Integrated battery sensing and thermal barrier assembly for traction battery arrays

Abstract

This disclosure provides an "integrated battery sensing and thermal barrier assembly for traction battery arrays." An integrated battery sensing and thermal barrier assembly for a traction battery pack is provided. An exemplary integrated battery sensing and thermal barrier assembly combines the functions of both a thermal barrier and a flexible printed circuit assembly into a single component. Therefore, the integrated battery sensing and thermal barrier assembly is configured to both mitigate heat transfer between the battery array and adjacent structures and monitor battery cell operating parameters.

Description

Technical Field

[0001] This disclosure relates generally to traction battery packs, and more specifically to an integrated battery sensing and thermal barrier assembly for use with traction battery arrays. Background Technology

[0002] Electrified vehicles include a traction battery pack that powers the vehicle's motor and other electrical loads. The traction battery pack comprises multiple battery cells and various other internal battery components that support the propulsion of the electric vehicle. Summary of the Invention

[0003] The traction battery pack according to an exemplary aspect of this disclosure includes, among other things, a plurality of battery cells arranged to extend between a first crossbeam assembly and a second crossbeam assembly. Each of the first and second crossbeam assemblies includes a trapezoidal frame and an integrated battery sensing and thermal barrier assembly mounted to the trapezoidal frame. The integrated battery sensing and thermal barrier assembly includes a thermally insulating sheet and a flexible printed circuit assembly.

[0004] In another non-limiting embodiment of the aforementioned traction battery pack, the plurality of battery cells include pouch cell batteries.

[0005] In another non-limiting embodiment of any of the aforementioned traction battery packs, the trapezoidal frame includes a plurality of cell tab openings, each cell tab opening being sized to receive one or more tab terminals of the plurality of battery cells.

[0006] In another non-limiting embodiment of any of the aforementioned traction battery packs, the tab terminals are engaged to the busbar via a busbar retainer.

[0007] In another non-limiting embodiment of any of the aforementioned traction battery packs, the sensing leads of the integrated battery sensing and thermal barrier assembly are coupled to the busbar.

[0008] In another non-limiting embodiment of any of the aforementioned traction battery packs, the trapezoidal frame includes grid posts received through mounting holes of the integrated battery sensing and thermal barrier assembly.

[0009] In another non-limiting embodiment of any of the aforementioned traction battery packs, adhesive tape secures the integrated battery sensing and thermal barrier assembly to the trapezoidal frame.

[0010] In another non-limiting embodiment of any of the aforementioned traction battery packs, the thermal insulation sheet is a flexible mica sheet.

[0011] In another non-limiting embodiment of any of the aforementioned traction battery packs, the flexible printed circuit assembly includes a plurality of conductive traces sandwiched between a first pressure-sensitive adhesive and a second pressure-sensitive adhesive.

[0012] In another non-limiting embodiment of any of the aforementioned traction battery packs, the connector end of the integrated battery sensing and thermal barrier assembly is operatively connected to the sensing unit.

[0013] In another non-limiting embodiment of any of the aforementioned traction battery packs, the thermal insulation sheet and the flexible printed circuit assembly together form a multilayer laminated structure of the integrated battery sensing and thermal barrier assembly.

[0014] In another non-limiting embodiment of any of the aforementioned traction battery packs, the multilayer laminated structure includes a weakening region that can be selectively opened to provide a path for allowing battery cell venting products to pass through the integrated battery sensing and thermal barrier assembly during battery thermal events.

[0015] In another non-limiting embodiment of any of the aforementioned traction battery packs, a heat-resistant material is applied to the flexible printed circuit assembly.

[0016] According to another exemplary aspect of this disclosure, the traction battery pack also includes, among other things, an integrated battery sensing and thermal barrier assembly, which includes a thermal insulation sheet and a flexible printed circuit assembly, the thermal insulation sheet and the flexible printed circuit assembly together forming a multilayer laminated structure of the integrated battery sensing and thermal barrier assembly.

[0017] In another non-limiting embodiment of the aforementioned traction battery pack, the integrated battery sensing and thermal barrier assembly is mounted to the trapezoidal frame of the battery array.

[0018] In another non-limiting embodiment of any of the aforementioned traction battery packs, the thermal insulation sheet is a flexible mica sheet.

[0019] In another non-limiting embodiment of any of the aforementioned traction battery packs, the flexible printed circuit assembly includes a plurality of conductive traces sandwiched between a first pressure-sensitive adhesive and a second pressure-sensitive adhesive.

[0020] In another non-limiting embodiment of any of the aforementioned traction battery packs, the sensing leads are mounted within a window of a multilayer laminated structure.

[0021] In another non-limiting embodiment of any of the aforementioned traction battery packs, a heat-resistant material is applied over the window.

[0022] The embodiments, examples, and alternatives (including any of their various aspects or corresponding features) described in the foregoing paragraphs, claims, or the following description and drawings may be used independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible.

[0023] Various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The accompanying drawings, which briefly describe the specific embodiments, are as follows. Attached Figure Description

[0024] Figure 1 An electric vehicle is shown schematically.

[0025] Figure 2 This is an exploded perspective view of a traction battery pack used in electric vehicles.

[0026] Figure 3 A selection portion of an exemplary battery array for a traction battery pack is shown.

[0027] Figure 4 yes Figure 3 An exploded view of the selected portion of the battery array.

[0028] Figure 5 The first side of the integrated battery sensing and thermal barrier assembly is shown.

[0029] Figure 6 It shows Figure 5 The second side of the integrated battery sensing and thermal barrier assembly.

[0030] Figure 7 This is a cross-sectional view of the integrated battery sensing and thermal barrier assembly. Detailed Implementation

[0031] This disclosure details an integrated battery sensing and thermal barrier assembly for a battery array used in a traction battery pack. An exemplary integrated battery sensing and thermal barrier assembly combines the functions of both a thermal barrier and a flexible printed circuit assembly into a single component. Therefore, the integrated battery sensing and thermal barrier assembly is configured to both mitigate heat transfer between the battery array and adjacent structures and monitor battery cell operating parameters. These and other features are discussed in more detail in the following paragraphs of this specific embodiment.

[0032] Figure 1An electrified vehicle 10 is schematically illustrated. The electrified vehicle 10 may include any type of electrified powertrain. In this embodiment, the electrified vehicle 10 is a battery electric vehicle (BEV). However, the concepts described herein are not limited to BEVs and can 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 embodiments, 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.

[0033] In the illustrated embodiment, the electrified vehicle 10 is depicted as a pickup truck. However, the electrified vehicle 10 may alternatively be a sedan, SUV, van, or any other vehicle configuration. Although specific component relationships are shown in the accompanying drawings of this disclosure, the illustrations are not intended to limit the disclosure. The placement and orientation of various components of the electrified vehicle 10 are schematically shown, and such placement and orientation may vary within the scope of this disclosure.

[0034] In this embodiment, the electrified vehicle 10 is a purely electric vehicle propelled solely by electricity (such as by one or more motors 12) without any assistance from an internal combustion engine. The motor 12 may operate as an electric motor, a generator, or both. The motor 12 receives electricity and may convert it into torque for driving one or more wheels 14 of the electrified vehicle 10.

[0035] Voltage bus 16 can electrically connect motor 12 to traction battery pack 18. Traction battery pack 18 is an exemplary electric vehicle battery. Traction battery pack 18 can be a high-voltage traction battery pack assembly including a group of battery cells capable of outputting power to power motor 12 and / or other electrical loads of electric vehicle 10. Other types of energy storage devices and / or output devices may alternatively or additionally be used to power electric vehicle 10.

[0036] The traction battery pack 18 can be fixed to the bottom 20 of the electric vehicle 10. However, within the scope of this disclosure, the traction battery pack 18 can be located elsewhere on the electric vehicle 10.

[0037] Figure 2 It shows the relationship with Figure 1Additional details relating to the traction battery pack 18 of the electrified vehicle 10. The traction battery pack 18 may include one or more battery arrays 22 (e.g., groups of battery modules or rechargeable battery cells 24) capable of outputting power to power the motor 12 and / or other electrical loads of the electrified vehicle 10. Other types of energy storage devices and / or output devices may alternatively or additionally be used to power the electrified vehicle 10.

[0038] One or more battery arrays 22 of the traction battery pack 18 may each include a plurality of battery cells 24, which store energy for powering various electrical loads of the electrified vehicle 10. Within the scope of this disclosure, the traction battery pack 18 may employ any number of battery arrays 22 and battery cells 24. Therefore, this disclosure should not be limited to… Figure 2 The height is shown as a schematic configuration.

[0039] In this embodiment, battery cell 24 is a lithium-ion pouch cell. However, battery cells with other geometries and / or chemical compositions (nickel-metal hydride, lead acid, etc.) may be used alternatively within the scope of this disclosure.

[0040] The battery array 22 and various other battery internal components (e.g., bus electrical hub, battery electrical control module, wiring, connectors, etc.) can be housed within the internal region 26 of the housing assembly 28. The housing assembly 28 of the traction battery pack 18 may include a housing cover 30 and a housing tray 32. The housing cover 30 may be secured (e.g., bolted, welded, adhered, etc.) to the housing tray 32 to provide the internal region 26 for housing the battery array 22 and other battery internal components of the traction battery pack 18.

[0041] The battery cells 24 of each battery array 22 can be stacked together and arranged along the stacking axis A. One or more thermal barrier assemblies 34 can be arranged along the corresponding stacking axis A of each battery array 22. The thermal barrier assemblies 34 can divide each battery array 22 into two or more groups or compartments. Each compartment can hold one or more of the battery cells 24 of the battery array 22.

[0042] The battery cells 24 of each battery array 22 can be arranged to extend laterally between a pair of beam assemblies 38. Among other functions, the beam assemblies 38 can be configured to electrically connect the battery cells 24 within each battery array 22 and to at least partially separate the battery arrays 22 from each other within an interior region 26 of the housing assembly 28.

[0043] The vertical underside of each battery array 22 may abut against a heat exchanger plate 40 positioned against the base plate of the housing tray 32. However, in another embodiment, the heat exchanger plate 40 may be omitted, and the vertical underside of each battery array 22 may be received in direct contact with the base plate of the housing tray 32. For the purposes of this disclosure, vertical and horizontal are references to the ground and the mounting of the traction battery pack 18. Figure 1 The general orientation of electric vehicles 10.

[0044] Each battery array 22 can be arranged to extend between opposing end plates 42 along its respective stacking axis A. The end plates 42 can be positioned between the ends of the battery array 22 and the longitudinally extending sidewalls 44 of the housing tray 32. Thus, the end plates 42 can extend along an axis that is substantially transverse to (e.g., perpendicular to) the stacking axis A of the battery array 22.

[0045] Figure 3 and Figure 4 It shows Figures 1 to 2 One of the battery arrays 22 in the traction battery pack. The additional battery array in the traction battery pack may have the same... Figures 3 to 4 The battery array 22 shown is a similar design.

[0046] Each crossbeam assembly 38 of the battery array 22 may include a trapezoidal frame 46 and an integrated battery sensing and thermal barrier assembly 48 that can be fixed to the trapezoidal frame 46. The trapezoidal frame 46 may be a one-piece or multi-piece injection-molded structure and may be made of any suitable thermoplastic material.

[0047] The trapezoidal frame 46 may include multiple cell tab openings 50 (in Figure 4 (Best shown in the diagram). The cell tab opening 50 may be an elongated slot formed through the trapezoidal frame 46. The posts 52 of the trapezoidal frame 46 may extend vertically between adjacent cell tab openings 50. The total number of cell tab openings 50 and posts 52 disposed within the trapezoidal frame 46 may vary and is therefore not intended to limit this disclosure.

[0048] Each cell tab opening 50 can be configured to receive one or more cell tab terminals (not shown) of one or more battery cells 24 of the battery array 22. Each cell tab terminal may protrude outward from the housing of one of the battery cells 24. In an embodiment, each battery cell 24 includes a pair of cell tab terminals, wherein one of the cell tab terminals protrudes from a first side of the housing and provides the positive terminal of the battery cell 24, and the other cell tab terminal protrudes from the opposite side of the housing and provides the negative terminal of the battery cell 24. The positive terminal can be electrically connected via a busbar 36 located on the first side of the battery array 22, and the negative terminal can be electrically connected via an additional busbar located on a second opposite side of the battery array 22. However, other configurations are also contemplated within the scope of this disclosure.

[0049] Busbar 36 may be a metal component. In an embodiment, busbar 36 is made of copper or aluminum. However, other materials or combinations of materials are contemplated within the scope of this disclosure. Busbar 36 may be joined (e.g., welded) to tab terminals to electrically connect to the battery cells 24 of the battery array 22.

[0050] Busbar 36 can be held by busbar retainer 99 (see...) Figure 4 It is held to the trapezoidal frame 46. The busbar holder 99 may be an elongated pin connector-like structure located between the busbar 36 and the integrated battery sensing and thermal barrier assembly 48.

[0051] The integrated battery sensing and thermal barrier assembly 48 can be fixed to the trapezoidal frame 46. As discussed further below, the integrated battery sensing and thermal barrier assembly 48 can be a multifunctional component configured to integrate the functions of both flexible printed circuitry and thermal barrier within a single component of the battery array 22.

[0052] In one embodiment, the trapezoidal frame 46 may include grid posts 56, which can be received through mounting holes 58 of the integrated battery sensing and thermal barrier assembly 48. The heads of the grid posts 56 may then be deformed, such as by means of, hot riveting or cold working, to mount the integrated battery sensing and thermal barrier assembly 48 to the trapezoidal frame 46.

[0053] Alternatively or additionally, one or more adhesive tapes 60 (see Figure 6 It can be fixed to the back side 62 of the integrated battery sensing and thermal barrier assembly 48. The back side 62 faces the trapezoidal frame 46. The adhesive tape 60 can fix the integrated battery sensing and thermal barrier assembly 48 to the trapezoidal frame 46. The adhesive tape 60 can also create a sealed interface between the trapezoidal frame 46 and the integrated battery sensing and thermal barrier assembly 48.

[0054] Now for reference Figure 5 , Figure 6 and Figure 7 Continue to refer to Figures 3 to 4 The integrated battery sensing and thermal barrier assembly 48 may include a multilayer laminated structure designed to provide a variety of functions. For example, the integrated battery sensing and thermal barrier assembly 48 may be used to monitor and transmit data associated with the battery cells 24 of the battery array 22 (e.g., temperature, voltage, current, state of charge, etc.) and to mitigate heat transfer between the battery array 22 and adjacent structures.

[0055] The multilayer laminated structure of the integrated battery sensing and thermal barrier assembly 48 may include a thermally insulating sheet 64, a first pressure-sensitive adhesive 66, a plurality of conductive traces 68, a second pressure-sensitive adhesive 70, and a dielectric film 72. The first pressure-sensitive adhesive 66 may be interfaced with the thermally insulating sheet 64, the conductive traces 68 may be sandwiched between the first pressure-sensitive adhesive 66 and the second pressure-sensitive adhesive 70, and the dielectric film 72 may be applied on the second pressure-sensitive adhesive 70.

[0056] The first pressure-sensitive adhesive 66, multiple conductive traces 68, the second pressure-sensitive adhesive 70, and the dielectric film 72 can cooperate to form a flexible printed circuit assembly 74 integrating a battery sensing and thermal barrier assembly 48. The thermal insulating sheet 64 and the flexible printed circuit assembly 74 together provide the integrated battery sensing and thermal barrier assembly 48.

[0057] The thermal insulation sheet 64 may be made of a flame-retardant and thermally insulating material. In an embodiment, the thermal insulation sheet 64 is a flexible mica sheet. However, the thermal insulation sheet 64 may be made of aerogel materials, refractory ceramic fibers, or other materials or combinations thereof that can provide flame-retardant and thermally insulating properties.

[0058] For example, during normal operating conditions and during battery thermal events, the thermal insulation sheet 64 can limit heat transfer between the battery array 22 and adjacent structures, such as another battery array. During a battery thermal event, the temperature and pressure within one or more of the battery cells 24 can increase, causing the battery cells 24 to release battery cell exhaust byproducts V. The thermal insulation sheet 64 can mitigate or even prevent the thermal effects of the heat associated with the battery cell exhaust byproducts V on adjacent battery arrays or other internal battery structures of the traction battery pack 18.

[0059] The multilayer laminated structure of the integrated battery sensing and thermal barrier assembly 48 can also be configured to provide a path that allows battery cell venting byproducts V to move outward away from the battery array 22, keeping the battery cell venting byproducts V away from non-venting battery cells 24, thereby preventing heat propagation across the battery array 22. To this end, the multilayer laminated structure of the integrated battery sensing and thermal barrier assembly 48 may include a plurality of weakened regions 76, each of which can be selectively opened to provide a path for allowing the battery cell venting byproducts V to escape from the battery array 22. The weakened regions 76 may melt, crack, or otherwise deform to allow the battery cell venting byproducts V to escape through the integrated battery sensing and thermal barrier assembly 48 during battery thermal events.

[0060] Multiple windows 78 can be formed through the multi-layered laminated structure of the integrated battery sensing and thermal barrier assembly 48 (in Figure 6 (Best shown in the diagram). Window 78 can be positioned aligned with busbar 36 of battery array 22. Sensing leads 80 can be installed within each window 78.

[0061] Each sensing lead 80 may be coupled to one of the busbars 36 and may be configured to collect data (e.g., temperature, voltage, current, state of charge, etc.) associated with the battery cells 24 of the battery array 22 as part of the battery management system of the traction battery pack 18. In an embodiment, the sensing lead 80 may be secured to the busbar 36 by one or more solder joints (e.g., laser solder joints).

[0062] After the sensing lead 80 is coupled to the busbar 36, a thermal barrier strip 88 can be applied over the window 78. The thermal barrier strip 88 can seal the opening formed by the window 78. The thermal barrier strip 88 can be applied to the outer side 90 of the multilayer laminated structure integrating the battery sensing and thermal barrier assembly 48. The outer side 90 is located on the side opposite to the back side 62 and therefore faces away from the trapezoidal frame 46.

[0063] Sensing leads 80 can be operatively connected to conductive traces 68 of the flexible printed circuit assembly 74. Data collected by sensing leads 80 can be fed via conductive traces 68 to connector terminals 82 of the flexible printed circuit assembly 74. Connector terminals 82, which may also include multilayer laminated structures, can be mounted to one of the end plates 42 of the battery array 22 and can be operatively connected to, for example, sensing units 84, such as a battery pack sensing module. Sensing units 84 can periodically transmit data to a controller associated with a battery management system as part of a control strategy for controlling the charging and discharging operations of the traction battery pack 18.

[0064] The exemplary integrated battery sensing and thermal barrier assembly of this disclosure integrates the functions of both a thermal barrier and a flexible printed circuit assembly into a single component. Existing battery array systems require separate thermal barrier and flexible printed circuit assemblies. Therefore, the proposed system provides a more efficient packaging design that simplifies battery array assembly.

[0065] While different non-limiting embodiments are shown having specific components or steps, the embodiments disclosed herein are not limited to those particular combinations. Some of the components or features from any of the non-limiting embodiments may be used in combination with features or components from any of the other non-limiting embodiments.

[0066] It should be understood that the same reference numerals identify corresponding or similar elements throughout all the figures. It should be understood that although particular arrangements of components are disclosed and shown in these exemplary embodiments, other arrangements may also benefit from the teachings of this disclosure.

[0067] The foregoing description should be interpreted as illustrative and not restrictive. Those skilled in the art will understand that certain modifications may be made within the scope of this disclosure. For these reasons, the appended claims should be examined to determine the true scope and content of this disclosure.

Claims

1. A traction battery pack comprising: Multiple battery cells are arranged to extend between a first crossbeam assembly and a second crossbeam assembly; as well as The first crossbeam assembly and the second crossbeam assembly each include a trapezoidal frame and an integrated battery sensing and thermal barrier assembly mounted to the trapezoidal frame. The integrated battery sensing and thermal barrier assembly includes a thermal insulation sheet and a flexible printed circuit assembly.

2. The traction battery pack of claim 1, wherein the plurality of battery cells include pouch cell batteries.

3. The traction battery pack of claim 1, wherein the trapezoidal frame includes a plurality of cell tab openings, each cell tab opening being sized to receive one or more tab terminals of the plurality of battery cells, and optionally, wherein the tab terminals are engaged to a busbar, and further optionally, wherein the busbar is engaged to the trapezoidal frame via a busbar retainer, and further optionally, wherein the sensing leads of the integrated battery sensing and thermal barrier assembly are engaged to the busbar.

4. The traction battery pack of claim 1, wherein the trapezoidal frame includes grid posts received through mounting holes of the integrated battery sensing and thermal barrier assembly.

5. The traction battery pack of claim 1, further comprising adhesive tape securing the integrated battery sensing and thermal barrier assembly to the trapezoidal frame.

6. The traction battery pack of claim 1, wherein the thermal insulation sheet is a flexible mica sheet.

7. The traction battery pack of claim 1, wherein the flexible printed circuit assembly includes a plurality of conductive traces sandwiched between a first pressure-sensitive adhesive and a second pressure-sensitive adhesive.

8. The traction battery pack of claim 1, wherein the connector end of the integrated battery sensing and thermal barrier assembly is operatively connected to the sensing unit.

9. The traction battery pack of claim 1, wherein the thermal insulation sheet and the flexible printed circuit assembly together form a multilayer laminated structure of the integrated battery sensing and thermal barrier assembly, and optionally, wherein the multilayer laminated structure includes a weakening region that can be selectively opened to provide a path for allowing battery cell venting products to pass through the integrated battery sensing and thermal barrier assembly during a battery thermal event.

10. The traction battery pack of claim 1, comprising a heat-resistant layer applied to the flexible printed circuit assembly.

11. A traction battery pack comprising: An integrated battery sensing and thermal barrier assembly, the integrated battery sensing and thermal barrier assembly comprising: A thermally insulating sheet and a flexible printed circuit assembly are provided together to form a multilayer laminated structure of the integrated battery sensing and thermal barrier assembly.

12. The traction battery pack of claim 11, wherein the integrated battery sensing and thermal barrier assembly is mounted to the trapezoidal frame of the battery array.

13. The traction battery pack of claim 11, wherein the thermal insulation sheet is a flexible mica sheet.

14. The traction battery pack of claim 11, wherein the flexible printed circuit assembly includes a plurality of conductive traces sandwiched between a first pressure-sensitive adhesive and a second pressure-sensitive adhesive.

15. The traction battery pack of claim 11, comprising sensing leads mounted within a window of the multilayer laminated structure, and optionally including a heat-resistant layer applied over the window.

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