Battery cell assembly and battery pack containing the same

Abstract

A battery cell assembly according to one embodiment of the present invention includes a battery cell stack comprising a first battery cell stack and a second battery cell stack in which a plurality of battery cells are stacked; a frame member housing the battery cell stack; and an inlet and an outlet for circulating a refrigerant inside the frame member, wherein the refrigerant flows into the frame member through the inlet and is discharged through the outlet, and the frame member includes an intermediate plate disposed between the first battery cell stack and the second battery cell stack, the intermediate plate having at least one opening through which the refrigerant passes.

Description

Technical Field

[0001] Cross-reference of related applications This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0024297 filed on February 20, 2024 and Korean Patent Application No. 10-2025-0019169 filed on February 14, 2025, and all the contents disclosed in the documents of the Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a battery cell assembly and a battery pack including the same, and more specifically, to a battery cell assembly and a battery pack including the same, which have improved cooling efficiency and safety, suppress the displacement amount with respect to the central portion of the frame member, and simplify the fixing structure of the battery cell stack within the frame member.

Background Art

[0003] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. Accordingly, many studies have been conducted on secondary batteries that can meet various requirements.

[0004] Secondary batteries have attracted much attention not only as an energy source for mobile devices such as mobile phones, digital cameras, and laptop computers, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0005] Recently, as the need for large-capacity secondary battery structures, including their use as an energy storage source for secondary batteries, has increased, the demand for battery packs with a medium- to large-module structure, in which a plurality of battery modules in which a plurality of secondary batteries are connected in series / parallel are assembled, has been increasing.

[0006] On the other hand, when a battery pack is configured by connecting a plurality of battery cells in series / parallel, it is common to configure a battery module including at least one battery cell and add other components using at least one battery module to configure the battery pack.

[0007] The battery cells that make up such medium- and large-sized battery modules are composed of rechargeable secondary batteries, and such high-power, high-capacity secondary batteries generate a large amount of heat during the charging and discharging process. In this case, the heat from multiple battery cells can combine in a confined space, causing the temperature to rise rapidly and drastically. In other words, while high output can be obtained in battery modules with multiple battery cells stacked on top of each other and in battery packs equipped with such battery modules, it is not easy to remove the heat generated by the battery cells during charging and discharging. If heat dissipation from the battery cells is not performed properly, the battery cells will deteriorate more quickly, shortening their lifespan and increasing the risk of explosion or fire.

[0008] Furthermore, battery modules included in vehicle battery packs are often exposed to direct sunlight and subjected to high-temperature conditions such as summer or desert regions. Also, because multiple battery modules are clustered together to increase the vehicle's driving range, flames or heat generated in one battery module can easily spread to adjacent modules, ultimately leading to the battery pack itself catching fire or exploding.

[0009] Furthermore, because battery packs consist of a structure that combines multiple battery modules, they are heavy and unsuitable for mounting multiple batteries in vehicles or other means of transportation, thus requiring an improvement in energy density.

[0010] Figure 1 is a perspective view showing a conventional battery pack. Figure 2 is an exploded perspective view of the battery pack shown in Figure 1.

[0011] Referring to Figures 1 and 2, a conventional battery pack 10 includes a lower pack frame 11 on which multiple battery modules 1 are mounted, an upper pack frame 12 located above the battery modules 1, and an internal beam 13 that demarcates the positions in the battery pack 10 where the battery modules 1 are mounted.

[0012] Thus, when battery modules 1 are installed inside a battery pack 10, the energy density of the battery pack 10 decreases due to the internal beams 13 that partition the battery modules 1. Therefore, in order to meet the efficiency requirements of a device, a larger number of battery packs 10 must be installed, which presented a problem. In addition, the weight of the battery pack 10 limited the number of battery packs 10 that could be installed in a device. Consequently, in order to reduce the weight of the battery pack 10 while simultaneously increasing its energy density, it was necessary to install a larger number of battery modules 1 inside the battery pack 10.

[0013] Figure 3 is a cross-sectional view showing one of the battery modules included in the battery pack shown in Figure 2.

[0014] Referring to Figure 3, a conventional battery module 1 includes a battery cell stack 3 containing battery cells 2 stacked in a predetermined direction, and a module frame 4 that houses the battery cell stack 3. The battery cell stack 3 is fixedly positioned on a thermally conductive resin layer 5 located on the lower surface of the module frame 4. In this case, a heat sink 6 located below the bottom of the module frame 4 may be provided to cool the heat generated in the battery cell stack 3.

[0015] However, the heatsink 6 does not directly contact the battery cell stack 3 to receive heat, which has the disadvantage of not being very efficient at cooling. In particular, an air gap is formed between the bottom of the module frame 4 and the thermally conductive resin layer 5, which hinders heat transfer. Currently, there is a need for a more effective method to cool the battery module 1.

[0016] In summary, the above points indicate the need for more effective methods to improve the cooling efficiency of battery modules. [Overview of the project] [Problems that the invention aims to solve]

[0017] The problem that the present invention aims to solve is to provide a battery cell assembly and a battery pack including the same that improve cooling efficiency and thus cooling performance, suppress the amount of displacement relative to the central part of the frame member, and simplify the fixing structure of the battery cell stack within the frame member.

[0018] The problems that this invention aims to solve are not limited to those described above, and any problems not mentioned will be clearly understood by a person with ordinary skill in the art to which this invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0019] A battery cell assembly according to one embodiment of the present invention includes a battery cell stack comprising a first battery cell stack and a second battery cell stack in which a plurality of battery cells are stacked; a frame member housing the battery cell stack; and an inlet and an outlet for circulating a refrigerant inside the frame member, wherein the refrigerant flows into the frame member through the inlet and is discharged through the outlet, and the frame member includes an intermediate plate disposed between the first battery cell stack and the second battery cell stack, the intermediate plate having at least one opening through which the refrigerant passes.

[0020] Adhesive layers are formed on the front and rear surfaces of the intermediate plate, and the first battery cell stack and the second battery cell stack can be fixed inside the frame member via the adhesive layers.

[0021] First busbar assemblies are arranged on the front and rear surfaces of the first battery cell stack, and second busbar assemblies are arranged on the front and rear surfaces of the second battery cell stack, and the first and second busbar assemblies facing the intermediate plate can each be in contact with the adhesive layer.

[0022] The intermediate plate can be integrated with the frame member.

[0023] The intermediate plate may be formed at the center of the frame member.

[0024] The at least one opening may be formed at the center of the intermediate plate.

[0025] The adhesive layer is made of an insulating adhesive composition, and the adhesive composition may contain an epoxy resin or a polyurethane.

[0026] Based on the intermediate plate, the inlet and the outlet are located on opposite sides of each other, the first battery cell stack is located between the inlet and the intermediate plate, and the second battery cell stack can be located between the outlet and the intermediate plate.

[0027] The refrigerant flowing in through the inlet can pass sequentially through the first battery cell stack, the opening of the intermediate plate, and the second battery cell stack, and be discharged through the outlet.

[0028] The inlet may be located below the center with reference to the height of the battery cell stack, and the outlet may be located above the center with reference to the height of the battery cell stack.

[0029] The first battery cell stack and the second battery cell stack may be arranged along a direction perpendicular to the stacking direction of the battery cells in the first battery cell stack and the second battery cell stack.

[0030] It further includes a first sealing assembly and a second sealing assembly that respectively cover the two open sides of the frame member, the inlet may be formed in the first sealing assembly, and the outlet may be formed in the second sealing assembly.

[0031] The inlet may be located below the center with respect to the height of the first sealing assembly, and the outlet may be located above the center with respect to the height of the second sealing assembly.

[0032] The battery cell includes electrode leads protruding in both directions, and when the direction between the electrode leads is defined as the longitudinal direction, the first sealing assembly, the first battery cell stack, the intermediate plate, the second battery cell stack, and the second sealing assembly can be positioned in order along the longitudinal direction.

[0033] The refrigerant is an insulating oil, and the refrigerant can come into direct contact with the battery cell stack housed inside the frame member.

[0034] Battery packs according to other embodiments of the present invention may include the battery cell assemblies described above. [Effects of the Invention]

[0035] According to the examples, the battery cell assembly and battery pack containing the same of the present invention can improve the cooling efficiency of the battery cell assembly and the battery pack containing the same by directly cooling the battery cells with a refrigerant.

[0036] Furthermore, energy density can be increased by arranging multiple battery cell stacks along the longitudinal direction within the battery cell assembly, and the fluidity of the refrigerant can be improved by placing an intermediate plate with openings between the multiple battery cell stacks.

[0037] In addition, the intermediate plate is positioned within the frame member, effectively suppressing the amount of displacement relative to the central part of the battery cell assembly. Furthermore, the battery cell stack is fixed to the adhesive layer formed on the intermediate plate, thereby simplifying the fixing structure of the battery cell stack within the frame member.

[0038] The effects of the present invention are not limited to those described above, and any effects not mentioned herein will be clearly understood by a person with ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawing]

[0039] [Figure 1] This is a perspective view showing a conventional battery pack. [Figure 2] Figure 1 is an exploded perspective view of the battery pack. [Figure 3] This is a cross-sectional view showing one of the battery modules included in the battery pack shown in Figure 2. [Figure 4] This is a perspective view of a battery cell assembly according to one embodiment of the present invention. [Figure 5] Figure 4 is an exploded perspective view of the battery cell assembly. [Figure 6] Figure 5 is a perspective view showing the frame components included in the battery cell assembly. [Figure 7] This is a cross-sectional view along the a-a' axis in Figure 6, showing the intermediate plate located inside the frame member in Figure 5. [Figure 8] Figure 7 is a cross-sectional view showing the adhesive layer formed on one surface of the intermediate plate. [Figure 9] Figure 5 is a perspective view showing the battery cell stack, the first busbar assembly, and the second busbar assembly included in the battery cell assembly. [Figure 10] This is a plan view showing one of the battery cells included in the battery cell stack shown in Figure 9. [Figure 11] Figure 5 is a perspective view showing the first battery cell stack and the first busbar assembly included in the battery cell assembly. [Figure 12] Figure 11 is an exploded perspective view of the first battery cell stack and the first busbar assembly. [Figure 13] Figure 9 is a perspective view showing the battery cell stack, the first busbar assembly, and the second busbar assembly with additional side plates placed on them. [Figure 14]Figure 13 is an exploded perspective view showing the first and second battery cell stacks, which are contained within the battery cell stack shown separately. [Modes for carrying out the invention]

[0040] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. The present invention can be realized in a variety of different forms and is not limited to the embodiments described herein.

[0041] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and the same or similar reference numerals are used throughout the specification for identical or similar components.

[0042] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and therefore the present invention is not necessarily limited to those shown. The thicknesses are shown enlarged in the drawings to clearly represent various layers and regions. In addition, the thicknesses of some layers and regions are exaggerated in the drawings for the sake of explanation.

[0043] Furthermore, when a specification as a whole states that a certain part "includes" a certain component, this means, unless otherwise stated, that it can further include other components rather than excluding them.

[0044] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0045] The following describes a battery cell assembly 100 according to one embodiment of the present invention.

[0046] Figure 4 is a perspective view of a battery cell assembly according to one embodiment of the present invention. Figure 5 is an exploded perspective view of the battery cell assembly of Figure 4. Figure 6 is a perspective view showing the frame members included in the battery cell assembly of Figure 5. Figure 7 is a cross-sectional view along the a-a' axis of Figure 6, showing an intermediate plate located inside the frame member of Figure 5. Figure 8 is a cross-sectional view showing an adhesive layer formed on one surface of the intermediate plate of Figure 7.

[0047] Referring to Figures 4 and 5, a battery cell assembly 100 according to one embodiment of the present invention includes a battery cell stack 120 comprising a first battery cell stack 120a and a second battery cell stack 120b, a module frame 200 housing the battery cell stack 120, and an inlet 421 and an outlet 461 for circulating a coolant inside the frame member 200. The first battery cell stack 120a and the second battery cell stack 120b are formed by stacking a plurality of battery cells 110. The coolant, the inlet 421 and the outlet 461 will be described later.

[0048] Referring to Figures 4 to 6, the frame member 200 may be for protecting the battery cell stack 120 and the electrical components connected thereto from external physical shocks. The battery cell stack 120 and the electrical components connected thereto can be housed in the internal space of the frame member 200.

[0049] The structure of the frame member 200 can be diverse. According to one embodiment of the present invention, the structure of the frame member 200 may be a monoframe structure. Here, the monoframe may be a form in which the top surface, bottom surface and both sides are integrated. As an example, the monoframe can be manufactured by injection molding.

[0050] The frame member 200 may be in an open configuration on both sides. More specifically, the frame member 200 can be provided in an open configuration along the longitudinal direction of the battery cell 110. In this case, the front and rear surfaces of the battery cell stack 120 are not obstructed by the frame member 200. The front and rear surfaces of the battery cell stack 120 can be obstructed by the first and second busbar assemblies 300a, 300b, sealing assembly 400, or end plate 500, which will be described later, thereby protecting the front and rear surfaces of the battery cell stack 120 from external physical impacts and the like.

[0051] Referring to Figures 6 and 7, in the battery cell assembly 100 according to this embodiment, the frame member 200 may include an intermediate plate 201 positioned between the first battery cell stack 120a and the second battery cell stack 120b. The intermediate plate 201 has at least one opening 201h through which the refrigerant passes. The opening 201h of the intermediate plate 201 will be described later along with the refrigerant, the inlet 421 and the outlet 461.

[0052] The intermediate plate 201 can be located inside the frame member 200 between the first battery cell stack 120a and the second battery cell stack 120b. In other words, the intermediate plate 201 can partition the space between the first battery cell stack 120a and the second battery cell stack 120b inside the frame member 200. To put it another way, the intermediate plate 201 may be formed in the center of the frame member 200.

[0053] The intermediate plate 201 can be integrated with the frame member 200. In other words, the intermediate plate 201 may be integrated with the top, bottom, and both sides of the frame member 200. That is, the intermediate plate 201 can be manufactured by injection molding together with the top, bottom, and both sides of the frame member 200. For example, the frame member 200 and the intermediate plate 201 may both be made of resin material. However, the material of the frame member 200 and the intermediate plate 201 is not limited to this, and any material that has sufficient rigidity and can be manufactured by injection molding may be included in this embodiment.

[0054] As a result, in the battery cell assembly 100 according to this embodiment, the intermediate plate 201 is integrated inside the frame member 200, and there is no need to insert a separate plate to partition the space between the first battery cell stack 120a and the second battery cell stack 120b, which offers advantages such as simplified assembly and reduced costs.

[0055] In addition, in the battery cell assembly 100 according to this embodiment, the intermediate plate 201 can complement the rigidity of the central part of the frame member 200 and can suppress displacement caused by internal hydraulic pressure generated by insulating oil circulating inside the frame member 200.

[0056] In particular, since the battery cell assembly 100 according to this embodiment has a structure in which a plurality of battery cell stacks 120a and 120b are arranged along the longitudinal direction of the battery cell assembly 100, as the length of the battery cell assembly 100 becomes relatively longer, the amount of displacement in the central part of the battery cell assembly 100 may also increase relatively.

[0057] In this embodiment, the battery cell assembly 100 has a structure in which the intermediate plate 201 is integrated into the central part of the frame member 200. This eliminates the need for additional space to arrange separate components for suppressing displacement in the central part of the battery cell assembly 100, thereby suppressing the increased displacement in the central part of the battery cell assembly 100 and effectively preventing damage to components and insulating oil leakage due to increased displacement.

[0058] Furthermore, the intermediate plate 201 is manufactured to be integrated with the frame member 200 by injection molding as described above, and the intermediate plate 201 can have sufficient rigidity while also being able to provide insulation on its own.

[0059] As a result, in the battery cell assembly 100 according to this embodiment, the intermediate plate 201 is positioned between the first battery cell stack 120a and the second battery cell stack 120b, thereby ensuring electrical insulation and creepage distance between the first battery cell stack 120a and the second battery cell stack 120b, or between the first busbar assembly (300a, Figure 9) and the second busbar assembly (300b, Figure 9).

[0060] Furthermore, the battery cell assembly 100 according to this embodiment does not include separate through-holes in the intermediate plate 201 for electrical connection between the first battery cell stack 120a and the second battery cell stack 120b, and there is no electrical connection between the first battery cell stack 120a and the second battery cell stack 120b. In other words, in the battery cell assembly 100 according to this embodiment, the first battery cell stack 120a and the second battery cell stack 120b can be electrically connected to external electrical components individually. To put it another way, in the battery cell assembly 100 of this embodiment, HV connection and LV connection in the first battery cell stack 120a can be formed independently of the second battery cell stack 120b, and similarly, HV connection and LV connection in the second battery cell stack 120b can be formed independently of the first battery cell stack 120a.

[0061] However, it is not limited to this, and unlike Figures 7 and 8, such an electrical connection between the first battery cell stack 120a and the second battery cell stack 120b can be made by forming separate through-holes in the intermediate plate 201, via the through-holes.

[0062] Referring to Figures 6 to 8, in the battery cell assembly 100 according to this embodiment, adhesive layers 205 may be formed on the front and rear surfaces of the intermediate plate 201. Here, the adhesive layer 205 may be formed on the entire front and rear surfaces of the intermediate plate 201. More specifically, the adhesive layer 205 may be formed on the entire surface of the intermediate plate 201 excluding the opening 201h, which will be described later.

[0063] As an example, when the adhesive layer 205 is bonded to the first battery cell stack 120a and the second battery cell stack 120b, or when the adhesive layer 205 is bonded to the first busbar assembly 300a and the second busbar assembly 300b, the thickness of the adhesive layer 205 formed on the front and rear surfaces of the intermediate plate 201 may be 0.1T or more and 0.2T or less, or 0.1 mm or more and 0.2 mm or less.

[0064] However, the thickness of the adhesive layer 205 is not limited to this, and any thickness that can stably maintain the state in which the adhesive layer 205 is bonded to the first battery cell laminate 120a and the second battery cell laminate 120b, or the state in which the adhesive layer 205 is bonded to the first busbar assembly 300a and the second busbar assembly 300b, may be included in this embodiment.

[0065] Here, the adhesive layer 205 can consist of an insulating adhesive composition. For example, the adhesive layer 205 may consist of a composition containing epoxy resin or polyurethane (PUR, PU).

[0066] As a result, in the battery cell assembly 100 according to this embodiment, insulating adhesive layers 205 are formed on the front and rear surfaces of the intermediate plate 201, thereby additionally ensuring electrical insulation and creepage distance between the first battery cell stack 120a and the second battery cell stack 120b, or between the first busbar assembly (300a, Figure 9) and the second busbar assembly (300b, Figure 9).

[0067] Furthermore, in the battery cell assembly 100 according to this embodiment, the first battery cell stack 120a and the second battery cell stack 120b can each be fixed inside the frame member 200 via an adhesive layer 205. More specifically, as will be described later, first busbar assemblies (300a, Figure 9) may be arranged on the front and rear surfaces of the first battery cell stack 120a, and second busbar assemblies (300b, Figure 9) may be arranged on the front and rear surfaces of the second battery cell stack 120b. Here, the first busbar assemblies 300a and the second busbar assemblies 300b facing the intermediate plate 201 may each be in contact with the adhesive layer 205.

[0068] As a result, in the battery cell assembly 100 according to this embodiment, the first battery cell stack 120a and the second battery cell stack 120b can be stably fixed inside the frame member 200, and there is no need to include a separate bonding structure such as a bolting joint to fix the first battery cell stack 120a and the second battery cell stack 120b inside the frame member 200, which offers advantages such as simplified assembly and reduced costs.

[0069] Figure 9 is a perspective view showing the battery cell stack, first busbar assembly, and second busbar assembly included in the battery cell assembly of Figure 5. Figure 10 is a plan view showing one of the battery cells included in the battery cell stack of Figure 9.

[0070] Referring to Figures 4, 5, 9, and 10, the battery cell 110 is a pouch-type battery cell and may include electrode leads 130 protruding in both directions. Such a pouch-type battery cell can be formed by housing an electrode assembly in a pouch case made of a laminate sheet containing a resin layer and a metal layer, and then bonding the outer periphery of the pouch case. Such a battery cell 110 may have a rectangular sheet structure. Specifically, the battery cell 110 according to this embodiment has a structure in which two electrode leads 130 protrude from one end 114a and the other end 114b of the battery body 113, respectively. More specifically, the electrode leads 130 may protrude in opposite directions, and one of such electrode leads 130 may be a positive electrode lead and the other a negative electrode lead. In this embodiment, the direction between the electrode leads 130 protruding in both directions of the battery cell 110 is referred to as the longitudinal direction of the battery cell 110. As an example, referring to Figures 9 and 10, the direction parallel to the x-axis can be considered to correspond to the longitudinal direction of the battery cell 110.

[0071] The battery cell 110 can be manufactured by housing an electrode assembly (not shown) in the battery case 114 and then bonding both ends 114a, 114b of the battery case 114 to a connecting side portion 114c. In other words, the battery cell 110 according to one embodiment of the present invention has a total of three sealing portions, which are sealed by methods such as fusion bonding, and the remaining side portion may consist of a folding portion 115.

[0072] Such battery cells 110 may consist of multiple cells, and multiple battery cells 110 can be stacked in a manner that allows them to be electrically connected to each other to form a battery cell stack 120. The battery cell stack 120 includes a first battery cell stack 120a and a second battery cell stack 120b. In particular, the battery cells 110 can be stacked in one direction while remaining upright, with one surface of the battery body 113 of the battery cells 110 facing each other. More specifically, as shown in Figures 5, 9, and 10, the battery cells 110 can be stacked in a direction from one side of the frame member 200 to another while remaining upright, with one surface of the battery body 113 of the battery cell 110 parallel to the side surface of the frame member 200. As an example, a configuration in which multiple battery cells 110 are stacked in a direction parallel to the y-axis is shown. In this way, when multiple battery cells 110 are stacked along a direction parallel to the y-axis, the electrode leads 130 of a single battery cell 110 can protrude along the x-axis and -x-axis directions, respectively.

[0073] Multiple battery cells 110 can be stacked in one region along a direction parallel to the y-axis to form a first battery cell stack 120a, and multiple battery cells 110 can be stacked in the other region along a direction parallel to the y-axis to form a second battery cell stack 120b.

[0074] The battery case 114 generally consists of a laminated structure of a resin layer / metal thin film layer / resin layer. For example, if the surface of the battery case consists of an O(oriented)-nylon layer, when stacking multiple battery cells to form a medium-to-large battery cell assembly, it tends to slip due to external impact. Therefore, in order to prevent this and maintain a stable stacked structure of the battery cells, an adhesive member such as double-sided tape or a chemical adhesive that bonds through a chemical reaction during bonding can be attached to the surface of the battery case to form the first battery cell stack 120a and the second battery cell stack 120b.

[0075] On the other hand, the first battery cell stack 120a and the second battery cell stack 120b are positioned along a direction perpendicular to the direction in which the battery cells 110 are stacked in the first battery cell stack 120a and the second battery cell stack 120b. In other words, the first battery cell stack 120a and the second battery cell stack 120b can be positioned along the direction in which the electrode leads 130 protrude relative to the battery cell 110. That is, the first battery cell stack 120a and the second battery cell stack 120b are positioned along the longitudinal direction of the battery cell 110. For example, as shown in Figure 10, when multiple battery cells 110 are stacked along a direction parallel to the y-axis to form the first battery cell stack 120a and the second battery cell stack 120b, the first battery cell stack 120a and the second battery cell stack 120b can be positioned along a direction parallel to the x-axis.

[0076] Referring to Figures 5 and 9, the battery cell assembly 100 according to this embodiment may include a first busbar assembly 300a located on the front and rear surfaces of the first battery cell stack 120a, and a second busbar assembly 300b located on the front and rear surfaces of the second battery cell stack 120b. Specifically, the first busbar assembly 300a can be positioned in the direction in which the electrode leads 130 of the battery cells 110 contained in the first battery cell stack 120a protrude. Similarly, the second busbar assembly 300b can be positioned in the direction in which the electrode leads 130 of the battery cells 110 contained in the second battery cell stack 120b protrude. The first busbar assembly 300a and the second busbar assembly 300b may each include a busbar frame, busbars, and terminal busbars, which will be described later.

[0077] Referring to Figures 5 and 9, the battery cell assembly 100 according to this embodiment may include a sealing assembly 400. The sealing assembly 400 can be positioned on both open sides of the frame member 200 to cover the battery cell stack 120. The sealing assembly 400 located on one open side of the frame member 200 may be a first sealing assembly 410, and the sealing assembly 400 located on the other open side of the frame member 200 may be a second sealing assembly 450. In other words, the battery cell assembly 100 according to this embodiment may further include a first sealing assembly 410 and a second sealing assembly 450 that cover both open sides of the frame member 200, respectively.

[0078] The sealing assembly 400 can isolate the open sides of the frame member 200 from the external environment. Specifically, when a refrigerant is injected into the frame member 200, the sealing assembly 400 can seal the refrigerant to prevent it from leaking out.

[0079] Referring to Figures 4, 5, and 9, the battery cell assembly 100 according to this embodiment may include end plates 500. The end plates 500 can be positioned on both open sides of the frame member 200 and formed to cover the sealing assembly 400. The end plate 500 located on one open side of the frame member 200 may be the first end plate 510, and the end plate 500 located on the other open side of the frame member 200 may be the second end plate 550.

[0080] Such an end plate 500 can physically protect the battery cell stack 120 and other electrical components from external impacts.

[0081] The following describes in detail the components included in the battery cell assembly 100 of this embodiment.

[0082] Figure 11 is a perspective view showing the first battery cell stack and the first busbar assembly included in the battery cell assembly of Figure 5. Figure 12 is an exploded perspective view of the first battery cell stack and the first busbar assembly of Figure 11. Figure 13 is a perspective view showing the battery cell stack, the first busbar assembly and the second busbar assembly of Figure 9 with additional side plates. Figure 14 is an exploded perspective view showing the first battery cell stack and the second battery cell stack included in the battery cell stack of Figure 13 separated.

[0083] Referring together to Figures 5, 9, 13, and 14, as described above, the battery cell stack 120 may include a first battery cell stack 120a and a second battery cell stack 120b arranged along the longitudinal direction of the battery cells 110. Furthermore, a first busbar assembly 300a may be located on the front and rear surfaces of the first battery cell stack 120a, and a second busbar assembly 300b may be located on the front and rear surfaces of the second battery cell stack 120b.

[0084] In this case, the first battery cell stack 120a and the first busbar assembly 300a can be collectively referred to as the first subassembly 100a, and the second battery cell stack 120b and the second busbar assembly 300b can be collectively referred to as the second subassembly 100b. Specifically, in this embodiment, the battery cell assembly 100 may consist of the first subassembly 100a and the second subassembly 100b, which are electrically coupled and located inside the frame member 200, or they may be individually mounted inside the frame member 200. In other words, the battery cell assembly 100 in this embodiment corresponds to a twin model battery cell assembly having the first subassembly 100a and the second subassembly 100b.

[0085] Referring to Figures 11 and 12, the first subassembly 100a may include a first battery cell stack 120a and a first busbar assembly 300a. The first busbar assembly 300a can be positioned on the front and rear surfaces of the first battery cell stack 120a, respectively. The first busbar assembly 300a can be positioned in the direction in which the electrode leads 130 of the battery cells 110 contained in the first battery cell stack 120a protrude. A first flexible printed circuit board (350a, FPCB) may also be provided, which is electrically connected to the first busbar assembly 300a.

[0086] The first battery cell stack 120a may include a plurality of battery cells 110, at least one first cooling fin 210a located between the plurality of battery cells 110, and a first compression pad 250a provided on one side of the outermost battery cell 110.

[0087] The first cooling fins 210a can be positioned between multiple battery cells 110. For example, the first cooling fins 210a can be positioned between two battery cells 110. Specifically, one first cooling fin 210a and another adjacent first cooling fin 210a can be positioned with two battery cells 110 in between.

[0088] The first cooling fin 210a may include a first plate 211a that contacts one side of the battery cell 110. Here, the one side of the battery cell 110 may be one side of the battery body (113, Figure 10) of the battery cell 110, extending along the longitudinal direction (x-axis direction).

[0089] One surface of the first plate 211a can be in contact with one surface of a battery cell 110 that is opposite to the surface of the first plate 211a. The other surface of the first plate 211a can be in contact with one surface of another adjacent battery cell 110 that is opposite to the other surface of the first plate 211a. In this case, although not specifically shown, an adhesive member is interposed between the surface of the battery cell 110 and the first plate 211a, so that the battery cell 110 and the first plate 211a can be bonded and fixed together. For example, the adhesive member may be an insulating tape.

[0090] The upper surface (in the z-axis direction) of the first plate 211a can contact the upper surface of the frame member 200, and the lower surface of the first plate 211a can contact the lower surface of the frame member 200. As a result, the first cooling fin 210a can be fixed and positioned within the frame member 200, and as a result, the battery cell 110 bonded to the first cooling fin 210a can also be fixed and positioned within the frame member 200.

[0091] If the size of the first plate 211a is larger than the size of the battery cell 110, the upper and lower parts of the battery cell 110 can be positioned at a certain distance from the upper and lower surfaces of the frame member 200. Specifically, if the height of the first plate 211a is longer than the height of the battery cell 110, the battery cell 110 can be positioned in the center of the first plate 211a and bonded in place. In this case, the upper and lower parts of the battery cell 110 can be positioned at a certain distance from the upper and lower surfaces of the frame member 200. Here, the height of the battery cell 110 and the first plate 211a refer to the length in the z-axis direction.

[0092] The first cooling fin 210a may further include a first plate 211a and a first projection 213a protruding from one end of the first plate 211a. For example, the first cooling fin 210a may be L-shaped. Specifically, referring to Figure 9, the first cooling fin 210a may include a first plate 211a having a surface corresponding to or larger than one side of the battery cell 110, and a first projection 213a protruding from one end of the first plate 211a parallel to the stacking direction (y-axis direction) of the first battery cell stack 120a.

[0093] The first projection 213a is a region that protrudes perpendicularly to the first plate 211a and can contact at least one of the upper or lower surfaces of the frame member 200. Specifically, one surface of the first projection 213a can be positioned opposite the upper or lower surface of the battery cell 110, and the other surface of the first projection 213a can contact the lower or upper surface of the frame member 200.

[0094] For example, one surface of the first protrusion 213a is positioned opposite the lower surface of the battery cell 110, and the upper and lower surfaces of the battery cell 110 can be fixed to the first plate 211a with a certain height above the upper and lower surfaces of the frame member 200. In other words, a certain space is provided between one surface of the first protrusion 213a and the lower surface of the battery cell 110, and between the upper surface of the frame member 200 and the upper surface of the battery cell 110, allowing the refrigerant, described later, to move between these spaces. In this case, the distance between one surface of the first protrusion 213a and the lower surface of the battery cell 110 can correspond to the distance between the upper surface of the frame member 200 and the upper surface of the battery cell 110.

[0095] The other side of the first protrusion 213a can come into contact with the bottom of the frame member 200. Specifically, the other side of the first protrusion 213a can come into contact with the bottom of the frame member 200 and be bonded and fixed, thereby allowing the first cooling fin 210a to be fixed and positioned within the frame member 200.

[0096] However, the shape of the first cooling fin 210a is not limited to this drawing; it may be a flat plate shape, or any shape is possible as long as it can contact the battery cell 110 and fix the battery cell 110 in place.

[0097] The first cooling fin 210a may be made of metal. Specifically, the first cooling fin 210a may be made of a metal with high thermal conductivity. Therefore, the first cooling fin 210a can directly receive the heat generated in the battery cell 110 by the charging and discharging of the battery. When heat is generated, the heat is transferred to the first cooling fin 210a in contact with the side surface of the battery cell 110, and the battery cell 110 is cooled firstly, and the refrigerant described later can come into direct contact with the upper and lower parts of the battery cell 110 to perform secondary cooling. This makes it possible to directly cool the upper and lower regions of the battery cell, which were previously relatively difficult to cool, and improves cooling efficiency.

[0098] The first compression pad 250a can be located on the outermost edge of the first battery cell stack 120a. Such a first compression pad 250a can absorb the swelling of the battery cell 110 due to charging and discharging. Specifically, the first compression pad 250a can improve the safety of the battery cell assembly 100 by preventing the battery case (114, Figure 10) of the battery cell 110 from cracking by pushing out the side of the frame member 200 as the battery cell 110 swells.

[0099] However, the first compression pad 250a is not limited to being located only on the outermost edge of the first battery cell stack 120a, but can also be located between the battery cells 110 that make up the first battery cell stack 120a.

[0100] The first busbar assembly 300a may include a first busbar frame 310a and a first busbar 330a mounted on the first busbar frame 310a.

[0101] The first busbar frame 310a is located on one surface of the first battery cell stack 120a, covering one surface of the first battery cell stack 120a, and may also be used to guide the connection between the first battery cell stack 120a and external equipment. The first busbar frame 310a can be located on one surface and the other surface of the first battery cell stack 120a.

[0102] The first busbar 330a can be mounted on the first busbar frame 310a. Specifically, the inner surface of the first busbar frame 310a can face the first battery cell stack 120a, and the first busbar 330a can be mounted on the outer surface of the first busbar frame 310a.

[0103] The first busbar frame 310a may include an electrically insulating material. The first busbar frame 310a can restrict the first busbar 330a from contacting other parts of the battery cell 110 other than the portion joined to the electrode lead (not shown), thereby preventing an electrical short circuit from occurring.

[0104] The first busbar 330a is mounted on the outer surface of the first busbar frame 310a and may be used to electrically connect the battery cells 110 contained in the first battery cell stack 120a and to electrically connect the first battery cell stack 120a to an external equipment circuit. The first busbar 330a is located on the first busbar frame 310a, and such a first busbar assembly 300a is covered by a sealing assembly 400 and an end plate 500, which will be described later, so that it can be protected from external impacts and the reduction in durability due to external moisture can be minimized.

[0105] The first busbar 330a can be electrically connected to the first battery cell stack 120a via the electrode leads 130 of the battery cells 110. Specifically, the electrode leads 130 of the battery cells 110 pass through slits formed in the first busbar frame 310a, then bend and can be connected to the first busbar 330a. The first busbar 330a allows the battery cells 110 contained in the first battery cell stack 120a to be electrically connected in series or parallel. There are no special restrictions on the method of connection between the electrode leads 130 and the first busbar 330a; for example, welding can be applied.

[0106] The first flexible printed circuit board 350a is mounted extending in the longitudinal direction of the battery cell 110 and is configured to sense the battery cell 110. That is, as shown in Figures 11 and 12, the first flexible printed circuit board 350a is located on the upper surface of the first battery cell stack 120a and senses voltage data and thermal data of the battery cell 110. In particular, the first flexible printed circuit board 350a can be electrically connected to the first busbar 330a while bending from one end toward the first busbar frame 310a. This allows it to sense the voltage data of each battery cell 110 and transmit it to the outside.

[0107] The second subassembly 100b may include a second battery cell stack 120b and a second busbar assembly 300b, the second busbar assembly 300b may include a second busbar frame 310b and a second busbar 330b. A second flexible printed circuit board 350b connecting the second busbar assembly 300b may also be provided.

[0108] The second busbar frame 310b is located on one surface of the second battery cell stack 120b, covering one surface of the second battery cell stack 120b, and may also be used to guide the connection between the second battery cell stack 120b and external equipment. The second busbar frame 310b can be located on one surface and the other surface of the second battery cell stack 120b.

[0109] The components included in the second subassembly 100b can be of the same or similar structure as the components included in the first subassembly 100a described earlier. Therefore, in order to avoid repetition of the explanation, a detailed explanation of the components included in the second subassembly 100b will be omitted.

[0110] Referring to Figures 13 and 14, in the battery cell assembly 100 according to this embodiment, side plates 270 may be provided on both sides of the first subassembly 100a and the second subassembly 100b, respectively.

[0111] The side plate 270 may be a plate extending along the longitudinal direction of the battery cell 110. For example, the side plate 270 may be made of a rigid metal.

[0112] More specifically, the side plate 270 may include a first side plate 270a provided on both sides of the first subassembly 100a, and a second side plate 270b provided on both sides of the second subassembly 100b. Here, the length of the first side plate 270a may correspond to the length of the first subassembly 100a, and the length of the second side plate 270b may correspond to the length of the second subassembly 100b.

[0113] The first side plate 270a can be positioned opposite the outermost battery cell 110 among the battery cells 110 included in the first subassembly 100a, and the second side plate 270b can be positioned opposite the outermost battery cell 110 among the battery cells 110 included in the second subassembly 100b.

[0114] Furthermore, the first side plate 270a can be positioned opposite the first compression pad 250a included in the first subassembly 100a, and the second side plate 270b can be positioned opposite the second compression pad 250b included in the second subassembly 100b.

[0115] As a result, in the battery cell assembly 100 according to this embodiment, the side plate 270 can protect the outermost battery cells 110 and compression pads 250a and 250b of the first subassembly 100a and the second subassembly 100b when they are inserted and mounted into the frame member 200 with the intermediate plate 201 in between.

[0116] Furthermore, the battery cell assembly 100 in this embodiment is a twin model having a first battery cell stack 120a and a second battery cell stack 120b, and because the battery cell stack 120 is longer than a typical battery cell stack, it may not be easy to insert and assemble it into the frame member 200. In this case, as shown in Figures 13 and 14, the side plate 270 can guide the insertion of the battery cell stack 120 into the frame member 200, allowing the battery cell assembly to be easily assembled without damaging the battery cells 110 and compression pads 250a, 250b.

[0117] The following describes in detail the structure for circulating a coolant inside the battery cell assembly according to this embodiment.

[0118] Referring again to Figures 4, 5, and 7-9, the battery cell assembly 100 according to this embodiment includes an inlet 421 and an outlet 461 for circulating a refrigerant inside the frame member 200. The refrigerant flows into the frame member 200 through the inlet 421 and is then discharged to the outside of the battery cell assembly 100 through the outlet 461.

[0119] The refrigerant can receive heat generated from the battery cell stack 120, the first and second busbar assemblies 300a, 300b, and other electrical components housed inside the frame member 200, while in direct contact with them.

[0120] The refrigerant may be a fluid. However, since the refrigerant comes into direct contact with the battery cell stack 120, the first and second busbar assemblies 300a, 300b, and other electrical components within the battery cell assembly 100, the refrigerant needs to be electrically insulated. Therefore, the refrigerant can be made of an insulating material. For example, the refrigerant may be an insulating oil.

[0121] In other words, in this embodiment, the refrigerant can directly cool the battery cell stack 120, the first and second busbar assemblies 300a, 300b, and other electrical components that generate heat within the battery cell assembly 100, while simultaneously receiving heat. Therefore, while conventional battery modules (1, see Figure 3) indirectly cool the battery module 1 using a heat sink 6 or the like, the battery cell assembly 100 in this embodiment can improve cooling efficiency through direct cooling, thereby extending the battery life.

[0122] In this embodiment, an intermediate plate 201 is placed between the first battery cell stack 120a and the second battery cell stack 120b, and at least one opening 201h is formed in the intermediate plate 201 through which the refrigerant passes.

[0123] For example, at least one opening 201h may be formed in the center of the intermediate plate 201, and more specifically, at least one opening 201h can be formed in the shape of a rectangle, with the top and bottom edges being longer than the side edges. In other words, the opening 201h can be formed to extend along the direction in which the battery cells 110 are stacked.

[0124] More specifically, with respect to the intermediate plate 201, the inlet 421 and the outlet 461 can be located on opposite sides of each other. The first battery cell stack 120a can be located between the inlet 421 and the intermediate plate 201, and the second battery cell stack 120b can be located between the outlet 461 and the intermediate plate 201.

[0125] The refrigerant that flows in through the inlet 421 can sequentially pass through the first battery cell stack 120a, the opening 201h of the intermediate plate 201, and the second battery cell stack 120b, and be discharged through the outlet 461.

[0126] Since the first battery cell stack 120a and the second battery cell stack 120b are both contained within a single frame member 200, there is a risk of short circuits occurring due to contact between the first battery cell stack 120a and the second battery cell stack 120b, or between the first busbar assembly 300a located on the other side of the first battery cell stack 120a and the second busbar assembly 300b located on one side of the second battery cell stack 120b.

[0127] Furthermore, as described above, the battery cell assembly 100 according to this embodiment includes a first battery cell stack 120a and a second battery cell stack 120b, and has a form that extends along the longitudinal direction. When the refrigerant circulates inside the frame member 200, a section may occur between the first battery cell stack 120a and the second battery cell stack 120b where the flow of the refrigerant stagnates.

[0128] Therefore, in this embodiment, the battery cell assembly 100 has an intermediate plate 201 with an electrically insulating adhesive layer 205 formed on its front and rear surfaces placed between the first battery cell stack 120a and the second battery cell stack 120b. The intermediate plate 201 was used to ensure electrical insulation and creepage distance between the first battery cell stack 120a and the second battery cell stack 120b, or between the first busbar assembly 300a and the second busbar assembly 300b.

[0129] Furthermore, by designing the intermediate plate 201 such that an opening 201h through which the refrigerant passes is formed in the center of the intermediate plate 201, stagnation of the refrigerant flow in the space between the first battery cell stack 120a and the second battery cell stack 120b is prevented. In other words, the aim was to improve cooling performance by ensuring the flow of the refrigerant.

[0130] Referring to Figures 5 and 9, as previously described, the battery cell assembly 100 may include a first sealing assembly 410 and a second sealing assembly 450 that cover the open sides of the frame member 200, respectively. The inlet 421 may be formed in the first sealing assembly 410, and the outlet 461 may be formed in the second sealing assembly 450.

[0131] As described above, the battery cell 110 according to this embodiment is a pouch-type battery cell and may include electrode leads 130 protruding in both directions. The direction between the electrode leads 130 protruding in both directions can be called the longitudinal direction of the battery cell 110. The direction parallel to the x-axis can correspond to the longitudinal direction of the battery cell 110. Along this longitudinal direction, the first sealing assembly 410, the first battery cell stack 120a, the intermediate plate 201, the second battery cell stack 120b, and the second sealing assembly 450 can be positioned in order. In other words, the refrigerant that flows in through the inlet 421 formed in the first sealing assembly 410 can pass sequentially through the first battery cell stack 120a, the opening 201h of the intermediate plate 201, and the second battery cell stack 120b, and be discharged through the outlet 461 formed in the second sealing assembly 450.

[0132] In the battery cell assembly 100 according to this embodiment, the first busbar assembly 300a, which is electrically connected to the battery cell stack, can be located on one open side of the frame member 200, and the first sealing assembly 410 can be mounted while covering the first busbar assembly 300a. More specifically, the first sealing assembly 410 can cover the first busbar assembly 300a located on one side of the first battery cell stack 120a.

[0133] The inlet 421 can be located below the center with respect to the height of the battery cell stack 120. The inlet 421 can be located close to the lower end of the first sealing assembly 410. Specifically, the inlet 421 can be located below the center with respect to the height of the first sealing assembly 410. Here, the height of the battery cell stack 120 and the first sealing assembly 410 refers to the length in the z-axis direction in the drawing.

[0134] Combining the positions of the inlet 421 and outlet 461 described earlier, the inlet 421 can be located below the center relative to the height of the battery cell stack 120, and the outlet 461 can be located above the center relative to the height of the battery cell stack 120. In other words, the inlet 421 can be located close to the lower end of the first sealing assembly 410, and the outlet 461 can be located close to the upper end of the second sealing assembly 450.

[0135] If the inlet 421 is located above the center of the battery cell stack 120, the refrigerant will flow into the battery cell assembly 100 from a higher position, potentially causing bubbles to form inside the refrigerant. Such bubbles can hinder the cooling effect.

[0136] Furthermore, if the outlet 461 is located below the center of the battery cell stack 120, the refrigerant that flows into the battery cell assembly 100 will fill up to the height of the outlet 461 and then escape to the outside. As a result, the inside of the battery cell assembly 100 may not be filled with a sufficient amount of refrigerant, which can lead to a decrease in cooling performance.

[0137] Therefore, in order to prevent bubbles from forming in the incoming refrigerant and to ensure that the inside of the battery cell assembly 100 is completely filled with refrigerant, it is preferable that the inlet 421 is located below the center with respect to the height of the battery cell stack 120, and the outlet 461 is located above the center with respect to the height of the battery cell stack 120.

[0138] In this embodiment, terms indicating directions such as front, back, left, right, up, and down were used, but such terms are merely for the convenience of explanation and will vary depending on the position of the object being examined, the observer's position, etc.

[0139] One or more battery cell assemblies according to the embodiment described above can be mounted together with various control and protection systems such as a Battery Management System (BMS), Battery Disconnect Unit (BDU), and cooling system to form a battery pack.

[0140] The aforementioned battery cell assemblies and battery packs are applicable to a variety of devices. Specifically, they can be applied to means of transportation such as electric bicycles, electric vehicles, and hybrids, as well as to ESS (Energy Storage Systems), but the present invention is not limited thereto and is applicable to a variety of devices that can use secondary batteries.

[0141] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention. [Explanation of Symbols]

[0142] 100: Battery cell assembly 110: Battery cell 120: Battery cell stack 120a: First battery cell stack 120b: Second battery cell stack 200: Frame component 201: Intermediate plate 205: Adhesive layer 210: Cooling fins 250: Compression pad 270: Side Plate 300a: First busbar assembly 300b: Second busbar assembly 400: Ceiling Assembly 500: End plate

Claims

1. A battery cell stack including a first battery cell stack and a second battery cell stack in which multiple battery cells are stacked, A frame member that houses the aforementioned battery cell stack, The frame member includes an inlet and an outlet for circulating a refrigerant, The refrigerant flows into the interior of the frame member through the inlet and is discharged through the outlet. The frame member includes an intermediate plate disposed between the first battery cell stack and the second battery cell stack. The intermediate plate is a battery cell assembly having at least one opening through which the refrigerant passes.

2. Adhesive layers are formed on the front and rear surfaces of the intermediate plate, The battery cell assembly according to claim 1, wherein the first battery cell stack and the second battery cell stack are each fixed inside the frame member via the adhesive layer.

3. First busbar assemblies are arranged on the front and rear surfaces of the first battery cell stack, Second busbar assemblies are arranged on the front and rear surfaces of the second battery cell stack, The battery cell assembly according to claim 2, wherein the first busbar assembly and the second busbar assembly facing the intermediate plate are in contact with the adhesive layer, respectively.

4. The battery cell assembly according to claim 1, wherein the intermediate plate is integrated with the frame member.

5. The battery cell assembly according to claim 1, wherein the intermediate plate is formed in the center of the frame member.

6. The battery cell assembly according to claim 1, wherein the at least one opening is formed in the center of the intermediate plate.

7. The adhesive layer is made of an insulating adhesive composition. The battery cell assembly according to claim 2, wherein the adhesive composition comprises an epoxy resin or polyurethane.

8. With respect to the intermediate plate, the inlet and the outlet are located on opposite sides of each other. The first battery cell stack is located between the inlet and the intermediate plate. The battery cell assembly according to claim 1, wherein the second battery cell stack is located between the outlet and the intermediate plate.

9. The battery cell assembly according to claim 8, wherein the refrigerant that flows in through the inlet passes sequentially through the first battery cell stack, the opening of the intermediate plate, and the second battery cell stack, and is discharged through the outlet.

10. The inlet is located below the center, with reference to the height of the battery cell stack. The battery cell assembly according to claim 1, wherein the outlet is located above the center with respect to the height of the battery cell stack.

11. The battery cell assembly according to claim 1, wherein the first battery cell stack and the second battery cell stack are arranged along a direction perpendicular to the direction in which the battery cells in the first battery cell stack and the second battery cell stack are stacked.

12. The system further includes a first sealing assembly and a second sealing assembly that cover the open sides of the frame member, respectively. The battery cell assembly according to claim 1, wherein the inlet is formed in the first sealing assembly and the outlet is formed in the second sealing assembly.

13. The inlet is located below the center with respect to the height of the first sealing assembly, The battery cell assembly according to claim 12, wherein the outlet is located above the center with respect to the height of the second sealing assembly.

14. The aforementioned battery cell includes electrode leads protruding in both directions. The battery cell assembly according to claim 12, wherein, when the direction between the electrode leads is the longitudinal direction, the first sealing assembly, the first battery cell stack, the intermediate plate, the second battery cell stack, and the second sealing assembly are arranged in order along the longitudinal direction.

15. The refrigerant is an insulating oil, The battery cell assembly according to claim 1, wherein the refrigerant is in direct contact with the battery cell stack housed inside the frame member.

16. A battery pack comprising a battery cell assembly according to any one of claims 1 to 15.

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