Traction battery pack thermal management assembly

Abstract

The invention provides a traction battery pack thermal management assembly. A traction battery pack assembly includes a housing assembly providing an interior region; and a stack of cells within the interior region. The cell stack comprises battery cells arranged along the axis of the cell stack. And the heat management assembly is arranged along the axis of the battery cell stack. The thermal management assembly includes a thermal barrier secured to the base assembly. The base assembly includes a clamping region and at least one protruding region. The clamping area is arranged along the axis of the battery cell stack and is clamped between the first battery cell and the second battery cell. And the protruding area is arranged on the outer side of the clamping area relative to the axis of the cell stack. The thermal barrier is secured to the at least one protruding region of the base assembly.

Description

Technical Field

[0001] The present disclosure generally relates to managing thermal energy within a traction battery pack. Background Art

[0002] The traction battery pack of an electrified vehicle may include groups of battery cells arranged in 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 be vented from the battery cells. Summary of the invention

[0003] In some aspects, the technology described herein relates to a traction battery pack assembly, the traction battery pack assembly comprising: a shell assembly, the shell assembly providing an internal area; a battery cell stack within the internal area, the battery cell stack having a plurality of battery cells arranged along an axis of the battery cell stack; and a thermal management assembly arranged along the axis of the battery cell stack, the thermal management assembly comprising a plurality of heat blocking members fixed to a base assembly, the base assembly comprising a clamping area and at least one protruding area, the clamping area being arranged along the axis of the battery cell stack and clamped between a first battery cell and a second battery cell, the at least one protruding area being outside the clamping area relative to the axis of the battery cell stack, the plurality of heat blocking members being fixed to the at least one protruding area of ​​the base assembly.

[0004] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the plurality of cells includes a plurality of pouch battery cells.

[0005] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the plurality of thermal barriers include thermal barriers secured to opposite axial sides of the at least one protruding region on a first outer side of the battery cell stack.

[0006] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the plurality of thermal barriers further includes thermal barriers secured to opposing axial sides of the at least one protruding region on an opposing second outer side of the battery cell stack.

[0007] In some aspects, the technology described herein relates to a traction battery pack assembly that also includes an adhesive that secures the plurality of thermal barriers to the at least one protruding area of ​​the base assembly.

[0008] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the adhesive is an adhesive tape.

[0009] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the base assembly includes a thermal barrier, the tape includes a first sheet of tape on a first axial side of the thermal barrier, and a second sheet of tape on an opposing second axial side of the thermal barrier.

[0010] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the first sheet strap secures at least one of the plurality of thermal barriers to the at least one protruding area on a first outer side of the battery cell stack, and secures at least one other of the plurality of thermal barriers to the at least one protruding area on an opposite second outer side of the battery cell stack.

[0011] In some aspects, the technology described herein relates to a traction battery pack assembly in which the base assembly is provided entirely by tape.

[0012] In some aspects, the technology described herein relates to a traction battery pack assembly in which the thermal management assembly is configured to inhibit exhaust byproducts exhausted from one or more battery cells on a first axial side of the thermal management assembly from moving adjacent to battery cells on an opposing second axial side of the thermal management assembly.

[0013] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the base assembly is a first material and the thermal barrier is a second, different material.

[0014] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the thermal barrier is a foam.

[0015] In some aspects, the technology described herein relates to a traction battery pack assembly wherein the base assembly includes mica.

[0016] In some aspects, the technology described herein relates to a method for managing thermal energy of a battery pack, the method comprising: within a housing assembly, using a base assembly of a thermal management assembly to support a thermal barrier disposed at opposite sides of a battery cell stack, the base assembly being at least partially sandwiched between a first battery cell and a second battery cell of the battery cell stack.

[0017] In some aspects, the technology described herein is directed to a method that also includes adhesively securing the plurality of thermal barriers to the base assembly.

[0018] In some aspects, the technology described herein is directed to a method that also includes securing at least some of the thermal barriers to the first axial side of the base assembly using tape.

[0019] In some aspects, the technology described herein is directed to a method that also includes securing the first battery cell to the first axial side of the base assembly using the tape.

[0020] In some aspects, the technology described herein is directed to a method that also includes securing some of the thermal barriers and the second battery cells to an opposing second side of the base assembly using the tape.

[0021] In some aspects, the technology described herein relates to a method wherein the base assembly is a tape.

[0022] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. 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 enlarged perspective view of a battery pack for an electrified vehicle.

[0026] Figure 3 Shown from Figure 2 An enlarged portion of the battery cell stack.

[0027] Figures 4 to 6 Shown from Figure 2 Illustration of an exemplary thermal management assembly for a battery pack.

[0028] Figures 7 to 9 Shown from Figure 2 0026] Figure 2 is a view of another exemplary thermal management assembly for a battery pack. DETAILED DESCRIPTION

[0029] The present disclosure details an exemplary thermal management assembly for a traction battery pack. The thermal management assembly can, among other things, help secure the battery cells together and help direct exhaust byproducts during a thermal event. The thermal management assembly can include multiple thermal barriers. Therefore, a separate thermal barrier may not be required.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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).

[0034] Each of the cell stacks 30 includes a plurality of battery cells 50 (or simply referred to as “cells”) and a plurality of thermal management assemblies 54. Within each of the cell stacks 30, the cells 50 are arranged in groups and disposed along the cell stack axis A. The thermal management assemblies 54 are disposed between the groups of cells 50 along the cell stack axis A.

[0035] The battery cells 50 store and supply power. Although a specific number of cell stacks 30 and cells 50 are shown in various figures of the present disclosure, the battery pack 14 may include any number of cell stacks 30 having any number of individual cells 50. A group of battery cells 50 may include multiple battery cells 50 or only one battery cell 50.

[0036] In an embodiment, the battery cell 50 is a lithium-ion pouch battery cell. However, battery cells having other geometries (cylindrical, prismatic, etc.), other chemistries (nickel-metal hydride, lead acid, etc.), or both may alternatively be used within the scope of the present disclosure.

[0037] At times, pressure and heat energy may increase within one or more of the battery cells 50. 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 associated battery cell 50 to rupture and exhaust byproducts, such as gases and debris, from within the battery cell 50. The exhaust byproducts may be released from the associated battery cell 50 through a designated vent 60 within the housing (such as a membrane that yields in response to the pressure increase) or through a ruptured area of ​​the associated battery cell 50.

[0038] The exhaust byproducts may have relatively high thermal energy levels. Directing the exhaust byproducts away from other battery cells 50 that are not venting may prevent those battery cells 50 from venting and prevent a venting event from cascading through the battery pack 14 .

[0039] In these examples, the battery pack 14 includes a cross member assembly 66 disposed between the battery cell stacks 30. The cross member assembly 66 includes a vent passage and an opening 70 leading to the vent passage. Exhaust byproducts exhausted through the vent openings 60 of one or more of the battery cells 50 can move into the vent passage through at least one of the openings 70. Gases and debris are transported through the vent passage through the housing vents 74 to an area outside the battery pack 14.

[0040] For example, when ventilation is not required, the opening 70, the housing vent 74, or both may be covered by a corresponding membrane. During ventilation, the exhaust byproducts may rupture the membrane so that the exhaust byproducts may flow from the battery cells 50 through the opening 70 to the ventilation passage and then through the housing vent 74. The exemplary cross member assembly 66 extends longitudinally in a direction parallel to the battery stack axis A. The cross member assembly 66 and the battery stack axis A extend in the vehicle transverse direction (i.e., from the driver's side to the passenger side).

[0041] The thermal management assembly 54 can help direct the exhaust byproducts outwardly relative to the corresponding battery stack axis A into the ventilation passages within the cross member assembly 66. The thermal management assembly 54 can help prevent the exhaust byproducts from moving from one group of battery cells 50 to another group of battery cells 50. Thus, thermal energy associated with the exhaust byproducts is prevented from heating the battery cells 50 in the other groups and causing those battery cells 50 to exhaust.

[0042] Reference now Figures 4 to 9 And continue to refer to Figure 2 and Figure 3 , the exemplary battery pack 14 includes a first type of thermal management assembly 54A ( Figures 4 to 6 ) and a second type of thermal management assembly 54B. The thermal management assembly 54A separates and divides the groups of battery cells 50. The thermal management assembly 54B is disposed between the battery cells 50 of the groups.

[0043] The thermal management assembly 54A includes a thermal barrier 80 and a plurality of thermal blocking members 84. The thermal barrier 80 includes a sandwich region 88 and at least one protruding region 92. Within the battery stack 30, the sandwich region 88 is sandwiched and axially compressed between the battery cells 50, and the at least one protruding region 92 is disposed outside the sandwich region 88 relative to the battery stack axis A.

[0044] In an exemplary embodiment, the heat blocking member 84 is fixed to opposite axial sides of the protruding region 92 on a first outer side of the cell stack 30 , and fixed to opposite axial sides of the protruding region 92 on an opposite second outer side of the cell stack 30 .

[0045] In this example, two protruding areas 92 are used to support the thermal block 84 on opposite sides of the cell stack 30. In other examples, the thermal management assembly may include a single protruding area on one horizontal side of the cell stack 30.

[0046] Furthermore, in another example, the thermal barrier 80 may alternatively or additionally be supported by at least one protruding area 92 vertically above or below the battery cell 50. For purposes of this disclosure, vertical and horizontal are referenced to the ground and the orientation of the vehicle 10 during normal operation.

[0047] In this example, the thermal barrier 80 is a mica-based sheet. In other examples, the thermal barrier 80 may be an aerogel sheet or a sheet having some other insulating material or combination of insulating materials. The thermal barrier 80 may extend to contact the housing assembly 34 and the cross member assembly 66 to effectively divide the groups of battery cells 50.

[0048] An adhesive may be used to secure the thermal block 84 to the protruding area 92 of the thermal barrier 80. In this example, the adhesive is a piece of tape 96A. The thermal management assembly 54A includes a piece of double-sided tape 96A on a first axial side of the thermal barrier 80, and a piece of tape 96A on an opposite second axial side of the thermal barrier 80. The pieces of tape 96A on each axial side of the thermal barrier 80 span from the protruding area 92 on the first outer side to the protruding area 92 on the opposite second outer side. In this example, the thermal barrier 80 and the pieces of tape 96A together provide a base assembly for the thermal management assembly 54A.

[0049] Thermal block 84 is secured to protruding area 92 of thermal barrier 80 using the area of ​​tape 96A located over protruding area 92. The remaining area of ​​tape 96A within sandwich area 88 helps to bond battery cells 50 to thermal barrier 80. In this example, thermal block 84 is a foam.

[0050] The thermal management assembly 54B includes a protruding area 92 and a sandwiching area 88, but omits the thermal barrier 80. The thermal management assembly 54B includes a piece of tape 96B and a plurality of thermal barriers 84 secured to the tape 96B in the protruding area 92. In the sandwiching area, the piece of tape 96B is used to secure one of the battery cells 50 in the battery stack 30 to an axially adjacent battery cell 50 in the battery stack 30. The tape 96B alone provides a base assembly for the exemplary thermal management assembly 54B. That is, the base assembly is entirely provided by the tape 96B in the thermal management assembly 54B.

[0051] After the cell stack 30 is assembled, the cell stack 30 includes heat blocks 84 along opposite outer sides of the cell stack 30. The battery cells 50 may include tab terminals (not shown) extending outwardly between axially adjacent heat blocks 84 for connection to one or more bus bar assemblies.

[0052] Features of the disclosed examples include a thermal management assembly that includes multiple thermal barriers. This can facilitate assembly because it may not be necessary to place the thermal barriers 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: a housing assembly providing an interior region; a cell stack within the interior region, the cell stack having a plurality of battery cells arranged along a cell stack axis; and A thermal management assembly is arranged along the axis of the battery stack, the thermal management assembly includes a plurality of heat blocking members fixed to a base assembly, the base assembly includes a clamping area and at least one protruding area, the clamping area is arranged along the axis of the battery stack and clamped between a first battery cell and a second battery cell, the at least one protruding area is outside the clamping area relative to the axis of the battery stack, and the plurality of heat blocking members are fixed to the at least one protruding area of ​​the base assembly.

2. The traction battery pack assembly of claim 1, wherein the plurality of battery cells comprises a plurality of pouch-type battery cells.

3. The traction battery pack assembly of claim 1 , wherein the plurality of heat blocks include heat blocks secured to opposite axial sides of the at least one protruding region on a first outer side of the battery cell stack, and optionally, wherein the plurality of heat blocks also include heat blocks secured to opposite axial sides of the at least one protruding region on an opposite second outer side of the battery cell stack.

4. The traction battery pack assembly of claim 1 further comprising an adhesive securing the plurality of thermal barriers to the at least one protruding area of ​​the base assembly, and optionally wherein the adhesive is an adhesive tape.

5. The traction battery pack assembly of claim 4, wherein the base assembly includes a thermal barrier, the tape includes a first sheet of tape on a first axial side of the thermal barrier, and a second sheet of tape on an opposing second axial side of the thermal barrier.

6. The traction battery pack assembly of claim 5 , wherein the first sheet band secures at least one of the plurality of heat barriers to the at least one protruding area on a first outer side of the battery cell stack, and secures at least one other of the plurality of heat barriers to the at least one protruding area on an opposite second outer side of the battery cell stack.

7. The traction battery pack assembly of claim 1 wherein said base assembly is provided entirely by adhesive tape.

8. The traction battery pack assembly of claim 1, wherein the thermal management assembly is configured to inhibit exhaust byproducts exhausted from one or more battery cells on a first axial side of the thermal management assembly from moving adjacent battery cells on an opposing second axial side of the thermal management assembly. 9 . The traction battery pack assembly of claim 1 , wherein the base assembly is a first material and the plurality of thermal barriers are a second, different material.

10. The traction battery pack assembly of claim 1, wherein the plurality of thermal barriers are foams.

11. The traction battery pack assembly of claim 1 , wherein the base assembly comprises mica.

12. A method for managing thermal energy of a battery pack, the method comprising: A thermal barrier disposed at opposite sides of a cell stack is supported within the housing assembly using a base assembly of a thermal management assembly at least partially sandwiched between a first battery cell and a second battery cell of the cell stack.

13. The method of managing battery pack thermal energy of claim 12, further comprising adhesively securing the plurality of thermal barriers to the base assembly, and optionally, further comprising securing at least some of the thermal barriers within the plurality of thermal barriers to the first axial side of the base assembly using an adhesive tape.

14. The method of managing thermal energy of a battery pack according to claim 13, further comprising securing the first battery cell to the first axial side of the base assembly using the tape, and optionally, further comprising securing at least some of the plurality of thermal barriers to an opposite second side of the base assembly using the tape.

15. The method of managing thermal energy of a battery pack as claimed in claim 14, wherein the base assembly is an adhesive tape.

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