Battery assembly and battery pack including same

Abstract

A battery assembly according to an embodiment of the present invention comprises: a plurality of battery cells; and a cell frame in which the battery cells are accommodated. A cooling flow path through which refrigerant flows in direct contact with at least some of the battery cells is provided inside the cell frame. The cooling flow path includes a plurality of cooling flow paths disposed along the longitudinal direction of the battery cells in which the battery cells extend. The flow direction of the refrigerant in any one of the plurality of cooling flow paths and that of the refrigerant in another one of the plurality of cooling flow paths are opposite to each other.

Description

Battery assembly and battery pack including same

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0056163, filed April 26, 2024, and Korean Patent Application No. 10-2024-0153476, filed November 1, 2024, the entire contents of which are incorporated herein by reference.

[0003] The present invention relates to a battery assembly and a battery pack including the same, and more particularly, to a battery assembly using an immersion cooling method and a battery pack including the same.

[0004] Secondary batteries, which offer high applicability across a wide range of product categories and possess electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electrical power sources. These batteries are widely used as an energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0005] Types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single secondary battery cell, or a single battery cell, is approximately 2.5 V to 4.5 V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting multiple battery cells in series. Furthermore, depending on the required charge / discharge capacity of the battery pack, a battery pack may be configured by connecting multiple battery cells in parallel. Therefore, the number of battery cells included in the battery pack may vary depending on the required output voltage or charge / discharge capacity.

[0006] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series / parallel, a battery cell assembly including multiple battery cells is created and housed in a module case to first configure a battery module, and then one or more of these battery modules are assembled and other components are added to configure a battery pack, or a battery pack is configured by arranging multiple battery cells within a pack frame and adding other components.

[0007] Since these battery cells are comprised of rechargeable secondary batteries, these high-power, high-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, causing the temperature to rise rapidly and severely. In other words, while battery packs containing multiple battery cells can achieve high output, it is difficult to remove the heat generated by the cells during charging and discharging. If the heat dissipation from the battery cells is inadequate, this can accelerate their deterioration, shorten their lifespan, and increase the risk of explosion or fire.

[0008] Moreover, 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 numerous battery cells are densely packed to increase vehicle range, flames or heat generated from a single battery cell can easily spread to neighboring cells, ultimately leading to fire or explosion within the battery pack itself.

[0009] In conventional battery modules, bottom cooling or side cooling methods have been used, which cool the battery module by installing a heat sink on the module case.

[0010] However, in the case of battery modules with this type of cooling method, the heat generated from the battery cells is transferred to a heat sink on one side of the module case for cooling, making it difficult to easily establish a heat transfer path to the other side of the module case. Consequently, the temperature difference between one end of the battery cell assembly and the other end is exacerbated, and the overall cooling efficiency is limited. If the temperature difference is not resolved, it can cause safety and durability issues in the battery module. If the cooling efficiency is poor, it can accelerate the deterioration of the battery cells, or if a thermal runaway occurs in some battery cells, it can spread due to a failure to respond quickly. This can lead to disasters such as fire or explosion of the battery module or the battery pack containing it, which can not only cause property damage but also pose safety issues.

[0011] To address these issues, a method has been proposed that directly cools the battery cells by filling the battery pack with coolant or insulating oil, rather than relying on bottom or side cooling. Specifically, immersion cooling, where coolant directly cools the battery cells within the pack, is being utilized to effectively cool high-capacity battery packs.

[0012] However, as battery assemblies and battery packs containing them become larger, the number of battery cells increases, and the number of components required for the battery assembly and battery pack increases, differences in the degree of cooling by the refrigerant occur in each area, so that uniform cooling of all battery cells within the battery assembly is not achieved, and thus the cooling efficiency of the entire battery assembly may be reduced. A decrease in the cooling efficiency of the battery assembly can lead to a decrease in the performance of the battery assembly and safety issues, and therefore, ensuring uniform cooling of all battery cells in an immersion cooling method is a critical development issue.

[0013] The problem to be solved by the present invention is to provide a battery assembly and a battery pack including the same that can eliminate cooling imbalance of battery cells and minimize thermal resistance deviation of battery cells.

[0014] However, the problems to be solved by the embodiments of the present invention 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.

[0015] According to one embodiment of the present invention, a battery assembly comprises: a plurality of battery cells; and a cell frame in which the battery cells are accommodated. A cooling channel is provided within the cell frame, through which a coolant flows in direct contact with at least a portion of the battery cells. The cooling channel includes a plurality of cooling channels arranged along a longitudinal direction of the battery cell along which the battery cell extends. A flow direction of the coolant in one of the plurality of cooling channels is opposite to a flow direction of the coolant in another of the plurality of cooling channels.

[0016] The longitudinal direction may be a direction between one side of the battery cell and the other side facing the one side. At least one of the electrode terminals of the battery cell may be located on the one side of the battery cell.

[0017] The above cell frame may include an inlet port through which the coolant flowing through the cooling channel and in direct contact with the battery cells is introduced, and an outlet port through which the coolant is discharged.

[0018] Any one of the plurality of cooling channels may be connected to the inlet port, and another one of the plurality of cooling channels may be connected to the outlet port.

[0019] The refrigerant introduced into the inlet port can flow along the cooling channels and then be discharged through the outlet port.

[0020] The area of ​​an area of ​​at least one of the plurality of cooling channels in which the flow direction of the refrigerant matches with the area of ​​contact with the battery cell may be 30% or more and 70% or less of the area of ​​an area of ​​contact with the entirety of the plurality of cooling channels with the battery cell.

[0021] The above cooling channels may include a first cooling channel and a second cooling channel. The flow direction of the refrigerant in the first cooling channel and the flow direction of the refrigerant in the second cooling channel may be opposite to each other.

[0022] The cell frame may include a separation part that separates the first cooling channel and the second cooling channel and is positioned between the first cooling channel and the second cooling channel.

[0023] Based on the longitudinal direction of the battery cell, the separation part may be positioned in a space between a point at 30% of the height of the battery cell and a point at 70% of the height of the battery cell.

[0024] The above cell frame may include a connecting hole connecting a plurality of cooling channels.

[0025] In the above connecting hole, the width of the space through which the refrigerant flows may be constant.

[0026] The above connecting hole may have a region in which the width of the space through which the refrigerant flows is narrowed.

[0027] In the above connecting hole, the difference in width between the widest part of the space through which the refrigerant flows and the narrowest part of the space through which the refrigerant flows may be 1.0 mm or more and 5 times or less of the spacing between the battery cells.

[0028] The above cell frame may include an inlet port and an outlet port through which the coolant flowing through the cooling channel and in direct contact with the battery cells is introduced and discharged, and a distribution mechanism may be provided in at least one of the inlet port or the outlet port to divide the coolant into a plurality of cooling channels. The connection holes may be provided in plurality, and the plurality of connection holes may correspond one-to-one with the cooling channels distributed by the distribution mechanism.

[0029] The spacing between the above battery cells may be 1.5 mm or more and 2.5 mm or less.

[0030] The above cell frame may include a bottom cell frame on which the battery cells are mounted and a cover cell frame positioned on the bottom cell frame.

[0031] The cover cell frame may include a middle cell frame and a top cell frame positioned on the middle cell frame. The space between the middle cell frame and the bottom cell frame and the space between the top cell frame and the middle cell frame may each correspond to the cooling channels.

[0032] Each of the above middle cell frame and the above top cell frame may be a member including an upper surface portion and a side portion extending downward from an edge of the upper surface portion.

[0033] The above middle cell frame may be a member including a middle portion, a first side portion extending upward from an edge of the middle portion, and a second side portion extending downward from an edge of the middle portion, and the top cell frame may be a member having a plate shape.

[0034] The above battery cells can be mounted directly on a vehicle or chassis while being housed in the cell frame.

[0035] A battery pack according to one embodiment of the present invention includes: the battery assembly; a pack frame that accommodates the battery assembly and has one side open; and a pack cover that covers the open side of the pack frame.

[0036] According to embodiments of the present invention, since a plurality of cooling channels are provided within the cell frame, arranged along the longitudinal direction of the battery cell and having opposite coolant flow directions, cooling variations for all battery cells within the battery assembly can be minimized, and thus thermal resistance variations for all battery cells can be minimized.

[0037] In addition, even if the battery assembly and the battery pack including it become larger, the degree of cooling by the refrigerant can be maintained uniformly in each zone.

[0038] Minimizing the temperature difference between battery cells can prevent deterioration of specific battery cells during long-term charge / discharge cycles, thereby extending the life of the battery assembly and the battery pack containing it, and ensuring safety.

[0039] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0040] FIG. 1 is a perspective view showing a battery assembly according to one embodiment of the present invention.

[0041] Fig. 2 is a plan view showing the battery assembly of Fig. 1 as viewed along the -z-axis direction on the xy plane.

[0042] Figure 3 is an exploded perspective view of the battery assembly of Figure 1.

[0043] Figures 4 (a) and 4 (b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention.

[0044] Fig. 5 is a cross-sectional view showing a cross-section taken along the cutting line C-C' in Fig. 4 (a).

[0045] Figure 6 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0046] Figure 7 is a partial perspective view of the battery assembly of Figure 1.

[0047] Fig. 8 is a cross-sectional view showing a cross-section taken along the cutting line A-A' of Fig. 2.

[0048] Figure 9 is a partial cross-sectional view showing an enlarged portion of “D” of Figure 8.

[0049] Fig. 10 is a partial cross-sectional view showing an enlarged portion of “E” of Fig. 8.

[0050] Fig. 11 is a cross-sectional view showing a cross-section taken along the cutting line B-B' of Fig. 2.

[0051] Fig. 12 is a partial cross-sectional view showing an enlarged portion of a part of Fig. 9.

[0052] FIG. 13 is a perspective view of a middle cell frame according to one embodiment of the present invention.

[0053] Fig. 14 is a cross-sectional perspective view showing the appearance cut along the cutting line F-F' of Fig. 13.

[0054] Figure 15 is a front view of the middle cell frame of Figure 14 as viewed from the front.

[0055] Fig. 16 is a cross-sectional view showing a cross-section taken along the cutting line G-G' of Fig. 13.

[0056] FIG. 17 is a perspective view of a top cell frame according to one embodiment of the present invention.

[0057] Fig. 18 is a cross-sectional perspective view showing the appearance cut along the cutting line H-H' of Fig. 17.

[0058] Figure 19 is a front view of the top cell frame of Figure 18 as viewed from the front.

[0059] Fig. 20 is a cross-sectional view showing a cross-section taken along the cutting line I-I' of Fig. 17.

[0060] FIG. 21 is a cross-sectional view illustrating the relationship between an inlet distribution mechanism and battery cells according to one embodiment of the present invention.

[0061] FIG. 22 is a cross-sectional view showing the relationship between an outlet distribution mechanism and battery cells according to one embodiment of the present invention.

[0062] Figures 23 (a) and (b) are drawings illustrating various shapes of connecting holes according to embodiments of the present invention.

[0063] FIG. 24 is a partial perspective view showing an enlarged portion of a middle cell frame according to one embodiment of the present invention.

[0064] FIG. 25 is a cross-sectional view of a battery assembly according to one embodiment of the present invention.

[0065] FIG. 26 is a cross-sectional view of a battery assembly according to another embodiment of the present invention.

[0066] FIG. 27 is a cross-sectional view of a battery assembly according to another embodiment of the present invention.

[0067] FIGS. 28 and 29 are exploded perspective views of a battery pack according to one embodiment of the present invention.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, it means that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the direction opposite to gravity.

[0072] 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.

[0073] 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.

[0074] Fig. 1 is a perspective view illustrating a battery assembly according to one embodiment of the present invention. Fig. 2 is a plan view illustrating the battery assembly of Fig. 1 as viewed along the -z-axis direction in the xy plane. Fig. 3 is an exploded perspective view of the battery assembly of Fig. 1.

[0075] Referring to FIGS. 1 to 3, a battery assembly (100) according to one embodiment of the present invention includes a plurality of battery cells (110); and a cell frame (120) in which the battery cells (110) are accommodated. A cooling channel is provided within the cell frame (120) through which a coolant flows in direct contact with at least a portion of the battery cells (110). Specific details regarding the cooling channel will be described later.

[0076] The coolant is in direct contact with the battery cells (110) and circulates inside the cell frame (120). That is, the battery assembly (100) according to the present embodiment uses an immersion cooling method in which the coolant directly cools the battery cells. In the present invention, at least a portion of the battery cells (110) may be cooled by contacting the coolant. That is, in one embodiment, a portion of the outer surface of the battery cells (110) may be in contact with the coolant, and in another embodiment, the entire outer surface of the battery cells (110) may be in contact with the coolant.

[0077] The cell frame (120) may include an inlet port (121) through which coolant flowing through the cooling channel and directly contacting the battery cells (110) is introduced, and an outlet port (122) through which the coolant is discharged.

[0078]

[0079] Hereinafter, a battery cell (110) according to the present embodiment will first be described in detail. The battery cell (110) according to the present embodiment may be any type of secondary battery, such as a square, cylindrical, or pouch-shaped battery cell. However, as an example, a cylindrical battery cell (110) will be described below.

[0080] Figures 4(a) and 4(b) are perspective and side views, respectively, of a battery cell according to an embodiment of the present invention. Figure 5 is a cross-sectional view taken along the cutting line C-C' in Figure 4(a). Figure 6 is a cross-sectional view of a battery cell according to an embodiment of the present invention.

[0081] Referring to FIGS. 4 to 6, the battery cell (110) according to the present embodiments may be a cylindrical cell and may have a vent portion (110V). The vent portion (110V) refers to a member or device provided in the battery cell (110) to discharge venting gas or the like inside the battery cell (110). In addition, each battery cell (110) may be provided with a first electrode terminal (111) and a second electrode terminal (112) as positive and negative electrode terminals.

[0082] For example, the battery cell (110) according to the present embodiment may be a cylindrical battery cell. Specifically, the battery cell (110) may include an electrode assembly (10); a battery can (20) that houses the electrode assembly (10) and has an open top; and a cap assembly (30) that is coupled to the open top of the battery can (20). A gasket (50) may be interposed between the battery can (20) and the cap assembly (30). Hereinafter, an exemplary structure of the battery cell (110) will be described, but the battery cell of the present invention is not limited to this structure.

[0083] The battery can (20) according to the present embodiment may be a cylindrical case with an open top, and may store an electrode assembly (10) and an electrolyte (not shown) in an internal storage space, and may include a metal material such as aluminum (Al).

[0084] The cap assembly (30) according to the present embodiment may include a top cap (31) having a plate shape and a connecting plate (32) electrically and mechanically connected to the top cap (31). The top cap (31) may include a metal material having electrical conductivity and may cover an open upper portion of the battery can (20). The top cap (31) may be electrically connected to a first segment (11) connected to a first electrode of the electrode assembly (10), and at the same time, may be electrically insulated from the battery can (20) by a gasket (50). Therefore, the cap assembly (30) according to the present embodiment including the top cap (31) may function as a first electrode terminal (111), which is an external terminal of the first electrode included in the electrode assembly (10).

[0085] Specifically describing the electrical connection between the top cap (31) and the first segments (11), the battery cell (110) according to the present embodiment may further include a first current collector (41) positioned on the upper portion of the electrode assembly (10). The first current collector (41) may include a conductive metal material such as aluminum, copper, steel, nickel, etc., and may be electrically connected to the first segments (11) of the electrode assembly (10). The electrical connection may be made through welding. A lead (60) may be connected to the first current collector (41). The lead (60) may extend upward from the electrode assembly (10) and be coupled to the connection plate (32). In another embodiment, the lead (60) may be directly coupled to the lower surface of the top cap (31). The coupling between the lead (60) and other components may be made through welding. Additionally, the first collector plate (41) may be formed integrally with the lead (60). In this case, the lead (60) may have a long plate shape extending outward from near the center of the first collector plate (41).

[0086] The first collector plate (41) may have a plurality of radially formed protrusions (not shown) on its lower surface. When the radially formed protrusions are provided, the first collector plate (41) may be pressed to press the protrusions into the bent first segments (11). The connection between the first collector plate (41) and the first segments (11) may be performed by, for example, laser welding. The laser welding may be performed by partially melting the base material of the first collector plate (41). In a variation, the welding between the first collector plate (41) and the first segments (11) may be performed with solder interposed. In this case, the solder may have a lower melting point compared to the first collector plate (41) and the first segments (11). The laser welding may be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0087] Meanwhile, the battery cell (110) according to the present embodiment may further include a second current collector (42) positioned at the bottom of the electrode assembly (10). Specifically, the second current collector (42) may be positioned between the electrode assembly (10) and the bottom (20F) of the battery can (20). The second current collector (42) may include a conductive metal material such as aluminum, copper, steel, nickel, etc., and may be electrically connected to the second segments (12) of the electrode assembly (10). One side of the second current collector (42) may be coupled to the second segments (12), and the opposite side of the second current collector (42) may be coupled to the bottom (20F) of the battery can (20). Welding may be applied to the coupling of the second current collector (42). Accordingly, the battery can (20) according to the present embodiment can function as a second electrode terminal (112), which is an external terminal of the second electrode included in the electrode assembly (10).

[0088] Meanwhile, the secondary battery according to the present embodiment may include an insulating plate (70). The insulating plate (70) may cover the first collector plate (41). The insulating plate (70) may cover the first collector plate (41) on the upper surface of the first collector plate (41), thereby preventing the first collector plate (41) from contacting the battery can (20), particularly the beading part (20B) of the battery can (20) described later. In addition, the insulating plate (70) may be provided with a separate lead hole so that a lead (60) extending upward from the first collector plate (41) may be drawn out. The lead (60) may be drawn out upward through the lead hole of the insulating plate (70) and coupled to the lower surface of the connecting plate (32) or the lower surface of the top cap (31).

[0089] The peripheral area of ​​the insulating plate (70) can be interposed between the first current collector (41) and the beading portion (20B) of the battery can (20), thereby fixing the assembly of the electrode assembly (10) and the first current collector (41). Accordingly, the assembly of the electrode assembly (10) and the first current collector (41) can be restricted from moving in the axial direction of the electrode assembly (10), thereby improving the assembly stability of the secondary battery. The insulating plate (70) can be made of an insulating polymer resin. In one example, the insulating plate (70) can include one or more materials selected from the group consisting of polyethylene, polypropylene, polyimide, and polybutylene terephthalate.

[0090] Meanwhile, the battery can (20) according to the present embodiment may include a crimping part (20C) and a beading part (20B). The crimping part (20C) is a part of the battery can (20) that surrounds the cap assembly (30) and the gasket (50). Specifically, the battery can (20) and the cap assembly (30) may be crimped with the gasket (50) interposed therebetween. That is, the crimping may be applied to the connection between the battery can (20) and the cap assembly (30). Accordingly, the crimping part (20C) may be formed in the battery can (20). More specifically, the crimping is performed by positioning the gasket (50) between the battery can (20) and the cap assembly (30), and then bending the upper end of the battery can (20) in the direction in which the cap assembly (30) is positioned.

[0091] The beading portion (20B) refers to a portion of the battery can (20) that is recessed toward the center in a region above the electrode assembly (10) among the side portions of the battery can (20), and is for the stable placement of the cap assembly (30) and the prevention of movement of the electrode assembly (10). That is, the cap assembly (30) according to the present embodiment and the gasket (50) surrounding it can be seated on the beading portion (20B) of the battery can (20). The above-described crimping connection can be performed in a state where the cap assembly (30) and the gasket (50) surrounding it are seated on the beading portion (20B).

[0092] The gasket (50) according to the present embodiment is positioned between the battery can (20) and the cap assembly (30), and can enhance the sealing property of the secondary battery. In addition, the gasket (50) may include an electrically insulating material, and may prevent a short circuit from occurring between the battery can (20), which functions as a second electrode terminal (112), and the cap assembly (30), which functions as a first electrode terminal (111). The gasket (50) may include one or more materials selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and perfluoroalkoxy alkane (PFA).

[0093] The vent portion (110V) according to the present embodiment can be formed on the lower surface of the battery cell (110). That is, it can be formed on the bottom portion (20F, see FIG. 6) of the battery can (20).

[0094] When a thermal event or thermal runaway phenomenon occurs inside a battery cell (110), high-temperature venting gas or particles may be generated. The vent part (110V) is a general term for a member or mechanism that can discharge such high-temperature venting gas or particles. For example, a notch part (110N) that is relatively thinner than the adjacent area may be formed at the bottom of the battery can among the lower surfaces of the battery cell (110). The notch part (110N) may have a constant circumference. When the internal pressure of the battery cell (110) increases due to high-temperature venting gas generated inside the battery cell (110), the notch part (110N) that is weak in rigidity due to its thin thickness may be ruptured first. The vent part (110V) is opened due to the rupture of the notch part (110N), and high-temperature venting gas or particles can be discharged through the opened vent part (110V).

[0095] However, the structure of this vent part (110V) is an example, and there is no special limitation on the shape of the vent part (110V) as long as it is a member or device that can discharge internal venting gas in the event of a thermal event or thermal runaway.

[0096] Meanwhile, although not specifically illustrated, the battery cell according to the present invention may be a square battery cell in which the electrode assembly is housed in a square can. That is, although the battery cell according to the present embodiment is depicted in the drawing as being a cylindrical battery cell, this is only one example of the structure of the battery cell of the present invention, and the battery cell according to another embodiment of the present invention may be a square battery cell.

[0097] Within the cell frame (120), battery cells (110) can be arranged in rows and columns, and the battery cells (110) can be electrically connected to each other via bus bars, etc., which will be described later.

[0098] Fig. 7 is a partial perspective view of the battery assembly of Fig. 1. Fig. 8 is a cross-sectional view taken along the line A-A' of Fig. 2. Fig. 9 is an enlarged partial cross-sectional view of part "D" of Fig. 8. Fig. 10 is an enlarged partial cross-sectional view of part "E" of Fig. 8. Fig. 11 is a cross-sectional view taken along the line B-B' of Fig. 2.

[0099] Referring to FIGS. 1 to 3 and 7 to 11 together, as described above, the battery assembly (100) includes a cell frame (120) in which battery cells (110) are accommodated, and a cooling path (300) is provided inside the cell frame (120) through which a coolant (CL) flows in direct contact with at least a portion of the battery cells (110).

[0100] A coolant (CL) can be circulated inside a cell frame (120) while in direct contact with the battery cells (110). The cell frame (120) may include an inlet port (121) through which the coolant (CL) flows into the inside of the cell frame (120) and an outlet port (122) through which the coolant is discharged to the outside of the cell frame (120). The coolant (CL) introduced into the inlet port (121) may flow along the cooling channels (300) and then be discharged through the outlet port (122). That is, the coolant (CL) is introduced into the inside of the cell frame (120) through the inlet port (121), and the introduced coolant (CL) flows along the cooling channels (300) of the cell frame (120) and directly contacts the battery cells (110). Afterwards, the refrigerant (CL) can be discharged to the outside of the cell frame (120) through the outlet port (122).

[0101] According to the present embodiment, a cooling path (300) through which a refrigerant (CL) flows may be provided inside the cell frame (120). This cooling path (300) may have a multi-layer cooling structure, and the multi-layer cooling structure will be described below.

[0102] The cooling channel (300) includes a plurality of cooling channels (300a, 300b) arranged along the longitudinal direction of the battery cell (110) along which the battery cell (110) extends. The flow direction of the coolant (CL) in one of the plurality of cooling channels (300a, 300b) is opposite to the flow direction of the coolant (CL) in another of the plurality of cooling channels (300a, 300b). In addition, the directions in which the coolant (CL) flows in the plurality of cooling channels (300a, 300b) may be perpendicular to the longitudinal direction of the battery cell (110).

[0103] The longitudinal direction of the battery cell (110) in which the battery cell (110) extends refers to a direction parallel to the width direction of a portion of the battery cell (110) that extends relatively long. For example, as illustrated in FIGS. 9 to 11, the battery cell (110) extends longer in the z-axis direction than in the y-axis direction, wherein the longitudinal direction of the battery cell (110) corresponds to a direction parallel to the z-axis direction.

[0104] The longitudinal direction of the battery cell (110) according to the present embodiment may be the direction between one side of the battery cell (110) and the other side facing the one side. At least one of the electrode terminals (111, 112) of the battery cell (110) may be located on the one side of the battery cell (110). For example, as illustrated in FIGS. 9 to 11, the one side and the other side of the battery cell (110) may be the upper surface (110T) of the battery cell (110) and the lower surface (110B) of the battery cell (110), respectively. At least one of the electrode terminals (111, 112) of the battery cell (110) may be located on the upper surface (110T) of the battery cell (110). In FIGS. 9 to 11, it is illustrated that all of the electrode terminals (111, 112) of the battery cell (110) are located on the upper surface (110T) of the battery cell (110). As illustrated in FIGS. 9 to 11, the longitudinal direction of the battery cell (110) may be the direction between the upper surface (110T) of the battery cell (110) and the lower surface (110B) of the battery cell (110), and the longitudinal direction of the battery cell (110) may be a direction parallel to the z-axis direction.

[0105] As described above, the longitudinal direction of the battery cell (110) refers to a direction parallel to the width direction of a portion that extends relatively long in the battery cell (110), and a plurality of cooling channels (300a, 300b) are arranged along the longitudinal direction, which is the width direction of a portion that extends relatively long in the battery cell (110).

[0106] For example, the plurality of cooling channels (300a, 300b) may include a first cooling channel (300a) and a second cooling channel (300b). The first cooling channel (300a) and the second cooling channel (300b) may be arranged along the z-axis direction corresponding to the longitudinal direction of the battery cell (110). The first cooling channel (300a) may be positioned above the second cooling channel (300b) based on the z-axis direction, and the second cooling channel (300b) may be positioned below the first cooling channel (300a) based on the z-axis direction.

[0107] According to the present embodiment, the cooling channel (300) through which the coolant (CL) flows within the cell frame (120) may have a multi-layer cooling structure. Specifically, the first cooling channel (300a) and the second cooling channel (300b) may be sequentially positioned along the longitudinal direction of the battery cell (110). The multi-layer cooling structure of the cooling channel (300) mentioned in the present invention means that the cooling channels are implemented in layers that are distinct from each other based on the longitudinal direction of the battery cell (110).

[0108] With respect to a point of the battery cell (110) along the length direction of the battery cell (110), a portion of the battery cell (110) below that point can be immersed in a second cooling passage (300b), and a portion of the battery cell (110) above that point can be immersed in a first cooling passage (300a).

[0109] As described above, the flow direction of the refrigerant (CL) in one of the plurality of cooling channels (300a, 300b) and the flow direction of the refrigerant (CL) in another one of the plurality of cooling channels (300a, 300b) are opposite to each other. That is, the flow direction of the refrigerant (CL) in the first cooling channel (300a) and the flow direction of the refrigerant (CL) in the second cooling channel (300b) may be opposite to each other.

[0110] One of the plurality of cooling channels (300a, 300b) may be connected to the inlet port (121), and another of the plurality of cooling channels (300a, 300b) may be connected to the outlet port (122). For example, the second cooling channel (300b) may be connected to the inlet port (121), and the first cooling channel (300a) may be connected to the outlet port (122). In addition, as illustrated in FIG. 10, the cell frame (120) may include a connecting hole (123) connecting the plurality of cooling channels (300a, 300b). According to one embodiment, the connecting hole (123) may connect the first cooling channel (300a) and the second cooling channel (300b). The refrigerant (CL) may flow along the second cooling channel (300b) after being introduced through the inlet port (121). The refrigerant (CL) flowing along the second cooling channel (300b) can be introduced into the first cooling channel (300a) through the connection hole (123). The refrigerant (CL) flowing along the first cooling channel (300a) can be discharged to the outside of the cell frame (120) through the outlet port (122).

[0111] It is preferable that the first cooling channel (300a) and the second cooling channel (300b) are not connected to each other until the refrigerant (CL) reaches the connection hole (123). That is, the first cooling channel (300a) and the second cooling channel (300b) can be connected to each other only through the connection hole (123). The direction in which the refrigerant (CL) flows in the first cooling channel (300a) and the direction in which the refrigerant (CL) flows in the second cooling channel (300b) may be opposite to each other. For example, the refrigerant (CL) may flow along the +y-axis direction in the second cooling channel (300b) connected to the inlet port (121), and the refrigerant (CL) may flow along the -y-axis direction in the first cooling channel (300a) connected to the outlet port (122).

[0112] Meanwhile, although the cooling channel (300) is depicted in the drawing as a two-layer cooling structure including a first cooling channel (300a) and a second cooling channel (300b), there is no particular limitation on the number of cooling channels, and a cooling structure of three or more layers is also possible. That is, the cooling channel according to another embodiment of the present invention may further include a third cooling channel in addition to the first and second cooling channels along the longitudinal direction of the battery cell (110). In addition, the cooling channel may include a fourth cooling channel, if necessary.

[0113] Below, the reason why the cooling path (300) according to the present embodiment has a multi-layer cooling structure will be explained.

[0114] If the cooling channel is formed as a single layer and the coolant (CL) flows in only one direction, there will be a difference in the order in which the coolant (CL) comes into contact with the plurality of battery cells (110), and a cooling imbalance may occur among the battery cells (110). As a comparative example of the present invention, a single-layer cooling channel in which the coolant (CL) flows in only one direction can be considered. In this comparative example, the battery cell adjacent to the inlet port is in direct contact with the coolant (CL), so heat dissipation is good, but the battery cell adjacent to the outlet port is in contact with the coolant (CL) that has already been heated by the battery cells, so heat dissipation is not good. Therefore, a cooling imbalance occurs among the battery cells (110), which may lead to a deterioration in the performance of the entire battery assembly.

[0115] On the other hand, the present embodiment having a cooling channel (300) of a multi-layer cooling structure can significantly reduce the cooling difference between the battery cells (110). The key to the multi-layer cooling structure is to provide a time difference in the part of each battery cell (110) that comes into contact with the coolant (CL) through the multi-layer cooling structure in which the flow directions of the coolant (CL) are opposite to each other. Referring again to FIGS. 9 and 11, in the case of the battery cell (110, the battery cell located on the far left in FIGS. 9 and 11) closest to the inlet port (121) and the outlet port (122), the part of the battery cell (110) located in the second cooling channel (300b) comes into contact with the coolant (CL) first, and the part of the battery cell (110) located in the first cooling channel (300a) comes into contact with the coolant (CL) last. That is, in the case of the battery cell (110) closest to the inlet port (121) and the outlet port (122), one part of the battery cell (110) can be in contact with the coolant (CL) in the coldest state, and another part of the battery cell (110) can be in contact with the coolant (CL) in the hottest state. On the other hand, in the case of the battery cell (110, the battery cell located on the farthest right in FIG. 10) located farthest from the inlet port (121) and the outlet port (122) and closest to the connection hole (123), the part of the battery cell (110) located in the second cooling channel (300b) comes into contact with the coolant (CL) relatively late, but the coolant (CL) can immediately pass through the connection hole (123) and come into contact with the part of the battery cell (110) located in the first cooling channel (300a). That is, in the case of the battery cell (110) located closest to the connection hole (123), it can be interpreted that all parts of the battery cell (110) are in contact with the coolant (CL) at an intermediate temperature.

[0116] When considering one battery cell (110) as a standard, thermal equilibrium can be achieved through heat transfer between the portion contacting the first cooling channel (300a) and the portion contacting the second cooling channel (300b). In conclusion, the battery cell (110, the battery cell located on the far left in FIGS. 9 and 11) closest to the inlet port (121) and the outlet port (122) and the battery cell (110, the battery cell located on the far right in FIG. 10) located farthest from the inlet port (121) and the outlet port (122) and closest to the connection hole (123) can be cooled to a similar degree.

[0117] In this way, by implementing the cooling channel (300) of the multi-layer cooling structure, it is possible to create a difference in the order in which each part of the multiple battery cells (110) comes into contact with the coolant (CL). Therefore, the problem of cooling imbalance between the battery cells (110) can be solved, and the cooling difference between the battery cells can be minimized. When the temperature difference between the battery cells (110) is minimized, deterioration of a specific battery cell (110) due to a long-term charge / discharge cycle can be prevented, thereby extending the life of the battery assembly and the battery pack including the same, and ensuring safety. Meanwhile, as described above, in order to solve the cooling difference between the battery cells (110), a multi-layer cooling structure such as a three-layer or four-layer cooling structure can be provided in addition to the two-layer cooling structure in another embodiment of the present invention.

[0118] Meanwhile, based on the positions of the battery cells (110), the inlet port (121) and the outlet port (122) may be located on the same side, and the connection hole (123) may be located on the opposite side of where the inlet port (121) and the outlet port (122) are located. However, this is an exemplary structure, and the positions of the inlet port (121), the outlet port (122), and the connection hole (123) are not particularly limited.

[0119] Meanwhile, the cell frame (120) according to the present embodiment may include a separation part (120S) for implementing the cooling path (300) into a plurality of cooling paths (300a, 300b) arranged along the longitudinal direction of the battery cell (110). The cooling path (300) may be divided into a plurality of cooling paths (300a, 300b) by the separation part (120S) inside the cell frame (120).

[0120] The plurality of cooling channels (300a, 300b) are separated from each other by a separation part (120S), and the refrigerants (CL) do not mix with each other. As described above, the cooling channels (300a, 300b) can be connected to each other only through a connection hole (123). The connection hole (123) can be provided in the separation part (120S).

[0121] For example, the cell frame (120) may include a separation part (120S) that separates a first cooling passage (300a) and a second cooling passage (300b) and is positioned between the first cooling passage (300a) and the second cooling passage (300b). The first cooling passage (300a) and the second cooling passage (300b) are separated from each other by the separation part (120S) and can be connected to each other only through a connection hole (123).

[0122] There are no special restrictions on the shape, thickness, material, etc. of the separation part (120S), as long as it can distinguish multiple cooling channels (300a, 300b). For example, in FIGS. 9 to 11, the separation part (120S) is shown as being included in the middle cell frame (120b) of the cover cell frame (120ab) described later.

[0123] Meanwhile, the coolant (CL) according to the present embodiment may be a fluid as a cooling medium. Since the coolant (CL) directly contacts the battery cells (110) within the battery assembly (100), the coolant (CL) may be electrically insulating. The coolant (CL) may be a material having insulating properties. For example, the coolant (CL) may be insulating oil. However, in the case of the battery assembly (100) according to the present embodiment, since the coolant (CL) is prevented from leaking to the outside of the top cell frame (120a) described below, a general coolant may also be used as the coolant (CL).

[0124] Referring to FIGS. 1 to 3 and 7 to 11 together, the cell frame (120) may include a bottom cell frame (120c) on which battery cells (110) are mounted, and a cover cell frame (120ab) positioned on the bottom cell frame (120c). The cover cell frame (120ab) may include a top cell frame (120a) and a middle cell frame (120b).

[0125] A bottom cell frame (120c) and a cover cell frame (120ab) are assembled to form an internal space, and battery cells (110) can be positioned in the internal space formed by the bottom cell frame (120c) and the cover cell frame (120ab), and a coolant (CL) can also circulate along the internal space to form a cooling path (300).

[0126] The inlet port (121) and the outlet port (122) may be positioned on the same side of the cell frame (120), or may be positioned on opposite sides. That is, there is no particular limitation on the positions of the inlet port (121) and the outlet port (122) in the cell frame (120). The inlet port (121) and the outlet port (122) may be formed in the cover cell frame (120ab) among the cell frames (120).

[0127] Fig. 12 is a partial cross-sectional view showing an enlarged portion of a part of Fig. 9.

[0128] Referring to FIGS. 9 to 12 together, the area of ​​the area where at least one cooling channel (300) among the plurality of cooling channels (300) in which the flow direction of the coolant (CL) matches is in contact with the battery cell (110) may be 30% or more and 70% or less of the area of ​​the area where all of the plurality of cooling channels (300) are in contact with the battery cell (110). In addition, the area of ​​the area where at least one cooling channel (300) among the plurality of cooling channels (300) in which the flow direction of the coolant (CL) matches is in contact with the battery cell (110) may be 40% or more and 60% or less of the area of ​​the area where all of the plurality of cooling channels (300) are in contact with the battery cell (110).

[0129] If the area of ​​the contact area of ​​at least one cooling channel (300) among the plurality of cooling channels (300) in which the flow direction of the coolant (CL) matches the area of ​​the contact area with the battery cell (110) is less than 30% and more than 70% of the area of ​​the contact area of ​​all of the plurality of cooling channels (300) with the battery cell (110), the area of ​​the area of ​​the area in which a specific cooling channel (300) is in contact with the battery cell (110) may be excessively large or excessively small. In this case, the degree of cooling for the battery cells (110) may vary for each zone, which may cause a cooling imbalance between the battery cells (110). Ultimately, the cooling difference between the battery cells (110) within the battery assembly (100) may increase.

[0130] For example, the cooling path (300) illustrated in FIG. 12 may include a first cooling path (300a) and a second cooling path (300b), and the flow direction of the refrigerant in the first cooling path (300a) and the second cooling path (300b) is opposite to each other.

[0131] From the perspective of the first cooling channel (300a), among the plurality of cooling channels (300), the cooling channel (300) in which the flow direction of the refrigerant (CL) is the same is the first cooling channel (300a). Accordingly, the area (A1) of the first cooling channel (300a) in contact with the battery cell (110) may be 30% or more and 70% or less of the area (A1, A2) of the first cooling channel (300a) and the second cooling channel (300b), which are the entirety of the plurality of cooling channels (300), in contact with the battery cell (110).

[0132] From the perspective of the second cooling channel (300b), among the plurality of cooling channels (300), the cooling channel (300) in which the flow direction of the refrigerant (CL) matches is the second cooling channel (300b). Accordingly, the area (A2) of the second cooling channel (300b) in contact with the battery cell (110) may be 30% or more and 70% or less of the area (A1, A2) of the first cooling channel (300a) and the second cooling channel (300b), which are the entirety of the plurality of cooling channels (300), in contact with the battery cell (110).

[0133]

[0134] Referring again to FIGS. 9 to 12, the cell frame (120) may include a separation part (120S) for implementing the cooling path (300) as a plurality of cooling paths (300a, 300b) arranged along the longitudinal direction of the battery cell (110).

[0135] For example, the cell frame (120) may include a separation part (120S) that separates the first cooling passage (300a) and the second cooling passage (300b) and is positioned between the first cooling passage (300a) and the second cooling passage (300b).

[0136] Based on the longitudinal direction of the battery cell (110), the separation part (120S) may be positioned in the space between the 30% point (P1) of the height (H1) of the battery cell (110) and the 70% point (P2) of the height (H1) of the battery cell (110). The longitudinal direction of the battery cell (110) may be a direction parallel to the z-axis in the direction between the upper surface (110T) of the battery cell (110) and the lower surface (110B) of the battery cell (110). The height (H1) of the battery cell (110) may correspond to the length from the lower surface (110B) of the battery cell (110) to the upper surface (110T) of the battery cell (110). In Fig. 12, it is illustrated that a separation part (120S) provided in a middle cell frame (120b) described later is positioned in a space between a point (P1) at 30% of the height (H1) of the battery cell (110) and a point (P2) at 70% of the height (H1) of the battery cell (110).

[0137] If, based on the longitudinal direction of the battery cell (110), the separation part (120S) is located in a space other than between the 30% point (P1) of the height (H1) of the battery cell (110) and the 70% point (P2) of the height (H1) of the battery cell (110), the area of ​​the area where one of the plurality of cooling channels (300a, 300b) comes into contact with the battery cell (110) may be excessively large or excessively small. In this case, the degree of cooling for the battery cells (110) may vary for each area, which may cause a cooling imbalance between the battery cells (110). As a result, the cooling difference between the battery cells (110) within the battery assembly (100) may increase.

[0138]

[0139] Below, a distribution mechanism provided in a battery assembly according to one embodiment of the present invention is specifically described.

[0140] Fig. 13 is a perspective view of a middle cell frame according to an embodiment of the present invention. Fig. 14 is a cross-sectional perspective view taken along the line F-F' of Fig. 13. Fig. 15 is a front view of the middle cell frame of Fig. 14 as seen from the front. Fig. 16 is a cross-sectional view taken along the line G-G' of Fig. 13. Fig. 17 is a perspective view of a top cell frame according to an embodiment of the present invention. Fig. 18 is a cross-sectional perspective view taken along the line H-H' of Fig. 17. Fig. 19 is a front view of the top cell frame of Fig. 18 as seen from the front. Fig. 20 is a cross-sectional view taken along the line I-I' of Fig. 17.

[0141] Referring to FIGS. 1, 7, 9, 13 to 20, the cell frame (120) may include an inlet port (121) through which coolant (CL) flows into the interior of the cell frame (120) and an outlet port (122) through which the coolant (CL) is discharged to the exterior of the cell frame (120). In the battery assembly (100) according to the present embodiment, a distribution mechanism (200) for dividing the coolant (CL) into a plurality of cooling channels (CH) may be provided in at least one of the inlet port (121) or the outlet port (122). In one embodiment of the present invention, distribution mechanisms (200) may be provided in each of the inlet port (121) and the outlet port (122). In other embodiments of the present invention, the distribution mechanism (200) may be provided in either the inlet port (121) or the outlet port (122).

[0142] The distribution mechanism (200) may include a plurality of distribution holes (200H). The distribution mechanism (200) may include a partition wall (200W) in which a plurality of distribution holes (200H) are formed. The distribution holes (200H) may be arranged at predetermined intervals along the direction in which the partition wall (200W) extends (in a direction parallel to the x-axis).

[0143] The refrigerant (CL) introduced into the inlet port (121) can flow inside the cell frame (120) while being divided into a plurality of cooling channels (CH) through a distribution mechanism (200) provided in the inlet port (121). Specifically, the refrigerant (CL) introduced into the inlet port (121) can be distributed into a plurality of cooling channels (CH) while passing through the distribution holes (200H) of the distribution mechanism (200) provided in the inlet port (121).

[0144] The coolant (CL) distributed to the plurality of cooling channels (CH) may flow along the inside of the cell frame (120) and then pass through the distribution mechanism (200) provided in the outlet port (122), and finally be discharged to the outside of the cell frame (120) through the outlet port (122). Specifically, the coolant (CL) distributed to the cooling channels (CH) may flow while contacting the battery cells (110), and then pass through the distribution holes (200H) of the distribution mechanism (200) provided in the outlet port (122) and be discharged through the outlet port (122). The cooling path (300) may be in a state of being distributed to the cooling channels (CH).

[0145] As the battery assembly (100) becomes larger, the number of battery cells (110) included in it increases, and the number of components required for the battery assembly (100) increases, there is a problem that the flow rate of the coolant varies from area to area and the coolant flows unevenly overall when applying the immersion cooling method. In this case, since the degree to which each battery cell (110) is cooled by the coolant is different, a cooling difference occurs between the battery cells (110), which may lead to a decrease in the cooling efficiency of the entire battery assembly (100). A decrease in the cooling efficiency of the battery assembly may cause a decrease in the performance of the battery assembly and a safety issue.

[0146] In the present invention, by providing a distribution mechanism (200) that divides the coolant (CL) into a plurality of cooling channels (CH) in at least one of the inlet port (121) and the outlet port (122), it is intended to improve the cooling efficiency for the battery cells (110) inside the battery assembly (100). Specifically, the coolant (CL) introduced through the inlet port (121) does not directly enter the space where the battery cells (110) are located, but can be distributed through the distribution hole (200H) and then introduced into the space where the battery cells (110) are located. Since the coolant (CL) is distributed to the plurality of cooling channels (CH) through the distribution mechanism (200) and flows inside the battery assembly (100), the coolant (CL) can be uniformly distributed throughout the inside of the battery assembly (100) rather than being concentrated in only some of a large number of battery cells (110). Accordingly, a uniform flow of the coolant (CL) throughout the battery assembly (100) is enabled, and the flow rate of the coolant (CL) can be maintained at a constant level for each zone. This enables uniform cooling of the entire battery cells (110), thereby minimizing cooling variations between the battery cells (110), and improving cooling efficiency for the entire battery assembly (100).

[0147] The distribution mechanism (200) according to the present embodiment may include an inlet distribution mechanism (210) provided close to the inlet port (121) among the inlet port (121) and the outlet port (122). The distribution mechanism (200) may include an outlet distribution mechanism (220) provided close to the outlet port among the inlet port (121) and the outlet port (122). The inlet distribution mechanism (210) may correspond to the distribution mechanism (200) provided in the inlet port (121) described above, and the outlet distribution mechanism (220) may correspond to the distribution mechanism (200) provided in the outlet port (122) described above. 13 to 16 illustrate exemplary structures of the inlet distribution mechanism (210), and 17 to 20 illustrate exemplary structures of the outlet distribution mechanism (220).

[0148] Each of the inlet distribution mechanism (210) and the outlet distribution mechanism (220) may include a plurality of distribution holes (200H). Each of the inlet distribution mechanism (210) and the outlet distribution mechanism (220) may include a partition wall (200W) in which a plurality of distribution holes (200H) are formed.

[0149] Looking at the positions of the inlet distribution mechanism (210) and the outlet distribution mechanism (220), the inlet distribution mechanism (210) can be located between the inlet port (121) and the battery cells (110). The outlet distribution mechanism (220) can be located between the outlet port (122) and the battery cells (110). The refrigerant (CL) introduced into the inlet port (121) can flow inside the cell frame (120) while being divided into a plurality of cooling channels (CH) through the distribution holes (200H) of the inlet distribution mechanism (210). After flowing inside the cell frame (120) while the plurality of cooling channels (CH) come into contact with the battery cells (110), it passes through the distribution holes (200H) of the outlet distribution mechanism (220) and can finally be discharged to the outside of the cell frame (120) through the outlet port (122).

[0150] In the present embodiment, the inlet port (121) may be formed in the middle cell frame (120b) among the cell frames (120), and accordingly, the inlet distribution mechanism (210) may also be provided in the middle cell frame (120b). In addition, the outlet port (122) may be formed in the top cell frame (120a) among the cell frames (120), and accordingly, the outlet distribution mechanism (220) may also be formed in the top cell frame (120a). However, this is an exemplary structure, and there is no particular limitation on the positions of the inlet port (121), the outlet port (122), the inlet distribution mechanism (210), and the outlet distribution mechanism (220) within the cell frame (120). In another embodiment of the present invention, the middle cell frame (120b) and the top cell frame (120a) may be formed as one integral part, and even in that case, the inlet port (121), the outlet port (122), the inlet distribution mechanism (210), and the outlet distribution mechanism (220) may be positioned without any separate restrictions.

[0151]

[0152] While the inlet distribution mechanism (210) can distribute the refrigerant (CL) introduced through the inlet port (121) to a plurality of cooling channels (CH), the outlet distribution mechanism (220) does not perform the function of directly distributing the refrigerant (CL) to a plurality of cooling channels (CH).

[0153] However, if the outlet distribution mechanism (220) is not provided, the refrigerant (CL) divided into a plurality of cooling channels (CH) is discharged directly through the outlet port (122), but the refrigerant (CL) flowing around the battery cell (110) located at a certain distance from the outlet port (122) may stagnate and not flow, or a vortex may be formed so that the refrigerant (CL) cannot flow properly and lingers nearby. In this case, the refrigerant (CL) is ultimately not discharged properly through the outlet port (122), and a loss of refrigerant (CL) flow occurs, resulting in a problem of reduced cooling efficiency.

[0154] Accordingly, in one embodiment of the present invention, by providing an inlet distribution mechanism (210) in the inlet port (121) and an outlet distribution mechanism (220) in the outlet port (122), it is intended to prevent the problem of the refrigerant (CL) stagnating and not flowing or the formation of a vortex in the refrigerant (CL). Although the outlet distribution mechanism (220) does not directly distribute the refrigerant (CL) to a plurality of cooling channels (CH), it can minimize the flow loss of the refrigerant (CL) and increase the cooling efficiency by inducing the plurality of cooling channels (CH) to be smoothly discharged ultimately through the outlet port (122).

[0155] However, the outlet distribution mechanism (220) is not essential in the present invention, and not only a battery assembly equipped with both an inlet distribution mechanism (210) and an outlet distribution mechanism (220), but also a battery assembly equipped with only an inlet distribution mechanism (210) can be applied to the present invention.

[0156]

[0157] Meanwhile, referring again to FIGS. 8 to 11, in the case of the battery assembly (100) according to the present embodiment, since the immersion cooling method, which is direct cooling using a refrigerant (CL), is applied, a stable waterproof sealing structure is essential to prevent the refrigerant (CL) from leaking to the outside. If the refrigerant (CL) leaks to the outside of the cell frame (120) of the battery assembly (100), the amount of refrigerant (CL) inside the cell frame (120) may become insufficient and the refrigerant (CL) may not circulate properly, which may deteriorate the cooling performance. In addition, the leaked refrigerant (CL) may have a negative effect on electrical components other than the battery assembly (100). The cell frame (120) may be formed by assembling a cover cell frame (120ab) and a bottom cell frame (120c), and there is a risk that the refrigerant (CL) may leak through the gap between them. When the cover cell frame (120ab) and the bottom cell frame (120c) are assembled, a hooking connection between the groove and the rib can be formed. The hooking connection between the groove and the rib can prevent the refrigerant (CL) from leaking into the gap between the cover cell frame (120ab) and the bottom cell frame (120c). In addition, a hooking connection between the groove and the rib can also be formed between the top cell frame (120a) and the middle cell frame (120b) of the cover cell frame (120ab).

[0158] In the battery assembly (100) according to the present embodiment, the cell frame (120) must be able to withstand the internal pressure due to the circulation of the coolant (CL). The internal pressure due to the circulation of the coolant (CL) can increase to a considerable level due to the pressure required for the coolant (CL) to move from the inlet port (121) to the outlet port (122). If the cell frame (120) cannot withstand the internal pressure due to the circulation of the coolant (CL) and is deformed, the coolant (CL) can easily leak. Therefore, it is an important issue for the cell frame (120) to withstand the internal pressure due to the circulation of the coolant (CL). In the present embodiment, an anti-slip assembly structure can be implemented by a hooking joint in which the grooves and ribs are interlocked. Accordingly, the cell frame (120) can stably withstand the internal pressure due to the circulation of the coolant (CL).

[0159] According to the present embodiment, a waterproof adhesive (500) may be applied on the bottom cell frame (120c). At least a portion of the waterproof adhesive (500) may be positioned between the bottom cell frame (120c) and the cover cell frame (120ab). There is no particular limitation on the material of the waterproof adhesive (500) as long as it exhibits waterproof performance and has impact resistance, adhesiveness, and electrical insulation properties. For example, the waterproof adhesive (500) may include a two-component epoxy-based material in which a curing agent is mixed into the main body.

[0160] In the present invention, the waterproof adhesive (500) applied on the bottom cell frame (120c) is referred to as the third waterproof adhesive (500c). The first and second waterproof adhesives (500a, 500b) will be described later.

[0161] In addition, at least a portion of the third waterproof adhesive (500c) may be positioned between the bottom cell frame (120c) and the cover cell frame (120ab). The third waterproof adhesive (500c) may bond the bottom cell frame (120c) and the cover cell frame (120ab) to each other. In addition, at least a portion of the third waterproof adhesive (500c) may prevent the coolant (CL) from leaking into the gap between the bottom cell frame (120c) and the cover cell frame (120ab). In addition, the degree of bonding between the bottom cell frame (120c) and the cover cell frame (120ab) is improved due to the third waterproof adhesive (500c), so that the cell frame (120) can better withstand the internal pressure resulting from the circulation of the coolant (CL).

[0162] Meanwhile, according to the present embodiment, a waterproof sealing structure can be implemented by providing grooves and ribs and applying a waterproof adhesive (500). Therefore, waterproof foam tape, sealant, silicone rubber material components such as O-rings, etc. may not be required. Accordingly, the manufacturing process of the battery assembly (100) is greatly simplified and the cost is reduced. However, this is a description of one example, and additional sealing materials such as the aforementioned foam tape, sealant, O-rings, etc. may be provided in the battery assembly as needed.

[0163] Additionally, the third waterproof adhesive (500c) can stably fix the battery cells (110) on the bottom cell frame (120c).

[0164] Referring to FIGS. 4, 5, and 8 to 11 together, the third waterproof adhesive (500c) can cover the vent portion (110V) of the battery cell (110). As described above, the vent portion (110V) corresponds to a member or mechanism provided in the battery cell (110) to discharge venting gas, etc. inside the battery cell (110). The vent portion (110V) can be formed on the lower surface of the battery cell (110), and the third waterproof adhesive (500c) applied on the bottom cell frame (120c) can cover the vent portion (110V). In addition, the third waterproof adhesive (500c) can cover a portion of the side surface of the battery cell (110) adjacent to the lower surface of the battery cell (110).

[0165] When a thermal event or thermal runaway phenomenon occurs inside the battery cell (110), high-temperature venting gas or particles may be discharged through the open vent part (110V). Generally, when gas is emitted from the battery cell (110), pieces of electrode plates or active materials inside the battery cell (110) may be discharged to the outside in a high-temperature state, and these high-temperature particles may appear in the form of sparks. The high-temperature venting gas or particles discharged through the vent part (110V) may tear the bottom cell frame (120c) and be discharged to the outside of the bottom cell frame (120c). Although not specifically illustrated, the high-temperature venting gas or particles may be discharged to the outside through a separate venting channel provided below the bottom cell frame (120c).

[0166] Since the third waterproof adhesive (500c) covers the vent portion (110V) of the battery cell (110) and a portion of the side of the battery cell (110) adjacent to the lower surface of the battery cell (110), the vent portion (110V) is not exposed. Accordingly, even if a thermal runaway occurs due to an abnormality in one of the battery cells (110), high-temperature venting gas or particles are not transmitted to the surrounding battery cells (110), so there is no risk of chain ignition.

[0167] In addition, the venting path of the battery cell (110) and the coolant (CL) can be separated from each other by the third waterproof adhesive (500c). As described above, insulating oil can be applied to the coolant (CL). Since the insulating oil is an oil component, when it comes into contact with venting gas or particles, it can cause additional thermal runaway, ignition, or explosion. The third waterproof adhesive (500c) can cover the vent part (110V) so that the vent part (110V) is not exposed to the coolant (CL). The third waterproof adhesive (500c) can block the high-temperature venting gas and particles discharged from the vent part (110V) of the battery cell (110) from coming into contact with the coolant (CL), thereby preventing the thermal runaway of the battery cell (110) from leading to ignition or explosion of the entire battery assembly (100).

[0168] Referring to FIGS. 3, 4, and 8 to 11 together, a battery assembly (100) according to the present embodiment may include a busbar frame assembly (130). The busbar frame assembly may include a busbar frame on which busbars (131) are arranged. The busbar frame assembly may include at least one busbar (131) connected to an electrode terminal. In addition, the busbar frame assembly may include a printed circuit board. The printed circuit board is provided to sense voltage data or thermal data of battery cells (110). For example, the printed circuit board may be connected to the electrode terminals (111, 112) of the battery cells (110) or the busbar (131). Accordingly, the voltage data of each battery cell (110) may be sensed and transmitted to the outside. The busbar frame assembly (130) may electrically connect the battery cells (110) in a series or parallel manner.

[0169] The battery cell (110) may be provided with a first electrode terminal (111) and a second electrode terminal (112) as positive and negative electrode terminals. The first electrode terminal (111) and the second electrode terminal (112) of the battery cell (110) may be provided on the upper surface (110T) of the battery cell (110). However, the positions of the first electrode terminal (111) and the second electrode terminal (112) in the battery cell (110) may vary depending on the design and are not necessarily limited to the upper surface of the battery cell (110). Electrical connection between the battery cells (110) may be achieved by a bus bar (131) connecting the first electrode terminal (111) and the second electrode terminal (112). For example, a bus bar (131) can electrically connect a first electrode terminal (111) of one battery cell (110) to a second electrode terminal (112) of another battery cell (110). In this way, an HV (High voltage) connection between battery cells (110) can be implemented. An HV connection is a connection that serves as a power source to supply power that requires high voltage, and refers to an electrical connection between battery cells or an electrical connection between a battery pack and a device.

[0170]

[0171] Fig. 21 is a cross-sectional view illustrating the relationship between an inlet distribution mechanism and battery cells according to one embodiment of the present invention. Fig. 22 is a cross-sectional view illustrating the relationship between an outlet distribution mechanism and battery cells according to one embodiment of the present invention.

[0172] Referring to FIGS. 13 to 22 together, in the battery assembly (100) according to the present embodiment, the battery cells (110) may be arranged to have a plurality of rows (R1-R10). FIGS. 21 and 22 illustrate battery cells (110) arranged to form ten rows (R1-R10). The rows (R1-R10) in which the battery cells (110) are arranged may be sequentially positioned along a direction perpendicular to a direction in which the coolant (CL) flows. In addition, within each row (R1-R10), the battery cells (110) may be arranged along the direction in which the coolant (CL) flows. The direction in which the coolant (CL) flows is parallel to the y-axis, and each row (R1-R10) may be sequentially positioned along a direction parallel to the x-axis. Additionally, within one column (R1-R10), battery cells (110) can be positioned along a direction parallel to the y-axis.

[0173] Any one of the plurality of cooling channels (CH) divided by the distribution mechanism (200) may be arranged to correspond to any one of the rows (R1-R10) of the battery cells (110). Here, correspondence means that there is a portion where one of the cooling channels (CH) overlaps any one of the rows (R1-R10) of the battery cells (110), and the position of the cooling channel (CH) does not necessarily have to correspond to the center of any one of the rows (R1-R10) of the battery cells (110).

[0174] As illustrated in FIG. 21, the refrigerant flowing into the inlet port (121) is distributed to a plurality of cooling channels (CH) by a plurality of distribution holes (200H) provided in the partition wall (200W) in the inlet distribution mechanism (210), and any one of the plurality of cooling channels (CH) may correspond to any one of the rows (R1-R10) of the battery cells (110). As illustrated in FIG. 22, the plurality of cooling channels (CH) pass through a plurality of distribution holes (200H) provided in the partition wall (200W) in the outlet distribution mechanism (220), and then are discharged through the outlet port (122), and any one of the plurality of cooling channels (CH) may correspond to any one of the rows (R1-R10) of the battery cells (110).

[0175] Since the cooling channels (CH) distributed by the distribution mechanism (200) correspond to one of the rows (R1-R10) of the battery cells (110), the flow rate of the coolant (CL) can be uniformly distributed to each row (R1-R10) of the battery cells (110) and between them, rather than the coolant (CL) being concentrated on only some of the battery cells (110). This enables uniform cooling of the entire battery cells (110), thereby minimizing cooling deviations between the battery cells (110), and improving cooling efficiency of the entire battery assembly (100).

[0176]

[0177] Meanwhile, a plurality of cooling channels (CH) divided by the distribution mechanism (200) may correspond one-to-one to each row (R1-R10) of battery cells (110). The number of cooling channels (CH) may be the same as the number of each row (R1-R10) of battery cells (110), and one cooling channel (CH) may correspond to one row of battery cells (110). As described above, the meaning of correspondence here is that one of the cooling channels (CH) overlaps with one row (R1-R10) of battery cells (110), and the position of the cooling channel (CH) does not necessarily have to correspond to the center of one row (R1-R10) of battery cells (110). Distribution holes (200H) formed in the bulkhead (200W) may also correspond one-to-one to each row (R1-R10) of battery cells (110), and the number of distribution holes (200H) may be the same as the number of rows (R1-R10) of battery cells (110), and one distribution hole (200H) may correspond to one row of battery cells (110).

[0178] Referring to Fig. 21, it is shown that battery cells (110) form 10 rows (R1-R10), and each of the distribution holes (200H) of the inlet distribution mechanism (210) and the cooling channels (CH) formed thereby are provided in a number of 10. Referring to Fig. 22, it is shown that battery cells (110) form 10 rows (R1-R10), and each of the distribution holes (200H) of the outlet distribution mechanism (220) and the cooling channels (CH) flowing into them are provided in a number of 10.

[0179] By implementing the cooling channels (CH) so as to be one-to-one with each row (R1-R10) of the battery cells (110), the flow rate of the coolant (CL) can be uniformly distributed to each row (R1-R10) of the battery cells (110) and between them, rather than the coolant (CL) being concentrated in only some of the battery cells (110). Accordingly, a uniform flow of the coolant (CL) is enabled for all rows (R1-R10) of the battery cells (110), and the flow rate of the coolant (CL) in all rows (R1-R10) of the battery cells (110) can be maintained constant. This enables uniform cooling of all the battery cells (110), thereby minimizing cooling deviations between the battery cells (110), and improving cooling efficiency of the entire battery assembly (100).

[0180]

[0181] Figures 23 (a) and (b) are drawings illustrating various shapes of connecting holes according to embodiments of the present invention.

[0182] Referring to FIG. 10 and FIG. 23 together, the cell frame (120) may include a connecting hole (123) that connects a plurality of cooling channels (300). The connecting hole (123) may be in the form of a hole formed in a separation part (120S) of the cell frame (120).

[0183] As the battery assembly (100) becomes larger, the number of battery cells (110) included in it increases, and accordingly, the path through which the coolant (CL) flows becomes longer. That is, as the battery assembly (100) becomes larger, the length of the cooling conduit (300) through which the coolant (CL) flows may increase. As the length of the cooling conduit (300) increases, the difference in pressure for circulating the coolant (CL) may increase. In other words, the pressure for circulating the coolant (CL) decreases as it approaches the outlet port (122), so that the pressure drop of the coolant (CL) according to the section of the cooling conduit (300) increases. The speed of the coolant (CL) also slows as it approaches the outlet port (122). The pressure difference of the coolant (CL) according to the section of the cooling path (300) may cause cooling deviation between battery cells (110) and a decrease in cooling efficiency for the entire battery assembly (100).

[0184] To solve the above problem, the cooling channels (300) can be designed to be connected through hole-shaped connecting holes (123) formed in the separation part (120S) of the cell frame (120). Specifically, the hole-shaped connecting holes (123) are provided to utilize Bernoulli's theorem.

[0185] Bernoulli's principle is a law that quantitatively expresses the relationship between the velocity, pressure, and height of a fluid. It utilizes the property that the sum of a fluid's potential energy and kinetic energy is always constant. According to Bernoulli's principle, a fluid's velocity increases when it passes through a narrow passage and decreases when it passes through a wide passage.

[0186] The refrigerant (CL) passing through the hole-shaped connecting hole (123) formed in the separation part (120S) of the cell frame (120) to move between the cooling passages (300) corresponds to the refrigerant (CL) suddenly flowing into a narrow passage. According to Bernoulli's theorem, the speed of the refrigerant (CL) increases when it passes through the connecting hole (123). That is, when the refrigerant (CL) moves from the second cooling passage (300b) through the connecting hole (123) to the first cooling passage (300a), the speed increases, and accordingly, the speed of the refrigerant (CL) in the first cooling passage (300a) can be quickly maintained, and the pressure drop of the refrigerant (CL) can be optimized.

[0187] As illustrated in (a) of Fig. 23, in the case of the connecting hole (123a) according to one embodiment of the present invention, the width of the space through which the refrigerant (CL) flows may be constant. As illustrated in (b) of Fig. 23, in the case of the connecting hole (123b) according to another embodiment of the present invention, the width of the space through which the refrigerant (CL) flows may have a region (N1) in which the width of the space through which the refrigerant (CL) flows narrows. For example, the width of the space through which the refrigerant (CL) flows in the connecting hole (123b) may narrow and then widen again. In the case of the connecting hole (123b) having a region (N1) in which the width of the space through which the refrigerant (CL) flows narrows, the effect of increasing the flow rate according to Bernoulli's theorem can be further maximized.

[0188] Referring to FIG. 21 and FIG. 23 (b) together, in a connecting hole (123b) having a region (N1) where the width of the space where the coolant (CL) flows is narrowed, the difference in width (WD) between the widest part (W1) of the space where the coolant (CL) flows and the narrowest part (W2) of the space where the coolant (CL) flows may be 1.0 mm or more and 5 times or less the spacing (G1, see FIG. 21) between the battery cells (110). For example, as will be described later, the spacing (G1) between the battery cells (110) may be 1.5 mm or more and 2.5 mm or less. The difference in width (WD) may be 1.0 mm or more and 12.5 mm or less.

[0189] If the above width difference (WD) is less than 1.0 mm, the effect of increasing the flow rate obtained as the coolant (CL) passes through the connecting hole (123b) may be minimal. If the above width difference (WD) is more than 5 times the gap (G1) between the battery cells (110), the narrowest part (W2) of the space where the coolant (CL) flows may become too narrow, which may actually hinder the flow of the coolant (CL).

[0190]

[0191] FIG. 24 is a partial perspective view showing an enlarged portion of a middle cell frame according to one embodiment of the present invention.

[0192] Referring to FIGS. 10, 21, 22, and 24, the connecting holes (123) connecting the cooling channels (300) in the multi-layer cooling structure can correspond one-to-one with the cooling channels (CH) distributed by the distribution mechanism (200). Since the connecting holes (123) are arranged to correspond one-to-one with the cooling channels (CH), the cooling channels (CH) can be maintained in both the first cooling channel (300a) and the second cooling channel (300b). That is, while the refrigerant (CL) flows from the second cooling channel (300b) to the first cooling channel (300a), the plurality of cooling channels (CH) in the second cooling channel (300b) can be maintained as is in the first cooling channel (300a). For example, FIG. 24 illustrates that battery cells (110) are provided with 10 connecting holes (123) corresponding to the number of rows (R1-R10). The 10 connecting holes (123) may be provided in the middle cell frame (120b) of the cell frame (120).

[0193]

[0194] Referring again to FIG. 21, in a battery assembly according to an embodiment of the present invention, the gap (G1) between battery cells (110) may be 1.5 mm or more and 2.5 mm or less. This may be an optimal gap (G1) for circulating coolant. If the gap (G1) between battery cells (110) is less than 1.5 mm, the flow rate of the coolant relatively increases, but there may be a problem of reduced cooling efficiency and increased differential pressure. In addition, if the gap (G1) between battery cells (110) exceeds 2.5 mm, the flow rate of the coolant relatively decreases, but there may be a problem of reduced cooling efficiency.

[0195]

[0196] FIG. 25 is a cross-sectional view of a battery assembly according to one embodiment of the present invention.

[0197] Referring to FIG. 3, FIG. 13, FIG. 17, and FIG. 25 together, the cell frame (120) may include a bottom cell frame (120c) on which battery cells (110) are mounted, and a cover cell frame (120ab) positioned on the bottom cell frame (120c). A cooling conduit (300) may be provided in the space between the bottom cell frame (120c) and the cover cell frame (120ab).

[0198] The cover cell frame (120ab) may include a middle cell frame (120b) and a top cell frame (120a) positioned on the middle cell frame (120b). The top cell frame (120a) and the middle cell frame (120b) according to the present embodiment may be an exemplary structure for implementing a cooling channel (300) of a multi-layer cooling structure.

[0199] The space between the middle cell frame (120b) and the bottom cell frame (120c) and the space between the top cell frame (120a) and the middle cell frame (120b) may each correspond to cooling passages (300). For example, the space between the middle cell frame (120b) and the bottom cell frame (120c) may be a second cooling passage (300b), and the space between the top cell frame (120a) and the middle cell frame (120b) may be a first cooling passage (300a). The inlet port (121) may be provided in the middle cell frame (120b), and the outlet port (122) may be provided in the top cell frame (120a).

[0200] Each of the middle cell frame (120b) and the top cell frame (120a) may be a member including an upper surface portion (120aT, 120bT) and a side surface portion (120aS, 120bS) extending downward from the edge of the upper surface portion (120aT, 120bT). The middle cell frame (120b) may include an upper surface portion (120bT) and a side surface portion (120bS) extending downward from the edge of the upper surface portion (120bT). The top cell frame (120a) may include an upper surface portion (120aT) and a side surface portion (120aS) extending downward from the edge of the upper surface portion (120aT). For example, the space between the upper surface (120bT) and the side surface (120bS) of the middle cell frame (120b) and the bottom cell frame (120c) can become the second cooling passage (300b). Additionally, the space between the upper surface (120aT) and the side surface (120aS) of the top cell frame (120a) and the upper surface (120bT) of the middle cell frame (120b) can become the first cooling passage (300a).

[0201] In the present embodiment, the separation part (120S) of the cell frame (120) can be implemented by the middle cell frame (120b). In other words, the separation part (120S) can be included in the middle cell frame (120b).

[0202]

[0203] Meanwhile, the battery cells (110) according to the present embodiment may be fitted into the inside of a cell frame (120). For example, a plurality of holes (120h) may be formed inside the cell frame, and each of the battery cells (110) may be fixed inside the cell frame (120) by being fitted into the holes (120h).

[0204] For example, the plurality of holes (120h) of the cell frame (120) may include a top cell frame hole (120ah), a middle cell frame hole (120bh), and a bottom cell frame hole (120ch). The top cell frame hole (120ah) may be formed in the top cell frame (120a), the middle cell frame hole (120bh) may be formed in the middle cell frame (120b), and the bottom cell frame hole (120ch) may be formed in the bottom cell frame (120c).

[0205] The battery cell (110) may be mounted on the bottom cell frame (120c) while being mounted in the bottom cell frame hole (120ch, see FIG. 3). However, in another embodiment of the present invention, there is no separate bottom cell frame hole, and the battery cell (110) may be mounted and fixed on the bottom cell frame (120c) by a third waterproof adhesive (500c, see FIGS. 9 to 11) applied on the bottom cell frame (120c).

[0206] The battery cells (110) can be mounted and fixed to the middle cell frame (120b) by being inserted into the middle cell frame holes (120bh). In addition, the battery cells (110) can be mounted and fixed to the top cell frame (120a) by being inserted into the top cell frame holes (120ah).

[0207] Meanwhile, as described above, the waterproof adhesive (500) according to the present embodiment may include a third waterproof adhesive (500c) applied on the bottom cell frame (120c). In addition, the waterproof adhesive (500) may include a first waterproof adhesive (500a) applied on the top cell frame (120a). The first waterproof adhesive (500a) applied on the top cell frame (120a) may prevent the coolant (CL) from leaking beyond the top cell frame (120a) to the upper region of the top cell frame (120a). When the battery cell (110) is mounted in the top cell frame hole (120ah) of the top cell frame (120a), the first waterproof adhesive (500a) may be applied to the upper surface of the top cell frame (120a) and the upper region of the battery cell (110).

[0208] As described above, electrical connection between battery cells (110) can be made by a bus bar (131) connecting the first electrode terminal (111) and the second electrode terminal (112). The electrical connection by the bus bar (131) can be made at the upper part of the cell frame (120), i.e., the upper part of the top cell frame (120a). The bus bar (131) can be located at the upper part of the cell frame (120), i.e., the upper part of the top cell frame (120a).

[0209] At least a portion of the bus bar (131) may be surrounded by a first waterproof adhesive (500a). In addition, the space surrounding the bus bar (131) may be filled with the first waterproof adhesive (500a). In addition, the first electrode terminal (111) and the second electrode terminal (112) of the battery cell (110) may be surrounded by the first waterproof adhesive (500a). In addition, the gap between the top cell frame hole (120ah) and the battery cell (110) fitted therein may be filled with the first waterproof adhesive (500a). Due to the first waterproof adhesive (500a), the coolant (CL) may be prevented from leaking into the upper region of the cell frame (120). In the battery assembly (100), the waterproof and airtight structure at the top thereof may be implemented by the first waterproof adhesive (500a).

[0210] The refrigerant (CL) may be an insulating oil or a coolant. If the refrigerant (CL), which is a coolant, comes into contact with the HV connection, a short circuit may occur, which may cause a serious safety issue. Furthermore, even if the refrigerant (CL) is an insulating oil, if the refrigerant (CL) comes into contact with the electrical connection between the battery cells (110), it may adversely affect the electrical connection between the battery cells (110). Therefore, in the present embodiment, the first waterproof adhesive (500a) applied to the upper portion of the cell frame (120) can minimize the effect of the refrigerant (CL) on the electrical connection between the battery cells (110).

[0211] The waterproof adhesive (500) may include a second waterproof adhesive (500b) applied on the middle cell frame (120b). As described above, in the cooling channel (300) of the multi-layer cooling structure, it is preferable that the first cooling channel (300a) and the second cooling channel (300b) are not connected to each other until the coolant (CL) reaches the connection hole (123). That is, the first cooling channel (300a) and the second cooling channel (300b) can be connected to each other only through the connection hole (123). This is because it creates a difference in the order in which each part of the multiple battery cells (110) comes into contact with the coolant (CL), and reduces the cooling deviation of the battery cells. The second waterproof adhesive (500b) can prevent the refrigerant (CL) of the first cooling passage (300a) from moving to the second cooling passage (300b) or the refrigerant (CL) of the second cooling passage (300b) from moving to the first cooling passage (300a) except for the connecting hole (123). A waterproof and airtight structure between the first cooling passage (300a) and the second cooling passage (300b) except for the connecting hole (123) can be formed by the second waterproof adhesive (500b). The gap between the middle cell frame hole (120bh) and the battery cell (110) fitted therein can be filled with the second waterproof adhesive (500b).

[0212] Fig. 26 is a cross-sectional view of a battery assembly according to another embodiment of the present invention. However, in Fig. 26, the inlet port and outlet port are omitted.

[0213] Referring to FIG. 26, a battery assembly (100) according to another embodiment of the present invention includes a plurality of battery cells (110); and a cell frame (120) in which the battery cells (110) are accommodated, and a cooling conduit (300) is provided inside the cell frame (120) through which a coolant (CL) flows in direct contact with at least a portion of the battery cells (110), and the cooling conduit (300) includes a plurality of cooling conduits (300a, 300b) arranged along the longitudinal direction of the battery cells (110) along which the battery cells (110) extend. The longitudinal direction of the battery cells (110) may be the direction between the upper surface (110T) and the lower surface (110B) of the battery cells (110). The cooling conduits (300) may be connected through a connecting hole (123). This is the same as the structure of the battery assembly described above.

[0214] The cell frame (120) may include a bottom cell frame (120c) on which battery cells (110) are mounted, and a cover cell frame (120ab) positioned on the bottom cell frame (120c). The cover cell frame (120ab) may include a middle cell frame (120b) and a top cell frame (120a) positioned on the middle cell frame (120b). The top cell frame (120a) and the middle cell frame (120b) according to the present embodiment may be another exemplary structure for implementing a cooling channel (300) of a multi-layer cooling structure.

[0215] The middle cell frame (120b) may be a member including a middle portion (120bM), a first side portion (120bS1) extending upward from the edge of the middle portion (120bM), and a second side portion (120bS2) extending downward from the edge of the middle portion (120bM). In addition, the top cell frame (120a) may be a member having a plate shape.

[0216] The space between the middle cell frame (120b) and the bottom cell frame (120c) and the space between the top cell frame (120a) and the middle cell frame (120b) may each correspond to cooling channels (300). For example, the space between the middle portion (120bM) of the middle cell frame (120b) and the second side portion (120bS2) and the bottom cell frame (120c) may become the second cooling channel (300b). Additionally, the space between the middle portion (120bM) of the middle cell frame (120b) and the first side portion (120bS1) and the top cell frame (120a) may become the first cooling channel (300a).

[0217] In the present embodiment, the separation part (120S) of the cell frame (120) may be implemented by the middle cell frame (120b). In other words, the separation part (120S) may correspond to the middle part (120bM) of the middle cell frame (120b).

[0218] In the case of the cell frame (120) illustrated in FIG. 26, there is a difference from the cell frame (120) illustrated in FIG. 25 in that the middle cell frame (120b) includes a middle portion (120bM), a first side portion (120bS1), and a second side portion (120bS2). The cell frame (120) illustrated in FIG. 26 has an advantage in that, compared to the cell frame (120) illustrated in FIG. 25, the portion where refrigerant leakage may occur can be reduced by one. In the cell frame (120) illustrated in FIG. 26, there is no need to worry about refrigerant leakage because the portion between the first cooling channel (300a) and the second cooling channel (300b) is a portion of the middle cell frame (120b) that is integrally formed without a gap. On the other hand, the cell frame (120) illustrated in FIG. 25 may require a second waterproof adhesive (500b, see FIG. 9) to prevent refrigerant leakage between the first cooling passage (300a) and the second cooling passage (300b).

[0219] Meanwhile, referring again to FIG. 26, a busbar frame (132) on which a busbar connected to the electrode terminals of the battery cells (110) is mounted may be positioned below the top cell frame (120a). The busbar frame (132) may serve the function of supporting the busbar.

[0220]

[0221] FIG. 27 is a cross-sectional view of a battery assembly according to another embodiment of the present invention.

[0222] Referring to FIG. 27, a battery assembly (100) according to another embodiment of the present invention includes a plurality of battery cells (110); and a cell frame (120) in which the battery cells (110) are accommodated, and a cooling conduit (300) is provided inside the cell frame (120) through which a coolant (CL) flows in direct contact with at least a portion of the battery cells (110), and the cooling conduit (300) includes a plurality of cooling conduits (300) arranged along the longitudinal direction of the battery cells (110) along which the battery cells (110) extend. The longitudinal direction of the battery cells (110) may be the direction between the upper surface (110T) and the lower surface (110B) of the battery cells (110). The cooling conduits (300) may be connected through a connecting hole (123).

[0223] The cooling path (300) may include a first cooling path (300a), a second cooling path (300b), a third cooling path (300c), and a fourth cooling path (300d). That is, FIG. 27 illustrates a battery assembly with a four-layer cooling structure. As previously described, three or more cooling paths may be provided as needed.

[0224] The first cooling channel (300a) and the second cooling channel (300b) may have opposite flow directions of refrigerant (CL), and the third cooling channel (300c) and the fourth cooling channel (300d) may have opposite flow directions of refrigerant (CL). In addition, the first cooling channel (300a) and the fourth cooling channel (300d) may have the same flow direction of refrigerant (CL), and the second cooling channel (300b) and the third cooling channel (300c) may have the same flow direction of refrigerant (CL). The refrigerant flow directions of the first cooling channel (300a), the second cooling channel (300b), the third cooling channel (300c), and the fourth cooling channel (300d) may be freely set as needed.

[0225] As described above, the area of ​​the area where at least one cooling channel (300) among the plurality of cooling channels (300) in which the flow direction of the coolant (CL) matches is in contact with the battery cell (110) may be 30% or more and 70% or less of the area of ​​the area where all of the plurality of cooling channels (300) are in contact with the battery cell (110). Here, the area of ​​the area where at least one cooling channel (300) in which the flow direction of the coolant (CL) matches is in contact with the battery cell (110) may be the sum of the areas where the first cooling channel (300a) and the fourth cooling channel (300d) are in contact with the battery cell (110). Alternatively, the area of ​​the area where at least one cooling channel (300) having the same flow direction of the coolant (CL) comes into contact with the battery cell (110) may be the sum of the areas where the second cooling channel (300b) and the third cooling channel (300c) come into contact with the battery cell (110). In this case, the area of ​​the area where all of the plurality of cooling channels (300) come into contact with the battery cell (110) may mean the sum of the areas where the first cooling channel (300a), the second cooling channel (300b), the third cooling channel (300c), and the fourth cooling channel (300d) come into contact with the battery cell (110).

[0226]

[0227] Referring again to FIGS. 7, 9, and 11, the bottom cell frame (120c) and the cover cell frame (120ab) according to the present embodiment can be coupled by a bolt member (700). For example, the bottom cell frame (120c) and the cover cell frame (120ab) may each include a protruding portion that protrudes in a direction parallel to the xy plane, and the bottom cell frame (120c) and the cover cell frame (120ab) may be coupled to each other by a bolt member (700) that penetrates and fastens through all of the protruding portions of each other. In one embodiment, the bolt member (700) may be coupled to a separate nut member, and in another embodiment, the bolt member (700) may pass through one of the bottom cell frame (120c) and the cover cell frame (120ab) and then be screw-coupled to a fastening hole formed in the other of the bottom cell frame (120c) and the cover cell frame (120ab). Since the bottom cell frame (120c) and the cover cell frame (120ab) are connected by the bolt member (700), the fixing force between the bottom cell frame (120c) and the cover cell frame (120ab) is increased, and the refrigerant leakage between the bottom cell frame (120c) and the cover cell frame (120ab) is prevented, so that the sealing property can be improved.

[0228] In addition, the middle cell frame (120b) and the top cell frame (120a) may also be coupled by a bolt member (700). For example, the middle cell frame (120b) and the top cell frame (120a) may each include a protruding portion that protrudes in a direction parallel to the xy plane, and the middle cell frame (120b) and the top cell frame (120a) may be coupled to each other by a bolt member (700) that penetrates and fastens all of the protruding portions of each other. In one embodiment, the bolt member (700) may be coupled to a separate nut member, and in another embodiment, the bolt member (700) may pass through one of the middle cell frame (120b) and the top cell frame (120a) and then be screw-coupled to a fastening hole formed in the other of the middle cell frame (120b) and the top cell frame (120a). Since the middle cell frame (120b) and the top cell frame (120a) are connected by the bolt member (700), the fixing force between the middle cell frame (120b) and the top cell frame (120a) is increased, and refrigerant leakage between the middle cell frame (120b) and the top cell frame (120a) is prevented, so that the sealing property can be improved.

[0229]

[0230] Meanwhile, referring back to FIG. 1, the battery assembly (100) according to one embodiment of the present invention illustrated in FIG. 1 can be mounted directly on a vehicle or chassis. That is, in the case of the battery assembly (100) according to the present embodiment, the battery cells (110) can be mounted directly on a vehicle or chassis while being housed in a cell frame (120). The inlet port (121) and outlet port (122) of the cell frame (120) can be connected to a refrigerant circulation system within the vehicle.

[0231] FIGS. 28 and 29 are exploded perspective views of a battery pack according to one embodiment of the present invention.

[0232] Referring to FIGS. 1, 28, and 29, a battery pack (1000) according to another embodiment of the present invention may include at least one battery assembly (100); a pack frame (1100) that accommodates at least one battery assembly (100) and has one open side; and a pack cover (1200) that covers the open side of the pack frame (1100). FIGS. 28 and 29 illustrate, by way of example, three battery assemblies (100) accommodated in the pack frame (1100).

[0233] The pack frame (1100) may include a bottom portion (1110) and a side beam (1120). At least one battery assembly (100) may be placed on the bottom portion (1110). The side beam (1120) may extend along an edge of the bottom portion (1110) and in a direction perpendicular to one surface of the bottom portion (1110). An internal space having an open upper portion may be provided by the bottom portion (1110) and the side beam (1120), and the battery assembly (100) may be stored in this internal space. The pack cover (1200) may cover an upper surface of the battery assembly (100) mounted on the pack frame (1100).

[0234] Meanwhile, the battery pack (1000) according to the present embodiment may include a filling member (1300) foamed into the space within the pack frame (1100) and the pack cover (1200). The filling member (1300) according to the present embodiment may be a foamed member. The filling member (1300) may be a foamed member that is filled into the space within the pack frame (1100) and the pack cover (1200) and then foamed.

[0235] The filling member (1300) according to the present embodiment may be formed of a resin. For example, the filling members (1300) may be formed of a resin or the like. The filling member (1300) may include air pockets, and an adhesive may be provided in the air pockets. The filling member (1300) may be foam rubber, i.e., cellular or sponge. The filling member (1300) may include an air-filled matrix structure. The filling member (1300) may be based on, for example, silicone, polyurethane, or other organic materials.

[0236] The filling member (1300) can be, for example, applied onto a pack frame (1100) and foamed into a plate shape, or foamed using a spray. The filling member (1300) can include a foaming accelerator.

[0237] When the filling member (1300) comes into contact with other components, it can be combined with the other components and fixedly support them while being cured thereafter. Therefore, the adhesive strength between the components that the filling member (1300) comes into contact with can be strengthened. In the present embodiment, the adhesive strength between the pack frame (1100), the pack cover (1200), and the battery assemblies (100) can be strengthened by the filling member (1300). In addition, the filling member (1300) can absorb vibrations and shocks applied to the battery pack (1000), so that the components within the battery pack (1000) do not separate or come off, thereby improving the safety and mechanical reliability of the battery pack.

[0238] Meanwhile, the battery pack (1000) according to the present embodiment may include an inlet pipe (1400) connected to an inlet port (121) of the battery assembly (100) and an outlet pipe (1500) connected to an outlet port (122) of the battery assembly (100).

[0239] The inlet pipe (1400) and the discharge pipe (1500) may each pass through the side beam (1120) and be connected to the inlet port (121) and the outlet port (122) of the battery assembly (100). In addition, the inlet pipe (1400) and the discharge pipe (1500) may be connected to a refrigerant circulation system inside the vehicle. The refrigerant supplied by the refrigerant circulation system inside the vehicle passes through the inlet pipe (1400) and reaches the inlet port (121). The refrigerant circulated inside the battery assembly (100) and discharged through the outlet port (122) is returned to the refrigerant circulation system again through the discharge pipe (1500).

[0240] 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.

[0241] One or more battery 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.

[0242] The above battery 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, as well as ESS (Energy Storage Systems), but is not limited thereto. It can also be applied to various devices that utilize secondary batteries.

[0243] 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.

[0244] Description of the symbol

[0245] 100: Battery assembly

[0246] 110: Battery cell

[0247] 120: Cell Frame

[0248] 120ab: Cover cell frame

[0249] 120c: Bottom cell frame

[0250] 300: Cooling Euro

Claims

1. Multiple battery cells; and including a cell frame in which the above battery cells are stored, The inside of the above cell frame is provided with a cooling channel through which a coolant flows in direct contact with at least a portion of the battery cell, The cooling channel includes a plurality of cooling channels arranged along the longitudinal direction of the battery cell along which the battery cell extends, A battery assembly in which the flow direction of the coolant in one of the plurality of cooling channels and the flow direction of the coolant in another of the plurality of cooling channels are opposite to each other.

2. In paragraph 1, The above longitudinal direction is the direction between one side of the battery cell and the other side facing the one side, A battery assembly in which at least one of the electrode terminals of the battery cell is positioned on the one surface of the battery cell.

3. In paragraph 1, A battery assembly in which the cell frame includes an inlet port through which the coolant flows through the cooling channel and comes into direct contact with the battery cells, and an outlet port through which the coolant is discharged.

4. In paragraph 3, Any one of the plurality of cooling channels is connected to the inlet port, A battery assembly wherein another one of the plurality of said cooling channels is connected to the said outlet port.

5. In paragraph 3, A battery assembly in which the refrigerant introduced into the inlet port flows along the cooling channels and is then discharged through the outlet port.

6. In paragraph 1, A battery assembly wherein the area of ​​an area of ​​at least one of the plurality of cooling channels in which the flow direction of the coolant matches the area of ​​the contact area with the battery cell is 30% or more and 70% or less of the area of ​​an area of ​​the contact area of ​​all of the plurality of cooling channels with the battery cell.

7. In paragraph 1, The above cooling channels include a first cooling channel and a second cooling channel, A battery assembly in which the flow direction of the coolant in the first cooling passage and the flow direction of the coolant in the second cooling passage are opposite to each other.

8. In paragraph 7, A battery assembly wherein the cell frame includes a separation part that separates the first cooling channel and the second cooling channel and is positioned between the first cooling channel and the second cooling channel.

9. In paragraph 8, A battery assembly in which the separation part is located in a space between a point at 30% of the height of the battery cell and a point at 70% of the height of the battery cell, based on the longitudinal direction of the battery cell.

10. In paragraph 1, The above cell frame is a battery assembly including a connecting hole connecting a plurality of cooling channels.

11. In paragraph 10, A battery assembly in which the width of the space through which the coolant flows is constant in the above connecting hole.

12. In paragraph 10, The above connecting hole is a battery assembly having an area in which the width of the space through which the coolant flows is narrowed.

13. In paragraph 12, A battery assembly in which, in the above connection hole, the difference in width between the widest part of the space through which the coolant flows and the narrowest part of the space through which the coolant flows is 1.0 mm or more and less than 5 times the spacing between the battery cells.

14. In paragraph 10, The cell frame includes an inlet port and an outlet port through which the coolant flowing through the cooling channel and in direct contact with the battery cells is introduced and discharged, A distribution mechanism is provided in at least one of the inlet port or the outlet port to divide the refrigerant into a plurality of cooling channels, A battery assembly having a plurality of above-mentioned connecting holes, wherein the plurality of above-mentioned connecting holes correspond one-to-one to the above-mentioned cooling channels distributed by the above-mentioned distribution mechanism.

15. In paragraph 1, A battery assembly wherein the gap between the battery cells is 1.5 mm or more and 2.5 mm or less.

16. In paragraph 1, The above cell frame is a battery assembly including a bottom cell frame on which the battery cells are mounted and a cover cell frame positioned on the bottom cell frame.

17. In paragraph 16, The above cover cell frame includes a middle cell frame and a top cell frame positioned on the middle cell frame, A battery assembly in which the space between the middle cell frame and the bottom cell frame and the space between the top cell frame and the middle cell frame each correspond to the cooling channels.

18. In paragraph 17, A battery assembly in which each of the middle cell frame and the top cell frame is a member including an upper surface portion and a side portion extending downward from an edge of the upper surface portion.

19. In paragraph 17, The above middle cell frame is a member including a middle portion, a first side portion extending upward from an edge of the middle portion, and a second side portion extending downward from an edge of the middle portion. The above top cell frame is a battery assembly having a plate-shaped member.

20. In paragraph 1, A battery assembly in which the battery cells are mounted directly on a vehicle or chassis while being housed in the cell frame.

21. Battery assembly according to paragraph 1; A pack frame housing the above battery assembly and having one side open; and A battery pack comprising a pack cover covering an open side of the pack frame.

Images