Bridge structure and secondary battery including the same

Abstract

The present invention relates to a bridge structure, and particularly to a bridge structure for joining stacked first and second electrode assemblies to each other, and provides a bridge structure including: a first weld portion to which a first electrode tab of the first electrode assembly is joined; a second weld portion to which a second electrode tab of the second electrode assembly is joined, and which is disposed in a diagonal direction inclined with respect to both of stacking directions of the first and second electrode assemblies with respect to the first weld portion; and a connection portion connecting the first and second weld portions to each other and extending in the diagonal direction.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application Nos. 10-2022-0105698, 10-2022-0105699 and 10-2022-0105700, filed on August 23, 2022, and Korean Patent Application No. 10-2023-0110485, filed on August 23, 2023, all of which are incorporated herein by reference. Technical Field

[0004] The present invention relates to a bridging structure and a secondary battery including the bridging structure, and more specifically, to a bridging structure capable of incorporating multiple electrode assemblies and a secondary battery including the bridging structure. Background Technology

[0005] Generally, rechargeable batteries refer to batteries that can be recharged and used not only as power sources for small household appliances such as mobile phones, laptops, and cameras, but also for vehicles. Among these rechargeable batteries, lithium-ion batteries are considered a type of vehicle power source. Lithium-ion batteries typically possess high performance and high stability, and are manufactured by selecting materials based on desired performance characteristics such as battery life, charge / discharge capacity, charge / discharge rate, temperature characteristics, and stability.

[0006] In particular, with the continuous improvement of electric vehicle technology, the secondary battery, as one of the three core components of electric vehicles, plays a crucial role in their performance. Currently, user demand for electric vehicles is gradually increasing, and so is the demand for the energy density of secondary batteries. Research is actively underway to increase the energy density of secondary batteries installed in electric vehicles in order to extend their range.

[0007] To manufacture secondary batteries with high energy density, it is advantageous to increase the thickness of the electrode assembly housed within the battery and generating electrical energy. However, to bond the protruding electrode tabs to the electrode leads, the increase in the length of the electrode tabs is as significant as the increase in the thickness of the electrode assembly. The problem is that when electrode tabs made of thin foil are configured to have long lengths, they are prone to damage, such as tearing due to impact, thus shortening the lifespan of the secondary battery. Furthermore, with use, when the secondary battery expands, the increased tension applied to the electrode tabs due to the expansion can also damage them. Summary of the Invention

[0008] Technical issues

[0009] To address the aforementioned problems, one object of the present invention is to provide a bridging structure and a secondary battery including the bridging structure, wherein the bridging structure can combine multiple electrode assemblies such that the length of the electrode terminals does not increase, and even when expansion occurs in the electrode assemblies, the impact that may be applied to the electrode terminals can be reduced.

[0010] Technical solution

[0011] According to one embodiment of the present invention, the present invention relates to a bridging structure for combining a first electrode assembly and a second electrode assembly, and provides a bridging structure comprising: a first welding portion, wherein an electrode terminal of the first electrode assembly is coupled to the first welding portion; a second welding portion, wherein an electrode terminal of the second electrode assembly is coupled to the second welding portion, and the second welding portion is disposed in an oblique direction inclined relative to the stacking direction of the first electrode assembly and the second electrode assembly; and a connecting portion connecting the first welding portion and the second welding portion to each other and extending in the oblique direction.

[0012] The bridging structure may further include a deformation inducing portion disposed at each of the two ends of the connection portion, which induces the connection portion to tilt more steeply in the oblique direction when a force is applied.

[0013] The deformation inducing part may include: a first deformation inducing part configured to cause an angle change between the first welded part and the connecting part; and a second deformation inducing part configured to cause an angle change between the second welded part and the connecting part.

[0014] The connecting part can be bent in one direction relative to the first welded part, and the second welded part can be bent in another direction relative to the connecting part.

[0015] The bridging structure may include a metallic material that is capable of elastic deformation at the deformation-inducing part.

[0016] The first welded part, the connecting part, and the second welded part can be formed by a single component that is continuously arranged in the length direction.

[0017] The connecting part can electrically connect the first welded part and the second welded part to each other.

[0018] The first weld and the second weld can be set to be parallel to each other.

[0019] The bridging structure may further include electrode leads that are coupled to one of the first and second weld portions.

[0020] According to another embodiment of the present invention, a secondary battery is provided, comprising: a first electrode assembly having a first electrode terminal piece disposed thereon; a second electrode assembly having a second electrode terminal piece disposed thereon; a bridging structure; and a housing accommodating the first electrode assembly, the second electrode assembly, and the bridging structure. The bridging structure relates to a bridging structure for joining stacked first and second electrode assemblies together, and includes: a first welding portion to which the electrode terminal piece of the first electrode assembly is joined; a second welding portion to which the electrode terminal piece of the second electrode assembly is joined, and the second welding portion is disposed in an oblique direction inclined relative to the stacking direction of the first and second electrode assemblies; and a connecting portion connecting the first and second welding portions to each other and extending in the oblique direction.

[0021] Beneficial effects

[0022] In this invention, multiple electrode assemblies can be combined to manufacture a secondary battery with increased thickness, thereby improving the energy density of the secondary battery. Furthermore, a bridging structure can be provided between the electrode leads and the electrode terminals, such that the electrode terminals are configured to have a short length to prevent damage to the electrode terminals due to the increased length of the electrode terminals.

[0023] Furthermore, in this invention, when expansion occurs in the secondary battery, the shape of the bridging structure can be elastically deformed, and the impact applied to the electrode terminals can be absorbed to reduce damage to the electrode terminals. Attached Figure Description

[0024] Figure 1 This is a perspective view showing the state of a secondary battery according to a first embodiment of the present invention, wherein the first electrode assembly and the second electrode assembly are combined by a bridging structure.

[0025] Figure 2 It shows when along Figure 1 The diagram shows the state of the first and second electrode assemblies combined through the bridging structure when viewed from direction A.

[0026] Figure 3 This is a perspective view showing the construction of the bridging structure according to a first embodiment of the present invention.

[0027] Figure 4a , 4b 4c and 4c are cross-sectional views showing the deformation of the bridging structure according to the first embodiment of the present invention when a force is applied to it.

[0028] Figure 5a This is a cross-sectional view showing the bridging structure according to a second embodiment of the present invention. Figure 5bThis is a cross-sectional view showing the bridging structure according to a third embodiment of the present invention. Detailed Implementation

[0029] The invention will now be described in more detail with reference to the accompanying drawings. The drawings are included to provide a further understanding of the invention and illustrate only embodiments thereof. The scope of the invention is not limited by the drawings. In the drawings, the same reference numerals refer to the same elements throughout. For ease of understanding, some parts may be enlarged, reduced, or omitted.

[0030] Furthermore, the terms or words used in this specification and claims should not be construed as having their conventional or dictionary-based meanings, but rather should be understood as having meanings and concepts that are within the scope of this invention, based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe and illustrate his or her invention.

[0031] First Embodiment

[0032] Reference Figures 1 to 3 The bridging structure 10 according to the present invention, as a first embodiment of the present invention, may include a first welding part 100, a second welding part 200, and a connecting part 300.

[0033] The bridging structure 10 can be configured to extend between the respective electrode terminals T1 and T2 of the stacked first electrode assembly J1 and second electrode assembly J2 to engage with the plurality of stacked electrode assemblies J1 and J2, thereby engaging with the respective electrode terminals T1 and T2 of the plurality of electrode assemblies J1 and J2 and electrically connecting the plurality of electrode assemblies J1 and J2 to each other.

[0034] Furthermore, since the bridging structure 10 is not combined with the electrode terminals of a single thick electrode assembly, but is combined with the electrode terminals T1 of the first electrode assembly J1 and the electrode terminals T2 of the second electrode assembly J2 respectively, the electrode terminals T1 and T2 of the first electrode assembly J1 and the second electrode assembly J2 can be configured to be shorter in length and combined with each other.

[0035] Electrode assemblies J1 and J2 may each have a structure in which a positive current collector / positive active material layer / separator / negative active material layer / negative current collector are sequentially stacked. The positive current collector may include a region coated with a positive active material layer and an uncoated positive electrode region, and the uncoated positive electrode region may protrude to the outside of the electrode assembly and may be a positive electrode terminal. The negative current collector may include a region coated with a negative active material layer and an uncoated negative electrode region, and the uncoated negative electrode region may protrude to the outside of the electrode assembly and may be a negative electrode terminal. A separator may be disposed between the positive and negative current collectors to prevent electrode current collectors with different polarities from contacting each other.

[0036] The first welding portion 100 may be disposed on one side of the bridging structure 10, and the first electrode contact T1 of the first electrode assembly J1 is bonded to a surface of the first welding portion 100. The first electrode contact T1 of the first electrode assembly J1 may be bonded to that surface of the first welding portion 100 by, for example, welding or brazing.

[0037] The first welding part 100 can be a flat plate with a predetermined width, so that the first electrode terminal piece T1 of the first electrode assembly J1 is joined to it.

[0038] The first welding part 100 may be made of a conductive metal material, so that the first electrode terminal T1 of the first electrode assembly J1 and the second electrode terminal T2 of the second electrode assembly J2 are electrically connected to each other.

[0039] The first welding part 100 can be configured as the first electrode terminal piece T1 parallel to the first electrode assembly J1.

[0040] The second welding part 200 can be combined with the second electrode terminal piece T2 of the second electrode assembly J2, and is disposed in an oblique direction that is inclined relative to the stacking direction of the first electrode assembly J1 and the second electrode assembly J2 relative to the first welding part 100.

[0041] Since the second welding part 200 is arranged in an oblique direction relative to the stacking direction of the first electrode assembly J1 and the second electrode assembly J2, the moving path of the welding device for welding the electrode terminals T1 and T2 of the electrode assemblies J1 and J2 to the first welding part 100 and the second welding part 200 respectively can be simplified, and the upper space of the first welding part 100 and the second welding part 200 can be open, thereby improving the convenience of welding when the welding device performs welding.

[0042] The second welding part 200 can be a flat plate with a predetermined width, so that the second electrode terminal piece T2 of the second electrode assembly J2 is combined with it.

[0043] The second welding part 200 can be made of a conductive metal material, so that the first electrode terminal T1 of the first electrode assembly J1 and the second electrode terminal T2 of the second electrode assembly J2 are electrically connected to each other.

[0044] The second welding part 200 can be configured as the second electrode terminal piece T2 parallel to the second electrode assembly J2.

[0045] The connecting portion 300 can connect the first welding portion 100 and the second welding portion 200 to each other, and extends in the oblique direction along the arrangement of the first welding portion 100 and the second welding portion 200 in the oblique direction.

[0046] The connecting part 300 may be made of a conductive metal material to electrically connect the first welding part 100 and the second welding part 200 to each other.

[0047] The connecting portion 300 can be configured to bend in one direction from the first welding portion 100, and the second welding portion 200 can be configured to bend in another direction from the connecting portion 300. Since the first welding portion 100 and the second welding portion 200 bend in opposite directions, the first welding portion 100 and the second welding portion 200 can be configured to be parallel to each other, and even when the connecting portion 300 is tilted in the oblique direction, the first welding portion 100 and the second welding portion 200 can remain parallel to each other.

[0048] The first welded portion 100, the connecting portion 300, and the second welded portion 200 can be provided by a single component continuously arranged in the length direction. In the bridging structure 10, a single component can be continuously arranged in the length direction by a bending process, without the need for a separate joining process, thereby reducing manufacturing costs and simplifying the manufacturing process.

[0049] The bridging structure 10 according to the invention may further include a deformation induction part 400.

[0050] The deformation inducing part 400 can be provided at each of the two ends of the connecting part 300, and when a force is applied, it induces the connecting part 300 to tilt more steeply or more gently in the oblique direction.

[0051] The bridging structure 10 may include a metallic material that is capable of elastic deformation at the deformation induction section 400.

[0052] Reference Figure 3 The deformation inducing part 400 may include a first deformation inducing part 410 and a second deformation inducing part 420.

[0053] Reference Figures 4a to 4c The first deformation induction part 410 may be provided at one end of the connecting part 300 and configured to change the angle α between the first welding part 100 and the connecting part 300.

[0054] The first deformation inducing part 410 may be provided on the region where the connecting part 300 bends in one direction from the first welded part 100. Since the first deformation inducing part 410 is provided on the region where stress is concentrated, including the bending structure, when a force is applied to the first welded part 100 or the connecting part 300, the first deformation inducing part 410 will deform, and due to the deformation of the first deformation inducing part 410, the angle α between the connecting part 300 and the first welded part 100 will change.

[0055] When expansion occurs in the secondary battery, causing deformation and expansion of the electrode assembly, and this force is applied to the bridging structure 10, the angle α between the connecting portion 300 and the first weld portion 100 will decrease (see...). Figure 4a Furthermore, when the expanding electrode assembly deforms and contracts, causing a force to be applied to the bridging structure 10, the angle α between the connecting portion 300 and the first welding portion 100 will increase (see...). Figure 4c In other words, the bridging structure 10 can change the spacing between electrode terminals T1 and T2 in response to the expansion and contraction deformation of the electrode assembly, thereby absorbing the impact that may be applied to electrode terminals T1 and T2.

[0056] Reference Figures 4a to 4c The second deformation induction part 420 may be provided at the other end of the connecting part 300 and configured to change the angle b between the second welding part 200 and the connecting part 300.

[0057] The second deformation inducing part 420 may be provided on the region where the connecting part 300 bends from the second welded part 200 in another direction. Since the second deformation inducing part 420 is provided on the region where stress is concentrated, including the bending structure, when a force is applied to the second welded part 200 or the connecting part 300, the second deformation inducing part 420 will deform, and due to the deformation of the second deformation inducing part 420, the angle b between the connecting part 300 and the second welded part 200 will change.

[0058] When the electrode assembly deforms and expands due to expansion within the secondary battery, causing a force to be applied to the bridging structure 10, the angle b between the connecting portion 300 and the second welded portion 200 will decrease (see...). Figure 4a Furthermore, when the electrode assembly contracts due to deformation from expansion, causing a force to be applied to the bridging structure 10, the angle b between the connecting portion 300 and the second welding portion 200 will increase (see...). Figure 4c In other words, the bridging structure 10 can change the spacing between electrode terminals T1 and T2 in response to the expansion and contraction deformation of the electrode assembly, thereby absorbing the impact that may be applied to the electrode terminals T1 and T2.

[0059] As a secondary battery deteriorates due to repeated charging and discharging, it may experience expansion and contraction. When expansion occurs, the electrode assemblies J1 and J2 housed within the secondary battery expand and change shape. This shape change can cause excessive force to be applied to the electrode terminals T1 and T2 connected to the electrode leads L, potentially damaging them and causing a short circuit. In the bridging structure 10 according to the invention, when expansion occurs in the secondary battery, the bridging structure 10 can deform to correspond to the shape changes of the electrode terminals T1 and T2, thereby reducing the impact that may be applied to the electrode terminals T1 and T2 connected to the bridging structure 10.

[0060] Furthermore, since the bridging structure 10 includes a metallic material capable of elastic deformation at the deformation-inducing section 400, when the electrode assemblies J1 and J2, which have expanded due to the expansion phenomenon, shrink back to a certain extent, the bridging structure 10 will recover from its deformed shape due to the elastic restoring force of the deformation-inducing section. This elastic restoring force is as large as the degree of shrinkage of the electrode assemblies J1 and J2 (see...). Figures 4a to 4c ).

[0061] Furthermore, when the first electrode assembly J1 or the second electrode assembly J2 expands due to expansion within the secondary battery, the angle of the connecting portion 300 along the oblique direction changes. Because of this change in the angle of the connecting portion 300, the first welding portion 100 and the second welding portion 200 can minimize the impacts that may be applied to the electrode contacts T1 and T2 during horizontal and vertical movement.

[0062] The bridging structure 10 may further include an electrode lead L, which is coupled to one of the first solder portion 100 and the second solder portion 200. The electrode lead L can be coupled by soldering to one of the first solder portion 100 and the second solder portion 200.

[0063] Electrode leads L can be directly coupled to electrode contacts T1 and T2, but an integrated structure can also be provided by coupling electrode leads L to one of the first welding portion 100 and the second welding portion 200 of the bridging structure 10, so that the coupling of the bridging structure 10 to the electrode contacts T1 and T2 of the electrode assemblies J1 and J2 can be performed quickly.

[0064] Second Embodiment

[0065] Reference Figure 5a The bridging structure 10 according to the second embodiment of the present invention may include a first welding part 110, a second welding part 210 and a connecting part 310.

[0066] The first welding part 110 can be a flat plate with a predetermined width, so that the first electrode terminal piece T1 of the first electrode assembly J1 is joined to it, and can be made of a conductive metal material.

[0067] The second welding part 210 can be combined with the second electrode terminal piece T2 of the second electrode assembly J2, and is disposed in an oblique direction that is inclined relative to the stacking direction of the first electrode assembly J1 and the second electrode assembly J2 relative to the first welding part 110.

[0068] The second welding part 210 can be a flat plate with a predetermined width, so that the second electrode terminal piece T2 of the second electrode assembly J2 is combined with it.

[0069] The second welding part 210 may be made of a conductive metal material.

[0070] The connecting portion 310 can connect the end of the first welding portion 110 and the end of the second welding portion 210 to each other. The connecting portion 310 can be configured to extend vertically from the first welding portion 110.

[0071] The connecting part 310 may be made of a conductive metal material to electrically connect the first welding part 110 and the second welding part 210 to each other.

[0072] The connecting portion 310 can be configured to bend in one direction from the first welding portion 110, and the second welding portion 210 can be configured to bend in another direction from the connecting portion 310. Since the first welding portion 110 and the second welding portion 210 bend in opposite directions, the first welding portion 110 and the second welding portion 210 can be configured to be parallel to each other.

[0073] When expansion occurs in electrode assemblies J1 and J2, the vertically extending connecting portion 310 can be deformed from a vertical angle to an inclined angle, the first welding portion 110 and the second welding portion 210 can move in a direction away from each other, and damage to the connected electrode terminals T1 and T2 can be prevented.

[0074] Third Embodiment

[0075] Reference Figure 5b The bridging structure 10 according to the present invention, as a third embodiment of the present invention, may include a first welding part 120, a second welding part 220 and a connecting part 320.

[0076] The first welding portion 120 can be a flat plate with a predetermined width, such that the first electrode terminal piece T1 of the first electrode assembly J1 is joined to it, and the first welding portion 120 can be made of a conductive metal material.

[0077] The second welding part 220 can be combined with the second electrode terminal piece T2 of the second electrode assembly J2, and is disposed in an oblique direction that is inclined relative to the stacking direction of the first electrode assembly J1 and the second electrode assembly J2 relative to the first welding part 120.

[0078] The second welding part 220 can be a flat plate with a predetermined width, so that the second electrode terminal piece T2 of the second electrode assembly J2 is combined with it.

[0079] The second welding part 220 can be made of a conductive metal material, so that the electrode terminal T1 of the first electrode assembly J1 and the second electrode terminal T2 of the second electrode assembly J2 are electrically connected to each other.

[0080] The second welding part 220 can be configured as an electrode terminal piece T2 parallel to the second electrode assembly J2.

[0081] The connecting portion 320 can connect the end of the first welding portion 120 to the end of the second welding portion 220. The connecting portion 320 can have an acute angle with respect to the first welding portion 120 and the second welding portion 220, respectively. Therefore, the first welding portion 120, the second welding portion 220 and the connecting portion 320 can be configured to have a "Z" shape.

[0082] The connecting part 320 may be made of a conductive metal material to electrically connect the first welding part 120 and the second welding part 220 to each other.

[0083] The connecting portion 320 can be configured to bend in one direction from the first welding portion 120, and the second welding portion 220 can be configured to bend in another direction from the connecting portion 320. Since the first welding portion 120 and the second welding portion 220 bend in opposite directions, the first welding portion 120 and the second welding portion 220 can be configured to be parallel to each other.

[0084] When electrode assemblies J1 and J2 expand due to expansion within them, the connecting portions 310, which have predetermined angles relative to the first welding portion 120 and the second welding portion 220, deform in a steeper direction, increasing the vertical distance between them. Therefore, the first welding portion 120 and the second welding portion 220 move away from each other, preventing damage to the electrode contacts T1 and T2 that are bonded to them.

[0085] Fourth embodiment

[0086] Reference Figure 1 The secondary battery according to the present invention, as a fourth embodiment of the present invention, may include a first electrode assembly J1, a second electrode assembly J2, a bridging structure 10, and a housing (not shown).

[0087] The housing (not shown) can accommodate the first electrode assembly J1, the second electrode assembly J2 and the bridging structure 10, and the first electrode assembly J1 and the second electrode assembly J2 can be combined with the bridging structure 10 to be electrically connected to each other. The bridging structure 10 relates to a bridging structure 10 for joining stacked first electrode assemblies J1 and second electrode assemblies J2 to each other, and may include: a first solder portion 100, 110, or 120, wherein a first electrode terminal T1 of the first electrode assembly J1 is joined to the first solder portion 100, 110, or 120; a second solder portion 200, 210, or 220, wherein a second electrode terminal T2 of the second electrode assembly J2 is joined to the second solder portion 200, 210, or 220, and the second solder portion is disposed in an oblique direction inclined relative to the first solder portion 100, 110, or 120 relative to the stacking direction of the first electrode assembly J1 and the second electrode assembly J2; and a connecting portion 300, 310, or 320 connecting the first solder portion 100, 110, or 120 to the second solder portion 200, 210, or 220 to each other, and extending in the oblique direction. The description of the first to third embodiments may replace a detailed description of the bridging structure 10.

[0088] Although the invention has been described with reference to embodiments, the invention is not limited thereto. Changes and modifications may be made to the embodiments without departing from the spirit and scope of the invention, and those skilled in the art will understand that such changes and modifications are considered to be within the scope of the invention.

[0089] [Explanation of reference numerals in the attached figures]

[0090] 10: Bridging structure; 100, 110, 120: First welded section

[0091] 200, 210, 220: Second welding part; 300, 310, 320: Connecting part

[0092] 400: Deformation induction unit; 410: First deformation induction unit

[0093] 420: Second deformation induction section J1: First electrode assembly

[0094] J2: Second electrode assembly; T1: First electrode connector

[0095] T2: Second electrode connector; L: Electrode lead

Claims

1. A secondary battery, comprising: The first electrode assembly is provided with a first electrode connector; The second electrode assembly is provided with a second electrode connector; Bridging structure; as well as The housing accommodates the first electrode assembly, the second electrode assembly, and the bridging structure. The bridging structure includes: The first welding part is where the first electrode terminal piece of the first electrode assembly is joined to the first welding part; The second welding portion, wherein the second electrode terminal of the second electrode assembly is joined to the second welding portion, and the second welding portion is disposed in an oblique direction inclined relative to the stacking direction of the first electrode assembly and the second electrode assembly relative to the first welding portion; and A connecting portion connects the first welded portion and the second welded portion to each other and extends in the oblique direction. The first electrode assembly and the second electrode assembly are connected in parallel.

2. The secondary battery according to claim 1, wherein, The bridging structure further includes a deformation inducing part disposed at each of the two ends of the connecting part and configured to induce the connecting part to tilt more steeply in the oblique direction when a force is applied.

3. The secondary battery according to claim 2, wherein, The deformation-inducing part includes: A first deformation-inducing portion is configured to cause an angle change between the first weld portion and the connecting portion; and The second deformation induction part is configured to cause the angle between the second welding part and the connecting part to change.

4. The secondary battery according to claim 3, wherein, The connecting portion is bent in one direction relative to the first welded portion, and The second welded portion bends in another direction relative to the connecting portion.

5. The secondary battery according to claim 2, wherein, The bridging structure comprises a metallic material capable of elastic deformation at the deformation-inducing portion.

6. The secondary battery according to claim 1, wherein, The first welded portion, the connecting portion, and the second welded portion are formed by a single component that is continuously arranged in the length direction.

7. The secondary battery according to claim 1, wherein, The connecting part electrically connects the first welding part and the second welding part to each other.

8. The secondary battery according to claim 1, wherein, The first weld and the second weld are arranged to be parallel to each other.

9. The secondary battery according to claim 1, wherein, The bridging structure also includes an electrode lead that is coupled to one of the first weld portion and the second weld portion.

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