KR102332332B1 - Battery pack - Google Patents

Abstract

The present invention provides a battery cell, one side of the battery cell, including an electrode assembly, a sealing case accommodating the electrode assembly, and first and second cell tabs having different polarities in order to improve durability and safety of the battery pack is disposed in, has a protection circuit module electrically connected to the first cell tab and the second cell tab, and an opening with one side open, accommodating the protection circuit module through the opening, in a longitudinal direction of the opening In the width in the direction perpendicular to the width, the width of both ends has a shape that is narrower than the width in the central portion, to provide a battery pack, including a module case.

Description

battery pack {Battery pack}

The present invention relates to a battery pack with improved durability.

The secondary battery, which is represented by a lithium secondary battery having high energy density and operating voltage, and excellent preservation and lifespan characteristics, is widely used as an energy source for various electronic products as well as various mobile devices. Depending on the type of external device in which it is used, a secondary battery may be used as a detachable structure that can be freely inserted and detached, or may be used as a built-in structure that is embedded in an external device. For example, in devices such as laptops, batteries can be inserted and removed according to the user's needs, whereas some devices such as mobile phones require the use of a built-in battery pack due to problems of structure and capacity.

On the other hand, since various combustible materials are embedded in a lithium secondary battery, there is a risk of heat generation and explosion due to overcharging, overcurrent, and other physical external shocks, so it has a big disadvantage in safety. Therefore, in a lithium secondary battery, a positive temperature coefficient (PTC) device, a protection circuit module (PCM), etc. are connected to the battery cell as safety devices capable of effectively controlling abnormal states such as overcharging and overcurrent.

In general, a secondary battery pack having a built-in structure uses a plate-shaped battery cell suitable for an electrical connection structure, and a PCM or the like is connected to the battery cell by welding or soldering via a conductive nickel plate. That is, in a state in which a nickel plate is welded or soldered to the electrode terminals of the battery cell, respectively, an F (flexible)-PCB is welded to one side of the double-sided tape, and a protective tape is attached to the other side in close contact with the battery cell, A battery pack is manufactured by connecting the PCM to the battery cell by welding the electrode tab and the nickel plate.

Such a battery pack has problems such as damage to the PCM having low mechanical rigidity or remarkably poor dimensional stability when an external shock is applied. Therefore, there is a high need for a technology capable of stably coupling the members mounted on the battery cell to each other and protecting the PCM at the same time.

An object of the present invention is to solve various problems including the above problems, and an object of the present invention is to provide a battery pack with improved durability. However, these problems are exemplary, and the scope of the present invention is not limited thereto.

According to an embodiment of the present invention, a battery cell comprising an electrode assembly, a sealing case accommodating the electrode assembly, and first and second cell tabs having different polarities; a protection circuit module disposed on one side of a battery cell and electrically connected to the first cell tab and the second cell tab; and having an opening at one side, accommodating the protection circuit module through the opening, in a width in a direction perpendicular to the longitudinal direction of the opening, the width of both ends having a shape that is narrower than the width of the central part, A battery pack having a case is provided.

According to this embodiment, the sealing case may include a sealing terrace for sealing the electrode assembly from the outside on one side, and may include overlapping portions folded to have a chamfer at both end corners of the sealing terrace.

According to this embodiment, both ends of the module case may be positioned to correspond to the overlapping portion of the sealing terrace.

According to this embodiment, the module case has an outer surface exposed to the outside, an inner surface into which the protection circuit module is inserted, and the inner surface may include a locker part for supporting the protection circuit module.

According to this embodiment, the inner surface of the module case has a first inner surface opposite to the first surface and a second inner surface opposite to the second surface, and the locker part is located on the first inner surface can do.

According to this embodiment, the module case may include an upper end including the first inner surface and a lower end including the second inner surface, and the upper end may have a first groove.

According to the present embodiment, the lower end may have a second groove.

According to the present embodiment, the width of the second groove may be wider than the width of the first groove.

According to the present embodiment, a width of the second grooves may be equal to or greater than a width of the first cell tab or the second cell tab.

According to the present embodiment, the module case may include protrusions protruding outward from both ends, respectively.

According to the present embodiment, an insulating member interposed between the battery cell and the module case may be further included.

According to an embodiment of the present invention made as described above, it is possible to implement a battery pack with improved durability of the battery pack. Of course, the scope of the present invention is not limited by these effects.

In addition, it goes without saying that the effects of the present invention may be derived from the contents to be described below with reference to the drawings in addition to the above-described contents.

1 is a front view schematically showing a battery pack according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view schematically illustrating the battery pack of FIG. 1 .
FIG. 3 is a front view schematically illustrating an assembly process of the battery pack of FIG. 1 .
4 is a cross-sectional view schematically illustrating a cross-section taken along line AA of the battery pack of FIG. 1 .
FIG. 5 is a front view schematically illustrating a module case of the battery pack of FIG. 1 .
FIG. 6 is a front view schematically illustrating a part of the battery pack of FIG. 1 including a module case;

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense.

In the following examples, the singular expression includes the plural expression unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have means that the features or components described in the specification are present, and the possibility of adding one or more other features or components is not excluded in advance.

In the following embodiments, when it is said that a part of a film, region, component, etc. is "on" or "on" another part, not only in the case of being "on" or "immediately on" of another part, but also in the middle This includes cases in which other films, regions, components, etc. are interposed.

In the following embodiments, the x-axis, the y-axis, and the z-axis are not limited to three axes on a Cartesian coordinate system, and may be interpreted in a broad sense including them. For example, the x-axis, y-axis, and z-axis may be orthogonal to each other, but may refer to different directions that are not orthogonal to each other.

In the drawings, the size of the components may be exaggerated or reduced for convenience of description. For example, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

1 is a front view schematically showing a battery pack according to an embodiment of the present invention, FIG. 2 is an exploded perspective view schematically showing the battery pack of FIG. 1, and FIG. 3 is an assembly process of the battery pack of FIG. It is a schematic front view showing.

1 and 2 , a battery pack according to an embodiment of the present invention includes a battery cell 100 , a protection circuit module 200 electrically connected to the battery cell 100 , and a protection circuit module 200 . Includes a module case 300 for accommodating. The battery cell 100 may include an electrode assembly (not shown), a sealing case 110 accommodating the electrode assembly, and a cell tab 102 .

The electrode assembly may include a first electrode plate coated with an electrode active material, a second electrode plate, and a separator interposed therebetween. The first electrode plate and the second electrode plate have different polarities. The electrode assembly may be manufactured by sequentially stacking a first electrode plate, a separator, and a second electrode plate, and then winding it to form a jelly-roll shape. As another embodiment, the electrode assembly may be a stacked electrode assembly in which a first electrode plate, a separator, and a second electrode plate are sequentially stacked.

The sealing case 110 may have an accommodation space for accommodating the electrode assembly. The sealing case 110 includes an opening on one side, and the electrode assembly may be accommodated therein through the opening. The sealing case 110 may be formed of a metal material, and may include, for example, an aluminum thin film. In detail, the sealing case 110 is typically formed to have a laminated structure covered with a synthetic resin such as nylon, polypropylene or polyethylene on the upper and lower surfaces of a thin metal film, and the inner surface is a heat-adhesive resin for sealing. is made of Accordingly, the sealing case 110 may be sealed by fusion of the heat-adhesive resin coated on the inner surface thereof by heating and pressing. In this embodiment, the sealing case 110 may accommodate the electrode assembly and the electrolyte, and may be a pouched-case having flexibility.

The sealing case 110 according to the present embodiment may have a sealing terrace 110a on one side. The sealing terrace 110a may be understood as a portion having an extra space formed on one surface of the sealed outer peripheral surfaces formed when the electrode assembly is sealed to the sealing case 110 of the laminate sheet.

The sealing case 110 according to the present embodiment includes a sealing terrace 110a for sealing the electrode assembly from the outside on one side, and both end edges of the sealing terrace 110a are folded overlapping portions 110b to have a chamfer shape. can be provided

Referring to FIG. 2 , the cell tab 102 may include a first cell tab 102a and a second cell tab 102b having different polarities. Although not shown, the first cell tab 102a and the second cell tab 102b may be respectively connected to an electrode assembly, for example, the first cell tab 102a is connected to the first electrode plate and the second cell tab ( 102b) is connected to the second electrode plate, so that the first cell tab 102a may have a positive electrode and the second cell tab 102b may have a negative electrode. The first cell tab 102a and the second cell tab 102b may be electrically connected to the protection circuit module 200 .

The protection circuit module 200 may be disposed on one side of the battery cell 100 and may be electrically connected to the battery cell 100 . The protection circuit module 200 may be electrically connected to the battery cell 100 to control charging and discharging of the battery cell 100, and to prevent overheating and explosion caused by overcharging, overdischarging or overcurrent. . The protection circuit module 200 may include an external terminal 204 elongated to the outside. The external terminal 204 may function to electrically connect the battery pack to an external device, and a connector 205 connected to the external device may be located at an end of the external terminal 204 .

The protection circuit module 200 may include a lead tab 202 on one surface, and the lead tab 202 is to be connected to the first cell tab 102a and the second cell tab 102b of the battery cell 100, respectively. can The lead tab 202 of the protection circuit module 200 and the cell tab 102 of the battery cell 100 may be connected by, for example, spot welding.

Although not shown, the protection circuit module 200 may include a circuit board, protection elements mounted on the circuit board, and a temperature sensor. The circuit board may extend in a longitudinal direction along one side of the battery cell 100 . The protection element may be a safety element including a passive element such as a resistor and a capacitor of a circuit board or an active element such as an electric field transistor, or an integrated circuit may be selectively formed.

The module case 300 may have an opening OP with one side open to accommodate the protection circuit module 200 . The protection circuit module 200 may be seated in the module case 300 through the opening OP of the module case 300 . The module case 300 may function to protect the protection circuit module 200 from external impact. The module case 300 will be described in detail with reference to FIGS. 3 to 5 .

Meanwhile, as shown in FIG. 2 , in order to protect the battery cell 100 and insulate it from the outside, insulating films 511 , 512 , 513 , 514 , 515 , 516 are attached to the outer surface of the battery cell 100 . can For example, the insulating films 511 , 512 , 513 , 514 , 515 , and 516 may be adhesive tapes having adhesive strength on one surface. Each of the insulating films 511 , 512 , 513 , 514 , 515 , and 516 is disposed to cover the front, rear, left, right, top, and bottom of the battery cell 100 , in particular, the upper part of the battery cell 100 . The insulating film 515 disposed on the battery cell 100 may function to fix the module case 300 to the battery cell 100 .

Referring to FIG. 2 , in the battery pack according to the present embodiment, first, the protection circuit module 200 may be electrically connected to the battery cell 100 . The battery cell 100 includes a first cell tab 102a and a second cell tab 102b, and the first cell tab 102a and the second cell tab 102b are the leads of the protection circuit module 200, respectively. It may be connected to the tab 202 . That is, as shown in FIG. 2 , the protection circuit module 200 may be disposed such that the external terminal 204 faces the first direction (-z direction) to be connected to the cell tabs 102 .

The protection circuit module 200 is inserted into the module case 300 while being connected to the cell tabs 102 of the battery cell 100 . The module case 300 has an opening OP open on one side, and in the process in which the protection circuit module 200 is inserted into the module case 300 , the module case 300 has an opening OP open on one side. is positioned to face the first direction (-z direction), and in that state, the protection circuit module 200 may be inserted into the module case 300 .

The battery cell 100 , the protection circuit module 200 , and the module case 300 assembled as described above may be provided as shown in FIG. 3 . Thereafter, the module case 300 is fixed through the jigs Z disposed on both sides, and rotates 180° around the rotation axis RAX. The module case 300 according to this embodiment may include protrusions 310 protruding outward at both ends, respectively, and these protrusions 310 are a process in which the jig Z rotates the module case 300 . It may serve as a handle of the jig (Z) so that it can be easily performed.

As shown in FIG. 1 , the rotated module case 300 may be seated on the sealing terrace 110a of the battery cell 100 . Therefore, the opening OP of the module case 300 may be finally arranged to face the second direction (+z direction), and the tab of the protection circuit module 200 also faces the second direction (+z direction). can be placed.

FIG. 4 is a cross-sectional view schematically illustrating a cross-section taken along line A-A of the battery pack of FIG. 1 .

1 and 4 together, the battery pack according to the present embodiment packaged through the above-described assembly process may include the module case 300 positioned on the sealing terrace 110a of the battery cell 100 . . The module case 300 may have a 'C' shape in cross section as shown in the cross-sectional view of FIG. 4 , and the opening OP on one side is in the second direction (+z direction) opposite to the battery cell 100 . ) can be opened to face.

In an embodiment, an insulating member 520 may be interposed between the module case 300 and the battery cell 100 . For example, the insulating member 520 may be an insulating film. The insulating member 520 prevents the heat generated in the battery cell 100 from being transferred to the module case 300 and the protection circuit module 200, and functions to insulate the module case 300 and the battery cell 100. can do. In FIG. 4 , the module case 300 is illustrated as being spaced apart from the insulating member 520 by a predetermined distance, but the module case 300 may be disposed to directly contact the insulating member 520 .

Meanwhile, an upper insulating film 515 may be positioned on the module case 300 . The upper insulating film 515 may be, for example, an insulating tape having adhesive strength on one surface, and may be positioned on the module case 300 to cover the module case 300 . As shown in FIGS. 1 and 4 , the upper insulating film 515 may be provided with a part extending toward the battery cell 100 , and disposed to cover a part of the module case 300 and the battery cell 100 . It can function to fix the module case 300 to the battery cell 100 .

FIG. 5 is a front view schematically showing the module case 300 of the battery pack of FIG. 1 , and FIG. 6 is a front view schematically showing a part including the module case 300 of the battery pack of FIG. 1 . FIG. 5 shows only the module case 300 separately, and FIG. 6 shows a structure in which the protection circuit module 200 and the module case 300 are mounted on the battery cell 100 .

5 and 6 , the module case 300 has an opening OP with one open side, and in a width in a direction perpendicular to the longitudinal direction of the opening OP, both ends 300e of The width we may be narrower than the width wc of the central portion 300c. Both end ends 300e of the module case 300 may be positioned to correspond to the overlapping portions 110b of the sealing terrace 110a, as shown in FIG. 6 .

As shown in FIG. 2 , the sealing case 110 according to this embodiment includes a sealing terrace 110a sealing the electrode assembly from the outside on one side, and both ends of the sealing terrace 110a have a chamfered shape. It may include an overlapping portion 110b folded so as to have it. The module case 300 is mounted on the sealing terrace 110a, and it is important to design the module case 300 to avoid the overlapping portion 110b of the sealing terrace 110a. If the module case 300 is not designed to avoid the overlapping portion 110b, the module case 300 cannot be compactly seated on the sealing terrace 110a, and the module case 300 is lifted and the protective circuit module ( It is difficult for the 200 ) to be stably connected to the battery cell 100 .

As the width (we) of both ends (300e) of the module case (300) is formed to be narrower than the width (wc) of the central portion (300c), both ends (300e) of the module case (300) have an excess space (s) ) occurs. The excess space s may be positioned to correspond to both end corners of the sealing terrace 110a. The battery cell 100 according to the present embodiment has a sealing terrace 110a on one side of the sealing case 110, and the sealing terrace 110a is formed to reduce external interference and compact the edges of the sealing terrace 110a. ) may be provided with an overlapping portion 110b folded to have a chamfer shape at both end corners. Since the overlapping portion 110b is formed by folding both end corners of the sealing terrace 110a, it may be formed thicker than other portions of the sealing terrace 110a. Therefore, the width (we) of both ends (300e) of the module case (300) is formed to be narrower than the width (wc) of the central portion (300c) to avoid the overlapping portion (110b), the module case (300) can be more stably seated on the sealing terrace 110a, and a battery pack having a compact structure can be implemented.

Meanwhile, the module case 300 according to the present embodiment may have an outer surface 300u exposed to the outside and an inner surface 300i into which the protection circuit module 200 is inserted. A locker part 320 for supporting the protection circuit module 200 may be positioned on the inner surface 300i of the module case 300 .

As described above, since the protection circuit module 200 is formed by integrating various elements and members on a plate-shaped circuit board, the protection circuit module 200 includes the first surface 200a and the first surface 200a with respect to the circuit board. It may have two surfaces 200b. The protection circuit module 200 includes a first surface 200a and a second surface 200b, and the inner surface 300i of the module case 300 is on the first surface 200a of the protection circuit module 200. It may have a first inner surface 300ia that faces and a second inner surface 300ib that faces the second surface 200b of the protection circuit module 200 . Referring to FIG. 5 , the locker part 320 may be located on the first inner surface 300ia corresponding to the upper end of the module case 300 . The locker unit 320 supports the protection circuit module 200 to prevent the protection circuit module 200 from being separated from the module case 300 .

Meanwhile, the module case 300 according to the present embodiment may have an upper end 300a including a first inner surface 300ia and a lower end 300b including a second inner surface 300ib. A first groove 330 may be positioned in the upper end 300a of the module case 300 . As an embodiment, the first grooves 330 may be respectively formed on both sides of the locker part 320 to facilitate fastening of the locker part 320 and the protection circuit module 200 .

In addition, the second groove 340 may be located in the lower end 300b of the module case 300 according to the present embodiment. As an embodiment, the second groove 340 may be symmetrically disposed on one side and the other side of the lower end portion 300b, respectively. The second groove 340 has a structure for avoiding interference with the module case 300 in which the protection circuit module 200 and the cell tab 102 connecting the battery cell 100 are inserted into the protection circuit module 200 . can be understood as

In the present embodiment, the width w4 of the second groove 340 may be wider than the width w3 of the first groove 330 . The second groove 340 is to avoid interference of the cell tab 102 as described above, and is preferably formed to have the same width as or greater than that of the cell tab 102 .

7 is a diagram schematically illustrating a partial manufacturing process of a battery pack according to an embodiment of the present invention.

Referring to FIG. 7 , in the battery pack according to an embodiment of the present invention, the protection circuit module 200 may be first inserted into the module case 300 and then connected to the battery cell 100 . That is, in the above-described embodiment, if the protection circuit module 200 is pre-connected to the battery cell 100 and then the protection circuit module 200 is inserted into the module case 300 to be manufactured, in this embodiment protection After the circuit module 200 is inserted into the module case 300 and integrated, it can be manufactured by connecting it to the battery cell 100 . In this case, the cell tab 102 of the battery cell 100 and the lead tab 202 of the protection circuit module 200 may be electrically connected through a welding method.

First, the protection circuit module 200 may be inserted into the module case 300 along the A direction as shown in FIG. 7A . The protection circuit module 200 inserted into the module case 300 may be integrated as shown in (b) of FIG. 7 . Thereafter, the cell tab 102 of the battery cell 100 and the lead tab 202 of the protection circuit module 200 may be connected by welding.

Although the present invention has been described with reference to the embodiment shown in the drawings, which is merely exemplary, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: battery cell
102: Cell tab
110a: sealed terrace
110b: overlap
110: case
200: protection circuit module
202: lead tab
204: external terminal
300: module case
300e: both ends of the module case
300c: central part of the module case
310: protrusion
320: locker unit
330: first groove
340: second groove
511, 512, 513, 514, 515, 516: insulating films

Claims (12)

A battery cell comprising an electrode assembly, a sealing case accommodating the electrode assembly, and a cell tab;
a protection circuit module disposed on one side of the battery cell and electrically connected to the cell tab; and
A module case having an opening at one side, accommodating the protection circuit module through the opening, and having a width at both ends of the opening in a width in a direction perpendicular to the longitudinal direction of the opening is narrower than the width at the center is equipped with;
The sealing case includes a sealing terrace on which the cell tab protrudes on one side and an overlapping portion of the sealing terrace,
Both ends of the module case are positioned to correspond to the overlapping portions of the sealing terrace, the battery pack. According to claim 1,
The sealing terrace seals the electrode assembly from the outside on one side,
The overlapping portion is folded to have a chamfer shape at both end corners of the sealing terrace. delete According to claim 1,
The module case has an outer surface exposed to the outside, and an inner surface into which the protection circuit module is inserted,
A battery pack comprising a locker portion supporting the protection circuit module on the inner surface. 5. The method of claim 4,
The protection circuit module has a first surface and a second surface opposite to each other,
The inner surface of the module case has a first inner surface opposite to the first surface and a second inner surface opposite to the second surface,
The locker portion is located on the first inner surface, the battery pack. 6. The method of claim 5,
The module case includes an upper end including the first inner surface and a lower end including the second inner surface,
The upper end has a first groove, the battery pack; 7. The method of claim 6,
The module case includes an upper end including the first inner surface and a lower end including the second inner surface,
wherein the lower end has a second groove. 8. The method of claim 7,
The width of the second groove is wider than the width of the first groove, the battery pack. 8. The method of claim 7,
The cell tab includes a first cell tab and a second cell tab,
A width of the second grooves is equal to or greater than a width of the first cell tab or the second cell tab. According to claim 1,
The module case includes, respectively, protrusions protruding outward from both ends of the battery pack. According to claim 1,
The battery pack further comprising an insulating member interposed between the battery cell and the module case. According to claim 1,
The cell tab includes a first cell tab and a second cell tab,
One surface of the module case corresponding to the first cell tab or the second cell tab has an open portion.

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