Heat suppression tank designs for managing heat energy within traction battery packs

Abstract

Heat suppression containers are provided for use within traction battery packs. An example heat suppression container includes an outer pouch and a heat suppressant contained within the outer pouch. The heat suppression container can be configured to release the heat suppressant when a temperature near the outer pouch exceeds a predefined temperature threshold. The heat suppressant can capture or trap particles associated with battery venting byproducts, thereby managing or even preventing the transfer of heat energy to nearby structures. The outer pouch of the heat suppression container can include one or more flag seals configured to position the heat suppression container relative to surrounding structures.

Description

AREA OF TECHNOLOGY

[0001] This disclosure relates generally to traction battery packs for electrified vehicles and in particular to heat suppression containers for managing the transfer of heat energy within battery banks of traction battery packs. GENERAL STATE OF THE ART

[0002] A high-voltage traction battery pack typically supplies power to the electric motors and other electrical consumers of an electrified vehicle. The traction battery pack contains a variety of battery cells and various other internal battery components that support the vehicle's electric drive system. SUMMARY

[0003] A traction battery pack according to an exemplary aspect of the present disclosure includes, among other things, a battery bank, a heat suppression container arranged within the battery bank and comprising an outer pouch, and a heat suppression agent contained within the outer pouch in a releasable manner. A first flag seal of the outer pouch is configured to form an interface with a bank housing of the battery bank.

[0004] In another non-restrictive embodiment of the aforementioned traction battery pack, the heat suppression container is arranged such that it extends between a first battery cell and a second battery cell of the battery bank.

[0005] In another non-restrictive embodiment of one of the aforementioned traction battery packs, the heat suppression container forms a cell-to-cell barrier of the battery bank.

[0006] In a further non-restrictive embodiment of any of the aforementioned traction battery packs, the heat suppression means is contained within the outer pouch by at least one heat-sealed seam.

[0007] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the outer pouch is configured to melt, rupture or otherwise deform to release the heat suppressant when a temperature near the heat suppression container exceeds a predefined temperature threshold.

[0008] In a further non-restrictive embodiment of any of the aforementioned traction battery packs, the outer pouch consists of a thermoplastic material.

[0009] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the heat suppressant comprises a plurality of silicon dioxide beads.

[0010] In a further non-restrictive embodiment of any of the foregoing traction battery packs, at least one of the plurality of silicon dioxide beads is contained in a pocket provided by the outer pouch.

[0011] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the heat suppression means comprises a single large-format prismatic element with a plurality of notched fracture points.

[0012] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the heat suppression means comprises a plurality of prismatic elements arranged together to form a large-format prismatic element.

[0013] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the first flag seal is arranged to form an interface with an upper bank cover of the bank housing.

[0014] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the second flag seal of the outer pouch is arranged to form an interface with a lower bank cover of the bank housing.

[0015] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the first flag seal is arranged to form an interface with a lower bank cover of the bank housing.

[0016] A battery bank for a traction battery pack according to another exemplary aspect of the present disclosure includes, among other things, a first battery cell, a second battery cell, and a heat suppression container arranged between the first battery cell and the second battery cell. The heat suppression container includes an outer pouch and a heat suppressant that is releasably contained in the outer pouch. The outer pouch includes a first heat-sealed seam and a first flag seal extending outwards from the first heat-sealed seam.

[0017] In a further non-restrictive embodiment of the aforementioned traction battery pack, the heat suppressant comprises at least one of solid silicon dioxide, aerogel, mica or basalt.

[0018] In a further non-restrictive embodiment of one of the foregoing traction battery packs, the first flag seal is configured to form an interface with a section of a bank housing that surrounds the first battery cell and the second battery cell.

[0019] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the outer pouch includes a second heat-sealed seam and a second flag seal extending outwards from the second heat-sealed seam.

[0020] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the first flag seal is configured to form an interface with a first section of a bank housing that surrounds the first battery cell and the second battery cell, and the second flag seal is configured to form an interface with a second section of the bank housing.

[0021] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the heat suppressant comprises a plurality of silicon dioxide beads.

[0022] In a further non-restrictive embodiment of any of the foregoing traction battery packs, the heat suppression means comprises a single large-format prismatic element having a plurality of notched fracture points or a plurality of prismatic elements arranged together to form a large-format prismatic element.

[0023] The embodiments, examples, and alternatives described in the preceding paragraphs, the claims, or the following description and drawings, including their various aspects or individual features, may be used independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, provided such features are not incompatible.

[0024] The various features and advantages of this disclosure will become apparent to the person skilled in the art from the following detailed description. The drawings accompanying the detailed description can be summarized as follows. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 schematically illustrates an electrified vehicle that includes a traction battery pack. Fig. Figure 2 is a cross-sectional view of selected sections of a battery bank within a traction battery pack. The battery bank includes a heat suppression canister configured to manage the transfer of heat energy across the battery bank. Fig. Figure 3 schematically illustrates the behavior of the heat suppression container. Fig. 2 during a battery thermal event. Fig. Figure 4 illustrates a pocket of an outer pouch of a heat suppression container. Fig. Figure 5 illustrates another example of a heat suppression container. Fig. Figure 6 illustrates another example of a heat suppression container. Fig. Figure 7 illustrates an outer pouch of a heat suppression container. Fig. Figure 8 illustrates selected sections of another exemplary battery bank with a heat suppression container. Fig. 9 is a cross-sectional view through section 9-9 from Fig. 8. Fig. Section 10 illustrates selected sections of another exemplary battery bank with a heat suppression container. Fig. 11 is a cross-sectional view through section 11-11 from Fig. 10. DETAILED DESCRIPTION

[0025] This disclosure details heat suppression containers for use within traction battery packs. An exemplary heat suppression container includes an outer pouch and a heat suppressant contained within the outer pouch in a releasable manner. The heat suppression container can be configured to release the heat suppressant when a temperature near the outer pouch exceeds a predefined temperature threshold. The heat suppressant can capture or trap particles associated with battery venting byproducts, thereby managing or even preventing the transfer of heat energy to nearby structures. The outer pouch can include one or more flag seals configured to position the heat suppression container relative to surrounding structures.These and other features are discussed in more detail in the following paragraphs of this detailed description.

[0026] Fig. Figure 1 schematically illustrates an electrified vehicle 10. The electrified vehicle 10 can include any type of electrified powertrain. In one embodiment, the electrified vehicle 10 is a battery electric vehicle (BEV). However, the concepts described in this document are not limited to BEVs and could extend 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 embodiment, the powertrain of the electrified vehicle 10 could be equipped with an internal combustion engine, which can be used either alone or in combination with other power sources to propel the electrified vehicle 10.

[0027] In the illustrated embodiment, the electrified vehicle 10 is depicted as an automobile. However, the electrified vehicle 10 could alternatively be a sport utility vehicle (SUV), a van, a pickup truck, or any other vehicle configuration. Although the figures in this disclosure illustrate a specific relationship between the components, these illustrations are not intended to limit this disclosure. The placement and orientation of the various components of the electrified vehicle 10 are shown schematically and could vary within the scope of this disclosure. Furthermore, the various figures accompanying this disclosure are not necessarily drawn to scale, and some features may be enlarged or reduced to highlight certain details of a particular component or system.

[0028] In the illustrated embodiment, the electrified vehicle 10 is a fully electric vehicle powered exclusively by electrical power, such as from one or more electric machines 12, without assistance from an internal combustion engine. The electric machine 12 can operate as an electric motor, an electric generator, or both. The electric machine 12 receives electrical power and can convert this power into torque to drive one or more wheels 14 of the electrified vehicle 10.

[0029] A voltage bus 16 can electrically couple the electric machine 12 to a traction battery pack 18. The traction battery pack 18 is an exemplary battery of an electrified vehicle. The traction battery pack 18 can be a high-voltage traction battery pack assembly comprising a variety of battery cells capable of outputting electrical power to supply the electric machine 12 and / or other electrical consumers of the electrified vehicle 10. Alternatively or additionally, other types of energy storage devices and / or output devices could also be used to supply the electrified vehicle 10 with electrical power.

[0030] The traction battery pack 18 can be attached to an underbody 20 of the electrified vehicle 10. However, within the scope of this disclosure, the traction battery pack 18 could be located at a different location on the electrified vehicle 10.

[0031] The traction battery pack 18 can include one or more battery banks 22 (e.g., battery modules or groups of rechargeable battery cells 24) capable of outputting electrical power to supply the electric machine 12 and / or other electrical consumers of the electrified vehicle 10. Alternatively or additionally, other types of energy storage devices and / or output devices could also be used to supply the electrified vehicle 10 with electrical power.

[0032] The one or more battery banks 22 of the traction battery pack 18 can each contain a plurality of battery cells 24 that store energy to power various electrical consumers of the electrified vehicle 10. The traction battery pack 18 could employ any number of battery cells 24 within the scope of this disclosure. Accordingly, this disclosure is not intended to limit the battery banks 22 to those described in the following documents. Fig. The highly schematic configuration shown in 1 may be limited.

[0033] In one embodiment, the battery cells 24 of each battery bank 22 are prismatic lithium-ion cells. However, within the scope of this disclosure, alternatively battery cells could be used that have other geometries (cylindrical, pouch, etc.), other chemical compositions (nickel-metal hydride, lead-acid, etc.), or both.

[0034] The battery banks 22 and various other battery-internal components (e.g., an electrical distribution bus, an electrical battery control module, wiring, connectors, etc.) can be housed within an interior compartment 26 of an enclosure assembly 28. The enclosure assembly 28 can, for example, include an enclosure cover and an enclosure shell. The enclosure cover can be attached to the enclosure shell (e.g., screwed, welded, glued, etc.) to provide the interior compartment 26. The size, shape, and overall configuration of the enclosure assembly 28 are not intended to limit this disclosure.

[0035] One or more of the battery cells 24 may periodically release venting byproducts, such as during an overcharge condition, an over-discharge condition, a short circuit, etc. The venting byproducts can be released from the battery cells 24 through a vent. Pressure increases within one of the battery cells 24 may cause the vent to burst, thereby creating a pathway for the venting byproducts to be released from the interior of the battery cell 24. This disclosure is primarily directed to heat suppression systems designed to manage the transfer of heat energy when one or more of the battery cells 24 release venting byproducts.

[0036] Fig. 2 and Fig. Figure 3 illustrates selected sections of a battery bank 22 of the traction battery pack 18. As explained in detail below, the battery bank 22 may include features designed to cope with the cell-to-cell transfer of heat energy across the battery bank 22.

[0037] The battery bank 22 can contain a plurality of battery cells 24. The total number of battery cells 24 provided within the battery bank 22 could vary and is not intended to limit the present disclosure. The battery cells 24 can be grouped together in a cell stack 30.

[0038] A bank housing 32 of the battery bank 22 can be arranged to substantially surround the cell stack 30. The bank housing 32 can include a top cover 36 and a bottom cover 38. The bank housing 32 could further include a pair of side plates and a pair of end plates (not shown for simplicity and clarity). The top cover 36, the bottom cover 38, the pair of side plates, and the pair of end plates can be connected to each other to form an internal volume 42 of the battery bank 22. The battery cells 24 can be positioned within the internal volume 42.

[0039] The battery bank 22 may further include one or more heat suppression vessels 34 designed to manage the transfer of heat energy across the cell stack 30. Each heat suppression vessel 34 may be strategically positioned within the battery bank 22 to create a cell-to-cell thermal barrier to manage the transfer of heat energy during battery venting events. For example, among other advantages, the heat suppression vessels 34 may be configured to mitigate the cell-to-cell or bank-to-bank transfer of heat energy when one or more of the battery cells 24 within the cell stack 30 release venting byproducts 40 (see Fig. 3) release during a heat event.

[0040] Each heat suppression vessel 34 can be arranged within the internal volume 42 of the battery bank 22. In one embodiment, the heat suppression vessels 34 are positioned axially between adjacent battery cells 24 of the cell stack 30. However, within the scope of this disclosure, other arrangements are also considered, and it is understood that the heat suppression vessels 34 could be arranged within any empty space of the battery bank 22 where it is desirable to limit the transfer of heat energy.

[0041] Each heat-suppression container 34 can include an outer pouch 44 and a heat-suppressing agent 46 contained within the outer pouch 44. The outer pouch 44 can be made of a suitable thermoplastic material. Suitable thermoplastic materials include, but are not limited to, polypropylene, high-density polyethylene, polyethylene terephthalate (PET), plastic laminates, and acrylic-based materials. However, this disclosure is not intended to limit the exact material composition of the outer pouch 44.

[0042] The heat-suppressing agent 46 can be contained within a hollow inner volume provided by the outer pouch 44. The heat-suppressing agent 46 can be made of a high-temperature material, such as solid silicon dioxide, aerogel, mica, basalt, etc. In this embodiment, the heat-suppressing agent 46 comprises a plurality of silicon dioxide beads 48. However, the heat-suppressing agent 46 could alternatively be provided, for example, in powder form.

[0043] The outer pouch 44 can be flexible and thus deform to conform to the silicon dioxide beads 48 and prevent them from shifting during vibrations, thereby reducing noise. In one embodiment, at least some of the silicon dioxide beads 48 can be contained in pockets 50 (see Fig. 4) shall be included, which are provided by the outer pouch 44.

[0044] The outer pouch 44 can be configured to melt, rupture, or otherwise deform to release the heat suppressant 46 when exposed to temperatures exceeding a predefined temperature threshold (e.g., between 150 and 250 degrees Celsius). Such temperatures may occur, for example, when one or more battery cells 24 near the heat suppression reservoir 34 vent and release the venting byproducts 40. Once released from the outer pouch 44, the silicon dioxide beads 48 can capture or trap particles associated with the venting byproducts 40, thereby managing or even preventing the transfer of heat energy toward the non-venting battery cells 24 of the cell stack 30 (schematically shown at reference numeral 99 in Figure 3). Fig. 3 illustrated).

[0045] The outer pouch 44 can include one or more flag seals 54 that maintain the positioning of the heat suppression vessel 34 relative to the bank housing 32. In one embodiment, the outer pouch 44 includes a first flag seal 54-1 that interfaces with the upper bank cover 36, and a second flag seal 54-2 that interfaces with the lower bank cover 38 (see Fig. 2) In a further embodiment, the outer pouch 44 includes a single flag seal 54-3, which forms an interface with the upper bank cover 36 (see Fig. 5) In yet another embodiment, the outer pouch 44 includes a single flag seal 54-4, which forms an interface with the lower bank cover 38 (see Fig. 6).

[0046] Each flag seal 54 can be sealed by a heat-sealed seam 52 (see Fig. 7) of the outer pouch 44. The heat-sealed seams 52 can be formed, for example, using a vacuum formation process. The heat-sealed seams 52 can contain the heat-suppressing agent 46 within the hollow inner volume provided by the outer pouch 44, thereby providing moisture resistance and preventing degradation of the silicon dioxide beads 48 over time.

[0047] Each flag seal 54 can extend outwards from one of the heat-sealed seams 52. Each flag seal 54 can be configured to bend relative to a remaining section of the outer pouch 44 to locate and retain the heat-suppression containers 34 relative to the battery cells 24 and the bank housing 32. The flag seals 54 can therefore accommodate height variations of the heat-suppression containers 34, prevent unwanted movement of the heat-suppression container 34 within the battery bank 22, and reduce noise.

[0048] Fig. 8 and Fig. Figure 9 illustrates another exemplary heat suppression container 134 that could be used as part of a heat suppression system for a battery bank 22. The heat suppression container 134 may include an outer pouch 44 and a heat suppression agent 146 contained within the outer pouch 44. The outer pouch 44 is essentially the same as described above with respect to the Fig. similar to the outer pouches described in 2-7, and can therefore include one or more flag seals 54 for positioning and holding the heat suppression container 134 relative to the battery cells 24 and the bank housing 32 of the battery bank 22.

[0049] The heat suppressant 146 can be contained within a hollow internal volume provided by the outer pouch 44. The heat suppressant 146 can be made of a high-temperature material, such as solid silicon dioxide, aerogel, mica, basalt, etc. In this embodiment, the heat suppressant 146 is configured as a single large-format prismatic element 60 with a plurality of notched fracture surfaces 62. The single large-format prismatic element 60 is dimensioned to accommodate a large portion of the hollow internal volume provided by the outer pouch 44. The notched fracture surfaces 62 are configured to facilitate the disassembly of the single large-format prismatic element 60 during a thermal event of a battery.

[0050] The outer pouch 44 can be configured to melt, rupture, or otherwise deform to release the heat suppressant 146 when exposed to temperatures exceeding a predefined temperature threshold (e.g., between 150 and 250 degrees Celsius). Such temperatures may occur, for example, when one or more battery cells 24 near the heat suppression reservoir 134 vent and release venting byproducts. Once the outer pouch 44 deforms, at least one section of the single large-format prismatic element 60 can break away at one or more of the notched fracture surfaces 62 and then capture or trap particles associated with the venting byproducts, thereby managing or even preventing the transfer of heat energy toward non-venting battery cells 24 of the battery bank.

[0051] Fig. 10 and Fig. Figure 11 illustrates another exemplary heat suppression container 234 that could be used as part of a heat suppression system for a battery bank 22. The heat suppression container 234 can include an outer pouch 44 and a heat suppression agent 246 contained within the outer pouch 44. The outer pouch 44 is essentially the same as described above with respect to the Fig. similar to the outer pouches described in 2-7, and can therefore include one or more flag seals 54 for positioning and holding the heat suppression container 234 relative to the battery cells 24 and the bank housing 32 of the battery bank 22.

[0052] The heat suppressant 246 can be contained within a hollow internal volume provided by the outer pouch 44. The heat suppressant 246 can be made of a high-temperature material, such as solid silicon dioxide, aerogel, mica, basalt, etc. In this embodiment, the heat suppressant 246 comprises a plurality of prismatic elements 70, which can be stacked or otherwise arranged together to form a large-format prismatic element 260. The large-format prismatic element 260 is dimensioned to accommodate a large portion of the hollow internal volume provided by the outer pouch 44.

[0053] The outer pouch 44 can be configured to melt, rupture, or otherwise deform to release the heat suppressant 246 when exposed to temperatures exceeding a predefined temperature threshold (e.g., between 150 and 250 degrees Celsius). Such temperatures may occur, for example, when one or more battery cells 24 near the heat suppression reservoir 234 vent and release venting byproducts. Once the outer pouch 44 deforms, one or more of the prismatic elements 70 can be released and then capture or trap particles associated with the venting byproducts, thereby managing or even preventing the transfer of heat energy toward non-venting battery cells 24 of the battery bank 22.

[0054] The exemplary heat suppression containers of this disclosure are designed to integrate dispersible, high-temperature-resistant materials to reduce the transfer of heat energy across a battery bank of a traction battery pack. The systems can provide numerous advantages over known solutions, including, but not limited to, a novel configuration that significantly slows down or even prevents cell-to-cell heat energy transfer, provides better space utilization, reduces noise, vibration, and roughness, simplifies installation and packaging, etc.

[0055] Although the different non-restrictive embodiments are illustrated by showing specific components or steps, the embodiments of this disclosure are not limited to these specific combinations. It is possible to use some of the components or features from any of the non-restrictive embodiments in combination with features or components from any of the other non-restrictive embodiments.

[0056] It is understood that identical reference numerals denote corresponding or similar elements in the multiple views. It is understood that although a specific component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the lessons of this disclosure.

[0057] The foregoing description is to be interpreted as illustrative and not as limiting. A person skilled in the art will understand that certain modifications may be covered by the scope of this disclosure. For these reasons, the following patent claims should be read carefully to determine the true scope and content of this disclosure.

Claims

[1] Traction battery pack, comprising: a battery bank; a heat suppression container arranged within the battery bank, comprising an outer pouch and a heat suppressant contained within the outer pouch that can be released; and a first flag seal of the outer pouch, configured to form an interface with a bank housing of the battery bank. [2] Traction battery pack according to claim 1, wherein the heat suppression container is arranged to extend between a first battery cell and a second battery cell of the battery bank to form a cell-to-cell barrier of the battery bank. [3] Traction battery pack according to claim 1 or 2, wherein the heat suppression means is contained within the outer pouch by at least one heat-sealed seam. [4] Traction battery pack according to any of the preceding claims, wherein the outer pouch is made of a thermoplastic material configured to melt, rupture or otherwise deform to release the heat suppressant when a temperature near the heat suppression container exceeds a predefined temperature threshold. [5] Traction battery pack according to any of the preceding claims, wherein the heat suppression agent comprises a plurality of silicon dioxide beads and wherein optionally at least one of the plurality of silicon dioxide beads is contained within a pocket provided by the outer pouch. [6] Traction battery pack according to one of the preceding claims, wherein the heat suppression means comprises a single large-format prismatic element with a plurality of notched fracture points. [7] Traction battery pack according to any of the preceding claims, wherein the heat suppression means comprises a plurality of prismatic elements arranged together to form a large-format prismatic element. [8] Traction battery pack according to any of the preceding claims, wherein the first flag seal is designed to form an interface with an upper bank cover of the bank housing, and wherein optionally a second flag seal of the outer pouch is designed to form an interface with a lower bank cover of the bank housing. [9] Traction battery pack according to any of the preceding claims, wherein the first flag seal is designed to form an interface with a lower bank cover of the bank housing. [10] Battery bank for a traction battery pack, comprising: a first battery cell; a second battery cell; and a heat suppression container arranged axially between the first battery cell and the second battery cell, comprising an outer pouch and a heat suppression agent contained within the outer pouch in a releasable manner, wherein the outer pouch includes a first heat-sealed seam and a first flag seal extending outwards from the first heat-sealed seam. [11] Traction battery pack according to claim 10, wherein the heat suppression agent comprises at least one of solid silicon dioxide, aerogel, mica or basalt. [12] Traction battery pack according to claim 10 or 11, wherein the first flag seal is configured to form an interface with a section of a bank housing surrounding the first battery cell and the second battery cell. [13] Traction battery pack according to any one of claims 10 to 12, wherein the outer pouch includes a second heat-sealed seam and a second flag seal extending outwards from the second heat-sealed seam, and wherein optionally the first flag seal is configured to form an interface with a first section of a bank housing surrounding the first battery cell and the second battery cell, and the second flag seal is configured to form an interface with a second section of the bank housing. [14] Traction battery pack according to any one of claims 10 to 13, wherein the heat suppression agent comprises a plurality of silicon dioxide beads. [15] Traction battery pack according to any one of claims 10 to 14, wherein the heat suppression means comprises a single large-format prismatic element having a plurality of notched fracture points or a plurality of prismatic elements arranged together to form a large-format prismatic element.

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