Battery module and manufacturing method thereof

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, and a cooling fin positioned between the battery cells. The cooling fin includes a first portion facing one of the battery cells and a second portion facing another of the battery cells, and an air layer is formed between the first portion and the second portion.

Description

[Technical field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0003179 filed on January 11, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a manufacturing method thereof, and more particularly to a battery module having improved fire safety and cooling performance and a manufacturing method thereof. [Background technology]

[0003] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras has become commonplace, the development of technologies related to these mobile devices is progressing vigorously. In addition, rechargeable secondary batteries are used as the power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc., as a solution to resolve air pollution caused by existing gasoline-powered vehicles that use fossil fuels, so there is an increasing need for the development of secondary batteries.

[0004] Currently, the secondary batteries in commercial use include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Among these, lithium secondary batteries are attracting attention due to their advantages of almost no memory effect compared to nickel-based secondary batteries, freedom in charging and discharging, extremely low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative active materials, respectively, and include an electrode assembly in which positive and negative electrode plates coated with the positive and negative active materials are disposed with a separator between them, and a battery case that hermetically houses the electrode assembly together with an electrolyte.

[0006] Generally, lithium secondary batteries can be classified into can-type secondary batteries, in which an electrode assembly is housed in a metal can, and pouch-type secondary batteries, in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet, depending on the shape of the exterior material.

[0007] In the case of secondary batteries used in small devices, two to three battery cells are arranged, while in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which a number of battery cells are electrically connected is used. In such battery modules, a number of battery cells are connected to each other in series or parallel to form a battery cell stack, thereby improving capacity and output. In addition, one or more battery modules can be attached with various control and protection systems such as a BMS (Battery Management System) and a cooling system to form a battery pack.

[0008] If the temperature of a secondary battery becomes higher than the appropriate temperature, the performance of the secondary battery may deteriorate, and in severe cases, there may be a risk of explosion or fire. In particular, in a battery module or battery pack having a large number of secondary batteries, i.e., battery cells, the temperature may rise more rapidly in a small space due to the sum of heat generated from the large number of battery cells. In other words, a battery module in which a large number of battery cells are stacked and a battery pack to which such a battery module is attached can obtain high output, but it is difficult to remove heat generated in the battery cells during charging and discharging. If the heat of the battery cells is not properly dissipated, the battery cells deteriorate quickly, shortening their lifespan and increasing the possibility of explosion or fire.

[0009] Furthermore, battery modules included in vehicle battery packs are often exposed to direct sunlight and may be placed in high temperature conditions such as in summer or in desert regions. Also, since a large number of battery cells are arranged in a concentrated manner to increase the mileage of a vehicle, fire or heat generated in any one battery cell can easily spread to adjacent battery cells, ultimately leading to explosion or fire of the battery pack itself.

[0010] FIG. 1 is a perspective view showing a conventional battery module.

[0011] Referring to FIG. 1, a conventional battery module 10 may include a battery cell stack 20 in which a plurality of battery cells 11 are stacked. The battery cells 11 may be pouch-type battery cells. Cooling fins 30 made of a metal plate material with high thermal conductivity may be disposed between the battery cells 11. The cooling fins 30 are effective in transferring heat generated in the battery cells 11, i.e., in dissipating heat from the battery module 10, but are insufficient in blocking the spread of a fire that occurs in the battery cells 11. In other words, since the cooling fins 30 made of a metal material with high thermal conductivity are in direct contact with the left and right battery cells 11, it is difficult to prevent the fire or heat from spreading to the adjacent battery cells 11 when a fire occurs due to heat generation in any one of the battery cells 11.

[0012] Therefore, there is a demand for a battery module that has the ability to block the propagation of fire as well as the ability to cool and dissipate heat from the battery cells. Summary of the Invention [Problem to be solved by the invention]

[0013] An object of the present invention is to provide a battery module and a manufacturing method thereof that can effectively dissipate heat generated from battery cells and at the same time prevent fire or heat generated from any one battery cell from spreading to adjacent battery cells.

[0014] However, the problem to be solved by the embodiments of the present invention is not limited to the above problem, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0015] A battery module according to an embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked, and a cooling fin positioned between the battery cells. The cooling fin includes a first portion facing one of the battery cells and a second portion facing the other of the battery cells, and an air layer is formed between the first portion and the second portion.

[0016] A first bead may be formed on the first portion, protruding toward the second portion, and a second bead may be formed on the second portion, protruding toward the first portion.

[0017] The cooling fin may be bent at least once to form the first portion and the second portion.

[0018] Based on the folded state, the cooling fin may further include a third portion located between the first portion and the second portion. A first bent portion connecting the first portion and the second portion is formed, and a second bent portion connecting the second portion and the third portion is formed, and the first portion, the second portion, and the third portion may be folded.

[0019] A first bead protruding toward the second portion may be formed in the first portion, and a second bead protruding toward the first portion may be formed in the second portion. An opening may be formed in the third portion, and the first bead and the second bead may face each other with the opening interposed therebetween.

[0020] A side flange portion may be located on both sides of the first portion or the second portion, and the side flange portion may be bent perpendicularly to one surface of the first portion or the second portion.

[0021] The first and second portions may be rectangular sheets having long and short sides, and the first and second bent portions may be formed on the long sides.

[0022] The battery module may further include a thermally conductive resin layer located under the battery cell stack, and the battery cells and the cooling fins may be in contact with the thermally conductive resin layer.

[0023] A method for manufacturing a battery module according to an embodiment of the present invention includes the steps of: manufacturing a cooling fin from a metal sheet; and stacking a plurality of battery cells to manufacture a battery cell stack by interposing the cooling fin between adjacent battery cells among the battery cells. The cooling fin includes a first portion in contact with one of the adjacent battery cells and a second portion in contact with the other of the adjacent battery cells, and an air layer is formed between the first portion and the second portion.

[0024] A first bead may be formed on the first portion protruding toward the second portion, and a second bead may be formed on the second portion protruding toward the first portion.

[0025] In the folded state, the cooling fin may further include a third portion located between the first portion and the second portion.

[0026] The step of manufacturing the cooling fin may include the steps of: bending the metal plate so that the second portion and the third portion are folded by forming a second bent portion connecting the second portion and the third portion; and bending the metal plate so that the first portion, the second portion, and the third portion are folded by forming a first bent portion connecting the first portion and the second portion.

[0027] A first bead protruding toward the second portion may be formed in the first portion, and a second bead protruding toward the first portion may be formed in the second portion. An opening may be formed in the third portion, and the first bead and the second bead may face each other across the opening.

[0028] A side flange portion may be formed on both sides of the first part or the second part, and the step of manufacturing the cooling fin may include the step of bending the side flange portion so that the side flange portion is perpendicular to one surface of the first part or the second part. Effect of the Invention

[0029] According to an embodiment of the present invention, cooling fins with an air layer formed inside are arranged between battery cells, thereby providing cooling and heat dissipation performance while also preventing a fire or heat generated in one battery cell from spreading to adjacent battery cells.

[0030] The effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the claims. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view showing a conventional battery module. [Diagram 2] 1 is a perspective view of a battery module according to an embodiment of the present invention; [Diagram 3] 3 is a perspective view showing a battery cell stack and cooling fins included in the battery module of FIG. 2. [Figure 4] 4 is a perspective view showing a battery cell included in the battery cell stack of FIG. 3. [Diagram 5] FIG. 4 is a perspective view showing the cooling fins of FIG. [Figure 6] 6 is a perspective view showing a state in which a portion corresponding to line B in the cooling fin of FIG. 5 is cut along the xy plane. [Figure 7] 6 is a perspective view showing a state in which a portion corresponding to line C in the cooling fin of FIG. 5 is cut along the xz plane. [Figure 8] 6 is a perspective view showing the cooling fin of FIG. 5 before the first, second and third parts are folded up. FIG. [Figure 9]9 is a plan view showing the cooling fins of FIG. 8 as viewed along the -y axis on the xz plane. [Figure 10] 3 is a cross-sectional view showing a part of a cross section taken along the line AA' in FIG. 2. [Figure 11] 4 is a view illustrating a step of manufacturing a cooling fin in a method for manufacturing a battery module according to an embodiment of the present invention; [Figure 12] 4 is a view illustrating a step of manufacturing a cooling fin in a method for manufacturing a battery module according to an embodiment of the present invention; [Figure 13] 4 is a view illustrating a step of manufacturing a cooling fin in a method for manufacturing a battery module according to an embodiment of the present invention; [Figure 14] 4 is a view illustrating a step of manufacturing a cooling fin in a method for manufacturing a battery module according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may, however, be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0033] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0034] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown. In the drawings, thicknesses are exaggerated to clearly express multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0035] In addition, when a part such as a layer, film, region, or plate is said to be "on" or "above" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. In addition, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" the opposite direction of gravity.

[0036] Also, throughout the specification, when a part "comprises" a certain element, this means that it may further include other elements, but not excluding other elements, unless specifically stated to the contrary.

[0037] Also, throughout the specification, "in a plane" means when the subject part is viewed from above, and "in cross section" means when the subject part is cut vertically and viewed from the side.

[0038] Fig. 2 is a perspective view of a battery module according to an embodiment of the present invention, Fig. 3 is a perspective view showing a battery cell stack and cooling fins included in the battery module of Fig. 2, Fig. 4 is a perspective view showing a battery cell included in the battery cell stack of Fig. 3.

[0039] A battery module 100 according to one embodiment of the present invention includes a battery cell stack 200 in which a plurality of battery cells 110 are stacked, and cooling fins 300 positioned between the battery cells 110 .

[0040] First, the battery cell 110 is preferably a pouch-type battery cell and may be formed in a rectangular sheet-type structure. The battery cell 110 according to the present embodiment includes protruding first and second electrode leads 111, 112. Specifically, the battery cell 110 according to the present embodiment has a structure in which the first and second electrode leads 111, 112 face each other with respect to the cell body 113 and protrude from one end 114a and the other end 114b, respectively. More specifically, the first and second electrode leads 111, 112 are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110. The first and second electrode leads 111, 112 have different polarities, and for example, one of them may be a positive electrode lead 111 and the other may be a negative electrode lead 112. That is, the positive electrode lead 111 and the negative electrode lead 112 may protrude in a direction facing each other with respect to one battery cell 110.

[0041] Meanwhile, the battery cell 110 can be manufactured by bonding both ends 114a, 114b of the cell case 114 and one side 114c connecting them with each other in a state where an electrode assembly (not shown) is housed in the cell case 114. In other words, the battery cell 110 according to this embodiment has a total of three sealing parts, which are structured to be sealed by a method such as heat fusion, and the remaining other side comprises a connecting part 115. The cell case 114 is made of a laminate sheet including a resin layer and a metal layer.

[0042] Such a battery cell 110 may be configured in a plurality of pieces, and the plurality of battery cells 110 may be stacked so as to be electrically connected to each other to form a battery cell stack 200. In particular, as shown in Figures 2 and 3, the plurality of battery cells 110 may be stacked along a direction parallel to the x-axis. Therefore, the electrode leads 111 and 112 may protrude in the y-axis direction and the -y-axis direction, respectively.

[0043] The cooling fin 300 according to the present embodiment will be described in detail below with reference to FIG. 3 and FIG. 5 to FIG.

[0044] Fig. 5 is a perspective view showing the cooling fin of Fig. 3. Fig. 6 is a perspective view showing the cooling fin of Fig. 5 cut along the xy plane at a portion corresponding to line B. Fig. 7 is a perspective view showing the cooling fin of Fig. 5 cut along the xz plane at a portion corresponding to line C.

[0045] 3 and 5 to 7, the cooling fin 300 according to the present embodiment includes a first portion 310 facing one of the battery cells 110 and a second portion 320 facing the other of the battery cells 110. An air layer AL is formed between the first portion 310 and the second portion 320. That is, the first portion 310 and the second portion 320 are made of metal plates and are spaced apart from each other to provide an empty space, i.e., an air layer AL, therebetween.

[0046] In the case of a conventional cooling fin (30, see FIG. 1), which is simply a single metal plate, there is no problem in transferring heat generated in the battery cell 11, but it is difficult to prevent a fire that occurs in a battery cell 11 from spreading to an adjacent battery cell 11. On the other hand, the cooling fin 300 according to the present embodiment has an air layer AL formed therein, and this air layer AL can function as a heat insulating layer. Even if a fire occurs due to heat generation in any one of the battery cells 110, the air layer AL provided between the battery cells 110 can delay the spread of the fire and heat to the adjacent battery cells 110. In other words, the safety of the battery module 100 can be improved by ensuring time for the fire to spread to the surrounding battery cells 110. In particular, when the battery module 100 is included in a vehicle battery pack, the spread of the fire between the battery cells 110 can be delayed, thereby ensuring time for the driver to escape from the fire. Furthermore, since the first portion 310 and the second portion 320, which are metal plates, face the battery cells 110, respectively, there is no abnormality in heat transfer in the upward or downward directions of the battery module 100. In particular, since the first portion 310 and the second portion 320 of the cooling fin 300 are in direct contact with the thermally conductive resin layer 1300 described below, there is no risk of a decrease in heat transfer performance. That is, the cooling fin 300 according to this embodiment has cooling and heat dissipation performance, and can also prevent a fire that breaks out in one battery cell from spreading to an adjacent battery cell.

[0047] The cooling fin 300 according to an embodiment of the present invention will be described in more detail below with reference to FIGS. 8 and 9, etc.

[0048] Fig. 8 is a perspective view showing a state before the first part, the second part, and the third part of the cooling fin in Fig. 5 are folded up. Fig. 9 is a plan view showing the cooling fin in Fig. 8 as viewed along the -y axis direction on the xz plane.

[0049] 6 to 9, the cooling fin 300 according to an embodiment of the present invention may be bent at least once to form a first portion 310 and a second portion 320. In other words, the first portion 310 and the second portion 320 are formed by bending a metal plate at least once, and the first portion 310 and the second portion 320 are separated by a portion where a single metal plate is bent.

[0050] More specifically, the cooling fin 300 may further include a third portion 330 located between the first portion 310 and the second portion 320 based on the folded state as shown in Fig. 6. A first bending portion BD1 connecting the first portion 310 and the second portion 320 is formed, and a second bending portion BD2 connecting the second portion 320 and the third portion 330 is formed, so that the first portion 310, the second portion 320, and the third portion 330 can be folded. Here, the first bending portion BD1 and the second bending portion BD2 refer to the bent portions of the metal plate. That is, the cooling fin 300 according to the present embodiment may have a structure in which the first portion 310, the second portion 320, and the third portion 330, which are one metal plate, are folded together to form an air layer AL therebetween. Also, the first portion 310 and the second portion may be in the form of a rectangular sheet having a long side and a short side, and the first bending portion BD1 and the second bending portion BD2 may be formed on the long side thereof.

[0051] Meanwhile, a first bead (310B) protruding in the direction of the second portion 320 may be formed on the first portion 310, and a second bead (320B) protruding in the direction of the first portion 310 may be formed on the second portion 320. This is also based on a state in which the first portion 310 and the second portion 320 are folded together.

[0052] When the first portion 310 and the second portion 320 are folded to face each other, the first bead 310B and the second bead 320B may face each other. More specifically, an opening 330P may be formed in the third portion 330, and when the first portion 310, the second portion 320, and the third portion 330 are folded together, the first bead 310B and the second bead 320B may face each other through the opening 330P, and the first bead 310B and the second bead 320B may contact each other. Due to the first bead 310B and the second bead 320B protruding in the directions facing each other, the cooling fin 300 may be a rectangular sheet having a concave shape. The first bead 310B and the second bead 320B may be formed only in a part of the first portion 310 and the second portion 320, not in the entirety, and may be formed in the center of each portion as shown in FIG. 8. Also, the opening 330P may be formed to correspond to the positions of the first bead 310B and the second bead 320B.

[0053] During repeated charging and discharging of the battery cells 110, the electrolyte inside the battery cells 110 may decompose, generating gas and causing the battery cells 110 to swell, i.e., a swelling phenomenon may occur. In particular, swelling may occur in each battery cell 110 in the stacking direction of the battery cells 110 (the direction parallel to the x-axis, see FIGS. 2 and 3).

[0054] In the case of a conventional cooling fin (30, see FIG. 1), which is simply a single metal plate, when any one of the adjacent battery cells 11 swells, the pressure is directly applied to the battery cell 11 located on the opposite side of the cooling fin 30. If the swelling of each battery cell 11 cannot be suppressed, this may cause structural deformation of the battery module 10 and may adversely affect the durability of the battery module 10.

[0055] On the other hand, in the case of the cooling fin 300 according to the present embodiment, a bead structure of the first bead 310B and the second bead 320B is provided, so that when the adjacent battery cell 110 expands, a uniform elastic force can be applied to the corresponding battery cell 110 as a reaction to the expansion. In addition, the elastic restoring force of the third portion 330 located between the first portion 310 and the second portion 320 can reduce the pressure transmitted to the battery cell 110 located on the opposite side when the battery cell 110 swells.

[0056] Meanwhile, a side flange portion 300F may be located on both sides of the first part 310 or the second part 320, and based on a state in which the first part 310 and the second part 320 are folded, such a side flange portion 300F may be bent perpendicularly to one surface of the first part 310 or the second part 320. FIG. 8 illustrates the side flange portion 300F before bending, and as shown in FIG. 6, the side flange portion 300F may be bent perpendicularly to one surface of the first part 310 or the second part 320. The air layer AL provided inside the cooling fin 300 may be configured to be surrounded by the first part 310, the second part 320, and the side flange portion 300F. The bent flange portion 300F may cover sharp parts of the first part 310 or the second part 320 to prevent the first part 310 or the second part 320 from damaging components inside the battery module 100, including the battery cell 110.

[0057] Meanwhile, referring again to Fig. 3, in some cases, an adhesive member 800 is provided between the battery cells 110 and the cooling fins 300. As the number of battery cells 110 increases, an adhesive member 800 having adhesive strength can be positioned to fix the battery cells 110 and the cooling fins 300 interposed therebetween to provide a structurally stable battery cell stack 200. Such an adhesive member 800 can be applied without any particular limitation as long as it is a thin member having adhesive properties. As one example, a double-sided tape can be used as the adhesive member 800.

[0058] Meanwhile, referring back to FIG. 2 and FIG. 3, the battery module 100 according to the present embodiment may include an elastic member 700, first and second sensing blocks 410 and 420, and a side pad 600.

[0059] The elastic member 700 includes an elastic material and can cover the front, rear and both side surfaces of the battery cell stack 200. Here, the front surface means the surface in the y-axis direction of the battery cell stack 200, the rear surface means the surface in the -y-axis direction of the battery cell stack 200, and the both side surfaces mean the surfaces in the x-axis and -x-axis directions of the battery cell stack 200, respectively. The lower part of the elastic member 700 is open, so that the top and bottom surfaces of the battery cell stack 200 can be exposed. Here, the top and bottom surfaces mean the surfaces in the z-axis and -z-axis directions of the battery cell stack 200, respectively.

[0060] The first sensing block 410 may be positioned between the front surface of the battery cell stack 200 and the elastic member 700, and the second sensing block 420 may be positioned between the rear surface of the battery cell stack 200 and the elastic member 700. The first sensing block 410 and the second sensing block 420 may include a material exhibiting electrical insulation, for example, a plastic material, a polymer material, or a composite material. In addition, the first sensing block 410 and the second sensing block 420 may have a basket shape and be configured to cover the front surface and the rear surface of the battery cell stack 200, respectively. The electrode leads (111, 112, see FIG. 4) of each battery cell 110 may be bent and joined after passing through slits formed in the first sensing block 410 and the second sensing block 420. As a result, the battery cells 110 may be connected to each other in series or parallel.

[0061] The plate-shaped side pads 600 are disposed between both sides of the battery cell stack 200 and the elastic member 700, and can complement the rigidity of the battery module 100 and perform a buffering function between the battery cells 110 and the elastic member 700. The side pads 600 can be made of a foam material.

[0062] Hereinafter, with reference to FIG. 10, a thermally conductive resin layer according to an embodiment of the present invention will be described in detail.

[0063] Fig. 10 is a cross-sectional view showing a portion of a cross section taken along cutting line A-A' in Fig. 2. At this time, Fig. 10 shows a cross section assuming that battery cell stack 200 in Fig. 2 is in contact with thermally conductive resin layer 1300.

[0064] The battery module 100 according to an embodiment of the present invention may further include a thermally conductive resin layer 1300 located under the battery cell stack 200. In one embodiment of the present invention, the battery module 100 of FIG. 2 may be housed in a pack frame to form a battery pack. In this case, the thermally conductive resin layer 1300 may be located at the bottom of the pack frame, and the lower surface of the battery cell stack 200 may be seated on the thermally conductive resin layer 1300. In another embodiment of the present invention, although not specifically shown, the battery cell stack may be inserted into a module frame to form a battery module. In this case, the thermally conductive resin layer 1300 may be located at the bottom of the module frame, and the lower surface of the battery cell stack 200 may be seated on the thermally conductive resin layer 1300.

[0065] The thermally conductive resin layer 1300 may be formed by applying a thermally conductive resin. The thermally conductive resin may include a thermally conductive adhesive material, and specifically may include at least one of a silicone material, a urethane material, and an acrylic material. The thermally conductive resin is liquid when applied, but hardens after application to serve to fix the plurality of battery cells 110 constituting the battery cell stack 200. In addition, the thermally conductive resin has excellent thermal conductivity properties, and can transfer heat generated in the battery module 100 to the outside to prevent the battery module 100 from overheating.

[0066] At this time, the battery cells 110 can be in direct contact with the thermally conductive resin layer 1300. This simplifies the heat transfer path toward the lower side of the battery module 100, and reduces the possibility of an air layer such as an air gap occurring. This improves the cooling performance of the battery module 100 or a battery pack including the battery module 100.

[0067] In addition, the cooling fins 300 may extend from the lower surface of the battery cell stack 200, so that the cooling fins 300 may also be in direct contact with the thermally conductive resin layer 1300. By configuring the cooling fins 300 facing the battery cells 110 to be in direct contact with the thermally conductive resin layer 1300, it is possible to maximize the heat dissipation performance.

[0068] Hereinafter, a method for manufacturing a battery module according to an embodiment of the present invention will be described in detail with reference to Figs. 2, 3, 8, and 11 to 14. However, parts that overlap with the contents previously described will be omitted to avoid repetition.

[0069] 2 and 3, a method for manufacturing a battery module 100 according to an embodiment of the present invention includes the steps of manufacturing cooling fins 300 from a metal plate material; and stacking a plurality of battery cells 110 and interposing the cooling fins 300 between adjacent battery cells 110 to manufacture a battery cell stack 200. The battery cell stack 200 can be manufactured by sequentially stacking a plurality of battery cells 110 and the cooling fins 300 disposed therebetween.

[0070] At this time, the cooling fin 300 includes a first portion 310 contacting one of the adjacent battery cells 110 and a second portion 320 contacting the other of the adjacent battery cells 110, and an air layer AL is formed between the first portion 310 and the second portion 320. In addition, a first bead 310B protruding toward the second portion 320 may be formed on the first portion 310, and a second bead 320B protruding toward the first portion 310 may be formed on the second portion 320. In addition, the cooling fin 300 may further include a third portion 330 located between the first portion 310 and the second portion 320 based on the folded state. The above content overlaps with the previously described content, so further description will be omitted.

[0071] As described above, the cooling fin 300 according to the present embodiment has a structure in which the first portion 310, the second portion 320, and the third portion 330, which are a single metal plate, are folded together to form an air layer AL therebetween. Hereinafter, the steps of manufacturing the cooling fin 300 will be described in detail with reference to Figs. 11 to 14.

[0072] 11 to 14 are views illustrating a step of manufacturing a cooling fin in a method for manufacturing a battery module according to an embodiment of the present invention, in which (b) of FIG. 11 to FIG. 14 is a side view of (a).

[0073] 11 and 12, the step of manufacturing the cooling fin 300 may include forming a second bending portion BD2 connecting the second portion 320 and the third portion 330, and bending the metal plate material M so that the second portion 320 and the third portion 330 are folded.

[0074] Next, referring to Figures 12 and 13, the step of manufacturing the cooling fin 300 may include a step of forming a first bending portion BD1 connecting the first portion 310 and the second portion 320, and bending a metal plate material M so that the first portion 310, the second portion 320, and the third portion 330 are folded.

[0075] At this time, forming the second bending portion BD2 or the first bending portion BD1 means bending the metal plate M. Also, an opening 330P may be formed in the third portion 330, and the first bead 310B and the second bead 320B may face each other through the opening 330P.

[0076] 13 and 14, a side flange portion 300F may be formed on both sides of the first portion 310 or the second portion 320. Although Figs. 11 and 12 show the case where the side flange portion 300F is formed on the second portion 320, it may also be formed on the first portion 310. It is preferable that the side on which the side flange portion 300F is formed is a side on which the first bending portion BD1 and the second bending portion BD2 are not formed.

[0077] The step of manufacturing the cooling fin 300 may include a step of bending the side flange portion 300F so that the side flange portion 300F is perpendicular to one surface of the first portion 310 or the second portion 320. Thus, it is possible to manufacture the cooling fin 300 configured such that the air layer AL is surrounded by the first portion 310, the second portion 320, and the side flange portion 300F.

[0078] In this embodiment, terms indicating directions such as front, back, left, right, up, and down are used, but these terms are used for convenience of explanation and may change depending on the position of the target object or the position of the observer, etc.

[0079] One or more battery modules according to the present embodiment described above may be mounted together with various control and protection systems, such as a Battery Management System (BMS) and a cooling system, to form a battery pack.

[0080] The battery module or battery pack can be applied to various devices, specifically, to transportation means such as electric bicycles, electric cars, and hybrid vehicles, but is not limited thereto, and can be applied to various devices that can use secondary batteries.

[0081] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0082] 100 Battery Module 200 Battery cell stack 300 Cooling Fins 310 Part 1 320 Part 2

Claims

1. A battery cell stack in which a plurality of battery cells are stacked; and cooling fins positioned between the battery cells; the cooling fin includes a first portion facing one of the battery cells and a second portion facing the other of the battery cells; An air layer is formed between the first portion and the second portion, A first bead is formed only at a center of the first portion so as to protrude toward the second portion, a second bead protruding toward the first portion is formed only at a center of the second portion.

2. The battery module according to claim 1 , wherein the first bead and the second bead are in contact with each other.

3. The battery module according to claim 1 , wherein the cooling fin is bent at least once to form the first portion and the second portion.

4. A battery cell stack in which a plurality of battery cells are stacked; and cooling fins positioned between the battery cells; the cooling fin includes a first portion facing one of the battery cells and a second portion facing the other of the battery cells; An air layer is formed between the first portion and the second portion, The cooling fin further includes a third portion located between the first portion and the second portion in a folded state, a first bending portion is formed connecting the first portion and the second portion, and a second bending portion is formed connecting the second portion and the third portion, and the first portion, the second portion, and the third portion are folded.

5. A first bead is formed in the first portion so as to protrude toward the second portion, A second bead is formed in the second portion so as to protrude toward the first portion, An opening is formed in the third portion, The battery module according to claim 4 , wherein the first bead and the second bead face each other across the opening.

6. A side flange portion is located on both sides of the first portion or the second portion, The battery module according to claim 4 or 5, wherein the side flange portion is bent perpendicularly to one surface of the first portion or the second portion.

7. The first and second portions are rectangular sheets having long and short sides, The battery module of claim 4 , wherein the first bent portion and the second bent portion are formed on the long side.

8. The battery cell stack further includes a thermally conductive resin layer located below the battery cell stack, The battery module according to any one of claims 1 to 7, wherein the battery cells and the cooling fins are in contact with the thermally conductive resin layer.

9. manufacturing the cooling fins from sheet metal; and manufacturing a battery cell stack by stacking a plurality of battery cells and interposing the cooling fins between adjacent battery cells among the battery cells; the cooling fin includes a first portion in contact with one of the adjacent battery cells and a second portion in contact with the other of the adjacent battery cells; A method for manufacturing a battery module, comprising the steps of: forming an air layer between the first portion and the second portion, A first bead is formed only at a center of the first portion so as to protrude toward the second portion, a second bead protruding toward the first portion is formed only at a center of the second portion.

10. The method for manufacturing a battery module according to claim 9 , wherein the first bead and the second bead are in contact with each other.

11. The method of claim 9 or 10, wherein the cooling fin further includes a third portion located between the first portion and the second portion in a folded state.

12. manufacturing the cooling fins from sheet metal; and manufacturing a battery cell stack by stacking a plurality of battery cells and interposing the cooling fins between adjacent battery cells among the battery cells; the cooling fin includes a first portion in contact with one of the adjacent battery cells and a second portion in contact with the other of the adjacent battery cells; A method for manufacturing a battery module, comprising the steps of: forming an air layer between the first portion and the second portion, The cooling fin further includes a third portion located between the first portion and the second portion in a folded state, The step of manufacturing the cooling fin comprises: forming a second bending portion connecting the second portion and the third portion and bending the metal plate such that the second portion and the third portion are folded; and forming a first bending portion connecting the first portion and the second portion, and bending the metal plate so that the first portion, the second portion, and the third portion are folded.

13. A first bead is formed in the first portion so as to protrude toward the second portion, A second bead is formed in the second portion so as to protrude toward the first portion, An opening is formed in the third portion, The method for manufacturing a battery module according to claim 12 , wherein the first bead and the second bead face each other across the opening.

14. A side flange portion is formed on both sides of the first portion or the second portion, The method of claim 12 or 13, wherein the manufacturing of the cooling fin comprises bending the side flange portion so that the side flange portion is perpendicular to one surface of the first portion or the second portion.

Images