Battery module, battery pack including same, and automobile

Abstract

A battery module according to one embodiment of the present invention includes a cell stack assembly including a plurality of battery cells and a flow path spacer interposed between adjacent battery cells, the flow path spacer including a sub-module having a coolant flow path that allows an insulating coolant to flow while directly contacting the battery cells; a module housing that accommodates the sub-module; a front sealing plate that covers one longitudinal side opening of the module housing and has an inlet for the inflow of the insulating coolant; and a rear sealing plate that covers the other longitudinal side opening of the module housing and has an outlet for the discharge of the insulating coolant.

Description

[Technical field]

[0001] The present invention relates to a battery module, a battery pack, and an automobile including the same, and more specifically, to a battery module having a structure in which an insulating coolant that flows into a module housing to cool battery cells directly contacts components such as electrode leads and bus bars of the battery cells to achieve efficient cooling, and which also enables efficient flow of the insulating coolant through flow paths between adjacent battery cells, and a battery pack and an automobile including the same. This application claims priority to Korean Patent Application No. 10-2021-0074423 filed on June 8, 2021, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0002] In the case of a battery module that employs an indirect water-cooling method using coolant, the coolant does not come into direct contact with the battery cells but indirectly comes into contact with the battery cells through the module housing that accommodates the battery cells, so the cooling performance is limited. Also, a separate cooling device such as a heat sink must be provided outside the module housing to form a cooling flow path, which increases the overall volume of the battery module and causes a loss of energy density.

[0003] To solve these problems with indirect water cooling, there is a need to develop a battery module with a structure that allows the coolant to flow directly into the module housing and come into direct contact with the battery cells and electrical connection components, thereby achieving rapid cooling. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a battery module having a structure that allows an insulating coolant to flow into the inside of the battery module and come into direct contact with the battery cells and electrical connection components, thereby achieving efficient cooling, and also having a structure that allows the coolant that has flowed into the inside of the battery module to flow smoothly.

[0005] The technical problems that the present invention aims to solve are not limited to the problems mentioned above, and other problems will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0006] In order to achieve the above object, a battery module according to one aspect of the present invention includes a cell stack assembly including a plurality of battery cells and a flow path spacer interposed between adjacent battery cells, the flow path spacer including a sub-module having a coolant flow path that allows an insulating coolant to flow while directly contacting the battery cells, a module housing that accommodates the sub-module, a front sealing plate that covers one longitudinal side opening of the module housing and has an inlet for the inflow of the insulating coolant, and a rear sealing plate that covers the other longitudinal side opening of the module housing and has an outlet for the discharge of the insulating coolant.

[0007] The coolant flow passage may extend along a length of the flow passage spacer.

[0008] The flow path spacer may alternately contact first battery cells disposed on one side of the flow path spacer and second battery cells disposed on the other side of the flow path spacer along a height direction of the flow path spacer.

[0009] The coolant flow path may include a first coolant flow path formed between the flow path spacer and the first battery cell, and a second coolant flow path formed between the flow path spacer and the second battery cell.

[0010] The first and second coolant flow paths may be alternately formed along a height direction of the flow path spacer.

[0011] The flow path spacer may include a first portion spaced apart from a first battery cell located on one side of the flow path spacer and a second battery cell located on the other side of the flow path spacer, and a second portion in contact with the first battery cell and the second battery cell.

[0012] The coolant flow path may include a first coolant flow path formed between the first portion and a first battery cell and between the first portion and a second battery cell, respectively, and a second coolant flow path surrounded by the second portion.

[0013] The insulating cooling fluid flowing through the first cooling fluid passage may provide cooling through direct contact, and the insulating cooling fluid flowing through the second cooling fluid passage may provide cooling through indirect contact.

[0014] The first and second coolant flow paths may be alternately formed along a height direction of the flow path spacer.

[0015] The flow path spacer may include a first spacer interposed between an upper end of the submodule and a module housing and between a lower end of the submodule and a module housing, respectively, and a second spacer interposed between a pair of adjacent battery cells.

[0016] The second spacer may be partially interposed within a space formed between the pair of adjacent battery cells.

[0017] The second spacer may be spaced apart from the first spacer.

[0018] The second spacer may include a plurality of spacer holes that communicate between the pair of adjacent battery cells.

[0019] Meanwhile, a battery pack and a vehicle according to an aspect of the present invention include a battery module according to an aspect of the present invention as described above. Effect of the Invention

[0020] According to one aspect of the present invention, the insulating coolant flows into the interior of the battery module and comes into direct contact with the battery cells and electrical connection components, and the coolant that flows into the interior of the battery module can flow smoothly, enabling efficient and rapid cooling.

[0021] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0022] [Figure 1] 1 is a perspective view showing a battery module according to an embodiment of the present invention; [Diagram 2] 1 is an exploded perspective view showing a battery module according to an embodiment of the present invention; [Diagram 3] 2 is a cross-sectional view taken along line AA' in FIG. [Figure 3a] 4A to 4C are diagrams showing another embodiment of the flow path spacer shown in FIG. [Figure 3b] 4 is a diagram showing still another embodiment of the flow path spacer shown in FIG. 3. FIG. [Figure 3c] 4 is a diagram showing still another embodiment of the flow path spacer shown in FIG. 3. FIG. [Figure 3d] 4 is a diagram showing still another embodiment of the flow path spacer shown in FIG. 3. FIG. [Figure 4] 2 is a view showing the battery module shown in FIG. 1 with a front end plate and a front sealing plate removed. [Diagram 5] FIG. 4 is a diagram showing the flow of insulating coolant for cooling. [Figure 6] FIG. 4 is a diagram showing the flow of insulating coolant for cooling. [Figure 7] 1 is a diagram showing a connection structure between a bus bar frame and a flow path spacer according to the present invention; [Figure 8] 1 is a diagram showing a specific structure of a terminal assembly according to the present invention; [Figure 9] 1 is a diagram showing a specific structure of a terminal assembly according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as being in accordance with the meaning and concept of the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of the term in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely one most preferred embodiment of the present invention, and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0024] 1 and 2, a battery module according to an embodiment of the present invention includes a sub-module 100, a module housing 200, a front sealing plate 300, and a rear sealing plate 400. In addition to the above-mentioned components, the battery module may further include a front end plate 500 and / or a rear end plate 600 and / or a pair of terminal assemblies 700.

[0025] 2 to 6, the sub-module 100 includes a cell stack assembly 110. In addition to the cell stack assembly 110, the sub-module 100 may further include a front bus bar frame assembly 120A and a rear bus bar frame assembly 120B.

[0026] The cell stack assembly 110 includes a plurality of battery cells 111 and at least one flow path spacer 112 interposed between adjacent battery cells 111. The cell stack assembly 110 may further include at least one buffer pad 113 interposed between adjacent battery cells 111. The battery cells 111, the flow path spacer 112, and the buffer pad 113 are stacked in a vertically standing form on the ground (a plane parallel to the XY plane) to form one cell stack assembly 110.

[0027] The battery cell 111 may be a pouch-type battery cell having a pair of electrode leads 111a extending in opposite directions along the longitudinal direction (X-axis direction) of the battery cell 111.

[0028] 3 to 3d and 5 and 6, the flow path spacer 112 is interposed between adjacent battery cells 111 and includes a coolant flow path 112a through which at least a portion of the insulating coolant flowing into the inside of the battery module can flow while directly contacting the battery cells 111. A plurality of coolant flow paths 112a may be provided. The coolant flow paths 112a extend along the longitudinal direction (X-axis direction) of the flow path spacer 112.

[0029] The flow path spacer 112 may be interposed between adjacent battery cells 111. In this case, since both sides of each battery cell 111 are in contact with the flow path spacer 112, the cooling effect is maximized and the insulating coolant flowing into the battery module is more smoothly flowed. Meanwhile, the number of the flow path spacers 112 may be about half the number of the battery cells 111. Specifically, the plurality of flow path spacers 112 may be arranged such that a pair of battery cells 111 is located between a pair of adjacent flow path spacers 112. In this case, only one side of each battery cell 111 is in contact with the flow path spacer 112. When the plurality of flow path spacers 112 are arranged in this manner, it is possible to realize both an improvement in the cooling efficiency of the battery cells 111 by direct cooling and an improvement in the energy density.

[0030] 3 together with FIGS. 5 and 6, the channel spacer 112 may have a shape in which a first battery cell located on one side of the channel spacer 112 and a second battery cell located on the other side of the channel spacer 112 are alternately contacted along a height direction (Z-axis direction) of the channel spacer 112. In this case, the coolant channel 112a includes a first coolant channel formed between the channel spacer 112 and the first battery cell, and a second coolant channel formed between the channel spacer 112 and the second battery cell. The first coolant channel and the second coolant channel are alternately formed along the height direction (Z-axis direction) of the channel spacer 112.

[0031] 3, the insulating coolant flowing through the first coolant flow path directly contacts the first battery cell to cool it, and the insulating coolant flowing through the second coolant flow path directly contacts the second battery cell to cool it.

[0032] Hereinafter, a structure of a channel spacer having a different shape from the channel spacer of Fig. 3 will be described with reference to Fig. 3a together with Fig. 5 and Fig. 6. The channel spacer 112 includes a first portion spaced apart from a first battery cell located on one side of the channel spacer 112 and a second battery cell located on the other side, and a second portion in contact with both of the pair of battery cells.

[0033] In this case, the coolant flow passage 112a includes a first coolant flow passage formed between the first portion and the first battery cell and between the second portion and the second battery cell, and a second coolant flow passage surrounded by the second portion. The insulating coolant flowing through the first coolant flow passage cools the battery cell 111 through direct contact, and the insulating coolant flowing through the second coolant flow passage cools the battery cell 111 through indirect contact. The first coolant flow passage and the second coolant flow passage are alternately formed along the height direction (Z-axis direction) of the flow passage spacer.

[0034] Next, with reference to FIGS. 3b to 3d as well as FIGS. 2, 5 and 6, the structure of a flow channel spacer having a different form from the flow channel spacer shown in FIGS. 3 and 3a described above will be described.

[0035] 3b to 3d together with FIGS. 2, 5 and 6, the flow path spacer 112 includes a first spacer 1121 and a second spacer 1122. The first spacer 1121 is interposed between an upper end of the sub-module 100 and the module housing 200, and between a lower end of the sub-module 100 and the module housing 200. The second spacer 1122 is interposed between a pair of adjacent battery cells 111.

[0036] The second spacer 1122 is partially interposed in a space formed between a pair of adjacent battery cells 111. The second spacer 1122 is spaced apart from the first spacer 1121 to form a coolant flow path 112a between the first spacer 1121 and the second spacer 1122. The insulating coolant flowing through the coolant flow path 112a directly contacts the battery cells 111 to cool them. The second spacer 1122 may have a plurality of spacer holes communicating between the pair of adjacent battery cells 111 as shown in FIG. 3d.

[0037] Meanwhile, in the present invention, the insulating coolant used for cooling is a coolant with improved insulating properties, and for example, insulating oil can be used.

[0038] The buffer pads 113 are interposed between adjacent battery cells 111 to absorb volume expansion caused by swelling of the battery cells 111 .

[0039] 4 to 7, the front bus bar frame assembly 120A and the rear bus bar frame assembly 120B are respectively coupled to one side and the other side in the longitudinal direction (X-axis direction) of the cell stack assembly 110 to electrically connect the plurality of battery cells 111 to each other. The front bus bar frame assembly 120A has an internal terminal 123, and the rear bus bar frame assembly 120B has substantially the same structure, except that it does not have the internal terminal 123. Therefore, a detailed description of the specific structure of the rear bus bar frame assembly 120B will be omitted, and the specific structure of the front bus bar frame assembly 120A will be mainly described.

[0040] The front bus bar frame assembly 120A includes a bus bar frame 121, a plurality of bus bars 122, and a pair of inner terminals 123. The bus bar frame 121 covers one side of the cell stack assembly 110 in the longitudinal direction (X-axis direction).

[0041] The bus bar frame 121 has a plurality of cooling liquid holes 121a. The cooling liquid holes 121a function as a passage through which the insulating cooling liquid that has flowed into the inside of the module housing 200 through the inlet P1 provided in the front sealing plate 300 passes through the bus bar frame 121 and flows to the cell stack assembly 110 side.

[0042] In consideration of this function, the coolant holes 121a may be formed at positions corresponding to the flow path spacers 112 provided in the cell stack assembly 110. In addition, the coolant holes 121a may have a size corresponding to the flow path spacers 112.

[0043] The coolant flowing into the cell stack assembly 110 through the coolant hole 121a formed in the front bus bar frame assembly 120A moves along the arrows (see FIGS. 5 and 6) through the coolant flow path 112a formed by the flow path spacer 112 to the rear bus bar frame assembly 120B. The insulating coolant that has moved to the rear bus bar frame assembly 120B flows to the rear sealing plate 400 through the coolant hole 121a formed in the rear bus bar frame assembly 120B and is discharged to the outside of the battery module through the outlet P2 provided in the rear sealing plate 400.

[0044] During this process, the insulating coolant directly contacts the electrode leads 111a of the battery cells 111, the bus bars 122, and the bodies of the battery cells 111, thereby effectively cooling the battery cells 111. In addition, when the front bus bar frame assembly 120A of the present invention includes the inner terminals 123, the insulating coolant also directly contacts the inner terminals 123.

[0045] The bus bar 122 is fixed on the bus bar frame 121 and is coupled to the electrode leads 111a drawn through lead slits formed in the bus bar frame 121 to electrically connect the plurality of battery cells 111. Like the bus bar frame 121, the bus bar 122 may have coolant holes formed at positions corresponding to the flow path spacers 112 so that an insulating coolant can pass through.

[0046] The internal terminals 123 are fixed on the bus bar frame 121 and coupled to electrode leads 111a of the battery cells 111 located at the outermost position among the battery cells 111 installed in the cell stack assembly 110. The internal terminals 123 function as high potential terminals. The internal terminals 123 located at one side in the longitudinal direction (Y-axis direction) of the bus bar frame 121 function as a positive high potential terminal, and the internal terminals 123 located at the other side in the longitudinal direction of the bus bar frame 121 function as a negative high potential terminal. The internal terminals 123 are electrically connected to external terminals 710 (see FIGS. 8 and 9) described below.

[0047] The insulating coolant flowing into the battery module can fill the space between the front sealing plate 300 and the front bus bar frame assembly 120A, and can also fill the space between the rear sealing plate 400 and the rear bus bar frame assembly 120B. As a result, the insulating coolant comes into contact with the electrode leads 111a, the bus bars 122, and the internal terminals 123, which are components that generate heat intensively, and can efficiently cool the battery module.

[0048] 5, 6 and 7, the bus bar frame 121 of the front bus bar frame assembly 120A and the bus bar frame 121 of the rear bus bar frame assembly 120B may have a plurality of guide ribs 121b formed on upper and lower ends along the longitudinal direction (Y-axis direction). The guide ribs 121b extend in a direction toward the cell stack assembly 110. The guide ribs 121b are formed at positions corresponding to the flow path spacers 112.

[0049] Meanwhile, fixing portions 112b having a shape corresponding to the guide ribs 121b are formed on both ends of the flow path spacer 112 in the longitudinal direction (X-axis direction). The guide ribs 121b and the fixing portions 112b limit the movement of the flow path spacer 112 in the vertical direction (Z-axis direction) and the longitudinal direction (X-axis direction). As a result, when the front bus bar frame assembly 120A and the rear bus bar frame assembly 120B are coupled to the cell stack assembly 110, the coupling positions can be guided, thereby increasing the convenience of assembly.

[0050] 1 to 6, the module housing 200 accommodates a sub-module 100 including a cell stack assembly 110, a front bus bar frame assembly 120A, and a rear bus bar frame assembly 120B. The module housing 200 has one and the other sides in the longitudinal direction (X-axis direction) open.

[0051] 5, 6, 8 and 9, the front sealing plate 300 covers an opening formed on one side in the longitudinal direction (X-axis direction) of the module housing 200. The front sealing plate 300 includes an inlet P1 for the inflow of insulating coolant. To prevent leakage of the insulating coolant, a gasket G may be interposed between a peripheral surface of the front sealing plate 300 and an inner surface of the module housing 200 (see FIG. 9).

[0052] The front sealing plate 300 has a pair of terminal holes 300a through which components for electrical connection between an internal terminal 123 provided in the front bus bar frame assembly 120A and an external terminal 710 (described later) can pass. The terminal holes 300a are formed at positions corresponding to the internal terminals 123.

[0053] 6, the rear sealing plate 400 covers the other opening in the longitudinal direction (X-axis direction) of the module housing 200 and includes an outlet P2 for discharging the insulating cooling liquid. As with the front sealing plate 300, a gasket G may be interposed between the peripheral surface of the front sealing plate 300 and the inner surface of the module housing 200 to prevent leakage of the insulating cooling liquid.

[0054] The front sealing plate 300 and the rear sealing plate 400 may be made of insulating resin for electrical insulation.

[0055] 8 and 9, the terminal assembly 700 includes an external terminal 710 located on the outer side of the front sealing plate 300, and a stud 720 that electrically connects the external terminal 710 and the battery cell 111. The stud 720 is fixed to the internal terminal 123. The stud 720 may be fixed to the internal terminal 123 by a push-in manner through the internal terminal 123. The stud 720 fixed to the internal terminal 123 is pulled out to the outside through a terminal hole 300a formed in the front sealing plate 300 and coupled to the external terminal 710.

[0056] The terminal assembly 700 may further include an annular terminal spacer 730 inserted into a terminal hole 300a formed in the front sealing plate 300. The terminal spacer 730 may be made of a metal material. When the terminal spacer 730 is provided, the stud 720 passes through the terminal spacer 730.

[0057] The terminal assembly 700 may further include a fastening nut 740 for fastening the external terminal 710 to the stud 720. The fastening nut 740 is fastened to the stud 720 passing through the terminal spacer 730 and the fastening portion 712 of the external terminal 710, thereby closely fixing the fastening portion 712 of the external terminal 710 to the terminal spacer 730. Thus, the internal terminal 123 and the external terminal 710 are electrically connected to each other through the terminal spacer 730.

[0058] The terminal assembly 700 may further include a first O-ring 750 covering an outer circumferential surface of the terminal spacer 730 and interposed between an inner surface of the front sealing plate 300 and the inner terminal 123. Referring to Fig. 9, the first O-ring 750 prevents the insulating cooling liquid that has flowed into the space between the front sealing plate 300 and the bus bar frame 121 from leaking out of the space between the inner surface of the terminal hole 300a and the terminal spacer 730 to the outside of the front sealing plate 300.

[0059] Also, the terminal assembly 700 may further include a second O-ring 760 positioned on the outer periphery of the stud 720 pressed into the internal terminal 123 and exposed in the space between the internal terminal 123 and the bus bar frame 121, and interposed between the internal terminal 123 and the bus bar frame 121. The second O-ring 760 prevents the insulating coolant that has flowed into the space between the front sealing plate 300 and the bus bar frame 121 from leaking out of the front sealing plate 300 from the space between the internal terminal 123 and the stud 720 and the space between the inner surface of the terminal spacer 730 and the stud 720.

[0060] 1, 2, 5 and 6, the front end plate 500 is fixed to the module housing 200, covering the front sealing plate 300. The rear end plate 600 is fixed to the module housing 200, covering the rear sealing plate 400.

[0061] The front end plate 500 includes a terminal exposing portion 500a that exposes a connecting portion 711 of an external terminal 710 to the outside of the front end plate 500, and an inlet exposing portion 500b that exposes the inlet P1 to the outside of the front end plate 500. The rear end plate 600 includes an outlet exposing portion 600b that exposes the outlet P2 to the outside of the rear end plate 600.

[0062] When the front end plate 500 and the rear end plate 600 are applied, gaskets may be interposed at the joining portion between the front end plate 500 and the module housing 200 and at the joining portion between the rear end plate 600 and the module housing 200 to prevent leakage of insulating coolant.

[0063] Meanwhile, a battery pack and a vehicle according to an embodiment of the present invention include the battery module according to the present invention as described above. The battery pack includes at least one battery module according to the present invention, and a pack housing accommodating at least one battery module. The battery module may be fastened to the pack housing through a fastening hole H formed in a front end plate 500 and / or a rear end plate 600. That is, the fastening hole H may provide a space into which a fastening means such as a bolt for fastening the pack housing to the battery module is inserted. Meanwhile, when the battery pack includes a plurality of battery modules, the plurality of battery modules may be fastened to each other through the fastening hole H formed in the front end plate 500 and / or the rear end plate 600.

[0064] A battery pack according to an embodiment of the present invention includes at least one battery module according to an embodiment of the present invention as described above. The battery pack may include additional components such as a pack housing and / or a Battery Management System (BMS) in addition to the at least one battery module.

[0065] An automobile according to an embodiment of the present invention includes at least one battery module and / or battery pack as described above. The automobile according to an embodiment of the present invention may be, for example, a hybrid automobile or an electric automobile that operates by receiving power from the battery module and / or battery pack of the present invention.

[0066] As described above, the present invention has been described using limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention belongs within the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0067] 100: Submodule 110: Cell stack assembly 111: Battery cell 111a: electrode lead 112: Flow path spacer 1121: First spacer 1122: Second spacer 112a: Coolant flow path 112b: Fixed part 113: Buffer pad 120A: Front busbar frame assembly 120B: Rear busbar frame assembly 121: Busbar frame 121a: Coolant hole 121b: Guide rib 122: Busbar 123: Internal terminal 200:Module housing 300: Front sealing plate 300a: Terminal hole P1: Inlet G: Gasket 400: Rear sealing plate P2: Outlet 500: Front end plate 500a: Exposed terminal part 500b: Inlet exposed part 600: Rear end plate 600b: Exposed outlet 700: Terminal Assembly 710: External terminal 711: Connection part 712: Fastening part 720: Stud 730: Terminal spacer 740: Fastening nut 750: First O-ring 760: Second O-ring

Claims

1. A sub-module including a cell stack assembly including a plurality of battery cells and a flow path spacer interposed between adjacent battery cells, the flow path spacer having a coolant flow path that allows an insulating coolant to flow while directly contacting the battery cells; a module housing that houses the sub-module; a front sealing plate covering one longitudinal side opening of the module housing and having an inlet for the inflow of insulating cooling liquid; a rear sealing plate covering the other longitudinal side opening of the module housing and having an outlet for discharging the insulating cooling liquid; Including, The cooling fluid flow path extends along a longitudinal direction of the module housing, The flow path spacer is a first portion spaced apart from a first battery cell located on one side of the flow passage spacer and a second battery cell located on the other side of the flow passage spacer; a second portion in contact with the first battery cell and the second battery cell; Including, The cooling fluid flow path includes: a first coolant flow path formed between the first portion and the first battery cell and between the second portion and the second battery cell; a second coolant flow passage surrounded by the second portion; a battery module.

2. The battery module according to claim 1 , wherein the coolant flow path extends along a longitudinal direction of the flow path spacer.

3. the insulating cooling fluid flowing through the first cooling fluid flow passage provides cooling through direct contact; The battery module according to claim 1 , wherein the insulating coolant flowing through the second coolant flow path provides cooling through indirect contact.

4. The battery module according to claim 1 , wherein the first coolant flow passages and the second coolant flow passages are alternately formed along a height direction of the flow passage spacer.

5. A battery pack comprising a battery module described in any one of claims 1 to 4.

6. A motor vehicle comprising a battery module described in any one of claims 1 to 4.

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