a sodium-sulfur battery due to a battery reaction is about 2 V, a single cell does not reach a practical voltage. For this reason, a predetermined number of cells are erected and assembled together to form a sodium-sulfur battery
This is referred to as a “module”), and this is housed in an insulated container for practical use.

[0005] As a heat insulating container for housing a module, a vacuum heat insulating container is widely used. FIG. 2 is a cross-sectional view showing an example of a vacuum insulated container that has been used for accommodating a conventional module. This vacuum insulated container has a box-shaped container main body 12 having an opening at the top, and a container composed of a plurality of unit cells 18 housed in the container main body 12 and then attached to the opening of the container main body 12. Consists of

The container body 12 and the container upper lid 11 have a structure having cavities 14 and 15 between outer peripheral walls 11a and 12a and inner peripheral walls 11b and 12b, respectively. Vacuum insulated containers
By applying vacuum to the cavities 14 and 15, heat insulation performance is provided. Container body 12 and container lid 1
In order to improve the strength and heat insulation of the container, a heat insulating board 17 made of glass wool, ceramic wool, or the like is accommodated in each of the cavities 14 and 15. On the upper part), a heat-resistant plate 10 made of a carbon plate having a thickness of about 1 mm is provided. As shown in FIG. 3, the heat-resistant plate 10 may be housed together with the heat insulating board 17 in the hollow portion 14 of the container upper lid 11 instead of the inside of the container upper lid 11.

The heat-resistant plate 10 is used to prevent a secondary disaster when a unit cell is damaged. That is, as described above, the sodium-sulfur battery contains therein a highly reactive active material of sodium and sulfur separated by a solid electrolyte, but the single cell is damaged and the active material inside the battery is directly If a reaction occurs and a fire occurs inside the vacuum insulated container due to the reaction heat, the vacuum insulated container will not be able to withstand the heat and will be melted down without the heat-resistant plate as described above, causing a fire to reach the outside of the vacuum insulated container. May spread and cause secondary disasters.

[0008]

However, heat-resistant plates (carbon plates) are very expensive. Further, since the heat-resistant plate is a good electrical conductor, it must be insulated by mica or the like when it is disposed inside the container top cover 11 (above the unit cell 18) as shown in FIG. Cause disaster. Further, since the heat-resistant plate is fragile, FIG.
When the heat-resistant plate 10 is arranged in the cavity 14 of the container upper lid as described above, it is difficult to handle the heat-resistant plate at the time of assembling the container upper lid, and the assembly operation itself becomes difficult. Furthermore, the heat-resistant plate may be damaged during transportation.

The present invention has been made in view of such conventional problems, and an object of the present invention is to prevent a secondary disaster at the time of breakage of a unit cell without using a heat-resistant plate. Another object of the present invention is to provide a vacuum insulated container for a sodium-sulfur battery.

[0010]

Means for Solving the Problems According to the present invention, there is provided a vacuum insulated container used for accommodating a battery module in which a plurality of sodium-sulfur single cells are erected and assembled. , A box-shaped container main body having an opening at the top, and a container upper lid attached to the opening of the container main body, wherein the container main body and the container upper lid have a hollow portion between the outer peripheral wall and the inner peripheral wall, respectively. A vacuum heat insulating container for a sodium-sulfur battery, characterized in that a granular fireproof material is filled in a cavity in a ceiling portion of the container upper lid.

[0011]

FIG. 1 is a sectional view showing an example of the structure of a vacuum insulated container according to the present invention. The vacuum insulated container of the present invention has a box-shaped container main body 2 having an opening at the top and a battery module including a plurality of unit cells 8 housed in the container main body 2 as in the related art. A container upper lid 1 mounted on the opening to seal the container. Container body 2
The container upper lid 1 has a structure having a cavity between outer peripheral walls 1a, 2a and inner peripheral walls 1b, 2b each formed of a metal plate such as stainless steel.

As a characteristic structure of the vacuum heat insulating container of the present invention, a granular fireproof material 6 is filled in the hollow portion 3 in the ceiling portion of the container upper lid 1. When the granular fireproof material 6 is filled in the hollow portion 3 in the ceiling portion of the container upper lid 1 as described above, the direct reaction of the active material due to the breakage of the unit cell 8 allows the inside of the vacuum insulated container to be used without using a heat-resistant plate. Can be prevented from spreading outside the container, and secondary disasters can be prevented. In addition, by not using a heat-resistant plate, the cost can be significantly reduced, and the assembly and handling of the vacuum insulated container can be facilitated.

As shown in the figure, only the hollow portion 3 in the ceiling portion of the container upper lid 1 that covers the upper part of the cell 8 needs to be filled with the granular fireproof material 6, and the other hollow portions 4 of the container upper lid 1 and In the hollow portion 5 of the container body 2, glass wool is conventionally used,
It is preferable to accommodate a heat insulating board 7 made of ceramic wool or the like. This is because filling all of the cavities with granular fireproof material deteriorates the heat insulation of the container as compared to the case where the heat insulating board is housed. This is because heat is easily concentrated above the unit cells, and most of the erosion of the vacuum insulated container due to an internal fire occurs at the ceiling portion of the container upper lid.

In the present invention, examples of the granular fireproof material to be filled in the hollow portion of the container upper cover include filled sand (fire extinguishing sand), lightweight aggregate, crushed glass, foamed glass, and the like. For example,
When fire extinguishing sand is used as the particulate fire-protection material, when a fire occurs in the vacuum insulated container, the heat from the fire causes the inner peripheral wall 1b of the container top lid 1 shown in FIG. The fire can be extinguished by the depression, heat absorption and suffocation effects, and the flame can be effectively prevented from leaking to the outside.

[0015]

As described above, in the vacuum insulated container of the present invention, even if the unit cell is damaged and a fire occurs inside the container due to heat generated by the direct reaction of the active material, the hollow portion of the container top lid can be used. Prevents the fire from spreading to the outside of the container by the granular fireproof material filled in the container. Therefore, a secondary disaster at the time of breakage of a unit cell can be effectively prevented without using an expensive and difficult-to-handle heat-resistant plate (carbon plate).

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the structure of a vacuum heat insulating container according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a conventional vacuum insulated container.

FIG. 3 is a cross-sectional view showing the structure of a conventional vacuum insulated container.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container upper lid, 2 ... Container main body, 3 ... Hollow part in the ceiling part of container upper lid, 4 ... Hollow part other than ceiling part of container upper lid, 5 ... Hollow part of container main body, 6 ... Granular fireproof material, 7 ... Heat insulation Board, 8 ... cell.

Continuation of the front page (72) Inventor Yoshihiko Kurashima 2-56, Suda-cho, Mizuho-ku, Nagoya-shi, Aichi Japan F Co. EJ03 HJ14 HJ15

Claims (1)

[Claims] 1. A vacuum insulated container used for accommodating a battery module in which a plurality of sodium-sulfur single cells are erected and assembled, wherein the vacuum insulated container has a box shape having an opening at an upper portion. The container body, comprising a container top lid attached to the opening of the container body, the container body and the container top lid each have a structure having a cavity between the outer peripheral wall and the inner peripheral wall, the container upper lid A vacuum heat insulating container for a sodium-sulfur battery, wherein a hollow fireproof material is filled in a hollow portion of a ceiling portion.