KR20090042611A - Energy storing device - Google Patents

Abstract

An energy storage device is provided to prevent the deformation due to pressure generated form the inside of a housing, to ensure the improved durability and to secure stability. An energy storage device(100) comprises a positive electrode and a negative electrode; positive electrode lead wire and negative electrode lead wire; a separation film separating the positive electrode and negative electrode; a housing of square column shape, accommodating the positive electrode, negative electrode, and separation film; electrolyte stored in the housing; and a positive electrode terminal(62) and a negative electrode terminal(64).

Description

Energy Storage {ENERGY STORING DEVICE}

The present invention relates to an energy storage device, and more particularly, an energy storage device capable of preventing deformation of the housing due to pressure generated therein by forming a permanent deformation part having a height in an inner side or an outer direction on a side of the housing. It is about.

In general, a battery and a capacitor are typical elements for storing electrical energy.

Ultra Capacitor, also called Super Capacitor, is an energy storage device with intermediate characteristics between an electrolytic capacitor and a secondary battery. It is a next generation energy that can be used and replaced with a secondary battery due to its high efficiency and semi-permanent life characteristics. Storage.

Ultracapacitors can be divided into electric double layer capacitors (EDLC) and pseudocapacitors according to energy storage mechanisms.

Pseudocapacitors involve chemical reactions, but their electrical behavior behaves like capacitors and is called pseudocapacitors. EDLC uses the property of charge adsorption on the electrical double layer at the electrode and electrolyte interfaces.

EDLC forms an electric double layer on the surface of the electrode material and the contact surface of the electrolyte by using a material having a large surface area such as activated carbon as an active material of the electrode.

That is, charge layers having different polarities at the interface between the electrode and the electrolyte solution are generated by the electrostatic effect. The charge distribution thus formed is called an electric double layer, and as a result, it has the same capacitance as in a battery.

However, the electric double layer capacitor has different charge / discharge characteristics from the battery, whereas the voltage characteristics of the battery during charge / discharge are similar to those of the plateau, In the case of the electric double layer capacitor, the voltage characteristic with time shows a linear graph characteristic during the charge / discharge process.

Therefore, the electric double layer capacitor has a characteristic that the amount of charged / discharged energy can be easily calculated by measuring a voltage.

On the other hand, the electric double layer capacitor as described above, because the mechanism for storing electricity stores the electric charge in the electric double layer formed at the interface of the electrolyte, unlike the storage battery using a chemical reaction, that is, because it uses the electrical storage by the accumulation of physical charge, No deterioration due to repeated use, high reversibility and long service life.

Therefore, it may be used as a battery replacement for applications that are not easy to maintain and require a long service life.

On the other hand, as described above, the electric double layer capacitor has a fast charge / discharge characteristic because it uses the principle of absorbing / desorbing the electric double layer generated at the interface between the electrode and the electrolyte, and accordingly, a mobile communication information device such as a mobile phone, notebook, PDA Not only as an auxiliary power source, but also as a main power source or auxiliary power source such as electric vehicles, night road lights, UPS (Uninterrupted Power Supply), etc., in which high capacity is required.

The electrodes of the electric double layer capacitor having such various uses have high energy through a large specific surface area, high power through low specific resistance, and electrochemical stability through suppression of an electrochemical reaction at an interface.

Therefore, currently active carbon powder or activated carbon fiber having a large specific surface area is most widely used as a main material of the electrode, and a low specific resistance is realized by mixing a conductor or spray coating of metal powder.

In addition, research and development of a more stable electrode material by suppressing the electrochemical side reactions occurring at the electrode interface through various methods.

On the other hand, the energy storage device generates gas as a by-product of the reaction that proceeds at the interface between the electrolyte and the electrode in the case of misuse such as overvoltage or prolonged use at high temperature.

The generation of these gases causes the pressure inside the housing to continue to increase, in some cases causing a sudden explosion in the vulnerable part of the housing.

By the way, in the case of the conventional energy storage device, the housing forming the appearance is configured in the form of a simple plate, there was a problem that the deformation occurs in the side portion of the housing due to the volume expansion caused by the internal pressure rise as described above.

In addition, when a plurality of energy storage devices are modularized and used to exhibit high voltage and high output characteristics, when unit energy storage devices cause a volume change due to internal pressure, they may be applied to a case, a printed circuit board (PCB), or other members of the module. There is a problem in that pressure is applied to ultimately cause deformation or breakage of components constituting the product, thus losing its original function.

The present invention has been made to solve the above problems, an object of the present invention, it is possible to prevent the deformation of the housing by the pressure generated from the inside of the housing without installing an additional member for preventing the deformation of the housing. To provide an energy storage device.

It is still another object of the present invention to provide an energy storage device capable of forming a structure which prevents deformation of a housing due to internal pressure by a simple machining process.

The object is, according to the present invention, an anode electrode and a cathode electrode; A positive lead wire and a negative lead wire; A separator disposed between the anode electrode and the cathode electrode to separate the cathode electrode and the cathode electrode; A housing having a rectangular pillar shape to accommodate the positive electrode, the negative electrode, and the separator; An electrolyte solution contained in the housing; And a positive electrode terminal and a negative electrode terminal to which the positive lead wire and the negative lead wire are respectively connected. The side of the housing includes a permanent deformation part having a height in the inner or outer direction with respect to a reference plane connecting both edges of the present side. Achieved by the energy storage device formed.

Here, the permanent deformation portion may be formed recessed in the inward direction from the side of the housing.

Here, the permanent deformation portion may be disposed in the central portion of the side of the housing.

In addition, the permanent deformation portion may extend along a height direction at the center of the side of the housing.

Here, another permanent deformation portion may be additionally formed between the side center portion of the housing and the side edge of the housing.

In addition, another permanent deformation portion extending along the height direction may be additionally formed between the side center portion of the housing and the side edge of the housing.

Here, the depth of the permanent deformation portion may be formed to a depth of 10% or more and 200% or less of the thickness of the lower housing.

Preferably, the cross section of the permanent deformation portion in a plane perpendicular to the height direction of the housing may be formed in the shape of an arc.

According to the present invention, the deformation of the housing due to the pressure generated from the inside of the housing can be prevented without providing an additional member for preventing the deformation of the housing.

In addition, the deformation of the housing due to internal pressure can be prevented by a simple machining process.

Thus, it is possible to form an energy storage device having a high energy density to the same weight.

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

Prior to this, the terms used in this specification and claims should not be construed in a dictionary sense, and the inventors may properly define the concept of terms in order to explain their invention in the best way. It should be construed as meaning and concept consistent with the technical spirit of the present invention.

Therefore, the configurations shown in the embodiments and drawings described herein are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It is to be understood that water and variations may exist.

1 is an external perspective view of an energy storage device according to the present invention, FIG. 2 is a conceptual view illustrating a deformation of a member including a fixed end and a free end from a mechanical point of view, and FIG. 3 is a bottom housing according to the prior art. 4 is a cross-sectional view showing a deformation state and a deformation state of a lower housing according to the present invention, and FIG. 4 is a view showing a permanent deformation portion of an energy storage device according to the present invention.

The energy storage device 100 according to the present invention includes a cathode electrode connected to a cathode lead wire, a cathode electrode connected to a cathode lead wire, a separator for separating the anode electrode and the cathode electrode between the anode electrode and the cathode electrode; And a housing accommodating the positive electrode, the negative electrode, and the separator, an electrolyte solution contained in the housings 40 and 50, and a positive electrode terminal 62 and a negative electrode terminal 64 to which the positive lead wire and the negative lead wire are respectively connected. It includes, the side of the housing 40 is formed with a permanent deformation portion 70 by processing having a height in the inner or outer direction with respect to the reference plane connecting both edges of the present side.

Energy storage device according to the present invention includes a housing (50, 40) and the positive electrode and the negative electrode embedded in the housing (50, 40).

The anode electrode includes an active material layer composed of a metallic current collector and porous activated carbon, and one side of the cathode electrode is connected to the cathode lead wire.

The current collector is usually configured in the form of a metal foil, and the active material layer is configured in the form of a wide coating coating on both sides of the metal current collector.

Preferably, the active material layer is removed from the current collector portion to which the positive lead wire is connected.

As described above, the lead wire may be manufactured in a separate configuration and connected to the current collector, but is not limited thereto. The lead wire and the current collector may be integrally formed.

The active material layer is a portion for storing the electrical energy of the positive electrode and the negative electrode, the current collector serves as a movement passage of the charge discharged or supplied from the active material layer.

Meanwhile, a separator for limiting electron conduction between the anode and cathode electrodes is disposed between the sequentially stacked electrodes of the anode and cathode, and an electrolyte is filled in the housings 50 and 40.

In this case, the porous active material layer has a micro surface area, and acts as an active material on the positive electrode and the negative electrode so that each surface thereof comes into contact with the electrolyte.

When voltage is applied to the electrodes, the positive and negative ions contained in the electrolyte move to the positive electrode and the negative electrode, respectively, to infiltrate into the pores of the porous active material layer.

The lower housing 40 of the housings 40 and 50 may be made of a metallic material, and preferably made of aluminum or an alloy thereof.

The lower housing 40 is a component for accommodating the separator and the lead wires for electrically separating the anode / cathode electrode and the cathode / cathode electrodes.

The upper housing 50 is combined with the lower housing 40 seen from the upper part of the lower housing 40, and the upper housing 50 may also be made of a metallic material, preferably made of aluminum or an alloy thereof. .

The upper housing 50 is coupled to the positive terminal 62 and the negative terminal 64 to which the positive lead wire and the negative lead wire are respectively connected.

Here, the outer surface of the positive electrode terminal 62 and the negative electrode terminal 64 may be threaded, and the positive and negative terminals 62 and 64 having the threaded processing are inserted from the lower side of the upper housing 50. It may be fixed to the upper housing 50 by nuts (63, 65).

Preferably, one side of the upper housing 50 may be additionally provided with a pressure discharge portion 66 for discharging the increased pressure in the energy storage device.

Here, the permanent deformation portion 70 may be formed recessed in the inward direction from the side of the lower housing 40.

The permanent deformation part 70 prevents deformation due to the pressure transferred to the lower housing 40 by an internal pressure increase due to a temperature increase generated from components contained in the lower housing 40. As a component to perform a role, it can be formed through a pressing process at the time of manufacturing the lower housing (40).

Here, with reference to FIG. 4, the permanent deformation portion 70 is formed to help understand the principle of improving the strength of the lower housing 40.

4 is a cross-sectional view showing deformation when a constant force F is applied to the member 105 fixed to the support end.

Here, when the member 105 receives a constant force (F) over the entire area of the member 105, the force distribution is transmitted equally to the entire area of the member 105, and is fixed to the support end The greater the bending momme acts on the free end (B) farthest from the fixed end (A) than the portion located in close proximity to the fixed end (A), the deformation amount is also increased.

At this time, when the force transmitted to the member 105 exceeds the elastic deformation range of the member 105, the permanent deformation (permanent deformation) occurs in the member 105.

As can be seen from the above, the deformation of the member 105 decreases as the proximity to the fixed end (A), the largest amount of deformation at the free end (B) which is the part farthest away from the fixed end (A) .

On the other hand, in a member supported on both sides by a fixed end, when a constant force is applied to the member, the center of the member, which is the part farthest from the fixed end located on both sides of the member, receives the greatest bending moment. As a result, the deformation amount is also the greatest.

In the case of the lower housing 40 of the energy storage device 100 according to the present invention, if there is a constant force transmitted to the side of the lower housing 40, as described above, the edge portion of the square pillar is formed of the fixed end. Function, the largest deformation occurs in the center of the side that is farthest away from the edge.

That is, the part most vulnerable to deformation due to pressure transmitted from the inside of the upper and lower housings 40 and 50 may be referred to as the center of the housing side surface.

FIG. 5A is a cross-sectional view illustrating a deformation width d1 when a constant force F is applied to one side of the lower housing 40 of a general energy storage device, and FIG. When a constant force F is applied to one side of the lower housing 40 of the energy storage device 100 according to the present invention, it is a cross-sectional view illustrating the deformation width d2.

In the case of FIG. 5A, the side surface of the lower housing 40 is deformed according to the magnitude F of the applied internal pressure, and the deformation amount d1 is also maximized at the center portion.

As shown in FIG. 5 (b), when the permanent deformation part 70 is formed in the center of the lower housing 40 side in the inward direction, the residual stress caused by the permanent deformation causes the central part of the lower housing 40 to face the inner side of the lower housing 40. It has an effect similar to that of providing a kind of fixed end, and resists lateral deformation in the outward direction due to internal pressure.

In this case, the cross-sectional shape in which the lower housing 40 is deformed according to the internal pressure is shown in FIG. It can be seen that.

Here, the permanent deformation portion 70 is disposed in the central portion of the side of the lower housing 40, it can maximize the effect of resisting the deformation caused by the internal pressure of the lower housing (40).

Meanwhile, as illustrated in FIGS. 3 and 7, the permanent deformation part 70 may be disposed at the center of the side surface of the lower housing 40 or extend along the height direction at the center of the side housing.

Preferably, the permanent deformation part 70 may increase the resistance to the internal pressure as it extends along the height direction at the center of the side of the lower housing 40, but of the energy storage device 100 to be configured. The height may be selectively changed depending on the thickness of the housing sheet.

Preferably, as shown in FIG. 6, the recessed depth d4 of the permanent deformation part 70 may be formed to a depth of 10% or more and 200% or less of the thickness d3 of the lower housing 40.

Here, when the recessed depth d4 of the permanent deformation part 70 is less than 10% of the thickness d3 of the lower housing 40, resistance to internal pressure is insufficient, and the permanent deformation part 70 When the depth of depression d4 of 200) exceeds 200% of the thickness d3 of the lower housing 40, a portion of the lower housing 40 where the permanent deformation part 70 is formed may be ruptured.

In addition, the cross section of the permanent deformation portion 70 in a plane perpendicular to the height direction of the lower housing 40 may be formed in the shape of an arc (弧).

Here, the shape of the permanent deformation part 70 may be provided in various shapes, but in order to increase the ease of processing, and to prevent the rupture of the lower housing 40 during processing, the permanent deformation part 70 is It is preferable that the cross section of is provided in the shape of an arc.

7 and 8 are an external perspective view of the permanent storage is formed in the energy storage device according to the present invention.

7, in addition to the permanent deformation part 70 disposed at the center of the lower housing 40 side to prevent deformation of the lower housing 40 due to the internal pressure of the energy storage device 100 as described above. Another permanently deformable portion 70-1 is additionally formed between the center of the lower housing 40 and the side edge of the lower housing 40.

Alternatively, as shown in FIG. 8, another permanent deformation part 70 extending along the height direction may be additionally formed between the side center portion of the lower housing 40 and the side edge of the lower housing 40.

As described above, when forming a plurality of permanent deformation parts 70, 70-1, by increasing the portion that serves as a fixed end, the resistance to the internal pressure than forming a single permanent deformation part 70 This can be increased.

Here, the number and shape of the permanent deformation parts 70 and 70-1 may be selectively formed according to the use environment and the required durability of the ultracapacitor 100.

As mentioned above, although the present invention has been described by way of limited embodiments and drawings, the technical idea of the present invention is not limited thereto, and a person having ordinary skill in the art to which the present invention pertains, Various modifications and variations may be made without departing from the scope of the appended claims.

1 is an external perspective view of an energy storage device according to the present invention;

2 is a conceptual diagram showing a deformation of a member including a fixed end and a free end from a mechanical point of view,

3 is a comparison of the deformation state of the lower housing according to the prior art and the deformation state of the lower housing according to the present invention,

4 is a cross-sectional view showing a permanent deformation portion of the energy storage device according to the present invention;

5 and 6 is an external perspective view showing a state in which the permanent deformation portion of another embodiment is formed in the energy storage device according to the present invention,

6 is an external perspective view showing a state in which an additional permanent deformation part is formed in the energy storage device according to the present invention.

Explanation of symbols on the main parts of the drawings

40: lower housing 50: upper housing

62: positive terminal 64: negative terminal

66: pressure discharge part 70: permanent deformation part

70-1: Additional permanent deformation

Claims (9)

An anode electrode and a cathode electrode; A positive lead wire and a negative lead wire; A separator disposed between the anode electrode and the cathode electrode to separate the cathode electrode and the cathode electrode; A housing having a rectangular pillar shape to accommodate the positive electrode, the negative electrode, and the separator; An electrolyte solution contained in the housing; And a positive electrode terminal and a negative electrode terminal to which the positive lead wire and the negative lead wire are respectively connected. Energy storage device, characterized in that the side of the housing is formed by a permanent deformation by processing having a height in the inward or outward direction with respect to the reference plane connecting both edges of the present side. The method of claim 1, The permanent deformation portion is formed in the energy storage device, characterized in that formed in the inward direction from the side of the housing. The method of claim 2, The permanent deformation portion is an energy storage device, characterized in that disposed in the central portion of the side of the housing. The method of claim 2, The permanent deformation portion extends along the height direction at the center of the housing side energy storage device. The method of claim 3, wherein Energy storage device, characterized in that the additional permanent deformation is formed between the central portion and the edge of the housing. The method of claim 4, wherein Energy storage device, characterized in that further formed between the permanent portion extending along the height direction between the central portion and the edge of the housing. The method according to any one of claims 3 to 4, Recessed depth of the permanent deformation portion is an energy storage device, characterized in that formed to a depth of more than 10% to 200% of the thickness of the housing. The method according to any one of claims 3 to 4, The cross section of the permanent deformation portion in a plane perpendicular to the height direction of the housing is formed in the shape of an arc (에너지). The method of claim 1, The energy storage device is characterized in that the ultracapacitor.

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