CN111916648A

CN111916648A - Battery pack

Info

Publication number: CN111916648A
Application number: CN202010272650.7A
Authority: CN
Inventors: 朴相勳
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2019-05-08
Filing date: 2020-04-09
Publication date: 2020-11-10
Anticipated expiration: 2040-04-09
Also published as: KR20200129463A; KR102344363B1; CN111916648B

Abstract

A battery pack is provided. The battery pack includes: a battery cell including a receiving part receiving the electrode assembly and a stage part formed on a front side of the receiving part; a circuit board electrically connected to the battery cell; a temperature cutoff device disposed on the stage portion between the battery cell and the circuit board; and a first lead located between the temperature cutoff device and the circuit board, wherein the first lead includes a device connection portion provided on one end of the first lead and connected to the temperature cutoff device, a board connection portion provided on the other end of the first lead and connected to the circuit board, and a bent portion provided on a rear side of the device connection portion and the board connection portion and connecting the device connection portion and the board connection portion to each other in a bent shape. Therefore, it is possible to provide a battery pack configured to protect a lead wire electrically connecting a battery cell to a circuit board and to prevent a contact or connection failure between the lead wire and the circuit board caused by deformation of the lead wire.

Description

Battery pack

This application claims the benefit of korean patent application No. 10-2019-0053895, filed by the korean intellectual property office at 5, 8, 2019, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

One or more embodiments relate to a battery pack.

Background

In general, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that is not rechargeable. The secondary battery is used as an energy source for devices such as mobile devices, electric vehicles, hybrid vehicles, electric bicycles, or uninterruptible power supplies. Depending on the type of external device using secondary batteries, the secondary batteries are used individually or secondary battery modules (packs) each including a plurality of secondary batteries connected as one unit are used.

Unlike small-sized mobile devices such as cellular phones, each of which is operable with a single battery for a certain period of time, devices such as electric vehicles or hybrid vehicles, which have long operating times and consume a large amount of electric power, may prefer battery modules (battery packs) each including a plurality of batteries (cells) to deal with problems related to power and capacity, and may increase the output voltage or output current of the battery modules by adjusting the number of batteries included in each battery module.

Disclosure of Invention

One or more embodiments include a battery pack configured to protect a lead electrically connecting a battery cell to a circuit board and prevent a failure of contact or connection between the lead and the circuit board caused by deformation of the lead.

One or more embodiments include a battery pack having an improved structure for making a battery pack including battery cells and a circuit board compact.

Additional aspects 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 disclosed embodiments.

According to one or more embodiments, a battery pack includes: a battery cell including a receiving part in which an electrode assembly is received and a stage part formed on a front side of the receiving part; a circuit board electrically connected to the battery cell; a temperature cutoff device disposed on the stage portion between the battery cell and the circuit board; and a first lead located between the temperature cutoff device and the circuit board, wherein the first lead includes a device connection portion provided on one end of the first lead and connected to the temperature cutoff device, a board connection portion provided on the other end of the first lead and connected to the circuit board, and a bent portion provided on a rear side of the device connection portion and a rear side of the board connection portion and connecting the device connection portion and the board connection portion to each other in a bent shape.

For example, the receiving portion may protrude upward from the platform portion, and the bent portion may support the board connection portion in an upward direction from the device connection portion to lift the height.

For example, the platform portion may include a first surface facing an upward direction in which the receiving portion protrudes from the platform portion and a second surface opposite to the first surface; and the device connection portion may be placed on the first surface of the stage portion.

For example, the bent portion may be located at a rear (rear) position adjacent to the accommodating portion.

For example, the bent portion may be in contact with the accommodating portion.

For example, the bent portion may form a rearmost portion of the first lead, and the board connection portion may form a foremost portion of the first lead.

For example, the curved portion may include a smoothly curved surface.

For example, the curved portion has a circular arc shape.

For example, the first lead may further include an intermediate connection portion connecting the device connection portion and the board connection portion to each other and including the bent portion, and the intermediate connection portion may be narrower than the device connection portion and the board connection portion.

For example, the first lead may be connected to one side of the temperature cut-off device, wherein the battery pack may further include a second lead connected to the other side of the temperature cut-off device.

For example, a first lead may electrically connect the temperature cut-off device and the circuit board to each other, and a second lead may electrically connect the temperature cut-off device to the battery cell.

For example, the temperature cutoff device may be placed on a first surface of the mesa portion, the first lead may extend upward from the first surface of the mesa portion to the elevated height through a bent portion of the first lead, and the second lead may be bent downward from the first surface through a bent portion of the second lead and may extend to a second surface of the mesa portion, the second surface of the mesa portion being opposite to the first surface of the mesa portion.

For example, the bent portion of the first lead and the bent portion of the second lead may be formed at front and rear positions of the land portion, respectively, which are opposite to each other.

For example, the battery cell may further include a first electrode tab and a second electrode tab electrically connected to the electrode assembly and extending outward through the terrace portion, the first electrode tab may be connected to the circuit board through the second lead, the temperature cutoff device, and the first lead, and the second electrode tab may be directly connected to the circuit board.

Drawings

Fig. 1 is an exploded perspective view illustrating a battery pack according to an embodiment;

fig. 2 is a perspective view illustrating a battery cell shown in fig. 1;

fig. 3 is an enlarged exploded perspective view illustrating a portion of the battery pack shown in fig. 1;

fig. 4 is an enlarged exploded perspective view illustrating a portion of the battery pack shown in fig. 3;

fig. 5 is a diagram illustrating a structure of the first lead illustrated in fig. 3 and 4;

fig. 6 and 7 are a diagram illustrating a process of soldering between a first lead and a circuit board according to an embodiment and a diagram illustrating a process of soldering between a first lead and a circuit board according to a corresponding comparative example, respectively;

fig. 8 is a diagram showing the temperature cutoff device shown in fig. 4; and

fig. 9 is a diagram showing the structure of the first lead and the second lead connected to the temperature cutoff device.

Detailed Description

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the embodiments are described below in order to explain aspects of the present specification by referring to the figures only. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression "at least one of a, b and c" means only a, only b, only c, two of a and b (species/species), two of a and c, two of b and c, all of a, b and c, or variations thereof.

A battery pack according to an embodiment will now be described with reference to the accompanying drawings.

Fig. 1 is an exploded perspective view illustrating a battery pack according to an embodiment. Referring to fig. 1, the battery pack may include: a battery cell 100; and a circuit board 200 electrically connected to the battery cell 100 to control the charging operation and the discharging operation of the battery cell 100. Further, the battery pack may further include: a frame 300 configured to accommodate the battery cell 100 and the circuit board 200 together; and a cover 400 placed on the frame 300 and coupled to the frame 300 to face the frame 300 for covering the battery cell 100 and the circuit board 200 together.

The frame 300 may include: a cell housing portion 300C on which the battery cells 100 are placed; and a circuit accommodating portion 300M on which the circuit board 200 is placed at a position adjacent to the single body accommodating portion 300C. The circuit board 200 may extend in a direction crossing the battery cells 100 and may be electrically connected to the battery cells 100, and the circuit receiving parts 300M on which the circuit board 200 is placed may be formed at positions facing the cell receiving parts 300C on which the battery cells 100 are respectively placed.

In an embodiment, the number of the battery cells 100 may be two or more, and the two or more battery cells 100 may be electrically connected to each other through the circuit board 200. For example, the circuit board 200 may be electrically connected to each battery cell 100, and may include a conductive pattern (not shown) for providing a charge and discharge path connected to each battery cell 100. For example, the circuit board 200 may include a conductive pattern (not shown) formed on the circuit board 200, and the plurality of circuit elements 210 may be mounted on the circuit board 200.

For example, the circuit board 200 may extend in a direction crossing the battery cells 100 and may be electrically connected to each of the battery cells 100. For example, the circuit board 200 may extend along the platform portion T of the battery cell 100 and may be electrically connected to the electrode tab 120 extending outward from the platform portion T. In addition, the circuit board 200 may collect charge and discharge current through the electrode tab 120 and may transfer the charge and discharge current to an external circuit (not shown).

Fig. 2 is a perspective view illustrating one of the battery cells 100 shown in fig. 1. Further, fig. 3 is an enlarged exploded perspective view illustrating a portion of the battery pack shown in fig. 1, and fig. 4 is an enlarged exploded perspective view illustrating a portion of the battery pack shown in fig. 3. Fig. 5 is a diagram illustrating a structure of the first lead 161 illustrated in fig. 3 and 4.

Referring to fig. 2, the battery cell 100 may include: an electrode assembly 110 having first and

second electrode plates

111 and 112 having different polarities and a separator (separator) 113 disposed between the first and

second electrode plates

111 and 112; a case P for accommodating an electrolyte (not shown) together with the electrode assembly 110; and an electrode tab 120 electrically connected to the electrode assembly 110 and extending outward from the case P. The electrode tab 120 may include a first electrode tab 121 electrically connected to the first electrode plate 111 and a second electrode tab 122 electrically connected to the second electrode plate 112, and the first and

second electrode tabs

121 and 122 may form different polarities of the battery cell 100.

Case P may include first case P1 and second case P2, first case P1 and second case P2 face each other and are coupled to each other to provide receiving portion (a) in which electrode assembly 110 is received, and additional portions of first case P1 and second case P2 surrounding receiving portion (a) may form sealing portion TS that hermetically seals receiving portion (a). The case P may include a folded portion P3 connecting the first case P1 and the second case P2 to each other such that the first case P1 and the second case P2 may be folded to face each other, and edge portions of the first case P1 and the second case P2 except for the folded portion P3 may form a sealing portion TS. The seal portion TS may include a land portion T and a side seal portion S, which is an area of the seal portion TS except for the seal portion TS. Here, the first and

second electrode tabs

121 and 122 may extend outward through the platform portion T, and the platform portion T may be opposite to the folded portion P3. The first and

second electrode tabs

121 and 122 extending outward through the platform portion T may be connected to the circuit board 200 (refer to fig. 3) disposed at a position adjacent to the platform portion T, and in particular, to the first and

second connection tabs

221 and 222 formed in the circuit board 200.

As shown in fig. 3, the platform portion T may be located in front of the receiving portion (a), and conversely, the receiving portion (a) may be located behind the platform portion T. In this specification, the front-rear direction may refer to a direction in which the platform portion T and the receiving portion (a) of the battery cell 100 are arranged, the position of the platform portion T may be relatively at the front side, and the position of the receiving portion (a) may be relatively at the rear side.

Referring to fig. 3, the battery pack may further include a temperature cutoff device (or referred to as a temperature protection device) 150, and the temperature cutoff device 150 is disposed on the charge and discharge path between the battery cell 100 and the circuit board 200 to block the charge and discharge path of the battery cell 100 when the battery pack is overheated. For example, the first electrode tab 121 of the battery cell 100 may be connected to the circuit board 200 via the temperature cutoff device 150, and the second electrode tab 122 may be directly connected to the circuit board 200. That is, the first electrode tab 121 of the battery cell 100 may be connected to the first connection tab 221 of the circuit board 200 via the first and

second leads

161 and 162 and the temperature cutoff device 150. In addition, the second electrode tab 122 of the battery cell 100 may be directly connected to the second connection tab 222 of the circuit board 200.

The temperature cutoff device 150 may be placed on the stage portion T. For example, the temperature cutoff device 150 may be placed on the first surface T1 of the stage portion T. That is, the platform portion T may include a first surface T1 and a second surface T2 facing away from each other, and the first surface T1 of the platform portion T may be formed on an upper side together with the receiving portion (a) and may face an upward direction in which the receiving portion (a) protrudes with respect to the platform portion T. Further, a second surface T2 of the platform portion T may be formed on a lower side opposite to the receiving portion (a). For example, the first surface T1 of the platform portion T may correspond to a surface of the platform portion T on a side of the first housing P1, which provides the accommodation portion (a), among the first housing P1 and the second housing P2. In the embodiment, the accommodation portion (a) may be formed in the first housing P1 of the first and second housings P1 and P2, and in this case, a surface of the platform portion T on the side of the first housing P1 may form the first surface T1, and a surface of the platform portion T on the side of the second housing P2 may form the second surface T2. However, in another embodiment, the receiving portion (a) may be formed in the first case P1 and the second case P2 in a distributed manner. In this case, the first surface T1 may be formed on one of the first case P1 and the second case P2, which has a greater protrusion height (h) than the other, or the first surface T1 may be formed on any one of the first case P1 and the second case P2 when the accommodating portion (a) is uniformly formed in the first case P1 and the second case P2.

Since a relatively large free space may be provided on the first surface T1 of the stage portion T due to the height (h) occupied by the accommodation portion (a), the temperature cutoff device 150 may be placed on the first surface T1 of the stage portion T. Since the height (h) occupied by the receiving portion (a) is not formed on the second surface T2 of the stage portion T, a height sufficient to receive the temperature cutoff device 150 may not be provided on the second surface T2 of the stage portion T.

The temperature cutoff device 150 may be connected to the circuit board 200 and the battery cell 100 through first and

second leads

161 and 162 connected to both sides of the temperature cutoff device 150, respectively, and the temperature cutoff device 150 may form a charge and discharge path between the circuit board 200 and the battery cell 100. Hereinafter, the structure of the first lead 161 located between the temperature cutoff device 150 and the circuit board 200 will be described.

Referring to fig. 4 and 5, the first lead 161 may include: a device connection portion 161a provided on one end of the first lead 161 and connected to the temperature cutoff device 150; a board connection portion 161b provided on the other end of the first lead 161 and connected to the circuit board 200; and a bent portion 161c provided on a rear side of the device connection portion 161a and the board connection portion 161b and connecting the device connection portion 161a and the board connection portion 161b to each other in a bent shape.

The bent portion 161c may support the board connection portion 161b at an upward lift height (i.e., a height of lift/raise) HD (refer to fig. 5) from the device connection portion 161 a. In other words, the bent portion 161c may support the board connection portion 161b from the first surface T1 of the platform portion T on which the device connection portion 161a is disposed to raise the height HD. The temperature cutoff device 150 bonded to the device connection portion 161a and the circuit board 200 bonded to the board connection portion 161b may have a height difference with respect to each other according to the height difference between the device connection portion 161a and the board connection portion 161 b.

The device connection portion 161a and the board connection portion 161b may be connected to each other by a bent portion 161c disposed on the rear side of the device connection portion 161a and the rear side of the board connection portion 161b, and thus, a structure for connecting the device connection portion 161a and the board connection portion 161b to each other is not formed on the front side of the device connection portion 161a or the board connection portion 161 b. In other words, the bent portion 161c may be arranged on the rear side of the device connection portion 161a and the rear side of the board connection portion 161b, that is, may be behind one of the device connection portion 161a and the board connection portion 161b (the one is more rearward than the other, for example, the device connection portion 161 a). That is, the bent portion 161c may be disposed on the rear side of the device connection portion 161a and may also be disposed on the rear side of the board connection portion 161b, but may not be disposed on the front side of the device connection portion 161a or the front side of the board connection portion 161 b. For example, the bent portion 161c may form the rearmost portion of the first lead 161, and the device connection portion 161a and the board connection portion 161b may be in front (or front) of the bent portion 161 c. In an embodiment, the bent portion 161c may form a rearmost portion of the first lead 161, and the board connection portion 161b may form a foremost portion of the first lead 161.

Fig. 6 and 7 are a diagram illustrating a process of soldering between the first lead 161 and the circuit board 200 according to the embodiment and a diagram illustrating a process of soldering between the first lead 16 and the circuit board 200 according to respective comparative examples, respectively.

Referring to fig. 6 and 7, in the embodiment and the comparative example, the board connection portion 161b or the board connection portion 16b may be brought into close contact with the circuit board 200 by using the soldering jig PS and then may be soldered by emitting the laser beam L. In this case, in the embodiment shown in fig. 6, since the bent portion 161c supporting the board connection portion 161b at the lift height HD is disposed at the rear position opposite to the board connection portion 161b disposed at the front position, the bent portion 161c is not deformed by the soldering jig PS for pressing the board connection portion 161b, or the board connection portion 161b and the circuit board 200 are not twisted due to the close contact state and are not separated from each other due to the deformation of the bent portion 161c, thereby fundamentally preventing soldering failure.

In the comparative example shown in fig. 7, since the bent portion 16c supporting the board connection portion 16b at the elevated height is formed at the front position adjacent to the board connection portion 16b, the bent portion 16c may be deformed by the welding jig PS for pressing the board connection portion 16b, and thus, the board connection portion 16b and the circuit board 200 may be welded to each other in a partially separated state. In this case, the output performance of the battery pack may be reduced due to the high resistance between the board connection part 16b and the circuit board 200.

Referring to fig. 6, in the embodiment, since the bent portion 161c supporting the board connection portion 161b at the lift height HD is disposed at a rear position opposite to the board connection portion 161b and adjacent to the accommodation portion (a), the board connection portion 161b may be disposed adjacent to the accommodation portion (a), and thus, the circuit board 200 coupled to the board connection portion 161b may be disposed adjacent to the accommodation portion (a), so that the battery pack may have a compact size in the front-rear direction.

In the comparative example shown in fig. 7, since the bent portion 16c supporting the board connection portion 16b at the elevated height is formed at a front position adjacent to the board connection portion 16b, and the board connection portion 16b must be formed at an end position distant from the bent portion 16c, the board connection portion 16b is positioned relatively distant from the accommodating portion (a) in the front direction, and therefore, the circuit board 200 joined to the board connection portion 16b is arranged at a front position relatively distant from the accommodating portion (a). Therefore, the size of the battery pack may increase in the front-rear direction, and the battery pack may not be compact. For example, the distance d2 between the temperature cutoff device 150 and the circuit board 200 in the comparative example shown in fig. 7 may be larger than the distance d1 between the temperature cutoff device 150 and the circuit board 200 in the embodiment shown in fig. 6 (d2> d 1).

Referring to fig. 5, the bent portion 161c may support the plate connecting portion 161b at the lift height HD, the bent portion 161c being disposed at a rear position opposite to the plate connecting portion 161b disposed at a front position, i.e., at a rear position adjacent to the accommodating portion (a). The bent portion 161c may be formed at a position adjacent to the accommodating portion (a), and in an embodiment, the bent portion 161c may contact the accommodating portion (a). The position of the board connection portion 161b may be moved rearward by changing the position of the bent portion 161c rearward toward the accommodating portion (a), and in this case, the position of the circuit board 200 coupled to the board connection portion 161b may also be moved rearward, so that the battery pack may have a compact size in the front-rear direction.

The bent portion 161c may support the plate connection portion 161b at the lift height HD. That is, the bent portion 161c may support the plate connection portion 161b from the first surface T1 of the platform portion T or the device connection portion 161a placed on the first surface T1 of the platform portion T in an upward direction at a raised height HD. In this case, the elevation height HD from the board connection portion 161b may be greater than the height of the temperature shut-off device 150 placed on the first surface T1 of the stage portion T. Therefore, the circuit board 200 bonded to the board connection portion 161b at the elevated height HD can be placed at a height away from the temperature cutoff device 150 so that the circuit board 200 does not physically interfere with the temperature cutoff device 150.

The lifting height HD of the board connection portion 161b may be lower than the height (h) of the receiving portion (a). When the lift height HD of the board connection part 161b is greater than the height (h) of the receiving part (a), the height of the circuit board 200 coupled to the board connection part 161b is outside the receiving part (a) and protrudes from the receiving part (a), and therefore, the vertical size of the battery pack may increase, thereby having a negative effect on the compactness of the battery pack. In the embodiment, the lift height HD of the board connection portion 161b may be set such that the uppermost portion 200u (refer to fig. 5) of the circuit board 200 coupled to the board connection portion 161b does not protrude from the accommodating portion (a), i.e., the height of the uppermost portion 200u of the circuit board 200 may be equal to or less than the height (h) of the accommodating portion (a).

The bent portion 161c may support the plate connection portion 161b at the lift height HD and may elastically support the plate connection portion 161 b. In this case, the circuit board 200 connected to the board connection portion 161b can also be elastically supported via the bent portion 161c, and since the bent portion 161c absorbs or reduces external impact while being flexibly deformed, the circuit board 200 can be protected from the external impact. In an embodiment, the bent portion 161c may have a smoothly bent surface connecting the device connection portion 161a and the board connection portion 161b to each other without having an angular or angled shape. For example, the curved portion 161c may be formed in a circular arc shape having a certain radius, and the plate connecting portion 161b may be elastically supported by the curved portion 161c having a smoothly curved surface at the lift height HD.

Fig. 8 is a diagram illustrating the temperature cutoff device 150 illustrated in fig. 4.

Referring to fig. 8, the device connection portion 161a and the board connection portion 161b of the first lead 161 may have relatively large widths Wa and Wb, respectively, to secure a large area for conduction with the temperature cutoff device 150 and the circuit board 200. In this specification, the widths Wa, Wb, and Wd of the first lead 161 may refer to the size of the first lead 161 measured in a direction perpendicular to the length direction of the first lead 161, and the device connection portion 161a and the board connection portion 161b are connected along the length direction of the first lead 161. The device connection portion 161a and the board connection portion 161b of the first lead 161 may have relatively large widths Wa and Wb, and an intermediate connection portion 161d having a relatively small width Wd may be formed between the device connection portion 161a and the board connection portion 161 b. Here, the intermediate connection portion 161d may include the bent portion 161c described above, and may collectively refer to an area between the device connection portion 161a and the board connection portion 161b, and a portion of the intermediate connection portion 161d extending in a bent shape may correspond to the bent portion 161 c.

The intermediate connection portion 161d may have a relatively small width Wd to expose the device connection portion 161a, and thus, since the device connection portion 161a is exposed in an upward direction, soldering between the device connection portion 161a and the temperature cutoff device 150 may be allowed. Since the intermediate connection portion 161d having the relatively small width Wd extends from the device connection portion 161a having the relatively large width Wa, the device connection portion 161a may not be covered by the intermediate connection portion 161 d. Since the intermediate connection portion 161d extends from the device connection portion 161a and is bent upward and then disposed over the device connection portion 161a, the intermediate connection portion 161d may have a relatively small width Wd to expose the device connection portion 161 a. Further,

reference numerals

151 and 152, which are not described yet, shown in fig. 8 denote different electrodes of the temperature cutoff device 150, and the different electrodes of the temperature cutoff device 150 may be connected to the first lead 161 and the second lead 162, respectively.

Fig. 9 is a diagram showing the structure of the first lead 161 and the second lead 162 connected to the temperature cutoff device 150.

Referring to fig. 4 and 9 together, the first lead line 161 may be connected to one side of the temperature cut-off device 150, and the second lead line 162 may be connected to the other side of the temperature cut-off device 150. For example, the first lead 161 and the second lead 162 may be connected to

different electrodes

151 and 152 of the temperature cutoff device 150, respectively. The first and

second leads

161 and 162 may form a charge and discharge path through which the battery cell 100 is connected to the temperature cutoff device 150 and the circuit board 200. For example, the first lead 161 may electrically connect the temperature cut-off device 150 and the circuit board 200 to each other, and the second lead 162 may electrically connect the temperature cut-off device 150 and the battery cell 100 to each other.

The second lead 162 may extend from the first surface T1 of the stage portion T, on which the temperature cutoff device 150 is placed, to the second surface T2 of the stage portion T through the bent portion 162c of the second lead 162, and may then be connected to the battery cell 100 or the first electrode tab 121 of the battery cell 100 on the second surface T2 of the stage portion T. The second lead 162 may include: a device connection portion 162a connected to the temperature cutoff device 150; a tab connection part 162b connected to the first electrode tab 121 of the battery cell 100; and a bent portion 162c bent to surround an end portion of the stage portion T and connecting the device connection portion 162a disposed on the first surface T1 of the stage portion T and the tab connection portion 162b disposed on the second surface T2 of the stage portion T together. Further, the tab connection part 162b may include a pair of metal segments adjacent to each other with the folding line FL (refer to fig. 4) therebetween and folded to face each other with the first electrode tab 121 therebetween. For example, a pair of metal segments forming the tab connection portion 162b may be welded together in a state where the metal segments are folded along the folding line FL such that the first electrode tab 121 faces each other with the first electrode tab 121 therebetween, and the tab connection portion 162b welded to the first electrode tab 121 may be bent along the bent portion 162c onto the second surface T2 of the platform portion T.

Referring to fig. 9, the temperature cutoff device 150 may be placed on the first surface T1 of the stage portion T. In this case, the device connection portion 161a of the first lead line 161 connected to one side of the temperature cutoff device 150 and the device connection portion 162a of the second lead line 162 connected to the other side of the temperature cutoff device 150 may be disposed on the first surface T1 of the stage portion T together with the temperature cutoff device 150. In this case, the first lead 161 disposed at one side of the temperature cutoff device 150 may extend upward from the first surface T1 of the stage portion T to the elevated height HD through the bent portion 161c of the first lead 161, and the second lead 162 disposed at the other side of the temperature cutoff device 1 part 50 may extend from the first surface T1 of the stage portion T to the second surface T2 of the stage portion T through the bent portion 162c bent downward. In this case, the bent portion 161c of the first lead 161 and the bent portion 162c of the second lead 162 may be at a rear position (rear position) and a front position (front position) of the stage portion T, respectively, which are opposite to each other. For example, the bent portion 161c of the first lead 161 may be at a rear position adjacent to the receiving portion (a), and the bent portion 162c of the second lead 162 may surround a front end portion of the stage portion T opposite to the receiving portion (a).

In the present disclosure, the temperature cut-off device 150 may refer to a temperature safety device capable of detecting the temperature of the battery cell 100 and interrupting or limiting the charge and discharge current at an abnormally high temperature, and regardless of the name of the temperature cut-off device 150, the temperature cut-off device 150 may refer to a temperature safety device capable of limiting or interrupting the charge and discharge current according to the temperature of the battery cell 100 by providing resistance varying with the temperature of the battery cell 100.

According to the present disclosure, since the bent portion 161c, which is a portion of the first lead 161 that electrically connects the battery cell 100 and the circuit board 200 to each other and supports the board connection portion 161b at the elevated height HD, is disposed at a rear position opposite to the board connection portion 161b, the bent portion 161c is not deformed by a welding jig for pressing the board connection portion 161b to the circuit board 200, or the board connection portion 161b and the circuit board 200 are not twisted due to a close contact state and are not separated from each other due to the deformation of the bent portion 161c, thereby fundamentally preventing a welding failure.

According to the present disclosure, in the first lead 161 electrically connecting the battery cell 100 and the circuit board 200 to each other, the bent portion 161c supporting the board connection portion 161b toward the circuit board 200 at the lift height HD is formed at the rear position opposite to the board connection portion 161b, and therefore, the battery pack can have a compact size in the front-rear direction.

It is to be understood that the embodiments described herein are to be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects in each embodiment should generally be considered as available for other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

Claims

1. A battery pack, comprising:

a battery cell including a receiving part receiving the electrode assembly and a stage part formed on a front side of the receiving part;

a circuit board electrically connected to the battery cell;

a temperature cutoff device disposed on the stage portion between the battery cell and the circuit board; and

a first lead wire located between the temperature cutoff device and the circuit board,

wherein the first lead includes: a device connection portion provided on one end of the first lead and connected to the temperature cutoff device; a board connection portion provided on the other end of the first lead and connected to the circuit board; and a bent portion provided on a rear side of the device connection portion and a rear side of the board connection portion and connecting the device connection portion and the board connection portion to each other in a bent shape.

2. The battery pack according to claim 1, wherein the receiving portion protrudes upward with respect to the platform portion, and

the bent portion supports the board connection portion in an upward direction from the device connection portion to raise the height.

3. The battery pack according to claim 1, wherein:

the platform portion includes a first surface facing in an upward direction and a second surface facing away from the first surface, the receiving portion protruding in the upward direction with respect to the platform portion; and is

The device connection portion is placed on the first surface of the stage portion.

4. The battery pack according to claim 1, wherein the bent portion is located at a rear position adjacent to the receiving portion.

5. The battery pack according to claim 4, wherein the bent portion is in contact with the receiving portion.

6. The battery pack according to claim 1, wherein the bent portion forms a rearmost part of the first lead, and

the board connection portion forms the foremost part of the first lead.

7. The battery pack of claim 1, wherein the curved portion comprises a smoothly curved surface.

8. The battery pack according to claim 7, wherein the curved portion has a circular arc shape.

9. The battery pack of claim 1, wherein the first lead further comprises: an intermediate connection portion connecting the device connection portion and the board connection portion to each other and including the bent portion, and

the intermediate connection portion is narrower than the device connection portion and the board connection portion.

10. The battery pack according to claim 1, wherein the first lead is connected to one side of the temperature cut-off device,

wherein the battery pack further includes a second lead connected to the other side of the temperature cut-off device.

11. The battery pack according to claim 10, wherein the first lead electrically connects the temperature cutoff device and the circuit board to each other, and

the second lead electrically connects the temperature cutoff device to the battery cell.

12. The battery pack according to claim 10, wherein the temperature shut-off device is placed on the first surface of the platform portion,

the first lead extends upwardly from the first surface of the platform portion to an elevated height through a bend portion of the first lead, and

the second lead is bent downward from the first surface through a bent portion of the second lead and extends to a second surface of the mesa portion, the second surface of the mesa portion facing away from the first surface of the mesa portion.

13. The battery pack according to claim 12, wherein the bent portion of the first lead and the bent portion of the second lead are formed at a rear position and a front position of the plateau portion, respectively, which are opposite to each other.

14. The battery pack of claim 10, wherein the battery cell further comprises a first electrode tab and a second electrode tab electrically connected to the electrode assembly and extending outward through the platform portion,

the first electrode tab is connected to the circuit board through the second lead, the temperature cutoff device, and the first lead, and

the second electrode tab is directly connected to the circuit board.