Battery module and battery pack including the battery module

Abstract

According to a battery module of one embodiment of the present invention, the battery module includes: a battery cell stack in which a plurality of battery cells are stacked; a bus bar frame connected to the battery cell stack; an electrode lead protruding from the battery cell stack and passing through a lead groove of the bus bar frame; and a bus bar electrically connected to the electrode lead, wherein the bus bar frame includes a base bottom and a first rib protruding from the base bottom, and the first rib supports the bus bar.

Description

Technical Field

[0001] The present disclosure relates to a battery module and a battery pack including the same, and more particularly, to a battery module having an improved welding structure and a battery pack including the same. Background Art

[0002] Secondary batteries that are easily applicable to various product groups and have electrical characteristics such as high energy density are widely used not only in portable devices but also in electric vehicles or hybrid vehicles driven by an electric drive source, energy storage systems, etc. Such secondary batteries are attracting attention as new environmentally friendly energy sources for improving energy efficiency because they have major advantages of significantly reducing fossil fuel use and not generating byproducts of energy use at all.

[0003] Small mobile devices use one or several batteries per device, while medium-sized or large-sized devices such as vehicles require high power and large capacity. Therefore, medium-sized or large-sized battery modules having a plurality of battery cells electrically connected to each other are used.

[0004] At the same time, with the utilization as an energy storage source in recent years, the demand for large-capacity structures has also been increasing, and the demand for battery packs with a multi-module structure having multiple battery modules has been growing, each battery module including multiple secondary batteries connected in series and / or parallel integrated together.

[0005] Meanwhile, when connecting a plurality of battery cells in series or in parallel to construct a battery pack, it is common to first construct a battery module consisting of at least one battery cell and then construct a battery pack by using the at least one battery module and adding other components.

[0006] The battery module includes a plurality of battery cells stacked on each other and a bus bar assembly electrically connecting electrode leads of the plurality of battery cells. Here, the bus bar assembly includes a bus bar frame having lead slots through which the electrode leads of each battery cell pass, and bus bar slots mounted on the bus bar frame and arranged to correspond to the number of lead slots, or having openings formed between the bus bars, and including bus bars connected to the electrode leads passing through the bus bar slots or the openings by welding or the like.

[0007] When a bus bar is connected to an electrode lead protruding from a battery cell stack in a battery module, a welding process may be performed. At this time, welding defects may occur depending on the bus bar or bus bar frame structure. In order to prevent these welding defects, it is necessary to improve the design of the bus bar or bus bar frame. Summary of the invention

[0008] Technical issues

[0009] An object of the present disclosure is to provide a battery module having an improved welding structure and a battery pack including the same.

[0010] However, the problems to be solved by the embodiments of the present disclosure are not limited to the above-mentioned problems, and various extensions can be made within the scope of the technical ideas included in the present disclosure.

[0011] Technical Solution

[0012] According to a battery module of one embodiment of the present disclosure, the battery module includes: a battery cell stack in which a plurality of battery cells are stacked; a bus bar frame connected to the battery cell stack; electrode leads protruding from the battery cell stack and passing through lead grooves of the bus bar frame; and a bus bar electrically connected to the electrode leads, wherein the bus bar frame includes a base portion and a first rib protruding from the base portion, and wherein the first rib supports the bus bar.

[0013] The electrode lead may pass through a lead groove of the bus bar frame and then be bent onto the bus bar, thereby welding the bent portion of the electrode lead to the bus bar.

[0014] The first rib may include a first sub-rib and a second sub-rib adjacent to each other, the bus bar may include a first portion supported by each of the first sub-rib and the second sub-rib, and a second portion located between the first sub-rib and the second sub-rib, and an upper surface of the second portion may have a half-blanked shape that is concave toward the base portion.

[0015] The portion to which the bus bar and the electrode lead are welded may be located on an extension line between the first sub-rib and the second sub-rib.

[0016] The electrode lead may be welded to the first portion, the electrode lead including a dummy portion extending from the welded portion and bent toward the second portion.

[0017] The dummy portion may be bent into the concave portion of the second portion.

[0018] The first portion of the bus bar and the second portion of the bus bar may be integrally formed.

[0019] The second portion of the bus bar may be separated from each of the first sub-rib and the second sub-rib.

[0020] The bus bar frame may further include a second rib located between the bus bars adjacent to each other, and a height of the second rib may be equal to or lower than a height of the electrode lead bent onto the bus bar.

[0021] A battery pack according to another embodiment of the present disclosure includes the above-mentioned battery module.

[0022] Beneficial Effects

[0023] According to an embodiment of the present disclosure, a rib is formed in a bus bar frame portion on which a bus bar is mounted, so that rigidity against bending of the bus bar can be enhanced by a welding jig during welding.

[0024] Furthermore, the ribs are located between the bus bars adjacent to each other, and the height of the partition ribs formed on the bus bar frame is formed equal to or lower than the height of the outermost electrode lead surface, thereby enabling the partition ribs to not interfere with the bending blade during welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view showing a portion of a battery module according to one embodiment of the present disclosure.

[0026] Figure 2 is along Figure 1 A cross-sectional view taken along the cutting line AA'.

[0027] Figure 3 is a plan view schematically showing a welding structure of an electrode lead and a bus bar of a comparative example.

[0028] Figure 4 It is shown Figure 3 Front view of the welded structure.

[0029] Figure 5 is a plan view schematically illustrating a welding structure of an electrode lead and a bus bar according to one embodiment of the present disclosure.

[0030] Figure 6 It is shown Figure 5 Front view of the welded structure.

[0031] Figure 7 is a schematic diagram illustrating a bus bar and a bus bar frame structure according to another embodiment of the present disclosure.

[0032] Figure 8 It shows that according to Figure 7 Schematic diagram of a bus bar and a bus bar frame structure of a comparative example.

[0033] Reference numerals

[0034] 130: Busbar frame

[0035] 280: Busbar

[0036] 130a: base

[0037] 130b: First rib

[0038] 130c: Second rib

[0039] 160: Electrode lead DETAILED DESCRIPTION

[0040] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the embodiments. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0041] In order to clearly describe the present disclosure, parts irrelevant to the description will be omitted, and like reference numerals refer to like elements throughout the specification.

[0042] In addition, in the drawings, the size and thickness of each element are arbitrarily illustrated for the convenience of description, and the present disclosure is not necessarily limited to the size and thickness shown in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for the sake of clarity. In the drawings, the thickness of some layers and regions is exaggerated for the convenience of description.

[0043] In addition, it will be understood that when an element such as a layer, film, region, or plate is referred to as being "on" or "over" another element, the element can be directly on the other element or there can also be intervening elements. Conversely, when an element is referred to as being "directly on" another element, this means that there are no intervening elements. Furthermore, the terms "on" or "above" mean disposed above or below a reference portion, and do not necessarily mean disposed at the upper end of the reference portion in a direction opposite to gravity.

[0044] Furthermore, throughout the specification, when a part is referred to as “including” certain components, unless otherwise mentioned, it means that the part may further include other components, and does not exclude the other components.

[0045] Furthermore, throughout the specification, when “plane” is mentioned, it means observing the target portion from the top, and when “cross-section” is mentioned, it means observing the target portion from the cross-section side cut vertically.

[0046] Figure 1 is a perspective view showing a portion of a battery module according to one embodiment of the present disclosure. Figure 2 is along Figure 1 A cross-sectional view taken along the cutting line AA'.

[0047] Reference Figure 1 and Figure 2 The battery module 100 according to the present embodiment includes a module frame 300, a battery cell stack 120 inserted into the module frame 300, and a bus bar frame 130 located at one opening side of the module frame 300 and connected to the battery cell stack 120. The battery cell stack 120 is formed by stacking a plurality of battery cells 110 in one direction.

[0048] The module frame 300 may be in the form of a single frame covering four surfaces except the front and rear surfaces of the battery cell stack 120. This means a frame that requires horizontal assembly in order to insert the battery cell stack 120 into the single frame. However, the module frame 300 is not limited to the single frame, and may have a shape including a U-shaped frame in which the upper surface, the front surface, and the rear surface are open, and an upper plate covering the upper portion of the cell stack 120.

[0049] A cell platform 135 extending from a bag covering the battery cell 110 is formed, and the electrode lead 160 protruding from the cell platform 135 may meet and pass through a lead slot (not shown). As the distance from the battery cell 110 increases, the distance between adjacent cell platforms 135 may become narrower and narrower. At this time, the electrode leads 160 protruding from the cell platform 135 may have the same polarity as each other. When the electrode leads 160 adjacent to each other have different polarities from each other, as the distance from the battery cell 110 increases, the distance between the cell platforms 135 where the electrode leads 160 protrude from each other may become wider and wider.

[0050] According to the embodiment, the compression pad 200 is formed between the outermost battery cell 110 and the side surface portion of the module frame 300. The compression pad 200 may be formed using a polyurethane-based material. The compression pad 200 may absorb thickness deformation of the battery cell 110 due to expansion and changes in the battery cell 110 due to external impact. At least one compression pad 200 may be formed not only between the outermost battery cell 110 and the side surface portion of the module frame 300, but also between adjacent battery cells 110.

[0051] A pass guide 260 is formed on the bus bar frame 130. Before forming the cell platform 135 allowing the electrode lead 160 of each of the three adjacent battery cells 110 to extend, the electrode lead 160 is guided to pass through the lead groove, and may be formed on one side of the bus bar frame 130. Specifically, the bus bar frame 130 may include a pass guide 260 located in the rear surface of the bus bar frame 130 positioned to be separated from the battery cell 110.

[0052] The passage guide 260 may form a predetermined guide space at the rear surface of the busbar frame 130 so that the three electrode leads 160 and the cell platform 135 may be close to each other before passing through the lead groove. The passage guide 260 may be provided in plurality. Here, a plurality of passage guides 260 may be provided to correspond to the number of the plurality of lead grooves. Thus, the adjacent electrode leads 160 in the plurality of battery cells 110 form three pairs, and then the electrode leads 160 may pass through the lead grooves via their respective passage guides 260 to form a group of electrode leads 160.

[0053] The number of electrode leads 160 forming the electrode lead 160 group is not limited to three and may be changed according to placement positions of electrode leads of the positive and negative electrodes of the battery cells 110 .

[0054] Figure 3 is a plan view schematically showing a welding structure of an electrode lead and a bus bar according to a comparative example. Figure 4 It is shown Figure 3 Front view of the welded structure.

[0055] Reference Figure 3 and Figure 4 , the bus bar 28 according to the comparative example has an opening portion formed in the center and may be electrically connected to the battery cell 11 via the electrode leads 15 and 16. The electrode leads 15 and 16 may have polarities different from each other and may be connected in series via one bus bar 28. The electrode leads 15 and 16 are bent onto the bus bar 28 in a direction protruding and extending from the battery cell 11, and the bent portions of the electrode leads 15 and 16 may be welded to the bus bar 28. When the welding jig presses the overlapping portions of the electrode leads 15 and 16 and the bus bar 28 from the front surface during welding, the bus bar 28 may be bent. When the bus bar 28 is bent in this manner, a gap is generated between the electrode leads 15 and 16 and the bus bar 28, which may cause welding defects.

[0056] Figure 5 is a plan view schematically illustrating a welding structure of an electrode lead and a bus bar according to one embodiment of the present disclosure. Figure 6 It is shown Figure 5 Front view of the welded structure.

[0057] Reference Figure 5 and Figure 6 The bus bar 280 included in the battery module according to the present embodiment has a half blanking shape. The half blanking shape may refer to a shape obtained by Figure 6The upper surface of the bus bar 280 is punched to about 2 / 3 of the height of the bus bar 280. Specifically, the bus bar 280 according to the present embodiment includes a first portion 280a in contact with the electrode lead 160 and a second portion 280b recessed based on the extended surface of the first portion 280a. The second portion 280b of the bus bar 280 may be recessed toward the base portion 130a of the bus bar frame 130 described later. The first portion 280a and the second portion 280b may be integrally formed.

[0058] The bus bar frame 130 included in the battery module according to the present embodiment includes a base portion 130a and a first rib 130b protruding from the base portion 130a. At this time, the first rib 130b supports the bus bar 280. The first electrode lead 160a and the second electrode lead 160b pass through the lead groove of the bus bar frame 130, and then are bent onto the bus bar 280. The bent portions of the first electrode lead 160a and the second electrode lead 160b may be welded to the bus bar 280.

[0059] The first rib 130b according to the present embodiment includes a first sub-rib 130b1 and a second sub-rib 130b2 adjacent to each other. The bus bar 280 includes a first portion 280a supported by each of the first sub-rib 130b1 and the second sub-rib 130b2 and a second portion 280b located between the first sub-rib 130b1 and the second sub-rib 130b2. At this time, the upper surface of the second portion 280b may have a half-blanking shape that is recessed toward the base portion 130a of the bus bar frame 130. At this time, the second portion 280b of the bus bar 280 may be separated from each of the first sub-rib 130b1 and the second sub-rib 130b2. The portion of the bus bar 280 to which the first electrode lead 160a and the second electrode lead 160b are welded may be located on an extension line of the first sub-rib 130b1 and the second sub-rib 130b2. The extension line of the first sub-rib 130b1 and the second sub-rib 130b2 has Figure 6 The first sub-rib 130b1 and the second sub-rib 130b2 are shown extending in an upward direction.

[0060] Figure 7 is a schematic diagram illustrating a bus bar and a bus bar frame structure according to another embodiment of the present disclosure. Figure 8 It shows that according to Figure 7 Schematic diagram of a bus bar and a bus bar frame structure of a comparative example.

[0061] Reference Figure 7 , after passing through the lead groove 138 of the busbar frame 130, the first electrode lead 160a and the second electrode lead 160b may be bent onto the busbar 280. Figure 7, portions where the first and second electrode leads 160a and 160b extend and pass through the lead groove 138 are omitted, but the first and second electrode leads 160a and 160b may extend to pass through the lead groove 138 in portions shown by dotted lines.

[0062] The bent portions of the first electrode lead 160a and the second electrode lead 160b are welded to the first portion 280a of the bus bar 280, and the first electrode lead 160a and the second electrode lead 160b may include a dummy portion 160D extending from the welded portion and bending toward the second portion 280b of the bus bar 280. The dummy portion 160D may be bent into the concave portion of the second portion 280b. In addition, the end of the second electrode lead 160b adjacent to the first electrode lead 160a may be bent in a direction different from the direction in which the dummy portion 160D is bent. In this way, the bus bar 280 according to the present embodiment has a half-punched shape, so when the first electrode lead 160a and the second electrode lead 160b are formed to be very long, the ends of the first electrode lead 160a and the second electrode lead 160b may be set in the concave second portion 280b. Therefore, it is possible to prevent adhesion of the overlapped portion for welding of the bus bar 280 and the first and second electrode leads 160 a and 160 b from being hindered.

[0063] The busbar frame 130 according to the present embodiment may further include a second rib 130c located between the busbars 280 adjacent to each other. The height of the second rib 130c may be equal to or lower than the height of the first electrode lead 160a and the second electrode lead 160b bent onto the busbar 280. In other words, the height difference h between the first electrode lead 160a and the second electrode lead 160b and the second rib 130c may be the same, or the height difference may be a positive number. With this structure, welding defects can be prevented by not interfering with the bending blade of the welding machine. Specifically, referring to Figure 8 , the second rib 130c corresponding to the partition rib may be disposed between two adjacent bus bars 280. At this time, if the height of the second rib 130c is higher than the height of the surface of the outermost first and second electrode leads 160a and 160b, the bending blade 500 that pushes the first and second electrode leads 160a and 160b to allow the first and second electrode leads 160a and 160b to be in close contact with the bus bar 280 during welding interferes with the second rib 130c, and thus the bus bar 280 and the first and second electrode leads 160a and 160b are not in close contact with each other, resulting in a welding defect.

[0064] Reference Figure 2 and Figure 7, a plurality of electrode leads 160 protrude from the cell platform 135, and the cell platform 135 extends from the bag covering the battery cell 110. The electrode leads 160 protruding from the cell platform 135 may be bent in a direction where the bus bar 280 is located. The bent electrode leads 160 overlap the same bus bar 280, and the plurality of electrode leads 160 and the bus bar 280 are welded simultaneously to form one welding point WD1 and WD2 at the first portion 280a of the bus bar 280, respectively.

[0065] In addition to the above differences, Figure 5 and Figure 6 The contents described in the embodiment of the present invention can be applied to this embodiment.

[0066] Meanwhile, one or more battery modules according to the embodiments of the present disclosure may be packaged in a pack case to form a battery pack.

[0067] The battery module and battery pack described above can be applied to various devices. These devices can be applied to vehicles such as electric bicycles, electric vehicles, hybrid vehicles, etc., but the present disclosure is not limited thereto, but can be applied to various devices that can use cylindrical batteries and battery packs including the cylindrical batteries, which also belong to the scope of the present invention.

[0068] Although preferred embodiments of the present disclosure have been described above, the scope of the present disclosure is not limited thereto, and modifications and improvements made by those skilled in the art using the basic concepts of the present disclosure defined in the appended claims also belong to the scope of the present disclosure.

[0069] Cross references to related applications

[0070] This application claims the rights to Korean Patent Application No. filed with the Korean Intellectual Property Office on November 15, 2019.

[0071] 10-2019-0146925, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A battery module, comprising: a battery cell stack in which a plurality of battery cells are stacked; a bus bar frame connected to the battery cell stack; an electrode lead protruding from the battery cell stack and passing through a lead groove of the busbar frame; as well as a bus bar electrically connected to the electrode lead, The busbar frame includes a base portion and a first rib portion protruding from the base portion. wherein the first rib supports the bus bar, wherein the portion of the bus bar to which the electrode lead is welded is located on an extension line of the first rib, and the extension line of the first rib has a direction in which the first rib extends upward, and The bus bar includes a first portion in contact with the electrode lead and a second portion recessed based on an extended surface of the first portion, and the first portion and the second portion are integrally formed.

2. The battery module according to claim 1, in, The electrode lead passes through the lead groove of the bus bar frame and is then bent onto the bus bar, thereby welding the bent portion of the electrode lead to the bus bar.

3. The battery module according to claim 2, in, The first rib includes a first sub-rib and a second sub-rib adjacent to each other, The first portion of the bus bar is supported by each of the first sub-rib and the second sub-rib, and the second portion of the bus bar is located between the first sub-rib and the second sub-rib, and An upper surface of the second portion has a half-blanked shape that is concave toward the base portion.

4. The battery module according to claim 3, in, The portion where the bus bar and the electrode lead are welded is located on an extension line between the first sub-rib and the second sub-rib, and the extension line of the first sub-rib and the second sub-rib has a direction in which the first sub-rib and the second sub-rib extend upward.

5. The battery module according to claim 4, in, The electrode lead is welded to the first portion, and the electrode lead includes a dummy portion extending from the welded portion and bent toward the second portion.

6. The battery module according to claim 5, in, The dummy portion is bent into the concave portion of the second portion.

7. The battery module according to claim 5, wherein: The electrode lead includes a first lead electrode and a second lead electrode, and an end portion of the second lead electrode adjacent to the first lead electrode is bent in a direction different from a direction in which the dummy portion is bent.

8. The battery module according to claim 3, in, The second portion of the bus bar is separated from each of the first sub-rib and the second sub-rib.

9. The battery module according to claim 2, in, The bus bar frame further includes a second rib located between the bus bars adjacent to each other, and The height of the second rib is equal to or lower than the height of the electrode lead bent onto the bus bar.

10. A battery pack comprising the battery module according to any one of claims 1 to 9.

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