Battery module and battery pack and vehicle including same

Abstract

The invention discloses a battery module with enhanced safety. A battery module according to one aspect of the present invention comprises: a cell stack comprising a plurality of battery cells stacked in at least one direction; and a module housing configured to accommodate the cell stack, in which at least one of the plurality of battery cells has a coating layer disposed on a surface thereof.

Description

Technical Field

[0001] The present disclosure relates to a battery module, a battery pack and a vehicle including the same, and more particularly, to a battery module with enhanced safety, a battery pack and a vehicle including the same.

[0002] This application claims priority to Korean Patent Application No. 10-2022-0167707 filed on December 5, 2022 and Korean Patent Application No. 10-2023-0043169 filed on March 31, 2023, the disclosures of which are incorporated herein by reference. Background Art

[0003] With the rapid increase in demand for portable electronic products such as laptop computers, camcorders, and mobile phones, and with the widespread commercialization of robots, electric vehicles, etc., active research on high-performance secondary batteries that can be repeatedly charged and discharged is underway.

[0004] Currently commercialized secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, lithium secondary batteries, etc. Among them, lithium secondary batteries have attracted much attention due to their advantages over nickel-based secondary batteries, such as almost no memory effect, free charge and discharge, extremely low self-discharge rate, and high energy density.

[0005] These lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative active materials, respectively. Lithium secondary batteries include: an electrode assembly, in which a positive plate and a negative plate coated with positive and negative active materials, respectively, are arranged with a separator sandwiched between them; and an outer shell, i.e., a battery case, which stores the electrode assembly together with the electrolyte.

[0006] Generally, lithium secondary batteries may be classified into can-type secondary batteries in which an electrode assembly is accommodated in a metal can and pouch-type secondary batteries in which an electrode assembly is accommodated in a pouch made of an aluminum laminate sheet, according to the shape of a case.

[0007] Recently, secondary batteries have been widely used in medium and large devices for driving and storing energy, such as electric vehicles and energy storage systems (ESS), and in small devices such as portable electronic devices. In this case, the battery module can be configured so that a plurality of secondary batteries electrically connected to each other are stored in the module housing. In addition, the above-mentioned plurality of battery modules can be connected to each other to configure a battery pack.

[0008] However, since the above-mentioned multiple battery cells or multiple battery modules are densely arranged in a narrow space, they may be susceptible to thermal events. In particular, when a thermal event occurs in any one battery cell, heat, flames, sparks, etc. may be generated. If the heat, etc. is transferred to another battery cell, an explosive chain reaction such as heat propagation (TP) may occur, which may cause an explosion or fire in the battery module.

[0009] Furthermore, medium-to-large-sized battery packs for electric vehicles and the like include a large number of battery cells and battery modules to increase output and / or capacity, and a user such as a driver may be present nearby, so that the risk of a thermal chain reaction may increase even more.

[0010] Therefore, when a thermal event occurs in a specific battery cell or battery module, a method is needed to delay heat transfer to other battery cells or battery modules to improve safety. Summary of the invention

[0011] Technical issues

[0012] The present disclosure is intended to solve the problems of the related art, and thus the present disclosure is intended to provide a battery module capable of improving safety by delaying heat transfer, etc., and a battery pack and a vehicle including the battery module.

[0013] The present disclosure also provides a battery pack having improved stability by including such a battery module, and a vehicle including the battery pack.

[0014] However, the technical problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art will clearly understand other problems not mentioned above from the description of the present invention described below.

[0015] Technical Solution

[0016] According to one aspect of the present disclosure, there is provided a battery module including: a cell stack including a plurality of battery cells stacked in at least one direction; and a module case configured to accommodate the cell stack.

[0017] At least one battery cell of the plurality of battery cells may have a coating on a surface thereof.

[0018] The coating may be applied over the entire surface of the battery cell.

[0019] The coating may be provided on the surfaces of all battery cells included in the cell stack.

[0020] The cell stack may include expansion absorbing pads disposed between the plurality of battery cells.

[0021] The two battery cells located on both sides of the expansion absorption pad may include coating layers disposed at positions corresponding to each other.

[0022] The coating may be a refractory coating.

[0023] The coating may include a silica material.

[0024] The expansion absorbing pad may be disposed in each space between adjacent battery cells.

[0025] The expansion absorption pad may be a thermally conductive pad having elasticity and heat resistance.

[0026] The swelling absorbent pad may comprise silicon.

[0027] The expansion absorbing pad may have a larger area than a surface of the battery cell facing the expansion absorbing pad.

[0028] A battery pack according to the present disclosure may include the battery module according to the present disclosure.

[0029] A vehicle according to the present disclosure may include a battery pack according to the present disclosure.

[0030] Beneficial Effects

[0031] According to one aspect of the present disclosure, the expansion absorbing pad can absorb or suppress the pressure generated by the expansion of the battery cell. The acceleration of thermal runaway caused by the expansion can be prevented. The thermal chain reaction can be delayed or prevented, in which the flame and / or heat generated by the thermal event occurring in a particular battery cell is transferred to other adjacent battery cells.

[0032] In particular, although pouch-type secondary batteries may be more susceptible to flame and / or heat than can-type batteries, due to the nature of the shell, according to the present disclosure, a coating can be formed on the surface of the pouch shell to enhance the delay effect or prevent the above-mentioned thermal chain reaction.

[0033] According to another aspect of the present disclosure, the expansion absorbing pad can more effectively absorb or suppress the pressure generated by the expansion of the battery cell. This is because the expansion absorbing pad is accommodated in the accommodation parts of the module case and the bus bar frame and then stably fixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a diagram showing the appearance of a battery module according to the present disclosure.

[0035] Figure 2 is an exploded perspective view of a battery module according to the present disclosure.

[0036] Figure 3 is a diagram showing a battery cell included in a battery module according to the present disclosure.

[0037] Figure 4 is shown along Figure 3 FIG. 1 is a diagram of an exemplary cross section taken along line BB′ in FIG. 1 .

[0038] Figure 5 is a diagram illustrating an expansion absorbing pad included in a battery module and two battery cells located at both sides thereof according to the present disclosure.

[0039] Figure 6 and Figure 7 is shown along Figure 1 FIG. 1 is a diagram of an exemplary cross section taken along line AA′ in FIG.

[0040] Figure 8 is a diagram illustrating a bus bar assembly included in a battery module according to the present disclosure.

[0041] Fig. 9 is a diagram showing a battery pack according to the present disclosure.

[0042] Fig.10 is a diagram showing a vehicle according to the present disclosure. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present disclosure are described in detail below in conjunction with the accompanying drawings. The accompanying drawings show preferred embodiments of the present disclosure and are used together with the detailed description of the present disclosure below to provide a further understanding of the technical concept of the present disclosure, so the present disclosure is not to be construed as being limited to the accompanying drawings. The same reference numerals represent the same elements. In addition, in the accompanying drawings, the thickness, proportion and size of the elements are exaggerated in order to effectively explain the technical content.

[0044] It should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure based on the principle allowing the inventor to appropriately define the terms for the best interpretation.

[0045] Although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the position of a target object or the position of an observer.

[0046] Therefore, the configurations proposed in the embodiments of this specification and the drawings only indicate the most preferred embodiments of the present disclosure, but do not represent all technical ideas of the present disclosure, and therefore it should be understood that various equivalents and modifications may be made thereto when the present application is filed.

[0047] Figure 1 is a diagram showing the appearance of a battery module according to the present disclosure. Figure 2 is an exploded perspective view of a battery module according to the present disclosure. Figure 3 is a diagram showing a battery cell included in a battery module according to the present disclosure. Figure 4 is shown along Figure 3 FIG. 1 is a diagram of an exemplary cross section taken along line BB′ in FIG. 1 .

[0048] refer to Figures 1 to 4, a battery module 10 according to the present disclosure may include a battery cell stack 100 and a module case 200 .

[0049] The cell stack 100 may include a plurality of battery cells 110 stacked in at least one direction.

[0050] Each battery cell 110 may be a secondary battery. The battery cell 110 may include an electrode assembly, an electrode lead 113 connected to the electrode assembly, and a battery case, which is sealed so that the electrode assembly is contained therein and the electrode lead 113 extends to the outside thereof. The electrolyte may be contained inside the battery case. In particular, the battery cell 110 disposed in the battery cell stack 100 may be a pouch-type secondary battery. The battery cell stack 100 may be configured so that a plurality of pouch-type secondary batteries are arranged side by side in a horizontal direction, and their wide surfaces face each other in an upright state.

[0051] At least one of the plurality of battery cells 110 may have a coating layer C formed on a surface thereof. The coating layer C may be coated on the entire surface of the battery cell 110. The coating layer C may be provided on a surface of each of all the battery cells 110.

[0052] The battery case may include a receiving portion 111 receiving the electrode assembly and a sealing portion 112 configured to extend outward from the periphery of the receiving portion 111 to seal the receiving portion 111. The coating C may be provided on the entire remaining surface of the battery cell 110 except for the electrode lead 113. That is, the coating C may be configured to cover both the receiving portion 111 and the sealing portion 112 of the pouch case. As described above, if the coating C is provided on the entire area of ​​the battery cell 110 except for the electrode lead 113, the flame retardancy of the battery cell 110 may be improved without affecting the electrical connection.

[0053] On the other hand, the coating C may also be provided on a portion of the electrode lead 113. The coating C may be configured to cover the remaining area of ​​the electrode lead 113 except for the area to be connected to other components (e.g., components such as bus bars, electrode leads of adjacent battery cells, terminals, etc.). In this case, the flame retardancy of the battery cell 110 may be further improved. However, the present disclosure is not limited thereto, and the coating C may be provided only in the receiving portion 111 of the pouch case.

[0054] The coating layer C may be formed by applying a coating material to the surface of the battery cell 110 in a spray coating method. However, in addition to this, the coating layer C may be provided on the surface of the battery cell 110 in various other ways.

[0055] The coating C may be a refractory coating C. The coating C may include a silicon dioxide material. The coating C may include an aluminum oxide material. The coating C may include a magnesium oxide material.

[0056] The expansion absorbing pad 120 may be disposed between the plurality of battery cells 110. The expansion absorbing pad 120 may be disposed between two adjacent battery cells 110. The expansion absorbing pad 120 may be disposed between every two adjacent battery cells 110. The expansion absorbing pad 120 may be configured in a plate shape.

[0057] The expansion absorption pad 120 may include an elastic material. The expansion absorption pad 120 may include a heat-resistant material capable of withstanding a predetermined level or more of flame or heat. The expansion absorption pad 120 may include a polyurethane material. The expansion absorption pad 120 may include a silicone material.

[0058] According to this configuration of the present disclosure, the expansion absorbing pad 120 can absorb or suppress the pressure generated by the expansion of the battery cell 110. On the other hand, according to this configuration of the present disclosure, the problem of accelerated thermal runaway caused by expansion can be prevented. On the other hand, according to this configuration of the present disclosure, the thermal chain reaction of flame and / or heat transfer generated by a thermal event occurring in a specific battery cell 110 to other adjacent battery cells 110 can be delayed or prevented.

[0059] In particular, although pouch-type secondary batteries may be relatively susceptible to flame and / or heat compared to can-type batteries, due to the nature of the shell, the coating C according to the present disclosure can be formed on the surface of the shell of the pouch, thereby delaying or preventing the above-mentioned thermal chain reaction.

[0060] The module housing 200 may be configured to accommodate the battery cell stack 100. The module housing 200 may be configured to have an accommodation space capable of accommodating the battery cell stack 100. The module housing 200 may include a housing body 210 including four covers constituting corresponding surfaces substantially in a square column shape and a pair of end covers 220 for covering the front and back sides of the battery cell stack 100.

[0061] Figure 5 is a diagram illustrating an expansion absorbing pad included in a battery module and two battery cells located at both sides thereof according to the present disclosure.

[0062] refer to Figure 5 , the two battery cells 110 located on both sides of the expansion absorbing pad 120 may respectively have the coating layers C on surfaces facing each other.

[0063] refer to Figure 5 , the expansion absorbing pad 120 may have a larger area than the surface of the battery cell 110 facing the expansion absorbing pad 120 .

[0064] If the battery case provided in the battery cell 110 includes a receiving portion 111 receiving the electrode assembly and a sealing portion 112 sealing the receiving portion 111, the two battery cells 110 located on both sides of the expansion absorbing pad 120 may have a coating C on an area corresponding to the receiving portion 111. The expansion absorbing pad 120 may have a larger area than the receiving portion 111 corresponding thereto. The expansion absorbing pad 120 may be configured to cover the entire receiving portion 111.

[0065] Figure 6 and Figure 7 is shown along Figure 1 FIG. 1 is a diagram of an exemplary cross section taken along line AA′ in FIG.

[0066] refer to Figure 6 and Figure 7 The module case 200 may have a first accommodation portion 201 in which the expansion absorption pad 120 is accommodated. The module case 200 may have the first accommodation portion 201 on an inner surface of the case body 210.

[0067] Reference Figure 6 , the first receiving portion 201 may be provided at a position corresponding to the expansion absorption pad 120. The first receiving portion 201 may be provided on an inner surface of at least one of the upper portion and the lower portion of the module housing 200. The first receiving portion 201 may be configured in the form of a groove extending substantially in a straight line from one end to the other end of the module housing 200. The first receiving portion 201 may be provided to correspond to the number of the expansion absorption pads 120.

[0068] According to this configuration of the present disclosure, the expansion absorbing pad 120 can more effectively absorb or suppress the pressure generated by the expansion of the battery cell 110. This is because the expansion absorbing pad 120 is accommodated in the first accommodation portion 201 of the module housing 200 and is stably fixed. On the other hand, according to this configuration, heat propagation between adjacent battery cells 110 can be more effectively prevented. This is because an empty space is prevented from being formed between the expansion absorbing pad 120 and the inner surface of the module housing 200.

[0069] In addition, refer to Figure 2 When the assembly of the battery cell stack 100 and the expansion absorbing pad 120 is stored in the module housing 200, a portion of the expansion absorbing pad 120 can be preferentially received in one end of the first accommodating portion 201 and then pushed to the other end so that the entire assembly can be slid to be accommodated therein.

[0070] refer to Figure 7, the battery module 10 may include an auxiliary expansion absorption pad 121 disposed between the battery cell stack 100 and the module housing 200. The battery module 10 may include two auxiliary expansion absorption pads 121, respectively, between the left side of the battery cell stack 100 (in the -X axis direction) and the left inner surface of the module housing 200 (in the -X axis direction) and between the right side of the battery cell stack 100 (in the X axis direction) and the right inner surface of the module housing 200 (in the X axis direction). The module housing 200 may have a second accommodating portion 202, and the auxiliary expansion absorption pad 121 is accommodated in the second accommodating portion 202. The second accommodating portion 202 may be disposed at a position corresponding to the auxiliary expansion absorption pad 121. In this case, the first accommodating portion 201 may be selectively provided.

[0071] According to such a configuration of the present disclosure, the auxiliary expansion absorbing pad 121 can delay or prevent a thermal chain reaction in which flame and / or heat generated by thermal runaway occurring in the battery cell 110 is transferred to the module case 200. Figure 2 When the assembly of the battery cell stack 100, the expansion absorbing pad 120 and the auxiliary expansion absorbing pad 121 stacked on each other is stored in the module housing 200, a portion of the auxiliary expansion absorbing pad 121 can be preferentially received in one end of the second accommodating portion 202 and then pushed to the other end so that the entire assembly can be slid to be accommodated therein.

[0072] Figure 8 is a diagram illustrating a bus bar assembly 400 included in a battery module 10 according to the present disclosure.

[0073] refer to Figure 8 , the battery module 10 may include a bus bar assembly 400 .

[0074] The bus bar assembly 400 may include a bus bar 420 electrically connecting the plurality of battery cells 110 and a bus bar frame 410 on which the bus bar 420 is disposed.

[0075] The bus bar frame 410 may have a bus bar seating portion 411 , an electrode lead receiving portion 412 receiving the electrode lead 113 , and a third receiving portion 413 .

[0076] Also refer to Figure 2, the third accommodating portion 413 can accommodate one end of the expansion absorption pad 120 in its longitudinal direction (Y-axis direction). The third accommodating portion 413 can be a groove extending in the height direction (Z-axis direction) of the busbar frame 410. The third accommodating portion 413 can be arranged on the inner surface of the busbar frame 410. The third accommodating portion 413 can be configured in the form of a groove recessed in the +Y-axis direction from the substantially flat inner surface of the busbar frame 410 to correspond to the shape of the expansion absorption pad 120. The third accommodating portion 413 can be configured in the form of a groove recessed in the +Y-axis direction from a protrusion formed in a substantially trapezoidal column shape on the inner surface of the busbar frame to correspond to the shape of the expansion absorption pad 120. However, the third accommodating portion 413 can be configured not only in the form of a groove, but also in the form of a hole through which the expansion absorption pad 120 passes.

[0077] According to this configuration of the present disclosure, the expansion absorbing pad 120 may be more stably fixed by the third receiving portion 413 of the bus bar frame 410 and the first receiving portion 201 of the module case 200 .

[0078] Fig. 9 is a diagram showing a battery pack according to the present disclosure.

[0079] refer to Fig. 9 , the battery pack 2 may include one or more battery modules 10 according to the above-mentioned present disclosure. In addition, in addition to the battery module 10, the battery pack 2 according to the present disclosure may also include various other elements, that is, various elements of the battery pack 2, such as BMS, bus bars, battery pack housing, relays, current sensors, etc., which are well known at the time of filing this disclosure.

[0080] Fig.10 is a diagram showing a vehicle according to the present disclosure.

[0081] refer to Fig.10 , the vehicle 1 may include one or more battery packs 2 according to the present disclosure described above. Furthermore, in addition to the battery pack 2, the vehicle 1 according to the present disclosure may also include various other elements included in the vehicle 1. For example, in addition to the battery pack 2 according to the present disclosure, the vehicle 1 according to the present disclosure may also include a vehicle body, a motor, a control device such as an ECU (Electronic Control Unit), and the like.

[0082] As described above, although the present disclosure has been described based on the preferred embodiments with reference to the accompanying drawings, it is obvious to those skilled in the art that various modified embodiments can be implemented within the technical scope of the present disclosure. Therefore, the scope of the present disclosure should be interpreted as including various modifications according to the described claims.

[0083] [Explanation of Reference Numerals]

[0084] 1: Vehicle

[0085] 2: Battery Pack

[0086] 10: Battery module

[0087] 100: Battery cell stack

[0088] 110: Battery cells

[0089] 111: Accommodation

[0090] 112: Sealing part

[0091] 113: Electrode lead

[0092] 120: Expandable absorbent pad

[0093] 121: Auxiliary expansion absorption pad

[0094] 200: Module housing

[0095] 201: First accommodation part

[0096] 202: Second accommodating portion

[0097] 210: Shell body

[0098] 220: End cap

[0099] 400: Busbar assembly

[0100] 410: Busbar frame

[0101] 411: bus bar placement portion 412: electrode lead accommodation portion 413: third accommodation portion 420: bus bar coating C

Claims

1. A battery module, comprising: A cell stack comprising a plurality of battery cells stacked in at least one direction; as well as a module housing configured to accommodate the battery cell stack, Wherein, at least one battery cell of the plurality of battery cells comprises a coating on a surface thereof.

2. The battery module according to claim 1, wherein: The coating is applied on the entire surface of the battery cell.

3. The battery module according to claim 1, wherein: The coating is provided on the surfaces of all battery cells included in the cell stack.

4. The battery module according to claim 1, wherein: The cell stack includes expansion absorbing pads disposed between the plurality of battery cells.

5. The battery module according to claim 4, wherein: Two battery cells located on both sides of the expansion absorption pad include the coating layer disposed at positions corresponding to each other.

6. The battery module according to claim 1, wherein: The coating is a fire-resistant coating.

7. The battery module according to claim 1, wherein: The coating includes a silicon oxide material.

8. The battery module according to claim 4, wherein: The expansion absorbing pads are disposed in respective spaces between adjacent battery cells.

9. The battery module according to claim 4, wherein: The expansion absorption pad is a thermally conductive pad with elasticity and heat resistance.

10. The battery module according to claim 4, wherein: The swelling absorbent pad comprises silicon.

11. The battery module according to claim 4, wherein: The expansion absorbing pad has a larger area than a surface of the battery cell facing the expansion absorbing pad. 12 . A battery pack comprising the battery module according to claim 1 .

13. A vehicle comprising the battery pack according to claim 12.

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