Battery module

Abstract

Provided is a battery module. The battery module may include: a battery cell; a side plate on one side of the battery cells; and an end plate connected to the side plate. The end plate may include a body. The battery module may also include an end cap on a side of the body facing the battery cells. At least a portion of the end cap includes a flexible material, and the end cap is configured to disperse a pressure applied to the end plate.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0117641 filed in the Korean Intellectual Property Office on September 5, 2023, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] One or more embodiments relate to a battery module. Background Art

[0003] A secondary battery is a battery designed to be able to charge and discharge, and can be used as an energy source for mobile devices, electric vehicles, hybrid vehicles, electric bicycles, and uninterruptible power supplies. Depending on the type of external device to which the secondary battery is applied, the secondary battery can be used in the form of a single battery cell, or in the form of a module or group in which a plurality of battery cells are connected and bundled into one unit.

[0004] As applications using secondary batteries increasingly require larger capacities, battery cells are gradually becoming larger to increase energy density. As the number and size of battery cells included in a battery module increase, the overall size and weight of the battery module are also increasing. In the process of manufacturing a battery module, multiple battery cells are compressed in the length direction. In this case, because the thickness of the battery cell is greater than the actual design value, there is a problem of excessive pressure concentrated in the center when the battery cell is pressed against the end plate. In addition, since the end plate is made of a material with high hardness (or rigidity), the battery cell expands and shear force is applied to the connection between the end plate and the side plate, which may cause durability problems for the battery module. This problem is a factor that deteriorates the reliability of the battery module as the number of battery cells increases and their size increases.

[0005] The above-mentioned related technologies are technical information owned by the inventor for deriving the present invention, or technical information acquired in the process of deriving the present invention, and may not necessarily be known technologies disclosed to the general public before applying for the present invention. Summary of the invention

[0006] One or more embodiments are directed to a battery module having durability and reliability by dispersing pressure applied to an end plate due to deformation or expansion of a battery cell.

[0007] However, the above-described battery module is illustrative, and the problem that the present disclosure seeks to solve is not limited thereto.

[0008] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments of the disclosure.

[0009] According to one or more embodiments, a battery module may include: a battery cell; a side plate on one side of the battery cell; and an end plate connected to the side plate. The end plate may include a body. The battery module may further include an end cap on a side of the body facing the battery cell. At least a portion of the end cap includes a flexible material, and the end cap is configured to disperse pressure applied to the end plate.

[0010] The end cap may be configured to be deformed into a shape corresponding to the battery cell closest to the end plate.

[0011] The center of the end cap may be configured to deform to become concave in response to one or more battery cells deforming or expanding.

[0012] The thickness of the end cap may gradually decrease in a direction from the end portion toward the center of the end cap.

[0013] A side of the body facing the end cover may include a connection groove, and a side of the end cover facing the body may include a connection protrusion in the connection groove.

[0014] The cross-sectional area of ​​the connecting groove may gradually increase from one side to the other side of the main body.

[0015] The connection groove may include an inclined surface inclined outwardly from one surface of the body toward the other surface of the body.

[0016] The inclined surface may include two inclined surfaces spaced apart in a width direction of the body. The connecting groove may include an opening in a surface of the body and a bottom surface opposing the opening and connecting the two inclined surfaces to each other.

[0017] The connection groove may include a corner portion between the two inclined surfaces and the bottom surface, and at least a portion of the corner portion may be curved.

[0018] The body may include two or more apertures, and the connection groove may be spaced apart from the apertures in a width direction of the body.

[0019] The central axis of the connecting groove may not overlap with the aperture.

[0020] The connection groove may extend in a height direction of the battery module and may include two or more connection grooves spaced apart in one direction, and the connection protrusion may include two or more connection protrusions corresponding to the connection grooves.

[0021] An inner surface of the end cover facing the battery cell may include a flexible material, and the main body may include a more rigid material than the end cover.

[0022] The body and the end caps may be formed by insert molding.

[0023] The end cover may include: a first guide protruding at an edge of the end cover and toward the battery cell; and a second guide extending from a lower portion of the first guide. The connection protrusion, the first guide, and the second guide may be integral and may include the same material.

[0024] The first guide may include a pair of first guides on both sides of the end cover in one direction, and the second guide may include a pair of second guides extending from lower ends of the pair of first guides along a lower edge of the end cover.

[0025] The end cap may further include a slit between the pair of second guide members.

[0026] A portion of one surface of the end cap facing the battery cell may be curved.

[0027] The end cap may have a concave center.

[0028]

[0013] Further aspects, features and advantages in addition to those described above will become apparent from the accompanying detailed description, claims and drawings for implementing the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above aspects and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which: Figure 1 shows a perspective view of a battery module; Figure 2 shows an exploded perspective view of a battery module; Figure 3 An exploded perspective view of the end plate is shown; Figure 4 A cross section of the end plate is shown; Figure 5 A perspective view of the end plate is shown; Figure 6 An enlarged portion of the end plate is shown; Figure 7 shows the pressure distribution on the end plate of a conventional battery module; Figure 8 shows the state before the battery cell in the battery module expands; Fig. 9 shows the pressure distribution on the end plates of the battery module; and Fig.10 A cross section of a battery module is shown. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to embodiments, examples of which are shown in the accompanying drawings, in which like reference numerals refer to like elements throughout. In this regard, the embodiments provided may have different forms and should not be construed as being limited to the descriptions set forth herein. Therefore, the embodiments are described below only by reference to the accompanying drawings to explain aspects of this specification. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. If a statement such as "at least one (of ...)" is placed after a column of elements, the entire column of elements is modified without modifying the individual elements of the column.

[0031] By referring to the detailed description and the accompanying drawings of the embodiments, some embodiments of the present disclosure and the methods according to some embodiments of the present disclosure can be understood. The described embodiments may have various modifications and may be implemented in different forms, and are not limited to the embodiments described herein. In addition, some features or all features of the various embodiments of the present disclosure may be combined with each other. Each embodiment may be implemented independently or in relation to each other. The described embodiments are provided as examples to ensure that the present disclosure is complete, and are also intended to fully convey the concept of the present disclosure to those skilled in the art. The present disclosure is subject to all modifications, equivalents and alternatives within the spirit and technical scope of the present invention. Therefore, processes, elements and techniques that are not necessary for those skilled in the art to fully understand the embodiments of the present disclosure may not be described.

[0032] Unless otherwise specified, throughout the drawings and the specification, the same reference numerals, letters or combinations thereof denote the same components, and thus descriptions already given are omitted. In addition, in order to clearly explain the present invention, parts irrelevant to the description have been omitted.

[0033] The relative sizes of elements, layers, and regions in the drawings may be exaggerated for clarity. The use of hatching and / or shading in the drawings is generally used to make the boundaries between adjacent elements clear. As such, unless otherwise specified, the presence or absence of cross-hatching or shading does not convey or indicate any preference or requirement for a particular material, material property, size, ratio, commonality between the illustrated elements, and / or any other characteristic, attribute, property, etc. of an element.

[0034] Here, various embodiments are described with reference to schematically illustrated embodiments and / or cross-sectional examples as intermediate structures. Therefore, the appearance of the drawings may change, for example, due to manufacturing techniques and / or tolerances. In addition, in order to explain the embodiments of the concepts according to the present invention, the description of the specific structures or functions disclosed in this specification is only an example. Therefore, the embodiments disclosed in this specification should not be interpreted as being limited to the shape of the regions shown, and include changes in shape caused, for example, by manufacturing.

[0035] The regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of a region of a device, and are not intended to limit the actual shape of a region of a device. In addition, as will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure.

[0036] Many specific details are set forth in the specification to provide a thorough understanding of various embodiments. However, various embodiments may be practiced without or including one or more of these specific details. In other instances, well-known structures and devices are shown in block diagram form to avoid unnecessarily obscuring various embodiments.

[0037] In order to describe the relationship between one element or feature shown in the drawings and another element or feature, spatial relative terms such as "below", "above", "lower", and "upper" may be used herein for ease of description. In addition to the orientation shown in the drawings, spatial relative terms are also intended to include different orientations of the device in use or operation. For example, when the device in the drawings is turned over, the element described as "below" or "bottom" of other elements or features will be oriented to be "above" the other elements or features. Therefore, as illustrative terms, "downward" and "down" can include both upward and downward directions. The device can be oriented in different directions (for example, rotated 90 degrees or in other directions), and the spatial relative descriptions used herein should be interpreted accordingly. Similarly, when a first part is described as being arranged "above" a second part, this may mean that the first part is arranged above or below the second part.

[0038] In addition, the expression "viewed from the top" means viewing the object portion from above, and the expression "in a schematic cross-sectional view" means when a schematic cross-section is taken by vertically cutting the object portion. The term "viewed from the side" means that the first object can be above, below or on the side of the second object, and vice versa. In addition, the term "superimposed" may include stacking, lamination, facing, extending, covering or partially covering, or any other suitable term that a person of ordinary skill in the art will understand. The expression "non-superimposed" may include meanings such as "away from" or "separated from..." and any other suitable equivalents recognized and understood by those skilled in the art. The term "facing" may mean that the first object may directly or indirectly face the second object. When there is a third object between the first object and the second object, the first object and the second object face each other, but can be understood as being indirectly relative to each other.

[0039] When an element, layer, region, or component is referred to as being "formed," "connected," or "bonded" to another element, layer, region, or component, the element, layer, region, or component may be directly formed on, directly connected to, or directly bonded to, another element, layer, region, or component, or may be indirectly formed on, indirectly connected to, or indirectly bonded to, another element, layer, region, or component. In addition, this may collectively refer to a direct or indirect combination or connection of elements, layers, regions, or components and an integral or non-integrated combination or connection of elements, layers, regions, or components, such that one or more elements, layers, regions, or components may be present. For example, when an element, layer, region, or component is referred to as being "electrically connected" or "electrically bonded" to another element, layer, region, or component, the element, layer, region, or component may be directly electrically connected or directly bonded to the other element, layer, region, or component, or other elements, layers, regions, or components may be present. However, "direct connection" or "direct combination" means that one component is directly connected or combined with another component without an intervening component, or directly on another component. In addition, in this specification, when a part of a layer, film, region, guide plate, etc. is formed in another part, the formation direction is not limited to the upper direction, and includes the part being formed on the side or lower part. On the contrary, when a part of a layer, film, region, guide plate, etc. is formed "below" another part, this includes the case where another part exists between the part and the other part and the case where the part is "immediately below" the other part. In addition, other expressions describing the relationship between components, such as "between...", "directly between...", "adjacent to..." and "directly adjacent to...", can be similarly interpreted. In addition, when an element or layer is referred to as "between" two elements or layers, it can be the only element between the two elements or layers, or other elements can be present between the two elements or layers.

[0040] For the purpose of this specification, expressions such as "at least one (kind / person) or more (kind / person)" or "any one (kind / person)" do not limit the order of the individual elements. For example, "at least one (kind / person) of X, Y and Z", "at least one (kind / person) of X, Y or Z", "at least one (kind / person) selected from the group consisting of X, Y and Z" may include only X, only Y, only Z, or any combination of two or more of X, Y and Z. Similarly, expressions such as "at least one (kind / person) of A and B" and "at least one (kind / person) of A or B" may include A, B, or A and B. As used herein, the term "and / or" generally includes any combination of one or more of the relevant listed items. For example, expressions such as "A and / or B" may include A, B, or A and B.

[0041] Terms such as "first", "second", "third", etc. may be used herein to describe various elements, components, regions, layers and / or sections, but these elements, components, regions, layers and / or sections are not limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Therefore, without departing from the spirit and scope of the present invention, the first element, first component, first region, first layer or first section described below may be referred to as the second element, second component, second region, second layer or second section. Describing an element as a "first" element may not require or imply the existence of a second or other element. Terms such as "first", "second", etc. may be used herein to distinguish between elements of different categories or groups. For clarity, terms such as "first", "second", etc. may refer to "first category (or first group)", "second category (or second group)", etc., respectively.

[0042] The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. As used herein, unless the context clearly indicates otherwise, singular terms are intended to include plural terms, and plural terms are also intended to include singular terms. When using the terms "comprising", "including" and "having" herein, it is intended to represent the presence of specified features, integers or steps. These statements do not exclude the presence or addition of one or more other functions, steps, operations, components and / or their groups.

[0043] When one or more embodiments may be implemented differently, a specific process order may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously or in an order opposite to the order described.

[0044] As used herein, the terms "substantially," "approximately," "approximately," and similar terms are used as approximate terms rather than as terms of degree, and are intended to account for the inherent deviations in measured or calculated values ​​that one of ordinary skill in the art would recognize. "Approximately" or "approximately" as used herein include the stated value and mean within an acceptable range of deviations for the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "approximately" may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure."

[0045] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and / or this specification, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0046] Figure 1 shows a perspective view of a battery module 10, Figure 2 shows an exploded perspective view of the battery module 10, Figure 3 An exploded perspective view of the end plate 200 is shown, Figure 4 shows a cross section of the end plate 200, Figure 5 shows a perspective view of the end plate 200, Figure 6 An enlarged portion of the end plate 200 is shown, Figure 7 shows the pressure distribution on the end plate EP of a conventional battery module, Figure 8 shows a state before the battery cell C in the battery module 10 expands, and Fig. 9 The pressure distribution on the end plate EP of the battery module 10 according to one embodiment of the present disclosure is shown.

[0047] The battery module 10 refers to a battery assembly in which a plurality of battery cells C are grouped into a group to protect the battery cells C from external impact, heat, vibration, etc. The battery module 10 may include a plurality of battery cells C having a prismatic shape, a pouch shape, or a cylindrical shape. Hereinafter, the description refers to an embodiment in which the battery module 10 includes a plurality of prismatic battery cells C. The battery module 10 may be used in large applications such as energy storage systems (ESS) or in small applications such as power tools. In one or more embodiments, the battery module 10 may be used in an electric vehicle. The battery module 10 may be used alone or may be electrically connected to other battery modules 10 to form a battery pack. The battery module 10 may vary according to the number of battery cells C, the field in which the battery module 10 is applied, and / or the specifications and capacity of the battery module 10. In one or more embodiments, the battery module 10 may have a rectangular parallelepiped shape that is elongated in one direction (e.g., the length direction of the battery module 10 or the X-axis direction).

[0048] The battery module 10 may include at least one battery cell C, a pair of side plates 100, a pair of end plates 200, a retainer 300, and a bus bar 400. In one or more embodiments, the battery module 10 may include a plurality of battery cells C, a side plate 100 located on the sides of the plurality of battery cells C, and an end plate 200 connected to the side plate 100. The end plate 200 may include a body 210 and an end cover 220, the end cover 220 being on a side of the body 210 facing the plurality of battery cells C, at least a portion of the end cover 220 including a flexible material configured to disperse pressure applied to the end plate 200.

[0049] One or more battery cells C may be included in the battery module 10. The number and arrangement of the battery cells C may vary according to the specifications and application targets of the battery module 10. In one or more embodiments, a total of 24 battery cells C may be arranged in the horizontal direction (e.g., in the length direction or X-axis direction of the battery module 10), and the 24 battery cells C may have a 2P (parallel) 12S (series) structure in which 12 pairs of battery cells C are connected in series, and each battery pair may have a structure in which two laterally adjacent battery cells C are connected in parallel. The number and arrangement of the battery cells C are not limited thereto and may vary. In one or more embodiments, a plurality of battery cells C may be arranged to form one or more rows and may be connected in series and / or in parallel to each other.

[0050] Each battery cell C may include a vent BH and an electrode E. In one or more embodiments, the vent BH may be located near the upper center of the battery cell C. If the battery cell C is damaged or operates abnormally and gas is generated inside the battery cell C, the vent BH may allow the generated gas to be discharged to the outside of the battery cell C. The electrode E may be located on the upper surface of the battery cell C, and two electrodes E may be spaced apart from each other on opposite sides of the vent BH. Each electrode E may be a positive electrode or a negative electrode. The electrodes E of multiple battery cells C may be connected to each other by a bus bar 400.

[0051] The side plate 100 may form an outer frame of the battery module 10 and may be located on at least one side of a plurality of battery cells C. In one or more embodiments, one side plate 100 may be located on corresponding sides (e.g., in the Y-axis direction) of a plurality of battery cells C. The side plate 100 may, together with the end plate 200, partition (form or define) a space in which a plurality of battery cells C are accommodated. The side plate 100 may be in contact with the side of the battery cell C, or may be spaced apart from the side of the battery cell C. The side plate 100 may have a plate shape that is elongated in the length direction (e.g., the X-axis direction) of the battery module 10, and both ends of the side plate 100 may be connected to both sides of the end plate 200 (e.g., both sides of the body 210). The side plate 100 may cover the sides of all battery cells C included in the battery module 10.

[0052] One or more end plates 200 may be provided on the battery module 10 to protect the battery cells C from external impact or foreign matter. The end plate 200 may have a size and shape corresponding to the size and shape of one of the battery cells C in the battery cells C. In one or more embodiments, the end plate 200 may have a long and thin rectangular parallelepiped shape in the width direction (e.g., Y-axis direction) of the battery module 10. The end plate 200 may have a width and / or height equal to or greater than the width and / or height of one of the battery cells C in the battery cells C. In one or more embodiments, one end plate 200 may be located at the corresponding end of the battery module 10 in the length direction (e.g., X-axis direction). Each end plate 200 may be connected to the side plate 100. Each end plate 200 may be connected to the retainer 300. The two end plates 200 provide a compressive force toward the center of the battery module 10 while being connected to the side plate 100, thereby allowing a plurality of battery cells C to be in close contact and keeping the plurality of battery cells C from deviating from their designated positions. The end plate 200 may be connected to the side plate 100 and / or the retainer 300 by laser welding, ultrasonic welding, screw connection, etc. In one or more embodiments, the end of each side plate 100 may be connected to each of the end plates 200 in the width direction (e.g., the Y-axis direction). The retainer 300 may be connected to the upper portion of the end plate 200.

[0053] The end plate 200 may include a body 210 , an end cover 220 , and an insulator 230 .

[0054] The main body 210 is located on one side of the end plate 200 and can support other components of the end plate 200. In one or more embodiments, the main body 210 may be located at the outermost part of the end plate 200 in the length direction (e.g., X-axis direction) of the battery module 10. The main body 210 may have a width and / or height equal to or greater than the width and / or height of one of the battery cells C in the battery cell C. The main body 210 may have a rectangular parallelepiped shape elongated in the width direction (e.g., Y-axis direction) of the battery module 10. The end cap 220 may be located on the inner side of the main body 210 facing one of the battery cells C in the battery cell C. The main body 210 may prevent (or at least mitigate) external impacts from being directly transmitted to the end cap 220 and the battery cell C, and may include a material with high rigidity. In one or more embodiments, at least a portion of the main body 210 may include metal and / or plastic. The main body 210 may have a hollow structure in which at least a portion of the interior is empty.

[0055] The body 210 may include a pair of connection grooves 211, a first aperture 212, and a second aperture 213. In one or more embodiments, the body 210 may include the connection groove 211 on one side of the body 210 facing the end cap 220. The body 210 may include a plurality of first apertures 212 and a plurality of second apertures 213.

[0056] The connection groove 211 may be on one side of the body 210 and may be connected to the connection protrusion 221 of the end cap 220. One or more connection grooves 211 may be formed on an inner surface of the body 210 facing the battery cell C and may extend in a height direction (eg, Z-axis direction) of the body 210. In one or more embodiments, as shown in FIG. Figure 4 As shown in , two connecting grooves 211 are spaced apart in the width direction (e.g., the Y-axis direction) of the main body 210, and one connecting protrusion 221 can be inserted into the corresponding connecting groove 211. The connecting groove 211 can be a groove for connecting the end cap 220 to the main body 210. The main body 210 and the end cap 220 can be formed by insert molding. In one or more embodiments, after the connecting groove 211 is inserted into the mold, if the material forming the end cap 220 is placed into the mold, the material can flow into the connecting groove 211, and if the molding is completed, the connecting protrusion 221 of the end cap 220 can be inserted into the connecting groove 211, and the end cap 220 can be fixed to the main body 210. The connecting groove 211 can extend in the height direction (e.g., the Z-axis direction) of the battery module 10, and can include a direction (e.g., Figure 3 A plurality of connecting grooves 211 spaced apart in the Y-axis direction.

[0057] The connection groove 211 may have a shape that prevents (or at least reduces) the body 210 and the end cap 220 from being easily separated from each other. The connection groove 211 may have a shape (e.g., a dovetail shape) whose cross-sectional area gradually widens from the inner side of the body 210 that contacts the end cap 220 toward the outer side. The cross-sectional area of ​​the connection groove 211 may gradually increase from one side to the other side. In one or more embodiments, as Figure 6As shown in , the connection groove 211 may include an inclined surface 2111, a bottom surface 2112 connected to the inclined surface 2111, and a corner portion 2113 between each inclined surface 2111 and the bottom surface 2112. The connection groove 211 may include an opening 2114 on one side of the body 210 (for example, on one side of the body 210 bordering the end cap 220). The inclined surface 2111 may include two inclined surfaces each extending outwardly from a boundary between the body 210 and the end cap 220 toward the outer surface of the body 210. In one or more embodiments, each of the inclined surfaces 2111 may be inclined outwardly toward the outer surface of the body 210. The inclined surface 2111 may include two inclined surfaces spaced apart in the width direction of the body 210. The angle θ of the inclined surface 2111 relative to the bottom surface 2112 may be in the range of about (approximately) 20 degrees to about (approximately) 70 degrees, or in the range of about (approximately) 10 degrees to about (approximately) 60 degrees, or in the range of about (approximately) 30 degrees to about (approximately) 80 degrees. The angle θ may be in the range of about (approximately) 30 degrees to about (approximately) 60 degrees. The depth of the connecting groove 211 may be approximately half or more of the width of the body 210. In one or more embodiments, the depth of the connecting groove 211 may be in the range of about (approximately) 60% to about (approximately) 90% of the width of the body 210, or in the range of about (approximately) 65% to about (approximately) 95% of the width of the body 210. The depth of the connecting groove 211 may be in the range of about (approximately) 50% to about (approximately) 80% of the width of the body 210. The bottom surface 2112 is parallel (or substantially parallel) to the body 210, and the opposite ends of the bottom surface 2112 can be connected to the two inclined surfaces 2111. The bottom surface 2112 can be positioned opposite to the opening 2114, and the two inclined surfaces 2111 can be connected to each other. The width of the bottom surface 2112 can be in the range of about (approximately) 1.5 times to about (approximately) 2.5 times the width of the opening 2114 of the connecting groove 211. The corner portion 2113 is a portion where the two inclined surfaces 2111 are connected to the bottom surface 2112, and at least a portion of the corner portion 2113 can have a curved shape. The corner portion 2113 can be located between the two inclined surfaces 2111 and the bottom surface 2112, and at least a portion of the corner portion 2113 can be curved. In one or more embodiments, each of the corner portions 2113 can have a convex shape toward the outside of the connecting groove 211. Due to such a shape of the connection groove, during the process of insert-molding the end plate 200 , the material of the end cap 220 may sufficiently flow into the connection groove 211 , and the contact area between the end cap 220 and the body 210 may be increased.

[0058] The connection groove 211 may be located outside the center of the body 210. The center of the body 210 may mean a range of about (approximately) ±10%, a range of about (approximately) ±20%, or a range of about (approximately) ±30% relative to the center of the width direction (e.g., Y-axis direction) of the body 210. In one or more embodiments, as Figure 4 As shown in , each connection groove 211 may be spaced apart from the center of the body 210 in the width direction (e.g., Y-axis direction) of the body 210. Because the center of the body 210 is an area that receives relatively high pressure if the battery cell C expands, a firm connection between the body 210 and the end cap 220 may be ensured by spacing or moving the connection groove 211 away from the center of the body 210 to prevent excessive stress from being concentrated in the connection groove 211. The battery cells C may be two battery cells C located at the outermost part in the length direction (e.g., X-axis direction) of the battery module 10 and in contact with the end plate 200. The battery cell C may move or deform due to the deformation or expansion of another battery cell C. The battery cell C may deform or expand during use. The connection groove 211 may be spaced apart from the end of the body 210 by a certain distance. In one or more embodiments, the distance from the end of the body 210 to the connection groove 211 may be in the range of about (approximately) 10% to about (approximately) 60% of the distance from the end of the body 210 to the center of the body 210. The connecting groove 211 may be spaced apart from the plurality of pores in the width direction (e.g., the Y-axis direction) of the body 210. That is, the connecting groove 211 may not be aligned with the first pore 212 or the second pore 213. The connecting groove 211 may not overlap with the first pore 212 and / or the second pore 213. In one or more embodiments, the central axis (e.g., the central axis in the Y-axis direction) of the connecting groove 211 may not overlap with the plurality of pores 212 and / or 213. The center of the connecting groove 211 in the width direction (e.g., the Y-axis direction) may not overlap with the first pore 212 or the second pore 213. Therefore, by maintaining a sufficient distance between the connecting groove 211 and the first pore 212 and / or the second pore 213, the body 210 between the connecting groove 211 and the first pore 212 and / or the second pore 213 may be prevented from being damaged when pressure is applied to the end plate 200.

[0059] The first pore 212 and the second pore 213 are empty spaces formed inside the body 210. In one or more embodiments, the first pore 212 may have the same or different shape as the second pore 213, and may include a plurality of first pores 212 and a plurality of second pores 213 in the width direction (e.g., the Y-axis direction) of the body 210. The first pore 212 and the second pore 213 may provide sufficient rigidity for the body 210, reduce the weight of the body 210, and reduce the amount of material used in the body 210. One or more first pores 212 may be formed in the center of the body 210. In one or more embodiments, the first pore 212 may have a trapezoidal shape and may be arranged in a direction (e.g., the width direction of the body 210 or the Y-axis direction). Figure 4 The first pores 212 are arranged in the Y-axis direction of the main body 210, and the orientations (e.g., upper and lower sides) of the first pores 212 are alternated. Each cross-sectional area of ​​the first pores 212 may be greater than each cross-sectional area of ​​the second pores 213. One or more second pores 213 may be spaced apart from the center of the main body 210. The second pores 213 may have a cross-sectional shape of various shapes such as a triangle, a circle, or a square.

[0060] The body 210 may further include a recessed portion 214. The recessed portion 214 may be on one surface of the body 210 and have a recessed shape extending toward the inside of the body 210. In one or more embodiments, the recessed portion 214 may be on a side of the body 210 opposite to the side of the body 210 facing the battery cell C. If the center of the end plate 200 receives a relatively large pressure as the battery cell C expands, the recessed portion 214 may form a free space in which the body can deform backward. The recessed portion 214 may be formed at a position corresponding to the center (or substantially the center) of the body 210.

[0061] The end cap 220 may be on one side of the main body 210. In one or more embodiments, the end cap 220 may be supported on the inner surface of the main body 210 so that the end cap 220 faces the battery cell C. The end cap 220 may have a shape corresponding to the shape of the battery cell C or the main body 210. The end cap 220 has a thin flat shape as a whole, and wings are formed at both ends in the width direction to form a space inside that can support the battery cell C. The battery cell C may refer to two battery cells C located at the outermost part in the length direction (e.g., X-axis direction) of the battery module 10. The end cap 220 may have a width and height greater than the width and height of the main body 210 and / or the battery cell C. At least a portion of the end cap 220 may include a deformable elastic material. At least a portion of the end cap 220 may include a flexible material. At least the inner side of the end cap 220 facing the battery cell C may be made of a flexible material, and the main body 210 may include a material more rigid than the end cap 220. In one or more embodiments, at least a portion of the end cap 220 may be made of ethylene-propylene diene monomer (EPDM) as a rubber material. Therefore, as the battery cell C expands, the end cap 220 deforms to absorb the pressure received by the end plate 200 and evenly disperses the pressure throughout the end cap 220, thereby preventing the pressure from being locally concentrated on the body 210.

[0062] For example, the end cap 220 may be deformed into a shape corresponding to the battery cell C closest to the end plate 200 among the plurality of battery cells C. For example, as one or more battery cells C among the plurality of battery cells C are deformed or expanded, the end cap 220 may be deformed to have a concave center. For example, as one or more battery cells C among the plurality of battery cells C are deformed or expanded, the end cap 220 may have a shape in which the thickness in one direction (e.g., the length direction of the end cap 220 or the length direction of the end plate 200) is increased. Figure 4 The shape gradually decreases from the end toward the center in the Y-axis direction.

[0063] For example, one or more of the plurality of battery cells C may be deformed or expanded, or there may be some variation in the thickness of the battery cells C, so that pressure exceeding the design value may be applied to one or both of the end plates 200. The expansion of the battery cells C may appear larger at the center. If the thickness at the center of the battery cells C is greater than the design value, relatively large pressure may be concentrated in the center of one or both of the end plates 200. However, in the related art, such as Figure 7 As shown in , in order to protect the battery cells C from external impact and prevent damage to the appearance of the battery cells C, the end plate EP and / or the end cover on the inner surface of the end plate EP include a material having relatively high rigidity. Therefore, the end plate EP does not evenly disperse the pressure applied by the battery cells C, and the center of the end plate EP ( Figure 7 The end plate EP is subjected to great pressure (dashed line in the figure). As a result, the end plate EP as a whole, including the center of the end plate EP, is easily deformed or damaged. Since the end plate EP is pressed in a direction perpendicular to the bonding force between the side plate S and the end plate EP, a shear force is generated at the connection between the end plate EP and the side plate S, and the connection between the end plate EP and the side plate S may be broken.

[0064] like Figure 8 As shown in , the battery module 10 includes an end plate 200, the end plate 200 includes a body 210 and an end cover 220, and at least a portion of the end cover 220 may include a deformable elastic material. At least a portion of the end cover 220 may include a flexible material. Therefore, even if the center of the battery cell C expands and a large pressure is concentrated in the center of the end plate 200, the shape of the end cover 220 may be deformed in response to the deformed shape and / or pressure distribution of the battery cell C. In one or more embodiments, as Fig. 9 As shown in , the center of the end cap 220 can be more compressed, and the amount of deformation of the end cap 220 can be reduced in the width direction (e.g., the Y-axis direction) as it moves toward the end of the end cap 220. In this regard, the end cap 220 can be deformed to have a concave shape at the center of the end cap 220 according to the pressure distribution of the battery cell C. According to the deformation of the battery cell C and / or the distribution of the pressure applied to the end cap 220 by the battery cell C, the end cap 220 can have a shape in which the thickness gradually increases from the center of the end cap 220 toward the side of the end cap 220 in the width direction (e.g., the Y-axis direction). The main body 210 supporting the end cap 220 may include a material having high rigidity and substantially not deforming. Therefore, while one side of the end cap 220 is supported by the main body 210, the other surface facing the battery cell C can be freely deformed according to the deformation of the battery cell C and / or the pressure distribution on the end cap 220. Therefore, the pressure applied by the battery cells C is uniformly (or substantially uniformly) dispersed not only to the center of the end cap 220 but also uniformly (or substantially uniformly) dispersed to the outside ( Fig. 9 ), the battery module 10 can prevent (or at least reduce) damage to the end plate 200 and firmly maintain the connection between the end plate 200 and the side plate 100.

[0065] The end cap 220 may include a connection protrusion 221, a first guide 222, a second guide 223, and a slit 224. The end cap 220 may include a pair of first guides 222 and a pair of second guides 223 at opposite sides in the width direction (e.g., the Y-axis direction). In one or more embodiments, the end cap 220 may include a connection protrusion 221 inserted into a connection groove 211 on one surface facing the body 210. The connection protrusion 221, the first guide 222, and the second guide 223 may all include the same material as the end cap 220. In one or more embodiments, the connection protrusion 221, the first guide 222, and / or the second guide 223 may include a deformable elastic material and / or a flexible material. The material may be a rubber such as ethylene propylene copolymer (EPDM). The connection protrusion 221, the first guide 222, and the second guide 223 may be formed as one piece (i.e., integral or monolithic) by injection molding. The connection protrusion 221, the first guide 222, and the second guide 223 may form one piece. The connection protrusion 221, the first guide 222, and the second guide 223 may be one or more separate components and may be detachably coupled to each other by welding, adhesive, threaded connection, etc. In one or more embodiments, the end cap 220 may include a first guide 222 protruding toward the battery cell C at an edge of the end cap 220 and a second guide 223 extending from a lower end of the first guide 222, and the connection protrusion 221, the first guide 222, and the second guide 223 may form one component including the same material.

[0066] The connection protrusion 221 may be on the end cap 220 and coupled to the connection groove 211 of the body 210. In one or more embodiments, a plurality of connection protrusions 221 may be on one surface of the end cap 220 facing the body 210. Figure 3 As shown in , two connection protrusions 221 may be spaced apart in the width direction (e.g., Y-axis direction) of the end cap 220. The connection protrusion 221 may extend in the height direction (e.g., Z-axis direction) of the end cap 220. The connection protrusion 221 may be formed over the entire height (or substantially the entire height) of the end cap 220 or may be formed on only a portion of the end cap 220. The connection protrusion 221 may be a coupling portion that is formed when the end cap 220 is insert-molded and is coupled to the body 210. The shape of the connection protrusion 221 may correspond to the shape of the connection groove 211 and may be the same as that of the reference numeral 211. Figure 6 The shapes of the described connection grooves 211 are the same (or substantially the same). In one or more embodiments, the connection protrusion 221 may include a plurality of connection protrusions 221 corresponding to the plurality of connection grooves 211 .

[0067] The first guide 222 may be on the end cover 220 to form a space in which one of the battery cells C is accommodated, and may support the battery cell C. For example, the first guide 222 is located at both sides of the end cover 220 in the width direction (e.g., the Y-axis direction), and a space may be formed between the two sides to accommodate one of the battery cells C in the battery cells C. The first guide 222 may be formed by Figure 4 A pair of first guides 222 located on both sides of the end cap 220 in the Y-axis direction of the end cap 220 is formed. The first guide 222 may protrude from the inner surface of the end cap 220 toward the battery cell C, and form a wing together with the second guide 223. The first guide 222 is configured to absorb and disperse the pressure applied to both sides of the end cap 220 as the battery cell C is deformed, and may partially suppress excessive deformation or expansion of the battery cell C.

[0068] The second guide 223 is located on the end cover 220 to form a space in which one of the battery cells C is accommodated, and may support the battery cell C. In one or more embodiments, the second guide 223 may be located at each corner on both sides of the lower portion of the end cover 220, and may extend from the lower end of the corresponding first guide 222 toward the center of the end cover 220. The second guide 223 may include a pair of second guides 223 extending from the lower ends of a pair of first guides 222 along the lower edge of the end cover 220. The second guide 223 may support one of the battery cells C together with the first guide 222. The second guide 223 may be configured to absorb and disperse the pressure applied downward to the end cover 220 as the battery cell C is deformed, and may partially suppress excessive deformation or expansion of the battery cell C.

[0069] The slit 224 may be located at a lower portion of the end cap 220. In one or more embodiments, as Figure 5 As shown in , the slit 224 may be between two second guides 223. The slit 224 is an empty space between the two second guides 223, and the second guide 223 may cover only a portion of the lower portion of the battery cell C. Therefore, the heat generated in the battery cell C may be smoothly discharged to the lower portion through the slit 224. In the width direction (e.g., the Y-axis direction), the length of the slit 224 may be greater than the length of the second guide 223. In one or more embodiments, the length of the slit 224 may be greater than the sum of the lengths of the plurality of second guides 223.

[0070] The insulator 230 may be between the end plate 200 and one of the battery cells C in the battery cells C. In one or more embodiments, the insulator 230 may include an insulating resin and may be on one side of the end cap 220 facing one of the battery cells C in the battery cells C. The insulator 230 may insulate the battery cell C from the end plate 200 and form a space between the battery cell C and the end plate 200 to allow air to flow and cool the battery cell C. At least a portion of the insulator 230 may include a flame retardant and / or an insulating material. The insulator 230 may have a size smaller than that of the end cap 220 and may have a shape and size corresponding to a surface of the battery cell C facing the insulator 230.

[0071] The retainer 300 may be on the battery module 10 to support the battery cell C and the bus bar 400. The retainer 300 may be located on one side (e.g., above) of the plurality of battery cells C, and may include an opening 310 to expose the electrode E in each battery cell C. The plurality of openings 310 may be formed at positions corresponding to the positions of the electrodes E. In one or more embodiments, the retainer 300 may include a plurality of openings 310 arranged in two rows on one side and the other side based on the center of the battery cell C. The window 320 corresponding to the exhaust hole BH of the battery cell C may be in the center of the retainer 300. The edges of the retainer 300 may be connected to the side plate 100 and the end plate 200. In one or more embodiments, the retainer 300 may have a rectangular shape including two long sides and two short sides, and the edges corresponding to the two long sides may be connected to the two side plates 100, respectively. The edges corresponding to the two short sides may be connected to the two end plates 200. In one or more embodiments, the long side of the retainer 300 may be parallel (or substantially parallel) to the length direction (e.g., X-axis direction) of the battery module 10. The retainer 300 may be connected to the side plate 100 and the end plate 200 by welding or screws. In the case where the retainer 300 is located on a plurality of battery cells C, a plurality of bus bars 400 may be supported on the retainer 300. The retainer 300 may include one or more retainers 300.

[0072] The bus bar 400 may include a conductive member such as a metal, and may be supported on the holder 300. The bus bar 400 may be connected to the electrode E of the battery cell C through the opening 310 of the holder 300 to electrically connect a plurality of battery cells C. In the case where the holder 300 is located on a plurality of battery cells C, a plurality of bus bars 400 may be supported on the holder 300. The bus bar 400 may correspond to the opening 310 of the holder 300, and may be electrically connected to the electrode E exposed through the opening 310. The bus bar 400 may connect a plurality of battery cells C in series and / or in parallel. In one or more embodiments, the bus bar 400 may connect two adjacent battery cells C in parallel in the length direction (e.g., the X-axis direction) of the battery module 10, and connect the battery cells C connected in parallel in series. In an embodiment where the battery module 10 is combined with other battery modules 10 to form a battery pack, the bus bar 400 may include an external terminal electrically connected to the other battery modules 10. The external terminal may be a terminal connected to a battery management system (BMS) of the battery pack.

[0073] The battery module 10 may also include a pair of spacers 500. The spacers 500 may be on the sides of the plurality of battery cells C to ensure the gap between the battery cells C and prevent the battery cells C from contacting each other. In one or more embodiments, the spacer 500 may be between the plurality of battery cells C and the side plate 100, and may include a protrusion protruding toward the plurality of battery cells C. The protrusion may be inserted between the battery cells C to form a gap between adjacent battery cells C in the length direction (e.g., X-axis direction) of the battery module 10. The battery cells C are insulated from each other by the gap formed by the spacer 500, and the air is configured to move through the space between the battery cells C, thereby allowing the battery cells C to be cooled. The gap formed by the spacer 500 may be used as a moving path for a fire extinguishing agent. At least a portion of the spacer 500 may include a flame retardant and / or a heat insulating material. In one or more embodiments, the spacer 500 may be formed by arranging a plurality of strips in directions intersecting each other. The spacer 500 may form a gap between the battery cell C and the side plate 100 and a gap between adjacent battery cells C. The spacer 500 may prevent the battery cells C from directly contacting the side plate 100 and may form a sufficient space between the battery cells C and the side plate 100 to allow air to smoothly move therebetween. In one or more embodiments, at least a portion of the spacer 500 may include ceramic paper or mica.

[0074] Fig.10A cross-section of an end plate 200A according to another embodiment of the present disclosure is shown. The end plate 200A may include a main body 210A and an end cover 220A. The end plate 200A may also include an insulator on the inner surface of the end cover 220A (e.g., a surface facing one of the battery cells C). The main body 210A and the connecting groove 211A, the first pore 212A, the second pore 213A, and the recessed portion 214A as a subassembly of the main body 210A are respectively the same as the above-mentioned main body 210, the connecting groove 211, the first pore 212, the second pore 213, and the recessed portion 214, and a detailed description thereof is omitted. The end cover 220A includes a connecting protrusion 221A, a first guide 222A, a second guide 223A, and a slit. The connection protrusion 221A, the first guide 222A, the second guide 223A, and the slit are respectively the same as the connection protrusion 221, the first guide 222, the second guide 223, and the slit 224 described above, and a detailed description thereof is omitted.

[0075] At least a portion of the end cap 220A may have a curved shape. In one or more embodiments, at least a portion of the surface of the end cap 220A facing the battery cell C may be curved. The end cap 220A may have a shape corresponding to the pressure distribution according to the expansion or deformation of the battery cell C or the thickness deviation (greater than the design value) of the battery cell C, and may have a concave inner surface. Before the battery cell C expands or deforms, the distance between the inner side of the end cap 220A and the facing side of the battery cell C is the longest at the center of the width direction (e.g., Y-axis direction) of the end cap 220A, and gradually shortens toward the two ends of the end cap 220A. Therefore, there may be some time before the battery cell C begins to expand or deform and applies pressure to the center of the end plate 200A. By reducing the pressure applied to the center of the end plate 200A, the deformation and damage of the end plate 200A can be reduced, and a firm connection between the side plate 100 and the end plate 200A can be maintained.

[0076] The battery module disperses pressure applied to the end plates in response to deformation or expansion of the battery cells, thereby reducing damage and deformation of the end plates and the battery cells and reducing shear force applied to the connection portions between the end plates and the side plates.

[0077] The battery module may evenly (or substantially evenly) distribute the pressure applied to the center of the end plate by including an end cap made of a flexible material.

[0078] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for the purpose of limitation. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A battery module, comprising: Multiple battery cells; a side plate on a side of the plurality of battery cells; as well as End panels, connected to the side panels, Wherein, the end plate comprises: the subject; and an end cover on a side of the body facing the plurality of battery cells, wherein at least a portion of the end cover includes a flexible material, and wherein the end cover is configured to disperse pressure applied to the end plate.

2. The battery module according to claim 1, wherein: The end cover has a shape that can be deformed to correspond to a battery cell that is closest to the end plate among the plurality of battery cells.

3. The battery module according to claim 1, wherein: The center of the end cap is configured to deform concavely in response to one or more of the plurality of battery cells deforming or expanding.

4. The battery module according to claim 1, wherein: The thickness of the end cap gradually decreases along a direction from an end of the end cap toward a center of the end cap.

5. The battery module according to claim 1, in, The body includes a connecting groove in one surface of the body facing the end cover, and Wherein, the end cover comprises a connecting protrusion in the connecting groove, and the connecting protrusion is on a side of the end cover facing the main body.

6. The battery module according to claim 5, wherein: The cross-sectional area of ​​the connecting groove gradually increases from one side of the main body to the other side.

7. The battery module according to claim 5, wherein: The connection groove includes an inclined surface inclined outwardly in a direction away from the one surface.

8. The battery module according to claim 7, in, The inclined surface includes two inclined surfaces spaced apart in a width direction of the body, and Wherein, the connecting groove comprises: an opening in the one surface; and A bottom surface is opposite to the opening and connects the two inclined surfaces to each other.

9. The battery module according to claim 8, wherein: The connection groove further includes a corner portion between the two inclined surfaces and the bottom surface, and wherein at least a portion of the corner portion is curved.

10. The battery module according to claim 5, in, The body includes a plurality of pores, and Wherein, the connecting groove is spaced apart from the plurality of pores in a width direction of the main body.

11. The battery module according to claim 10, wherein: A central axis of the connecting groove does not overlap with the plurality of apertures.

12. The battery module according to claim 5, in, The connection groove extends in the height direction of the battery module and includes a plurality of connection grooves spaced apart in one direction, and Wherein, the connecting protrusion includes a plurality of connecting protrusions corresponding to the plurality of connecting grooves.

13. The battery module according to claim 1, in, An inner surface of the end cap facing one of the plurality of battery cells includes a flexible material, and Wherein, the body comprises a material that is more rigid than the end cap.

14. The battery module according to claim 1, wherein: The body and the end cap are formed by insert molding.

15. The battery module according to claim 5, wherein: The end cap comprises: a first guide member at an edge of the end cover and protruding toward the plurality of battery cells; and a second guide member extending from a lower portion of the first guide member, Wherein, the connecting protrusion, the first guide member and the second guide member are integral and comprise the same material.

16. The battery module according to claim 15, in, The first guide member includes a pair of first guide members on both sides of the end cover in one direction, and The second guide member includes a pair of second guide members extending from the lower ends of the pair of first guide members and along the lower edge of the end cover.

17. The battery module according to claim 16, wherein: The end cap also includes a slit between the pair of second guides.

18. The battery module according to claim 1, wherein: At least a portion of one surface of the end cover facing the plurality of battery cells is curved.

19. The battery module according to claim 18, wherein: The end cap has a concave center.

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