Battery module

Abstract

A battery module according to an embodiment of the present invention may comprise: a case in which an accommodation space is formed; the plurality of battery cells are positioned in the accommodating space; the fixing part is arranged on the inner bottom surface of the shell; and connection parts, each of which includes a cell bonding part located between the plurality of battery cells and a fixing bonding part connected to the cell bonding part and bonded to the fixing part.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2022-0077843, filed on Jun. 24, 2022, which is hereby incorporated by reference in its entirety.

[0002] The invention relates to a battery module. Background Art

[0003] Generally, secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries and lithium-ion polymer batteries, and such secondary batteries are used for small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game consoles, power tools, electric bicycles, etc., as well as large products requiring high power such as electric vehicles and hybrid vehicles, storage devices for storing surplus electricity or renewable energy, and backup power storage devices.

[0004] Generally, in order to manufacture a secondary battery, first, an electrode active material slurry is applied to a positive electrode collector and a negative electrode collector to manufacture a positive electrode and a negative electrode. Then, the electrodes are stacked on both sides of a separator to form an electrode assembly. In addition, the electrode assembly is housed in a battery case, and then the battery case is sealed after an electrolyte is injected therein.

[0005] Such secondary batteries are divided into pouch-type secondary batteries and can-type secondary batteries according to the material of the shell containing the electrode assembly. In the pouch-type secondary battery, the electrode assembly is contained in a bag made of a flexible polymer material. In addition, in the can-type secondary battery, the electrode assembly is contained in a shell made of a metal or plastic material.

[0006] Generally, a pouch-type battery case is manufactured by press-processing a flexible pouch film to form a cup portion. Then, when the cup portion is formed, a secondary battery is manufactured by accommodating an electrode assembly inside the cup portion and sealing a corner portion, which is a peripheral portion of the cup portion.

[0007] In addition, a battery module is manufactured by coupling a plurality of secondary batteries and placing the coupled secondary batteries into a housing. Such secondary batteries (ie, battery cells) are housed inside the housing and connected and fixed to the inner surface of the housing by an adhesive having a resin component.

[0008] In a state where the battery cell is coupled to the inner surface of the shell by an adhesive, when a battery cell expansion phenomenon occurs, a large tensile force acts on the shell of the battery cell. Here, expansion refers to a phenomenon in which the lithium ion electrolyte in the bag vaporizes and thus the battery becomes convex due to pressure. In particular, in the case of a pouch-type battery cell, as described above, the bag is composed of a cup portion and a corner portion, the cup portion forming an internal accommodation space, and the corner portion being a sealing portion around the cup portion. Since the reduction in the raw material thickness of the corner portion is greater than the reduction in the raw material thickness of the cup portion during the press-molding process of the bag, when a tensile force is generated on the outer surface of the bag, a greater tensile force is applied to the corner portion.

[0009] Therefore, when the battery cells connected to the adhesive are pushed due to expansion, a large pulling force is applied to the corners, resulting in gas explosion or leakage of the battery cells. In order to prevent this phenomenon, a battery module having an improved connection structure between the adhesive and the battery cells is required. Summary of the invention

[0010] Technical issues

[0011] An object of the present invention to solve the above-mentioned problems is to provide a battery module which improves the structure of a connection portion connecting a fixing portion with a battery cell to prevent the battery cell from being damaged.

[0012] Technical Solution

[0013] A battery module according to an embodiment of the present invention includes: a shell body, in which a accommodating space is defined; a plurality of battery cells, which are arranged in the accommodating space; a fixing portion, which is arranged on an inner bottom surface of the shell body; and a connecting portion, which includes a cell bonding portion arranged between the plurality of battery cells and a fixing bonding portion connected to the cell bonding portion and bonded to the fixing portion.

[0014] The plurality of battery cells may be stacked in a direction parallel to a bottom surface of the case, and the cell bonding portion may be perpendicular to the bottom surface of the case.

[0015] The longitudinal direction of the fixing adhesive portion may be perpendicular to the longitudinal direction of the cell adhesive portion.

[0016] Each of the plurality of battery cells and the fixing portion may be spaced apart from each other by a predetermined distance.

[0017] A fixing adhesive portion may be provided between the battery cell and the fixing part.

[0018] A top surface of the fixing adhesive portion may be spaced apart from a bottom surface of the battery cell.

[0019] The connection part may further include an inclined portion disposed to be inclined between the cell adhesive portion and the fixing adhesive portion.

[0020] The battery module may further include an adhesive pad configured to bond the plurality of battery cells to each other in a stacking direction of the plurality of battery cells.

[0021] The adhesive pads and the cell adhesive portions may be alternately stacked in a stacking direction of the plurality of battery cells.

[0022] A plurality of connecting parts may be provided.

[0023] The thermal conductivity of the connection may be greater than the thermal conductivity of each of the battery cells.

[0024] The thermal conductivity of the fixing portion may be greater than the thermal conductivity of each of the battery cells.

[0025] Beneficial Effects

[0026] According to the preferred embodiments of the present invention, the structure of the connection part connecting the fixing part with the battery cell can be improved to prevent the battery cell from being damaged and exploded, thereby improving the stability and life of the battery module.

[0027] Furthermore, effects that are obvious to those skilled in the art can be predicted from the configuration according to the embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the present invention, serve to further understand the technical idea of ​​the present invention. Therefore, the present invention should not be construed as being limited to the accompanying drawings.

[0029] Figure 1 is a cross-sectional view of a battery module according to a comparative example.

[0030] Figure 2 is a cross-sectional view showing a state in which swelling occurs in a battery cell according to a comparative example.

[0031] Figure 3 is a cross-sectional view of a battery module according to an embodiment.

[0032] Figure 4 is a cross-sectional view illustrating a battery cell, a connecting portion, and a fixing portion of a battery module according to another embodiment. DETAILED DESCRIPTION

[0033] Below, the preferred embodiments of the present invention will be described in detail 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 several different forms and is not limited or restricted by the following examples.

[0034] In order to clearly explain the present invention, detailed descriptions of parts that are irrelevant to the description or related known technologies that may unnecessarily obscure the gist of the present invention have been omitted, and in this specification, reference numerals are added to the components in each figure. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

[0035] 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 interpret his or her invention.

[0036] Figure 1 is a cross-sectional view of a battery module according to a comparative example.

[0037] Reference Figure 1 , the battery module according to the comparative example may include a case C1 and a battery cell C2 disposed inside the case C1. For example, the battery module according to the comparative example may include an adhesive layer C3 on an inner bottom surface of the case C1, and a plurality of battery cells C2 may be bonded and fixed by the adhesive layer C3.

[0038] Figure 2 is a cross-sectional view showing a state in which swelling occurs in the battery cell C2 according to the comparative example.

[0039] Reference Figure 2 In the structure of the comparative example, when the battery cell C2 expands due to internal vaporization and damage of the battery cell C2, refer to Figure 2 In a state where the bottom surfaces of the plurality of battery cells are fixed to the adhesive layer C3, the battery cell C2 may be Figure 2 Receive external force to one side in the direction of the middle arrow.

[0040] When each battery cell C2 is a pouch-type battery consisting of a cup portion and a corner portion, since the reduction in thickness of the corner portion is greater than the reduction in thickness of the cup portion during the press-molding process of the pouch, when tension occurs at the connection between the pouch and the adhesive layer C3, a large tension may act on the corner portion connected to the adhesive layer C3.

[0041] Therefore, according to the structure according to the comparative example, when expansion occurs, the corners of the battery cell C2 that are susceptible to tension may be damaged. Therefore, due to damage or destruction of the battery cell C2, an accident of battery module explosion due to discharge of internal gas and flame may occur.

[0042] In order to compensate for this problem, the battery module 1 according to the embodiment of the present invention may include the following structures and functions.

[0043] Figure 3 is a cross-sectional view of a battery module 1 according to an embodiment.

[0044] Reference Figure 3 , the battery module 1 can accumulate electric energy by accommodating a plurality of battery cells 11 inside the housing 10, and can output the accumulated electric energy to the outside by being connected to an external terminal. For example, the battery module 1 may include a housing 10 defining a housing space therein, and a plurality of battery cells 11 may be stacked on each other and disposed and fixed in the housing space. In this case, the battery cell 11 may include a bag and an electrode assembly accommodated in the bag, the bag including a cup portion and a corner portion. The cup portion may refer to a portion formed to be recessed in the central portion of the bag by a press molding process of the bag, and the corner portion may refer to a side sealing portion formed along the periphery of the cup portion.

[0045] The battery module 1 can prevent the plurality of battery cells 11 from being damaged due to expansion through a connection structure in which the plurality of battery cells 11 are connected to the inner surface of the housing 10. In other words, the battery module 1 can improve the connection structure so as to reduce damage to the corners of the pockets of the battery cells 11. In addition, the battery module 1 can more effectively release heat generated in the plurality of battery cells 11 to the outside through the connection structure.

[0046] Specifically, the battery module 1 may further include a fixing portion 12 and a connecting portion 13 .

[0047] The fixing portion 12 may fix the plurality of battery cells 11 to the inside of the housing 10. For example, the fixing portion 12 may be provided on the inner bottom surface of the housing 10 and connected to the plurality of battery cells 11. Specifically, the bottom surface of the fixing portion 12 may be connected to the inner bottom surface of the housing 10, and the top surface of the fixing portion 12 may be connected to the plurality of battery cells 11. More specifically, the top surface of the fixing portion 12 may be connected to the plurality of battery cells 11 through a connecting portion 13 to be described later.

[0048] The fixing portion 12 may include an adhesive material. For example, the fixing portion 12 may include a resin material and may be applied to the inner bottom surface of the housing 10, and then cured in a state of being bonded and connected to a connecting portion 13 to be described later after being applied to the inner bottom surface of the housing 10, so as to connect the inner bottom surface of the housing 10 to the plurality of battery cells 11.

[0049] The connection part 13 is connected to the plurality of battery cells 11 and the fixing part 12 to connect the plurality of battery cells 11 to the fixing part 12. For example, the connection part 13 may be provided between the plurality of battery cells 11 to protrude from the plurality of battery cells 11 to one side in a state of being coupled to the plurality of battery cells 11 so as to be connected to the fixing part 12, thereby connecting the plurality of battery cells 11 to the fixing part 12. In this case, the plurality of battery cells 11 are connected to the fixing part 12 only through the connection part 13, and the plurality of battery cells 11 may not be in contact with the fixing part 12. The plurality of battery cells 11 and the fixing part 12 may be provided to be spaced apart from each other by a predetermined distance.

[0050] The connection part 13 may include a cell adhesive portion 130 and a fixing adhesive portion 131 .

[0051] The cell bonding portion 130 may be disposed between the plurality of battery cells 11. For example, the cell bonding portion 130 may be disposed between the plurality of battery cells 11 according to the direction in which the plurality of battery cells 11 are stacked. In this case, the plurality of battery cells 11 may be stacked in a direction parallel to the bottom surface of the case 10. That is, since the cell bonding portion 130 is disposed in the space between the stacked plurality of battery cells 11, the cell bonding portion 130 may include a structure in which the battery cells 11 are coupled and connected to both sides thereof.

[0052] Specifically, the longitudinal direction of the cell adhesive portion 130 may be perpendicular to the bottom surface of the case 10. In other words, when viewed in a side view, the cell adhesive portion 130 may include a structure extending toward the top surface and the bottom surface. The cell adhesive portion 130 may protrude from the plurality of battery cells 11 toward the bottom surface of the case 10 in a state where it is disposed and connected between the plurality of battery cells 11, and then may be connected to the fixing adhesive portion 131.

[0053] The fixing adhesive portion 131 may be connected to the cell adhesive portion 130 and adhered to the fixing portion 12. For example, the top surface of the fixing adhesive portion 131 may be connected to the lower portion of the cell adhesive portion 130, and the bottom surface of the fixing adhesive portion 131 may be adhered to the top surface of the fixing portion 12. That is, the fixing adhesive portion 131 may be provided between the plurality of battery cells 11 and the fixing portion 12 to connect the cell adhesive portion 130 to the fixing portion 12.

[0054] In this case, the fixed adhesive portion 131 may not contact the plurality of battery cells 11. Since the fixed adhesive portion 131 does not contact the plurality of battery cells 11, even if the plurality of battery cells 11 are pushed due to expansion, the structure in which the fixed adhesive portion 131 and the plurality of battery cells 11 are spaced apart from each other can prevent the tension from acting on the battery cells 11 through the fixed adhesive portion 131 or prevent the battery cells 11 from being damaged.

[0055] The longitudinal direction of the fixed adhesive portion 131 may be perpendicular to the longitudinal direction of the cell adhesive portion 130. In other words, the fixed adhesive portion 131 may be vertically connected to the cell adhesive portion 130 and may be arranged in parallel with the bottom surface of the housing 10. For example, due to the structure of the cell adhesive portion 130 and the fixed adhesive portion 131, the connection portion 13 may include an "L" shape. Specifically, when viewed in a side view, the adhesive length of the fixed adhesive portion 131 to the fixed portion 12 may be greater than the width of the cell adhesive portion 130.

[0056] According to the structure of the connection part 13, when viewed in a side view, in a state where the connection part 13 is coupled between a plurality of stacked battery cells 11, the bottom surface of the connection part 13 (i.e., the bottom surface of the fixing adhesive portion 131) may be in contact with and connected to the fixing part 12 over a wider area. In other words, the connection part 13 may be coupled to the battery cell 11 over a wider area through the cell adhesive portion 130, and connected to the fixing part over a wider area through the fixing adhesive portion 131, and thus, the coupling force and fixing force between the plurality of battery cells 11 may be increased.

[0057] In addition, since the cell adhesive portion 130 is not limited to a specific area of ​​the bag of the battery cell 11, but is coupled to the battery cell 11 over a wider area including the cup portion and the corner portion of the bag of the battery cell 11, the tension caused by expansion can be dispersed to a wider area of ​​the bag of the battery cell 11. Similarly, even if the battery cell 11 is pushed due to expansion, since the fixing adhesive portion 131 is coupled to the fixing portion 12 over a wider area, the tension generated between the fixing adhesive portion 131 and the fixing portion 12 can be dispersed to a wider area.

[0058] Therefore, the structure of the connection part 13 as described above can prevent the bag from being damaged due to the concentration of tensile force generated by the expansion phenomenon at the relatively weak corners. Therefore, secondary problem conditions such as explosion of the battery module 1 can be prevented from occurring.

[0059] In addition, when high temperature heat is generated in the battery cell 11 due to expansion, in order to more effectively release the heat of the battery cell 11, the fixing portion 12 and the connecting portion 13 may have a thermal conductivity higher than that of the battery cell 11. Specifically, the fixing portion 12 may include an adhesive made of a resin material having a thermal conductivity higher than that of the battery cell 11. In addition, the connecting portion 13 may include a plate shape made of a metal material having a thermal conductivity higher than that of the battery cell 11.

[0060] The connection part 13 can transfer the heat generated in the battery cell 11 to the outside more effectively through the structural features of the above-mentioned battery cell bonding part 130 and the fixed bonding part 131. In other words, in the case of the comparative example where the connection part 13 does not exist, the battery cell C2 can be directly connected to the bonding layer C3, and the high-temperature heat generated due to internal vaporization can be transferred to the bonding layer C3. In this process, the heat at the side of the battery cell C2 directly connected to the bonding layer C3 can be immediately released through the bonding layer C3, but the heat at the other side of the battery cell C2 not connected to the bonding layer C3 may not be effectively released. Unlike the comparative example, since the connection part 13 according to the present invention is arranged between a plurality of battery cells 11, connected to a plurality of battery cells 11 over a wider area, and relatively far away from the fixing part 12, the high-temperature heat generated in the battery cell 11 can be released more effectively.

[0061] Furthermore, in order to improve the damage prevention effect and heat dissipation effect of the connection portion 13 and the fixing portion 12, the connection portion 13 may be provided in plurality, which are respectively provided between the plurality of battery cells 11. That is, although the fixing portion 12 is integrally formed on the inner bottom surface of the housing 10, the connection portion 13 may be provided in plurality to prevent each battery cell 11 from being damaged and to effectively transfer heat generated in each battery cell 11 to the fixing portion 12.

[0062] The adhesive pad 14 may adhere the plurality of battery cells 11 according to the stacking direction of the plurality of battery cells 11. For example, the adhesive pad 14 may be disposed between the stacked battery cells 11 to allow the plurality of battery cells 11 to contact and couple with each other. That is, like the cell adhesive portion 130, the adhesive pad 14 may be perpendicular to the bottom surface of the housing 10 in the longitudinal direction. Specifically, in a state where the battery cells 11 are disposed between the cell adhesive portion 130 and the adhesive pad 14, the adhesive pad 14 and the cell adhesive portion 130 may be stacked alternately with each other in the stacking direction of the plurality of battery cells 11. In other words, the battery cells 11, the cell adhesive portion 130, the battery cells 11, and the adhesive pad may be repeatedly stacked in sequence.

[0063] Due to the function of the adhesive pad 14 as described above, the coupling force between the plurality of battery cells 11 may be increased, and thus the plurality of battery cells 11 may be more fixed to the inside of the case 10, and damage to the battery cells 11 due to expansion may be reduced.

[0064] Hereinafter, a battery module 2 in which the structure of a connection portion is partially modified according to another embodiment will be described, and the same details as those of the configuration and function of the above-described battery module will be omitted below.

[0065] Figure 4 is a cross-sectional view showing a battery cell 21 , a connecting portion 23 , and a fixing portion 22 of a battery module 2 according to another embodiment.

[0066] Reference Figure 4 The battery module 2 according to another embodiment may include a plurality of battery cells 21, a connection part 23, and a fixing part 22 having the same configuration as the above-mentioned battery module 1. In addition, the connection part 23 according to another embodiment may include a cell adhesive part 230 and a fixing adhesive part 231.

[0067] In addition, the connection portion 23 according to another embodiment may further include an inclined portion 232 .

[0068] The inclined portion 232 may be obliquely disposed between the cell bonding portion 230 and the fixed bonding portion 231. For example, the inclined portion 232 may include a shape inclined relative to the longitudinal direction of the cell bonding portion 230 and the fixed bonding portion 231. In other words, the cell bonding portion 230 and the fixed bonding portion 231 may be perpendicular to each other, and the inclined portion 232 may include a shape inclined at an angle of 45 degrees relative to the cell bonding portion 230 and the fixed bonding portion 231.

[0069] According to the structure of the inclined portion 232, even if the battery cell 21 is pushed due to expansion and a pulling force is generated between the fixed adhesive portion 231 and the fixed portion, the inclined portion 232 can buffer the external force transmitted from the battery cell 21 to the fixed portion to reduce the pulling force between the fixed adhesive portion 231 and the fixed portion 22.

[0070] Therefore, since the connection part 23 according to another embodiment further includes the inclined portion 232 , damage of the battery cell 21 due to expansion may be further minimized to prevent secondary problems such as an explosion phenomenon due to damage of the battery cell 21 .

[0071] The above-disclosed subject matter is to be considered illustrative rather than restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments that fall within the true spirit and scope of the present invention.

[0072] Therefore, the embodiments of the present invention should be considered as illustrative rather than restrictive, and the technical idea of ​​the present invention is not limited to the aforementioned embodiments.

[0073] Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

[0074] [Explanation of symbols]

[0075] 1: Battery module

[0076] 10: Shell

[0077] 11: Battery Cell

[0078] 12: Fixed part

[0079] 13: Connection

[0080] 14: Adhesive pad

[0081] 130: Battery cell bonding part

[0082] 131: Fixed bonding part

[0083] 232: Inclined part

Claims

1. A battery module, comprising: a housing, wherein a receiving space is defined in the housing; A plurality of battery cells, wherein the plurality of battery cells are arranged in the accommodation space; a fixing portion, the fixing portion being arranged on an inner bottom surface of the housing; as well as A connecting portion includes a cell bonding portion and a fixed bonding portion, the cell bonding portion is disposed between the plurality of battery cells, and the fixed bonding portion is connected to the cell bonding portion and bonded to the fixed portion.

2. The battery module according to claim 1, wherein: The plurality of battery cells are stacked in a direction parallel to the bottom surface of the housing, and The cell bonding portion is perpendicular to the bottom surface of the case.

3. The battery module according to claim 2, wherein: The longitudinal direction of the fixing adhesive portion is perpendicular to the longitudinal direction of the battery cell adhesive portion.

4. The battery module according to claim 1, wherein: Each of the plurality of battery cells and the fixing portion are spaced apart from each other by a predetermined distance.

5. The battery module according to claim 4, wherein: The fixing adhesive portion is provided between the battery cell and the fixing part.

6. The battery module according to claim 5, wherein: A top surface of the fixing adhesive portion is spaced apart from a bottom surface of the battery cell.

7. The battery module according to claim 6, wherein: The connection portion further includes an inclined portion disposed to be inclined between the battery cell bonding portion and the fixed bonding portion. 8 . The battery module according to claim 1 , further comprising an adhesive pad configured to bond the plurality of battery cells to each other in a stacking direction of the plurality of battery cells.

9. The battery module according to claim 8, wherein: The adhesive pads and the cell adhesive portions are alternately stacked in a stacking direction of the plurality of battery cells.

10. The battery module according to claim 1, wherein: The connecting portion is provided in plurality.

11. The battery module according to claim 1, wherein: The thermal conductivity of the connecting portion is greater than the thermal conductivity of each of the battery cells.

12. The battery module according to claim 1, wherein: The fixing portion has a thermal conductivity greater than a thermal conductivity of each of the battery cells.

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