Battery module with flexible busbar

Abstract

A battery module is disclosed, which includes a plurality of battery cells arranged in rows and a bus bar electrically connecting the plurality of battery cells, wherein the bus bar includes a high-current bus bar having a central area and a peripheral area, a step bus bar electrically connecting the central area of ​​the high-current bus bar and the plurality of battery cells, and a wavy bus bar electrically connecting the peripheral area of ​​the high-current bus bar and the plurality of battery cells.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0051646 filed in the Korean Intellectual Property Office on April 21, 2021, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] Embodiments relate to a battery module having a flexible bus bar. Background Art

[0003] Secondary batteries are power storage systems that provide excellent energy density for storing electrical energy in the form of chemical energy. Compared with non-rechargeable primary batteries, secondary batteries are rechargeable and can be used in IT devices such as smart phones, cellular phones, laptops, and tablet PCs. Recently, in order to help reduce or prevent environmental pollution, interest in electric vehicles has increased, and therefore, high-capacity secondary batteries are being used in electric vehicles. Such secondary batteries may have characteristics such as high density, high output, and stability.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute the prior art. Summary of the invention

[0005] An embodiment can be implemented by providing a battery module, which includes a plurality of battery cells arranged in rows and a bus bar electrically connecting the plurality of battery cells, wherein the bus bar includes a high-current bus bar having a central area and a peripheral area, a stepped bus bar electrically connecting the central area of ​​the high-current bus bar and the plurality of battery cells, and a wavy bus bar electrically connecting the peripheral area of ​​the high-current bus bar and the plurality of battery cells.

[0006] The thickness of the large current bus bar may be greater than the thickness of the stepped bus bar, and the thickness of the large current bus bar may be greater than the thickness of the corrugated bus bar.

[0007] The large current bus bar may include a rectangular plate-shaped body and a protrusion protruding outward from a central region of the body.

[0008] The high current bus bar may include copper or aluminum, and the stepped bus bar or the wavy bus bar may include aluminum.

[0009] The stepped bus bar may include a body region welded to a central region of the high current bus bar, at least one branch region extending from the body region and welded to a corresponding battery cell among the plurality of battery cells, and a first inclined region inclined downward between the body region and the at least one branch region.

[0010] The height of the first inclined region may be equal to the thickness of the large-current bus bar.

[0011] The at least one branch region may include a pair of branch regions respectively extending from opposite ends of the body region.

[0012] The corrugated bus bar may include: an inner body region welded to a peripheral region of a high current bus bar; a first branch region extending from the inner body region and welded to one of a plurality of battery cells; a first inclined region sloping downward between the inner body region and the first branch region; an outer body region on the outer side of the inner body region; a bent region connecting the inner body region and the outer body region; a second branch region welded to another of the plurality of battery cells; and a second inclined region sloping downward between the outer body region and the second branch region.

[0013] The height of the curved region may be 2 to 5 times the thickness of the curved region.

[0014] The height of the bent region may be greater than the thickness of the high current bus bar.

[0015] The bent region may have a cross-sectional shape in which a rounded portion is applied to a right-angle shape or a chamfered portion is applied to a trapezoidal shape.

[0016] The height of the second inclined region may be equal to the thickness of the large current bus bar. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Features will be apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the accompanying drawings.

[0018] Figure 1 is a plan view of an exemplary battery module according to the present disclosure.

[0019] Figure 2 is a partially enlarged view of an exemplary battery module according to the present disclosure.

[0020] Figure 3A and Figure 3B are perspective and front views of an exemplary flexible bus bar according to the present disclosure.

[0021] Figure 4A and Figure 4B is a cross-sectional view of an exemplary bending region of a flexible bus bar according to the present disclosure. DETAILED DESCRIPTION

[0022] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings, however, example embodiments may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey exemplary implementations to those skilled in the art.

[0023] In the accompanying drawings, the sizes of layers and regions are exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being "on" another layer or element, the layer or element can be directly on the other layer or element, or there may be intervening layers or elements. In addition, it will be understood that when a layer is referred to as being "between" two layers, the layer can be the only layer between the two layers, or there may be one or more intervening layers. Like reference numerals refer to like elements throughout.

[0024] As used herein, the terms "or" and "and / or" include any and all combinations of one or more of the associated listed items, for example, "A or B" will include A, B, or A and B. Further, it will be understood that when element A is referred to as being "connected to" element B, element A may be directly connected to element B, or an intervening element C may be present between element A and element B such that element A and element B are indirectly connected to each other.

[0025] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. It will also be understood that when the terms "include or include" and / or their variations are used in this specification, the stated features, quantities, steps, operations, elements and / or components are indicated, but the presence or addition of one or more other features, quantities, steps, operations, elements, components and / or their groups is not excluded.

[0026] It will be understood that, although the terms first, second, etc. can be used herein to describe various members, elements, regions, layers and / or parts, these members, elements, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish a member, element, region, layer and / or part from another member, element, region, layer and / or part, and are not intended to mean or require sequential inclusion. Therefore, for example, without departing from the teachings of the present disclosure, the first member, first element, first region, first layer and / or first part discussed below can be referred to as the second member, second element, second region, second layer and / or second part.

[0027] For ease of description, spatially relative terms such as "under", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature to another (other) element or feature as shown in the figure. It will be understood that the spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the elements or features in the figure are turned over, the elements described as "under" or "below" other elements or features will subsequently be positioned as "on" or "above" the other elements or features. Therefore, the exemplary term "under" can include both "above" and "under" orientations.

[0028] Figure 1 is a plan view of an exemplary battery module 100 according to the present disclosure, Figure 2 is a partially enlarged view of an exemplary battery module 100 according to the present disclosure, and Figure 3A and Figure 3B are perspective and front views of an exemplary flexible bus bar 120 according to the present disclosure.

[0029] like Figure 1 , Figure 2 , Figure 3A and Figure 3B As shown in , a battery module 100 according to an embodiment may include a plurality of battery cells 110 and a plurality of bus bars 120 electrically connecting the plurality of battery cells 110 .

[0030] In an embodiment, a generally plate-shaped insulating retainer 130 may be between the battery cell 110 and the bus bar 120. In an embodiment, the end plates 141 and 142 may be located at opposite ends of the battery module 100 in the longitudinal direction (e.g., in the first direction), and the side plates 151 and 152 may be located at opposite ends of the battery module 100 in the width direction. In an embodiment, the output terminal may be connected to the last or outer opposite end of the bus bar 120, or another battery module may be connected thereto. In an embodiment, the bus bar 120 may be electrically connected to a battery monitoring system board. In an embodiment, a voltage sensor or a current sensor may be connected to the bus bar 120, and the bus bar 120 may be electrically connected to the battery monitoring system board.

[0031] The battery cell 110 may include a rechargeable secondary battery. In an embodiment, the battery cell 110 may be a prismatic battery cell, a pouch-type battery cell, or a cylindrical battery cell. In an embodiment, the battery cell 110 may include a positive terminal or a negative terminal. Hereinafter, the positive terminal and the negative terminal are simply referred to as terminals 111.

[0032] In an implementation, the plurality of battery cells 110 may be arranged in a row in the first direction, and thus, the plurality of terminals 111 may also be arranged in a row in the first direction.

[0033] The bus bar 120 may electrically connect the plurality of battery cells 110. In an embodiment, the bus bar 120 may connect the plurality of battery cells 110 in parallel or connect the plurality of battery cells 110 in series.

[0034] The bus bar 120 may include, for example, a high-current bus bar 121, a stepped bus bar 122, and a wave bus bar 123. For example, the bus bar 120 may be a multi-piece bus bar including separate pieces bonded together.

[0035] In an embodiment, the large current busbar 121 may include a rectangular plate-shaped body 1211 and a protrusion 1212 protruding outward from the central area of ​​the body 1211. In an embodiment, the length direction of the large current busbar 121 may be defined as a first direction, and the width direction of the large current busbar 121 may be defined as a second direction. In an embodiment, the protrusion 1212 may protrude from the central area in the second direction. In an embodiment, the width of the central area where the current of the large current busbar 121 is concentrated may be relatively wide, so that heat can be quickly dissipated. In an embodiment, by providing the protrusion 1212, a voltage sensor may be connected to the protrusion 1212, thereby facilitating the installation of the voltage sensor. In an embodiment, the large current busbar 121 may include, for example, copper, copper alloy, aluminum or aluminum alloy. In an embodiment, the thickness of the large current busbar 121 (for example, in a vertical direction orthogonal to the first direction and the second direction) may be in a range from about 1 mm (millimeter) to about 10 mm. The large current bus bar 121 may allow current to flow from the stepped bus bar 122 and the wavy bus bar 123 in a concentrated manner, or may allow current to flow to the stepped bus bar 122 and the wavy bus bar 123 in a divided manner. Therefore, a relatively large current may flow through the large current bus bar 121 compared to the stepped bus bar 122 and the wavy bus bar 123. In an embodiment, the large current bus bar 121 may be coupled to and fixed to a latch protrusion 131 in the insulating holder 130 on the battery cell 110. In an embodiment, the large current bus bar 121 may also be referred to as a first bus bar for convenience.

[0036] The stepped bus bar 122 may electrically connect the central region of the large current bus bar 121 and the plurality of battery cells 110. In an embodiment, the stepped bus bar 122 may include a body region 1221, (eg, at least one) branch region 1222, and an inclined region 1223.

[0037] The body region 1221 may extend substantially in a first direction (e.g., longitudinally). The body region 1221 may be laser welded or ultrasonically welded to the central region of the high-current bus bar 121. Thus, the welding region 1224 may be between the body region 1221 of the stepped bus bar 122 and the central region of the high-current bus bar 121. In an embodiment, approximately two welding regions 1224 may be provided, and may be provided in an approximately circular shape or annular shape.

[0038] The branch region 1222 may extend from the opposite end of the main region 1221 to connect to the battery cell 110. In an embodiment, the branch region 1222 may be laser welded or ultrasonically welded to the terminal 111 of the battery cell 110. Therefore, the welding region 1225 may be between the branch region 1222 of the stepped bus bar 122 and the terminal 111 of the battery cell 110. In an embodiment, the welding region 1225 may have a substantially horseshoe shape (∩). In an embodiment, the branch region 1222 may extend from the main region 1221 in a second direction (perpendicular to the first direction). In an embodiment, the branch region 1222 may include a pair of branch regions extending from the (e.g., opposite) ends of the main region 1221. In an embodiment, two battery cells 110 may be connected in series or in parallel through the stepped bus bar 122.

[0039] The inclined region 1223 may have a downwardly inclined shape between the body region 1221 and the branch region 1222. In an embodiment, a height of the inclined region 1223 (eg, in a vertical direction) may be substantially equal to a thickness of the large current bus bar 121. In an embodiment, the inclined region 1223 may be bent at least 1 to 5 times.

[0040] In an embodiment, the stepped bus bar 122 may include, for example, copper, a copper alloy, aluminum, or an aluminum alloy. In an embodiment, the thickness of the stepped bus bar 122 (e.g., in the vertical direction) may be in the range of about 0.1 mm to about 2 mm. In an embodiment, for convenience, the stepped bus bar 122 may also be referred to as a second bus bar.

[0041] The corrugated bus bar 123 may include an inner body region 1231, a first branch region 1232, a first inclined region 1233, an outer body region 1234, a bent region 1235, a second branch region 1236, and a second inclined region 1237. In an embodiment, a pair of corrugated bus bars 123 may be located at opposite ends of the large current bus bar 121, respectively.

[0042] The inner body region 1231 may be laser welded or ultrasonically welded to the peripheral region of the high current bus bar 121. Thus, a weld region 1238 may be between the inner body region 1231 of the corrugated bus bar 123 and the peripheral region of the high current bus bar 121. In an embodiment, the weld region 1238 may be provided in a generally circular shape or an annular shape.

[0043] The first branch region 1232 may extend from the inner body region 1231 and be welded to the battery cell 110. In an embodiment, the first branch region 1232 may extend from the inner body region 1231 in the second direction and may be laser welded or ultrasonically welded to the terminal 111 of the battery cell 110. Thus, the welding region 1239 may be between the first branch region 1232 of the corrugated bus bar 123 and the terminal 111 of the battery cell 110. In an embodiment, the welding region 1239 may have, for example, a substantially horseshoe shape (∩).

[0044] The first inclined region 1233 may be inclined downward between the inner body region 1231 and the first branch region 1232 . In an embodiment, a height of the first inclined region 1233 may be equal to or similar to a thickness of the large-current bus bar 121 .

[0045] The outer body region 1234 may extend from the inner body region 1231. In an embodiment, the outer body region 1234 may extend outward from the inner body region 1231 in a first direction (perpendicular to the second direction).

[0046] The bending region 1235 may connect the inner body region 1231 and the outer body region 1234. In an embodiment, the height of the bending region 1235 (e.g., the distance from the vertex of the bending region 1235 to the region where the bending region is connected to the inner body region 1231 or the outer body region 1234 in the vertical direction) may be about 2 times to about 5 times the thickness of the bending region 1235 (e.g., in the vertical direction). In an embodiment, the height of the bending region 1235 may be greater than the thickness of the large current bus bar 121 (e.g., in the vertical direction). In an embodiment, the bending region 1235 may be bent 2 to 5 times (e.g., between the inner body region 1231 and the outer body region 1234). In an embodiment, the bending region 1235 may be bent in a wave shape. In an embodiment, the bending region 1235 may be bent in a substantially ∪ shape. In an embodiment, the bending region 1235 may have a shape in which a rounded corner portion or a chamfered corner portion is applied to a right angle shape (refer to Figure 4A The curved area 1235A) or the rounded corner portion or the chamfered corner portion is applied to the trapezoidal shape (refer to Figure 4B The cross-sectional shape or lateral shape of the curved area 1235B).

[0047] When charging and discharging are repeated, the battery module 100 expands. The position of the terminal 111 of the battery cell 110 changes, and therefore, stress is applied to the bus bar 120 connected to the terminal 111 of the battery cell 110, and the bus bar 120 is displaced or deformed. Relatively large stress is applied to the portion of the bus bar 120 at the outermost portion of the battery module 100, and the bus bar 120 is damaged. According to an embodiment, by providing a corrugated bus bar 123, displacement or deformation of the bus bar can be prevented even when the battery module 100 expands. In addition, by providing a substantially ∪-shaped bending area 1235 to the corrugated bus bar 123, the stress applied to the bus bar 120 can be absorbed, and thus displacement and deformation of the bus bar can be prevented.

[0048] The second branch region 1236 may extend from the outer body region 1234 to be connected to the battery cell 110. In an embodiment, the second branch region 1236 may extend from the outer body region 1234 in the second direction to be laser welded or ultrasonically welded to the terminal 111 of the battery cell 110. Therefore, the welding region 1240 may be between the second branch region 1236 of the corrugated bus bar 123 and the terminal 111 of the battery cell 110. In an embodiment, the welding region 1240 may have a horseshoe shape or a substantially circular shape or annular shape.

[0049] The second inclined region 1237 may be inclined downward between the outer body region 1234 and the second branch region 1236. In an embodiment, a height of the second inclined region 1237 may be equal to or similar to a thickness of the large-current bus bar 121.

[0050] In an embodiment, the corrugated bus bar 123 may include, for example, copper, a copper alloy, aluminum, or an aluminum alloy. In an embodiment, the thickness of the corrugated bus bar 123 may be in a range from about 0.1 mm (millimeter) to about 2 mm. In some examples, for convenience, the corrugated bus bar 123 may also be referred to as a third bus bar.

[0051] The battery module 100 according to the embodiment may include a highly flexible bus bar 120, and a plurality of battery cells 110 may be connected in series or in parallel. In an embodiment, the flexible bus bar 120 may not be damaged before reaching the EOL (end of life) of the battery module 100. In an embodiment, the flexible bus bar 120 may contribute to effective heat dissipation due to a large area. In an embodiment, when an impact is applied to the flexible bus bar 120 in the battery module 100, the damage may be minimized. In an embodiment, the flexible bus bar 120 may include a corrugated bus bar 123, and if an impact is applied along a first direction of the battery module 100, a short circuit caused by contact between the bus bars 120 may be prevented. In an embodiment, according to the deformation of the corrugated bus bar 123, the corrugated bus bar 123 may not contact another opposite or adjacent bus bar 120. In an embodiment, the flexible bus bar 120 may provide a structure of a high-capacity bus bar 120 with a low height. Therefore, the ratio of the space used by the battery cell 110 may be increased.

[0052] One or more embodiments may provide a battery module having a flexible bus bar, and having a high-capacity and high-heat-dissipating flexible bus bar, wherein the flexible bus bar allows a large current to flow so as to be applied to a high-capacity battery cell, the bus bar has excellent heat dissipation performance, and will not break or be damaged even when the battery cell expands.

[0053] The battery module according to the embodiment may provide a flexible bus bar which is not broken, displaced, or deformed when the battery cells are expanded or enlarged or when subjected to an impact from the outside.

[0054] The battery module according to the embodiment may provide a flexible bus bar in which little heat is generated even when a large current flows.

[0055] The battery module according to the embodiment may provide a flexible bus bar in which little heat is generated even when a large current flows and a voltage sensor or the like is easily mounted.

[0056] The battery module according to the embodiment may provide a flexible bus bar having a small resistance.

[0057] The battery module according to the embodiment may provide a flexible bus bar that is easily welded to the battery cells.

[0058] The battery module according to the embodiment may provide a flexible bus bar having a small thickness.

[0059] The battery module according to the embodiment may provide a flexible bus bar capable of easily electrically connecting a plurality of battery cells.

[0060] The battery module according to the embodiment may provide a flexible bus bar in which a bent region absorbs stress and is not easily broken even when an external impact is applied thereto.

[0061] Example embodiments have been disclosed herein, and although specific terms are employed, they are used and will be interpreted only in a general and descriptive sense and not for purposes of limitation. In some cases, as will be apparent to one of ordinary skill in the art upon filing this application, unless otherwise specifically noted, features, characteristics, and / or elements described in conjunction with a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments. Therefore, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A battery module, comprising: A plurality of battery cells are arranged in rows; as well as A bus bar electrically connects the plurality of battery cells. Among them, the busbar includes: a high-current busbar having a central area and a peripheral area; a stepped busbar located on the central area of ​​the high-current busbar and welded to the central area of ​​the high-current busbar to electrically connect the central area of ​​the high-current busbar and the multiple battery cells; and a corrugated busbar located on the peripheral area of ​​the high-current busbar and welded to the peripheral area of ​​the high-current busbar to electrically connect the peripheral area of ​​the high-current busbar and the multiple battery cells.

2. The battery module according to claim 1, wherein: The thickness of the high current bus bar is greater than the thickness of the stepped bus bar, and The thickness of the large-current bus bar is greater than the thickness of the corrugated bus bar.

3. The battery module according to claim 1, wherein: The high current bus bar comprises: a rectangular plate-like body; and A protrusion protrudes outward from a central area of ​​the body.

4. The battery module according to claim 1, wherein: The high current bus bar comprises copper or aluminum, and The stepped bus bar or the corrugated bus bar includes aluminum.

5. The battery module according to claim 1, wherein: The stepped bus bar comprises: a main body region welded to the central region of the high current bus bar; at least one branch region extending from the main body region and welded to a corresponding battery cell among the plurality of battery cells; and A first inclined region is inclined downward between the main region and the at least one branch region.

6. The battery module according to claim 5, wherein: The height of the first inclined region is equal to the thickness of the high-current bus bar.

7. The battery module according to claim 5, wherein: The at least one branch region includes a pair of branch regions respectively extending from opposite ends of the main body region.

8. The battery module according to claim 1, wherein: The corrugated bus bar comprises: an inner body region welded to the peripheral region of the high current bus bar; a first branch region extending from the inner body region and welded to one of the plurality of battery cells; a first inclined region, inclined downward between the inner body region and the first branch region; an outer body region on an outer side of the inner body region; a curved region connecting the inner body region and the outer body region; a second branch region welded to another battery cell among the plurality of battery cells; and A second inclined region is inclined downward between the outer main body region and the second branch region.

9. The battery module according to claim 8, wherein: The height of the bending region is 2 to 5 times the thickness of the bending region.

10. The battery module according to claim 8, wherein: The height of the bent area is greater than the thickness of the high-current bus bar.

11. The battery module according to claim 8, wherein: The bent region has a cross-sectional shape in which a rounded portion is applied to a right-angle shape or a chamfered portion is applied to a trapezoidal shape.

12. The battery module according to claim 9, wherein: The height of the second inclined region is equal to the thickness of the large current bus bar.

13. A battery module, comprising: A plurality of battery cells are arranged in rows; as well as A bus bar electrically connects the plurality of battery cells. The busbar includes: a large current busbar having a central area and a peripheral area, and including a rectangular plate-shaped body and a protrusion protruding outward from the central area of ​​the body; a stepped busbar electrically connecting the central area of ​​the large current busbar and the plurality of battery cells; and a corrugated busbar electrically connecting the peripheral area of ​​the large current busbar and the plurality of battery cells. Among them, the corrugated busbar includes an inner main body area welded to the peripheral area of ​​the high current busbar, a first branch area extending from the inner main body area along the width direction of the main body of the high current busbar and welded to one of the multiple battery cells, an outer main body area arranged on the outer side of the inner main body area along the length direction of the main body, a bent area bent in a generally U shape to connect the inner main body area and the outer main body area, and a second branch area welded to another battery cell among the multiple battery cells.

14. The battery module according to claim 13, wherein: The thickness of the high current bus bar is greater than the thickness of the stepped bus bar, and The thickness of the large-current bus bar is greater than the thickness of the corrugated bus bar.

15. The battery module according to claim 13, wherein: The high current bus bar comprises copper or aluminum, and The stepped bus bar or the corrugated bus bar includes aluminum.

16. The battery module according to claim 13, wherein: The stepped bus bar comprises: a main body region welded to the central region of the high current bus bar; at least one branch region extending from the main body region and welded to a corresponding battery cell among the plurality of battery cells; and A first inclined region is inclined downward between the main region and the at least one branch region.

17. The battery module according to claim 16, wherein: The height of the first inclined region is equal to the thickness of the high-current bus bar.

18. The battery module according to claim 16, wherein: The at least one branch region includes a pair of branch regions respectively extending from opposite ends of the main body region.

19. The battery module according to claim 13, wherein: The corrugated bus bar further comprises: a first inclined region, inclined downward between the inner body region and the first branch region; and A second inclined region is inclined downward between the outer main body region and the second branch region.

20. The battery module according to claim 13, wherein: The height of the bending region is 2 to 5 times the thickness of the bending region.

21. The battery module according to claim 13, wherein: The height of the bent area is greater than the thickness of the high-current bus bar.

22. The battery module according to claim 13, wherein: The bent region has a cross-sectional shape in which a rounded portion is applied to a right-angle shape or a chamfered portion is applied to a trapezoidal shape.

23. The battery module according to claim 19, wherein: The height of the second inclined region is equal to the thickness of the large current bus bar.

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