Battery cell unit and device including same

Abstract

A battery cell unit according to an embodiment of the present invention comprises: a plurality of battery cells; and a cover assembly which covers at least part of the outer surfaces of the battery cells. The cover assembly comprises: an inflow part through which refrigerant is introduced into the cover assembly; a discharge part which discharges the refrigerant from the interior of the cover assembly; and a gas discharge part which discharges gas generated from the battery cells. The gas discharge part is formed on one side of the cover assembly different from at least one side of the cover assembly in which the inflow part and the discharge part are formed.

Description

Battery cell unit and device including the same

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

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0051057 filed April 18, 2025, 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 cell unit and a device including the same, and more specifically, to a battery cell unit with increased cooling performance and improved safety and a device 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 oil, rather than 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 refrigerant directly cools the battery cells inside the battery pack.

[0012] Meanwhile, gas can be generated internally within battery cells due to overheating or overcharging. Such gas poses a risk of causing structural damage to the battery pack or inducing safety accidents such as fire or explosion. Accordingly, there is a need for new structural technology that can efficiently control and vent the gas generated within the battery pack to improve the safety of the battery pack.

[0013] The problem that the present invention aims to solve is to provide a battery cell unit with increased cooling performance and improved safety, and a device including the same.

[0014] 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.

[0015] A battery cell unit according to one embodiment of the present invention comprises: a plurality of battery cells; and a cover assembly covering at least a portion of the outer surface of the battery cells. The cover assembly comprises an inlet portion for introducing a refrigerant into the interior of the cover assembly, an outlet portion for discharging the refrigerant from the interior of the cover assembly, and a gas outlet portion for discharging gas generated from the battery cells. The gas outlet portion is formed on one surface of the cover assembly different from at least one surface of the cover assembly where the inlet portion and the outlet portion are formed.

[0016] In the battery cell unit above, a busbar connected to the electrode leads of the battery cells and a busbar frame on which the busbar is mounted may be provided.

[0017] At least a portion of the refrigerant introduced into the cover assembly may come into contact with the busbar.

[0018] The above inlet may include a busbar cooling inlet formed in a portion of one side of the cover assembly corresponding to the busbar.

[0019] A busbar cooling channel may be formed in the busbar frame to guide the flow of the refrigerant so that it comes into contact with the busbar.

[0020] The above busbar cooling channel may be a groove formed in the busbar frame.

[0021] At least one spacer may be located between at least some of the above battery cells, and a flow path hole through which refrigerant flows may be formed in the spacer.

[0022] The above inlet may include a cell cooling inlet, and at least a portion of the cell cooling inlet may overlap with at least a portion of the flow path hole.

[0023] Based on the battery cells, one side of the cover assembly having the gas discharge portion formed thereon may be located in the direction in which at least one of the electrode leads protrudes from the battery cell.

[0024] A first sealing member may be positioned on one surface of the cover assembly in which the gas discharge portion is formed. The first sealing member may be positioned to avoid the gas discharge portion.

[0025] Based on the above battery cells, a second sealing member may be located in the direction opposite to the direction in which one side of the cover assembly, on which the gas discharge portion is formed, is located.

[0026] A third sealing member may be located at least one of the following: between the battery cells and one side of the cover assembly where the inlet is formed, or between the battery cells and the other side of the cover assembly where the outlet is formed. The third sealing member may be located avoiding the inlet or the outlet.

[0027] In the battery cell unit above, a busbar connected to the electrode leads of the battery cells and a busbar frame on which the busbar is mounted may be provided. A gas discharge hole connected to the gas discharge part may be formed in the busbar frame.

[0028] A fourth sealing member may be provided between the busbar frame and one side of the cover assembly.

[0029] The above-mentioned fourth sealing member can be positioned to avoid the gas discharge hole.

[0030] One side of the cover assembly where the gas discharge portion is formed may be perpendicular to the other side of the cover assembly where the inlet portion is formed.

[0031] One side of the cover assembly having the gas discharge portion formed thereon may be perpendicular to the other side of the cover assembly having the discharge portion formed thereon.

[0032] A device according to one embodiment of the present invention includes the battery cell unit.

[0033] According to embodiments of the present invention, the battery cell unit is equipped with a refrigerant that is introduced into the cover assembly to cool the battery cells, as well as a gas discharge means for discharging gas generated from the battery cells. Accordingly, the cooling performance of the battery cell unit can be enhanced while simultaneously efficiently controlling and discharging the gas, thereby improving the safety of the battery cell unit.

[0034] 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.

[0035] The following drawings attached to this specification illustrate embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0036] FIGS. 1 and FIGS. 2 are perspective views showing a battery cell unit according to an embodiment of the present invention at different angles.

[0037] FIG. 3 is a perspective view showing a battery cell according to one embodiment of the present invention.

[0038] FIG. 4 is an exploded perspective view of a battery cell unit according to one embodiment of the present invention.

[0039] FIG. 5 is an exploded perspective view of the components excluding the upper surface portion of a battery cell unit according to one embodiment of the present invention.

[0040] FIGS. 6 and 7 are perspective views showing battery cells, spacers, and pads according to an embodiment of the present invention.

[0041] FIG. 8 is an exploded perspective view showing a battery cell unit according to one embodiment of the present invention.

[0042] FIG. 9 is a perspective view showing a battery cell unit without an upper surface.

[0043] FIG. 10 is a perspective view showing a part of the cover assembly and a spacer according to one embodiment of the present invention.

[0044] FIG. 11 is a perspective view showing a spacer according to one embodiment of the present invention.

[0045] FIG. 12 is a perspective view showing a pad according to one embodiment of the present invention.

[0046] FIG. 13 is a plan view showing one side of a battery cell unit according to one embodiment of the present invention.

[0047] FIG. 14 is a perspective view showing a busbar frame and a busbar according to one embodiment of the present invention.

[0048] FIG. 15 is a partial drawing showing an enlarged view of section “B” of FIG. 9.

[0049] FIG. 16 is a perspective view showing a battery assembly according to one embodiment of the present invention.

[0050] FIG. 17 is a cross-sectional perspective view showing a cross section cut along the cutting line A-A' of FIG. 16.

[0051] FIG. 18 is a cross-sectional view of FIG. 17 as seen along the -x-axis direction in the yz plane.

[0052] FIG. 19 is a cross-sectional perspective view showing only the configuration of the housing in FIG. 17.

[0053] FIG. 20 is an exploded perspective view of a battery assembly according to one embodiment of the present invention.

[0054] FIG. 21 is an exploded perspective view showing a battery assembly according to one embodiment of the present invention.

[0055] FIG. 22 is an exploded perspective view showing a battery assembly according to one embodiment of the present invention.

[0056] FIG. 23 is a top view of a battery assembly without a ceiling.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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 on" another part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" 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.

[0061] 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.

[0062] 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.

[0063] FIGS. 1 and FIGS. 2 are perspective views showing a battery cell unit according to an embodiment of the present invention at different angles. In particular, FIG. 1 shows a portion of the battery cell unit (100) where the inlet portion (200N) is visible, and FIG. 2 shows a portion of the battery cell unit (100) where the outlet portion (200U) is visible. FIG. 3 is a perspective view showing a battery cell according to an embodiment of the present invention. FIG. 4 is an exploded perspective view of a battery cell unit according to an embodiment of the present invention. FIG. 5 is an exploded perspective view of the components of a battery cell unit according to an embodiment of the present invention, excluding the upper surface portion.

[0064] Referring to FIGS. 1 to 5, a battery cell unit (100) according to one embodiment of the present invention comprises a plurality of battery cells (110); and a cover assembly (200) that covers at least a portion of the outer surface of the battery cells (110). Additionally, the cover assembly (200) includes an inlet (200N) for introducing a refrigerant into the interior of the cover assembly (200), an outlet (200U) for discharging the refrigerant from the interior of the cover assembly (200), and a gas outlet (200G) for discharging gas generated from the battery cells (110).

[0065] The refrigerant can flow into the interior of the cover assembly (200) in which the battery cells (110) are housed through the inlet (200N). The refrigerant flowing into the interior of the cover assembly (200) cools the battery cells (110). Afterward, the refrigerant can be discharged to the outside of the cover assembly (200) through the outlet (200U). The refrigerant can cool the battery cells (110) while undergoing the circulation process described above. The refrigerant can flow directly into the space where the battery cells (110) are located to cool the battery cells (110). In one embodiment, at least a portion of the battery cells (110) may come into contact with the refrigerant to be cooled.

[0066] Gas generated from the battery cell (110) can move to the outside of the battery cell unit (100) through a gas discharge section (200G) formed in the cover assembly (200). For example, high-temperature gas may be generated from the battery cell (110) when a thermal event or thermal runaway occurs in at least one of the multiple battery cells (110). If this gas is not properly discharged to the outside of the battery cell unit (100), structural damage to the battery cell unit (100) may occur, and the thermal event or thermal runaway may propagate to adjacent battery cells (110). In particular, since the gas contains high-temperature metal particles, if it is not properly discharged, it may cause safety accidents such as fire or explosion.

[0067] In the battery cell unit (100) according to the present embodiment, the gas generated from the battery cell (110) can move to the outside of the battery cell unit (100) through the gas discharge section (200G). Specifically, although not illustrated, the battery cell unit (100) according to the present embodiment has a directional venting structure in which the gas generated from the battery cell (110) is discharged in a pre-designed direction through the gas discharge section (200G). Because the gas generated from the battery cell (110) moves along the designed direction, the gas can be efficiently controlled and smoothly discharged to the outside. Accordingly, the propagation of a thermal event or thermal runaway to adjacent battery cells (110) can be blocked, and the occurrence of a fire or explosion in the battery cell unit (100) can be prevented.

[0068] As described above, the battery cell unit (100) according to the present embodiment is equipped with a direct cooling means using a refrigerant, as well as a gas exhaust means for efficiently exhausting gas generated from the battery cell. Accordingly, the safety of the battery cell unit can be improved by increasing the cooling performance of the battery cell unit while simultaneously efficiently controlling and exhausting the gas.

[0069] The gas discharge portion (200G) according to the present embodiment is formed on at least one side of the cover assembly (200) in which the inlet portion (200N) and the discharge portion (200U) are formed, and on one side of the other cover assembly (200). As will be described later, the cover assembly (200) according to the present embodiment may include a first side portion (210), a second side portion (220), a third side portion (230), and a fourth side portion (240) that cover the sides of the battery cells (110), and may include an upper surface portion (250) located on the upper side of the battery cells (110).

[0070] In one embodiment of the present invention, the gas discharge portion (200G) may be formed on the upper surface portion (250), the inlet portion (200N) may be formed on the first side portion (210), and the discharge portion (200U) may be formed on the third side portion (230). However, this is an exemplary structure, and there are no special restrictions on the location of the gas discharge portion (200G), the inlet portion (200N), and the discharge portion (200U), respectively, as long as the portion where the gas discharge portion (200G) is formed does not coincide with the portions where the inlet portion (200N) and the discharge portion (200U) are formed.

[0071] As described above, the battery cell unit (100) according to the present embodiment is equipped with a direct cooling means using a refrigerant as well as a gas discharge means for efficiently discharging gas generated from the battery cell, thereby increasing cooling performance while simultaneously efficiently controlling and discharging the gas, which can increase the safety of the battery cell unit. However, since the structure involves the refrigerant flowing into the interior of the battery cell unit (100) to cool the battery cells (110), there may be a problem where the refrigerant interferes with the gas discharge path. That is, if the refrigerant circulation path and the gas discharge path interfere with each other, the following problems may occur.

[0072] For example, gas generated from at least some of the battery cells (110) must move to the outside of the battery cell unit (100) through the gas discharge section (200G) and finally be discharged, but a refrigerant introduced into the cover assembly (200) may obstruct this venting path of the gas. If the gas is not properly discharged due to obstruction by the refrigerant, structural damage to the battery cell unit may occur, and there is a risk of safety accidents such as fire or explosion ultimately being caused.

[0073] In addition, as mentioned above, cooling oil or insulating oil may be applied as a refrigerant; however, since cooling oil or insulating oil is an oil component, when it comes into contact with gas or particles contained therein, it can cause additional thermal runaway, ignition, explosion, etc.

[0074] In addition, during the process of emitting gas through the gas discharge section (200G), a problem may occur in which some of the refrigerant is lost as it is discharged together. If the refrigerant is lost in this way, the overall cooling performance of the battery cell unit (100) may be reduced, and a temperature difference between the battery cells (110) may be induced, which may cause performance degradation and a shortened lifespan.

[0075] To resolve the above-mentioned problem caused by mutual interference between the refrigerant circulation path and the gas discharge path, it is necessary to clearly separate the refrigerant circulation path and the gas discharge path in the battery cell unit (100). Accordingly, in this embodiment, the gas discharge section (200G) may be formed on at least one side of the cover assembly (200) where the inlet section (200N) and the discharge section (200U) are formed, and on one side of the other cover assembly (200). By distinguishing the parts where refrigerant circulation occurs by the inlet section (200N) and the discharge section (200U) and the parts where gas discharge occurs by the gas discharge section (200G) into different regions based on the battery cell unit (100), the mutual influence between the refrigerant circulation path and the gas discharge path can be minimized. That is, the refrigerant circulation path and the gas discharge path are implemented in different regions of the battery cell unit (100) to clearly separate them. Through this, thermal management efficiency can be maximized, and the safety and durability of the battery cell unit can be significantly improved. Ultimately, the above-mentioned problems caused by mutual interference between the refrigerant circulation path and the gas discharge path can be prevented.

[0076] In one embodiment of the present invention, one side of a cover assembly (200) having a gas discharge portion (200G) formed thereon may be perpendicular to the other side of a cover assembly (200) having an inlet portion (200N) formed thereon. Additionally, one side of a cover assembly (200) having a gas discharge portion (200G) formed thereon may be perpendicular to the other side of a cover assembly (200) having a discharge portion (200U) formed thereon. In an exemplary structure, the gas discharge portion (200G) may be formed on an upper surface portion (250), the inlet portion (200N) may be formed on a first side portion (210), the discharge portion (200U) may be formed on a third side portion (230), and the upper surface portion (250) may be perpendicular to each of the first side portion (210) and the third side portion (230). In this exemplary structure, the refrigerant can be introduced into the battery cell unit (100) through an inlet (200N) formed in the first side portion (210) and then moved out of the battery cell unit (100) through an outlet (200U) formed in the third side portion (230). The refrigerant can move along the -x-axis direction. On the other hand, the gas generated in the battery cell (110) can be guided to be discharged in the +z-axis direction through a gas outlet (200G) formed in the upper portion (250). In this way, by setting the refrigerant circulation path and the gas discharge path to be formed in different regions of the battery cell unit (100) and along different directions, the refrigerant circulation path and the gas discharge path can be clearly separated and the influence between them can be minimized.

[0077]

[0078] 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 applied to any type of secondary battery, such as a prismatic, cylindrical, or pouch-type battery cell. However, below, a pouch-type battery cell (110) will be described as an example.

[0079] The battery cell (110) according to the present embodiment may be in the form of an electrode assembly having electrode leads (111, 112) protruding in one or both directions, housed in a case (114). The battery cell (110) may be in the shape of a rectangular sheet. The battery cell (110) may have a bottom portion (114a), a top portion (114b), and both ends (114c, 114d).

[0080] A battery cell (110) can be formed by housing an electrode assembly in a case (114) of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the case (114). For example, the battery cell (110) may have a structure in which two electrode leads (111, 112) protrude in one direction. The electrode leads (111, 112) may protrude from the upper part (114b) of the battery cell (110). As another embodiment, a structure in which the electrode leads (111, 112) of the battery cell (110) protrude in opposite directions is also possible. The electrode leads (111, 112) protruding from the battery cell (110) may be electrode leads having different polarities. Specifically, among the electrode leads (111, 112), the first electrode lead (111) may be a positive electrode lead and the second electrode lead (112) may be a negative electrode lead.

[0081] A battery cell (110) can be manufactured by bonding the two ends (114c, 114d) of a case (114) and the upper end (114b) connecting them, while the electrode assembly (not shown) is housed in the case (114). In other words, a battery cell (110) according to one embodiment of the present invention has a total of three sealing parts, and the sealing parts are sealed by a method such as fusion, and the remaining lower end (114a) can be made of a folding part. That is, the battery cell (110) according to the present embodiment may be a pouch-type secondary battery in which the electrode assembly is housed inside the case (114) and the upper end (114b) and both ends (114c, 114d) of the case (114) are sealed to form a sealing part.

[0082] The case (114) of the laminate sheet may include an inner resin layer for sealing, a metal layer for preventing penetration of material, and an outermost resin layer. Based on the electrode assembly inside the case (114), the inner resin layer may be located at the innermost position, the outer resin layer at the outermost position, and the metal layer may be located between the inner resin layer and the outer resin layer.

[0083] The outer resin layer may possess excellent tensile strength and weather resistance relative to its thickness and electrical insulation properties to protect the electrode assembly from the outside. This outer resin layer may include polyethylene terephthalate (PET) resin or nylon resin. The metal layer may prevent air, moisture, etc. from entering the interior of the pouch-type secondary battery. This metal layer may include aluminum (Al). The inner resin layers may be thermally fused together by applied heat and / or pressure while the electrode assembly is embedded. This inner resin layer may include casted polypropylene (CPP) or polypropylene (PP).

[0084] A case (114) may be divided into two parts, and a concave-shaped storage portion may be formed in at least one of the two parts so that an electrode assembly can be seated thereon. Along the outer circumference of this storage portion, the inner resin layers of the two parts of the case (114) may be bonded together to form a sealing portion. In this way, the pouch case is sealed so that a battery cell (110), which is a pouch-type secondary battery, can be manufactured.

[0085] These battery cells (110) may be composed of multiple units. For example, multiple battery cells (110) may be stacked along one direction so that they can be electrically connected to each other. The battery cells (110) may be stacked along a direction perpendicular to one side of the cell body (113). For example, multiple battery cells (110) may be stacked upright along a direction parallel to the y-axis. Accordingly, electrode leads (111) may protrude in a direction perpendicular to the direction in which the battery cells (110) are stacked. For example, the electrode leads (111, 112) may protrude toward the z-axis direction.

[0086]

[0087] Meanwhile, the refrigerant in the present invention serves as a cooling medium for cooling a heat-generating object, and there are no restrictions on its form or material. Refrigerants of various phases may be applied. For example, a cooling medium in a solid, fluid, liquid, or gaseous state may be applied to the refrigerant without limitation. Furthermore, bubbles, paraffin, or phase change materials (PCMs) may be applied to the refrigerant.

[0088] As an example, the refrigerant may be a fluid. The refrigerant may be cooling water or cooling oil. Meanwhile, within the battery cell unit (100), the refrigerant may come into direct contact with the battery cells (110) and electrode leads (111, 112), and the refrigerant may be electrically insulated. The refrigerant may be a material having insulating properties. For example, the refrigerant may be insulating oil. However, these are exemplary materials, and as described above, any material capable of cooling an object requiring cooling may be applied to the refrigerant in the present invention without limitation.

[0089]

[0090] Referring again to FIGS. 1 to 5, in a battery cell unit according to one embodiment of the present invention, a first sealing member (700a) may be located on one surface of a cover assembly (200) having a gas discharge portion (200G) formed therein. For example, the gas discharge portion (200G) may be formed on the upper surface portion (250) of the cover assembly (200), and the first sealing member (700a) may be located on the upper surface portion (250) of the cover assembly (200).

[0091] The first sealing member (700a) according to the present embodiment may be positioned to avoid the gas discharge portion (200G). Additionally, the first sealing member (700a) may be positioned outside the gas discharge portion (200G) on the one surface of the cover assembly (200) where the gas discharge portion (200G) is formed. Here, the fact that the first sealing member (700a) is positioned outside the gas discharge portion (200G) may mean that the first sealing member (700a) is positioned closer to the edge of the one surface of the cover assembly (200) than to the gas discharge portion (200G).

[0092] For example, FIG. 4 shows that the first sealing member (700a) is positioned outside the gas discharge portion (200G), avoiding the gas discharge portion (200G). The first sealing member (700a) may extend along the outside of the gas discharge portion (200G).

[0093] The first sealing member (700a) according to the present embodiment can help to clearly separate the refrigerant circulation path and the gas discharge path. The first sealing member (700a), which is positioned outside the gas discharge section (200G) and avoids the gas discharge section (200G), can prevent the refrigerant from penetrating the gas discharge path through which gas is discharged via the gas discharge section (200G). That is, the refrigerant cannot penetrate the area where gas is discharged via the gas discharge section (200G) by means of the first sealing member (700a). By clearly separating the gas discharge path through the gas discharge section (200G) from the refrigerant circulation path, the first sealing member (700a) according to the present embodiment can prevent various problems caused by mutual interference between the refrigerant circulation path and the gas discharge path.

[0094] Meanwhile, in a battery cell unit according to one embodiment of the present invention, a second sealing member (700b) may be located in a direction opposite to the direction in which one side of the cover assembly (200) having the gas discharge portion (200G) formed therein is located, with respect to the battery cells (110). In other words, the battery cells (110) may be located between one side of the cover assembly (200) having the gas discharge portion (200G) formed therein and the second sealing member (700b).

[0095] For example, the gas discharge portion (200G) may be formed on the upper surface portion (250) of the battery cell unit (100), and the second sealing member (700b) may be located on the lower surface portion of the battery cell unit (100) located opposite the upper surface portion (250) of the battery cell unit (100). Battery cells (110) may be located between the upper surface portion (250) where the gas discharge portion (200G) is formed and the second sealing member (700b).

[0096] The second sealing member (700b) according to the present embodiment can cover the entire end portion of the battery cells (110). This second sealing member (700b) can minimize the discharge of gas generated from the battery cells (110) to other parts of the battery cell unit (100) rather than to the gas discharge portion (200G). Since the entire opposite side of the battery cell unit (100) is covered by the second sealing member (700b), it is difficult for the gas generated from the battery cells (110) to be discharged in the direction of the opposite side of the battery cell unit (100). That is, the second sealing member (700b) can more clearly establish a directional venting structure of the battery cell unit that discharges gas through the gas discharge portion (200G). Additionally, since the second sealing member (700b) prevents the refrigerant from penetrating through the other side of the battery cell unit (100), the second sealing member (700b) can help to clearly separate the refrigerant circulation path and the gas discharge path.

[0097] Meanwhile, in a battery cell unit according to one embodiment of the present invention, at least one third sealing member (700c) may be located between the battery cells (110) and one side of the cover assembly (200) where the inlet portion (200N) is formed, or between the battery cells (110) and the other side of the cover assembly (200) where the outlet portion (200U) is formed. For example, the inlet portion (200N) may be formed on the first side portion (210) of the cover assembly (200), and the outlet portion (200U) may be formed on the third side portion (230) of the cover assembly (200), and at least one third sealing member (700c) may be located between the battery cells (110) and the first side portion (210) or between the battery cells (110) and the third side portion (230). For example, FIG. 4 shows third sealing members (700c) positioned between the battery cells (110) and the first side portion (210), and between the battery cells (110) and the third side portion (230), respectively. For convenience of explanation, in FIG. 4, one of the third sealing members (700c) is shown spaced apart from the first side portion (210), and the other third sealing member (700c) is shown in contact with the third side portion (230). These third sealing members (700c) can minimize the discharge of gas generated from the battery cells (110) to other parts of the battery cell unit (100) other than the gas discharge portion (200G). Due to the third sealing members (700c), it is difficult for the gas generated from the battery cells (110) to be discharged in the direction where the inlet portion (200N) or the discharge portion (200U) is located. That is, the third sealing member (700c) can more clearly establish the directional venting structure of the battery cell unit that discharges gas through the gas discharge section (200G). In addition, the third sealing member (700c) can prevent the gas generated from the battery cell (110) from affecting the path through which the refrigerant flows from the inlet section (200N) to the discharge section (200U).In this way, the third sealing member (700c) can help to clearly separate the refrigerant circulation path and the gas discharge path.

[0098] Additionally, the third sealing member (700c) according to the present embodiment may be located in a direction perpendicular to the direction in which the battery cells (110) are stacked, with respect to the battery cells (110). For example, in FIG. 4, the battery cells (110) may be stacked along the y-axis direction, and the third sealing member (700c) may be located in the +x-axis direction or the -x-axis direction perpendicular to the y-axis direction, with respect to the battery cells (110). Gas generated from the battery cells (110) is not easily discharged in the y-axis direction, which is the direction in which the battery cells (110) are stacked in the battery cell unit (100). As will be described later, a pad may be provided at the outermost side of the direction in which the battery cells (110) are stacked, and the gas cannot be discharged by penetrating this pad. Usually, the gas can be discharged in the +x-axis direction or the -x-axis direction, which is perpendicular to the direction in which the battery cells (110) are stacked. In order to minimize the discharge of gas in the +x-axis or -x-axis direction and to induce discharge through the gas discharge section (200G), a third sealing member (700c) may be provided as described above.

[0099] At least one third sealing member (700c) may be positioned to avoid the inlet (200N) or the outlet (200U). The third sealing member (700c) may be positioned in an area on one side of the cover assembly (200) where the inlet (200N) is formed but the inlet (200N) is not present. Additionally, the third sealing member (700c) may be positioned in an area on the other side of the cover assembly (200) where the outlet (200U) is formed but the outlet (200U) is not present. For example, FIG. 4 shows one third sealing member (700c) positioned to avoid the inlet (200N) in the first side portion (210) where the inlet (200N) is formed, and another third sealing member (700c) positioned to avoid the outlet (200U) in the third side portion (230) where the outlet (200U) is formed. Since the third sealing member (700c) is positioned to avoid the inlet (200N) or the outlet (200U), the third sealing member (700c) does not interfere with the flow of refrigerant moving inside the cover assembly (200) from the inlet (200N) to the outlet (200U).

[0100]

[0101] FIGS. 6 and 7 are perspective views showing battery cells, a spacer, and a pad according to an embodiment of the present invention. FIG. 8 is an exploded perspective view showing a battery cell unit according to an embodiment of the present invention. FIG. 9 is a perspective view showing a battery cell unit without an upper surface. FIG. 8 shows a battery cell unit equipped with an upper surface (250), and FIG. 9 shows a battery cell unit with the upper surface (250) removed.

[0102] Referring to FIGS. 4 through 9, a cover assembly (200) according to one embodiment of the present invention may include a first side portion (210), a second side portion (220), a third side portion (230), and a fourth side portion (240) that cover the sides of the battery cells (110), and may include an upper surface portion (250) located above the battery cells (110). Although not specifically illustrated, in one embodiment, the cover assembly (200) may further include a lower surface portion located below the battery cells (110). In addition, in another embodiment, the cover assembly (200) may not include a lower surface portion, and the lower ends of the battery cells (110) may come into contact with a second sealing member (700b, see FIG. 4).

[0103] As described above, the gas discharge section (200G) may be formed on the upper surface (250), the inlet section (200N) may be formed on the first side section (210), and the discharge section (200U) may be formed on the third side section (230). However, this is an exemplary structure, and there are no special restrictions on the location of the gas discharge section (200G), the inlet section (200N), and the discharge section (200U), respectively, as long as the part where the gas discharge section (200G) is formed does not coincide with the parts where the inlet section (200N) and the discharge section (200U) are formed.

[0104] The refrigerant can be introduced into the interior of the cover assembly (200) through the inlet (200N) and moved to the exterior of the cover assembly (200) through the outlet (200U). The refrigerant moving from the inlet (200N) to the outlet (200U) can cool the battery cells (110) inside the cover assembly (200).

[0105] At least one spacer (500) may be located in at least some of the spaces between the battery cells (110). Additionally, at least one pad (600) may be located in at least some of the spaces between the battery cells (110). Furthermore, pads (600) may be located at each of the outermost points in the direction in which the battery cells (110) are stacked. The detailed structure of the spacer (500) and the pad will be described later.

[0106] Meanwhile, in the battery cell unit (100), a busbar (400) connected to the electrode leads (111, 112) of the battery cells (110) and a busbar frame (300) on which the busbar (400) is mounted may be provided. The busbar (400) and the busbar frame (300) may be positioned in the direction in which the electrode leads (111, 112) protrude relative to the battery cells (110). For example, the electrode leads (111, 112) may protrude from the battery cells (110) in the +z-axis direction, and the busbar (400) and the busbar frame (300) may be positioned in the +z-axis direction relative to the battery cells (110).

[0107] The busbar (400) is configured to guide the electrical connection of the battery cells (110) and may include an electrically conductive material. For example, the busbar (400) may include a metal material. The busbar (400) may be electrically connected to the electrode leads (111, 112), and for example, a welded joint may be formed between the busbar (400) and the electrode leads (111, 112). A series connection between the battery cells (110) may be formed by connecting the first electrode lead (111) of one battery cell (110) and the second electrode lead (112) of another battery cell (110) to the busbar (400). Additionally, a parallel connection between the battery cells (110) may be formed by connecting the same electrode leads (111, 112) of each of the battery cells (110) to the busbar (400). High voltage (HV) connections between battery cells (110) can be implemented in this form. An HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to electrical connections between battery cells or electrical connections between a battery pack and a device.

[0108] A busbar (400) may be mounted on one side of a busbar frame (300). The busbar (400) may be mounted on the opposite side of the busbar frame (300) that faces the battery cells (110). A lead hole (320) may be formed in the busbar frame (300), and the electrode leads (111, 112) of the battery cells (110) may pass through the lead hole (320) and be connected to the busbar (400). The electrode leads (111, 112) of the battery cells (110) may pass through the lead hole (320) and then be bent to be connected to the busbar (400). The busbar frame (300) may include a material that is electrically insulating. For example, the busbar frame (300) may include a plastic material.

[0109]

[0110] FIG. 10 is a perspective view showing a part of the cover assembly and a spacer according to one embodiment of the present invention. FIG. 11 is a perspective view showing a spacer according to one embodiment of the present invention.

[0111] Referring to FIGS. 4 through 7, FIGS. 10, and FIGS. 11, as described above, at least one spacer (500) may be positioned between at least some of the battery cells (110). The spacer (500) may be in surface contact with the battery cells (110). A flow path hole (500H) through which a refrigerant flows may be formed in the spacer (500). The flow path hole (500H) may be in a form that penetrates along the direction in which the spacer (500) extends. For example, the spacer (500) may extend along the x-axis direction, and the flow path hole (500H) may also be in a form that penetrates along the x-axis direction.

[0112] A portion of the refrigerant introduced into the cover assembly (200) through the inlet (200N) may flow along the flow path hole (500H) of the spacer (500). Heat generated from the battery cell (110) may be transferred to the refrigerant flowing along the spacer (500) and the flow path hole (500H) inside the spacer (500), thereby allowing heat dissipation to occur. Additionally, another portion of the refrigerant introduced into the cover assembly (200) through the inlet (200N) may flow in direct contact with the battery cells (110) rather than through the flow path hole (500H).

[0113]

[0114] FIG. 12 is a perspective view showing a pad according to one embodiment of the present invention.

[0115] Referring to FIGS. 4 through 7 and FIG. 20, as described above, at least one pad (600) may be located among at least some of the battery cells (110). Additionally, pads (600) may be located at each of the outermost sides in the direction in which the battery cells (110) are stacked.

[0116] The number of pads (600) can be determined in various ways depending on the number and size of the battery cells (110), the material of the electrodes applied, etc. FIG. 7 illustrates a configuration in which pads (600) are located among some of the battery cells (110).

[0117] The pad (600) may be a foam-shaped member and can absorb swelling of the battery cells (110). If the swelling phenomenon of the battery cells (110) is not absorbed and controlled, the pressure inside the battery cell unit (100) increases and the volume increases, which may have a negative effect on the structural stability of the battery cell unit (100). Accordingly, the swelling of the battery cells (110) is partially absorbed by placing a pad (600) that is compressed when pressure is applied, either at the outermost side of the battery cells (110) or between the battery cells (110). As long as the pad (600) can be compressed to absorb the swelling of the battery cells (110), there are no special restrictions on the material, and, for example, it may include a polyurethane material.

[0118] Meanwhile, a pouch may cover at least a portion of the outer surface of the pad (600). The pouch can block the refrigerant from being absorbed by the pad (600) and penetrating into the gas discharge path. For example, the first side (610), the second side (620), and the top surface (630) of the pad (600) may be covered by the pouch. The first side (610) and the second side (620) of the pad (600) may correspond to the surfaces facing the battery cells (110). Due to the material properties of the pad (600), the refrigerant may be absorbed into the pad (600). There may be a problem in that the refrigerant absorbed into the pad (600) penetrates into the path of the gas discharged from the gas discharge section (200G). To prevent this problem, a pouch covering at least a portion of the outer surface of the pad (600) is provided. That is, even if the refrigerant is absorbed into the pad (600), it can be blocked from moving to the gas discharge path by the pouch. The pouch may include, for example, an aluminum material. A pouch made of aluminum has moisture resistance and heat resistance, so it can prevent the refrigerant or moisture from penetrating into the gas discharge path.

[0119]

[0120] Below, an exemplary structure of a cooling channel provided inside a battery cell unit (100) will be described.

[0121] FIG. 13 is a plan view showing one side of a battery cell unit according to an embodiment of the present invention. FIG. 14 is a perspective view showing a busbar frame and a busbar according to an embodiment of the present invention. FIG. 15 is a partial view showing an enlarged view of section “B” of FIG. 9.

[0122] Referring together to FIGS. 1, FIGS. 2, FIGS. 5, FIGS. 9 to 11, FIGS. 13 to 15, as described above, the battery cell unit (100) includes an inlet section (200N) for introducing a refrigerant into the battery cell unit (100) and an outlet section (200U) for discharging the refrigerant from the battery cell unit (100). The inlet section (200N) according to one embodiment of the present invention may include a cell cooling inlet section (200N1) and a busbar cooling inlet section (200N2). The outlet section (200U) according to one embodiment of the present invention may include a cell cooling outlet section (200U1) and a busbar cooling outlet section (200U2). When looking at the battery cell unit (100) along a direction parallel to the x-axis, the cell cooling inlet (200N1) and the cell cooling outlet (200U1) can be positioned to correspond to each other, and the busbar cooling inlet (200N2) and the busbar cooling outlet (200U2) can be positioned to correspond to each other.

[0123] At least a portion of the refrigerant introduced into the cover assembly (200) may come into contact with the busbar (400). As at least a portion of the refrigerant comes into contact with the busbar (400), the busbar (400) may be directly cooled. During repeated charging and discharging of the battery cell (110), a large amount of heat is generated in the battery cell (110), and it is important to control the heat of the battery cell (110) by discharging this heat using a cooling means. If the heat dissipation of the battery cell (110) is not properly performed, the degradation of the battery cell (110) accelerates, shortening its lifespan, and increasing the possibility of explosion or ignition. In the case of a battery cell (110) undergoing repeated charging and discharging, heat is particularly concentrated in the electrode leads (111, 112), which are the parts where the aforementioned HV connection is made, and in at least one busbar (400) connected thereto. In the battery cell unit according to the present embodiment, a refrigerant can come into contact with the busbar (400) and directly cool the busbar (400). Cooling can be achieved through contact with the refrigerant for the busbar (400), which is one of the parts of the battery cell (110) where the most heat is generated. Accordingly, the overall cooling performance of the battery cells (110) can be improved, and furthermore, the possibility of explosion or ignition of the battery cell unit (100) can be significantly reduced.

[0124] As an exemplary structure for cooling a busbar, the inlet (200N) may include a busbar cooling inlet (200N2) formed on a portion of one side of the cover assembly (200) corresponding to the busbar (400), and the outlet (200U) may include a busbar cooling outlet (200U2) formed on a portion of the other side of the cover assembly (200) corresponding to the busbar (400).

[0125] A portion of the refrigerant may flow into the busbar cooling inlet (200N2) and come into contact with the busbar (400). Subsequently, the refrigerant may move to the outside of the cover assembly (200) through the busbar cooling outlet (200U2).

[0126] A busbar cooling channel (300F) may be formed in the busbar frame (300) to guide the flow of refrigerant so that it comes into contact with the busbar (400). For example, the busbar cooling channel (300F) may be a groove formed in the busbar frame (300). The busbar cooling channel (300F) may be positioned corresponding to the busbar cooling inlet (200N2) and the busbar cooling outlet (200U2), respectively, and may extend from the busbar cooling inlet (200N2) to the busbar cooling outlet (200U2). A busbar (400) may be positioned on one side of the busbar cooling channel (300F). In the groove-shaped busbar cooling channel (300F), the busbar (400) may be positioned in the open part of the groove.

[0127] The refrigerant introduced through the busbar cooling inlet (200N2) can flow along the busbar cooling path (300F), come into contact with the busbar (400), and directly cool the busbar (400). The refrigerant flowing along the busbar cooling path (300F) can move to the outside of the cover assembly (200) through the busbar cooling discharge (200U2).

[0128] Meanwhile, the inlet section (200N) may include a cell cooling inlet section (200N1), and the outlet section (200U) may include a cell cooling outlet section (200U1). The cell cooling inlet section (200N1) and the cell cooling outlet section (200U1) may be provided in parts corresponding to the battery cells (110).

[0129] A portion of the refrigerant may flow into the cell cooling inlet (200N1) and may flow while in contact with the battery cells (110). Subsequently, the refrigerant may move to the outside of the cover assembly (200) through the cell cooling outlet (200U1). Additionally, as described above, a flow path hole (500H) through which the refrigerant flows may be formed in the spacer (500), and at least a portion of the cell cooling inlet (200N1) may overlap with at least a portion of the flow path hole (500H). Additionally, at least a portion of the cell cooling outlet (200U1) may overlap with at least a portion of the flow path hole (500H). A portion of the refrigerant introduced into the cell cooling inlet (200N1) may cool the battery cells (110) while flowing along the flow path hole (500H) inside the spacer (500).

[0130] A portion of the refrigerant introduced into the cell cooling inlet (200N1) may flow in contact with the battery cells (110), and another portion of the refrigerant may flow along the flow path hole (500H) of the spacer (500). Subsequently, the refrigerant may move to the outside of the cover assembly (200) through the cell cooling outlet (200U1).

[0131] In addition, as another embodiment of the present invention, parts of both ends of the flow path holes of the spacer (500) may be opened. As the refrigerant flows along the flow path holes of the spacer (500), it may simultaneously come into contact with one surface of the battery cell (110).

[0132]

[0133] Referring together to FIGS. 4, 5, 8, 9 and 14, one side of a cover assembly (200) having a gas exhaust portion (200G) formed thereon may be positioned in the direction in which at least one of the electrode leads (111, 112) protrudes from the battery cell (110) with respect to the battery cell (110). For example, an upper surface portion (250) having a gas exhaust portion (200G) formed thereon may be positioned in the direction in which at least one of the electrode leads (111, 112) protrudes from the battery cell (110) with respect to the battery cell (110).

[0134] In the case of the present embodiment, the direction of the directional venting may be the direction in which the electrode leads (111, 112) protrude. That is, the gas generated in the battery cell (110) may be designed to be discharged along the direction in which at least one of the electrode leads (111, 112) protrudes from the battery cell (110). In the battery cell (110), gas is often discharged as the seal of the case (114, see FIG. 3) is released in the direction in which the electrode leads (111, 112) protrude. Accordingly, the directional venting structure may also be designed so that the gas is discharged along the direction in which at least one of the electrode leads (111, 112) protrudes from the battery cell (110).

[0135] A gas discharge hole (310) may be formed in the busbar frame (300). The gas discharge hole (310) may be connected to a gas discharge section (200G) formed in the cover assembly (200). In the present invention, the connection of the gas discharge hole (310) to the gas discharge section (200G) means that the gas discharge hole (310) and the gas discharge section (200G) are positioned in correspondence with each other, and the space of the gas discharge hole (310) overlaps with at least a portion of the space of the gas discharge section (200G). That is, it means a structure in which gas can move from the gas discharge hole (310) to the gas discharge section (200G).

[0136] Gas generated from the battery cell (110) can move through the gas discharge hole (310) in the direction where the gas discharge section (200G) and the venting space described later are located. Additionally, a lead hole (320) through which the electrode leads (111, 112) of the battery cells (110) pass can be formed in the busbar frame (300). Gas generated from the battery cell (110) can move through the lead hole (320) in the direction where the gas discharge section (200G) and the venting space described later are located.

[0137] Meanwhile, a fourth sealing member (700d) may be positioned between one side of the busbar frame (300) and the cover assembly (200). For example, the fourth sealing member (700d) may be positioned between the busbar frame (300) and the upper surface (250) of the cover assembly (200).

[0138] The fourth sealing member (700d) according to the present embodiment may be positioned to avoid the gas discharge hole (310) and the lead hole (320). Additionally, the fourth sealing member (700d) may be positioned outside the gas discharge hole (310) and the lead hole (320) in the busbar frame (300). Here, the fact that the fourth sealing member (700d) is positioned outside the gas discharge hole (310) and the lead hole (320) may mean that the fourth sealing member (700d) is positioned closer to the edge of the busbar frame (300) than the gas discharge hole (310) and the lead hole (320). For example, FIGS. 5, 8, and 9 show that the fourth sealing member (700d) is positioned outside the gas discharge hole (310) and the lead hole (320), avoiding both the gas discharge hole (310) and the lead hole (320). The fourth sealing member (700d) may extend along the outside of the gas discharge hole (310) and the lead hole (320).

[0139] The fourth sealing member (700d) according to the present embodiment not only fixes one side of the busbar frame (300) and the battery cell unit (100), but also helps to clearly separate the refrigerant circulation path and the gas discharge path. Specifically, the fourth sealing member (700d) can be fixed by contacting each of the inner sides of the busbar frame (300) and the battery cell unit (100). At this time, the fourth sealing member (700d), which is positioned outside the gas discharge hole (310) and the lead hole (320) to avoid the gas discharge hole (310) and the lead hole (320), can prevent the refrigerant from penetrating the gas discharge path through which the gas passes the gas discharge hole (310) and the lead hole (320). That is, the refrigerant introduced into the interior of the cover assembly (200) through the inlet (200N) cannot penetrate into the area between the one side of the cover assembly (200) where the gas discharge section (200G) is formed and the busbar frame (300) by the fourth sealing member (700d). The fourth sealing member (700d) according to the present embodiment can prevent various problems caused by mutual interference between the refrigerant circulation path and the gas discharge path by clearly separating the gas discharge path, through which gas is discharged through the gas discharge hole (310) and the lead hole (320), from the refrigerant circulation path.

[0140]

[0141] FIG. 16 is a perspective view showing a battery assembly according to an embodiment of the present invention. FIG. 17 is a cross-sectional perspective view showing a cross section cut along the cutting line A-A' of FIG. 16. FIG. 18 is a cross-sectional view showing FIG. 17 viewed along the -x-axis direction in the yz plane. FIG. 19 is a cross-sectional perspective view showing only the housing configuration in FIG. 17. FIG. 20 is an exploded perspective view of a battery assembly according to an embodiment of the present invention.

[0142] Referring to FIGS. 1, FIGS. 2 and FIGS. 16 to 20, a battery cell unit (100) according to one embodiment of the present invention may be housed in a housing (1100) to form a battery assembly (1000). The housing (1100) may be provided with an inlet (1200) and an outlet (1300) for circulating a refrigerant into the housing (1100). Additionally, a venting space (VS, see FIG. 18) through which the gas moves, connected to a gas discharge section (200G), may be provided in the housing (1100).

[0143] In the battery assembly (1000), a refrigerant can be introduced into the space where the battery cell unit (100) is housed inside the housing (1100) through the inlet (1200). The refrigerant introduced into the space where the battery cell unit (100) is housed inside the housing (1100) can flow into the interior of the cover assembly (200) through the inlet (200N). The refrigerant flowing into the interior of the cover assembly (200) cools the battery cells (110). Afterward, the refrigerant can move to the outside of the cover assembly (200) through the discharge section (200U). The refrigerant discharged through the discharge section (200U) can pass through the space where the battery cell unit (100) is housed and move to the outside of the battery assembly (1000) through the outlet (1300).

[0144] In the housing (1100) according to the present embodiment, a venting space (VS) through which the gas moves may be provided, which is connected to a gas discharge section (200G). Gas generated from the battery cell (110) may move from the gas discharge section (200G) to the venting space (VS). Specifically, although not illustrated, the gas that has moved to the venting space (VS) may be discharged to the outside of the battery assembly (1000) through a separate venting device provided in the housing (1100). That is, the battery assembly (1000) according to the present embodiment may have a directional venting structure in which the gas is discharged in a predetermined direction, such as when the gas generated from the battery cell (110) moves to the venting space (VS) of the housing (1100) through the gas discharge section (200G).

[0145] A housing (1100) according to one embodiment of the present invention can accommodate a battery cell unit (100) as described above. In other words, the housing (1100) has an internal space, and a battery cell unit (100) can be located in this internal space.

[0146] For example, the housing (1100) may include a first side wall portion (1110), a second side wall portion (1120), a third side wall portion (1130), a fourth side wall portion (1140), a ceiling portion (1150), and a bottom portion (1160). The battery cell unit (100) may be placed on the bottom portion (1160). The first side wall portion (1110), the second side wall portion (1120), the third side wall portion (1130), and the fourth side wall portion (1140) may protrude upward from the edge of the bottom portion (1160) and may cover the sides of the battery cell unit (100). The ceiling portion (1150) can be combined with the first side wall portion (1110), the second side wall portion (1120), the third side wall portion (1130), and the fourth side wall portion (1140), and can cover the upper surface of the battery cell unit (100).

[0147] A sealed internal space may be formed by the first side wall section (1110), the second side wall section (1120), the third side wall section (1130), the fourth side wall section (1140), the ceiling section (1150), and the floor section (1160), and the battery cell unit (100) may be located in this internal space. There are no special restrictions on the joining form of each of the first side wall section (1110), the second side wall section (1120), the third side wall section (1130), the fourth side wall section (1140), the ceiling section (1150), and the floor section (1160), but, for example, welding may be performed.

[0148] Additionally, there is no particular limit to the number of battery cell units (100) stored inside the housing (1100). For example, one battery cell unit (100) may be stored inside the housing (1100), and as another example, multiple battery cell units (100) may be stored inside the housing (1100). FIG. 20 illustrates, as an example, two battery cell units (100) stored inside the housing (1100). A housing (1100) according to one embodiment of the present invention may further include a partition (1170) that separates the space in which multiple battery cell units (100) are stored. For example, FIG. 20 illustrates one partition (1170) that separates the space in which two battery cell units (100) are located.

[0149] Meanwhile, the inlet (1200) and outlet (1300) according to the present embodiment may be configurations for circulating a refrigerant into the housing (1100). Specifically, the refrigerant may move through the inlet (1200) to an internal space within the housing (1100) where a battery cell unit (100) is housed. Afterward, the refrigerant may move to the outside of the battery assembly (1000) through the outlet (1300) after cooling the battery cell unit (100).

[0150] As long as the refrigerant can be circulated inside the housing (1100), there are no special restrictions on the shape or number of the inlet (1200) and outlet (1300). Although the inlet (1200) is shown connected to the first side wall (1110) and the outlet (1300) is shown connected to the third side wall (1130), this is an exemplary structure, and it goes without saying that the inlet (1200) and the outlet (1300) can each be connected to different side walls.

[0151] Additionally, although the inlet (1200) and outlet (1300) are depicted as being in the form of pipes, in another embodiment, the inlet and outlet may be in the form of holes formed in the side walls (1110, 1120, 1130, 1140). The refrigerant introduced through the hole-shaped inlet flows along the space formed inside the side walls (1110, 1120, 1130, 1140) and can move to the internal space where the battery cell unit (100) is housed. Afterward, it can flow along the space formed inside the other side walls (1110, 1120, 1130, 1140) and then be discharged through the hole-shaped outlet.

[0152]

[0153] FIG. 21 is an exploded perspective view showing a battery assembly according to one embodiment of the present invention. FIG. 22 is an exploded perspective view showing a battery assembly according to one embodiment of the present invention.

[0154] Referring to FIGS. 1, FIG. 2 and FIGS. 17 to 22, a venting hole (1100H) connected to a venting space (VS) may be formed on the inner surface of the housing (1100), and a gas discharge portion (200G) formed on one surface of the cover assembly (200) may be connected to the venting hole (1100H).

[0155] In the present invention, the fact that the venting hole (1100H) is connected to the gas discharge section (200G) means that the venting hole (1100H) and the gas discharge section (200G) are positioned in correspondence with each other, and that the space of the venting hole (1100H) overlaps with at least a portion of the space of the gas discharge section (200G). That is, it means a structure in which gas can move from the gas discharge section (200G) to the venting hole (1100H).

[0156] Similarly, the connection between the venting space (VS) and the venting hole (1100H) may mean that the venting hole (1100H) is located in a portion corresponding to the venting space (VS) so that the space of the venting hole (1100H) can be shared with the venting space (VS). In other words, it means a structure in which gas can pass through the venting hole (1100H) and move to the venting space (VS).

[0157] For example, the venting space (VS) according to the present embodiment may be formed in the ceiling portion (1150) of the housing (1100). However, this is just one example and there are no special restrictions on the location where the venting space (VS) is provided. According to another embodiment, the venting space (VS) may be formed in the bottom portion (1160) or other side wall portions (1110, 1120, 1130, 1140) of the housing (1100).

[0158] The ceiling portion (1150) may include a first plate (1151) and a second plate (1152). The first plate (1151) and the second plate (1152) may be positioned apart from each other by a predetermined distance, and a venting space (VS) may be formed between the first plate (1151) and the second plate (1152).

[0159] The first plate (1151) may be located closer to the battery cell unit (100) than the second plate (1152), and a venting hole (1100H) may be formed in this first plate (1151). As described above, the gas discharge portion (200G) of the battery cell unit (100) may be connected to this venting hole (1100H).

[0160] As described above, the gas generated in the battery cell (110) is discharged from the battery cell unit (100) through the gas discharge section (200G) of the cover assembly (200). The gas discharged through the gas discharge section (200G) can pass through the venting hole (1100H) and move to the venting space (VS). That is, as shown in FIG. 18, the gas (VG) generated in the battery cell (110) can pass through the gas discharge section (200G) and the venting hole (1100H) and move to the venting space (VS). The gas (VG) flowing along the venting space (VS) can be discharged to the outside of the battery assembly (1000) through a separate venting device (not shown) provided in the housing (1100). For example, gas (VG) flowing along the venting space (VS) can move into the space between the fourth side wall (1140) and the battery cell unit (100), and then be discharged through a venting device (not shown) connected to this space.

[0161] Meanwhile, the first sealing member (700a) according to the present embodiment not only fixes one side of the battery cell unit (100) and the inner side of the housing (1100), but also helps to clearly separate the refrigerant circulation path and the gas discharge path. Specifically, the first sealing member (700a) can be in contact with each of the one side of the battery cell unit (100) and the inner side of the housing (1100) to fix them. At this time, the first sealing member (700a), which is positioned outside the gas discharge section (200G) and avoids the gas discharge section (200G), can prevent the refrigerant from penetrating the gas discharge path in which the gas travels from the gas discharge section (200G) to the venting space (VS). That is, the refrigerant introduced into the internal space of the housing (1100) through the inlet (1200) cannot penetrate into the area between the gas discharge section (200G) and the venting hole (1100H) by the first sealing member (700a). The first sealing member (700a) according to the present embodiment can prevent various problems caused by mutual interference between the refrigerant circulation path and the gas discharge path by clearly separating the gas discharge path from the gas discharge section (200G) to the venting space (VS) from the refrigerant circulation path.

[0162] Meanwhile, referring again to FIGS. 17 to 19, FIGS. 21 and FIGS. 22, a battery assembly (1000) according to one embodiment of the present invention may include a fifth sealing member (700e) located between a first plate (1151) and a second plate (1152). The fifth sealing member (700e) may extend along the edge of the first plate (1151) and the edge of the second plate (1152). According to the present embodiment, a venting space (VS) provided in the housing (1100) may correspond to a space surrounded by the first plate (1151), the second plate (1152), and the fifth sealing member (700e).

[0163] Meanwhile, the first to fifth sealing members (700a, 700b, 700c, 700d, 700e) according to the present embodiment have no particular restrictions on their shape or material as long as they can exhibit a sealing function or an adhesive function. The first to fifth sealing members (700a, 700b, 700c, 700d, 700e) may be formed by applying an adhesive or resin that exhibits a sealing function. As long as the adhesive or resin exhibits sealing performance and possesses impact resistance, adhesiveness, 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 hardener is mixed with a main component. In addition, as another example, a foam member, a sealant, a gasket, etc. may be applied to the first to fifth sealing members (700a, 700b, 700c, 700d, 700e).

[0164]

[0165] Referring together to FIGS. 1, 5, 8, 9, 14, 21, and 22, a gas discharge unit (200G) according to one embodiment of the present invention may include a first gas discharge unit (200G1) and a second gas discharge unit (200G2). The first gas discharge unit (200G1) may be connected to a gas discharge hole (310) of a busbar frame (300). Additionally, the second gas discharge unit (200G2) may be connected to a lead hole (320) of a busbar frame (300).

[0166] Meanwhile, the venting hole (1100H) formed on the inner surface of the housing (1100) may include a first venting hole (1100H1) and a second venting hole (1100H2). The first gas discharge section (200G1) may be connected to the first venting hole (1100H1). Additionally, the second gas discharge section (200G2) may be connected to the second venting hole (1100H2).

[0167] A portion of the gas generated from the battery cell (110) may pass through the gas discharge hole (310), the first gas discharge section (200G1), and the first venting hole (1100H1) of the busbar frame (300) in sequence to move to the venting space (VS). Additionally, a portion of the gas generated from the battery cell (110) may pass through the lead hole (320), the second gas discharge section (200G2), and the second venting hole (1100H2) of the busbar frame (300) in sequence to move to the venting space (VS).

[0168]

[0169] FIG. 23 is a top view of a battery assembly without a ceiling.

[0170] Referring to FIG. 23, the battery cell unit (100) according to the present embodiment can be fixed inside the housing (1100) through bolting. The battery cell unit (100) may include a mounting portion (200M). For example, the mounting portion (200M) may be provided on the second side portion (220) and the fourth side portion (240) of the cover assembly (200). Some of the bolts (1400) may be fastened to the mounting portion (200M) formed on the second side portion (220) after penetrating the second side wall portion (1120). Other of the bolts (1400) may be fastened to the mounting portion (200M) formed on the fourth side portion (240) after penetrating the fourth side wall portion (1140).

[0171]

[0172] Referring again to FIG. 3 and FIG. 8, as described above, in the case of a battery cell (110) according to one embodiment of the present invention, the upper part (114b) and both ends (114c, 114d) of the case (114) may be sealed to form a sealing part, and the lower part (114a) may be made of a folding part.

[0173] Gas generated in such battery cells (110) can be discharged mainly through the sealing portion. That is, due to increased internal pressure, the sealing is released in some parts of the sealing portion, and gas can be discharged by bursting out through the released sealing portion.

[0174] In this embodiment, the sealing portion of the battery cell (110) may face the gas discharge portion (200G), and the folding portion of the battery cell (110) may face in the opposite direction to where the gas discharge portion (200G) is located. The upper portion (114b), which is the sealing portion of the battery cell (110), may face the gas discharge portion (200G), and the lower portion (114a), which is the folding portion, may face in the opposite direction to where the gas discharge portion (200G) is located. Through this arrangement, a directional venting structure in which gas generated from the battery cell (110) is induced to be discharged through the gas discharge portion (200G) can be more clearly established.

[0175] 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 observer.

[0176] One or more battery cell units according to the embodiment described above can be mounted in a device together with various control and protection systems, such as a Battery Management System (BMS), a Battery Disconnect Unit (BDU), and a cooling system.

[0177] The above battery cell unit 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.

[0178] 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.

[0179] Explanation of the symbols

[0180] 100: Battery cell unit

[0181] 200: Cover Assembly

[0182] 200N: Inlet

[0183] 200U: Discharge section

[0184] 200G: Gas exhaust part

[0185] 300: Busbar Frame

[0186] 400: Busbar

[0187] 1000: Battery assembly

[0188] 1100: Housing

[0189] 1200: Inlet

[0190] 1300: Outlet

Claims

1. Multiple battery cells; and A cover assembly covering at least a portion of the outer surface of the battery cells; comprising, The above cover assembly includes an inlet for introducing a refrigerant into the interior of the cover assembly, an outlet for discharging the refrigerant from the interior of the cover assembly, and a gas outlet for discharging gas generated from the battery cell. The above gas discharge portion is a battery cell unit formed on one side of the cover assembly other than at least one side of the cover assembly in which the inlet portion and the discharge portion are formed.

2. In Paragraph 1, A battery cell unit having a busbar connected to the electrode leads of the battery cells and a busbar frame on which the busbar is mounted.

3. In Paragraph 2, A battery cell unit in which at least a portion of the refrigerant introduced into the interior of the cover assembly contacts the busbar.

4. In Paragraph 2, The above-mentioned inlet is a battery cell unit including a busbar cooling inlet formed in a portion of one side of the cover assembly corresponding to the busbar.

5. In Paragraph 2, A battery cell unit having a busbar cooling channel formed in the above busbar frame to guide the flow of the refrigerant to come into contact with the busbar.

6. In Paragraph 5, The above busbar cooling channel is a battery cell unit that is a groove formed in the busbar frame.

7. In Paragraph 1, At least one spacer is located between at least some of the above battery cells, and A battery cell unit in which a flow path hole for refrigerant is formed in the above spacer.

8. In Paragraph 7, The above-mentioned inlet includes a cell cooling inlet, and A battery cell unit in which at least a portion of the cell cooling inlet overlaps with at least a portion of the flow path hole.

9. In Paragraph 1, A battery cell unit having one side of the cover assembly having the gas exhaust portion formed thereon located in the direction in which at least one of the electrode leads protrudes from the battery cell, based on the battery cells.

10. In Paragraph 1, A first sealing member is located on one surface of the cover assembly in which the gas discharge portion is formed, and The first sealing member is a battery cell unit located to avoid the gas discharge portion.

11. In Paragraph 1, A battery cell unit having a second sealing member located in the opposite direction to the direction in which one side of the cover assembly, on which a gas discharge portion is formed, is located, based on the battery cells above.

12. In Paragraph 1, A third sealing member is located at least one of the following: between the battery cells and one side of the cover assembly where the inlet is formed, or between the battery cells and the other side of the cover assembly where the outlet is formed. The above third sealing member is a battery cell unit located avoiding the inlet or the outlet.

13. In Paragraph 1, A busbar connected to the electrode leads of the battery cells and a busbar frame on which the busbar is mounted are provided, A battery cell unit having a gas discharge hole connected to the above gas discharge section formed in the busbar frame.

14. In Paragraph 13, A battery cell unit having a fourth sealing member provided between the busbar frame and one side of the cover assembly.

15. In Paragraph 14, The above-mentioned fourth sealing member is a battery cell unit positioned to avoid the above-mentioned gas discharge hole.

16. In Paragraph 1, One side of the cover assembly having the gas discharge portion formed thereon is a battery cell unit perpendicular to the other side of the cover assembly having the inlet portion formed thereon.

17. In Paragraph 1, One side of the cover assembly having the gas discharge portion formed thereon is a battery cell unit perpendicular to the other side of the cover assembly having the discharge portion formed thereon.

18. A device comprising a battery cell unit according to paragraph 1.

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