Joint structure of components, battery module, and battery pack

Abstract

The present application relates to a joining structure of components, a battery module, and a battery pack, the joining structure of components including: a first component (110); and a second component (300) in the shape of a plate including an overlapping portion (310) overlapping the first component (110) and a protruding portion (320) protruding from the overlapping portion (310) in a first direction. A joining portion (10) in which the first component (110) and the second component (300) are joined by welding or fusion is formed in the overlapping portion (310). The joining portion (10) includes a cutout portion (10C) located on the opposite side with respect to the protruding portion (320).

Description

Technical Field

[0001] This technology relates to the joining structure of components, battery modules, and battery packs. Background Technology

[0002] In the past, multiple components were overlapped and joined together by welding or other methods. Examples of existing lap joint structures include those described in International Publication No. 2017 / 131186, Japanese Patent Application Publication No. 2010-158717, and Japanese Patent Application Publication No. 2002-079387.

[0003] From the perspective of increasing joint strength, there is a need to increase the area of ​​the joint achieved by welding or fusion. On the other hand, considering the concern that the heat effect (heat storage) of welding or fusion may lead to poor joints such as cracks, there is also a need to minimize the area of ​​the joint. Considering both of these contradictory requirements, it cannot be said that existing lap joint structures are necessarily sufficient. Summary of the Invention

[0004] The purpose of this technology is to provide a joint structure for components, battery modules, and battery packs that can both ensure joint strength and reduce the thermal impact during jointing.

[0005] The joining structure of the components involved in this technology includes: a first component; and a plate-shaped second component, including an overlapping portion that overlaps with the first component and a protruding portion that protrudes from the overlapping portion along a first direction. A joint is formed in the overlapping portion, whereby the first component and the second component are joined by welding or fusion. The joint includes a cutout located on the opposite side of the protruding portion.

[0006] The battery module involved in this technology includes: a single cell, including electrode terminals as a first component; and a busbar as a second component, wherein the battery module includes a connection structure of the above-mentioned components as a connection structure between the electrode terminals and the busbar.

[0007] The battery pack involved in this technology has a housing and the aforementioned battery module housed in the housing.

[0008] The above and other objects, features, aspects, and advantages of the invention will become clear from the following detailed description of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0009] Figure 1 It is a 3D diagram representing a single battery.

[0010] Figure 2 This is an external view of the casing that houses the battery module, including the single battery cell.

[0011] Figure 3 It is a three-dimensional diagram showing the interior of the outer shell.

[0012] Figure 4 It is a top view showing the interior of the outer casing.

[0013] Figure 5 This is a perspective view showing the connection structure between the electrode terminals and the busbar.

[0014] Figure 6 This is a diagram showing the positional relationship between the joint and the point of force (one of the diagrams).

[0015] Figure 7 This is a diagram showing the positional relationship between the joint and the point of force (Part Two).

[0016] Figure 8 This is a diagram showing the positional relationship between the joint and the point of force (Part Three).

[0017] Figure 9 This is a diagram showing the positional relationship between the joint and the point of force (Figure 4).

[0018] Figure 10 This is a diagram (number five) showing the positional relationship between the joint and the point of force.

[0019] Figure 11 This is a diagram (one of) used to illustrate the shape of the joint.

[0020] Figure 12 This is a diagram (second one) used to illustrate the shape of the joint. Detailed Implementation

[0021] The following describes the implementation of this technology. Where the same or equivalent parts are labeled with the same reference numerals in the accompanying drawings, there are instances where the description is not repeated.

[0022] Furthermore, in the embodiments described below, when numbers, quantities, etc., are mentioned, the scope of this technology is not necessarily limited to those numbers, quantities, etc., unless specifically stated otherwise. Additionally, in the embodiments described below, each constituent element is not necessarily essential to this technology unless specifically stated otherwise. Furthermore, this technology is not limited to necessarily achieving all the effects mentioned in these embodiments.

[0023] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a structure is included, other structures besides that structure may be included, or other structures besides that structure may not be included.

[0024] Furthermore, in this specification, when using geometric terms and terms indicating positional / directional relationships such as "parallel," "orthogonal," "45° oblique," "coaxial," and "along," these terms allow for manufacturing errors or slight variations. In this specification, when using terms indicating relative positional relationships such as "upper side" and "lower side," these terms are used to indicate the relative positional relationship in one state. Depending on the orientation of each mechanism (e.g., reversing the overall structure vertically), the relative positional relationship can be reversed or rotated by any angle.

[0025] In this specification, "battery" is not limited to lithium-ion batteries and may include other batteries such as nickel-metal hydride batteries. In this specification, "electrode" can be used to refer to both the positive and negative electrode. Additionally, "electrode plate" can be used to refer to both the positive and negative electrode plates.

[0026] Figure 1 This is a 3D diagram representing a single battery (100). For example... Figure 1 As shown, the single cell 100 is formed into a generally rectangular parallelepiped shape with a flat surface. Within the battery pack, the single cells 100 are stacked along the Y-axis direction (first direction).

[0027] The electrode terminal 110 includes a positive terminal 111 and a negative terminal 112. The positive terminal 111 and the negative terminal 112 are arranged in the X-axis direction (second direction). The electrode terminal 110 is disposed on the upper surface of the square housing 120.

[0028] The upper and bottom surfaces of the housing 120, located along the Z-axis (third direction), are approximately rectangular in shape, with the longer side along the X-axis and the shorter side along the Y-axis. Electrodes and electrolyte are housed within the housing 120. A gas vent valve 121 is provided on the upper surface of the housing 120. When the pressure inside the housing 120 increases, the gas vent valve 121 opens to release the gas inside the housing 120.

[0029] Furthermore, the single cell involved in this technology is not necessarily limited to a square single cell 100. For example, even a cylindrical single cell can be used with the joining structure of the components involved in this technology.

[0030] Figure 2 This is an external view of battery pack 1. Figure 2 As shown, the battery pack 1 includes a housing 200. The housing 200 includes a cover 210, a body 220, and a cooling plate 230. The cover 210, the body 220, and the cooling plate 230 constitute structural components for ensuring the strength of the housing 200.

[0031] Figure 3 This is a three-dimensional view showing the interior of the outer casing 200. Figure 4This is a top view showing the interior of the outer casing 200. (Example) Figure 3 , Figure 4 As shown, a battery module consisting of multiple individual cells 100 is housed within the internal space of the housing 200. The multiple individual cells 100 are arranged along the Y-axis direction (first direction). The multiple individual cells 100 are housed within the internal space of the housing 200 in a constrained state along the Y-axis direction. The multiple individual cells 100 are electrically connected to each other via a busbar 300.

[0032] Figure 5 This is a perspective view showing the connection structure between the electrode terminal 110 (first component) and the busbar 300 (second component). (See diagram below.) Figure 5 As shown, the busbar 300 includes: an overlapping portion 310 that overlaps with the electrode terminal 110; and a protruding portion 320 that protrudes from the overlapping portion 310 along the Y-axis direction.

[0033] A joint 10 is formed in the overlapping portion 310 to join the electrode terminal 110 to the busbar 300. The electrode terminal 110 and the busbar 300 are joined by welding or fusion. As a specific example, the joint 10 is formed by laser welding or ultrasonic welding, but the method of forming the joint 10 is not limited to these.

[0034] The joint 10 is formed in a generally C-shape, including a first part 10A and a second part 10B.

[0035] Part 10A extends in a direction intersecting the Y-axis. More specifically, in Figure 5 In the example shown, part 10A extends along the X-axis direction, which is orthogonal to the Y-axis direction. Part 10A can be divided into multiple parts.

[0036] Part 2 10B extends from both ends of Part 1 10A toward the opposite side along the Y-axis relative to the protrusion 320.

[0037] An imaginary force point 20 exists at the protruding portion 320. Forces in any direction can be applied to the force point 20. For example, when the electrode terminals 110 of adjacent single cells 100 are misaligned relative to each other in the Z-axis direction, a force in the Z-axis direction can be applied to the force point 20. When a force in the Z-axis direction is applied to the force point 20, a force in the peeling direction is applied to the joint portion 10 of the overlapping portion 310. When a force in the X-axis or Y-axis direction is applied to the force point 20, a force in the shearing direction is applied to the joint portion 10 of the overlapping portion 310.

[0038] Figures 6-10 This is a diagram illustrating an example of the positional relationship between the joint 10 and the point of force. Figure 6 , Figure 7 This refers to the joint 10 involved in the comparative example. Figures 8-10This refers to the joint 10 involved in the embodiment of this invention.

[0039] like Figures 6-10 As shown, as a hypothetical force point 20, a strip-shaped force point 20 can be imagined ( Figure 6 , Figure 8 ) and point-like force points 20 ( Figure 7 , Figure 9 , Figure 10 ).

[0040] exist Figure 6 , Figure 7 In the comparative example shown, a generally rectangular joint 10 is formed. Figure 8 , Figure 9 In the illustrated embodiment, the generally C-shaped joint 10 includes: a first portion 10A extending along the X-axis; and a second portion 10B extending from both ends of the first portion 10A toward opposite sides relative to the force point 20 along the Y-axis. Figure 10 In the modified example shown, the generally C-shaped joint 10 includes: a curved (arc-shaped) first portion 10A opposite to the force point 20; and a second portion 10B extending from both ends of the first portion 10A toward opposite sides relative to the force point 20.

[0041] From the viewpoint of increasing the joint strength in the joint 10, such as Figure 6 , Figure 7 As shown in the comparative example, there is a requirement to maximize the area of ​​the joint 10. On the other hand, considering the concern that the thermal effects (heat storage) caused by the formation of the joint 10 may lead to poor bonding such as cracks at the joint 10, there is also a requirement to minimize the area of ​​the joint 10. A structure for the joint 10 that satisfies these two contradictory requirements is sought.

[0042] Figure 8 , Figure 9 The joint 10 in the illustrated embodiment, by including a first portion 10A extending along the X-axis and a second portion 10B extending along the Y-axis, can ensure the required joint strength under shear loads relative to both the X-axis and Y-axis directions. Furthermore, by providing the first portion 10A on the side close to the force point 20, the joint 10 can be selectively positioned at a location where the stress is higher when a load is applied at the force point 20. In other words, it is possible to both suppress the reduction in joint strength and effectively reduce the thermal effects during the formation of the joint 10. By reducing the thermal effects, the occurrence of poor jointing due to residual deformation at the joint 10 can be suppressed. Regarding these points, Figure 10 The same applies to the joint 10 involved in the modified example shown.

[0043] Next, refer to Figure 11 , Figure 12 Let's illustrate an example of the shape of the joint 10. Figure 11 , Figure 12 In the example shown, a cutout 10C is formed on the side opposite to the protrusion 320 and the force point 20. The area enclosed by the cutout 10C ( Figure 11 , Figure 12 The area enclosed by the double-dotted line and the outline of the joint 10 is smaller than the area of ​​the joint 10.

[0044] By providing the notch 10C on the opposite side of the protrusion 320 and the force point 20, the joint 10 can be selectively positioned at a location where the stress is relatively high when a load is applied at the force point 20. In other words, it is possible to both suppress the reduction of joint strength and effectively reduce the thermal effects during the formation of the joint 10. By reducing the thermal effects, it is possible to suppress the occurrence of poor jointing caused by residual deformation at the joint 10.

[0045] exist Figure 11 , Figure 12 In the example shown, the total width (D1) of the joint 10 along the X-axis is approximately 2 to 6 times (more preferably 2 to 3 times) the width (D2) of the cutout 10C along the X-axis. Furthermore, the difference (H1 - H2) between the total width (H1) of the joint 10 along the Y-axis and the width (H2) of the cutout 10C is approximately 1.4 to 4 times (more preferably 1.4 to 1.7 times) the thickness (T) of the busbar 300 (second component).

[0046] By adjusting the dimensional relationship between the joint 10 and the cut-out portion 10C to the range described above, it is possible to both suppress the reduction in joint strength and effectively reduce the thermal effects during the formation of the joint 10. By reducing the thermal effects, it is possible to suppress the occurrence of poor jointing caused by residual deformation at the joint 10.

[0047] Furthermore, when such Figure 12 In cases where the contour of the joint 10 has slight irregularities, as in the example, the total width (D1, H1) of the joint 10 essentially refers to the dimension at the location of maximum width. However, extreme irregularities that do not actually contribute to the increase or decrease in the area of ​​the joint 10 are not included in the total width (D1, H1) of the joint 10. The same applies to the width (D2, H2) of the cutout 10C.

[0048] like Figure 12As shown in the example, the cutout 10C can be formed to avoid the hole 30 provided in the component forming the joint 10. The outline shape of the cutout 10C is not limited to a portion of a generally rectangular, generally circular, or generally oblong (generally elliptical) shape, but can be as follows: Figure 12 As shown, it has a slightly uneven contour, or it can be a polygonal shape such as a triangle.

[0049] The joining structure of the components involved in this technology is not limited to the example of the joining portion 10 between the electrode terminal 110 and the busbar 300 described above. For example, this technology can also be applied to the joining portion between the busbar and the voltage detection line in a battery module. In addition, although the electrode terminal 110 and the busbar 300 are typically metal components, this technology can also be applied to joining portions that include resin components.

[0050] Embodiments of the present invention have been described, but it should be considered that the embodiments disclosed herein are illustrative rather than restrictive in all respects. The scope of the present invention is shown by the technical solutions claimed in this application, and is intended to include all modifications within the same meaning and scope as the technical solutions claimed in this application.

Claims

1. A joining structure for a component, characterized in that, have: Part 1; and The plate-shaped second component includes an overlapping portion that overlaps with the first component and a protruding portion that projects from the overlapping portion along a first direction. A joint is formed in the overlapping portion, where the first component and the second component are joined by welding or fusion. The joint includes a cutout located on the opposite side relative to the protruding portion. The second component, located on the opposite side of the protruding portion relative to the joint, has a hole formed, and the cutout is formed in the joint in a manner that avoids the hole.

2. The joining structure of the component according to claim 1, characterized in that, The area enclosed by the cut is smaller than the area of ​​the joint.

3. The joining structure of the component according to claim 1 or 2, characterized in that, The entire width D1 of the joint along the second direction orthogonal to the first direction is more than 2 times and less than 6 times the width D2 of the cut along the second direction.

4. The joining structure of the components according to claim 1 or 2, characterized in that, The difference H1-H2 between the entire width H1 of the joint along the first direction and the width H2 of the cut is more than 1.4 times and less than 4 times the plate thickness T of the second component.

5. The joining structure of the components according to claim 1 or 2, characterized in that, The joint is formed in a roughly C-shape.

6. A battery module, characterized in that, have: A single cell, including electrode terminals as a first component; and As the second component, the busbar The battery module includes the joining structure of the component according to any one of claims 1 to 5 as the joining structure of the electrode terminal and the busbar.

7. A battery pack, characterized in that, The battery module of claim 6, having a housing and being housed within the housing.

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