Battery assembly and device including same

Abstract

A battery assembly according to one embodiment of the present invention comprises: a battery cell stack in which a plurality of battery cells are stacked; a housing in which the battery cell stack is accommodated; an inlet and an outlet for circulating a coolant into the housing; and at least one cooling spacer positioned at at least one location between the battery cells. The cooling spacer includes at least one cooling hole through which the coolant moves.

Description

Battery assembly and device including the same

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

[0002] The present application claims the benefit of priority based on Korean Patent Application No. 10-2025-0015311 dated February 6, 2025 and Korean Patent Application No. 10-2025-0199876 dated December 16, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of the specification.

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

[0004] With the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly rising. Accordingly, extensive research is being conducted on secondary batteries capable of meeting various requirements.

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

[0006] Recently, with the increasing need for large-capacity secondary battery structures, including their utilization as energy storage sources, there is a growing demand for medium-to-large battery assemblies in which multiple secondary batteries are connected in series or parallel.

[0007] Since the battery cells constituting these medium-to-large battery assemblies 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, which can cause the temperature to rise rapidly and severely. In other words, while battery assemblies equipped with 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 degradation of the cells accelerates, shortening their lifespan and increasing the risk of explosion or ignition.

[0008] Furthermore, battery assemblies 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 assemblies are densely packed to extend a vehicle's driving range, flames or heat generated in one battery assembly can easily propagate to neighboring ones, potentially leading to the ignition or explosion of the device itself.

[0009] The problem that the present invention aims to solve is to provide a battery assembly and a device including the same that can effectively dissipate and cool heat generated in battery cells within the battery assembly, while simultaneously stably fixing the position of the battery cell stack to prevent damage caused by external shock or vibration.

[0010] 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.

[0011] A battery assembly according to one embodiment of the present invention comprises: a battery cell stack in which a plurality of battery cells are stacked; a housing in which the battery cell stack is housed; an inlet and an outlet for circulating a refrigerant into the housing; and at least one cooling spacer located at least one of the places between the battery cells. The cooling spacer includes at least one cooling hole through which the refrigerant moves.

[0012] At least one of the above cooling holes may be drilled along the direction of the side with the longer width of the battery cell.

[0013] The above cooling spacer can be fixed to the housing.

[0014] The above cooling spacer can be fixed to the housing with a fixing member.

[0015] A portion of the above refrigerant may flow in the space between the battery cell stack and the lower portion of the housing.

[0016] The above housing may have an open top surface, and a top cover assembly covering the open top surface of the housing may be provided.

[0017] The above cooling spacer can be fixed to the top cover assembly.

[0018] A portion of the above refrigerant may flow in the space between the battery cell stack and the top cover assembly.

[0019] The above housing and the above top cover assembly can be welded together.

[0020] The above housing and the above top cover assembly can be joined by friction stir welding.

[0021] The above housing may include: a first housing comprising side portions covering both sides of the battery cell stack and a bottom portion covering the bottom surface of the battery cell stack; and a second housing covering one side of the battery cell stack and coupled to the first housing.

[0022] The first housing and the second housing can be welded together.

[0023] The first housing and the second housing can be joined by friction stir welding.

[0024] The above inlet and the above outlet may be provided in the housing, and the outlet may be located on the side opposite to the side where the inlet is located.

[0025] A terminal assembly electrically connected to the battery cell stack can be coupled to the housing.

[0026] The terminal assembly may include a terminal busbar; a gasket abutting the side of the housing; and a bolt penetrating the terminal busbar and the gasket.

[0027] The terminal assembly may further include a busbar electrically connected to at least one of the battery cells, and the battery cell stack and the terminal assembly may be electrically connected as the bolt is coupled to the busbar.

[0028] A connector assembly electrically connected to the battery cell stack may be coupled to the housing. The connector assembly may include: an LV (Low Voltage) connector electrically connecting the battery cell stack and a BMS module; a connector coupled to a module connector; a printed circuit board connected to the module connector; a gasket located between the connector assembly and the housing; and a connector assembly cover.

[0029] According to one embodiment of the present invention, a device including the battery assembly is provided.

[0030] According to embodiments of the present invention, in a battery assembly having an inlet and an outlet for circulating a refrigerant, at least one cooling spacer is provided at least one location between the battery cells, thereby diversifying the path through which the refrigerant travels, so that heat generated in the battery cells inside the battery assembly can be effectively released and cooled.

[0031] Furthermore, by robustly welding the housing of the battery assembly to the top cover assembly, a sealed structure can be provided that allows for stable circulation of refrigerant without leakage. The welded joint between the housing and the top cover assembly not only enhances the structural stability of the battery assembly by increasing resistance to external shocks or vibrations, but also maximizes cooling performance by ensuring airtightness without the need for additional sealing materials. This enables effective thermal management of the battery cells and ensures the long-term reliability and durability of the battery system.

[0032] 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.

[0033] FIG. 1 is a perspective view showing a battery assembly according to one embodiment of the present invention.

[0034] Figure 2 is a plan view showing the battery assembly of Figure 1.

[0035] Figure 3 is a plan view showing the battery assembly of Figure 1.

[0036] FIG. 4 is a perspective view showing a housing according to one embodiment of the present invention.

[0037] Figure 5 is an exploded perspective view showing the housing of Figure 4.

[0038] FIG. 6 is an exploded perspective view showing a battery assembly including a top cover assembly according to one embodiment of the present invention.

[0039] FIG. 7 is a perspective view showing a battery cell according to one embodiment of the present invention.

[0040] Figure 8 is a cross-sectional view showing a cross-section cut along the cutting line A-A' of Figure 3.

[0041] FIG. 9 is a cross-sectional view showing a battery cell stack, a housing, and a cooling spacer according to one embodiment of the present invention.

[0042] FIG. 10 is a perspective view showing a cooling spacer according to one embodiment of the present invention.

[0043] FIG. 11 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0044] FIG. 12 is a perspective view showing a terminal assembly according to one embodiment of the present invention.

[0045] FIG. 13 is a perspective view showing the terminal assembly of FIG. 12 viewed from a different angle.

[0046] FIG. 14 is a cross-sectional perspective view showing a cross section cut along the cutting line B-B' of FIG. 3.

[0047] FIG. 15 is a perspective view showing a connector assembly according to one embodiment of the present invention.

[0048] FIG. 16 is a perspective view showing the connector assembly of FIG. 15 viewed from a different angle.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] FIG. 1 is a perspective view showing a battery assembly (100) according to an embodiment of the present invention. FIG. 2 is a plan view showing the battery assembly (100) of FIG. 1. FIG. 3 is a plan view showing the battery assembly (100) of FIG. 1. FIG. 4 is a perspective view showing a housing (130) according to an embodiment of the present invention. FIG. 5 is an exploded perspective view showing the housing (130) of FIG. 4. FIG. 6 is an exploded perspective view showing a battery assembly (100) including a top cover assembly (140) according to an embodiment of the present invention. FIG. 7 is a perspective view showing a battery cell according to an embodiment of the present invention.

[0056] Referring to FIGS. 1 to 7, a battery assembly (100) according to one embodiment of the present invention comprises: a battery cell stack (120) in which a plurality of battery cells (110) are stacked; a housing (130) in which the battery cell stack (120) is housed; an inlet (160) and an outlet (170) for circulating a refrigerant into the housing (130); and at least one cooling spacer located at least one of the places between the battery cells (110). The cooling spacer will be described later.

[0057] The housing (130) may include: a first housing (131) comprising side portions (131a) covering both sides of the battery cell stack (120) and a bottom portion (131b) covering the bottom surface of the battery cell stack (120); and a second housing (132) covering one side of the battery cell stack and coupled to the first housing. The battery cell stack (120) may be fixed within the housing (130).

[0058] The battery cell (110) according to the present embodiment may be a battery cell of various shapes, for example, a pouch-type battery cell, a prismatic battery cell, or a cylindrical battery cell.

[0059] First, the battery cell (110) may be a pouch-type battery in which an electrode assembly having electrode leads (111) protruding in one or both directions is housed in a pouch case (114). However, this is merely one example, and the battery cell according to another embodiment of the present invention may be a cylindrical or prismatic battery cell. For convenience of explanation, the following description will be based on a pouch-type battery cell (110).

[0060] The battery cell (110) may have a rectangular sheet shape. The battery cell (110) may be formed by housing an electrode assembly in a pouch case (114) of a laminate sheet comprising a resin layer and a metal layer, and then bonding the outer periphery of the pouch case (114). For example, the battery cell (110) may have a structure in which two electrode leads (111) face each other and protrude from one end and the other end of the cell body (113), respectively. As another embodiment, a structure in which all electrode leads (111) of the battery cell (110) protrude in one direction is also possible. One of the electrode leads (111) is a positive electrode lead, and the other is a negative electrode lead.

[0061] The battery cell (110) may have a sealing portion, which is a portion that is bonded to the outer periphery of the pouch case (114). Specifically, the battery cell (110) may be manufactured by bonding the two ends (114c, 114d) of the pouch case (114) and the upper portion (114b) connecting them, while the electrode assembly (not shown) is housed in the pouch case (114). Sealing portions may be formed on the two ends (114c, 114d) and the upper portion (114b) of the pouch case (114). In other words, the battery cell (110) according to one embodiment of the present invention has a total of three sealing portions, and the sealing portions are structured to be sealed by a method such as fusion, and the remaining lower portion (114a) may be made of a folding portion. That is, the battery cell (110) according to the present embodiment may be a pouch-type battery cell in which an electrode assembly is housed inside a pouch case (114) and the outer periphery of the pouch case (114) is sealed to form a sealing portion. In FIG. 5, only the sealing portions formed at both ends (114c, 114d) of the pouch case (114) are shown, and the upper portion (114b) is shown in a state where the sealing portion is folded to one side after the sealing is completed.

[0062] The pouch 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 pouch 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.

[0063] 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).

[0064] A pouch 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, a sealing portion may be provided by bonding the inner resin layers of the two parts of the pouch case (114) to each other. In this way, the pouch case (114) is sealed so that a battery cell (110), which is a pouch-type battery, can be manufactured.

[0065] Meanwhile, referring to FIG. 7, the sealing portions at both ends (114c, 114d) of the battery cell (110) where the electrode lead (111) protrudes from the battery cell (110) correspond to the so-called terrace part of the battery cell (110). This terrace part may be thinner than the cell body (113) of the battery cell (110).

[0066] In the battery assembly (100) according to the present embodiment, battery cells (110) may be provided in plurality. For example, battery cells (110) may be stacked along one direction to form a battery cell stack (120) so that they can be electrically connected to each other. Battery cells (110) may be stacked from one side (131a) of the housing (130) to another side (131a) such that one side of the battery cells (110) is parallel to some of the side portions (131a) of the housing (130).

[0067] The housing (130) according to the present embodiment is structured to cover the sides and bottom of the battery cell stack (120), thereby protecting the battery cell stack (120) from external impact and the environment. The side portion (131a) and bottom portion (131b) of the housing (130) may be integral as a single structure. Through this, the assembly and manufacturing process of the battery assembly (100) can be simplified, and the structural strength of the battery assembly (100) can be improved.

[0068] Specifically, according to the present embodiment, a housing (130) including side portions (131a) and a bottom portion (131b) may have an open top portion. As the battery cell stack (120) is housed through the open top portion of this housing (130), the sides and bottom portions of the battery cell stack (120) can each be covered by the side portions (131a) and the bottom portion (131b). In the case of a conventional housing, the top portion, bottom portion, and two side portions are integrated, and the side portions in the Y-axis and -Y-axis directions of FIG. 4 are open. The battery cell stack (120) was housed through the open side portions of this conventional housing, but there was a risk that the battery cell stack (120) would be damaged during the process. On the other hand, in the case of the housing (130) according to the present embodiment, the battery cell stack (120) is housed through the upper surface portion, so there is less risk of damage to the battery cell stack (120) during the housing process, and thus the assembly is superior compared to conventional housings.

[0069] Additionally, the battery cell stack (120) can be fixed inside the housing (130) and maintained stably. By stably fixing the battery cell stack (120) to the housing (130), positional variation of the battery cell (110) can be minimized. This protects the battery cell (110) from external shocks or vibrations, thereby preventing performance degradation of the battery assembly (100) and extending the lifespan of the battery cell (110). Furthermore, the fixing structure of the battery cell stack (120) is simple, which can reduce manufacturing costs and facilitate maintenance of the battery assembly (100).

[0070] The housing (130) according to the present embodiment may include a first housing (131) that covers both sides and the bottom surface of the battery cell stack (120), and a second housing (132) that is coupled to the first housing (131) and covers one side of the battery cell stack (120). The first housing (131) and the second housing (132) may include a metal material.

[0071] Specifically, the first housing (131) can be designed to cover both sides and the bottom surface of the battery cell stack (120), and can be formed as an integral structure for supporting and protecting the battery cell stack (120). The first housing (131) can be manufactured from a metal material with high rigidity, such as an aluminum alloy or a magnesium alloy, to enhance durability against shock and vibration. Additionally, the first housing (131) can stably fix both sides and the bottom surface of the battery cell stack (120) to prevent movement of the battery cells due to external forces. The previously described side portions (131a) and bottom portion (131b) may be components of the first housing (131).

[0072] The second housing (132) according to the present embodiment can be designed to be combined with the first housing (131) to cover one side of the battery cell stack (120). The second housing (132) can form a completely sealed structure so that the internal space of the housing (130) through which the refrigerant circulates is not exposed to the outside. The second housing (132) can also be made of a metal material with high rigidity, such as an aluminum alloy or a magnesium alloy.

[0073] This structure, formed by combining the first housing (131) and the second housing (132), can not only stably support and fix the battery cell stack (120) but also protect the battery cell from the external environment. Additionally, it can effectively dissipate heat from the battery cell stack (120) while the internal refrigerant circulates. In particular, since the first housing (131) is made of a metal with excellent thermal conductivity while covering both sides and the bottom of the battery cell stack (120), heat generated from the battery cell can be effectively released to the outside through the first housing (131). Furthermore, the second housing (132) covers one side of the battery cell stack (120) to seal the battery cell stack (120), thereby creating an environment where the refrigerant can circulate consistently within the housing (130). Through this, the cooling efficiency of the battery assembly (100) can be significantly improved.

[0074] Accordingly, the combined structure of the first housing (131) and the second housing (132) according to the present embodiment can provide the effect of simultaneously maximizing the stability and cooling performance of the battery cell (110). The high resistance to external shock can improve the durability of the battery assembly (100), and the improved cooling performance can also ensure the thermal stability of the battery cell (110). Through these effects, the lifespan and performance of the battery assembly (100) are improved, and the long-term stability of the battery cell can be secured.

[0075] According to the present embodiment, the refrigerant may be introduced into the housing (130) through the inlet (160) and then discharged to the outside of the battery assembly (100) through the outlet (170). The battery assembly (100) according to the present embodiment may be subjected to a cooling method in which the refrigerant is circulated. That is, the refrigerant may be filled into the internal space of the housing (130), and the battery cells (110) may be directly cooled by continuously circulating the refrigerant through the inlet (160) and the outlet (170). The cooling method of the present embodiment can be distinguished from conventional cooling methods in that the refrigerant does not stagnate but continues to circulate. The circulation of the refrigerant can maximize heat transfer efficiency by continuously removing the thermal boundary layer on the surface of the battery cells (110). At the same time, the thermal capacity of the refrigerant filled inside the housing (130) acts as a buffer to mitigate rapid temperature changes. Another important effect of the cooling method of the present embodiment is the suppression of thermal runaway propagation. Even if abnormal heat generation occurs in one battery cell (110), the surrounding circulating refrigerant can quickly absorb the heat and discharge it outside the housing (130), thereby effectively blocking heat propagation to adjacent battery cells (110).

[0076] The refrigerant may be a fluid. For example, the refrigerant may be cooling oil, insulating oil, or cooling water. However, since the refrigerant comes into direct contact with the battery cell stack (120), other electrical components, and terminal assembly (180) within the battery assembly (100), it needs to be electrically insulated. Therefore, the refrigerant may be insulating oil as a material having insulating properties. Specifically, the heat of the battery cell stack (120) can be effectively managed by circulating the refrigerant inside the housing (130). By circulating the refrigerant in direct contact with the battery cell stack (120), the heat of the battery cell (110) can be efficiently released.

[0077] In the first and second directions, which are opposite to and parallel to the direction in which the battery cells (110) are stacked, the inlet (160) may be positioned offset in the first direction from the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked. The outlet (170) may be positioned offset in the second direction from the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked. That is, it is preferable for the inlet (160) and the outlet (170) to be located on opposite sides of each other with respect to the direction in which the battery cells (110) are stacked. Only when the inlet (160) and the outlet (170) are arranged in this way can the refrigerant flow through the entire space inside the housing (130) and evenly cool all the battery cells (110). If the inlet (160) and the outlet (170) are located together at the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked, the refrigerant will flow only to the central part, which has the least flow resistance, so the refrigerant will not flow well to the battery cells (110) located at the outer part of the battery cell stack (120). Consequently, this can lead to an imbalance in cooling within the battery assembly (100). For example, as shown in FIG. 6, the battery cells (110) can be stacked along a direction parallel to the X-axis. In this case, the first and second directions described above may be directions parallel to the X-axis. The inlet (160) may be positioned in the -X-axis direction relative to the center of the battery cell stack (120) in the direction in which the battery cells (110) are stacked, and the outlet (170) may be positioned in the X-axis direction relative to the center of the battery cell stack (120) along the axial direction.

[0078] The first housing (131) and the second housing (132) according to the present embodiment may be welded together. As described above, the first housing (131) and the second housing (132) may include a metal material. For example, the first housing (131) and the second housing (132) may include a metal material with high rigidity, such as an aluminum alloy or a magnesium alloy. By joining the first housing (131) and the second housing (132) through welding, they can provide a stable structure even against shocks or vibrations that may occur outside the housing (130).

[0079] Unlike a conventional monoframe structure, the housing (130) according to the present embodiment has an open upper surface portion and can accommodate a battery cell stack (120) through the height direction of the housing (130). In a conventional monoframe structure, the battery cell stack (120) must be inserted in the length direction of the housing, which resulted in poor assembly. However, by assembling the housing (130) according to the present embodiment through the height direction, the assembly distance can be shortened to about 1 / 10 to 1 / 5 compared to the length direction, thereby reducing the risk of damage to the battery cell stack (120) and simplifying the assembly process.

[0080] In addition, the reason the first housing (131) and the second housing (132) are manufactured separately and welded together in this embodiment is that there is no suitable method to achieve an integral form without applying welding. In particular, although an integral form can be considered through an injection molding process, in this case, a draft angle (approximately 3 degrees or more, 5 degrees or less) must be applied, and as a result, the tolerance between the dimensions of the lower housing and the upper housing is likely to exceed the general level. Therefore, in this embodiment, the first housing (131) and the second housing (132), which include metal materials, are manufactured separately, and a stable and robust housing (130) of the battery assembly (100) can be formed through welding. Such a structure can prevent refrigerant leakage and simultaneously satisfy the function of protecting the battery cell stack (120) from external shocks and vibrations, while ensuring both assemblability and structural stability.

[0081] Since the housing (130) is sealed through welding, external dust or moisture can be prevented from penetrating into the housing (130), and the refrigerant circulating inside the housing (130) can be maintained without leakage. In particular, the welded joint does not require the use of additional adhesive or packing at the joint, thereby reducing adverse effects on the cooling performance inside the housing (130).

[0082] Additionally, the welded joint of the first housing (131) and the second housing (132) can contribute to the stable fixation of the battery cell stack (120). As the housing (130) is welded, the battery cell stack (120) is kept completely sealed from the outside, and the position of the battery cell stack (120) may not easily change. This sealed structure increases the efficiency of the cooling system and allows for the dissipation of internal heat and the circulation of the refrigerant to be consistent.

[0083] That is, through the welded joint of the first housing (131) and the second housing (132), the battery assembly (100) can secure more robust structural integrity and effectively protect the battery cell (110) from the external environment. The housing (130) joined by welding has strong resistance to external shocks or vibrations and can maximize cooling efficiency by preventing refrigerant leakage. In addition, since no additional sealant or adhesive is required, the manufacturing process is simplified, and the heat dissipation characteristics of the housing (130) can be maintained. This increases the long-term reliability of the battery assembly (100) and ensures the thermal stability of the battery cell (110), thereby contributing to extending the lifespan and improving the performance of the entire battery system.

[0084] High-precision welding techniques, such as TIG (Tungsten Inert Gas) welding or laser welding, may be used as welding joining methods. These methods are particularly suitable for materials with high thermal conductivity, such as aluminum alloys, and can be advantageous for maintaining the integrity of the housing (130) that houses the battery cell (110).

[0085] Additionally, the first housing (131) and the second housing (132) can be joined by friction stir welding. Friction stir welding is a method that forms a strong bond in a solid state without welding rods or filler materials, joining metals by pressing a rotating non-consumable tool into the joint at high temperature and high pressure. Friction stir welding is particularly suitable for welding materials that have high thermal conductivity and are sensitive to thermal deformation, such as aluminum alloys, and can provide high airtightness and strong joint strength.

[0086] When the first housing (131) and the second housing (132) are joined using friction stir welding, melting does not occur at the joint, so the internal structure of the material can be maintained, and as a result, thermal deformation can be significantly reduced. Since the friction stir welding method generates heat locally during welding, there is a low possibility that the entire housing (130) will be deformed or cracked by heat, and the compatibility between the battery cell stack (120) and the housing (130) can also be maintained. This further increases the structural stability of the battery assembly (100) and prevents cracking at the joint or leakage of the refrigerant due to thermal expansion.

[0087] In this embodiment, when applying friction stir welding for complete sealing of the housing, the following conditions may be required.

[0088] First, a joint design may be required. For friction stir welding, a butt joint is preferable, and the gap between the joint surfaces should be minimized. The joint thickness can be set within a range that ensures sufficient joint strength and appropriate heat generation control. The joint area between the first housing (131) and the second housing (132) must be flat, and the joint line may be in the form of a straight line or a gentle curve.

[0089] The following friction stir welding tool may be required. The friction stir welding tool consists of a shoulder section and a pin section; the shoulder section is responsible for forming the joint surface, while the pin section is responsible for stirring and mixing the materials. The shape of the friction stir welding tool is optimized according to the materials to be joined and their thickness; in particular, for aluminum alloy housings, a threaded pin may be effective. The shoulder section can have a concave or flat shape, which can be selected based on the required quality of the joint surface.

[0090] The following process conditions may be required. The rotational speed and feed rate of the friction stir welding tool are set considering the characteristics and thickness of the joining materials, and solid-state joining can be achieved by maintaining an appropriate temperature range (below the material's melting point). Stable joint formation can be ensured by setting the inclination angle of the friction stir welding tool. Heat generated during the joining process is controlled via a backing plate, which contributes to ensuring uniform quality of the joint.

[0091] Complete airtightness with respect to the refrigerant may be essential for the housing according to the present embodiment. The joint formed by friction stir welding must provide a sealed structure that prevents refrigerant leakage and may not undergo corrosion or deterioration even after prolonged contact with the refrigerant. The joint may have durability against pressure fluctuations and temperature cycles resulting from refrigerant circulation. In particular, in the case of a vehicle battery assembly, the integrity of the joint may be maintained even under vibration and shock conditions.

[0092] Friction stir welding between the housing (130) and the top cover assembly (140) is also performed using the same principle, and in particular, since the upper joint is a process for final sealing after assembly of the battery cell stack (120), a process design that minimizes thermal impact on internal components during joining may be required.

[0093] In addition, friction stir welding has the characteristic of keeping the surface smooth after joining, so there is almost no need for additional finishing or surface treatment. This simplifies the production process and further improves the durability and stability of the housing (130) joint. The friction stir welding method is environmentally friendly because it does not use unnecessary welding materials during welding, and cost savings can also be expected as no additional materials are required.

[0094] Referring again to FIG. 6, the housing (130) may have an open top surface, and a top cover assembly (140) covering the open top surface of the housing (130) may be provided in the battery assembly (100) according to the present embodiment.

[0095] The top cover assembly (140) according to the present embodiment can completely cover the open portion of the housing (130). The refrigerant can flow along the internal space of the housing (130) and the top cover assembly (140). The top cover assembly (140) can protect the upper part of the battery assembly (100), maintain airtightness, and prevent external impact and contamination. That is, the top cover assembly (140) can protect the interior of the housing (130) from external dust, water, foreign substances, etc. Through this, the durability of the battery assembly (100) can be improved and malfunctions or failures can be prevented.

[0096] That is, due to the addition of the top cover assembly (140), the battery assembly (100) can be completely sealed from the external environment and form a sealed structure in which the refrigerant can circulate efficiently within the housing (130). This helps the refrigerant to uniformly cool all areas of the battery cell stack (120), thereby maximizing the cooling efficiency of the battery assembly (100). In addition, the top cover assembly (140) has an external heat dissipation structure, which prevents overheating of the battery cell stack (120) and maintains a stable temperature. This improves the lifespan and performance of the battery cell (110) and provides structural stability with enhanced durability against external shocks or vibrations.

[0097] In one embodiment of the present invention, the housing (130) and the top cover assembly (140) may be joined together by bolting. A gasket may be interposed between the side portion (131a) of the housing (130) and the edge of the top cover assembly (140). With the gasket interposed in place, the housing (130) and the top cover assembly (140) may be bolted together. This ensures airtightness between the housing (130) and the top cover assembly (140), thereby preventing refrigerant leakage.

[0098] In another embodiment of the present invention, the housing (130) and the top cover assembly (140) may be welded together. The top cover assembly (140) may include a metal material.

[0099] When the housing (130) and the top cover assembly (140) are welded together, the welded joint can be completely sealed from the external environment, thereby providing a sealed structure that allows the internal refrigerant to circulate stably. Additionally, by preventing external moisture, dust, and contaminants from entering the housing (130), the reliability of the battery cell (110) and the cooling system can be increased. Through the welded joint of the housing (130) and the top cover assembly (140), resistance to external shocks or vibrations can be strengthened, and the structural stability of the entire housing (130) can be increased.

[0100] In addition, since the welded joint does not require the use of additional sealing material between the housing (130) and the top cover assembly (140), the manufacturing process can be simplified, and cooling efficiency can be maximized by eliminating unnecessary bonding materials. Because the gap between the housing (130) and the top cover assembly (140) is completely sealed due to the welded joint, the refrigerant can be evenly distributed throughout the battery cell stack (120) inside the housing (130), thereby improving thermal management. That is, the refrigerant inside the housing (130) can be efficiently circulated to uniformly cool all battery cells (110), contributing to the optimization of battery performance and lifespan.

[0101] High-precision welding technologies, such as TIG (Tungsten Inert Gas) welding or laser welding, can be primarily used for welding joints.

[0102] As an embodiment of the present invention, the housing (130) and the top cover assembly (140) can be joined by friction stir welding. When the housing (130) and the top cover assembly (140) are joined by friction stir welding, the welded joint can maintain strong airtightness as an integrated structure. Unlike general welding, which joins materials by melting them at high temperatures, friction stir welding joins by deforming the materials themselves in a solid state; thus, the joint between the housing (130) and the top cover assembly (140) is uniformly bonded, and the bonding strength is increased. The friction stir welding method provides high strength while minimizing deformation caused by heat, allowing the housing (130) and the top cover assembly (140) to have strong resistance to external shocks or vibrations.

[0103] By joining the housing (130) and the top cover assembly (140) using friction stir welding, the battery assembly (100) can maintain structural stability by minimizing thermal deformation of the welded joint and can prevent intrusion from the outside by providing an integrated sealed structure even after welding. As a result, the internal coolant can circulate uniformly within the housing (130) and effectively cool the battery cell (110), which can contribute to improving the performance and lifespan of the battery cell (110). In addition, the friction stir welding method produces a smooth surface and excellent strength of the welded joint, allowing the housing (130) to have strong durability against external shocks or vibrations. Therefore, the welded joint using the friction stir welding method can ensure long-term reliability of the battery assembly (100) and provide the effect of reducing production costs by simplifying the manufacturing process.

[0104] FIG. 8 is a cross-sectional view showing a cross section cut along the cutting line A-A' of FIG. 3. FIG. 9 is a cross-sectional view showing a battery cell stack, a housing, and a cooling spacer according to an embodiment of the present invention. FIG. 10 is a perspective view showing a cooling spacer according to an embodiment of the present invention.

[0105] Referring to FIGS. 1 to 3 and FIGS. 6 to 10, at least one cooling spacer (200) is located at at least one location among a plurality of battery cells (110), and the cooling spacer (200) includes at least one cooling hole (200H) through which a refrigerant moves.

[0106] In one embodiment, cooling spacers (200) may be interposed between all of the battery cells (110), and in another embodiment, at least one cooling spacer (200) may be interposed between some of the battery cells (110).

[0107] The cooling hole (200H) may be drilled along the direction of the wider side of the battery cell (110). The battery cell (110) according to the present embodiment may have a rectangular sheet shape and, accordingly, may have relatively wider sides and relatively shorter sides. In the present embodiment, the wider side of the battery cell (110) may be a side that extends along the Y-axis direction. At least one cooling hole (200H) of the cooling spacer (200) may also be drilled along the Y-axis direction. The refrigerant introduced through the inlet (160) may flow along the internal space of the housing (130) and then be discharged through the outlet (170). A portion of the refrigerant introduced through the inlet (160) may flow along the cooling hole (200H) of the cooling spacer (200) and then be discharged through the outlet (170).

[0108] The cooling spacer (200) may include a main body (210) positioned between battery cells (110) and surface-cooling the battery cells (110). The main body (210) of the cooling spacer (200) may be a plate-shaped member having a surface perpendicular to the direction in which the battery cells (110) are stacked, and one surface of the main body (210) may be parallel to one surface of the cell body (113, see FIG. 7) of the battery cell (110). At least one cooling hole (200H) of the cooling spacer (200) may be provided in the main body (210).

[0109] The cooling spacer (200) according to the present embodiment may have a surface facing one side of the battery cells (110) of the battery cell stack (120). The cooling spacer (200) may cool the battery cells (110) surface. One side of the cooling spacer (200) may come into contact with one side of the battery cell (110) facing the one side of the cooling spacer (200). The other side of the cooling spacer (200) may come into contact with one side of the battery cell (110) facing the other side of the cooling spacer (200).

[0110] Meanwhile, the cooling spacer (200) can be bonded and fixed to adjacent battery cells (110). In another embodiment, an adhesive member may be interposed between at least a portion of one side of the battery cell (110) and at least a portion of one side of the cooling spacer (200), and an adhesive member may be interposed between at least a portion of one side of an adjacent battery cell (110) and at least a portion of the other side of the cooling spacer (200). That is, the battery cell (110) and the cooling spacer (200) can be bonded and fixed in at least some area. For example, the adhesive member may be an insulating tape or an adhesive.

[0111] The size of the cooling spacer (200) according to the present embodiment may be larger than the size of the battery cell (110). The height of the cooling spacer (200) (in the Z-axis direction of FIG. 9) may be greater than the height of the battery cell (110). In this case, the battery cell (110) may be attached to the cooling spacer (200) and positioned as if floating inside the housing (130) without contacting the housing (130). Specifically, the upper edge and lower edge of the battery cell (110) may be positioned at a certain height from one end and the other end of the cooling spacer (200). More specifically, when the height of the cooling spacer (200) (in the Z-axis direction of FIG. 9) is higher than the height of the battery cell (110) (in the Z-axis direction of FIG. 9), the battery cell (110) may be positioned at the center of the cooling spacer (200) and fixed with adhesive.

[0112] As described above, the cooling spacer (200) may include a plurality of cooling holes (200H) formed along the longitudinal direction. The cooling holes (200H) provide a path for the refrigerant to move, allowing the refrigerant to flow between the battery cells (110). At least a portion of the refrigerant may move to the plurality of cooling holes (200H). In this case, since the refrigerant moves while receiving heat generated from the battery cells (110), it can effectively cool the battery cells (110) located in the center of the battery cell stack (120) with respect to the direction in which the battery cells (110) are stacked. According to the present embodiment, a portion of the refrigerant may directly cool the battery cells (110) by coming into direct contact with them, while at the same time, another portion of the refrigerant may indirectly cool the battery cells (110) through the cooling spacer (200) by moving along the cooling holes (200H).

[0113] Additionally, the cooling spacer (200) includes a plurality of cooling holes (200H) drilled along the direction of the wider side of the battery cell (110), so that the battery cell (110) can be cooled uniformly. This prevents damage caused by overheating of a specific part of the battery cell (110).

[0114] The cooling spacer (200) can effectively disperse heat within the battery cell stack (120) and allow the refrigerant to circulate between the battery cells (110), thereby optimizing the thermal management of the entire battery assembly (100). As a result, the temperature of the battery cells (110) is maintained uniformly, and the performance and lifespan of the battery assembly (100) can be improved. Additionally, the cooling spacer (200) can be positioned between the battery cells (110) to improve the structural stability of the entire battery assembly (100). This can increase the mechanical strength of the battery assembly (100) and increase the durability of the battery assembly (100) against external shocks or vibrations.

[0115] In the battery assembly (100) according to the present embodiment, a portion of the refrigerant may flow in the space between the battery cell stack (120) and the lower portion (131b) of the housing (130). As shown in FIG. 8, a portion of the refrigerant may flow in the first space (S1) formed between the battery cell stack (120) and the lower portion (131b) of the housing (130).

[0116] Additionally, a portion of the refrigerant may flow in the space between the battery cell stack (120) and the top cover assembly (140). As illustrated in FIG. 8, a portion of the refrigerant may flow in a second space (S2) formed between the battery cell stack (120) and the top cover assembly (140).

[0117] According to the present embodiment, a portion of the refrigerant can directly cool the battery cells (110) by coming into direct contact with them, and at the same time, another portion of the refrigerant can indirectly cool the battery cells (110) through the cooling spacer (200) by moving along the cooling hole (200H), and another portion of the refrigerant can directly cool the top and bottom of the battery cells (110) by moving along the first space (S1) at the bottom and the second space (S2) at the top of the battery cell stack (120).

[0118] Meanwhile, the cooling spacer (200) can be fixed to the housing (130). For example, the cooling spacer (200) can be fixed to the lower portion (131b) of the housing (130). Additionally, the cooling spacer (200) can be fixed to the bottom of the top cover assembly (140).

[0119] In the present invention, the cooling spacer (200) may be fixed to at least one of the lower portion (131b) of the housing (130) or the top cover assembly (140). In other words, in one embodiment, the cooling spacer (200) may be fixed to either the lower portion (131b) of the housing (130) or the top cover assembly (140), and in another embodiment, the cooling spacer (200) may be fixed to both the lower portion (131b) of the housing (130) and the top cover assembly (140).

[0120] In the cooling system of the present embodiment, the cooling spacer (200) may be a key component for controlling the flow of refrigerant. By fixing the cooling spacer (200) to at least one of the lower portion (131b) of the housing (130) or the bottom of the top cover assembly (140), the battery cell stack (120) can be positioned in the center of the internal space of the housing (130), and a flow path can be secured through which the refrigerant can flow around all sides of the battery cell (110). As the cooling spacer (200) is fixed to at least one of the lower portion (131b) of the housing (130) or the bottom of the top cover assembly (140), the battery cell stack (120) is positioned in the center of the internal space of the housing (130), so that a first space (S1) can be secured between the battery cell stack (120) and the lower portion (131b) of the housing (130), and a second space (S2) can be secured between the battery cell stack (120) and the top cover assembly (140). In one embodiment of the present invention, a portion of the refrigerant flows along the cooling holes (200H) of the cooling spacer (200) to cool the battery cells (110) on the surface, and at the same time, another portion of the refrigerant flows through the first space (S1) at the bottom and the second space (S2) at the top of the battery cell stack (120) to cool the battery cells (110) in multiple directions, thereby increasing the overall cooling performance of the battery cell stack (120).

[0121] Meanwhile, the cooling holes (200H) of the cooling spacer (200) can promote the flow of refrigerant between the battery cells (110). The refrigerant passing through the cooling holes (200H) can be converted from laminar flow to turbulent flow to improve heat transfer. Additionally, the cooling spacer (200) can maintain a constant distance between the battery cells (110) to secure a flow path for the refrigerant so that the refrigerant can circulate without blockage.

[0122] When the cooling spacer (200) is fixed to the lower portion (131b), it can support the load of the battery cell stack (120) while securing the first space (S1), which is the lower refrigerant flow path. Additionally, when the cooling spacer (200) is fixed to the bottom of the top cover assembly (140), it can form a support structure against the refrigerant pressure in the upward direction to prevent deformation of the top cover assembly (140) and secure the second space (S2), which is the upper refrigerant flow path.

[0123] The material of the cooling spacer (200) can be selected in consideration of a circulating immersion cooling environment. An engineering plastic can be used that does not change in physical properties even when exposed to insulating oil for a long period, maintains dimensional stability in the battery operating temperature range (e.g., -20°C or higher and 80°C or lower), and ensures electrical insulation between battery cells (110).

[0124] As described above, the cooling spacer (200) according to the present embodiment can be fixed to the lower portion (131b) of the housing (130). Through this, the cooling spacer (200) and the battery cells (110) can be securely maintained in position within the battery assembly (100). For example, the cooling spacer (200) can be fixed to adjacent battery cells (110) by the adhesive member described above, and the cooling spacer (200) can be fixed to the lower portion (131b) of the housing (130). In this way, in the case of the battery assembly (100) according to the present embodiment, the position of the battery cell stack (120) inside the housing (130) can be fixed and maintained by the cooling spacer (200). If the position of the battery cell stack (120) is not fixed while the refrigerant flows inside the housing (130), significant problems may arise regarding the durability and stability of the battery assembly (100), and the flow path of the refrigerant may not be secured. Conventionally, a separate fixing frame was placed inside the housing to solve these problems. In this embodiment, a separate fixing frame is unnecessary because the battery cell stack (120) can be fixed inside the housing (130) using a cooling spacer (200). That is, in addition to the cooling function for the battery cells (110), the cooling spacer (200) can fix the position of the battery cell stack (120) inside the housing (130) to improve the durability and stability of the battery assembly (100), and at the same time secure multiple flow paths for the battery cells (110) to cool the battery cells (110) in various ways. The cooling spacer (200) can enable the refrigerant to circulate effectively. Through this, the refrigerant can be evenly distributed throughout the battery cell stack (120) to maximize cooling performance. Additionally, by fixing the cooling spacer (200) to the lower portion (131b) of the housing (130), the mechanical stability of the battery assembly (100) can be increased.In other words, it can help the battery assembly (100) withstand external shocks or vibrations. As a result, the durability of the battery assembly (100) can be increased and reliability can be ensured.

[0125] Meanwhile, the cooling spacer (200) can be fixed to the lower portion (131b) of the housing (130) by a fixing member. For example, the cooling spacer (200) can be fixed to the lower portion (131b) of the housing (130) by a first fixing member (310). The cooling spacer (200) can be adhered to the lower portion (131b) of the housing (130) through the first fixing member (310).

[0126] The cooling spacer (200) may include a lower extension (220) located at the bottom of the main body (210). The lower extension (220) may extend along a direction perpendicular to one side of the main body (210) from the bottom of the main body (210). The lower extension (220) may extend along the direction in which the battery cells (110) are stacked.

[0127] The first fixing member (310) may be positioned between the lower extension (220) of the cooling spacer (200) and the lower portion (131b) of the housing (130). The lower extension (220) of the cooling spacer (200) may be adhered to the lower portion (131b) of the housing (130) through the first fixing member (310).

[0128] The lower extension (220) can provide a predetermined area to which the first fixing member (310) can be applied. By the lower extension (220), the area required for the cooling spacer (200) to be adhered and fixed to the lower portion (131b) can be secured.

[0129] Additionally, the lower extension (220) can transfer heat absorbed by the main body (210) from the battery cell (110) to the housing (130). The lower extension (220), having a predetermined area, can come into direct or indirect contact with the inner surface of the housing (130). Heat generated from the battery cell (110) can move through the main body (210) to the lower extension (220), and finally be transferred to the housing (130) and discharged to the outside of the battery assembly (100).

[0130] Additionally, the lower extension (220) can perform the function of a support so that the cooling spacer (200) can be fixed inside the housing (130). Since the lower extension (220) has a predetermined area, the cooling spacer (200) can maintain a more stable upright state.

[0131] The first fixing member (310) may include foam tape, tape, adhesive resin, or adhesive. For example, FIGS. 9 and 10 show that a cooling spacer (200) is fixed to the lower portion (131b) of the housing (130) by the first fixing member (310).

[0132] A cooling spacer (200) according to one embodiment of the present invention can be fixed to the lower surface (131b) of a housing (130) by a first fixing member (310) which is a foam tape. This simplifies the assembly process of the cooling spacer (200). By using the first fixing member (310) which is a foam tape, the cooling spacer (200) can be easily fixed without a complex mechanical fixing device. This simplifies the assembly process of the battery assembly (100) and saves time. In addition, the cooling spacer (200) can be kept from moving out of position, thereby maintaining stable thermal management performance.

[0133] Additionally, the foam tape may be a foam tape with shock absorption and vibration damping functions. Thus, the durability of the battery assembly (100) can be ensured in the event of external shock or vibration. Additionally, the foam tape can perform the function of compensating for the assembly tolerance of the battery cell stack (120) and the cooling spacer (200) in the height direction.

[0134] Meanwhile, as illustrated in FIG. 8, a top cover assembly (140) covering the open upper surface of the housing (130) may be provided, and a cooling spacer (200) may be fixed to the bottom of the top cover assembly (140).

[0135] As described above, the top cover assembly (140) can completely cover the open portion of the housing (130). The refrigerant can flow along the internal space of the housing (130) and the top cover assembly (140). The top cover assembly (140) can protect the top of the battery assembly (100), maintain airtightness, and prevent external impact and contamination. The top cover assembly (140) can protect the interior of the housing (130) from external dust, water, foreign substances, etc. Through this, the durability of the battery assembly (100) can be improved and malfunctions or failures can be prevented. The cooling spacer (200) can be fixed to the top cover assembly (140). The cooling spacer (200) can be fixed to the top cover assembly (140) with a fixing member. For example, FIG. 8 illustrates that a cooling spacer (200) is fixed to the bottom of the top cover assembly (140) by a second fixing member (320).

[0136] The cooling spacer (200) may include an upper extension (230) located at the upper part of the main body (210). The upper extension (230) may extend along a direction perpendicular to one side of the main body (210) from the upper part of the main body (210). The upper extension (230) may extend along the direction in which the battery cells (110) are stacked.

[0137] The second fixing member (320) may be positioned between the upper extension (230) of the cooling spacer (200) and the lower end of the top cover assembly (140). The upper extension (230) of the cooling spacer (200) may be attached to the top cover assembly (140) through the second fixing member (320).

[0138] The upper extension (230) can provide a predetermined area to which the second fixing member (320) can be applied. By the upper extension (230), the area required for the cooling spacer (200) to be adhered and fixed to the top cover assembly (140) can be secured.

[0139] Additionally, the upper extension (230) can transfer heat absorbed by the main body (210) from the battery cell (110) to the top cover assembly (140). The upper extension (230), having a predetermined area, can come into direct or indirect contact with the inner surface of the housing (130). Heat generated from the battery cell (110) can move through the main body (210) to the upper extension (230), and finally be transferred to the top cover assembly (140) and discharged to the outside of the battery assembly (100).

[0140] Meanwhile, since the refrigerant flowing into the inlet (160) has pressure required for its circulation, the pressure of this refrigerant is applied to the top cover assembly (140), which may cause deformation and damage to the top cover assembly (140). In the battery assembly (100) according to the present embodiment, the cooling spacer (200) is fixed to the bottom of the top cover assembly (140), thereby supplementing the structural stability of the top cover assembly (140) and preventing the top cover assembly (140) from being deformed or damaged by the pressure of the refrigerant. Additionally, the upper extension (230) of the cooling spacer (200) can perform the function of a support, so that the top cover assembly (140) can be fixed. Since the upper extension (230) has a predetermined area, the adhesive strength between the top cover assembly (140) and the cooling spacer (200) can be stably secured.

[0141] The second fixing member (320) according to the present embodiment can firmly attach the cooling spacer (200) to the top cover assembly (140) so that the cooling spacer (200) and the battery cells (110) do not move. As a result, the structural stability of the battery assembly (100) is increased, and the battery assembly (100) can be protected from vibrations or shocks that may occur during use. The second fixing member (320) may include foam tape, tape, adhesive resin, or adhesive.

[0142] The cooling spacer (200) according to the present embodiment can be bonded and fixed to adjacent battery cells (110), and the cooling spacer (200) can be fixed to the bottom of the top cover assembly (140). In this way, in the case of the battery assembly (100) according to the present embodiment, the position of the battery cell stack (120) inside the housing (130) and the top cover assembly (140) can be fixed and maintained by the cooling spacer (200). If the position of the battery cell stack (120) is not fixed while the refrigerant flows inside the housing (130) and the top cover assembly (140), a major problem may occur with the durability and stability of the battery assembly (100), and the refrigerant flow path may not be secured. Conventionally, a separate fixing frame was placed inside the housing to solve this problem. In this embodiment, a separate fixing frame is unnecessary because the battery cell stack (120) can be fixed inside the housing (130) and top cover assembly (140) using a cooling spacer (200). That is, in addition to the cooling function for the battery cells (110), the cooling spacer (200) can fix the position of the battery cell stack (120) inside the housing (130) and top cover assembly (140) to improve the durability and stability of the battery assembly (100), and at the same time secure various refrigerant flow paths for the battery cells (110) to cool the battery cells (110) in multiple ways.

[0143] In addition, by attaching the cooling spacer (200) using the first fixing member (310) or the second fixing member (320), the installation of the cooling spacer (200) can be simplified and maintenance can be easy. In other words, the cooling spacer (200) can be assembled quickly and simply without complex mechanical fixing methods.

[0144] In accordance with the present embodiment, the cooling spacer (200) can effectively contact the top cover assembly (140), thereby improving thermal conductivity. That is, heat can be effectively dispersed, and overheating of the battery assembly (100) can be prevented. In addition, as the gap between the cooling spacer (200) and the top cover assembly (140) is eliminated, the flow of refrigerant within the battery assembly (100) is optimized, thereby effectively removing heat from the battery cell (110).

[0145] In the cooling method according to the present embodiment, the spacing and arrangement of the cooling spacers (200) may be important design elements that determine the refrigerant flow characteristics and heat transfer efficiency. By setting an appropriate spacing between the cooling spacers (200), an optimal balance between refrigerant flow resistance and heat transfer efficiency can be achieved. If the spacing is excessively narrow, pressure loss increases, and if it is excessively wide, uneven heat transfer may occur due to the formation of vortices.

[0146] The batch density of the cooling spacer (200) can be designed to be differentiated in the refrigerant inlet, central, and discharge sections. In the inlet section near the inlet (160), a relatively high batch density can be used to induce uniform dispersion of the refrigerant, a stable flow can be formed in the central section, and smooth refrigerant discharge can be facilitated in the discharge section near the outlet (170).

[0147] A plurality of cooling holes (200H) formed in the cooling spacer (200) can provide a refrigerant flow path penetrating the battery cell (110) in the longitudinal direction (Y-axis direction). The size and number of these cooling holes (200H) can be optimized by considering the refrigerant circulation volume and pressure loss of the entire system. Local flow disturbances occurring around the cooling holes (200H) can provide an additional effect of promoting heat transfer.

[0148] A particularly important point is that in the structure according to the present embodiment, the cooling spacer (200) is fixed to the lower portion (131b) of the first housing (131) or the top cover assembly (140), thereby performing a structural role of stably supporting the battery cell stack (120) against fluid force due to refrigerant circulation, and securing a space around the battery cell stack (120) through which the refrigerant can flow, thereby diversifying the cooling path for the battery cell stack (120). This ensures the positional stability of the battery cell stack (120) while guaranteeing the free circulation of the refrigerant. In addition, in the cooling system according to the present embodiment, the cooling spacer (200) can also perform the role of securing an electrical insulation distance between the battery cells (110).

[0149] In the case of the battery assembly (100) according to the present embodiment, the housing (130) and the top cover assembly (140) must be able to withstand the fluid pressure resulting from the circulation of refrigerant within them. The fluid pressure resulting from the circulation of refrigerant can increase to a significant level due to the pressure required for the refrigerant to move from the inlet (160) to the outlet (170). If the housing (130) and the top cover assembly (140) deform and fail to withstand the fluid pressure resulting from the circulation of refrigerant, the refrigerant may easily leak. Therefore, it is an important issue that the housing (130) and the top cover assembly (140) withstand the fluid pressure resulting from the circulation of refrigerant.

[0150] The side portion (131a) and bottom portion (131b) of the housing (130) according to the present embodiment may be a single integrated structure. Accordingly, the housing (130) can withstand the fluid pressure of the refrigerant in the lateral direction of the battery assembly (100) and can control displacement in the lateral direction. However, since the housing (130) and the top cover assembly (140) are combined with each other and are not integrated structures, it may be difficult to withstand the fluid pressure of the refrigerant in the upper direction where the top cover assembly (140) is located. Accordingly, in the present embodiment, the cooling spacer (200) is fixed to the bottom of the top cover assembly (140) so that the top cover assembly (140) can withstand the fluid pressure of the refrigerant in the upper direction. In addition to the coupling structure between the housing (130) and the top cover assembly (140), the cooling spacer (200) is fixed to the bottom of the top cover assembly (140), so the displacement of the top cover assembly (140) can be controlled in the upward direction.

[0151] In the cooling structure according to the present embodiment, the upper and lower fixing of the cooling spacer (200) may be an important structural feature that effectively disperses fluid pressure due to refrigerant circulation. A double fixing structure in which the cooling spacer (200) is fixed to the lower portion (131b) by a first fixing member (310) and fixed to the top cover assembly (140) from the top by a second fixing member (320) can stably support the entire battery cell stack (120) inside the housing (130). This structure evenly disperses the dynamic pressure and static pressure generated as the refrigerant circulates from the inlet (160) to the outlet (170), thereby preventing localized stress concentration and preventing deformation or damage to the battery cell (110).

[0152] Meanwhile, referring to FIG. 3, the inlet (160) and the outlet (170) may be located in either the first housing (131) or the second housing (132). For example, the inlet (160) may be located in the first housing (131) and the outlet (170) may be located in the second housing (132).

[0153] FIG. 11 is a plan view showing a battery assembly according to another embodiment of the present invention.

[0154] Referring to FIG. 11, both the inlet (160) and the outlet (170) may be located in the first housing (131). In this case, the refrigerant can circulate through a short path to provide a rapid cooling effect. Additionally, it can help maximize the use of space inside the housing (130) and minimize the size of the overall battery assembly (100).

[0155] Referring again to FIGS. 1 through 5, the inlet (160) may be located in either the first housing (131) or the second housing (132), and the outlet (170) may be located on the side opposite to the side where the inlet (160) is located. In this case, the refrigerant may travel along a long path across the housing (130). This allows for more uniform and effective cooling to be achieved across the entire battery cell stack (120). The placement of the refrigerant may be optimized according to the thermal management requirements of the battery assembly (100) and may contribute to improving the performance and stability of the battery assembly (100).

[0156] FIG. 12 is a perspective view showing a terminal assembly (180) according to one embodiment of the present invention. FIG. 13 is a perspective view showing the terminal assembly (180) of FIG. 12 viewed from a different angle. FIG. 14 is a cross-sectional perspective view showing a cross section cut along the cutting line B-B' of FIG. 3.

[0157] Referring to FIGS. 1 to 3 and FIGS. 12 to 14, a terminal assembly (180) electrically connected to a battery cell stack (120) may be coupled to a housing (130). The terminal assembly (180) may be coupled to a first housing (131) or a second housing (132).

[0158] The terminal assembly (180) according to the present embodiment is a component that is electrically connected to the battery cell stack (120) and an external power supply or battery management system (BMS) to allow current to flow stably. The terminal assembly (180) is designed to efficiently maintain an electrical connection with the battery cell stack (120) and may include components such as a terminal busbar (181), a bolt (183), and a gasket (182).

[0159] When the terminal assembly (180) according to the present embodiment is coupled to the housing (130), the structure may be such that the passage for electrical connection between the battery cell stack (120) and the outside is protected from the outside of the housing (130). At this time, the terminal busbar (181), which is a major component of the terminal assembly (180), is connected to the electrode lead of the battery cell to allow current to flow smoothly and may be arranged in a manner that minimizes electrical contact resistance. In addition, a gasket (182) resistant to high temperature and vibration is applied to the coupling portion of the housing (130) to which the terminal assembly (180) is coupled, thereby ensuring airtightness so that the electrical connection portion is protected from external moisture or dust.

[0160] That is, by coupling the terminal assembly (180) to the housing (130), the electrical connection between the battery cell stack (120) and the external device can be established stably and efficiently. This structure can protect the terminal assembly (180) from the external environment, thereby extending the lifespan of the electrical connection and contributing to increasing the reliability of the battery system.

[0161] Referring again to FIGS. 1 to 3 and FIGS. 12 to 14, the terminal assembly (180) may include a terminal busbar (181); a gasket (182) that contacts the side of the housing (130); and a bolt (183) that penetrates the terminal busbar (181) and the gasket (182).

[0162] The terminal busbar (181) according to the present embodiment may be electrically connected to the electrode lead or electrode terminal of the battery cell (110). A portion of the terminal busbar (181) may be exposed to the outside of the battery assembly (100). The battery assembly (100) may form a High Voltage (HV) connection with another battery assembly or electrical component through this terminal busbar (181). Here, the HV connection is a connection that serves as a power source to supply power requiring high voltage, and refers to a connection between battery cells (110) or between battery assemblies (100).

[0163] The gasket (182) according to the present embodiment can provide a physical sealing effect through close contact with the side portion (131a) of the housing (130). As a result, external dust or water can be prevented from penetrating into internal electronic devices or components, thereby improving the durability and reliability of the terminal assembly (180). The gasket (182) can be formed from an elastic material. For example, the gasket (182) can be formed from rubber. Therefore, when pressure is applied to the gasket (182), the shape of the gasket (182) changes, and the sealing effect can be increased. The gasket (182) can be positioned along the edge of the housing (130).

[0164] The bolt (183) according to the present embodiment can provide structural stability by firmly securing the terminal busbar (181) and the gasket (182). This minimizes deformation caused by mechanical vibration or impact. Additionally, the gasket (182) or the terminal busbar (181) can be easily replaced or repaired.

[0165] Referring again to FIGS. 1 to 3 and FIGS. 12 to 14, the terminal assembly (180) further includes a bus bar (184) electrically connected to at least one of the battery cells, and as a bolt (183) is coupled to the bus bar (184), the battery cell stack (120) and the terminal assembly (180) can be electrically connected.

[0166] The busbar (184) according to the present embodiment may be configured to guide electrical connections between battery cells (110). The busbar (184) is sufficient if it comprises a metal material with excellent electrical conductivity, and is not limited to its shape or material.

[0167] Additionally, the bolt (183) can electrically connect the terminal busbar (181) and the battery cell stack (120). The bolt (183) according to the present embodiment can not only function to secure the terminal assembly (180) to the side portion (131a) of the housing (130), but also function to guide the electrical connection between the terminal busbar (181) and the battery cell stack (120).

[0168] Specifically, the busbar (184) can be electrically connected to the electrode lead (111) or electrode terminal of the battery cell (110), and on the other hand, can be electrically connected to the terminal busbar (181). Through bolt connection, the electrical connection between the battery cell stack (120) and the terminal assembly (180) can be maintained stably. In particular, the bolt connection can prevent electrical connection instability caused by external shock or vibration and can provide a structurally robust connection. As a result, electrical signals generated in the battery cell stack (120) can be stably transmitted to an external electrical system through the busbar (184) and the terminal busbar (181).

[0169] In this embodiment, an electrical insulating material may be additionally applied to maintain an electrical connection between the busbar (184) and the battery cell stack (120). For example, the contact area where the electrical connection is made may be insulated to prevent an electrical short circuit. This can improve electrical stability within the battery assembly (100).

[0170] FIG. 15 is a perspective view showing a connector assembly (150) according to one embodiment of the present invention. FIG. 16 is a perspective view showing the connector assembly (150) of FIG. 15 viewed from a different angle.

[0171] Referring to FIGS. 1 through 6, FIG. 15, and FIG. 16, a connector assembly (150) electrically connected to a battery cell stack (120) may be coupled to a housing (130). The connector assembly (150) may include: an LV (Low Voltage) connector electrically connecting the battery cell stack (120) and a BMS module; a connector coupled to a module connector (152); a printed circuit board (153) connected to the module connector (152); a gasket (182) located between the connector assembly (150) and the housing (130); and a connector assembly (150) cover.

[0172] The LV connector (151) according to the present embodiment can transmit a low-voltage signal and, through this, can be electrically connected to a Battery Management System (BMS). The LV connector (151) can increase the reliability of the entire battery assembly (100) system by minimizing electrical contact failure or signal loss.

[0173] The module connector (152) according to the present embodiment can function to transmit voltage information of battery cells (110) or temperature information inside the battery assembly (100) to the outside. The printed circuit board (153) is located on the upper surface of the battery cell stack (120) and can sense voltage data or thermal data of the battery cells (110). The printed circuit board (153) can process and transmit electrical signals.

[0174] The gasket (154) according to the present embodiment may be formed of an elastic material. For example, the gasket (154) may be formed of rubber. When pressure is applied to the gasket (154), the shape of the gasket (154) changes, thereby maintaining the airtightness of the battery assembly (100) and protecting the inside of the battery assembly (100) from the external environment. That is, by providing mechanical sealing between the connector assembly (150) and the housing (130), the intrusion of external dust, moisture, chemicals, etc., can be prevented. The gasket (154) may be positioned along the edge of the connector assembly cover (155).

[0175] The connector assembly cover (155) according to the present embodiment can protect the connector assembly (150) from the external environment. This reduces the risk of damage to the contacts or short circuits, thereby increasing the safety of the battery assembly (100). The connector assembly cover (155) can be detachably coupled to the housing (130) through bolt coupling.

[0176] According to another embodiment of the present invention, a device including a battery assembly (100) is provided.

[0177] One or more battery assemblies (100) 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 device.

[0178] The battery assembly (100) can be applied to various devices. Specifically, it can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, but is not limited thereto and can be applied to various devices capable of using secondary batteries.

[0179] 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.

[0180] 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.

[0181] Explanation of the symbols

[0182] 100: Battery assembly

[0183] 110: Battery cell

[0184] 120: Battery cell stack

[0185] 130: Housing

[0186] 131: 1st Housing

[0187] 132: 2nd Housing

[0188] 140: Top cover assembly

[0189] 150: Connector Assembly

[0190] 160: Inlet

[0191] 170: Outlet

[0192] 180: Terminal Assembly

[0193] 200: Cooling Spacer

Claims

1. A battery cell stack comprising multiple stacked battery cells; A housing in which the above battery cell stack is housed; An inlet and an outlet for circulating refrigerant into the housing; and Includes at least one cooling spacer located at least one location among the battery cells; and The above cooling spacer is a battery assembly comprising at least one cooling hole through which the refrigerant moves.

2. In Paragraph 1, A battery assembly in which at least one of the above cooling holes is drilled along the direction of the longer side of the battery cell.

3. In Paragraph 1, The above cooling spacer is a battery assembly fixed to the housing.

4. In Paragraph 1, A battery assembly in which the cooling spacer is fixed to the housing by a fixing member.

5. In Paragraph 1, A portion of the above refrigerant flows in the space between the battery cell stack and the lower portion of the housing, in a battery assembly.

6. In Paragraph 1, The above housing has an open top surface, and A battery assembly having a top cover assembly that covers the open upper surface of the housing.

7. In Paragraph 6, The above cooling spacer is a battery assembly fixed to the above top cover assembly.

8. In Paragraph 6, A portion of the above refrigerant flows in the space between the battery cell stack and the top cover assembly.

9. In Paragraph 6, A battery assembly in which the housing and the top cover assembly are welded together.

10. In Paragraph 6, A battery assembly in which the housing and the top cover assembly are joined by friction stir welding.

11. In Paragraph 1, The above housing is, A first housing comprising side portions covering both sides of the battery cell stack and a bottom portion covering the bottom surface of the battery cell stack; and A battery assembly comprising: a second housing that covers one side of the battery cell stack and is coupled to the first housing.

12. In Paragraph 11, The first housing and the second housing are welded together to form a battery assembly.

13. In Paragraph 11, A battery assembly in which the first housing and the second housing are joined by friction stir welding.

14. In Paragraph 1, The above inlet and the above outlet are provided in the housing, and The above outlet is a battery assembly located on the side opposite to the side where the above inlet is located.

15. In Paragraph 1, A battery assembly in which a terminal assembly electrically connected to the battery cell stack is coupled to the housing.

16. In Paragraph 15, The above terminal assembly is, Terminal Bus Bar; A gasket in contact with the side of the above housing; and A bolt penetrating the terminal busbar and the gasket; A battery assembly including 17. In Paragraph 16, The terminal assembly further includes a busbar electrically connected to at least one of the battery cells, and A battery assembly in which the above bolt is coupled to the above busbar, and the above battery cell stack and the above terminal assembly are electrically connected.

18. In Paragraph 1, A connector assembly electrically connected to the battery cell stack is coupled to the housing, and The above connector assembly is, An LV (Low Voltage) connector that electrically connects the above battery cell stack and the BMS module; A connector that combines with a module connector; A printed circuit board connected to the above module connector; A gasket located between the connector assembly and the housing; and Connector assembly cover; A battery assembly including 19. A device comprising a battery assembly according to paragraph 1.

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