Battery modules with improved electrode lead connection structures, battery packs including them, and vehicles.

Abstract

A battery module according to an embodiment of the present invention includes: a battery stack including a first battery cell having a first electrode lead and a second battery cell having a second electrode lead and adjacent to the first battery cell; a busbar frame having a pair of lead slits through which the first electrode lead and the second electrode lead pass; and a busbar fixed to the busbar frame, wherein the first electrode lead and the second electrode lead are arranged on the busbar in a state of engagement with each other, and a weld portion for engagement with the busbar is formed in the area where the first electrode lead and the second electrode lead are engaged.

Description

Technical Field

[0001] The present invention relates to a battery module including an improved electrode lead connection structure, a battery pack including the battery module, and a vehicle, and more specifically, to a battery module that modifies the shape of the electrode leads to minimize the amount of busbar used, and a battery pack including the battery module and a vehicle.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0101956, filed in Korea on August 13, 2020, the disclosure of which is incorporated herein by reference. Background Technology

[0003] The busbar frame 2, including the busbar 3, is typically used to electrically connect multiple pouch cell units constituting a battery stack. In this case, the electrode lead 1 of each of adjacent pouch cell units passes through a lead slit 2a formed in the busbar frame 2, and a pair of electrode leads 1 passing through the lead slit 2a are welded to the busbar 3, which is formed of a conductive material and fixed to the busbar frame 2. Thus, adjacent cell units are electrically connected to each other.

[0004] In this case, the busbar 3 includes a pair of plates 3a, which are branched so that a pair of electrode leads 1 are respectively coupled to the pair of plates 3a.

[0005] Thus, when a pair of electrode leads 1 are electrically connected to each other using a busbar 3 comprising a pair of branches 3a, the manufacturing cost inevitably increases because as many plates 3a as electrode leads 1 are required. Furthermore, when a pair of electrode leads 1 are coupled to a pair of split plates 3a in a one-to-one manner, the length of the current path flowing between the pair of electrode leads 1 increases and the resistance value increases, thereby increasing the risk of energy loss.

[0006] Therefore, structural improvements are needed to minimize the use of expensive conductive metal material in the busbar 3 and to minimize the current flow path between a pair of adjacent electrode leads 1. Summary of the Invention

[0007] Technical issues

[0008] The present invention aims to solve the problems of the prior art. Therefore, the present invention aims to reduce the manufacturing cost of battery modules by minimizing the amount of conductive metal material required to manufacture the busbar when battery cells are electrically connected to each other, while maintaining sufficient coupling force and minimizing the coupling area between the busbar and the electrode leads.

[0009] The present invention also aims to prevent energy loss due to increased resistance by minimizing the current flow path between a pair of electrode leads electrically connected by a busbar.

[0010] However, the technical problems to be solved by the present invention are not limited to those described above, and those skilled in the art will understand other technical problems from the following description.

[0011] Technical solution

[0012] A battery module according to an embodiment of the present invention includes: a battery stack, the battery stack including a first battery cell having a first electrode lead and a second battery cell having a second electrode lead and adjacent to the first battery cell; a busbar frame including a pair of lead slits through which the first electrode lead and the second electrode lead pass; and a busbar fixed to the busbar frame, wherein the first electrode lead and the second electrode lead are located on the busbar in a state where the longitudinal ends of the first electrode lead and the longitudinal ends of the second electrode lead are engaged with each other, and a weld portion for bonding to the busbar is formed in the region where the first electrode lead and the second electrode lead are engaged with each other.

[0013] The first electrode lead may include a plurality of first protrusions extending from a longitudinal end.

[0014] Multiple first protrusions may be spaced apart from each other in the width direction of the first electrode lead.

[0015] The second electrode lead may include a plurality of second protrusions extending from the longitudinal end.

[0016] Multiple second protrusions may be spaced apart from each other in the width direction of the second electrode lead.

[0017] Each of the plurality of second protrusions may be located in the space formed between adjacent first protrusions among the plurality of first protrusions.

[0018] The welded portion can be formed on multiple first protrusions and multiple second protrusions.

[0019] The length of each of the first and second protrusions can correspond to the width of the busbar.

[0020] The welded portion can be formed along the entire longitudinal direction of each of the first and second protrusions.

[0021] The busbar can be located between a pair of lead slits.

[0022] The surfaces of the longitudinal ends of the first electrode lead and the longitudinal ends of the second electrode lead can form the same plane.

[0023] The battery pack according to an embodiment of the present invention includes a battery module according to an embodiment of the present invention.

[0024] The vehicle according to an embodiment of the present invention includes a battery module according to an embodiment of the present invention.

[0025] Beneficial effects

[0026] According to one aspect of the invention, when battery cells are electrically connected to each other, the amount of conductive metal material required to manufacture the busbar can be minimized by minimizing the coupling area between the busbar and the electrode leads while maintaining sufficient coupling force, thereby reducing the manufacturing cost of the battery module.

[0027] Furthermore, according to another aspect of the invention, the length of the current path flowing between a pair of electrode leads electrically connected by a busbar can be significantly reduced, thus preventing energy loss due to increased resistance. Attached Figure Description

[0028] The accompanying drawings illustrate preferred embodiments of the invention and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the invention. Therefore, the invention should not be construed as limited to the drawings.

[0029] Figure 1 and Figure 2 This is a diagram showing the structure of a conventional battery module.

[0030] Figure 3 This is a diagram illustrating a battery module according to an embodiment of the present invention.

[0031] Figure 4 This is a diagram illustrating the battery stack of the present invention.

[0032] Figure 5 This is a diagram illustrating the busbar frame and busbar of the present invention.

[0033] Figure 6 This is an enlarged partial view showing the coupling between a pair of electrode leads and a busbar in a battery module according to an embodiment of the present invention.

[0034] Figure 7 This is a partially enlarged view showing the coupling between a pair of electrode leads and a busbar in a battery module according to another embodiment of the present invention. Detailed Implementation

[0035] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings. Before description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather interpreted based on the meaning and concept corresponding to the technical aspects of the invention, in accordance with the principle that allows the inventors to appropriately define terms to obtain the best interpretation. Therefore, the description presented herein is merely a preferred example and is for illustrative purposes only, and is not intended to limit the scope of the invention. It should be understood that other equivalents and modifications can be made to the invention without departing from its scope.

[0036] In the following text, reference will be made to Figures 3 to 7 A battery module according to an embodiment of the present invention is described. (Refer to...) Figures 3 to 7 According to an embodiment of the present invention, the battery module includes a battery stack 10, a busbar frame 20, and a busbar 30.

[0037] A battery stack 10 is formed by stacking multiple battery cells, including a first battery cell 11 and a second battery cell 12 that are adjacent to each other. The battery cells constituting the battery stack 10 may be, for example, pouch-type battery cells, and in this case, a pair of electrode leads with different polarities are led out in opposite directions.

[0038] First battery cells 11 and second battery cells 12 facing each other are stacked such that first electrode leads 11a and second electrode leads 12a have opposite polarities. First electrode leads 11a extend to one side of the first battery cell 11 in the longitudinal direction, and second electrode leads 12a extend to one side of the second battery cell 12 adjacent to the first battery cell 11 in the longitudinal direction and are adjacent to the first electrode leads 11a.

[0039] This stacking arrangement of the battery stack 10 is used to connect multiple battery cells, including a first battery cell 11 and a second battery cell 12, in series. That is, by electrically connecting first electrode leads 11a and second electrode leads 12a with different polarities, the first battery cells 11 and the second battery cells 12 that are adjacent to each other are connected in series.

[0040] The busbar frame 20 has a generally rectangular plate shape and is located on one side and the other side of the battery stack 10 in the longitudinal direction (parallel to the Y-axis). Preferably, the busbar frame 20 is formed of a non-conductive material to insulate the plurality of busbars 30 described below. A pair of busbar frames 20 are provided to connect the plurality of battery cells constituting the battery stack 10 in series.

[0041] The busbar frame 20 includes at least one lead connection region S. When multiple lead connection regions S are provided, they are spaced apart from each other in the longitudinal direction (parallel to the X-axis) of the busbar frame 20. A pair of lead slits 21 are formed in each lead connection region S. The length of each lead slit 21 corresponds to the width of an electrode lead, and the width of each lead slit 21 corresponds to the thickness of the electrode lead, such that the electrode lead passes through the lead slit 21, and the lead slit 21 extends in the width direction (parallel to the Z-axis) of the busbar frame 20. Furthermore, the pair of lead slits 21 are spaced apart from each other in the longitudinal direction (parallel to the X-axis) of the busbar frame 20.

[0042] Busbars 30 are formed of conductive metal, and there are as many busbars 30 as there are lead connection areas S. Busbars 30 are fixedly disposed between a pair of lead slits 21 located in the lead connection area S. Busbars 30 extend longitudinally along the width direction (parallel to the Z-axis) of busbar frame 20.

[0043] The positions of the first electrode lead 11a and the second electrode lead 12a, which extend parallel to each other in the same direction, are arranged to correspond one-to-one with a pair of lead slits 21 formed in a lead connection region S.

[0044] Reference Figure 6 The first electrode lead 11a passes through the lead slit 21 and bends toward the busbar 30. Similarly, the second electrode lead 12a passes through the lead slit 21 and bends toward the busbar 30 and the first electrode lead 11a.

[0045] The first electrode lead 11a and the second electrode lead 12a are located on the busbar 30 with their longitudinal ends joined together. In this case, the surfaces of the longitudinal ends of the first electrode lead 11a and the second electrode lead 12a can form a coplanar plane. That is, the first electrode lead 11a and the second electrode lead 12a do not overlap each other. According to this coupling structure, the risk of welding failure caused by the increased thickness of the objects to be welded during the welding process between the first electrode lead 11a and the busbar 30 and between the second electrode lead 12a and the busbar 30 can be significantly reduced. A weld portion W for bonding to the busbar 30 is formed in the area where the first electrode lead 11a and the second electrode lead 12a are joined together. That is, each of the first electrode lead 11a and the second electrode lead 12a is welded to the busbar 30.

[0046] For the connection between the first electrode lead 11a and the second electrode lead 12a, the first electrode lead 11a includes a plurality of first protrusions P1 extending from a longitudinal end, and the second electrode lead 12a includes a plurality of second protrusions P2 extending from a longitudinal end. The first protrusions P1 can extend from the longitudinal end of the first electrode lead 11a along the longitudinal direction of the first electrode lead 11a. Similarly, the second protrusions P2 can extend from the longitudinal end of the second electrode lead 12a along the longitudinal direction of the second electrode lead 12a. Therefore, the first protrusions P1 and the second protrusions P2 can extend toward each other. The plurality of first protrusions P1 are spaced apart from each other in the width direction of the first electrode lead 11a, and similarly, the plurality of second protrusions P2 are spaced apart from each other in the width direction of the second electrode lead 12a. Each of the plurality of second protrusions P2 is positioned to fill the space formed between adjacent first protrusions P1. In this case, the first protrusions P1 and the second protrusions P2 can be in close contact with each other such that the surfaces of the first protrusions P1 and the second protrusions P2 form a coplanar plane.

[0047] The welded portion W can be formed on multiple first protrusions P1 and multiple second protrusions P2. Although in Figure 6 The weld portion W is formed in a dotted pattern only on a portion of the entire area of ​​each of the first protrusion P1 and the second protrusion P2, but this is only an example. The weld portion W can be formed on the entire area where the first electrode lead 11a and the busbar 30 overlap with each other, and on the entire area where the second electrode lead 12a and the busbar 30 overlap with each other, to securely fix the first electrode lead 11a and the second electrode lead 12a to the busbar 30. Alternatively, for ease of welding, the weld portion W can be formed longitudinally in the longitudinal direction (parallel to the Z-axis) of the busbar 30 to pass through the central portion in the longitudinal direction (parallel to the X-axis) of the first protrusion P1 and the central portion in the longitudinal direction (parallel to the X-axis) of the second protrusion P2.

[0048] When viewed from the top of the busbar 30, each of the first protrusion P1 and the second protrusion P2 may have the following characteristics: Figure 6 The trapezoidal shape shown may also have a rectangular shape, a triangular shape, or a shape with rounded longitudinal ends.

[0049] Reference Figure 7To increase the coupling force between the first electrode lead 11a and the busbar 30, and between the second electrode lead 12a and the busbar 30, each of the first protrusion P1 and the second protrusion P2 can be formed such that the length D of each of the first protrusion P1 and the second protrusion P2 corresponds to the width of the busbar 30. That is, the length D of each of the first protrusion P1 and the second protrusion P2 can be substantially the same as the width of the busbar 30. In this case, preferably, the weld portion W is formed along the entire longitudinal direction of the first protrusion P1 (parallel to the X-axis) and along the entire longitudinal direction of the second protrusion P2.

[0050] According to the battery module of the present invention as described above, since a pair of electrode leads 11a and 12a are located on the busbar 30 in a state where the pair of electrode leads 11a and 12a are joined together, and a weld portion W is formed in the area where the pair of electrode leads 11a and 12a are joined together, the width of the busbar 30 can be minimized without reducing the width of the coupling area between the electrode leads 11a and 12a and the busbar 30. Therefore, the material cost required to manufacture the busbar 30 formed of conductive metal material can be minimized, and the coupling force between the electrode leads 11a and 12a and the busbar 30 can be ensured, thereby improving productivity and product quality.

[0051] A battery pack according to an embodiment of the present invention includes at least one battery module according to the present invention as described above. Furthermore, a vehicle according to an embodiment of the present invention includes at least one battery module according to the present invention as described above or at least one battery pack according to an embodiment of the present invention.

[0052] The invention has been described in detail. However, it should be understood that while the detailed description and specific examples illustrate preferred embodiments of the invention, they are given by way of illustration only, as various variations and modifications within the scope of the invention as defined by the appended claims will become apparent to those skilled in the art from this detailed description.

Claims

1. A battery module, comprising: A battery stack, comprising a first battery cell having a first electrode lead and a second battery cell having a second electrode lead and adjacent to the first battery cell; a busbar frame including a pair of lead slits through which the first electrode lead and the second electrode lead pass; and a busbar fixed to the busbar frame. The first electrode lead and the second electrode lead are located on the busbar with their longitudinal ends joined together. A weld portion for bonding to the busbar is formed in the area where the first electrode lead and the second electrode lead are joined together, so as to minimize the width of the busbar and ensure the coupling force between the first electrode lead and the second electrode lead. The first electrode lead includes a plurality of first protrusions extending from the longitudinal end of the first electrode lead. The second electrode lead includes a plurality of second protrusions extending from the longitudinal end of the second electrode lead. Each of the plurality of second protrusions is located in the space between adjacent first protrusions formed among the plurality of first protrusions. The welded portion is formed along the entire longitudinal direction of each of the first protrusion and the second protrusion.

2. The battery module according to claim 1, wherein, The plurality of first protrusions are spaced apart from each other in the width direction of the first electrode lead.

3. The battery module according to claim 1, wherein, The plurality of second protrusions are spaced apart from each other in the width direction of the second electrode lead.

4. The battery module according to claim 1, wherein, The welded portion is formed on the plurality of first protrusions and the plurality of second protrusions.

5. The battery module according to claim 1, wherein, The length of each of the first protrusion and the second protrusion corresponds to the width of the busbar.

6. The battery module according to claim 1, wherein, The busbar is located between the pair of lead slits.

7. The battery module according to claim 1, wherein, The surface of the longitudinal end of the first electrode lead and the surface of the longitudinal end of the second electrode lead form the same plane.

8. A battery pack comprising a battery module according to any one of claims 1 to 7.

9. A vehicle comprising a battery module according to any one of claims 1 to 7.

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