Patent Application
20100216011
This application claims the benefit of Korean Application No. 10-2009-0016316, filed Feb. 26, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
Aspects of the present invention relate to a battery pack.
2. Description of the Related Art
Secondary batteries may be manufactured and used in an individual battery (that is, in a bare cell) according to types of apparatuses using the secondary batteries. However, the secondary batteries may be manufactured and used in a battery pack formed of a plurality of individual batteries. When the plurality of bare cells is manufactured as a battery pack, the bare cells are electrically connected to each other via a lead plate.
The lead plate is generally formed from a thin flat plate. When one bare cell is connected to another bare cell, the lead plate is bent such as to be connected with a side of each of the two bare cells. Therefore, the lead plate needs to be smoothly bent (bent more easily than a conventional lead plate without the hole or the groove) such that no damage occurs in a bent portion thereof.
Aspects of the present invention provide a battery pack having a lead plate that can be smoothly bent and does not become damaged by vibration.
According to an aspect of the present invention, there is provided a battery pack including: a plurality of bare cells including a first bare cell and a second bare cell; and a lead plate electrically connecting the first bare cell and the second bare cell, wherein a hole is formed in a bent area of the lead plate.
The hole may be located at a middle of a width between a first length side and a second length side of the lead plate and/or may be located at a middle of a length between a first width side and a second width side of the lead plate.
The hole may have a substantially circular shape, and/or the hole may have a diameter of about 0.2 mm to about 1 mm.
According to another aspect of the present invention, there is provided a battery pack including: a plurality of bare cells including a first bare cell and a second bare cell; and a lead plate electrically connecting the first bare cell and the second bare cell, wherein a groove is formed in a bent area of the lead plate.
The groove may be formed in a straight line shape parallel to a width direction between a first length side and a second length side of the lead plate.
The groove may include a plurality of sub grooves arranged parallel to a width direction between a first length side and a second length side of the lead plate, and each of the plurality of sub grooves may be formed to have a substantially circular shape.
The groove may be located at a middle of a width between a first length side and a second length side of the lead plate, and may be located at a middle of a length between a first width side and a second width side of the lead plate.
The groove may have a depth less than about 5/100 mm, and may have a length with a ratio to a width between a first length side and a second length side of the lead plate of 1:3 to 1:2.
A first side of the groove, closest to a first length side of the lead plate, and a second side of the groove, closest to a second length side of the lead plate, may be spaced apart from the first length side and the second length side of the lead plate, respectively.
According to yet another aspect of the present invention, there is provided a lead plate of a battery pack including a first bare cell and a second bare cell, the lead plate including: a bent area with a hole formed therein to allow the lead plate to be smoothly bent and to prevent the lead plate from breaking by a vibration thereof, wherein the lead plate connects the first bare cell and the second bare cell.
According to still another aspect of the present invention, there is provided a lead plate of a battery pack including a first bare cell and a second bare cell, the lead plate including: a bent area with a groove formed therein to allow the lead plate to be smoothly bent and to prevent the lead plate from breaking by a vibration thereof, wherein the lead plate connects the first bare cell and the second bare cell.
According to another aspect of the present invention, there is provided a method of connecting a first bare cell to a second bare cell in a battery pack, the method including: forming a hole or a groove in a middle area of a lead plate; bending the lead plate at the middle area thereof; connecting the first bare cell to a first side of the bent lead plate, and the second bare cell to a second side, opposite the first side, of the bent lead plate.
Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.
Hereinafter, a battery pack 10 according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Each of the plurality of bare cells 100 may include an electrode assembly (not illustrated), a can accommodating the electrode assembly, and a cap assembly coupled at an opening of the can accommodating the electrode assembly.
In
The bare cells 100 may be connected in series by the lead plate 200 including a first lead plate 210 provided at a B1 electric potential end between the first bare cell 110 and the second bare cell 120, and a second lead plate 220 provided at a B2 electric potential end between the second bare cell 120 and the third bare cell 130. The lead plate 200 and bare cells 100 may be coupled to each other by welding. The lead plate 200 may be bent at a middle portion thereof and may be formed in a substantially flattened C shape. Furthermore, the lead plate 200 may be made of a metal having high electric conductibility, such as copper, nickel, aluminum, etc. The lead plate 200 may be directly electrically connected with the protective circuit module 400, though it is understood that aspects of the present invention are not limited thereto. For example, according to other aspects, the lead plate 200 may be electrically connected with the protective circuit module 200 via a cover lay film on which conductive metal patterns are formed. The structure of the lead plate 200 will be described in detail later.
A terminal plate 300 may be located on the positive terminal of the first bare cell 110 and the negative terminal of the third bare cell 130 (not shown). The terminal plate 300 may be formed of a metal having high electric conductibility, such as copper, nickel, aluminum, etc. Moreover, the terminal plate 300 may be directly electrically connected with the protective circuit module 400, though it is understood that aspects of the present invention are not limited thereto. For example, according to other aspects, the terminal plate 300 may be electrically connected with the protective circuit module 400 via the cover lay film on which conductive metal patterns are formed.
The protective circuit module 400 may be provided at a side of the bare cells 100, and may be electrically connected to the lead plates 200 and the terminal plates 300. The protective circuit module 400 may include protective circuit devices and connectors. Furthermore, the protective circuit module 400 may check a charge-discharge state, a current, a voltage, and a temperature of the bare cells 100 to protect the battery pack 10.
Hereinafter, the lead plate 200 will be explained in detail. In the embodiment illustrated in
The lead plate 210 may be formed in a flat plate of which the length L is larger than the width W thereof. The length sides of the lead plate 210 include a first length side 210a and a second length side 210b. Two width sides of the lead plate 210 are referred to as a first width side 210c and a second width side 210d, respectively. The first and second width sides 210c and 210d may be formed in a curve as illustrated in
Furthermore, the lead plate 210 may be bent at a middle portion thereof to connect the first bare cell 110 and the second bare cell 120. Here, the bent middle portion of the lead plate 210 is referred to as a bent area B. As illustrated, a hole 211 is formed in the bent area B to pass through the lead plate 210. The hole 211 may be formed to have a substantially circular shape, though aspects of the present invention are not limited thereto.
The hole 211 may be formed at a middle of the bent area B. Therefore, the hole 211 may be located at a middle of the width W between the first length side 210a and the second length side 210b of the lead plate 210, and may be located at a middle of the length L between the first width side 210c and the second width side 210d of the lead plate 210. Furthermore, the hole 211 may be formed in the bent area B of the lead plate 210, and allows the lead plate 210 to be smoothly bent when the lead plate 210 is bent to electrically connect the first bare cell 110 and the second bare cell 120.
The hole 211 formed in the lead plate 210 may have a diameter D1 of about 0.2 mm to about 1 mm, though aspects of the present invention are not limited thereto. That is, in the current embodiment, when the diameter D1 of the hole 211 is smaller than 0.2 mm, the lead plate 210 may not be bent smoothly. Moreover, when the diameter D1 of the hole 211 is larger than 1 mm, the lead plate 210 may be cracked from a portion in which the hole 211 is formed during a bending process. Although while the lead plate 210 is being bent, no crack may be generated, when the lead plate 210 is vibrated by the rocking of the battery pack 10 later, the lead plate 210 may be cracked from the portion in which the hole 211 is formed, and may eventually break. Therefore, the size of the hole 211 formed in the bent area B of the lead plate 210 is accurately controlled corresponding to the size of the lead plate 210. According to the current embodiment, when the hole 211 has the size between 0.2 mm and 1 mm, the hole 211 may allow the lead plate 210 to be smoothly bent, and may prevent the lead plate 210 from being broken by vibration of the lead plate 210. Furthermore, to smoothly bend the lead plate 210 and to protect the lead plate 210 from being broken by a vibration thereof, the lead plate 210 may be provided with only one hole 211 having the size of the above-described numerical range in the bent area B thereof.
There may be some differences in composition between the lead plate 210 according to other embodiments of the present invention and the lead plate 210 according to an embodiment of the present invention as described with reference to
The groove 511 is formed in the bent area B of the lead plate 510, and allows the lead plate 510 to be smoothly bent when the lead plate 510 is bent to electrically connect the first bare cell and the second bare cell. At this time, to prevent a portion in which the groove 511 is formed from being broken, the lead plate 510 may be bent so that a surface of the lead plate 510 on which the groove 511 is formed becomes an inner side of the lead plate 510 after being bent.
The groove 511 may have a depth D2 less than about 5/100 mm, though it is understood that aspects of the present invention are not limited thereto. That is, in the current embodiment, when the depth D2 of the groove 511 is 5/100 mm and over, the lead plate 510 may be cracked from the portion in which the groove 511 is formed during a bending process. Although while the lead plate 510 is being bent, no crack is generated, when the lead plate 510 is vibrated by the rocking of the battery pack later, the lead plate 510 may be cracked from the portion in which the groove 511 is formed, and may eventually break. Accordingly, the depth D2 is determined to allow the lead plate 510 to be smoothly bent, and to prevent the lead plate 510 from being broken by vibration of the lead plate 510.
Also, the groove 511 may have a length L1 with a ratio to the width W between the first and second length sides 510a and 510b of the lead plate 510 of 1:3 to 1:2, though it is understood that aspects of the present invention are not limited thereto. That is, in the current embodiment, when the length L1 of the groove 511 is shorter than ⅓ of the width W of the lead plate 510, the lead plate 510 may not be bent smoothly. When the length L1 of the groove 511 is longer than ½ of the width W of the lead plate 510, the lead plate 510 may be cracked from the portion in which the groove 511 is formed during a bending process. Although while the lead plate 510 is being bent, no crack is generated, when the lead plate 510 is vibrated by the rocking of the battery pack later, the lead plate 510 may be cracked from the portion in which the groove 511 is formed, and may eventually break. Accordingly, the length L1 is determined to allow the lead plate 510 to be smoothly bent, and to prevent the lead plate 510 from being broken by vibration of the lead plate 510.
Furthermore, a first side 511a and a second side 511b of the groove 511 corresponding to each of the first length side 510a and the second length side 510b of the lead plate 510 may be spaced apart from the first length side 510a and the length long side 510b, respectively to prevent the groove 511 from breaking during a bending process.
Therefore, the depth, length, and/or position of the groove 511 formed in the bent area B of the lead plate 510 are accurately controlled according to the size of the lead plate 510. When the groove 511 has a size corresponding to the numerical ranges described above, the groove 511 may allow the lead plate 510 to be smoothly bent, and may prevent the lead plate 510 from being broken by vibration of the lead plate 510. Furthermore, to smoothly bend the lead plate 510 and protect the lead plate 510 from being broken by vibration thereof, the lead plate 510 may be provided with only one groove having a size corresponding to the numerical ranges described above in the bent area B thereof.
Hereinafter, a lead plate according to another embodiment of the present invention will be explained.
If the groove 611 having the plurality of sub grooves 611a, 611b, 611c, and 611d is thought of as one groove, the groove 611 may be formed in a middle of the bent area B of the lead plate 610. Therefore, the groove 611 may be located at a middle of the width W between a first length side 610a and a second length side 610b of the lead plate 610, and may be located at a middle of the length between a first width side 610c and a second width side 610d of the lead plate 610. Furthermore, the groove 611 may be formed in the bent area B of the lead plate 610, and allows the lead plate 610 to be smoothly bent when the lead plate 610 is bent to electrically connect the first bare cell and the second bare cell. At this time, to prevent the bent area B in which the groove 611 is formed from being broken, the lead plate 610 may be bent so that a surface of the lead plate 610 on which the groove 611 is formed becomes an inner side of the lead plate 610 after being bent.
The groove 611 may have a depth less than 5/100 of the thickness of the lead plate 610, though it is understood that aspects of the present invention are not limited thereto. That is, in the current embodiment, when the depth of the groove 611 is greater than or equal to 5/100 of the thickness of the lead plate 610, the lead plate 610 may be cracked from a portion in which the groove 611 is formed during a bending process. Although while the lead plate 610 is being bent, no crack is generated, when the lead plate 610 is vibrated by the rocking of the battery pack later, the lead plate 610 may be cracked from the portion in which the groove 611 is formed, and may eventually break. Accordingly, the depth is determined to allow the lead plate 610 to be smoothly bent, and to prevent the lead plate 610 from being broken by vibration of the lead plate 610.
Also, if the groove 611 formed in the plurality of sub grooves 611a, 611b, 611c, and 611d is thought of as one groove, the groove 611 may have a length L2 with a ratio to the width W between the first and second long sides 610a and 610b of the lead plate of 1:3 to 1:2, though it is understood that aspects of the present invention are not limited thereto. That is, in the current embodiment, when the length L2 of the groove 611 is shorter than ⅓ of the width W of the lead plate 610, the lead plate 610 may not be bent smoothly. Moreover, when the length L2 of the groove 611 is longer than ½ of the width W of the lead plate 610, the lead plate 610 may be cracked from a portion in which the groove 611 is formed during a bending process. Although while the lead plate 610 is being bent, no crack is generated, when the lead plate 611 is vibrated by the rocking of the battery pack later, the lead plate 610 may be cracked from the portion in which the groove 611 is formed, and may eventually break. Accordingly, the length L2 is determined to allow the lead plate 610 to be smoothly bent, and to prevent the lead plate 610 from being broken by vibration of the lead plate 610
The first and second sub grooves 611a and 611d of the groove 611 corresponding to each of the first and second length sides 610a and 610b of the lead plate 610 may be spaced apart from the first length side 610a and the second length side 610b, respectively to prevent the first and second sub grooves 611a and 611d from breaking during a bending process.
The depth, length, position, and number of the groove 611 formed in the bent area B of the lead plate 610 are accurately controlled according to the size of the lead plate 610. When the groove 611 including the plurality of sub grooves 611a, 611b, 611c, and 611d has a size corresponding to the numerical ranges as described above, the groove 611 may allow the lead plate 610 to be smoothly bent, and may prevent the lead plate 610 from being broken by vibration of the lead plate 610. Furthermore, to smoothly bend the lead plate 610 and protect the lead plate 610 from being broken by vibration thereof, the lead plate 610 may be provided with only one groove 611 having a size corresponding to the numerical ranges described above in the bent area B thereof.
A battery pack according to aspects of the present invention is provided with a lead plate having a hole or at least one groove formed in a bent area thereof to smoothly bend the lead plate, and to prevent the lead plate from being broken by vibration. As a result, the battery pack according to aspects of the present invention has an improved reliability.
Although the first lead plate 210 connecting the first bare cell 110 and the second bare cell 120 has been explained above, it is understood that the second lead plate 220 connecting the second bare cell 120 and the third bare cell 130 may have the same or similar features as those of the first lead plate 210. Furthermore,
Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2009-0016316 | Feb 2009 | KR | national |
