Battery cell assembly with thermal barrier

Abstract

The present disclosure provides a battery cell assembly with a thermal barrier. A traction battery pack assembly includes a battery cell and a thermal barrier secured to the battery cell. The thermal barrier has a slot that receives at least one terminal of the battery cell. The battery cell can be a soft package type battery cell. The thermal barrier may be a foam.

Description

Technical Field

[0001] The present disclosure relates generally to managing thermal energy within a traction battery pack, and more particularly to incorporating thermal barriers into a battery cell assembly. Background Art

[0002] The traction battery pack of an electrified vehicle may include groups of battery cells arranged into one or more cell stacks. From time to time, pressure and heat within one or more battery cells may build up and cause gases and debris to vent from those battery cells. Summary of the invention

[0003] In some aspects, the technology described herein relates to a traction battery pack assembly including: a battery cell; and a thermal barrier secured to the battery cell, the thermal barrier having at least one slot that receives a terminal of the battery cell.

[0004] In some aspects, the technology described herein relates to a traction battery pack assembly, which also includes a housing assembly, which provides an internal area and a cell stack within the internal area, and the battery cells located within the cell stack and arranged along a cell stack axis of the cell stack.

[0005] In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the battery cell is a first battery cell and the at least one slot includes a first slot that receives a terminal of the first battery cell, and the at least one slot of the thermal barrier also includes a second slot that receives a terminal of a second battery cell, and the second battery cell is adjacent to the first battery cell along the cell stack axis.

[0006] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the thermal barrier is a first thermal barrier secured to a first side of the battery cell and further includes a second thermal barrier secured to an opposing second side of the battery cell.

[0007] In some aspects, the technology described herein relates to a traction battery pack assembly, wherein the first side and the second side are a first exterior side and a second exterior side of the battery cell.

[0008] In some aspects, the technology described herein relates to a traction battery pack assembly in which the battery cells are pouch-type battery cells.

[0009] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the at least one terminal is at least one tab terminal.

[0010] In some aspects, the technology described herein relates to a traction battery pack assembly that also includes an adhesive that secures the thermal barrier to the battery cell.

[0011] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the adhesive is an adhesive tape.

[0012] In some aspects, the technology described herein relates to a traction battery pack assembly in which the thermal barrier is adhesively secured to the housing of the battery cell.

[0013] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the thermal barrier is a foam.

[0014] In some aspects, the technology described herein relates to a method of managing thermal energy of a battery pack, the method comprising: securing a thermal barrier to a battery cell to provide a battery cell assembly; and after the securing, positioning the battery cell assembly next to other battery cell assemblies to provide a cell stack.

[0015] In some aspects, the technology described herein is directed to a method 12 that also includes adhesively securing the thermal barrier to the battery cell.

[0016] In some aspects, technology described herein is directed to a method 12 that also includes receiving a terminal of a battery cell within an aperture of a thermal barrier.

[0017] In some aspects, the technology described herein is directed to a method 14 wherein the terminals are tab terminals and the battery cells are pouch cells.

[0018] In some aspects, technology described herein is directed to a method 12 wherein the thermal barrier is a foam.

[0019] In some aspects, techniques described herein are directed to a method 12 that also includes positioning a cell stack within a housing assembly.

[0020] In some aspects, the technology described herein relates to a method wherein the thermal barrier is a first thermal barrier secured to a first side of the battery cell and further comprising securing a second thermal barrier to a second side of the battery cell.

[0021] In some aspects, the technology described herein relates to a method in which a first thermal barrier and a second thermal barrier each include an aperture to receive a terminal of a battery cell.

[0022] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings may be taken independently or in any combination, including any of their individual aspects or corresponding individual features. Features described in conjunction with one embodiment are applicable to all embodiments, unless such features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] According to the detailed description, various features and advantages of the disclosed examples will become apparent to those skilled in the art. The drawings attached to the detailed description can be briefly described as follows:

[0024] Figure 1 A side view of an exemplary electrified vehicle is shown.

[0025] Figure 2 Shown from Figure 1 An expanded perspective view of a battery pack for an electrified vehicle.

[0026] Figure 3 Shown from Figure 2 The expanded portion of the battery cell stack.

[0027] Figures 4 to 6 Shown from Figure 3 2 is a view of an exemplary battery cell assembly with a cell stack. DETAILED DESCRIPTION

[0028] The present disclosure details an exemplary battery cell assembly for a traction battery pack. The battery cell assembly includes at least one thermal barrier attached to the battery cell. The thermal barrier can help direct exhaust byproducts during a thermal event. Because the thermal barrier is integrated with the battery cell, it may not be necessary to install the thermal barrier separately from the battery cell.

[0029] refer to Figure 1 , the electrified vehicle 10 includes a battery pack 14, an electric motor 18, and wheels 22. The battery pack 14 supplies power to the electric motor 18, which can convert electricity into mechanical power to drive the wheels 22.

[0030] In the exemplary embodiment, the battery pack 14 is secured to an underbody 26 of the electrified vehicle 10. In other examples, the battery pack 14 may be located elsewhere on the electrified vehicle 10.

[0031] The electrified vehicle 10 is a pure electric vehicle. In other examples, the electrified vehicle 10 is a hybrid electric vehicle that selectively uses torque provided by an internal combustion engine (as an alternative or supplement to an electric machine) to drive wheels. In general, the electrified vehicle 10 can be any type of vehicle having a battery pack.

[0032] refer to Figure 2 and Figure 3 , the battery pack 14 includes a plurality of cell stacks 30 held within an interior of a housing assembly 34. In an exemplary embodiment, the housing assembly 34 includes a housing cover 38 and a housing tray 42. The housing cover 38 is secured to the housing tray 42 to provide an interior area 44 that accommodates the cell stacks 30. The housing cover 38 may be secured to the housing tray 42 using, for example, mechanical fasteners (not shown).

[0033] Each of the cell stacks 30 includes a plurality of battery cell assemblies 50 (or simply referred to as "cell assemblies") and a plurality of separators 54. Within each of the cell stacks 30, the cell assemblies 50 are arranged in groups and are disposed along the cell stack axis A. The separators 54 are disposed between the groups of the cell assemblies 50 along the cell stack axis A. The battery cell assembly 50 group may include a plurality of battery cell assemblies 50 or only one battery cell assembly 50.

[0034] The separator 54 may be a mica-based material. In other examples, the separator 54 may be an aerogel sheet or a sheet having some other insulating material or combination of insulating materials.

[0035] Although a specific number of cell stacks 30 and cell assemblies 50 are shown in the various figures of this disclosure, the battery package 14 may include any number of cell stacks 30 having any number of individual cell assemblies 50 .

[0036] The battery cell assembly 50 includes battery cells 52 for storing and supplying power. In an embodiment, the battery cells 52 are lithium-ion soft-pack battery cells. Each of the battery cells 52 includes a terminal tab 58 extending laterally outward from the housing 68.

[0037] Although described as pouch cells, battery cells having other geometries (cylindrical, prismatic, etc.), other chemistries (nickel-metal hydride, lead acid, etc.), or both may alternatively be utilized within the scope of the present disclosure.

[0038] At times, pressure and heat energy may increase within one or more of the battery cells 52. For example, the increase in pressure and heat energy may be due to an overcharge condition. The increase in pressure and heat energy may cause the vent 72 within the housing 68 of the associated battery cell 52 to rupture. Exhaust byproducts V (such as gases and debris) are then exhausted from the battery cell 52. The exhaust byproducts V may be released from the associated battery cell 52 through the vent 72 within the housing 68 (such as a membrane that yields in response to the pressure increase) or through a ruptured area of ​​the housing 68.

[0039] The exhaust byproducts V may have relatively high thermal energy levels. Directing the exhaust byproducts V away from other battery cells 52 that are not venting may prevent those battery cells 52 from venting and prevent a venting event from cascading through the battery pack 14 .

[0040] In these examples, the battery pack 14 includes a cross member assembly 76 disposed between the battery cell stacks 30. The cross member assembly 76 includes an exhaust passage and an opening 80 leading to the exhaust passage. Exhaust byproducts V exhausted through the exhaust ports 72 of one or more of the battery cell assemblies 50 may move through at least one of the openings 80 into one of the exhaust passages. The exhaust byproducts V are transmitted from the exhaust passage through the housing exhaust ports 84 to an area outside the battery pack 14.

[0041] For example, when venting is not required, the opening 80, the housing vent 84, or both may be covered by a corresponding membrane. During venting, the exhaust byproducts may rupture the membrane so that the exhaust byproducts may flow from the battery cells 52 through the opening 80 to the exhaust passage and then through the housing vent 84. The example cross member assembly 76 extends longitudinally in a direction parallel to the cell stack axis A. The cross member assembly 76 and the cell stack axis A extend in the vehicle lateral direction (i.e., from the driver's side to the passenger side).

[0042] The separators 54 may extend vertically and horizontally from the cell stack axis A to contact the housing assembly 34 and the cross member assembly 76 to effectively divide the groups of battery cell assemblies 50 .

[0043] Reference now Figures 3 to 6 And continue to refer to Figure 2 , the battery cell assembly 50 includes a thermal barrier 88 attached to the battery cell 52. The thermal barrier 88 can assist in exhaust. Specifically, the thermal barrier 88 can help fill and isolate the otherwise open space within the interior area 44, which can guide and direct the exhaust byproducts V outward through the opening 80 into the exhaust passage within the cross member assembly 76.

[0044] The thermal barriers 88 can work with the dividers 54 to confine the exhaust byproducts V and can help block the exhaust byproducts from moving from one group of battery cell assemblies 50 to another group of battery cell assemblies 50. Thus, the heat energy associated with the exhaust byproducts is prevented from heating the battery cells 52 in other groups and causing those battery cells 52 to exhaust.

[0045] In this example, the battery cell assemblies 50 each include two thermal blocks 88. Other example battery cell assemblies 50 may include a single thermal block 88 (eg, if thermal blocking is desired on only one side of the cell stack) or more than two thermal blocks.

[0046] The thermal blocks 88 are disposed along the exterior sides of the battery cells 52. In this example, the thermal blocks 88 each include an aperture 92 that receives one of the terminal tabs 58. The terminal tab 58 may extend from the housing 68 through the aperture 92 to a bus bar (not shown).

[0047] In this example, the thermal blocks 88 each include a notch 96 that receives a portion of the housing 68 , which may help position the thermal blocks 88 relative to the housing 68 and the terminal blades 58 .

[0048] The thermal barrier 88 may be secured to the battery cell 52 using an adhesive. For example, the adhesive may be an adhesive tape. The thermal barrier 88 is secured to the battery cell 52 before the battery cell 52 is assembled into the cell stack 30.

[0049] In this example, the heat barrier 88 is a foam. In particular, the heat barrier 88 is a closed-cell foam.

[0050] In the case of the exemplary battery cell assembly 50, after assembling the battery cell assembly 50 and separators 54 to provide the cell stack 30, the cell stack 30 includes heat barriers 88 along opposing exterior sides of the cell stack 30. Apertures 92 allow the terminal tabs 58 to extend to the busbars if desired.

[0051] In this example, the battery cell 52 includes a heat block 88 that receives one of the terminal tabs 58. In another example, the heat block 88 may be axially wider and include a slot for receiving a terminal tab of an axially adjacent battery cell (the cell lacking an attached heat block). Figure 5 An example of how the heat barrier 88 can expand axially is shown in phantom in region 88A. The heat barrier 88 will be molded to include region 88A.

[0052] Features of the disclosed examples include a battery cell assembly with an integrated thermal barrier. The thermal barrier can help reduce conductive heat energy transfer between battery cells, among other things. Integrating the thermal barrier into the battery cell assembly can facilitate assembly because it may not be necessary to place the thermal barrier separately within the battery pack.

[0053] The foregoing description is illustrative and non-restrictive in nature. Changes and modifications to the disclosed examples may become apparent to those skilled in the art, and the changes and modifications do not necessarily depart from the essence of the present disclosure. Therefore, the scope of protection granted to the present disclosure can only be determined by studying the attached claims.

Claims

1. A traction battery pack assembly, comprising: Battery cells; and A thermal barrier is secured to the battery cell, the thermal barrier having at least one slot for receiving a terminal of the battery cell.

2. The traction battery pack assembly of claim 1 further comprising a housing assembly providing an interior region and a cell stack within the interior region, the battery cell within the cell stack and disposed along a cell stack axis of the cell stack, and optionally wherein the battery cell is a first battery cell and the at least one slot comprises a first slot for receiving a terminal of the first battery cell, the at least one slot of the thermal barrier further comprises a second slot for receiving a terminal of a second battery cell, the second battery cell being adjacent to the first battery cell along the cell stack axis.

3. The traction battery pack assembly of claim 1 , wherein the thermal barrier is a first thermal barrier secured to a first side of the battery cell, and further comprising a second thermal barrier secured to an opposite second side of the battery cell, and optionally wherein the first side and the second side are a first outer side and a second outer side of the battery cell.

4. The traction battery pack assembly of claim 1, wherein the battery cell is a soft pack battery cell.

5. The traction battery pack assembly of claim 1, wherein the terminals are tab terminals.

6. The traction battery pack assembly of claim 1 further comprising an adhesive securing the thermal barrier to the battery cells, and optionally wherein the adhesive is a tape.

7. The traction battery pack assembly of claim 1 wherein the thermal barrier is adhesively secured to the housing of the battery cell.

8. The traction battery pack assembly of claim 1, wherein the thermal barrier is foam.

9. A method for managing thermal energy of a battery pack, comprising: securing a thermal barrier to a battery cell to provide a battery cell assembly; as well as After the fixing, the battery cell assembly is positioned next to other battery cell assemblies to provide a cell stack.

10. The method of managing thermal energy of a battery pack of claim 9, further comprising adhesively securing the thermal barrier to the battery cell.

11. The method of managing thermal energy of a battery pack of claim 9, further comprising receiving terminals of the battery cells within apertures of the thermal barrier.

12. The method of managing thermal energy of a battery pack as claimed in claim 11, wherein the terminals are tab terminals and the battery cells are pouch cells.

13. The method of managing thermal energy of a battery pack as claimed in claim 9, wherein the thermal barrier is a foam.

14. The method of managing thermal energy of a battery pack as recited in claim 9, further comprising positioning the cell stack within a housing assembly.

15. The method of claim 9, wherein the thermal barrier is a first thermal barrier secured to a first side of the battery cell, and further comprising securing a second thermal barrier to a second side of the battery cell, and optionally wherein the first thermal barrier and the second thermal barrier each include an aperture to receive a terminal of the battery cell.

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