HANGING LOCKING LAYER OF A TRACTION BATTERY PACK

Abstract

A traction battery pack assembly comprises an enclosure and a battery bank within an interior space of the enclosure. The battery bank contains a plurality of battery cells. The assembly further includes a hanging barrier within the interior space of the enclosure. The hanging barrier includes a mounting flange extending transversely from a hanging section.

Description

AREA OF TECHNOLOGY

[0001] This disclosure generally relates to barrier layers for a traction battery pack and in particular to barrier layers that are suspended and may include a foam cushion. GENERAL STATE OF THE ART

[0002] A traction battery pack of an electric vehicle can contain groups of battery cells arranged in one or more cell stacks. The traction battery pack includes a variety of battery cells and various other internal battery components that support the electric vehicle's propulsion system. During a thermal event, battery cells may vent. SUMMARY

[0003] In some aspects, the techniques described herein relate to a traction battery pack assembly comprising: an enclosure; a battery bank within an interior of the enclosure, the battery bank comprising a plurality of battery cells; and a hanging barrier within the interior of the enclosure, the hanging barrier comprising a mounting flange extending transversely from a hanging section.

[0004] In some aspects, the techniques described herein relate to an assembly in which the mounting flange is secured to an upward-facing surface of the battery bank.

[0005] In some aspects, the techniques described herein relate to an assembly which further includes at least one slide-in fastening element that secures the mounting flange to the upward-facing surface of the battery bank.

[0006] In some aspects, the techniques described herein relate to an assembly in which the suspended barrier layer within the interior is secured solely by the mounting flange.

[0007] In some aspects, the techniques described herein relate to an assembly in which the hanging section is spaced apart from the battery bank.

[0008] In some aspects, the techniques described herein relate to an assembly in which the hanging section is horizontally spaced from the battery bank.

[0009] In some aspects, the techniques described herein relate to an assembly in which the hanging section is spaced apart from an end plate of the battery bank.

[0010] In some aspects, the techniques described herein relate to an assembly wherein the hanging section is arranged between a side wall of the enclosure and an end plate of the battery bank, wherein the hanging section is spaced from both the side wall and the end plate.

[0011] In some aspects, the techniques described herein relate to an assembly in which the hanging section extends vertically from a vertically upper edge of the end plate to a vertically lower edge of the end plate.

[0012] In some aspects, the techniques described herein relate to an assembly, with the hanging section including a shielding layer and a foam pad.

[0013] In some aspects, the techniques described herein relate to an assembly, where the shielding layer and the mounting flange are sections of a material web.

[0014] In some aspects, the techniques described herein relate to an assembly, where the material web is a mica material web.

[0015] In some aspects, the techniques described herein relate to an assembly where the material web has an L-shape.

[0016] In some aspects, the techniques described herein relate to an assembly in which the mounting flange extends horizontally and the shielding layer extends vertically.

[0017] In some aspects, the techniques described herein relate to an assembly, where the foam padding includes an expanding foam.

[0018] In some aspects, the techniques described herein relate to an assembly in which the foam padding contains a variety of endothermic fillers.

[0019] In some aspects, the techniques described herein relate to an assembly in which the foam padding is glued to the shielding layer.

[0020] In some aspects, the techniques described herein relate to an assembly in which the foam padding is arranged between the shielding layer and an end plate of the battery bank.

[0021] In some aspects, the techniques described herein relate to an assembly, wherein the battery bank is a first battery bank, and further comprising a plurality of second battery banks within the enclosure, each of the plurality of second battery banks comprising at least one hanging barrier layer.

[0022] In some aspects, the techniques described herein relate to an assembly, where the hanging barrier layer is a hanging thermal barrier.

[0023] The embodiments, examples, and alternatives described in the preceding paragraphs, the claims, or the following description and drawings, which may include any of their various aspects or individual features, can be considered independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, provided such features are not incompatible. BRIEF DESCRIPTION OF THE FIGURES

[0024] The various features and advantages of the disclosed examples will be apparent to the person skilled in the art from the detailed description. The figures accompanying the detailed description can be briefly described as follows: Fig. Figure 1 illustrates a side view of an electrified vehicle. Fig. Figure 2 illustrates a split view of a traction battery pack from the electrified vehicle. Fig. 1 according to an exemplary embodiment of the present disclosure. Fig. Figure 3 illustrates a perspective close-up view of a hanging barrier layer positioned within the battery pack. Fig. 2 moves. Fig. Figure 4 illustrates a side view of the hanging barrier layer made of Fig. 3 in an installation position in which the hanging barrier layer hangs from a battery bank of the traction battery pack. DETAILED DESCRIPTION

[0025] This disclosure describes in detail exemplary barrier layers used within a traction battery pack. In particular, the disclosure describes suspended barrier layers that may include a foam pad.

[0026] With reference to Fig. 1 includes an electrified vehicle 10, a battery pack 14, an electric machine 18, and wheels 22. The battery pack 14 supplies the electric machine 18 with power, which can convert electrical power into mechanical power to drive the wheels 22.

[0027] In the exemplary embodiment, the battery pack 14 is attached to an underbody 26 of the electrified vehicle 10. In other examples, the battery pack 14 could be located elsewhere on the electrified vehicle 10.

[0028] The electrified vehicle 10 is a fully electric vehicle. In other examples, the electrified vehicle 10 is a hybrid electric vehicle that selectively drives wheels using torque provided by an internal combustion engine instead of, or in addition to, an electric motor. Generally, the electrified vehicle 10 could be any type of vehicle that incorporates a battery pack.

[0029] With reference to Fig. 2, Fig. 3 to Fig.In the exemplary embodiment, the battery pack 14 comprises a plurality of battery banks 30, which are held within a battery pack enclosure 34. The enclosure 34 includes an enclosure cover 38 and an enclosure shell 42. The enclosure cover 38 is secured to the enclosure shell 42 to provide an interior 44 that accommodates the battery banks 30. The enclosure cover 38 can be secured to the enclosure shell 42, for example, by mechanical fasteners.

[0030] Each of the battery banks 30 contains a multitude of battery cells 50 (or simply "cells") which are arranged in relation to each other along a respective cell stack axis A A stacked side by side and inserted between end plates 52.

[0031] The battery cells 50 store electrical power and supply it. Although the various figures of this revelation illustrate a specific number of battery banks 30 and cells 50, the battery pack 14 could contain any number of battery banks 30, each containing any number of individual cells 50.

[0032] In one embodiment, the battery cells are 50 lithium-ion pouch cells. Alternatively, however, battery cells having other geometries (cylindrical, prismatic, etc.), other chemical compositions (nickel-metal hydride, lead-acid, etc.), or both, could be used within the scope of this disclosure.

[0033] From time to time, pressure and thermal energy within one or more of the battery cells 50 in the battery pack 14 may increase. This can cause the battery cells 50 to expel venting byproducts, which may contain gas and dirt.

[0034] The venting by-products can be expelled from the associated battery cell 50 through a defined vent opening 54 within the casing of the battery cell 50, such as a membrane that yields in response to increased pressure, or through a torn area of ​​the associated battery cell 50.

[0035] In this example, each of the battery banks 30 includes a thermal shield 56 positioned on top of the battery cells 50. The thermal shield 56 can be a mica thermal shield. The thermal shield 56 can include shield vents 58 that allow venting byproducts expelled through the vents 54 of one or more of the battery cells 50 to move vertically upwards through the thermal shield into the interior 44. The shield vents 58 can include a screen or a membrane.

[0036] Among other things, the thermal shielding 56 prevents venting byproducts that have moved through the shielding vents 58 in the thermal shields 56 from flowing directly adjacent to the non-venting battery cells 50. This could increase the thermal energy levels in the non-venting battery cells 50 and potentially cause these battery cells 50 to vent.

[0037] A hanging barrier layer 62 is arranged at the axial ends of each battery bank 30. The hanging barrier layers 62 can shield areas of the interior 44 from the venting byproducts released by the battery cells 50. Some of the exemplary hanging barrier layers 62A are positioned between end plates 52 of the battery banks 30 and a side wall 66 of the casing shell 42. These hanging barrier layers 62A can, for example, help to prevent particles within the venting byproducts from impacting the side wall 66. Other hanging barrier layers 62B are arranged near the center of the battery pack between one of the end plates 52 and another hanging barrier layer 62B.

[0038] The thermal shields 56 and the hanging barrier layers 62 can shield certain areas within the interior 44 from the venting byproducts. The venting byproducts can then be discharged from the interior 44 through a casing vent 68 into an area surrounding the battery pack 14.

[0039] The suspended barrier layers 62 each include a mounting flange 70 extending transversely from a suspended section 74. In the exemplary embodiment, the mounting flange 70 extends horizontally, and the suspended section 74 extends vertically downwards from the mounting flange 70. Horizontal and vertical, as used in this disclosure, refer to a general orientation of the battery pack 14 on the ground when it is installed in the vehicle 10.

[0040] The suspended barrier layer 62 is considered a suspended barrier layer because the suspended barrier layer 62 is configured to be suspended by the mounting flange 70 on an associated battery bank 30 without being attached or supported elsewhere.

[0041] In this example, the suspended barrier layers 62 are supported exclusively by the mounting flange 70 and a connection of the mounting flange 70 to an upward-facing surface 78 of the associated bench, which in this example is provided by one of the heat shields 56. The mounting flange 70 can be connected to the upward-facing surface 78 using at least one insert fastener 82, such as a plurality of insert rivets.

[0042] The hanging section 74 can extend vertically from a vertically upper edge of the end plate to a vertically lower edge of the end plate. In this example, the hanging section 74 of the hanging barrier layer includes a shielding layer 86 and a foam pad 90.

[0043] The mounting flange 70 and the shielding layer 86 of the hanging section 74 are distinct areas of the same L-shaped material web. The material web can be relatively rigid, allowing the mounting flange 70 to support the shielding layer 86 and the foam pad 90 attached to the shielding layer 86. The material web providing the mounting flange 70 and the shielding layer 86 can be a mica material web.

[0044] The exemplary mounting flange 70 is shown as a lip. Other types of mounting flanges could be used in other examples. For instance, the mounting flange 70 could comprise a multitude of individual tabs extending horizontally from the hanging section 74.

[0045] The foam pad 90 can be glued to the shielding layer 86. The shielding layer 86 holds the foam pad 90 in a position that is spaced outwards by a distance D from the end plate 52 of the battery bank 30.

[0046] The foam pad 90 can contain an intumescent foam that expands in response to thermal energy levels reaching a threshold, which may be associated with a venting event. The expansion of the foam pad 90 during the thermal event can help to fill gaps and other areas within the interior 44 and shield areas of the interior 44 from the venting byproducts V.

[0047] The foam padding 90 can contain a variety of endothermic fillers, either instead of or in addition to the foam padding. During a thermal event, these endothermic fillers can help suppress the thermal event by absorbing thermal energy.

[0048] During the assembly of the battery pack 14, spacing the foam pad 90 by the distance D from the end plate facilitates the positioning of the hanging barrier layer 62 within the interior 44.

[0049] In particular, during assembly, the battery banks 30 can first be positioned within the interior 44 of the enclosure shell 42. A fitter can then move the suspended barrier layer 62 vertically downwards from top to bottom towards its installation position. The gap D, which can be, for example, 6 mm or more, provides clearance for inserting the shielding layer 86 and the foam padding 90. Since the suspended barrier layer 62 is secured solely by the mounting flange 70, which is accessible from above the battery banks 30, there is no need for the fitter to access areas further inside the enclosure shell 42 between the end plate 52 and the side wall 66, which can be relatively difficult to reach.

[0050] After the hanging barrier layer 62 is vertically positioned, the insertion fasteners 82 are used to attach the mounting flange 70 and secure the hanging barrier layer 62. In the secured state, the foam pad 90 maintains the distance D from the end plate of the associated battery bank 30 due to the relatively rigid mounting flange 70 and the shielding layer 86.

[0051] After assembly, maintaining the distance D after assembly can help reduce the likelihood of vibration problems associated with the contact between the foam pad 90 and the end plate 52.

[0052] The preceding description is exemplary and not limiting. Variations and modifications of the disclosed examples may be apparent to a person skilled in the art, which do not necessarily deviate from the core of this disclosure. Therefore, the scope of protection granted by this disclosure can only be determined by reading the following patent claims.

Claims

[1] Traction battery pack assembly comprising: a covering; a battery bank within an interior space of the casing, wherein the battery bank comprises a plurality of battery cells; and a hanging barrier layer within the interior of the enclosure, wherein the hanging barrier layer includes a mounting flange extending transversely from a hanging section. [2] Assembly according to claim 1, wherein the mounting flange is secured to an upward-facing surface of the battery bank, and optionally further comprising at least one insertion mounting element that secures the mounting flange to the upward-facing surface of the battery bank. [3] Assembly according to claim 2, wherein the suspended barrier layer within the interior is secured exclusively by the mounting flange. [4] Assembly according to claim 1, wherein the hanging section is spaced apart from the battery bank. [5] Assembly according to claim 1, wherein the hanging section is horizontally spaced from the battery bank and wherein the hanging section is optionally spaced from an end plate of the battery bank. [6] Assembly according to claim 1, wherein the hanging section is arranged between a side wall of the casing and an end plate of the battery bank, wherein the hanging section is spaced apart from both the side wall and the end plate and wherein the hanging section optionally extends vertically from a vertically upper edge of the end plate to a vertically lower edge of the end plate. [7] Assembly according to claim 1, wherein the hanging section comprises a shielding layer and a foam pad and wherein the shielding layer and the mounting flange are optionally sections of a material web. [8] Assembly according to claim 7, wherein the material web is a mica material web. [9] Assembly according to claim 7, wherein the material web has an L-shape. [10] Assembly according to claim 7, wherein the mounting flange extends horizontally and the shielding layer extends vertically. [11] Assembly according to claim 7, wherein the foam pad comprises a foam-forming foam, a plurality of endothermic fillers or both. [12] Assembly according to claim 7, wherein the foam padding is glued to the shielding layer. [13] Assembly according to claim 7, wherein the foam padding is arranged between the shielding layer and an end plate of the battery bank. [14] Assembly according to claim 1, wherein the battery bank is a first battery bank, and further comprising a plurality of second battery banks within the casing, each of the plurality of second battery banks comprising at least one hanging barrier layer. [15] Assembly according to claim 1, wherein the hanging barrier layer is a hanging thermal barrier.

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