Battery module and battery pack containing the same

Abstract

A battery module according to one embodiment of the present application includes a battery cell stack in which a plurality of battery cells are stacked, a busbar frame located on at least one face of the battery cell stack, and at least two busbars mounted on the busbar frame, wherein the busbar frame includes at least one insulating rib protruding between two adjacent busbars, and the insulating rib is formed on a first face facing either of the two busbars and includes a plurality of protrusions projecting toward the opposing busbar.

Description

Technical Field

[0004]

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2023 - 0140912 filed on October 20, 2023, and all the contents disclosed in the document of the Korean patent application are included as part of this specification.

[0002] This application relates to a battery module and a battery pack including the same, and more specifically, to a battery module including a bus bar frame with improved insulation performance between bus bars and a battery pack including the same.

Background Art

[0003] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. In particular, secondary batteries are attracting great attention not only as an energy source for mobile devices such as mobile phones, digital cameras, notebook computers, and wearable devices, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] Currently, commercially available secondary batteries include nickel - cadmium batteries, nickel - metal hydride batteries, nickel - zinc batteries, lithium secondary batteries, etc. Among these, lithium secondary batteries have attracted attention for their advantages of almost no memory effect, free charge and discharge, very low self - discharge rate, and high energy density compared to nickel - based secondary batteries.

[0005] Such lithium secondary batteries mainly use lithium - based oxides and carbon materials as the positive electrode active material and the negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate coated with such positive electrode active material and negative electrode active material, respectively, are arranged with a separator therebetween, and a battery case for hermetically storing the electrode assembly together with an electrolyte.

[0006] Generally, lithium-ion secondary batteries can be classified into two types based on the shape of their casing: can-type secondary batteries, in which the electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which the electrode assembly is housed in an aluminum laminate sheet pouch.

[0007] In the case of secondary batteries used in small devices, two to three battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module is used in which many battery cells are electrically connected. In such battery modules, the capacity and output are improved by connecting many battery cells in series or parallel to each other to form a stack of battery cells. Furthermore, one or more battery modules can be installed together with various control and protection systems such as a BMS (Battery Management System) and a cooling system to form a battery pack.

[0008] When a stack of battery cells is formed using multiple battery cells and these are combined into a single battery module, electrical connections between the multiple battery cells are made via busbars. Specifically, the busbars can be mounted on an insulating busbar frame, and the electrode leads of the battery cells pass through slits formed in the busbar frame, then bend and connect to the busbars.

[0009] In this case, multiple busbars that are not electrically connected to each other, such as busbars with different polarities and terminal busbars for external connections, are arranged next to each other on a single busbar frame, and the insulation performance between them can become a problem. That is, sufficient insulation must be ensured between busbars that are not electrically connected to each other, and for this purpose, sufficient creepage distance should be ensured. However, as capacitance and output increase, the required creepage distance value increases further, and given the constraints on the size of the space in which components are mounted, designs that ensure sufficient creepage distance are required. [Overview of the project] [Problems that the invention aims to solve]

[0010] The problem that the present invention aims to solve is to provide a battery module with improved insulation performance by ensuring sufficient creepage distance between busbars in a limited space, and a battery pack including the same.

[0011] The problems that this application seeks to solve are not limited to those described above, and any problems not mentioned herein will be clearly understood by a person with ordinary skill in the art to which this application pertains, based on this specification and the accompanying drawings. [Means for solving the problem]

[0012] A battery module according to one embodiment of the present application includes a battery cell stack in which a plurality of battery cells are stacked, a busbar frame located on at least one face of the battery cell stack, and at least two busbars mounted on the busbar frame, wherein the busbar frame includes at least one insulating rib protruding between two adjacent busbars, and the insulating rib is formed on a first face facing either of the two busbars and includes a plurality of protrusions projecting toward the opposing busbar.

[0013] The busbar frame is formed of an insulating material, and the insulating ribs can be injection molded integrally with the busbar frame.

[0014] The direction in which the insulating rib protrudes may be a first direction perpendicular to one surface of the busbar frame on which the busbar is mounted.

[0015] The direction in which the protruding portion protrudes may be perpendicular to the first direction and parallel to one surface of the busbar frame, which is a second direction.

[0016] At least one of the insulating ribs may be formed adjacent to the busbar mounted on the busbar frame, specifically the busbar mounted on the outermost part of the busbar frame.

[0017] The creepage distance of the surface where the protrusion is formed may be twice or more the creepage distance of the surface where the protrusion is not formed.

[0018] The length by which the insulating rib protrudes may be longer than the thickness of the bus bar in the direction in which the insulating rib protrudes.

[0019] The plurality of protrusions can form a concavo-convex structure while being separated from each other.

[0020] The maximum width of the insulating rib including the protrusion may be smaller than the separation distance between the two adjacent bus bars.

[0021] A battery pack according to another embodiment of the present invention includes the battery module described above. [[ID=二十一]] [Advantages of the Invention] [[ID=二十二]] [[ID=二十三]] [[ID=二十四]]

[0022] [[ID=二十五]] [[ID=二十六]]According to the embodiment, it is possible to provide a battery module with improved insulation performance by ensuring a sufficient creepage distance between bus bars within a limited space, and a battery pack including the same. [[ID=二十七]] [[ID=二十八]]

[0023] [[ID=二十九]] [[ID=三十]]The effects of the present application are not limited to the effects described above, and the effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present application belongs from the present specification and the accompanying drawings. [[ID=三十一]] [[ID=三十二]] [Brief Description of the Drawings] [[ID=三十三]] [[ID=三十四]] [[ID=三十五]]

[0024] [[ID=三十六]] [[ID=三十七]] [Figure 1] [[ID=三十八]]It is an exploded perspective view showing a battery module according to an embodiment of the present invention. [[ID=三十九]] [[ID=四十]] [Figure 2] [[ID=四十一]]In the battery module of FIG. 1, it is a drawing showing a bus bar frame to which a bus bar is attached. [[ID=四十二]] [[ID=四十三]] [Figure 3] [[ID=四十四]]It is an exploded perspective view of FIG. 2. [[ID=四十五]] [[ID=四十六]] [Figure 4] [[ID=四十七]]It is a perspective view showing a state in which the A region of FIG. 2 is enlarged and a cross section viewed from the -Z axis direction to the +Z axis direction is seen. [[ID=四十八]] [Figure 5] This is a drawing showing an enlarged view of the insulating rib portion in the cross-section of FIG. 4. [Figure 6A] This is a drawing showing the creepage distance with the insulating rib. [Figure 6B] This is a drawing showing the creepage distance with the insulating rib.

Embodiments for Carrying Out the Invention

[0025] Hereinafter, referring to the accompanying drawings, various embodiments of the present application will be described in detail so that those having ordinary knowledge in the technical field to which the present application belongs can easily implement them. The present application can be realized in various different forms and is not limited to the embodiments described here.

[0026] To clearly explain the present application, parts that are unnecessary for the explanation are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0027] <000​​​​​​​​​​​​​​​​Figure 1 is an exploded perspective view showing a battery module according to one embodiment of the present invention.

[0032] Referring to Figure 1, the battery module 10 according to this embodiment includes a battery cell stack 100 formed by stacking multiple battery cells, a module frame 200 that houses the battery cell stack 100, and an end plate 400. The battery module 10 also includes a busbar frame 300 located on at least one side of the battery cell stack 100.

[0033] For example, the module frame 200 may have a monoframe configuration in the shape of a rectangle that surrounds the top, bottom, and sides of the battery cell stack 100. However, the module frame 200 is not limited to this and may consist of an upper plate that covers the top of the battery cell stack 100, a U-shaped frame with an open top surface, front, and rear, or it may be replaced with a frame of other shapes, such as a lower plate combined with an inverted U-shaped frame with an open bottom surface, front, and rear. Such a module frame 200 may include a metal material with a predetermined strength to protect the battery cell stack 100, the busbar frame 300, and other electrical components from the outside.

[0034] The battery cells forming the battery cell stack 100 may be pouch-type battery cells, but are not limited to this, and various forms of battery cells may be used. The multiple battery cells are stacked so as to be electrically connected to each other to form the battery cell stack 100. For example, as shown in Figure 1, the multiple battery cells may be stacked along a direction parallel to the y-axis. This allows the electrode leads to protrude in the x-axis direction and the -x-axis direction, respectively. Busbar frames 300 can be positioned on both sides of the battery cell stack 100 in the direction in which the electrode leads protrude. That is, busbar frames 300 can be positioned on the front (x-axis direction) and rear (-x-axis direction) of the battery cell stack 100. However, this is an exemplary arrangement, and the position of the busbar frames 300 is not limited to this, and may be positioned to cover the other side of the battery cell stack 100. In other words, the busbar frames 300 can be appropriately changed in any position that allows for electrical connection between the electrode leads and the busbars depending on the direction in which the electrode leads protrude, and are not particularly limited.

[0035] An end plate 400 is formed on the outside of the busbar frame 300. The end plate 400 protects the busbar frame 300 and the multiple electrical components connected thereto from external impacts, has a battery module mounting structure that allows the battery module 10 to be attached to the battery pack, and at the same time guides the electrical connection between the busbar frame 300 and the external power supply by allowing the terminal busbar of the busbar 310 to protrude to the outside through openings formed in the end plate 400.

[0036] The busbar frame 300 and the configuration coupled with the busbar frame 300 will be described in more detail below with reference to Figures 2 and 3.

[0037] Figure 2 is a diagram showing the busbar frame with the busbars attached in the battery module of Figure 1, and Figure 3 is an exploded perspective view of Figure 2.

[0038] Referring to Figures 2 and 3, multiple busbars 310 are mounted on one side of the busbar frame 300. In this case, the side on which the busbars 310 are mounted is the side opposite to the battery cell stack 100, i.e., the outer side, and as shown in Figure 1, the end plate 400 is connected to the side on which the busbars 310 are mounted while the busbars 310 are mounted.

[0039] The busbar 310 may include busbars responsible for electrical connections within the module and terminal busbars for electrical connections with the external configuration. For example, a busbar positioned on the outermost side in the y-axis direction in Figure 2 and having a bent upper section can be a terminal busbar. The bent upper section of the terminal busbar has a hole into which a bolt or the like can be inserted for electrical connection to the outside, and a nut mounting chamber 340 is provided protruding from the busbar frame 300, into which a nut or the like that can be mounted to connect with the bolt. The bent upper section of the terminal busbar can be coupled so that it is positioned above the nut mounting chamber 340. Such a nut mounting chamber 340 can be formed integrally with the busbar frame 300 by injection molding when the busbar frame 300 is formed.

[0040] Furthermore, a sensing assembly 330 may be mounted on the busbar frame 300. The sensing assembly 330 may include module connectors, connecting cables, and joining members, and is electrically connected to the battery cell via the busbar 310 to transmit various information about the battery cell to an external BMS (Battery Management System) for control.

[0041] Insulating ribs 320 may be formed between adjacent busbars 310. The insulating ribs 320 may be structures that protrude along the x-axis from one surface of the busbar frame 300, traversing between the busbars 310. The insulating ribs 320 that protrude along the x-axis in this way extend along the length of the busbars 310, i.e., along the z-axis, so that the busbars 310 are insulated from each other over a large area corresponding to the length of the busbars 310. In other words, the insulating ribs 320 can interrupt unnecessary electrical connections between adjacent busbars 310 and maintain insulation. Preferably, the length of the protruding insulating rib 320 (length in the x-axis direction) is greater than the thickness of the busbar 310. This ensures sufficient insulation performance between the busbars 310. At the same time, such insulating ribs 320 can be formed integrally with the busbar frame 300 by injection molding when the busbar frame 300 is formed.

[0042] The following will provide a more detailed explanation of the battery module according to this embodiment, particularly the insulating rib 320, with reference to Figures 4 and 5.

[0043] Figure 4 is a perspective view showing an enlarged view of area A in Figure 2, with the cross-section viewed from the -Z axis direction to the +Z axis direction. Figure 5 is a drawing showing an enlarged view of the insulating rib portion in the cross-section of Figure 4.

[0044] As shown in Figures 4 and 5, the insulating rib 320 includes a main lip 321 projecting outward from one surface of the busbar frame 300, i.e., in the x-axis direction, and a plurality of protrusions 322 projecting from one surface 320b of the main lip 321 toward adjacent busbars 310, i.e., in the y-axis direction. The plurality of protrusions 322 can be spaced apart from each other to form an overall uneven structure. By including the plurality of protrusions 322 and forming an uneven structure in this way, the creepage distance between two adjacent busbars 310 with the insulating rib 320 in between can be increased.

[0045] Here, creepage distance refers to the minimum distance along the surface of the insulator between two conductors. The longer the creepage distance, the greater the distance one conductor moves across the surface of the insulator to the other conductor, thus improving insulation performance.

[0046] An insulating rib 320 according to one embodiment of the present invention can increase the creepage distance between busbars 310 by including a plurality of protrusions 322. In this embodiment, the example shows that the protrusions 322 are formed on only one of the two sides of the insulating rib 320, but it is not limited to this, and the protrusions 322 may be formed on both sides, or only on the side opposite to the one shown in the drawing, and is not particularly limited. The position and size of the insulating rib 320 may change depending on the specifications of the device, and the position and size of the protrusions 322 can be designed differently depending on the design structure. However, even in this case, the width of the entire insulating rib 320 including the amount of protrusion of the protrusions 322, that is, the width of the insulating rib 320 in the x-axis direction from the drawing, must be designed to be smaller than the separation distance between two adjacent busbars 310. If the width of the insulating rib 320 is too large, interference will occur during the process of assembling the busbars 310 to the busbar frame 300, which is undesirable.

[0047] In this embodiment, insulating ribs 320 are provided only between the terminal busbar 310 and the inner busbar 310. However, the embodiment is not limited to this, and insulating ribs 320 may also be provided between the inner busbars 310. However, it is preferable that insulating ribs 320 be provided at positions adjacent to terminal busbars where higher insulation performance is required.

[0048] On the other hand, as shown in Figure 5, by providing multiple protrusions 322, the creepage distance can be made approximately twice as long as that of a surface without protrusions 322. For example, if the width and depth of all protrusions 322 are the same on a surface 320a without protrusions 322 and a surface 320b with protrusions 322 (i.e., Lb1=Lb2=Lb3=Lb4=Lb5=Lb6), the creepage distance of the surface 320b with protrusions 322 will increase by approximately twice the cross-sectional length (La) of the corresponding surface 320a. However, this is merely an example, and the amount of increase in creepage distance can be adjusted by changing the width, depth, and number of protrusions 322. Nevertheless, to ensure stable insulation performance, it is preferable that the increased creepage distance is at least twice as long.

[0049] Next, with reference to Figures 6A and 6B, we will explain in more detail the difference in creepage distance due to the presence or absence of protrusion formation.

[0050] Figures 6A and 6B are drawings showing creepage distances in insulating ribs according to one embodiment and a comparative example of the present invention.

[0051] As shown in Figure 6A, the insulating rib 320 of this embodiment, with the protrusion 322 formed thereon, can be seen to form an even longer creepage distance (C1) compared to the creepage distance (C2) of the insulating rib 320' in Figure 6B, which does not include the protrusion. In particular, despite this significant increase in creepage distance, the space between the busbars 310 remains substantially unchanged, and the space occupied by the insulating rib 320 does not increase significantly. Therefore, this embodiment demonstrates that even in a narrow space, the creepage distance can be efficiently increased and insulation performance can be stably ensured.

[0052] The aforementioned battery module may be included in a battery pack. The battery pack has a structure in which one or more battery modules according to this embodiment are assembled and packaged together with a battery management system (BMS) that manages the temperature and voltage of the batteries, a cooling device, and other components.

[0053] The aforementioned battery pack can be applied to a variety of devices. Such devices include means of transport such as electric bicycles, electric vehicles, and hybrid vehicles, but the present invention is not limited thereto and is applicable to a variety of devices that can use battery modules and battery packs including them, and this also falls within the scope of the present invention.

[0054] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0055] 10: Battery module 100: Battery cell stack 200: Module Frame 300: Busbar Frame 310: Bus bar 320: Insulating Rib 322:Protrusion 330: Sensing Assembly 340: Nut mounting room 400: End plate

Claims

1. A battery cell stack in which multiple battery cells are stacked, A busbar frame located on at least one surface of the battery cell stack, and The busbar frame includes at least two busbars, The busbar frame includes at least one insulating rib protruding between the two adjacent busbars, A battery module in which the insulating rib is formed on a first surface facing one of the two busbars and includes a plurality of protrusions projecting toward the opposing busbar.

2. The battery module according to claim 1, wherein the busbar frame is formed of an insulating material, and the insulating ribs are injection molded integrally with the busbar frame.

3. The battery module according to claim 1, wherein the direction in which the insulating rib protrudes is a first direction perpendicular to one surface of the busbar frame on which the busbar is mounted.

4. The battery module according to claim 3, wherein the direction of protrusion of the protruding portion is perpendicular to the first direction and parallel to one surface of the busbar frame, in a second direction.

5. The battery module according to claim 1, wherein at least one of the insulating ribs is formed adjacent to the busbar mounted on the busbar frame, which is the outermost busbar mounted on the busbar frame.

6. The battery module according to claim 1, wherein the creepage distance of the surface on which the protrusion is formed is at least twice the creepage distance of the surface on which the protrusion is not formed.

7. The battery module according to claim 1, wherein the length of the protruding insulating rib is longer than the thickness of the busbar in the direction in which the insulating rib protrudes.

8. The battery module according to claim 1, wherein the plurality of protrusions are spaced apart from each other to form an uneven structure.

9. The battery module according to claim 1, wherein the maximum width of the insulating rib including the protrusion is smaller than the separation distance between two adjacent busbars.

10. A battery pack comprising the battery module described in claims 1 to 9.

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