Battery module and battery pack including same

Abstract

This battery module according to an embodiment of the present invention includes: a battery cell stack in which a plurality of battery cells is stacked; busbar frames formed on the front and rear surfaces of the battery cell stack, respectively; a connection part connected to the upper part of the battery cell stack and connecting the busbar frames formed on the front and rear surfaces to each other; a first connector connected to both ends of the connection part; a second connector fixed to the busbar frames and coupled to the first connector; and a dam part disposed under the second connector and fixed to the busbar frames.

Description

Battery module and battery pack including the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0173642 filed November 28, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a battery module and a battery pack including the same, and more specifically, to a battery module having a sensing connection having improved durability and a battery pack including the same.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to such mobile devices is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to charge and discharge freely with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0006] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and a battery case that seals and houses the electrode assembly together with an electrolyte.

[0007] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0008] In the case of secondary batteries used in small devices, 2 to 3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, battery modules in which multiple battery cells are electrically connected are used. In such battery modules, capacity and output are improved by connecting multiple battery cells in series or parallel to form a stack of battery cells. One or more battery modules can be mounted together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system, to form a battery pack.

[0009] A battery pack includes battery modules as a sub-concept, and battery modules include battery cells as a sub-concept. Furthermore, the number of battery cells in a battery module or the number of battery modules in a battery pack can be determined in various ways depending on the output or capacity of the battery pack required for an electric vehicle.

[0010] This battery module comprises a battery cell stack in which a plurality of battery cells are stacked, busbar frames formed at each end of the battery cell stack, and a connecting part connecting the busbar frames at both ends.

[0011] Connectors are attached to both ends of the connection section and respectively coupled to connectors fixed to busbar frames positioned at both ends of the battery cell stack. However, due to space constraints, there are limitations in firmly securing the connectors fixed to the busbar frames using bolting or similar methods. Consequently, when force is applied to the connectors of the connection section, a strong force is also applied to the connectors fixed to the busbar frames; in this case, problems such as the fixed portion becoming detached from the busbar frames may occur.

[0012] The problem that the present invention aims to solve is to provide a battery module and a battery pack including the same, which can be firmly fixed so that a connector connected to a connection part formed of a flexible flat cable does not detach, and which can be firmly fixed without any issues regarding space utilization.

[0013] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0014] A battery module according to one embodiment of the present invention comprises: a battery cell stack having a plurality of battery cells stacked therein; a busbar frame formed on the front and rear sides of the battery cell stack, respectively; a connecting part connected to the upper side of the battery cell stack and connecting the busbar frames formed on the front and rear sides to each other; a first connector connected to both ends of the connecting part; a second connector fixed to the busbar frame and coupled with the first connector; and a dam part disposed below the second connector and fixed to the busbar frame.

[0015] The above dam portion may be positioned to surround the lower part of the second connector and both sides of the second connector.

[0016] It may further include a coating portion located between the above dam portion and the above second connector, on which a coating liquid is applied and cured.

[0017] The thickness of the coating portion may be equal to or smaller than the height of the dam portion.

[0018] It further includes a flexible printed circuit board coupled to the busbar frame and connected to the plurality of battery cells and the second connector, and the second connector can be fixed to the flexible printed circuit board by soldering.

[0019] The above dam portion can be fixed on the flexible printed circuit board.

[0020] The above connection may be formed of a flexible flat cable (FFC).

[0021] The above connection may include a connection body located on the upper side of the battery cell stack, and a connection cable that is bent at both ends of the connection body in a direction toward the busbar frame and connected to the first connector.

[0022] The above coating may be insulating.

[0023] A battery pack according to one embodiment of the present invention includes one or more of the battery modules.

[0024] According to a battery module according to one embodiment of the present invention, a connector connected to a connection part formed of a flexible flat cable can be stably supported so as not to detach, while minimizing the space required for such a support structure.

[0025] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0026] FIG. 1 is an exploded perspective view of a battery module according to one embodiment of the present invention.

[0027] Figure 2 is a drawing showing the connection part of Figure 1 and the busbar frame combined.

[0028] FIG. 3 is an enlarged perspective view showing the first connector mounted on the second connector.

[0029] Figure 4 is an enlarged front view showing the first connector mounted on the second connector.

[0030] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0031] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0032] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0033] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0034] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0035] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0036] Hereinafter, a battery module according to one embodiment of the present invention will be described.

[0037] FIG. 1 is an exploded perspective view of a battery module according to one embodiment of the present invention, and FIG. 2 is a drawing showing the connection part of FIG. 1 and the busbar frame combined.

[0038] Referring to FIGS. 1 and 2, a battery module according to one embodiment of the present invention comprises a battery cell stack (100) in which a plurality of battery cells are stacked, a busbar frame (300) formed on the front and rear of the battery cell stack (100), a connecting part (400) connecting the busbar frame (300), a first connector (430) coupled to both ends of the connecting part (400), and a second connector (440) fixed to the busbar frame (300) and coupled to the first connector (430).

[0039] The battery module in the present embodiment may further include a lower frame (210) formed with a U-shaped structure on the bottom surface and both sides to cover the bottom surface and both sides of the battery cell stack (100), and an upper frame (220) to cover the top surface of the battery cell stack (100). However, the case accommodating the battery cell stack (100) is not limited thereto, and may be a rectangular tube-shaped case that encloses the bottom surface, top surface, and both sides of the battery cell stack (100), or may be a structure in which an inverted U-shaped upper frame is combined with a bottom plate that encloses the top surface and both sides, and is not particularly limited. In addition, a battery pack may be directly formed by assembling multiple battery cell stacks (100) without such a case, and may be modified in various ways.

[0040] The battery cell is a secondary battery and may be composed of a pouch-type secondary battery. The battery cell may be composed of multiple units, and the multiple battery cells may be stacked together so as to be electrically connected to each other to form a battery cell stack (100). Each of these multiple battery cells may include an electrode assembly, a battery case, and an electrode lead protruding from the electrode assembly, although not specifically illustrated. Meanwhile, as illustrated in FIG. 1, the multiple battery cells may be arranged parallel to both sides of the lower frame (210) and stacked sequentially along the y-axis direction.

[0041] A battery cell stack (100) is formed by being surrounded by a lower frame (210) that covers the bottom surface and both sides, and an upper frame (220) that covers the top surface. At this time, the battery cell stack (100) is inserted onto the lower frame (210), and then the battery cell stack (100) can be mounted inside the frame by covering the upper side of the battery cell stack (100) through the upper frame. The lower frame (210) and the upper frame (220) are joined together to accommodate the battery cell stack (100) located inside the frame. At this time, the two frames can be joined by welding; however, the method of joining the frames is not limited to this and can be implemented through various embodiments.

[0042] A busbar frame (300) is formed on the front and rear surfaces of the battery cell stack (100). The busbar frame (300) includes a busbar and a cell connection board, and can electrically connect the electrode leads of a plurality of battery cells through a busbar mounted on the busbar frame (300). For example, the electrode leads of the battery cells can be bent and connected to the busbar after passing through a slit formed in the busbar frame (300).

[0043] The busbar frame (300) is formed with a first busbar frame (310) formed on one side of the battery cell stack (100) and a second busbar frame (320) formed on the other side of the battery cell stack (100), so that the electrode leads on both sides of the battery cell stack (100) can be electrically connected.

[0044] End plates (510, 520) can be attached to the open front and rear surfaces of the combined lower frame (210) and upper frame (220). That is, the end plates (510, 520) can cover the first and second busbar frames (310, 320).

[0045] The end plates (510, 520) can protect various electrical components provided in the first and second busbar frames (310, 320) from external shocks and simultaneously guide the electrical connection between the first and second busbar frames (310, 320) and an external power source. An insulating member (not shown) may be inserted between the end plates (510, 520) and the first and second busbar frames (310, 320), thereby blocking unnecessary electrical connections between the busbar frames (310, 320) and the end plates (510, 520).

[0046] A connecting portion (400) is provided between the first and second busbar frames (310, 320) to electrically connect the first and second busbar frames (310, 320). Conventionally, a flexible printed circuit board (FPC) is provided between the busbar frames, and the two busbar frames are connected through the flexible printed circuit board, and a cover plate is installed on the top of the flexible printed circuit board to prevent damage to the flexible printed circuit board. However, according to one embodiment of the present invention, the cover plate that protected and supported the flexible printed circuit board is removed, and the first and second busbar frames (310, 320) are connected using a flexible flat cable (FFC) formed from a flat cable that does not require a protective member such as a cover plate, instead of the flexible printed circuit board. By connecting the two busbar frames via FFC in this way, the height of the battery module is reduced, which increases the energy density of the battery itself and allows for securing installation space for the battery module, thereby improving driving performance and fuel efficiency when the battery module is installed in a vehicle.

[0047] As described above, according to one embodiment of the present invention, a connecting part (400) formed of FFC is located between the upper frame (220) and the battery cell stack (100). That is, the connecting part (400) can be positioned and fixed on the upper part of the battery cell stack (100).

[0048] The connecting portion (400) may include a connecting body (410) located on the upper side of the battery cell stack (100) and a connecting cable (420) that is bent toward the busbar frame (300) at both ends of the connecting body (410) and connected to the first connector (430). The connecting portion (400) is formed of a flexible flat cable, i.e., a soft cable, and can be bent, and since the circuit for electrical connection between the busbar frames is inserted inside the cable, it is easy to cope with external impacts.

[0049] Additionally, the connecting portion (400) can be formed in a flexible, flat shape, that is, a flat shape. Therefore, compared to the case of a wire-type sensing circuit with a strong reaction force against bending, it can be bent flexibly, making it easy to set a specific position during automatic assembly. Furthermore, while the wire type requires an additional structure to protect the wire and requires a separate assembly process rather than being applied directly to the battery module, the flexible flat cable can be applied directly to the battery module assembly without a separate protective structure.

[0050] The first connector (430) may have an insertion portion (not shown) into which a connecting cable (420) is inserted, and depending on the bending direction of the connecting cable (420), the opening direction of this insertion portion may face upward (z-axis direction).

[0051] The connection portion (400) is connected to a flexible printed circuit board (FPCB, 600) mounted on the upper part of the busbar frame (300) through a first connector (430). That is, the connection portion (400) and the flexible printed circuit board (600) are connected by the first connector (430) being connected to a second connector (440) connected to the flexible printed circuit board (600).

[0052] At this time, the second connector (440) may be fixed to the flexible printed circuit board (600) by soldering. That is, since the second connector (440), which is connected to the connection part (400) formed by the small component FFC, is also a small component, there are limitations to fixing it with additional components such as bolting. For this reason, it is fixed only by soldering to the flexible printed circuit board (600). In this structure, if the force applied when connecting the first connector (430) to the second connector (440) exceeds the force that the soldering can withstand, the second connector (440) may detach. To prevent this, the present embodiment further includes a damper (610) positioned at the bottom (lower in the z-axis direction) of the second connector (440). That is, by further including a dam portion (610) formed to wrap around the bottom surface and the lower portions of both sides of the second connector (440), it is possible to prevent the second connector (440) from being pushed out.

[0053] The configuration will be described in more detail below with further reference to FIGS. 3 and FIGS. 4.

[0054] FIG. 3 is an enlarged perspective view showing the first connector mounted on the second connector, and FIG. 4 is an enlarged front view showing the first connector mounted on the second connector.

[0055] As illustrated in FIGS. 3 and 4, the dam portion (610) may be formed by being fixed on a flexible printed circuit board (600) fixed to a busbar frame (300). At this time, the dam portion (610) may be formed to cover the entire lower portion of the second connector (440) and the lower portion of the side, i.e., the lower corner. Additionally, it may be formed to have an internal space in a shape protruding from the flexible printed circuit board (600). This dam portion (610) may be formed integrally with the flexible printed circuit board (600), or it may be manufactured as a separate structure and then attached, and is not particularly limited.

[0056] A coating portion (620) may be formed in the space formed by the dam portion (610). The coating portion (620) may be formed between the second connector (440) and the dam portion (610), and may be formed as a conformal coating generally used for circuit boards, etc. That is, it may be formed by applying and curing a coating liquid such as an acrylic, olefin, silicone, urethane, or fluorine-based coating. The coating portion (620) has insulating properties and may be formed in the inner space formed by the dam portion (610) to have a thickness equal to or smaller than the height of the protruding dam portion (i.e., height in the x-axis direction).

[0057] In this way, by forming a double support structure of a coating part (620) and a dam part (610) on the lower part of the second connector (440), the second connector (440) can be prevented from being pushed even when a load is applied by the fastening of the first connector (430), thereby preventing the second connector (440) from coming off. That is, unlike the case where the second connector (440) is supported only by a shelf-shaped support structure, the coating part (620) formed on the inner side together with the dam part (610) is a double structure, so it can prevent coming off more effectively. Furthermore, if only the coating part (620) is formed, it is difficult to specify the area where the coating liquid is applied, which may cause problems in the manufacturing process, but since the coating part (620) is formed on the inner side of the dam part (610), manufacturability can also be ensured. In particular, since the fixation of the second connector (440) is still achieved solely through a soldering-based support structure, unlike a bolting-type support structure that requires a separate space, the space required for fixation can be minimized while the second connector (440) can be stably supported.

[0058] One or more battery modules according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0059] The above-mentioned battery module or battery pack can be applied to various devices. Such devices may be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but are not limited thereto and can be applied to various devices capable of using secondary batteries.

[0060] 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 using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0061] [Explanation of the symbol]

[0062] 100: Battery cell

[0063] 210: Lower frame

[0064] 220: Upper frame

[0065] 300: Busbar Frame

[0066] 310: 1st busbar frame

[0067] 320: Second busbar frame

[0068] 400: Connection

[0069] 410: Connecting main body

[0070] 420: Connection cable

[0071] 430: 1st connector

[0072] 440: 2nd connector

[0073] 510, 520: End plates

[0074] 600: Flexible Printed Circuit Board (FPCB)

[0075] 610: Dam

[0076] 620: Coating section

Claims

1. A battery cell stack comprising multiple stacked battery cells; Busbar frames formed on the front and rear sides, respectively, of the above-mentioned battery cell stack; A connecting part connected to the upper part of the battery cell stack and connecting the busbar frames formed on the front and rear surfaces to each other; A first connector connected to both ends of the above-mentioned connection part; A second connector fixed to the busbar frame and coupled with the first connector; and A battery module comprising a dam portion disposed at the lower part of the second connector and fixed to the busbar frame.

2. In Paragraph 1, The above dam portion is a battery module positioned to surround the lower part of the second connector and both sides of the second connector.

3. In Paragraph 2, A battery module further comprising a coating portion located between the above-mentioned dam portion and the above-mentioned second connector, on which a coating liquid is applied and cured.

4. In Paragraph 3, A battery module in which the thickness of the coating portion is equal to or smaller than the height of the dam portion.

5. In Paragraph 1, It further includes a flexible printed circuit board coupled to the busbar frame and connected to the plurality of battery cells and the second connector, The above second connector is a battery module fixed to the above flexible printed circuit board by soldering.

6. In Paragraph 5, The above dam portion is a battery module fixed on the above flexible printed circuit board.

7. In Paragraph 1, The above connection is a battery module formed by a flexible flat cable (FFC).

8. In Paragraph 1, The above connecting part is, A connecting body located on the upper side of the battery cell stack; and A battery module comprising a connecting cable that is bent at both ends of the connecting body in a direction toward the busbar frame and connected to the first connector.

9. In Paragraph 3, The above coating part is an insulating battery module.

10. A battery pack comprising one or more battery modules according to paragraph 1.

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