Battery cell assembly and battery pack including same

Abstract

A battery cell assembly according to one embodiment of the present invention comprises: a sub-assembly including a battery cell stack formed by stacking a plurality of battery cells; a frame member accommodating the sub-assembly; an inter bus bar electrically connected to the battery cells included in the sub-assembly; a terminal member including one end having a thread formed therein; a frame hole formed on at least one side surface of the frame member; and a terminal bus bar assembly covering the frame hole and connected to the terminal member, wherein an inter bus bar hole is formed in the inter bus bar, and the one end of the terminal member is coupled to the inter bus bar hole through the frame hole.

Description

Battery cell assembly and battery pack including the same

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0045811, filed April 4, 2024, and Korean Patent Application No. 10-2025-0035933, filed March 20, 2025, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery cell assembly and a battery pack including the same, and more particularly, to a battery cell assembly including an HV (High Voltage) electrical connection structure having improved cooling efficiency and safety and sealing performance from an external environment, and a battery pack including the same.

[0004] As technological developments and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Accordingly, extensive research is being conducted on secondary batteries that can meet diverse needs.

[0005] Secondary batteries are attracting much attention not only as an energy source for mobile devices such as cell phones, digital cameras, and laptops, but also as a power source for power devices such as electric bicycles, electric cars, and hybrid electric vehicles.

[0006] Recently, as the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, the demand for battery packs with medium- to large-sized module structures that assemble battery modules in which a number of secondary batteries are connected in series / parallel is increasing.

[0007] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series / parallel, it is common to configure a battery module composed of at least one battery cell and configure a battery pack by adding other components using at least one battery module.

[0008] The battery cells that make up these medium- to large-sized battery modules are composed of rechargeable secondary batteries. Therefore, these high-output, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from multiple battery cells accumulates in a small space, which can cause the temperature to rise rapidly and severely. In other words, battery modules with multiple battery cells stacked on top of each other and battery packs equipped with such battery modules can achieve high output, but it is difficult to remove the heat generated from the battery cells during charging and discharging. If the heat dissipation of the battery cells is not properly performed, the deterioration of the battery cells will be accelerated, shortening their lifespan and increasing the risk of explosion or fire.

[0009] Moreover, battery modules included in vehicle battery packs are frequently exposed to direct sunlight and may be subjected to high-temperature conditions, such as summer or desert environments. Furthermore, because multiple battery modules are densely packed together to increase vehicle range, flames or heat generated in one battery module can easily spread to neighboring modules, ultimately leading to ignition or explosion of the battery pack itself.

[0010] In addition, since the battery pack is composed of a structure in which multiple battery modules are combined, it is heavy and unsuitable for loading multiple batteries into a means of transportation such as an automobile, so there is a need to improve the energy density.

[0011] Fig. 1 is a perspective view showing a conventional battery pack. Fig. 2 is an exploded perspective view of the battery pack of Fig. 1.

[0012] Referring to FIGS. 1 and 2, a conventional battery pack (10) includes a lower pack frame (11) on which a plurality of battery modules (1) are mounted, an upper pack frame (12) positioned above the battery modules (1), and an internal beam (13) that defines a location where the battery modules (1) are mounted within the battery pack (10).

[0013] In this way, when a battery module (1) is mounted inside a battery pack (10), the energy density of the battery pack (10) decreases due to the internal beam (13) that partitions between the battery modules (1), so there was a problem that a larger number of battery packs (10) had to be equipped to meet the efficiency required in a device, etc. In addition, there was a limit to the number of battery packs (10) that could be equipped in a device due to the weight of the battery pack (10). Therefore, in order to reduce the weight of the battery pack (10) and increase the energy density of the battery pack (10) at the same time, there was a need to mount a larger number of battery modules (1) inside the battery pack (10).

[0014] FIG. 3 is a cross-sectional view showing a cross-section of one of the battery modules included in the battery pack of FIG. 2.

[0015] Referring to FIG. 3, a conventional battery module (1) includes a battery cell stack (3) including battery cells (2) stacked in a preset direction, and a module frame (4) that accommodates the battery cell stack (3), and the battery cell stack (3) is fixedly positioned on a thermally conductive resin layer (5) positioned on the lower surface of the module frame (4). In this case, a heat sink (6) positioned below the bottom of the module frame (4) may be provided to cool the heat generated in the battery cell stack (3).

[0016] However, the heat sink (6) has a disadvantage in that its cooling efficiency is not very high because it does not directly contact the battery cell stack (3) and receives heat. In particular, an air gap may be formed between the bottom of the module frame (4) and the thermally conductive resin layer (5), which is a factor that hinders heat transfer. There is a need for a more effective method for cooling the battery module (1).

[0017] In summary, a more effective method is needed to improve the cooling efficiency of battery modules.

[0018] The problem to be solved by the present invention is to provide a battery cell assembly including an HV (High Voltage) electrical connection structure having improved cooling efficiency, thereby improving cooling performance, and having sealing performance from an external environment, and a battery pack including the same.

[0019] The problems to be solved by the present invention are not limited to the problems described above, and problems not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0020] According to one embodiment of the present invention, a battery cell assembly comprises a sub-assembly including a battery cell stack formed by stacking a plurality of battery cells; a frame member accommodating the sub-assembly; and an inter-bus bar electrically connected to the battery cells included in the sub-assembly; a terminal member including one end portion having a thread formed therein; a frame hole formed on at least one side of the frame member; and a terminal bus bar assembly covering the frame hole and connected to the terminal member, wherein an inter-bus bar hole is formed in the inter-bus bar, and one end portion of the terminal member is coupled to the inter-bus bar hole through the frame hole.

[0021] The terminal busbar assembly includes a terminal busbar electrically connected to the terminal member, and a terminal busbar frame made of an electrically insulating material that surrounds at least a portion of the terminal busbar, wherein one end of the terminal busbar is exposed to the outside of the terminal busbar frame, the other end of the terminal busbar has a terminal busbar hole formed therein, and one end of the terminal member can pass through the terminal busbar hole and be coupled to the inter-busbar hole.

[0022] The terminal member includes a threaded end, and the other end of the terminal member can be connected to a nut by passing through the terminal bus bar hole.

[0023] A gasket may be positioned between the nut coupled to the other end of the terminal member and the terminal bus bar hole.

[0024] At least one side of the frame member has a frame recessed portion formed that is recessed from the outer surface of the frame member toward the inside of the frame member, the frame hole is formed in the frame recessed portion, and the sizes of the frame recessed portion and the terminal bus bar assembly may be the same.

[0025] The space between the above frame recess and the terminal busbar assembly may be filled with a sealing member.

[0026] The sub-assembly includes a first sub-assembly including a first battery cell stack and a second sub-assembly including a second battery cell stack, and the inter-busbar includes a pair of first inter-busbars electrically connected to the battery cells included in the first sub-assembly and a pair of second inter-busbars electrically connected to the battery cells included in the second sub-assembly, and the terminal member is configured in plurality and is electrically connected to the pair of first inter-busbars and the pair of second inter-busbars, respectively, and the pair of first inter-busbars and the pair of second inter-busbars can be respectively positioned in a space between the first battery cell stack and the second battery cell stack.

[0027] The frame hole includes a pair of first frame holes located on one side of the frame member and a pair of second frame holes located on the other side of the frame member, and the terminal busbar assembly includes a first terminal busbar assembly covering the pair of first frame holes and a second terminal busbar assembly covering the pair of second frame holes, and the first terminal busbar assembly is electrically connected to one of the pair of first inter-busbars and one of the pair of second inter-busbars, and the second terminal busbar assembly can be electrically connected to the other of the pair of first inter-busbars and the other of the pair of second inter-busbars.

[0028] It includes an inlet and an outlet for circulating refrigerant inside the frame member, and the refrigerant can be introduced into the frame member through the inlet and discharged through the outlet.

[0029] The sub-assembly may include a first sub-assembly including a first battery cell stack and a second sub-assembly including a second battery cell stack, and an insulating plate may be disposed between the first sub-assembly and the second sub-assembly, and an opening through which the coolant passes may be formed in the insulating plate.

[0030] Based on the above insulating plate, the inlet and the outlet may be positioned on opposite sides, the first sub-assembly may be positioned between the inlet and the insulating plate, and the second sub-assembly may be positioned between the outlet and the insulating plate.

[0031] The refrigerant introduced through the inlet may sequentially pass through the first sub-assembly, the opening of the insulating plate, and the second sub-assembly, and be discharged through the outlet.

[0032] The frame member may further include a first sealing assembly and a second sealing assembly covering each of the open sides, wherein the inlet may be coupled to the first sealing assembly and the outlet may be coupled to the second sealing assembly.

[0033] The above battery cell is a pouch-type battery cell and includes electrode leads protruding in both directions, and when the direction between the electrode leads is referred to as the longitudinal direction, the first sealing assembly, the first sub-assembly, the insulating plate, the second sub-assembly, and the second sealing assembly may be sequentially positioned along the longitudinal direction.

[0034] The above refrigerant is an insulating oil, and the above refrigerant can come into direct contact with the battery cell stack housed inside the frame member.

[0035] A battery pack according to another embodiment of the present invention may include the battery cell assembly described above.

[0036] According to embodiments, the battery cell assembly of the present invention and the battery pack including the same can increase the cooling efficiency of the battery cell assembly and the battery pack including the same through direct cooling of the coolant to the battery cells.

[0037] Additionally, energy density can be increased by arranging multiple sub-assemblies along the length direction within the battery cell assembly, and the flowability of the coolant can be improved by arranging an insulating plate with openings formed between the multiple sub-assemblies.

[0038] In addition, since the electrical connection structure between the terminal busbar and the inter busbar includes a sealing structure, sealing performance for the HV (High Voltage) electrical connection structure can be secured from the external environment.

[0039] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0040] Figure 1 is a perspective view showing a conventional battery pack.

[0041] Figure 2 is an exploded perspective view of the battery pack of Figure 1.

[0042] FIG. 3 is a cross-sectional view showing a cross-section of one of the battery cell assemblies included in the battery pack of FIG. 2.

[0043] Figure 4 is a perspective view of a battery cell assembly according to one embodiment of the present invention.

[0044] Fig. 5 is a drawing showing the HV electrical connection structure based on the upper part of the battery cell assembly of Fig. 4.

[0045] Fig. 6 is an exploded perspective view showing the terminal bus bar assembly included in the battery cell assembly of Fig. 4.

[0046] Fig. 7 is an enlarged view of the second terminal bus bar assembly in the battery cell assembly of Fig. 4.

[0047] Fig. 8 is an exploded perspective view showing the sub-assemblies and frame members included in the battery cell assembly of Fig. 4.

[0048] Figure 9 is an exploded perspective view of the battery cell assembly of Figure 4 with the frame member and end plate removed.

[0049] Fig. 10 is an enlarged view of the portion where the first inter-bus bar and the second inter-bus bar of Fig. 9 are located.

[0050] Figure 11 is an exploded perspective view of the subassembly of Figure 9.

[0051] Figure 12 is an exploded perspective view of the first subassembly of Figure 11.

[0052] Fig. 13 is an exploded perspective view showing the first sub-assembly of Fig. 12 separated.

[0053] Figure 14 is a drawing showing the battery cell of Figure 13.

[0054] 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 invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0055] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0056] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0057] Additionally, throughout the specification, whenever a part is said to “include” a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0058] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0059] Hereinafter, a battery cell assembly (100) according to one embodiment of the present invention will be described.

[0060] Fig. 4 is a perspective view of a battery cell assembly according to one embodiment of the present invention. Fig. 5 is a drawing showing an HV electrical connection structure based on the upper portion of the battery cell assembly of Fig. 4.

[0061] Referring to FIGS. 4 and 5, a battery cell assembly (100) according to one embodiment of the present invention includes a pair of sub-assemblies (100a, 100b) including a first sub-assembly (100a) and a second sub-assembly (100b) each formed by stacking a plurality of battery cells (110, FIG. 12); a frame member (200) that accommodates the sub-assemblies (100a, 100b); and an inlet (421) and an outlet (461) for circulating a coolant into the interior of the frame member (200). The coolant, inlet (421), and outlet (461) will be described later.

[0062] Referring to FIG. 4, the frame member (200) may be configured to protect the first sub-assembly (100a), the second sub-assembly (100b), and the electrical components connected thereto from external physical impact. The first sub-assembly (100a), the second sub-assembly (100b), and the electrical components connected thereto may be accommodated in the internal space of the frame member (200).

[0063] The structure of the frame member (200) may vary. According to one embodiment of the present invention, the structure of the frame member (200) may be a monoframe structure. Here, the monoframe may have an integrated upper surface, lower surface, and both sides. For example, the monoframe may be manufactured by injection molding.

[0064] The frame member (200) may be open on both sides. More specifically, the frame member (200) may be provided in an open form along the longitudinal direction of the battery cell (110, FIG. 12). In this case, one side of the first sub-assembly (100a) and the second sub-assembly (100b) may not be covered by the frame member (200).

[0065] More specifically, the front and rear sides of the first battery cell stack (120a, FIG. 12) included in the first sub-assembly (100a) may be covered by the first front bus bar assembly (301a), the first rear bus bar assembly (302a), the sealing assembly (400), or the end plate (500) described below, and through this, both the front and rear sides of the first battery cell stack (120a, FIG. 12) may be protected from external physical impacts, etc. Although the above description has been made based on the first sub-assembly (100a), the same description may also be made for the second sub-assembly (100b).

[0066] Referring to FIG. 5, a battery cell assembly (100) according to one embodiment of the present invention may include a first terminal bus bar assembly (350a) and a second terminal bus bar assembly (350b) formed on each of both sides of a frame member.

[0067] More specifically, in the first terminal busbar assembly (350a), the first positive terminal busbar (352a) and the first negative terminal busbar (353a) may be exposed to the outside of the first terminal busbar frame (351a). Additionally, in the second terminal busbar assembly (350b), one end of the second positive terminal busbar (352b) and one end of the second negative terminal busbar (353b) may be exposed to the outside of the second terminal busbar frame (351b), respectively.

[0068] However, the positions of the first positive terminal bus bar (352a) and the first negative terminal bus bar (353a) are not limited to those in FIG. 5, and may be changed from those in FIG. 5. This can also be explained in the same way for the second positive terminal bus bar (352b) and the second negative terminal bus bar (353b).

[0069] In addition, the first inter-bus bar (340a, FIG. 11) included in the first sub-assembly (100a) may be electrically connected to the other end of the first negative terminal bus bar (353a) in the first terminal bus bar assembly (350a) and the other end of the second positive terminal bus bar (352b) in the second terminal bus bar assembly (350b), respectively. In addition, the second inter-bus bar (340b, FIG. 11) included in the second sub-assembly (100b) may be electrically connected to the other end of the first positive terminal bus bar (352a) in the first terminal bus bar assembly (350a) and the other end of the second negative terminal bus bar (353b) in the second terminal bus bar assembly (350b), respectively.

[0070] Accordingly, the first sub-assembly (100a) can be connected to another battery cell assembly or a BDU (Battery Disconnect Unit) through one end of the first negative terminal bus bar (353a) exposed to the outside in the first terminal bus bar assembly (350a) and one end of the second positive terminal bus bar (352b) exposed to the outside in the second terminal bus bar assembly (350b), and can form an HV (High voltage) connection with them. In addition, the second sub-assembly (100b) can be connected to another battery cell assembly or a BDU (Battery Disconnect Unit) through one end of the first positive terminal bus bar (352a) exposed to the outside from the first terminal bus bar assembly (350a) and one end of the second negative terminal bus bar (353b) exposed to the outside from the second terminal bus bar assembly (350b), and can form an HV (High voltage) connection with them.

[0071] In the first terminal busbar assembly (350a), one end of the first positive terminal busbar (352a) and one end of the first negative terminal busbar (353a) may be positioned adjacent to each other, and the first terminal busbar assembly (350a) may have a size of a first width (d1) along the longitudinal direction of the frame member (200). In addition, in the second terminal busbar assembly (350b), one end of the second positive terminal busbar (352b) and one end of the second negative terminal busbar (353b) may be spaced apart from each other by a second distance (d2), and the second terminal busbar frame (351b) may have an empty space formed between one end of the second positive terminal busbar (352b) and one end of the second negative terminal busbar (353b).

[0072] Here, the size of the first width (d1) of the first terminal busbar assembly (350a) may be smaller than the second distance (d2) between the second positive terminal busbar (352b) and the second negative terminal busbar (353b) in the second terminal busbar assembly (350b).

[0073] Accordingly, since the battery cell assembly (100) according to the present embodiment is arranged along the width direction of the other battery cell assembly (100) and the frame member (200), the first terminal bus bar assembly (350a) included in the battery cell assembly (100) according to the present embodiment and the second terminal bus bar assembly (350b) included in the other battery cell assembly (100) can be arranged in a form in which they are interlocked with each other, thereby providing the advantages of increased ease of assembly and space efficiency and simplification of the HV electrical connection structure.

[0074] Below, the connection structure between the terminal busbar assembly (350a, 350b) and a pair of sub-assemblies (100a, 100b) will be described in more detail.

[0075] Fig. 6 is an exploded perspective view showing the terminal busbar assembly included in the battery cell assembly of Fig. 4 in isolation. Fig. 7 is an enlarged view showing the second terminal busbar assembly in the battery cell assembly of Fig. 4.

[0076] Referring to FIG. 6, a battery cell assembly (100) according to one embodiment of the present invention includes an inter-bus bar (340a, 340b, FIG. 11) electrically connected to a battery cell (110, FIG. 12) included in a pair of sub-assemblies (100a, 100b); a terminal member (354a, 354b) including one end having a thread formed therein; a frame hole (200H) formed on at least one side of a frame member (200); and a terminal bus bar assembly (350a, 350b) covering the frame hole (200H) and connected to the terminal member (354a, 354b).

[0077] More specifically, in the battery cell assembly (100) according to the present embodiment, a frame recessed portion (205) may be formed on at least one side of the frame member (200) so as to be recessed from the outer surface of the frame member (200) toward the inside of the frame member (200).

[0078] In addition, a frame hole (200H) may be formed in the frame recess (205). More specifically, the frame hole (200H) may include a pair of first frame holes located on one side of the frame member (200) and a pair of second frame holes located on the other side of the frame member (200), and the terminal busbar assembly (350a, 350b) may include a first terminal busbar assembly (350a) covering the pair of first frame holes (200H) and a second terminal busbar assembly (350b) covering the pair of second frame holes (200H).

[0079] For example, as shown in FIG. 6, a pair of first frame holes (200H) may be formed in the frame recessed portion (205), and a pair of first terminal members (354a) having different polarities may pass through the pair of frame holes (200H) respectively to be electrically connected to the inter-bus bars (340a, 340b, FIG. 11) inside the frame member (200). Although FIG. 6 is described based on one side of the frame member (200), a second terminal member (354b) may also be electrically connected to the inter-bus bars (340a, 340b, FIG. 11) inside the frame member (200) for a pair of first frame holes (200H) located on the other side of the frame member (200).

[0080] The sizes of the frame recessed portion (205) and the terminal busbar assembly (350a, 350b) may be the same. More specifically, the space between the frame recessed portion (205) and the terminal busbar assembly (350a, 350b) may be filled with a sealing member (357a, 357b). That is, the sealing member (357a, 357b) may have the same size as the frame recessed portion (205) and / or the terminal busbar assembly (350a, 350b).

[0081] For example, the sealing member (357a, 357b) may be made of the same material as the sealant, but is not limited thereto, and any member having sealing performance and heat resistance may be included in the present embodiment.

[0082] Accordingly, the battery cell assembly (100) according to the present embodiment has a sealing member (357a, 357b) formed between the frame member (200) and the terminal bus bar assembly (350a, 350b), thereby improving the sealing performance between the frame member (200) and the terminal bus bar assembly (350a, 350b) and the sealing performance of the HV electrical connection structure.

[0083] In addition, as described later in FIGS. 9 to 14, the battery cell assembly (100) according to the present embodiment has the advantage that an insulating coolant can flow inside the frame member (200), and the sealing member (357a, 357b) described above can effectively prevent leakage and leakage of the insulating coolant.

[0084] Referring to FIGS. 6 and 7, the terminal busbar assembly (350a, 350b) includes a terminal busbar (352a, 353a, 352b, 353b) electrically connected to a terminal member (354a, 354b), and a terminal busbar frame (351a, 351b) made of an electrically insulating material that surrounds at least a portion of the terminal busbar (352a, 353a, 352b, 353b).

[0085] Below, the second terminal busbar assembly (350b) is described as a reference, and the same description can be applied to the first terminal busbar assembly (350a).

[0086] More specifically, referring to FIGS. 6 and 7, the second terminal busbar assembly (350b) may include a pair of second terminal busbars (352b, 353b) each electrically connected to a pair of second terminal members (354b) and a second terminal busbar frame (351b) made of an electrically insulating material that surrounds at least a portion of the pair of second terminal busbars (352b, 353b).

[0087] Here, a pair of second terminal members (354b) may have different polarities, and a pair of second terminal bus bars (352b, 353b) may also have different polarities. At this time, a pair of second terminal members (354b) and a pair of second terminal bus bars (352b, 353b) may be electrically connected to each other with the same polarity.

[0088] In addition, it may be a structure in which the second terminal busbar frame (351b) and a pair of second terminal busbars (352b, 353b) are integrated, or a structure in which a pair of second terminal busbars (352b, 353b) are inserted into the second terminal busbar frame (351b). For example, the second terminal busbar frame (351b) may be manufactured by injection molding together with a pair of second terminal busbars (352b, 353b).

[0089] More specifically, as shown in FIGS. 6 and 7, one end (352b1, 353b1) of a pair of second terminal bus bars (352b, 353b) may be exposed to the outside of the second terminal bus bar frame (351b). For example, one end (352b1, 353b1) of a pair of second terminal bus bars (352b, 353b) may be exposed to the upper portion of the second terminal bus bar frame (351b). However, the position of the one end (352b1, 353b1) of the pair of second terminal bus bars (352b, 353b) is not limited thereto, and any position where electrical connection with another battery cell assembly (100) is easy may be included in the present embodiment.

[0090] In addition, as shown in FIGS. 6 and 7, the other ends (352b2, 353b2) of a pair of second terminal bus bars (352b, 353b) are formed with second terminal bus bar holes (352bh, 353bh), respectively, and one end of a pair of second terminal members (354b) having threads formed thereon can pass through the second terminal bus bar holes (352bh, 353bh), respectively, and be coupled to inter-bus bar holes (345ah, 341bh, FIG. 10) located inside the frame member.

[0091] Additionally, as shown in FIGS. 6 and 7, the other end of the second terminal member (354b) may also be formed with screw threads, and the other end of the second terminal member (354b) may pass through the second terminal bus bar hole (352bh, 353bh) and be coupled with the second nut (355b).

[0092] Accordingly, in the battery cell assembly (100) according to the present embodiment, an electrical connection structure between the inter-busbar (340a, 340b, FIG. 11) inside the frame member (200) by a pair of second terminal members (354b) and a pair of second terminal busbars (352b, 353b) of the second terminal busbar assembly (350b) can be stably formed based on the second terminal busbar assembly (350b).

[0093] The above description can be equally applied to the first terminal busbar assembly (350a), and even with the first terminal busbar assembly (350a) as a reference, an electrical connection structure between the inter-busbar (340a, 340b, FIG. 11) inside the frame member (200) by the pair of first terminal members (354a) and the pair of first terminal busbars (352a, 353a) of the first terminal busbar assembly (350a) can be stably formed.

[0094] In addition, in the battery cell assembly (100) according to the present embodiment, a second gasket (356b) may be positioned between the second nut (355b) and the second terminal busbar holes (352bh, 353bh) respectively coupled to the other ends of a pair of second terminal members (354b) of the second terminal busbar assembly (350b). For example, the second gasket (356b) may be made of the same material as a commonly used gasket, but is not limited thereto, and any material having sealing performance and heat resistance may be included in the present embodiment. As another example, the second gasket (356b) may have an O-ring shape, but is not limited thereto, and any material having a shape that can be easily coupled between each component may be included in the present embodiment.

[0095] Accordingly, in the battery cell assembly (100) according to the present embodiment, a second gasket (356b) is positioned between the second terminal busbar frame (351b) and a pair of second terminal members (354b) based on the second terminal busbar assembly (350b), thereby further improving the sealing performance between the frame member (200) and the second terminal busbar assembly (350b) and the sealing performance of the HV electrical connection structure.

[0096] The above description can be equally applied to the first terminal busbar assembly (350a), and even with the first terminal busbar assembly (350a) as a reference, a first gasket (356a) is positioned between the first terminal busbar frame (351a) and a pair of first terminal members (354a), thereby further improving the sealing performance between the frame member (200) and the first terminal busbar assembly (350a) and the sealing performance of the HV electrical connection structure.

[0097] Fig. 8 is an exploded perspective view showing the sub-assembly and frame member included in the battery cell assembly of Fig. 4 separated. Fig. 9 is an exploded perspective view of the battery cell assembly of Fig. 4 with the frame member and end plate removed. Fig. 10 is an enlarged view showing a portion where the first inter-bus bar and the second inter-bus bar of Fig. 9 are located. Fig. 11 is an exploded perspective view of the sub-assembly of Fig. 9. Fig. 12 is an exploded perspective view of the first sub-assembly of Fig. 11.

[0098] Referring to FIGS. 6, 9, and 11, in the battery cell assembly (100) according to the present embodiment, a pair of sub-assemblies (100a, 100b) includes a first sub-assembly (100a) including a first battery cell stack (120a) and a second sub-assembly (100b) including a second battery cell stack (120b). Here, the inter-bus bars (340a, 340b) may include a pair of first inter-bus bars (340a) electrically connected to the battery cells (100) included in the first sub-assembly (100a) and a pair of second inter-bus bars (340b) electrically connected to the battery cells (110) included in the second sub-assembly (100b). A pair of first inter-bus bars (340a) and a pair of second inter-bus bars (340b) may be positioned in the space between the first battery cell stack (120a) and the second battery cell stack (120b), respectively.

[0099] A pair of first inter-busbars (340a) may include a first positive inter-busbar (341a) and a first negative inter-busbar (345a), and a pair of second inter-busbars (340b) may include a second positive inter-busbar (341b) and a second negative inter-busbar (345b).

[0100] Here, the terminal members (354a, 354b) are configured in plurality and can be electrically connected to a pair of first inter-bus bars (340a) and a pair of second inter-bus bars (340b), respectively. More specifically, the pair of first terminal members (354a) can be electrically connected to a first negative inter-bus bar (345a) and a second positive inter-bus bar (341b), and the pair of second terminal members (354b) can be electrically connected to a first positive inter-bus bar (341a) and a second positive inter-bus bar (345b).

[0101] Additionally, the first terminal busbar assembly (350a) may be electrically connected to one of the pair of first inter-busbars (340a) and one of the pair of second inter-busbars (340b), and the second terminal busbar assembly (350b) may be electrically connected to the other of the pair of first inter-busbars (340a) and the other of the pair of second inter-busbars (340b). More specifically, the first terminal busbar assembly (350a) may be electrically connected to the first negative inter-busbar (345a) and the second positive inter-busbar (341b), and the second terminal busbar assembly (350b) may be electrically connected to the first positive inter-busbar (341a) and the second negative inter-busbar (345b).

[0102] Referring to FIG. 10, in the battery cell assembly (100) according to the present embodiment, a first negative electrode inter-bus bar hole (345ah) may be formed in a first negative electrode inter-bus bar (345a), and a second positive electrode inter-bus bar hole (341bh) may be formed in a second positive electrode inter-bus bar (341b). Although not illustrated in FIG. 10, the first positive electrode inter-bus bar (341a) and the second negative electrode inter-bus bar (345a) may be described in the same manner.

[0103] One end of the terminal member (354a, 354b) described above can be connected to the first negative inter-busbar hole (345ah) and the second positive inter-busbar hole (341bh), respectively, through the frame hole (200H) formed in the frame member (200). More specifically, one end of a pair of first terminal members (354a) connected to the first terminal busbar assembly (350a) can pass through the frame hole (200H) and be connected to the first negative inter-busbar hole (345ah) and the second positive inter-busbar hole (341bh), respectively. Although not illustrated in FIG. 10, the first positive inter-busbar (341a) and the second negative inter-busbar (345a) can also be described in the same manner.

[0104] Accordingly, in the battery cell assembly (100) according to the present embodiment, an electrical connection structure between the inter-bus bar (340a, 340b) located inside the battery cell assembly (100) and the terminal bus bar assembly (350a, 350b) located outside the battery cell assembly (100) can be stably formed.

[0105] Below, a detailed description will be given of a pair of sub-assemblies (100a, 100b) included in a battery cell assembly (100) according to the present embodiment. Most of the description will be based on the first sub-assembly (100a), but the same description can also be given for the second sub-assembly (100b).

[0106] Fig. 13 is an exploded perspective view showing the first battery cell stack of Fig. 12 in isolation. Fig. 14 is a drawing showing the battery cell of Fig. 13.

[0107] Referring to FIG. 8 and FIGS. 12 to 14, the battery cell (110) is a pouch-type battery cell and may include electrode leads (130) protruding in both directions. This pouch-type battery cell may be formed by housing an electrode assembly in a pouch case of a laminate sheet including a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. This battery cell (110) may have a rectangular sheet structure. Specifically, the battery cell (110) according to the present embodiment has a structure in which two electrode leads (130) protrude from one end (114a) and the other end (114b) of the battery body (113), respectively. More specifically, the electrode leads (130) may protrude in opposite directions, and one of these electrode leads (130) may be a positive electrode lead and the other may be a negative electrode lead. In this embodiment, the direction between the electrode leads (130) protruding in both directions of the battery cell (110) is referred to as the longitudinal direction of the battery cell (110). For example, referring to FIG. 8 and FIGS. 12 to 14, a direction parallel to the x-axis may correspond to the longitudinal direction of the battery cell (110).

[0108] The battery cell (110) can be manufactured by accommodating an electrode assembly (not shown) in the battery case (114) and bonding the two ends (114a, 114b) of the battery case (114) and one side (114c) connecting them. In other words, the battery cell (110) according to one embodiment of the present invention has a total of three sealing portions, and the sealing portions have a structure in which they are sealed by a method such as fusion, and the remaining other side portion can be formed as a folding portion (115).

[0109] These battery cells (110) may be configured in multiple units, and the multiple battery cells (110) are stacked so as to be electrically connected to each other to form a battery cell stack (120a, 120b). More specifically, the first sub-assembly (100a) includes a first battery cell stack (120a), and the second sub-assembly (100b) includes a second battery cell stack (120b).

[0110] In particular, the battery cells (110) may be stacked along one direction while standing upright, with one side of the battery body (113) of the battery cells (110) facing each other. More specifically, as illustrated in FIG. 8 and FIGS. 12 to 14, the battery cells (110) may be stacked in a direction from one side of the frame member (200) to the other side while standing upright, such that one side of the battery body (113) of the battery cells (110) is parallel to the side sides of the frame member (200). As an example, a plurality of battery cells (110) are stacked along a direction parallel to the y-axis. When the plurality of battery cells (110) are stacked along a direction parallel to the y-axis in this way, the electrode leads (130) of one battery cell (110) may protrude along the x-axis direction and the -x-axis direction, respectively.

[0111] In one area, a plurality of battery cells (110) may be stacked along a direction parallel to the y-axis to form a first battery cell stack (120a), and in another area, a plurality of battery cells (110) may be stacked along a direction parallel to the y-axis to form a second battery cell stack (120b).

[0112] The battery case (114) is generally composed of a laminate structure of a resin layer / metal film layer / resin layer. For example, if the surface of the battery case is composed of an O(oriented)-nylon layer, when a plurality of battery cells are laminated to form a medium- to large-sized battery cell assembly, the battery case tends to slip easily due to external impact. Therefore, in order to prevent this and maintain a stable laminated structure of the battery cells, an adhesive material such as a pressure-sensitive adhesive such as a double-sided tape or a chemical adhesive that is bonded by a chemical reaction during bonding may be attached to the surface of the battery case to form a first battery cell laminate (120a) and a second battery cell laminate (120b).

[0113] Meanwhile, the first battery cell stack (120a) and the second battery cell stack (120b) are arranged along a direction perpendicular to the direction in which the battery cells (110) in the first battery cell stack (120a) or the second battery cell stack (120b) are stacked. In other words, the first battery cell stack (120a) and the second battery cell stack (120b) may be arranged along the direction in which the electrode leads (130) protrude based on the battery cells (110). That is, the first battery cell stack (120a) and the second battery cell stack (120b) are arranged along the longitudinal direction of the battery cells (110). For example, as illustrated in FIG. 10, when a plurality of battery cells (110) are stacked along a direction parallel to the y-axis to form a first battery cell stack (120a) and a second battery cell stack (120b), the first battery cell stack (120a) and the second battery cell stack (120b) can be positioned along a direction parallel to the x-axis.

[0114] Referring to FIGS. 11 and 12, the battery cell assembly (100) according to the present embodiment may include a first sub-assembly (100a) and a second sub-assembly (100b) arranged along the longitudinal direction of the battery cell (110). Specifically, the battery cell assembly (100) according to the present embodiment may be such that the first sub-assembly (100a) and the second sub-assembly (100b) arranged inside a frame member (200) are electrically coupled to each other, or are individually mounted inside the frame member (200). That is, the battery cell assembly (100) according to the present embodiment corresponds to a twin model battery cell assembly having the first sub-assembly (100a) and the second sub-assembly (100b).

[0115] Here, the first sub-assembly (100a) may include a first battery cell stack (120a) and a first bus bar assembly (301a, 302a), and the second sub-assembly (100b) may include a second battery cell stack (120b) and a second bus bar assembly (301b, 302b). Here, the first battery cell stack (120a) and the second battery cell stack (120b) may be arranged along the longitudinal direction of the battery cell (110).

[0116] In addition, the first sub-assembly (100a) may have first busbar assemblies (301a, 302a) positioned on each of the front and rear surfaces of the first battery cell stack (120a), and the second sub-assembly (100b) may have second busbar assemblies (301b, 302b) positioned on each of the front and rear surfaces of the second battery cell stack (120b).

[0117] More specifically, the first busbar assemblies (301a, 302a) may be positioned in the direction in which the electrode leads (130) of the battery cells (110) included in the first battery cell stack (120a) protrude. In addition, the second busbar assemblies (301b, 302b) may be positioned in the direction in which the electrode leads (130) of the battery cells (110) included in the second battery cell stack (120b) protrude. The first busbar assemblies (301a, 302a) and the second busbar assemblies (301b, 302b) may each include a busbar frame, a busbar, and a terminal busbar, which will be described later.

[0118] Referring to FIGS. 8 and 9, the battery cell assembly (100) according to the present embodiment may include a sealing assembly (400). The sealing assembly (400) may be formed to be positioned on both open sides of the frame member (200) and cover a pair of sub-assemblies (100a, 100b). The sealing assembly (400) positioned on one open side of the frame member (200) may be a first sealing assembly (410), and the sealing assembly (400) positioned on the other open side of the frame member (200) may be a second sealing assembly (450). That is, the battery cell assembly (100) according to the present embodiment may further include a first sealing assembly (410) and a second sealing assembly (450) that cover both open sides of the frame member (200), respectively.

[0119] The sealing assembly (400) can isolate the open sides of the frame member (200) from the external environment. Specifically, the sealing assembly (400) can serve to seal the inside of the frame member (200) so that the refrigerant does not leak to the outside when the refrigerant is injected into the inside of the frame member (200).

[0120] Referring to FIG. 4, the battery cell assembly (100) according to the present embodiment may include an end plate (500). The end plate (500) may be formed to be positioned on both open sides of the frame member (200) and cover the sealing assembly (400). The end plate (500) positioned on one open side of the frame member (200) may be a first end plate (510), and the end plate (500) positioned on the other open side of the frame member (200) may be a second end plate (550). The inlet (421) may be coupled to a first inlet hole (510H) formed in the first end plate (510), and the outlet (461) may be coupled to a first outlet hole (550H) formed in the second end plate (550).

[0121] These end plates (500) can physically protect the battery cell stack (120) and other electrical components from external impact.

[0122] Referring to FIGS. 11 to 13, the first sub-assembly (100a) may include a first battery cell stack (120a) and a first busbar assembly (301a, 302a). More specifically, the first busbar assemblies (301a, 302a) may be positioned on the front and rear sides of the first battery cell stack (120a), respectively. The first busbar assemblies (301a, 302a) may be positioned in a direction in which the electrode leads (130) of the battery cells (110) included in the first battery cell stack (120a) protrude. In addition, a first flexible printed circuit board (370a, Flexible Printed Circuit Board, FPCB) electrically connected to the first busbar assemblies (301a, 302a) may be provided.

[0123] The first battery cell stack (120a) may include a plurality of battery cells (110), at least one first cooling fin (210a) positioned between the plurality of battery cells (110), and a first compression pad (250a) provided on one surface of a battery cell (110) positioned at the outermost side among the battery cells (110).

[0124] The first cooling fin (210a) may be positioned between a plurality of battery cells (110). For example, the first cooling fin (210a) may be positioned between two or more battery cells (110). Specifically, one first cooling fin (210a) and another adjacent first cooling fin (210a) may be positioned with two or more battery cells (110) therebetween.

[0125] The first cooling fin (210a) may include a first plate (211a) that is in contact with one side of the battery cell (110). Here, the one side of the battery cell (110) may be one side of the battery body (113, FIG. 14) of the battery cell (110), which may be one side of the battery cell (110) that extends along the longitudinal direction (x-axis direction).

[0126] One side of the first plate (211a) can be in contact with one side of a battery cell (110) facing the one side of the first plate (211a). The other side of the first plate (211a) can be in contact with one side of another adjacent battery cell (110) facing the other side of the first plate (211a). In this case, although not specifically illustrated, an adhesive member is interposed between the side of the battery cell (110) and the first plate (211a), so that the battery cell (110) and the first plate (211a) can be adhesively fixed. For example, the adhesive member can be an insulating tape.

[0127] The upper surface (z-axis direction) of the first plate (211a) can be in contact with the upper surface of the frame member (200), and the lower surface of the first plate (211a) can be in contact with the lower surface of the frame member (200). Accordingly, the first cooling fin (210a) can be fixedly positioned within the frame member (200), and thereby the battery cell (110) attached to the first cooling fin (210a) can also be fixedly positioned within the frame member (200).

[0128] When the size of the first plate (211a) is larger than the size of the battery cell (110), the upper and lower portions of the battery cell (110) can be positioned at a constant distance from the upper and lower surfaces of the frame member (200). Specifically, when the height of the first plate (211a) is longer than the height of the battery cell (110), the battery cell (110) can be positioned at the center of the first plate (211a) and be adhesively fixed. In this case, the upper and lower portions of the battery cell (110) can be positioned at a constant distance from the upper and lower surfaces of the frame member (200). Here, the heights of the battery cell (110) and the first plate (211a) refer to the lengths in the z-axis direction.

[0129] The first cooling fin (210a) may further include a first plate (211a) and a first protrusion (213a) protruding from one end of the first plate (211a). For example, the first cooling fin (210a) may have an L shape. Specifically, referring to FIG. 12, the first cooling fin (210a) may include a first plate (211a) having a surface corresponding to or larger than one side of the battery cell (110), and a first protrusion (213a) protruding from one end of the first plate (211a) so as to be parallel to the stacking direction (y-axis direction) of the first battery cell stack (120a).

[0130] The first protrusion (213a) is an area that protrudes in a direction perpendicular to the first plate (211a) and can be in contact with at least one of the upper or lower surface of the frame member (200). Specifically, one surface of the first protrusion (213a) can be positioned to face the upper or lower surface of the battery cell (110), and the other surface of the first protrusion (213a) can be in contact with the lower or upper surface of the frame member (200).

[0131] For example, one side of the first protrusion (213a) may be positioned facing the lower surface of the battery cell (110), and the upper and lower surfaces of the battery cell (110) may be positioned while being adhesively fixed to the first plate (211a) at a predetermined height from the upper and lower surfaces of the frame member (200). That is, a predetermined space may be provided between one side of the first protrusion (213a) and the lower surface of the battery cell (110) and between the upper surface of the frame member (200) and the upper surface of the battery cell (110), so that a coolant, which will be described later, may move between these spaces. In this case, the distance between one side of the first protrusion (213a) and the lower surface of the battery cell (110) may correspond to the distance between the upper surface of the frame member (200) and the upper surface of the battery cell (110).

[0132] The other surface of the first protrusion (213a) can be in contact with the bottom of the frame member (200). Specifically, the other surface of the first protrusion (213a) can be bonded and fixed while in contact with the bottom of the frame member (200), thereby allowing the first cooling fin (210a) to be fixed and positioned within the frame member (200).

[0133] However, the shape of the first cooling fin (210a) is not limited to this drawing, and may be a flat plate shape, and any shape is possible as long as it can be in contact with the battery cell (110) and fix the battery cell (110).

[0134] The first cooling fin (210a) may be made of metal. Specifically, the first cooling fin (210a) may be made of a metal having high thermal conductivity. Therefore, the first cooling fin (210a) can directly receive heat generated from the battery cell (110) by charging and discharging the battery. When heat is generated, the heat is primarily cooled as it is transferred to the first cooling fin (210a) in contact with the side surface of the battery cell (110), and a coolant, which will be described later, can directly contact the upper and lower portions of the battery cell (110) to perform secondary cooling. Accordingly, direct cooling is possible even for the upper and lower portions of the battery cell, which were relatively difficult to cool in the past, thereby improving cooling efficiency.

[0135] In addition, the second cooling fin (290a) may be positioned between a plurality of battery cells (110). For example, the second cooling fin (290a) may be positioned between two or more battery cells (110). Specifically, one second cooling fin (290a) and another adjacent second cooling fin (290a) may be positioned with two or more battery cells (110) therebetween. More specifically, the second cooling fin (290a) differs from the first cooling fin (210a) in that it does not include a separate protrusion, and other features thereof may be generally described in the same manner as the first cooling fin (210a).

[0136] The first compression pad (250a) may be positioned between the battery cells (110) included in the first battery cell stack (120a) or may be positioned at the outermost side of the first battery cell stack (120a). The first compression pad (250a) may serve to absorb swelling of the battery cells (110) due to charging and discharging. Specifically, the first compression pad (250a) may prevent the battery case (114, FIG. 14) of the battery cells (110) from breaking by pushing the side surface of the frame member (200) as the battery cells (110) swell, thereby improving the safety of the battery cell assembly (100).

[0137] Referring to FIGS. 11 and 12, the first busbar assembly (301a, 302b) included in the first sub-assembly (100a) may include a first front busbar assembly (301a) covering the front of the first battery cell stack (120a) and a first rear busbar assembly (302a) covering the rear of the first battery cell stack (120a).

[0138] Here, the first front busbar assembly (301a) may include a first front busbar frame (311a) and a first busbar (331a) mounted on the first front busbar frame (311a), respectively.

[0139] The first front bus bar frame (311a) may be positioned on the front surface of the first battery cell stack (120a) to cover the front surface of the first battery cell stack (120a) and at the same time guide the connection between the first battery cell stack (120a) and an external device.

[0140] A first bus bar (331a) may be mounted on the first front bus bar frame (311a). For example, the inner surface of the first front bus bar frame (311a) may face the first battery cell stack (120a), and the first bus bar (331a) may be mounted on the outer surface of the first front bus bar frame (311a).

[0141] The first front busbar frame (311a) may include an electrically insulating material. The first front busbar frame (311a) may limit contact between the first busbar (331a) and other parts of the battery cells (110) other than the part where the first busbar (331a) is connected to the electrode lead (not shown), thereby preventing electrical shorts from occurring.

[0142] The first bus bar (331a) may be mounted on the outer surface of the first front bus bar frame (311a) and may be used to electrically connect the battery cells (110) included in the first battery cell stack (120a) and electrically connect the first battery cell stack (120a) with an external device circuit. The first bus bar (331a) is positioned on the first front bus bar frame (311a), and the first front bus bar assembly (301a) is covered by the sealing assembly (400) and end plate (500) described below, so that it can be protected from external impacts, etc., and deterioration of durability due to external moisture, etc. can be minimized.

[0143] The first bus bar (331a) can be electrically connected to the first battery cell stack (120a) through the electrode lead (130) of the battery cell (110). Specifically, the electrode lead (130) of the battery cell (110) can be bent after passing through a slit formed in the first front bus bar frame (311a) and connected to the first bus bar (331a). The battery cells (110) included in the first battery cell stack (120a) can be electrically connected in series or parallel by the first bus bar (331a). There is no particular limitation on the connection method between the electrode lead (130) and the first bus bar (331a), and for example, welding may be applied.

[0144] The first flexible printed circuit board (370a) is configured to extend in the longitudinal direction of the battery cells (110) and be mounted to sense the battery cells (110). That is, as shown in FIGS. 11 and 12, the first flexible printed circuit board (370a) is positioned on the upper surface of the first battery cell stack (120a) and senses voltage data or thermal data of the battery cells (110). In particular, the first flexible printed circuit board (370a) can be electrically connected to the first bus bar (331a) while being bent toward the first bus bar frame (310a) at one end. Accordingly, the voltage data of each battery cell (110) can be sensed and transmitted to the outside.

[0145] Here, the first rear busbar assembly (302a) may include a first rear busbar frame (312a) and a first busbar (331a) mounted on each of the first rear busbar frames (312a). The description of the first rear busbar assembly (302a) may be largely the same as that described for the first front busbar assembly (301a) described above, and only the different parts will be described below.

[0146] More specifically, in the first rear busbar assembly (302a), the first inter-busbar (340a) may be positioned on each of both sides of the first rear busbar frame (312a). Here, the first inter-busbar (340a) may be electrically connected to the first busbar (331a) mounted on the first rear busbar frame (312a). More specifically, the first inter-busbar (340a) may include a first positive inter-busbar (341a) and a first negative inter-busbar (345a) having different polarities. In addition, as described above, the first positive inter-busbar (341a) and the first negative inter-busbar (345a) may be electrically connected to terminal busbars (353a, 352b) included in terminal busbar assemblies (350a, 350b) positioned outside the frame member (200).

[0147] In addition, the first rear busbar assembly (302a) may be positioned on the rear surface of the first battery cell stack (120a) to cover the rear surface of the first battery cell stack (120a) and at the same time guide the connection between the first battery cell stack (120a) and an external device. In particular, the first rear busbar assembly (302a) may be positioned inside the frame member (200) so that the electrical connection structure between the first inter busbar (340a) and the terminal busbars (353a, 352b) may be protected from external impacts, etc.

[0148] Referring to FIGS. 8, 9, and 11, in the battery cell assembly (100) according to the present embodiment, the first sub-assembly (100a) and the second sub-assembly (100b) may be arranged such that the first rear bus bar assembly (302a) of the first sub-assembly (100a) and the second rear bus bar assembly (302b) of the second sub-assembly (100b) face each other. In other words, the first rear bus bar assembly (302a) of the first sub-assembly (100a) and the second rear bus bar assembly (302b) of the second sub-assembly (100b) may be positioned at the center of the battery cell assembly (100).

[0149] Accordingly, the first rear busbar assembly (302a) and the second rear busbar assembly (302b) are positioned at the center of the battery cell assembly (100), so that when a plurality of battery cell assemblies (100) are arranged along the width direction of the battery cell assembly (100), the electrical connection structure between the first inter busbar (340a) and the terminal busbar (353a, 352b) and the electrical connection structure between the second inter busbar (340b) and the terminal busbar (352a, 353b) can be arranged between adjacent battery cell assemblies (100).

[0150] That is, in a structure in which a plurality of battery cell assemblies (100) are arranged, the electrical connection structure between the first inter bus bar (340a) and the terminal bus bar (353a, 352b) and the electrical connection structure between the second inter bus bar (340b) and the terminal bus bar (352a, 353b) can be more reliably protected from external impacts, etc.

[0151] Referring to FIG. 9, in the battery cell assembly (100) according to the present embodiment, a side plate (270) may be provided that covers both sides of the first sub-assembly (100a) and the second sub-assembly (100b). Here, the length of the side plate (270) may correspond to the sum of the lengths of the first sub-assembly (100a) and the second sub-assembly (100b). However, the shape of the side plate (270) is not limited thereto, and a plurality of side plates (270) may cover both sides of the first sub-assembly (100a) and the second sub-assembly (100b), respectively.

[0152] The side plate (270) may be a plate extending along the length of the battery cell (110). For example, the side plate (270) may be a metal having rigidity.

[0153] The side plate (270) can be positioned facing the outermost battery cell (110) among the battery cells (110) included in the first sub-assembly (100a) and the outermost battery cell (110) among the battery cells (110) included in the second sub-assembly (100b).

[0154] Accordingly, in the battery cell assembly (100) according to the present embodiment, the side plate (270) can play a role in protecting the outermost battery cell (110) or compression pad (250a) of the first sub-assembly (100a) and the second sub-assembly (100b) when the first sub-assembly (100a) and the second sub-assembly (100b) are each inserted and mounted in the frame member (200) with the insulating plate (700) therebetween.

[0155] In addition, the battery cell assembly (100) of the present embodiment is a twin model having a first battery cell stack (120a) and a second battery cell stack (120b), and since the battery cell stack (120) is longer than a typical battery cell stack, it may not be easy to assemble by inserting it into the frame member (200). In this case, as illustrated in FIGS. 8 and 9, the side plate (270) guides the insertion of the battery cell stack (120) into the frame member (200), thereby enabling the battery cell assembly to be easily assembled without damage to the battery cells (110) and / or the compression pads (250a, 250b).

[0156] Referring to FIGS. 9 and 10, a side recessed portion (270a) may be formed at the center of the side plate (270) included in the battery cell assembly (100) of the present embodiment. Here, the side recessed portion (270a) may be a portion formed by recessing from the upper portion of the side plate (270) toward the center. Here, the inter-bus bars (340a, 340b) of the first sub-assembly (100a) and the second sub-assembly (100b) of the present embodiment may be exposed to the outside of the side plate (270) through the side recessed portion (270a).

[0157] Accordingly, the side plate (270) can help to protect the components inside the battery cell assembly (100) and facilitate assembly of the battery cell assembly (100) as described above, while also stably assisting the electrical connection inside and outside the battery cell assembly (100).

[0158] Below, a structure for circulating a coolant inside a battery cell assembly according to the present embodiment will be described in detail.

[0159] Referring again to FIGS. 4, 9, and 11, the battery cell assembly (100) according to the present embodiment includes an inlet (421) and an outlet (461) for circulating a coolant into the interior of the frame member (200). The coolant is introduced into the interior of the frame member (200) through the inlet (421) and then discharged to the exterior of the battery cell assembly (100) through the outlet (461).

[0160] The above refrigerant can receive heat generated from the first battery cell stack (120a), the second battery cell stack (120b), the first bus bar assembly (301a, 302a), the second bus bar assembly (301b, 302b) and other electrical components stored inside the frame member (200) by directly contacting them.

[0161] The above-described refrigerant may be a fluid. However, since the refrigerant directly contacts the first battery cell stack (120a), the second battery cell stack (120b), the first bus bar assembly (301a, 302a), the second bus bar assembly (301b, 302b) and other electrical components within the battery cell assembly (100), the refrigerant needs to be electrically insulated. Accordingly, the refrigerant may be a material having insulating properties. For example, the refrigerant may be an insulating oil.

[0162] That is, in the case of the present embodiment, the coolant can directly contact and transfer heat to the first battery cell stack (120a), the second battery cell stack (120b), the first bus bar assembly (301a, 302a), the second bus bar assembly (301b, 302b) and other electrical components that generate heat within the battery cell assembly (100), thereby directly cooling them. Therefore, compared to indirectly cooling the battery module (1) using a heat sink (6) or the like in a conventional battery module (1, see FIG. 3), the battery cell assembly (100) according to the present embodiment can improve cooling efficiency through direct cooling, thereby extending the life of the battery.

[0163] At this time, in the present embodiment, an insulating plate (700) is placed between the first battery cell stack (120a) and the second battery cell stack (120b), and an opening (700H) through which the coolant passes is formed in the insulating plate (700). For example, the opening (700H) may be formed in the center of the insulating plate (700), and more specifically, the opening (700H) may be opened in a rectangular shape in which the upper and lower sides are longer than the two side sides. That is, the opening (700H) may be opened so as to extend along the direction in which the battery cells (110) are stacked.

[0164] The insulating plate (700) includes a first insulating protrusion (700B1) positioned at the top and a second insulating protrusion (700B2) positioned at the bottom, and the first insulating protrusion (700B1) and the second insulating protrusion (700B2) can be stably combined in a form in which the first rear busbar assembly (302a) and the second rear busbar assembly (302b) are interlocked, respectively.

[0165] The insulating plate (700) may include a material having electrical insulating properties. For example, the insulating plate (700) may be a plastic injection molded product.

[0166] More specifically, with respect to the insulating plate (700), the inlet (421) and the outlet (461) may be positioned on opposite sides. The first battery cell stack (120a) may be positioned between the inlet (421) and the insulating plate (700), and the second battery cell stack (120b) may be positioned between the outlet (461) and the insulating plate (700).

[0167] The refrigerant introduced through the inlet (421) can sequentially pass through the first battery cell stack (120a), the opening (700H) of the insulating plate (700), and the second battery cell stack (120b), and be discharged through the outlet (461).

[0168] Since both the first battery cell stack (120a) and the second battery cell stack (120b) are included within one frame member (200), there is a risk of a short circuit occurring due to contact between the first battery cell stack (120a) and the second battery cell stack (120b) or contact between the first rear bus bar assembly (302a) located at the rear of the first battery cell stack (120a) and the second rear bus bar assembly (302b) located at the rear of the second battery cell stack (120b).

[0169] In addition, as described above, the battery cell assembly (100) according to the present embodiment has a shape extending in the longitudinal direction, including the first battery cell stack (120a) and the second battery cell stack (120b). When the coolant circulates inside the frame member (200), a section where the flow of the coolant stagnates may occur between the first battery cell stack (120a) and the second battery cell stack (120b).

[0170] Accordingly, in this embodiment, an insulating plate (700) having electrical insulation is placed between the first battery cell stack (120a) and the second battery cell stack (120b). By using the insulating plate (700), electrical insulation and creepage distance are secured between the first battery cell stack (120a) and the second battery cell stack (120b), or between the first rear bus bar assembly (302a) located at the rear of the first battery cell stack (120a) and the second rear bus bar assembly (302b) located at the rear of the second battery cell stack (120b).

[0171] In addition, by designing the insulating plate (700) so that an opening (700H) through which the refrigerant passes is formed in the center of the insulating plate (700), the flow of the refrigerant is prevented from stagnating in the space between the first battery cell stack (120a) and the second battery cell stack (120b). In other words, the flow of the refrigerant is secured to increase the cooling performance.

[0172] Referring to FIGS. 4 and 9, as described above, the battery cell assembly (100) may include a first sealing assembly (410) and a second sealing assembly (450) that cover the open sides of the frame member (200), respectively. The inlet (421) may be coupled to a second inlet hole (410H) formed in the first sealing assembly (410), and the outlet (461) may be coupled to a second outlet hole (450H) formed in the second sealing assembly (450).

[0173] As described above, the battery cell (110) according to the present embodiment is a pouch-type battery cell and may include electrode leads (130) protruding in both directions. The direction between the electrode leads (130) protruding in both directions may be referred to as the longitudinal direction of the battery cell (110). A direction parallel to the x-axis may correspond to the longitudinal direction of the battery cell (110). Along this longitudinal direction, the first sealing assembly (410), the first battery cell stack (120a), the insulating plate (700), the second battery cell stack (120b), and the second sealing assembly (450) may be sequentially positioned. That is, the refrigerant introduced through the inlet (421) formed in the first sealing assembly (410) can sequentially pass through the first battery cell stack (120a), the opening (700H) of the insulating plate (700), and the second battery cell stack (120b), and be discharged through the outlet (461) formed in the second sealing assembly (450).

[0174] In the battery cell assembly (100) according to the present embodiment, the first front bus bar assembly (301a) electrically connected to the first battery cell stack (120a) and the second front bus bar assembly (301b) electrically connected to the second battery cell stack (120b) may be positioned on an open surface of the frame member (200). Here, the first sealing assembly (410) may be mounted while covering the first front bus bar assembly (301a), and the second sealing assembly (450) may be mounted while covering the second front bus bar assembly (301b). More specifically, the first sealing assembly (410) can cover the first front bus bar assembly (301a) located on one side of the first battery cell stack (120a), and the second sealing assembly (450) can cover the second front bus bar assembly (301b) located on one side of the second battery cell stack (120b).

[0175] In addition, unlike FIG. 4, the inlet (421) may be positioned lower than the center based on the height of the battery cell stack (120). The inlet (421) may be positioned close to the lower end of the first sealing assembly (410). Specifically, the inlet (421) may be positioned lower than the center based on the height of the first sealing assembly (410). Here, the height of the battery cell stack (120) or the first sealing assembly (410) refers to the length in the z-axis direction in the drawing.

[0176] In summary, the position of the inlet (421) and the position of the outlet (461) described above can be positioned lower than the center based on the height of the battery cell stack (120), and the outlet (461) can be positioned higher than the center based on the height of the battery cell stack (120). That is, the inlet (421) can be positioned close to the lower end of the first sealing assembly (410), and the outlet (461) can be positioned close to the upper end of the second sealing assembly (450).

[0177] If the inlet (421) is located above the center based on the height of the battery cell stack (120), there is a possibility that bubbles may form inside the coolant because the coolant flows into the inside of the battery cell assembly (100) as if it were falling from a high position. These bubbles become a factor that hinders the cooling effect.

[0178] In addition, if the outlet (461) is located lower than the center based on the height of the battery cell stack (120), the coolant introduced into the inside of the battery cell assembly (100) is filled only up to the height of the outlet (461) and then escapes to the outside, so the inside of the battery cell assembly (100) is not filled with a sufficient amount of coolant, which may result in a decrease in cooling performance.

[0179] Therefore, in order to prevent bubbles from forming in the incoming coolant and to fill the inside of the battery cell assembly (100) with coolant, it is preferable that the inlet (421) be positioned lower than the center based on the height of the battery cell stack (120), and the outlet (461) be positioned higher than the center based on the height of the battery cell stack (120).

[0180] In this example, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0181] One or more battery cell assemblies according to the above-described embodiment can be mounted together with various control and protection systems such as a BMS (Battery Management System), a BDU (Battery Disconnect Unit), and a cooling system to form a battery pack.

[0182] The above-mentioned battery cell assembly or battery pack can be applied to various devices. Specifically, it can be applied to transportation vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, or to ESS (Energy Storage Systems), but is not limited thereto. It can also be applied to various devices that can use secondary batteries.

[0183] Although the 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 made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0184] [Explanation of symbols]

[0185] 100: Battery cell assembly

[0186] 100a: First subassembly

[0187] 100b: Second subassembly

[0188] 110: Battery cell

[0189] 120: Battery cell stack

[0190] 200: Absence of frame

[0191] 200H: Frame hole

[0192] 205: Frame depression

[0193] 301a: First front busbar assembly

[0194] 302a: Second rear busbar assembly

[0195] 301b: First front busbar assembly

[0196] 302b: Second rear busbar assembly

[0197] 350a: Terminal 1 busbar assembly

[0198] 350b: Second terminal busbar assembly

[0199] 340a: 1st inter-busbar

[0200] 340b: Second Inter Busbar

[0201] 400: Sealing assembly

[0202] 700: Insulating plate

[0203] 700H: Aperture

Claims

1. A sub-assembly including a battery cell stack formed by stacking a plurality of battery cells; a frame member accommodating the above subassembly; and An inter-bus bar electrically connected to the battery cell included in the sub-assembly; A terminal member comprising one end having a thread formed therein; a frame hole formed on at least one side of the frame member; and Covering the above frame hole, and including a terminal busbar assembly connected to the terminal member, A battery cell assembly in which an inter-busbar hole is formed in the inter-busbar, and one end of the terminal member is connected to the inter-busbar hole through the frame hole.

2. In paragraph 1, The above terminal busbar assembly, A terminal bus bar electrically connected to the above terminal member, and A terminal busbar frame comprising a material that surrounds at least a portion of the terminal busbar and is electrically insulating, One end of the terminal busbar is exposed to the outside of the terminal busbar frame, and the other end of the terminal busbar has a terminal busbar hole formed therein. A battery cell assembly in which one end of the terminal member passes through the terminal busbar hole and is coupled to the inter busbar hole.

3. In paragraph 2, The terminal member includes a threaded end, A battery cell assembly in which the other end of the terminal member passes through the terminal bus bar hole and is coupled with a nut.

4. In paragraph 3, A battery cell assembly having a gasket positioned between a nut coupled to the other end of the terminal member and the terminal bus bar hole.

5. In paragraph 1, At least one side of the frame member has a frame recess formed on the outer surface of the frame member, which is recessed toward the inside of the frame member, The frame hole is formed in the above frame recessed portion, A battery cell assembly in which the above frame recess and the above terminal bus bar assembly have the same size.

6. In paragraph 5, A battery cell assembly in which the space between the frame recess and the terminal busbar assembly is filled with a sealing member.

7. In paragraph 1, The sub-assembly comprises a first sub-assembly including a first battery cell stack and a second sub-assembly including a second battery cell stack, The above inter-busbar includes a pair of first inter-busbars electrically connected to the battery cells included in the first sub-assembly and a pair of second inter-busbars electrically connected to the battery cells included in the second sub-assembly. The terminal member is composed of a plurality of terminal members, and is electrically connected to the pair of first inter-bus bars and the pair of second inter-bus bars, respectively. A battery cell assembly in which the first inter-bus bar and the second inter-bus bar are each positioned in the space between the first battery cell stack and the second battery cell stack.

8. In paragraph 7, The frame hole includes a pair of first frame holes located on one side of the frame member and a pair of second frame holes located on the other side of the frame member, The terminal busbar assembly includes a first terminal busbar assembly covering the pair of first frame holes and a second terminal busbar assembly covering the pair of second frame holes, The first terminal busbar assembly is electrically connected to one of the pair of first inter-busbars and one of the pair of second inter-busbars, A battery cell assembly in which the second terminal busbar assembly is electrically connected to another one of the pair of first inter-busbars and another one of the pair of second inter-busbars.

9. In paragraph 1, Includes an inlet and an outlet for circulating refrigerant into the interior of the above frame member, A battery cell assembly in which the refrigerant flows into the frame member through the inlet and is discharged through the outlet.

10. In paragraph 9, The sub-assembly comprises a first sub-assembly including a first battery cell stack and a second sub-assembly including a second battery cell stack, An insulating plate is placed between the first sub-assembly and the second sub-assembly, A battery cell assembly having an opening formed in the insulating plate through which the coolant passes.

11. In paragraph 10, Based on the above insulating plate, the inlet and the outlet are located on opposite sides, The first sub-assembly is positioned between the inlet and the insulating plate, A battery cell assembly wherein the second sub-assembly is positioned between the outlet and the insulating plate.

12. In paragraph 11, A battery cell assembly in which the refrigerant introduced through the inlet sequentially passes through the first sub-assembly, the opening of the insulating plate, and the second sub-assembly, and is discharged through the outlet.

13. In paragraph 9, Further comprising a first sealing assembly and a second sealing assembly covering each of the open sides of the frame member, A battery cell assembly wherein the inlet is coupled to the first sealing assembly and the outlet is coupled to the second sealing assembly.

14. In paragraph 13, The above battery cell includes electrode leads protruding in both directions, A battery cell assembly in which the first sealing assembly, the first sub-assembly, the insulating plate, the second sub-assembly, and the second sealing assembly are sequentially positioned along the longitudinal direction, when the direction between the electrode leads is referred to as the longitudinal direction.

15. In paragraph 9, The above refrigerant is insulating oil, A battery cell assembly in which the refrigerant is in direct contact with the battery cell stack stored inside the frame member.

16. A battery pack comprising a battery cell assembly according to paragraph 1.

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