JPH02199777A - Sodium-sulfur battery - Google Patents

Abstract

PURPOSE:To simplify the assembling process by forming a sodium receiving chamber and an inert gas receiving chamber by partitioning in a sodium vessel, and providing a hole communicating the both chambers at the time of heating in a part of a partition wall. CONSTITUTION:An inert gas vessel 11 is assembled and contained in the inside of a sodium vessel 5 and partitioned into a receiving chamber 12 of sodium Na and a receiving chamber 13 of an inert gas G. As the inert gas vessel 11 is exposed to vacuum state in the sodium vessel 5, its internal gas is sealed until it is combined into a battery. A deforming member 14 consisting of shape memory alloy is disposed in its inner part, and a perforating needle i5 facing the partition wall 11a of the inert gas vessel 11 is provided at the top end thereof. Thus, when the temperature of the battery is raised to the operating temperature after this sodium vessel 5 is installed to the cathode part of the battery, the perforating needle 15 is stuck to the partition wall 11a by the deformation of the deforming member 14 to form a communicating hole 16 in the partition wall 11a, and the receiving chamber 13 of an inert gas G is communicated with the receiving chamber 12 of sodium Na. Hence, the assembling process is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sodium-sulfur battery, and particularly to an improvement in a sodium container for containing sodium as a cathode active material.

[Prior Art] Conventionally, a sodium-sulfur battery having a structure as shown in FIG. 5, for example, is known.

That is, the anode container 1 is formed into a cylindrical shape with a bottom, and an insulating ring 2 made of α-alumina is bonded by thermopressure to the upper end surface of the anode container 1. A cathode fitting 3 is heat-pressure bonded to the upper surface of the insulating ring 2, and a solid electrolyte tube 4 made of β1-alumina is bonded and fixed to the inner peripheral surface of the insulating ring 2.

In the anode chamber R1 formed between the anode container 1 and the solid electrolyte tube 4, a conductive material M for the anode such as a carbon mat impregnated with molten sulfur S as an anode active material is stored. There is. In addition, in the cathode chamber R2 formed inside the solid electrolyte tube 4, metallic sodium N as a cathode active material is contained.
A sodium container 5 having a cylindrical shape with a lid and a bottom is housed for storage of a.

A small hole 5b through which sodium Na flows out is provided in the bottom surface 5a of the sodium container 5. In addition, a pressure chamber R3 in the upper closed space of the sodium container 5 is filled with a gas G that is inert to sodium, such as nitrogen gas or argon gas, at a predetermined pressure, and this gas pressure keeps sodium Na constantly flowing. It is pressurized in the direction of flowing out from the small hole 5b.

When discharging, the small hole 5b of the sodium container 5 is
Sodium Na flowing out becomes sodium ions, passes through the solid electrolyte tube 4, and reacts with sulfur S in the anode conductive material M as follows to generate sodium polysulfide.

2Na+XS-+Na2Sx Further, during charging, a reaction opposite to that during discharging occurs, and sodium Na and sulfur S are respectively generated.

By the way, when manufacturing a sodium-sulfur battery having the conventional structure as described above, as shown in FIG. ), and in this state, the edge of the container 5 was sealed by vacuum welding or the like. Thereafter, as shown in FIG. 7, this sodium container 5 is housed in the solid electrolyte tube 4 via the tubular partition 6, and the insulating ring 2 and cathode fitting 3 are bonded and fixed to the upper end of the fixed electrolyte tube 4. I was assembling the cathode structure.

[Problem to be solved by the invention ff] However, with this conventional configuration, when manufacturing the sodium container 5, it takes time to quantify several mg of sodium nitride NaNs, and it is difficult to handle because moisture is avoided. It was necessary to carry out the process in an atmosphere with as little moisture as possible, resulting in poor workability and efficiency. In addition, sodium nitride is extremely dangerous and must be handled with great care.

The present invention was made by focusing on the problems existing in the conventional technology, and its purpose is to develop a sodium-sulfur battery that can simplify the battery assembly process. It is about providing.

[Means for Solving the Problem] In order to achieve the above object, the sodium-
In a sulfur battery, a sodium storage chamber and an inert gas storage chamber are partitioned into a sodium container for storing sodium as a cathode active material during battery assembly;
A communication hole is provided in a part of the partition wall for communicating the compartments during heating.

[Function] According to the sodium-sulfur battery configured as described above, since sodium nitride is not used, safety is increased, and the battery characteristics can be stabilized because there is less contamination with water and the like. ! Since there is no need for quantitative filling of sodium nitride, the battery can be assembled easily and in a short time.

[Example] Hereinafter, a first example of a sodium-sulfur battery embodying the present invention will be described in detail based on FIGS. 1 and 2.

As shown in FIG. 1, an inert gas container 11 is assembled and housed inside the sodium container 5, and the inside of the sodium container 5 is divided into a storage chamber 12 for sodium Na and an inert gas container 11. It is divided into a storage chamber 13 for gas G. The storage chamber 13 in the inert gas container 11 is filled with an inert gas G such as nitrogen or argon in advance before the inert gas container 11 is assembled into the sodium container 5. r! of the sodium container 5 to prevent oxidation of sodium Na. The IA edge is sealed by vacuum welding or the like.

As shown in FIG. 2, since the inert gas container 11 is exposed to a vacuum state within the sodium container 5, the internal gas is sealed until it is assembled into a battery. A deformable member 14 made of a shape memory alloy is disposed inside the deformable member 14, and a piercing needle 15 is provided at the tip thereof facing the partition wall 11a of the inert gas container 11. After the sodium container 5 is assembled into the negative balance section of the battery, when the battery is heated to the operating temperature, the temperature inside the inert gas container 11 is 1.
When the temperature exceeds 00°C, the deformation of the deformable member 14 causes the piercing needle 15 to pierce the partition wall 11a, forming a communication hole 16 in the partition wall 11a, through which the inert gas G is accommodated. The chamber 13 communicates with the sodium Na storage chamber 12.

Now, according to this embodiment, unlike the conventional configuration shown in FIGS. 6 and 7, sodium nitride NaNs for generating the inert gas G is not used.
There is no need to quantify sodium nitride NaNs, and the workability and efficiency are good, and there is no danger in handling.
There are no problems with humidity.

In this way, the battery can be assembled easily and in a short time, simplifying the assembly process and reducing battery manufacturing costs.

[Another Embodiment] Next, another embodiment of the present invention will be described based on FIGS. 3 and 4.

First, in the second embodiment shown in FIG. 3, a communication hole 16 is formed in advance in the partition wall 11a of the inert gas container 11, and the communication hole 16 is sealed with a sealing material 17 made of a low melting point metal such as solder. ing. When the temperature inside the inert gas container 11 reaches 100°C or higher when the battery is heated to the operating temperature while the battery is assembled, the sealing material 17 is melted and the communication hole 16 is opened. The inert gas G storage chamber 13 is communicated with the sodium Na storage chamber 12 through the communication hole 16 .

In addition, in the third embodiment shown in FIG. 4, by fitting the compartment body 18 made of a metal plate or wire mesh into the sodium container 5, the interior of the sodium container 5 is divided into a storage chamber 12 for sodium Na and an inert gas G. It is divided into a storage chamber 13 and a storage chamber 13. In addition, the gap between the partition body 18 made of a metal plate and the inner circumferential surface of the sodium container 5, or the partition body 18 made of a wire mesh.
The mesh serves as a communication hole for communicating the two station compartments 12 and 13. Generally, at a temperature of about 120 to 150°C for filling sodium, the sodium filled in the storage chamber 12 has poor thermal properties, so the communication hole is blocked, that is, there is a gap between the metal plate and the inner circumferential surface of the sodium container. Sodium does not flow out into the inert gas storage chamber 13 through the communication hole of the wire mesh, etc., and a predetermined amount of gas is stored and secured in the inert gas storage chamber. When the temperature of the battery is not raised to the operating temperature, the sodium Na is dissolved, the communication hole is opened, and the inert gas flows into the sodium storage chamber 12.

Therefore, also in this second and third embodiment.

As in the case of the first embodiment described above, the battery assembly process can be simplified.

Note that the present invention is not limited to the configurations of the respective embodiments described above; for example, in the first embodiment, the deformable member 14 is formed of a bimetal, and in the second embodiment, a sealing material of a low melting point metal is used. It is also possible to change the structure of each part arbitrarily and embody it without departing from the spirit of the present invention, such as using metallic sodium Na as a cathode active material for 17.

[Effect of the invention] Since this invention is configured as explained above,
There is no need to charge a fixed amount of sodium nitride, and the workability and efficiency are good. Also, there is no danger in handling and there are no problems with moisture.In this way, assembly can be done easily and in a short time, and the assembly process can be improved. This has the excellent effect of simplifying the structure and reducing battery manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of a sodium container in a sodium-sulfur battery embodying the present invention;
The figure is a sectional view showing an enlarged internal structure of the inert gas container, FIG. 3 is a sectional view of an inert gas container showing a second embodiment of the invention, and FIG. 4 is a sectional view showing a third embodiment of the invention. 5 is a sectional view showing the configuration of a conventional sodium-sulfur battery, FIG. 6 is a sectional view showing a sodium container with a conventional configuration, and FIG. 7 is a sectional view of a sodium container with a conventional configuration. FIG. 2 is a cross-sectional view showing the assembled cathode structure. 5... Sodium container, 11... Inert gas container,
11a... Compartment wall, 12... Sodium storage chamber,
13...Inert gas storage chamber, 16...Communication hole, 1
8... Compartment body, Na... Sodium, G... Inert gas. Patent applicant Nippon Insulator Co., Ltd. Agent
Patent Attorney On 1) Hiroyoshi) a bji Figure 7 Figure 5

Claims (1)

[Claims] 1. In the sodium container (5) for accommodating sodium (Na) as a cathode active material,
storage chamber (12) and inert gas (G) storage chamber (13)
A sodium-sulfur battery, characterized in that a part of the partition wall (11a) is provided with a communication hole (16) for communicating the two chambers during heating.