Battery module, manufacturing method thereof, and battery pack including the battery module

Abstract

A battery module according to an embodiment of the present invention, the battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a first L-shaped frame that houses the battery cell stack and has an upper surface and a first side surface; and a second L-shaped frame that houses the battery cell stack and has a lower surface and a second side surface, wherein the first L-shaped frame and the second L-shaped frame surround four surfaces of the battery cell stack, any one of the first L-shaped frame and the second L-shaped frame has a protrusion, the other of the first L-shaped frame and the second L-shaped frame has a groove portion formed at a position corresponding to the protrusion, and the protrusion and the groove portion are engaged with each other, so that the first L-shaped frame and the second L-shaped frame are coupled to each other.

Description

Technical Field

[0001] The present disclosure relates to a battery module and a method for manufacturing the same, and more particularly, to a battery module that is easy to assemble and a method for manufacturing the same. Background Art

[0002] Secondary batteries have received much attention as an energy source in various products such as mobile devices and electric vehicles. A secondary battery is a powerful energy resource that can replace the use of existing products using fossil fuels and is attracting much attention as an environmentally friendly energy source since it does not produce by-products due to energy use.

[0003] Recently, as the need for a large-capacity secondary battery structure (including applications where a secondary battery is used as an energy storage source) has been increasing, the demand for a battery pack with a multi-module structure, which is an assembly of battery modules in which a plurality of secondary batteries are connected in series / parallel, is increasing.

[0004] Meanwhile, when a plurality of battery cells are connected in series / parallel to construct a battery pack, a battery module composed of battery cells is generally constructed first, and then a battery pack is constructed by using at least one battery module and adding other components.

[0005] A battery module includes a battery cell stack in which a plurality of battery cells are stacked and a module frame for accommodating the battery cell stack.

[0006] Figure 1 is a view showing a state in which a battery cell stack is assembled into a conventional module frame formed by an upper surface, a lower surface, a left surface, and a right surface.

[0007] Referring to Figure 1 , a conventional battery module may include a battery cell stack 10 in which a plurality of battery cells are stacked, and a single frame 20 that accommodates the battery cell stack and is formed by an upper surface, a lower surface, a left surface, and a right surface.

[0008] At this time, the battery cell stack 10 must be inserted inside the single frame 20, and friction and pressure may be generated between the battery cell stack 10 and the inner surface of the single frame 20. Therefore, there is a problem that the assembly difficulty between the battery cell stack 10 and the single frame 20 is very high.

[0009] Figure 2 is a view showing a state in which a battery cell stack is assembled in a conventional module frame formed by a U-shaped frame.

[0010] Referring to Figure 2, a conventional battery module may include a battery cell stack 30 in which a plurality of battery cells are stacked, a U-shaped frame 40 for accommodating the battery cell stack 30, and an upper plate 50 for covering the upper surface of the battery cell stack 30.

[0011] At this time, in order to insert the battery cell stack 30 into the U-shaped frame 40, the following process steps may be required: expanding two side surface portions of the U-shaped frame 40 to both sides, inserting the battery cell stack 30 between the two expanded side surface portions, and pressing the two expanded side surface portions open again after inserting the battery cell stack 30. While undergoing the above-described process steps, cumulative stress may occur in the U-shaped frame 40.

[0012] In addition, the upper plate 50 and the U-shaped frame 40 are joined to each other by welding, but the welded portion of the U-shaped frame 40 is located at the upper ends of the two side surface portions. Therefore, when the plurality of battery cells of the battery cell stack 30 expand, stress concentration may occur and the connection between the U-shaped frame 40 and the upper plate 50 may become loose, and the U-shaped frame 40 is likely to be damaged. Summary of the Invention

[0013] Technical Problem

[0014] An object of the present disclosure is to provide a battery module having improved assembly performance and a method for manufacturing the same.

[0015] The object of the present disclosure is not limited to the above object, and other objects not described herein should be clearly understood by those skilled in the art from the following detailed description.

[0016] Technical Solution

[0017] To achieve the above object, according to an embodiment of the present disclosure, there is provided a battery module including: a battery cell stack in which a plurality of battery cells are stacked; a first frame that accommodates the battery cell stack and includes an upper surface for covering the upper portion of the battery cell stack; and a second frame that accommodates the battery cell stack and includes a lower surface for covering the lower portion of the battery cell stack, wherein a protrusion is formed in either the first frame or the second frame, and a groove portion is formed at a position corresponding to the protrusion in the other of the first frame and the second frame, and the first frame and the second frame are joined by engaging the protrusion with the groove portion.

[0018] A first raised portion that gently protrudes downward may be formed at the side end edge of the upper surface of the first frame to engage with the second frame, and a second raised portion that gently protrudes upward may be formed at the side end edge of the lower surface of the second frame to engage with the first frame.

[0019] The protrusion may be formed on the raised surfaces of the first raised portion and the second raised portion.

[0020] To achieve the above object, according to another embodiment of the present disclosure, there is provided a battery module including: a battery cell stack in which a plurality of battery cells are stacked; a first L-shaped frame that houses the battery cell stack and is formed by an upper surface and a first side surface; and a second L-shaped frame that houses the battery cell stack and is formed by a lower surface and a second side surface, wherein the first L-shaped frame and the second L-shaped frame surround four surfaces of the battery cell stack, a protrusion is formed in any one of the first L-shaped frame and the second L-shaped frame, a groove portion is formed at a position corresponding to the protrusion in the other of the first L-shaped frame and the second L-shaped frame, and the first L-shaped frame and the second L-shaped frame are coupled by engaging the protrusion with the groove portion.

[0021] A first raised portion that gently protrudes downward may be formed at a side end edge of the upper surface of the first L-shaped frame to engage with an upper end portion of the second side surface of the second L-shaped frame, and a second raised portion that gently protrudes upward may be formed at a side end edge of the lower surface of the second L-shaped frame to engage with a lower end portion of the first side surface of the first L-shaped frame.

[0022] A protrusion may be formed on the raised surfaces of the first raised portion and the second raised portion, a groove portion may be formed on the upper end portion of the second side surface and the lower end portion of the first side surface, and the first L-shaped frame and the second L-shaped frame may be coupled while the protrusion engages with the groove portion.

[0023] The protrusion may be prominently formed at an outer edge portion of the raised surfaces of the first raised portion and the second raised portion.

[0024] The protrusions may be respectively formed at the center and both sides of the first raised portion and the second raised portion, and the groove portions may be formed at positions corresponding to the respective protrusions.

[0025] The lower surface of the first raised portion and the upper end surface of the second side surface, and the upper surface of the second raised portion and the lower end surface of the first side surface may be respectively joined by welding.

[0026] To achieve the above object, according to still another embodiment of the present disclosure, there is provided a method for manufacturing a battery module, the method including the steps of: inserting a battery cell stack into a second L-shaped frame toward a second side surface; coupling a first L-shaped frame with the second L-shaped frame to cover the battery cell stack; and coupling the first L-shaped frame with the second L-shaped frame by welding.

[0027] Before the step of inserting the battery cell stack into the second L-shaped frame, the method may further include the step of attaching compression pads to both side surfaces of the battery cell stack.

[0028] In the step of inserting the battery cell stack into the second L-shaped frame, the battery cell stack may be inserted into the second L-shaped frame while the compression pad is being squeezed by the second side surface.

[0029] According to another embodiment of the present disclosure, the battery module may be included in a battery pack.

[0030] Technical effects

[0031] The battery module and the method of manufacturing the battery module according to an embodiment of the present disclosure adopt an assembly structure of two L-shaped frames, thereby providing effects of improving the assembly performance of the frame structure, enhancing durability, and achieving sharing between the two L-shaped frames.

[0032] The effects of the present disclosure are not limited to the above-mentioned effects, and those skilled in the art will clearly understand other effects not described above from the description of the appended claims. Brief description of the drawings

[0033] Figure 1 is a diagram showing a state in which a battery cell stack is assembled into a conventional module frame formed by an upper surface, a lower surface, a left surface, and a right surface;

[0034] Figure 2 is a diagram showing a state in which a battery cell stack is assembled in a conventional module frame formed by a U-shaped frame;

[0035] Figure 3 is an exploded perspective view of a battery module according to an embodiment of the present disclosure;

[0036] Figure 4 is a schematic diagram showing the structures of a first L-shaped frame and a second L-shaped frame according to an embodiment of the present disclosure;

[0037] Figure 5 is a schematic diagram showing a state in which a battery cell stack is assembled into a second L-shaped frame according to an embodiment of the present disclosure;

[0038] Figure 6 is a diagram showing the state of assembling the first L-shaped frame in the state of Figure 5 ; and

[0039] Figure 7 is a diagram showing the state of connecting the first L-shaped frame and the second L-shaped frame by welding in the state of Figure 6 ;

[0040] [Description of Reference Signs]

[0041] 100: Battery cell stack

[0042] 110: Compression pad

[0043] 200: First L-shaped frame

[0044] 200a: first side surface

[0045] 210: First ridge

[0046] 211: The bulge

[0047] 212: Groove

[0048] 300: Second L-shaped frame

[0049] 300a: second side surface

[0050] 310: Second ridge

[0051] 311: The Prominence

[0052] 312: Groove DETAILED DESCRIPTION

[0053] It should be understood that the exemplary embodiments described below are described exemplarily to help understand the present disclosure, and the present disclosure may be variously modified to be implemented differently from the exemplary embodiments described herein. However, in the description of the present disclosure, when it is determined that the specific description and illustration may unnecessarily confuse the subject matter of the present disclosure, the specific description and illustration of well-known functions or constituent elements will be omitted. In addition, in order to help understand the present disclosure, the drawings are not illustrated in actual proportion, and the size of a portion of the constituent elements may be exaggerated.

[0054] As used herein, terms such as first, second, etc. may be used to describe various components, and the components are not limited by these terms. These terms are only used to distinguish one component from another component.

[0055] In addition, the terms used herein are only used to describe specific exemplary embodiments and are not intended to limit the scope of the present disclosure. Singular expressions include plural expressions unless they have clear opposite meanings in the context. It should be understood that the terms "include", "comprise" and "have" used herein are intended to specify the presence of the features, quantities, steps, constituent elements, movements, parts or combinations thereof, but it should be understood that they do not exclude the possibility of the presence or addition of one or more other features, quantities, steps, movements, constituent elements, parts or combinations thereof.

[0056] In the following, reference will be made to Figure 3 andFigure 4 Describe a battery module according to an embodiment of the present disclosure.

[0057] Figure 3 is an exploded perspective view of a battery module according to an embodiment of the present disclosure. Figure 4 is a schematic structural view showing a first L-shaped frame and a second L-shaped frame according to an embodiment of the present disclosure.

[0058] Refer to Figure 3 and Figure 4 According to an embodiment of the present disclosure, a battery module includes: a battery cell stack body 100 in which a plurality of battery cell stacks are stacked, a first L-shaped frame 200 that houses the battery cell stack body 100 and is formed by an upper surface and a first side surface 200a, and a second L-shaped frame 300 that houses the battery cell stack body 100 and is formed by a lower surface and a second side surface 300a.

[0059] The battery cell is a secondary battery and can be configured as a pouch-type secondary battery. Such a battery cell can be composed of a plurality of units, and the plurality of battery cells can be stacked together to be electrically connected to each other, thereby forming the battery cell stack body 100. Each of the plurality of battery cells may include an electrode assembly, a battery case, and an electrode lead protruding from the electrode assembly.

[0060] Refer to Figure 3 According to, compression pads 110 may be attached to two side surfaces of the battery cell stack body 100. The expansion of the battery cell stack body 100 can be absorbed by the compression pads 110.

[0061] According to this embodiment, the first L-shaped frame 200 and the second L-shaped frame 300 surround four surfaces of the battery cell stack body 100, protrusions 211 and 311 are formed in any one of the first L-shaped frame 200 and the second L-shaped frame 300, groove portions 212 and 312 are formed at positions corresponding to the protrusions 211 and 311 in the other of the first L-shaped frame 200 and the second L-shaped frame 300, and the first L-shaped frame 200 and the second L-shaped frame 300 are coupled by engaging the protrusions 211 and 311 with the groove portions 212 and 312.

[0062] When inserting a battery cell laminate into a conventional single-frame structure formed by an upper surface, a lower surface, a left surface, and a right surface, there is a risk of interference between the inner surface of the single frame and the battery cell laminate. In addition, when inserting the battery cell laminate into a conventional U-shaped frame structure, a process of expanding and retracting the side surface portions of the U-shaped frame is required, which may cause cumulative stress. When the battery cell laminate inserted into the U-shaped frame expands, stress concentrates at the welded portion between the upper side plate and the upper end portions of the two side surfaces of the U-shaped frame, posing a risk of damaging the frame structure.

[0063] Therefore, according to an embodiment of the present disclosure, the battery cell laminate 100 is accommodated via the structures of two first L-shaped frames 200 and a second L-shaped frame 300, thereby eliminating another step of having to expand the frame when inserting the battery cell laminate 100. In addition, since the battery cell laminate 100 can be easily assembled toward the second side surface 300a of the second L-shaped frame 300, the assembly performance can be improved compared to the conventional case.

[0064] In addition, even when the battery cell laminate 100 expands in the state of being inserted into the first L-shaped frame 200 and the second L-shaped frame 300, the position of the frame coupling portion can be located at the frame side surface portion by means of the raised portion welding structure or the protrusion-recess coupling structure described later, thereby improving the stress concentration structure caused by expansion, and thus ensuring the durability of the frame structure.

[0065] In addition, in the case of the first L-shaped frame 200 and the second L-shaped frame 300, they are formed in a symmetric structure with each other, such that they can be produced from only one frame structure during frame production and then assembled with each other, thereby realizing the generalization of frame products.

[0066] According to this embodiment, as Figure 4 shown, a first raised portion 210 that gently protrudes downward can be formed at the side end edge of the upper surface of the first L-shaped frame 200 to engage with the upper end portion of the second side surface 300a of the second L-shaped frame 300. In addition, a second raised portion 310 that gently protrudes upward can be formed at the side end edge of the lower surface of the second L-shaped frame 300 to engage with the lower end portion of the first side surface 200a of the first L-shaped frame 200.

[0067] In addition, according to this embodiment, protrusions 211 and 311 are formed on the raised surfaces of the first raised portion 210 and the second raised portion 310, and recess portions 212 and 312 are formed on the lower end portion of the first side surface 200a and the upper end portion of the second side surface 300a, and the first L-shaped frame 200 and the second L-shaped frame 300 can be coupled while the protrusions 211 and 311 are coupled with the recess portions 212 and 312.

[0068] More specifically, the protrusions 311 formed on the raised surface of the second raised portion 310 formed in the second L-shaped frame 300 can be coupled to the groove portions 212 formed on the lower end portion of the first side surface 200a of the first L-shaped frame 200. In addition, the protrusions 211 formed on the raised surface of the first raised portion 210 formed in the first L-shaped frame 200 can be coupled to the groove portions 312 formed on the upper end portion of the second side surface 300a of the second L-shaped frame 300.

[0069] Referring to Figure 4 , the protrusions 211 and 311 can be formed at the center and both sides of the first raised portion 210 and the second raised portion 310, and the groove portions 212 and 312 can be formed at positions corresponding to the respective protrusions 211 and 311.

[0070] However, the protrusions 211 and 311 and the groove portions 212 and 312 are not limited to Figure 4 the structures shown, and the protrusions 211 and 311 formed on each raised portion can be formed in a number of four or more. In addition, a plurality of groove portions 212 and 312 can be formed to correspond to the protruding positions of the protrusions 211 and 311 formed in a plurality. At this time, the positions of the protrusions 211 and 311 and the groove portions 212 and 312 can be formed symmetrically with respect to the center of the coupling surface between the frames, regardless of the number.

[0071] According to the present embodiment, the protrusions 211 and 311 can be prominently formed at the outer edge portions of the raised surfaces of the first raised portion 210 and the second raised portion 310. In the portions where the protrusions 211 and 311 are formed, when an expansion phenomenon of the battery cell stack 100 inserted therein occurs, a double-layer structure in which the protrusions 211 and 311 are coupled to the first side surface 200a and the second side surface 300a so as to overlap each other is formed, so that due to the expansion, the force acting on the side surface of the frame in the direction perpendicular to the side surface portion of the frame can be effectively responded to.

[0072] In addition, the protrusions 211 and 311 are located at the outer edges of the raised surfaces, so that when assembling between the first L-shaped frame 200 and the second L-shaped frame 300, the assembling position of the frames between the first L-shaped frame 200 and the second L-shaped frame 300 can be guided via the protrusions 211 and 311, and the first L-shaped frame 200 and the second L-shaped frame 300 can be assisted to be coupled to each other at an accurate position.

[0073] Referring to Figure 4 and Figure 7, the lower surface of the first raised portion 210 and the upper end surface of the second side surface 300a, as well as the upper surface of the second raised portion 310 and the lower end surface of the first side surface 200a can be connected by welding respectively. Therefore, in addition to the protrusion-recess connection structure between the protrusion portions 211, 311 and the recess portions 212, 312, a welding-connection structure between the raised surfaces and the upper and lower end surfaces of the frame can also be adopted, so that a double connection structure can be formed between the first L-shaped frame 200 and the second L-shaped frame 300. Thus, the connection force between the first L-shaped frame 200 and the second L-shaped frame 300 can be strengthened, and the durability of the frame structure can be further enhanced.

[0074] Meanwhile, in the above text, it has been described that the battery module includes a first L-shaped frame 200 and a second L-shaped frame 300, the first raised portion 210 and the second raised portion 310 are formed in the first L-shaped frame 200 and the second L-shaped frame 300, and the two L-shaped frames 200 and 300 are connected by engaging the protrusion portions 211 and 311 with the recess portions 212 and 312. However, the above method of connecting the two L-shaped frames 200 and 300 can also be applied to frames with other shapes.

[0075] For example, the frame surrounding the outer surface of the battery cell stack 100 can include two sub-frames, namely, the first frame and the second frame. Here, the shapes of the first frame and the second frame can be set as plate shape, U shape or other shapes, and can be set as various shapes not mentioned here.

[0076] The first frame can include an upper surface covering the upper part of the battery cell stack 100, and the second frame can include a lower surface covering the lower part of the battery cell stack 100. A protrusion portion is formed in either the first frame or the second frame, a recess portion can be formed in the other frame, and the first frame and the second frame are connected by engaging the protrusion portion and the recess portion.

[0077] In addition, a first raised portion protruding downward is formed at the side end edge of the upper surface of the first frame, and a second raised portion protruding upward is formed at the side end edge of the lower surface of the second frame. Here, protrusion portions can be formed on the first raised portion and the second raised portion. Recess portions can be formed in the portion of the second frame corresponding to the first raised portion and the portion of the first frame corresponding to the second raised portion, so that the protrusion portions and the recess portions can be engaged with each other.

[0078] Therefore, even if expansion occurs in the state where the battery cell stack 100 is inserted into the first frame and the second frame, the position of the frame connection portion is located at the side surface portion of the frame through the raised portion welding structure or the protrusion-recess connection structure, thus ensuring the durability of the frame structure, and thus improving the stress concentration structure caused by expansion.

[0079] On the other hand, the first raised portion, the second raised portion, the protruding portion, and the groove portion include all the contents of the first raised portion 210, the second raised portion 310, the protruding portions 211 and 311, and the groove portions 212 and 312 described with reference to the above-mentioned drawings and the like, and their detailed descriptions will be omitted to avoid redundant descriptions.

[0080] Next, a method of manufacturing a battery module according to an embodiment of the present disclosure will be described with reference to Figures 5 to 7 FIG. 10 is a view showing a state in which a battery cell laminate is assembled into a second L-shaped frame according to an embodiment of the present disclosure.

[0081] Figure 5 FIG. 11 is a view showing a state in which a first L-shaped frame is assembled in the state of Figure 6 FIG. 12 is a view showing a state in which the first L-shaped frame and the second L-shaped frame are joined by welding in the state of Figure 5 FIG. 13 is a view showing a state in which the first L-shaped frame and the second L-shaped frame are joined by welding in the state of Figure 7 FIG. 14 is a view showing a state in which the first L-shaped frame and the second L-shaped frame are joined by welding in the state of Figure 6 FIG. 15 is a view showing a state in which the first L-shaped frame and the second L-shaped frame are joined by welding in the state of

[0082] With reference to Figures 5 to 7 FIGS. 10 to 15, a method of manufacturing a battery module according to an embodiment of the present disclosure includes: inserting the battery cell laminate 100 shown in Figure 5 FIG. 10 into the second L-shaped frame 300 toward the second side surface 300a; joining the first L-shaped frame 200 shown in Figure 6 FIG. 11 to the second L-shaped frame 300 to cover the battery cell laminate 100; and joining the first L-shaped frame 200 and the second L-shaped frame 300 by welding.

[0083] As described above, after inserting the battery cell laminate 100 toward the second side surface 300a of the second L-shaped frame 300, it is sufficient to cover the first L-shaped frame 200, so that the joining between the battery cell laminate and the frame can be easily performed.

[0084] According to the present embodiment, before the step of inserting the battery cell laminate 100 into the second L-shaped frame 300, the method further includes a step of attaching compression pads 110 to both side surfaces of the battery cell laminate 100. The expansion of the battery cell laminate 100 is absorbed via the compression pads 110 to help ensure the durability of the frame structure.

[0085] In addition, according to the present embodiment, in the step of inserting the battery cell stack 100 into the second L-shaped frame 300, the battery cell stack 100 can be inserted into the second L-shaped frame 300 while the compression pad 110 is being pressed by the second side surface 300a. When the battery cell stack 100 is inserted into the frame, damage may occur due to a collision between the battery cell stack 100 and the frame. Therefore, according to the present embodiment, the battery cell stack 100 attached with the compression pad 110 is inserted into the interior of the second L-shaped frame 300 toward the second side surface 300a, thereby being able to prevent in advance damage caused by a collision between the second side surface 300a and the side surface of the battery cell stack 100. That is, the compression pad 110 can function as a buffer when the battery cell stack 100 and the second side surface 300a are assembled.

[0086] The above battery module can be included in a battery pack. The battery pack can have a structure in which one or more battery modules according to the present embodiment are gathered together and packaged together with a battery management system (BMS) and a cooling device that control and manage battery temperature, voltage, etc.

[0087] The battery pack can be applied to various devices. Such devices can be applied to transportation means such as electric bicycles, electric vehicles, and hybrid vehicles, but the present disclosure is not limited thereto, and can be applied to various devices that can use the battery module, which also belongs to the scope of the present disclosure.

[0088] Although the present invention has been shown and described with reference to the preferred embodiments, the scope of the present disclosure is not limited thereto, and those skilled in the art can design many other modifications and embodiments without departing from the spirit and scope of the principles of the invention described in the appended claims. In addition, these modified embodiments should not be understood separately according to the technical spirit or viewpoints of the present disclosure.

[0089] Cross-reference to related applications

[0090] This application claims the priority of Korean Patent Application No. 10-2020-0122295 filed with the Korean Intellectual Property Office on September 22, 2020, and Korean Patent Application No. 10-2021-0094713 filed with the Korean Intellectual Property Office on July 20, 2021, the disclosures of which are incorporated herein by reference in their entirety.

Claims

1. A battery module, the battery module comprising: A battery cell stack in which a plurality of battery cells are stacked; A first frame that houses the battery cell stack and includes an upper surface for covering an upper portion of the battery cell stack; And A second frame that houses the battery cell stack and includes a lower surface for covering a lower portion of the battery cell stack, Wherein, a plurality of protrusions are formed in any one of the first frame and the second frame, and a plurality of groove portions are formed at positions corresponding to the protrusions in the other of the first frame and the second frame, and the first frame and the second frame are respectively coupled by a protrusion-groove coupling structure that engages the protrusions with the groove portions, Wherein, at least one of the protrusions and at least one of the groove portions are formed between a plurality of welding coupling structures located between the first frame and the second frame, Wherein: A first raised portion that gently protrudes downward is formed in a side end edge of the upper surface of the first frame for engaging with the second frame, A second raised portion that gently protrudes upward is formed in a side end edge of the lower surface of the second frame for engaging with the first frame, Wherein, a lower surface of the first raised portion and an upper end surface of the second frame and an upper surface of the second raised portion and a lower end surface of the first frame are joined by welding to form the welding coupling structure, Wherein, the protrusions are prominently formed at an outer edge portion of a raised surface of the first raised portion and the second raised portion, and Wherein, the groove portions are formed in a portion of the second frame corresponding to the first raised portion and a portion of the first frame corresponding to the second raised portion, whereby the protrusions and the groove portions are engaged with each other.

2. The battery module according to claim 1, wherein, Compression pads are attached to both side surfaces of the battery cell stack.

3. A battery module, the battery module comprising: A battery cell stack in which a plurality of battery cells are stacked; A first L-shaped frame that houses the battery cell stack and is formed by an upper surface and a first side surface; And A second L-shaped frame that houses the battery cell stack and is formed by a lower surface and a second side surface, Wherein, the first L-shaped frame and the second L-shaped frame surround four surfaces of the battery cell stack, A plurality of protrusions are formed in any one of the first L-shaped frame and the second L-shaped frame, and a plurality of groove portions are formed at positions corresponding to the protrusions in the other of the first L-shaped frame and the second L-shaped frame, and the first L-shaped frame and the second L-shaped frame are respectively coupled by a protrusion-groove coupling structure that engages the protrusions with the groove portions, Wherein, at least one of the protrusions and at least one of the groove portions are formed between a plurality of welding coupling structures located between the first L-shaped frame and the second L-shaped frame, Wherein: A first raised portion that gently protrudes downward is formed at a side end edge of the upper surface of the first L-shaped frame to engage with an upper end portion of the second side surface of the second L-shaped frame. A second raised portion that gently protrudes upward is formed at a side end edge of the lower surface of the second L-shaped frame to engage with a lower end portion of the first side surface of the first L-shaped frame. Wherein, a lower surface of the first raised portion and an upper surface of the upper end of the second L-shaped frame, and an upper surface of the second raised portion and a lower surface of the lower end of the first L-shaped frame are joined by welding to form the welded joint structure, and wherein, the protruding portions are prominently formed at outer edge portions of the raised surfaces of the first raised portion and the second raised portion. Wherein, the protruding portions are formed on the raised surfaces of the first raised portion and the second raised portion, and groove portions are formed on the upper end portion of the second side surface and the lower end portion of the first side surface, and the groove portions are formed at positions corresponding to the respective protruding portions, whereby the protruding portions and the groove portions are engaged with each other.

4. The battery module according to claim 3, wherein: The first L-shaped frame and the second L-shaped frame are joined while the protruding portions and the groove portions are joined.

5. The battery module according to claim 3, wherein: The protruding portions are respectively formed at the center and both sides of the first raised portion and the second raised portion.

6. The battery module according to claim 3, wherein: The lower surface of the first raised portion and the upper end surface of the second side surface, and the upper surface of the second raised portion and the lower end surface of the first side surface are respectively joined by welding.

7. A method for manufacturing the battery module according to any one of claims 3 to 6, the method comprising the following steps: Inserting a battery cell laminate into the second L-shaped frame toward the second side surface of the second L-shaped frame; Joining the first L-shaped frame and the second L-shaped frame to cover the battery cell laminate; and Joining the first L-shaped frame and the second L-shaped frame by welding.

8. The method according to claim 7, wherein: Before the step of inserting the battery cell laminate into the second L-shaped frame, the method further comprises the following step: attaching compression pads to both side surfaces of the battery cell laminate.

9. The method according to claim 8, wherein: In the step of inserting the battery cell laminate into the second L-shaped frame, the battery cell laminate is inserted into the second L-shaped frame while the compression pads are squeezed by the second side surface.

10. A battery pack including the battery module according to any one of claims 1 to 6.

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