Battery pack container assembly containing reagent mixture

Abstract

The present disclosure provides a battery pack container assembly containing a reagent mixture. A battery pack assembly includes a container assembly containing a reagent mixture. The container assembly is configured to release the reagent mixture in response to a thermal event proximate the container assembly. The reagent mixture may include sodium silicate particles, one or more ceramic-based beads, alumina microparticles, melamine poly (zinc phosphate), and aluminum trihydrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 543,544, filed on October 11, 2023, and which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a battery pack assembly in a vehicle. Background Art

[0004] A high voltage traction battery pack may power the motor and other electrical loads of an electrified vehicle. The traction battery pack may include a plurality of individual battery cells. From time to time, the traction battery pack may experience a thermal event in which one or more of the battery cells vents and exhausts battery exhaust byproducts. The exhaust byproducts may include gases and effluent particulates. Summary of the invention

[0005] In some aspects, the technology described herein relates to a battery pack assembly that includes 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 the container assembly.

[0006] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes sodium silicate.

[0007] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture further includes silicon dioxide and aluminum oxide.

[0008] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes 25% to 40% sodium silicate.

[0009] In some aspects, the technology described herein relates to a battery pack assembly wherein the sodium silicate includes sodium silicate particles, each of the sodium silicate particles having a diameter of 5 microns to 100 microns.

[0010] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes one or more ceramic-based compounds.

[0011] In some aspects, the technology described herein relates to a battery pack assembly wherein the one or more ceramic-based compounds include zirconium dioxide, aluminum oxide, silicon dioxide, or some combination of these.

[0012] In some aspects, the technology described herein relates to a battery pack assembly wherein the one or more ceramic-based compounds include greater than 10% zirconium dioxide, greater than 45% aluminum oxide, and greater than 40% silicon dioxide.

[0013] In some aspects, the technology described herein relates to a battery pack assembly wherein the one or more ceramic-based compounds include a plurality of beads provided by the one or more ceramic-based compounds.

[0014] In some aspects, the technology described herein relates to a battery pack assembly wherein the plurality of beads each have a diameter of 2 mm to 3 mm.

[0015] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes 25% to 40% ceramic-based beads.

[0016] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes a plurality of aluminum oxide particles having a diameter ranging from 5 microns to 30 microns.

[0017] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes 5% to 10% aluminum oxide particles.

[0018] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes melamine poly(zinc phosphate).

[0019] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes 5% to 10% melamine poly(zinc phosphate).

[0020] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes aluminum trihydrate.

[0021] In some aspects, the technology described herein relates to a battery pack assembly wherein the reagent mixture includes 3% to 5% aluminum trihydrate.

[0022] In some aspects, the technology described herein relates to a battery pack assembly comprising: a mixture of sodium silicate particles, one or more ceramic-based beads, alumina particles, melamine poly(zinc phosphate), and aluminum trihydrate; and 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.

[0023] In some aspects, the technology described herein relates to a battery pack assembly wherein the mixture includes: 25% to 30% sodium silicate particles, 25% to 40% ceramic-based beads, 5% to 10% alumina particles, 5% to 8% melamine poly(zinc phosphate) and 3% to 5% aluminum trihydrate.

[0024] In some aspects, the technology described herein relates to a battery pack assembly wherein the one or more ceramic-based beads include greater than 10% zirconium dioxide, greater than 45% aluminum oxide, and greater than 40% silicon dioxide.

[0025] 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 apply to all embodiments, unless such features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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:

[0027] Figure 1 A side view of an electrified vehicle is shown.

[0028] Figure 2 Shown from Figure 1 An enlarged perspective view of a battery pack for an electrified vehicle.

[0029] Figure 3 An example container assembly that can release a reagent mixture is shown.

[0030] Figure 4 Schematically shows Figure 2 A top view of a portion of one of the battery arrays of FIG. 1 and showing a container assembly (such as, Figure 3 How the container assembly) can be incorporated into the battery pack. DETAILED DESCRIPTION

[0031] A battery pack may include at least one container assembly that can release a reagent mixture during a thermal event. The released reagent helps to inhibit the thermal event from cascading through the battery pack. The present disclosure relates to specific combinations of reagents used in such a container assembly.

[0032] 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 the electricity into mechanical power to drive the wheels 22. Therefore, the battery pack 14 is a traction battery pack.

[0033] 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. A voltage bus 30 electrically couples the electric machine 18 to the traction battery pack 14.

[0034] 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.

[0035] In the illustrated embodiment, the electrified vehicle 10 is a pure electric vehicle that is propelled solely by electricity, such as by one or more electric machines 18, without assistance from an internal combustion engine. The electric machines 18 may operate as electric motors, generators, or both. The electric machines 18 receive electricity and may convert the electricity into torque for driving one or more wheels 22 of the electrified vehicle 10.

[0036] refer to Figure 2 And continue to refer to Figure 1 The example traction battery pack 14 includes a battery array 34 that is capable of outputting electricity to power 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 electrically power the electrified vehicle 10.

[0037] The 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 various electrical loads of the electrified vehicle 10. Each of the battery arrays 34 includes, among other things, 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. Although a specific number of battery arrays 34 and cells 38 are shown in various figures of the present disclosure, the battery pack 14 may include any number of battery arrays 34 each having any number of individual cells 38.

[0038] Within the scope of the present disclosure, the traction battery pack 14 may employ any number of battery cells 38. Therefore, the present disclosure should not be limited to Figure 1 A highly schematic configuration is shown in FIG.

[0039] In an 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.

[0040] The battery array 34 and various other battery internal components (e.g., bus electrical center, battery electric control module, wiring, connectors, etc.) can be housed within the interior area 42 of the housing assembly 46. The housing assembly 46 can include, for example, a housing cover and a housing tray. The housing cover can be secured (e.g., bolted, welded, bonded, etc.) to the housing tray to provide the interior area 42. The size, shape, and overall configuration of the housing assembly 46 are not intended to limit the present disclosure.

[0041] One or more of the battery cells 38 may periodically release exhaust byproducts through a vent. An increase in pressure within one of the battery cells 38 may cause the housing of the battery cell 38 to rupture, thereby creating a vent that provides a path for the exhaust byproducts to be released from the interior of the battery cell. The present disclosure is generally directed to a thermal suppression system designed to manage the transfer of thermal energy when one or more of the battery cells 38 releases exhaust byproducts.

[0042] As explained in further detail below, the battery array 34 and the rest of the battery pack 14 may incorporate features designed to manage inter-cell thermal energy transfer, particularly across the battery array 34 .

[0043] Reference now Figure 3 and Figure 4 , and continue to refer to Figure 1 and Figure 2 , the example battery array 34 includes a thermal suppression system 50 for managing thermal energy transfer across the battery array 34. The example thermal suppression system 50 includes a plurality of container assemblies 54 that can be strategically positioned within the battery array 34 for managing thermal energy transfer during exhaust events. For example, among other benefits, the container assemblies 54 can be configured to mitigate inter-cell and / or inter-array thermal energy transfer when one or more of the battery cells 38 within the battery array 34 release exhaust byproducts V.

[0044] In this example, each container assembly 54 includes a housing 66, a cover 70, and a reagent mixture 74 contained within the housing 66 by the cover 44. The container assemblies 54 of the thermal suppression system 50 can be arranged in a void space located within the battery array 34. In an embodiment, at least some of the container assemblies 54 are positioned between the cell tab terminals 58 of adjacent battery cells 38. In another embodiment, at least some of the container assemblies 54 are positioned between the cell tab terminals 58 of one of the battery cells 38 and the inter-cell barriers 62 of the battery array 34. However, other arrangements are contemplated within the scope of the present disclosure, and it should be understood that the container assemblies 54 can be arranged in any void space of the battery array 34 where it is desired to limit the transfer of thermal energy.

[0045] In some examples, the container assembly 54 can be integrally formed within another component of the battery pack 14. For example, the frame of the bus bar module can be formed to include a plurality of recesses that provide a container. The reagent mixture can be contained within the internal volume provided by each of the recesses. A cover or hinged cover integrally formed with the frame can retain the thermal inhibitor within the recesses.

[0046] The housing 66 can include any shape (e.g., cylindrical, rectangular, spherical, etc.) and can be made of a suitable polymer material (e.g., polypropylene, polyethylene, silicone, TPV, acrylic, or some combination of these). The housing 66 includes support feet 82 that help position and secure the container assembly 54 within the desired void space of the battery array 34 (e.g., between adjacent battery cell tab terminals 58). In other examples, the housing 66 does not include support feet 82.

[0047] The cover 70 may include any shape (e.g., oval, oblong, trapezoidal, etc.) and may be made of the same or different material as the housing 66. The cover 70 may be made of polypropylene, silicone, ethylene propylene diene monomer (EPDM) rubber, thermoplastic elastomer (TPE), etc.

[0048] In this example, the reagent mixture 78 is held within the hollow interior volume established by the housing 66. The reagent mixture 78 may be made of a high temperature material such as solid silica, aerogel, mica, basalt, etc. For example, the reagent mixture 78 may be provided in the form of beads, microparticles, and / or powders.

[0049] Each of the plurality of container assemblies 54 is configured to release a reagent mixture 78 in response to a thermal event proximate to the container assembly 54. The housing 66, the cover 70, or both may be designed to melt, rupture, or otherwise deform to release the reagent mixture 74 when exposed to a temperature exceeding a predefined temperature threshold (e.g., between 150 degrees Celsius and 250 degrees Celsius). For example, such temperatures may exist when one or more battery cells 38 proximate to the container assembly 54 experience a thermal event and emit exhaust byproducts V. Once released, the reagent mixture 74 may capture or trap particulates associated with the exhaust byproducts V, thereby managing or even preventing the transfer of thermal energy to non-exhaust battery cells 38 of the battery array 34 (at Figure 3 The unruptured container assembly 54 may also reduce the movement of exhaust byproducts V toward the non-exhaust battery cells 38 of the battery array 34 .

[0050] The reagent mixture 78 as a release can include heat absorbing materials and materials that help electrical isolation. Example materials can include sodium silicate, ceramic-based compounds, melamine poly (zinc phosphate), aluminum trihydrate and silicon dioxide. Other potential reagents included in the reagent mixture 78 can include silicon dioxide, mica, basalt, aerogel, etc.

[0051] Sodium silicate can help absorb heat energy. The sodium silicate can be in particle form. The diameter of the sodium silicate particles can be 5 microns to 100 microns. In an example embodiment, 25% to 40% of the reagent mixture is sodium silicate.

[0052] The ceramic-based compound may include zirconium dioxide, aluminum oxide, and silicon dioxide. The ceramic-based compound may be in the form of beads having a diameter ranging from 2 mm to 3 mm. In an exemplary embodiment, 25% to 40% of the reagent mixture 78 is provided by beads of the ceramic-based compound. The ceramic-based compound may include greater than 10% zirconium dioxide, greater than 45% aluminum oxide, and greater than 40% silicon dioxide. Aluminum oxide may help to electrically isolate during thermal events.

[0053] In other examples, the ceramic-based compound is 100% silicon dioxide, and zirconium dioxide and aluminum oxide are omitted.

[0054] The reagent mixture 78 may include additional alumina (outside of the ceramic-based compound) that acts as a filler between the beads of the ceramic-based compound. The additional alumina may be particles ranging in diameter from 5 microns to 30 microns. The additional alumina may "fill in the gaps between the larger beads and particles within the reagent mixture 78". Likewise, the alumina may aid in electrical isolation during thermal events. In an exemplary embodiment, 5% to 10% of the reagent mixture 78 is filler alumina.

[0055] The melamine poly(zinc phosphate) may help generate nitrogen to capture oxygen generated from the electrodes during a thermal event during which exhaust byproducts V are released from within one or more of the battery cells 38. Reducing available oxygen may help inhibit thermal events that cascade through the battery cells 38 of the battery pack 14.

[0056] In an example embodiment, 5% to 8% of the reagent mixture is melamine poly(zinc phosphate). The melamine poly(zinc phosphate) can catalyze the formation of a layer that supports an effective expansion effect. The melamine poly(zinc phosphate) can act as a synergist to support suppression of airborne particulates during a thermal event. Due to endothermic decomposition, the melamine poly(zinc phosphate) can act as a heat sink. The melamine poly(zinc phosphate) can assist in electrical isolation during a thermal event, particularly with respect to exhaust byproducts V and surrounding components.

[0057] Aluminum trihydrate may undergo an endothermic reaction during a thermal event to help reduce temperatures during the thermal event, particularly the temperature of the exhaust byproducts V. In an exemplary embodiment, 3% to 5% of the reagent mixture is aluminum trihydrate.

[0058] In other examples, aluminum trihydrate is omitted from the reagent mixture 78 and is not included in the container assembly 54 .

[0059] In an example, the reagent mixture 78 has silicon dioxide, aluminum oxide, and sodium silicate, with the silicon dioxide beads being significantly larger than the aluminum oxide and sodium silicate particles.

[0060] 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 battery pack assembly, comprising: A container assembly contains a reagent mixture, the container assembly being configured to release the reagent mixture in response to a thermal event proximate the container assembly.

2. The battery pack assembly of claim 1, wherein the reagent mixture comprises sodium silicate, and optionally, wherein the reagent mixture further comprises silicon dioxide and aluminum oxide.

3. The battery pack assembly of claim 1, wherein the reagent mixture comprises 25% to 40% sodium silicate, and optionally, wherein the sodium silicate comprises sodium silicate particles, each of the sodium silicate particles having a diameter of 5 microns to 100 microns.

4. The battery pack assembly of claim 1, wherein the reagent mixture comprises one or more ceramic-based compounds.

5. The battery pack assembly of claim 4, wherein the one or more ceramic-based compounds include zirconium dioxide, aluminum oxide, silicon dioxide, or some combination thereof.

6. The battery pack assembly of claim 4, wherein the one or more ceramic-based compounds include greater than 10% zirconium dioxide, greater than 45% aluminum oxide, and greater than 40% silicon dioxide.

7. The battery pack assembly of claim 4, wherein the one or more ceramic-based compounds include a plurality of beads provided by the one or more ceramic-based compounds, and optionally, wherein each of the plurality of beads has a diameter of 2 mm to 3 mm.

8. The battery pack assembly of claim 1, wherein the reagent mixture comprises 25% to 40% ceramic-based beads.

9. The battery pack assembly of claim 1, wherein the reagent mixture comprises a plurality of aluminum oxide particles having a diameter ranging from 5 microns to 30 microns, and optionally, wherein the reagent mixture comprises 5% to 10% aluminum oxide particles.

10. The battery pack assembly of claim 1, wherein the reagent mixture comprises melamine poly(zinc phosphate).

11. The battery pack assembly of claim 1, wherein the reagent mixture comprises 5% to 10% melamine poly(zinc phosphate).

12. The battery pack assembly of claim 1, wherein the reagent mixture comprises aluminum trihydrate.

13. The battery pack assembly of claim 1, wherein the reagent mixture comprises 3% to 5% aluminum trihydrate.

14. A battery pack assembly, comprising: a mixture of sodium silicate particles, one or more ceramic-based beads, alumina particles, melamine poly(zinc phosphate), and aluminum trihydrate; as well as A container assembly contains the mixture, the container assembly being configured to release the mixture in response to a thermal event proximate the container assembly.

15. The battery pack assembly of claim 14, wherein the mixture comprises 25% to 30% sodium silicate particles, 25% to 40% ceramic-based beads, 5% to 10% alumina particles, 5% to 8% melamine poly(zinc phosphate) and 3% to 5% aluminum trihydrate, and optionally, wherein the one or more ceramic-based beads comprise greater than 10% zirconium dioxide, greater than 45% alumina and greater than 40% silica.

Images