Battery module

Abstract

Provided is a battery module including: a metal case having an upper plate portion, a bottom plate portion, and a peripheral wall portion connecting the peripheral edge portions of the upper plate portion and the bottom plate portion to each other; and a plurality of battery cells disposed in an internal space of the case, the case having at least one partition wall connecting the bottom plate portion and the upper plate portion to divide the internal space into a plurality of accommodation spaces, at least one battery cell being disposed in each of the plurality of accommodation spaces, and a through hole being formed in the upper plate portion.

Description

Technical Field

[0001] This invention relates to battery modules. Background Technology

[0002] Japanese Patent Application Publication No. 2024-508505 discloses a battery module comprising a battery cell stack formed by stacking multiple laminated battery cells and a housing for housing the battery cell stack.

[0003] In the battery module described in Patent Application Publication No. 2024-508505, if at least one battery cell disposed within the casing experiences thermal runaway, the heat from that battery cell can easily be transferred to other battery cells. That is, the battery module described in Patent Application Publication No. 2024-508505 is prone to a thermal cascade reaction when at least one battery cell experiences thermal runaway. Summary of the Invention

[0004] The present invention takes into account the above facts and aims to provide a battery module that makes it difficult for thermal cascading to occur between multiple battery cells when at least one of multiple battery cells disposed in the housing experiences thermal runaway.

[0005] The battery module of the first embodiment includes: a housing made of metal, having an upper plate, a bottom plate, and a peripheral wall connecting the peripheral portions of the upper plate and the bottom plate; and a plurality of battery cells disposed in the internal space of the housing, the housing having at least one partition wall connecting the bottom plate and the upper plate, dividing the internal space into a plurality of storage spaces, at least one of the battery cells being disposed in each of the plurality of storage spaces, and a through hole being formed in the upper plate opposite to the storage space.

[0006] The metal casing of the battery module of the first embodiment has at least one partition wall that connects a bottom plate and a top plate and divides the internal space of the casing into multiple storage spaces. At least one battery cell is housed in each of the multiple storage spaces. Therefore, when a battery cell located in one storage space experiences thermal runaway, the heat from that runaway battery cell is difficult to transfer to battery cells housed in storage spaces different from the storage space containing that battery cell. Furthermore, the heat from the runaway battery cell is transferred to the bottom plate via the partition wall and easily dissipated to the outside of the casing via the bottom plate. Additionally, the heat from the runaway battery cell is discharged through through holes formed in the top plate opposite to the storage spaces. Therefore, in the battery module of the first embodiment, when at least one of the multiple battery cells housed in the casing experiences thermal runaway, it is difficult for a thermal cascading effect to occur between the multiple battery cells.

[0007] In the second type of battery module, the cooler contacts the outer surface of the aforementioned base plate, based on the first type.

[0008] In the second type of battery module, since the cooler is in contact with the outer surface of the base plate, the heat from the thermally runaway battery cell can be easily dissipated to the cooler through the partition wall and the base plate.

[0009] The third type of battery module is based on the first or second type, wherein the bottom plate, the partition wall, and a pair of side walls that are part of the peripheral wall are integrally formed, and the top plate is welded to the side walls.

[0010] In the third type of battery module, the base plate, the partition wall, and a pair of side walls that are part of the peripheral wall are integrally molded, thus the mechanical strength of the casing can be increased.

[0011] The fourth type of battery module is based on the third type, in which the aforementioned side wall portion is parallel to the aforementioned partition wall.

[0012] The fourth type of battery module can be manufactured by extrusion molding to produce the base plate, partition wall and a pair of side walls.

[0013] The fifth type of battery module, based on the first or second type, has a housing with multiple parallel partition walls.

[0014] The fifth type of battery module has a housing with multiple parallel partition walls. Therefore, multiple battery cells can be housed in the housing in a unidirectional arrangement. That is, a larger number of battery cells can be accommodated while effectively utilizing the internal space of the housing.

[0015] As described above, the battery module of the present invention has the following excellent effect: when at least one of the multiple battery cells disposed in the housing experiences thermal runaway, it is difficult to generate a thermal cascading effect between the multiple battery cells. Attached Figure Description

[0016] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0017] Figure 1 This is a schematic perspective view of the battery module in the implementation method.

[0018] Figure 2 This is a schematic exploded 3D view of the battery module;

[0019] Figure 3 It is along Figure 1 A sectional view along line 3-3. Detailed Implementation

[0020] The battery module of the embodiment will now be described with reference to the accompanying drawings. Furthermore, the arrows UP, FR, and LH in each figure represent the upper side in the vertical direction of the vehicle, the front side in the longitudinal direction of the vehicle, and the left side in the horizontal direction of the vehicle, respectively.

[0021] In this embodiment, the battery module 10 is mounted on an electrified vehicle. The vehicle in this embodiment is a battery electric vehicle.

[0022] In this embodiment, the battery module 10 is housed inside a battery casing (not shown) fixed to the vehicle body. The power from the battery module 10 (cell 30) is supplied, for example, to an electric motor (not shown) that provides rotational drive force to the vehicle's drive wheels.

[0023] like Figure 1 As shown, the battery module 10 is a roughly rectangular parallelepiped component with the longitudinal direction of the vehicle as its length. The module housing (shell) 12 that constitutes the shape of the battery module 10 is made of aluminum alloy. The module housing 12 includes a housing body 13, a front panel (peripheral wall) 19, a rear panel (peripheral wall) 20, and a cover (upper panel) 45.

[0024] The main body 13 of the housing includes a base plate 15, a pair of side wall portions (peripheral wall portions) 16 extending upward from the left and right side edges of the base plate 15, and a plurality of partition walls 17 fixed to the upper surface of the base plate 15 and located between the left and right side wall portions 16. The base plate 15, side wall portions 16, and partition walls 17 are all flat plates. The planar shape of the base plate 15 is a rectangle with a front-to-back dimension larger than its left-to-right dimension. The side wall portions 16 and partition walls 17 have the same rectangular shape on their sides and are parallel to each other. The front-to-back dimensions of the base plate 15, side wall portions 16, and partition walls 17 are the same.

[0025] The shell body 13 of this structure is manufactured by extruding aluminum alloy material using an extrusion molding machine (not shown). Therefore, the shell body 13 manufactured by the extrusion molding machine has open front and back sides.

[0026] A front plate 19 and a rear plate 20, made of aluminum alloy, are fixed to the front and rear end faces of the main body 13 by welding, respectively. The front shapes of the front plate 19 and the rear plate 20 are the same rectangles, and the vertical dimensions of the front plate 19 and the rear plate 20 are the same as those of the side wall 16. The front plate 19 and the rear plate 20 can be manufactured, for example, by stamping.

[0027] Furthermore, storage spaces 22 with open front and rear surfaces and upper surface are formed between the base plate 15, side wall 16, partition wall 17, front plate 19 and rear plate 20, and between the two partition walls 17, front plate 19 and rear plate 20 adjacent to the base plate 15.

[0028] Each laminated battery cell 30 includes a positive electrode (not shown), a negative electrode (not shown), a separator (not shown), and a laminated film 31. The laminated film 31 has a left structural portion and a right structural portion, which are fused together to form a pouch-like component. This pouch-like component covers the laminate containing the positive electrode, negative electrode, and separator. A portion of the positive terminal and a portion of the negative terminal of the laminate are located on the outside of the laminated film 31. The positive and negative terminals of each battery cell 30 are joined to a busbar (not shown) by laser welding.

[0029] At the upper edge of the battery cell 30 with this configuration, a venting section 32 is formed, which is constructed by the upper edges of the left and right sides of the welded laminate 31. The venting section 32 is normally closed. That is, the bag-shaped component formed by the laminate 31 normally seals the positive electrode plate, negative electrode plate, separator, and electrolyte. However, for example, when the internal pressure of the battery cell 30 reaches a predetermined value due to an internal short circuit, the venting section 32 opens, and debris inside the battery cell 30 is discharged from the venting section 32 to the outside of the battery cell 30. This debris includes, for example, internal electrodes (current collector terminals), electrolyte, and gas.

[0030] Each storage space 22 of the housing body 13 houses a plurality of battery cells 30 arranged in a left-right direction. Adjacent battery cells 30 in each storage space 22 are in surface contact with each other. Furthermore, the battery cells 30 located at the left and right ends of each storage space 22 are in surface contact with the side wall portion 16 or the partition wall 17. An aluminum alloy plate, i.e., a cover 45, is brought into contact with the upper surfaces of the housing body 13, the front panel portion 19, and the rear panel portion 20, which house the plurality of battery cells 30 and busbars, etc. The outer periphery of the cover 45 is fixed to the upper ends of the housing body 13 (side wall portion 16), the front panel portion 19, and the rear panel portion 20 by welding. A plurality of through holes 46, consisting of elongated holes, are formed in the cover 45. Each through hole 46 is opposed to any storage space 22 in the vertical direction. The cover 45 can be manufactured, for example, by stamping.

[0031] Furthermore, a cooler 50 is provided on the bottom surface of the base plate portion 15 of the housing body 13. The cooler 50 is in contact with the entire bottom surface of the base plate portion 15. The cooler 50 includes: a housing 51, which is a hollow body with a generally rectangular planar shape; an electric pump; a temperature control device; a pipe, both ends of which are connected to the housing 51 and the electric pump and temperature control device are connected in the middle; and a refrigerant, which is a liquid filling the interior of the housing 51 and the pipe. When the electric pump operates, the refrigerant circulates in a predetermined direction inside the housing 51 and the pipe. In addition, the temperature control device can extract heat from the refrigerant or impart heat to the refrigerant.

[0032] Functions and effects

[0033] Next, the function and effects of the implementation method will be explained.

[0034] For example, if an internal short circuit occurs in any of the battery cells 30 in the battery module 10, the internal pressure of that battery cell 30 increases. When the internal pressure of the battery cell 30 reaches a predetermined value, the venting portion 32 of the laminate 31 opens. That is, the upper edge of the left component of the laminate 31 separates from the upper edge of the right component. Therefore, the high-temperature debris inside the battery cell 30 is discharged upwards from the module housing 12 through the through hole 46 of the cover 45. At this time, the partition wall 17 prevents the debris from moving toward the adjacent storage space 22. Therefore, the heat from the thermally runaway battery cell 30 is difficult to transfer to the battery cell 30 stored in a different storage space 22 than the storage space 22 that contains the battery cell 30 that discharged the debris.

[0035] Furthermore, the heat from the thermally runaway battery cell 30 is easily transferred to the base plate 15 via the side wall portion 16 and the partition wall 17. Especially when the thermally runaway battery cell 30 is in direct contact with the side wall portion 16 or the partition wall 17, the heat from the battery cell 30 is easily transferred to the base plate 15 via the side wall portion 16 or the partition wall 17. Furthermore, the heat transferred to the base plate 15 is absorbed by the cooler 50, which is at a lower temperature than the base plate 15, through the internal flow of refrigerant cooled by the temperature control device. Furthermore, the heat transferred to the cover 45 via the side wall portion 16 and the partition wall 17 dissipates from the upper surface of the cover 45 to the outside of the module housing 12. Therefore, the heat from the battery cell 30 housed in the storage space 22 in the central part of the left-right direction of the module housing 12 is also easily absorbed by the cooler 50 and the cover 45 via the partition wall 17.

[0036] Furthermore, the heat from the thermally runaway battery cell 30, as well as a portion of the debris emitted from the battery cell 30, is discharged to the outside of the module housing 12 through the through hole 46 located directly above the housing space 22 containing the battery cell 30. That is, debris containing high-temperature gases is unlikely to fill the module housing 12.

[0037] Therefore, in the battery module 10 of this embodiment, when at least one of the multiple battery cells 30 disposed in the module housing 12 experiences thermal runaway, it is difficult to generate a thermal cascade between the multiple battery cells 30.

[0038] Furthermore, the housing body 13 is an integrally molded product having a base plate 15, a side wall 16, and a partition wall 17, which easily improves the mechanical strength of the housing body 13 and the module housing 12.

[0039] Furthermore, the housing body 13 can be manufactured by extrusion molding, thus making the manufacturing of the housing body 13 easy.

[0040] Furthermore, the housing body 13 has multiple parallel sidewalls 16 and partition walls 17. Therefore, multiple battery cells 30 can be stored in the housing body 13 in a unidirectional (left-right) arrangement. That is, a larger number of battery cells 30 can be placed in each storage space 22 while effectively utilizing the internal space of the housing body 13 (module housing 12).

[0041] The battery modules of each embodiment have been described above, but they can be appropriately designed and modified without departing from the spirit of the present invention.

[0042] For example, after manufacturing the base plate 15, side wall 16 and partition wall 17 separately, the side wall 16 and partition wall 17 can be fixed to the base plate 15 by welding or the like.

[0043] Alternatively, the cooler 50 can contact any of the front surface, rear surface, and side surface of the module housing 12. In this case, it is preferable that a portion of the cooler 50 contacts the base plate portion 15. Alternatively, an object (e.g., a thin film sheet) with a higher thermal conductivity than the outer surface of the module housing 12 can be provided, and the cooler 50 can contact this object. That is, the cooler 50 can also contact the outer surface of the module housing 12 indirectly, rather than directly.

[0044] The number of storage spaces 22 can be any number, as long as there are multiple spaces.

[0045] The number of battery cells 30 stored in a storage space 22 can also be one. However, in this case, it is preferable that the battery cell 30 is in contact with the side wall portion 16 or the partition wall 17.

[0046] The number, location, and size of the through holes 46 formed in the cover 45 may also differ from those described above.

[0047] The battery cell 30 can also be a different type of battery cell than the laminated type. Preferably, the battery cell has a release valve (safety valve) at its upper end that opens when the internal pressure of the battery cell reaches a specified value.

[0048] The module housing (shell) 12 can also be made of a metal different from aluminum. An example of such a metal is iron.

[0049] The vehicle can be an electrified vehicle that is different from a pure electric vehicle. For example, the vehicle can be a hybrid electric vehicle or a plug-in hybrid electric vehicle.

Claims

1. A battery module, wherein, have: The housing is made of metal and has an upper plate, a bottom plate, and a peripheral wall that connects the upper plate and the bottom plate to each other. as well as Multiple battery cells are disposed within the internal space of the housing. The housing has at least one partition wall connecting the bottom plate and the top plate, dividing the internal space into multiple storage compartments. At least one of the battery cells is provided in each of the multiple storage spaces. A through hole is formed on the upper plate, which is opposite to the storage space.

2. The battery module according to claim 1, wherein, The cooler is in contact with the outer surface of the base plate.

3. The battery module according to claim 1 or 2, wherein, The base plate, the partition wall, and the pair of side walls that are part of the peripheral wall are integrally formed. The upper plate is welded to the side wall.

4. The battery module according to claim 3, wherein, The side wall portion is parallel to the partition wall.

5. The battery module according to claim 1 or 2, wherein, The housing has a plurality of parallel partition walls.

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