Thermal barrier foam system for traction battery array

Abstract

The invention provides a thermal barrier foam system for a traction battery array. A battery array for a traction battery pack is provided. An exemplary battery array may include a thermal barrier foam system including one or more foam blocks arranged to fill void spaces within the battery array to mitigate inter-cell and / or inter-array thermal propagation. The foam block may be secured to a hook structure of a bus bar module of the battery array. The hook structure may be integrated as part of a bus bar module or attachable to part of a separate structure of the bus bar module.

Description

Technical Field

[0001] The present disclosure relates generally to electrified vehicle traction battery packs, and more particularly to a thermal barrier foam system for mitigating heat propagation within a battery array of a traction battery pack. Background Art

[0002] An electrified vehicle includes a traction battery pack for powering the vehicle's electric motor and other electrical loads. The traction battery pack includes a plurality of battery cells and various other battery internal components that support electric vehicle propulsion. Summary of the invention

[0003] A battery array for a traction battery pack according to an exemplary aspect of the present disclosure includes, among other things: a bus bar module; a hook structure connected to the bus bar module; and a foam block attached to the hook structure.

[0004] In another non-limiting embodiment of the foregoing battery array, the bus bar modules are covered by a plate member of the array housing.

[0005] In another non-limiting embodiment of any of the foregoing battery arrays, the hook structure is an integral subcomponent of a bus bar module frame of the bus bar module.

[0006] In another non-limiting embodiment of any of the foregoing battery arrays, the hook structure includes a base hook and an auxiliary hook protruding outwardly from a side of the base hook.

[0007] In a further non-limiting embodiment of any of the foregoing battery arrays, the foam block is overmolded around the hook structure.

[0008] In another non-limiting embodiment of any of the foregoing battery arrays, the hook structure is part of a support fixture that is clipped to the bus bar module.

[0009] In another non-limiting embodiment of any of the foregoing battery arrays, a hook structure extends from a base of the support fixture.

[0010] In a further non-limiting embodiment of any of the foregoing battery arrays, the foam block is overmolded around the hook structure.

[0011] In another non-limiting embodiment of any of the foregoing battery arrays, the hook structure includes a flexible clamp that engages a clamp structure of a bus bar module frame of the bus bar module when the support fixture is moved into engagement with the bus bar module frame.

[0012] In another non-limiting embodiment of any of the foregoing battery arrays, a hook structure is disposed at a vertical upper section of a bus bar module frame of the bus bar module, and further comprising a second hook structure disposed at a vertical lower section of the bus bar module frame. A second foam block is attached to the second hook structure.

[0013] According to another exemplary aspect of the present disclosure, a battery array for a traction battery pack includes, in particular: a cell stack; a bus bar module, which is configured to electrically connect multiple battery cells of the cell stack; a first foam block, which is attached to a first hook structure of the bus bar module and is positioned to fill a first space between the cell stack and the bus bar module; and a second foam block, which is attached to a second hook structure of the bus bar module and is positioned to fill a second space between the cell stack and the bus bar module.

[0014] In another non-limiting embodiment of the foregoing battery array, the first hook structure is disposed at a vertical upper section of a bus bar module frame of the bus bar module, and the second hook structure is disposed at a vertical lower section of the bus bar module frame.

[0015] In another non-limiting embodiment of any of the foregoing battery arrays, the first hook structure is an integral subcomponent of the bus bar module frame and the second hook structure is part of a support fixture that is clipped to the bus bar module frame.

[0016] In another non-limiting embodiment of any of the foregoing battery arrays, the first hook structure includes a base hook and an auxiliary hook protruding outwardly from a side of the base hook.

[0017] In another non-limiting embodiment of any of the foregoing battery arrays, the base hook includes a pair of hook legs at least partially separated by a notch.

[0018] In another non-limiting embodiment of any of the foregoing battery arrays, the auxiliary hook comprises a design that mimics a design of the base hook.

[0019] In a further non-limiting embodiment of any of the foregoing battery arrays, the first foam block is overmolded around the first hook structure.

[0020] In another non-limiting embodiment of any of the foregoing battery arrays, a second hook structure extends from a base of the support fixture.

[0021] In a further non-limiting embodiment of any of the foregoing battery arrays, the second foam block is overmolded around the second hook structure.

[0022] In another non-limiting embodiment of any of the foregoing battery arrays, the second hook structure includes a flexible clamp that engages a clamp structure of the bus bar module frame when the support fixture is moved into engagement with the bus bar module frame.

[0023] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings (including any of their various aspects or corresponding individual features) may be adopted independently or in any combination. Features described in conjunction with one embodiment apply to all embodiments, unless such features are incompatible.

[0024] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 An electrified vehicle is schematically shown.

[0026] Figure 2 The battery array of the traction battery pack is shown.

[0027] Figure 3 Shows Figure 2 A battery array is shown in FIG. 1 , wherein a portion of the array housing is removed to better illustrate the battery cell stack and a pair of bus bar modules of the battery array.

[0028] Figure 4 It passes through Figure 3 Cross-sectional view of section 4-4.

[0029] Figure 5 A bus bar module including a thermal barrier foam system is shown.

[0030] Figure 6 yes Figure 5 Exploded view of selected parts of the busbar module.

[0031] Figure 7 Shows Figure 5 Foam blocks of the Thermal Barrier Foam System.

[0032] Figure 8 This is a partial exploded view of the battery array.

[0033] Fig. 9 yes Figure 8 A magnified view of a portion of the thermal barrier foam system of a battery array.

[0034] Fig.10 yes Figure 8 and Fig. 9 Exploded view of the thermal barrier foam system.

[0035] Fig.11 The connection of the foam block to the busbar module is shown. DETAILED DESCRIPTION

[0036] The present disclosure details a battery array for a traction battery pack. An exemplary battery array may include a thermal barrier foam system comprising one or more foam blocks arranged to fill void spaces within the battery array to mitigate inter-cell and / or inter-array heat propagation. The foam blocks may be secured to a hook structure of a bus bar module of the battery array. The hook structure may be integrated as part of the bus bar module or as part of a separate structure attachable to the bus bar module. These and other features are discussed in more detail in the following paragraphs of this detailed description.

[0037] Figure 1 An electrified vehicle 10 is schematically shown. The electrified vehicle 10 may include any type of electrified powertrain. In one embodiment, the electrified vehicle 10 is a battery electric vehicle (BEV). However, the concepts described herein are not limited to BEVs and may be extended to other electrified vehicles, including but not limited to hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles, etc. Therefore, although not specifically shown in the exemplary embodiment, the powertrain of the electrified vehicle 10 may be equipped with an internal combustion engine, which may be used alone or in combination with other power sources to propel the electrified vehicle 10.

[0038] In the illustrated embodiment, the electrified vehicle 10 is depicted as an automobile. However, the electrified vehicle 10 may alternatively be a sport utility vehicle (SUV), a van, a pickup truck, or any other vehicle configuration. Although specific component relationships are shown in the drawings of the present disclosure, the drawings are not intended to limit the present disclosure. The placement and orientation of the various components of the electrified vehicle 10 are shown schematically and may vary within the scope of the present disclosure. In addition, the various drawings attached to the present disclosure are not necessarily drawn to scale, and some features may be enlarged or minimized to emphasize certain details of a particular component or system.

[0039] In one embodiment, the electrified vehicle 10 is a pure electric vehicle that is propelled solely by electricity, such as by one or more electric machines 12, without any assistance from an internal combustion engine. The electric machines 12 can operate as electric motors, generators, or both. The electric machines 12 receive electricity and can convert the electricity into torque for driving one or more wheels 14 of the electrified vehicle 10.

[0040] Voltage bus 16 may electrically couple electric machine 12 to traction battery pack 18. Traction battery pack 18 is an exemplary electrified vehicle battery. Traction battery pack 18 may be a high voltage traction battery pack assembly that includes a plurality of battery cell groups capable of outputting electrical power to power electric machine 12 and / or other electrical loads of electrified vehicle 10. Other types of energy storage devices and / or output devices may alternatively or additionally be used to power electrified vehicle 10.

[0041] The traction battery pack 18 may be secured to an underbody 20 of the electrified vehicle 10 . However, the traction battery pack 18 may be located elsewhere on the electrified vehicle 10 within the scope of the present disclosure.

[0042] Figure 2 , Figure 3 and Figure 4 A traction battery pack (e.g., such as Figure 1 An exemplary battery array 22 of a traction battery pack 18). Figures 2 to 4 One or more battery arrays of similar design to the battery array 22 shown in Figure 1 may be packaged within the traction battery pack 18. As explained in further detail below, the battery array 22 may incorporate thermal barrier features designed to limit inter-cell and / or inter-array heat propagation during battery thermal events associated with the battery array 22. For example, a battery thermal event may occur during an overcharge condition, an over-discharge condition, or other condition.

[0043] The battery array 22 may include a plurality of battery cells 24 (in Figure 3 and Figure 4 ). In one embodiment, the battery cells 24 are lithium-ion pouch cells. However, within the scope of the present disclosure, battery cells having other geometries (cylindrical, prismatic, etc.) and / or chemistries (nickel-metal hydride, lead acid, etc.) may alternatively be utilized. The total number of battery cells 24 disposed within the battery array 22 may vary and is therefore not intended to limit the present disclosure.

[0044] The battery cells 24 may be stacked side by side along the stack axis to form a group of battery cells 24. The group of battery cells 24 may be referred to as a cell stack 25. The cell stack 25 may be subdivided into two or more cell groups, but the exact configuration of the cell stack 25 is not intended to limit the present disclosure.

[0045] The cell stack 25 may be arranged to extend between a pair of bus bar modules 26 configured to electrically connect the battery cells 24 of the cell stack 25. For example, one bus bar module 26 may be provided along each longitudinal side of the cell stack 25.

[0046] Each bus bar module 26 may include a plurality of bus bars (not shown) held within a bus bar module frame 30. The total number of bus bars held within each bus bar module frame 30 is not intended to limit the present disclosure. The bus bars may be metal components of the bus bar modules 26, and the bus bar module frames 30 may be plastic components of the bus bar modules 26. In one embodiment, the bus bars are made of copper or aluminum, and the bus bar module frames 30 are made of polypropylene or polyethylene. However, other materials are contemplated within the scope of the present disclosure.

[0047] The battery cells 24, bus bar modules 26, and various external and internal components of the battery array 22 may be housed in an array housing 28 (in Figure 2 24). For example, the array housing 28 can be arranged to substantially surround the cell stack 25 of the battery cells 24. The array housing 28 can include a plurality of plate members 36. In one embodiment, the plate members 36 can be arranged to provide a top cover, a bottom cover, a pair of side covers, and a pair of end covers for the battery array 22. However, other configurations of the array housing 28 are contemplated within the scope of the present disclosure. Each bus bar module 26 can be positioned between the cell stack 25 and one of the plate members 36.

[0048] Now the main reference Figure 4 and Figure 5 The bus bar module frame 30 of each bus bar module 26 may include a plurality of slots 32. Each slot 32 may be sized and shaped to receive a cell tab terminal 34 of one or more of the battery cells 24 (see Figure 4 ). Each cell tab terminal 34 may protrude outwardly from the housing 35 of its corresponding battery cell 24. The cell tab terminals 34 may extend through the slots 32 so that at least a portion of each cell tab terminal 34 is located on a side of the bus bar module frame 30 opposite its corresponding battery cell 24. Adjacent cell tab terminals 34 may then be joined together, such as by one or more bus bars, to electrically connect the battery cells 24 of the battery array 22 to one another. Once electrically coupled, the battery cells 24 may supply the power necessary to achieve electric propulsion of the electrified vehicle 10.

[0049] The battery array 22 may additionally include a thermal barrier foam system 38 designed to mitigate heat propagation and other effects of a battery thermal event. The thermal barrier foam system 38 may include a plurality of foam blocks 40. The foam blocks 40 may be strategically positioned within void spaces present within the battery array 22 to mitigate the effects of a battery thermal event. For example, the thermal barrier foam system 38 may be configured to mitigate inter-cell and / or inter-array heat propagation, increase thermal insulation between battery cells 24 of the battery array 22, absorb heat, etc., among other benefits.

[0050] In one embodiment, the foam blocks 40 are positioned to fill the void space extending between the cell stack 25 and each bus bar module 26. One or more of the foam blocks 40 may embody a different size and / or shape than other foam blocks 40 of the thermal barrier foam system 38.

[0051] Each foam block 40 may be made of silicone-based foam and may be pre-cast or overmolded to a desired size and shape. However, within the scope of the present disclosure, other foam materials or material combinations may be utilized alternatively or additionally, including but not limited to polyurethane foam.

[0052] Now the main reference Figure 6 and Figure 7 , the bus bar module frame 30 of each bus bar module 26 may include a plurality of hook structures 42 adapted to attach a first portion of a foam block 40 of a thermal barrier foam system 38 to the bus bar module frame 30. The hook structures 42 may be disposed on an inner side 44 of the bus bar module frame 30. The inner side 44 may face in a direction toward the battery cell stack 25. The hook structures 42 may be disposed along a vertical upper section 46 of the bus bar module frame 30. For purposes of this disclosure, vertical and horizontal are referenced to the ground in a normal orientation of the electrified vehicle 10 during operation.

[0053] In one embodiment, each hook structure 42 is an integral subcomponent of the bus bar module frame 30. For example, each hook structure 42 may be integrally molded as a part of the bus bar module frame 30. In another embodiment, the hook structure 42 is a separate component that may be attached (e.g., welded, adhered, etc.) to the bus bar module frame 30.

[0054] Each hook structure 42 includes a base hook 48 and at least one auxiliary hook 50 that protrudes outwardly from one side of the base hook 48 to provide a layered design. The base hook 48 may include a pair of hook legs 52 that protrude outwardly in a direction away from the inner side 44 of the bus bar module frame 30. A notch 55 may at least partially separate the hook legs 52 from each other. The auxiliary hook 50 may include a design that mimics the design of the base hook 48, albeit in reduced proportions.

[0055] One foam block 40 can be secured to each hook structure 42 of the bus bar module frame 30. In one embodiment, one foam block 40 is overmolded around each hook structure 42. However, other attachment methods are contemplated within the scope of the present disclosure. The layered design of the hook structure 42 can provide increased fixing strength between the foam block 40 and the bus bar module frame 30.

[0056] Now the main reference Figure 8 , Fig. 9 , Fig.10 and Fig.11 , the second portion of the foam block 40 of the thermal barrier foam system 38 may alternatively or additionally be attached to the bus bar module frame 30 by a support fixture 54. The support fixture 54 may be connected at a vertical lower section 56 of the bus bar module frame 30. The support fixture 54 may be made of a plastic material. However, other materials or material combinations are contemplated within the scope of the present disclosure.

[0057] The support fixture 54 may include a base 58 and a plurality of hook structures 60 protruding upward from the base 58. One foam block 40 may be secured to each hook structure 60 of the support fixture 54. In one embodiment, the foam block 40 is overmolded around the hook structure 60. However, other attachment methods are contemplated within the scope of the present disclosure.

[0058] In one embodiment, the support fixture 54 can be clamped or snap-connected to the vertical lower section 56 of the bus bar module frame 30 to secure the foam block 40 relative to the bus bar module frame 30. For example, one or more of the hook structures 60 of the support fixture 54 can include a flexible clamp 62 that is adapted to engage a corresponding clamp structure 64 of the bus bar module frame 30 (see FIG. Fig.11 ). When the support fixture 54 is moved into engagement with the bus bar module frame 30, the flexible clamp 62 can engage the clamp structure 64 to snap-connect the support fixture 54, and therefore the foam block 40, to the bus bar module frame 30. Once attached, the support fixture 54 can establish a portion of the vertical lower section 56 of the bus bar module frame 30. The opposite configuration is also contemplated, wherein the clamp of the bus bar module 26 flexes when the support fixture 54 is moved into engagement with the bus bar module 26.

[0059] The exemplary battery array of the present disclosure includes a thermal barrier foam system designed to mitigate the effects of battery thermal events within the battery array. The thermal barrier foam system can provide many advantages over known solutions, including but not limited to presenting a novel configuration that significantly slows or even prevents inter-cell heat propagation during battery thermal events.

[0060] Although different non-limiting embodiments are shown as having specific components or steps, the embodiments of the present disclosure are not limited to these specific combinations. Some components or features from any one of the non-limiting embodiments may be used in combination with features or components from any one of the other non-limiting embodiments.

[0061] It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings.It should be understood that although particular component arrangements are disclosed and shown in these exemplary embodiments, other arrangements may also benefit from the teachings of the present disclosure.

[0062] The foregoing description should be interpreted as illustrative and not in any limiting sense. It will be appreciated by those skilled in the art that certain modifications may occur within the scope of the present disclosure. For these reasons, the attached claims should be studied to determine the true scope and content of the present disclosure.

Claims

1. A battery array for a traction battery pack, the battery array comprising: Bus bar module; a hook structure connected to the bus bar module; as well as A foam block is attached to the hook structure. 2 . The battery array according to claim 1 , wherein the bus bar module is covered by a plate member of an array case.

3. The battery array of claim 1 or 2, wherein the hook structure is an integral sub-component of a bus bar module frame of the bus bar module.

4. The battery array of claim 3, wherein the hook structure comprises a base hook and an auxiliary hook protruding outwardly from one side of the base hook, and optionally, wherein the foam block is overmolded around the hook structure.

5. A battery array as claimed in any preceding claim, wherein the hook structure is part of a support fixture that is clipped to the bus bar module.

6. The battery array of claim 5, wherein the hook structure extends from a base of the support fixture.

7. The battery array of claim 6, wherein the foam block is overmolded around the hook structure.

8. The battery array of claim 5, wherein the hook structure comprises a flexible clamp that engages a clamp structure of a bus bar module frame of the bus bar module when the support fixture is moved into engagement with the bus bar module frame.

9. The battery array of any preceding claim, wherein the hook structure is disposed at a vertical upper section of a bus bar module frame of the bus bar module, and further comprising a second hook structure disposed at a vertical lower section of the bus bar module frame, and a second foam block attached to the second hook structure.

10. A battery array for a traction battery pack, the battery array comprising: Battery cell stack; a bus bar module configured to electrically connect a plurality of battery cells of the battery cell stack; a first foam block attached to the first hook structure of the bus bar module and positioned to fill a first space between the cell stack and the bus bar module; as well as A second foam block is attached to the second hook structure of the bus bar module and is positioned to fill a second space between the cell stack and the bus bar module.

11. A battery array as described in claim 10, wherein the first hook structure is arranged at a vertical upper section of a bus bar module frame of the bus bar module, and the second hook structure is arranged at a vertical lower section of the bus bar module frame, and optionally, wherein the first hook structure is an integral sub-component of the bus bar module frame and the second hook structure is part of a supporting fixture clamped to the bus bar module frame.

12. A battery array as described in claim 11, wherein the first hook structure includes a base hook and an auxiliary hook protruding outward from one side of the base hook, and optionally, wherein the base hook includes a pair of hook legs, and the pair of hook legs are at least partially separated by a recess, and further optionally, wherein the auxiliary hook includes a design that mimics the design of the base hook.

13. The battery array of claim 12, wherein the first foam block is overmolded around the first hook structure.

14. A battery array as described in claim 12, wherein the second hook structure extends from the base of the support fixture, and optionally, wherein the second hook structure includes a flexible clamp that engages the clamp structure of the bus bar module frame when the support fixture is moved into engagement with the bus bar module frame.

15. The battery array of claim 12, wherein the second foam block is overmolded around the second hook structure.

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