KR20190058840A - Electrochemical energy storage device of axial type - Google Patents

Abstract

The present invention relates to an axial type electrochemical energy storage device to reduce a contact resistance by increasing a contact area between an electrode and a terminal. According to the present invention, the axial type electrochemical energy storage device comprises: a battery element including a first electrode, a separator, a second electrode, and an electrolyte and including a first electrode bonding unit extended from the first electrode to be formed in a lower part and a second electrode bonding unit extended from the second electrode to be formed in an upper part; a lower terminal plate bonded to the first electrode bonding unit in a lower part of the battery element to be electrically connected; and an upper terminal plate bonded to the second electrode bonding unit in an upper part of the battery element facing the lower terminal plate to be electrically connected.

Description

[0001] The present invention relates to an electrochemical energy storage device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochemical energy storage device, and more particularly, to an axial-type electrochemical energy storage device for reducing a contact resistance by increasing a contact area between an electrode and a terminal.

In the information age, high-value-added industries that collect and utilize diverse and useful information in real time through various information and communication devices are leading. In order to secure the reliability of such systems, it is recognized that supply of stable energy is an important factor.

As part of securing stable energy, an electrochemical energy storage device, which can convert electrical energy into chemical energy and store it, and convert it into electric energy when necessary, is used.

Electrochemical energy storage devices include electrolytic capacitors, super capacitors, electric double layer capacitors (EDLC), and lithium ion capacitors (LIC) And a can type. The can shape includes a cylindrical shape (wound type), a square shape, and the like. At this time, the cylindrical shape is formed by winding the electric storage element in the form of a jelly roll, and then winding it in a cylindrical case. The cylindrical shape is also referred to as an axial type.

Electrochemical energy storage devices of an axial type For example, electric double layer capacitors (EDLC) and lithium ion capacitors include a cylindrical case mainly made of aluminum (Al) and a capacitor built in a cylindrical case. Such an axial type electric double layer capacitor (EDLC) is mainly applied for the purpose of driving a motor of a wind power, a solar, an electric car or a hybrid car. At this time, the capacitor element is formed by winding a band-shaped electrode laminate body, specifically a band-shaped electrode laminate body made of an anode and a cathode electrode element, and a separator interposed between the anode and cathode electrode elements, And is formed by taping the outer periphery so that the winding shape is not loosened. The capacitor element thus wound is impregnated with the electrolytic solution, and then embedded in the cylindrical case. A terminal plate for electrically connecting the capacitor element to the outside is disposed on the upper part of the winded capacitor element.

In addition, a neck portion is formed at an upper portion of the case to prevent the terminal plate from being pushed down, and the wound electric element is embedded after the neck is formed in the case. The charge element and the external terminal are electrically connected by a terminal. Then, the terminal board is fixed to the case through a curling process in which the upper end of the case is bent.

In the conventional axial type electrochemical energy storage device, there is a problem that the performance is deteriorated due to a high contact resistance between the winded capacitor and the terminal plate.

In addition, the case is joined to the lower terminal plate to serve as a terminal, and performance is deteriorated due to high contact resistance between the lower terminal plate and the case.

Further, a gas releasing part (gas discharging part) is provided on the upper terminal plate. Since the gas releasing part has a membrane structure of a membrane structure, it is complicated in structure and is difficult to manufacture.

Korean Patent No. 10-1416808 (2014.07.09.)

Accordingly, it is an object of the present invention to provide an axial-type electrochemical energy storage device for increasing a contact area between an electrode and a terminal to reduce a contact resistance.

The electrochemical energy storage device of the present invention includes a first electrode, a separator, a second electrode, and an electrolytic solution. The electrochemical energy storage device includes a first electrode junction extending from the first electrode to a lower portion, A lower terminal plate electrically connected to the first electrode connection portion at a lower portion of the electric storage element, and a second electrode connection portion extended from the second electrode connection portion at an upper portion of the electric storage device facing the lower terminal plate, And an upper terminal plate which is joined to the electrode connection portion and electrically connected thereto.

In the axial-type electrochemical energy storage device according to the present invention, the first electrode and the second electrode are formed of a metal foil, and are respectively wound and attached to the separator.

The first and second electrode junctions may be formed by pressing a metal foil extending from the first electrode and the second electrode. In the electrochemical energy storage device of the axial-type electrochemical energy storage device according to the present invention,

In the electrochemical energy storage device of an axial type according to the present invention, the electric storage element may include a bottom inner plate interposed between and bonded to the first electrode joint portion and the lower terminal plate, and a bottom inner plate between the second electrode joint portion and the upper terminal plate And a top inner plate which is interposed between and bonded to the top inner plate.

In the axial type electrochemical energy storage device according to the present invention, the lower terminal plate and the upper terminal plate are joined to the bottom inner plate and the top inner plate by laser welding or ultrasonic welding.

The electrochemical energy storage device of the axial type according to the present invention may further include a case in which an opening is formed on one side and the capacitor element is inserted through the opening so that the lower terminal plate faces the bottom surface.

In the axial-type electrochemical energy storage device according to the present embodiment, the metal foil extending from the first electrode and the second electrode is pressed to form the first and second electrode joint portions, so that the storage device and the upper or lower terminal So that the contact resistance can be reduced.

FIG. 1 is a view showing an apparatus for storing an electrochemical type of electrochemical energy according to an embodiment of the present invention.
2 is an enlarged view of a portion A in Fig.
3 is an enlarged view of a portion B in Fig.
4 is a view illustrating a gas discharge unit of an axial type electrochemical energy storage device according to an embodiment of the present invention.

In the following description, only parts necessary for understanding embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not disturb 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 an enlarged view of a portion A of FIG. 1, FIG. 3 is an enlarged view of a portion B of FIG. 1, and FIG. 4 is a view illustrating a gas discharge unit of an axial type electrochemical energy storage device according to an embodiment of the present invention.

1 to 4, an axial type electrochemical energy storage device 100 according to an embodiment of the present invention includes a capacitor element 10, a lower terminal plate 20, a case 30, an upper terminal plate 40 And a gasket 60 made of a rubber material. The capacitor element 10 stores electrochemical energy. The lower terminal plate 20 is electrically connected to the lower portion of the capacitor element 10 by being joined thereto. The case 30 has an opening 31 on one side and the capacitor element 10 is inserted through the opening 31 so that the lower terminal plate 20 faces the bottom. The upper terminal plate 40 is inserted into the opening 31 of the case 30 and electrically connected to the battery element 10 and is fixed by beading and curling to the upper end of the case 30 . The gasket 60 is interposed between the upper terminal plate 40 and the case 30.

In the axial type electrochemical energy storage device 100 according to the present embodiment, the upper terminal plate 40 is used as an anode terminal, and the case 30 connected to the lower terminal plate 20 can be used as a cathode terminal.

Although the electrochemical energy storage device 100 according to the embodiment of the present invention has been described in the form of a cylindrical structure, the electrochemical energy storage device 100 may be realized in the form of a quadrangular pole.

Here, the capacitor element 10 includes a winding core 11 and an electrode stack body 13 wound around the winding core 11. A bottom inner plate 15 and a top inner plate 17 are bonded to the lower and upper portions of the electrode stack body 13, respectively.

The electrode stack body 13 includes a first electrode, a second electrode, a separator, and an electrolytic solution. Here, the first electrode may be a positive electrode, and the second electrode may be a negative electrode. 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. Wherein the first electrode and the second electrode are formed of a metal foil. In this electrode stack body 13, the positive electrode, the negative electrode, and the separator are sequentially wound around the core 11 to form a cylindrical shape as a whole. For example, the electrode stack body 13 may have a cell structure forming a supercapacitor, an electric double layer capacitor (EDLC), and a lithium ion capacitor (LIC).

The electrode stack body 13 includes a first electrode bonding portion 18 and a second electrode bonding portion 19.

The first electrode junction 18 extends from the first electrode to the bottom. That is, the first electrode is formed of a metal foil, and is disposed so as to protrude downward from the separation membrane. And the first electrode bonding portion 18 may be formed by pressing the protruding first electrode.

The first electrode joint portion 18 is formed by pressing the first electrode protruded downward from the separator and is brought into contact with the bottom inner plate 15 so that the first electrode and the bottom inner plate 18 are connected to each other through the first electrode joint portion 18. [ It is possible to widen the contact area with the electrode 15 and reduce the contact resistance.

The second electrode junction 19 extends upward from the second electrode. That is, the second electrode is formed of a metal foil, and is arranged to protrude upward from the separation membrane. The second electrode bonding portion 19 may be formed by pressing the protruded second electrode.

A second electrode protruding upward from the separation membrane is pressed to form a second electrode bonding portion 19 and is brought into contact with the top inner plate 17 so that the second electrode and the top inner plate 17 are bonded to each other through the second electrode bonding portion 19, It is possible to widen the contact area with the contact surface 17 and reduce the contact resistance.

The case 30 is for separating the battery element 10 from the outside and can be manufactured in various materials and shapes depending on the type of the battery element 10. [ The case 30 has a tubular shape in which an opening 31 is formed on one side and the other side is closed. The case 30 is provided with an internal space 33 into which the power storage device 10 can be inserted through the opening 31. [ As the material of the case 30, a metal material such as aluminum, stainless steel, or tin-plated steel may be used.

In case 30, " B " represents the beading portion and " C " represents the curling portion. The beading portion is recessed inwardly from the outer surface of the case (30). The curled portion is formed by bending the upper end of the case 30 in a C shape and coming into close contact with the gasket 60 and the insulating plate 49. As a result, the case 30 and the upper terminal plate 40 are electrically separated from each other.

The lower terminal plate 20 is bonded to the lower portion of the electric storage element 10 and bonded thereto via the bottom inner plate 15. [ Here, the lower terminal plate 20 may serve to support the bottom inner plate 15 and may be joined to the bottom inner plate 15 by laser welding or ultrasonic welding.

The lower terminal plate 20 can be joined to the case 30 by external ultrasonic welding. Accordingly, the contact resistance between the case 30 and the lower terminal plate 20 can be minimized.

The upper terminal plate 40 is bonded to the upper portion of the electric storage element 10, and is joined via the upper inner plate 17. [ As a method of joining the upper terminal plate 40 and the upper inner plate 17, laser welding or ultrasonic welding may be used.

At this time, the lower terminal board 20 and the upper terminal board 40 may be made of the same metal material as the case 30. [

The bottom inner plate 15 and the top inner plate 17 are electrically connected to the lower surface and the upper surface of the electrode stack body 13, respectively. Since the lower terminal plate 20 and the upper terminal plate 40 are electrically connected to the electrode stack body 13 through the bottom inner plate 15 and the top inner plate 17, The output characteristics of the electrochemical energy storage device 100 can be improved.

The upper terminal plate 40 includes a terminal plate body 41 having a terminal 47, an insulating plate 49, and a gas discharging portion 51. The terminal plate body 41 has a terminal 47 formed thereon and an electrolyte injection hole 43 formed at the center thereof. The insulating plate 49 is attached to the upper surface of the terminal plate body 41 outside the electrolyte injection hole 43 and the edge of the gasket 60 and the upper end of the curled case 30 are closely fixed to the edge portion. The gas discharge unit 51 is coupled to the electrolyte injection hole 43 and discharges the gas generated in the case 30 through the electrolyte injection hole 43 to the outside.

Here, the terminal 47 is formed so as to protrude from the central portion of the upper surface of the terminal plate body 41. An electrolyte injection hole 43 is formed on the inner side of the terminal 47 and an insulating plate 49 is located on the outer side of the terminal 47 lower than the terminal 47. At this time, the electrolyte injection hole 43 may be formed through the upper and lower surfaces of the terminal plate body 41, and a female screw acid may be formed on the inner surface.

The insulating plate 49 prevents electric short-circuiting between the case 30 and the upper terminal plate 40. The insulating plate 49 allows the upper end of the case 30 to be curled to be stably stuck on the upper terminal board 40 stably together with the gasket 60. As the material of the insulating plate 49, a plastic material such as PE (polyethylene), PP (polypropylene), PPS (polyphenylene sulfide), PEEK (polyetheretherketone) or PTFE (polytetrafluoroethylene) may be used.

The gas discharging portion 51 includes a sealing portion 53 inserted into the lower portion of the electrolyte injection hole 43 and a sealing portion 55 joined to the electrolyte injection hole 43 in the upper portion of the sealing portion 53 . The electrolyte injection hole 43 has an insertion hole 44 connected to the lower surface of the terminal plate body 41 and a fastening hole 45 having an inner diameter wider than the insertion hole 44 and fastened to the sealing portion 55 . Here, the fastening hole 45 may be formed with a female screw. A hole is formed in the sealing portion 55 so as to penetrate the center portion. Here, the sealing portion 53 may be formed of an elastic material including rubber. For example, butyl rubber can be used as the sealing portion 53. [

The sealing portion 55 seals the electrolyte injection hole 43 by pressing the sealing portion 53. When gas is generated in the inner space 33 of the case 30, the gas pushes the sealing portion 53 toward the sealing portion 55. When the sealing portion 53 is contracted by the pressure exerted by the gas and a gap is formed between the sealing portion 53 and the insertion hole 44, the gas escapes through the gap. When a gap is formed between the sealing portion 53 and the insertion hole 44, the gas escapes through the gap. The gas that has escaped through the gap between the sealing portion 53 and the insertion hole 44 is discharged to the outside through a hole formed in the sealing portion 55 and a gap between the sealing portion 55 and the fastening hole 45 . When a certain amount of gas is discharged, the contracted sealing portion 53 is restored to its original shape by the restoring force and blocks the insertion hole 44 again.

The sealing portion 55 may be formed on the outer surface of the sealing portion 55 with a male screw acid corresponding to the female screw thread of the electrolyte injection hole 43 and screwed into the electrolyte injection hole 43.

The electrolytic solution can be injected into the inner space 33 of the case 30 through the electrolyte injection hole 43 before sealing the electrolyte injection hole 43 through the gas discharge portion 51. [ At this time, it is preferable that the electrolyte is injected after the opening portion 31 of the case 30 is sealed with the upper terminal plate 40. After the electrolyte is injected, the electrolyte injection hole 43 is sealed with the gas discharge portion 51. Further, the gas discharging portion 51 can be used when performing the replacement of the electrolytic solution. The sealing part 53 is removed from the electrolyte injection hole 43 and then the electrolytic solution is replaced and the sealing part 55 is joined to the sealing part 55 after the sealing part 53 is coupled, To the electrolyte injection hole (43) to perform electrolyte replacement.

The gasket 60 suppresses leakage of the electrolyte between the case 30 and the upper terminal plate 40. As the material of the gasket 60, butyl rubber may be used.

After the lower terminal plate 20, the electric storage element 10 and the upper terminal plate 40 are inserted into the inner space 33 of the case 30 through the opening 31 of the case 30, the gasket 60 The upper end of the case 30 is brought into close contact with the upper terminal board 40 by beading and curling so as to seal the opening 31 of the case 30. That is, in the present embodiment, since the opening portion 31 of the case 30 can be sealed with the upper terminal plate 40 by beading and curling without welding to the upper terminal plate 40, ) Sealing can be performed more simply. Further, since the open portion 31 of the case 30 can be sealed without welding, the leakage problem of the electrolyte through the existing welded portion can be solved, and the rigidity against external impact can be increased.

In the axial-type electrochemical energy storage device 100 according to the present embodiment, the metal foil extending from the first electrode and the second electrode is pressed to form the first and second electrode joint portions 18 and 19, The contact area between the capacitor element and the upper or lower terminal can be increased to reduce the contact resistance.

The electrochemical energy storage device 100 of the axial type according to the present embodiment includes a sealing portion 53 provided on the upper terminal plate 40 and a gas discharging portion 51 including a sealing portion 55. In this case, 30 can be smoothly discharged to the outside, so that the structure of the gas discharging portion 51 can be simplified.

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: Capacitor element
11: Reason
13: electrode laminate
15: Bottom inner plate
17: Top inner plate
18: First electrode junction
19: Second electrode junction
20: Lower terminal board
30: Case
31:
33: Internal space
40: upper terminal board
41: terminal plate body
43: Electrolyte injection hole
44: insertion hole
45: fastening hole
47: terminal
49: Insulating plate
51:
53: Sealing part
55:
60: Gasket
100: Electrochemical energy storage device

Claims (6)

A capacitor including a first electrode, a separator, a second electrode, and an electrolyte; a first electrode junction extending downward from the first electrode; and a second electrode junction extended upward from the second electrode;
A lower terminal plate connected to the lower portion of the electric storage element by being electrically connected to the first electrode connection portion;
An upper terminal plate connected to the upper portion of the electric storage device facing the lower terminal plate and electrically connected to the second electrode connection portion;
And an electrochemical energy storage device of an axial type. The method according to claim 1,
Wherein the first electrode and the second electrode are formed of a metal foil and are respectively wound and attached to the separation membrane. 3. The method of claim 2,
Wherein the first and second electrode joint portions are formed by pressing a metal foil extending from the first electrode and the second electrode. The method of claim 3,
Wherein the charge-
A bottom inner plate interposed between and bonded to the first electrode joint portion and the lower terminal board;
A top inner plate interposed between and bonded to the second electrode bonding portion and the upper terminal plate;
Further comprising an electrochemical energy storage device for storing the electrochemical energy. 5. The method of claim 4,
Wherein the lower terminal plate and the upper terminal plate are joined to the bottom inner plate and the top inner plate by laser welding or ultrasonic welding. 5. The method of claim 4,
A case in which an opening is formed on one side and the capacitor element is inserted through the opening so that the lower terminal plate faces the bottom;
Further comprising an electrochemical energy storage device for storing the electrochemical energy.

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