Battery module and manufacturing method thereof

Abstract

A battery module according to one embodiment of the present invention includes at least one battery cell having a vent portion, and a heat dissipation portion arranged to face the vent portion of the at least one battery cell and dissipate heat from the battery cell, the heat dissipation portion including a heat dissipation film having one side attached to the battery cell to face the vent portion of the battery cell, and a heat dissipation case coupled to the other side opposite to the one side of the heat dissipation film to form a cooling flow path.

Description

[Technical field]

[0001] The present invention relates to a battery module and a manufacturing method thereof, and more particularly, to a battery module and a manufacturing method thereof, in which, when an internal fire occurs in a battery cell, a heat dissipation film is ruptured due to pressure caused by opening a vent of the battery cell, and cooling water flows down to the battery cell through the broken part of the heat dissipation film, thereby suppressing the flame of the ignited battery cell.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0000843 dated January 4, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] FIG. 1 is a diagram illustrating side ignition when a battery cell catches fire in a battery module according to the prior art.

[0004] In general, a battery module 10 includes at least one battery cell 11 and a heat sink 12 attached to the battery cell 11. The heat sink 12 may be formed by attaching an aluminum plate material by a brazing method, or by attaching an aluminum plate material and a plastic plate material by a heterogeneous joining method.

[0005] The battery cell 11 is provided with a vent portion 11a. When the internal pressure of the battery cell increases, the vent portion 11a is designed to open preferentially over other portions of the battery cell 11. When a fire occurs inside the battery cell, the vent portion 11a opens and flames erupt to the outside of the battery cell 11.

[0006] Referring to FIG. 1, when the vent portion 11a side of the battery cell 11 is attached to the heat sink 12 as in the conventional case, when a fire occurs inside the battery cell 11, the heat sink 12 blocks the vent portion 11a of the battery cell 11, and the vent portion 11a does not open when the battery cell 11 catches fire.

[0007] If the vent portion 11a of the battery cell 11 is not opened, the internal pressure of the battery cell 11 continues to increase, causing a phenomenon in which the side of the battery cell is broken and flames erupt onto the side of the battery cell.

[0008] The flame that erupts onto the side of the battery cell 11 is transmitted to adjacent battery cells 11, causing a chain reaction of ignition. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of one aspect of the present invention is to provide a battery module and a manufacturing method thereof in which, when an internal fire occurs in a battery cell, a heat dissipation film is ruptured due to the pressure caused by opening a vent of the battery cell, and cooling water flows down to the battery cell through the damaged part of the heat dissipation film, thereby extinguishing the flame of the ignited battery cell.

[0010] Another object of one embodiment of the present invention is to provide a battery module capable of preventing successive ignitions of battery cells, and a manufacturing method of the battery module. [Means for solving the problem]

[0011] A battery module according to one aspect of the present invention includes at least one battery cell having a vent portion, and a heat dissipation portion arranged opposite the vent portion of the at least one battery cell for dissipating heat from the battery cell.

[0012] In addition, the heat dissipation part includes a heat dissipation film having one side attached to the battery cell so as to face the vent part of the battery cell, and a heat dissipation case coupled to the other side opposite to the one side of the heat dissipation film and having a cooling flow path through which coolant flows.

[0013] In addition, the heat dissipation film may be provided so as to be damaged when the vent portion of the battery cell is ignited.

[0014] In addition, the heat dissipation portion may be configured such that the coolant flowing through the cooling passage passes through a damaged portion of the heat dissipation film and flows to a vent portion of the battery cell.

[0015] The heat dissipation film may be a film in which a polymer resin film is pressure-bonded to an aluminum film.

[0016] Also, the heat dissipation film may include a polypropylene (PP) film, an aluminum film, a nylon film, and a polyethylene terephthalate (PET) film. In this case, the polypropylene (PP) film, the aluminum film, the nylon film, and the polyethylene terephthalate (PET) film may be laminated in order to form the heat dissipation film.

[0017] The heat dissipation case may have a film coupling part coupled to the heat dissipation film, and at least one flow groove provided to have a step with respect to the film coupling part. In this case, the heat dissipation film may surround the at least one flow groove, and a cooling flow path may be provided in a space between the at least one flow groove and the heat dissipation film.

[0018] The at least one flow channel may include a reference channel and a plurality of branch channels branching from the reference channel.

[0019] The heat dissipation part may include a port that is fluidly connected to the flow channel and provided in the heat dissipation case, and a cooling unit that is connected to the port and configured to supply and collect cooling water through the port.

[0020] The heat dissipation case may be made of synthetic resin.

[0021] The synthetic resin may include a polypropylene (PP) resin.

[0022] According to yet another aspect of the present invention, there is provided a method for manufacturing a battery module, the method including: forming a heat dissipation case having a cooling flow path by a vacuum injection method; and thermocompressing a heat dissipation film to the heat dissipation case.

[0023] The method for manufacturing the battery module may also include bonding a heat dissipation film to the battery cell such that a portion of a vent portion of the battery cell is positioned above the cooling channel.

[0024] Also, the heat dissipation film may be formed by sequentially laminating a polypropylene (PP) film, an aluminum film, a nylon film, and a polyethylene terephthalate (PET) film.

[0025] The heat dissipation case may include a polypropylene (PP) resin. Effect of the Invention

[0026] As described above, the battery module and the manufacturing method thereof according to at least one aspect of the present invention have the following advantages.

[0027] When a fire breaks out inside a battery cell, the heat dissipation film of the heat dissipation part bursts due to the pressure generated when the vent of the battery cell is opened, and the coolant flows down to the battery cell through the burst heat dissipation film, enabling the flames of the ignited battery cell to be quickly extinguished.

[0028] In addition, the temperature rise of the ignited battery cell and the adjacent battery cells can be suppressed, thereby ensuring the safety of the battery module.

[0029] In addition, since the heat dissipation film is formed in the form of a thin film in the micrometer range, the heat dissipation film may burst due to the force of opening the vent when an internal fire occurs in the battery cell, which prevents the side explosion of the battery cell and thus prevents chain fires of the battery cells. [Brief description of the drawings]

[0030] [Figure 1] 1 is a diagram illustrating side ignition when a battery cell ignites in a battery module according to the related art; [Diagram 2] 1 is a schematic perspective view of a battery module according to an embodiment of the present invention; [Diagram 3] 1 is a schematic cross-sectional view of a battery module according to an embodiment of the present invention; [Figure 4] 1 is a schematic cross-sectional view of a heat dissipation case and a heat dissipation film coupled together according to an embodiment of the present invention; [Diagram 5] 1 is a schematic cross-sectional view of a heat dissipation film according to an embodiment of the present invention. [Figure 6] 1 is a schematic cross-sectional view of a heat sink and a battery cell according to an embodiment of the present invention; [Figure 7] 11 is a diagram illustrating a process in which coolant is discharged from a heat dissipation part to suppress a flame of a battery cell when an internal fire occurs in one of the battery cells in a battery module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a battery module and a method for manufacturing the battery module according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0032] FIG. 2 is a schematic perspective view of a battery module according to one embodiment of the present invention, FIG. 3 is a schematic cross-sectional view of a battery module according to one embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view of a combined heat dissipation case and heat dissipation film according to one embodiment of the present invention.

[0033] In addition, FIG. 5 is a schematic cross-sectional view of a heat dissipation film according to one embodiment of the present invention, FIG. 6 is a schematic cross-sectional view of a combined heat dissipation part and battery cell according to one embodiment of the present invention, and FIG. 7 is a diagram illustrating a process in which coolant is discharged from the heat dissipation part to extinguish a flame in a battery cell when an internal fire occurs in one of the battery cells in a battery module according to one embodiment of the present invention.

[0034] The battery module 100 according to an embodiment of the present invention includes at least one battery cell 110 and a heat sink 120. The battery module 100 may include a plurality of battery cells 110.

[0035] Each battery cell 110 has a vent portion 111. For example, the battery cell 110 may be a cylindrical battery cell 110, and may include electrodes and a separator wound therein. The vent portion 111 is provided at one end of the battery cell 110. Since the battery cell 110 is a known product, detailed description thereof will be omitted in this embodiment.

[0036] In addition, the heat dissipation portion 120 is disposed to face the vent portions 111 of the plurality of battery cells 110 and is provided to dissipate heat from the plurality of battery cells 110.

[0037] The heat dissipation part 120 includes a heat dissipation film 121 having one side attached to the battery cell 110 so as to face the vent part 111 of the battery cell 110, and a heat dissipation case 123 coupled to the other side opposite to the one side of the heat dissipation film 121 and having a cooling flow path 125 through which coolant flows.

[0038] 3 and 4, the heat dissipation part 120 may include a heat dissipation film 121, a heat dissipation case 123, a port 129, and a cooling unit 150. The heat dissipation part 120 is disposed to face a vent part of at least one battery cell 110, and dissipates heat generated during charging of the battery cell 110 through the coolant.

[0039] Also, the heat dissipation film 121 may be a film having insulating properties and heat dissipation properties. The heat dissipation film 121 may be a thin film having a thickness in the micrometer (μm) unit, for example, the heat dissipation film 121 has a thickness of 10 μm to 900 μm.

[0040] In addition, the heat dissipation film 121 may be provided such that it is broken when the vent portion 111 of the battery cell 110 catches fire. In this case, the heat dissipation film 121 may be provided such that a local region directly facing the vent portion 111 is partially broken.

[0041] The heat dissipation part 120 may be configured such that the cooling water flowing through the cooling passage 125 passes through a damaged portion of the heat dissipation film 121 and flows to the vent part 111 a of the battery cell 110 .

[0042] Also, the heat dissipation film 121 may be a film in which a polymer resin film is compressed onto an aluminum film. Referring to Fig. 5, the heat dissipation film 121 may be a film in which a polypropylene (PP) film 121a, an aluminum film 121b, a nylon film 121c, and a polyethylene terephthalate (PET) film are laminated and compressed in this order.

[0043] Also, the heat dissipation case 123 may have a film coupling part 123a coupled to the heat dissipation film 121, and at least one flow channel 123b provided to have a step with respect to the film coupling part 123a. The heat dissipation case 123 may have the heat dissipation film 121 surrounding the at least one flow channel 123b while being thermocompressed to the film coupling part 123a, and a cooling flow channel 125 may be provided in the space between the at least one flow channel 123b and the heat dissipation film. That is, the flow channel 123b is formed to have a step at the film coupling part 123a, and has a structure that is open to the film coupling part 123a side. At this time, the heat dissipation film 121 is coupled to the film coupling part 123a so as to surround the open part of the flow channel 123b, and forms a cooling flow channel together with the flow channel 123b.

[0044] At least one flow groove 123b includes a reference groove 123b-1 and at least one branch groove 123b-2 branched from the reference groove 123b-1. The heat dissipation part 120 may include a cooling unit 150 that is fluidly connected to the flow groove 123b and is connected to a port 129 and the port 127 provided in the heat dissipation case to supply and recover cooling water through the port. In addition, a port 129 may be provided in the reference groove 123b-1.

[0045] Here, each branch groove 123b-2 may be connected to the reference groove 123b-1 and may be provided to be separated from each other. At least one branch groove 123b-2 may be provided parallel to the arrangement direction of the plurality of battery cells 110.

[0046] The heat dissipation case 123 may be made of synthetic resin. The heat dissipation case 123 may be injection molded from synthetic resin by a vacuum injection method. Here, the synthetic resin may include polypropylene (PP)-based resin.

[0047] In this embodiment, the heat dissipation case 123 and the heat dissipation film 121 are made of a resin material. At this time, when the contact portion between the heat dissipation case 123 and the heat dissipation film 121 is thermally compressed or thermally sealed, the heat dissipation film 121 is coupled to the film coupling portion 123a of the heat dissipation case 123.

[0048] A port 129 is provided in the heat dissipation case 123. The port 129 is provided in the heat dissipation case 123 so as to be fluidly movable with the reference groove 123b-1. The port 129 is a passage through which the cooling water flows into the cooling flow passage 125.

[0049] The port 129 may be coupled to the heat dissipation case 123 by any one of an adhesive, a dissimilar joining method, and a bolting method. A sealing process may be performed between the port 129 and the heat dissipation case 123 by using a sealing member.

[0050] A cooling unit 150 is connected to the port 129. The cooling unit 150 is a device that supplies cooling water to the cooling flow passage and recovers the cooling water in the cooling flow passage to the outside.

[0051] 6 and 7, the heat dissipation portion 120 is coupled to at least one battery cell 110 such that at least a portion of the vent portion 111 of the battery cell 110 is located on the cooling channel 125. At this time, the heat dissipation portion 120 may be coupled to the battery cell 110 by an adhesive 130.

[0052] In addition, the battery cell 110 may be attached to the heat dissipation part 120 such that the area placed on the film bonding part 123a is minimized and the area facing the cooling channel 125 is maximized. This is to allow the vent part 111 of the battery cell 110 to be more easily opened in the event of an internal fire of the battery cell 110.

[0053] Referring to FIG. 7, when an internal fire occurs in the battery cell 110, the vent portion 111 of the battery cell 110 is opened, and the force of the vent portion 111 pushing up the heat dissipation film 121 causes the heat dissipation film 121 to burst, causing the cooling water flowing through the cooling passage 125 to flow down onto the ignited battery cell 110.

[0054] Accordingly, one embodiment of the present invention can quickly extinguish the flame of the ignited battery cell 110, suppress the temperature rise of the ignited battery cell 110 and the adjacent battery cells 110, and ensure the safety of the battery module 100.

[0055] A method for manufacturing a battery module according to an embodiment of the present invention will now be described.

[0056] The method for manufacturing the battery module includes forming a heat dissipation case having a cooling channel by a vacuum injection method, and thermocompressing a heat dissipation film onto the heat dissipation case.

[0057] The manufacturing method also includes bonding a heat dissipation film to the battery cell such that a portion of a vent portion of the battery cell is positioned above the cooling channel.

[0058] Specifically, a heat dissipation case 123 having at least one flow passage groove 123b is prepared (S1). The heat dissipation case 123 is prepared by the following process.

[0059] A metal mold (not shown) having a shape corresponding to the heat dissipation case 123 is prepared (S1-1). The metal mold preferably has a structure that embodies the structure of the heat dissipation case 123 such that at least one flow channel 123b has a step with respect to the film bonding portion 123a.

[0060] Synthetic resin is poured into the metal mold (S1-2). Here, the synthetic resin is preferably a polypropylene (PP)-based resin.

[0061] After the synthetic resin is poured into the mold, the mold is heated, and the synthetic resin in the mold is softened (S1-3).

[0062] After that, the synthetic resin softens and the air inside the mold is sucked out by the vacuum injection method. Through this process, the synthetic resin softened in the mold is molded according to the shape of the mold to produce a heat sink case (S1-4).

[0063] Thereafter, the heat dissipation case is separated from the mold (S1-5).

[0064] Finally, port openings are drilled in the heat dissipation case (S1-6). Here, the port openings are openings in which the ports are installed.

[0065] Next, when the heat dissipation case 123 is prepared, the heat dissipation film 121 is bonded to the heat dissipation case 123 (S2, S3).

[0066] Here, the heat dissipation film 121 is a thin film having a thickness in micrometers (μm). The heat dissipation film 121 may be a film in which a polypropylene (PP) film, an aluminum film, a nylon film, and a PET film are laminated and compressed.

[0067] The heat dissipation film 121 covers at least one flow passage groove 123b and is thermocompression bonded to the film coupling part 123a of the heat dissipation case 123. The heat dissipation film 121 is coupled to the heat dissipation case 123 to form a heat dissipation part 120 having a cooling flow passage 125 (S3).

[0068] A port 129, which is a passage for cooling water, is installed in the heat dissipation case 123 (S4). The port 129 is inserted into a port opening (not shown) and fixed to the heat dissipation case 123 by an adhesive. Alternatively, the port 129 may be coupled to the port opening (not shown) by either a heterogeneous joining method or a bolting method. Then, a gap between the port 129 and the heat dissipation case 123 is sealed by a sealing member.

[0069] The heat dissipation portion 120 is bonded to the at least one battery cell 110 such that the heat dissipation film 121 contacts the bottom surface of the at least one battery cell 110 (S5). In the step (S5), it is preferable that the at least one battery cell 110 is bonded to the heat dissipation portion 120 such that a partial area of ​​the vent portion 111 of the battery cell 110 is placed on the cooling channel 125.

[0070] The above-described preferred embodiments of the present invention have been disclosed for illustrative purposes, and those skilled in the art having ordinary skill in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be understood to fall within the scope of the following claims. [Industrial Applicability]

[0071] According to a battery module and a manufacturing method thereof related to at least one embodiment of the present invention, when an internal fire occurs in a battery cell, the heat dissipation film of the heat dissipation part is ruptured due to the pressure generated when the vent part of the battery cell is opened, and cooling water flows down to the battery cell through the ruptured heat dissipation film, thereby quickly extinguishing the flame of the ignited battery cell. [Explanation of symbols]

[0072] 100 Battery Module 110 Battery Cell 111 Vent section 120 Heat dissipation part 121 Heat dissipation film 123 Heat sink case 125 Cooling Channel

Claims

1. at least one battery cell having a vent; a heat dissipation portion disposed to face a vent portion of the at least one battery cell and configured to dissipate heat from the battery cell; Including, The heat dissipation part includes a heat dissipation film attached to the battery cell so as to face the vent part of the battery cell; a heat dissipation case coupled to the other surface of the heat dissipation film opposite to the one surface of the heat dissipation film and having a cooling flow path through which cooling water flows; a battery module.

2. The battery module according to claim 1 , wherein the heat dissipation film is provided so as to be broken when the vent portion of the battery cell is ignited.

3. The battery module according to claim 2 , wherein the heat dissipation portion is configured such that the cooling water flowing through the cooling flow passage passes through a portion where the heat dissipation film is damaged and flows to a vent portion of the battery cell.

4. The battery module according to claim 1 , wherein the heat dissipation film is an aluminum film to which a polymer resin film is press-bonded.

5. The battery module according to claim 1 , wherein the heat dissipation film comprises a polypropylene (PP) film, an aluminum film, a nylon film, and a polyethylene terephthalate (PET) film.

6. The heat dissipation case is a film coupling part coupled to the heat dissipation film; At least one flow channel provided to have a step with respect to the film bonding portion; having the heat dissipation film surrounds the at least one flow channel, The battery module according to claim 1 , wherein a cooling channel is provided in a space between the at least one flow channel and the heat dissipation film.

7. The at least one flow channel is A reference groove; a plurality of branch grooves branching from the reference groove; The battery module of claim 6 .

8. The heat dissipation portion is a port provided in the heat dissipation case and connected to the flow passage groove so as to be capable of moving fluid therethrough; a cooling unit connected to the port for supplying and recovering cooling water through the port; The battery module of claim 6 , further comprising:

9. The battery module according to claim 5 , wherein the heat dissipation case is made of a synthetic resin.

10. The battery module according to claim 9 , wherein the synthetic resin comprises a polypropylene (PP)-based resin.

11. A method for manufacturing a battery module according to any one of claims 1 to 10, comprising the steps of: forming a heat dissipation case having a cooling passage by a vacuum injection method; a step of thermocompressing a heat dissipation film onto a heat dissipation case; A method for manufacturing a battery module, comprising:

12. The method for manufacturing a battery module according to claim 11, comprising: bonding a heat dissipation film to the battery cell such that a partial area of ​​a vent portion of the battery cell is positioned on the cooling channel.

13. The method for manufacturing a battery module according to claim 11, wherein the heat dissipation film comprises a polypropylene (PP) film, an aluminum film, a nylon film, and a polyethylene terephthalate (PET) film.

14. The method of manufacturing a battery module according to claim 11, wherein the heat dissipation case includes a polypropylene (PP)-based resin.

Images