Battery pack and device including same

Abstract

The battery pack according to an embodiment of the present invention comprises: a plurality of battery cells; a pack frame including a bottom frame and side frames forming an accommodation space in which the battery cells are accommodated; and a refrigerant which flows and directly cools the battery cells in the accommodation space. An inlet port for introducing the refrigerant and an outlet port for discharging the refrigerant are provided in the side frames. Hollows are formed inside the side frames, and each of the hollows communicates with the inlet port and the outlet port.

Description

Battery pack and device including same

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

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0013810, filed January 30, 2024, the entire contents of which are incorporated herein by reference.

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

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

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

[0006] Recently, as the need for large-capacity secondary battery structures has increased, including the use of secondary batteries as energy storage sources, the demand for battery packs that combine multiple secondary batteries is increasing.

[0007] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series / parallel, it is common to configure the battery pack by arranging the multiple battery cells within a pack frame and adding other components.

[0008] Since these battery cells are composed of rechargeable secondary batteries, these high-power, large-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from multiple battery cells accumulates in a small space, causing the temperature to rise rapidly and severely. In other words, while a battery pack containing multiple battery cells can achieve high output, it is difficult to remove the heat generated by the cells during charging and discharging. If the heat dissipation of the battery cells is not properly performed, the deterioration of the cells will be accelerated, shortening their lifespan and increasing the risk of explosion or fire.

[0009] Moreover, vehicle battery packs are frequently exposed to direct sunlight and may be subjected to high-temperature conditions, such as summer or desert regions. Furthermore, because multiple battery modules are densely packed to increase vehicle range, flames or heat generated from a single battery cell can easily spread to neighboring cells, ultimately leading to fire or explosion within the battery pack itself. Therefore, to effectively cool high-capacity battery packs, immersion cooling, in which a refrigerant directly cools the cells within the pack, is being utilized.

[0010] The problem to be solved by the present invention is to provide a battery pack having an efficient refrigerant circulation structure and a device including the same in immersion cooling, which directly cools battery cells using a refrigerant.

[0011] However, the problems to be solved by the embodiments of the present invention are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0012] According to one embodiment of the present invention, a battery pack comprises: a plurality of battery cells; a pack frame including a bottom frame and a side frame forming a storage space in which the battery cells are stored; and a coolant flowing in the storage space to directly cool the battery cells. An inlet port for introducing the coolant and an outlet port for discharging the coolant are provided in the side frame. Hollows are formed inside the side frame, and each of the hollows is connected to the inlet port and the outlet port.

[0013] The above side frame may be a rectangular structure with hollow sections formed inside.

[0014] The inlet port and the outlet port may be located on the opposite side of the side frame that faces the battery cells.

[0015] A cooling hole communicating with the hollow can be formed on the surface of the side frame facing the battery cells.

[0016] The above refrigerant may flow into the storage space or be discharged from the storage space while flowing through the cavity.

[0017] The above cavity may include an inlet cavity connected to the inlet port and an outlet cavity connected to the outlet port. The inlet cavity and the outlet cavity may be separated from each other.

[0018] The above refrigerant can be introduced into the storage space through the inlet port and the inlet cavity. The refrigerant that directly cools the battery cells can be discharged to the outside through the discharge cavity and the outlet port.

[0019] The side frame may include a first side frame and a second side frame positioned opposite each other with the battery cells interposed therebetween. Both the inlet port and the outlet port may be formed in the first side frame.

[0020] The above-mentioned cavity may include an inlet cavity connected to the inlet port and an outlet cavity connected to the outlet port. A vertical beam dividing the storage space into a first zone and a second zone may be positioned on the bottom frame. The refrigerant may sequentially flow through the first zone and the second zone.

[0021] A separation frame may be positioned between the battery cells and the second side frame. The coolant may circulate along the inlet cavity of the first side frame, the first zone, the cavity inside the separation frame, the second zone, and the discharge cavity of the first side frame.

[0022] The above-mentioned cavity may include an inlet cavity connected to the inlet port and an outlet cavity connected to the outlet port. A vertical beam dividing the storage space into a first zone and a second zone and having a passage formed therein may be positioned on the bottom frame. The refrigerant flowing in the first zone and the refrigerant flowing in the second zone may flow in the same direction.

[0023] The refrigerant can circulate along the inlet cavity of the first side plate, the first zone and the second zone, the passage inside the vertical beam, and the discharge cavity of the first side plate.

[0024] The above battery cells may include a vent portion. A venting channel may be formed in the bottom frame to guide venting gas or particles discharged from the vent portion of the battery cells.

[0025] A vertical beam dividing the storage space into a plurality of zones may be positioned on the bottom frame. The venting channel corresponding to one of the zones may have an independent venting path that is not shared with the venting channel corresponding to another zone.

[0026] A device according to one embodiment of the present invention includes the battery pack.

[0027] According to embodiments of the present invention, in immersion cooling that directly cools battery cells using a refrigerant, by utilizing the hollow spaces formed inside the side frame as cooling channels through which the refrigerant flows, space utilization can be increased and an efficient refrigerant circulation structure can be implemented.

[0028] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0029] Figures 1 and 2 are perspective views of a battery pack according to one embodiment of the present invention.

[0030] FIG. 3 is a perspective view showing a pack frame included in the battery pack of FIGS. 1 and 2.

[0031] Figures 4 (a) and 4 (b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention.

[0032] Fig. 5 is a cross-sectional view showing a cross-section taken along the cutting line A-A' in Fig. 4 (a).

[0033] Figure 6 is a cross-sectional view of a battery cell according to another embodiment of the present invention.

[0034] Figure 7 is a cross-sectional perspective view of a battery pack according to one embodiment of the present invention.

[0035] Figure 8 is a partial cross-sectional view showing an enlarged portion of “B” of Figure 7.

[0036] Figure 9 is an enlarged partial cross-sectional view of part “C” of Figure 8.

[0037] Fig. 10 is a partial cross-sectional view showing an enlarged portion of “D” of Fig. 8.

[0038] FIG. 11 is an exploded perspective view showing battery cells, a holding frame, and a spacer according to one embodiment of the present invention.

[0039] Figures 12 and 13 are perspective views showing a first side frame according to one embodiment of the present invention.

[0040] FIG. 14 is a cross-sectional perspective view showing a cross-section cut along a portion including an inlet port of a first side frame according to one embodiment of the present invention.

[0041] Figure 15 is a partial cross-sectional view showing an enlarged portion of “E” of Figure 14.

[0042] FIG. 16 is a cross-sectional perspective view showing a cross-section cut along a portion including an outlet port for a first side frame according to one embodiment of the present invention.

[0043] Figure 17 is a partial cross-sectional view showing an enlarged portion of “F” of Figure 16.

[0044] FIG. 18 is a partial perspective view showing an enlarged view of an inlet port and an outlet port formed in a first side frame according to one embodiment of the present invention.

[0045] Fig. 19 is a cross-sectional perspective view showing a cross-section cut along a portion including an inlet port in the first side frame of Fig. 18.

[0046] Fig. 20 is a cross-sectional perspective view showing a cross-section cut along a portion including an outlet port in the first side frame of Fig. 18.

[0047] Fig. 21 is a partial perspective view showing a part of a bottom frame according to one embodiment of the present invention.

[0048] Figure 22 is a plan view showing a bottom frame and battery cells according to one embodiment of the present invention.

[0049] FIG. 23 is a perspective view showing a first side frame according to another embodiment of the present invention.

[0050] Fig. 24 is a partial cross-sectional view showing a cross-section taken along the cutting line G-G' of Fig. 23.

[0051] Fig. 25 is a partial cross-sectional view showing a cross-section taken along the cutting line H-H' of Fig. 23.

[0052] Fig. 26 is a partial perspective view showing a part of a bottom frame according to another embodiment of the present invention.

[0053] Fig. 27 is a partial cross-sectional view showing a cross-section taken along the cutting line I-I' of Fig. 26.

[0054] Figure 28 is a plan view showing a bottom frame and battery cells according to another embodiment of the present invention.

[0055] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0056] In order to clearly explain the present invention, parts that are not related to the description are omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0057] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0058] Furthermore, when we say that a layer, membrane, region, plate, or other part is "on" or "over" another part, this includes not only cases where it is "directly on" the other part, but also cases where there are other parts in between. Conversely, when we say that a part is "directly on" another part, it means that there are no other parts in between. Furthermore, saying that a part is "on" or "over" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "above" or "over" the direction opposite to gravity.

[0059] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0060] Additionally, throughout the specification, when we say "in plan", we mean when the target portion is viewed from above, and when we say "in cross section", we mean when the target portion is viewed from the side in a cross-section cut vertically.

[0061] FIG. 1 and FIG. 2 are perspective views of a battery pack according to one embodiment of the present invention. FIG. 3 is a perspective view showing a pack frame included in the battery pack of FIG. 1 and FIG. 2.

[0062] Referring to FIGS. 1 to 3, a battery pack (100) according to one embodiment of the present invention includes: a pack frame (200) including a bottom frame (210) and a side frame (220) forming a storage space (SS) in which the battery cells (110) are stored; and a coolant flowing in the storage space (SS) to directly cool the battery cells (110). An inlet port (910) for introducing the coolant and an outlet port (920) for discharging the coolant are provided in the side frame (220) of the pack frame (200). Hollows are formed inside the side frame (220), and each of the hollows is connected to the inlet port (910) and the outlet port (920). That is, in the case of the battery pack (100) according to the present embodiment, it is not a conventional indirect cooling method in which a heat sink through which a coolant flows is provided in the battery pack, but rather an immersion cooling method in which a coolant flows inside the pack frame (200) and comes into contact with the battery cells (110) to directly cool the battery cells (110).

[0063] The side frame (220) according to the present embodiment has a cavity inside. For example, the side frame (220) may have a square pipe structure with cavities formed inside, and may include a metal material. Accordingly, the weight of the battery pack (100) can be reduced, while at the same time ensuring the rigidity of the battery pack (100).

[0064] In addition, in the battery pack (100) of the immersion cooling method, each of the hollows inside the side frame (220) is connected to the inlet port (910) and the outlet port (920), so that the hollows inside the side frame (220) can be utilized as a cooling path for supplying and discharging a coolant. The side frame (220) can function as a member for circulating the coolant, beyond a simple exterior frame. Accordingly, the components for supplying the coolant can be reduced, thereby reducing the weight and volume of the battery pack (100) and improving the assembling ability of the battery pack (100).

[0065] Below, the battery cell (110) according to the present embodiment will be described in detail.

[0066] Figures 4(a) and 4(b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention. Figure 5 is a cross-sectional view taken 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.

[0067] Referring to FIGS. 4 to 6 together, the battery cell (110) according to the present embodiments may have a vent part (110V). The vent part (110V) is a general term for a member or device provided in the battery cell (110) to discharge venting gas, etc. inside the battery cell (110).

[0068] For example, the battery cell (110) according to the present embodiment may be a cylindrical battery cell. Specifically, the battery cell (110) may include an electrode assembly (10); a battery can (20) that houses the electrode assembly (10) and has an open top; and a cap assembly (30) that is coupled to the open top of the battery can (20). A gasket (50) may be interposed between the battery can (20) and the cap assembly (30). Hereinafter, an exemplary structure of the battery cell (110) will be described, but the battery cell of the present invention is not limited to this structure.

[0069] The battery can (20) according to the present embodiment may be a cylindrical case with an open top, and may store an electrode assembly (10) and an electrolyte (not shown) in an internal storage space, and may include a metal material such as aluminum (Al).

[0070] The cap assembly (30) according to the present embodiment may include a top cap (31) having a plate shape and a connecting plate (32) electrically and mechanically connected to the top cap (31). The top cap (31) may include a metal material having electrical conductivity and may cover an open upper portion of the battery can (20). The top cap (31) may be electrically connected to a first segment (11) connected to a first electrode of the electrode assembly (10), and at the same time, may be electrically insulated from the battery can (20) by a gasket (50). Therefore, the cap assembly (30) according to the present embodiment including the top cap (31) may function as a first electrode terminal (111), which is an external terminal of the first electrode included in the electrode assembly (10).

[0071] Specifically describing the electrical connection between the top cap (31) and the first segments (11), the battery cell (110) according to the present embodiment may further include a first current collector (41) positioned on the upper portion of the electrode assembly (10). The first current collector (41) may include a conductive metal material such as aluminum, copper, steel, nickel, etc., and may be electrically connected to the first segments (11) of the electrode assembly (10). The electrical connection may be achieved through welding. A lead (60) may be connected to the first current collector (41). The lead (60) may extend upward from the electrode assembly (10) and be coupled to the connection plate (32). In another embodiment, the lead (60) may be directly coupled to the lower surface of the top cap (31). The coupling between the lead (60) and other components may be achieved through welding. Additionally, the first collector plate (41) may be formed integrally with the lead (60). In this case, the lead (60) may have a long plate shape extending outward from near the center of the first collector plate (41).

[0072] The first collector plate (41) may have a plurality of radially formed protrusions (not shown) on its lower surface. When the radially formed protrusions are provided, the first collector plate (41) may be pressed to press the protrusions into the bent first segments (11). The connection between the first collector plate (41) and the first segments (11) may be performed by, for example, laser welding. The laser welding may be performed by partially melting the base material of the first collector plate (41). In a variation, the welding between the first collector plate (41) and the first segments (11) may be performed with solder interposed. In this case, the solder may have a lower melting point compared to the first collector plate (41) and the first segments (11). The laser welding may be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0073] Meanwhile, the battery cell (110) according to the present embodiment may further include a second current collector (42) positioned at the bottom of the electrode assembly (10). Specifically, the second current collector (42) may be positioned between the electrode assembly (10) and the bottom (20F) of the battery can (20). The second current collector (42) may include a conductive metal material such as aluminum, copper, steel, nickel, etc., and may be electrically connected to the second segments (12) of the electrode assembly (10). One side of the second current collector (42) may be coupled to the second segments (12), and the opposite side of the second current collector (42) may be coupled to the bottom (20F) of the battery can (20). Welding may be applied to the coupling of the second current collector (42). Accordingly, the battery can (20) according to the present embodiment can function as a second electrode terminal (112), which is an external terminal of the second electrode included in the electrode assembly (10).

[0074] Meanwhile, the secondary battery according to the present embodiment may include an insulating plate (70). The insulating plate (70) may cover the first collector plate (41). The insulating plate (70) may cover the first collector plate (41) on the upper surface of the first collector plate (41), thereby preventing the first collector plate (41) from contacting the battery can (20), particularly the beading part (20B) of the battery can (20) described later. In addition, the insulating plate (70) may be provided with a separate lead hole so that a lead (60) extending upward from the first collector plate (41) may be drawn out. The lead (60) may be drawn out upward through the lead hole of the insulating plate (70) and coupled to the lower surface of the connecting plate (32) or the lower surface of the top cap (31).

[0075] The peripheral area of ​​the insulating plate (70) can be interposed between the first current collector (41) and the beading portion (20B) of the battery can (20), thereby fixing the assembly of the electrode assembly (10) and the first current collector (41). Accordingly, the assembly of the electrode assembly (10) and the first current collector (41) can be restricted from moving in the axial direction of the electrode assembly (10), thereby improving the assembly stability of the secondary battery. The insulating plate (70) can be made of an insulating polymer resin. In one example, the insulating plate (70) can include one or more materials selected from the group consisting of polyethylene, polypropylene, polyimide, and polybutylene terephthalate.

[0076] Meanwhile, the battery can (20) according to the present embodiment may include a crimping part (20C) and a beading part (20B). The crimping part (20C) is a part of the battery can (20) that surrounds the cap assembly (30) and the gasket (50). Specifically, the battery can (20) and the cap assembly (30) may be crimped with the gasket (50) interposed therebetween. That is, the crimping may be applied to the connection between the battery can (20) and the cap assembly (30). Accordingly, the crimping part (20C) may be formed in the battery can (20). More specifically, the crimping is performed by positioning the gasket (50) between the battery can (20) and the cap assembly (30), and then bending the upper end of the battery can (20) in the direction in which the cap assembly (30) is positioned.

[0077] The beading portion (20B) refers to a portion of the battery can (20) that is recessed toward the center in a region above the electrode assembly (10) among the side portions of the battery can (20), and is for the stable placement of the cap assembly (30) and the prevention of movement of the electrode assembly (10). That is, the cap assembly (30) according to the present embodiment and the gasket (50) surrounding it can be seated on the beading portion (20B) of the battery can (20). The above-described crimping connection can be performed in a state where the cap assembly (30) and the gasket (50) surrounding it are seated on the beading portion (20B).

[0078] The gasket (50) according to the present embodiment is positioned between the battery can (20) and the cap assembly (30), and can enhance the sealing property of the secondary battery. In addition, the gasket (50) may include an electrically insulating material, and may prevent a short circuit from occurring between the battery can (20), which functions as a second electrode terminal (112), and the cap assembly (30), which functions as a first electrode terminal (111). The gasket (50) may include one or more materials selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and perfluoroalkoxy alkane (PFA).

[0079] The vent portion (110V) according to the present embodiment can be formed on the lower surface of the battery cell (110). That is, it can be formed on the bottom portion (20F, see FIG. 6) of the battery can (20).

[0080] When a thermal event or thermal runaway phenomenon occurs inside a battery cell (110), high-temperature venting gas or particles may be generated. The vent part (110V) is a general term for a member or mechanism that can discharge such high-temperature venting gas or particles. For example, a notch part (110N) that is relatively thinner than the adjacent area may be formed at the bottom of the battery can among the lower surfaces of the battery cell (110). The notch part (110N) may have a constant circumference. When the internal pressure of the battery cell (110) increases due to high-temperature venting gas generated inside the battery cell (110), the notch part (110N) that is weak in rigidity due to its thin thickness may be ruptured first. The vent part (110V) is opened due to the rupture of the notch part (110N), and high-temperature venting gas or particles can be discharged through the opened vent part (110V).

[0081] However, the structure of this vent part (110V) is an example, and there is no special limitation on the shape of the vent part (110V) as long as it is a member or device that can discharge internal venting gas in the event of a thermal event or thermal runaway.

[0082] Meanwhile, although not specifically illustrated, the battery cell according to the present invention may be a square battery cell in which the electrode assembly is housed in a square can. That is, although the battery cell according to the present embodiment is depicted in the drawing as being a cylindrical battery cell, this is only one example of the structure of the battery cell of the present invention, and the battery cell according to another embodiment of the present invention may be a square battery cell.

[0083] Meanwhile, referring again to FIGS. 1 to 3, as described above, the pack frame (200) according to the present embodiment includes a bottom frame (210) and a side frame (220) that form a storage space (SS) in which battery cells (110) are stored. Battery cells (110) may be placed on the bottom frame (210), and a side frame (220) may be connected along an edge of the bottom frame (210). For example, the side frame (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) may be arranged along four sides of an edge of the bottom frame (210) having a rectangular shape. A storage space with an open upper portion is provided by the bottom frame (210) and the side frame (220), and battery cells (110) can be arranged in this storage space. After the battery cells (110) are arranged in the storage space, the open upper portion of the storage space can be covered by the pack upper cover (610). The pack upper cover (610) can be joined to the side frame (220) of the pack frame (200), and for example, welding or adhesive joining can be applied. The battery cells (110) can be sealed by the pack frame (200) and the pack upper cover (610). In addition, although not specifically illustrated, a gasket may be interposed between the pack upper cover (610) and the side frame (220) to enhance sealing properties.

[0084] Meanwhile, the battery pack (100) according to the present embodiment may include a mounting portion (220M1) and a mounting beam (220M2) provided on a side frame (220) for fixing the battery pack (100). For example, the mounting portions (220M1) are formed on the first side frame (221) and the second side frame (222), and the mounting beams (220M2) are formed on the third side frame (223) and the fourth side frame (224), as illustrated in FIGS. 1 and 2. The mounting portion (220M1) and the mounting beam (220M2) may be utilized when mounting the battery pack (100) to a device. For example, when mounting a battery pack (100) to a vehicle device, a mounting portion (220M1) and a mounting beam (220M2) can be fixed to the chassis of the vehicle.

[0085]

[0086] Below, the battery pack structure for preventing coolant leakage in the immersion cooling method according to the present embodiment will be described in detail.

[0087] Fig. 7 is a cross-sectional perspective view of a battery pack according to an embodiment of the present invention. Fig. 8 is a partial cross-sectional view enlarged and showing part “B” of Fig. 7. Fig. 9 is a partial cross-sectional view enlarged and showing part “C” of Fig. 8. Fig. 10 is a partial cross-sectional view enlarged and showing part “D” of Fig. 8. Fig. 11 is an exploded perspective view showing battery cells, a holding frame, and a spacer according to an embodiment of the present invention.

[0088] Referring to FIGS. 2, 3, 7 to 11, the battery pack (100) according to the present embodiment may further include a spacer (300) positioned on the upper portion of the bottom frame (210) and in which battery cells (110) are mounted, and a holding frame (400) positioned on the upper portion of the spacer (300) and in which holes (400H) into which battery cells (110) are fitted are formed.

[0089] The coolant (CL) introduced into the inlet port (910) can flow in 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 Fig. 8, the coolant (CL) flowing in the space between the spacer (300) and the holding frame (400) can directly cool the battery cells (110) by coming into contact with the battery cells (110).

[0090] As described above, an inlet port (910) and an outlet port (920) may be formed in the side frame (220). As an example, the inlet port (910) and the outlet port (920) formed in the first side frame (221) are illustrated in FIGS. 2 and 3. The coolant (CL) introduced through the inlet port (910) may flow along the space between the spacer (300) and the holding frame (400) to cool the battery cells (110) and then be discharged through the outlet port (920). The inlet port (910) and the outlet port (920) are connected to a coolant circulation system (not shown) outside the battery pack (100), so that the coolant (CL) can be continuously circulated.

[0091] The holding frame (400) may be positioned between the spacer (300) and the pack upper cover (610). A hole (400H) is formed in the holding frame (400) so that the battery cells (110) can be inserted into the hole (400H). To this end, the hole (400H) of the holding frame (400) may have a shape corresponding to the outer shape of the battery cell (110). When the battery cell (110) is a cylindrical battery, the hole (400H) of the holding frame (400) may be circular, and when the battery cell (110) is a square battery, the hole (400H) of the holding frame (400) may be square.

[0092] In addition, the holding frame (400) may include protrusions (400P). As illustrated in FIG. 11, the protrusions (400P) of the holding frame (400) may be hooked to the side frame (220) or the vertical beam (700) described later. Due to the hooked connection of the protrusions (400P), the holding frame (400) may be mounted to the side frame (220) or the vertical beam (700) while being spaced apart from the spacer (300) by a certain distance. As the holding frame (400) is spaced apart from the spacer (300) by a certain distance, a space for the refrigerant (CL) to flow may be secured.

[0093] The spacer (300) may be placed on the bottom frame (210). The spacer (300) may be formed with a mounting portion (310) on which the battery cells (110) may be mounted. The battery cells (110) may not be positioned directly on the bottom frame (210), but may be placed on the bottom frame (210) with the battery cells (110) mounted on the mounting portions (310) of the spacer (300). To this end, the mounting portion (310) of the spacer (300) may have a shape corresponding to the outer shape of the battery cell (110). When the battery cell (110) is a cylindrical battery, the mounting portion (310) of the spacer (300) may be circular, and when the battery cell (110) is a square battery, the mounting portion (310) of the spacer (300) may be square. Since the battery cells (110) are positioned in the mounting portion (310) of the spacer (300), the battery cells (110) can be stably placed and fixed in the space inside the pack frame (200).

[0094] As described above, the spacer (300) and the holding frame (400) can define a space in which the refrigerant (CL) flows and prevent the refrigerant (CL) 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. In this way, by preventing refrigerant leakage, the safety of the battery pack (100) can be enhanced along with its cooling performance.

[0095] Specifically, in an area above the holding frame (400), a bus bar (130) that guides the electrical connection of the battery cells (110) can be connected to the electrode terminals (111, 112) of the battery cells (110). As described above, the cap assembly (30) and the 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 bus bar (130) to the first electrode terminal (111) or the second electrode terminal (112), an HV connection, which is an electrical connection of the battery cells (110), can be formed. The HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to an electrical connection between battery cells or an electrical connection between a battery pack and a device. That is, in an area above the holding frame (400), the electrical connection of the battery cells (110) can be formed. In other words, the space through which the coolant (CL) flows and the space of the HV connection through which the electrical connection of the battery cells (110) is made can be separated from each other by the holding frame (400). As will be described later, the coolant (CL) may be an insulating oil or a coolant. If the coolant (CL), which is a coolant, comes into contact with the HV connection, a short circuit may occur, which may cause a serious safety problem. In addition, even if the coolant (CL) is an insulating oil, if the coolant (CL) comes into contact with the part through which the electrical connection of the battery cells (110) is made, it may have a negative effect on the electrical connection of the battery cells (110). Therefore, in the present embodiment, by separating the space through which the coolant (CL) flows by the holding frame (400) and the space through which the electrical connection of the battery cells (110) is made, the effect of increasing the cooling performance through direct cooling of the coolant (CL) can be maintained, while minimizing the effect of the coolant (CL) on the electrical connection of the battery cells (110).

[0096] In the battery pack (100) according to the present embodiment, a first waterproof adhesive (500a) may be applied to the upper portion of the holding frame (400). Due to the first waterproof adhesive (500a) applied to the upper portion of the holding frame (400), the coolant (CL) may be prevented from leaking beyond the holding frame (400) to the upper portion of the holding frame (400). In a state where the battery cell (110) is mounted in the hole (400H) of the holding frame (400), the first waterproof adhesive (500a) may be applied to the upper surface of the holding frame (400) and the upper portion of the battery cell (110).

[0097] As mentioned above, the battery pack (100) may include a pack upper cover (610) covering the open upper portion of the pack frame (200), and a first waterproof adhesive (500a) may be applied to a 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). In addition, the space surrounding the bus bar (130) may be filled with the first waterproof adhesive (500a). Furthermore, the space between the holding frame (400) and the pack upper cover (610) may be filled with the first waterproof adhesive (500a). Due to the holding frame (400) and the first waterproof adhesive (500a), the refrigerant (CL) may be prevented from leaking into the upper region of the holding frame (400).

[0098] In the battery pack (100) according to the present embodiment, a second waterproof adhesive (500b) may be applied to a surface of the spacer (300) that faces the battery cells (110). Specifically, the second waterproof adhesive (500b) may be applied on the mounting portion (310) of the spacer (300). Due to the spacer (300) and the second waterproof adhesive (500b), the coolant (CL) may be prevented from leaking beyond the spacer (300) to the lower region of the spacer (300).

[0099] The first waterproof adhesive (500a) and the second waterproof adhesive (500b) according to the present embodiment have no particular limitations on their materials, as long as they exhibit waterproof performance and have impact resistance, adhesiveness, and electrical insulation properties. For example, the first waterproof adhesive (500a) and the second waterproof adhesive (500b) may include a two-component epoxy-based material in which a curing agent is mixed into the main body.

[0100] Meanwhile, the coolant (CL) according to the present embodiment may be a fluid. Since the coolant (CL) directly contacts the battery cells (110) within the battery pack (100), the coolant (CL) may be electrically insulating. The coolant (CL) may be a material having insulating properties. For example, the coolant (CL) may be insulating oil. However, in the case of the battery pack (100) according to the present embodiment, since the coolant (CL) is prevented from leaking into areas other than the space between the spacer (300) and the holding frame (400), a general coolant may also be applied as the coolant (CL).

[0101]

[0102] Below, the refrigerant circulation structure in the battery pack (100) according to the present embodiment will be described.

[0103] 12 and 13 are perspective views illustrating a first side frame according to an embodiment of the present invention. Specifically, FIG. 12 shows a surface of the first side frame where the inlet port (910) and the outlet port (920) are located, and FIG. 13 shows an opposite surface of the surface of the first side frame where the inlet port (910) and the outlet port (920) are located. FIG. 14 is a cross-sectional perspective view showing a cross-section along a portion including the inlet port of the first side frame according to an embodiment of the present invention. FIG. 15 is a partial cross-sectional view showing an enlarged portion “E” of FIG. 14. FIG. 16 is a cross-sectional perspective view showing a cross-section along a portion including the outlet port of the first side frame according to an embodiment of the present invention. FIG. 17 is a partial cross-sectional view showing an enlarged portion “F” of FIG. 16.

[0104] Referring to FIG. 3 and FIG. 12 to FIG. 17 together, as described above, an inlet port (910) for introducing refrigerant and an outlet port (920) for discharging refrigerant are provided in the side frame (220). For example, the inlet port (910) and the outlet port (920) may be located in the first side frame (221) among the side frames (220).

[0105] In addition, an inlet port (910) and an outlet port (920) may be positioned on the opposite side of the side of the side frame (220) that faces the battery cells (110). Hollows (220C) are formed inside the side frame (220), and each of the hollows (220C) is connected to the inlet port (910) and the outlet port (920). Meanwhile, a cooling hole (220H) that is connected to the hollow (220C) may be formed on the side of the side frame (220) that faces the battery cells (110). That is, in the side frame (220), the cooling hole (220H) may be positioned on the opposite side of the inlet port (910) and the outlet port (920).

[0106] In the battery pack (100) of the immersion cooling method according to the present embodiment, the hollow space (220C) inside the side frame (220) can be utilized as a cooling path for supplying and discharging a coolant. That is, the coolant (CL) can flow through the hollow space (220C) and be introduced into the storage space (SS) where the battery cells (110) are located, or be discharged from the storage space (SS).

[0107] Meanwhile, for convenience of explanation, in FIGS. 12 to 17, both sides of the first side frame (221) are expressed as being open so that the hollow portion (220C) is visible. However, in reality, as illustrated in FIGS. 1 to 3, a sealing plate (220S) may be attached to both sides of the first side frame (221). The hollow portions (220C) inside the side frame (220) are closed on both sides. That is, the hollow portions (220C) have a sealed structure in which all sides are closed except for the path through the inlet port (910), the outlet port (920), and the cooling hole (220H).

[0108] Meanwhile, the inlet port (910) and the outlet port (920) according to the present embodiment may be located together on either side frame (220). For example, the inlet port (910) and the 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 the outlet port (920). Since this refrigerant circulation system (not shown) may be provided only on one side of the battery pack (100) (in the present embodiment, on the side where the first side frame (221) is located), it may be helpful in increasing the space utilization within the device in which the battery pack (100) is mounted.

[0109] Meanwhile, the hollow (220C) according to the present 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 inlet hollow (220C1) and the outlet hollow (220C2) that are not connected to each other are provided to separate the path of the refrigerant flowing in and the path of the refrigerant flowing out in the refrigerant circulation structure. In other words, the refrigerant flowing in the inlet hollow (220C1) does not mix with the refrigerant flowing in the outlet hollow (220C2).

[0110] In addition, the cooling hole (220H) formed on the opposite side of the surface where the inlet port (910) and the outlet port (920) are formed may include an inlet cooling hole (220H1) connected to the inlet cavity (220C1); and an exhaust cooling hole (220H2) connected to the exhaust cavity (220C2). The inlet port (910), the inlet cavity (220C1), and the inlet cooling hole (220H1) may be connected to each other, and the outlet port (920), the exhaust cavity (220C2), and the exhaust cooling hole (220H2) may be connected to each other.

[0111] Accordingly, the refrigerant (CL) can be introduced into the storage space (SS) through the inlet port (910) and the inlet cavity (220C1). More specifically, the refrigerant (CL) can be introduced into the storage space (SS) where the battery cells (110) are placed through the inlet port (910), the inlet cavity (220C1), and the inlet cooling hole (220H1) in sequence.

[0112] Meanwhile, the coolant (CL) that directly cools the battery cells (110) can be discharged to the outside through the discharge hole (220C2) and the outlet port (920). More specifically, the coolant (CL) that directly cools the battery cells (110) by flowing around the battery cells (110) within the storage space (SS) can be discharged to the outside through the discharge cooling hole (220H2), the discharge hole (220C2) and the outlet port (920) and returned to the coolant circulation system. As the coolant (CL) circulates within the battery pack (100) through a series of processes as described above, immersion cooling can be achieved.

[0113]

[0114] Below, the circulation form of the refrigerant (CL) according to one embodiment of the present invention will be described in detail.

[0115] Fig. 18 is a partial perspective view showing an enlarged view of an inlet port and an outlet port formed in a first side frame according to an embodiment of the present invention. Fig. 19 is a cross-sectional perspective view showing a cross-section cut along a portion including an inlet port in the first side frame of Fig. 18. Fig. 20 is a cross-sectional perspective view showing a cross-section cut along a portion including an outlet port in the first side frame of Fig. 18. Fig. 21 is a partial perspective view showing a part of a bottom frame according to an embodiment of the present invention. Fig. 22 is a plan view showing a bottom frame and battery cells according to an embodiment of the present invention. In particular, Fig. 22 shows a view of the bottom frame and battery cells when viewed along the -z-axis direction on the xy plane.

[0116] Referring to FIGS. 2, 3, 13, 15, 17 to 22 together, as described above, the side frame (220) according to the present embodiment may include a first side frame (221), a second side frame (222), a third side frame (223), and a fourth side frame (224). Here, the first side frame (221) and the second side frame (222) may be positioned on opposite sides with the battery cells (110) interposed therebetween. In addition, as described above, both an inlet port (910) and an outlet port (920) may be formed in the first side frame (221).

[0117] Meanwhile, in the battery pack (100) according to the present embodiment, a vertical beam (700) that divides the battery cells (110) into a plurality of battery cell groups may be positioned on the bottom frame (210). The vertical beam (700) may be positioned upright on the bottom frame (210) such that one side of the vertical beam (700) is perpendicular to one side of the bottom frame (210). The storage space (SS) in which the battery cells (110) are stored may be divided into a plurality of zones (Z1, Z2, Z3, Z4) by the vertical beam (700). As an example, three vertical beams (700) are shown positioned at a certain interval on the bottom frame (210). The storage space (SS) may be divided into a first zone (Z1), a second zone (Z2), a third zone (Z3), and a fourth zone (Z4) by the three vertical beams (700).

[0118] Meanwhile, the battery pack (100) according to the present embodiment may include a separation frame (800) positioned adjacent to the side frame (220). For example, the separation frame (800) may be positioned adjacent to the second side frame (222). The separation frame (800) may be positioned between the battery cells (110) and the second side frame (222), and may be placed on the bottom frame (210). A venting space (VS), which is a space through which venting gas discharged from the battery cells (110) is discharged, may be formed between the separation frame (800) and the second side frame (222). The venting space (VS) will be described later.

[0119] The vertical beam (700) and the separation frame (800) according to the present embodiment may be metal frames having an internal cavity, similar to the side frame (220). Specifically, the vertical beam (700) and the separation frame (800) may be metal frames in the form of a square pipe having a cavity. Accordingly, the weight of the battery pack (100) can be reduced, and at the same time, the rigidity of the battery pack (100) can be secured. In addition, since the bottom frame (210), the side frame (220), the vertical beam (700), and the separation frame (800) include metal materials, welding can be used for the connection between the respective frames. There is no particular limitation on the method of welding, but, for example, MIG welding (Metal Inert Gas Welding) or FSW (Friction Stir Welding) can be applied.

[0120] Meanwhile, the battery pack (100) according to the present embodiment may further include a pack lower cover (620) that covers the lower portion of the bottom frame (210). The pack lower cover (620) may be a plate-shaped member including a metal material.

[0121] As described above, the coolant (CL) can be sequentially introduced into the storage space (SS) where the battery cells (110) are placed through the inlet port (910), the inlet cavity (220C1), and the inlet cooling hole (220H1). At this time, the coolant (CL) can sequentially flow through the first zone (Z1) and the second zone (Z2) by the vertical beam (700) that divides the storage space (SS) into the first zone (Z1) and the second zone (Z2). In addition, the coolant (CL) can sequentially flow through the third zone (Z3) and the fourth zone (Z4) by the vertical beam (700) that divides the storage space (SS) into the third zone (Z3) and the fourth zone (Z4). The direction of the coolant (CL) flowing in the first zone (Z1) may be opposite to the direction of the coolant (CL) flowing in the second zone (Z2). Additionally, the direction of the refrigerant (CL) flowing in the third zone (Z3) may be opposite to the direction of the refrigerant (CL) flowing in the fourth zone (Z4).

[0122] Specifically, among the cooling holes (220H) formed in the side frame (220), the inlet cooling holes (220H1) may be connected to the first zone (Z1) and the third zone (Z3), and the discharge cooling holes (220H2) may be connected to the second zone (Z2) and the fourth zone (Z4). In addition, separation frame holes (800H) may be formed on the outer surface of the separation frame (800). Specifically, the separation frame (800) may have an internal hollow space, and the separation frame holes (800H) may be connected to the hollow space inside the separation frame (800).

[0123] The refrigerant (CL) can flow into the first zone (Z1) and the third zone (Z3) sequentially through the inlet port (910), the inlet hollow (220C1), and the inlet cooling hole (220H1). The refrigerant (CL) flowing through the first zone (Z1) and the third zone (Z3) can move to the hollow inside the separation frame (800) through the separation frame holes (800H) corresponding to the first zone (Z1) and the third zone (Z3). Thereafter, the refrigerant (CL) can move to 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) flowing through the second zone (Z2) and the fourth zone (Z4) can be discharged to the outside of the battery pack (100) through the discharge cooling hole (220H2), the discharge cavity (220C2), and the outlet port (920).

[0124] That is, the coolant (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 discharge hollow (220C2) of the first side frame (221). Another coolant (CL) can 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 discharge hollow (220C2) of the first side frame (221). Through the circulation structure of these coolants (CL), direct cooling of the battery cells (110) can be achieved. In particular, the hollow (220C) of the existing side frame (220) and the hollow of the separation frame (800) are utilized as structures for circulating coolant, and by appropriately arranging vertical beams (700), a uniform flow of coolant (CL) is implemented for each zone. The uniform flow of coolant (CL) for each zone can reduce the cooling deviation between each battery cell (110), which can lead to improved performance of the battery pack (100).

[0125]

[0126] Below, the circulation form of the refrigerant (CL) according to another embodiment of the present invention will be described in detail.

[0127] Fig. 23 is a perspective view showing a first side frame according to another embodiment of the present invention. Fig. 24 is a partial cross-sectional view showing a cross-section taken along the line G-G' of Fig. 23. Fig. 25 is a partial cross-sectional view showing a cross-section taken along the line H-H' of Fig. 23. Fig. 26 is a partial perspective view showing a part of a bottom frame according to another embodiment of the present invention. Fig. 27 is a partial cross-sectional view showing a cross-section taken along the line I-I' of Fig. 26. Fig. 28 is a plan view showing a bottom frame and battery cells according to another embodiment of the present invention. In particular, Fig. 28 shows the bottom frame and the battery cells as viewed along the -z-axis direction on the xy plane.

[0128] Referring to FIGS. 23 to 28, a battery pack (100) according to another embodiment of the present invention may include a bottom frame (210) and a side frame (220), and the side frame (220) may include a first side frame (221), a second side frame (222), a third side frame (223), and a fourth side frame (224), and both an inlet port (910) and an outlet port (920) may be formed in the first side frame (221). In addition, an inlet port (910), an outlet port (920), an inlet hollow (220C1), a discharge hollow (220C2), an inlet cooling hole (220H1), and a discharge cooling hole (220H2) may be formed in 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 zones (Z1, Z2, Z3, Z4) and a separation frame (800) positioned between the battery cells (110) and the second side frame (222). A detailed description of each configuration described above is omitted as it overlaps with the previously described content.

[0129] In the battery pack (100) according to the present embodiment, the coolant (CL) may sequentially flow into the storage space (SS) in which the battery cells (110) are placed through the inlet port (910), the inlet hollow (220C1), and the inlet cooling hole (220H1). At this time, a passage (700P) may be formed inside a vertical beam (700) that divides the storage space (SS) into a first zone (Z1) and a second zone (Z2). The coolant (CL) flowing in the first zone (Z1) and the coolant (CL) flowing in the second zone (Z2) may flow in the same direction. In addition, the coolants (CL) flowing along the first to fourth zones (Z1, Z2, Z3, Z4) may flow in the same direction from the first side frame (221) to the second side frame (222).

[0130] Specifically, among the cooling holes (220H) formed in the side frame (220), the inlet cooling holes (220H1) may be connected to the first zone (Z1), the second zone (Z2), the third zone (Z3), and the fourth zone (Z4), and the discharge cooling holes (220H2) may be connected to a passage (700P) inside the vertical beam (700). In addition, vertical beam holes (700H) may be formed on the outer surface of the vertical beam (700), and the vertical beam holes (700H) may be connected to a passage (700P) inside the vertical beam (700).

[0131] The refrigerant (CL) can be introduced into the first to fourth zones (Z1, Z2, Z3, Z4) sequentially through the inlet port (910), the inlet cavity (220C1), and the inlet cooling hole (220H1). The refrigerant (CL) flowing through each of the first to fourth zones (Z1, Z2, Z3, Z4) can move to the passage (700P) inside the vertical beam (700) through the vertical beam holes (700H). Thereafter, the refrigerant (CL) can move back along the passage (700P) toward the location where the first side frame (221) is located. The refrigerant (CL) flowing along the passage (700P) can be discharged to the outside of the battery pack (100) through the discharge cooling hole (220H2), the discharge cavity (220C2), and the outlet port (920).

[0132] That is, the coolant (CL) can circulate along the inlet cavity (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 cavity (220C2) of the first side frame (221). More specifically, the coolant (CL) can circulate along the inlet cavity (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 cavity (220C2) of the first side frame (221). Through this circulation structure of the coolants (CL), direct cooling of the battery cells (110) can be achieved. In particular, the hollow portion (220C) of the existing side frame (220) and the passage (700P) of the vertical beam (700) are utilized as structures for circulating coolant, and by appropriately arranging the vertical beams (700), a uniform flow of coolant (CL) is implemented for each zone. The uniform flow of coolant (CL) for each zone can reduce the cooling deviation between each battery cell (110), which can lead to improved performance of the battery pack (100).

[0133]

[0134] Below, the directional venting structure of the battery pack (100) according to the present embodiment will be described.

[0135] Referring again to FIGS. 2, 3, 5, 8 to 10, the vent portion (110V) of the battery cell (110) according to the present embodiment may face the spacer (300). More specifically, the vent portion (110V) of the battery cell (110) may face the mounting portion (310) of the spacer (300). The spacer (300) according to the present embodiment may include a spacer venting portion (320a) which is a portion facing the vent portion (110V); and an outer circumference (320b) surrounding the spacer venting portion (320a). The spacer venting portion (320a) may have a thinner thickness than the outer circumference (320b) or may have a notched groove. Due to a thermal event or thermal runaway of the battery cell (110), high-temperature venting gas and particles are discharged from the vent portion (110V) of the battery cell (110), and due to the pressure of the venting gas, the spacer venting portion (320a) may be separated from the outer peripheral portion (320b) and the spacer venting portion (320a) may be opened. That is, the high-temperature venting gas and particles may be discharged downward through the vent portion (110V) and the opened spacer venting portion (320a). Thereafter, the high-temperature venting gas and particles may move along a preset path through the venting channel (VC) provided in the bottom frame (210). Hereinafter, the specific structures of the bottom frame (210) and the venting channel (VC) will be described.

[0136] According to one embodiment of the present invention, a bottom frame (210) may be formed with a venting channel (VC) that guides high-temperature venting gas or particles discharged from a vent portion (110V) of a battery cell (110). Specifically, the bottom frame (210) may include 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).

[0137] In the first frame (211), through holes (211H) may be formed. When viewed in the height direction, the through holes (211H) may be positioned so as to overlap at least a portion with the vent portion (110V) of the battery cell (110). The through holes (211H) may be arranged to correspond one-to-one with the vent portion (110V). Similarly, the through holes (211H) may be arranged to correspond one-to-one with the spacer venting portions (320a).

[0138] High-temperature venting gas and particles that pass through the vent part (110V) and the open spacer venting part (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 flow into the venting channel (VC) are discharged to the outside of the battery pack (100). The battery pack (100) according to the present embodiment has a so-called “bottom venting” structure that discharges high-temperature venting gas and particles, etc. to the outside using the bottom frame (210). The HV connection described above is a connection that serves as a power source to supply power that requires high voltage, and refers to a connection between battery cells, etc. If high-temperature venting gas or particles, etc., due to a thermal event of the battery cell (110) come into contact with a high-voltage path such as an HV connection, a short circuit or arc discharge, etc., may occur, which may lead to additional explosion and flame generation. On the other hand, in the case of the battery pack (100) according to the present embodiment, as mentioned above, since it has a “bottom venting” structure, high-temperature venting gas or particles caused by a thermal event are discharged downward, i.e., toward the bottom frame (210). Therefore, there is no risk of high-temperature venting gas or particles, etc., reaching a high-voltage path such as an HV connection, and ultimately, safety against thermal runaway can be enhanced.

[0139] Moreover, in the case of the present embodiment, since the holding frame (400) additionally covers the area where the electrode terminals (111, 112) of the battery cells (110) and the bus bar (130) are located, it is possible to completely block high-temperature venting gas or particles from reaching the area where the electrode terminals (111, 112) of the battery cells (110) and the bus bar (130) are located.

[0140] In addition, since the battery pack (100) according to the present embodiment has a “lower venting” structure, the influence of high-temperature venting gas or particles on the coolant (CL) flowing in the space between the spacer (300) and the holding frame (400) can be minimized.

[0141] In addition, the spacer (300) and the second waterproof adhesive (500b) can prevent the refrigerant (CL) from leaking into the lower area of ​​the spacer (300), as well as prevent high-temperature venting gas or particles from leaking out in the upper direction rather than the lower direction where the bottom frame (210) is located.

[0142] Meanwhile, as described above, a vertical beam (700) dividing the storage space (SS) into a plurality of zones (Z1, Z2, Z3, Z4) may be positioned on the bottom frame (210). A venting channel (VC) corresponding to one zone may have an independent venting path that is not shared with the venting channel (VC) corresponding to another zone. For example, four second frames (212) corresponding to each of the four zones (Z1, Z2, Z3, Z4) may be provided. A venting channel (VC) in one second frame (212) may have an independent venting path that is not communicated with the venting channel (VC) in another second frame (212).

[0143] Additionally, the second frame (212) may have at least one bulkhead (212W), and the bulkhead (212W) may divide the second frame (212) into a plurality of venting channels (VC).

[0144] In this way, some venting channels (VC) do not share each other's space and may have independent venting paths. Therefore, high-temperature venting gas and particles passing through one venting channel (VC) do not propagate to other venting channels (VC). Accordingly, the propagation of a thermal event occurring in a specific battery cell (110) to other battery cells (110) can be minimized. Accordingly, high-temperature venting gas or particles do not flow back into other battery cells (110) that are connected to other venting channels (VC), and ultimately, thermal events are not propagated or triggered to other battery cells (110). In the present embodiment, by implementing independent venting paths between venting channels (VC), thermal runaway transfer between battery cells (110) is minimized and explosion and structural collapse of the battery pack can be prevented.

[0145] High-temperature venting gas and particles flowing along the venting channel (VC) of the bottom frame (210) can move to the venting space (VS) between the separation frame (800) and the second side frame (222), and then be finally discharged to the outside through the venting device formed in the second side frame (222). There is no particular limitation on the specific form of the venting device, and the venting device may be a valve structure that opens or ruptures when the internal pressure exceeds a certain level.

[0146] In this example, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0147] The battery pack according to the embodiment described above can be applied to various devices. Specifically, it can be applied to transportation vehicles such as electric bicycles, electric vehicles, and hybrid vehicles, as well as ESS (Energy Storage Systems), but is not limited thereto. It can also be applied to various devices capable of using secondary batteries.

[0148] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0149] Description of the symbol

[0150] 100: Battery pack

[0151] 110: Battery cell

[0152] 110V: Vent

[0153] 200: Pack Frame

[0154] 210: Bottom Frame

[0155] 220: Side Frame

[0156] 220C: Hollow

[0157] 300: Spacer

[0158] 400: Holding Frame

[0159] 610: Pack top cover

[0160] 620: Pack bottom cover

[0161] 910: Inlet port

[0162] 920: Outlet Port

Claims

1. Multiple battery cells; A pack frame including a bottom frame and a side frame that form a storage space in which the battery cells are stored; and A refrigerant flowing in the storage space to directly cool the battery cells; An inlet port for introducing the refrigerant and an outlet port for discharging the refrigerant are provided on the side frame. A battery pack in which hollows are formed inside the side frame, and each of the hollows is connected to the inlet port and the outlet port.

2. In paragraph 1, The above side frame is a battery pack having a tubular structure with hollow spaces formed inside.

3. In paragraph 1, A battery pack in which the inlet port and the outlet port are located on opposite sides of the side frame facing the battery cells.

4. In paragraph 3, A battery pack in which a cooling hole communicating with the hollow is formed on the surface of the side frame facing the battery cells.

5. In paragraph 1, A battery pack in which the refrigerant flows through the hollow space and flows into or out of the storage space.

6. In paragraph 1, The above hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port, A battery pack in which the above inlet cavity and the above outlet cavity are separated from each other.

7. In paragraph 6, The above refrigerant flows into the storage space through the inlet port and the inlet cavity, A battery pack in which the refrigerant that directly cools the above battery cells is discharged to the outside through the discharge cavity and the outlet port.

8. In paragraph 1, The side frame includes a first side frame and a second side frame positioned opposite each other with the battery cells interposed therebetween, A battery pack in which both the inlet port and the outlet port are formed in the first side frame.

9. In paragraph 8, The above hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port, A vertical beam dividing the above storage space into a first zone and a second zone is positioned on the bottom frame, A battery pack in which the refrigerant flows sequentially through the first zone and the second zone.

10. In paragraph 9, A separation frame is positioned between the above battery cells and the second side frame, A battery pack in which the refrigerant circulates along the inlet cavity of the first side frame, the first zone, the hollow inside the separation frame, the second zone, and the discharge cavity of the first side frame.

11. In paragraph 8, The above hollow includes an inlet hollow connected to the inlet port and an outlet hollow connected to the outlet port, A vertical beam dividing the above storage space into a first zone and a second zone and having a passage formed inside is positioned on the bottom frame, A battery pack in which the refrigerant flowing in the first zone and the refrigerant flowing in the second zone flow in the same direction.

12. In paragraph 11, A battery pack in which the refrigerant circulates along the inlet cavity of the first side plate, the first zone and the second zone, the passage inside the vertical beam, and the discharge cavity of the first side plate.

13. In paragraph 1, The above battery cells include a vent portion, A battery pack in which a venting channel is formed in the bottom frame to guide venting gas or particles discharged from the vent section of the battery cell.

14. In paragraph 13, A vertical beam dividing the above storage space into multiple zones is positioned on the bottom frame, A battery pack in which the venting channel corresponding to one of the above zones has an independent venting path that is not shared with the venting channel corresponding to another of the above zones.

15. A device including a battery pack according to paragraph 1.

Images