KR20140051496A - Case having safety vent, method of manufacturing thereof and energy storage device using the case - Google Patents

Abstract

The present invention relates to a case with a safety vent, a manufacturing method thereof, and an energy storage device using the same. The purpose of the present invention is to manufacture the safety vent for solving an explosion problem easily and simply, occurring inside a case by quickly discharging gas generated inside the case to the outside through the safety vent. The case according to the present invention comprises a case body and the safety vent. The case body is made from a metal material and has a cylindrical shape. The safety vent is formed on the outer circumferential surface of the case body by a press process, has a thinner thickness than the thickness of the periphery by the press process, and has a long groove at the center in the axial direction of the case body.

Description

[0001] The present invention relates to a case having a safety valve, a method of manufacturing the same, and an energy storage device using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy storage device and a manufacturing method thereof, and more particularly, to a case having a safety valve that discharges gas generated in a case to the outside, a manufacturing method thereof, and an energy storage device using the same.

In addition to various portable electronic devices, electric vehicles require an energy storage device for a power supply system or a system for controlling or supplying an instantaneous overload. Such an energy storage device is used for a Ni-MH battery, Secondary batteries such as Ni-Cd batteries, lead acid batteries and lithium secondary batteries, and super capacitors, aluminum electrolytic capacitors, and ceramic capacitors having high output densities and close to unlimited charge / discharge life.

In particular, the super capacitor includes an electric double layer capacitor (EDLC), a pseudo capacitor, and a hybrid capacitor such as a lithium ion capacitor.

Here, the electric double layer capacitor is a capacitor using an electrostatic charge phenomenon occurring in an electric double layer formed at the interface of different phases, and has a charge / discharge speed faster than that of a battery in which the energy storage mechanism depends on a chemical reaction, And it is widely used as a backup power source, and the potential as an auxiliary power source for electric vehicles in the future is also unlimited.

A pseudocapacitor is a capacitor that converts a chemical reaction into electrical energy using an electrode and an oxidation-reduction reaction of an electrochemical oxide. The pseudocapacitor has a storage capacity about 5 times larger than that of the electric double layer capacitor because the electric double layer capacitor can store the electric charge near the surface of the electrode material as compared with the electric double layer capacitor formed on the surface of the electrochemical double layer type electrode. As the metal oxide electrode material, RuOx, IrOx, MnOx and the like are used.

And the lithium ion capacitor is a new concept secondary battery system which combines the high output and long life characteristics of the existing electric double layer capacitors and the high energy density of the lithium ion battery. Electric double layer capacitors using the physical adsorption reaction of electric charges in the electric double layer have been limited in their application to various applications due to their low energy density despite excellent power characteristics and lifetime characteristics. As a means for solving the problem of such an electric double layer capacitor, a lithium ion capacitor using a carbon-based material capable of inserting and separating lithium ions as a negative electrode active material has been proposed. The lithium ion capacitor has a structure in which lithium ions, And the cell voltage can realize a high voltage of 3.8 V or more, which is much higher than that of the conventional electric double layer capacitor by 2.5 V, and can exhibit a high energy density.

The basic structure of such a supercapacitor is composed of an electrode, an electrolyte, a current collector, and a soft separator having a relatively large surface area such as a porous electrode. A voltage of several volts is applied to both ends of the unit cell electrode, And an electrochemical mechanism that is generated by adsorbing ions on the surface of the electrode by moving along the electric field. Such a cell is sealed in a metal or plastic case and has a structure in which a positive electrode and a negative electrode terminal are exposed to the outside.

Such an energy storage device may inevitably generate gas during operation. Particularly in the case of a super capacitor, it occurs slowly over a long period of time.

Such gas generation increases the internal pressure of the energy storage device. Therefore, methods are employed in which the case is made rigid in consideration of an increase in the internal pressure of the energy storage device, or a space is provided in the case so that the internal pressure does not rise above a predetermined value.

However, these methods increase the weight and volume of the case, deteriorate the performance of the energy storage device, and increase the price.

In particular, in an energy storage device using a liquid electrolyte such as a supercapacitor, the gas generated inside is present on the surfaces of the electrolytic solution and the active material, thereby reducing the available area and acting as an obstacle in the electrolyte, The reliability can be lowered.

Accordingly, it is an object of the present invention to provide a case having a safety valve capable of quickly discharging gas generated in a case, a method of manufacturing the same, and an energy storage device using the same.

It is another object of the present invention to provide a method of manufacturing a case having a safety valve that can easily and easily form a safety valve, a case made of the method, and an energy storage device using the case.

In order to achieve the above object, the present invention provides a method of manufacturing a battery case, comprising the steps of preparing a cylindrical case body made of a metal material, and pressing a part of the outer circumferential surface of the case body with a press in a state in which a support rod is inserted into the case body And a forming step of forming a safety side having a thickness thinner than the periphery of the case.

In the method of manufacturing a case according to the present invention, in the preparation step, the material of the case body may be one of aluminum, stainless steel or tin-plated steel.

In the method of manufacturing a case according to the present invention, in the forming step, the pressing surface of the press for pressing the outer circumferential surface of the case body is flat, and protrusions are formed on the pressing surface in parallel with the axial direction of the case body .

The method of manufacturing a case according to the present invention is characterized in that, in the forming step, the safety valve comprises: a jaw formed by stepping down vertically in an axial direction of the case body by pressing of the press; And a processing surface which is pressed by the surface and formed flat, and a groove pressed by the projection is formed at a central portion of the processing surface.

In the method of manufacturing a case according to the present invention, in the forming step, the thickness of the safety valve gradually increases toward the outer side with respect to the groove.

The present invention also provides a case for an energy storage device including a case body and a safety valve. The case body is made of a metal material and is cylindrical. Further, the safety valve is formed on the outer circumferential surface of the case body by press working, and is thinner in thickness than the periphery by the press working, and a groove is formed in a central portion in the axial direction of the case body.

In the case of the energy storage device according to the present invention, the safety side includes a jaw and a machined surface. The jaw is formed to be stepped down vertically in the axial direction of the case body by pressing of the press. The machined surface is connected to the jaw, pressed by the pressing surface of the press to be flat, and the groove is formed at the center portion.

The present invention also provides an energy storage device comprising a cell assembly and a case. The cell assembly stores electrical energy. The case is housed in the cell assembly and sealed, and a safety valve is formed to discharge gas generated in the cell assembly to the outside. The case includes a case body and a safety valve. The case body is made of a metal material and is cylindrical. Further, the safety valve is formed on the outer circumferential surface of the case body by press working, and is thinner in thickness than the periphery by the press working, and a groove is formed in a central portion in the axial direction of the case body.

According to the present invention, since the safety valve is formed on the outer circumferential surface of the case, the gas generated inside the case can be rapidly discharged to the outside through the safety valve to solve the explosion problem caused by the gas generated inside the case.

Also, since the safety valve according to the present invention can be formed by pressing part of the outer circumferential surface of the case with a press, it is possible to easily form the safety valve in the process of manufacturing the case. It is possible to reduce the manufacturing cost of the energy storage device including the case by pressing a part of the outer circumferential surface of the case with a press without adding any additional equipment to the case.

1 is a perspective view showing an energy storage device according to an embodiment of the present invention.
2 is a cross-sectional view of Fig.
3 is a perspective view showing the terminal plate of Fig. 1;
Fig. 4 is a bottom view showing the terminal plate of Fig. 3; Fig.
Fig. 5 is an exploded perspective view of the gas release device installed in the terminal plate of Fig. 4;
6 is a sectional view taken along the line 6-6 in Fig.
7 is a sectional view taken along the line 7-7 in Fig.
8 is an enlarged view of a portion A in Fig.
9 is a perspective view showing a case having a safety side in Fig.
10 is a sectional view taken along the line 9-9 in Fig.
11 to 13 are views showing steps of a method of manufacturing a case having a safety valve according to an embodiment of the present invention.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, and the description of other parts will be omitted so as not to obscure the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

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

1 is a perspective view showing an energy storage device according to an embodiment of the present invention. 2 is a cross-sectional view of Fig.

1 and 2, the energy storage device 100 according to the present embodiment includes a cell assembly 10, a case 20, and a gas release device 50, and may have a cylindrical structure. The cell assembly 10 stores electrical energy. The case 20 is provided with a gas discharge hole 25 and a safety valve 40 so that the cell assembly 10 is accommodated and sealed so that the gas generated in the cell assembly 10 can be discharged to the outside, And an attachment hole 27 is formed in the inner side in communication with the hole 25. [ The gas release device 50 is inserted into the mounting hole 27 of the case 20 and discharges the gas generated in the case 20 through the gas discharge hole 25 to the outside.

Although the energy storage device 100 according to the present embodiment has been described as an example of a cylindrical structure, it may be implemented in the form of a square column.

Here, the cell assembly 10 includes a winding core 12 and a cell 14 wound around the winding core 12. Here, the cell 14 includes a cathode, a cathode, a separator, and an electrolyte. The anode produces electrons by an oxidation reaction. The cathode absorbs the generated electrons and a reduction reaction occurs. The separator is interposed between the cathode and the anode to physically separate the cathode and the anode so as to separate the oxidation and reduction reactions from each other. Electrolyte is a transport medium of ions that store electrical energy in the anode and cathode. In this cell assembly 10, an anode, a cathode, and a separator are wound around a winding core 12 in turn to form a cylindrical shape as a whole.

The case 20 is for separating the cell assembly 20 from the outside and can be manufactured in various materials and shapes depending on the type of the cell assembly 10. [ The case 20 includes a case body 21, a pair of terminal plates 23 and 24, and a safety valve 40.

The case body 21 has a tubular shape in which openings 22a and 22b are formed on both sides thereof, and the cell assembly 10 is housed. The case body 21 may be made of a metal material such as aluminum, stainless steel or tin-plated steel or may be made of a material such as PE (polyethylene), PP (polypropylene), PPS (polyphenylene sulfide), PEEK (polyetheretherketone) ) Can be used. When the safety valve 40 is formed on the case body 21, the above-described metal material may be used as the material of the case body 21. [

The pair of terminal boards 23 and 24 covers the openings 22a and 22b on both sides of the case body 21 to seal the space in which the cell assembly 10 is housed and a gas release device 50 is installed. The pair of terminal boards 23 and 24 are connected to the upper terminal plate 23 covering the first opening 22a of the case body 21 and the lower terminal plate 23 covering the second opening 22b of the case body 21. [ 24). The pair of terminal plates 23 and 24 are respectively formed with electrode terminals 23a and 24a so as to protrude outward from the central portion. The pair of terminal plates 23 and 24 are respectively electrically connected to the positive electrode and the negative electrode of the cell assembly 10 through a pair of connecting plates 31 and 33, respectively. The first connecting plate 31 of the pair of connecting plates 31 and 33 is connected to the upper terminal plate 23 and the second connecting plate 33 is connected to the lower terminal plate 24. [

The pair of terminal plates 23 and 24 are formed with projections 23b and 24b on the opposite sides of the surface on which the electrode terminals 23a and 24a are formed. The protrusions 23b and 24b are formed in the central portions of the terminal plates 23 and 24 and are inserted into the core 12 when the energy storage device 100 is assembled so that the positions of the first and second connection plates 31 and 33 . The pair of terminal boards 23 and 24 include an upper terminal board 23 and a lower terminal board 24. [

The pair of terminal plates 23 and 24 are provided with a mounting hole 27 and a gas discharging hole 25 for discharging the gas generated from the cell assembly 10 to the outside of the case 20, respectively. The mounting holes 27 can be formed at positions spaced apart from the central portions of the terminal plates 23 and 24 because the electrode terminals 23a and 24a are formed at the central portions of the terminal plates 23 and 24. [ The gas release device 50 is inserted into the installation hole 27 and installed. The gas discharge hole 25 is formed to communicate with the mounting hole 27 and can be formed to have a diameter of 1 pi (phi). The gas discharge hole 25 is formed smaller than the mounting hole 27. The mounting hole 27 is located on the side facing the cell assembly 10 and the gas discharge hole 25 is located on the opposite side to discharge the gas that has passed through the gas release device 50 out of the case 20.

The safety valve 40 is broken when the internal pressure of the case 20 exceeds the critical pressure due to the gas generated in the case 20, thereby preventing the case 20 from exploding. The critical pressure may be varied between 12 and 15 kg / cm < ² >, although it may vary depending on the energy storage device 100. The safety valve 40 is formed on the outer circumferential surface of the case body 21. The safety valve 40 may be formed on the outer circumferential surface of the case body 21 close to the upper terminal plate 23.

When the internal pressure of the case 20 exceeds the external pressure due to the gas generated in the case 20, the gas releasing device 50 discharges the gas in the case 20 to the outside, 20 is prevented from rising. The gas releasing device 50 is installed in each of the pair of terminal plates 23 and 24 to discharge the gas generated in the cell assembly 10 out of the case 20. The gas release device 50 is installed in an installation hole 27 formed in the inner surface of the terminal plate 23, 24 facing the cell assembly 10.

In this embodiment, the gas release device 50 is provided on each of the pair of terminal plates 23 and 24. However, the gas release device 50 may be provided on only one of the pair of terminal plates 23 and 24. [ And may be installed on the upper terminal plate 23 when one gas releasing device 50 is installed.

In this embodiment, since the electrode terminals 23a and 24a are formed at the central portions of the pair of terminal plates 23 and 24, the gas release device 50 is disposed at a position apart from the central portion of the terminal plates 23 and 24, The gas release device may be provided at the central portion of the terminal plate if the electrode terminal is formed at a position spaced apart from the center portion.

3 to 6, the gas releasing device 50 is installed on the upper terminal plate 23, and the gas releasing device 50 is mounted on the upper terminal plate 23 The structure is mainly described as follows. 3 is a perspective view showing the upper terminal plate 23 of FIG. 4 is a bottom view showing the upper terminal plate 23 of Fig. 5 is an exploded perspective view of the gas release device 50 provided on the upper terminal plate 23 of Fig. And Fig. 6 is a sectional view taken along line 6-6 of Fig.

The gas release device 50 according to the present embodiment includes a porous plate 51, a gas-permeable membrane 53 and a support plate 57. The gas release device 50 has a structure in which the porous plate 51, the gas- The porous plate 51 is inserted into the mounting hole 27 and has a plurality of first holes 52 connected to the gas discharging hole 25. The gas permeable membrane 53 is formed on the porous plate 51 by being inserted into the attaching hole 27 and formed in the center portion and having a passing portion 54 through which the gas passes and an edge portion of the passing portion 54 Has a thicker sealing ring (56) than the thickness of the passage portion (54). The supporting plate 57 is inserted into the mounting hole 27 and is installed in close contact with the sealing ring 56 of the gas-passing film 53. The second hole 58 is formed at a position facing the gas- Respectively.

At this time, the mounting hole 27 into which the gas releasing device 50 is inserted may include first to third mounting holes 27a, 27b, 27c. The first mounting hole 27a is provided in communication with the gas discharging hole 25 and has a larger inner diameter than the gas discharging hole 25. [ The second installation hole 27b communicates with the first installation hole 27a and has an inner diameter larger than that of the first installation hole 27a and the porous plate 51 and the gas passage film 53 are inserted and installed. The third mounting hole 27c communicates with the second mounting hole 27b and has an inner diameter larger than that of the second mounting hole 27b and the supporting plate 57 is inserted to seal the sealing ring 56 So that the inside of the sealing ring 56 is sealed against the outside of the sealing ring 56.

The porous plate 51 is formed in a region where a plurality of first holes 52 face the passing portion 54 inside the sealing ring 56. The plurality of first holes 52 are larger than the gas discharge holes 27 and the second holes 58 are larger than the gas discharge holes 27 so that the gas can be stably discharged to the outside through the gas discharge hole 25. [ . The plurality of first holes 52 may be uniformly formed. As the material of the porous plate 51, aluminum may be used.

The porous plate 51 is mounted on the bottom surface of the edge portion of the second mounting hole 27b formed between the first mounting hole 27a and the second mounting hole 27b. The first space 28 corresponding to the size of the first installation hole 27a is formed between the porous plate 51 and the gas discharge hole 25. Therefore, The gas that has passed through the gas discharge port 52 is stably discharged into the gas discharge hole 25.

That is, since the first space 28 is provided, the gas can stably pass through the porous plate 51 and be discharged to the outside through one gas vent 25. For example, when there is no first space 28, a plurality of gas discharge holes must be formed on the terminal plate so as to correspond to the plurality of first holes 52 of the porous plate 51, so that the manufacturing process may be complicated.

The sealing ring 56 of the gas-passing film 53 protrudes from the edge of one surface of the passage portion 54. One surface of the passage portion 54 is a surface facing the support plate 57. As a result, one surface of the passing portion 54 is spaced apart from the supporting plate 57, and the other surface facing the one surface of the passing portion 54 comes into contact with the porous plate 51. The porous plate 51 and the support plate 57 come into close contact with the sealing ring 56 at the outer periphery of the gas passage film 53 so that the gas passes through the passage portion 54 while preventing the gas from being drawn out of the sealing ring 56, To the gas discharge hole (25).

A part of the sealing ring 56 of the gas passage film 53 protrudes out of the second mounting hole 27b so that the third mounting hole 27c ). As a result, the sealing ring 56 can be compressed by the support plate 57 inserted into the third installation hole 27c to maintain airtightness.

Since the second space 29 is formed between the support plate 57 and the passing portion 54 of the gas passage film 53, the gas injected through the second hole 58 of the support plate 57 Is diffused through the second space (29) and is moved to the plurality of first holes (52) of the upper porous plate (51) through the entire passage portion (54)

Here, the material of the gas passing layer 53 may be one of butyl rubber, polyethylene (PE), and polypropylene (PP).

The support plate 57 is inserted into the mounting hole 27 of the case 20, and the edge portion thereof is joined to the case 20 and fixed. The support plate 57 is mounted on the bottom surface of the edge portion of the third installation hole 27c formed between the second installation hole 27b and the third installation hole 27c. The supporting plate 57 presses the sealing ring 56 of the gas-passing film 53 protruded above the bottom surface of the third mounting hole 27c. The support plate 57 is fixedly joined to the inner side surface of the third installation hole 27c and soldering, spot welding, laser welding or plasma welding is used as the bonding method . Reference numeral 59 denotes a portion where the support plate 57 is joined. As the material of the support plate 57, aluminum may be used.

Thus, the gas releasing device 50 has a structure in which the porous plate 51 and the support plate 57 are provided on both sides of the gas-permeable membrane 53. The range in which the gas permeable membrane 53 can expand by the gas is confined between the porous plate 51 and the support plate 57. This suppresses the problem that the gas permeable membrane 53 is expanded and damaged more than necessary can do.

The pair of terminal boards 23 and 24 according to the present embodiment includes the upper terminal board 23 and the lower terminal board 24 as described above, as shown in Figs.

The upper terminal plate 23 covers and seals the first opening 22a of the case body 21. The electrode terminal 23a is electrically connected to the anode of the cell assembly 10 via the first connection plate 31 .

The lower terminal plate 24 covers and seals the second opening 22b of the case body 21. The electrode terminal 24a is electrically connected to the cathode of the cell assembly 10 via the second connection plate 33 Lt; / RTI > At this time, the outer edge of the lower terminal plate 24 and the outer edge of the second connecting plate 33 may be joined to the case body 21 by welding.

 Here, the upper terminal plate 23 according to the present embodiment will be described with reference to FIGS. 2, 7, and 8. FIG. 7 is a sectional view taken along line 7-7 of Fig. 8 is an enlarged view of a portion A in Fig.

The upper terminal plate 23 according to the present embodiment includes a first terminal plate 91, a second terminal plate 93, a first sealing member 95, and a second sealing member 97. The first terminal plate 91 is formed with an electrode terminal 23a protruding from one surface thereof. The second terminal plate 93 is located on one side of the first terminal plate 91 and has a ring shape whose outer edge covers an edge portion of the first terminal plate 91. The first sealing member 95 is interposed between the first and second terminal plates 91 and 93 to bond the first and second terminal plates 91 and 93 to each other. The second sealing member 97 is engaged with the edge surface of the first terminal plate 91 below the second terminal plate 93. At this time, the upper terminal plate 23 may further include a spacer 99 interposed between the first and second terminal plates 91 and 93 inside the second sealing member 97.

The first terminal plate 91 is formed with an electrode terminal 23a protruding from a central portion of one surface of the first terminal plate 91. The protrusion 23b coupled to the core 12 of the cell assembly 10 at the center portion of the opposite surface, Is formed. The first terminal plate 91 is provided with an installation groove 91a in which a ring-shaped second terminal plate 93 can be inserted and positioned at one edge of the first terminal plate 91. The first connection plate 31 may be welded to the other surface of the first terminal plate 91. The first connection plate 31 is bonded to the first terminal plate 91 so as to be spaced apart from the inner surface of the case body 21. [ The first connection plate 31 is formed with a hole through which the projection 23b of the first terminal plate 91 can pass.

The second terminal plate 93 is inserted into the mounting groove 91a provided in the first terminal plate 91 via the first sealing member 95 and includes a mounting portion 93a and an insertion portion 93b. The mounting portion 93a is mounted on the upper end of the case body 21 and can be joined to the case body 21 by welding. The insertion portion 93b is connected to the mounting portion 93a and is inserted into the case body 21 and is welded to the inner side surface of the case body 21. The outer surface of the insertion portion 93b is connected to the second sealing member 97 And can be located on the same plane as the outer surface.

The reason why the upper terminal plate 23 is manufactured so that the outer surface of the insertion portion 93b and the outer surface of the second sealing member 97 are located on the same plane is to maintain stable airtightness. The outer surface of the insertion portion 93b and the outer surface of the second sealing member 97 are not on the same plane and deviation occurs when the first opening 22a of the case body 21 is sealed with the upper terminal plate 23, , One of the insertion portion 93b and the second sealing member 97 can not be stably fused on the inner side surface of the case body 21. [

A portion below the mounting portion 93a of the second terminal plate 93 is inserted while the upper terminal plate 23 is inserted into the first opening 22a of the case body 21, (21).

As the material of the first sealing member 95, the second sealing member 97 and the spacer 99, an insulating material capable of electrically separating the first and second terminal plates 91 and 93 can be used. For example, PE may be used as the material of the first and second sealing members 95 and 97. As the material of the spacer 99, PPS may be used.

The first sealing member 95 mediates physical coupling between the first and second terminal plates 91 and 93 and electrically separates the first and second terminal plates 91 and 93 from each other.

The spacer 99 electrically separates the first and second terminal plates 91 and 93 from each other with the first sealing member 95. The spacer 99 may have a ring shape. An insertion groove 99a into which the spacer 99 can be inserted is provided at the opposite parts of the edge portions of the first and second terminal plates 91 and 93.

The second sealing member 97 mediates bonding between the case body 21 and the upper terminal plate 23. [ The second sealing member 97 can bond the case body 21 and the upper terminal plate 23 to each other by heating. As the heating method of the second sealing member 97, a high frequency induction heating method can be used. At this time, the second sealing member 97 is heated by inserting the upper terminal plate 23 into the first opening 22a of the case body 21 and mounting the second terminal plate 93 on the upper end of the case body 21 Lt; / RTI >

Thus, the first and second terminal plates 91 and 93 are electrically separated from each other by the first sealing member 95, the second sealing member 97, and the spacer 99. The first terminal plate 91 may be electrically connected to the anode of the cell assembly 10 through the first connection plate 31. The second terminal plate 93 may be connected to the case body 21 and electrically connected to the cathode of the cell assembly 10.

The upper terminal plate 23 according to the present embodiment has a structure in which the first and second terminal plates 91 and 93 are joined to each other through the first sealing member 95 and the first and second terminal plates 91 and 93 Since the second sealing member 97 has a double sealing structure that is joined to the case body 21 through the second sealing member 97 interposed between the first and second terminal plates 91 and 93 and between the first and second terminal plates 23 and 23 And the leakage of the liquid electrolyte through the interface between the case body 21 and the case body 21 can be suppressed.

That is, in the case of the conventional energy storage device, leakage may occur through the interface between the case body and the terminal plate, or the electrolyte contained in the case body may leak through the terminal plate itself. However, in the present embodiment, since the second terminal plate 93 is joined to the case body 21 by welding in addition to the second sealing member 97 between the case body 21 and the upper terminal plate 23, Generation can be suppressed. A first sealing member 95 is interposed between the first and second terminal plates 91 and 93 and a second sealing member 97 is provided on the outer periphery of the first and second terminal plates 91 and 93 It is possible to suppress leakage of the electrolytic solution through the space between the first and second terminal plates 91 and 93. [

On the other hand, in this embodiment, the spacer 99 and the second sealing member 97 are separately formed. However, the spacer 99 and the second sealing member 97 may be integrally formed.

The upper terminal plate 23 according to this embodiment can be manufactured as follows. The first terminal plate 93 is inserted into the mounting groove 91a of the first terminal plate 91 and the first sealing member 95 in the liquid phase is inserted into the first and second terminal plates 91 , 93).

Next, the liquid first sealing member 95 is cured to fix the first and second terminal plates 91 and 93 via the first sealing member 95.

The upper terminal plate 23 according to the present embodiment can be obtained by inserting the spacer 99 into the insertion groove 99a and then inserting the second sealing member 95 so as to cover the periphery of the spacer 99. [

A method of sealing the first opening 22a of the case body 21 with the upper terminal board 23 according to the present embodiment will now be described.

The mounting portion 93a of the upper terminal plate 23 is first connected to the case body 22a through the first opening 22a with the upper terminal plate 23 positioned on the first opening 22a of the case body 21, 21).

Next, the second terminal plate 93 is bonded to the inner surface and the upper end of the case body 21 by spot welding.

Then, the second sealing member 97 is bonded to the inner surface of the case body 21 through high frequency induction heating of the second sealing member 97.

At this time, in this embodiment, the example of performing the high frequency induction heating process after the spot welding has been disclosed, but it may be performed in the opposite manner.

The safety valve according to the present embodiment will be described with reference to FIGS. 9 and 10. FIG. Here, FIG. 9 is a perspective view showing a case having a safety side in FIG. 10 is a sectional view taken along the line 8-8 in Fig.

The safety valve 40 can be formed on the outer circumferential surface of the case body 21 by press working. The relief side 40 is formed to be thinner in thickness than the periphery by press working and a groove 45 is formed in a central portion of the safety side 40 in the axial direction of the case body 21. [

The safety valve 40 includes a jaw 41 and a machined surface 43 on which a groove 45 is formed. The jaw 41 is formed to be stepped down vertically in the axial direction of the case body 21 by pressurization of the press. The machined surface 43 is connected to the jaw 41 and pressed by the pressing surface of the press to be flat, and a groove 45 is formed at the center.

Assuming that the case body 21 in which the safety valve 40 is formed has a certain thickness, the thickness of the case body 21 increases toward the outer side with respect to the groove 45.

Therefore, in the energy storage device 100 having the case 20 in which the safety valve 40 according to the present embodiment is formed, gas is generated inside the case 20 and the inside of the case 20 When the pressure exceeds the critical pressure, the inner pressure of the tubular case 20 can be rapidly adjusted from the groove 45 having the thinnest thickness at the safety valve 40. [

The case body 21 having such a safety valve 40 can be manufactured by the manufacturing method shown in Figs. 11 to 13 are views showing respective steps according to a method of manufacturing the case 20 having the safety valve 40 according to the embodiment of the present invention.

First, as shown in Fig. 11, a cylindrical case body 21 having a constant thickness is prepared.

Next, as shown in Fig. 12, the support rod 70 is inserted through the first opening 22a of the case body 21. Then, as shown in Fig. Subsequently, the press 80 is placed on the case body 21.

The press 80 has a structure in which the pressing surface 81 facing the outer circumferential surface of the case body 21 is flat and the protrusion 83 is formed on the pressing surface 81 in parallel with the axial direction of the case body 21 .

Then, as shown in FIG. 13, a portion of the outer circumferential surface of the case body 21 is pressed by the press 80 to form the safety valve 40. That is, when the case body 21 is pressed by the press 80 in a state in which the case body 21 is supported by the support rod 70, the pressing surface 81 and the projection 83 formed on the press 80 are pressed against the outer peripheral surface of the case body 21 And the safety valve 40 is formed by engraving. The jaw 41 and the machining surface 43 are formed by the pressing surface 81 of the press 80 and the groove 45 is formed by the projection 83. [

On the other hand, in this embodiment, the example in which the safety valve 40 is formed by press working is described, but the present invention is not limited thereto. The safety valve 40 may be formed through physical cutting. In the case of cutting, the safety valve 40 can be formed by performing the process of forming the jaw 41 and the machining surface 43 of the safety valve 40 and the process of forming the groove 45.

Since the safety valve 40 is formed on the outer peripheral surface of the case body 21 as described above, the gas generated inside the case 20 is rapidly discharged to the outside through the safety valve 40, The problem of explosion of the case 20 can be solved.

The safety valve 40 according to the present embodiment can be formed by pressing part of the outer circumferential surface of the case body 21 with the press 80 so that the safety valve 40 can be easily formed in the process of manufacturing the case body 21. [ . It is possible to form the safety valve 40 by pressing a part of the outer circumferential surface of the case body 21 with the press 80 without adding any additional mechanism to the case 20. Therefore, the energy storage device 100 including the case 20, It is possible to simplify the manufacturing process and reduce the manufacturing cost.

A process of discharging the gas generated in the case 20 through the gas release device 50 and the safety valve 40 in the energy storage device 100 according to the present embodiment will now be described.

When gas is generated in the cell assembly 10 built in the case 20, the pressure inside the case 20 is increased. When the internal pressure of the case 20 exceeds the external pressure, the gas is discharged to the outside through the gas releasing device 50 provided on the terminal plates 23 and 24. [

The gas first flows through the second hole 58 of the support plate 57 and the introduced gas is dispersed through the second space 29 formed by the support plate 57 and the gas passage film 53. The dispersed gas passes through the gas passing film 53 and the porous plate 51.

The gas having passed through the porous plate 51 is discharged to the outside through the gas discharge hole 25 connected to the first space 28 formed by the porous plate 51 and the first mounting hole 27a.

On the other hand, when the amount of gas generated in the case 20 is larger than the amount of gas discharged through the gas releasing device 50, the internal pressure of the case 20 is increased. When the internal pressure exceeds the critical pressure, the safety valve 40 provided in the case main body 21 bursts, and the internal pressure of the case 20 is quickly lowered.

As described above, the gas discharge hole 25 is formed in the case 20 of the energy storage device 100 according to the present embodiment, and the gas passage film 53 is provided in the gas discharge hole 25, The gas generated inside the case 20 can be quickly discharged to the outside.

Since the gas release device 50 according to the present embodiment has a structure in which the porous plate 51 and the support plate 57 are provided on both sides of the gas passage film 53, Can be stably discharged to the outside.

Since the gas permeable membrane 53 is supported by the porous plate 51 and the support plate 57 and is limited in its expandable range, The problem of damaging the film 53 can be suppressed.

Since the gas-passing film 53 according to the present embodiment has a structure in which the sealing ring 56 serving as an O-ring is integrally formed on the outer periphery of the passing portion 54 through which the gas passes, There is an advantage that the release device 50 can be easily assembled to the case 20. [

The passage portion 54 of the gas passage film 53 is provided in a state of being closely attached to the porous plate 51 and the sealing ring 56 is provided between the passage portion 54 and the support plate 57, The gas that has passed through the second hole 58 of the support plate 57 passes through the second space 29 formed by the passing portion 54 and the support plate 57, The pressure is concentrated in accordance with the gas discharged to a specific portion of the gas passing film 53 and the gas permeable film 53 is prevented from being damaged, To the outside.

It should be noted that the embodiments disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: Cell assembly 12: Core
14: cell 20: case
21: Case main body 22a, 22b:
23: upper terminal plate 23a, 24a: electrode terminal
23b, 24b: projection 24: lower terminal plate
25: gas discharge hole 27: mounting hole
27a: first mounting hole 27b: second mounting hole
27c: third mounting hole 28: first space
29: second space 31: first connection plate
33: second connecting plate 40:
41: chin 43: machined surface
45: groove 50: gas release device
51: Porous plate 52: First hole
53: gas-passing film 54:
56: sealing ring 57: support plate
58: second hole 70: support rod
80: Press 81: Pressure face
83: projection 91: first terminal plate
93: second terminal plate 95: first sealing member
97: second sealing member 99: spacer
100: Energy storage device

Claims (10)

Preparing a cylindrical case body made of a metal material;
A forming step of pressing a part of an outer peripheral surface of the case body with a press in a state where a support rod is inserted into the case body to form a safety valve having a thinner thickness than the periphery;
Wherein the energy storage device has a safety side. 2. The method according to claim 1,
Wherein a material of the case body is one of aluminum, stainless steel, and tin-plated steel. 3. The method according to claim 2, wherein, in the forming step,
Wherein the pressing surface of the press for pressing the outer circumferential surface of the case body is flat and the protrusion is formed on the pressing surface in parallel with the axial direction of the case body. 4. The method according to claim 3, wherein, in the forming step,
Wherein the safety side includes a jaw which is formed so as to be stepped down vertically in an axial direction of the case body by pressing of the press and a machined surface which is pressed and flattened by a pressing surface of the press connected to the jaw, Wherein a groove is formed in the central portion of the surface by the projection. 5. The method according to claim 4, wherein, in the forming step,
Wherein the thickness of the safety valve is increased toward the outer side with respect to the groove. A cylindrical case body made of a metal material;
A safety valve formed on the outer circumferential surface of the case body by press working and formed thinner than the periphery by the press working and having a groove formed in the center portion thereof in the axial direction of the case body;
Wherein the energy storage device has a safety side. The method according to claim 6,
Wherein the case body is made of aluminum, stainless steel or tin-plated steel. 8. The method of claim 7,
A jaw formed to be stepped down vertically in the axial direction of the case body by pressing of the press;
A machined surface connected to the jaw and pressurized by the pressing surface of the press so as to be flat and having the groove formed at a central portion thereof;
Wherein the energy storage device has a safety side. 9. The method of claim 8,
And the thickness increases toward the outer side with respect to the groove. A cell assembly for storing electrical energy;
And a case having a safety valve for discharging the gas generated in the cell assembly to the outside,
In this case,
A cylindrical case body made of a metal material;
A safety valve formed on the outer circumferential surface of the case body by press working and formed thinner than the periphery by the press working and having a groove formed in a central portion thereof in the axial direction of the case body;
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