WO2016027978A1 - Energy storage device having improved heat-dissipation characteristic - Google Patents

Abstract

An energy storage device having an improved heat-dissipation characteristic is disclosed. The energy storage device, according to the present invention, comprises: a cell assembly formed by connecting at least two cylindrical energy storage cells in series; a case having an accommodation part in a shape corresponding to the outer side surface of the energy storage cells so as to accommodate the cell assembly; and a heat-dissipation pad provided between the outer side surface of the energy storage cells of the cell assembly and the inner side surface of the accommodation part, wherein the case comprises at least two case blocks and the accommodation part is formed by combining the case blocks.

Description

Energy storage device with improved heat dissipation

The present invention relates to an energy storage device, and more particularly, to an energy storage device with improved heat dissipation characteristics.

In addition, the present application claims priority based on Korean Patent Application No. 10-2014-0107939, filed August 19, 2014, all the contents disclosed in the specification and drawings of the application is incorporated in this application.

In addition, this application claims the priority based on Korea Patent Application No. 10-2014-0179732 filed December 12, 2014, all the contents disclosed in the specification and drawings of the application is incorporated in this application.

In addition, this application claims the priority based on Korean Patent Application No. 10-2015-0086880 filed on June 18, 2015, all the contents disclosed in the specification and drawings of the application is incorporated in this application.

In general, an ultracapacitor is also called a supercapacitor, and is an energy storage device having intermediate characteristics between an electrolytic capacitor and a secondary battery. Ultracapacitors can be used with secondary batteries due to their high efficiency and semi-permanent life characteristics, and are next-generation electrical energy storage devices that can replace secondary batteries.

Ultracapacitors are often used as battery replacements for applications that are not easy to maintain and require long service life. Ultracapacitors have fast charge and discharge characteristics and can be used as auxiliary power sources for mobile communication information devices such as mobile phones, laptops, and PDAs. It is also ideally suited for mains or auxiliary power sources, such as electric vehicles, night road lights and uninterrupted power supplies, which require high capacity.

In applying such ultracapacitors, in order to be used as a high voltage battery, thousands of farads or hundreds of volts of high voltage modules are required. The high voltage module can be configured by connecting a plurality of ultracapacitors in a case in need quantity.

1 is a view showing the configuration of an ultracapacitor module according to the prior art.

As shown in FIG. 1, the ultracapacitor module according to the related art covers a case 20 for accommodating the ultracapacitor array 10, the ultracapacitor array 10, and upper and lower entrances of the case 20. 30, 40). The ultracapacitor array 10 is composed of a plurality of ultracapacitors in which electrode terminals are connected by a bus bar 11 and coupled by a nut.

Ultracapacitor modules can improve energy storage by driving multiple ultracapacitors. However, the heat generated when the ultracapacitor module is driven also increases rapidly, which may reduce the reliability and stability of the ultracapacitor module.

Ultracapacitor module according to the prior art as described above, through the busbar 11, which is a connection member for connecting the adjacent ultracapacitor, and the cover 20, 40 of the upper and lower surfaces of the metal covering the case 20 Mainly radiate heat. By the way, the side of the case 20 is made of synthetic resin in order to reduce the weight of the ultracapacitor module and lower the production cost, and has a plate shape, so that the contact area with the ultracapacitor is small, so that heat dissipation is hardly achieved.

In addition, according to the prior art as described above, the ultracapacitor can radiate heat mainly through the busbars 11, but the busbars 11 cannot radiate efficiently because the heat radiation area is narrow, so that the temperature inside the case is increased. As the rise occurs, the life of the ultracapacitor is reduced.

(Patent Document 1) Korean Registered Patent No. 10-1341474 (announced on December 13, 2013)

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in order to receive energy storage cells, such as ultracapacitors, into a case, a heat dissipation is achieved through a case surface having a small contact area, thereby improving heat dissipation characteristics. The purpose is to provide.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

Energy storage device according to an aspect of the present invention for achieving the above object, a cell assembly formed by connecting at least two cylindrical energy storage cells in series; A case accommodating the cell assembly, the housing having a shape corresponding to an outer surface of the energy storage cell; And a heat dissipation pad disposed between an outer side surface of the energy storage cell of the cell assembly and an inner side surface of the accommodating part, wherein the case includes at least two case blocks. The receiving portion is formed.

The center angle of the energy storage cell in contact with the heat radiating pad may be 30 degrees to 60 degrees.

An arc formed by the accommodation portion may have a length greater than or equal to the length of the heat radiation pad.

The heat dissipation pad may have elasticity, and a distance between the accommodating part and the energy storage cell may be larger than a diameter tolerance of the energy storage cells while being smaller than a thickness before the heat dissipation pad.

The heat dissipation pad may be attached to the energy storage cell.

The heat dissipation pad may be a heat conductive filler.

An adhesive layer may be provided on one side of the heat radiation pad.

The energy storage cell may be an ultracapacitor.

The case block may include a plurality of convex portions having an arc shape identical to an outer shape of the energy storage cell; A convex portion connecting portion connecting the plurality of convex portions; And a concave portion formed between the convex portion and the convex portion connecting portion.

At least one heat sink may protrude vertically in the recess.

The case block may be any one of an 'L' shape or a 'c' shape.

When the case block has an 'L' shape, one of the outermost convex portions of the plurality of convex portions may be connected to connect an arc shape of the convex portion.

The case block may further include a case block connecting portion extending from one of the outermost convex portions and bent in a length direction of the case block.

When the case block has a 'c' shape, the outermost convex portions of the plurality of convex portions may be connected so that an arc shape of the convex portion continues.

The case block may further include a case block connecting portion extending from each of the outermost convex portions and bent in a length direction of the case block.

The convex connection portion may be formed with a tab for fixing the cover.

The distance between the energy storage cell and the case is far from the end point of the heat dissipation pad to insulate the energy storage cell from the case.

An insulating film may be further formed on an outer surface of the energy storage cell.

The present invention improves the heat dissipation characteristics by widening the contact area between the energy storage cell and the case by providing a heat dissipation pad between the case and the energy storage cell as well as heat dissipation through connection members such as nuts and bus bars.

The present invention facilitates the installation of the heat dissipation pad and reduces the cost of manufacturing the case by manufacturing a case accommodating several energy storage cells by combining a plurality of case blocks.

The present invention optimizes the product mass of the energy storage device while improving heat dissipation characteristics.

The present invention improves product stability by naturally separating the case and the energy storage cell by increasing the distance between the energy storage cell and the case from both ends of the heat radiation pad.

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve as a further understanding of the spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is a view showing an energy storage device module according to the prior art,

2 is a diagram illustrating a configuration of an energy storage device according to an embodiment of the present disclosure;

3 is a view showing a connection between energy storage cells according to another embodiment of the present invention;

4 is a cross-sectional view taken along line II-II ′ of FIG. 2;

5 is a view showing the configuration of a case block according to an embodiment of the present invention;

6 is a diagram illustrating a configuration of a case block according to another embodiment of the present invention.

FIG. 7 is a diagram illustrating a center angle when a heat dissipation pad contacts an energy storage cell according to an embodiment of the present invention.

8 is a view showing the contact shape, the heat dissipation efficiency and the product mass of the heat radiation pad and the energy storage cell according to an embodiment of the present invention with angles.

9 is a graph showing a change in heat dissipation efficiency and product mass according to a contact angle according to an embodiment of the present invention.

FIG. 10 is an enlarged view of a portion A of FIG. 2.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are consistent with the technical spirit of the present invention on the basis of the principle that the concept of the term may be appropriately defined in order to best explain the invention of its own. It must be interpreted as meaning and concept. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

In addition, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

2 is a diagram illustrating a configuration of an energy storage device according to an embodiment of the present invention, FIG. 3 is a diagram illustrating a connection between energy storage cells according to another embodiment of the present invention, and FIG. 4 is II- of FIG. 2. It is a figure which shows the cross section along the II 'line.

2 to 4, the energy storage device according to the present embodiment includes a case 200 for receiving a cell assembly 100 and a cell assembly 100 in which at least two or more energy storage cells 110 are connected in series. ).

The cell assembly 100 may be formed by connecting at least two or more energy storage cells 110 in series. The energy storage cell 110 may be an ultracapacitor, and in describing the present embodiment, the energy storage cell is described as an ultracapacitor. However, the present invention is not limited thereto, and the energy storage cell may be any cell capable of storing electrical energy such as a secondary battery or a battery.

Ultracapacitor 110 has a fast charging and discharging characteristics, and accordingly, as well as an auxiliary power source of mobile communication information devices such as mobile phones, laptops, PDAs, electric vehicles, hybrid vehicles, solar cell power supply, uninterruptible power supply that requires high capacity It can be used as a main power supply or an auxiliary power supply such as an uninterruptible power supply (UPS).

The ultracapacitor 110 may have a cylindrical shape, and as shown in FIG. 2, the ultracapacitor 110 may be connected in series with another ultracapacitor in the longitudinal direction in which the electrode is formed to form the cell assembly 100. At this time, the connection of neighboring ultracapacitors may be connected by connecting members, for example, nuts and busbars.

In addition, as shown in FIG. 3, in a state where the ultracapacitor 110 is placed in parallel, the positive terminal of the first ultracapacitor and the negative terminal of the second ultracapacitor are connected to the busbar 130, the nut 150, and the like. The cell assembly 100 may be formed by connecting in series using the same connection member. In this case, the plurality of ultracapacitors 110 are connected to the positive terminal and the negative terminal by the busbars 130, and are coupled by the nut 150 to form the cell assembly 100. The cell assembly 100 may be accommodated in the case 200 to form an ultracapacitor module.

The case 200 may accommodate the cell assembly 100 formed by connecting the ultracapacitor 110 in series. The case 200 may include a receiving unit having a shape corresponding to an outer surface of the ultracapacitor 110 to accommodate the cell assembly 100 formed by connecting the ultracapacitor 110 in series.

The case 200 may be formed by combining at least two or more case blocks (510 of FIG. 5 or 610 of FIG. 6) of the same shape. A receptacle for accommodating the cell assembly 100 may be formed by coupling the case block 510 of FIG. 5 or 610 of FIG. 6. The case block 510 of FIG. 5 or 610 of FIG. 6 will be described in detail below with reference to FIGS. 5 and 6.

5 is a diagram illustrating a configuration of a case block according to an embodiment of the present invention.

Referring to FIG. 5, the case block 510 may have an 'L' shape and has a receiving portion 518 in a shape corresponding to an outer shape of the ultracapacitor 110. When the ultracapacitor 110 has a cylindrical shape, the inner surface of the case block 510 in contact with the outer surface of the ultracapacitor 110 may have a cylindrical round shape. The case 200 may be completed by combining four 'L' shaped case blocks, and thus an accommodating part 518 may be formed.

More specifically, as shown in FIG. 5, the case block 510 may include a plurality of convex parts 511 and convex parts 511 having the same arc shape as the outer shape of the ultracapacitor 110. Convex portion connecting portion 513 to connect, a concave portion 512 formed between the convex portion 511 and the convex portion connecting portion 513, and case block connecting portion 514, 515 connecting the case block 510.

The plurality of convex portions 511 has the same arc shape as the outer shape of the ultracapacitor 110 to form an accommodating portion 518 for accommodating the ultracapacitor 110, and a heat radiation pad 210 is formed therein. Attached. The heat dissipation pad 210 emits heat generated in the ultracapacitor 110 to the convex portion 511, and also functions to insulate the ultracapacitor 110 and the convex portion 511 (that is, the case 200). The convex parts 511 are connected by the convex part connecting part 513, and a tab for fixing the upper cover and the lower cover which covers the case 200 is formed at the convex part connecting part 513. The tab is a structure for bolting (bolting) process is inserted into the bolt for fixing the case 200 and the cover.

The cave block 510 formed by connecting the plurality of convex portions 511 may have an 'L' shape. In order to connect the case block 510 in the width direction, one of the outermost convex portions is arranged and connected in the width direction, and the other convex portions are arranged and connected in the longitudinal direction. In other words, one of the outermost convex portions in the longitudinal direction of the plurality of convex portions 511 is connected so that an arc shape of the convex portion 511 is continued.

The concave portion 512 is formed between the convex portion 511 and the convex portion connecting portion 513. The concave portion 512 is formed by folding a part of the convex portion 511 outward, which is for securing an insulation distance, which will be described later. In the recess 512, a plurality of heat sinks 517 are vertically installed at regular intervals to radiate heat generated from the ultracapacitor 110 to the outside. That is, the heat sink 517 is vertically installed at regular intervals in order to increase heat radiation efficiency through the air flow between the heat sinks 517. In addition, a plurality of heat sinks 517 are installed to widen the heat dissipation area. At this time, the height of the heat sink 517 is formed to be the same as the height of the convex connection portion 513. In FIG. 5, the concave portion 512 is not formed on both sides of the convex connection portion 513 located on the leftmost side in the longitudinal direction, but similarly to the other convex connection portion 513, the concave portions 512 on both sides. Can be formed.

Case block connections 514 and 515 connect the cable block 510. The case block connecting portion 514 of the case block connecting portions 514 and 515 extends from the convex portion 511 and is bent in the longitudinal direction, and connects the case block 510 in the width direction. The case block connecting portion 515 of the case block connecting portions 514 and 515 extends from the convex portion 511 and is bent in the width direction, and connects the case block 510 in the longitudinal direction.

6 is a diagram illustrating a configuration of a case block according to another embodiment of the present invention.

Referring to FIG. 6, the case block 610 may have a 'c' shape and has a receiving portion 618 in a shape corresponding to an outer shape of the ultracapacitor 110. When the ultracapacitor has a cylindrical shape, the inner surface of the case block 610 contacting the outer surface of the ultracapacitor 110 may have a cylindrical round shape. The case 200 may be completed by combining two 'c' shaped case blocks, and thus an accommodating part 618 may be formed.

More specifically, as shown in FIG. 6, the case block 610 may include a plurality of convex parts 611 and convex parts 611 having the same arc shape as the outer shape of the ultracapacitor 110. Convex portion connecting portion 613 to connect, a concave portion 612 formed between the convex portion 611 and the convex portion connecting portion 613, and a case block connecting portion 614 for connecting the case block 610.

The plurality of convex portions 611 have the same arc shape as the outer side of the ultracapacitor 110 to form an accommodating portion 618 for accommodating the ultracapacitor 110, and a heat radiation pad 210 is formed therein. Attached. The heat dissipation pad 210 emits heat generated in the ultracapacitor 110 to the convex portion 611, and also functions to insulate the ultracapacitor 110 and the convex portion 611 (that is, the case 200). The convex parts 611 are connected by the convex part connecting part 613, and the tabs for fixing the upper cover and the lower cover which cover the case 200 are formed in the convex part connecting part 613. The tab is a structure for bolting (bolting) process is inserted into the bolt for fixing the case 200 and the cover.

The cave block 610 formed by connecting the plurality of convex portions 611 has a 'c' shape. In order to connect the two case blocks 610 in the width direction, the outermost convex portions are arranged in the width direction and connected, and the remaining convex portions are arranged in the longitudinal direction and connected. That is, the outermost convex portions of the plurality of convex portions 611 are connected so that arc shapes of the convex portions 611 are continued.

The recess 612 is formed between the convex portion 611 and the convex portion connecting portion 613. The concave portion 612 is formed by folding a part of the convex portion 611 outward, which is for securing an insulation distance, which will be described later. A plurality of heat sinks 617 are vertically installed at the recesses 612 at regular intervals to radiate heat generated from the ultracapacitor 110 to the outside. That is, the heat sink 617 is vertically installed at regular intervals in order to increase the heat radiation efficiency through the air flow between the heat sink 617. A plurality of heat sinks 617 are installed to widen the heat radiation area. At this time, the height of the heat sink 617 is formed to be the same as the height of the convex connection portion 613. In FIG. 6, the concave portion 612 is not formed at both sides of the convex connection portion 613 positioned at the outermost side in the longitudinal direction, but like the other convex connection portion 613, the concave portion 612 is formed at both sides. Can be formed.

The case block connecting portion 614 connects the cable block 610. The case block connecting portion 614 extends from the convex portion 611 and is bent in the longitudinal direction, and connects the case block 610 in the width direction.

The case 200 formed by the combination of the case blocks 510 and 610 described above with reference to FIGS. 5 and 6 may be formed of a metal material. The receiving portions 518 and 618 formed inside the case 200 are manufactured to maximize the shape of the ultracapacitor 110 in a form corresponding to the outer surface of the ultracapacitor 110. Therefore, the heat dissipation effect may be enhanced by maximizing the contact surface between the case 200 and the ultracapacitor 110 to increase the area where heat is released.

As described above, according to the present embodiment, the heat dissipation pad 210 is attached to the inner surfaces of the accommodating parts 518 and 618 to further improve the heat dissipation effect. That is, when the cell assembly 100 is inserted into the receiving portions 518 and 618, the receiving portion 518 may be positioned between the cell assembly 100 and the receiving portions 518 and 618. The heat dissipation pad 210 may be attached to an inner surface of the 618. The heat dissipation pad 210 may be attached to the inner surfaces of the accommodating parts 518 and 618 in the length direction of the electrode of the ultracapacitor 110. The width of the heat radiation pad 210 is smaller than the length of the arc formed by the receiving portions 518 and 618. If the width of the heat radiation pad 210 is greater than the length of the arc formed by the accommodating portions 518 and 618, a part of the heat dissipation pad 210 may not come into contact with the accommodating portions 518 and 618 to radiate heat. Because you can't. Conversely, the receptacles 518 and 618 should have an arc of length longer than the width of the heat dissipation pad 210.

The heat dissipation pad 210 may include a heat conductive filler for heat transfer, for example, metal powder or ceramic powder. Examples of the metal powder may be any one or a mixture of two or more of aluminum, silver, copper, nickel and tungsten. In addition, examples of the ceramic powder may be silicon, graphite, and carbon black. In the embodiment of the present invention is not limited to the material of the heat radiation pad 210. Alternatively, the heat dissipation pad 210 may be made of silicon synthetic rubber.

The heat dissipation pad 210 may serve to fix the ultracapacitor 110 accommodated in the case 200. That is, when the ultracapacitor 110 is accommodated in the case 200, the heat dissipation pad 210 may directly contact the ultracapacitor 110 to prevent the ultracapacitor 110 from moving. Even if the receiving portions 518 and 618 are manufactured in a form corresponding to the outer surface of the ultracapacitor 110, the intimate contact surface with the ultracapacitor 110 may not be formed, and thus, proper heat dissipation may not be achieved. Therefore, by attaching the heat dissipation pad 210 to the inner surfaces of the receiving portions 518 and 618 in contact with the ultracapacitor 110, the case 200 is fixed while the ultracapacitor 110 is fixed in the case 200. It is possible to increase the heat dissipation effect by widening the contact area between the ultracapacitor 110.

In addition, the heat radiation pad 210 may have elasticity. A plurality of ultracapacitors 110 are inserted into the case 200, and there may be a difference in diameter for each ultracapacitor 110. Accordingly, the ultracapacitor 110 may not be completely pressed onto the heat radiation pad 210. Therefore, by using the heat radiation pad 210 having elasticity in consideration of the diameter difference between the ultra-capacitor 110, all the ultra-capacitor 110 can be sufficiently compressed to the heat radiation pad 210. In this case, the thickness before the compression of the heat radiation pad 210 is preferably larger than the diameter tolerance of the ultracapacitors 110. For example, when the standard diameter of the ultracapacitors 110 is 60.7 mm and the tolerance is ± 0.7 mm, the thickness before compression of the heat radiation pad 210 is preferably greater than 1.4 mm (0.7 mm × 2), for example. Have a thickness of 2mm.

When the heat dissipation pad 210 has elasticity, when the ultra capacitor 110 is inserted into the case 200, the heat dissipation pad 210 is deformed to fit the outer shape of the ultra capacitor 110 and thus the ultra capacitor 110 is formed. Adhesion can be increased, resulting in an increase in contact area. Therefore, the heat dissipation efficiency can be further increased as the contact area is increased.

Meanwhile, in relation to the use of the heat radiation pad 210, the space between the accommodating portions 518 and 618 of the case 200 and the ultracapacitor 110 is smaller than the thickness before compression of the heat radiation pad 210 and the ultracapacitor. It is desirable to be larger than the diameter tolerance of 110. The interval between the accommodating parts 518 and 618 and the ultracapacitor 110 is an interval when the assembling of the energy storage device is completed without using the heat dissipation pad 210. The gap should be larger than the diameter tolerance of the ultracapacitors 110, because if the gap is smaller than the diameter tolerance, case assembly may be incomplete and a gap may occur. The reason why the interval should be smaller than the thickness before the heat radiation pad 210 is compressed is to allow the ultracapacitors 110 to be sufficiently compressed to the heat radiation pad 210. When the gap is smaller than the thickness before the compression of the heat radiating pad 210, the ultra-capacitors 110 to the heat-compressing pad 210 during the assembly of the case, thus fixing the ultra-capacitor 110 in the case 200 The heat dissipation effect may be enhanced by increasing the contact area between the ultracapacitor 110 and the heat dissipation pad 210.

In addition, although not shown in the drawing, one side surface of the heat radiation pad 210 may be provided with an adhesive layer to easily bond the heat radiation pad to the receiving portions 518 and 618 of the case 200. Here, the adhesive layer may further include a thermally conductive filler, such as a metal powder or a ceramic powder, to prevent the thermal conductivity from being lowered through the adhesive layer.

According to the present exemplary embodiment, the heat dissipation pad 210 is attached to the inner surface of the case 200, that is, the outer surface of the ultracapacitor 110 and the inner surface of the accommodating parts 518 and 618. The heat dissipation through the heat dissipation may be further improved, and the case 200 may be discharged by effectively transferring heat generated inside the case 200 to the outside by using a material having excellent thermal conductivity such as copper or aluminum. You can.

Conventionally, heat was mainly released by a connection member that connects the adjacent ultracapacitors 110, that is, busbars, but the busbars had a small area capable of emitting heat, so the effect was insignificant. For example, when the busbar has a horizontal length of 100 (mm) and a vertical length of 28 (mm), the area capable of dissipating heat through the busbar per ultracapacitor is 100 * 28/2 (the area of the busbar per ultra capacitor). ) * 2 (Top & Bottom side) = 2800 (mm ² ).

However, as described above, according to the present embodiment, the heat inside the case 200 may be more efficiently released to the outside by releasing heat through the side surface of the case 200, that is, by increasing the heat dissipation area. In addition, the heat dissipation performance may be further improved by attaching a heat dissipation member having excellent thermal conductivity, that is, a heat dissipation pad 210 to the inner surface of the case 200 that the ultracapacitor 110 contacts.

For example, as shown in FIG. 4, when the contact angle of the ultracapacitor contacting the heat dissipation pad 210, that is, the center angle is 60 degrees, the heat dissipation area per ultracapacitor is 2 * 3.14 * (60 (the diameter of the ultracapacitor) / 2). * 130 (length of the thermal pad) (mm) * 60 (angle) * 2/360 = 8164 (mm ² ). At this time, the reason for multiplying the angle by 2 is that the heat radiation pad 210 is attached to two places in the present embodiment. In general, the center angle is an angle made by two radii in a circle or a sector, and in the embodiment of the present invention, the center angle is a portion of the ultra-capacitor 110 that is in contact with the heat dissipation pad 210 and the ultra-capacitor 110. The angle created by the two radii that connect the two ends of. FIG. 7 is a view illustrating a center angle when the heat dissipation pad 210 and the ultracapacitor 110 contact each other according to an embodiment of the present invention. As shown in FIG. 7, the center angle α is a heat dissipation pad 210. ) And the ultracapacitor 110 is an angle formed by two radii connecting the two ends of the contact portion from the center of the ultracapacitor 110. The both ends mean both ends when the heat dissipation pad 210 is compressed between the ultracapacitor 110 and the case 200.

On the other hand, the contact angle of the ultracapacitor 110 in contact with the heat dissipation pad 210, that is, the center angle α is preferably 30 degrees to 60 degrees. The heat radiation efficiency when the center angle α is 30 degrees or more is much greater than the heat radiation efficiency when the center angle α is less than 30 degrees. The larger the contact area between the heat dissipation pad 210 and the ultracapacitor 110, that is, the greater the center angle α of the ultracapacitor 110 in contact with the heat dissipation pad 210, the better the heat dissipation efficiency. The product mass of the storage device becomes large. When the center angle α is 30 degrees to 60 degrees, the product mass is gradually increased, but when the center angle α is larger than 60 degrees, the product mass is rapidly increased. Therefore, the center angle α of the ultracapacitor 110 in contact with the heat radiating pad 210 is preferably 30 degrees to 60 degrees. This will be described with reference to the drawings.

8 is a view showing the contact shape, the heat dissipation efficiency, and the product mass of the heat radiation pad and the energy storage cell according to an embodiment of the present invention according to the angle, Figure 9 is a heat dissipation efficiency according to the contact angle according to an embodiment of the present invention And graphs showing changes in product mass.

First, the conditions for calculating the heat dissipation efficiency are shown in Table 1 below, and 18 ultracapacitors are used as energy storage cells.

Table 1

division	Substance	Density [kg / m 3 ]	Thermal conductivity [W / m · k]	Specific heat [kj / kgK]	Viscosity [Pa · s]
air	air	Incompressible Body	0.0242	1006.43	1.7894 × 10 -5
Case / cell	Al-6063-O	2,700	218	871	-
Heat resistant pad	SB-7100 S / TUTG-E	1540	1.4	871	-

Heat dissipation efficiency is calculated using the following formula.

The product mass adds the total weight of the ultracapacitors, the mass of the case, the mass of the heat dissipation pad, and the mass of the other components.

Referring to FIG. 8, an energy storage cell, that is, an ultracapacitor 110, is inserted into the accommodating parts 518 and 618 formed between the case blocks, and the ultracapacitor 110 and the inner surface of the accommodating parts 518 and 618 are inserted into the accommodating part 518 and 618. The heat dissipation pad 210 which contacts is attached. In order to increase the contact area between the ultracapacitor 110 and the heat dissipation pad 210, the width of the heat dissipation pad 210 should be increased and thus the length of the arcs of the accommodating parts 518 and 618 must be increased at the same time. . As such, when the contact area between the ultracapacitor 110 and the heat dissipation pad 210 increases, the center angle of the ultracapacitor 110 in contact with the heat dissipation pad 210 increases. The depths of the recesses 512 and 612 formed on the outer surface of the case 200 between the adjacent ultracapacitors 110 are increased.

In FIG. 9, the left Y axis represents heat dissipation efficiency and the right Y axis represents product mass. In FIG. 9, reference numeral 910 is a heat dissipation efficiency and reference numeral 920 is a graph of product mass. As shown in FIG. 8 and FIG. 9, when the center angle α of the ultracapacitor 110 in contact with the heat radiation pad 210 is increased, the heat radiation efficiency of the energy storage device is improved. In particular, when the center angle α is 30 degrees or more, the heat dissipation efficiency is drastically improved than when the center angle α is less than 30 degrees. For example, when the center angle α is 10 degrees, the heat radiation efficiency is 90.66%. When the center angle α is 30 degrees, the heat radiation efficiency is 97.28%. When the center angle α is 30 degrees, the heat radiation efficiency is very good. The numbers indicated along the heat dissipation efficiency graph in FIG. 9 indicate an increase in heat dissipation efficiency per degree. For example, when the center angle α increases from 10 degrees to 20 degrees, the heat radiation efficiency increases by 0.36% point (3.6% ÷ 10) per degree on average. When the central angle α increases from 20 degrees to 25 degrees, the heat dissipation efficiency increases by 0.30% point per degree on average. As shown in FIG. 9, the heat dissipation efficiency is greatly increased to the center angle α of 30 degrees, and the increase in heat dissipation efficiency is slowed at the central angle α. Therefore, the center angle α of the ultracapacitor 110 in contact with the heat radiation pad 210 is preferably 30 degrees or more.

However, when the center angle α of the ultracapacitor 110 in contact with the heat dissipation pad 210 becomes greater than 30 degrees, the product mass of the energy storage device increases accordingly. The reason is that the width of the heat dissipation pad 210 increases, so that the mass of the heat dissipation pad 210 increases, and the length of the arcs of the accommodating parts 518 and 618 also increases simultaneously, between the adjacent ultracapacitors 110. The concave portions 512 and 612 formed on the outer surface of the case 200 are increased in depth to increase the mass of the case 200. As shown in Figs. 8 and 9, the product mass gradually increases until the center angle α becomes 60 degrees, but when the center angle α exceeds 60 degrees, the product mass rapidly increases. That is, the product mass increase rate at the center angle α exceeding 60 degrees is greater than the product mass increase rate at the center angle α below 60 degrees. The numbers indicated along the product mass graph in FIG. 9 indicate the increase in product mass per degree. For example, when the center angle α increases from 10 degrees to 20 degrees, the product mass increases by 0.25% point (2.5% ÷ 10) per degree. When the central angle α increases from 20 degrees to 22.5 degrees, the product mass increases by 0.23 percentage points per degree on average. As shown in FIG. 9, the product mass gradually increases up to 60 degrees of the central angle α, and the product mass rapidly increases when the central angle α exceeds 60 degrees. For example, when the center angle (α) increases from 55 degrees to 60 degrees, the product mass increases by 0.34 percentage points per degree, while when the center angle (α) increases from 60 degrees to 65 degrees, the product mass increases by 0.45 percentage points per degree. This greatly increases. Therefore, the center angle α of the ultracapacitor 110 in contact with the heat radiation pad 210 is preferably 30 degrees to 60 degrees.

FIG. 10 is an enlarged view of a portion A of FIG. 2. Referring to FIG. 10, the distance 1010 between the case 200 and the ultracapacitor 110 gradually increases from the recesses 512 and 612 formed by folding the case 200 back. That is, the distance 1010 between the case 200 and the ultracapacitor 110 is gradually increased from the tips of the recesses 512 and 612. The case 200 away from the adjacent concave portions 512 and 612 of a particular cell meets the case 200 away from the adjacent concave portions 512 and 612 of the neighboring cell at the convex connection portions 513 and 613. To achieve. As described above, the heat dissipation pad 210 functions to insulate between the case 200 and the ultracapacitor 110 in addition to the heat dissipation function. From the portion where the heat dissipation pad 210 is not present, that is, the point at which the heat dissipation pad 210 ends, the distance 200 between the case 200 and the ultracapacitor 110 is indirectly increased, thereby indirectly the case 200 and the ultracapacitor 110. Insulation between them. As an insulation measure other than securing the insulation distance, an insulation film may be applied to the outer surface of each cell, or an insulation coating may be applied. In addition, as shown in FIG. 10, a space 1020 in which a harness for sensing and balancing is installed is formed between the neighboring ultracapacitor 110 and the case 200. The harness passes through this space 1020 and further heats up with the flow of air present in this space 1020.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

Claims (18)

1. A cell assembly formed by connecting at least two cylindrical energy storage cells in series;

   A case accommodating the cell assembly, the housing having a shape corresponding to an outer surface of the energy storage cell; And

   And a heat dissipation pad disposed between an outer side surface of the energy storage cell of the cell assembly and an inner side surface of the receiving portion.

   The case includes at least two case blocks,

   And the receiving portion is formed by the combination of the case blocks.
2. The method of claim 1,

   And a center angle of the energy storage cell in contact with the heat radiating pad is 30 degrees to 60 degrees.
3. The method of claim 2,

   The length of the arc (arc) formed by the accommodating portion, characterized in that more than the length of the heat radiation pad.
4. The method of claim 1,

   The heat dissipation pad has elasticity,

   The space between the receiving portion and the energy storage cell, energy storage device, characterized in that less than the thickness before the compression pad of the heat dissipation pad and larger than the diameter tolerance of the energy storage cells.
5. The method according to any one of claims 1 to 4,

   The heat dissipation pad is attached to the energy storage cell.
6. The method according to any one of claims 1 to 4,

   The heat dissipation pad is an energy storage device, characterized in that the heat conducting filler.
7. The method according to any one of claims 1 to 4,

   An energy storage device having improved heat dissipation performance, characterized in that an adhesive layer is provided on one side of the heat dissipation pad.
8. The method according to any one of claims 1 to 4,

   The energy storage cell is an energy storage device, characterized in that the heat dissipation characteristics, characterized in that the ultracapacitor.
9. The method according to any one of claims 1 to 4,

   The case block,

   A plurality of convex portions having the same arc shape as the outer shape of the energy storage cell;

   A convex portion connecting portion connecting the plurality of convex portions; And

   And a concave portion formed between the convex portion and the convex portion connecting portion.
10. The method of claim 9,

    At least one heat sink protrudes vertically in the concave portion.
11. The method of claim 9,

    The case block,

    Energy storage device, characterized in that any one of the 'L' shape or '' 'shape.
12. The method of claim 11,

    When the case block has an 'L' shape,

    One of the outermost convex portions of the plurality of convex portions is connected to the arc shape of the convex portion is connected.
13. The method of claim 12,

    The case block,

    And a case block connecting portion extending from one of the outermost convex portions and bent in a length direction of the case block.
14. The method of claim 11,

    If the case block is a 'c' shape,

    The outermost convex portions of the plurality of convex portions, the energy storage device, characterized in that connected so that the arc (arc) shape of the convex portion continues.
15. The method of claim 14,

    The case block,

    And a case block connecting portion extending from each of the outermost convex portions and bent in the longitudinal direction of the case block.
16. The method of claim 9,

    The convex connection portion is an energy storage device, characterized in that the tab for fixing the cover is formed.
17. The method of claim 1,

    The energy storage device, characterized in that the distance between the energy storage cell and the case away from the end point of the heat radiation pad to insulate between the energy storage cell and the case.
18. The method of claim 1,

    Energy storage device, characterized in that the insulating film is further formed on the outer surface of the energy storage cell.

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