Battery assembly and battery pack comprising same

Abstract

A battery assembly according to one embodiment of the present invention comprises: a plurality of battery cells; and a cell frame in which the battery cells are accommodated. The cell frame includes a bottom cell frame on which the battery cells are seated and a cover cell frame positioned on the bottom cell frame. A cooling fluid is in direct contact with the battery cells and circulates inside the cell frame. The bottom cell frame is coupled or attached to the cover cell frame.

Description

Battery assembly and battery pack including the same

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

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0196006 filed on December 24, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a battery assembly and a battery pack including the same, and more specifically, to a battery assembly with improved cooling performance and a battery pack including the same.

[0004] Secondary batteries, which have high applicability across product groups and electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources. These secondary batteries are widely used as an energy source for enhancing eco-friendliness and energy efficiency, not only because of the primary advantage of being able to drastically reduce the use of fossil fuels, but also because they do not generate any by-products from energy use.

[0005] Types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, that is, unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack may be formed by connecting multiple battery cells in series. Additionally, a battery pack may be formed by connecting multiple battery cells in parallel depending on the charge / discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack can be set in various ways depending on the required output voltage or charge / discharge capacity.

[0006] Meanwhile, when configuring a battery pack by connecting multiple battery cells in series or parallel, it is common to first form a battery module by creating a battery cell assembly containing multiple battery cells and housing it in a module case, and then configuring a battery pack by assembling one or more of these battery modules and adding other components, or by arranging multiple battery cells within a pack frame and adding other components.

[0007] Since these battery cells consist of rechargeable secondary batteries, such high-output, high-capacity secondary batteries generate a significant amount of heat during the charging and discharging process. In this case, the heat emitted from multiple battery cells is aggregated within a confined space, causing the temperature to rise rapidly and severely. In other words, while battery packs containing multiple cells can achieve high output, it is not easy to dissipate the heat generated by the cells during charging and discharging. If heat dissipation from the battery cells is not properly carried out, the cells degrade rapidly, shortening their lifespan and increasing the risk of explosion or ignition.

[0008] Furthermore, automotive battery packs are frequently exposed to direct sunlight and may be subjected to high-temperature conditions, such as during the summer or in desert regions. Additionally, because multiple battery cells are densely packed to extend a vehicle's driving range, flames or heat generated in a single battery cell can easily spread to neighboring cells, ultimately leading to the ignition or explosion of the battery pack itself.

[0009] In conventional battery modules, bottom cooling or side cooling methods have been used, in which a heat sink is mounted on the module case of the battery module to cool it.

[0010] However, in the case of battery modules using this cooling method, heat generated from the battery cells is transferred to a heat sink on one side of the module case for cooling, making it difficult to establish a heat transfer path to the other side of the module case. Consequently, there are limitations, such as intensified temperature differences between one end and the other of the battery cell assembly, or unsatisfactory overall cooling efficiency. If these temperature differences are not resolved, issues regarding the safety and durability of the battery module arise. Poor cooling efficiency can accelerate the degradation of battery cells or lead to the spread of thermal runaway if a rapid response is not possible when it occurs in some cells. This can result in disasters such as ignition and explosion of the battery module or the battery pack containing it, causing not only property damage but also safety issues.

[0011] To solve this problem, it has been proposed to use a method of directly cooling the battery cells by filling the inside of the battery pack with coolant or cooling fluid instead of relying on bottom cooling or side cooling. In other words, to effectively cool high-capacity battery packs, a method is being used in which a cooling fluid directly cools the battery cells inside the battery pack.

[0012] However, implementing this cooling method requires a stable sealing structure. Since the cooling fluid circulates within the battery pack, various components can be used to create the sealing structure. However, as the cooling fluid circulation structure and the sealing structure to prevent leakage are required, the number of necessary components increases, and the space occupied by these parts leads to a decrease in the battery pack's space utilization efficiency.

[0013] Accordingly, there is a need to develop a battery assembly that minimizes unnecessary space waste while maintaining space utilization or battery capacity, while featuring a structure in which a cooling fluid directly cools the battery cells and a stable sealing structure.

[0014] The problem to be solved by the present invention is to provide a battery assembly with improved space utilization and a battery pack including the same, in a cooling structure in which a cooling fluid cools battery cells.

[0015] However, the problems that the embodiments of the present invention aim to solve 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.

[0016] A battery assembly according to one embodiment of the present invention comprises: a plurality of battery cells; and a cell frame in which the battery cells are housed. The cell frame comprises a bottom cell frame on which the battery cells are seated and a cover cell frame located on the bottom cell frame. A cooling fluid circulates inside the cell frame while in direct contact with the battery cells. The bottom cell frame is combined or assembled with the cover cell frame.

[0017] The above bottom cell frame may be a single member.

[0018] The bottom cell frame may include a basket that covers a portion of the outer side of the cover cell frame.

[0019] The basket may extend along the outer perimeter of the area where the battery cells are seated in the bottom cell frame.

[0020] The basket may be located on the outer side of the cover cell frame.

[0021] A first sealing member may be located in the basket above.

[0022] The basket may include a first portion connected at the boundary between the bottom cell frame and the cover cell frame, and a second portion protruding upward from the first portion.

[0023] A first sealing member may be located in the space between the first part, the second part, and the outer side of the cover cell frame.

[0024] The above cover cell frame may include a groove formed on the outer perimeter of the area where the battery cells are seated.

[0025] The above groove may be formed in the portion of the cover cell frame facing the bottom cell frame.

[0026] The above groove may extend along the outer perimeter of the area where the battery cells are seated.

[0027] The above groove may be indented in the upward direction from the cover cell frame.

[0028] A second sealing member may be located in the above groove.

[0029] The cell frame may include an inlet port through which the cooling fluid flows into the cell frame and an outlet port through which the cooling fluid is discharged to the outside of the cell frame.

[0030] The vent portion of the battery cell may face the bottom cell frame.

[0031] Venting gas discharged from the vent portion of the battery cell can pass through and be discharged while rupturing or melting the bottom cell frame.

[0032] The above battery cells may be fitted inside the cell frame.

[0033] The above battery cells can be directly mounted on a vehicle or chassis while housed in the cell frame.

[0034] A battery pack according to one embodiment of the present invention comprises: at least one battery assembly; a pack frame housing at least one battery assembly and having one side open; and a pack cover covering the open side of the pack frame.

[0035] According to embodiments of the present invention, in a cell frame that provides a space for housing battery cells and circulating a cooling fluid, by minimizing the components required for the cell frame, the space utilization rate of the battery assembly can be improved and the battery capacity can be increased.

[0036] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0037] FIG. 1 is a perspective view showing a battery assembly according to one embodiment of the present invention.

[0038] Figure 2 is a plan view showing the battery assembly of Figure 1 as viewed along the -z axis direction in the xy plane.

[0039] Figure 3 is an exploded perspective view of the battery assembly of Figure 1.

[0040] FIG. 4 (a) and (b) are a perspective view and a side view, respectively, of a battery cell according to one embodiment of the present invention.

[0041] Figure 5 is a cross-sectional view showing the cross-section cut along the cutting line C-C' in Figure 4 (a).

[0042] FIG. 6 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0043] FIG. 7 is a partial perspective view of a battery assembly according to one embodiment of the present invention.

[0044] Figure 8 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 2.

[0045] Figure 9 is a partial cross-sectional view showing an enlarged view of section “D” of Figure 8.

[0046] Figure 10 is a partial cross-sectional view showing an enlarged view of section “E” of Figure 8.

[0047] Figure 11 is a cross-sectional view showing a cross-section cut along the cutting line B-B' of Figure 2.

[0048] FIG. 12 is a partial cross-sectional view showing an enlarged view of the “F” portion of FIG. 9.

[0049] FIG. 13 is a partial cross-sectional view showing an enlarged view of the “G” portion of FIG. 10.

[0050] FIG. 14 is a cross-sectional perspective view of a battery assembly according to one embodiment of the present invention.

[0051] Figure 15 is a partial cross-sectional view showing an enlarged view of the “H” portion of Figure 14.

[0052] FIG. 16 is a cross-sectional perspective view of a cell frame according to one embodiment of the present invention.

[0053] FIG. 17 is a partial cross-sectional view showing an enlarged view of section “I” of FIG. 16.

[0054] FIG. 18 is a partial perspective view showing a bottom cell frame according to one embodiment of the present invention.

[0055] FIG. 19 is a plan view of a middle cell frame among cover cell frames according to one embodiment of the present invention, viewed from below.

[0056] FIG. 20 is a perspective view showing a top cell frame, a busbar frame assembly, and a first waterproof adhesive according to one embodiment of the present invention.

[0057] FIG. 21 is a perspective view showing battery cells, a second waterproof adhesive, and a bottom cell frame according to one embodiment of the present invention.

[0058] FIGS. 22 and FIGS. 23 are exploded perspective views of a battery pack according to one embodiment of the present invention.

[0059] 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 present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0060] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0061] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0062] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0063] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0064] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0065] FIG. 1 is a perspective view showing a battery assembly according to an embodiment of the present invention. FIG. 2 is a plan view showing the battery assembly of FIG. 1 viewed along the -z axis direction in the xy plane. FIG. 3 is an exploded perspective view of the battery assembly of FIG. 1.

[0066] Referring to FIGS. 1 to 3, a battery assembly (100) according to one embodiment of the present invention comprises a plurality of battery cells (110); and a cell frame (120) in which the battery cells (110) are housed. The cell frame (120) comprises a bottom cell frame (120c) on which the battery cells (110) are seated and a cover cell frame (120ab) located on the bottom cell frame (120c). In the battery assembly (100), a cooling fluid circulates inside the cell frame (120) while in direct contact with the battery cells (110). That is, in the battery assembly (100) according to the present embodiment, a method is applied in which the cooling fluid directly cools the battery cells. In the present invention, at least a portion of the battery cells (110) may be cooled by contacting the cooling fluid. That is, in one embodiment, a portion of the outer surface of the battery cell (110) may be in contact with the cooling fluid, and in another embodiment, the entire outer surface of the battery cell (110) may be in contact with the cooling fluid.

[0067] The bottom cell frame (120c) is combined or assembled with the cover cell frame (120ab). The combination may include being joined via an adhesive or adhesive member, or being joined by welding. In the case of assembly, the bottom cell frame (120c) and the cover cell frame (120ab) may be assembled using a separate restraining member, or a part of the bottom cell frame (120c) and a part of the cover cell frame (120ab) may be assembled by interlocking with each other. That is, in the present invention, if the bottom cell frame (120c) and the cover cell frame (120ab) are combined or assembled with each other to form a cell frame (120) having an internal space in which battery cells (110) are housed and cooling fluid flows, various structures may be applied without separate limitations on the method of combination or assembly.

[0068] Meanwhile, the bottom cell frame (120c) according to the present embodiment may be a single member. More specifically, the bottom cell frame (120c) may be a single member having a flat plate-like area.

[0069] A cell frame (120) having an internal space in which battery cells (110) are housed and cooling fluid flows can be formed by combining or assembling a bottom cell frame (120c), which is a single component, with a cover cell frame (120ab). Since a bottom cell frame (120c), which is a single component, is applied, the number of parts required for the battery assembly (100) in a structure in which cooling fluid cools the battery cells can be reduced. In addition, since the thickness of the bottom cell frame (120c) is reduced, the overall height can be reduced while maintaining the battery capacity of the battery assembly (100), thereby improving the space utilization rate of the battery assembly (100). Furthermore, the area requiring sealing to prevent leakage of cooling fluid from the battery assembly (100) can be reduced, thereby reducing the risk of leakage of cooling fluid.

[0070] As one example of the present invention, the bottom cell frame (120c) may be manufactured not by a plastic injection molding method, but by a metal press method. When manufactured by a metal press method, the bottom cell frame (120c) may naturally include a metal material, and for example, may include an aluminum material. A thin bottom cell frame (120c) can be manufactured through a metal press method. Since a thin, single-member bottom cell frame (120c) can be manufactured, a directional venting structure using the bottom cell frame (120c) described later can be easily implemented.

[0071]

[0072] Hereinafter, the battery cell (110) according to the present embodiment will be described in detail. The battery cell (110) according to the present embodiment may be any type of secondary battery, such as a prismatic, cylindrical, or pouch-type battery cell. However, below, as an example, the battery cell (110) which is a cylindrical cell will be described.

[0073] FIG. 4(a) and FIG. 4(b) are a perspective view and a side view, respectively, of a battery cell according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a cross section cut along the cutting line C-C' in FIG. 4(a). FIG. 6 is a cross-sectional view of a battery cell according to an embodiment of the present invention.

[0074] Referring to FIGS. 4 to 6, the battery cell (110) according to the embodiments may be a cylindrical cell and may have a vent portion (110V). The vent portion (110V) is a general term for a component or mechanism provided in the battery cell (110) to discharge venting gas, etc., inside the battery cell (110). In addition, each battery cell (110) may be provided with a first electrode terminal (111) and a second electrode terminal (112) as positive and negative electrode terminals.

[0075] 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). An exemplary structure of the battery cell (110) is described below, but the battery cell of the present invention is not limited to such a structure.

[0076] The battery can (20) according to the present embodiment may be a cylindrical case with an open top, and may contain an electrode assembly (10) and an electrolyte (not shown) in an internal storage space, and may include a metal material such as aluminum (Al).

[0077] 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 coupled to the top cap (31). The top cap (31) may include an electrically conductive metal material and may cover the open top 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). Accordingly, 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).

[0078] To specifically describe 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 plate (41) located on the upper part of the electrode assembly (10). The first current collector plate (41) may include a conductive metal material such as aluminum, copper, steel, nickel, etc., and may be electrically connected to the first segments (11) of the electrode assembly (10). The electrical connection may be made through welding. A lead (60) may be connected to this first current collector plate (41). The lead (60) may extend in the upward direction of the electrode assembly (10) and be connected to the connecting plate (32). In another embodiment, the lead (60) may be directly connected to the lower surface of the top cap (31). The connection between the lead (60) and other parts may be made through welding. Additionally, the first collector plate (41) may be formed integrally with the lead (60). In this case, the lead (60) may have an elongated plate shape extending outward from near the center of the first collector plate (41).

[0079] The first collector plate (41) may have a plurality of irregularities (not shown) formed radially on its lower surface. When radial irregularities are provided, the first collector plate (41) can be pressed to press the irregularities into the bent first segments (11). The connection between the first collector plate (41) and the first segments (11) can be achieved, for example, by laser welding. Laser welding can be performed by partially melting the base material of the first collector plate (41). In a modified example, welding between the first collector plate (41) and the first segments (11) can 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). Laser welding can be replaced by resistance welding, ultrasonic welding, spot welding, etc.

[0080] Meanwhile, the battery cell (110) according to the present embodiment may further include a second current collector plate (42) located at the bottom of the electrode assembly (10). Specifically, the second current collector plate (42) may be located between the electrode assembly (10) and the bottom portion (20F) of the battery can (20). The second current collector plate (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 plate (42) may be connected to the second segments (12), and the opposite side of the second current collector plate (42) may be connected to the bottom portion (20F) of the battery can (20). Welding may be applied to the connection of the second current collector plate (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).

[0081] Meanwhile, the secondary battery according to the present embodiment may include an insulating plate (70). The insulating plate (70) may cover the first current collector plate (41). By covering the first current collector plate (41) on the upper surface of the first current collector plate (41), the insulating plate (70) can block the first current collector plate (41) from contacting the battery can (20), particularly the beading part (20B) of the battery can (20) described later. Additionally, the insulating plate (70) may be provided with a separate lead hole so that a lead (60) extending upward from the first current collector plate (41) can be drawn out. The lead (60) can 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).

[0082] The perimeter area of ​​the insulating plate (70) is interposed between the first current collector plate (41) and the beading portion (20B) of the battery can (20) to fix the combination of the electrode assembly (10) and the first current collector plate (41). Accordingly, the movement of the combination of the electrode assembly (10) and the first current collector plate (41) in the axial direction of the electrode assembly (10) is restricted, thereby improving the assembly stability of the secondary battery. The insulating plate (70) may be made of an insulating polymer resin. In one example, the insulating plate (70) may include one or more materials selected from the group consisting of polyethylene, polypropylene, polyimide, or polybutylene terephthalate.

[0083] 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 together with the gasket (50) in between. That is, a crimping connection may be applied to the connection between the battery can (20) and the cap assembly (30). Accordingly, the crimping part (20C) may be formed on the battery can (20). More specifically, the crimping connection is achieved by placing 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 where the cap assembly (30) is located.

[0084] The beading portion (20B) refers to a portion of the battery can (20) that is indented towards the center in an area above the electrode assembly (10) among the side portions of the battery can (20), and is intended for stable placement of the cap assembly (30) and prevention of movement of the electrode assembly (10). That is, the cap assembly (30) and the gasket (50) surrounding it according to the present embodiment can be seated on the beading portion (20B) of the battery can (20). With the cap assembly (30) and the gasket (50) surrounding it seated on the beading portion (20B), the crimping coupling described above can be performed.

[0085] The gasket (50) according to the present embodiment is positioned between the battery can (20) and the cap assembly (30) to improve the sealing performance of the secondary battery. Additionally, the gasket (50) may include an electrically insulating material and can block 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). This gasket (50) may include one or more materials selected from the group consisting of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and perfluoroalkoxyalkane (PFA).

[0086] The vent portion (110V) according to the present embodiment may be formed on the lower surface of the battery cell (110). That is, it may be formed on the bottom portion (20F, see FIG. 6) of the battery can (20).

[0087] If a thermal event or thermal runaway occurs inside a battery cell (110), high-temperature venting gas or particles may be generated. The vent section (110V) is a general term for a component or mechanism capable of discharging such high-temperature venting gas or particles. For example, a notch section (110N) with a thickness relatively thinner than the adjacent area may be formed on the bottom of the battery cell (110), specifically on the bottom of the battery can. The notch section (110N) may form a certain circumference. If the internal pressure of the battery cell (110) increases due to high-temperature venting gas generated inside the battery cell (110), the notch section (110N), which has weak rigidity due to its thin thickness, may rupture first. Due to the rupture of the notch (110N), the vent (110V) is opened, and high-temperature venting gas or particles can be discharged through the vent (110V) thus opened.

[0088] However, the structure of such a vent section (110V) is merely one example, and there are no special restrictions on the shape of the vent section (110V) as long as it is a component or mechanism capable of discharging internal venting gas during a thermal event or thermal runaway.

[0089] Meanwhile, although not specifically illustrated, the battery cell according to the present invention may be a prismatic battery cell in which an electrode assembly is housed in a prismatic can. That is, although the battery cell according to the present embodiment is depicted in the drawings as a cylindrical battery cell, this is merely one example of the structure of the battery cell of the present invention, and the battery cell according to other embodiments of the present invention may be a prismatic battery cell.

[0090] Battery cells (110) can be arranged in columns and rows within a cell frame (120), and the battery cells (110) can be electrically connected to each other via a busbar, etc., described later.

[0091] FIG. 7 is a partial perspective view of a battery assembly according to an embodiment of the present invention. FIG. 8 is a cross-sectional view showing a cross section cut along the cutting line A-A' of FIG. 2. FIG. 9 is a partial cross-sectional view showing an enlarged portion of “D” of FIG. 8. FIG. 10 is a partial cross-sectional view showing an enlarged portion of “E” of FIG. 8. FIG. 11 is a cross-sectional view showing a cross section cut along the cutting line B-B' of FIG. 2. Specifically, FIG. 8 is a cross-sectional view showing the inlet port (121) of the battery assembly, and FIG. 11 is a cross-sectional view showing the outlet port (122) of the battery assembly. Additionally, FIG. 7 shows a state in which the first sealing member (800a) is not positioned in the basket (400) described later for convenience of explanation.

[0092] Referring together to FIGS. 1 to 3 and FIGS. 7 to 11, as described above, the battery assembly (100) includes a cell frame (120) in which battery cells (110) are housed, and the cell frame (120) includes a bottom cell frame (120c) on which the battery cells (110) are seated and a cover cell frame (120ab) located on the bottom cell frame (120c).

[0093] A bottom cell frame (120c) and a cover cell frame (120ab) are assembled to form an internal space, and battery cells (110) can be positioned in the internal space formed by the bottom cell frame (120c) and the cover cell frame (120ab), and a cooling fluid (CL) can also circulate along the internal space to directly cool the battery cells (110).

[0094] A cooling fluid (CL) circulates inside a cell frame (120) while in direct contact with the battery cells (110). The cell frame (120) may include an inlet port (121) through which the cooling fluid (CL) flows into the interior of the cell frame (120) and an outlet port (122) through which the cooling fluid is discharged to the outside of the cell frame (120). That is, the cooling fluid (CL) flows into the interior of the cell frame (120) through the inlet port (121), and the incoming cooling fluid (CL) flows along the interior space of the cell frame (120) and comes into direct contact with the battery cells (110). Subsequently, the cooling fluid (CL) circulating in the interior space of the cell frame (120) can be discharged to the outside of the cell frame (120) through the outlet port (122). That is, a cooling channel (300) through which the cooling fluid (CL) flows may be provided inside the cell frame (120). These cooling channels (300) may have a multi-layer cooling structure, which will be described later.

[0095] The inlet port (121) and the outlet port (122) may be located on the same side of the cell frame (120) or on opposite sides. That is, there is no particular restriction on the location of the inlet port (121) and the outlet port (122) in the cell frame (120). The inlet port (121) and the outlet port (122) may be formed in the cover cell frame (120ab) of the cell frame (120).

[0096] Meanwhile, the cooling fluid (CL) according to the present embodiment may be a fluid as a cooling medium. Since the cooling fluid (CL) is in direct contact with the battery cells (110) within the battery assembly (100), the cooling fluid (CL) may be electrically insulated. The cooling fluid (CL) may be a material having insulating properties. For example, the cooling fluid (CL) may be a cooling oil. However, in the case of the battery assembly (100) according to the present embodiment, general cooling water may also be used as the cooling fluid (CL) because leakage of the cooling fluid (CL) to the outside of the top cell frame (120a) is prevented.

[0097] FIG. 12 is a partial cross-sectional view showing an enlarged portion of “F” in FIG. 9. FIG. 13 is a partial cross-sectional view showing an enlarged portion of “G” in FIG. 10. FIG. 14 is a cross-sectional perspective view of a battery assembly according to an embodiment of the present invention. FIG. 15 is a partial cross-sectional view showing an enlarged portion of “H” in FIG. 14. FIG. 16 is a cross-sectional perspective view of a cell frame according to an embodiment of the present invention. FIG. 17 is a partial cross-sectional view showing an enlarged portion of “I” in FIG. 16. FIG. 18 is a partial perspective view showing a bottom cell frame according to an embodiment of the present invention.

[0098] For convenience of explanation, FIG. 14 shows a state in which the first sealing member (800a) is not positioned in the basket (400), and FIG. 15 shows a state in which the first sealing member (800a) is positioned in the basket (400). Through FIG. 14, the specific structure of the basket (400) can be clearly confirmed.

[0099] Referring together to FIGS. 7 to 18, the bottom cell frame (120c) according to the present embodiment may include a basket (400) that covers a portion of the outer side of the cover cell frame (120ab). The basket (400) according to the present embodiment may be a portion of the bottom cell frame (120c) that covers a portion of the outer side of the cover cell frame (120ab). The basket (400) may be formed on the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c). A first sealing member (800a) may be positioned in such a basket (400). Specifically, the basket (400) may be formed on the outer perimeter of the area where the battery cells (110) are seated when viewed along a direction perpendicular to one side of the bottom cell frame (120c). Here, looking along a direction perpendicular to one side of the bottom cell frame (120c) means looking at the bottom cell frame (120c) along the z-axis direction or the -z-axis direction on the xy plane.

[0100] In the case of the battery assembly (100) according to the present embodiment, since a direct cooling method using a cooling fluid (CL) is applied, a stable sealing structure is essential to prevent the cooling fluid (CL) from leaking to the outside. If the cooling fluid (CL) leaks to the outside of the cell frame (120) of the battery assembly (100), the amount of cooling fluid (CL) inside the cell frame (120) becomes insufficient and the circulation of the cooling fluid (CL) is not properly carried out, which may lead to a decrease in cooling performance. In addition, the leaked cooling fluid (CL) may have an adverse effect on other electrical components other than the battery assembly (100). The cell frame (120) is formed by assembling a bottom cell frame (120c) and a cover cell frame (120ab), and there is a risk that the cooling fluid (CL) may leak through the gap between the bottom cell frame (120c) and the cover cell frame (120ab).

[0101] In the battery assembly (100) according to the present embodiment, by forming a basket (400) on the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c), a space can be provided in which the first sealing member (800a) can be positioned. By placing the first sealing member (800a) in the basket (400), the length of the sealing interface is extended, thereby preventing the cooling fluid (CL) from leaking from the gap between the bottom cell frame (120c) and the cover cell frame (120ab).

[0102] The basket (400) may extend along the outer perimeter of the area where the battery cells (110) of the bottom cell frame (120c) are seated. Additionally, the first sealing member (800a) may also extend along the outer perimeter of the area where the battery cells (110) of the bottom cell frame (120c) are seated.

[0103] As an example in the present invention, the basket (400) may be continuously extended along the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c). The first sealing member (800a) may also be continuously extended along the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c). That is, the basket (400) and the first sealing member (800a) may surround the outer perimeter of the area where the battery cells (110) are seated.

[0104] Additionally, as another example of the present invention, a basket (400) or a first sealing member (800a) may be partially located on the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c). That is, the basket (400) may be selectively located in the area where sealing is required. Furthermore, the basket (400) may extend along the outer perimeter of the area where the battery cells (110) are seated, while the first sealing member (800a) may be partially located only in the area where sealing is required on the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c). Selectively providing the basket (400) or the first sealing member (800a) in the area where sealing is required may also be in accordance with the present invention.

[0105] However, in order to prevent the cooling fluid (CL) from leaking out of the gap between the bottom cell frame (120c) and the cover cell frame (120ab), as previously described, it may be preferable for the basket (400) and the first sealing member (800a) to be formed along the outer perimeter of the area where the battery cells (110) are seated in the bottom cell frame (120c).

[0106] The basket (400) according to the present embodiment may be located on the outside of the cover cell frame (120ab). The basket (400) being located on the outside of the cover cell frame (120ab) may mean that the basket (400) is located further away from the outer side of the cover cell frame (120ab) relative to the point where the battery cells (110) are located. Since the basket (400) is located on the outside of the cover cell frame (120ab), the first sealing member (800a) can cover the boundary between the bottom cell frame (120c) and the cover cell frame (120ab) on the outside of the cover cell frame (120ab), thereby preventing leakage of the cooling fluid (CL).

[0107] Specifically, with reference to FIGS. 12, 13 and 15, etc., the basket (400) according to the present embodiment may include a first part (410) connected at the boundary between the bottom cell frame (120c) and the cover cell frame (120ab), and a second part (420) protruding upward from the first part (410). The basket (400) may be located on the outside of the cover cell frame (120ab) while including the first part (410) and the second part (420) of such a structure.

[0108] A first sealing member (800a) may be located in the space between the first part (410), the second part (420), and the outer side of the cover cell frame (120ab). In this embodiment, the basket (400) includes a second part (420) that protrudes upward from the first part (410), and the space where the first sealing member (800a) is located can be naturally provided without any separate additional parts. That is, the first sealing member (800a) that prevents leakage of the cooling fluid (CL) can be provided in the battery assembly (100) solely through the structure of the basket (400).

[0109] Additionally, since the first part (410) extends from the boundary between the bottom cell frame (120c) and the cover cell frame (120ab) and the second part (420) protrudes upward from this first part (410), the first sealing member (800a) located in the space between the second part (420) and the outer side of the cover cell frame (120ab) can be positioned to cover the gap between the bottom cell frame (120c) and the cover cell frame (120ab). Accordingly, in this embodiment, the first sealing member (800a) can block the leakage of cooling fluid (CL) from the gap between the bottom cell frame (120c) and the cover cell frame (120ab), and can also increase the bonding strength between the bottom cell frame (120c) and the cover cell frame (120ab).

[0110] The fact that the second part (420) protrudes upward from the first part (410) is not limited to the second part (420) protruding perpendicularly to the first part (410). The present invention includes, as an example, all forms in which the second part (420) protrudes upward at a certain angle to the first part (410) so as to form a predetermined space between the first part (410), the second part (420), and the outer side of the cover cell frame (120ab).

[0111] Meanwhile, the basket (400) in the present invention is formed around the outer perimeter of the area where the battery cells (110) of the bottom cell frame (120c) are seated, and there are no special restrictions on its shape or manufacturing process, provided that it can provide a space where the first sealing member (800a) is located. For example, the basket (400) may be a structure formed by extending from the bottom cell frame (120c) as an integral part of the bottom cell frame (120c). That is, the basket (400) may be a part of the bottom cell frame (120c) that is formed together when the bottom cell frame (120c) is manufactured by a metal press method. As shown in FIG. 18, the bottom cell frame (120c) may be a single member having a flat plate-like area, and the basket (400) may be a part that extends along the edge of the plate-like area of ​​the bottom cell frame (120c) and protrudes upward.

[0112] As another example, the basket (400) may be a structure that is separate from the bottom cell frame (120c) but is attached to the bottom cell frame (120c) using a method such as physical restraint, bonding by an adhesive member, ultrasonic welding, or welding.

[0113] The first sealing member (800a) applied in the present invention has no particular restrictions on its shape or material as long as it can perform the function of preventing the cooling fluid (CL) from leaking inside the cell frame (120). For example, the first sealing member (800a) may be formed by applying an adhesive that exhibits a sealing function. As long as the adhesive exhibits sealing performance and possesses impact resistance, adhesion, and electrical insulation properties, there are no particular restrictions on its material; for example, it may include a two-component epoxy-based material in which a curing agent is mixed with a main component. It may be preferable to form the first sealing member (800a) by applying the adhesive in order to prevent the leakage of the cooling fluid (CL) while located in the space formed by the basket (400). As another example, silicone rubber material parts such as foam tape, sealant, and O-rings may be applied to the first sealing member (800a).

[0114]

[0115] Hereinafter, a groove structure according to one embodiment of the present invention will be described.

[0116] FIG. 19 is a plan view of a middle cell frame among a cover cell frame according to an embodiment of the present invention, viewed from below. Specifically, the cover cell frame (120ab) may include a middle cell frame (120b) described later, and FIG. 19 is a drawing of such a middle cell frame (120b) viewed along the +z-axis direction on the xy-plane.

[0117] Referring to FIGS. 9 through 19 together, a cover cell frame (120ab) according to one embodiment of the present invention may include a groove (120G) formed on the outer perimeter of an area where battery cells (110) are seated. Specifically, the groove (120G) may be formed on the outer perimeter of an area where battery cells (110) are seated when viewed along a direction perpendicular to one surface of the separation part (120M) described later within the cover cell frame (120ab). Here, viewing along a direction perpendicular to one surface of the separation part (120M) means viewing the cover cell frame (120ab) along the z-axis direction or the -z-axis direction on the xy plane. FIG. 19 shows the middle cell frame (120b) of the cover cell frame (120ab) as viewed along the +z axis direction in the xy plane, and in FIG. 19, a groove (120G) is formed on the outer circumference of the middle cell frame hole (120bh) into which the battery cells (110) are fitted.

[0118] To explain the positional relationship between the basket (400) and the groove (120G), the basket (400) may be located further away from the battery cells (110) than the groove (120G). Specifically, when viewed along a direction perpendicular to one side of the bottom cell frame (120c), the basket (400) may be located further away from the battery cells (110) than the groove (120G). Since the basket (400) may be located on the outside of the cover cell frame (120ab), it may be located further out than the groove (120G).

[0119] In the battery assembly (100) according to the present embodiment, the groove (120G) may be formed in the portion of the cover cell frame (120ab) facing the bottom cell frame (120c). The groove (120G) may be in the shape of being indented upward from the cover cell frame (120ab).

[0120] By forming a groove (120G) on the outer perimeter of the area where the battery cells (110) are seated in the cover cell frame (120ab), the length of the waterproof interface is extended, thereby preventing the cooling fluid (CL) from leaking from the gap between the bottom cell frame (120c) and the cover cell frame (120ab). Additionally, a second sealing member (800b) may be positioned in the groove (120G). The second sealing member (800b) can complement the sealing performance that prevents the cooling fluid (CL) from leaking from the gap between the cover cell frame (120ab) and the bottom cell frame (120c).

[0121] As one example in the present invention, the groove (120G) may extend along the outer perimeter of the area where the battery cells (110) are seated. The second sealing member (800b) may also extend continuously along the outer perimeter of the area where the battery cells (110) are seated. That is, the groove (120G) and the second sealing member (800b) may surround the outer perimeter of the area where the battery cells (110) are seated.

[0122] Additionally, as another example of the present invention, the groove (120G) or the second sealing member (800b) may be partially located on the outer perimeter of the area where the battery cells (110) are seated. That is, the groove (120G) may be selectively located in the area where sealing is required. Furthermore, the groove (120G) may extend along the outer perimeter of the area where the battery cells (110) are seated, while the second sealing member (800b) may be partially located only in the area where sealing is required on the outer perimeter of the area where the battery cells (110) are seated. Selectively providing the groove (120G) or the second sealing member (800b) in the area where sealing is required may also be in accordance with the present invention.

[0123] However, in order to prevent the cooling fluid (CL) from leaking out of the gap between the bottom cell frame (120c) and the cover cell frame (120ab), as previously described, it may be preferable that the groove (120G) and the second sealing member (800b) be formed to extend along the outer perimeter of the area where the battery cells (110) are seated.

[0124] As described above, a second sealing member (800b) may be positioned in the groove (120G). With the second sealing member (800b) positioned in the groove (120G), the bottom cell frame (120c) and the cover cell frame (120ab) can be secured to each other.

[0125] The second sealing member (800b) can prevent the cooling fluid (CL) from leaking through the gap between the bottom cell frame (120c) and the cover cell frame (120ab). The groove (120G) and the second sealing member (800b) can improve the sealing performance between the bottom cell frame (120c) and the cover cell frame (120ab). Since the groove (120G) according to the present embodiment provides a space where the second sealing member (800b) is located, it can help maintain the sealing performance between the bottom cell frame (120c) and the cover cell frame (120ab). Additionally, when the adhesive described below is applied to the second sealing member (800b), the degree of bonding and sealing between the bottom cell frame (120c) and the cover cell frame (120ab) is improved due to the second sealing member (800b), so that the cell frame (120) can better withstand the internal pressure resulting from the circulation of the cooling fluid (CL).

[0126] The second sealing member (800b) applied in the present invention has no particular restrictions on its shape or material as long as it can perform the function of preventing the cooling fluid (CL) from leaking inside the cell frame (120). For example, the second sealing member (800b) may be formed by applying an adhesive that exhibits a sealing function. As long as the adhesive exhibits sealing performance and possesses impact resistance, adhesion, and electrical insulation properties, there are no particular restrictions on its material; for example, it may include a two-component epoxy-based material in which a curing agent is mixed with the main component. It may be preferable to form the second sealing member (800b) by applying the adhesive in order to prevent the leakage of the cooling fluid (CL) by being located in the space formed by the groove (120G). As another example, silicone rubber material parts such as foam tape, sealant, and O-rings may be applied to the second sealing member (800b). For example, the same material may be applied to the first sealing member (800a) and the second sealing member (800b).

[0127] Meanwhile, referring again to FIG. 19, the groove (120G) may have a zigzag shape along the outer circumference of the area where the battery cells (110) are seated. A second sealing member (800b) that may be located in this groove (120G) may also have a zigzag shape corresponding to the shape of the groove (120G). In the parts having different slopes in the zigzag shape, the direction in which the internal pressure due to the circulation of the cooling fluid (CL) acts is different from each other, so the internal pressure can be dispersed. Therefore, the groove (120G) and the second sealing member (800b) that are connected in a zigzag shape can help the cell frame (120) withstand the internal pressure due to the circulation of the cooling fluid (CL).

[0128] Referring again to FIGS. 3, FIGS. 4, FIGS. 9 through 11, the battery assembly (100) according to the present embodiment may include a busbar assembly (130). The busbar assembly (130) may include a busbar frame on which busbars (131) are arranged. The busbar assembly (130) may include at least one busbar (131) connected to an electrode terminal. Additionally, the busbar assembly (130) may include a printed circuit board. The printed circuit board is provided to sense voltage data or thermal data of the battery cells (110). For example, the printed circuit board may be connected to the electrode terminals (111, 112) of the battery cells (110) or to the busbar (131). Accordingly, voltage data of each battery cell (110) can be sensed and transmitted externally. The busbar assembly (130) may electrically connect the battery cells (110) in a series or parallel form.

[0129] A battery cell (110) may be provided with a first electrode terminal (111) and a second electrode terminal (112) as positive and negative electrode terminals. These first electrode terminal (111) and second electrode terminal (112) of the battery cell (110) may be provided on the upper surface of the battery cell (110). However, the location of the first electrode terminal (111) and the second electrode terminal (112) in the battery cell (110) may vary depending on the design and is not necessarily limited to the upper surface of the battery cell (110). Electrical connection between the battery cells (110) may be made by a bus bar (131) connecting the first electrode terminal (111) and the second electrode terminal (112). For example, a busbar (131) can electrically connect the first electrode terminal (111) of one battery cell (110) and the second electrode terminal (112) of another battery cell (110). In this form, a high voltage (HV) connection between battery cells (110) can be implemented. An 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.

[0130]

[0131] Hereinafter, as an embodiment of the present invention, a multi-layer cooling structure of a battery assembly will be described in detail.

[0132] Referring again to FIGS. 3, FIGS. 9 to 11, FIGS. 16, and FIGS. 17, as described above, a cooling fluid (CL) can be introduced into the interior of the cell frame (120) through the inlet port (121) and then discharged to the outside of the cell frame (120) through the outlet port (122). A cooling channel (300) through which the cooling fluid (CL) flows is provided inside the cell frame (120). At this time, the cooling channel (300) may be a multi-layer cooling structure.

[0133] Specifically, the cooling channel (300) through which the cooling fluid (CL) flows may include a first cooling channel (300a) and a second cooling channel (300b). The first cooling channel (300a) and the second cooling channel (300b) may be positioned sequentially along the length direction of the battery cell (110) to which the battery cell (110) extends. Here, the length direction of the battery cell (110) refers to a direction parallel to the width direction of the portion that extends relatively long from the battery cell (110). For example, as illustrated in FIGS. 9 to 11, the battery cell (110) extends with a width in the z-axis direction longer than its width in the y-axis direction, where the length direction of the battery cell (110) corresponds to a direction parallel to the z-axis direction. Additionally, the length direction of the battery cell (110) may be a direction between one side of the battery cell (110) and the other side facing said one side. At least one of the electrode terminals (111, 112) of the battery cell (110) may be located on the one surface of the battery cell (110). For example, as shown in FIGS. 9 to 11, the one surface and the other surface of the battery cell (110) may be the upper surface of the battery cell (110) and the lower surface of the battery cell (110), respectively. At least one of the electrode terminals (111, 112) of the battery cell (110) may be located on the upper surface of the battery cell (110).

[0134] For example, the first cooling channel (300a) may be located above the second cooling channel (300b). The multilayer cooling structure of the cooling channel (300) mentioned in the present invention means that layered cooling channels are implemented that are distinct from each other based on the vertical direction of the battery cell (110).

[0135] Based on the midpoint of the battery cell (110) along the length direction of the battery cell (110), the portion of the battery cell (110) below the midpoint may be in contact with the second cooling channel (300b), and the portion of the battery cell (110) above the midpoint may be in contact with the first cooling channel (300a).

[0136] The cell frame (120) may include an inlet port (121) and an outlet port (122). The second cooling channel (300b) may be connected to the inlet port (121), and the first cooling channel (300a) may be connected to the outlet port (122). Additionally, as shown in FIG. 10, the cell frame (120) may include a connecting hole (123) connecting the first cooling channel (300a) and the second cooling channel (300b). Cooling fluid (CL) may flow along the second cooling channel (300b) after being introduced through the inlet port (121). Cooling fluid (CL) flowing along the second cooling channel (300b) may be introduced into the first cooling channel (300a) through the connecting hole (123). The cooling fluid (CL) flowing along the first cooling channel (300a) can be discharged to the outside of the cell frame (120) through the outlet port (122). It is preferable that the first cooling channel (300a) and the second cooling channel (300b) are not connected to each other until the cooling fluid (CL) reaches the connection hole (123). That is, the first cooling channel (300a) and the second cooling channel (300b) can be connected to each other only through the connection hole (123). The direction in which the cooling fluid (CL) flows in the first cooling channel (300a) and the direction in which the cooling fluid (CL) flows in the second cooling channel (300b) may be opposite to each other. For example, in the second cooling channel (300b) connected to the inlet port (121), a cooling fluid (CL) may flow along the +y-axis direction, and in the first cooling channel (300a) connected to the outlet port (122), a cooling fluid (CL) may flow along the -y-axis direction.

[0137] There is no special limitation on the number of connection holes (123), and connection holes (123) may be provided as one or multiple. Based on the location of the battery cells (110), the inlet port (121) and the outlet port (122) may be located on the same side, and the connection hole (123) may be located on the opposite side from where the inlet port (121) and the outlet port (122) are located. However, this is an exemplary structure, and the locations of the inlet port (121), the outlet port (122), and the connection hole (123) are not specifically limited.

[0138] Meanwhile, although the cooling channel (300) is depicted in the drawing as a two-layer cooling structure including a first cooling channel (300a) and a second cooling channel (300b), there is no particular limitation on the number of cooling channels, and a cooling structure of three or more layers is also possible. That is, the cooling channel according to another embodiment of the present invention may further include a third cooling channel in addition to the first and second cooling channels along the longitudinal direction of the battery cell (110). Additionally, the cooling channel may include a fourth cooling channel as needed.

[0139] Below, we will explain why the cooling channel (300) according to the present embodiment has a multi-layer cooling structure.

[0140] If the cooling channel is formed as a single layer and the cooling fluid (CL) flows in only one direction, there will be a difference in the performance of the cooling fluid (CL) acting on multiple battery cells (110), and cooling imbalance may occur among the battery cells (110). As a comparative example of the present invention, a single-layer cooling channel in which the inlet port and the outlet port are located on opposite sides and the cooling fluid (CL) flows in only one direction can be considered. In this comparative example, the battery cell adjacent to the inlet port comes into direct contact with the cooling fluid (CL), so heat dissipation is well achieved, whereas the battery cell adjacent to the outlet port comes into contact with the cooling fluid (CL) that has already been heated by the battery cells, so heat dissipation is not well achieved. Therefore, cooling imbalance occurs among the battery cells (110), which may lead to a decrease in the performance of the entire battery assembly.

[0141] On the other hand, the present embodiment having a cooling channel (300) of a multi-layer cooling structure can significantly reduce the cooling variation between these battery cells (110). The key to the multi-layer cooling structure is to create a time difference in the parts of each battery cell (110) that come into contact with the cooling fluid (CL) through the multi-layer cooling structure. Referring again to FIGS. 9 and 11, in the case of the battery cell (110, the leftmost battery cell in FIGS. 9 and 11) closest to the inlet port (121) and outlet port (122), the part of the battery cell (110) located in the second cooling channel (300b) comes into contact with the cooling fluid (CL) first, and the part of the battery cell (110) located in the first cooling channel (300a) comes into contact with the cooling fluid (CL) last. That is, in the case of the battery cell (110) closest to the inlet port (121) and outlet port (122), one part of the battery cell (110) may come into contact with the coldest cooling fluid (CL) and another part of the battery cell (110) may come into contact with the hottest cooling fluid (CL). On the other hand, in the case of the battery cell (110, the battery cell located furthest to the right in FIG. 10) located furthest from the inlet port (121) and outlet port (122) and closest to the connection hole (123), the part of the battery cell (110) located in the second cooling channel (300b) comes into contact with the cooling fluid (CL) relatively late, but this cooling fluid (CL) may pass through the connection hole (123) immediately and come into contact with the part of the battery cell (110) located in the first cooling channel (300a). That is, in the case of the battery cell (110) located closest to the connection hole (123), it can be interpreted that all parts of the battery cell (110) are in contact with a cooling fluid (CL) at an intermediate temperature.In this way, by implementing a cooling channel (300) of a multi-layer cooling structure, a difference in the order of contact with the cooling fluid (CL) can be created for each part of the multiple battery cells (110). Therefore, the problem of cooling imbalance between battery cells can be resolved, and the cooling deviation of the battery cells can be minimized. As described above, in order to resolve the cooling deviation between battery cells (110), in another embodiment of the present invention, a multi-layer cooling structure such as three layers, four layers, etc., beyond a two-layer cooling structure may be provided.

[0142] The cover cell frame (120ab) according to the present embodiment may include a separating part (120M) for implementing a cooling channel (300) into a plurality of cooling channels (300a, 300b) arranged along the longitudinal direction of the battery cell (110). The plurality of cooling channels (300a, 300b) are separated from each other by the separating part (120M), and the cooling fluid (CL) does not mix with each other. As described above, the cooling channels (300a, 300b) can be connected to each other only through a connecting hole (123). The connecting hole (123) may be provided in the separating part (120M). As long as the separating part (120M) can separate the plurality of cooling channels (300a, 300b), there are no special restrictions on its shape, thickness, material, etc.

[0143] The cover cell frame (120ab) according to the present embodiment may include a middle cell frame (120b) and a top cell frame (120a) located above the middle cell frame (120b). A separation part (120M) may be provided in the middle cell frame (120b) of the cover cell frame (120ab).

[0144] Specifically, referring to FIG. 17 together with FIGS. 9 to 11, the middle cell frame (120b) may include a separating part (120M) and a side part (120S). The separating part (120M) and the side part (120S) may be integral with each other. Middle cell frame holes (120bh) may be formed in the separating part (120M), and each of the battery cells (110) may be fitted into the middle cell frame holes (120bh).

[0145] The side part (120S) may include a first side part (120S1) extending downward from the edge of the separation part (120M) and a second side part (120S2) extending upward from the edge of the separation part (120M). The space between the separation part (120M), the second side part (120S2), and the bottom cell frame (120c) may be a second cooling channel (300b). Additionally, the space between the separation part (120M), the first side part (120S1), and the top cell frame (120a) may be a first cooling channel (300a).

[0146] A middle cell frame (120b) including a separation part (120M) and a side part (120S) may be an exemplary structure for implementing a plurality of cooling channels (300). In the case of such a structure, the middle cell frame (120b) has the advantage that there is no need to worry about leakage of cooling fluid in the part between the first cooling channel (300a) and the second cooling channel (300b) because the part between the first cooling channel (300a) and the second cooling channel (300b) in the cell frame (120) is a middle cell frame (120b) part that is integrated without gaps.

[0147]

[0148] Meanwhile, with reference to FIGS. 3, FIGS. 9 to 11, FIGS. 16, and FIGS. 17, the battery cells (110) according to the present embodiment may be fitted inside a cell frame (120). For example, a plurality of holes (120h) may be formed inside the cell frame (120), and each of the battery cells (110) may be fixed inside the cell frame (120) in a form fitted into the holes (120h).

[0149] For example, a plurality of holes (120h) of the cell frame (120) may include a top cell frame hole (120ah) and a middle cell frame hole (120bh). The top cell frame hole (120ah) may be formed in the top cell frame (120a), and the middle cell frame hole (120bh) may be formed in the middle cell frame (120b). In particular, the middle cell frame hole (120bh) may be provided in the separation part (120M) of the middle cell frame (120b). The battery cell (110) may be fitted into the middle cell frame hole (120bh) and mounted and fixed to the middle cell frame (120b). Additionally, the battery cells (110) may be fitted into the top cell frame hole (120ah) and mounted and fixed to the top cell frame (120a).

[0150] Meanwhile, as described above, the bottom cell frame (120c) is combined or assembled with the cover cell frame (120ab). As an example of the assembly, the bottom cell frame (120c) and the cover cell frame (120ab) can be assembled using a separate restraining member. FIG. 17 illustrates the use of a bolt member (700) as an example of the restraining member. For example, the bolt member (700) can pass through a hole formed in the bottom cell frame (120c) and then be fastened to a nut hole formed in the cover cell frame (120ab). As described above, in the present invention, since various structures can be applied without separate restrictions on the method of combining or assembling the bottom cell frame (120c) and the cover cell frame (120ab), the bolt member (700) corresponds to one example of such a structure. However, the bottom cell frame (120c) may be a single thin member manufactured through a metal press process, in which case it may be preferable to apply an assembly structure utilizing a bolt member (700).

[0151] In the cover cell frame (120ab), various types of joining or assembly structures may be applied between the middle cell frame (120b) and the top cell frame (120a). For example, as shown in FIG. 17, a bolt member (700) may be utilized. After the bolt member (700) passes through a hole formed in the top cell frame (120a), it may be bolted / nut fastened into a nut hole formed in the middle cell frame (120b).

[0152]

[0153] FIG. 20 is a perspective view showing a top cell frame, a busbar frame assembly, and a first waterproof adhesive according to an embodiment of the present invention. FIG. 21 is a perspective view showing battery cells, a second waterproof adhesive, and a bottom cell frame according to an embodiment of the present invention.

[0154] Referring to FIGS. 20 and 21, the battery assembly (100) according to the present embodiment may include a waterproof adhesive (500a, 500b) applied to the inside and outside of a cell frame (120). There are no special restrictions on the material of the waterproof adhesive (500a, 500b) as long as it exhibits waterproof performance and possesses impact resistance, adhesiveness, and electrical insulation properties. For example, the waterproof adhesive (500a, 500b) may include a two-component epoxy-based material in which a curing agent is mixed into the main component.

[0155] The waterproof adhesive (500a, 500b) may include a first waterproof adhesive (500a) applied on the cover cell frame (120ab) and a second waterproof adhesive (500b) applied on the bottom cell frame (120c).

[0156] The first waterproof adhesive (500a) can be applied to the cover cell frame (120ab), particularly to the top cell frame (120a). The first waterproof adhesive (500a) can prevent the cooling fluid (CL) from leaking over the cover cell frame (120ab) into the upper region of the cover cell frame (120ab). With the battery cell (110) mounted in the top cell frame hole (120ah) of the top cell frame (120a), the first waterproof adhesive (500a) can be applied to the upper surface of the top cell frame (120a) and the upper region of the battery cell (110).

[0157] As previously explained, electrical connection between battery cells (110) can be made by a bus bar (131) connecting the first electrode terminal (111) and the second electrode terminal (112). Electrical connection by the bus bar (131) can be made at the top of the cover cell frame (120ab). The bus bar (131) can be located at the top of the cover cell frame (120ab) and also at the top of the top cell frame (120a) of the cover cell frame (120ab).

[0158] At least a portion of the busbar (131) may be surrounded by the first waterproof adhesive (500a). Additionally, the surrounding space of the busbar (131) may be filled with the first waterproof adhesive (500a). Additionally, the first electrode terminal (111) and the second electrode terminal (112) of the battery cell (110) may be surrounded by the first waterproof adhesive (500a). Additionally, the gap between the top cell frame hole (120ah) and the battery cell (110) fitted therein may be filled with the first waterproof adhesive (500a). Due to the first waterproof adhesive (500a), the cooling fluid (CL) may be prevented from leaking into the upper region of the cover cell frame (120ab). In the battery assembly (100), the sealing structure at the top thereof may be implemented by the first waterproof adhesive (500a).

[0159] Referring again to FIGS. 4, FIGS. 5, FIGS. 9 to 11, and FIGS. 21, the second waterproof adhesive (500b) applied on the bottom cell frame (120c) can stably secure the battery cells (110) on the bottom cell frame (120c).

[0160] Additionally, the second waterproof adhesive (500b) can cover the vent portion (110V) of the battery cell (110). As described above, the vent portion (110V) corresponds to a component or mechanism provided in the battery cell (110) to discharge venting gas, etc., inside the battery cell (110). The vent portion (110V) can be formed on the lower surface of the battery cell (110), and the second waterproof adhesive (500b) applied on the bottom cell frame (120c) can cover this vent portion (110V). Additionally, the second waterproof adhesive (500b) can cover a portion of the side of the battery cell (110) adjacent to the lower surface of the battery cell (110).

[0161] If a thermal event or thermal runaway occurs inside the battery cell (110), high-temperature venting gas or particles may be discharged through the open vent section (110V). Generally, when gas is ejected from the battery cell (110), pieces of electrode plates or active material inside the battery cell (110) may be discharged to the outside while heated to a high temperature, and these high-temperature particles may appear in the form of sparks. The high-temperature venting gas or particles discharged through the vent section (110V) may be discharged to the outside of the bottom cell frame (120c) while rupturing or melting the bottom cell frame (120c). Although not specifically illustrated, the high-temperature venting gas or particles may be discharged to the outside through a separate venting channel provided below the bottom cell frame (120c).

[0162] Since the second waterproof adhesive (500b) covers the vent portion (110V) of the battery cell (110) and a portion of the side of the battery cell (110) adjacent to the bottom surface of the battery cell (110), the vent portion (110V) is not exposed. Accordingly, even if there is a thermal runaway due to an abnormality in one of the battery cells (110), high-temperature venting gas or particles are not transmitted to surrounding battery cells (110), so it is not vulnerable to chain ignition.

[0163] Additionally, the venting path of the battery cell (110) and the cooling fluid (CL) can be separated from each other by the second waterproof adhesive (500b). As described above, a cooling oil may be applied to the cooling fluid (CL). Since the cooling oil is an oil component, when it comes into contact with the venting gas or particles, it can cause additional thermal runaway, ignition, and explosion. The second waterproof adhesive (500b) can cover the vent section (110V) so that the vent section (110V) is not exposed to the cooling fluid (CL). The second waterproof adhesive (500b) blocks the high-temperature venting gas and particles discharged from the vent section (110V) of the battery cell (110) from coming into contact with the cooling fluid (CL), thereby preventing the thermal runaway of the battery cell (110) from leading to ignition or explosion of the entire battery assembly (100).

[0164] Meanwhile, referring to FIGS. 9 to 11, FIGS. 17, and FIG. 20, a locking connection between the rib (120R) and the indentation (120G') can be formed between the top cell frame (120a) and the middle cell frame (120b).

[0165] A rib (120R) can be formed on the outer perimeter of the area where the battery cells (110) are located in the top cell frame (120a). The rib (120R) of the top cell frame (120a) can be engaged with the recess (120G') of the middle cell frame (120b). With this engaging engagement, an anti-slip assembly structure can be implemented between the top cell frame (120a) and the middle cell frame (120b). By engaging the rib (120R) and the recess (120G'), the length of the waterproof interface between the top cell frame (120a) and the middle cell frame (120b) can be increased, thereby improving sealing performance. An anti-slip assembly structure can be implemented by the engaging engagement in which the rib (120R) and the recess (120G') are engaged in an alternating manner. Accordingly, the top cell frame (120a) can stably withstand internal pressure due to the circulation of the cooling fluid (CL).

[0166] Additionally, as described above, a first waterproof adhesive (500a, see FIG. 20) may be applied to the upper surface of the top cell frame (120a). Although not specifically illustrated, a portion of the first waterproof adhesive (500a) may be filled into the portion where the rib (120R) and the indentation (120G') are joined. Due to the first waterproof adhesive (500a) filled into the portion where the rib (120R) and the indentation (120G') are joined, the bonding strength between the top cell frame (120a) and the middle cell frame (120b) is increased, and the leakage of cooling fluid (CL) through the gap between the top cell frame (120a) and the middle cell frame (120b) can be prevented.

[0167] Meanwhile, referring to FIGS. 4, 5, 9 to 11, the vent portion (110V) of the battery cell (110) according to the present embodiment may face the bottom cell frame (120c). If a thermal event or thermal runaway occurs inside the battery cell (110), high-temperature venting gas discharged through the vent portion (110V) may pass through the bottom cell frame (120c) and be discharged to the outside of the bottom cell frame (120c). The venting gas discharged from the vent portion (110V) of the battery cell (110) may pass through the bottom cell frame (120c) and be discharged while rupturing or melting the bottom cell frame (120c). The venting gas may be discharged to the outside through a separate venting channel provided below the bottom cell frame (120c). That is, in the case of the battery assembly (100) according to the present embodiment, it may have a directional venting structure that induces the discharge of venting gas in the downward direction of the bottom cell frame (120c).

[0168] The bottom cell frame (120c) normally supports the battery cells (110), but when venting gas is discharged from the vent portion (110V) of the battery cell (110), it must be able to effectively discharge the venting gas under the bottom cell frame (120c). To this end, it is desirable for the bottom cell frame (120c) to have a sufficiently thin thickness so that it ruptures or melts due to the venting gas. To implement a bottom cell frame (120c) having such a thin thickness, the metal press method described above may be applied. Since it is difficult to manufacture a bottom cell frame (120c) with a sufficiently thin thickness using the plastic injection molding method, a double-structured bottom cell frame is required, which includes a separate plate with a thin thickness in addition to the frame. The application of a double-structured bottom cell frame means that the number of parts increases, and the size and height of the battery assembly increase, resulting in a decrease in space utilization efficiency. Additionally, there is a problem that a sealing part must be added between the double structures.

[0169] In contrast, the bottom cell frame (120c) manufactured through a metal press process can be implemented as a single member with a sufficiently thin thickness. Therefore, this bottom cell frame (120c) has the advantage of effectively venting the venting gas under the bottom cell frame (120c) without increasing the number of parts or reducing space utilization.

[0170] Meanwhile, referring again to FIG. 11, the cell frame (120) according to the present embodiment may include a distribution mechanism (200), and the distribution mechanism (200) may include an inlet distribution mechanism (210) disposed adjacent to an inlet port (121) and an outlet distribution mechanism (220) disposed adjacent to an outlet port (122). The inlet distribution mechanism (210) may be provided between the inlet port (121) and the battery cells (110), and the outlet distribution mechanism (220) may be provided between the outlet port (122) and the battery cells (110).

[0171] Each of the inlet distribution mechanism (210) and the outlet distribution mechanism (220) may include a partition wall and a plurality of distribution holes formed in the partition wall. In FIG. 11, the inlet distribution mechanism (210) is shown with a cross-section including distribution holes, while the outlet distribution mechanism (220) is shown with a cross-section not including distribution holes.

[0172] These distribution holes can be positioned to correspond to the rows in which the battery cells are arranged. The cooling fluid (CL) introduced through the inlet port (121) does not enter the space where the battery cells are located directly, but is distributed through the distribution holes and then introduced into the space where the battery cells are located. Accordingly, the cooling fluid (CL) is not concentrated on only some of the large number of battery cells (110), but can be evenly distributed and flow over all of the battery cells (110). Therefore, uniform cooling of all of the battery cells (110) becomes possible, which can lead to an improvement in the performance of the battery assembly.

[0173] The cooling fluid (CL) distributed into multiple channels by the inlet distribution mechanism (210) can be discharged through the outlet port (122) after passing through the outlet distribution mechanism (220). By providing the outlet distribution mechanism (220) at the outlet port (122), the problem of the cooling fluid (CL) distributed into multiple channels becoming stagnant and not flowing or forming a vortex can be prevented.

[0174] Meanwhile, referring again to FIG. 1, the battery assembly (100) according to one embodiment of the present invention illustrated in FIG. 1 can be mounted directly onto a vehicle or chassis. That is, in the case of the battery assembly (100) according to the present embodiment, the battery cells (110) can be mounted directly onto a vehicle or chassis with the battery cells housed in a cell frame (120). The inlet port (121) and outlet port (122) of the cell frame (120) can be connected to a cooling fluid circulation system within the vehicle.

[0175] FIGS. 22 and FIGS. 23 are exploded perspective views of a battery pack according to one embodiment of the present invention.

[0176] Referring to FIGS. 1, 22, and 23, a battery pack (1000) according to another embodiment of the present invention may include at least one battery assembly (100); a pack frame (1100) that accommodates at least one battery assembly (100) and has one side open; and a pack cover (1200) that covers the open side of the pack frame (1100). FIGS. 22 and 23 illustrate, as an example, that three battery assemblies (100) are accommodated in the pack frame (1100).

[0177] The pack frame (1100) may include a bottom portion (1110) and a side beam (1120). At least one battery assembly (100) may be placed on the bottom portion (1110). The side beam (1120) may extend along the edge of the bottom portion (1110) and extend in a direction perpendicular to one side of the bottom portion (1110). By the bottom portion (1110) and the side beam (1120), an internal space with an open top may be provided, and the battery assembly (100) may be housed in this internal space. The pack cover (1200) may cover the upper surface of the battery assembly (100) mounted on the pack frame (1100).

[0178] Meanwhile, the battery pack (1000) according to the present embodiment may include a filling member (1300) foamed in the space within the pack frame (1100) and the pack cover (1200). The filling member (1300) according to the present embodiment may be a foamed member. The filling member (1300) may be a foamed member that is foamed after being filled in the space within the pack frame (1100) and the pack cover (1200).

[0179] The filling member (1300) according to the present embodiment may be formed of a resin. For example, the filling members (1300) may be formed of resin or the like. The filling member (1300) may include an air pocket, and an adhesive may be provided in the air pocket. The filling member (1300) may be foamed rubber, i.e., cellular or sponge. The filling member (1300) may include an air-filled matrix structure. The filling member (1300) may be based, for example, silicone, polyurethane, or other organic materials.

[0180] The filling member (1300) can be foamed into a plate shape by, for example, applying it onto a pack frame (1100) or by using a spray. The filling member (1300) may include a foaming promoter.

[0181] When the filling member (1300) comes into contact with other components, it subsequently hardens and combines with the other components to provide fixed support. Thus, the adhesive force between the components that the filling member (1300) comes into contact with can be strengthened. In this embodiment, the adhesive force between the pack frame (1100), the pack cover (1200), and the battery assembly (100) can be strengthened by the filling member (1300). Additionally, the filling member (1300) can absorb vibrations and shocks applied to the battery pack (1000), so that the components within the battery pack (1000) do not separate or detach, thereby improving the safety and mechanical reliability of the battery pack.

[0182] Meanwhile, the battery pack (1000) according to the present embodiment may include an inlet pipe (1400) connected to an inlet port (121) of the battery assembly (100) and an outlet pipe (1500) connected to an outlet port (122) of the battery assembly (100).

[0183] Each of the inlet pipe (1400) and the outlet pipe (1500) can pass through the side beam (1120) and be connected to the inlet port (121) and outlet port (122) of the battery assembly (100). Additionally, the inlet pipe (1400) and the outlet pipe (1500) can be connected to a cooling fluid circulation system inside the vehicle. Cooling fluid supplied by the cooling fluid circulation system inside the vehicle reaches the inlet port (121) via the inlet pipe (1400). Cooling fluid that circulates inside the battery assembly (100) and is discharged through the outlet port (122) is returned to the cooling fluid circulation system through the outlet pipe (1500).

[0184] In this embodiment, terms indicating directions such as front, back, left, right, up, and down have been used; however, these terms are for convenience of explanation only and may vary depending on the location of the object or the position of the observer.

[0185] One or more battery assemblies according to the embodiment described above can be mounted together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system, to form a battery pack.

[0186] The above battery assembly or battery pack can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, or to Energy Storage Systems (ESS), but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0187] 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 using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0188] Explanation of the symbols

[0189] 100: Battery assembly

[0190] 110: Battery cell

[0191] 120: Cell Frame

[0192] 120ab: Cover cell frame

[0193] 120c: Bottom cell frame

[0194] 120G: Groove

[0195] 120R: Rib

[0196] 400: Basket

[0197] 800a: First sealing member

[0198] 800b: Second sealing member

Claims

1. Multiple battery cells; and A cell frame in which the above battery cells are housed; and The cell frame comprises a bottom cell frame on which the battery cells are seated and a cover cell frame located on the bottom cell frame. A cooling fluid circulates inside the cell frame in direct contact with the battery cells, and A battery assembly in which the bottom cell frame is combined or assembled with the cover cell frame.

2. In Paragraph 1, The above bottom cell frame is a battery assembly that is a single component.

3. In Paragraph 1, The above bottom cell frame is a battery assembly comprising a basket that covers a portion of the outer side of the above cover cell frame.

4. In Paragraph 3, The basket is a battery assembly that extends along the outer perimeter of the area where the battery cells are seated in the bottom cell frame.

5. In Paragraph 3, The basket is a battery assembly located on the outer side of the cover cell frame.

6. In Paragraph 3, A battery assembly in which a first sealing member is located in the basket above.

7. In Paragraph 3, The above basket is a battery assembly comprising a first portion connected at the boundary between the bottom cell frame and the cover cell frame and a second portion protruding upward from the first portion.

8. In Paragraph 7, A battery assembly in which a first sealing member is located in the space between the first part, the second part, and the outer side of the cover cell frame.

9. In Paragraph 1, The above cover cell frame is a battery assembly comprising a groove formed on the outer perimeter of an area where the battery cells are seated.

10. In Paragraph 9, The above groove is a battery assembly formed in the portion of the cover cell frame facing the bottom cell frame.

11. In Paragraph 9, The above groove is a battery assembly that extends along the outer perimeter of the area where the battery cells are seated.

12. In Paragraph 9, The above groove is a battery assembly in which the groove is indented in an upward direction from the cover cell frame.

13. In Paragraph 9, A battery assembly in which a second sealing member is located in the above groove.

14. In Paragraph 1, The cell frame comprises a battery assembly including an inlet port through which the cooling fluid flows into the cell frame and an outlet port through which the cooling fluid is discharged to the outside of the cell frame.

15. In Paragraph 1, A battery assembly in which the vent portion of the battery cell faces the bottom cell frame.

16. In Paragraph 15, A battery assembly in which venting gas discharged from the vent portion of the battery cell passes through and is discharged while rupturing or melting the bottom cell frame.

17. In Paragraph 1, The above battery cells are a battery assembly in which they are fitted inside the cell frame.

18. In Paragraph 1, A battery assembly in which the above battery cells are housed in the cell frame and are mounted directly to a vehicle or chassis.

19. At least one battery assembly according to paragraph 1; A pack frame housing at least one of the above-mentioned battery assemblies and having one side open; and A battery pack comprising a pack cover covering an open side of the pack frame.

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