Battery assembly and battery pack containing it

Abstract

A battery assembly according to one embodiment of the present invention includes a plurality of battery cells; and a cell frame in which the battery cells are housed. Inside the cell frame, there is a cooling channel through which the refrigerant 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 from which the battery cell extends. The flow direction of the refrigerant in at least one of the plurality of cooling channels is opposite to the flow direction of the refrigerant in at least one of the other of the plurality of cooling channels.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2024 - 0056163 filed on April 26, 2024 and Korean Patent Application No. 10 - 2024 - 0153476 filed on November 1, 2024, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference as part of this specification.

[0002] 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.

Background Art

[0003] Secondary batteries, which are highly applicable to a wide range of product groups and have electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electrical drive source. Such secondary batteries not only have the primary advantage of significantly reducing the use of fossil fuels but also are environmentally friendly in that they do not generate any by - products due to energy use and are widely used as an energy source for enhancing energy efficiency.

[0004] 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 is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells may be connected in series to form a battery pack. Alternatively, depending on the required charge and discharge capacity of the battery pack, multiple battery cells may be connected in parallel to form a battery pack. Thus, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge and discharge capacity.

[0005] On the other hand, when configuring a battery pack by connecting multiple battery cells in series or parallel, a battery module is first constructed by manufacturing a battery cell assembly containing multiple battery cells and housing it in a module case. Common methods include assembling one or more such battery modules and adding other components to them to form a battery pack, or arranging multiple battery cells within a pack frame and then adding other components to form a battery pack.

[0006] Because such battery cells are composed 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 numerous battery cells can accumulate in a confined space, potentially causing a rapid increase in temperature. In other words, while battery packs containing many battery cells can achieve high output, it is not easy to remove the heat generated from the battery cells during charging and discharging. If heat dissipation from the battery cells is not efficient, the battery cells will degrade more quickly, their lifespan will be shortened, and the risk of explosion or fire will increase.

[0007] Furthermore, in the case of vehicle battery packs, they are frequently exposed to direct sunlight and may be subjected to high-temperature conditions such as summer or desert regions. Also, because a large number of battery cells are densely arranged to increase the vehicle's driving range, flames or heat generated from one battery cell can easily spread to adjacent battery cells, potentially leading to the battery pack itself catching fire or exploding.

[0008] Traditionally, battery modules have utilized bottom cooling or side cooling methods, which involve attaching a heat sink to the module case of the battery module for cooling.

[0009] However, with this type of cooling system, heat generated from the battery cells is transferred to a heatsink on one side of the module case for cooling, and a heat transfer path cannot be easily provided on the other side of the module case. Therefore, there are limitations, such as a large temperature difference between one end and the other end of the battery cell assembly, or insufficient overall cooling efficiency. If the temperature difference is not resolved, safety and durability issues will arise for the battery module. Poor cooling efficiency can accelerate the degradation of battery cells, and if thermal runaway occurs in some battery cells, it may not be possible to respond quickly, potentially leading to thermal runaway propagation. This can lead to disasters such as fire and explosion of the battery module or the battery pack containing it, which can cause not only property damage but also safety issues.

[0010] To solve these problems, it has been proposed to use a method that directly cools the battery cells by filling the inside of the battery pack with cooling water or insulating oil, rather than relying on bottom cooling or side cooling. In other words, for the effective cooling of high-capacity battery packs, an immersion cooling method is used in which a refrigerant directly cools the battery cells inside the battery pack.

[0011] However, as battery assemblies and the battery packs they contain become larger, the number of battery cells increases, and the number of components required for the battery assembly and battery pack also increases. This can lead to differences in the degree to which different areas are cooled by the refrigerant, resulting in uneven cooling of all battery cells within the battery assembly and potentially reducing the overall cooling efficiency of the battery assembly. Since reduced cooling efficiency of the battery assembly can lead to decreased performance and safety issues, ensuring uniform cooling of all battery cells using immersion cooling is a critical development challenge. [Overview of the project] [Problems that the invention aims to solve]

[0012] The problem that the present invention aims to solve is to provide a battery assembly and a battery pack including the same that can eliminate cooling imbalances to battery cells and minimize deviations in the thermal resistance of battery cells.

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

[0014] A battery assembly according to one embodiment of the present invention includes a plurality of battery cells and a cell frame in which the battery cells are housed. Inside the cell frame are cooling channels through which a refrigerant flows in direct contact with at least a portion of the battery cells. The cooling channels include a plurality of cooling channels arranged along the longitudinal direction of the battery cells from which they extend. The direction of flow of the refrigerant in at least one of the plurality of cooling channels is opposite to the direction of flow of the refrigerant in at least one of the other of the plurality of cooling channels.

[0015] The aforementioned longitudinal direction may be the direction connecting one side of the battery cell with the other side facing that side. At least one of the electrode terminals of the battery cell may be located on the one side of the battery cell.

[0016] The cell frame may include an inlet port into which the refrigerant flows, which is in direct contact with the battery cell, and an outlet port into which the refrigerant is discharged.

[0017] At least one of the multiple cooling channels may be connected to the inlet port, and at least one of the other multiple cooling channels may be connected to the outlet port.

[0018] The refrigerant that flows in from the inlet port may flow along the cooling channel and then be discharged from the outlet port.

[0019] Of the plurality of cooling channels, the area in which at least one cooling channel whose refrigerant flow direction coincides with the battery cell may be 30% or more and 70% or less of the total area in contact with the battery cell of the plurality of cooling channels.

[0020] The cooling channel 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.

[0021] The cell frame may include a separation part that divides the first cooling channel and the second cooling channel and is positioned between the first cooling channel and the second cooling channel.

[0022] With respect to the length of the battery cell, the separation part may be positioned in a space ranging from 30% to 70% of the height of the battery cell.

[0023] The self-frame may include a connecting hole that connects a plurality of cooling channels.

[0024] In the connecting hole, the width of the space through which the refrigerant flows may be constant.

[0025] The connecting hole may have a region where the width of the space through which the refrigerant flows becomes narrower.

[0026] In the connecting hole, the difference in width between the portion where the width of the space through which the refrigerant flows is the widest and the portion where the width of the space through which the refrigerant flows is the narrowest may be 1.0 mm or more and 5 times or less the interval between the battery cells.

[0027] The self-frame may include an inlet port through which the refrigerant that directly contacts the battery cell flows in and an outlet port through which the refrigerant is discharged, and a distribution mechanism for distributing the refrigerant to a plurality of cooling channels may be provided in at least one of the inlet port or the outlet port. A plurality of the connecting holes are provided, and the plurality of connecting holes can correspond one-to-one with the cooling channels that receive the distribution by the distribution mechanism.

[0028] The interval between the battery cells may be 1.5 mm or more and 2.5 mm or less.

[0029] The self-frame may include a bottom self-frame on which the battery cell is seated and a cover self-frame disposed on the bottom self-frame.

[0030] The cover self-frame may include a middle self-frame and a top self-frame disposed on the middle self-frame. The space between the middle self-frame and the bottom self-frame and the space between the top self-frame and the middle self-frame each correspond to the cooling channel.

[0031] Each of the middle cell frame and the top cell frame may be a member that includes an upper surface portion and a side portion extending downward from the edge of the upper surface portion.

[0032] The middle cell frame may be a member including an intermediate portion, a first side portion extending upward from the edge of the intermediate portion, and a second side portion extending downward from the edge of the intermediate portion, and the top cell frame may be a plate-shaped member.

[0033] The battery cells may be mounted on the vehicle or chassis as they are, while housed in the cell frame.

[0034] A battery pack according to one embodiment of the present invention includes the battery assembly, a pack frame housing the battery assembly and having one side open, and a pack cover covering the open side of the pack frame. [Effects of the Invention]

[0035] According to an embodiment of the present invention, the cell frame is provided with multiple cooling channels arranged along the longitudinal direction of the battery cell, with the direction of refrigerant flow being opposite to each other. This minimizes the cooling deviation for all battery cells within the battery assembly, and thereby minimizes the deviation in thermal resistance for all battery cells.

[0036] Furthermore, even if the battery assembly and the battery pack containing it become larger, the degree to which each area is cooled by the refrigerant can be maintained uniformly.

[0037] Minimizing temperature differences between battery cells can prevent degradation of specific battery cells during long charge-discharge cycles, thereby extending the lifespan of the battery assembly and the battery pack containing it, and ensuring safety.

[0038] The effects of the present invention are not limited to those described above, and other effects not mentioned will be clearly understood by those skilled in the art from the claims. [Brief explanation of the drawing]

[0039] [Figure 1] This is a perspective view showing a battery assembly according to one embodiment of the present invention. [Figure 2] Figure 1 is a plan view showing the battery assembly as seen along the -z axis in the xy plane. [Figure 3] Figure 1 is an exploded perspective view of the battery assembly. [Figure 4] (a) and (b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention. [Figure 5] This is a cross-sectional view showing a section taken along the cutting line C-C' in Figure 4(a). [Figure 6] This is a cross-sectional view of a battery cell according to one embodiment of the present invention. [Figure 7] Figure 1 is a partial perspective view of the battery assembly. [Figure 8] This is a cross-sectional view showing a section cut along the cutting line A-A' in Figure 2. [Figure 9] This is a partial cross-sectional view showing an enlarged view of section "D" in Figure 8. [Figure 10] This is a partial cross-sectional view showing an enlarged view of the "E" portion in Figure 8. [Figure 11] This is a cross-sectional view showing a section cut along the cutting line B-B' in Figure 2. [Figure 12] This is a partial cross-sectional view showing an enlarged portion of Figure 9. [Figure 13] This is a perspective view of a middle cell frame according to one embodiment of the present invention. [Figure 14] Figure 13 is a cross-sectional perspective view showing the result of cutting along the cutting line F-F'. [Figure 15] Figure 14 is a front view showing the middle cell frame as seen from the front. [Figure 16]This is a cross-sectional view showing a section cut along the cutting line G-G' in Figure 13. [Figure 17] This is a perspective view of a top cell frame according to one embodiment of the present invention. [Figure 18] Figure 17 is a cross-sectional perspective view showing the result of cutting along the cutting line H-H'. [Figure 19] Figure 18 is a front view showing the top cell frame as seen from the front. [Figure 20] This is a cross-sectional view showing a section cut along the cutting line I-I' in Figure 17. [Figure 21] This is a cross-sectional view showing the relationship between an inlet distribution mechanism and a battery cell according to one embodiment of the present invention. [Figure 22] This is a cross-sectional view showing the relationship between an outlet distribution mechanism and a battery cell according to one embodiment of the present invention. [Figure 23] (a) and (b) are drawings showing various forms of connecting holes according to embodiments of the present invention. [Figure 24] This is a partial perspective view showing an enlarged portion of a middle cell frame according to one embodiment of the present invention. [Figure 25] This is a cross-sectional view of a battery assembly according to one embodiment of the present invention. [Figure 26] This is a cross-sectional view of a battery assembly according to another embodiment of the present invention. [Figure 27] This is a cross-sectional view of a battery assembly according to another embodiment of the present invention. [Figure 28] This is an exploded perspective view of a battery pack according to one embodiment of the present invention. [Figure 29] This is an exploded perspective view of a battery pack according to one embodiment of the present invention. [Modes for carrying out the invention]

[0040] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement it. The present invention can be embodied in various different forms and is not limited to the embodiments described herein.

[0041] To clearly explain the present invention, unnecessary parts have been omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

[0042] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrarily shown for illustrative purposes and are not necessarily limited to those shown in the present invention. In the drawings, the thicknesses of some layers and regions are shown enlarged to clearly represent them. Also, in the drawings, the thicknesses of some layers and regions are shown exaggerated for illustrative purposes.

[0043] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on top of" or "above" another part, this includes not only cases where it is "directly on top" of the other part, but also cases where there are other parts in between.

[0044] Conversely, when one part is "directly above" another part, it means that there is no other part in between. Also, being "above" or "on top of" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "on top of" in the opposite direction of gravity.

[0045] Furthermore, when a specification states that a part of it "includes" a certain component, unless otherwise specified, this means that it may include other components rather than excluding them.

[0046] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0047] Figure 1 is a perspective view showing a battery assembly according to one embodiment of the present invention. Figure 2 is a plan view showing the battery assembly of Figure 1 as seen along the -z axis in the xy plane. Figure 3 is an exploded perspective view of the battery assembly of Figure 1.

[0048] Referring to Figures 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 housed. Inside the cell frame 120, there is a cooling channel through which a refrigerant flows in direct contact with at least a portion of the battery cells 110. The specific details regarding the cooling channel will be described later.

[0049] The coolant is in direct contact with the battery cell 110 and circulates inside the cell frame 120. In other words, the battery assembly 100 according to this embodiment is subject to an immersion cooling method in which the coolant directly cools the battery cell. In the present invention, at least a portion of the battery cell 110 may be in contact with the coolant for cooling. That is, in one embodiment, a portion of the outer surface of the battery cell 110 can be in contact with the coolant, and in another embodiment, the entire outer surface of the battery cell 110 can be in contact with the coolant.

[0050] The cell frame 120 may include an inlet port 121 into which a coolant flows through the cooling channel and comes into direct contact with the battery cell 110, and an outlet port 122 into which the coolant is discharged.

[0051] First, the battery cell 110 according to this embodiment will be described in detail. The battery cell 110 according to this embodiment can be applied to any form of secondary battery, such as prismatic, cylindrical, or pouch-type battery cells. However, as an example, the cylindrical battery cell 110 will be described below.

[0052] Figures 4(a) and 4(b) are perspective and side views, respectively, of a battery cell according to one embodiment of the present invention. Figure 5 is a cross-sectional view showing the cross section obtained by cutting along the cutting line C-C' in Figure 4(a). Figure 6 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0053] Referring to Figures 4 to 6, the battery cell 110 in this embodiment may be a cylindrical cell and may have a vent section 110V. The vent section 110V is a general term for a member or mechanism provided in the battery cell 110 that can discharge vent gas and the like from inside the battery cell 110. In addition, each battery cell 110 may be equipped with a first electrode terminal 111 and a second electrode terminal 112 as positive and negative electrode terminals.

[0054] As an example, the battery cell 110 according to this 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 placed between the battery can 20 and the cap assembly 30. An exemplary structure of the battery cell 110 will be described below, but the battery cell of the present invention is not limited to such a structure.

[0055] The battery can 20 in this embodiment may be a cylindrical case with an open top, but it can accommodate the electrode assembly 10 and electrolyte (not shown) in its internal storage space and may contain a metallic material such as aluminum (Al).

[0056] The cap assembly 30 according to this embodiment may include a top cap 31 having a plate shape and a connecting plate 32 electrically and mechanically coupled to such top cap 31.

[0057] The top cap 31 comprises a conductive metal material and can cover the open top of the battery can 20. Such a top cap 31 may be electrically connected to the first segment 11 which is connected to the first electrode of the electrode assembly 10, and at the same time electrically insulated from the battery can 20 by a gasket 50. Thus, the cap assembly 30 according to this embodiment, including the top cap 31, can function as the first electrode terminal 111, which is the external terminal of the first electrode included in the electrode assembly 10.

[0058] To give a more specific explanation of the electrical connection between the top cap 31 and the first segment 11, the battery cell 110 according to this embodiment may further include a first current collector plate 41 provided on the upper part of the electrode assembly 10. The first current collector plate 41 may be made of a conductive metallic material such as aluminum, copper, steel, or nickel, and may be electrically connected to the first segment 11 of the electrode assembly 10. The electrical connection can be made by welding. Leads 60 are connected to such a first current collector plate 41. The leads 60 can extend upward from the electrode assembly 10 and be coupled to a coupling plate 32. In another embodiment, the leads 60 may be directly coupled to the lower surface of the top cap 31. The coupling between the leads 60 and other components can be made by welding. Alternatively, the first current collector plate 41 may be formed integrally with the leads 60. In this case, the leads 60 may have an elongated plate shape extending outward from near the center of the first current collector plate 41.

[0059] The first current collector plate 41 may be provided with a plurality of radially arranged protrusions (not shown) on its lower surface.

[0060] If radial irregularities are provided, the first current collector plate 41 may be pressed to press the irregularities into the curved first segmented piece 11. The joint between the first current collector plate 41 and the first segmented piece 11 can be performed, for example, by laser welding. Laser welding can be performed in a manner that partially melts the base material of the first current collector plate 41. As a modification, the welding between the first current collector plate 41 and the first segmented piece 11 can be performed with solder interposed. In this case, the solder may have a lower melting point compared to the first current collector plate 41 and the first segmented piece 11. Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0061] On the other hand, the battery cell 110 according to this embodiment may further include a second current collector plate 42 provided at the bottom of the electrode assembly 10. Specifically, the second current collector plate 42 may be positioned between the electrode assembly 10 and the bottom 20F of the battery can 20. The second current collector plate 42 may include a conductive metallic material such as aluminum, copper, steel, or nickel, and may be electrically connected to the second segment 12 of the electrode assembly 10. One side of the second current collector plate 42 may be coupled to the second segment 12, and the opposite side of the second current collector plate 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 plate 42. Thus, the battery can 20 according to this embodiment can function as a second electrode terminal 112, which is an external terminal of the second electrode included in the electrode assembly 10.

[0062] On the other hand, the secondary battery according to this embodiment may include an insulating plate 70. The insulating plate 70 can cover the first current collector plate 41. By covering the first current collector plate 41 with its upper surface, the insulating plate 70 can prevent the first current collector plate 41 from coming into contact with the battery can 20, in particular with the beading part 20B of the battery can 20, which will be described later. The insulating plate 70 may also have separate lead holes through which leads 60 extending upward from the first current collector plate 41 can be drawn out. The leads 60 may be drawn out upward through the lead holes in the insulating plate 70 and connected to the lower surface of the connecting plate 32 or the lower surface of the top cap 31.

[0063] The peripheral region of the insulating plate 70 is interposed between the first current collector plate 41 and the beading portion 20B of the battery can 20, and can fix the assembly of the electrode assembly 10 and the first current collector plate 41. Therefore, the assembly of the electrode assembly 10 and the first current collector plate 41 restricts the axial movement 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. For example, the insulating plate 70 may include one or more materials selected from the group consisting of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0064] On the other hand, the battery can 20 according to this 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 encloses the cap assembly 30 and the gasket 50. Specifically, the battery can 20 and the cap assembly 30 can be crimped and engaged with the gasket 50 in between. That is, crimp engagement can be applied to the connection between the battery can 20 and the cap assembly 30. Therefore, a crimping part 20C may be formed on the battery can 20. More specifically, after placing the gasket 50 between the battery can 20 and the cap assembly 30, crimp engagement is performed by bending one upper end of the battery can 20 in the direction in which the cap assembly 30 is positioned.

[0065] The beading portion 20B refers to a portion of the battery can 20's side surface, specifically the area above the electrode assembly 10, where a part of the battery can 20 is curved inward toward the center. This portion is intended for the stable placement of the cap assembly 30 and to prevent the electrode assembly 10 from moving. In other words, the cap assembly 30 and the gasket 50 surrounding it according to this embodiment can be fixed onto the beading portion 20B of the battery can 20. With the cap assembly 30 and the gasket 50 surrounding it fixed onto the beading portion 20B, the aforementioned crimping engagement can be performed.

[0066] The gasket 50 according to this embodiment is placed between the battery can 20 and the cap assembly 30, and can improve the sealing performance of the secondary battery. The gasket 50 may also contain an electrically insulating material, and can prevent short circuits from occurring between the battery can 20, which functions as the second electrode terminal 112, and the cap assembly 30, which functions as the first electrode terminal 111. Such a gasket 50 may contain one or more materials selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and perfluoroalkoxyalkane (PFA).

[0067] The vent portion 110V in this embodiment may be formed on the lower surface of the battery cell 110. That is, it may be formed on the bottom portion 20F of the battery can 20 (see Figure 6).

[0068] When a thermal event or thermal runaway occurs inside a single battery cell 110, high-temperature vent gases and particles may be generated. The vent section 110V is a general term for a component or mechanism that can discharge such high-temperature vent gases and particles. As an example, a notch section 110N can be formed on the underside of the battery cell 110, which is relatively thinner than the area adjacent to the bottom of the battery can. The notch section 110N can form a constant shape in the circumferential direction. If the internal pressure of the battery cell 110 increases due to the high-temperature vent gas generated inside a single battery cell 110, the notch section 110N, which is thin and therefore less rigid, may rupture first. The rupture of the notch section 110N may open the vent section 110V, and the high-temperature vent gases and particles may be discharged through this opened vent section 110V.

[0069] However, the structure of the vent section 110V is just one example, and the form of the vent section 110V is not particularly limited as long as it is a component or mechanism that can discharge the internal vent gas in the event of a thermal event or thermal runaway.

[0070] On the other hand, although not specifically shown, the battery cell according to the present invention may be a rectangular battery cell in which the electrode assembly is housed in a rectangular can. That is, although the battery cell according to this embodiment is shown in the drawings as a cylindrical battery cell, this is just one example of the structure of the battery cell according to the present invention, and the battery cell according to other embodiments of the present invention may be a rectangular battery cell.

[0071] Within the cell frame 120, the battery cells 110 may be arranged in columns and rows, and the battery cells 110 may be electrically connected to each other via a busbar or the like, as described later.

[0072] Figure 7 is a partial perspective view of the battery assembly in Figure 1. Figure 8 is a cross-sectional view showing a section cut along the cutting line A-A' in Figure 2. Figure 9 is a partial cross-sectional view showing an enlarged view of section "D" in Figure 8. Figure 10 is a partial cross-sectional view showing an enlarged view of section "E" in Figure 8. Figure 11 is a cross-sectional view showing a section cut along the cutting line B-B' in Figure 2.

[0073] Referring to Figures 1 to 3 and Figures 7 to 11, as described above, the battery assembly 100 includes a cell frame 120 in which the battery cells 110 are housed, and inside the cell frame 120 there is a cooling channel 300 in which a refrigerant (CL, Coolant) flows in direct contact with at least a portion of the battery cells 110.

[0074] The refrigerant CL can come into direct contact with the battery cell 110 and circulate inside the cell frame 120. The cell frame 120 may include an inlet port 121 into which the refrigerant CL flows into the cell frame 120 and an outlet port 122 into which the refrigerant is discharged to the outside of the cell frame 120. The refrigerant CL that flows into the inlet port 121 may flow along the cooling channel 300 and then be discharged to the outlet port 122. That is, the refrigerant CL flows into the cell frame 120 from the inlet port 121 and comes into direct contact with the battery cell 110 by flowing along the cooling channel 300 of the cell frame 120. Thereafter, the refrigerant CL may be discharged to the outside of the cell frame 120 from the outlet port 122.

[0075] In this embodiment, a cooling channel 300 through which the refrigerant CL flows may be provided inside the cell frame 120. Such a cooling channel 300 may be a multi-layer cooling structure, and a multi-layer cooling structure will be described below.

[0076] The cooling channel 300 includes a plurality of cooling channels 300a, 300b arranged along the longitudinal direction of the battery cell 110, from which the battery cell 110 extends. The flow direction of the refrigerant CL in one of the plurality of cooling channels 300a, 300b is opposite to the flow direction of the refrigerant CL in the other of the plurality of cooling channels 300a, 300b. In addition, the direction in which the refrigerant CL flows in the plurality of cooling channels 300a, 300b may be perpendicular to the longitudinal direction of the battery cell 110.

[0077] The length direction of the battery cell 110, to which the battery cell 110 extends, is parallel to the width direction of the relatively longer portion of the battery cell 110. For example, as shown in Figures 9 to 11, the battery cell 110 extends longer in the z-axis direction than in the y-axis direction, and in this case, the length direction of the battery cell 110 is parallel to the z-axis direction.

[0078] The longitudinal direction of the battery cell 110 in this embodiment may be the direction connecting one side of the battery cell 110 and the other side facing that side. At least one of the electrode terminals 111 and 112 of the battery cell 110 may be located on the one side of the battery cell 110. For example, as shown in Figures 9 to 11, the one side and the other side of the battery cell 110 may be the upper surface 110T and the lower surface 110B of the battery cell 110, respectively. At least one of the electrode terminals 111 and 112 of the battery cell 110 may be located on the upper surface 110T of the battery cell 110. In Figures 9 to 11, both electrode terminals 111 and 112 of the battery cell 110 are shown located on the upper surface 110T of the battery cell 110. As shown in Figures 9 to 11, the longitudinal direction of the battery cell 110 may be the direction connecting the upper surface 110T and the lower surface 110B of the battery cell 110. Thus, the longitudinal direction of the battery cell 110 may be parallel to the z-axis direction.

[0079] As described above, the longitudinal direction of the battery cell 110 refers to the direction parallel to the width direction of the relatively long portion of the battery cell 110, and the multiple cooling channels 300a and 300b are arranged along the longitudinal direction, which is the width direction of the relatively long portion of the battery cell 110.

[0080] As an example, the multiple 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 length direction of the battery cell 110. The first cooling channel 300a may be positioned above the second cooling channel 300b with respect to the z-axis direction, and the second cooling channel 300b may be positioned below the first cooling channel 300a with respect to the z-axis direction.

[0081] According to this embodiment, the cooling channel 300 through which the refrigerant CL flows inside 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 arranged sequentially along the longitudinal direction of the battery cell 110. The multi-layer cooling structure of the cooling channel 300 referred to in this invention means that a partitioned layered cooling channel is realized with respect to the longitudinal direction of the battery cell 110.

[0082] Using any one point along the length of the battery cell 110 as a reference, the portion of the battery cell 110 below that point can be immersed in the second cooling channel 300b, and the portion of the battery cell 110 above that point can be immersed in the first cooling channel 300a.

[0083] As described above, the flow direction of the refrigerant CL in one of the multiple cooling channels 300a and 300b is opposite to the flow direction of the refrigerant CL in the other of the multiple cooling channels 300a and 300b. 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.

[0084] One of the multiple cooling channels 300a, 300b may be connected to the inlet port 121, and the other of the multiple 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. Also, as shown in Figure 10, the cell frame 120 may include a connecting hole 123 that connects the multiple cooling channels 300a, 300b. In one embodiment, the connecting hole 123 can connect the first cooling channel 300a and the second cooling channel 300b. After the refrigerant CL flows in through the inlet port 121, it can flow along the second cooling channel 300b. The refrigerant CL that has flowed along the second cooling channel 300b can flow into the first cooling channel 300a via the connecting hole 123. The refrigerant CL that has flowed along the first cooling channel 300a may be discharged to the outside of the cell frame 120 via the outlet port 122.

[0085] It is preferable that the first cooling channel 300a and the second cooling channel 300b are not connected until the refrigerant CL reaches the connecting hole 123. That is, the first cooling channel 300a and the second cooling channel 300b may be connected only via the connecting 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. For example, in the second cooling channel 300b connected to the inlet port 121, the refrigerant CL may flow along the +y axis, and in the first cooling channel 300a connected to the outlet port 122, the refrigerant CL may flow along the -y axis.

[0086] On the other hand, although the drawings show the cooling channel 300 as a two-layer cooling structure including a first cooling channel 300a and a second cooling channel 300b, the number of cooling channels is not particularly limited, and cooling structures with three or more layers are also possible. That is, the cooling channel according to other embodiments 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. Furthermore, the cooling channel may also include a fourth cooling channel as needed.

[0087] The reason why the cooling channel 300 in this embodiment has a multi-layer cooling structure will be explained below.

[0088] If the cooling channel is formed as a single layer and the refrigerant CL flows in only one direction, differences will occur in the order in which the refrigerant CL contacts multiple battery cells 110, potentially leading to a cooling imbalance for each battery cell 110. As a comparative example of the present invention, a single-layer cooling channel in which the refrigerant CL flows in only one direction can be considered. In such a comparative example, battery cells adjacent to the inlet port come into direct contact with the refrigerant CL, resulting in good heat dissipation. However, battery cells adjacent to the outlet port come into contact with the refrigerant CL that has already been heated by the battery cell, resulting in poor heat dissipation. Consequently, a cooling imbalance occurs for each battery cell 110, which could lead to a decrease in the overall performance of the battery assembly.

[0089] On the other hand, this embodiment, which has a multi-layer cooling structure with cooling channels 300, can significantly reduce the cooling deviation between such battery cells 110. The characteristic of this multi-layer cooling structure is that, by having a multi-layer cooling structure in which the flow directions of the refrigerant CL are opposite to each other, a time difference is created in the parts of each battery cell 110 that come into contact with the refrigerant CL. Referring again to Figures 9 to 11, in the case of the battery cell 110 closest to the inlet port 121 and outlet port 122 (the battery cell located furthest to the left in Figures 9 and 11), the part of the battery cell 110 located in the second cooling channel 300b comes into contact with the refrigerant CL first, and the part of the battery cell 110 located in the first cooling channel 300a comes into contact with the refrigerant CL last. That is, in the case of the battery cell 110 closest to the inlet port 121 and outlet port 122, a part of the battery cell 110 comes into contact with the coldest refrigerant CL, while another part of the battery cell 110 comes into contact with the hottest refrigerant CL. On the other hand, in the case of the battery cell 110 located furthest from the inlet port 121 and outlet port 122 and closest to the connecting hole 123 (the battery cell located on the far right in Figure 10), the portion of the battery cell 110 located in the second cooling channel 300b comes into contact with the refrigerant CL relatively late, but this refrigerant CL can immediately pass through the connecting hole 123 and come into contact with the portion of the battery cell 110 located in the first cooling channel 300a. In other words, in the case of the battery cell 110 located closest to the connecting hole 123, it can be interpreted that all parts of the battery cell 110 come into contact with the refrigerant CL at an intermediate temperature.

[0090] When using one battery cell 110 as a reference, thermal equilibrium can be achieved through heat transfer in the portion in contact with the first cooling channel 300a and the portion in contact with the second cooling channel 300b. In conclusion, the battery cell 110 closest to the inlet port 121 and outlet port 122 (the battery cell located furthest to the left in Figures 9 and 11) and the battery cell 110 furthest from the inlet port 121 and outlet port 122 and closest to the connecting hole 123 (the battery cell located furthest to the right in Figure 10) can be cooled to a similar degree.

[0091] In this way, by realizing a multi-layer cooling structure with cooling channels 300, it is possible to create differences in the order in which each part of the various battery cells 110 come into contact with the coolant CL. Therefore, the problem of cooling imbalance between battery cells 110 can be solved, and the cooling deviation between battery cells can be minimized. Minimizing the temperature deviation between battery cells 110 prevents the degradation of specific battery cells 110 during long charge-discharge cycles, thereby extending the lifespan of the battery assembly and the battery pack containing it, and ensuring safety. On the other hand, as described above, in order to eliminate the cooling deviation between battery cells 110, in other embodiments of the present invention, a multi-layer cooling structure such as a 3-layer or 4-layer structure can be provided in addition to the 2-layer cooling structure.

[0092] On the other hand, with respect to the position of the battery cell 110, the inlet port 121 and outlet port 122 can be located on the same side of each other, and the connecting hole 123 can be located on the opposite side from where the inlet port 121 and outlet port 122 are located. However, this is just one example structure, and there are no particular restrictions on the positions of the inlet port 121, outlet port 122, and connecting hole 123.

[0093] On the other hand, the cell frame 120 according to this embodiment may include a separation part 120S for realizing the cooling channel 300 with a plurality of cooling channels 300a, 300b arranged along the longitudinal direction of the battery cell 110. Within the cell frame 120, the separation part 120S can separate the cooling channel 300 into a plurality of cooling channels 300a, 300b.

[0094] Multiple cooling channels 300a and 300b are separated by the separation part 120S, and the refrigerant CL does not mix. As described above, the cooling channels 300a and 300b may be connected to each other only through the connecting hole 123. The connecting hole 123 may be provided in the separation part 120S.

[0095] As an example, the cell frame 120 may include a separation part 120S that divides the first cooling channel 300a and the second cooling channel 300b and is positioned between the first cooling channel 300a and the second cooling channel 300b. The first cooling channel 300a and the second cooling channel 300b are separated by the separation part 120S and connected only via a connecting hole 123.

[0096] The separation part 120S is not particularly limited in shape, thickness, or material, as long as it can partition multiple cooling channels 300a and 300b. As an example, Figures 9 to 11 illustrate the separation part 120S as being included in the middle cell frame 120b of the cover cell frame 120ab, which will be described later.

[0097] On the other hand, the refrigerant CL in this embodiment may be a fluid as a cooling medium. Since the refrigerant CL is in direct contact with the battery cell 110 within the battery assembly 100, the refrigerant CL can be electrically insulated. The refrigerant CL may be an insulating material. For example, the refrigerant CL may be insulating oil. However, in the case of the battery assembly 100 according to this embodiment, general cooling water can also be used as the refrigerant CL because leakage of the refrigerant CL to the outside of the top cell frame 120a, which will be described later, is prevented.

[0098] Referring to Figures 1-3 and 7-11, the cell frame 120 may include a bottom cell frame 120c on which the battery cells 110 are mounted, and a cover cell frame 120ab positioned on top of the bottom cell frame 120c. The cover cell frame 120ab may include a top cell frame 120a and a middle cell frame 120b.

[0099] The bottom cell frame 120c and the cover cell frame 120ab are assembled to form an internal space, in which the battery cell 110 can be positioned, and the refrigerant CL can also circulate along the internal space to form a cooling channel 300.

[0100] The inlet port 121 and the outlet port 122 can be located on the same side of the cell frame 120 or on opposite sides of each other. In other words, there are no particular restrictions 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 on the cover cell frame 120ab of the cell frame 120.

[0101] Figure 12 is a partial cross-sectional view showing an enlarged portion of Figure 9.

[0102] Referring to Figures 9 to 12, the area in contact with the battery cell 110 of at least one cooling channel 300 among the multiple cooling channels 300, where the flow direction of the refrigerant CL coincides, may be 30% or more and 70% or less of the total area in contact with the battery cell 110 of the multiple cooling channels 300. Alternatively, the area in contact with the battery cell 110 of at least one cooling channel 300 among the multiple cooling channels 300, where the flow direction of the refrigerant CL coincides, may be 40% or more and 60% or less of the total area in contact with the battery cell 110 of the multiple cooling channels 300.

[0103] If, for any reason, at least one of the multiple cooling channels 300, whose flow direction of the refrigerant CL coincides, has a contact area with the battery cell 110 that is less than 30% but greater than 70% of the total contact area of ​​the multiple cooling channels 300 with the battery cell 110, then the area of ​​contact of a particular cooling channel 300 with the battery cell 110 may be too large or too small. In such a case, the degree of cooling to the battery cell 110 may vary from area to area, potentially leading to a cooling imbalance between the battery cells 110. Ultimately, this could increase the cooling deviation between the battery cells 110 within the battery assembly 100.

[0104] For example, the cooling channel 300 shown in Figure 12 may include a first cooling channel 300a and a second cooling channel 300b, where the flow direction of the refrigerant is opposite in the first cooling channel 300a and the second cooling channel 300b.

[0105] From the perspective of the first cooling channel 300a, among the multiple cooling channels 300, only the first cooling channel 300a has the same flow direction for the refrigerant CL. In contrast, the area A1 in which the first cooling channel 300a contacts the battery cell 110 may be 30% or more and 70% or less of the area A1 and A2 in which the first cooling channel 300a and the second cooling channel 300b contact the battery cell 110, which is the total area of ​​the multiple cooling channels 300.

[0106] From the perspective of the second cooling channel 300b, among the multiple cooling channels 300, the only cooling channel 300 in which the flow direction of the refrigerant CL coincides is the second cooling channel 300b. In contrast, the area A2 in which the second cooling channel 300b contacts the battery cell 110 may be 30% or more and 70% or less of the area A1 and A2 in which the first cooling channel 300a and the second cooling channel 300b contact the battery cell 110, which is the entire area of ​​the multiple cooling channels 300.

[0107] Referring again to Figures 9 to 12, the cell frame 120 may include a separation part 120S for realizing the cooling channel 300 with a plurality of cooling channels 300a, 300b arranged along the longitudinal direction of the battery cell 110.

[0108] As an example, the cell frame 120 may include a separation part 120S that divides the first cooling channel 300a and the second cooling channel 300b and is positioned between the first cooling channel 300a and the second cooling channel 300b.

[0109] Based on the length of the battery cell 110, the separation part 120S may be positioned in the space between 30% and 70% of the height H1 of the battery cell 110. The length of the battery cell 110 may be parallel to the z-axis in the direction connecting the top surface 110T and the bottom surface 110B of the battery cell 110. The height H1 of the battery cell 110 can correspond to the length from the bottom surface 110B to the top surface 110T of the battery cell 110. Figure 12 shows that the separation part 120S provided on the middle cell frame 120b, which will be described later, is positioned in the space between point P1, which is 30% of the height H1 of the battery cell 110, and point P2, which is 70% of the height H1 of the battery cell 110.

[0110] If, for any reason, the isolation part 120S is positioned in a space other than between point P1, which is 30% of the height H1 of the battery cell 110, and point P2, which is 70% of the height H1 of the battery cell 110, the area in which one of the multiple cooling channels 300a, 300b contacts the battery cell 110 may be too wide or too narrow. In such a case, the degree of cooling to the battery cell 110 may vary from area to area, which may result in a cooling imbalance between the battery cells 110. Ultimately, this may increase the cooling deviation between the battery cells 110 inside the battery assembly 100.

[0111] The following describes in detail a distribution mechanism provided in a battery assembly according to one embodiment of the present invention.

[0112] Figure 13 is a perspective view of a middle cell frame according to one embodiment of the present invention. Figure 14 is a cross-sectional perspective view showing the middle cell frame of Figure 13 cut along the cutting line F-F'. Figure 15 is a front view of the middle cell frame of Figure 14 as seen from the front. Figure 16 is a cross-sectional view showing the cross-section cut along the cutting line G-G' of Figure 13. Figure 17 is a perspective view of a top cell frame according to one embodiment of the present invention. Figure 18 is a cross-sectional perspective view showing the top cell frame of Figure 17 cut along the cutting line H-H'. Figure 19 is a front view of the top cell frame of Figure 18 as seen from the front. Figure 20 is a cross-sectional view showing the cross-section cut along the cutting line I-I' of Figure 17.

[0113] Referring to Figures 1, 7, 9, and 13-20, the cell frame 120 may include an inlet port 121 through which the refrigerant CL flows into the cell frame 120 and an outlet port 122 through which the refrigerant CL is discharged to the outside of the cell frame 120. In the battery assembly 100 according to this embodiment, a distribution mechanism 200 for distributing the refrigerant CL to a plurality of cooling channels CH may be provided at least one of the inlet port 121 or the outlet port 122. In one embodiment of the present invention, the distribution mechanism 200 may be provided at both the inlet port 121 and the outlet port 122. In another embodiment of the present invention, the distribution mechanism 200 can be provided at either the inlet port 121 or the outlet port 122.

[0114] The distribution mechanism 200 may include a plurality of distribution holes 200H. The distribution mechanism 200 may also include a partition wall 200W in which a plurality of distribution holes 200H are formed. The distribution holes 200H may be spaced apart at predetermined intervals along the direction in which the partition wall 200W extends (a direction parallel to the x-axis).

[0115] The refrigerant CL that flows into the inlet port 121 can flow inside the cell frame 120 after being distributed to multiple cooling channels CH by a distribution mechanism 200 provided in the inlet port 121. Specifically, the refrigerant CL that flows into the inlet port 121 may pass through the distribution hole 200H of the distribution mechanism 200 provided in the inlet port 121 and be distributed to multiple cooling channels CH.

[0116] The refrigerant CL distributed to the multiple cooling channels CH may flow along the inside of the cell frame 120, 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 via the outlet port 122. Specifically, the refrigerant CL distributed to the cooling channels CH may flow in contact with the battery cells 110, then pass through the distribution holes 200H of the distribution mechanism 200 provided in the outlet port 122, and be discharged via the outlet port 122. The cooling flow path 300 may be in a state where it is distributed to the cooling channels CH.

[0117] As the battery assembly 100 increases in size, the number of battery cells 110 it contains also increases, and the number of components required for the battery assembly 100 increases. When applying the immersion cooling method, there is a problem in that the refrigerant flow rate deviation occurs in different areas, resulting in uneven refrigerant flow overall. In this case, the degree to which each battery cell 110 is cooled by the refrigerant differs, resulting in cooling deviations between battery cells 110, which can lead to a decrease in the overall cooling efficiency of the battery assembly 100. A decrease in the cooling efficiency of the battery assembly may cause a decrease in the performance and safety of the battery assembly.

[0118] In this invention, the cooling efficiency for battery cells 110 inside the battery assembly 100 is improved by providing a distribution mechanism 200 in at least one of the inlet port 121 or outlet port 122 that distributes refrigerant CL to a plurality of cooling channels CH. Specifically, refrigerant CL flowing in from the inlet port 121 does not immediately enter the space where the battery cells 110 are located, but is distributed via the distribution hole 200H before entering the space where the battery cells 110 are located. Because the refrigerant CL is distributed to a plurality of cooling channels CH via the distribution mechanism 200 and flows inside the battery assembly 100, the refrigerant CL does not concentrate in only a portion of the many battery cells 110, but rather the flow rate of refrigerant CL can be uniformly distributed throughout the battery assembly 100. Therefore, the flow of refrigerant CL becomes uniform throughout the battery assembly 100, and the flow velocity of refrigerant CL can be maintained constant in each area. This enables uniform cooling of the entire battery cell 110, minimizes cooling deviations between the battery cells 110, and improves the overall cooling efficiency of the battery assembly 100.

[0119] The distribution mechanism 200 according to this embodiment may include an inlet distribution mechanism 210 provided in close proximity to the inlet port 121, of the inlet port 121 and the outlet port 122. The distribution mechanism 200 may also include an outlet distribution mechanism 220 provided in close proximity to the outlet port, of the inlet port 121 and the outlet port 122. The inlet distribution mechanism 210 may correspond to the distribution mechanism 200 provided at the inlet port 121 as described above, and the outlet distribution mechanism 220 may correspond to the distribution mechanism 200 provided at the outlet port 122 as described above. Figures 13 to 16 illustrate an exemplary structure of the inlet distribution mechanism 210, and Figures 17 to 20 illustrate an exemplary structure of the outlet distribution mechanism 220.

[0120] 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.

[0121] Regarding the positions of the inlet distribution mechanism 210 and the outlet distribution mechanism 220, the inlet distribution mechanism 210 may be located between the inlet port 121 and the battery cell 110. The outlet distribution mechanism 220 may be located between the outlet port 122 and the battery cell 110. The refrigerant CL that flows into the inlet port 121 can flow inside the cell frame 120 after being divided into multiple cooling channels CH via the distribution hole 200H of the inlet distribution mechanism 210. The multiple cooling channels CH may come into contact with the battery cell 110, flow inside the cell frame 120, then pass through the distribution hole 200H of the outlet distribution mechanism 220, and finally be discharged to the outside of the cell frame 120 via the outlet port 122.

[0122] In this embodiment, the inlet port 121 may be formed on the middle cell frame 120b of the cell frame 120, and consequently, the inlet distribution mechanism 210 may also be provided on the middle cell frame 120b. The outlet port 122 may be formed on the top cell frame 120a of the cell frame 120, and consequently, the outlet distribution mechanism 220 may also be formed on the top cell frame 120a. However, this is an exemplary structure, and there are no particular restrictions on the positions of the inlet port 121, outlet port 122, inlet distribution mechanism 210, and outlet distribution mechanism 220 within the cell frame 120. In other embodiments of the present invention, the middle cell frame 120b and the top cell frame 120a may be a single part formed integrally, and in that case as well, the inlet port 121, outlet port 122, inlet distribution mechanism 210, and outlet distribution mechanism 220 may be arranged without further restrictions.

[0123] While the inlet distribution mechanism 210 can distribute the refrigerant CL that has flowed in through the inlet port 121 to multiple cooling channels CH, the outlet distribution mechanism 220 does not perform the function of directly distributing the refrigerant CL to multiple cooling channels CH.

[0124] However, if the outlet distribution mechanism 220 is not provided, the refrigerant CL, which has been divided into multiple cooling channels CH, will be directly discharged through the outlet port 122. However, the refrigerant CL flowing around the battery cell 110, which is located at a certain distance from the outlet port 122, may stagnate and not flow, or vortices may occur, preventing the refrigerant CL from flowing properly and causing it to accumulate nearby. In this case, the refrigerant CL will ultimately not be able to be properly discharged through the outlet port 122, resulting in a loss of refrigerant CL flow and a decrease in cooling efficiency.

[0125] In contrast, in one embodiment of the present invention, in addition to providing an inlet distribution mechanism 210 at the inlet port 121, an outlet distribution mechanism 220 is provided at the outlet port 122 to prevent problems such as stagnation and failure of the refrigerant CL to flow or the formation of vortices in the refrigerant CL. The outlet distribution mechanism 220 does not perform the function of directly distributing the refrigerant CL to multiple cooling channels CH, but by guiding the refrigerant CL from the multiple cooling channels CH so that it is ultimately discharged smoothly through the outlet port 122, the flow loss of the refrigerant CL can be minimized and the cooling efficiency can be increased.

[0126] However, the outlet distribution mechanism 220 is not essential in the present invention, and the present invention can be applied not only to battery assemblies that are equipped with both the inlet distribution mechanism 210 and the outlet distribution mechanism 220, but also to battery assemblies that are equipped with only the inlet distribution mechanism 210.

[0127] On the other hand, referring again to Figures 8 to 11, in the case of the battery assembly 100 according to this embodiment, since the immersion cooling method, which is direct cooling using refrigerant CL, is applied, a stable waterproof sealed structure is essential to prevent refrigerant CL from leaking to the outside. If 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 will be insufficient, and the circulation of refrigerant CL will not be smooth, which may reduce the cooling performance. In addition, the leaked refrigerant CL may adversely affect other electrical components other than the battery assembly 100. The cell frame 120 may be in a form in which a cover cell frame 120ab and a bottom cell frame 120c are assembled, and there is a risk of refrigerant CL leaking from the gap between them. When the cover cell frame 120ab and the bottom cell frame 120c are assembled, the grooves and ribs can be engaged. The engagement of the grooves and ribs can prevent refrigerant CL from leaking from the gap between the cover cell frame 120ab and the bottom cell frame 120c. Furthermore, the grooves and ribs can also engage between the top cell frame 120a and the middle cell frame 120b of the cover cell frame 120ab.

[0128] In the battery assembly 100 according to this embodiment, the cell frame 120 must be able to withstand the internal pressure associated with the circulation of refrigerant CL inside. The internal pressure associated with the circulation of refrigerant CL can increase to a considerable level due to the pressure required for the refrigerant CL to move from the inlet port 121 to the outlet port 122. If the cell frame 120 deforms because it cannot withstand the internal pressure associated with the circulation of refrigerant CL, the refrigerant CL may easily leak. Therefore, it is important that the cell frame 120 can withstand the internal pressure associated with the circulation of refrigerant CL. In this embodiment, a sliding prevention assembly structure can be realized by an engagement in which the grooves and ribs are joined so as to intersect. Therefore, the cell frame 120 can stably withstand the internal pressure associated with the circulation of refrigerant CL.

[0129] According to this embodiment, a waterproof adhesive 500 can be applied to the bottom cell frame 120c. At least a portion of the waterproof adhesive 500 may be placed between the bottom cell frame 120c and the cover cell frame 120ab. The material of the waterproof adhesive 500 is not particularly limited, as long as it exhibits waterproof performance and has impact resistance, adhesion, and electrical insulation properties. As an example, the waterproof adhesive 500 may include a two-component epoxy-based material in which a curing agent is mixed with the main component.

[0130] In this invention, the waterproof adhesive 500 applied to the bottom cell frame 120c refers to the third waterproof adhesive 500c. The first and second waterproof adhesives 500a and 500b will be described later.

[0131] Furthermore, at least a portion of the third waterproof adhesive 500c may be placed 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 together. In addition, at least a portion of the third waterproof adhesive 500c can prevent the refrigerant CL from leaking through the gap between the bottom cell frame 120c and the cover cell frame 120ab. Moreover, the third waterproof adhesive 500c improves the degree of bonding between the bottom cell frame 120c and the cover cell frame 120ab, allowing the cell frame 120 to withstand the internal pressure associated with the circulation of the refrigerant CL more effectively.

[0132] On the other hand, according to this embodiment, a water-resistant sealed structure can be achieved by providing grooves and ribs and applying waterproof adhesive 500. Therefore, components made of silicone rubber material, such as waterproof foam tape, sealant, and O-rings, are not required. Consequently, the manufacturing process of the battery assembly 100 is very simple, and costs are reduced. However, this is just one example, and additional sealing members such as the foam tape, sealant, and O-rings mentioned above can be provided to the battery assembly as needed.

[0133] Furthermore, the third waterproof adhesive 500c can stably fix the battery cell 110 onto the bottom cell frame 120c.

[0134] Referring to Figures 4, 5, and 8-11, 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 component or mechanism provided in the battery cell 110 that allows vent gas and the like to be discharged from inside the battery cell 110. The vent portion 110V may 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 such a vent portion 110V. In addition, the third waterproof adhesive 500c can cover a portion of the side surface of the battery cell 110 that is adjacent to the lower surface of the battery cell 110.

[0135] When a thermal event or thermal runaway occurs inside the battery cell 110, high-temperature vent gas and particles may be discharged through the open vent section 110V. Generally, when gas is ejected from the battery cell 110, electrode plate pieces and active material pieces inside the battery cell 110 may be discharged to the outside in a heated state, but such high-temperature particles may appear in the form of sparks or other forms. The high-temperature vent gas and particles discharged through the vent section 110V may tear the bottom cell frame 120c and be discharged to the outside of the bottom cell frame 120c. Although not specifically shown in the figures, the high-temperature vent gas and particles may also be discharged to the outside through a separate vent channel provided below the bottom cell frame 120c.

[0136] The third waterproof adhesive 500c covers the vent portion 110V of the battery cell 110 and a portion of the side surface of the battery cell 110 adjacent to the bottom surface of the battery cell 110, so the vent portion 110V is not exposed. Therefore, even if thermal runaway occurs due to an abnormality in one of the battery cells 110, high-temperature vent gas and particles are not transmitted to the surrounding battery cells 110, and the battery cell is not vulnerable to chain ignition.

[0137] Furthermore, the vent path of the battery cell 110 and the refrigerant CL can be separated by the third waterproof adhesive 500c. As mentioned above, insulating oil can be applied to the refrigerant CL. Since insulating oil is an oil component, it may cause additional thermal runaway, ignition, or explosion when it comes into contact with vent gas or particles. The third waterproof adhesive 500c can cover the vent section 110V so that it is not exposed to the refrigerant CL. The third waterproof adhesive 500c blocks the high-temperature vent gas and particles discharged from the vent section 110V of the battery cell 110 from coming into contact with the refrigerant CL, thereby preventing thermal runaway of the battery cell 110 from leading to ignition or explosion of the entire battery assembly 100.

[0138] Referring to Figures 3, 4, and 8-11, the battery assembly 100 according to this embodiment may include a busbar frame assembly 130. The busbar frame assembly may include a busbar frame on which the busbars 131 are arranged. The busbar frame assembly may include at least one busbar 131 connected to the electrode terminals. The busbar frame assembly may also include a printed circuit board. The printed circuit board is provided to sense voltage data and thermal data of the battery cells 110. For example, the printed circuit board may be connected to the electrode terminals 111, 112 and the busbars 131 of the battery cells 110. Thus, the voltage data of each battery cell 110 can be sensed and transmitted to the outside. The busbar frame assembly 130 can electrically connect the battery cells 110 in series or parallel.

[0139] The battery cell 110 may be equipped with a first electrode terminal 111 and a second electrode terminal 112 as positive and negative electrode terminals. These first and second electrode terminals 111 and 112 of the battery cell 110 may be located on the upper surface 110T of the battery cell 110. However, the positions of the first and second electrode terminals 111 and 112 in the battery cell 110 can 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 can be achieved by a busbar 131 connecting the first electrode terminal 111 and the second electrode terminal 112. For example, the busbar 131 can electrically connect the first electrode terminal 111 of one battery cell 110 to the second electrode terminal 112 of another battery cell 110. In this configuration, a high-voltage (HV) connection between the battery cells 110 can be achieved. HV connection refers to connections that act as a power source to supply power requiring high voltage, such as electrical connections between battery cells or electrical connections between battery packs and devices.

[0140] Figure 21 is a cross-sectional view illustrating the relationship between an inlet distribution mechanism and a battery cell according to one embodiment of the present invention. Figure 22 is a cross-sectional view illustrating the relationship between an outlet distribution mechanism and a battery cell according to one embodiment of the present invention.

[0141] Referring to Figures 13 to 22, in the battery assembly 100 according to this embodiment, the battery cells 110 may be arranged to have multiple rows R1 to R10. Figures 21 and 22 illustrate how the battery cells 110 are arranged to form 10 rows R1 to R10. The rows R1 to R10 in which the battery cells 110 are arranged may be sequentially located along a direction perpendicular to the direction in which the refrigerant CL flows. Within each row R1 to R10, the battery cells 110 may be arranged along the direction in which the refrigerant CL flows. The direction in which the refrigerant CL flows is parallel to the y-axis, and each row R1 to R10 may be sequentially located along a direction parallel to the x-axis. Within a single row R1 to R10, the battery cells 110 may be located along a direction parallel to the y-axis.

[0142] Any one of the multiple cooling channels CH that receive distribution from the distribution mechanism 200 can be provided so as to correspond to any one of the rows R1 to R10 of the battery cell 110. Here, "correspond" means that there is a portion in which one of the cooling channels CH overlaps with any one of the rows R1 to R10 of the battery cell 110, and the position of the cooling channel CH does not necessarily have to be in the center of any one of the rows R1 to R10 of the battery cell 110.

[0143] As shown in Figure 21, the refrigerant flowing into the inlet port 121 is distributed to multiple cooling channels CH by multiple distribution holes 200H provided in the partition wall 200W in the inlet distribution mechanism 210, and any one of the multiple cooling channels CH can correspond to any one of the rows R1 to R10 of the battery cell 110. As shown in Figure 22, after the multiple cooling channels CH pass through multiple distribution holes 200H provided in the partition wall 200W in the outlet distribution mechanism 220, they are discharged through the outlet port 122, and any one of the multiple cooling channels CH can correspond to any one of the rows R1 to R10 of the battery cell 110.

[0144] Since the cooling channels CH distributed by the distribution mechanism 200 correspond to one of each row R1 to R10 of the battery cell 110, the refrigerant CL is not concentrated in only a portion of the battery cell 110, but rather the flow rate of refrigerant CL can be uniformly distributed to each row R1 to R10 and the spaces between them. This enables uniform cooling of the entire battery cell 110, minimizes cooling deviations between the battery cells 110, and improves the cooling efficiency of the entire battery assembly 100.

[0145] On the other hand, the multiple cooling channels CH distributed by the distribution mechanism 200 can correspond one-to-one with each row R1 to R10 of the battery cell 110. The number of cooling channels CH may be the same as the number of rows R1 to R10 of the battery cell 110, and one cooling channel CH can correspond to one row of the battery cell 110. As described above, "correspond" here means that there is a portion in which one of the cooling channels CH overlaps with one of the rows R1 to R10 of the battery cell 110, and the position of the cooling channel CH does not necessarily have to be at the center of one of the rows R1 to R10 of the battery cell 110. The distribution holes 200H formed in the partition wall 200W can also correspond one-to-one with each row R1 to R10 of the battery cell 110, and the number of distribution holes 200H may be the same as the number of rows R1 to R10 of the battery cell 110, and one distribution hole 200H can correspond to one row of the battery cell 110.

[0146] Referring to Figure 21, it is shown that the battery cells 110 form 10 rows R1 to R10, providing 10 distribution holes 200H of the inlet distribution mechanism 210 and 10 cooling channels CH formed thereon. Referring to Figure 22, it is shown that the battery cells 110 form 10 rows R1 to R10, providing 10 distribution holes 200H of the outlet distribution mechanism 220 and 10 cooling channels CH into which the water flows.

[0147] By creating a cooling channel CH that corresponds one-to-one with each row R1-R10 of the battery cell 110, the flow rate of refrigerant CL can be uniformly distributed to each row R1-R10 and the spaces between them, rather than being concentrated in only a portion of the battery cell 110. Therefore, the flow of refrigerant CL becomes uniform across all rows R1-R10 of the battery cell 110, and the flow velocity of refrigerant CL in all rows R1-R10 of the battery cell 110 can be maintained at a constant level. This enables uniform cooling of the entire battery cell 110, minimizes cooling deviations between battery cells 110, and increases the overall cooling efficiency of the battery assembly 100.

[0148] Figures 23(a) and 23(b) are diagrams illustrating various forms of connecting holes according to embodiments of the present invention.

[0149] Referring to both Figures 10 and 23, the cell frame 120 may include connecting holes 123 that connect a plurality of cooling channels 300. The connecting holes 123 may be in the form of holes formed in the separation part 120S of the cell frame 120.

[0150] As the battery assembly 100 increases in size, the number of battery cells 110 it contains increases, and accordingly, the path through which the refrigerant CL flows becomes longer. In other words, as the battery assembly 100 increases in size, the length of the cooling channel 300 through which the refrigerant CL flows can increase. The longer the cooling channel 300, the greater the pressure difference circulating the refrigerant CL can become. That is, the pressure circulating the refrigerant CL decreases as it approaches the outlet port 122, and the pressure drop of the refrigerant CL in each section of the cooling channel 300 becomes larger. The velocity of the refrigerant CL also slows down as it approaches the outlet port 122. Such pressure differences in the refrigerant CL in each section of the cooling channel 300 may cause cooling deviations between the battery cells 110 and a decrease in the overall cooling efficiency of the battery assembly 100.

[0151] To solve this problem, the cooling channel 300 can be designed to be connected via a hole-shaped connecting hole 123 formed in the separation part 120S of the cell frame 120. Specifically, a hole-shaped connecting hole 123 is provided to utilize Bernoulli's theorem.

[0152] Bernoulli's theorem is a law that quantitatively describes the relationship between fluid velocity, pressure, and height, utilizing the property that the sum of a fluid's potential and kinetic energy is always constant. According to Bernoulli's theorem, the velocity of a fluid increases when passing through a narrow passage and decreases when passing through a wide passage.

[0153] As the refrigerant CL moves between the cooling channels 300, passing through the hole-shaped connecting hole 123 formed in the separation part 120S of the cell frame 120 is equivalent to the refrigerant CL suddenly flowing into a narrow passage. According to Bernoulli's theorem, the velocity of the refrigerant CL increases when passing through the connecting hole 123. That is, as the refrigerant CL moves from the second cooling channel 300b through the connecting hole 123 to the first cooling channel 300a, its velocity increases, and accordingly, the velocity of the refrigerant CL can be maintained at a high speed in the first cooling channel 300a, thereby optimizing the pressure drop of the refrigerant CL.

[0154] As shown in Figure 23(a), in the case of a 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 shown in Figure 23(b), in the case of a connecting hole 123b according to another embodiment of the present invention, there may be a region N1 in which the width of the space through which the refrigerant CL flows narrows. For example, in a connecting hole 123b, the width of the space through which the refrigerant CL flows can narrow and then widen again. In the case of a connecting hole 123b having a region N1 in which the width of the space through which the refrigerant CL flows narrows, the effect of the flow velocity increase associated with Bernoulli's theorem can be further maximized.

[0155] Referring to both Figure 21 and Figure 23(b), in the connecting hole 123b having a region N1 where the width of the space through which the refrigerant CL flows narrows, the difference in width WD between the widest part W1 of the space through which the refrigerant CL flows and the narrowest part W2 of the space through which the refrigerant CL flows is 1.0 mm or more, and may be 5 times or less the distance G1 between the battery cells 110 (see Figure 21). As an example, as will be described later, the distance 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.

[0156] If the width difference WD is less than 1.0 mm, the effect of the resulting increase in flow velocity as the refrigerant CL passes through the connecting hole 123b may be insufficient. If the width difference WD is more than five times the distance G1 between the battery cells 110, the narrowest part W2 of the space through which the refrigerant CL flows becomes very narrow, which may actually hinder the flow of the refrigerant CL.

[0157] Figure 24 is a partial perspective view showing an enlarged portion of a middle cell frame according to one embodiment of the present invention.

[0158] Referring to Figures 10, 21, 22, and 24, in a multi-layer cooling structure, the connecting holes 123 that connect the cooling channels 300 can correspond one-to-one with the cooling channels CH distributed by the distribution mechanism 200. By providing the connecting holes 123 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 multiple cooling channels CH in the second cooling channel 300b can be maintained in the first cooling channel 300a as well. As an example, Figure 24 shows that 10 connecting holes 123 are provided so as to correspond to the number of rows R1 to R10 in the 10 battery cells 110. The 10 connecting holes 123 may also be provided in the middle cell frame 120b of the cell frame 120.

[0159] Referring again to Figure 21, in a battery assembly according to one embodiment of the present invention, the spacing G1 between battery cells 110 may be 1.5 mm or more and 2.5 mm or less. This may be the optimal spacing G1 for the circulation of the refrigerant. If the spacing G1 between battery cells 110 is less than 1.5 mm, problems may occur such as a relative increase in refrigerant flow velocity or a decrease in cooling efficiency, leading to an increase in differential pressure. Also, if the spacing G1 between battery cells 110 exceeds 2.5 mm, problems may occur such as a relative decrease in refrigerant flow velocity or a decrease in cooling efficiency.

[0160] Figure 25 is a cross-sectional view of a battery assembly according to one embodiment of the present invention.

[0161] Referring to Figures 3, 13, 17, and 25, the cell frame 120 may include a bottom cell frame 120c on which the battery cells 110 are mounted, and a cover cell frame 120ab positioned on top of the bottom cell frame 120c. A cooling channel 300 may be provided in the space between the bottom cell frame 120c and the cover cell frame 120ab.

[0162] The cover cell frame 120ab may include a middle cell frame 120b and a top cell frame 120a located on the middle cell frame 120b. The top cell frame 120a and middle cell frame 120b in this embodiment may be an example structure for realizing the cooling channel 300 of the multilayer cooling structure.

[0163] 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, can each correspond to a cooling channel 300. For example, the space between the middle cell frame 120b and the bottom cell frame 120c may become a second cooling channel 300b, or the space between the top cell frame 120a and the middle cell frame 120b may become a first cooling channel 300a. The inlet port 121 may be provided on the middle cell frame 120b, and the outlet port 122 may be provided on the top cell frame 120a.

[0164] The middle cell frame 120b and the top cell frame 120a may each be a component including upper surfaces 120aT, 120bT and side surfaces 120aS, 120bS extending downward from the edges of the upper surfaces 120aT, 120bT. The middle cell frame 120b may include the upper surface 120bT and the side surfaces 120bS extending downward from the edges of the upper surface 120bT. The top cell frame 120a may include the upper surface 120aT and the side surfaces 120aS extending downward from the edges of the upper surface 120aT. For example, the space between the upper surface 120bT and side surfaces 120bS of the middle cell frame 120b and the bottom cell frame 120c may become the second cooling channel 300b. Furthermore, the space between the upper surface portion 120aT and the side portion 120aS of the top cell frame 120a and the upper surface portion 120bT of the middle cell frame 120b may also become the first cooling channel 300a.

[0165] In this embodiment, the separation part 120S of the cell frame 120 may be realized by the middle cell frame 120b. That is, the separation part 120S may be included in the middle cell frame 120b.

[0166] On the other hand, the battery cell 110 according to this embodiment may be fitted inside the 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 in a form fitted into the holes 120h.

[0167] As an example, the multiple 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.

[0168] The battery cell 110 can be fixed onto the bottom cell frame 120c while mounted in the bottom cell frame hole 120ch (see Figure 3). However, in other embodiments of the present invention, there may be no separate bottom cell frame hole, and the battery cell may be fixed onto the bottom cell frame 120c by a third waterproof adhesive 500c (see Figures 9 to 11) applied to the bottom cell frame 120c.

[0169] The battery cell 110 may be fitted into the middle cell frame hole 120bh and mounted and secured to the middle cell frame 120b. Alternatively, the battery cell 110 may be fitted into the top cell frame hole 120ah and mounted and secured to the top cell frame 120a.

[0170] On the other hand, as described above, the waterproof adhesive 500 according to this embodiment may include a third waterproof adhesive 500c applied to the bottom cell frame 120c. Furthermore, the waterproof adhesive 500 may also include a first waterproof adhesive 500a applied to the top cell frame 120a. The first waterproof adhesive 500a applied to the top cell frame 120a prevents the refrigerant CL from leaking beyond the top cell frame 120a into the upper region of the top cell frame 120a. With the battery cell 110 mounted in the top cell frame hole 120ah of the top cell frame 120a, the first waterproof adhesive 500a can be applied to the upper surface of the top cell frame 120a and the upper region of the battery cell 110.

[0171] As mentioned above, electrical connections between battery cells 110 can be made via a busbar 131 connecting the first electrode terminal 111 and the second electrode terminal 112. The electrical connection via the busbar 131 can be made at the top of the cell frame 120, i.e., at the top of the top cell frame 120a.

[0172] The busbar 131 may be located on top of the cell frame 120, that is, on top of the top cell frame 120a.

[0173] At least a portion of the busbar 131 may be surrounded by the first waterproof adhesive 500a. The space around the busbar 131 may also be filled with the first waterproof adhesive 500a. The first electrode terminal 111 and the second electrode terminal 112 of the battery cell 110 may also be surrounded by the first waterproof adhesive 500a. The gap between the top cell frame hole 120ah and the battery cell 110 fitted therein can also be filled with the first waterproof adhesive 500a. The first waterproof adhesive 500a can prevent the coolant CL from leaking into the upper region of the cell frame 120. In the battery assembly 100, a waterproof and airtight structure at its upper end can be achieved by the first waterproof adhesive 500a.

[0174] The refrigerant CL may be insulating oil or coolant. When the refrigerant CL, which is coolant, comes into contact with the HV connection, a short circuit may occur, potentially causing serious safety problems. Even if the refrigerant CL is insulating oil, if it comes into contact with the part of the battery cell 110 where the electrical connections are made, it may adversely affect the electrical connections of the battery cell 110. In contrast, in this embodiment, the first waterproof adhesive 500a applied to the top of the cell frame 120 minimizes the effect of the refrigerant CL on the electrical connections of the battery cell 110.

[0175] The waterproof adhesive 500 may also include a second waterproof adhesive 500b applied to 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 until the refrigerant CL reaches the connecting hole 123. That is, the first cooling channel 300a and the second cooling channel 300b can only be connected via the connecting hole 123. This is because it is possible to create a difference in the order in which each part of the various battery cells 110 comes into contact with the refrigerant CL, thereby reducing the cooling deviation of the battery cells. The second waterproof adhesive 500b is the portion excluding the connecting hole 123 and can prevent the refrigerant CL from the first cooling channel 300a from moving to the second cooling channel 300b, or vice versa. The waterproof and airtight structure between the first cooling channel 300a and the second cooling channel 300b, excluding the connecting hole 123, may be formed by the second waterproof adhesive 500b. The gap between the middle cell frame hole 120bh and the battery cell 110 fitted therein may be filled with the second waterproof adhesive 500b.

[0176] Figure 26 is a cross-sectional view of a battery assembly according to another embodiment of the present invention. However, the inlet port and outlet port are not shown in Figure 26.

[0177] Referring to Figure 26, another embodiment of the present invention, a battery assembly 100, includes a plurality of battery cells 110 and a cell frame 120 in which the battery cells 110 are housed, wherein the cell frame 120 is provided with a cooling channel 300 through which a coolant CL flows in direct contact with at least a portion of the battery cells 110, and the cooling channel 300 includes a plurality of cooling channels 300a, 300b arranged along the longitudinal direction of the battery cells 110 from which the battery cells 110 extend. The longitudinal direction of the battery cells 110 may be the direction connecting the upper surface 110T and the lower surface 110B of the battery cells 110. The cooling channels 300 may be connected via connecting holes 123. This is the same structure as the battery assembly described above.

[0178] The cell frame 120 may include a bottom cell frame 120c on which the battery cell 110 is fixed, and a cover cell frame 120ab positioned on top of 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 top of the middle cell frame 120b. The top cell frame 120a and middle cell frame 120b in this embodiment may be other exemplary structures for realizing the cooling channels 300 of the multilayer cooling structure.

[0179] The middle cell frame 120b may be a member including an intermediate portion 120bM, a first side portion 120bS1 extending upward from the edge of the intermediate portion 120bM, and a second side portion 120bS2 extending downward from the edge of the intermediate portion 120bM. The top cell frame 120a may be a plate-shaped member.

[0180] 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, can each correspond to a cooling channel 300. For example, the space between the intermediate portion 120bM of the middle cell frame 120b, the second side portion 120bS2, and the bottom cell frame 120c can be designated as the second cooling channel 300b. Alternatively, the space between the intermediate portion 120bM of the middle cell frame 120b, the first side portion 120bS1, and the top cell frame 120a can be designated as the first cooling channel 300a.

[0181] In this embodiment, the separation part 120S of the cell frame 120 can be realized by the middle cell frame 120b. That is, the separation part 120S can correspond to the intermediate part 120bM of the middle cell frame 120b.

[0182] The cell frame 120 shown in Figure 26 differs from the cell frame 120 shown in Figure 25 in that the middle cell frame 120b includes an intermediate section 120bM, a first side section 120bS1, and a second side section 120bS2. The cell frame 120 shown in Figure 26 has the advantage of reducing the number of areas where refrigerant leakage may occur by one compared to the cell frame 120 shown in Figure 25. In the cell frame 120 shown in Figure 26, the portion between the first cooling channel 300a and the second cooling channel 300b is the middle cell frame 120b portion, which is an integrated form without gaps, so there is no need to worry about refrigerant leakage.

[0183] On the other hand, the cell frame 120 shown in Figure 25 may require a second waterproof adhesive 500b (see Figure 9) to prevent refrigerant leakage between the first cooling channel 300a and the second cooling channel 300b.

[0184] On the other hand, referring again to Figure 26, a busbar frame 132 on which busbars connected to the electrode terminals of the battery cell 110 are mounted may be positioned below the top cell frame 120a. The busbar frame 132 can serve the function of supporting the busbars.

[0185] Figure 27 is a cross-sectional view of a battery assembly according to another embodiment of the present invention.

[0186] Referring to Figure 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 housed, wherein the cell frame 120 is provided with cooling channels 300 through which a coolant CL flows in direct contact with at least a portion of the battery cells 110, and the cooling channels 300 include a plurality of cooling channels 300 arranged along the longitudinal direction of the battery cells 110 from which the battery cells 110 extend. The longitudinal direction of the battery cells 110 may be the direction connecting the upper surface 110T and the lower surface 110B of the battery cells 110. The cooling channels 300 may be connected via connecting holes 123.

[0187] The cooling channel 300 may include a first cooling channel 300a, a second cooling channel 300b, a third cooling channel 300c, and a fourth cooling channel 300d. That is, Figure 27 illustrates a battery assembly with a four-layer cooling structure. As explained earlier, three or more cooling channels can be provided as needed.

[0188] 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. Furthermore, 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 can be freely set as needed.

[0189] As explained earlier, the area in which at least one cooling channel 300, among the multiple cooling channels 300, whose flow direction of the refrigerant CL coincides with that of the battery cell 110, is in contact with the battery cell 110 may be 30% or more and 70% or less of the total area in contact with the battery cell 110 of all the cooling channels 300. Here, the area in which at least one cooling channel 300, whose flow direction of the refrigerant CL coincides with that of the battery cell 110, is in contact with the battery cell 110 may be the sum of the areas in contact with the battery cell 110 of the first cooling channel 300a and the fourth cooling channel 300d. Alternatively, the area in which at least one cooling channel 300, whose flow direction of the refrigerant CL coincides with that of the battery cell 110, is in contact with the battery cell 110 may be the sum of the areas in contact with the battery cell 110 of the second cooling channel 300b and the third cooling channel 300c. In this case, the area of ​​contact between the battery cell 110 and the entire cooling channel 300 may mean the sum of the areas of contact between the battery cell 110 and the first cooling channel 300a, the second cooling channel 300b, the third cooling channel 300c, and the fourth cooling channel 300d.

[0190] Referring again to Figures 7, 9, and 11, the bottom cell frame 120c and the cover cell frame 120ab in this embodiment may be joined by a bolt member 700. For example, each of the bottom cell frame 120c and the cover cell frame 120ab may include a protruding portion that projects in a direction parallel to the xy plane, and the bottom cell frame 120c and the cover cell frame 120ab may be joined by a bolt member 700 that is fastened through all of the protruding portions of each other. In one embodiment, the bolt member 700 may be joined 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 screw-connect 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 joined by bolt members 700, the fixing force between the bottom cell frame 120c and the cover cell frame 120ab is increased, preventing refrigerant leakage between the bottom cell frame 120c and the cover cell frame 120ab and improving sealing performance.

[0191] Furthermore, the middle cell frame 120b and the top cell frame 120a may also be joined by bolt members 700. For example, each of the middle cell frame 120b and the top cell frame 120a may include a protruding portion that projects in a direction parallel to the xy plane, and the middle cell frame 120b and the top cell frame 120a may be joined by bolt members 700 that fasten through all of the protruding portions of each other. In one embodiment, the bolt member 700 may be joined 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-connected 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 joined by bolt members 700, the fixing force between the middle cell frame 120b and the top cell frame 120a is increased, preventing refrigerant leakage between the middle cell frame 120b and the top cell frame 120a and improving sealing. On the other hand, referring again to Figure 1, the battery assembly 100 according to one embodiment of the present invention shown in Figure 1 can be directly mounted on a vehicle or chassis. That is, in the case of the battery assembly 100 according to this embodiment, the battery cells 110 can be directly mounted on a vehicle or chassis with the cell frames 120 housed in them. The inlet port 121 and outlet port 122 of the cell frame 120 may be connected to a refrigerant circulation system in the vehicle.

[0192] Figures 28 and 29 are exploded perspective views of a battery pack according to one embodiment of the present invention.

[0193] Referring to Figures 1, 28, and 29, another embodiment of the present invention, a battery pack 1000, may include at least one battery assembly 100, a pack frame 1100 housing the at least one battery assembly 100 and having one side open, and a pack cover 1200 covering the open side of the pack frame 1100. Figures 28 and 29 show, as an example, three battery assemblies 100 housed in the pack frame 1100.

[0194] The pack frame 1100 may include a bottom 1110 and side beams 1120. At least one battery assembly 100 may be placed on the bottom 1110. The side beams 1120 may be connected along the edge of the bottom 1110 and may extend perpendicular to one surface of the bottom 1110. The bottom 1110 and side beams 1120 may provide an internal space in which the top is open, and the battery assembly 100 may be housed in such an internal space. The pack cover 1200 may cover the top surface of the battery assembly 100 mounted on the pack frame 1100.

[0195] On the other hand, the battery pack 1000 according to this embodiment may include a foamed filling member 1300 in the space within the pack frame 1100 and the pack cover 1200. The filling member 1300 according to this embodiment may be a foamed material. The filling member 1300 may be a foamed material that foams after being filled into the space within the pack frame 1100 and the pack cover 1200.

[0196] The filler member 1300 in this embodiment may be formed of resin. For example, the filler member 1300 may be formed of resin or the like. The filler member 1300 may include air pockets, and adhesive may be provided in these air pockets. The filler member 1300 may be foamed rubber, i.e., cellular or sponge. The filler member 1300 may include an air-charging matrix structure. The filler member 1300 may be based on, for example, silicone, polyurethane or other organic materials.

[0197] The filling material 1300 may be applied to the pack frame 1100, for example, and foamed into a plate-like shape, or foamed using a spray. The filling material 1300 may also contain a foaming accelerator.

[0198] When the filler member 1300 comes into contact with other components, it subsequently hardens and bonds with the other components, allowing them to be fixedly supported. Therefore, the adhesive force between the components in contact with the filler member 1300 can be strengthened. In this embodiment, the filler member 1300 can strengthen the adhesive force between the pack frame 1100, the pack cover 1200, and the battery assembly 100. In addition, the filler member 1300 can absorb vibrations and shocks applied to the battery pack 1000, preventing the components within the battery pack 1000 from separating or detaching, thereby improving the safety and mechanical reliability of the battery pack.

[0199] On the other hand, the battery pack 1000 according to this embodiment may also include an inlet pipe 1400 connected to the inlet port 121 of the battery assembly 100 and an outlet pipe 1500 connected to the outlet port 122 of the battery assembly 100.

[0200] The inlet pipe 1400 and the outlet pipe 1500 may each pass through the side beam 1120 and be connected to the inlet port 121 and outlet port 122 of the battery assembly 100. Alternatively, the inlet pipe 1400 and the outlet pipe 1500 may be connected to a refrigerant circulation system inside the vehicle. The refrigerant supplied by the refrigerant circulation system inside the vehicle reaches the inlet port 121 via the inlet pipe 1400. The refrigerant that circulates inside the battery assembly 100 and is discharged through the outlet port 122 is recovered again into the refrigerant circulation system via the outlet pipe 1500.

[0201] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but these terms are for convenience of explanation and can change depending on the position of the object in question, the position of the observer, etc.

[0202] 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.

[0203] The aforementioned battery assemblies and battery packs can be applied to a variety of devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as to ESS (Energy Storage Systems), but are not limited to these, and can be applied to various devices that can use secondary batteries.

[0204] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto. Various modifications and improvements by those skilled in the art, utilizing the basic concepts of the present invention as defined in the claims below, also fall within the scope of the present invention. [Explanation of symbols]

[0205] 100 Battery Assembly 110 battery cells 120 Cell Frame 120ab Cover Cell Frame 120c bottom cell frame 300 Cooling channel

Claims

1. Multiple battery cells, The cell frame in which the battery cell is housed includes, Inside the cell frame, there is a cooling channel through which the refrigerant 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 from which the battery cell extends, A battery assembly in which the flow direction of the refrigerant in at least one of the plurality of cooling channels is opposite to the flow direction of the refrigerant in at least one of the plurality of cooling channels.

2. The aforementioned longitudinal direction is the direction connecting one side of the battery cell with the other side facing that side. The battery assembly according to claim 1, wherein at least one of the electrode terminals of the battery cell is arranged on one side of the battery cell.

3. The aforementioned cell frame is An inlet port through which the refrigerant flows, which is in direct contact with the battery cell, The battery assembly according to claim 1, further comprising an outlet port from which the refrigerant is discharged.

4. At least one of the multiple cooling channels is connected to the inlet port, The battery assembly according to claim 3, wherein at least one of the plurality of cooling channels is connected to the outlet port.

5. The battery assembly according to claim 3, wherein the refrigerant that flows in from the inlet port flows along the cooling channel and is then discharged from the outlet port.

6. The battery assembly according to claim 1, wherein, of the plurality of cooling channels, the area in which at least one cooling channel whose direction of flow of the refrigerant coincides with the battery cell is 30% or more and 70% or less of the area in which the plurality of cooling channels as a whole contact the battery cell.

7. The cooling channel includes a first cooling channel and a second cooling channel, The battery assembly according to claim 1, wherein the flow direction of the refrigerant in the first cooling channel and the flow direction of the refrigerant in the second cooling channel are opposite.

8. The battery assembly according to claim 7, wherein the cell frame includes a separation part that demarcates the first cooling channel and the second cooling channel and is disposed between the first cooling channel and the second cooling channel.

9. The battery assembly according to claim 8, wherein, with respect to the length of the battery cell, the separation part is positioned in a space from 30% to 70% of the height of the battery cell.

10. The battery assembly according to claim 1, wherein the cell frame includes connecting holes for connecting a plurality of cooling channels.

11. The battery assembly according to claim 10, wherein the width of the space through which the refrigerant flows is constant in the connecting hole.

12. The battery assembly according to claim 10, wherein the connecting hole has a region in which the width of the space through which the refrigerant flows is narrowed.

13. The battery assembly according to claim 12, wherein in the 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 is 1.0 mm or more, and is 5 times or less the distance between the battery cells.

14. The aforementioned cell frame is An inlet port through which the refrigerant flows, which is in direct contact with the battery cell, The outlet port from which the refrigerant is discharged includes, A distribution mechanism for distributing the refrigerant to a plurality of cooling channels is provided in at least one of the inlet port or the outlet port. The aforementioned connecting holes are provided in multiple locations. The battery assembly according to claim 10, wherein the plurality of connecting holes correspond one-to-one with the cooling channels that receive distribution by the distribution mechanism.

15. The battery assembly according to claim 1, wherein the spacing between the battery cells is 1.5 mm or more and 2.5 mm or less.

16. The aforementioned cell frame is The bottom cell frame on which the aforementioned battery cell is attached, The battery assembly according to claim 1, further comprising a cover cell frame disposed on top of the bottom cell frame.

17. The aforementioned cover cell frame is Middle cell frame, Includes a top cell frame positioned on top of the middle cell frame, The battery assembly according to claim 16, wherein 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. The battery assembly according to claim 17, wherein 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 the edge of the upper surface portion.

19. The middle cell frame is a member that includes an intermediate portion, a first side portion extending upward from the edge of the intermediate portion, and a second side portion extending downward from the edge of the intermediate portion. The battery assembly according to claim 17, wherein the top cell frame is a plate-shaped member.

20. The battery assembly according to claim 1, wherein the battery cells are housed in the cell frame and mounted on a vehicle or chassis as is.

21. A battery assembly according to any one of claims 1 to 20, A pack frame housing the aforementioned battery assembly, with one side open, A battery pack comprising a pack cover that covers one open side of the pack frame.

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