Battery pack cell array to battery pack thermal runaway exhaust system using tundish channel system

Abstract

The invention relates to a battery pack cell array to battery pack thermal runaway exhaust system using a tundish channel system. A battery pack for a vehicle includes a housing including at least one battery pack vent between an interior and an exterior of the housing. A plurality of battery cells are disposed within the housing. A channel system includes an array of channels positioned in communication with a vent on each of the plurality of battery cells, and the array of channels is in communication with a main channel in communication with the at least one battery pack vent, where the channel system is isolated from the remainder of the volume of the battery pack.

Description

Technical Field

[0001] The present disclosure relates to a battery cell array to battery pack thermal runaway venting system using a mid pack channel system. Background Art

[0002] The information provided in this section is for the purpose of generally introducing the background of the present disclosure. No admission is made, either explicitly or implicitly, that the work of the presently named inventors described in this section is prior art to the present disclosure, nor is it admitted that the work is prior art to the present disclosure, as described in this section, which may not otherwise be identified as prior art at the time of filing.

[0003] Ventilation of battery cells of a battery pack of an electric vehicle is known in the art. The exhaust system must remain open for gas to pass through during a thermal event so that the gas can reach the vent port of the battery pack. For electrical isolation, structural performance and thermal insulation, the rest of the battery pack is typically filled with a potting resin (foaming or non-foaming). Controlling the location of the potting is challenging. The variability of foam expansion makes the baseline system incompatible with foam potting. Summary of the invention

[0004] The main purpose of the present disclosure is to create a closed volume for a thermal runaway exhaust system. The closed volume cannot be blocked by potting materials during the manufacturing process.

[0005] According to one aspect of the present disclosure, a battery pack for a vehicle includes a housing including at least one pack vent between an interior and an exterior of the housing. A plurality of battery cells are disposed within the housing. A channel system includes an array of channels positioned in connection with the vent on each of the plurality of battery cells, and the array of channels is connected to a main channel that communicates with the at least one pack vent, wherein the channel system is isolated from the remainder of the volume of the battery pack.

[0006] According to another aspect, the housing contains a potting material encapsulating the channel system.

[0007] According to another aspect, the potting material is one of a foamed and a non-foamed polymer resin.

[0008] According to another aspect, the channel system is isolated to prevent potting material from entering the exhaust system.

[0009] According to another aspect, the channel array includes a plurality of battery cell engagement plates and a plurality of tray plates.

[0010] According to another aspect, the gap between adjacent battery cell engagement plates and adjacent tray plates is less than half the thickness of the battery cell engagement plates and the tray plates, respectively.

[0011] According to another aspect, the main channel includes a plurality of main channels.

[0012] According to another aspect, the at least one battery pack vent includes a plurality of battery pack vents.

[0013] According to another aspect, the housing includes a plurality of sub-modules, and each sub-module includes an array of channels.

[0014] According to another aspect, the channel array includes ribs defining a plurality of channels beneath the battery, extending longitudinally or transversely relative to the vehicle and connected by a series of openings in the ribs.

[0015] According to another aspect, a thermal runaway sensor is in the primary channel.

[0016] According to another aspect, the main channel is connected to the channel array along an array face.

[0017] According to another aspect, the main channel extends along the center of the housing to divide the housing into separate sections.

[0018] According to another aspect, the main channel is formed by a flexible tube connecting the channel array to the at least one battery pack vent.

[0019] According to another aspect, the main channel is formed directly in the potting material so that there is no separate wall material.

[0020] According to another aspect, the main passage contains a series of spark arresters whose apertures decrease as the gas travels toward the battery pack exhaust port.

[0021] According to another aspect, at least one cooling element is arranged along the main channel.

[0022] According to another aspect, the channel system includes a plurality of battery cell engagement plates and a plurality of tray plates, the tray plates including ribs to define an array of channels; and a plurality of holes in the battery cell engagement plates and in communication with vents in the plurality of battery cells.

[0023] According to another aspect, a breakable sheet is provided between the plurality of battery cell engagement plates and the plurality of tray plates.

[0024] According to another aspect, a battery pack for a vehicle includes a housing including at least one vent between an interior and an exterior of the housing. A plurality of battery cells are disposed within the housing. A channel system includes an array of channels positioned in connection with the vent on each of the plurality of battery cells, and the array of channels is connected to a main channel that communicates with the at least one battery pack vent of the housing. At least one cooling element is adjacent to the main channel.

[0025] The present invention discloses the following scheme:

[0026] Solution 1. A battery pack for a vehicle, comprising:

[0027] a housing including at least one pack vent between an interior and an exterior of the housing;

[0028] a plurality of battery cells disposed within the housing; and

[0029] A channel system comprising a channel array positioned in connection with the exhaust port on each of the plurality of battery cells, and the channel array is connected to a main channel, the main channel being connected to the at least one exhaust port of the housing, wherein the channel system is isolated from the rest of the volume of the battery pack.

[0030] Option 2. The battery pack for a vehicle according to Option 1, wherein the housing contains a potting material that encapsulates the channel system.

[0031] Option 3. The battery pack for a vehicle according to Option 2, wherein the potting material is one of a foamed and non-foamed polymer resin.

[0032] Option 4. The battery pack for a vehicle according to Option 1, wherein the channel system is isolated to prevent the potting material from entering the exhaust system.

[0033] Option 5. The battery pack for a vehicle according to Option 1, wherein the channel array includes a plurality of battery cell engagement plates and a plurality of tray plates.

[0034] Aspect 6. The battery pack for a vehicle according to aspect 5, wherein a gap between adjacent battery cell joining plates and adjacent tray plates is less than half of the thickness of the battery cell joining plates and the tray plates, respectively.

[0035] Option 7. The battery pack for a vehicle according to Option 1, wherein the main channel comprises a plurality of main channels.

[0036] Option 8. The battery pack for a vehicle according to Option 1, wherein the at least one battery pack vent comprises a plurality of battery pack vents.

[0037] Option 9. A battery pack for a vehicle according to Option 1, wherein the housing includes a plurality of sub-modules, and each sub-module includes a channel array.

[0038] Option 10. A battery pack for a vehicle according to Option 1, wherein the channel array includes ribs defining a plurality of channels below the battery, which extend longitudinally or transversely relative to the vehicle and are connected by a series of openings in the ribs.

[0039] Solution 11. A battery pack for a vehicle according to Solution 1, further comprising a thermal runaway sensor in the main channel.

[0040] Option 12. The battery pack for a vehicle according to Option 1, wherein the main channel is connected to the channel array along an array surface.

[0041] Option 13. The battery pack for a vehicle according to Option 1, wherein the main channel extends along the center of the shell to divide the shell into partitioned blocks.

[0042] Embodiment 14. The battery pack for a vehicle according to Embodiment 1, wherein the main channel is formed by a hose connecting the channel array to the at least one battery pack exhaust port.

[0043] Embodiment 15. The battery pack for a vehicle according to Embodiment 2, wherein the main channel is directly formed in the potting material so that there is no separate wall material.

[0044] Embodiment 16. A battery pack for a vehicle according to Embodiment 1, wherein the main channel contains a series of spark arresters, the apertures of which decrease as the gas travels toward the exhaust port of the battery pack.

[0045] Embodiment 17. The battery pack for a vehicle according to Embodiment 1, further comprising at least one cooling belt arranged along the main channel.

[0046] Option 18. A battery pack for a vehicle according to Option 1, wherein the channel system includes a plurality of battery cell joining plates and a plurality of tray plates, the tray plates including ribs to define a channel array; and a plurality of holes in the battery cell joining plates and connected to exhaust ports in the plurality of battery cells.

[0047] Aspect 19. The battery pack for a vehicle according to aspect 18, further comprising a breakable sheet between the plurality of battery cell engaging plates and the plurality of tray plates.

[0048] Solution 20. A battery pack for a vehicle, comprising:

[0049] a housing including at least one exhaust port between an interior and an exterior of the housing;

[0050] a plurality of battery cells disposed within the housing;

[0051] a channel system comprising an array of channels positioned in connection with the vent on each of the plurality of battery cells, and the array of channels is connected to a main channel that communicates with the at least one battery pack vent of the housing; and

[0052] At least one cooling element is adjacent to the primary channel.

[0053] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0055] Figure 1 is a partial cross-sectional view of a battery pack having a vent system according to the principles of the present disclosure;

[0056] Figure 2 is a schematic diagram of a battery pack having an exhaust system having an array of channels connecting individual battery cells to a main channel;

[0057] Figure 3 is a detailed view of the connection between the channel array and the main channel;

[0058] Figure 4 is a perspective cross-sectional view of the main channel of the battery pack exhaust system;

[0059] Figure 5 is a perspective view of an alternative tubing forming the main channel of the battery pack vent system;

[0060] Figure 6 is a cross-sectional view of a battery tray of a channel array;

[0061] Figure 7 is a cross-sectional view of the interface between adjacent battery trays;

[0062] Figure 8 is a schematic diagram of a spark arrester disposed along a main exhaust passage; and

[0063] Fig. 9 is a schematic diagram of a cooling zone arranged along the main exhaust passage.

[0064] In the drawings, reference numerals may be repeated to designate similar and / or identical elements. DETAILED DESCRIPTION

[0065] refer to Figure 1 , schematically showing a battery pack 10, which includes a housing 12 having a bottom shear plate 14, a top shear plate 16 and a side wall shell 18 (see Figure 2 A plurality of battery cells 20 are disposed within the housing 12. The battery cells 20 each include an electrical terminal 22 for connection to a bus bar or other system 23 for electrical connection. The battery cells 20 each include a vent 24 in communication with a channel array 26.

[0066] like Figure 2 As shown in FIG. 1 , the channel array 26 connects the exhaust port 24 of each battery cell 20 to the battery pack exhaust port 28 provided in the housing 12 via a main channel 30, and the main channel 30 connects the outlet hole 32 of the channel array 26 to the battery pack exhaust port 28. The channel array 26 includes a plurality of channels 34 separated by a series of ribs 36, and the ribs 36 include openings 38 to connect the exhaust port 24 of each battery cell 20 to the outlet hole 32 of the channel array 26.

[0067] For example, Figure 2 As shown in FIG. 1 , exhaust gas from battery cell 20x passes through channel 34x, through opening 38x in rib 36x, and then to outlet port 32 as shown by the directional arrows. Figure 2 As shown in FIG, the ribs 36 include openings 38 to allow the exhaust ports 24 of the individual battery cells 20 to communicate through and across the channels 34 to the outlet holes 32. The channels 34 and openings 38 may have many alternative configurations to communicate the gas from the battery cells 20 to the outlet holes 32. This system facilitates a longer gas travel path to allow the gas temperature to be reduced before the gas leaves the battery pack.

[0068] refer to Figure 3 , showing a plan view of a channel array 26 comprised of interlocking channel plates 40 that interlock with adjacent channel plates 40 and connect individual battery cells to one of a plurality of outlet apertures 32 that connect to the main channel 30 at a plurality of inlet apertures 42 along the main channel 30.

[0069] refer to Figure 4, the main channel 30 can be formed by a bottom 44 and a top 46, which are joined to each other to define the main channel 30 between them and communicate with an optional gas guide plate 48, which can direct the exhaust gas to the thermal sensor 50 in the exhaust path 52. The battery pack exhaust port 28 is set at the end of the exhaust path 52. The main channel 30 can be a circular or non-circular cross-section. The main channel 30 can be a hose with a defined wall material, or can be molded into the potting material using a tool. The tool can be a rigid reusable mold or a removable flexible inflatable bag.

[0070] refer to Figure 5 The main channel 30' can be made of a tube structure 54 that can have a circular, oval, rectangular, square or other cross-section. The tube structure includes a pair of inlet holes 42 to connect to the channel array 26.

[0071] refer to Figure 6-7 , showing a channel array 26 including a battery cell joining plate 56 and a tray plate 58 that combine to define a channel 34 therebetween. The battery cell joining plate 56 and the tray plate 58 may be formed as injection molded parts. A breakable sheet 60 may be added below the battery cell joining plate 56 to thermally shield the remaining cells during a thermal runaway event of a single cell. A sealant may be added to help hold the breakable sheet 60 in place. The breakable sheet 60 may be made of mica, phenolic resin, or another thermoelastic but brittle material that may break in response to a thermal event of the battery cell 20. The battery cell joining plate 56 includes holes 62 that communicate with the exhaust ports of each battery cell 20. One of the battery cell joining plate 56 and the tray plate 58 includes ribs 36 to define channels 34 of the channel array 26 that connect each hole 62 to the outlet hole 32. The ribs 36 may be sealed to the opposing battery cell joining plate 56 or tray plate 58 to provide a sealed channel 34. In addition, as Figure 7 As shown in FIG. 5 , scarf joints 64 are provided at the interface of adjacent battery cell joining plates 56. The gap between the scarf joints 64 is less than half the thickness of the battery cell joining plates 56 (typically less than 2-3 mm). Figure 1 As shown in FIG. 1 , the battery pack 10 is at least partially filled with a potting material 66. The scarf joint 64 prevents the potting material 66 from entering the battery channel array 26. The joint 64 can be further sealed with a sealant or tape.

[0072] The entire exhaust system is sealed so that the potting material 66 cannot enter the system during the manufacturing process. With the channel 34 sealed, the foam or non-foam potting material 66 can be filled to the extent that it contacts the upper and lower shear plates 14, 16 so that the upper-lower shear plates can be connected by the potting material 66. Once the potting is in place, the exhaust system is fully sealed to trap the gas. In another variation, each block of cells may have its own main channel or multiple main channels 30 that connect to more than one individual battery pack exhaust port 28.

[0073] refer to Figure 8 , showing the main channel 30, which includes an inlet hole 42, configured to be connected to the outlet hole 32 of the channel array 26. The main channel 30 may include a series of spark arresters 66, 68, 70, which can filter out sparks passing through the main channel. The spark arrester can be formed as a screen with holes that gradually become smaller in the direction of flow. The transition from large spark arresters to fine spark arresters provides improved particle filtration, resulting in a higher exhaust auto-ignition temperature outside the battery pack to increase the allowable temperature of the exhaust gas safely leaving the rechargeable energy storage system. The separation of the spark arrester from the battery pack exhaust port 28 can provide less restriction on the flow through the battery pack exhaust port 28, thereby providing a higher flow rate, so that it is possible to reduce the size or number of battery pack-level exhaust ports required.

[0074] refer to Fig. 9 The main channel 30 may be cooled using a cooling element, such as a cooling strip 72 facing the main channel 30 to reduce the temperature of the gas exhausted from the battery pack exhaust port 28 .

[0075] The battery pack 10 includes a closed ventilation system for conveying the gases exhausted from the battery experiencing thermal runaway and reducing its temperature. The purpose of creating such a closed system is to ensure that the potting material 66 used to encapsulate the battery cells 20 does not enter the exhaust system during the manufacturing process of the battery pack 10, and to contain and keep the hot exhaust away from the remaining battery cells 20.

[0076] The above description is only exemplary and is absolutely not intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be limited thereto, because after studying the drawings, the specification and the following claims, other modifications will become apparent. It should be understood that one or more steps in the method may be implemented in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more features described in any embodiment of the present disclosure may be implemented in any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and the mutual replacement of one or more embodiments is still within the scope of the present disclosure.

[0077] Various terms are used to describe the spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including "connected," "engaged," "coupled," "adjacent," "next to," "on top of," "on," "under," and "disposed." Unless explicitly described as "directly," when describing the relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which there are no other intervening elements between the first element and the second element, or an indirect relationship in which there are one or more intervening elements (spatially or functionally) between the first element and the second element. The phrase "at least one of A, B, and C" as used herein should be interpreted to mean a logical (A or B or C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

Claims

1. A battery pack for a vehicle, comprising: a housing including at least one pack vent between an interior and an exterior of the housing; a plurality of battery cells disposed within the housing; and A channel system comprising a channel array positioned in connection with the exhaust port on each of the plurality of battery cells, and the channel array is connected to a main channel, the main channel being connected to the at least one exhaust port of the housing, wherein the channel system is isolated from the rest of the volume of the battery pack. 2 . The battery pack for a vehicle according to claim 1 , wherein the housing contains a potting material encapsulating the channel system. 3 . The battery pack for a vehicle according to claim 1 , wherein the channel system is isolated to prevent a potting material from entering an exhaust system. 4 . The battery pack for a vehicle according to claim 1 , wherein the channel array comprises a plurality of battery cell engagement plates and a plurality of tray plates. 5 . The battery pack for a vehicle according to claim 1 , wherein the main channel comprises a plurality of main channels. 6 . The battery pack for a vehicle according to claim 1 , wherein the at least one battery pack vent comprises a plurality of battery pack vents. 7 . The battery pack for a vehicle according to claim 1 , wherein the housing comprises a plurality of sub-modules, and each sub-module comprises a channel array. 8 . The battery pack for a vehicle according to claim 1 , wherein the channel array comprises ribs defining a plurality of channels below the battery, which extend longitudinally or transversely relative to the vehicle and are connected by a series of openings in the ribs. 9 . The battery pack for a vehicle according to claim 1 , wherein the main channel is connected to the channel array along an array surface. 10 . The battery pack for a vehicle according to claim 1 , wherein the main channel extends all the way along the center of the housing to divide the housing into partitioned blocks.

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