Battery packs and devices containing them

Abstract

A battery pack according to one embodiment of the present invention includes a plurality of battery cells, a pack frame including a bottom frame and side frames that form a storage space in which the battery cells are housed, and a refrigerant that flows through the storage space to directly cool the battery cells. The side frames are provided with an inlet port for the inflow of the refrigerant and an outlet port for the discharge of the refrigerant. Hollows are formed inside the side frames, and each of the hollows is in communication with the inlet port and the outlet port.

Description

Technical Field

[0001] The present invention relates to a battery pack and a device including the same. More specifically, it relates to a battery pack using an immersion cooling method and a device including the same.

[0002] Cross-reference to Related Applications This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0013810, filed on January 30, 2024, and all the contents disclosed in the document of the Korean Patent Application are incorporated herein by reference.

Background Art

[0003] With the increasing development of technology and demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. Accordingly, research on secondary batteries that can meet various requirements has been actively conducted.

[0004] Secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, and notebook computers, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0005] Recently, there has been an increasing need for a large-capacity secondary battery structure, including the use of secondary batteries as an energy storage source, and the demand for battery packs that combine a number of secondary batteries has been increasing.

[0006] On the other hand, when configuring a battery pack by connecting a plurality of battery cells in series / parallel, it is common to arrange the plurality of battery cells in a pack frame and add other components to configure the battery pack.

[0007] Because these battery cells are configured as rechargeable secondary batteries, a large amount of heat is generated during the charging and discharging process in such high-power, high-capacity secondary batteries. In this case, the heat from numerous battery cells can be amplified in a confined space, causing a rapid rise 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 by the battery cells during charging and discharging. If heat dissipation from the battery cells is not properly managed, the battery cells will deteriorate more quickly, shortening their lifespan and increasing the risk of explosion or fire.

[0008] Furthermore, in the case of vehicle battery packs, they are often exposed to direct sunlight and may be subjected to high-temperature conditions such as summer or desert regions. Also, because numerous battery modules are arranged intensively to increase the vehicle's driving range, flames or heat generated in one battery cell can easily propagate to adjacent battery cells, ultimately leading to the ignition or explosion of the battery pack itself. Therefore, for effective cooling of high-capacity battery packs, an immersion cooling method is used, in which a coolant directly cools the battery cells inside the battery pack. [Overview of the project] [Problems that the invention aims to solve]

[0009] The problem that this invention aims to solve is to provide a battery pack having an efficient refrigerant pure ring structure, and a device including the same, using an immersion cooling method that directly cools battery cells using a refrigerant.

[0010] 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]

[0011] A battery pack according to one embodiment of the present invention includes a plurality of battery cells, a pack frame including a bottom frame and side frames that form a storage space in which the battery cells are housed, and a refrigerant that flows through the storage space to directly cool the battery cells. The side frames are provided with an inlet port for the inflow of the refrigerant and an outlet port for the discharge of the refrigerant. Hollows are formed inside the side frames, and each of the hollows is in communication with the inlet port and the outlet port.

[0012] The side frame may be a rectangular tube structure with the hollow formed inside.

[0013] The inlet port and outlet port may be located on the side of the side frame opposite to the side facing the battery cell.

[0014] Cooling holes communicating with the hollow space may be formed on the side of the side frame facing the battery cell.

[0015] The refrigerant can flow through the hollow space, enter the storage space, or be discharged from the storage space.

[0016] The hollow may include an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port. The inlet hollow and the outlet hollow may be separated from each other.

[0017] The refrigerant can flow into the storage space through the inlet port and the inlet cavity. The refrigerant that has directly cooled the battery cell can be discharged to the outside through the discharge cavity and the outlet port.

[0018] The side frame may include a first side frame and a second side frame located on opposite sides of the battery cells. The inlet port and the outlet port may both be formed in the first side frame.

[0019] The hollow space may include an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port. A vertical beam dividing the storage space into a first and second zones may be located on the bottom frame. The refrigerant may flow sequentially through the first and second zones.

[0020] A separation frame may be positioned between the battery cell and the second side frame. The refrigerant can circulate along the inlet cavity of the first side frame, the first area, the internal cavity of the separation frame, the second area, and the discharge cavity of the first side frame.

[0021] The hollow space may include an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port. The storage space may be divided into a first and a second zone, and a vertical beam with a passage formed inside may be located on the bottom frame. The refrigerant flowing through the first zone and the refrigerant flowing through the second zone may flow along the same direction.

[0022] The refrigerant can circulate along the inlet cavity of the first side plate, the first and second zones, the passage inside the vertical beam, and the discharge cavity of the first side plate.

[0023] The battery cell may include a vent portion. The bottom frame may have vent channels formed therein for guiding venting gas and particles discharged from the vent portion of the battery cell.

[0024] The vertical beams that divide the storage space into multiple areas may be located on the bottom frame. The venting channel corresponding to any one of the areas may have an independent venting channel that is not shared with the venting channels corresponding to other areas.

[0025] The device according to an embodiment of the present invention includes the battery pack.

Advantages of the Invention

[0026] According to an embodiment of the present invention, in an immersion cooling method of directly cooling a battery cell using a refrigerant, by utilizing the hollow formed inside the side frame as a cooling flow path through which the refrigerant flows, space utilization can be improved, and an efficient refrigerant circulation structure can be realized.

[0027] The advantages of the present invention are not limited to the advantages mentioned above, and other advantages not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Brief Description of the Drawings

[0028] [Figure 1] It is a perspective view of a battery pack according to an embodiment of the present invention. [Figure 2] It is a perspective view of a battery pack according to an embodiment of the present invention. [Figure 3] It is a perspective view showing a pack frame included in the battery packs of FIGS. 1 and 2. [Figure 4] (a) and (b) are respectively a perspective view and a side view of a battery cell according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view showing a cross-section cut along the cutting line A - A' in (a) of FIG. 4. [Figure 6] It is a cross-sectional view of a battery cell according to another embodiment of the present invention. [Figure 7] It is a cross-sectional perspective view of a battery pack according to an embodiment of the present invention. [Figure 8] It is a partial cross-sectional view showing an enlarged view of the "B" part in FIG. 7. [Figure 9] It is a partial cross-sectional view showing an enlarged view of the "C" part in FIG. 8. [Figure 10] It is a partial cross-sectional view showing an enlarged view of the "D" part in FIG. 8. [Figure 11]This is an exploded perspective view showing a battery cell, a holding frame, and a spacer according to one embodiment of the present invention. [Figure 12] This is a perspective view showing a first side frame according to one embodiment of the present invention. [Figure 13] This is a perspective view showing a first side frame according to one embodiment of the present invention. [Figure 14] This is a cross-sectional perspective view showing a section cut along the portion of the first side frame that includes the inlet port, according to one embodiment of the present invention. [Figure 15] This is a partial cross-sectional view showing an enlarged view of the "E" portion of Figure 14. [Figure 16] This is a cross-sectional perspective view showing a section cut along the portion of the first side frame that includes the outlet port, according to one embodiment of the present invention. [Figure 17] This is a partial cross-sectional view showing an enlarged view of the "F" portion of Figure 16. [Figure 18] This is a partial perspective view showing an enlarged view of the inlet port and outlet port formed on the first side frame according to one embodiment of the present invention. [Figure 19] Figure 18 is a cross-sectional perspective view showing a section of the first side frame cut along the portion containing the inlet port. [Figure 20] Figure 18 is a cross-sectional perspective view showing a section of the first side frame cut along the portion containing the outlet port. [Figure 21] This is a partial perspective view showing a part of the bottom frame according to one embodiment of the present invention. [Figure 22] This is a plan view showing a bottom frame and a battery cell according to one embodiment of the present invention. [Figure 23] This is a perspective view showing a first side frame according to another embodiment of the present invention. [Figure 24] This is a partial cross-sectional view showing a cross-section taken along the cutting line G-G' in Figure 23. [Figure 25]This is a partial cross-sectional view showing a cross-section taken along the cutting line H-H' in Figure 23. [Figure 26] This is a partial perspective view showing a portion of the bottom frame according to another embodiment of the present invention. [Figure 27] This is a partial cross-sectional view showing a section cut along the cutting line I-I' in Figure 26. [Figure 28] This is a plan view showing a bottom frame and battery cell according to another embodiment of the present invention. [Modes for carrying out the invention]

[0029] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached 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 implemented in a variety of different forms and is not limited to the embodiments described herein.

[0030] To clearly explain the present invention, irrelevant parts have been omitted, and throughout the specification, identical or similar components are given the same reference numerals.

[0031] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrarily indicated for the sake of explanation, and therefore the present invention is not necessarily limited to those shown. In the drawings, the thicknesses are shown enlarged to clearly represent multiple layers and regions. Also, in the drawings, the thicknesses of some layers and regions are shown exaggerated for the sake of explanation.

[0032] Furthermore, when a layer, membrane, region, plate, or other part is "on top of" or "on above" another part, this includes not only when it is "directly above" the other part, but also when another part exists in between. Conversely, when we say that one part is "directly above" another part, it means that there is no other part in the middle. Also, when we say that a part is "on top of" or "on above" a reference part, it means that it is located above or below the reference part, and does not necessarily mean that it is located "on top of" or "on above" the opposite direction of gravity.

[0033] Furthermore, throughout the specification, when a part "includes" a certain component, unless otherwise stated, it does not exclude other components, but rather means that other components may be included.

[0034] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the cross-section of the subject is viewed from the side after being cut vertically.

[0035] Figures 1 and 2 are perspective views of a battery pack according to one embodiment of the present invention. Figure 3 is a perspective view showing the pack frame included in the battery pack of Figures 1 and 2.

[0036] Referring to Figures 1 to 3, a battery pack 100 according to one embodiment of the present invention includes a plurality of battery cells 110, a pack frame 200 including a bottom frame 210 and a side frame 220 that form a storage space (SS) in which the battery cells 110 are housed, and a refrigerant that flows through the storage space (SS) to directly cool the battery cells 110. Of the pack frame 200, the side frame 220 is provided with an inlet port 910 for the inflow of the refrigerant and an outlet port 920 for the discharge of the refrigerant. A hollow is formed inside the side frame 220, and each of these hollows communicates with the inlet port 910 and the outlet port 920. In other words, the battery pack 100 according to this embodiment corresponds to an immersion cooling method battery pack 100 in which the refrigerant flows through the inside of the pack frame 200, comes into contact with the battery cells 110, and directly cools the battery cells 110, rather than the conventional indirect cooling method in which a heat sink through which the refrigerant flows is provided in the battery pack.

[0037] The side frame 220 in this embodiment has a cavity inside. For example, the side frame 220 may be a square pipe structure with a cavity formed inside, and may include a metal material. This reduces the weight of the battery pack 100 while simultaneously ensuring the rigidity of the battery pack 100.

[0038] Furthermore, in the immersion cooling method battery pack 100, the hollow space inside the side frame 220 communicates with the inlet port 910 and outlet port 920, respectively, allowing the hollow space inside the side frame 220 to be utilized as a cooling path for supplying and discharging refrigerant. The side frame 220 can function as a component for refrigerant circulation, going beyond a simple outer frame. This reduces the number of components required for supplying refrigerant, thereby reducing the weight and volume of the battery pack 100 and improving its ease of assembly.

[0039] Below, we will first describe in detail the battery cell 110 according to this embodiment.

[0040] 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 a section cut along the cutting line A-A' in Figure 4(a). Figure 6 is a cross-sectional view of a battery cell according to another embodiment of the present invention.

[0041] Referring to Figures 4 to 6, the battery cell 110 according to this embodiment may have a vent section 110V. The vent section 110V is a general term for components and mechanisms provided in the battery cell 110 that allow venting gas and the like to be discharged from inside the battery cell 110.

[0042] As an example, the battery cell 110 in 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 interposed between the battery can 20 and the cap assembly 30. The following describes an exemplary structure of the battery cell 110, but the battery cell of the present invention is not limited to such a structure.

[0043] The battery can 20 in this embodiment may be a cylindrical case with an open top, and can house an electrode assembly 10 and an electrolyte (not shown) in its internal storage space, and may include a metallic material such as aluminum (Al).

[0044] The cap assembly 30 according to this embodiment may include a plate-shaped top cap 31 and a connecting plate 32 electrically and mechanically coupled to such top cap 31. The top cap 31 may include an electrically conductive metallic material and cover the open top of the battery can 20. Such a top cap 31 may be electrically connected to a first segment piece 11 connected to the first electrode of the electrode assembly 10, and at the same time be 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, may function as a first electrode terminal 111, which is an external terminal of the first electrode included in the electrode assembly 10.

[0045] To give a more specific explanation of the electrical connection between the top cap 31 and the first segment piece 11, the battery cell 110 according to this embodiment may further include a first current collector plate 41 located on top of the electrode assembly 10. The first current collector plate 41 is made of a conductive metallic material such as aluminum, copper, steel, or nickel, and can be electrically connected to the first segment piece 11 of the electrode assembly 10. The electrical connection can be made by welding. Leads 60 can be connected to such a first current collector plate 41. The leads 60 extend upward from the electrode assembly 10 and can be coupled to a connecting plate 32. In another embodiment, the leads 60 may be directly coupled to the underside of the top cap 31. The coupling between the leads 60 and other components can be done by welding. Alternatively, the first current collector plate 41 can 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.

[0046] The first current collector plate 41 may have a plurality of radially formed protrusions (not shown) on its lower surface. If radial protrusions are provided, the first current collector plate 41 can be pressed to press the protrusions into the curved first segment piece 11. The joint between the first current collector plate 41 and the first segment piece 11 can be performed, for example, by laser welding. Laser welding can be performed by partially melting the base material of the first current collector plate 41. In a modified example, welding between the first current collector plate 41 and the first segment 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 segment piece 11. Laser welding can also be performed by resistance welding, ultrasonic welding, spot welding, etc.

[0047] On the other hand, the battery cell 110 according to this embodiment may further include a second current collector plate 42 located at the bottom of the electrode assembly 10. Specifically, the second current collector plate 42 may be located 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 piece 12 of the electrode assembly 10. One side of the second current collector plate 42 may be coupled to the second segment piece 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 can 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.

[0048] On the other hand, the secondary battery according to this embodiment may include an insulating plate 70. The insulating plate 70 may cover the first current collector plate 41. By covering the first current collector plate 41 from its upper surface, the insulating plate 70 can prevent the first current collector plate 41 from coming into contact with the battery can 20, and in particular, with the beading part 20B of the battery can 20, which will be described later. The insulating plate 70 may also be provided with other lead holes through which leads 60 extending upward from the first current collector plate 41 can be drawn out. The leads 60 can 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.

[0049] The edge 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. As a result, the assembly of the electrode assembly 10 and the first current collector plate 41 restricts the axial movement of the electrode assembly 10, which can improve the assembly stability of the secondary battery. The insulating plate 70 may 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.

[0050] 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 the 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 may be joined by crimping with the gasket 50 in between. That is, crimping can be applied to the joining of the battery can 20 and the cap assembly 30. This allows the crimping part 20C to be formed on the battery can 20. More specifically, after the gasket 50 is placed between the battery can 20 and the cap assembly 30, the crimping is performed by bending one upper end of the battery can 20 in the direction in which the cap assembly 30 is placed.

[0051] The beading portion 20B refers to the area of ​​the side surface of the battery can 20 above the electrode assembly 10, where a part of the battery can 20 is curved inward toward the center, and is for the stable positioning of the cap assembly 30 and to prevent the electrode assembly 10 from flowing. In other words, the cap assembly 30 and the gasket 50 surrounding it according to this embodiment can be fixed on the beading portion 20B of the battery can 20. With the cap assembly 30 and the gasket 50 surrounding it fixed on the beading portion 20B, the crimping bond described above can be performed.

[0052] 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 also contains an electrically insulating material and can prevent a short circuit 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).

[0053] The vent portion 110V in this embodiment can be formed on the lower surface of the battery cell 110. That is, it can be formed on the bottom portion 20F of the battery can 20 (see Figure 6).

[0054] When a thermal event or thermal runaway occurs inside any one of the battery cells 110, high-temperature venting 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 venting gases and particles. For example, a notch section 110N may be formed on the underside of the battery cell 110, at the bottom of the battery can, with a thickness that is relatively thinner than the adjacent area. The notch section 110N may form a certain circumference. If the internal pressure of the battery cell 110 increases due to high-temperature venting gas generated inside any one of the battery cells 110, the notch section 110N, which has low rigidity due to its thin thickness, may rupture first. The rupture of the notch section 110N opens the vent section 110V, and high-temperature venting gases and particles may be discharged through this opened vent section 110V.

[0055] However, this structure of the vent section 110V is just one example, and there are no special restrictions on the form of the vent section 110V as long as it is a component or mechanism that can discharge the internal venting gas in the event of a thermal event or thermal runaway.

[0056] 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 represented 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.

[0057] On the other hand, referring again to Figures 1 to 3, as described above, the pack frame 200 according to this embodiment includes a bottom frame 210 and side frames 220 that form a storage space (SS) in which the battery cells 110 are housed. The battery cells 110 can be placed in the bottom frame 210, and the side frames 220 can be connected along the edges of such a bottom frame 210. For example, the side frames 220 may include a first side frame 221, a second side frame 222, a third side frame 223, and a fourth side frame 224. The first side frame 221, the second side frame 222, the third side frame 223, and the fourth side frame 224 can be arranged along the four sides of the edges of the rectangular bottom frame 210. The bottom frame 210 and the side frames 220 provide a storage space with an open top, in which the battery cells 110 can be placed. After the battery cells 110 are placed in the storage space, the open top of the storage space can be covered by the pack top cover 610. The pack top cover 610 is joined to the side frames 220 of the pack frame 200, and joining by welding or adhesive may be applied, for example. The battery cells 110 can be sealed by the pack frame 200 and the pack top cover 610. Although not specifically shown, a gasket may be interposed between the pack top cover 610 and the side frames 220 to enhance the seal.

[0058] On the other hand, the battery pack 100 according to this embodiment may include a mounting portion 220M1 and a mounting beam 220M2 provided on the side frame 220 for fixing the battery pack 100. As an example, Figures 1 and 2 show that the mounting portion 220M1 is formed on the first side frame 221 and the second side frame 222, and the mounting beam 220M2 is formed on the third side frame 223 and the fourth side frame 224. The mounting portion 220M1 and the mounting beam 220M2 can be utilized when fixing the battery pack 100 to a device. For example, when fixing the battery pack 100 to a vehicle device, the mounting portion 220M1 and the mounting beam 220M2 can be fixed to the vehicle's chassis.

[0059] The following describes in detail the battery pack structure for preventing refrigerant leakage in the immersion cooling method according to this embodiment.

[0060] Figure 7 is a cross-sectional perspective view of a battery pack according to one embodiment of the present invention. Figure 8 is a partial cross-sectional view showing an enlarged view of portion "B" in Figure 7. Figure 9 is a partial cross-sectional view showing an enlarged view of portion "C" in Figure 8. Figure 10 is a partial cross-sectional view showing an enlarged view of portion "D" in Figure 8. Figure 11 is an exploded perspective view showing a battery cell, holding frame, and spacer according to one embodiment of the present invention.

[0061] Referring to Figures 2, 3, and 7-11, the battery pack 100 according to this embodiment may further include a spacer 300 located on top of the bottom frame 210, on which the battery cells 110 are fixed, and a holding frame 400 located on top of the spacer 300, on which holes 400H are formed in which the battery cells 110 are sandwiched.

[0062] The refrigerant (CL) flowing into the inlet port 910 can flow in the space between the spacer 300 and the holding frame 400 so as to directly cool the battery cells 110 inside the pack frame 200. As shown in Figure 8, the battery cells 110 can be directly cooled by bringing the refrigerant (CL) flowing in the space between the spacer 300 and the holding frame 400 into contact with the battery cells 110.

[0063] As described above, the side frame 220 may have an inlet port 910 and an outlet port 920. As an example, Figures 2 and 3 show a first side frame 221 with an inlet port 910 and an outlet port 920. The refrigerant (CL) flowing in through such an inlet port 910 can flow along the space between the spacer 300 and the holding frame 400, cool the battery cell 110, and then be discharged through the outlet port 920. The inlet port 910 and the outlet port 920 may be connected to a refrigerant circulation system (not shown) outside the battery pack 100 so that the refrigerant (CL) can circulate continuously.

[0064] The holding frame 400 may be positioned between the spacer 300 and the pack upper cover 610. Holes 400H are formed in the holding frame 400, and the battery cells 110 may be sandwiched in such holes 400H. Therefore, the holes 400H of the holding frame 400 may have a shape corresponding to the outer shape of the battery cells 110. If the battery cells 110 are cylindrical, the holes 400H of the holding frame 400 may be circular, and if the battery cells 110 are rectangular, the holes 400H of the holding frame 400 may be square.

[0065] Furthermore, the holding frame 400 may include a protruding portion 400P. As shown in Figure 11, the protruding portion 400P of the holding frame 400 can be locked and coupled to the side frame 220 or the vertical beam 700, which will be described later. By locking and coupling the protruding portion 400P, the holding frame 400 can be fixed to the side frame 220 or the vertical beam 700 at a certain distance from the spacer 300. The holding frame 400 is locked and coupled at a certain distance from the spacer 300, ensuring a space for the refrigerant (CL) to flow.

[0066] The spacer 300 may be placed on the bottom frame 210. The spacer 300 may have a fixing portion 310 on which the battery cell 110 can be fixed. The battery cell 110 is not located directly above the bottom frame 210, and the battery cell 110 may be placed on the bottom frame 210 while fixed to the fixing portion 310 of the spacer 300. For this reason, the fixing portion 310 of the spacer 300 may have a shape corresponding to the outer shape of the battery cell 110. If the battery cell 110 is a cylindrical battery, the fixing portion 310 of the spacer 300 may be circular, and if the battery cell 110 is a prismatic battery, the fixing portion 310 of the spacer 300 may be square. By positioning the battery cell 110 on the fixing portion 310 of the spacer 300, the battery cell 110 can be stably positioned and fixed in the space inside the pack frame 200.

[0067] As described above, the spacer 300 and the holding frame 400 can set a space through which the refrigerant (CL) flows and prevent the refrigerant (CL) from flowing into other spaces. The spacer 300 corresponds to the lower limit of the refrigerant flow, and the holding frame 400 corresponds to the upper limit of the refrigerant flow. In this way, by preventing refrigerant leakage, the cooling performance of the battery pack 100 can be improved along with its safety.

[0068] Specifically, in the region above the holding frame 400, busbars 130 that guide the electrical connections of the battery cells 110 can be connected to the electrode terminals 111 and 112 of the battery cells 110. As mentioned above, the cap assembly 30 and battery can 20 of the battery cells 110 can function as the first electrode terminals 111 and second electrode terminals 112 of the battery cells 110. By connecting the busbars 130 to such first electrode terminals 111 or second electrode terminals 112, HV connection, which is the electrical connection of the battery cells 110, can be performed. HV connection is a connection that acts as a power source to supply power requiring high voltage, and means electrical connections between battery cells and electrical connections between the battery pack and devices. In other words, the electrical connections of the battery cells 110 can be performed in the upper region of the holding frame 400. That is, the holding frame 400 can separate the space through which the coolant (CL) flows from the space for HV connection where the electrical connections of the battery cells 110 are made. As will be described later, the refrigerant (CL) may be insulating oil or cooling water. When the refrigerant (CL), which is cooling water, comes into contact with the HV connection part, a short circuit may occur, potentially causing serious safety problems. Also, even if the refrigerant (CL) is insulating oil, if the refrigerant (CL) comes into contact with the part where the electrical connections of the battery cell 110 are made, it may adversely affect the electrical connections of the battery cell 110. In contrast, in this embodiment, by separating the space through which the refrigerant (CL) flows from the space where the electrical connections of the battery cell 110 are made in the holding frame 400, the effect of increased cooling performance through direct cooling of the refrigerant (CL) can be maintained, and the effect of the refrigerant (CL) on the electrical connections of the battery cell 110 can be minimized.

[0069] In the battery pack 100 according to this embodiment, the first waterproof adhesive 500a can be applied to the upper part of the holding frame 400. The first waterproof adhesive 500a applied to the upper part of the holding frame 400 can prevent the refrigerant (CL) from leaking beyond the holding frame 400 into the upper region of the holding frame 400. With the battery cells 110 fixed in the holes 400H of the holding frame 400, the first waterproof adhesive 500a can be applied to the upper surface of the holding frame 400 and the upper region of the battery cells 110.

[0070] As described above, the battery pack 100 may include a pack upper cover 610 that covers the open top of the pack frame 200, and the first waterproof adhesive 500a can be applied to the space between the holding frame 400 and the pack upper cover 610. In particular, at least a portion of the bus bar 130 may be surrounded by the first waterproof adhesive 500a. The space around the bus bar 130 can also be filled with the first waterproof adhesive 500a. Furthermore, the space between the holding frame 400 and the pack upper cover 610 may also be filled with the first waterproof adhesive 500a. Such a holding frame 400 and the first waterproof adhesive 500a can prevent the coolant (CL) from leaking into the upper region of the holding frame 400.

[0071] In the battery pack 100 according to this embodiment, the second waterproof adhesive 500b can be applied to the surface of the spacer 300 that faces the battery cell 110. Specifically, the second waterproof adhesive 500b can be applied to the fixing portion 310 of the spacer 300. The spacer 300 and the second waterproof adhesive 500b can prevent the refrigerant (CL) from leaking beyond the spacer 300 into the area below the spacer 300.

[0072] The first waterproof adhesive 500a and the second waterproof adhesive 500b in this embodiment are not limited in their material, as long as they exhibit waterproofing performance and possess impact resistance, adhesion, and electrical insulation properties. For example, the first waterproof adhesive 500a and the second waterproof adhesive 500b may include a two-component epoxy material in which a curing agent is mixed with a main component.

[0073] On the other hand, the refrigerant (CL) in this embodiment may be a fluid. Since the refrigerant (CL) is in direct contact with the battery cells 110 within the battery pack 100, the refrigerant (CL) may be electrically insulating. The refrigerant (CL) may be an insulating material. For example, the refrigerant (CL) may be insulating oil. However, in the case of the battery pack 100 according to this embodiment, general cooling water can also be used as the refrigerant (CL) because leakage of the refrigerant (CL) to areas other than the space between the spacer 300 and the holding frame 400 is prevented.

[0074] The following describes the refrigerant pure ring structure in the battery pack 100 according to this embodiment.

[0075] Figures 12 and 13 are perspective views showing a first side frame according to one embodiment of the present invention. Specifically, Figure 12 shows the side of the first side frame on which the inlet port 910 and outlet port 920 are located, and Figure 13 shows the opposite side of the first side frame on which the inlet port 910 and outlet port 920 are located. Figure 14 is a cross-sectional perspective view showing a section of the first side frame cut along the portion containing the inlet port, according to one embodiment of the present invention. Figure 15 is a partial cross-sectional view showing an enlarged view of portion "E" in Figure 14. Figure 16 is a cross-sectional perspective view showing a section of the first side frame cut along the portion containing the outlet port, according to one embodiment of the present invention. Figure 17 is a partial cross-sectional view showing an enlarged view of portion "F" in Figure 16.

[0076] Referring to both Figure 3 and Figures 12 to 17, as described above, the side frame 220 is provided with an inlet port 910 for the inflow of refrigerant and an outlet port 920 for the discharge of refrigerant. As an example, the inlet port 910 and the outlet port 920 can be located on the first side frame 221 of the side frame 220.

[0077] Furthermore, the inlet port 910 and outlet port 920 can be positioned on the side of the side frame 220 opposite to the side facing the battery cell 110. A hollow 220C is formed inside the side frame 220, and each of the hollows 220C communicates with the inlet port 910 and the outlet port 920. On the other hand, a cooling hole 220H can be formed on the side of the side frame 220 that faces the battery cell 110, communicating with the hollow 220C. That is, the cooling hole 220H can be positioned on the side frame 220 opposite to the inlet port 910 and the outlet port 920.

[0078] In the battery pack 100 using the immersion cooling method according to this embodiment, the hollow space 220C inside the side frame 220 can be utilized as a cooling path for supplying and discharging refrigerant. That is, the refrigerant (CL) can flow through the hollow space 220C into the storage space (SS) where the battery cells 110 are located, and can also be discharged from the storage space (SS).

[0079] On the other hand, for the sake of explanation, Figures 12 to 17 show the first side frame 221 with both sides open so that the hollow 220C is visible. However, in reality, as shown in Figures 1 to 3, sealing plates 220S can be attached to both sides of the first side frame 221. The hollow 220C inside the side frame 220 is closed on both sides. That is, the hollow 220C has a sealed structure with all four sides closed except for the paths passing through the inlet port 910, the outlet port 920, and the cooling hole 220H.

[0080] On the other hand, the inlet port 910 and outlet port 920 in this embodiment may be located together on either one of the side frames 220. For example, the inlet port 910 and outlet port 920 may be formed on the first side frame 221. A refrigerant circulation system (not shown) for circulating refrigerant (CL) may be connected to the inlet port 910 and outlet port 920. Such a refrigerant circulation system (not shown) may be provided on only one side of the battery pack 100 (in this embodiment, the side on which the first side frame 221 is located), which may help to increase the usability of space within the device on which the battery pack 100 is fixed.

[0081] On the other hand, the hollow 220C according to this embodiment may include an inlet hollow 220C1 connected to the inlet port 910 and an outlet hollow 220C2 connected to the outlet port 920. The inlet hollow 220C1 and the outlet hollow 220C2 may be separated from each other. The reason for providing an inlet hollow 220C1 and an outlet hollow 220C2 that do not communicate with each other is to separate the path of the refrigerant flowing in and the path of the refrigerant being discharged in the refrigerant pure ring structure. That is, the refrigerant flowing through the inlet hollow 220C1 is not mixed with the refrigerant flowing through the outlet hollow 220C2.

[0082] Furthermore, the cooling hole 220H formed on the opposite side of the surface on which the inlet port 910 and outlet port 920 are formed may include an inlet cooling hole 220H1 connected to the inlet hollow 220C1 and an outlet cooling hole 220H2 connected to the outlet hollow 220C2. The inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1 are in communication with each other, and the outlet port 920, the outlet hollow 220C2, and the outlet cooling hole 220H2 are in communication with each other.

[0083] As a result, the refrigerant (CL) can flow into the storage space (SS) through the inlet port 910 and the inlet hollow 220C1. More specifically, the refrigerant (CL) can flow into the storage space (SS) where the battery cell 110 is located, sequentially through the inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1.

[0084] On the other hand, the refrigerant (CL) that directly cools the battery cell 110 can be discharged to the outside through the discharge cavity 220C2 and the outlet port 920. More specifically, the refrigerant (CL) that flows around the battery cell 110 within the storage space (SS) and directly cools the battery cell 110 can be discharged to the outside through the discharge cooling hole 220H2, the discharge cavity 220C2, and the outlet port 920 and returned to the refrigerant circulation system. Through this series of processes, immersion cooling can be performed inside the battery pack 100 by the circulation of the refrigerant (CL).

[0085] The following describes in detail a refrigerant (CL) circulation method according to one embodiment of the present invention.

[0086] Figure 18 is a magnified partial perspective view showing the inlet port and outlet port formed on the first side frame according to one embodiment of the present invention. Figure 19 is a cross-sectional perspective view showing a section of the first side frame of Figure 18 cut along the portion containing the inlet port. Figure 20 is a cross-sectional perspective view showing a section of the first side frame of Figure 18 cut along the portion containing the outlet port. Figure 21 is a partial perspective view showing a part of the bottom frame according to one embodiment of the present invention. Figure 22 is a plan view showing the bottom frame and battery cell according to one embodiment of the present invention. In particular, Figure 22 shows the bottom frame and battery cell viewed along the -z axis direction on the xy plane.

[0087] Referring to Figures 2, 3, 13, 15, and 17-22, as described above, the side frame 220 according to this embodiment may include a first side frame 221, a second side frame 222, a third side frame 223, and a fourth side frame 224.

[0088] Here, the first side frame 221 and the second side frame 222 may be positioned on opposite sides of each other with the battery cell 110 in between. Also, as described above, both the inlet port 910 and the outlet port 920 may be formed on the first side frame 221.

[0089] On the other hand, in the battery pack 100 according to this embodiment, vertical beams 700 that divide the battery cells 110 into multiple battery cell groups may be arranged on the bottom frame 210. The vertical beams 700 may be arranged upright on the bottom frame 210 such that one surface of the vertical beams 700 is perpendicular to one surface of the bottom frame 210. The storage space (SS) in which the battery cells 110 are housed can be divided into multiple areas (Z1, Z2, Z3, Z4) by such vertical beams 700. As an example, it is shown that three vertical beams 700 are arranged on the bottom frame 210 at regular intervals. The storage space (SS) can be divided into a first area (Z1), a second area (Z2), a third area (Z3), and a fourth area (Z4) by the three vertical beams 700.

[0090] On the other hand, the battery pack 100 according to this embodiment may include a separation frame 800 arranged adjacent to the side frame 220. For example, the separation frame 800 may be arranged adjacent to the second side frame 222. The separation frame 800 may be arranged between the battery cell 110 and the second side frame 222 and placed on the bottom frame 210. A venting space (VS) may be formed between the separation frame 800 and the second side frame 222, which is a space through which venting gas discharged from the battery cell 110 is discharged. The venting space (VS) will be described later.

[0091] The vertical beam 700 and the separation frame 800 in this embodiment may be metal frames with internal cavities, similar to the side frame 220. Specifically, the vertical beam 700 and the separation frame 800 may be metal frames in the form of square pipes with cavities. This reduces the weight of the battery pack 100 while simultaneously ensuring its rigidity. Furthermore, since the bottom frame 210, side frame 220, vertical beam 700, and separation frame 800 all contain metal materials, welding can be used to connect the frames. There are no particular restrictions on the welding method, but as an example, MIG welding (Metal Inert Gas Welding) or FSW (Friction Stir Welding) can be applied.

[0092] On the other hand, the battery pack 100 according to this embodiment may further include a lower cover 620 of the pack that covers the lower part of the bottom frame 210. The lower cover 620 of the pack may be a plate-shaped member made of a metal material.

[0093] As described above, the refrigerant (CL) can flow into the storage space (SS) where the battery cells 110 are located, passing sequentially through the inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1. At this time, the vertical beam 700 that divides the storage space (SS) into a first zone (Z1) and a second zone (Z2) allows the refrigerant (CL) to flow sequentially through the first zone (Z1) and the second zone (Z2). Furthermore, the vertical beam 700 that divides the storage space (SS) into a third zone (Z3) and a fourth zone (Z4) allows the refrigerant (CL) to flow sequentially through the third zone (Z3) and the fourth zone (Z4). The direction of the refrigerant (CL) flowing through the first zone (Z1) may be opposite to the direction of the refrigerant (CL) flowing through the second zone (Z2). Furthermore, the direction of the refrigerant (CL) flowing through the third zone (Z3) may be opposite to the direction of the refrigerant (CL) flowing through the fourth zone (Z4).

[0094] Specifically, of the cooling holes 220H formed in the side frame 220, the inlet cooling hole 220H1 may communicate with the first area (Z1) and the third area (Z3), and the discharge cooling hole 220H2 may communicate with the second area (Z2) and the fourth area (Z4). In addition, separation frame holes 800H may be formed on the outer surface of the separation frame 800. Specifically, the separation frame 800 has an internal hollow, and the separation frame holes 800H may be connected to the internal hollow of the separation frame 800.

[0095] The refrigerant (CL) may flow into the first zone (Z1) and the third zone (Z3) through the inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1 in sequence. The refrigerant (CL) that has flowed through the first zone (Z1) and the third zone (Z3), respectively, may move into the hollow inside the separation frame 800 through the separation frame holes 800H corresponding to the first zone (Z1) and the third zone (Z3). Subsequently, the refrigerant (CL) may move into the second zone (Z2) and the fourth zone (Z4) through the separation frame holes 800H corresponding to the second zone (Z2) and the fourth zone (Z4). The refrigerant (CL) that has flowed through the second zone (Z2) and the fourth zone (Z4), respectively, may be discharged to the outside of the battery pack 100 through the discharge cooling hole 220H2, the discharge hollow 220C2, and the outlet port 920.

[0096] In other words, the refrigerant (CL) can circulate along the inlet hollow 220C1 of the first side frame 221, the first zone (Z1), the hollow inside the separation frame 800, the second zone (Z2), and the outlet hollow 220C2 of the first side frame 221. Other refrigerants (CL) can also circulate along the inlet hollow 220C1 of the first side frame 221, the third zone (Z3), the hollow inside the separation frame 800, the fourth zone (Z4), and the outlet hollow 220C2 of the first side frame 221. Direct cooling of the battery cell 110 can be achieved through this pure circulating structure of refrigerant (CL). In particular, by utilizing the hollow 220C of the existing side frame 220 and the hollow of the separation frame 800 as structures for refrigerant circulation, and by appropriately arranging the vertical beam 700, a uniform flow of refrigerant (CL) in each zone is achieved. A uniform flow of refrigerant (CL) in each zone can reduce cooling deviations between each battery cell 110, which leads to improved performance of the battery pack 100.

[0097] The following describes in detail another embodiment of the present invention concerning the circulation of the refrigerant (CL).

[0098] Figure 23 is a perspective view showing a first side frame according to another embodiment of the present invention. Figure 24 is a partial cross-sectional view showing a cross section cut along the cutting line G-G' in Figure 23. Figure 25 is a partial cross-sectional view showing a cross section cut along the cutting line H-H' in Figure 23. Figure 26 is a partial perspective view showing a part of the bottom frame according to another embodiment of the present invention. Figure 27 is a partial cross-sectional view showing a cross section cut along the cutting line I-I' in Figure 26. Figure 28 is a plan view showing the bottom frame and battery cell according to another embodiment of the present invention. In particular, Figure 28 shows the bottom frame and battery cell viewed along the -z axis direction on the xy plane.

[0099] Referring to Figures 23 to 28, in another embodiment of the present invention, the battery pack 100 includes a bottom frame 210 and side frames 220, the side frames 220 including a first side frame 221, a second side frame 222, a third side frame 223, and a fourth side frame 224, and the inlet port 910 and outlet port 920 may all be formed on the first side frame 221. In addition, the inlet port 910, outlet port 920, inlet hollow 220C1, outlet hollow 220C2, inlet cooling hole 220H1, and outlet cooling hole 220H2 may be formed on the first side frame 221. The battery pack 100 may include a vertical beam 700 that divides the storage space (SS) into a plurality of areas (Z1, Z2, Z3, Z4), and a separation frame 800 located between the battery cell 110 and the second side frame 222. Detailed explanations of each of the above configurations are omitted as they would be redundant with what was explained earlier.

[0100] In the battery pack 100 according to this embodiment, the refrigerant (CL) can flow into the storage space (SS) where the battery cells 110 are arranged, sequentially through the inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1. At this time, a passage 700P can be formed inside the vertical beam 700 that divides the storage space (SS) into a first area (Z1) and a second area (Z2). The refrigerant (CL) flowing through the first area (Z1) and the refrigerant (CL) flowing through the second area (Z2) can flow along the same direction. In addition, the refrigerant (CL) flowing along the first to fourth areas (Z1, Z2, Z3, Z4) can flow from the first side frame 221 to the second side frame 222 along the same direction.

[0101] Specifically, among the cooling holes 220H formed in the side frame 220, the inlet cooling hole 220H1 communicates with the first area (Z1), the second area (Z2), the third area (Z3), and the fourth area (Z4), while the exhaust cooling hole 220H2 can communicate with the passage 700P inside the vertical beam 700. In addition, a vertical beam hole 700H is formed on the outer surface of the vertical beam 700, and the vertical beam hole 700H can be connected to the passage 700P inside the vertical beam 700.

[0102] The refrigerant (CL) may flow into the first to fourth zones (Z1, Z2, Z3, Z4) sequentially through the inlet port 910, the inlet hollow 220C1, and the inlet cooling hole 220H1. After flowing through the first to fourth zones (Z1, Z2, Z3, Z4), the refrigerant (CL) may move through the vertical beam hole 700H to the passage 700P inside the vertical beam 700. The refrigerant (CL) may then move along the passage 700P again towards the location where the first side frame 221 is positioned. The refrigerant (CL) that has flowed along the passage 700P may be discharged to the outside of the battery pack 100 through the discharge cooling hole 220H2, the discharge hollow 220C2 zone, and the outlet port 920.

[0103] In other words, the refrigerant (CL) can circulate along the inlet hollow 220C1 of the first side frame 221, the first zone (Z1) and the second zone (Z2), the passage 700P inside the vertical beam 700, and the discharge hollow 220C2 of the first side frame 221. More specifically, the refrigerant (CL) can circulate along the inlet hollow 220C1 of the first side frame 221, the first to fourth zones (Z1, Z2, Z3, Z4), the passage 700P inside the vertical beam 700, and the discharge hollow 220C2 of the first side frame 221. Direct cooling of the battery cell 110 can be achieved through such a pure ring structure of refrigerant (CL). In particular, by utilizing the hollow 220C of the existing side frame 220 and the passage 700P of the vertical beam 700 as structures for refrigerant circulation, and by appropriately positioning the vertical beam 700, a uniform flow of refrigerant (CL) in each zone is achieved. A uniform flow of refrigerant (CL) in each zone can reduce cooling deviations between each battery cell 110, which leads to improved performance of the battery pack 100.

[0104] The directional venting structure of the battery pack 100 according to this embodiment will be described below.

[0105] Referring again to Figures 2, 3, 5, and 8-10, the vent portion 110V of the battery cell 110 in this embodiment may face the spacer 300. More specifically, the vent portion 110V of the battery cell 110 may face the fixing portion 310 of the spacer 300. The spacer 300 in this embodiment may include a spacer venting portion 320a, which is the part that faces the vent portion 110V, and an outer peripheral portion 320b that surrounds the spacer venting portion 320a. The spacer venting portion 320a may have a thinner thickness than the outer peripheral portion 320b, or it may have a notched groove. Due to a thermal event or thermal runaway in the battery cell 110, high-temperature venting gas and particles are discharged from the vent section 110V of the battery cell 110. The pressure of the venting gas separates the spacer venting section 320a from the outer periphery 320b, and the spacer venting section 320a can be opened. That is, high-temperature venting gas and particles can be discharged downwards through the vent section 110V and the opened spacer venting section 320a. Subsequently, the high-temperature venting gas and particles can move along a predetermined path through the venting channel (VC) provided in the bottom frame 210. The specific structure of the bottom frame 210 and the venting channel (VC) will be described below.

[0106] In one embodiment of the present invention, the bottom frame 210 may have a venting channel (VC) that guides high-temperature venting gas and particles discharged from the vent portion 110V of the battery cell 110. Specifically, the bottom frame 210 includes a first frame 211 and a second frame 212 positioned below the first frame 211, and a venting channel (VC) may be formed between the first frame 211 and the second frame 212.

[0107] The first frame 211 may have a through-hole 211H. When viewed along the height direction, the through-hole 211H may be positioned so that at least a portion of it overlaps with the vent portion 110V of the battery cell 110. The through-hole 211H may be provided in a one-to-one correspondence with the vent portion 110V. Similarly, the through-hole 211H may be provided in a one-to-one correspondence with the spacer venting portion 320a.

[0108] High-temperature venting gas and particles that have passed through the vent section 110V and the open spacer venting section 320a may flow into the venting channel (VC) inside the bottom frame 210 through the through-hole 211H. The high-temperature venting gas and particles that have flowed into the venting channel (VC) are discharged to the outside of the battery pack 100. The battery pack 100 according to this embodiment has a so-called "bottom venting" structure that uses the bottom frame 210 to discharge high-temperature venting gas and particles to the outside. The HV connection described above is a connection that serves as a power source to supply power requiring high voltage, and means connections between battery cells, etc. If high-temperature venting gas and particles from thermal events in the battery cell 110 come into contact with a high-voltage path such as an HV connection, a short circuit or arc discharge may occur, which could lead to further explosion and flame generation. On the other hand, in the case of the battery pack 100 according to this embodiment, as described above, it has a "lower venting" structure, so that high-temperature venting gas and particles caused by thermal events are discharged downwards, i.e., to the bottom frame 210. Therefore, there is no risk of high-temperature venting gas and particles coming into contact with high-voltage paths such as HV coupling, and ultimately, safety against thermal runaway phenomena can be enhanced.

[0109] Furthermore, in this embodiment, the holding frame 400 further covers the area where the electrode terminals 111 and 112 of the battery cell 110 and the busbar 130 are located, thus completely blocking high-temperature venting gas and particles from reaching the area where the electrode terminals 111 and 112 of the battery cell 110 and the busbar 130 are located.

[0110] Furthermore, because the battery pack 100 according to this embodiment has a "lower venting" structure, the influence of high-temperature venting gas and particles on the refrigerant (CL) flowing in the space between the spacer 300 and the holding frame 400 can be minimized.

[0111] Furthermore, the spacer 300 and the second waterproof adhesive 500b not only prevent the refrigerant (CL) from leaking in the lower region of the spacer 300, but can also prevent high-temperature venting gas and particles from leaking upward rather than downward, where the bottom frame 210 is located.

[0112] On the other hand, as described above, vertical beams 700 that divide the storage space (SS) into multiple areas (Z1, Z2, Z3, Z4) may be arranged on the bottom frame 210. A venting channel (VC) corresponding to any area may have an independent venting channel that is not shared with the venting channels (VC) corresponding to other areas. As an example, four second frames 212 can be provided, each corresponding to one of the four areas (Z1, Z2, Z3, Z4). A venting channel (VC) in any of the second frames 212 may not communicate with the venting channels (VC) in any of the other second frames 212 and may have an independent venting channel.

[0113] Furthermore, the second frame 212 has at least one partition wall 212W, and the partition wall 212W can divide the second frame 212 into multiple venting channels (VCs).

[0114] Thus, some venting channels (VCs) may have independent venting paths without sharing space with each other. As a result, high-temperature venting gas and particles passing through one venting channel (VC) are not propagated to other venting channels (VCs). This minimizes the propagation of thermal events generated in a particular battery cell 110 to other battery cells 110. Therefore, high-temperature venting gas and particles do not flow back into other battery cells 110 that are in communication with other venting channels (VCs), and consequently, thermal events are not propagated or triggered in other battery cells 110. In this embodiment, by realizing independent venting paths for the venting channels (VCs), thermal runaway transitions between battery cells 110 are minimized, preventing explosion and structural collapse of the battery pack.

[0115] The high-temperature venting gas and particles flowing along the venting channel (VC) of the bottom frame 210 move into the venting space (VS) between the separation frame 800 and the second side frame 222, and can then be finally discharged to the outside through a venting device formed on the second side frame 222. There are no particular limitations on the specific form of the venting device, and the venting device may be a valve structure that opens or bursts when the internal pressure exceeds a certain level.

[0116] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but such terms are merely for explanatory convenience and may change depending on the position of the object in question, the observer's position, etc.

[0117] The battery pack according to the embodiment described above can be applied to a variety of devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as ESS (Energy Storage Systems), but it is not limited to these and can be applied to various devices that can use secondary batteries.

[0118] 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 made by those skilled in the art, utilizing the basic concepts of the present invention as defined in the following claims, also fall within the scope of the present invention. [Explanation of Symbols]

[0119] 100 Battery Pack 110 battery cells 110V vent section 200 Pack Frame 210 Bottom Frame 220 Side Frame 220C hollow 300 Spacer 400 Holding Frame 610 Pack Top Cover 620 pack bottom cover 910 Inlet Port 920 Outlet Port

Claims

1. It is a battery pack, Multiple battery cells, A pack frame including a bottom frame and side frames that form a storage space in which the battery cells are housed, The storage space includes a coolant that flows while directly cooling the battery cells, The side frame is provided with an inlet port for the inflow of the refrigerant and an outlet port for the discharge of the refrigerant. A hollow space is formed inside the side frame, and each of these hollow spaces is in communication with the inlet port and the outlet port. Battery pack.

2. The side frame is a rectangular tube structure with the hollow formed inside. The battery pack according to claim 1.

3. The inlet port and outlet port are located on the side of the side frame opposite to the side facing the battery cell. The battery pack according to claim 1.

4. Cooling holes communicating with the hollow are formed on the side of the side frame that faces the battery cell. The battery pack according to claim 3.

5. The refrigerant flows through the hollow space, enters the storage space, or is discharged from the storage space. The battery pack according to claim 1.

6. The aforementioned hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port. The inlet cavity and the outlet cavity are separated from each other. The battery pack according to claim 1.

7. The refrigerant flows into the storage space through the inlet port and the inlet hollow, The refrigerant that directly cooled the battery cell is discharged to the outside through the discharge cavity and the outlet port. The battery pack according to claim 6.

8. The side frame includes a first side frame and a second side frame that are positioned opposite each other with respect to the battery cells, In the first side frame, the inlet port and the outlet port are all formed. The battery pack according to claim 1.

9. The aforementioned hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port. A vertical beam that divides the storage space into a first area and a second area is arranged on the bottom frame, The refrigerant flows sequentially through the first and second zones. The battery pack according to claim 8.

10. A separation frame is placed between the battery cell and the second side frame. The refrigerant circulates along the inlet cavity of the first side frame, the first area, the internal cavity of the separation frame, the second area, and the discharge cavity of the first side frame. The battery pack according to claim 9.

11. The hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port, dividing the storage space into a first and second area, and a vertical beam with a passage formed inside is arranged on the bottom frame. The refrigerant flowing through the first area and the refrigerant flowing through the second area flow along the same direction. The battery pack according to claim 8.

12. The refrigerant circulates along the inlet cavity of the first side plate, the first and second zones, the passage inside the vertical beam, and the discharge cavity of the first side plate. The battery pack according to claim 11.

13. The aforementioned battery cell includes a vent portion, The bottom frame has a venting channel formed therein that guides the venting gas and particles discharged from the vent portion of the battery cell. The battery pack according to claim 1.

14. A vertical beam that divides the storage space into multiple areas is arranged on the bottom frame, The venting channel corresponding to any one of the aforementioned areas has an independent venting channel that is not shared with the venting channel corresponding to the other aforementioned area. The battery pack according to claim 13.

15. A device comprising a battery pack according to any one of claims 1 to 14.

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