Battery module housing and battery module including the same

Abstract

According to the battery module shell of the embodiment of the invention, the welding defect is improved through the stepped structure, so that the binding force between the parts of the shell is increased, and the yield of the battery module is improved.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0065689, filed on May 27, 2022, and Korean Patent Application No. 10-2023-0062507, filed on May 15, 2023, which are hereby incorporated by reference in their entirety.

[0002] The present invention relates to a battery module housing and a battery module comprising the battery module housing. Background Art

[0003] Generally, types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, lithium-ion polymer batteries, etc. These secondary batteries are suitable for and used not only in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game consoles, power tools, electric bicycles, but also in large products such as electric vehicles and hybrid vehicles requiring high output, energy storage systems for storing surplus generated electricity or new renewable energy, and backup energy storage systems.

[0004] In order to manufacture these secondary batteries, positive and negative electrodes are manufactured by coating positive and negative current collectors with electrode active material slurry, and then the positive and negative electrodes are stacked on both sides of a separator to provide an electrode assembly having a predetermined shape. Thereafter, a battery case accommodates the electrode assembly and is sealed after injecting an electrolyte.

[0005] As described above, the battery case accommodates the electrode assembly and is injected with an electrolyte to manufacture a battery cell. A plurality of battery cells are housed in a frame-shaped case in a state of being coupled to each other to be protected from external impact, heat, vibration, etc. Thus, a battery module can be manufactured, and then a control component such as a battery management system (BMS) can be provided in the battery module to complete a battery pack.

[0006] In the process of accommodating battery cells in a battery module case and welding the battery module case, there is a problem of welding defects occurring, thereby reducing the yield of the battery module. Therefore, a battery module case having a structure that can easily weld the battery module case and increase welding bonding strength is required. Summary of the invention

[0007] Technical issues

[0008] An object of the present invention to solve the above-mentioned problems is to provide a battery module case having improved welding defects.

[0009] Technical Solution

[0010] A battery module housing according to an embodiment of the present invention may include: a main body, which includes a bottom plate and a pair of side plates respectively connected to two side portions of the bottom plate; an end plate, which covers each of the front surface and the rear surface of the main body respectively arranged on the front side and the rear side along the longitudinal direction of the bottom plate to be connected to the main body; and a cover plate, which covers a surface of the main body parallel to the longitudinal direction of the bottom plate to be connected to the main body, wherein one side of the bottom plate connected to the end plate is arranged in a stepped shape.

[0011] The bottom plate may include a body portion; and a step portion provided in a stepped shape at each of both ends of the body portion.

[0012] The end plates may be coupled and connected to the stepped portion.

[0013] The end plate may include a coupling portion which is recessed to correspond to a shape of the step portion.

[0014] Based on observing the side plate, the connecting portion may have a first surface connected to and perpendicular to the bottom surface of the end plate and a second surface connected to and perpendicular to the first surface, wherein the step portion is connected to each of the first surface and the second surface so that the end plate and the body are connected to each other.

[0015] Based on when viewing the side plate, the step portion may be provided in a stepped shape toward the center of the body portion at each of both sides of the body portion, and each of the front surface and the rear surface may be provided by the step portion and the side plate.

[0016] The thickness of the step portion may be greater than the thickness of the body portion.

[0017] The thickness of the step portion may be 1.2 mm or more.

[0018] Beneficial Effects

[0019] According to the preferred embodiments of the present invention, welding defects may be improved to increase the bonding force between components of a case and improve the yield of a battery module.

[0020] In addition, effects that can be easily predicted by those skilled in the art from the configuration according to the preferred embodiments of the present invention can be included. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following drawings attached to this specification illustrate preferred embodiments and functions of the present invention, so as to further understand the technical concept of the present invention together with the detailed description of the present invention. The present invention should not be interpreted as being limited to the drawings.

[0022] Figure 1 is a perspective view of a battery module case according to an embodiment of the present invention.

[0023] Figure 2 is an exploded view of a battery module case according to an embodiment of the present invention.

[0024] Figure 3 is a perspective view of a main body according to an embodiment of the present invention.

[0025] Figure 4 It is along Figure 1 A cross-sectional view of the battery module housing taken along line AA'. DETAILED DESCRIPTION

[0026] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments described herein.

[0027] In order to clearly describe the present invention, parts that are irrelevant to the description or detailed description of related well-known technologies that may unnecessarily obscure the subject matter of the present invention will be excluded. Throughout the specification, the same reference numerals refer to the same elements.

[0028] Furthermore, the terms or words used in the specification and claims should not be restrictively interpreted as ordinary meanings or dictionary-based meanings, but should be interpreted as meanings and concepts consistent with the scope of the present invention based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe and explain his or her invention.

[0029] Figure 1 is a perspective view of a battery module case 10 according to an embodiment of the present invention.

[0030] Reference Figure 1 , the battery module housing 10 may have a housing space defined therein to accommodate a cell assembly to be described later. The battery module housing 10 may accommodate the cell assembly to protect the cell assembly from the external environment such as external impact and heat. In addition, the battery module housing 10 may be manufactured by accommodating the cell assembly therein in a state where one of its surfaces is open and assembling and welding the opening portion. For example, in a rectangular parallelepiped frame having an open front surface M1 and a rear surface M2, the front surface M1 and the rear surface M2 may be covered and welded to manufacture the battery module housing 10. During welding of the battery module housing 10, the battery module housing 10 may be more stably welded by a stepped structure of part of the battery module housing 10. Specifically, the thickness of each portion to be welded may be adjusted so that the bonding force between the components of the battery module housing 10 is further increased.

[0031] Figure 2is an exploded view of the battery module case 10 according to the embodiment of the present invention.

[0032] Reference Figure 2 The battery module housing 10 may include a main body 100 , an end plate 101 and a cover plate 102 .

[0033] The main body 100 may be a frame used as a reference for manufacturing the battery module housing 10. In other words, the main body 100 is a frame in a shape with one side open, and may be a frame that defines a receiving space, and is assembled with the end plate 101 and the cover plate 102, which will be described later. Specifically, the main body 100 may have a longitudinal direction, and include a rectangular parallelepiped structure in which the front surface M1 and the rear surface M2 are open in the longitudinal direction. In addition, the main body 100 may include a structure in which one surface M3 parallel to the longitudinal direction is open. According to such a structure, the main body 100 may have a shape in which three surfaces of the rectangular parallelepiped are open.

[0034] Figure 3 is a perspective view of a main body 100 according to an embodiment of the present invention.

[0035] Reference Figure 3 , the main body 100 may include a bottom plate 1000 and a side plate 1001. For example, the bottom plate 1000 may constitute the bottom surface of the main body 100. In a state where the bottom plate 1000 constitutes the bottom surface of the main body 100, the side plate 1001 may be connected to each of the two side portions of the bottom plate 1000. In other words, a pair of side plates 1001 may be respectively connected to the two side portions of the bottom plate 1000 in the longitudinal direction of the bottom plate 1000. In this case, the side plate 1001 may be vertically connected to the bottom plate 1000. Therefore, such a front surface M1 and a rear surface M2 may be provided, each of which is defined by one side of the bottom plate 1000 and one side of each side plate of the pair of side plates 1001.

[0036] The bottom plate 1000 may have a stepped portion. For example, the bottom plate 1000 may include a body portion 1000a and a stepped portion 1000b. The body portion 1000a may be disposed at the central portion of the bottom plate 1000 and have a plate shape having a uniform thickness. The stepped portion 1000b is a portion connected to each of the two ends of the body portion 1000a and may have a stepped shape. Specifically, the stepped portion 1000b may not be connected to the two ends of the body portion 1000a connected to the side plate 1001, but may be connected to the two ends of the body portion 1000a connected to the end plate 101, respectively. In other words, the stepped portion 1000b may be connected to the two ends of the body portion 1000a constituting the above-mentioned front surface M1 and rear surface M2, respectively. That is, each of the front surface M1 and rear surface M2 may be provided by the stepped portion 1000b and the side plate 1001.

[0037] More specifically, the step portion 1000b may be provided in a stepped shape on each of the two sides of the body portion 1000a toward the center of the body portion 1000a based on viewing the side plate 1001. In addition, the thickness of the step portion 1000b may be greater than the thickness of the body portion 1000a. That is, the bottom plate 1000 may have a structure in which, in a state in which the body portion 1000a is provided at the center, the step portion 1000b on each of the two sides of the body portion 1000a protrudes upward based on viewing the side plate 1001.

[0038] The end plates 101 may be connected to the body 100 to cover the front surface M1 and the rear surface M2 of the body 100. In other words, the end plates 101 may be provided in pairs, and a pair of end plates 101 may be provided at the front and rear sides of the body 100 to be connected to the body 100, respectively.

[0039] Figure 4 It is along Figure 1 A cross-sectional view of the battery module housing taken along line AA'.

[0040] Reference Figure 4 , the end plate 101 may be coupled and connected to the stepped portion 1000b. Specifically, the end plate 101 may include a coupling portion 1010 that is recessed to correspond to the shape of the stepped portion 1000b. For example, based on observing the side plate 1001, the coupling portion 1010 may have a first surface 1010a, a second surface 1010b, and a third surface 1010c.

[0041] The first surface 1010a may be connected to the bottom surface 101a of the end plate 101 and be perpendicular to the bottom surface 101a. In addition, the second surface 1010b may be connected to the first surface 1010a and be perpendicular to the first surface 1010a. Finally, the third surface 1010c may be connected to the second surface 1010b and be perpendicular to the second surface 1010b. In this case, in a case where an extension line of the bottom surface 101a of the end plate 101 matches an extension line of the bottom surface of the stepped portion 1000b, the stepped portion 1000b may be inserted toward the first surface 1010a to be coupled and welded to each of the first surface 1010a and the second surface 1010b, so that the end plate 101 and the main body 100 are coupled to each other.

[0042] Hereinafter, description will be given of the contents and results of an experiment for measuring weldability between the body 100 and the end plate 101. Specifically, during welding of the step portion 1000b to the end plate 101, the length of a welding defect occurring was measured.

[0043] More specifically, a drain hole is defined in the central portion of the step portion 1000b, and the portion to be welded is provided at each of both sides of the drain hole in the step portion 1000b. In this case, the welded portion at one side has a length of 85 mm. In the experiment, when the welded portion at one side is welded, the thickness L of the step portion 1000b is measured. 1 The length of the weld defect that occurs.

[0044] Measure the thickness L of the step portion 1000b 1 The results of the lengths of the welding defects that occurred are shown in Table 1 below.

[0045] [Table 1]

[0046] <![CDATA[L 1 ]]> Welding defect length 1.2mm 0.78mm 1.1mm 3.45mm 0.9mm 15.98mm

[0047] Referring to Table 1, when the thickness L of the step portion 1000b is 1 When the thickness L of the step portion 1000b is 1.1 mm or more, it can be confirmed that the length of the welding defect is significantly reduced. 1 It may be 1.1 mm or larger. Preferably, the thickness L of the step portion 1000b is 1 It can be 1.2 mm or larger. When the thickness L of the step portion 1000b is 1 When the diameter is 1.2 mm or larger, it can be confirmed that the length of the welding defect is significantly reduced.

[0048] In addition, considering the thickness of the joint portion of the end plate 101, the thickness L of the step portion 1000b is 1 Can be 1.5mm or smaller. Figure 4 In the cross section observed in FIG. 1 , the sum of the thickness of the step portion 1000b and the thickness of the end plate 101 may be 3 mm. In other words, as the thickness of the step portion 1000b increases, the thickness of the end plate 101 may decrease.

[0049] When the thickness L of the step portion 1000b is 1 When it is greater than 1.5 mm, the thickness of the end plate 101 may be reduced, causing a problem that the welding bonding is significantly reduced due to melting and welding by introducing from the step portion 1000 b into the end plate 101. That is, in order to ensure the welding depth, the thickness L of the step portion 1000 b is 1 It may be no greater than the thickness of the end plate 101 .

[0050] Therefore, when the thickness L of the stepped portion 1000b of the bottom plate 1000 according to the embodiment of the present invention is 1 When the thickness is designed to be 1.2 mm to 1.5 mm, the weldability between the bottom plate 1000 and the end plate 101 can be greatly improved.

[0051] As described above, since the thickness of the step portion 1000b is adjusted relative to the main body portion 1000a, the body 100 and the end plate 101 can be welded to each other with higher bonding force, and due to the higher bonding force, the battery module housing 10 can be prevented from being damaged, so that the yield of the battery module is greatly improved.

[0052] The cover plate 102 may be connected to the body 100 to cover one surface M3 of the body 100 parallel to the longitudinal direction of the bottom plate 1000. For example, the one surface M3 may refer to the top surface M3. In this case, the cover plate 102 may be connected to the body 100 to cover the top surface M3 of the opening of the body 100.

[0053] Hereinafter, a battery module manufactured using the above-described battery module case 10 will be described. In the battery module according to the embodiment of the present invention, contents overlapping with those regarding the above-described battery module case 10 will be omitted.

[0054] The battery module according to the embodiment of the present invention may include a cell assembly structure accommodated inside a battery module case 10 to store electric energy and output the stored electric energy to the outside through a connection terminal.

[0055] For example, the electrode cell into which the electrolyte is injected and activated in a state where the electrode assembly is included may be arranged in plurality to manufacture a cell assembly. That is, the cell assembly may be an assembly of a plurality of batteries.

[0056] The battery module case 10 may accommodate such a battery cell assembly therein and be welded to block interaction between the battery cell assembly and an external space so that the battery cell assembly is protected from external factors such as impact and heat.

[0057] Specifically, the battery module case 10 may include a body 100, an end plate 101, and a cap plate 102. In addition, the body 100 may include a bottom plate 1000 and side plates 1001, and the bottom plate 1000 may include a body portion 1000a and a stepped portion 1000b.

[0058] As described above, the thickness of the stepped portion 1000b can be adjusted to reduce the length of the welding defect between the body 100 and the end plate 101, so that the bonding force between the body 100 and the end plate 101 is increased. Therefore, the possibility of damage to the battery module can be reduced, and the yield of the battery module can be improved during the manufacturing process of the battery module.

[0059] The description of the present invention is intended to be illustrative and one skilled in the art to which the present invention pertains may make various changes and modifications without departing from the spirit and scope of the present invention as defined in the appended claims.

[0060] Therefore, the embodiments described herein are intended to describe rather than limit the technical concept of the present invention. The scope of the technical concept of the present invention is not limited by the embodiments.

[0061] Furthermore, the protection scope of the present invention should be determined by reasonable interpretation of the appended claims, and all technical concepts falling within the equivalent scope of the present application should be interpreted as being within the right scope of the present application.

[0062] [Explanation of Reference Numerals]

[0063] 10: Battery module housing

[0064] 100: Main body

[0065] 101: End plate

[0066] 102: Cover

[0067] 1000: Base plate

[0068] 1001: Side panels

[0069] 1000a: Main body

[0070] 1000b: Stepped section

[0071] 1010: Connection part

[0072] 1010a: first surface

[0073] 1010b: Second surface

[0074] 1010c: Third surface

[0075] 101a: Bottom surface of end plate

[0076] M1: Front surface

[0077] M2: rear surface

[0078] M3: One Surface

[0079] L 1 : Thickness of the step portion

[0080] L 2 : The thickness of the main body

Claims

1. A battery module housing, comprising: A main body, the main body comprising a bottom plate and a pair of side plates respectively connected to two side portions of the bottom plate; an end plate configured to cover each of a front surface and a rear surface of the main body respectively provided at the front side and the rear side in the longitudinal direction of the bottom plate to be connected to the main body; as well as a cover plate configured to cover a surface of the main body parallel to the longitudinal direction of the bottom plate so as to be connected to the main body, Wherein, a side of the bottom plate connected to the end plate is arranged in a stepped shape.

2. The battery module housing according to claim 1, wherein: The bottom plate comprises: The body part; and A step portion is provided in a stepped shape at each of both ends of the body portion.

3. The battery module housing according to claim 2, wherein: The end plate is coupled and connected to the stepped portion.

4. The battery module housing according to claim 3, wherein: The end plate includes a coupling portion that is recessed to correspond to a shape of the step portion.

5. The battery module housing according to claim 4, wherein: Based on the fact that when observing the side plate, the connecting portion has a first surface and a second surface, the first surface is connected to and perpendicular to the bottom surface of the end plate, and the second surface is connected to and perpendicular to the first surface, wherein the stepped portion is coupled to each of the first surface and the second surface such that the end plate and the body are coupled to each other.

6. The battery module housing according to claim 2, wherein: Based on the fact that the step portion is arranged in a stepped shape toward the center of the body portion on each of the two sides of the body portion when the side plate is viewed, and Each of the front surface and the rear surface is provided by the step portion and the side plate.

7. The battery module housing according to claim 6, wherein: The thickness of the step portion is greater than the thickness of the body portion.

8. The battery module housing according to claim 7, wherein: The thickness of the step portion is 1.2 mm or more.

9. A battery module, comprising: The battery module housing according to claim 1; as well as A battery cell assembly is housed inside the battery module housing.

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