Battery packs and devices containing them

Abstract

We provide battery packs and devices containing them that offer superior cooling performance and other advantages. [Solution] 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 housing space in which the battery cells are housed; spacers located on the top of the bottom frame on which the battery cells are fixed; a holding frame located on the top of the spacers and having holes formed therein in which the battery cells are sandwiched; and a coolant that flows through the spacers and the holding frame to directly cool the battery cells inside the pack frame.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2024 - 0013809 filed on January 30, 2024, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0002] The present invention relates to a battery pack and a device including the same, and more specifically, to an immersion - cooled battery pack and a device including the same.

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, starting from the utilization of secondary batteries as an energy storage source, and the demand for battery packs that aggregate multiple 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, such high-power, high-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from multiple battery cells can be added together in a confined space, potentially causing a rapid increase in temperature. In other words, while battery packs containing multiple 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 properly managed, the battery cells will degrade more quickly, their lifespan will be shortened, and the risk of explosion or fire will increase.

[0008] 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 multiple battery modules are arranged intensively to extend the vehicle's driving range, flames or heat generated from one battery cell can easily propagate to neighboring cells, potentially leading to the battery pack itself catching fire or exploding. Therefore, to effectively cool high-capacity battery packs, immersion cooling, a method in which a refrigerant directly cools the battery cells inside the battery pack, is used. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The problem that this invention aims to solve is to provide a battery pack and a device including the same that can improve cooling performance by immersion cooling, which directly cools battery cells using a refrigerant, while preventing refrigerant leakage.

[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 housing space in which the battery cells are housed; spacers located on top of the bottom frame on which the battery cells are fixed; a holding frame located on top of the spacers, with holes formed therein in which the battery cells are sandwiched; and a coolant flowing through the space between the spacers and the holding frame to directly cool the battery cells inside the pack frame.

[0012] The first waterproof adhesive can be applied to the upper part of the holding frame.

[0013] In the region above the holding frame, busbars that guide the electrical connections of the battery cells can be connected to the electrode terminals of the battery cells.

[0014] At least a portion of the busbar can be surrounded by the first waterproof adhesive.

[0015] The battery pack may further include a pack top cover that covers the open top of the pack frame. A first waterproof adhesive can be applied to the space between the holding frame and the pack top cover.

[0016] A foam member can be provided on the lower surface of the upper cover of the pack.

[0017] The second waterproof adhesive can be applied to the surface of the spacer that faces the battery cell.

[0018] The battery pack may further include a lower pack cover that covers the lower part of the bottom frame. When viewed along the height direction, a junction line can be formed between the lower pack cover and the bottom frame along the outer circumference of the area where the battery cells are located.

[0019] The aforementioned battery cell may have a vent portion.

[0020] The vent portion of the battery cell can face the spacer.

[0021] The spacer can include a spacer venting portion that is a portion facing the vent portion; and an outer peripheral portion surrounding the spacer venting portion. The spacer venting portion can have a thickness thinner than that of the outer peripheral portion or can have a notching groove.

[0022] A venting channel for guiding venting gas and particles discharged from the vent portion of the battery cell can be formed in the bottom frame.

[0023] The bottom frame can include a first frame and a second frame located below the first frame.

[0024] The venting channel can be formed between the first frame and the second frame.

[0025] A through hole can be formed in the first frame. When viewed along the height direction, the through hole can be positioned so as to at least partially overlap with the vent portion of the battery cell.

[0026] A vertical beam that divides the battery cell into a plurality of battery cell groups can be located above the bottom frame.

[0027] The venting channel corresponding to one of the battery cell groups can have an independent venting flow path that is not shared with the venting channel corresponding to the other battery cell groups.

[0028] The venting channel can communicate with a venting device provided in the side frame.

[0029] The device according to an embodiment of the present invention includes the battery pack.

Advantages of the Invention

[0030] According to an embodiment of the present invention, in immersion cooling in which a battery cell is directly cooled using a refrigerant, since the refrigerant flows in the region between a spacer on which the battery cell is fixed and a holding frame in which holes for sandwiching the battery cell are formed, the cooling performance can be increased while preventing the refrigerant from leaking to the outside.

[0031] Also, when a thermal event occurs in the battery cell, high-temperature venting gas, particles, flames, etc. ejected from the battery cell move along a specific path intended in advance by a venting channel formed in the bottom frame and are discharged to the outside of the battery pack.

[0032] [[ID=1-six]]The advantages of the present invention are not limited to the above advantages, 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

[0033] [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] It is a perspective view showing a state in which a battery cell, a spacer, a holding frame, etc. according to an embodiment of the present invention are assembled. [Figure 5] It is a perspective view showing a battery cell and a holding frame according to an embodiment of the present invention. [Figure 6] It is an exploded perspective view of the battery cell and the holding frame of FIG. 5. [Figure 7](a) and (b) are a perspective view and a side view of a battery cell according to one embodiment of the present invention, respectively. [Figure 8] This is a cross-sectional view showing a section cut along the cutting line AA in Figure 7(a). [Figure 9] This is a cross-sectional view of a battery cell according to one embodiment of the present invention. [Figure 10] This is a cross-sectional perspective view of a battery pack according to one embodiment of the present invention. [Figure 11] This is a partial cross-sectional view showing an enlarged view of section "B" in Figure 10. [Figure 12] This is a partial cross-sectional view showing an enlarged view of the "C" portion of Figure 11. [Figure 13] This is a partial cross-sectional view showing an enlarged view of the "D" portion of Figure 11. [Figure 14] This is a perspective view showing a battery cell and spacer according to one embodiment of the present invention. [Figure 15] This is a magnified partial perspective view of a spacer according to one embodiment of the present invention. [Figure 16] This is a cross-sectional perspective view of a pack frame according to one embodiment of the present invention. [Figure 17] This is a partial cross-sectional view showing an enlarged view of the "E" portion of Figure 16. [Figure 18] This is a partial cross-sectional view showing an enlarged view of the "F" portion of Figure 17. [Figure 19] This is a partial cross-sectional view of a battery pack according to another embodiment of the present invention. [Figure 20] This is a perspective view showing a pack frame according to one embodiment of the present invention, with the first side frame removed. [Figure 21] This is an exploded perspective view of the bottom frame according to one embodiment of the present invention. [Figure 22] This is a plan view showing a battery cell according to one embodiment of the present invention and the welding lines around it. [Figure 23] This is a plan view showing a battery cell and a lower pack cover according to one embodiment of the present invention. [Figure 24]This is a partial perspective view showing a part of the bottom frame according to one embodiment of the present invention. [Figure 25] This is a partial perspective view showing the bottom frame of Figure 24 with the first frame removed. [Figure 26] This is a partial perspective view showing the bottom frame of Figure 25 with the separation frame removed. [Figure 27] This is a plan view showing a part of the bottom frame according to one embodiment of the present invention. [Figure 28] This is a plan view showing the bottom frame of Figure 27 with the first frame removed. [Modes for carrying out the invention]

[0034] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be implemented in several different forms and is not limited to the embodiments described herein.

[0035] To clearly explain the present invention, irrelevant parts have been omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

[0036] 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.

[0037] Furthermore, when a layer, membrane, region, plate, or other part is "on top of" or "on top of" another part, this includes not only when it is "directly above" the other part, but also when there is another part 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 top of" 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 top of" the opposite direction of gravity.

[0038] Furthermore, throughout the specification, when a part "includes" a certain component, unless otherwise stated, it means that it may include other components rather than excluding them.

[0039] 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.

[0040] 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. Figure 4 is a perspective view showing the assembled battery cell, spacer, and holding frame according to one embodiment of the present invention. Figure 5 is a perspective view showing the battery cell and holding frame according to one embodiment of the present invention. Figure 6 is an exploded perspective view of the battery cell and holding frame of Figure 5.

[0041] Referring to Figures 1 to 6, 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 side frames 220 that form a housing space for housing the battery cells 110; spacers 300 located on the top of the bottom frame 210 on which the battery cells 110 are fixed; a holding frame 400 located on the top of the spacers 300, with holes 400H formed therein for sandwiching the battery cells 110; and a refrigerant flowing through the space between the spacers 300 and the holding frame 400 to directly cool the battery cells 110 inside the pack frame 200. In other words, the battery pack 100 according to this embodiment corresponds to an immersion cooling type battery pack 100 in which the refrigerant flows inside the pack frame 200 and comes into contact with the battery cells 110, directly cooling the battery cells 110, rather than the conventional indirect cooling method which provides a heat sink through which the refrigerant flows in the battery pack.

[0042] In the battery pack 100 according to this embodiment, the refrigerant flows through the space between the spacer 300 and the holding frame 400, preventing it from flowing through other spaces. In other words, the spacer 300 and the holding frame 400 can define the space through which the refrigerant flows, preventing it from leaking 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. By preventing refrigerant leakage in this way, the safety and cooling performance of the battery pack 100 can be improved.

[0043] Below, we will first describe in detail the battery cell 110 according to this embodiment.

[0044] Figures 7(a) and 7(b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention. Figure 8 is a cross-sectional view showing a section cut along the cutting line AA of Figure 7(a). Figure 9 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0045] Referring to Figures 7 to 9, the battery cell 110 according to this embodiment can have a vent section 110V. The vent section 110V is a general term for the 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.

[0046] For 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.

[0047] The battery can 20 according to this embodiment is a cylindrical case with an open top, capable of housing an electrode assembly 10 and an electrolyte (not shown) in its internal storage space, and may be made of a metallic material such as aluminum (Al).

[0048] 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 may 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.

[0049] 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 may be made of a conductive metallic material such as aluminum, copper, steel, or nickel, and may be electrically connected to the first segment piece 11 of the electrode assembly 10. The electrical connection may be made by welding. In such an embodiment, a lead 60 may be connected to the first current collector plate 41. The lead 60 may extend upward from the electrode assembly 10 and be coupled to a coupling plate 32. In another embodiment, the lead 60 may also be directly coupled to the underside of the top cap 31. The coupling between the lead 60 and other components may be made by welding. Alternatively, the first current collector plate 41 may be formed integrally with the lead 60. In this case, the lead 60 may have a long plate-like shape extending outward from near the center of the first current collector plate 41.

[0050] The first current collector plate 41 may have a plurality of radially formed protrusions (not shown) on its lower surface. When 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 in a manner that partially melts 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 can have a lower melting point compared to the first current collector plate 41 and the first segment piece 11. Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0051] On the other hand, the battery cell 110 according to this embodiment may further include a second current collector plate 42 located below 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 metal 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 may be applied to the coupling of the second current collector plate 42. Thus, the battery can 20 according to this embodiment may function as a second electrode terminal 112, which is an external terminal of the second electrode included in the electrode assembly 10.

[0052] 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 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, particularly the beading portion 20B (Beading part) of the battery can 20, which will be described later. The insulating plate 70 may also be provided with separate lead holes so that 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.

[0053] The peripheral 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, thereby fixing the assembly of the electrode assembly 10 and the first current collector plate 41. This 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. As an example, the insulating plate 70 may include one or more materials selected from the group consisting of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0054] 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 portion of the battery can 20 that surrounds the cap assembly 30 and the gasket 50. Specifically, the battery can 20 and the cap assembly 30 can be crimped together with the gasket 50 in between. That is, crimp bonding can be applied to the bonding between 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 placing the gasket 50 between the battery can 20 and the cap assembly 30, crimp bonding is performed by bending one end of the upper part of the battery can 20 in the direction in which the cap assembly 30 is located.

[0055] 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 curves inward toward the center, and is intended for the stable positioning 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 crimping bond described above can be performed.

[0056] The gasket 50 according to this embodiment is located 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 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 purple olalkoxy alkane (PFA).

[0057] 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 9).

[0058] When a thermal event or thermal runaway occurs inside a single battery cell 110, high-temperature venting gas and particles may be generated. The vent section 110V is a general term for components and mechanisms that can discharge such high-temperature venting gas and particles. As an example, a notch section 110N can be formed on the bottom surface of the battery cell 110, at the bottom of the battery can, where the thickness is relatively thinner than the adjacent area. The notch section 110N can form a certain circumference. When 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 gas and particles can be discharged through this opened vent section 110V.

[0059] However, the structure of the vent section 110V described above is just one example, and there are no special limitations 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.

[0060] On the other hand, although not specifically shown in the illustrations, 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. In other words, although the battery cell according to this embodiment is depicted as a cylindrical battery cell in the drawings, this is just one exemplary 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.

[0061] 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 housing space in which the battery cells 110 are housed. The battery cells 110 are placed on the bottom frame, and the side frames 220 can be connected along the periphery 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 periphery of the rectangular bottom frame 210. The bottom frame 210 and the side frames 220 provide a housing space with an open top, in which the battery cells 110 can be placed. After the battery cells 110 are placed in the housing space, the open top of the housing space can be covered by the pack top cover 610. The pack top cover 610 can be joined to the side frame 220 of the pack frame 200, for example, by welding or by using adhesive. The battery cell 110 can be sealed by the pack frame 200 and the pack top cover 610. Although not specifically shown, a gasket can be interposed between the pack top cover 610 and the side frame 220 to enhance the seal.

[0062] 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. When attaching the battery pack 100 to a device, the mounting portion 220M1 and the mounting beam 220M2 can be utilized. For example, when attaching 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.

[0063] The following describes in detail the battery pack structure for preventing refrigerant leakage in the immersion cooling method according to this embodiment.

[0064] Figure 10 is a cross-sectional perspective view of a battery pack according to one embodiment of the present invention. Figure 11 is a partial cross-sectional view showing an enlarged portion of "B" in Figure 10. Figure 12 is a partial cross-sectional view showing an enlarged portion of "C" in Figure 11. Figure 13 is a partial cross-sectional view showing an enlarged portion of "D" in Figure 11. Figure 14 is a perspective view showing a battery cell and spacer according to one embodiment of the present invention. Figure 15 is a partial perspective view showing an enlarged portion of the spacer according to one embodiment of the present invention.

[0065] Referring to Figures 2-6 and 10-15, as described above, the battery pack 100 according to this embodiment includes a spacer 300 located on top of the bottom frame 210, on which the battery cells 110 are fixed; a holding frame 400 located above the spacer 300, on which holes 400H are formed, in which the battery cells 110 are sandwiched; and a coolant (CL) flowing through the space between the spacer 300 and the holding frame 400 to directly cool the battery cells 110 inside the pack frame 200. As shown in Figure 11, the coolant (CL) flowing through the space between the spacer 300 and the holding frame 400 can directly cool the battery cells 110 while in contact with them.

[0066] An inlet port 910 and an outlet port 920 can be formed in the side frame 220. As an example, Figures 2 and 3 show a first side frame 221 with an inlet port 910 and an outlet port 920 formed therein. 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 can be connected to a refrigerant circulation system (not shown) outside the battery pack 100, allowing the refrigerant (CL) to circulate continuously.

[0067] The holding frame 400 can 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 can be sandwiched in these holes 400H. Therefore, the holes 400H of the holding frame 400 can 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 can be circular, and if the battery cells 110 are rectangular, the holes 400H of the holding frame 400 can be square.

[0068] Furthermore, the holding frame 400 may include protrusions. As shown in Figure 11, the protrusion 400P of the holding frame 400 can be locked and coupled to the side frame 220 or the vertical beam 700 described later. By locking and coupling the protrusion 400P, the holding frame 400 can be attached to the side frame 220 or the vertical beam 700 while remaining a certain distance away from the spacer 300. The holding frame 400 is kept a certain distance away from the spacer 300, ensuring a space for the refrigerant (CL) to flow.

[0069] The spacer 300 can be placed on the bottom frame 210. The spacer 300 can have a fixing portion 310 on which the battery cell 110 can be fixed. Rather than the battery cell 110 being directly located on the bottom frame 210, the battery cell 110 can be fixed to the fixing portion 310 of the spacer 300 and then placed on the bottom frame 210. For this reason, the fixing portion 310 of the spacer 300 can have a shape that corresponds 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 can be circular, and if the battery cell 110 is a rectangular battery, the fixing portion 310 of the spacer 300 can 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.

[0070] As described above, the spacer 300 and the holding frame 400 set a space through which the refrigerant (CL) flows and prevent the refrigerant (CL) from leaking into other spaces. The spacer 300 corresponds to the lower limit of refrigerant flow, and the holding frame 400 corresponds to the upper limit of refrigerant flow. In this way, by preventing refrigerant leakage, the safety and cooling performance of the battery pack 100 can be improved.

[0071] 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 cell 110 can function as the first electrode terminal 111 and the second electrode terminal 112 of the battery cell 110. By connecting the busbars 130 to these first electrode terminal 111 and second electrode terminal 112, HV connections, which are the electrical connections of the battery cells 110, can be made. HV connections are connections as a power source to supply power that requires high voltage, and refer to 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 made in the region above the holding frame 400. That is, the holding frame 400 separates the space through which the refrigerant (CL) flows from the space for HV connections 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. If 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 using the holding frame 400, the effect of the refrigerant (CL) on the electrical connections of the battery cell 110 can be minimized while maintaining the effect of increased cooling performance due to the direct cooling of the refrigerant (CL).

[0072] 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 prevents the refrigerant (CL) from leaking beyond the holding frame 400 into the area above the holding frame 400. With the battery cells 110 mounted 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 area above the battery cells 110.

[0073] 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 may 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 may 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 area above the holding frame 400.

[0074] Figure 16 is a cross-sectional perspective view of a pack frame according to one embodiment of the present invention. Figure 17 is a partial cross-sectional view showing an enlarged view of portion "E" in Figure 16. Figure 18 is a partial cross-sectional view showing an enlarged view of portion "F" in Figure 17.

[0075] Referring to Figures 11, 12, and 14-18, 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 prevent the refrigerant (CL) from leaking beyond the spacer 300 into the lower region of the spacer 300.

[0076] 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 properties such as impact resistance, adhesion, and electrical insulation. For example, the first waterproof adhesive 500a and the second waterproof adhesive 500b may include two-component epoxy materials in which a curing agent is mixed with a main component.

[0077] 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) 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 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.

[0078] Figure 19 is a partial cross-sectional view of a battery pack according to another embodiment of the present invention.

[0079] Referring to Figure 19, as described above, the first waterproof adhesive 500a can be applied to the space between the holding frame 400 and the pack upper cover 610. In another embodiment of the present invention, the battery pack 100 may be provided with a foam member 611 on the lower surface of the pack upper cover 610. The foam member 611 may be a foamed material and can be attached to the lower surface of the pack upper cover 610. The space between the holding frame 400 and the foam member 611 can be filled with the first waterproof adhesive 500a.

[0080] High-temperature venting gas and particles from inside the battery cell 110 are discharged from the vent section 110V of the battery cell 110. These high-temperature venting gases and particles can be discharged to the outside of the battery pack 100 through the venting channel (VC) of the bottom frame 210, which will be described later. At this time, in order to prevent the venting gases and particles from being discharged towards the upper cover 610 of the pack rather than in the direction of the venting channel (VC) of the bottom frame 210, a foam member 611 can be attached to the underside of the upper cover 610 of the pack. In other words, the foam member 611 can be a kind of top potting member.

[0081] Figure 20 is a perspective view showing a pack frame according to one embodiment of the present invention, with the first side frame removed. Figure 21 is an exploded perspective view of the bottom frame according to one embodiment of the present invention.

[0082] Referring to Figures 20 and 21 together with Figures 3, 5, 6, 12, 16, 17, 18, etc., as described above, the pack frame 200 includes a bottom frame 210 and side frames 220. A venting channel (VC) can be formed in the bottom frame 210 according to one embodiment of the present invention. Specifically, the bottom frame 210 may include a first frame 211 and a second frame 212 located below the first frame 211, and a venting channel (VC) can be formed between the first frame 211 and the second frame 212. The detailed structure of the bottom frame 210 and the venting channel (VC) will be described later.

[0083] In the battery pack 100 according to this embodiment, vertical beams 700 that divide the battery cells 110 into multiple battery cell groups 110G can be positioned on the bottom frame 210. The vertical beams 700 can be positioned 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. As an example, Figures 2 to 6 show that three vertical beams 700 are positioned on the bottom frame 210 at regular intervals. This allows the battery cells 110 to be divided into four battery cell groups 110G.

[0084] On the other hand, the battery pack 100 according to this embodiment may include a separation frame 800 located adjacent to the side frame 220. For example, the separation frame 800 may be located adjacent to the second side frame 222. The separation frame 800 may be located between the second side frame 222 and the battery cell 110, and may be placed on the bottom frame 210. A venting space (VS) can 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 separation frame 800 and the venting space (VS) will be described later.

[0085] The side frame 220, vertical beam 700, and separation frame 800 in this embodiment may be metal frames having internal cavities. Specifically, the side frame 220, vertical beam 700, and separation frame 800 can be square pipe-shaped metal frames 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 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.

[0086] On the other hand, the battery pack 100 according to this embodiment may further include a pack lower cover 620 that covers the lower part of the bottom frame 210. The pack lower cover 620 may be a plate-shaped member made of a metal material.

[0087] The following describes the joint line between the pack's lower cover 620 and the bottom frame 210.

[0088] Figure 22 is a plan view showing a battery cell and the surrounding welding lines according to one embodiment of the present invention. Figure 23 is a plan view showing a battery cell and the lower cover of the pack according to one embodiment of the present invention.

[0089] Referring to Figures 11, 17, and 20-23, when viewed along the height direction, a junction line (BL) can be formed between the pack's lower cover 620 and the bottom frame 210 along the outer circumference of the area where the battery cell 110 is located. Here, viewing along the height direction means viewing along one surface of the bottom frame 210, perpendicular to that surface. More specifically, viewing along the height direction can correspond to viewing along the -z axis direction on the xy plane, as shown in Figures 22 and 23.

[0090] The joint line (BL) between the pack lower cover 620 and the bottom frame 210 may be the area where welding is performed. In particular, the area where the pack lower cover 620 and the bottom frame 210 are welded may be the area where the side frame 220, vertical beam 700, and separation frame 800 are located. That is, the side frame 220, bottom frame 210, and pack lower cover 620 can be joined together by welding. Also, the vertical beam 700, bottom frame 210, and pack lower cover 620 can be joined together by welding. Also, the separation frame 800, bottom frame 210, and pack lower cover 620 can be joined together by welding. In Figure 22, the joint line (BL) surrounding the outer circumference of the battery cell 110 may be the area where the side frame 220, bottom frame 210, and pack lower cover 620 are joined together. Furthermore, the junction line (BL) located between the battery cell groups 110G in Figure 22 may be the portion where the vertical beam 700, bottom frame 210, and pack lower cover 620 are joined together. Also, in Figure 22, the junction line (BL) located directly above each battery cell group 110G may be the portion where the separation frame 800, bottom frame 210, and pack lower cover 620 are joined together.

[0091] On the other hand, the pack lower cover 620 according to this embodiment may include an indented portion 620D that curves upward. Such an indented portion 620D may be a portion that curves upward for joining with the vertical beam 700. The indented portion 620D of the pack lower cover 620 is joined with the bottom frame 210 and the vertical beam 700, and a joint line (BL) can be formed in that portion.

[0092] As mentioned above, the joint line (BL) between the pack lower cover 620 and the bottom frame 21, formed along the outer circumference of the area where the battery cell 110 is located, can also be the part to which the side frame 220 is joined. Such a joint line (BL) not only fixes the side frame 220, the bottom frame 210, and the pack lower cover 620 together, but also provides a leak prevention function to prevent refrigerant (CL) from leaking to the outside of the battery pack 100. Specifically, in the downward direction of the battery cell 110, the spacer 300 and the second waterproof adhesive 500b described earlier can provide a primary refrigerant leak prevention function. The joint line (BL) formed along the outer circumference of the area where the battery cell 110 is located can provide a secondary refrigerant leak prevention function in the downward direction of the battery cell 110. That is, even if refrigerant (CL) leaks through the spacer 300 and the second waterproof adhesive 500b, such refrigerant (CL) is sealed by the joint line (BL) and does not leak to the outside. Similarly, junction lines (BL) located between battery cell groups 110G and junction lines (BL) located directly above battery cell groups 110G can also function to prevent refrigerant (CL) from leaking to the outside.

[0093] On the other hand, welding between the pack lower cover 620 and the bottom frame 210 can be performed from one side of the pack lower cover 620 in only one direction. This is because the opposite side has the side frame 220, vertical beam 700, or separation frame 800, etc. In such cases where welding is performed from one side of the pack lower cover 620 in only one direction, the FSW (Friction Stir Welding) method is preferably applied.

[0094] The directional venting structure of the battery pack 100 according to this embodiment will be described below.

[0095] Referring again to Figures 8, 12, 14, 15, and 18, the vent portion 110V of the battery cell 110 in this embodiment can face the spacer 300. More specifically, the vent portion 110V of the battery cell 110 can 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 may have notched grooves. 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, allowing the spacer venting section 320a to open. In other words, the 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.

[0096] Figure 24 is a partial perspective view showing a part of the bottom frame according to one embodiment of the present invention. Figure 25 is a partial perspective view showing the bottom frame of Figure 24 with the first frame removed. Figure 26 is a partial perspective view showing the bottom frame of Figure 25 with the separation frame removed. Figure 27 is a plan view showing a part of the bottom frame according to one embodiment of the present invention. Figure 28 is a plan view showing the bottom frame of Figure 27 with the first frame removed.

[0097] Referring to Figures 24 to 28 together with Figures 11, 12, 17, 18, 21, etc., a bottom frame 210 according to one embodiment of the present invention can have a venting channel (VC) formed to guide high-temperature venting gas and particles discharged from the vent portion 110V of the battery cell 110. Specifically, the bottom frame 210 may include a first frame 211 and a second frame 212 located below the first frame 211, and a venting channel (VC) can be formed between the first frame 211 and the second frame 212.

[0098] A through-hole 211H can be formed in the first frame 211. When viewed along the height direction, the through-hole 211H can be positioned so as to overlap at least a portion with the vent portion 110V of the battery cell 110. The through-hole 211H can be provided in a one-to-one correspondence with the vent portion 110V. Similarly, the through-hole 211H can be provided in a one-to-one correspondence with the spacer venting portion 320a.

[0099] High-temperature venting gas and particles that have passed through the vent section 110V and the open spacer venting section 320a can 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 refers to the connection between battery cells, etc., as a connection that serves as a power source to supply power requiring high voltage. 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 additional explosions and flames. On the other hand, in the case of the battery pack 100 according to this embodiment, as mentioned above, it has a "lower venting" structure, so that high-temperature venting gas and particles caused by thermal events are discharged downwards, i.e., from 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 connections, and ultimately safety against thermal runaway phenomena can be enhanced.

[0100] 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 bus bar 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 bus bar 130 are located.

[0101] 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.

[0102] Furthermore, the spacer 300 and the second waterproof adhesive 500b not only prevent the refrigerant (CL) from leaking into the lower region of the spacer 300, but also prevent high-temperature venting gas and particles from leaking upward rather than downward towards the bottom frame 210.

[0103] On the other hand, as described above, the vertical beam 700 can divide the battery cell 110 into multiple battery cell groups 110G. A venting channel (VC) corresponding to one battery cell group 110G may have an independent venting channel that is not shared with the venting channels (VC) corresponding to other battery cell groups 110G. As an example, as shown in Figures 14 and 21, four second frames 212 can be provided, each corresponding to one of four battery cell groups 110G. A venting channel (VC) in one second frame 212 may not communicate with the venting channels (VC) in other second frames 212 and may have an independent venting channel.

[0104] Furthermore, the second frame 212 may have at least one partition wall 212W, which can divide the second frame 212 into multiple venting channels (VCs).

[0105] Thus, some venting channels (VCs) do not share space with each other and can have independent venting paths. 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 specific 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 to or triggered in other battery cells 110. In this embodiment, by realizing unique venting paths between venting channels (VCs), thermal runaway transitions between battery cells 110 are minimized, preventing explosion and structural collapse of the battery pack.

[0106] On the other hand, the venting channel (VC) in this embodiment can communicate with a venting device 220D provided on the side frame 220. High-temperature venting gas and particles flowing along the venting channel (VC) can be discharged to the outside of the battery pack 100 through such a venting device 220D. There are no particular limitations on the specific form of the venting device 220D, and the venting device 220D may be a valve structure that opens or bursts when the internal pressure exceeds a certain level. Figure 26 shows four venting devices 220D formed on the second side frame 222.

[0107] The following describes an example structure of the venting path from the venting channel (VC) to the venting device 220D.

[0108] As described above, the battery pack 100 according to this embodiment may include a separation frame 800 located adjacent to the side frame 220. The separation frame 800 may be positioned upright on the bottom frame 210 such that one surface of the separation frame 800 is perpendicular to one surface of the bottom frame 210. One surface of the separation frame 800 may be perpendicular to one surface of the vertical beam 700. The separation frame 800 may be located between the second side frame 222 and the battery cell 110, and a venting space (VS) may be formed between the separation frame 800 and the second side frame 222. Such a venting space (VS) can communicate with a venting device 220D.

[0109] As shown in Figures 21 and 27, the first frame 211 of the bottom frame 210 may have not only a through hole 211H but also an opening 211P. Such an opening 211P can communicate with a venting space (VS). When viewed along the height direction, the through hole 211H and the opening 211P can be located on opposite sides of each other with respect to the separation frame 800. That is, the separation frame 800 can separate the region in which the through hole 211H is formed from the region in which the opening 211P is formed.

[0110] Referring to Figures 24 and 25, the high-temperature venting gas and particles discharged from the vent section of the battery cell can flow into the venting channel (VC) provided between the first frame 211 and the second frame 212 through the through-hole 211H of the first frame 211. The incoming high-temperature venting gas and particles will flow along the direction in which the venting channel (VC) extends.

[0111] Referring to Figures 25 to 28, the high-temperature venting gas and particles flowing along the venting channel (VC) can flow into the venting space (VS) through the opening 211P of the first frame 211. Within this venting space (VS), the space can be divided and not shared by each battery cell group 110G. Finally, the high-temperature venting gas and particles that have flowed into the venting space (VS) can be discharged to the outside of the battery pack 100 through the venting device 220D.

[0112] In this embodiment, a long venting path is provided along the venting channel (VC), and a separate venting space (VS) may be provided in addition to the venting channel (VC). High-temperature venting gas and particles move along the elongated venting path, and the venting path is bent by the venting space (VS). While the venting gas flows along such a venting channel (VC) and venting space (VS), the temperature of the venting gas and particles can be reduced. Therefore, it is possible to prevent the venting gas and particles from causing an explosion. Furthermore, as the venting path becomes longer, it is possible to prevent oxygen flowing in from outside the battery pack 100 from meeting the venting gas, etc., thus preventing an explosion. In addition, larger particles can be filtered out in the venting path.

[0113] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but these terms are for explanatory convenience and may vary depending on the position of the object in question, the observer's position, etc.

[0114] 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 is not limited to these, and can be applied to various devices that can use secondary batteries.

[0115] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize 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]

[0116] 100 Battery Pack 110 battery cells 110V vent section 200 Pack Frame 210 Bottom Frame 220 Side Frame 300 Spacer 400 Holding Frame 500a 1st Waterproof Adhesive 500b Second Waterproof Adhesive 610 Pack Top Cover 620 Pack Bottom Cover

Claims

1. Multiple battery cells; A pack frame including a bottom frame and side frames that form a housing space in which the battery cells are housed; and Includes a spacer located on the upper part of the bottom frame, on which the battery cell is fixed; The aforementioned battery cell has a vent portion, A battery pack in which a venting channel is formed in the bottom frame to guide venting gas and particles discharged from the vent portion of the battery cell.

2. The battery pack according to claim 1, wherein the vent portion of the battery cell faces the spacer.

3. The spacer includes a spacer venting portion which is the portion facing the vent portion, and an outer peripheral portion which surrounds the spacer venting portion. The battery pack according to claim 2, wherein the spacer venting portion has a thinner thickness than the outer circumference or has a notched groove.

4. The bottom frame includes a first frame and a second frame located below the first frame. The battery pack according to claim 1, wherein the venting channel is formed between the first frame and the second frame.

5. A through hole is formed in the bottom frame. The battery pack according to claim 1, wherein, when viewed along the height direction, the through-hole is positioned such that at least a portion of it overlaps with the vent portion of the battery cell.

6. The battery pack according to claim 5, wherein the through-hole is provided so as to correspond one-to-one with the vent portion.

7. The battery pack according to claim 1, wherein a vertical beam that divides the battery cell into a plurality of battery cell groups is located on the bottom frame.

8. The battery pack according to claim 7, wherein the venting channel corresponding to one of the battery cell groups has an independent venting channel that is not shared with the venting channels corresponding to other battery cell groups.

9. The battery pack according to claim 1, wherein the venting channel is in communication with a venting device provided on the side frame.

10. The aforementioned venting channels are provided in multiple quantities, The battery pack according to claim 1, wherein the venting channels have independent venting channels that are not shared with each other.

11. The battery pack according to claim 1, wherein a refrigerant is provided inside the pack frame to directly cool the battery cells.

12. A device comprising a battery pack according to any one of claims 1 to 11.

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