Battery module and manufacturing method thereof

Abstract

According to an embodiment of the present disclosure, a battery module includes: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a thermally conductive resin layer formed between a lower surface of the module frame and the battery cell stack, wherein the plurality of battery cells include a sealing portion formed to extend downward from a bottom surface of a cell shell for accommodating an electrode assembly, wherein the sealing portion is located inside the thermally conductive resin layer and is respectively formed to be folded toward the bottom surface of the cell shell, and wherein an adhesive layer is formed between the folded portion of the sealing portion and the bottom surface of the cell shell.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0048916, filed on April 22, 2020, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

[0003] The present disclosure relates to a battery module and a method for manufacturing the battery module, and more particularly, to a battery module having improved cooling performance and a method for manufacturing the battery module. Background Art

[0004] Secondary batteries have attracted significant attention as energy sources for various products, such as mobile devices and electric vehicles. They are a powerful energy resource that can replace the use of existing products using fossil fuels and are attracting attention as an environmentally friendly energy source because they do not produce byproducts due to energy use.

[0005] Recently, with the increasing necessity of large-capacity secondary battery structures (including the use of secondary batteries as energy storage sources), the demand for multi-module structure battery packs is growing, which are components of battery modules in which multiple secondary batteries are connected in series or parallel.

[0006] Meanwhile, when a plurality of battery cells are connected in series / parallel to construct a battery pack, a method is common in which a battery module composed of at least one battery cell is constructed and then other components are added to the at least one battery module to construct a battery pack.

[0007] Such a battery cell may include a battery cell stack in which a plurality of battery cells are stacked, a module frame for accommodating the battery cell stack, and a thermally conductive resin layer formed between a lower surface of the module frame and the battery cell stack.

[0008] Figure 1 is a view showing a state in which an air layer is formed between a sealing portion of a battery cell and a bottom surface of the battery cell in a conventional battery module.

[0009] refer to Figure 1According to a conventional battery module, a thermally conductive resin layer 30 is formed between a battery cell stack in which a plurality of battery cells 10 are stacked and a module frame 20, and a sealing portion 11 is formed to contact the thermally conductive resin layer 30, the sealing portion 11 being formed to extend from the cell case of the battery cell 10. In this case, the sealing portion 11 is made to contact the thermally conductive resin layer 30 in a state of being folded toward the bottom surface 10a of the battery cell, thereby making it possible to utilize the space below the battery cell stack 100.

[0010] However, when the sealing portion 11 is as in Figure 1 When the battery module is folded as shown in FIG, an air layer may be formed between the folded portion of the seal portion 11 and the portion of the battery cell bottom surface 10a corresponding to the folded portion of the seal portion 11. Due to this air layer, a gap is generated between the thermally conductive resin layer 30 and the battery cell 10, which causes a problem of deteriorating the cooling performance of the battery module. Summary of the Invention

[0011] Technical issues

[0012] An object of the present disclosure is to provide a battery module having improved cooling performance and a method for manufacturing the battery module.

[0013] The objects of the present disclosure are not limited to the aforementioned objects, and other objects not described herein should be clearly understood by those skilled in the art from the following detailed description.

[0014] Technical Solution

[0015] To achieve the above purpose, according to one embodiment of the present disclosure, a battery module is provided, which includes: a battery cell stack in which a plurality of battery cells are stacked; a module frame for accommodating the battery cell stack; and a thermally conductive resin layer formed between a lower surface of the module frame and the battery cell stack, wherein the plurality of battery cells include a sealing portion formed to extend downward from a bottom surface of a cell shell for accommodating an electrode assembly, wherein the sealing portion is located inside the thermally conductive resin layer and is respectively formed to be folded toward the bottom surface of the cell shell, and wherein an adhesive layer is formed between the folded portion of the sealing portion and the bottom surface of the cell shell.

[0016] The battery module may further include a fixing member formed to cover the folded portion of the sealing portion.

[0017] The fixing member may be formed to cover an end portion of the sealing portion.

[0018] The fixing member may be formed to cover an outer surface of the folded portion of the sealing portion, an end portion of the sealing portion, a bottom surface of the cell case, and a portion of a body surface of the cell case.

[0019] The fixing member may be formed of an insulating material.

[0020] The adhesive layer may be formed of a double-sided tape or an adhesive.

[0021] The bonding layer may be formed from a thermal interface material.

[0022] An adhesive layer may be fixed between the folded portion of the sealing portion and the bottom surface of the cell case.

[0023] To achieve the above purpose, according to another embodiment of the present disclosure, a method for manufacturing a battery module is provided, the method comprising the following steps: inserting an adhesive material between a sealing portion formed to extend downward from a plurality of battery cells included in a battery cell stack and the bottom surfaces of the plurality of battery cells; fixing the sealing portion and the bottom surfaces respectively by folding the sealing portion in a direction in which the adhesive material is located; and injecting a thermally conductive resin between the lower side of the battery cell stack and the lower surface portion of the module frame so that the thermally conductive resin contacts the sealing portion, thereby forming a thermally conductive resin layer.

[0024] After the step of respectively fixing between the sealing portion and the bottom surface, the method may further include the step of attaching a fixing member so as to cover each of the folded sealing portions.

[0025] According to yet another embodiment of the present disclosure, a battery pack including the above-mentioned battery module can be provided.

[0026] Beneficial effects

[0027] The battery module and the method for manufacturing the battery module according to the embodiment of the present disclosure provide effects of improving cooling performance and insulation performance of the battery module.

[0028] The effects of the present disclosure are not limited to the above-described effects, and further other effects not described above will be clearly understood by those skilled in the art from the description of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a view showing a state in which an air layer is formed between a sealing portion of a battery cell and a bottom surface of the battery cell in a conventional battery module;

[0030] Figure 2 is an exploded perspective view showing a battery module according to an embodiment of the present disclosure;

[0031] Figure 3 is a view showing a battery cell according to an embodiment of the present disclosure;

[0032] Figure 4 It is along Figure 2 A cross section taken along line AA of FIG. 1 is a view showing a state where an adhesive layer is formed according to an embodiment of the present disclosure;

[0033] Figure 5 It is along Figure 2 A cross section taken along line AA of FIG. 1 is a view showing a state where an adhesive layer is formed according to another embodiment of the present disclosure;

[0034] Figure 6 yes Figure 4 Section B in FIG. 1 is a view showing a state in which an adhesive material according to an embodiment of the present disclosure is inserted between a sealing portion and a bottom surface of a battery cell;

[0035] Figure 7 yes Figure 4 Section B in FIG. 1 , which is a view showing a state in which the sealing portion according to an embodiment of the present disclosure is folded toward the bottom surface of the battery cell; and

[0036] Figure 8 yes Figure 4 Section B in FIG. 1 is a view showing a state in which a thermally conductive resin is injected into a portion where a sealing portion is located according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] It should be understood that the exemplary embodiments described below are schematically described to aid understanding of the present disclosure, and that various modifications can be made to the present disclosure to implement the present disclosure 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 of a well-known function or constituent element may unnecessarily obscure the subject matter of the present disclosure, the specific description and illustration will be omitted. In addition, to aid understanding of the present disclosure, the drawings are not shown based on actual scale, but some parts of the constituent elements may be exaggerated in size.

[0038] As used herein, terms such as first, second, etc. may be used to describe various components, and these components are not limited by these terms. These terms are only used to distinguish one component from another.

[0039] 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 a clear opposite meaning in the context. It should be understood that as used herein, the terms "include," "comprise," and "have" are intended to indicate the presence of the described features, numbers, steps, movements, constituent elements, parts, or combinations thereof, but it should be understood that these terms do not exclude the possibility of the presence or addition of one or more other features, numbers, steps, movements, constituent elements, parts, or combinations thereof.

[0040] In the following, reference will be made to Figure 2 and Figure 3 A structure of a battery module according to an embodiment of the present disclosure is described.

[0041] Figure 2 is an exploded perspective view illustrating a battery module according to an embodiment of the present disclosure. Figure 3 is a view illustrating a battery cell according to an embodiment of the present disclosure.

[0042] refer to Figure 2 and Figure 3 , a battery module according to an embodiment of the present disclosure includes: a battery cell stack 100 in which a plurality of battery cells are stacked; a module frame 200 for accommodating the battery cell stack 100; and a thermally conductive resin layer 500 formed between a lower surface of the module frame 200 and the battery cell stack 100.

[0043] The battery cell 110 is a secondary battery and may be configured as a pouch-type secondary battery. Such a battery cell 110 may be composed of a plurality of cells, and the plurality of battery cells may be stacked together to be electrically connected to each other, thereby forming a battery cell stack 100. Figure 3 As shown in , a plurality of battery cells 110 may include electrode leads 111 and 112 protruding from an electrode assembly and a cell case 113 for accommodating the electrode assembly.

[0044] The electrode assembly may include a positive electrode plate, a negative electrode plate, a separator, etc. The cell case 113 is used to encapsulate the electrode assembly and may be composed of a laminated sheet including a resin layer and a metal layer.

[0045] The cell housing 113 includes a first sealing portion 114 and a second sealing portion 115, each formed to extend in the direction in which the first electrode lead 111 and the second electrode lead 112 are located; and a third sealing portion 116 and a fourth sealing portion 117, each connected to the first and second sealing portions and formed to extend from an edge portion of the cell housing where the first and second electrode leads 111 and 112 are not formed, to the outside of the cell housing. The sealing portions 114, 115, 116, and 117 can be formed to extend outward from the cell housing 113 and form a four-sided sealing structure capable of sealing the cell housing 113, in which the electrode assembly is housed.

[0046] The first and second electrode leads 111 and 112 have a structure in which they face each other and protrude from the first and second sealing portions 114 and 115 of the cell housing 113, respectively. The first and second sealing portions 114 and 115 are formed to surround the first and second electrode leads 111 and 112, respectively. In the battery cell stack 100, the first and second sealing portions 114 and 115 are formed in the front and rear surfaces of the battery cell stack 100, and the third and fourth sealing portions 116 and 117 are formed in the upper and lower surfaces of the battery cell stack. The third sealing portion 116 is formed on the upper surface of the battery cell stack 100, and the fourth sealing portion 117 is formed in the lower surface of the battery cell stack 100. The fourth sealing portion 117 formed in the lower surface of the battery cell stack 100 can come into contact with the thermally conductive resin layer 500.

[0047] The module frame 200 may house the battery cell stack 100, as well as a bus bar frame 310 and an upper plate 320 coupled to the battery cell stack 100 at the upper, lower, left, and right surfaces of the battery cell stack 100. According to an embodiment of the present disclosure, the module frame 200 may be formed as a single frame structure in which the upper, lower, left, and right surfaces are integrally formed, but the present disclosure is not limited thereto and may also employ a structure formed of a U-shaped frame and an upper plate for covering the upper side of the U-shaped frame.

[0048] The upper plate 320 may be formed on the upper surface of the battery cell stack 100 to cover the battery cell stack 100. The bus bar frame 310 may be formed at the front and rear ends of the upper plate 320. By combining the front and rear surfaces of the battery cell stack 100 with the bus bar frame 310, electrical connection between the electrode leads and the bus bars can be guided through the bus bars formed in the bus bar frame 310.

[0049] The upper plate 320 and the busbar frame 310 can be hingedly coupled. When the upper plate 320 and the busbar frame 310 are coupled to the battery cell stack 100, the upper plate 320 is positioned on the upper surface of the battery cell stack 100, and then the busbar frames 310 at both ends rotate about a rotation axis formed by the hinge coupling with the upper plate 320, thereby enabling the busbar frame 310 to be installed to cover each of the front and rear surfaces of the battery cell stack 100. According to an embodiment of the present disclosure, the busbar frame 310 can be installed on the front and rear surfaces of the battery cell stack 100 so as to be perpendicular to the upper plate 320.

[0050] The end plate 400 can be formed on the outside of the battery cell stack 100 and the bus bar frame 310, and is formed to cover the battery cell stack 100 and the bus bar frame 310. The end plate 400 can protect the bus bar frame 310 and various electrical components connected to the bus bar frame 310 from external impact, and has a battery module mounting structure as a component of the frame.

[0051] A thermally conductive resin can be injected between the lower side surface of the battery cell stack 100 and the lower surface portion of the module frame 200 to form a thermally conductive resin layer 500. The thermally conductive resin may include a thermally conductive adhesive material, and specifically, the thermally conductive resin may include at least one of a silicone material, a polyurethane material, and an acrylic material. The thermally conductive resin is liquid during coating, but solidifies after coating, thereby being able to play a role in fixing one or more battery cells 110 constituting the battery cell stack 100. In addition, the thermally conductive resin has excellent thermal conductivity, so that the heat generated in the battery cell 110 can be quickly transferred to the outside of the battery module to perform a cooling function of the battery module.

[0052] In the following, reference will be made to Figure 2 and Figure 4 A battery module in which an adhesive layer is formed between a sealing portion and a bottom surface of a cell case according to an embodiment of the present disclosure is described.

[0053] Figure 4 It is along Figure 2 1 is a cross-section taken along line AA of FIG. 1 , which is a view illustrating a state in which an adhesive layer is formed according to an embodiment of the present disclosure.

[0054] According to an embodiment of the present disclosure, a plurality of battery cells 110 include a fourth sealing portion 117, which is formed to extend downward from a cell shell 113 for accommodating an electrode assembly, and the fourth sealing portion 117 is respectively located in the interior of the thermally conductive resin layer 500 and is formed to be folded to the bottom surface of the cell shell 113, and an adhesive layer 600 is formed between the folded portion of the fourth sealing portion 117 and the bottom surface 113b of the cell shell 113.

[0055] Conventionally, an air layer may be formed in the space between the folded portion of the sealing portion 117 and the portion of the bottom surface 113b of the cell shell corresponding to the folded portion of the fourth sealing portion 117, and due to the air layer, a gap is generated between the thermally conductive resin layer 30 and the battery cell 10, which causes the problem of deterioration of the cooling performance of the battery module.

[0056] However, according to an embodiment of the present disclosure, an adhesive layer 600 is formed between the folded portion of the fourth sealing portion 117 and the bottom surface 113b of the cell shell, so that the folded portion of the fourth sealing portion 117 is fixed to the bottom surface 113b of the cell shell through the adhesive layer 600, and at the same time, the generation of an air layer that may be formed between the folded portion of the fourth sealing portion 117 and the bottom surface 113b of the cell shell is minimized. As a result, heat transfer between the thermally conductive resin layer 500 and the plurality of battery cells 110 can be smoothly performed, thereby improving the cooling performance of the battery module.

[0057] According to an embodiment of the present disclosure, the adhesive layer 600 can be formed of an adhesive material (such as a double-sided tape or an adhesive). As a result, the fourth sealing portion 117 and the bottom surface 113b of the cell housing are fixed in a state where the distance between the fourth sealing portion 117 and the bottom surface 113b of the cell housing is minimized, so that the gap between the main body of the battery cell 110 and the thermally conductive resin layer 500 can be reduced, thereby improving the cooling performance through heat transfer.

[0058] The adhesive layer 600 may be formed of a thermal interface material (TIM). By forming the adhesive layer 600 as a thermal interface material, in addition to the adhesive layer 600's fixing function between the fourth sealing portion 117 and the bottom surface 113b of the cell housing, heat transfer is also smoothly performed through the adhesive layer 600 itself formed of the thermal interface material, thereby improving the cooling performance of the battery module.

[0059] In the following, reference will be made to Figure 2 and Figure 5 A battery module having a fixing member according to another embodiment of the present disclosure is described.

[0060] Figure 5 It is along Figure 2 This is a cross-section taken along line AA of FIG. 1 , which is a view illustrating a state in which an adhesive layer is formed according to another embodiment of the present disclosure.

[0061] According to an embodiment of the present disclosure, a fixing member 700 may be further included, which is formed to cover the folded portion of the fourth sealing portion 117. The fixing member 700 may be formed to cover the end 117e of the fourth sealing portion 117. Because the end 117e of the fourth sealing portion 117 is a portion where the sealing surface is cut and requires insulation treatment. Therefore, the fixing member 700 is formed to cover the end 117e of the fourth sealing portion 117, thereby interrupting the electrical connection with the outside through the end 117e of the fourth sealing portion 117. In order to perform the insulation function, the fixing member 700 may be formed of an insulating material.

[0062] In addition, as in Figure 5As shown in FIG, the fixing member 700 can be formed to cover the outer surface of the folded portion of the fourth seal 117, the end 117e of the fourth seal 117, the bottom surface 113b of the battery cell 113, and a portion of the battery cell housing surface 113a. Thus, the fixing member 700 allows the folded portion of the seal 117 and the bottom surface 113b of the battery cell housing to be fixed together with the adhesive layer 600, thereby further strengthening the fixing force between the fourth seal 117 and the bottom surface 113b of the battery cell housing. In addition, one end of the fixing member 700 is attached from the outer surface of the folded portion of the fourth seal 117 to a portion of the battery cell housing surface 113a, allowing the fixing member 700 to completely cover the bottom surface of the fourth seal 117. The contact area between the fixing member 700 and the battery cell 110 is increased, allowing the fixing member 700 to fully and closely contact the lower portion of the battery cell 110.

[0063] In the following, reference will be made to Figures 6 to 8 A method of manufacturing a battery module according to an embodiment of the present invention is described.

[0064] Figure 6 yes Figure 4 , which is a view showing a state in which the adhesive material according to an embodiment of the present disclosure is inserted between the sealing portion and the bottom surface of the battery cell. Figure 7 yes Figure 4 , which is a view showing a state in which the sealing portion is folded toward the bottom surface of the battery cell according to an embodiment of the present disclosure. Figure 8 yes Figure 4 Section B in FIG. 1 is a view showing a state in which a thermally conductive resin is injected into a portion where a sealing portion is located according to an embodiment of the present disclosure.

[0065] The manufacturing method of the battery module according to the embodiment of the present disclosure can be performed in the following order: a step (1) of inserting the adhesive material 600 between the sealing portion 117 formed to extend downward from the plurality of battery cells 110 in the battery cell stack 100 and the bottom surfaces 113b of the plurality of battery cells 110; Figure 6 by folding the fourth sealing portion 117 in the direction in which the adhesive material 600 is located and respectively fixing the sealing portion 117 and the bottom surface 113b between the step ( Figure 7 and injecting a thermally conductive resin between the lower side of the battery cell stack 100 and the lower surface portion of the module frame 200, so that the thermally conductive resin contacts the fourth sealing portion 117 thereby forming a thermally conductive resin layer 500 step ( Figure 8 ).

[0066] The step of inserting the adhesive material 600 between the fourth sealing portion 117 and the bottom surface 113b of the plurality of battery cells 110 may include the step of attaching the adhesive material 600 to the inner surface of the fourth sealing portion 117. Moreover, in a modified example, the method may include the step of attaching the adhesive material 600 to the bottom surface 113b corresponding to the portion where the fourth sealing portion 117 is folded.

[0067] After the step of respectively performing the fixing between the sealing portions and the bottom surface, the method may further include the step of attaching a fixing member so as to cover each of the folded sealing portions.

[0068] The battery module can be included in a battery module. The battery module may have a structure in which one or more battery modules according to the embodiments of the present disclosure are aggregated and packaged together with a battery management system (BMS) and a cooling device that controls and manages the temperature, voltage, etc. of the battery.

[0069] The battery pack can be applied to various devices. Such a device can be applied to a vehicle device such as an electric bicycle, an electric vehicle, or a hybrid vehicle, but the present disclosure is not limited thereto and can be applied to various devices that can use the battery module, which also falls within the scope of the present disclosure.

[0070] Although the preferred embodiments of the present disclosure have been shown and described above, the scope of the present disclosure is not limited thereto, and those skilled in the art will be able to design many other modifications and embodiments that fall within the spirit and scope of the principles of the present invention described in the appended claims. In addition, these modified embodiments should not be understood separately from the technical spirit or viewpoints of the present disclosure.

[0071] Description of Reference Numerals

[0072] 200: Module Framework

[0073] 310: Busbar frame

[0074] 320: On the board

[0075] 400: End plate

[0076] 500: Thermal conductive resin layer

[0077] 117: Fourth seal

[0078] 117e: End of the fourth sealing portion

[0079] 113a: Monolithic shell surface

[0080] 113b: bottom surface

[0081] 600: Adhesive layer (adhesive material)

[0082] 700: Fixed components

Claims

1. A battery module comprising: a battery cell stack in which a plurality of battery cells are stacked; a module frame, the module frame being used to accommodate the battery cell stack; and a thermally conductive resin layer formed between a lower surface of the module frame and the battery cell stack, wherein the plurality of battery cells include a sealing portion formed to extend downward from a bottom surface of a cell case for accommodating the electrode assembly, wherein the sealing portions are located inside the thermally conductive resin layer and are respectively formed to be folded toward the bottom surface of the single body case, wherein an adhesive layer is formed between the folded portion of the seal portion and the bottom surface of the cell case, and Herein, the battery module further includes a fixing member formed to cover the folded portion of the sealing portion.

2. The battery module according to claim 1, wherein: The fixing member is formed to cover an end portion of the sealing portion.

3. The battery module according to claim 1, wherein: The fixing member is formed to cover an outer surface of the folded portion of the seal portion, an end portion of the seal portion, the bottom surface of the cell case, and a portion of a body surface of the cell case.

4. The battery module according to claim 1, wherein: The fixing member is formed of an insulating material.

5. The battery module according to claim 1, wherein: The adhesive layer is formed of a double-sided adhesive tape or an adhesive.

6. The battery module according to claim 1, wherein: The bonding layer is formed of a thermal interface material.

7. The battery module according to claim 1, wherein: The adhesive layer is fixed between the folded portion of the seal portion and the bottom surface of the cell case.

8. A method for manufacturing a battery module, the battery module comprising a module frame for accommodating a battery cell stack, The method comprises the following steps: inserting an adhesive material between sealing portions formed to extend downward from a plurality of battery cells included in the battery cell stack and bottom surfaces of cell cases of the plurality of battery cells; by folding the sealing portion in the direction in which the adhesive material is located, fixing between the sealing portion and the bottom surface, respectively, so that an adhesive layer is formed between the folded portion of the sealing portion and the bottom surface of the cell case; injecting a thermally conductive resin between a lower side of the battery cell stack and a lower surface portion of the module frame so that the thermally conductive resin contacts the sealing portion, thereby forming a thermally conductive resin layer; and A fixing member is attached so as to cover each of the folded sealing portions.

9. The method according to claim 8, wherein: After the step of fixing between the sealing portion and the bottom surface, respectively, the step of attaching the fixing member is performed. 10 . A battery pack comprising the battery module according to claim 1 .

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