KR20130075435A - Sodium-sulfur rechargeable battery and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A sodium-sulfur battery with excellent anti-corrosion and bond strength when grafting metal and ceramics together is provided to simplify the junction process. CONSTITUTION: A sodium-sulfur battery includes an anode container (14) accommodating sulfur, a cathode container (12) accommodating sodium, an electrolyte pipe (10) installed between the anode container and the cathode container and selectively moves only sodium ions, an insulator (20) insulating the cathode container and the anode container, a metal collar (16) installed on the cathode container and welded into the insulator, and a metal bracket (19) installed on the anode container and welded into the insulator. The metal collar or/and the metal bracket has/have a terminal welded on the insulator by an insertion metal (30) intermediation located on one side and extended to the outside of the body.

Description

SODIUM-SULFUR RECHARGEABLE BATTERY AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to a sodium sulfur battery. More particularly, the present invention relates to a sodium sulfur battery and a method for manufacturing the same, in which the joint structure of ceramic and metal is improved.

Generally, a sodium-sulfur battery is developed as a large-capacity power storage battery because of its high energy density, charge / discharge efficiency, self-discharge, and irregular charge / discharge characteristics.

Sodium sulfur batteries use sodium alumina (Na) as the cathode, sulfur (S) as the anode, and beta-alumina ceramics of the solid electrolyte having sodium ion conductivity as the electrolyte. The sodium sulfur battery includes an anode tube enclosing an electrolyte tube and an electrolyte tube. The electrolyte tube has a structure in which a beta-alumina ceramic having a property of passing only sodium ions is formed in a tube shape. The inside of the electrolyte tube is filled with sodium, and sulfur and carbon felt are placed between the electrolyte tube and the positive electrode container. The sodium ion is transferred between the cathode and the anode through the beta alumina, which is an electrolytic tube, to charge and discharge the battery.

Sodium sulfur batteries are insulators that insulate the positive and negative electrodes, and alpha-alumina ceramics are used.

Ceramics are widely used as components of chemical industry devices because of their excellent corrosion resistance, electrical insulation and mechanical properties at high temperatures. However, since ceramics are hard and brittle, moldability is inferior to metal materials. In particular, due to the lack of toughness, the resistance to impact force is weak.

Therefore, it is difficult to manufacture parts of a sodium sulfur battery using only ceramics, and it is often used as a bonding material with a metal material. In order to insulate the negative electrode from the positive electrode in the battery design, the ceramic parts must be used, and the metal should be well bonded. The upper and lower ends of the insulator are respectively joined with a ring-shaped metal collar and a metal bracket. The negative electrode container is coupled to the insulator through the metal collar, and the positive electrode container is coupled to the insulator through the metal bracket.

As a method of joining such a component, a brazing method in which a metalizing layer is formed on a surface of a ceramic and a solder is melted and joined is generally used. There is also a method of joining at the melting point by using an active metal member containing titanium between the ceramic and the metal part.

However, in the above-described prior art, it is difficult to select aluminum as the component material of the battery because the temperature of the insertion member for bonding is mostly 800 degrees or more. Furthermore, it is difficult to apply the brazing process because the temperature at the time of glass bonding (bonding of ceramic and ceramic) is around 900 degrees. In addition, Si and the like are contained in the metal component used as the insertion member, and when the temperature is above the complete melting point and solidified from the liquid to solid, Si forms crystals of continuous shape such as dendrite. As a result, corrosion resistance to Na present in the battery is sharply deteriorated and the life of the battery is shortened.

Thus, in the bonding of ceramic and metal, there is provided a sodium sulfur battery excellent in corrosion resistance to sodium and good bonding strength, and a method of manufacturing the same.

In addition, the present invention provides a sodium sulfur battery and a method of manufacturing the same, in which a separate terminal bonding process can be omitted, thereby simplifying the bonding process.

To this end, in the sodium sulfur battery manufacturing method comprising the step of bonding a metal material to an insulator that insulates the positive electrode and the negative electrode of the sodium sulfur battery,

Manufacturing an insert metal joined between the insulator and the metal material, inserting the insert metal between the insulator and the metal material, and joining the insulator and the metal material through the insert metal.

In the manufacturing step of the insertion metal may include the step of integrally forming a terminal extending outward on the outer peripheral surface of the insertion metal.

The insulator and the metal material may be bonded through a thermal compression bonding process.

The method may further include supporting a terminal by disposing a guide jig outside the terminal of the insertion metal when the insulator and the metal material are bonded to each other.

The method may further include arranging a center fixture inside the insertion metal to center the bonding position of the insertion metal when the insulator and the metal material are joined.

The metal material may be a metal collar bonded between the negative electrode container and the insulator, and / or a metal bracket installed in the positive electrode container and bonded to the insulator.

On the other hand, the present sodium sulfur battery includes a positive electrode container containing sulfur, a negative electrode container containing sodium, an electrolyte tube installed between the positive electrode container and the negative electrode container to selectively move only sodium ions, and the negative electrode container between the negative electrode container and the positive electrode container. And an insulator for insulating the positive electrode container, a metal collar installed in the negative electrode container and bonded to the insulator, and a metal bracket installed in the positive electrode container and bonded to the insulator, wherein the metal collar or / and the metal bracket is inserted into the insulator. Bonded via, the insertion metal may include a terminal formed on one side and extending to the outside.

The insertion metal may have a ring shape and may have a structure in which one side of the outer circumferential surface thereof extends vertically to form a terminal.

The terminal may be integrally formed with the insertion metal.

Thus, according to this embodiment, when joining a metal material to the insulator which is alpha alumina ceramic, the ceramic metal joint part with high corrosion resistance with respect to sodium can be obtained.

In addition, the bonding process of the ceramic and the metal material through the one bonding process, as well as the terminal can be bonded to the battery at the same time, it is possible to minimize the inconvenience of the separate bonding of the battery, the thermal deformation generated during the terminal bonding.

In addition, it is possible to increase productivity by simplifying the battery manufacturing process and shortening the required time.

In addition, the terminal can be installed without welding, thereby significantly reducing the electrical resistance generated at the welded portion, thereby increasing the charge and discharge efficiency of the battery.

1 is a cross-sectional view of a sodium sulfur battery according to an embodiment of the present invention.
Figure 2 is a schematic perspective view showing the insertion metal of the sodium sulfur battery according to this embodiment.
3 is a schematic view for explaining a sodium sulfur battery process according to the present embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It will be apparent to those skilled in the art that the embodiments described below may be modified in various forms without departing from the spirit and scope of the present invention, .

The drawings are schematic and illustrate that they are not drawn to scale. The relative dimensions and ratios of the parts in the figures are shown exaggerated or reduced in size for clarity and convenience in the figures, and any dimensions are merely illustrative and not restrictive.

1 shows a sodium sulfur battery according to this embodiment.

1, the sodium sulfur secondary battery 100 of the present embodiment includes an electrolyte tube 10 made of beta alumina ceramics, a negative electrode container 12 positioned inside the electrolyte tube 10 and filled with sodium, And a positive electrode container (14) located outside the tube (10).

The positive electrode container 14 is disposed outside the electrolyte pipe 10, and a felt collector 18 containing sulfur is filled between the positive electrode container 14 and the electrolyte pipe 10. The felt collector 18 is, for example, carbon felt having pores therein, and sulfur is contained in the pores. An insulator 20 is installed between the negative electrode container 12 and the positive electrode container 14 to insulate the negative electrode container 12 from the positive electrode container 14. The positive electrode container 14 has a cylindrical shape and is made of a metal material such as aluminum or stainless steel. In addition, a corrosion resistant layer containing chromium, molybdenum or the like as a main component may be coated on the surface of the positive electrode container 14.

The cathode container 12 may contain sodium, and an inert gas such as nitrogen gas or argon gas may be filled at a predetermined pressure in the inner upper space.

The negative electrode container may be made of a metal material such as aluminum, stainless steel, and the like as the positive electrode container 14. The surface of the negative electrode container 12 may be coated with a corrosion resistant layer composed mainly of chromium, molybdenum, or the like.

In the lower end of the cathode vessel 12, an opening 13 through which the sodium can escape so that sodium filled in the anode vessel 12 can contact the electrolyte tube 10 is formed. Sodium which has passed through the opening 13 is filled between the electrolyte tube 10 and the cathode vessel 12 and comes into contact with the inner wall of the electrolyte tube 10.

The electrolyte tube 10 is made of a beta alumina ceramic capable of passing sodium ions. The electrolyte tube 10 is installed in a tube shape and surrounds the cathode container 12 at a predetermined interval.

The present sodium sulfur secondary battery 100 uses sodium as a negative electrode and sulfur as a positive electrode. Accordingly, during discharging of the present sodium sulfur secondary battery 100, sodium ions pass through the electrolyte tube 10 to the positive electrode side, and react with sulfur and electrons to become sodium polysulfide. At the time of charging, sodium polysulfide releases electrons and separates into sodium ion and sulfur. The sodium ion passes through the electrolytic tube 10, moves to the cathode side, receives electrons, and returns to sodium. Charging and discharging of the sodium sulfur secondary battery 100 is performed at a temperature of about 300 ° C to 350 ° C.

In the sodium sulfur battery, an insulator 20 is installed between the negative electrode container 12 and the positive electrode container 14 to prevent a short between the negative electrode and the positive electrode, thereby forming the negative electrode container 12 and the positive electrode container 14. Insulate.

The insulator 20 is a ring-shaped structure made of alpha alumina ceramic, and is installed between the anode container 14 and the cathode container 12 to insulate the two members.

The negative electrode container and the positive electrode container are fixed to the insulator 20 through the metal collar 16 and the metal bracket 19, which are metal materials bonded to the insulator 20. The negative electrode container is coupled to the insulator 20 through the metal collar 16, and the positive electrode container is coupled to the insulator 20 through the metal bracket 19.

The metal collar 16 is formed in a ring shape of a metal material and disposed inside the insulator 20. The lower end of the metal collar 16 is bonded to the upper surface of the insulator 20, and the upper end is extended to join the negative electrode container 12. The metal bracket 19 is a structure for connecting the insulator 20 and the positive electrode container 14, and is formed in a ring shape made of a metal material and disposed outside the insulator 20. The lower end of the metal bracket 19 is bonded to the lower end of the insulator 20.

The metal collar 16 and the metal bracket 19 are made of an aluminum alloy, and are welded to the insulator 20 made of alpha alumina ceramic material through a thermocompression bonding process.

Here, the metal collar 16 and the metal bracket 19 may be bonded to the insulator 20 through the same process by the same metal material, the metal bracket 19 to the structure to be bonded to the insulator 20 as an example. Explain.

In the present embodiment, the metal bracket 19 is bonded between the insulator 20, which is a ceramic, and the insertion metal 30, which is a bonding material, between the metal bracket 19, which is a metal material.

The insertion metal 30 may be an Al-Si-Mg system, and is not particularly limited.

As shown in FIG. 2, the insertion metal 30 has a ring shape, and on one side thereof, the terminal 32 is formed to protrude vertically.

The terminal 32 may be understood as a structure for electrical connection between the battery and the battery. Since the insertion metal 30 is inserted between the metal bracket 19 and the insulator 20, which are metal materials bonded to the positive electrode container 14, the insertion metal 30 is electrically connected to the positive electrode container. Therefore, in this embodiment, the terminal 32 formed on the insertion metal 30 serves as a terminal of the positive electrode.

The terminal 32 is integrally formed with the insertion metal 30. The terminal 32 is vertically bent at the outer end of the insertion metal 30 and extends upwardly. The terminal 32 may have a curved surface having an arc shape, such as an outer circumferential surface of the insertion metal 30 having a ring shape, and may be formed in a planar shape.

Insertion metal 30 is a ring-shaped structure is not particularly limited with respect to the installation position of the terminal (32). For example, the terminal 32 may be integrally formed with one portion of the ring-shaped insertion metal 30 having a width of about 10 to 20 mm and a thickness of about 1 to 1.5 mm. The size of the terminal 32 may vary depending on the size or shape of the battery, and enough to protrude to the top of the battery at the insertion metal 30 junction position to serve as a terminal.

As such, by bonding the metal bracket 19 and the insulator 20 through the insertion metal 30 having the terminal 32 integrally formed, the insertion metal 30 serves as an insertion material for joining the metal bracket to the insulator. At the same time, the terminal 32 protrudes upward of the battery to serve as a positive electrode terminal. Therefore, the anode terminal of the battery does not need to be separately installed.

Here, the present embodiment has been described as an insertion metal 30 for bonding the metal bracket 19 as an example, but is not limited thereto and may be equally applicable to the insertion metal for bonding the metal collar forming the cathode. In this case, the insertion metal for metal color joining can also serve as a negative electrode terminal is formed integrally.

On the other hand, as described above with respect to the process for manufacturing a battery by bonding a metal bracket to the insulator as follows.

The manufacturing process of the present embodiment includes the steps of manufacturing an insertion metal to be bonded between the insulator and the metal material, inserting the insertion metal between the insulator and the metal material, joining the insulator and the metal material via the insertion metal, And forming a terminal integrally with the insertion metal during the manufacturing step of the insertion metal.

Here, the insulator and the metal material may be bonded through a thermal compression bonding process. That is, when the insertion metal 30 is placed on the bonding surface of the insulator 20, the metal bracket 19, which is a metal material, is placed on the insertion metal 30, and is subjected to thermal compression bonding (TCB) process. Join the metal bracket. The thermal compression bonding is bonded at an ambient temperature of 600 degrees and a vacuum degree of 10 ⁻⁴ torr or more using a pressing member 50 for pressing the upper and lower portions of the insulator 20 and the metal bracket 19.

In this process, as shown in FIG. 3, the terminal 32 integrally formed in the insertion metal 30 protrudes upward from the battery through the metal bracket 19 and the insulator 20. Since the internal ambient temperature is about 600 degrees during the thermal compression bonding process, the terminal 32 may be inclined.

In this regard, the manufacturing method further includes supporting the terminal. As shown in FIG. 3, in order to support the terminal, a guide jig 40 is disposed outside the terminal 32 of the insertion metal 30 when the insulator 20 and the metal bracket 19 made of metal are joined. do. The guide jig 40 is disposed outside the terminal 32 to maintain the terminal in a vertical state when the insulator and the metal are joined.

In addition, the manufacturing method further includes the step of centering the joining position of the insertion metal by placing a central jig 42 inside the insertion metal 30 when joining the insulator 20 and the metal bracket 19 of the metal material. do.

As shown in FIG. 3, the central jig 42 is disposed toward the center of the insertion metal 30 in the form of a ring. The center jig 42 can be used to more easily center the junction.

As described above, the present sodium sulfur battery bonds the insulator and the metal material by using the insertion metal 30 in which the terminal 32 is integrally formed, so that the insertion metal 30 bonds the insulator and the metal material and is formed on the insertion metal 30. The terminal 32 protrudes above the battery to serve as the terminal 32. Therefore, it is possible to reduce the effort of welding the terminal separately manufactured by the battery.

While the illustrative embodiments of the present invention have been shown and described, various modifications and alternative embodiments may be made by those skilled in the art. Such variations and other embodiments will be considered and included in the appended claims, all without departing from the true spirit and scope of the invention.

10: Electrolyte tube 12: Negative electrode container
13: opening 14: positive electrode container
16: metal color 19: metal bracket
20: insulator 30: insert metal
32: terminal

Claims (7)

A positive electrode container containing sulfur, a negative electrode container containing sodium, an electrolyte tube installed between the positive electrode container and the negative electrode container to selectively move only sodium ions, and an insulator that insulates the negative electrode container and the positive electrode container between the negative electrode container and the positive electrode container. A metal collar installed in the negative electrode container and bonded to the insulator, and including a metal bracket installed in the positive electrode container and bonded to the insulator,
The metal collar or / and the metal bracket is bonded to the insulator via an insertion metal, the insertion metal is a sodium sulfur battery comprising a terminal formed on one side and extending to the outside. The method of claim 1,
The terminal is a sodium sulfur battery formed integrally with the insertion metal. In the sodium sulfur battery manufacturing method comprising the step of bonding a metal material to the insulator which insulates the positive electrode and negative electrode of a sodium sulfur battery,
Manufacturing an insert metal joined between the insulator and the metal material, inserting the insert metal between the insulator and the metal material, and joining the insulator and the metal material through the insert metal.
Sodium sulfur battery manufacturing method comprising the step of integrally forming a terminal extending outward on the outer peripheral surface of the insertion metal in the manufacturing step metal. The method of claim 3, wherein
The method of manufacturing a sodium sulfur battery, wherein the insulator and the metal material are bonded through a thermal compression bonding process. The method according to claim 3 or 4,
Wherein said metal material is a metal collar bonded between the negative electrode container and the insulator and / or a metal bracket installed in the positive electrode container and bonded to the insulator. The method of claim 5, wherein
And arranging a guide jig outside the terminal of the insertion metal when the insulator and the metal are joined to support the terminal. The method according to claim 6,
And arranging a center fixture inside the insertion metal to center the bonding position of the insertion metal when the insulator and the metal material are bonded to each other.

Images