KR20160022207A - Energy storage device having improved heat-dissipating - Google Patents

Abstract

The present invention discloses an energy storage device having improved heat dissipation. The energy storage device according to the present invention includes a cell assembly where at least two cylindrical energy storage cells are connected in series; a case which comprises an accommodating part of which the shape corresponds to the outside of the energy storage cell and accommodates the cell assembly; and a heat dissipation pad which is installed between the outside of the energy storage cell of the cell assembly and the inside of the accommodating part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy storage device having improved heat dissipation characteristics,

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

In general, an Ultra Capacitor is an energy storage device having an intermediate property between an electrolytic capacitor and a secondary battery, which is also referred to as a super capacitor. Due to its high efficiency and semi-permanent lifetime characteristics, It is the next generation electric energy storage device.

Ultracapacitors are also used to replace batteries for applications where maintenance is not easy and long service life is required. Ultracapacitors have fast charging and discharging characteristics and thus can be used not only as auxiliary power sources for mobile communication information devices such as mobile phones, laptops and PDAs, but also for electric vehicles requiring high capacity, nighttime road signs, main power sources such as UPS (Uninterrupted Power Supply) Or an auxiliary power source, and is widely used for such a purpose.

In applying such ultracapacitors, thousands of Farads or hundreds of volts of high voltage modules are required for use as high voltage cells. The high-voltage module can be constructed by connecting a plurality of ultracapacitors in a required number and connecting them in the case.

1 is a view showing a configuration of a conventional ultracapacitor module.

As shown in FIG. 1, a conventional ultracapacitor module has a plurality of ultracapacitors connected to electrode terminals by a bus bar and coupled by a nut to form an ultracapacitor array 10, and the ultracapacitor array 10 are housed in a case 20 and can be constructed by covering the upper and lower lower openings of the case 20 housing the ultracapacitor array 10 with the plates 30 and 40.

At this time, the ultracapacitor module can improve energy storage characteristics by driving a plurality of ultracapacitors, but the heat generated when the ultracapacitor module is driven sharply increases together, so that the reliability and stability of the ultracapacitor module may be deteriorated.

Accordingly, in the conventional ultracapacitor module according to the related art, heat is mainly dissipated through metal plates on the upper and lower surfaces covering the bus bar and the case, which are connecting members connecting the adjacent ultracapacitors. The side surface of the case is made of synthetic resin to reduce the weight of the ultracapacitor module and reduce the production cost, and the side surface of the case is in the form of a plate, so that the area of contact with the ultracapacitor is small.

According to the conventional technology, the ultracapacitor can radiate heat mainly through the bus bar. Since the bus bar has a small heat dissipation area, heat can not be efficiently radiated. As the temperature inside the case rises, There is a problem that the lifetime of the battery is reduced.

Korean Patent No. 10-1341474 (published on December 13, 2013)

The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an energy storage device in which energy storage cells such as ultracapacitors are housed in a case, The purpose is to provide.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided an energy storage device including: a cell assembly having at least two or more cylindrical energy storage cells connected in series; A case having a receiving portion having a shape corresponding to an outer surface of the energy storage cell, the case housing the cell assembly; And a heat dissipation pad disposed between an outer surface of the energy storage cell of the cell assembly and an inner surface of the accommodation portion.

The center angle of the energy storage cell in contact with the heat dissipation pad may range from 30 degrees to 60 degrees.

The length of the arc formed by the receiving portion may be greater than or equal to the length of the heat-radiating pad.

The gap between the receiving portion and the energy storage cell may be smaller than the thickness before pressing of the heat radiation pad and may be larger than the diameter tolerance of the energy storage cells.

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

The heat dissipation pad may be a heat conduction filler.

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

The energy storage cell may be an ultracapacitor.

The case includes at least two case blocks, and the receiving portion can be formed by engaging the case blocks.

The case block includes: a plurality of convex portions having an arc shape identical to an outer shape of the energy storage cell; A convex 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 radiating plate may be vertically protruded from the concave portion.

The case block may be either an 'L' character shape or a 'C' character shape.

When the case block is L-shaped, one of the outermost protrusions of the plurality of protrusions may be connected so that an arc shape of the protrusions continues.

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

When the case block is 'C' shaped, 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 being bent in the longitudinal direction of the case block.

A tab for fixing the cover may be formed on the convex portion connection portion.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention. And should not be construed as limiting.
Figure 1 shows a prior art energy storage module,
FIG. 2 illustrates a configuration of an energy storage device according to an embodiment of the present invention. FIG.
FIG. 3 illustrates a connection between energy storage cells according to another embodiment of the present invention; FIG.
4 is a cross-sectional view taken along a line II-II 'in FIG. 2,
5 is a view showing a configuration of a case block according to an embodiment of the present invention.
6 is a view showing a configuration of a case block according to another embodiment of the present invention.
7 is a view showing a central angle when the heat dissipating pad and the energy storage cell are in contact with each other according to an embodiment of the present invention.
FIG. 8 is a view showing the contact shape, heat dissipation efficiency, and product mass of the heat dissipating pad and the energy storage cell according to an embodiment of the present invention.
9 is a graph showing changes in heat dissipation efficiency and product mass according to the contact angle according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims are to be construed in accordance with the technical idea of the present invention based on the principle that the concept of a term can be properly defined in order to describe its own invention in the best way It must be interpreted as meaning and concept. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 2 is a view illustrating a configuration of an energy storage device according to an embodiment of the present invention. FIG. 3 is a view illustrating a connection between energy storage cells according to another embodiment of the present invention. Sectional view taken along line II 'in FIG.

2 to 4, an energy storage device according to an embodiment of the present invention includes a cell assembly 100 in which at least two energy storage cells 110 are connected in series, a case 200 for accommodating the cell assembly 100, ).

The cell assembly 100 may include at least two energy storage cells 110 connected in series. The energy storage cell 110 may be an ultracapacitor. In this embodiment, the energy storage cell is an ultra capacitor. However, the energy storage cell is not limited to a cell capable of storing electric energy such as a secondary battery and a battery.

The ultracapacitor 110 has fast charging and discharging characteristics and accordingly can be used not only as an auxiliary power source for a mobile communication information device such as a mobile phone, a notebook computer, a PDA, etc., but also an electric car or a hybrid vehicle requiring a high capacity, (Uninterruptible Power Supply: UPS) or the like.

The ultracapacitor 110 may have a cylindrical shape and may be connected in series with another ultracapacitor in the longitudinal direction in which the electrode is formed, as shown in FIG. 2, to configure the cell assembly 100. At this time, the connection of the adjacent ultracapacitor may be connected by a connecting member, for example, a nut and a bus bar.

3, the positive terminal of the first ultracapacitor and the negative terminal of the second ultracapacitor may be connected to the bus bar 130 and the nut 150, And the cell assembly 100 can be formed by connecting them in series using the same connecting member. The plurality of ultracapacitors are connected to the positive terminal and the negative terminal by the bus bar 130 and are coupled by the nuts 150 to form the cell assembly 100. The cell assembly 100 includes a case 200 ) To constitute an ultracapacitor module.

The case 200 may receive the cell assembly 100 in which the ultracapacitor 110 is connected in series. The case 200 may have a receiving portion having a shape corresponding to the outer surface of the ultracapacitor 110 to receive the cell assembly 100 formed by connecting the ultracapacitor 110 in series.

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

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

5, the case block 510 may have an L shape and may have a receiving portion 518 corresponding to the external shape of the ultracapacitor 110. When the ultracapacitor has a cylindrical shape, the inner surface of the case block 510 which contacts the outer surface of the ultracapacitor may have a cylindrical round shape, and four case blocks of the 'L' And thus the receiving portion 518 can be formed.

5, the case block 510 includes a plurality of convex portions 511 and convex portions 511 having the same arc shape as the external shape of the ultracapacitor 110 A concave portion 512 formed between the convex portion 511 and the convex portion connection 513 and a case block connection portion 514 and 515 connecting the case block 510 to each other.

The plurality of convex portions 511 have the same arc shape as the outer side of the ultracapacitor 110 to form the accommodating portion 518 for accommodating the ultracapacitor 110, Respectively. These convex portions 511 are connected by the convex connecting portion 513 and the convex connecting portion 513 is formed with a tab for fixing the upper cover and the lower cover which cover the case 200. [

One of the outermost convex portions is arranged in the width direction so that the cube block 510 formed by connecting the plurality of convex portions 511 has an L shape and connects the case block 510 in the width direction And the remaining convex portions are connected in a longitudinal direction. That is, one of the outermost convex portions in the longitudinal direction of the plurality of convex portions 511 is connected so that the convex portion 511 has an arc shape.

The concave portion 512 is formed between the convex portion 511 and the convex portion 513. A plurality of heat sinks 517 are vertically installed in the recess 512 at regular intervals to discharge heat generated in the ultracapacitor 110 to the outside. That is, the heat sinks 517 are vertically installed at regular intervals to increase the heat radiation efficiency through the air flow between the heat sinks 517, and a plurality of heat sinks 517 are installed to widen the heat radiation area. At this time, the height of the heat sink 517 is formed to be equal to the height of the convex portion 513. 5, the concave portion 512 is not formed on both sides of the convex portion connecting portion 513 located at the leftmost position in the longitudinal direction. However, like the other convex portion connecting portion 513, the concave portion 512 is formed on both sides, Can be formed.

The case block connecting portions 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 to connect 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 to connect the case block 510 in the longitudinal direction.

6 is a view showing a configuration of a case block according to another embodiment of the present invention.

6, the case block 610 may have a "C" shape and has a receiving portion 618 of a shape corresponding to the external shape of the ultracapacitor 110. When the ultracapacitor is in the shape of a cylinder, the inner side of the case block 610, which contacts the outer surface of the ultracapacitor, may have a round cylindrical shape, and two case blocks of the ' And thus the receiving portion 618 can be formed.

6, the case block 610 includes a plurality of convex portions 611, convex portions 611 having the same arc shape as the external shape of the ultracapacitor 110 A concave portion 612 formed between the convex portion 611 and the convex portion connecting portion 613 and a case block connecting portion 614 connecting the case block 610 to each other.

The plurality of convex portions 611 have the same arc shape as the outer shape of the ultracapacitor 110 to form a receiving portion 618 for receiving the ultracapacitor 110, Respectively. These convex portions 611 are connected by the convex connecting portion 613 and the convex connecting portion 613 is formed with an upper cover for covering the case 200 and a tab for fixing the lower cover.

In order to connect the two case blocks 610 in the width direction, the cube block 610 formed by connecting the plurality of convex portions 611 is arranged in the width direction and connected And the remaining convex portions are arranged in the longitudinal direction and connected. In other words, the outermost convex portions of the plurality of convex portions 611 are connected so as to form an arc shape of the convex portion 611.

The concave portion 612 is formed between the convex portion 611 and the convex portion connecting portion 613. A plurality of heat sinks 617 are vertically installed in the concave portion 612 at regular intervals to discharge heat generated in the ultracapacitor 110 to the outside. That is, the heat sinks 617 are vertically installed at regular intervals to increase the heat radiation efficiency through the air flow between the heat sinks 617, and a plurality of heat sinks 617 are installed to widen the heat radiating area. At this time, the height of the heat radiating plate 617 is formed to be equal to the height of the convex connecting portion 613. 6, the concave portion 612 is not formed on both sides of the convex portion connecting portion 613 located at the outermost position in the longitudinal direction. However, like the other convex portion connecting portion 613, the concave portion 612 is formed on 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 to connect the case block 610 in the width direction.

The case 200 formed by combining the case blocks 510 and 610 described above with reference to FIGS. 5 and 6 may be formed of a metal material and may include a receiving portion 518 formed in the case 200, 618 may maximize the contact surface with the ultracapacitor by increasing the area of the ultracapacitor so as to maximize the heat dissipation effect by maximizing the shape of the ultracapacitor in a shape corresponding to the outer surface of the ultracapacitor.

As described above, according to the present embodiment, the heat radiation pads 210 are attached to the inner surfaces of the receiving portions 518 and 618 to further improve the heat radiation effect. That is, when the cell assembly 100 is inserted into the accommodating portions 518 and 618, the accommodating portions 518 and 618 may be positioned between the cell assembly 100 and the accommodating portions 518 and 618, And 618, respectively. The heat radiating pad 210 may be attached to the inner surfaces of the receiving portions 518 and 618 in the electrode longitudinal direction of the ultracapacitor 110. The width of the heat radiating pad 210 is smaller than the length of the arc formed by the receiving portions 518 and 618. If the width of the heat radiating pad 210 is larger than the length of the arc formed by the accommodating portions 518 and 618, a part of the heat radiating pad 210 does not come into contact with the accommodating portions 518 and 618, I can not. Conversely, the receptacles 518 and 618 must have arcs that are longer than the width of the heat-radiating pad 210.

The heat dissipation pad 210 may include a heat conductive filler for heat transfer, for example, a metal powder or a 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. Further, examples of the ceramic powder may be silicone, graphite, and carborn black. The material of the heat radiation pad 210 is not limited to the material of the embodiment of the present invention. Alternatively, the material of the heat dissipation pad 210 may be a silicone synthetic rubber.

The heat dissipation pad 210 may serve to fix an ultracapacitor accommodated in the case 200. That is, when the ultracapacitor is accommodated in the case 200, the heat dissipating pad 210 may directly prevent the ultracapacitor from moving, thereby preventing the ultracapacitor from moving. Even if the accommodating portions 518 and 618 are formed in a shape corresponding to the outer surface of the ultracapacitor, a close contact surface with the ultracapacitor 110 may not be formed, and proper heat dissipation may not be achieved. Therefore, the heat dissipation pad 210 is attached to the inner surfaces of the accommodating portions 518 and 618 that are in contact with the ultracapacitor 110, thereby fixing the ultracapacitor 110 in the case 200, ) And the ultracapacitor 110 can be widened to enhance the heat radiating effect.

Also, the heat dissipation pad 210 may have elasticity. A plurality of ultracapacitors 110 may be inserted into the case 200. The ultracapacitors 110 may have different diameters and thus the ultracapacitor 110 may not be completely pressed onto the heat radiating pad 210. [ Therefore, considering the difference in diameter between the ultracapacitors 110, using the elastic heat-radiating pads 210 allows all the ultracapacitors 110 to be sufficiently pressed to the heat-dissipating pads 210. At this time, it is preferable that the thickness of the heat dissipation pad 210 before compression is 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 of the heat-dissipating pad 210 before compression is preferably larger than 1.4 mm (0.7 mm 2) So as to have a thickness of 2 mm.

The heat dissipation pad 210 may be deformed to conform to the external shape of the ultracapacitor 110 when the ultracapacitor 110 is inserted into the case 200 when the heat dissipation pad 210 is elastic, So that the contact area is increased. Therefore, the heat radiation efficiency can be further increased as the contact area increases.

The gap between the accommodating portion 300 of the case 200 and the ultracapacitor 110 is smaller than the thickness of the ultraviolet absorber pad 210 before compression of the heat dissipating pad 210, The diameter tolerances of the first and second layers are preferably larger. Here, the distance between the accommodating portions 518 and 618 and the ultracapacitor 110 is an interval when the assembly of the energy storage device is completed without using the heat-radiating pad 210. The reason why the gap is larger than the diameter tolerance of the ultracapacitors 110 is that if the gap is smaller than the diameter tolerance, the case assembly becomes incomplete and a gap may occur. The reason why the gap is smaller than the thickness before squeezing of the heat-radiating pad 210 is that the ultracapacitors 110 can be sufficiently pressed on the heat-radiating pad 210. When the gap is smaller than the thickness before compression bonding of the heat dissipation pad 210, the ultracapacitors 110 compress the heat dissipation pad 210 during assembly of the case, and thus the ultracapacitor 110 is fixed in the case 200 The contact area between the ultracapacitor 110 and the heat radiating pad 210 can be widened to enhance the heat radiating effect.

Although not shown in the drawing, an adhesive layer may be provided on one side of the heat-radiating pad 210 to easily bond the heat-radiating pad to the receiving portions 518 and 618 of the case 200. The adhesive layer may further include a heat conductive filler such as a metal powder or a ceramic powder to prevent the thermal conductivity from being lowered through the adhesive layer.

The heat dissipation pad 210 may be attached to the inner surface of the housing 200 or the inner surface of the accommodating portion 518 or 618 corresponding to the outer surface of the ultracapacitor 110, The case 200 can be made of a material having a high thermal conductivity such as copper or aluminum to effectively transmit the heat generated in the case 200 to the outside Can be released.

Conventionally, heat is mainly emitted by the connecting member connecting the adjacent ultracapacitors 110, that is, the bus bar. However, the area where the bus bar can radiate heat is small and the effect is insignificant. For example, when the bus bar has a length of 100 (mm) and a length of 28 (mm), the area capable of radiating heat through the bus bar per one ultracapacitor is 100 * 28 / ) * 2 (Top & Bottom side) = 2800 (mm ² ).

However, as described above, according to the present embodiment, the heat inside the case 200 can be discharged to the outside more efficiently by discharging the heat through the side surface of the case 200, that is, by increasing the heat radiation area. Further, by attaching the heat radiating member having excellent thermal conductivity, that is, the heat radiating pad 210, to the inner surface of the case 200 in contact with the ultracapacitor 110, the heat radiating performance can be further improved.

For example, as shown in FIG. 4, when the contact angle, that is, the central angle of the ultracapacitor in contact with the heat dissipating pad 210 is 60 degrees, the heat dissipating area per one ultracapacitor is 2 * 3.14 * (60 (diameter of the ultra capacitor) / 2) * 130 (length of heat dissipation pad) (mm) * 60 (angle) * 2/360 = 8164 (mm ² ) The reason why the angle is multiplied by 2 is that the heat dissipation pad 210 is attached to two places in this embodiment. In general, the center angle is an angle formed by two radii in a circle or a sector. In the embodiment of the present invention, the center angle is a distance from a center of the ultracapacitor 110 to a portion contacting the center of the ultracapacitor 110 when the heat- It is the angle made by the two radii that connect the ends of. 7 is a view showing a central angle when the heat radiating pad 210 and the ultracapacitor 110 are in contact with each other according to an embodiment of the present invention. ) And the ultracapacitor 110 are in contact with each other, the two radii connecting the ends of the contact portion of the ultracapacitor 110 are formed. The opposite ends of the heat sink pad 210 are both ends of the heat sink pad 210 when the heat sink pad 210 is pressed between the ultracapacitor 110 and the case 200.

The contact angle of the ultracapacitor 110 in contact with the heat dissipation pad 210, that is, the central angle?, Is preferably in the range of 30 to 60 degrees. The heat radiation efficiency when the central angle alpha is 30 degrees or more is much larger than the heat radiation efficiency when the central angle alpha is less than 30 degrees. The larger the contact area between the heat radiating pad 210 and the ultracapacitor 110 is, that is, the greater the central angle? Of the ultracapacitor 110 in contact with the heat radiating pad 210, the better the heat dissipation efficiency. The product mass of the storage device becomes large. When the central angle alpha is in the range of 30 to 60 degrees, the product mass gradually increases, but when the central angle alpha is larger than 60 degrees, the mass of the product increases sharply. Therefore, the center angle alpha of the ultracapacitor 110 contacting the heat dissipation pad 210 is preferably in the range of 30 to 60 degrees. This will be described with reference to the drawings.

FIG. 8 is a view showing the contact shape, heat dissipation efficiency, and product mass of the heat dissipating pad and the energy storage cell according to an embodiment of the present invention, and FIG. 9 is a graph showing heat dissipation efficiency according to the contact angle according to an embodiment of the present invention And the mass of the product.

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

division Material name density
[kg / m ³ ] Thermal conductivity
[W / m · k] specific heat
[kj / kgK] Viscosity
[Pa · s] air air Incompressible
Ideal gas 0.0242 1006.43 1.7894 × 10 ^-5 Case / cell Al-6063-O 2,700 218 871 - Heat-radiating pad SB-7100 S / TUTG-E 1540 1.4 871 -

The 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 pad, and the mass of the other components.

8, an energy storage cell, that is, an ultracapacitor 110 is inserted into the accommodating portions 518 and 618 formed between the case blocks, and an ultracapacitor 110 and a capacitor are formed on the inner surfaces of the accommodating portions 518 and 618, And a heat dissipating pad 210 which is in contact therewith is attached. In order to increase the contact area between the ultracapacitor 110 and the heat radiating pad 210, the width of the heat radiating pad 210 must be increased and the arc length of the accommodating portions 518 and 618 must be simultaneously increased . 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 adjacent ultracapacitors 110 increase.

In FIG. 9, the left Y-axis represents heat dissipation efficiency and the right Y-axis represents product mass. 9, reference numeral 910 denotes a heat dissipation efficiency, and reference numeral 920 denotes a product mass. As shown in FIGS. 8 and 9, when the center angle? Of the ultracapacitor 110 in contact with the heat radiating pad 210 is increased, the heat radiation efficiency of the energy storage device is improved. In particular, when the central angle? Is 30 degrees or more, the heat dissipation efficiency sharply increases as compared with the case where the central angle? Is less than 30 degrees. For example, when the central angle α is 10 °, the heat radiation efficiency is 90.66%. When the central angle α is 30 °, the heat radiation efficiency is 97.28%, and when the central angle α is 30 °, the heat radiation efficiency is extremely improved. Therefore, the center angle alpha of the ultracapacitor 110 in contact with the heat dissipation pad 210 is preferably 30 degrees or more.

However, if the central angle alpha of the ultracapacitor 110 in contact with the heat dissipation pad 210 is increased to 30 degrees or more, the product mass of the energy storage device increases accordingly. This is because the width of the heat dissipation pad 210 increases and the mass of the heat dissipation pad 210 increases and the arc length of the accommodating portions 518 and 618 also increases simultaneously, The depth of the recesses 512 and 612 formed on the outer surface of the case 200 of the case 200 increases and the mass of the case 200 also increases. As shown in FIGS. 8 and 9, the mass of the product gradually increases until the central angle alpha becomes 60 degrees, but when the central angle alpha exceeds 60 degrees, the product mass sharply increases. That is, the product mass increase rate at a central angle alpha of more than 60 degrees is greater than the product mass increase rate at the central angle alpha of 60 degrees or less. Therefore, the center angle alpha of the ultracapacitor 110 in contact with the heat radiating pad 210 is preferably in the range of 30 to 60 degrees.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

100: cell assembly
110: Energy storage cell
200: Case
210: heat-radiating pad
430: heat radiating plate

Claims (17)

A cell assembly in which at least two or more cylindrical energy storage cells are connected in series;
A case having a receiving portion having a shape corresponding to an outer surface of the energy storage cell, the case housing the cell assembly; And
And a heat dissipation pad disposed between the outer surface of the energy storage cell of the cell assembly and the inner surface of the receiving portion. The method according to claim 1,
Wherein a center angle of the energy storage cell in contact with the heat dissipation pad is 30 degrees to 60 degrees. 3. The method of claim 2,
Wherein a length of an arc formed by the accommodating portion is equal to or greater than a length of the heat-radiating pad. The method according to claim 1,
The heat dissipation pad has elasticity,
Wherein an interval between the accommodating portion and the energy storage cell is smaller than a thickness before compression of the heat radiation pad and is larger than a diameter tolerance of the energy storage cells. 5. The method according to any one of claims 1 to 4,
Wherein the heat dissipation pad is attached to the energy storage cell. 5. The method according to any one of claims 1 to 4,
Wherein the heat dissipation pad is a heat conduction filler. 5. The method according to any one of claims 1 to 4,
And an adhesive layer is provided on one side surface of the heat dissipation pad. 5. The method according to any one of claims 1 to 4,
Wherein the energy storage cell is an ultracapacitor. 5. The method according to any one of claims 1 to 4,
Wherein the case includes at least two case blocks,
And the accommodating portion is formed by engagement of the case block. 10. The method of claim 9,
In the case block,
A plurality of convex portions having the same arc shape as the outer shape of the energy storage cell;
A convex connecting portion connecting the plurality of convex portions; And
And a concave portion formed between the convex portion and the convex portion connecting portion. 11. The method of claim 10,
Wherein at least one heat sink is vertically protruded from the concave portion. 11. The method of claim 10,
In the case block,
Shaped or an " a " -shape. ≪ / RTI > 13. The method of claim 12,
When the case block has an L shape,
Wherein one of the outermost convex portions of the plurality of convex portions is connected so as to form an arc shape of the convex portion. 14. The method of claim 13,
In the case block,
And a case block connection portion extending from one of the outermost convex portions and bent in the longitudinal direction of the case block. 13. The method of claim 12,
When the case block is in a " C " shape,
Wherein the outermost protrusions of the plurality of protrusions are connected to each other so as to form an arc shape of the protrusions. 16. The method of claim 15,
In 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. 11. The method of claim 10,
And a tab for fixing the lid is formed on the convex portion connecting portion.

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