KR100919106B1 - Energy storing device - Google Patents

Abstract

An energy storage device according to the present invention includes a cathode electrode and a cathode electrode, an anode lead wire and an anode lead wire, a separator for separating the anode electrode and the cathode electrode between the anode electrode and the cathode electrode, and the anode electrode and the cathode A housing accommodating an electrode and a separation membrane, an electrolyte solution contained in the housing, an anode terminal and a cathode terminal connected to the anode lead wire and the cathode lead wire, respectively, and a pressure releasing member coupled to the housing to discharge pressure in the housing; And a fixing member for fixing the pressure discharging member to the housing, wherein the pressure discharging member includes a pressure discharging member housing and a movable member for opening and closing the pressure discharging member housing built in the pressure discharging member housing. And an elastic member for applying an elastic force to the movable member, wherein the pressure relief member is 0.3 to 1 .2 configured to open in the pressure range of MPa.

As a result, the pressure releasing member for discharging the internal pressure of the housing can be repeatedly used, while the deformation of the housing can be prevented, and the pressure releasing member can be installed by a simple process to assemble the product. Yield can be improved.

Description

Energy Storage Device {ENERGY STORING DEVICE}

The present invention relates to an energy storage device and a pressure discharge member used therein, and more particularly, to a pressure discharge member having an open pressure configured to prevent deformation of the housing and an energy storage device including the same.

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.

The quasi-capacitor involves a chemical reaction, but the electrical behavior behaves like a capacitor and is called a quasi-capacitor. EDLC uses the property of charge adsorption on the electrical double layer at the electrode and electrolyte interface.

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 charging and discharging 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, mobile communication information devices such as mobile phones, laptops, PDAs, etc. It is very suitable as main power supply or auxiliary power supply for electric vehicles, night road lights, uninterrupted power supply (UPS), etc. as well as auxiliary power supply of high capacity.

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.

However, in the energy storage device, gas is generated as a by-product of the reaction that proceeds at the interface between the electrolyte and the electrode when misused such as overvoltage or long-term use at a 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.

In the conventional energy storage device, in order to solve this problem, a notch is formed on a part of the housing so that the notch part ruptures above a certain pressure, thereby releasing pressure.

However, in this manner, the housing remains open after the rupture due to the rupture of the housing, which causes the leakage of the electrolyte or the inflow of impurities, thereby significantly lowering the electrical performance of the capacitor.

The present invention has been made to solve the above problems, an object of the present invention can be configured to repeatedly use the pressure release member for discharging the pressure inside the housing of the energy storage value, it is possible to prevent deformation of the housing It is to provide a pressure discharge member for an energy storage device and a storage device including the same, the pressure of the range is set to the open pressure.

Another object of the present invention, by forming a pressure discharge member made of a material that does not cause a chemical reaction with the electrolyte injected into the energy storage device, the pressure discharge member for an energy storage device that can improve durability and an energy storage device including the same To provide.

Still another object of the present invention is to provide an energy storage device capable of improving the assembly yield of a product by constituting the pressure discharge unit by a simple process.

Still another object of the present invention is to provide an energy storage device which can more firmly maintain the installation structure of the pressure discharge portion.

The present invention has been made to achieve the above object, the energy storage device according to the present invention is a positive electrode and a negative electrode, a positive electrode lead and a negative electrode lead wire, the positive electrode and the negative electrode is located between the positive electrode and the negative electrode A separator for separating an electrode, a housing accommodating the positive electrode, a negative electrode, and a separator, an electrolyte solution contained in the housing, a positive electrode terminal and a negative electrode terminal to which the positive lead wire and the negative lead wire are respectively connected; And a pressure releasing member for discharging the pressure in the housing and a fixing member for fixing the pressure releasing member to the housing, wherein the pressure releasing member is embedded in the pressure releasing member housing and the pressure releasing member housing. And a movable member for opening and closing the pressure discharging member housing and applying an elastic force to the movable member. It includes an elastic member, the pressure relief member is configured to open in the pressure range of 0.3 to 1.2 MPa.

Here, the movable member is preferably composed of butyl rubber.

In addition, the pressure relief member housing is preferably made of stainless steel or an alloy thereof.

Here, the pressure discharge member housing is composed of a pressure discharge member upper housing and the pressure discharge member lower housing, the pressure discharge member upper housing and the pressure discharge member lower housing by the combination of the pressure discharge member engaging portion is formed.

On the other hand, the housing is provided with a housing support for supporting the pressure release member engaging portion, the fixing member may be screwed to the housing.

Preferably, a polygonal groove is formed on the fixing member.

Preferably, a sealing member is installed between the pressure release member catching portion and the housing support of the housing.

Here, the spring constant of the elastic member may be configured in the range of 0.1 to 1.5 kgf / cm.

On the other hand, the pressure discharge member for energy storage device according to the present invention, the pressure discharge member is a pressure discharge member housing, a movable member for opening and closing the pressure discharge member housing built in the pressure discharge member housing, and the movable member An elastic member for applying an elastic force to the pressure discharge member housing is configured to open in a pressure range of 0.3 to 1.2 MPa.

Here, the movable member is preferably composed of butyl rubber.

In addition, the pressure relief member housing is preferably made of stainless steel or an alloy thereof.

Here, the pressure discharge member housing is composed of a pressure discharge member upper housing and the pressure discharge member lower housing, the pressure discharge member upper housing and the pressure discharge member lower housing by the combination of the pressure discharge member engaging portion is formed.

Here, the spring constant of the elastic member may be configured in the range of 0.1 to 1.5 kgf / cm.

According to the present invention, the pressure discharging member for discharging the pressure inside the housing of the energy storage can be repeatedly used, and the deformation of the housing can be prevented.

In addition, while improving the durability of the energy storage device, it is possible to install the pressure releasing member by a simple process to improve the assembly yield of the product.

In addition, it is possible to more firmly maintain the installation structure of the pressure relief member.

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

Figure 2 is an exploded perspective view of the pressure discharge unit is installed in the upper housing,

3 is a cross-sectional view of the pressure discharge unit is installed in the upper housing,

4 is a view showing the operating principle of the pressure discharge unit,

5 is a view showing another embodiment of the pressure discharge unit.

Explanation of symbols on the main parts of the drawings

40, 50: housing 62: positive terminal

64: cathode terminal 72: pressure discharge member

73: elastic member 74: fixing member

75: movable member 77: communication member engaging portion

78: elastic movable member

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.

Figure 1 is an external perspective view of the energy storage device according to the present invention, Figure 2 is an exploded perspective view of the pressure discharge member is installed in the upper housing, Figure 3 is a cross-sectional view of the pressure discharge member is installed in the upper housing.

1 to 3, the energy storage device according to the present invention separates the positive electrode and the negative electrode between the positive electrode and the negative electrode, the positive lead wire and the negative lead wire, and are located between the positive electrode and the negative electrode. A separator, a housing (40, 50) for accommodating the anode electrode, a cathode electrode and the separator, an electrolyte solution contained in the housing (40, 50), and an anode terminal to which the anode lead wire and the cathode lead wire are respectively connected ( 62) and the negative electrode terminal 64, a pressure releasing member 72 coupled to the housing for discharging pressure in the housings 40 and 50, and for fixing the pressure releasing member 72 to the housing. And a fixed member 74, wherein the pressure relief member 72 is embedded in the pressure relief member housings 72-1 and 72-2 and the pressure relief member housings 72-1 and 72-2. A movable member 75 for opening and closing the pressure relief member housings 72-1 and 72-2; It includes an elastic member 73 for applying an elastic force to the eastern member 75, the pressure discharge member housing (72-1, 72-2) is configured to open in the pressure range of 0.3 to 1.2 MPa.

The cell of the energy storage device according to the present invention includes a housing (50, 40) made of a metal material 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.

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 penetrate 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.

Although the shape of the lower housing 40 is illustrated as a hexahedron shape in FIG. 1, the shape of the lower housing 40 is not limited thereto and may be configured in a cylindrical shape.

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 electrode.

The upper housing 50 is coupled to the lower housing 40 seen from the upper portion of the lower housing 40, the upper housing 50 may also be made of a metallic material, preferably composed of aluminum or an alloy thereof. do.

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).

2, a housing opening 52 is formed at one side of the upper housing 50 to communicate with the outside air. The housing opening 52 has a pressure releasing member for discharging the increased pressure in the energy storage device. 70 is installed.

The pressure releasing member 70 is formed by the combination of the pressure releasing member upper housing 72-1 and the pressure releasing member lower housing 72-2, and the pressure releasing member 72 is attached to the fixing member 74. It is fixed to the housing opening 52 by the.

Here, the housings 72-1 and 72-1 of the pressure relief member 70 are made of stainless steel or an alloy thereof to prevent corrosion by the electrolyte.

The housing opening 52 is provided with a housing support part 54 for supporting the pressure relief member 72, and the pressure relief member upper housing 72-1 and the pressure relief member lower housing 72-2. The pressure release member catching part 77 which can be supported by the housing support part 54 is formed by the combination.

Here, a rectangular groove 74-1 is preferably formed on the upper surface of the fixing member 74, and a thread 74-2 for screwing the upper housing 50 is formed at the lower portion thereof.

The square groove 74-1 is configured to easily rotate the fixing member 74 by inserting a tool such as a wrench, and the shape of the groove 74-1 is limited to the square. It can be formed of various polygons such as hexagons.

As described above, in the state in which the pressure discharge member 72 is mounted on the housing opening 52, the fixing member 74 is screwed to the upper housing 50 to press the pressure discharge member 72. As a result, the pressure relief member 72 may be firmly installed in the upper housing 50 by a simple operation of rotating the fixing member 74.

In addition, a sealing member 79 may be additionally installed between the pressure relief member 72 and the housing support 54 to further increase the airtightness between each other.

4 is a view showing the operating principle of the pressure relief member (72).

Referring to FIG. 4, the pressure releasing member 72 is elastic to apply elastic force to the disk-shaped movable member 75 and the movable member 75 which are movable while resisting the pressure in the housings 40 and 50. The member 73 is included.

The movable member 75 is formed of a butyl rubber material, and is configured to prevent corrosion due to the reaction with the electrolyte.

Here, the pressure discharge member lower housing 72-1 is formed with a first pressure discharge opening 71-1 for passing the pressure in the housings 40 and 50, and the pressure discharge member upper housing 72 One side of −2) is provided with a second pressure discharge opening 71-2 for discharging the pressure in the housings 40 and 50 to the outside.

If the pressure in the housings 40 and 50 is excessive, the gas in the housings 40 and 50 passes through the first pressure discharge opening 71-1 due to the excessive pressure, and the movable member 75. ) Is pressed upwards.

The movable member 75 is moved upward by the pressing, and when the movable member 75 is moved to a position higher than the second pressure discharge opening 71-2, the second pressure discharge opening is Through 71-2, the pressure is discharged to the outside air.

At this time, since the movable member 75 is under pressure by the elastic member 73, if the pressure in the housing 40, 50 is reduced below a predetermined pressure, the movable member 75. ) Will return to the original position.

Here, when the pressure in the housing (40, 50) is a pressure range of 0.3 to 1.2 MPa, the movable member 75 is moved to a position higher than the second pressure discharge opening (71-2) to discharge to the outside air It is composed.

If the pressure in the housings 40 and 50 is less than 0.3 MPa, the internal pressure typically deforms or breaks the housings 40 and 50, which are composed of aluminum or alloys of 0.1 to 0.3 millimeters thick. Since it does not cause, it is not required that the movable member 75 is moved upward so that the pressure is discharged to the outside air.

Moreover, when the movable member 75 is configured to move upward at a low pressure as described above, the movable member 75 includes the movable member 75 due to abrasion caused by friction caused by such frequent movement. The service life of the pressure relief member is significantly shortened, and as a result, the service life of the energy storage device including the pressure relief member can also be shortened.

If the pressure in the housings 40 and 50 is greater than 1.2 MPa, if the movable member 75 is moved upward and the pressure is not discharged to the outside air, the aluminum or an alloy thereof may be formed by the internal pressure as described above. The configured housings 40 and 50 can be deformed or broken.

As described above, the pressure discharging member 72 is configured to open in the pressure range, thereby discharging such excess pressure in the case of excessive pressure generation, and then closing the inside of the upper / lower housings 40 and 50 in a closed state. As a result, the service life can be significantly extended while preventing the deformation or breakage of the housings 40 and 50 due to excessive internal pressure.

The spring constant of the elastic member required to constitute such a pressure range is in the range of 0.1 to 1.5 kgf / cm.

Comparative Example 1

The pressure relief member housings were made of steel, steel, nickel plating, and stainless steel, respectively, and were left to stand for 72 hours at 60 ° C.

In all three cases, there was no change in the relative humidity of 30%, but in the 95% relative humidity condition, the surface corrosion was found in the pressure relief member housing made of steel and the pressure relief member housing composed of steel and nickel plating.

However, the pressure relief member housing made of stainless steel was not changed.

Comparative Example 2

The pressure relief member housings were made of steel, steel, nickel plated, and stainless steel, respectively, and left in tap water and distilled water for 72 hours at 60 ° C.

In the case of tap water, corrosion was found on the surface of the pressure exhaust member housing made of steel and the pressure exhaust member housing made of steel and nickel plating, but the pressure exhaust member housing made of stainless steel was not changed.

In addition, in the case of distilled water, a local corrosion occurred in the pressure discharge member housing made of steel, but the pressure discharge member housing made of steel and nickel plating and the pressure discharge member housing made of stainless steel did not change.

Comparative Example 3

The pressure relief member housings were made of steel, steel and nickel plating, and stainless steel, respectively, and were left to stand in a mixture of salt and water for 72 hours at 60 ° C.

In the case of the pressure relief member housing made of steel and the pressure relief member housing made of steel and nickel plated material, corrosion was found on the surface, but the pressure relief member housing made of stainless steel was not changed.

Comparative Example 4

Movable member made of butyl rubber

Release pressure (MPa) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Water content in the product (ppm) 200 70 50 48 46 48 46 45 43 48 48 43 Whether the product is deformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed transform

Movable member made of ethylene-propylene rubber (EPDM)

Release pressure (MPa) 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Water content in the product) ppm 450 200 100 100 120 110 70 100 93 103 88 120 Whether the product is deformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed Undeformed

The movable member was composed of a butyl rubber material and an ethylene-propylene rubber material, respectively, and was charged and tested for 2000 hours under a temperature of 70 ° C. and a relative humidity of 95%.

First, in the case of adopting a movable member made of butyl rubber material, since deformation has occurred in the product while the opening pressure is set to 1.3 MPa, the opening pressure of the housing by the elastic member is set within the range of 1.2 MPa. It can be seen that it is preferable.

In addition, when the opening pressure is set to a low pressure of 0.2 MPa, the minimum opening pressure is set to 0.3 MPa or more because the amount of water in the electrolyte filled in the product suddenly increased to 200 ppm due to moisture infiltration due to external air inflow. It can be seen that it is preferable.

On the other hand, in the case where the movable member made of ethylene-propylene rubber material is employed, no deformation occurs in the product even when the opening pressure is set to 1.3 MPa, but the movable member itself made of the ethylene-propylene rubber material is deformed instead.

  In addition, when the opening pressure is set to a low pressure of 0.2 MPa, it can be seen that the amount of water in the electrolyte filled in the product suddenly increased to 450 ppm due to moisture infiltration due to the inflow of external air.

In general, in the open pressure range of 0.3 to 1.2 MPa, when the movable member made of ethylene-propylene rubber is used, the amount of moisture in the electrolyte is more than twice as large as that of the movable member made of butyl rubber. have.

This is a result of the external air and the moisture contained therein are introduced by the movable member made of ethylene-propylene rubber material to react with the electrolyte during corrosion for 2000 hours.

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.

Therefore, various modifications may be made to the internal configuration of the communication member 72 configured to be repeatedly used and the specific configuration of the fixing member 74 for fixing the communication member to the housing.

Claims (13)

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 accommodating the positive electrode, the negative electrode and the separator; An electrolyte solution contained in the housing; A positive electrode terminal and a negative electrode terminal to which the positive lead wire and the negative lead wire are respectively connected; A pressure releasing member coupled to the housing for releasing pressure in the housing; A fixing member for fixing the pressure discharge member to the housing, The pressure discharge member is a pressure discharge member housing; A movable member embedded in the pressure discharging member housing for opening and closing the pressure discharging member housing through displacement by pressure and return to the original position; It includes an elastic member for applying an elastic force when the displacement and return of the movable member, The pressure discharging member housing is composed of a pressure discharging member upper housing and a pressure discharging member lower housing, and forms a pressure discharging member catching portion by a combination of the pressure discharging member upper housing and the pressure discharging member lower housing. The housing is provided with a housing support for supporting the pressure release member engaging portion, the fixing member is screwed to the housing, The pressure dissipation member is an energy storage device, characterized in that configured to open in a pressure range of 0.3 to 1.2 MPa. The method of claim 1, The movable member is an energy storage device, characterized in that consisting of butyl rubber. The method of claim 1, The pressure dissipating member housing is made of stainless steel or an alloy thereof. delete delete The method of claim 1, Energy storage device, characterized in that the polygonal groove formed on the top of the fixing member. The method of claim 1, Energy storage device, characterized in that the sealing member is installed between the pressure release member catching portion and the housing support of the housing. The method of claim 1, Energy saving device, characterized in that the spring constant of the elastic member is in the range of 0.1 to 1.5 kgf / cm. delete delete delete delete delete