Battery module housing that contains a stack of battery cells

Abstract

The present invention relates to a housing for accommodating a battery cell laminate in a battery module. Specifically, in the frame included in the housing, a cutout portion is formed on the inner surface of the frame adjacent to a protruding fragile portion (bat-ear) provided at a part of the corner portions of each battery cell included in the battery cell laminate so as to avoid interference with the protruding fragile portion, and a double injection portion that is joined to the processed surface of the cutout portion by double injection, has a shape recessed compared to the inner surface, covers the cutout portion while avoiding interference with the fragile portion, and is formed so as to constitute a part of the inner surface. The present invention provides a frame including the double injection portion, a housing including the frame, a battery module including the housing, a battery pack including the battery module, and a vehicle including the battery pack, etc.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0065622 filed on May 27, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module housing for accommodating a battery cell stack, and more particularly, to a battery module housing with improved space utilization, insulation, and manufacturing process economy.

Background Art

[0003] Secondary batteries, which are highly applicable to a wide range of products and have electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles or hybrid vehicles driven by an electric drive source, power storage devices, etc. These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency improvement, not only because of their primary advantage of significantly reducing the use of fossil fuels but also because they do not generate any by-products from energy use. <​​​​​​​​​​​

[0007] Figures 1 and 2 are perspective views and exploded perspective views, respectively, of a battery module before and after assembly, which has a U-shaped frame with the top and front and rear surfaces open. Referring to these drawings, the battery module 0 having a U-shaped frame includes a battery cell stack 1 made up of stacked battery cells 11 and a housing that houses it. The housing includes a frame 2 that covers the bottom and both sides in the width direction (Y1), an upper plate 10 that covers the top, and a pair of end plates 20 that cover both sides in the length direction (X1). The frame 2 has a shape in which the bottom surface 21 and both side walls in the width direction are connected.

[0008] The battery cell stack 1 is an assembly formed by stacking a plurality of pouch-type battery cells 11, and is housed in the housing such that the normal direction (Z2) of each battery cell 11 coincides with the width direction of the housing.

[0009] Figure 3 is a perspective view showing a unit of a pouch-type battery cell 11. Referring to this, the battery cell 11 has a structure in which an electrode assembly, electrode tabs, and electrode leads are housed in a pouch made of a material in which insulating material is coated on both sides of a metal sheet, and the electrode leads have portions that protrude to the outside of the pouch in the longitudinal direction (X2). The pouch is folded along the longitudinal direction as an axis, and three sides excluding the folded portion are heat-sealed. At this time, a weak portion 11b is formed by compression at both corner portions located between the one end in the width direction (Y2) on the side with the folded portion and the two ends in the longitudinal direction that are sealed on the lead film, and this weak portion 11b is also called a bat-ear. The vulnerable portion 11b has a shape that protrudes from the battery cell 11 toward one side in the width direction, and there is a possibility that it may interfere with the inner surface of the frame 2 when assembling the battery module 0. If such interference occurs, the sealing of the pouch may become poor and the insulation performance may decrease. In addition, the protruding shape of the vulnerable portion 11b increases the separation distance between the battery cell stack 1 and the frame 2, and it becomes necessary to form a thicker thermally conductive resin layer between the battery cell stack 1 and the frame 2 to help cool the battery cell 11, which reduces economic efficiency.

[0010] On the other hand, in order to solve this problem, conventional methods have involved machining the bottom surface 21 of the frame 2 in the area where there is a possibility of interference with the weak part 11b, thereby creating a stepped portion that is lower in height than other parts of the bottom surface 21, thereby avoiding interference between the weak part 11b and the frame 2, improving space utilization, and then applying insulating tape to the stepped portion to prevent insulation failure. However, the application of the insulating tape is an additional step performed after machining the stepped portion, which is a cumbersome and uneconomical process, and because it is done manually, defects can occur. [Overview of the project] [Problems that the invention aims to solve]

[0011] This invention was conceived against the backdrop of the prior art described above, and aims to provide a battery module housing that can reduce interference with vulnerable parts of a battery cell while ensuring insulation performance.

[0012] Another objective of the present invention is to maximize space utilization by providing a frame shape that corresponds to the protruding shape of the weak portion, thereby reducing the separation distance between the battery cell stack and the frame, and thus reducing the thickness of the thermally conductive resin layer provided between the battery cell stack and the frame, and thereby ensuring economic efficiency.

[0013] Another technical problem of the present invention is to provide a housing that exhibits stable performance through an economical process, by simplifying the complex processes of machining existing stepped portions and attaching insulating tape, in a frame that does not interfere with the aforementioned weak parts and ensures insulating performance.

[0014] Another technical challenge of the present invention is to reduce the possibility of defects occurring due to the fact that existing insulating tape application processes are manual processes.

[0015] A further technical problem of the present invention is to provide a housing that can be produced by the economical process described above and exhibits stable interference prevention and insulation performance, a battery module including the same, a battery pack including the battery module, and a vehicle including the battery pack, etc.

[0016] The technical problems of the present invention are not limited to the purposes mentioned above, and other purposes and advantages of the present invention not mentioned can be understood from the following description and more clearly from the embodiments of the present invention. Furthermore, it is clear that the purposes and advantages of the present invention can be achieved by the means and combinations thereof described in the claims. [Means for solving the problem]

[0017] To solve the above problems, the present invention provides a housing for accommodating a battery cell stack in a battery module, wherein a cutout portion is formed in the housing by cutting off a portion of each battery cell that may interfere with the end of a weak part protruding from one side in the width direction, and the cutout portion is covered with a double injection-molded portion made of double-injected synthetic resin.

[0018] The housing may include a U-shaped frame with a bottom surface and side walls in the width direction (Y1) connected, an upper plate covering the top, and end plates covering both sides in the length direction (X1). The bottom surface and side walls of the frame may be a single bent member, or they may be separate members joined to each other.

[0019] The frame may be made of metal sheet material and can be manufactured by plastic deformation by pressing, but other materials and processing methods are not excluded.

[0020] The cut-out portion can be formed on an existing frame by press cutting, or it can be formed in advance when cutting a metal sheet material that is plastically deformed by pressing. The formation can be done by any method, as long as it is formed in a shape in which a part of the frame is cut off to prevent interference with the end of the weak part of the battery cell on the frame.

[0021] The cut-out portion can be formed on the bottom surface of the frame.

[0022] The cut-out portion can be machined to have a curved shape that extends into the bottom surface, leaving a portion of the thickness of the bottom surface of the frame, or it can be cut to have a shape that completely penetrates the bottom surface.

[0023] The cut-out portion can be formed on one or both ends of the frame in the longitudinal direction.

[0024] The cut-out portion can be formed at one end portion in the length direction of the frame, with the corners where both side walls and the bottom surface of the frame intersect as the boundaries in the width direction thereof.

[0025] The double injection portion may be made of an insulating synthetic resin.

[0026] The double injection portion may be made of a thermally conductive synthetic resin while being insulating.

[0027] The double injection portion can be joined to the processed surface of the cut-out portion by double injection.

[0028] The double injection portion may have a shape sunken more than the bottom surface of the frame where the cut-out portion is formed. On the other hand, a thermally conductive resin layer can be provided between the frame and the battery cell laminate. The thickness of these thermally conductive resin layers can be determined by the separation distance between the battery cell laminate and the frame. If the thickness of the thermally conductive resin layer is too thick, the economy will decline. Therefore, the sunken shape can be formed to have a step corresponding to the protruding degree of the vulnerable portion so as to reduce the separation distance.

[0029] The thickness of the double injection portion may be thinner than the thickness of the bottom surface, or may be thicker or the same as that.

[0030] The lower surface of the double injection portion can also form a step with the lower surface of the bottom surface, or may be continuous without a step.

[0031] A housing according to one embodiment of the present invention includes a U-shaped frame made by plastically deforming a metal sheet, and a cutout is provided on the bottom surface at one end of the frame in the longitudinal direction, with the corners where the bottom surface and both side walls intersect being the widthwise boundary, and a double injection-molded section is connected to the processed surface of the cutout, the thickness of the double injection-molded section is thinner than the thickness of the bottom surface, the lower surface of the double injection-molded section is continuous with the lower surface of the bottom surface at the same height and without any steps, and the upper surface may be formed to be recessed downward compared to the upper surface of the bottom surface, creating a step between them.

[0032] A housing according to another embodiment of the present invention includes a U-shaped frame made by plastically deforming a metal sheet, wherein a cutout is provided at one end of the frame in the longitudinal direction, with the corners where the bottom surface and both side walls intersect being the widthwise boundary, and the cutout is formed to penetrate the bottom surface, and a double injection-molded section is connected to the processed surface of the cutout, the thickness of the double injection-molded section being the same as the thickness of the bottom surface, the double injection-molded section as a whole protruding below the bottom surface, and the upper and lower surfaces of the bottom surface may both be formed to form a step.

[0033] The double injection section can be formed to cover a portion of the inner bottom surface of the processed surface of the cut-out section.

[0034] A housing according to yet another embodiment of the present invention includes a U-shaped frame made by plastically deforming a metal sheet, wherein a cutout is provided on the bottom surface at one end of the frame in the longitudinal direction, with the corners where its bottom surface and both side walls intersect serving as its widthwise boundary, and a double injection-molded portion is connected to the processed surface of the cutout and a part of the inner bottom surface of the boundary of the cutout, the thickness of the double injection-molded portion is thinner than the thickness of the bottom surface, the lower surface of the double injection-molded portion is continuous with the lower surface of the bottom surface at the same height and without any steps, and its upper surface may be formed to be recessed downwards compared to the upper surface of the bottom surface, creating a step with the bottom surface.

[0035] Means for solving the above problems can also be provided by the present invention, such as a battery module housing, a battery module including the same, a battery pack including the battery module, and a vehicle equipped with the battery pack. [Effects of the Invention]

[0036] According to the present invention, by providing a cut-out portion that cuts out the part where interference occurs between the frame included in the battery module housing and the vulnerable portion of each battery cell in the battery cell stack housed inside, the interference between the vulnerable portion and the frame can be minimized.

[0037] According to yet another aspect of the present invention, by providing the cut-out portion corresponding to the weak portion, the separation distance between the frame and the battery cell stack is reduced, maximizing space utilization, and the thickness of the thermally conductive resin layer provided between the frame and the battery cell stack can be reduced, thereby improving the economic efficiency in the production of the battery module.

[0038] According to yet another aspect of the present invention, by covering the cut-out portion with a double injection-molded portion made of insulating synthetic resin, the fragile portion and the frame are electrically insulated, thereby improving the stability of the battery module.

[0039] From yet another perspective, the present invention provides process economy by first creating the stepped portion through a two-step process of machining the existing stepped portion and then applying insulating tape, and then performing the insulating treatment, thereby allowing the stepped portion to be created and the insulating treatment to be performed simultaneously using only a double injection process.

[0040] From yet another perspective, the present invention makes it possible to prevent battery module defects due to defects in the insulating tape by replacing the manual process of attaching the insulating tape with an automated process of double injection.

[0041] In addition, the present invention can have various other effects, which will be described in each embodiment, or effects that can be easily inferred by those skilled in the art will not be described. [Brief explanation of the drawing]

[0042] [Figure 1] This is a perspective view showing the assembled state of a battery module, including a U-shaped frame. [Figure 2] This is an exploded perspective view showing the battery module, including the U-shaped frame, before assembly. [Figure 3] This is a perspective view showing one unit of a pouch-type battery cell. [Figure 4] This is a perspective view showing a U-shaped frame according to one embodiment of the present invention. [Figure 5] This is an enlarged side cross-sectional view showing one embodiment of the present invention, in which the thickness of the double injection section is thinner than the thickness of the bottom surface of the frame. [Figure 6] This is an enlarged side cross-sectional view showing one embodiment of the present invention, in which the thickness of the double injection section is the same as the thickness of the bottom surface of the frame. [Figure 7] This is an enlarged side cross-sectional view showing one embodiment of the present invention, in which a double injection section covers a portion of the inner bottom surface of the boundary of the cut surface. [Figure 8] This is a drawing showing a vehicle equipped with a battery pack, including a battery module with an improved housing. [Modes for carrying out the invention]

[0043] The aforementioned objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, so that a person with ordinary skill in the art to which the present invention pertains can easily implement the technical concept of the present invention. In describing the present invention, if a specific description of known technology according to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0044] Even if terms like "first," "second," etc., are used to indicate various components, these components are certainly not limited by these terms. These terms are merely used to distinguish one component from another, and unless otherwise stated, the first component may also be the second component.

[0045] In the entire specification, unless otherwise stated, each component may be singular or plural.

[0046] In the following, the placement of any configuration "above (or below)" a component or "above (or below)" a component means not only that the configuration is placed in contact with the upper (or lower) surface of the component, but also that other configurations may be interposed between the component and any configuration placed on (or below) it.

[0047] Furthermore, if it is stated that one component is “linked,” “joined,” or “connected” to another component, it should be understood that the components may be directly linked to or connected to one another, but may also be “interposed” between each component, or each component may be “linked,” “joined,” or “connected” through other components.

[0048] In this specification, singular expressions include plural expressions unless otherwise explicitly stated in the context. Terms such as “composed of” or “including” in this application should not be interpreted as necessarily including all of the multiple components or steps described in the specification, but rather as meaning that some of the components or steps may not be included, or that further components or steps may be included.

[0049] In the entire specification, "A and / or B" means A, B, or A and B unless otherwise specified, and "C to D" means C or greater and D or less unless otherwise specified.

[0050] For the sake of explanation, in this specification, with respect to a battery module, the direction parallel to the bottom surface of the frame and passing through both end plates of the battery module is referred to as the length direction (X1), the direction parallel to the bottom surface of the frame and normal to the plane formed by each battery cell contained in the battery cell stack is referred to as the width direction (Y1), and the direction parallel to the bottom surface of the frame is referred to as the height direction (Z1).

[0051] In this specification, with respect to a battery cell, the direction parallel to the battery cell and passing through both electrode leads is referred to as the length direction (X2), the direction perpendicular to the length direction and parallel to the battery cell is referred to as the width direction (Y2), and the direction corresponding to the normal direction of the battery cell is referred to as the normal direction or height direction (Z2).

[0052] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

[0053] Figures 1 and 2 are perspective views and exploded perspective views, respectively, of a battery module 0 having a U-shaped frame 2 with the top and front and rear surfaces open, showing the module before and after assembly. Referring to these drawings, the battery module 0 having a U-shaped frame 2 may include a battery cell stack 1 made up of stacked battery cells 11 and a housing that houses it. The housing may include a frame 2 that covers the bottom and both sides in the width direction (Y1), an upper plate 10 that covers the top, and a pair of end plates 20 that cover both sides in the length direction (X1).

[0054] The frame 2 may be U-shaped, with the bottom surface 21 and both side walls in the width direction connected. The U-shaped frame 2 may be formed by joining the plate material constituting the bottom surface 21 and each plate material constituting the side walls, or it may be formed from a single plate material that is bent at the corners where the bottom surface 21 and the side walls intersect.

[0055] The frame 2 may be made of a metal sheet, and can be manufactured by plastically deforming the metal sheet by pressing. However, it is acceptable as long as it has the U-shape described above, regardless of the material or manufacturing process.

[0056] The frame 2 can be assembled together with the end plate 20 and the upper plate 10 to form a housing. This assembly may be done by welding or other joining methods, or by other methods such as friction fitting or bolt fastening.

[0057] On the other hand, the battery cell stack 1 is an assembly assembled by stacking a plurality of pouch-type battery cells 11, and the electrode leads (positive electrode leads and negative electrode leads) that protrude from the outside of the battery cells 11 may include busbars that connect leads with the same polarity or opposite polarity. The busbars can be electrically connected to the end plates 20 so that the battery cell stack 1 is electrically connected to the outside.

[0058] The battery cell stack 1 can be housed in the housing such that the normal direction (Z2) of each battery cell 11 coincides with the width direction of the housing. In this case, the battery cell stack 1 may be housed in the housing such that the vulnerable portion 11b of the battery cell 11, which will be described later, faces the bottom surface 21 of the frame 2 in the width direction.

[0059] Figure 3 is a perspective view showing a unit of the pouch-type battery cell 11. Referring to Figure 3, the battery cell 11 mainly consists of an electrode assembly, electrode tabs, and electrode leads housed in a pouch made of a material in which insulating material is coated on both sides of a metal sheet, with a portion of the electrode leads extending outwards from the pouch.

[0060] The electrode assembly has a structure in which a positive electrode plate and a negative electrode plate are laminated multiple times with a separation membrane in between. The electrode tabs extend and protrude from the positive electrode plate and the negative electrode plate, respectively, and can be configured so that those with the same polarity overlap each other. The electrode leads are electrically connected to the electrode tabs by welding, and a portion of the electrode leads extends in the longitudinal direction (X2) to the outside of the lead film surrounding the electrode leads and the pouch heat-welded thereon, thereby electrically connecting the electrode assembly to the outside.

[0061] The pouch is made of a metal sheet coated with an insulating material. A symmetrical rectangular metal sheet is folded in half along its axis of symmetry (which becomes one end in the width direction after folding), and the other three sides, excluding the folded portion, are heat-sealed to form the pouch. At this time, the two corner portions between the folded portion at one end in the width direction and the adjacent ends in the length direction are pressed together during the sealing process, thereby forming a weak portion (bat-ear) 11b that protrudes from the corner portion to one side in the width direction. Because the weak portion 11b has a protruding shape, it may interfere with the frame 2. If such interference occurs, it may result in poor sealing and / or insulation performance of the weak portion 11b.

[0062] On the other hand, a thermally conductive resin layer can be provided between the battery cell stack 1 and the frame 2 for the purpose of cooling the battery cell stack 1. The cooling effect refers to the function of the thermally conductive resin layer between the battery cell stack 1 and the frame 2 to conduct the heat generated in the battery cell stack 1 to the frame 2, making it easier to dissipate to the outside, in order to prevent a decrease in battery performance caused by the heat generated in the battery cell stack 1 not being effectively discharged to the outside of the battery module due to the insulating effect of the separation space between the battery cell stack 1 and the frame 2. In this case, the larger the separation space, the thicker the thermally conductive resin layer has to be, which reduces the economic efficiency of production. However, due to the protruding shape of the weak portion 11b, when the battery cell stack 1 is housed in a frame 2 having a flat inner surface, the separation distance between the battery cell stack 1 and the frame 2 is too far in parts other than the protruding portion of the weak portion 11b, which reduces the usability of the space and may cause the thermally conductive resin layer to become too thick.

[0063] In this regard, the present invention provides a battery module housing having a structure in which a cut-out portion 22 is formed by cutting off the protruding end of the fragile portion 11b in the frame 2 and the portion where interference may occur, and the cut-out portion 22 is covered by a double injection portion 23.

[0064] Figure 4 is a perspective view showing a U-shaped frame 2 according to one embodiment of the present invention. Referring to Figure 4, the end of the fragile portion 11b and the portion where interference occurs in the U-shaped frame 2 are cut out to provide a cut-out portion 22, and a double-injected portion 23, which is double-injected with synthetic resin, covers the cut-out portion 22.

[0065] The cut-out portion 22 can be formed by additionally cutting the existing frame 2 by pressing, or it can be formed in advance during the process of cutting a metal sheet material that is plastically deformed to the shape of the frame 2 by pressing. The method of forming the cut-out portion 22 can vary, as long as it has a shape in which a part of the frame 2 is removed in order to avoid interference between the weak portion 11b and the frame 2.

[0066] The cutout portion can be formed on the bottom surface 21 of the frame 2. For example, the cutout portion 22 can be formed on one end of the bottom surface 21 of the frame 2 in the longitudinal direction. Alternatively, the cutout portion 22 can be formed on the side wall of the frame 2. The location of the cutout portion 22 can be anywhere there is room for interference with the fragile portion 11b. For example, the location of the cutout portion 22 may be on the edge of the frame 2, or it may be inside any surface of the frame 2.

[0067] The cut-out portion 22 can be formed in a shape that curves into the bottom surface 21 or inner surface of the frame 2, leaving a portion of its thickness, or it can be formed so as to completely penetrate the formed surface. For example, the cut-out portion 22 can be formed by cutting so as to completely penetrate one side or part of both ends in the longitudinal direction of the bottom surface 21 of the frame 2. By performing trimming with a press, it is possible to form the cut-out portion 22 in a shape that completely penetrates the frame 2 at a low cost.

[0068] The cut-out portion 22 can be formed on the bottom surface 21 of the frame 2, with the corners where the bottom surface 21 and the side walls in the width direction intersect serving as its widthwise boundary.

[0069] The double injection section 23 may be made of synthetic resin and can be formed by double injection to connect to the processed surface 22m of the cut-out section 22 and cover the cut-out section 22. The cover means that the double injection section 23 fills the space of the cut-out section 22, which is created when the inner surface of the frame 2 curves inward or penetrates to the outside, thereby constituting a part of the inner wall of the frame 2.

[0070] The double injection section 23 may cover the cut-off section 22 and also extend outward. For example, the double injection section 23 may extend outward in the longitudinal direction relative to the side wall of the frame 2 even after covering the cut-off section 22 formed on one end of the bottom surface 21 of the frame 2.

[0071] The double injection section 23 does not cover the entire indented or penetrating space of the cut-out section 22, and may have an indented or penetrating shape at one end of itself. The curved or penetrating shape can be formed such that the penetrating portion is covered by a corresponding part of another component, such as the end plate 20.

[0072] The double injection section 23 may have a recessed shape compared to the inner surface of the frame 2 where the cut-out section 22 is formed. The recessed shape means that the surface where the cut-out section 22 is formed has a relative depth compared to the inner surface of the surface where the cut-out section 22 is not formed. For example, the recessed portion may have the shape of a groove, a groove, or a step. By providing the recessed shape, the double injection section 23 can prevent the vulnerable portion 11b of the battery cell 11 from interfering with the double injection section 23, even though the double injection section 23 covers the cut-out section 22.

[0073] The degree of indentation of the double injection section 23 can be determined to form a step corresponding to the degree of protrusion of the weak portion 11b. By the amount of the protrusion of the weak portion 11b, the double injection section 23 is indented compared to the inner surface of the frame 2, thereby reducing the separation distance between the battery cell laminate 1 and the frame 2. As a result, the thermal conductive resin layer can be made thinner, which is economical, or even without the thermal conductive resin layer, the heat generated in the battery cell laminate 1 can be easily conducted to the frame 2 and discharged to the outside.

[0074] The recessed shape or step can be formed along the processed surface 22m of the cut-out portion 22 in the width direction and / or in the length direction. For example, as in the embodiment described later, the double injection portion 23 may have a shape that is recessed compared to the bottom surface 21, with respect to the width direction boundary and the length direction boundary of the cut-out portion 22.

[0075] The double injection section 23 may be made of an insulating synthetic resin. In this case, even if the sealing or insulation of the fragile section 11b becomes poor, or if interference occurs between the fragile section 11b and the double injection section 23, the insulating state can be maintained because the double injection section 23 is insulating.

[0076] The double injection section 23 may be made of a thermally conductive synthetic resin, or it may be made of an insulating and thermally conductive synthetic resin. In this case, the double injection section 23 may also facilitate the conduction and dissipation of heat generated in the battery cell laminate 1 to the outside.

[0077] In this embodiment, the double injection section 23 is shown to be manufactured by double injection, but it is also possible to construct the double injection section 23 by insert injection or other methods. In other words, the term "double injection section" itself does not limit the manufacturing method of the said configuration to double injection.

[0078] Figure 5 is an enlarged side cross-sectional view showing one embodiment of the present invention. Referring to Figure 5, the double injection section 23 is formed to be thinner than the bottom surface 21 of the frame 2, so that it can have a recessed shape compared to the bottom surface 21. In this case, the lower surface of the bottom surface 21 and the lower surface of the double injection section 23 may be continuous with each other without any steps. In this case, if the frame 2 is placed on a flat bottom, a stable structure can be maintained. Figure 5 shows only the side view, i.e., the cross-section in the width direction of the frame 2, but if the processed surface 22m of the cut-out section 22 is also formed in the length direction, the same applies to the front view, i.e., the cross-section in the length direction of the frame 2.

[0079] For example, a housing according to one embodiment of the present invention, with reference to Figures 4 and 5, includes a U-shaped frame 2 made by plastically deforming a metal sheet, and a cutout portion 22 is provided in the bottom surface 21, with the corners where the bottom surface 21 and both side walls intersect serving as the widthwise boundary at one end of the frame 2 in the longitudinal direction, and a double injection section 23 is connected to the processed surface 22m of the cutout portion 22, the thickness of the double injection section 23 is thinner than the thickness of the bottom surface 21, the lower surface of the double injection section 23 is continuous with the lower surface of the bottom surface 21 at the same height and without any steps, and the upper surface is recessed downward compared to the upper surface of the bottom surface 21, forming a step only to the extent of the protrusion of the weak portion 11b of the battery cell 11.

[0080] Figure 6 is an enlarged side cross-sectional view showing another embodiment of the present invention. Referring to this, the double injection section 23 may have a thickness similar to that of the bottom surface 21 of the frame 2, but it itself protrudes downward compared to the bottom surface 21, and the upper surface of the double injection section 23 has a negative step difference with respect to the upper surface of the bottom surface 21, and the lower surface of the double injection section 23 has a positive step difference with respect to the lower surface of the bottom surface 21. The negative or positive step difference means that the upper or lower surface of the double injection section 23 is recessed or protrudes compared to the upper or lower surface of the bottom surface 21. In this way, the double injection section 23 or the bottom surface 21 can be prevented from becoming unnecessarily thick or so thin as to be unable to maintain strength, and a recessed shape can be formed that does not cause interference. Figure 6 shows only the side view, i.e., the cross-section in the width direction of the frame 2. However, if the processed surface 22m of the cut-out portion 22 is also formed in the length direction, the same applies to the front view, i.e., the cross-section in the length direction of the frame 2.

[0081] For example, a housing according to one embodiment of the present invention described with reference to Figures 4 and 6 includes a U-shaped frame 2 made by plastically deforming a metal sheet, and a cutout portion 22 is provided at one end of the frame 2 in the longitudinal direction, with the corners where the bottom surface 21 and both side walls intersect as its widthwise boundary, and the cutout portion 22 is formed to penetrate the bottom surface 21, and a double injection-molded portion 23 is connected to the processed surface of the cutout portion 22, the thickness of the double injection-molded portion 23 is the same as the thickness of the bottom surface 21, the double injection-molded portion 23 as a whole protrudes below the bottom surface 21, and the upper and lower surfaces of the bottom surface 21 may both be formed to have a step difference equal to the protrusion of the weak portion 11b of the battery cell 11.

[0082] Figure 7 is an enlarged side cross-sectional view showing yet another embodiment of the present invention. Referring to Figure 7, the double injection section 23 can cover not only the cut-out section 22 but also a portion of the inner bottom surface 21 of the boundary of the cut-out section 22. In this way, it is possible to prevent the phenomenon of damage to the insulation and sealing of the battery cell 11 caused by the formation of sharp steps or the like at the boundary of the area where the depression occurs, thereby preventing possible insulation performance defects. Figure 7 shows only the side view, i.e., the widthwise cross-section of the frame 2, but if the processed surface 22m of the cut-out section 22 is also formed in the lengthwise direction, the same applies to the front view, i.e., the lengthwise cross-section of the frame 2.

[0083] For example, a housing according to one embodiment of the present invention described with reference to Figures 4 and 7 includes a U-shaped frame 2 made by plastically deforming a metal sheet, and a cutout portion 22 is provided in the bottom surface 21, which penetrates the frame 2, with the corners where the bottom surface 21 and both side walls intersect being its widthwise boundary, and the processed surface 22m of the cutout portion 22 and a part of the inner bottom surface 21 of the boundary of the cutout portion 22 are connected to a double injection portion 23, the thickness of the double injection portion 23 is thinner than the thickness of the bottom surface 21, the lower surface of the double injection portion 23 is continuous with the lower surface of the bottom surface 21 at the same height and without any steps, and the upper surface is recessed downward compared to the upper surface of the bottom surface 21, forming a step between the upper surface of the bottom surface 21 and the degree of protrusion of the weak portion 11b of the battery cell 11.

[0084] Figure 8 shows a vehicle (V) equipped with a battery pack (P) including a battery module with an improved housing. Of course, the present invention can provide a battery module including the housing disclosed above, a battery pack (P) including the battery module, and a vehicle (V) equipped with the battery pack (P). Since the manufacturing methods for such battery packs (P) and vehicles (V) are known to the ordinary art, they are omitted from this specification.

[0085] The embodiments described above should be understood to be illustrative and not restrictive in all respects, and the scope of the present invention is indicated more by the claims described below than by the detailed description above. The meaning and scope of the claims described below, as well as any modifications and variations conceivable forms derived from their equivalent concepts, should be interpreted as being included within the scope of the present invention.

[0086] As described above, the present invention has been explained with reference to the illustrative drawings. However, the present invention is not limited by the embodiments and drawings disclosed herein, and it is obvious to an ordinary person of the art that various modifications can be made within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described and explained while embodiments of the present invention have been described above, it is natural to acknowledge that the effects that can be predicted by such configuration should also be acknowledged. [Explanation of Symbols]

[0087] 0 Battery Modules 10 Top plate 20 End Plates 1. Battery cell stack 11 battery cells 11b Weak part / bat-ear 2 frames 21 Bottom 22 Cut-off section 22m machined surface 23 Dual injection unit V Automobile P Battery Pack X1 Frame (Bottom) Length Direction Y1 Frame (bottom) width direction Z1 frame height direction X2 Battery cell length direction Y2: Width direction of the battery cell Z2 Battery cell height direction (normal direction)

Claims

1. A housing for accommodating a stack of battery cells, the housing comprises: A frame for housing the battery cell stack, the frame including a bottom surface on which the battery cell stack is arranged; A cut-off portion formed by cutting off one end of the bottom surface in the longitudinal direction, wherein when the battery cell stack is placed on the bottom surface, the cut-off portion does not interfere with the end of a fragile part of the battery cell stack that protrudes downward in the width direction to each battery cell of the battery cell stack; and A double injection molding section, one end of which is connected to the machined surface of the cut-off section, wherein the double injection molding section includes a portion in the longitudinal direction of the frame in which a step is formed downward from the one end toward the other end of the double injection molding section; housing.

2. The housing according to claim 1, wherein the frame is made of a metal plate and the double injection molding section is made of an insulating synthetic resin.

3. The housing according to claim 2, wherein the insulating synthetic resin is also a thermally conductive synthetic resin.

4. The frame has a U-shape with both sides and the top open in the longitudinal direction, The housing according to any one of claims 1 to 3, wherein the cut-out portion has a shape that curves inward into the bottom surface, with the corners where the side walls and bottom surface of the frame intersect as its widthwise boundaries.

5. The housing according to claim 4, wherein the double injection section is continuous with at least a portion of the processed surface of the cut-out section, and replaces the curved bottom surface of the frame, thereby forming a portion of the bottom surface.

6. The housing according to claim 5, wherein the height of the bottom surface of the double injection section is recessed below the height of the bottom surface of the frame, forming a step.

7. The housing according to claim 6, wherein the double injection section extends longitudinally from the frame.

8. The housing according to claim 6, wherein the height-direction thickness of the double injection section is the same as the height-direction thickness of the bottom surface of the frame, and the lower surface of the double injection section is formed to protrude downward compared to the lower surface of the frame.

9. The housing according to claim 6, wherein the height thickness of the double injection section is thinner than the height thickness of the bottom surface of the frame, and the lower surface of the double injection section is formed continuously at the same height as the lower surface of the frame.

10. The double injection section covers up to a part of the inner bottom surface of the interface of the cut-out section. The housing according to claim 6.

11. The frame has a U-shape with both sides and the top open in the longitudinal direction, The cut-out portion is formed at one end in the longitudinal direction of the bottom surface of the frame, and is formed to completely penetrate the bottom surface, with the corners where the side walls of the frame and the bottom surface intersect serving as its widthwise boundary. The housing according to any one of claims 1 to 3, wherein the double injection section is formed to cover the area that has been penetrated.

12. The housing according to claim 11, wherein the height of the bottom surface of the double injection section is recessed below the height of the bottom surface of the frame, forming a step.

13. The housing according to claim 12, wherein the double injection section extends longitudinally from the frame.

14. The housing according to claim 12, wherein the height-direction thickness of the double injection section is the same as the height-direction thickness of the bottom surface of the frame, and the lower surface of the double injection section is formed to protrude downward compared to the lower surface of the frame.

15. The housing according to claim 12, wherein the height-direction thickness of the double injection section is thinner than the height-direction thickness of the bottom surface of the frame, and the lower surface of the double injection section is formed continuously at the same height as the lower surface of the frame.

16. The housing according to claim 12, wherein the double injection portion covers up to a part of the inner bottom surface of the interface of the cut-out portion.

17. A battery module comprising a battery cell stack comprising battery cells having a vulnerable portion, and a housing that accommodates the battery cell stack, The aforementioned housing is A frame for housing the battery cell stack, the frame including a bottom surface on which the battery cell stack is arranged; A cut-off portion formed by cutting off one end of the bottom surface in the longitudinal direction, wherein when the battery cell stack is placed on the bottom surface, the cut-off portion does not interfere with the end of a fragile portion that protrudes downward in the width direction from each battery cell of the battery cell stack; and A double injection molding section, one end of which is connected to the machined surface of the cut-off section, wherein the double injection molding section includes a portion in the longitudinal direction of the frame in which a step is formed downward from the one end toward the other end of the double injection molding section; Battery module.

18. The cut-out portion is formed to completely penetrate a part of the frame, The battery module according to claim 17, wherein the double injection portion is formed to cover the area that has been penetrated.

19. The battery module according to claim 17, wherein the inner surface of the double injection portion includes a surface that is further recessed than the inner surface of the frame on which the cut-out portion is provided.

20. The frame comprises side walls spaced apart from each other in the width direction, and a bottom surface connecting the lower ends of the side walls in the width direction. The battery module according to claim 17, wherein the cut-out portion is located at one end in the longitudinal direction of the bottom surface.

21. The battery module according to claim 20, wherein the cut-out portion provides a portion in which one end of the bottom surface of the frame is recessed longitudinally inward than one end of the side walls in the longitudinal direction.

22. The battery module according to claim 17, wherein the double injection portion covers up to a part of the inner bottom surface of the interface of the cut-out portion.

23. A battery pack comprising a battery module according to any one of claims 17 to 22.

24. A vehicle equipped with the battery pack of claim 23.

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