Busbar and battery pack including same busbar

Abstract

The invention of the present application relates to a bus bar comprising: a bus bar body having a structure in which multiple conductive layers are stacked; coupling parts located at both ends of the bus bar body to fix the multiple conductive layers; and an insulating layer provided on at least a part of an outer surface of the bus bar body, wherein connections between the multiple conductive layers are established only at the coupling parts.

Description

A busbar and a battery pack including the busbar

[0001] This application claims the benefit of priority to Korean Patent Application No. 2024-0094540, filed July 17, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a busbar and a battery pack including the busbar. Specifically, the present invention relates to a busbar and a battery pack including the busbar, which can electrically connect a plurality of electrical components while preventing unnecessary wasted space when electrical components of various sizes are stacked in various shapes along the height or width direction within the battery pack.

[0003]

[0004] As carbon emission regulations become stricter, demand for eco-friendly energy is increasing, and the number of devices using lithium secondary batteries as an energy source is increasing.

[0005] Among these, the proportion of lithium secondary batteries assembled into battery modules and battery packs is increasing in fields that require high-output and high-capacity energy sources, such as electric vehicles.

[0006] In general, a battery pack is manufactured by housing and assembling a battery cell stack in which a plurality of battery cells are closely arranged to form a series and / or parallel connection within a pack case. The battery pack can be designed by taking into consideration the capacity and output required by the device to which the battery pack is applied.

[0007] When manufacturing a high-capacity battery pack, it may be difficult to manufacture the desired high-capacity battery pack by using only battery modules of a certain size or by arranging the battery modules only in a certain direction.

[0008] Figure 1 is a perspective view and a cross-sectional view of a conventional bus bar.

[0009] Referring to FIG. 1, (a) is a perspective view of the entire busbar, and (b) is a perspective view showing a cross-section of the busbar of (a) cut along line A'-A". The busbar (100) includes a busbar body (110) made of a conductive material, a connecting portion (130) located at each of both ends of the busbar body (110), and an insulating layer (120) added to the remaining portion of the busbar body (110) excluding the connecting portion (130). Referring to (b), since the busbar body (110) is configured in the form of a single metal bar, it is configured in a structure that makes it difficult to deform the shape of the busbar (100), such as by bending or twisting it.

[0010] When connecting battery modules using busbars of a fixed thickness and shape, if the battery modules or electrical components are not stacked in a standardized configuration within the battery pack, numerous busbars may be required to form the connection, making it difficult to efficiently utilize the internal space of the battery pack. Consequently, the internal space of the battery pack may not be utilized for increased capacity and may be wasted unnecessarily.

[0011] If the wasted space can be reduced in this way and the space occupied by the battery module within the battery pack can be increased, battery packs with larger capacities can be manufactured, and thus the need for a busbar that can be freely bent or transformed into various shapes has arisen.

[0012] Accordingly, Patent Document 1 relates to a flexible busbar and a manufacturing method thereof, wherein the flexible busbar includes a conductor portion in which a plurality of metal plates are laminated, a first terminal portion and a second terminal portion located at both ends in the longitudinal direction of the conductor portion, and an insulating resin coating layer added to the outer surface of the conductor portion.

[0013] The method for manufacturing a flexible busbar of Patent Document 1 includes the steps of stacking a plurality of metal plates, applying insulating resin to the surfaces except for the edges on both sides, fixing one edge of the metal plates, processing the metal plates into a predetermined shape, and fixing the other edge of the metal plates.

[0014] Patent Document 2 relates to a flexible busbar, wherein the flexible busbar includes a conductor portion in which a plurality of plate-shaped conductors are laminated, terminal portions formed at both ends of the conductor portion in the longitudinal direction, and a tube member surrounding a certain section of the conductor portion.

[0015] The method for manufacturing a flexible busbar of Patent Document 2 includes the steps of stacking plate-shaped conductors, welding a first terminal portion to one longitudinal end of the plate-shaped conductor, covering the plate-shaped conductor, bending the covered conductor portion into a specific shape, and welding a second terminal portion to the other longitudinal end of the plate-shaped conductor.

[0016] In this way, since the flexible busbars of Patent Documents 1 and 2 are manufactured by manufacturing a finished product by deforming the conductor portion to have a certain shape during the manufacturing process, it is possible to manufacture a flexible busbar having a specific shape, but it is difficult to deform and use the flexible busbar to suit various environments in which the flexible busbar is applied.

[0017] Accordingly, there is a high need for a bus bar that can be easily transformed into a shape as needed so that it can be connected to the terminals of various battery modules arranged within a battery pack.

[0018] (Prior art literature)

[0019] (Patent Document 1) Korean Patent Publication No. 2021-0053531 (May 12, 2021)

[0020] (Patent Document 2) Korean Patent Publication No. 2020-0116880 (October 13, 2020)

[0021]

[0022] The present invention is intended to solve the above-mentioned problems, and aims to provide a bus bar that can be easily bent to suit the usage environment and thus freely deformed in shape, and a battery pack including the bus bar.

[0023]

[0024] To achieve this purpose, a busbar according to the present invention comprises a busbar body having a structure in which a plurality of conductive layers are laminated, a fusion portion joined to both ends of the busbar body to fix the plurality of conductive layers, and an insulating layer added to at least a portion of the outer surface of the busbar body, wherein the plurality of conductive layers can be connected to each other only at the fusion portion.

[0025] The bus bar body has connecting parts positioned at each end, and a through hole for fastening is formed in the connecting parts. The insulating layer can be added to surround the outer surface of the bus bar body except for the connecting parts.

[0026] At least one of the above plurality of conductive layers may have at least one through hole or slit formed therein.

[0027] All of the above plurality of conductive layers have the through holes or slits formed therein, and all of the conductive layers can be formed in the same shape.

[0028] The entirety of the plurality of conductive layers may have the through holes or slits formed therein, and the area of ​​the through holes or slits may increase from the innermost conductive layer to the outermost conductive layer among the plurality of conductive layers.

[0029] Each of the above plurality of challenge layers may be configured in a grid pattern in which the first line and the second line intersect.

[0030] The above plurality of challenge layers may be configured such that the thickness and spacing of the first line and the second line are constant.

[0031] Among the plurality of conductive layers, the thickness of the first line and the second line may decrease and the spacing between the first line and the second line may increase as the thickness goes from the innermost conductive layer to the outermost conductive layer.

[0032] Among the above multiple conductive layers, the thickness of the conductive layers may decrease from the innermost conductive layer to the outermost conductive layer.

[0033] The above-mentioned fusion portion may be formed by welding to attach and fix the ends of the plurality of conductive layers.

[0034] An inflexible bus bar having an insulating layer added to the outer surface of the metal bar can be coupled to at least one of the first end and the second end of the bus bar body.

[0035] The present invention also provides a battery pack in which electrical components are electrically connected using the bus bar, wherein the battery pack includes the bus bar and electrical components to which the bus bar is connected, and the bus bar can be connected to the electrical components in a state in which at least one bent portion is formed.

[0036]

[0037] The present invention can also be provided in a form in which various means for solving the above problem are combined.

[0038]

[0039] The bus bar according to the present invention can be freely transformed into a shape suitable for the usage environment.

[0040] Therefore, the space required to connect electrical components within the battery pack can be minimized, thereby reducing unnecessary wasted space within the battery pack.

[0041]

[0042] Figure 1 is a perspective view and a cross-sectional view of a conventional bus bar.

[0043] Figure 2 is a perspective view and a partially enlarged cross-section of a bus bar according to the present invention.

[0044] Figure 3 is an exploded perspective view of a busbar body according to the first embodiment.

[0045] Figure 4 is an exploded perspective view of a busbar body according to the second embodiment.

[0046] Figure 5 is an exploded perspective view of a busbar body according to the third embodiment.

[0047] Fig. 6 is an exploded perspective view of a busbar body according to the fourth embodiment.

[0048] Figure 7 is a perspective view and a cross-sectional view of a bus bar according to the fifth embodiment.

[0049] Figure 8 is an enlarged view of a portion of Figure 7.

[0050]

[0051] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. When describing the operating principles of the embodiments of the present invention in detail, detailed descriptions of known functions or components will be omitted if they are deemed to unnecessarily obscure the gist of the present invention.

[0052] Parts with similar functions and actions are designated by the same drawing reference numerals throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless otherwise specifically stated, but rather implies the inclusion of additional components.

[0053] The description that concretizes or adds to the components may be applied to all inventions unless there is a special limitation, and is not limited to the description of a specific invention.

[0054] Throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0055] Throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0056] The present invention is described in detail with examples according to the drawings.

[0057] Figure 2 is a perspective view and a partially enlarged cross-section of a bus bar according to the present invention.

[0058] Referring to FIG. 2, (a) is a full perspective view of the bus bar (200), and (b) is a partially enlarged view showing a cross-section along line B'-B" of (a).

[0059] A busbar (200) according to the present invention includes a busbar body (210) having a structure in which a plurality of conductive layers (211) are laminated, and an insulating layer (220) is added to at least a portion of the outer surface of the busbar body (210). In order to secure the plurality of conductive layers (211), a fusion portion (240) is bonded to both ends of the busbar body (210).

[0060] The plurality of conductive layers (211) are formed by stacking separate layers that are separated from each other, and are connected to each other only at the fusion portion (240). Specifically, when both ends of the plurality of conductive layers (211) are welded in a stacked state, a fusion portion (240) is formed in which the ends of the plurality of conductive layers (211) are fused and fixed.

[0061] The plurality of conductive layers (211) may be composed of the same material as the busbar body of a conventional rod-shaped busbar, for example, may be composed of copper, aluminum or an alloy thereof.

[0062] Joints (230) having through holes for fastening, such as bolts, for inserting fastening members are formed at each end of the busbar body (210), and an insulating layer (220) is added to cover the outer surface of the busbar body (210) except for the joints (230).

[0063] The insulating layer (220) may be configured in the form of an adhesive layer added to one surface of a substrate made of an insulating material, or may be configured in the form of a heat-shrinkable tube. The insulating material is not particularly limited, but may be configured of, for example, one or more selected from the group consisting of silicone series, polyethylene, polypropylene, rubber, ceramic, polycarbonate, and polybutylene terephthalate.

[0064] The busbar according to the present invention is configured to be freely deformable in shape, and is configured in a form in which a plurality of conductive layers are laminated. When bending is required depending on the environment in which the busbar is applied, at least one of the plurality of conductive layers is formed with at least one through hole or slit to increase the flexibility of the conductive layer so that the plurality of conductive layers can be easily bent. In addition, since there may be differences in the angle and direction in which the conductive layer on the inner side and the conductive layer on the outer side in the direction of lamination among the plurality of laminated conductive layers, the conductive layers can be configured to have different shapes and different thicknesses depending on the positions of the conductive layers.

[0065] Figure 3 is an exploded perspective view of a busbar body according to the first embodiment.

[0066] Referring to Fig. 3, the busbar body (210) is configured with multiple conductive layers (211) all having the same shape. Each of the multiple conductive layers (211) has through holes of a certain size uniformly distributed at regular intervals over the entire area.

[0067] In this way, the ductility of the busbar body (210) is improved by the through holes formed in each of the conductive layers (211), so that it can be easily deformed.

[0068] In addition, when multiple conductive layers (211) are stacked, the outer conductive layer may be bent more than the inner conductive layer, which may generate greater stress. However, since a through hole is formed, the stress generated when the outer conductive layer is bent can be buffered.

[0069] Meanwhile, unlike the shape shown in Fig. 3, a shape in which the positions of the through holes formed in each of the plurality of conductive layers (211) are not aligned but are misaligned is also included in the scope of the present invention.

[0070] In addition, the shape of the through hole may be formed in various shapes such as a polygon, an ellipse, etc., in addition to a circular shape on a plane. In one specific example, when slits are formed in a plurality of conductive layers (211), a straight slit may be formed parallel to the longitudinal direction.

[0071] Figure 4 is an exploded perspective view of a busbar body according to the second embodiment.

[0072] Referring to FIG. 4, each of the plurality of conductive layers (311) in the busbar body (310) is configured in a grid pattern in which the first line (301) and the second line (302) intersect. That is, the plurality of conductive layers (311) may be manufactured in a form in which the first line (301) and the second line (302) composed of linear conductive metal are fixed in a grid pattern.

[0073] As in the busbar body (310) illustrated in Fig. 4, a plurality of conductive layers (311) may be configured in a form in which all of the same conductive layers (311) are laminated so that the thickness and spacing of the first line (301) and the second line (302) are configured to be constant.

[0074] Alternatively, unlike the busbar body (310) illustrated in FIG. 4, the thickness of the first line (301) and the second line (302) may be reduced and the spacing between the first line (301) and the second line (302) may be increased as the thickness of the first line (301) and the second line (302) decreases and the spacing between the first line (301) and the second line (302) increases, as the thickness of the first line (301) and the second line (302) decreases and the spacing between ... increases, respectively, along the stacking direction among the plurality of conductive layers (311).

[0075] In the stacking direction, the outer conductive layers may be subjected to greater stress during the bending process than the inner conductive layers. The outer conductive layers can be configured to have more empty space by reducing the thickness of the first and second lines and increasing the spacing between them. This can alleviate the greater stress generated when the outer conductive layers are bent, thereby reducing the stress deviation generated in multiple conductive layers, thereby preventing the conductive layers joined at the weld from separating.

[0076] Figure 5 is an exploded perspective view of a busbar body according to the third embodiment.

[0077] Referring to FIG. 5, the busbar body (410) is similar to the busbar body (210) illustrated in FIG. 3 in that through holes are formed throughout the plurality of conductive layers, but the busbar body (410) differs in the number of through holes formed in the plurality of conductive layers.

[0078] Specifically, the area of ​​the through holes or slits increases from the innermost conductive layer to the outermost conductive layer along the stacking direction among the plurality of conductive layers. Among the conductive layers illustrated in FIG. 5, the innermost conductive layer (411c) has the smallest number of through holes, the number of through holes in the conductive layer (411b) is greater than the number of through holes in the conductive layer (411c), and the number of through holes in the outermost conductive layer (411a) is greater than the number of through holes in the conductive layer (411b).

[0079] By forming a larger number of penetration holes in the conductive layer disposed on the outside among the plurality of conductive layers in this way, when bending the busbar body (410), the conductive layer on the outside can be cushioned from receiving greater stress than the conductive layer on the inside, thereby preventing the conductive layers joined at the weld from being separated.

[0080] Fig. 6 is an exploded perspective view of a busbar body according to the fourth embodiment.

[0081] Referring to FIG. 6, the busbar body (510) is configured so that a plurality of conductive layers (511a, 511b, 511c) are laminated, and the thickness of the conductive layers is configured so that the thickness of the conductive layers decreases from the innermost conductive layer (511c) to the outermost conductive layer (511a) along the lamination direction.

[0082] That is, the thickness (Dc) of the innermost conductive layer (511c) is the thickest, the thickness (Db) of the conductive layer (511b) outside the conductive layer (511c) is thinner than the thickness (Dc), and the thickness (Da) of the outermost conductive layer (511a) is formed to be thinner than the thickness (Db).

[0083] In this way, by configuring the thickness of the conductive layer arranged on the outside among the plurality of conductive layers to be thinner so that it can be bent more easily, the stress on the conductive layer on the outside when bending the busbar body (510) is relieved from being greater than the stress on the conductive layer on the inside, thereby reducing the stress deviation occurring in the plurality of conductive layers, and thus preventing the conductive layers joined at the weld from being separated.

[0084] Fig. 7 is a perspective view and a cross-sectional view of a bus bar according to the fifth embodiment, and Fig. 8 is an enlarged view of a portion of Fig. 7.

[0085] Referring to FIGS. 7 and 8, (a) of FIG. 7 is a perspective view of the entire busbar (600), and (b) is a cross-sectional perspective view showing a cross-section along the line C'-C" of (a). The busbar (600) is configured in a form in which a busbar (100) that is difficult to deform in shape is coupled to the left side of a busbar (200) that is free to deform in shape. That is, the busbar (600) according to the present invention may be configured in a form in which an inflexible busbar having an insulating layer added to the outer surface of the metal bar is coupled to at least one of the first end and the second end of the busbar body of the busbar (200). Accordingly, unlike as illustrated in FIG. 7, the busbar (100) may be coupled to the right side of the busbar (200), or the busbars (100) may be coupled to each of the ends on both sides of the busbar (200).

[0086] Since the bus bar (100) and the bus bar (200) can be joined by welding, a weld (650) can be formed between the bus bar (100) and the bus bar (200).

[0087] In this way, the specific form in which the inflexible bus bar and the flexible bus bar are connected to form a welded portion (650) may be, for example, composed of a first unit composed of an inflexible bus bar and a flexible bus bar, a second unit composed of an inflexible bus bar, a flexible bus bar, and an inflexible bus bar, and a third unit composed of a flexible bus bar, an inflexible bus bar, and a flexible bus bar, and may be composed of a form in which two or more of the same ones, two or more different ones, or the same and different ones are selected in combination among the first to third units.

[0088] By using a hybrid busbar (600) in which a flexible busbar such as busbar (100) and an inflexible busbar such as busbar (200) are combined, it is possible to obtain both the advantages of free shape deformation of the flexible busbar and the advantages of excellent strength and fast electrical conductivity of the inflexible busbar.

[0089] The present invention also provides a battery pack comprising a busbar according to the present invention and electrical components to which the busbar is coupled. In the battery pack, the busbar is coupled to the electrical components in a state in which at least one bend portion is formed. Since the busbar according to the present invention can be freely deformed, the space required for the busbar to be coupled can be minimized regardless of the location and size of the electrical components arranged in the battery pack. Accordingly, since more battery cells can be arranged in the space that was unnecessarily wasted by using a busbar of a non-bendable form, a battery pack with a higher capacity can be manufactured compared to a conventional battery pack of the same volume.

[0090]

[0091] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0092] (Explanation of symbols)

[0093] 100, 200, 600: Busbar

[0094] 110, 210, 310, 410, 510: Busbar body

[0095] 120, 220: Insulation layer

[0096] 130, 230: Joint

[0097] 211, 311, 411a, 411b, 411c, 511a, 511b, 511c: conductive layers

[0098] 240: Fusion section

[0099] 301: First line

[0100] 302: Second line

[0101] 650: Welding

[0102] Da, Db, Dc: thickness

Claims

1. A busbar body having a structure in which multiple conductive layers are laminated; A fusion member bonded to both ends of the busbar body to fix the plurality of conductive layers; and An insulating layer added to at least a portion of the outer surface of the above busbar body; Including, A bus bar in which the above plurality of conductive layers are connected to each other only at the fusion portion.

2. In paragraph 1, A busbar having connecting portions positioned at each end of the busbar body, through holes for fastening formed in the connecting portions, and the insulating layer added to surround the outer surface of the busbar body except for the connecting portions.

3. In paragraph 1, A bus bar in which at least one of the plurality of conductive layers has at least one through hole or slit formed therein.

4. In paragraph 3, A bus bar in which all of the above plurality of conductive layers have the through holes or slits formed therein, and all of the conductive layers have the same shape.

5. In paragraph 3, The entirety of the above plurality of conductive layers is formed with the through hole or slit, A bus bar in which the area of ​​the through hole or slit increases from the innermost conductive layer to the outermost conductive layer among the plurality of conductive layers.

6. In paragraph 1, Each of the above plurality of conductive layers is a busbar configured in a grid pattern in which a first line and a second line intersect.

7. In paragraph 6, The above plurality of conductive layers are bus bars in which the thickness and spacing of the first line and the second line are constant.

8. In paragraph 6, A bus bar in which the thickness of the first line and the second line decreases and the spacing between the first line and the second line increases as one moves from the innermost conductive layer to the outermost conductive layer among the plurality of conductive layers.

9. In paragraph 1, A busbar in which the thickness of the conductive layers decreases from the innermost conductive layer to the outermost conductive layer among the above-mentioned plurality of conductive layers.

10. In paragraph 1, A bus bar in which the above-mentioned fusion portion is formed by welding to attach and fix the ends of the plurality of conductive layers.

11. In paragraph 1, A busbar having an inflexible busbar with an insulating layer added to the outer surface of the metal bar, coupled to at least one of the first end and the second end of the busbar body.

12. A busbar according to any one of clauses 1 to 11, and electrical components to which the busbar is coupled, A battery pack connected to the above-mentioned electric components in a state where the above-mentioned bus bar is bent so as to form at least one bend portion.

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