Panel assembly, battery cell block including same, battery module and battery pack

Abstract

The panel assembly of the present invention is installed in a battery cell stack in which a plurality of battery cells are stacked, and is for absorbing swelling pressure of the battery cells, and includes a first panel having a first protrusion protruding in a thickness direction of the battery cells and connected to a lower end of the first protrusion to surround the first protrusion, and a second panel having a first through hole and disposed opposite the first panel, and facing inner sides of the first panel and the second panel are coupled to each other in a state in which the first protrusion is inserted into the first through hole such that an end of the first protrusion protrudes through the first through hole, and when an end of the first protrusion is pressed by swelling pressure of the battery cells, the panel assembly elastically deforms in a direction opposite to the protruding direction of the first protrusion to absorb the swelling pressure. The present invention also provides a battery cell block including the panel assembly, and a battery module including the battery cell block. The present invention also provides a battery pack including the battery module.

Description

[Technical field]

[0001] The present invention relates to a panel assembly for absorbing swelling pressure of a battery cell.

[0002] The present invention also relates to a battery cell block, a battery module, and a battery pack including the panel assembly.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0134383 dated October 18, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0004] In recent years, secondary batteries that can be charged and discharged have been widely used as energy sources for wireless mobile devices. In the case of secondary batteries used in small devices, two to three battery cells are arranged, but in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which many battery cells are electrically connected is used. In such battery modules, many battery cells are connected to each other in series or parallel to form a battery cell stack, thereby improving capacity and output.

[0005] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is formed by stacking a positive electrode, a negative electrode, and a separator. The battery cell can be repeatedly charged and discharged due to electrochemical reactions between the components. However, if the charging and discharging is repeated excessively or due to defects in the battery cell itself, the temperature inside the battery cell may abnormally increase. That is, due to the above-mentioned defects, a side reaction occurs between the active material of the electrode assembly and the electrolyte, and the temperature of the battery cell may abnormally increase. At this time, the electrolyte may be vaporized and gas may be generated due to the abnormal battery cell temperature. If an excessive amount of gas is generated by vaporizing the electrolyte, a swelling phenomenon occurs in which the battery cell swells. When swelling of a battery cell occurs, the volume expansion of the battery cell may pressurize adjacent battery cells, causing damage. Or, heat may be transferred from a high-temperature battery cell where swelling has occurred to other adjacent battery cells. If this is left unattended, it may cause a fire, explosion, or the like of the battery cell or the battery pack. Therefore, a part or device capable of absorbing the swelling of the battery cell is required.

[0006] FIG. 1 is a schematic diagram showing swelling occurring in a battery cell of a conventional battery cell stack.

[0007] Referring to FIG. 1, a battery cell stack 10 is formed by stacking a plurality of battery cells 11. Compression pads 12 may be disposed between the battery cells 11 at regular intervals. The lower diagram of FIG. 1 is a schematic diagram showing swelling occurring in a battery cell 11 of the battery cell stack 10. As shown in the figure, when the thickness of the battery cell 11 changes due to swelling, the compression pad 12 may absorb or cushion the deformation. Specifically, when the thickness of the battery cell 11 changes, the compression pad 12 elastically deforms accordingly, thereby absorbing the deformation of the battery cell 11. Such compression pads 12 may be manufactured using a polyurethane-based material.

[0008] However, the compression pad 12 described above does not support the battery cells sufficiently due to its own low rigidity, and also has the problem of being damaged when the battery cells repeatedly swell due to the swelling pressure.

[0009] Therefore, it can be said that there is a need to develop a part or device that can sufficiently absorb the swelling of the battery cell while firmly supporting the battery cell. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent Publication No. 2022-0294070 Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been devised to solve the above problems, and aims to provide a panel assembly that can effectively absorb thickness deformation and swelling pressure caused by swelling of a battery cell.

[0012] The present invention also provides a battery cell block, a battery module, and a battery pack including the above panel assembly. [Means for solving the problem]

[0013] The present invention provides a panel assembly for absorbing swelling pressure of a battery cell, which is installed in a battery cell stack in which a plurality of battery cells are stacked, and includes a first panel having at least one first protrusion protruding in a thickness direction of the battery cells and connected to a lower end of the first protrusion to surround the first protrusion, and a second panel having at least one first through hole and disposed opposite the first panel, in which facing inner surfaces of the first panel and the second panel are coupled to each other in a state in which the first protrusion is inserted into the first through hole such that a leading end of the first protrusion protrudes through the first through hole, and when a leading end of the first protrusion is pressurized due to a swelling pressure of the battery cell, the panel assembly is elastically deformed in a direction opposite to a direction in which the first protrusion protrudes, thereby absorbing the swelling pressure.

[0014] As a specific example, the first protrusion may be provided on the first panel with a size corresponding to the size of the electrode assembly housed in the battery cell, and the first through hole may be provided on the second panel corresponding to the first protrusion.

[0015] As an example, a gap may be formed between an outer circumferential surface of the first protrusion inserted into the first through hole and an inner circumferential surface of the first through hole.

[0016] As one example, the inner surface of the first protrusion may have a concave shape corresponding to the protruding shape of the first protrusion when viewed from the side opposite to the surface from which the first protrusion protrudes.

[0017] As another example, the inner surface of the first panel may have a plurality of first bonding points spaced apart from the first protrusion at a predetermined interval, and the inner surface of the second panel may have a plurality of second bonding points spaced apart from the first through hole at a predetermined interval and positioned corresponding to the positions of the first bonding points, and the opposing inner surfaces of the first and second panels may be bonded together by bonding between the corresponding first and second bonding points.

[0018] As a specific example, the first attachment point may be located on an outer corner of the first protrusion or on an inner surface of the first panel along both side edges of the first protrusion, and the second attachment point may be located on an outer corner of the first through hole or on an inner surface of the second panel along both side edges of the first through hole.

[0019] As a more specific example, the first binding sites may be spaced apart from one another, and the second binding sites may be spaced apart from one another.

[0020] As one example, the first protrusions may be provided in a plurality of locations spaced apart at a predetermined interval along the longitudinal direction and / or width direction of the first panel, and the first through holes may be provided in a plurality of locations spaced apart at a predetermined interval along the longitudinal direction and / or width direction of the second panel to correspond to the first protrusions.

[0021] As another example, the first panel further includes at least one second through hole spaced apart from the first protrusion, and the second panel further includes at least one second protrusion protruding in a thickness direction of the battery cell, having a lower end connected to the second panel and surrounded by the second panel, and spaced apart from the first through hole and disposed on the second panel. In a state in which the first protrusion and the second protrusion are inserted into the first through hole and the second through hole, respectively, such that an end of the first protrusion and an end of the second protrusion protrude through the first through hole and the second through hole, respectively, when an end of the first protrusion and an end of the second protrusion are pressurized due to a swelling pressure of the battery cell, the first protrusion and the second protrusion may elastically deform in a direction opposite to a protruding direction to absorb the swelling pressure.

[0022] As a specific example, the first protrusion and the second through hole may be provided in multiple numbers along the longitudinal direction and / or the width direction of the first panel, and the first through hole may correspond to the first protrusion, and the second protrusion may correspond to the second through hole, and the first through hole and the second protrusion may be provided in multiple numbers along the longitudinal direction and / or the width direction of the second panel.

[0023] As a more specific example, the first protrusion and the second through hole may be irregularly arranged along the longitudinal direction and / or the width direction of the first panel, and the first through hole and the second protrusion may be irregularly arranged along the longitudinal direction and / or the width direction of the second panel, such that the first through hole corresponds to the first protrusion and the second protrusion corresponds to the second through hole.

[0024] As another example, the first protrusion and the second through hole may be regularly arranged along the longitudinal direction and / or the width direction of the first panel, and the first through hole and the second protrusion may be regularly arranged along the longitudinal direction and / or the width direction of the second panel, such that the first through hole corresponds to the first protrusion and the second protrusion corresponds to the second through hole.

[0025] As a specific example, the first and second panels may be metal panels.

[0026] As another aspect of the present invention, a battery cell block may be provided that includes a battery cell stack in which a plurality of battery cells are stacked, and the panel assembly installed between the battery cells and / or on at least one side of the battery cell stack.

[0027] As another aspect of the present invention, a battery module including the above-described battery cell block can be provided.

[0028] As another aspect of the present invention, a battery pack including the above-mentioned battery module can be provided. Effect of the Invention

[0029] According to the present invention, thickness expansion or swelling pressure caused by swelling of a battery cell can be effectively absorbed. [Brief description of the drawings]

[0030] [Figure 1] 1 is a schematic diagram showing the occurrence of swelling in a battery cell of a conventional battery cell stack; [Diagram 2] 1A and 1B are schematic diagrams illustrating a first panel and a second panel according to a first embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic diagram showing how a first panel and a second panel are joined together according to the first embodiment of the present invention. [Figure 4] 1 is a side cross-sectional view of a panel assembly according to a first embodiment of the present invention. [Diagram 5] 4 is a schematic diagram illustrating a state in which the panel assembly according to the first embodiment of the present invention is elastically displaced due to swelling of a battery cell. FIG. [Figure 6] 3 is a side cross-sectional view of the panel assembly, which is a schematic illustration of a state in which the panel assembly according to the first embodiment of the present invention is elastically displaced due to swelling of a battery cell; FIG. [Figure 7] 3 is a schematic diagram showing positions at which joining points of a panel assembly according to a first embodiment of the present invention are arranged. FIG. [Figure 8] 5A and 5B are schematic diagrams illustrating a first panel and a second panel according to a modified example of the first embodiment of the present invention. [Figure 9] 10 is a schematic diagram showing a state in which a panel assembly according to a modified example of the first embodiment of the present invention is elastically displaced due to swelling of a battery cell. FIG. [Figure 10] 6A and 6B are schematic diagrams illustrating a first panel and a second panel according to a second embodiment of the present invention. [Figure 11] FIG. 11 is an enlarged view of one side end of a panel assembly according to a second embodiment of the present invention. [Figure 12]11 is a side cross-sectional view of a panel assembly according to a second embodiment of the present invention, illustrating a state in which the panel assembly is elastically displaced due to swelling of a battery cell. FIG. [Figure 13] 10A and 10B are schematic diagrams illustrating a first panel and a second panel according to a modified example of the second embodiment of the present invention. [Figure 14] FIG. 2 is a front view of a battery cell block with a panel assembly installed in the battery cell stack of the present invention. [Figure 15] FIG. 11 is a schematic diagram illustrating how a panel assembly according to a second embodiment of the present invention absorbs swelling of a battery cell within a battery cell stack. [Figure 16] 10 is an exploded perspective view of a battery module including a battery cell block in which a panel assembly according to a second embodiment of the present invention is installed. FIG. [Figure 17] 11 is a schematic diagram showing a state in which a battery module including a battery cell block having a panel assembly according to a second embodiment of the present invention is installed in a battery pack. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] The panel assembly of the present invention is installed in a battery cell stack in which a plurality of battery cells are stacked, and is for absorbing swelling pressure of the battery cells. The panel assembly includes a first panel having at least one first protrusion protruding in a thickness direction of a battery cell and connected to a lower end of the first protrusion to surround the first protrusion, and a second panel having at least one first through hole and disposed opposite the first panel, in which, in a state in which the first protrusion is inserted into the first through hole such that a tip end of the first protrusion protrudes through the first through hole, the first panel and the second panel are coupled to each other, and when a tip end of the first protrusion is pressed by a swelling pressure of the battery cell, the panel assembly is elastically deformed in a direction opposite to a protruding direction of the first protrusion to absorb the swelling pressure.

[0032] As another aspect of the present invention, a battery cell block may be provided that includes a battery cell stack in which a plurality of battery cells are stacked, and the panel assembly installed between the battery cells and / or on at least one side of the battery cell stack.

[0033] As another aspect of the present invention, a battery module including the above-described battery cell block can be provided.

[0034] As another aspect of the present invention, a battery pack including the above-mentioned battery module can be provided.

[0035] The present invention will be described in detail below. Before that, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concept of the term to best describe his own invention.

[0036] In this application, the terms "comprise" and "have" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and may be understood as not precluding the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. In addition, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only the case where it is "directly under" the other part, but also the case where there is another part in between. In addition, in this application, being "on" may include not only the case where it is located on the top, but also the case where it is located on the bottom.

[0037] The panel assembly according to the present invention is installed in a battery cell stack in which a plurality of battery cells are stacked. The battery cell stack may be formed by stacking the battery cells in a thickness direction. At this time, the panel assembly may also be stacked together with the battery cells in the thickness direction. That is, in FIG. 1, the panel assembly according to the present invention may be installed at least one of the positions where the compression pad 12 is installed.

[0038] The panel assembly of the present invention will be specifically described below with reference to the drawings.

[0039] (First embodiment) FIG. 2 is a schematic diagram showing a first panel 110 and a second panel 120 according to a first embodiment of the present invention, FIG. 3 is a schematic diagram showing how the first panel 110 and the second panel 120 according to the first embodiment of the present invention are joined together, and FIG. 4 is a side cross-sectional view of a panel assembly 100 according to the first embodiment of the present invention.

[0040] 2 and 3, the panel assembly 100 of the present invention includes a first panel 110 having at least one first protrusion 111 protruding in the thickness direction of a battery cell 11 and connected to a lower end of the first protrusion 111 to surround the first protrusion 111, and a second panel 120 having at least one first through hole 121 and arranged opposite the first panel 110.

[0041] The panel assembly of the present invention is installed in a battery cell stack to absorb the swelling pressure of the battery cells included in the battery cell stack. For this purpose, the panel assembly is provided with a displacement mechanism that can be elastically displaced in response to swelling of the battery cells. The battery cell 11 (e.g., a pouch-type battery cell) may have a rectangular shape that is long horizontally. The swelling pressure is concentrated on the wide side of the battery cell, i.e., both sides perpendicular to the thickness direction of the battery cell. Therefore, the panel assembly 100 is installed on the wide side of the battery cell in the battery cell stack.

[0042] The panel assembly 100 of the present invention includes two panels, a first panel 110 and a second panel 120. The first panel 110 and the second panel 120 may have a shape corresponding to the side shape (wide side shape) of the battery cell 11. This allows the swelling pressure transmitted from the wide side of the battery cell 11 to be effectively dispersed or absorbed.

[0043] The first panel 110 and the second panel 120 may be panels made of plastic or metal, which is an elastically deformable material. Plastic panels have the advantage of being lightweight and easy to mold. However, due to the material characteristics, there is a limit to the number of times that they can be repeatedly elastically deformed, and they are poor in durability. In particular, when thermal runaway occurs in a battery module or a battery pack, the plastic panels may melt.

[0044] Meanwhile, metal panels are advantageous in terms of durability and rigidity. Whereas the conventional compression pad 12 may be damaged by repeated swelling pressure, the metal panel is not easily damaged and can maintain its shape even when swelling pressure is repeatedly applied. In addition, the metal panel has excellent elastic deformation performance and can stably absorb swelling pressure. In particular, even if a fire occurs, the metal panel can support the battery cells without melting like the conventional compression pad 12, and can function as a flame blocking member. As a result, the panel 110, 120 or panel assembly 100 can delay or block the spread of fire to adjacent cells.

[0045] The first panel 110 and the second panel 120 made of metal can be manufactured by press molding a panel material. When manufacturing by press molding in this way, the panels 110, 120 can be manufactured in various shapes depending on the press mold. The specific press molding method is a conventionally known technique, so a detailed description will be omitted.

[0046] As a displacement mechanism, the panel assembly 100 of the present invention is provided with a protrusion that can be elastically displaced, and a space in which the protrusion can be displaced, that is, a through hole.

[0047] The protrusions and through holes are provided in the first panel 110 and the second panel 120, respectively. The first panel 110 and the second panel 120 are disposed opposite to each other, and the opposing inner surfaces are coupled to each other. A characteristic feature of the present invention is that, even though the first panel 110 and the second panel 120 are coupled to each other, the protrusions are not restricted and can elastically deform in a direction opposite to the protruding direction.

[0048] The protrusions installed on the first panel 110, i.e., the first protrusions 111, protrude in the thickness direction of the battery cell relative to the panel body. Since the swelling pressure of the battery cell mainly affects the thickness direction of the battery cell, the first protrusions 111 also protrude in the thickness direction of the battery cell. One or more first protrusions 111 may be provided on the first panel 110. For example, one may be provided with a size that can cover most of the side surfaces of the battery cell 11. However, as described later, a plurality of first protrusions 111 spaced apart from each other in the longitudinal direction or width direction of the battery cell may be provided. As long as the swelling pressure can be effectively absorbed, the number and area of ​​the first protrusions 111 are not limited. In the present embodiment, an example in which one first protrusion 111 is provided is shown. That is, one wide protrusion may be formed so that the area of ​​the first protrusion 111 can cover most of the battery cell 11. The battery cell 11 includes an electrode assembly inside a battery cell case, and the electrode assembly occupies most of the battery cell area. Therefore, the size of the first protrusion 111 can correspond to the size of the electrode assembly. That is, the single first protrusion 111 can extend on the first panel 110 in the longitudinal direction and the width direction of the first panel 110 so as to correspond to the size of the electrode assembly.

[0049] The panel body of the first panel 110 is connected to a lower end of the first protrusion 111. That is, the first protrusion 111 extends from the panel body and is capable of elastically deforming with respect to the first panel 110. The panel body has a portion surrounding the first protrusion 111 to support the first protrusion 111 during elastic deformation.

[0050] Referring to FIG. 4, the first protrusion 111 is composed of a protruding surface 111a located at the tip and an edge surface 111b connected to the protruding surface 111a at one end and connected to the first panel 110 at the other end. The protruding surface 111a is a surface that contacts a side surface of the battery cell 11 when the panel assembly 100 is installed in a battery cell stack. In addition, the inner surface of the first protrusion 111 may have a concave shape (hereinafter, a concave portion 111c) corresponding to the protruding shape of the first protrusion when viewed from the side opposite to the surface from which the first protrusion protrudes. The concave portion 111c has a shape in which one side surface in the opposite direction to the protruding direction is open. In the panel assembly 100 of the present invention, the first protrusion 111 is elastically deformed to absorb the swelling pressure of the battery cell 11. As described above, the first protrusion 111 of the present embodiment has the form of a protruding plate portion extended from the panel body. In addition, since the inner surface of the first protrusion 111 is concave to correspond to the protruding shape of the first protrusion, a space is formed on the rear surface side of the first protrusion 111. Therefore, the first protrusion 111 can be easily elastically displaced through the space on the concave side. The thickness of the panel or the first protrusion 111 (protruding plate portion) can be suitably selected to facilitate elastic displacement. Considering the energy density of the battery module or the battery pack, it is preferable to form the panel or the first protrusion 111 as thin as possible.

[0051] Further, a battery cell 11 may be disposed on the side where the recess 111c is formed, i.e., on the surface opposite to the surface where the first protrusion 111 protrudes. In this case, the expansion of the battery cell 11 can be accommodated via the recess 111c, and therefore the swelling pressure of the battery cell 11 can be absorbed.

[0052] The second panel 120 is disposed opposite to the first panel 110 and includes a first through hole 121 corresponding to the first protrusion 111. Since the first protrusion 111 of the first panel is inserted into the first through hole 121, the size and shape of the first through hole 121 correspond to the size and shape of the first protrusion 111. However, the size and shape of the first through hole 121 do not have to be completely the same as those of the first protrusion 111. Preferably, the first through hole 121 may be formed slightly larger than the first protrusion 111 so that the first protrusion 111 can be freely elastically displaced through the first through hole 121. That is, when the first protrusion 111 is inserted into the first through hole 121, a gap G may be formed between the outer circumferential surface of the first protrusion 111 and the inner circumferential surface of the first through hole 121.

[0053] Meanwhile, the second panel 120 may be made of the same material as the first panel 110 or a different material.

[0054] The first through hole 121 may be provided in at least one second panel 120. In this embodiment, since one first protrusion 111 is provided, one first through hole 121 is also provided in the second panel 120 so as to correspond to the size of the first protrusion 111.

[0055] When the first panel 110 and the second panel 120 are combined, the first protrusion 111 is inserted to protrude through the first through hole 121. That is, the first protrusion 111 is inserted into the first through hole 121 such that a tip end of the first protrusion 111 protrudes through the first through hole 121.

[0056] The present invention is characterized in that the first protrusion 111 can be freely elastically displaced even when the first panel 110 and the second panel 120 are joined together. In this case, the first through hole 121 provides a space in which the first protrusion 111 can be displaced. When the battery cell 11 installed in the battery cell stack swells due to the internal gas, the swelling pressure acts on the panel assembly 100 facing the battery cell. That is, the expanded side surface of the battery cell 11 presses the tip portion (protruding surface) of the first protrusion 111. In this case, the first protrusion 111 is elastically displaced in the direction opposite to the protruding direction of the first protrusion 111 (i.e., in the direction opposite to the protruding direction). Since a recess 111c is formed on the inner side surface of the first protrusion 111, the protruding plate portion (tip portion) having a relatively thin thickness is elastically displaced in the direction opposite to the protruding direction. At this time, the first protrusion 111 can easily deform in the direction opposite to the protruding direction without being restricted by the first through hole 121. For this reason, the size of the first through hole 121 can be made slightly larger than that of the first protrusion 111, as described above.

[0057] FIG. 5 is a schematic diagram showing a state in which the panel assembly 100 according to the first embodiment of the present invention is elastically displaced due to swelling of a battery cell, FIG. 6 is a side cross-sectional view of the panel assembly 100 showing a state in which the panel assembly 100 according to the first embodiment of the present invention is elastically displaced due to swelling of a battery cell, and FIG. 7 is a schematic diagram showing the positions at which the joining points 230, 330 of the panel assembly 100 according to the first embodiment of the present invention are located.

[0058] 5 to 7, the first panel 110 and the second panel 120 are inserted into the first through hole 121 such that the leading end of the first protrusion 111 protrudes through the first through hole 121. In this manner, in a state in which the first protrusion 111 is inserted into the first through hole 121, the opposing inner surfaces of the first panel 110 and the second panel 120 are coupled to each other. That is, the first protrusion 111 is only inserted into the first through hole 121 and is not coupled to the first through hole 121. Therefore, as shown in FIG. 5, when the leading end of the first protrusion 111 is pressed by the swelling pressure of the battery cell 11, the first protrusion 111 is elastically deformed in a direction opposite to the protruding direction to absorb the swelling pressure.

[0059] Although the first panel 110 and the second panel 120 are joined together, the elastic displacement of the first protrusion 111 provided on the first panel is not restricted.

[0060] 3 and 7, in this embodiment, the first panel 110 has a plurality of first attachment points 113 spaced apart from the first protrusion 111 on an inner side. The inner side refers to a side where the first panel 110 and the second panel 120 face each other. Similarly, the second panel 120 has a plurality of second attachment points 123 spaced apart from the first through-hole 121 on an inner side. Here, the first attachment points 113 and the second attachment points 123 may be arranged to correspond to each other. When the first attachment points 113 and the second attachment points 123 are closely arranged with the first protrusion 111 and the first through-hole 121, the elastic displacement of the first protrusion 111 may be restricted. Therefore, it is preferable that the first protrusion 111 and the first attachment points 113 are spaced apart from each other at a predetermined interval. Similarly, it is preferable that the first through-hole 121 and the second attachment points 123 are spaced apart from each other at a predetermined interval. The predetermined interval means the interval between the end of the first protrusion 111 where the first protrusion 111 and the panel body are connected and the coupling point. If this interval is too narrow, the lower edge of the first protrusion 111 is restricted by the coupling force of the coupling points (coupling parts) 113 and 123, making it difficult for the first protrusion 111 to freely deform elastically. The predetermined interval may be, for example, 1 to 5 mm. However, it is not limited thereto and may vary depending on the materials of the first panel and the second panel, the size of the battery cell, etc.

[0061] The first attachment points 113 may be spaced apart from one another. Also, the second attachment points 123 may be spaced apart from one another. Since the attachment points 113, 123 are distributed, the attachment force applied to the first panel 110 and the second panel 120 is also distributed. Therefore, the first panel 110 and the second panel 120 may be prevented from being attached to each other by an excessive attachment force. As a result, the attachment force applied to the first protrusion 111 is also weakened, and the displacement movement of the first protrusion 111 becomes freer.

[0062] Referring to FIG. 7(a), the portion indicated by the dotted line in FIG. 7(a) is the outer corner C of the first through hole 121. The first attachment point 113 may be disposed on the inner surface of the first panel 110 at the outer corner of the first protrusion 111. Also, the second attachment point 123 may be disposed on the inner surface of the second panel 120 at the outer corner C of the first through hole 121. FIG. 7(a) shows a panel assembly 100 in which the first panel 110 and the second panel 120 are attached. For convenience of illustration, only the second attachment point 123 of the second panel 120 and the outer corner C of the first through hole 121 are shown in the drawing. However, referring to FIG. 3, it can be seen that the first attachment point 113 and the second attachment point 123 are disposed to correspond to each other.

[0063] Referring to Fig. 7(b), the portion indicated by the dotted line in Fig. 7(b) indicates the edge of the first through hole. In Fig. 7(b), the first attachment point 113 (second attachment point 123) may be disposed along both left and right edges R of the first protrusion 111 (both left and right edges of the first through hole 121). That is, the first attachment point 113 may be disposed on the inner surface of the first panel 110 along both edges of the first protrusion 111. The second attachment point 123 may also be disposed on the inner surface of the second panel 120 along both edges R of the first through hole 121.

[0064] Alternatively, in FIG. 7(b), the first connecting point 113 (second connecting point 123) may be disposed along both upper and lower edges R' of the first protrusion 111 (both left and right edges of the first through hole 121).

[0065] 7, when the connection points 113, 123 are disposed along the outer corner C or both side edges R, R' of the first protrusion 111 (first through hole 121), the first panel 110 and the second panel 120 can be connected in a balanced manner, thereby improving the structural stability of the panel assembly 100.

[0066] The first and second joining points 113 and 123 may be welding points that are spot welded. Spot welding requires a short welding time, and the heating area is limited to the vicinity of the welded portion. Therefore, the first and second panels 110 and 120 are less twisted by the welding, and damage during the joining process can be minimized. In addition, the area of ​​the joining points can be minimized by spot welding, so that even when the first and second panels 110 and 120 are joined, the joining force does not reach the first protrusion 111. This ensures stable displacement movement of the first protrusion 111. Spot welding is a well-known technique, and a detailed description thereof will be omitted.

[0067] In addition, the panel assembly 100 of the present invention may have improved structural rigidity compared to the conventional compression pad 12 because the two panels 110, 120 are joined together, and therefore may provide stronger support for the battery cells compared to the conventional compression pad 12.

[0068] A specific operation process of the displacement mechanism of the present invention will be described with reference to Figures 5 and 6. When the battery cell swells, the pressure is applied to the tip of the first protrusion, i.e., the protruding surface 111a. In the illustrated example, since both longitudinal ends of the first panel 110 and the second panel 120 are fixed, only the first protrusion 111 is elastically displaced in the direction opposite to the protruding direction. That is, despite the coupling of the opposing inner surfaces of the first panel 110 and the second panel 120, the first protrusion 111 can be elastically displaced without being restricted by the first through hole 121.

[0069] Meanwhile, in the illustrated example, a gap G is formed between an outer circumferential surface, i.e., an edge surface 111b, of the first protrusion 111 inserted into the first through hole 121 and an inner circumferential surface of the first through hole 121. That is, the size of the first protrusion 111 may be slightly smaller than the size of the first through hole 121. As a result, the first protrusion 111 may be easily elastically displaced through the first through hole 121 when pressure is applied to the protruding surface 111a of the first protrusion 111.

[0070] The dotted lines in FIG. 6 show the battery cell 11 and the first panel 110 in a state where swelling does not occur. At this time, the side surface of the battery cell 11 and the protruding surface 111a of the first protrusion are in contact with each other. If swelling of the battery cell occurs in the above state, the battery cell 11 expands in the thickness direction as shown by the solid lines. In this case, the side surface of the battery cell presses the protruding surface 111a of the first protrusion. As a result, the first protrusion 111 is elastically displaced in the direction opposite to the protruding direction. In FIG. 6, the first panel 110 and the second panel 120 appear to be completely separated from each other. However, this is for convenience of illustration, and in reality, both ends of the first panel 110 and the second panel 120 are fixed as shown in FIG. 5.

[0071] Moreover, the elastically deformed first protrusion 111 has a tendency to return to its original position (the position indicated by the dotted line). That is, when the first protrusion 111 is elastically displaced, the first protrusion 111 presses the battery cell 11 in the protruding direction. This makes it possible to stably support the battery cell even when the battery cell swells.

[0072] 6, due to the elastic displacement of the first protrusion 111, a separation space S is formed between the first panel 110 and the second panel 120. The separation space S can be utilized as a cooling channel for air-cooling the panel assembly 100 and further the battery cells 11. Therefore, the panel assembly 100 of the present invention can effectively absorb swelling of the battery cells and at the same time cool the battery cells to retard heat propagation.

[0073] (Modification of the first embodiment) FIG. 8 is a schematic diagram showing a first panel 110′ and a second panel 120′ according to a modified example of the first embodiment of the present invention, and FIG. 9 is a schematic diagram showing a panel assembly according to a modified example of the first embodiment of the present invention elastically displaced due to swelling of a battery cell.

[0074] 8 and 9, the first protrusions 111 may be provided in a plurality of numbers spaced apart at predetermined intervals along the lengthwise direction and / or widthwise direction of the first panel 110'. Also, the first through holes 121 may be provided in a plurality of numbers spaced apart at predetermined intervals along the lengthwise direction and / or widthwise direction of the second panel 120' to correspond to the first protrusions 111. In the illustrated example, two first protrusions 111 and two first through holes 121 are provided.

[0075] This modified example is the same as the first embodiment in that the first protrusion 111 can be elastically displaced in the direction opposite to the protruding direction when swelling of the battery cell occurs, as shown in Fig. 9. However, it differs from the first embodiment in that two first protrusions 111 and two first through holes 121 are provided along the longitudinal direction of the first panel 110' and the second panel 120'.

[0076] 9, the area of ​​the first through-hole 121 in the second panel 120' is reduced compared to the first embodiment. Since the through-hole area is reduced, the strength of the second panel 120' is improved. As a result, the overall strength of the panel assembly can be improved. Also, since the size of the first protrusion 111 is smaller than that of the first embodiment, the first protrusion 111 can be elastically displaced even with a smaller swelling pressure.

[0077] Therefore, the panel assembly according to this modified example can more strongly support the battery cells.

[0078] In the present embodiment, an example in which two first protrusions 111 and two first through holes 121 are provided has been described, but more than two may be provided. The number of the first protrusions 111 and the first through holes 121 may be suitably determined according to the size of the battery cell and the magnitude or pressure distribution of the swelling pressure. The first protrusions 111 may have the same size and shape or may have different sizes and shapes. However, the size and shape of the first through holes 121 corresponding to the first protrusions 111 must match the size and shape of the corresponding first protrusions 111.

[0079] In addition, configurations that overlap with other embodiments can be applied directly to the panel assembly according to this modified example, and therefore detailed explanations thereof will be omitted.

[0080] Second embodiment FIG. 10 is a schematic diagram showing a first panel 210 and a second panel 220 according to a second embodiment of the present invention, FIG. 11 is an enlarged view of one end portion of a panel assembly 200 according to a second embodiment of the present invention, and FIG. 12 is a side cross-sectional view of a panel assembly showing a state in which the panel assembly 200 according to the second embodiment of the present invention is elastically displaced due to swelling of a battery cell.

[0081] 10 and 11, the first panel 210 may further include at least one second through hole 212 disposed on the first panel 210 away from the first protrusion 211. This embodiment includes an additional displacement mechanism in addition to the displacement mechanisms of the first protrusion 211 and the first through hole 212. As the additional displacement mechanism, the first panel 210 includes the second through hole 212, and the second panel 220 includes, in addition to the first through hole 221, a second protrusion 222 inserted into the second through hole 212.

[0082] At least one second protrusion 222 and one second through hole 212 may be provided. That is, one second protrusion 222 and one second through hole 212 each having a relatively large size may be provided.

[0083] In short, the first panel 210 may be provided with at least one each of the first protrusion 211 and the second through hole 212. Also, the second panel 220 may be provided with at least one each of the second protrusion 222 and the first through hole 221.

[0084] As an example, the first protrusions 211 and the second through-holes 212 may be provided in a plurality along the lengthwise direction and / or widthwise direction of the first panel 210.

[0085] In the illustrated example, a plurality of first protrusions 211 and a plurality of second through holes 212 are provided along the longitudinal direction and the width direction of the first panel 210. A plurality of the first protrusions 211 and a plurality of the second through holes 212 may be arranged along the longitudinal direction of the first panel 210. For example, in order to absorb the swelling pressure of a battery cell that is long in the longitudinal direction, the first protrusions 211 and the second through holes 212 may be arranged along the longitudinal direction. Also, a plurality of the first protrusions 211 and the second through holes 212 may be arranged along the width direction of the first panel 210.

[0086] The first protrusion 211 and the second through hole 212 do not have to be arranged in a plurality along the entire length or width of the first panel 210. That is, the first protrusion 211 and the second through hole 212 may be provided along a portion of the length or width of the first panel 210. In this case, the swelling pressure of the battery cell 11 corresponding to the portion where the first protrusion 211 and the second through hole 212 are provided may be partially relieved. When the swelling pressure of a portion of the battery cell is relieved, the gas collected in the remaining portion of the battery cell may move to the portion of the battery cell case where the swelling pressure is relieved. Therefore, even when the first protrusion 211 and the second through hole 212 are provided along a portion of the length or width of the first panel 210, the swelling pressure of the battery cell can be absorbed.

[0087] Similarly, the second protrusions 222 and first through holes 221 may be arranged in one or more locations along the longitudinal or width direction, or along both the longitudinal and width directions, of the second panel 220, corresponding to the second through holes 212 and the first protrusions 211.

[0088] Such an arrangement of the protrusions 211, 222 and the through-holes 212, 221 can absorb swelling pressure more uniformly along the length and width directions of the battery cells 11. Also, the area occupied by the through-holes 212, 221 in each panel 210, 220 can be reduced, improving the overall structural strength of the panel assembly 200. Therefore, according to the present embodiment, the battery cells can be firmly supported while effectively absorbing swelling of the battery cells.

[0089] Meanwhile, the first protrusions 211 and the second through holes 212 may be arranged in various patterns on the first panel 210. In the embodiment of Figs. 10 and 11, the first protrusions 211 and the second through holes 212 are regularly arranged along the length and width directions of the first panel 210. Also, the first through holes 221 and the second protrusions 222 are correspondingly regularly arranged along the length and width directions of the second panel 220. However, the present invention is not limited thereto, and the first through holes 221 and the second protrusions 222 may be regularly arranged in only one of the length and width directions.

[0090] Similar to the first protruding portion 211, the second protruding portion 222 has a lower end connected to the panel body of the second panel 220 and is surrounded by the panel body. Therefore, the second protruding portion 222 is supported by the panel body of the second panel 220 and can be elastically deformed.

[0091] The first protrusion 211 is disposed on the first panel 210 and spaced apart from the second through-hole 212 .

[0092] Correspondingly, the second protrusion 222 is disposed on the second panel 220 away from the first through-hole 221 .

[0093] At this time, the first panel 210 and the second panel 220 are joined together in a state in which the protrusions 211, 222 are inserted into the through holes 221, 212 of the other panel.

[0094] As described above, since the plurality of protrusions 211, 222 are inserted into the corresponding through holes 221, 212, respectively, the first panel 210 and the second panel 220 can be joined at a fixed position. Also, each of the through holes 221, 212 is surrounded by the first panel 210 and the second panel 220. Therefore, compared to the first embodiment in which one through hole is formed large, the structural strength of the panel assembly 200 can be improved. Therefore, not only can the swelling pressure of the battery cell 11 be absorbed, but the battery cell can also be effectively protected from external impact.

[0095] 11 and 12, the first protrusion 211 and the second protrusion 222 are inserted into the first through hole 221 and the second through hole 212, respectively, such that the leading end of the first protrusion 211 and the leading end of the second protrusion 222 protrude through the first through hole 221 and the second through hole 212, respectively. In this manner, in a state in which the protrusions 211, 222 are inserted into the corresponding through holes 221, 212, when the leading end of the first protrusion 211 and the leading end of the second protrusion 222 are pressurized by the swelling pressure of the battery cell, the first protrusion 211 and the second protrusion 222 are elastically deformed in a direction opposite to the protruding direction to absorb the swelling pressure. That is, in a state where the protrusions 211, 222 are inserted into the corresponding through holes 221, 212, the movement of the protrusions 211, 222 is not restricted by the through holes 221, 212, which is the same as in the first embodiment.

[0096] 11 and 12, protrusions 211 and 222 are provided on both sides of the panel assembly 200 facing the sides of the battery cells. Therefore, the panel assembly 200 according to the present embodiment can more effectively absorb swelling that occurs in the battery cells arranged on both sides of the panel assembly 200. Also, recesses 222c are formed on the sides opposite to the protruding directions of the protrusions 211 and 222. Therefore, when swelling occurs simultaneously in the battery cells on both sides of the panel assembly 200, the swelling can be more efficiently absorbed through the elastic displacement of the protrusions 211 and 222 and the space of the recesses 222c.

[0097] In addition, configurations that overlap with other embodiments may be applied to the panel assembly 200 according to this embodiment as they are, and therefore detailed descriptions thereof will be omitted.

[0098] (Modification of the second embodiment) FIG. 13 is a schematic diagram showing a first panel 210' and a second panel 220' according to a modified example of the second embodiment of the present invention.

[0099] In this modified example, the first protrusions 211 and the second through holes 212 are irregularly arranged along the longitudinal and width directions of the first panel 210'. However, the present invention is not limited thereto, and the first through holes 221 and the second through holes 212 may be irregularly arranged along the longitudinal or width directions of the first panel 210'. In this case, the position of the first through hole 221 in the second panel 220' corresponds to the position of the first protrusion 211, and the position of the second protrusion 222 corresponds to the position of the second through hole 212, which is the same as the second embodiment.

[0100] As described above, the protrusions 211, 222 and the through holes 221, 212 may be irregularly arranged to design a panel assembly having various patterns. For example, the protrusions 211, 222 may be concentrated in a portion of the battery cell where gas is particularly generated. Therefore, this modified example can deal with the swelling phenomenon of the battery cell in various environments and conditions.

[0101] In addition, configurations that overlap with other embodiments may be applied to the panel assembly according to this embodiment as they are, and therefore detailed descriptions thereof will be omitted.

[0102] Third embodiment FIG. 14 is a front view of battery cell blocks 1000, 1000' in which panel assemblies 100, 200 are installed in battery cell stacks 300, 300' of the present invention, FIG. 15 is a schematic diagram showing how a panel assembly 200 according to the second embodiment of the present invention absorbs swelling of battery cells within the battery cell stack 300', FIG. 16 is an exploded perspective view of a battery module 2000 including a battery cell block 1000' in which a panel assembly 200 according to the second embodiment of the present invention is installed, and FIG. 17 is a schematic diagram showing how the battery module 2000 is installed in a battery pack 3000.

[0103] FIG. 14(a) shows a state where the panel assembly according to the first embodiment or its modified example is installed in a battery cell stack 300. FIG. 14(b) shows a state where the panel assembly according to the second embodiment or its modified example is installed in a battery cell stack 300'. As shown in the figure, a plurality of battery cells 11 are stacked to form a battery cell stack, and a panel assembly according to the present invention is installed between the battery cells 11 and on both sides of the battery cell stack to form a battery cell block. The panel assembly may be installed at a position where it can absorb the swelling pressure of the battery cells 11. Thus, it may be installed between the battery cells 11 stacked in the battery cell stack. Alternatively, it may be installed on one or both sides of the battery cell stack 300, 300'. In this embodiment, the panel assembly is installed between the battery cells and on both sides of the battery cell stack to stably absorb the swelling pressure of the battery cell stack.

[0104] When the panel assembly is disposed on the side of the battery cell block 1000, 1000', it can absorb external impacts and protect the battery cell stack 300, 300'. Also, the panel assembly 100, 200 according to the present invention can be installed together with a conventional compression pad 12. In this case, swelling of the battery cells can be absorbed more effectively.

[0105] Referring to FIG. 15, even if swelling occurs in the battery cell stack, the swelling can be effectively absorbed by the panel assembly 200 of the present invention.

[0106] Fig. 16 shows a battery module including the battery cell block having the panel assembly of the present invention. That is, a battery module can be configured by storing the battery cell block inside a module housing. Here, the module housing can be configured in a rectangular prism shape surrounding the four sides, top, bottom, left and right, of the battery cell stack, as in a normal battery module. Alternatively, as in the example of Fig. 16, the module housing can be configured in a so-called moduleless structure in which at least some of the top, bottom, left and right sides of the battery cell stack are open.

[0107] In FIG. 16, the upper and lower portions of the battery cell stack are open, and plates 2100 and 2200 are provided along the side edges of the battery cell stack. The module-less battery module 2000 of FIG. 16 includes an end plate 2100 disposed on the side where the lead 11a of the battery cell stack protrudes, and a side plate 2200 disposed on both sides of the battery cell stack. The module-less battery module 2000 can reduce the overall volume and weight of the battery module by reducing the number of parts of the module housing. In the illustrated example, the panel assembly 200 according to the second embodiment is disposed on the battery cell stack, but the panel assembly 100 according to the first embodiment can be disposed thereon. Alternatively, the panel assembly 100 according to the first embodiment can be disposed on both sides of the battery cell stack, and the panel assembly 200 according to the second embodiment can be disposed between the battery cells.

[0108] FIG. 17 discloses a battery pack 3000 including the battery module 2000. The battery pack may include a base plate 3100 on which the battery module is installed, and a pack side wall plate 3200 surrounding an edge of the base plate. The battery pack 3000 may further include a center frame 3300 crossing the center of the base plate. The battery modules are accommodated in two rows based on the center frame 3300. The battery pack 3000 may further include a partition member disposed perpendicular to the center frame 3300 and partitioning the accommodation space of the battery module. In the illustrated example, the battery module 2000 with the upper and lower surfaces of the battery cell stack open is installed in the battery pack 3000. At this time, the side plate 2200 of the battery module 2000 may replace the partition member 3400 of the battery pack. In this case, the overall weight of the battery pack is reduced, the space occupied by the internal components is reduced, and more battery cells can be mounted. Therefore, in this case, the energy density of the battery pack may be further improved. In addition, a thermally conductive resin layer 3500 may be installed between the base plate 3100 and the open lower surface of the battery cell stack. The thermally conductive resin layer 3500 may be in direct contact with the battery cell stack to improve cooling efficiency.

[0109] (Experimental Example) In order for the panel assemblies 100 and 200 to absorb the swelling of the battery cells, the thickness of each panel 110, 120, 210, and 220 must be appropriately selected. If the panel thickness is too thick, the deformation of the panel is restricted and the protrusions do not elastically displace.

[0110] Table 1 below shows the results of evaluating the degree to which the battery cell absorbs swelling when the thickness of the panels 210, 220 and the protruding lengths of the protruding parts 211, 222 of the second embodiment are changed.

[0111] [Table 1] Experimental example 1 Experimental example 2 Experimental example 3 Experimental example 4 Thickness of the first and second panels (A) (mm) 1.5 1 0.75 0.5 Length of the first protrusion and the second protrusion (B) (mm) 2.5 2 2.5 1.5 Panel assembly thickness (C) (mm) 5.0 4.0 5.0 3.0 Maximum compression thickness (D) 4.0 3.0 3.25 2.0 Maximum compression ratio 20% 25% 35% 33%

[0112] In this experimental example, the thicknesses of the first panel 210 and the second panel 220, and the protruding lengths of the first protruding portion 211 and the second protruding portion 222 were set to be the same.

[0113] 12 and Table 1, the panel thickness A is the thickness of the panel body of the first panel 210 or the panel body of the second panel 220. In addition, the protruding length B is the length that the first protruding portion 211 protrudes from the panel body of the first panel 210 or the length that the second protruding portion 222 protrudes from the panel body of the second panel 220.

[0114] The thickness C of the panel assembly 100 refers to the thickness of the panel assembly 200 before swelling of the battery cells. That is, it refers to the thickness of the panel assembly in a state where the panel assembly 200 is not pressurized due to swelling of the battery cells. In this case, the thickness C is the maximum thickness of the panel assembly 200 in a state where the first protrusion 211 is inserted into the first through-hole 221 and the second protrusion 222 is inserted into the second through-hole 212.

[0115] The thickness D at maximum compression is the minimum thickness measured at the point where the protrusions 211 and 222 protruding from both sides of the panel assembly are no longer elastically displaced when pressure is applied to the protrusions. Therefore, the degree to which the panel assembly 200 absorbs swelling can be evaluated as the ratio of the thickness C of the panel assembly to the thickness D at maximum compression. That is, an experimental example having a large maximum compression ratio, which is the ratio of the thickness C of the panel assembly to the thickness D at maximum compression, can be evaluated as having a better swelling absorption ability than other experimental examples.

[0116] As shown in Table 1, it was confirmed that the thickness of the panel assembly was reduced by elastically displacing the protrusion in the direction opposite to the protruding direction in all experimental examples. Therefore, even if the thickness of the panel is changed, there is only a difference in degree, and the panel assembly according to the present invention can effectively absorb the swelling of the battery cell.

[0117] When comparing the panel thickness A and maximum compression ratio of each experimental example in Table 1, when the panel thickness A was less than 1 mm (Experimental Examples 3 and 4), the maximum compression ratio was higher than when the panel thickness A was 1 mm or more (Experimental Examples 1 and 2). In other words, a smaller panel thickness A can be more advantageous in absorbing swelling.

[0118] When referring to Table 1 above, the thickness of the panel of the present invention may be preferably 1 mm or less. More preferably, the thickness of the panel may be 0.75 mm or less and 0.5 mm or more. Even more preferably, the thickness of the panel may be 0.75 mm.

[0119] The above description is merely illustrative of the technical idea of ​​the present invention, and various modifications and variations are possible within the scope of the essential characteristics of the present invention if one has ordinary knowledge in the technical field to which the present invention belongs. Therefore, the drawings disclosed in the present invention are for the purpose of explanation, not for the purpose of limiting the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such drawings. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

[0120] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious that these terms are used for convenience of explanation and may change depending on the position of the object of interest, the position of the observer, etc. [Explanation of symbols]

[0121] 10: Conventional battery cell stack 11: Battery cell 11a: Lead 12: Compression pad 100, 100', 200, 200': Panel Assembly 110, 210: First panel 120, 220: 2nd panel 111, 211: 1st protrusion 111a:Protruding surface 111b:Edge surface 111c: Recess 113, 123, 230, 330: Joining point (joining part) 121, 221: First through hole 212: Second through hole 222:Second protrusion 222c: Recess 300, 300': Battery cell stack 1000, 1000': Battery cell block 2000: Battery module 2100: End plate 2200: Side plate 3000: Battery pack 3100: Base plate 3200: Pack side wall plate 3300: Center frame 3400: Partition wall material 3500: Thermally conductive resin layer

Claims

1. A panel assembly that is installed in a battery cell stack in which a plurality of battery cells are stacked, and absorbs swelling pressure of the battery cells, a first panel including at least one first protruding portion protruding in a thickness direction of the battery cell, the first panel being connected to a lower end of the first protruding portion and surrounding the first protruding portion; a second panel having at least one first through hole and disposed opposite the first panel; and in a state in which the first protrusion is inserted into the first through hole such that a tip end of the first protrusion protrudes through the first through hole, the first panel and the second panel are coupled to each other on opposing inner surfaces thereof, When a tip end of the first protrusion is pressed by a swelling pressure of the battery cell, the first protrusion is elastically deformed in a direction opposite to a protruding direction to absorb the swelling pressure.

2. The panel assembly of claim 1 , wherein the first panel and the second panel have a shape corresponding to a side shape of the battery cell.

3. the first protrusion is provided on the first panel and has a size corresponding to a size of an electrode assembly accommodated in the battery cell; The panel assembly according to claim 1 , wherein the first through hole is also provided in the second panel so as to correspond to the first protrusion.

4. The panel assembly according to claim 1 , wherein the first protrusion is elastically displaceable without being restricted by the first through hole, despite the joining of the opposing inner surfaces of the first panel and the second panel.

5. The panel assembly of claim 4 , wherein a gap is formed between an outer circumferential surface of the first protrusion inserted into the first through hole and an inner circumferential surface of the first through hole.

6. The panel assembly according to claim 1 , wherein an inner surface of the first protrusion has a concave shape corresponding to a protruding shape of the first protrusion when viewed from a side opposite to a surface from which the first protrusion protrudes.

7. The first panel has an inner surface provided with a plurality of first connection points spaced apart from the first protrusion at a predetermined interval, a plurality of second connecting points are provided on an inner surface of the second panel, the second connecting points being spaced apart from the first through holes by a predetermined distance and arranged corresponding to the positions of the first connecting points; 2. The panel assembly of claim 1, wherein opposing interior surfaces of the first and second panels are joined by bonds between corresponding first and second bond points.

8. the first connecting point is disposed on an outer side of a corner of the first protrusion or on an inner surface of the first panel along both side edges of the first protrusion; The panel assembly of claim 7 , wherein the second connection point is disposed on an inner surface of the second panel along an outer corner of the first through hole or along both side edges of the first through hole.

9. the first bonding points are spaced apart from one another, The panel assembly of claim 7 , wherein the plurality of second bonding points are spaced apart from one another.

10. The panel assembly of claim 7 , wherein the first and second bonding points are spot welded welds.

11. The first protrusions are provided in a plurality of positions spaced apart from each other at predetermined intervals along at least one of a longitudinal direction and a width direction of the first panel, The panel assembly of claim 1 , wherein the first through holes are provided in a plurality of positions spaced apart at predetermined intervals along at least one of a lengthwise direction and a widthwise direction of the second panel to correspond to the first protrusions.

12. the first panel further includes at least one second through hole disposed on the first panel spaced apart from the first protrusion; the second panel further includes at least one second protrusion protruding in a thickness direction of the battery cell, a lower end of which is connected to the second panel and surrounded by the second panel, and a spaced apart from the first through hole and disposed on the second panel; 2. The panel assembly of claim 1, wherein when the first protrusion and the second protrusion are inserted into the first through hole and the second through hole, respectively, such that a tip end of the first protrusion and a tip end of the second protrusion protrude through the first through hole and the second through hole, respectively, and when the tip end of the first protrusion and the tip end of the second protrusion are pressurized by a swelling pressure of the battery cell, the first protrusion and the second protrusion are elastically deformed in a direction opposite to a protruding direction to absorb the swelling pressure.

13. The first protrusions and the second through holes are each provided in a plurality along at least one of a longitudinal direction and a width direction of the first panel, 13. The panel assembly of claim 12, wherein the first through hole corresponds to the first protrusion, and the second protrusion corresponds to the second through hole, and the first through hole and the second protrusion are each provided in a plurality along at least one of the longitudinal direction and the width direction of the second panel.

14. the first protrusions and the second through holes are irregularly arranged along at least one of a longitudinal direction and a width direction of the first panel; 14. The panel assembly of claim 13, wherein the first through holes and second protrusions are irregularly positioned along at least one of a length and a width of the second panel such that the first through holes correspond to the first protrusions and the second protrusions correspond to the second through holes.

15. the first protrusions and the second through holes are regularly arranged along at least one of a longitudinal direction and a width direction of the first panel; 14. The panel assembly of claim 13, wherein the first through holes and the second protrusions are regularly arranged along at least one of the length direction and the width direction of the second panel, such that the first through holes correspond to the first protrusions and the second protrusions correspond to the second through holes.

16. The panel assembly of claim 1 , wherein the first and second panels are metal panels.

17. a battery cell stack in which a plurality of battery cells are stacked; and a panel assembly according to any one of claims 1 to 16 disposed between the battery cells and on at least one of the sides of the battery cell stack.

18. A battery module comprising the battery cell block according to claim 17.

19. A battery pack comprising the battery module according to claim 18.

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