Battery pack bus bar shield

Abstract

The invention provides a battery pack bus bar shield. A battery pack assembly includes a housing assembly providing an interior region. A battery cell is located within the interior region. The battery cells each include at least one tab terminal protruding outward from the array axis. The frame provides at least one slot that receives a portion of the at least one tab terminal. At least one bus bar is fixed to the frame. The bus bar shield is disposed between the at least one cell and the at least one bus bar within the battery pack.

Description

Technical Field

[0001] The present disclosure generally relates to a shield used within a battery pack, and more particularly, to a shield that prevents exhaust by-products from moving towards a bus bar.

[0002] Cross - Reference to Related Applications

[0003] This application claims the benefit of U.S. Provisional Application No. 63 / 599,186, filed on November 15, 2023, and the U.S. Provisional Application is incorporated herein by reference. Background Art

[0004] High - voltage traction battery packs can power the motors and other electrical loads of electrified vehicles. A traction battery pack can include a plurality of individual battery cells. The traction battery pack may occasionally experience a thermal event in which one or more of the battery cells vent and expel battery exhaust by - products. The exhaust by - products can include gases and effluent particles. Summary of the Invention

[0005] In some aspects, the technology described herein relates to a battery pack assembly that includes: an enclosure assembly that provides an internal area; a plurality of battery cells that are arranged along an array axis and disposed within the internal area; each of the plurality of battery cells includes at least one tab terminal that protrudes outwardly from the array axis; a frame that provides at least one slot that receives a portion of the at least one tab terminal; at least one bus bar that is fixed to the frame; and a bus bar shield that is located between at least one cell and at least one bus bar within the battery pack.

[0006] In some aspects, the technology described herein relates to a battery pack assembly, wherein the frame is located between the at least one bus bar and the bus bar shield.

[0007] In some aspects, the technology described herein relates to a battery pack assembly, wherein the bus bar shield is directly fixed to the frame.

[0008] In some aspects, the technology described herein relates to a battery pack assembly, wherein the bus bar shield includes a plurality of fingers.

[0009] In some aspects, the technology described herein relates to a battery pack assembly, wherein the plurality of fingers are a plurality of tapered fingers.

[0010] In some aspects, the technology described herein relates to a battery pack assembly, wherein the at least one tab terminal extends between the plurality of fingers.

[0011] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield includes three fingers.

[0012] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield is ceramic fiber, mica, fiberglass, or some combination thereof.

[0013] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield is provided by a sheet of material having at least one shield slot, and at least one tab terminal extends through the shield slot.

[0014] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the at least one tab terminal is fixed to the at least one busbar.

[0015] In some aspects, the techniques described herein relate to a battery pack assembly, further comprising: a container assembly that holds a reagent mixture, the container assembly being configured to release the reagent mixture in response to a thermal event proximate to the container assembly, the container assembly being disposed between a plurality of battery cells and the frame.

[0016] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield is directly fixed to the container assembly.

[0017] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield is configured to wrap around the container assembly during installation of the container assembly within the battery pack.

[0018] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the busbar shield is located between the container assembly and the frame.

[0019] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the reagent is configured to electrically isolate heat transfer, impede heat transfer, or both when released from the container assembly.

[0020] In some aspects, the techniques described herein relate to a battery pack assembly, wherein the reagent mixture includes sodium silicate.

[0021] In some aspects, the techniques described herein relate to a battery pack assembly that includes: a housing assembly that provides an interior region; a plurality of battery cells disposed along an array axis and within the interior region, each of the plurality of battery cells including at least one tab terminal that protrudes outwardly from the array axis; a busbar module having a frame and a plurality of busbars mounted to the frame; a plurality of container assemblies disposed between the busbar module and the plurality of battery cells alongside the plurality of battery cells, each of the plurality of container assemblies holding a reagent mixture, the container assemblies being configured to release the reagent mixture in response to a thermal event proximate to the container assemblies; and one or more busbar shields disposed between the busbar module and the plurality of battery cells alongside the plurality of container assemblies, the at least one tab terminal extending through slots in the busbar shields between the plurality of container assemblies and through slots in the frame to connect to at least one of the busbars within the plurality of busbars.

[0022] In some aspects, the techniques described herein relate to a battery pack assembly in which the busbar shield is located between the plurality of container assemblies and the frame.

[0023] In some aspects, the techniques described herein relate to a battery pack assembly in which the busbar shield is fixed to the frame.

[0024] The embodiments, examples, and alternatives of the foregoing paragraphs, claims, or the following description and drawings may be employed independently or in any combination, including any of their various aspects or respective individual features. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In accordance with the detailed description, the various features and advantages of the disclosed examples will become apparent to those skilled in the art. The drawings accompanying the detailed description may be briefly described as follows:

[0026] Figure 1 A side view of an electrified vehicle is shown.

[0027] Figure 2 Shows from Figure 1 An exploded perspective view of a battery pack of the electrified vehicle.

[0028] Figure 3 Shows Figure 2 A schematic top view of a portion of a battery array of the battery pack, and shows how the container assemblies and busbar shields may be incorporated into the battery pack.

[0029] Figure 4 An exemplary container assembly that can release a reagent mixture is shown.

[0030] Figure 5 Shown at Figure 4 is a cross-sectional view taken along line 5-5.

[0031] Figure 6 Shown is a top perspective view of a bus bar module of a battery pack from Figure 2 .

[0032] Figure 7 Shown is Figure 6 a portion of the bus bar module of DETAILED DESCRIPTION

[0033] The battery pack may include a bus bar. During a thermal event, thermal energy and particulates may reach the bus bar. The battery pack may include at least one container assembly that can release a reagent mixture during a thermal event. The released reagent helps inhibit the thermal event from cascading through the battery pack. The present disclosure relates to a bus bar shield that prevents thermal energy and particulates from reaching the bus bar.

[0034] Referring to Figure 1 , the electrified vehicle 10 includes a battery pack 14, an electric motor 18, and wheels 22. The battery pack 14 powers the electric motor 18, which may convert electrical power into mechanical power to drive the wheels 22. Thus, the battery pack 14 is a traction battery pack.

[0035] In an exemplary embodiment, the battery pack 14 is fixed to the body floor 26 of the electrified vehicle 10. In other examples, the battery pack 14 may be located elsewhere on the electrified vehicle 10. A voltage bus 30 electrically couples the electric motor 18 to the traction battery pack 14.

[0036] The electrified vehicle 10 is a battery 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 the electric motor) to drive the wheels. Generally, the electrified vehicle 10 can be any type of vehicle having a battery pack.

[0037] In the illustrated embodiment, the electrified vehicle 10 is a battery electric vehicle that is propelled only by electricity (such as by one or more electric motors 18) without assistance from an internal combustion engine. The electric motor 18 can operate as an electric motor, a generator, or both. The electric motor 18 receives electrical power and can convert the electrical power into torque for driving one or more wheels 22 of the electrified vehicle 10.

[0038] Referring to Figure 2 and Figure 3And continuing to refer to Figure 1 the exemplary traction battery pack 14 includes a battery array 34 that is capable of outputting electrical power to supply the electric machine 18 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.

[0039] One or more battery arrays 34 of the traction battery pack 14 each include a plurality of battery cells 38 that store energy for powering the various electrical loads of the electrified vehicle 10. Each of the battery arrays 34 includes battery cells 38 (or simply "cells") stacked side by side relative to one another along a respective battery array axis. The battery cells 38 store and supply electrical power. Within each of the battery arrays 34, one or more groups of the cells 38 may be separated from one another by a thermal barrier 40.

[0040] Although a specific number of battery arrays 34 and cells 38 are shown in the various figures of the present disclosure, the battery pack 14 may include any number of battery arrays 34, each of the any number of battery arrays having any number of individual cells 38.

[0041] Within the scope of the present disclosure, the traction battery pack 14 may employ any number of battery cells 38. Accordingly, the present disclosure should not be limited to Figure 2 and Figure 3 the configurations shown.

[0042] In one embodiment, the battery cells 38 of each battery array 34 are prismatic lithium-ion cells. However, within the scope of the present disclosure, battery cells having other geometries (cylindrical, pouch, etc.), other chemistries (nickel metal hydride, lead acid, etc.), or both may alternatively be utilized.

[0043] The battery arrays 34 and various other battery internal components (e.g., bus electrical centers, battery electric control modules, wiring, connectors, etc.) may be housed within an interior region 42 of a housing assembly 46. The housing assembly 46 may include, for example, a housing cover and a housing tray. The housing cover may be secured (e.g., bolted, welded, adhered, etc.) to the housing tray to provide the interior region 42. The size, shape, and overall configuration of the housing assembly 46 are not intended to limit the present disclosure.

[0044] Within the interior region 42, each of the battery arrays 34 is positioned between a pair of busbar modules 50, each of the pair of busbar modules having a frame 54 and a plurality of individual busbars 58 mounted to the frame 54. The tab terminals 60 of the battery cells 38 project outwardly from the battery array axis, extend through slots in the frame 54, and fold over the busbars 58. The busbars 58 and the tab terminals 60 may be joined together via a weld joint.

[0045] During a thermal event, one or more of the battery cells 38 can periodically release exhaust by-products V( Figure 3 ) through the vent 68. The exhaust by-products V can include gases and particulate matter. The present disclosure is primarily directed to protecting regions of the battery pack 14, particularly the bus bars 58, from the exhaust by-products V.

[0046] Now referring to Figures 3 to 5 , and continuing to refer to Figure 1 and Figure 2 , the exemplary battery array 34 includes a thermal suppression system for managing heat transfer across the battery array 34. The exemplary thermal suppression system includes a plurality of container assemblies 70 that can be strategically positioned within the battery array 34 for managing heat transfer during an exhaust event. For example, among other benefits, the container assemblies 70 can be configured to mitigate inter-cell and / or inter-array heat transfer when one or more of the battery cells 38 within the battery array 34 release the exhaust by-products V.

[0047] In this example, each container assembly 70 includes a housing 74, a cover 78, and a reagent mixture 82 received within the housing 74 by the cover 78. The container assemblies 70 of the thermal suppression system can be disposed within void spaces located within the battery array 34.

[0048] In one embodiment, at least some of the container assemblies 70 are positioned between the tab terminals 60 of adjacent battery cells 38, or between the tab terminal 60 of one of the battery cells 38 and one of the thermal barriers 40 of the battery array 34. However, other arrangements are envisioned within the scope of the present disclosure, and it should be understood that the container assemblies 70 can be disposed within any void space within the battery array 34 or the battery pack 14 where heat transfer is desired to be restricted.

[0049] In some examples, the container assemblies 70 can be integrated within another component of the battery pack 14. For example, the frame 54 of the bus bar module can be formed to include a plurality of cavities that provide the container assemblies 70. The reagent mixture 82 can be received within the internal volume provided by each of the cavities. The cover 78 can be integrated into the frame 54 to retain the reagent mixture within the cavities.

[0050] The housing 74 can include any shape (e.g., cylindrical, rectangular, spherical, etc.) and can be made of a suitable polymeric material (e.g., polypropylene, polyethylene, silicone, TPV, acrylic, or some combination thereof). In the exemplary embodiment, the housing 74 includes support feet 86 that assist in positioning and securing the container assembly 70 within the desired void space of the battery array 34 (e.g., between adjacent tab terminals 60). In other examples, the housing 74 does not include support feet 86.

[0051] The cover 78 can include any shape (e.g., oval, oblong, trapezoidal, etc.) and can be made of the same or different material as the housing 74. The cover 78 can be made of polypropylene, silicone, ethylene propylene diene monomer (EPDM) rubber, thermoplastic elastomer (TPE), etc.

[0052] In this example, the reagent mixture 82 is held within the hollow interior volume established by the housing 74. The reagent mixture 82 can be made of high-temperature materials such as solid silica, aerogel, mica, basalt, etc. For example, the reagent mixture 82 can be provided in the form of beads, microparticles, and / or powders.

[0053] The plurality of container assemblies 70 are each configured to release the reagent mixture 82 in response to a thermal event proximate to the container assembly 70. The housing 74, the cover 78, or both can be designed to melt, rupture, or otherwise deform to release the reagent mixture 82 when exposed to a temperature exceeding a predefined temperature threshold (e.g., between 150 degrees Celsius and 250 degrees Celsius). For example, such a temperature may exist when one or more battery cells 38 proximate to the container assembly 70 experience a thermal event and vent exhaust by-products V. Once released, the reagent mixture 82 can capture or trap particles associated with the exhaust by-products V, thereby managing or even preventing the transfer of thermal energy toward the non-venting battery cells 38 of the battery array. The non-rupturing container assemblies 70 can also reduce the movement of the exhaust by-products V toward the non-venting battery cells 38 of the battery array 34.

[0054] The released reagent mixture 82 can include heat-absorbing materials and materials that contribute to electrical isolation. Example materials can include sodium silicate, ceramic-based compounds, melamine poly(zinc phosphate), aluminum trihydrate, and silica. Other potential reagents included within the reagent mixture 82 can include silica, mica, basalt, aerogel, etc.

[0055] Now referring to Figure 6 and Figure 7 and continuing to refer to Figure 3 , another feature of the exemplary thermal suppression system includes a bus bar shield 100 that is disposed on the outer side of the container assembly 70 and the inner side of the bus bar 58. Thus, the bus bar shield 100 is disposed between the bus bar 58 and the cell 38. The exemplary bus bar 58 is on the outer side of the associated frame 54. In another example, the frame 54 can be on the outer side of the bus bar 58.

[0056] During a thermal event, the reagent mixture 82 can prevent and trap particulate matter within the exhaust by-product V from moving outwardly to the bus bar 58 and along the axis A towards other battery cells 38. The particulate matter can include conductive particles. Preventing the conductive particles from contacting the bus bar 58 or being directly adjacent to the bus bar can help prevent the conductive particles from becoming conductors and reduce heat convection. Preventing heat energy and particulate matter can also help protect the frame 54.

[0057] In this example, the bus bar shield 100 can help prevent and trap heat energy and particulate matter that have passed through the reagent 82 from contacting the bus bar 58 and other battery cells 38 or being directly adjacent to the bus bar and other battery cells. In an example where the container assembly 70 with the reagent mixture 82 is omitted from the battery pack 14, the bus bar shield 100 can still help prevent heat energy and particulate matter from reaching the bus bar 58.

[0058] In an exemplary embodiment, each of the bus bar shields 100 includes three tapered fingers 102. Other examples can have bus bar shields 100 with one or two fingers or more than three fingers.

[0059] The bus bar shield 100 can be ceramic fiber, mica, fiberglass, or some combination thereof. The bus bar shield 100 can be partially compressed when installed.

[0060] The bus bar shield 100 can be a sheet of material having holes (such as slots) that permit tab terminals from the battery cells 38 to extend outwardly to the bus bar 58.

[0061] In an exemplary embodiment, the suppression device container assembly 70 is removable from the bus bar shield 100. In other examples, the container assembly 70 can be attached to the bus bar shield 100 before being installed within the housing assembly 46. The container assembly 70 can be glued, heat welded to the bus bar shield 100, etc.

[0062] In some examples, the bus bar shield 100 can be wound around the container assembly 70 when inserted into the housing assembly 46 between the battery cell 38 and the bus bar 58. After installation, the bus bar shield 100 can be unfolded from the wound position to the installed position.

[0063] The foregoing description is exemplary in nature and not restrictive. Variations and modifications made to the disclosed examples may become apparent to those skilled in the art, and such variations and modifications do not necessarily depart from the nature of the disclosure. Accordingly, the scope of protection conferred upon the disclosure can be determined only by studying the appended claims.

Claims

1. A battery pack assembly, comprising: a housing assembly providing an interior region; a plurality of battery cells disposed along an array axis and disposed within the interior region; Each of the plurality of battery cells includes at least one tab terminal protruding outwardly from the array axis; a frame providing at least one slot that receives a portion of the at least one tab terminal; at least one bus bar secured to the frame; as well as A bus bar shield is located between at least one battery cell and at least one bus bar in a battery pack. 2 . The battery pack assembly of claim 1 , wherein the frame is located between the at least one bus bar and the bus bar shield. 3 . 3 . The battery pack assembly of claim 1 , wherein the bus bar shield is directly fixed to the frame.

4. The battery pack assembly of claim 1, wherein the bus bar shield comprises a plurality of fingers, and optionally wherein the plurality of fingers are a plurality of tapered fingers.

5. The battery pack assembly of claim 4, wherein the at least one tab terminal extends between the plurality of fingers, and optionally wherein the at least one tab terminal is secured to the at least one bus bar. 6 . The battery pack assembly of claim 1 , wherein the bus bar shield comprises three fingers.

7. The battery pack assembly of claim 1, wherein the bus bar shield is ceramic fiber, mica, glass fiber, or some combination thereof.

8. The battery pack assembly of claim 1, wherein the bus bar shield is provided by a sheet of material having at least one shield slot, the at least one tab terminal extending through the shield slot.

9. The battery pack assembly according to claim 1, further comprising: A container assembly holds a reagent mixture, the container assembly being configured to release the reagent mixture in response to a thermal event proximate the container assembly, the container assembly being disposed between a plurality of battery cells and the frame, and optionally wherein the bus bar shield is directly secured to the container assembly. 10 . The battery pack assembly of claim 9 , wherein the bus bar shield is configured to wrap around the container assembly during installation of the container assembly within the battery pack.

11. The battery pack assembly of claim 9, wherein the bus bar shield is located between the container assembly and the frame.

12. The battery pack assembly of claim 9, wherein the reagent is configured to electrically isolate thermal energy transfer, prevent thermal energy transfer, or both when released from the container assembly, wherein the reagent mixture optionally includes sodium silicate.

13. A battery pack assembly, comprising: a housing assembly providing an interior region; a plurality of battery cells disposed along an array axis and disposed within the interior region, each of the plurality of battery cells comprising at least one tab terminal protruding outwardly from the array axis; a bus bar module having a frame and a plurality of bus bars mounted to the frame; a plurality of container assemblies disposed between the bus bar module and the plurality of battery cells along side the plurality of battery cells, the plurality of container assemblies each holding a reagent mixture, the container assemblies being configured to release the reagent mixture in response to a thermal event proximate the container assemblies, the plurality of container assemblies; and One or more bus bar shields are disposed along side the plurality of container assemblies between the bus bar module and the plurality of battery cells, the at least one tab terminal extending through the slots in the bus bar shields between the plurality of container assemblies and through the slots in the frame to connect to at least one of the bus bars within the plurality of bus bars. 14 . The battery pack assembly of claim 13 , wherein the bus bar shield is located between the plurality of container assemblies and the frame.

15. The battery pack assembly of claim 13, wherein the bus bar shield is fixed to the frame.

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