Traction battery pack filtering system and filtering method

Abstract

The invention provides a traction battery pack filtering system and a filtering method. An apparatus may include a housing assembly providing an interior housing at least one battery array. An apparatus may include a pressure relief valve that delivers an exhaust byproduct stream from an interior of a housing assembly when the pressure relief valve is in an open position. An apparatus may include a filtration system having at least one first filter to filter the stream, the first filter having a first permeability, and at least one second filter to filter the stream, the second filter having a second permeability different from the first permeability.

Description

Technical Field

[0001] The present disclosure relates generally to electrified vehicle traction battery packs and, more particularly, to a filtration system for filtering battery exhaust byproducts. Background Art

[0002] Electrified vehicles differ from conventional motor vehicles in that they are selectively driven using one or more electric machines powered by a traction battery. The electric machines may drive the electrified vehicle in place of or in addition to an internal combustion engine. Exemplary electrified vehicles include hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), fuel cell vehicles (FCVs), and battery electric vehicles (BEVs). Summary of the invention

[0003] In some aspects, the technology described herein relates to a traction battery assembly, comprising: a housing assembly that provides an interior that houses at least one battery array; a pressure relief valve that transmits a flow of exhaust byproducts from the interior of the housing assembly when the pressure relief valve is in an open position; and a filtration system having at least one first filter that filters the flow and at least one second filter that filters the flow, the first filter having a first permeability and the second filter having a second permeability different from the first permeability.

[0004] In some aspects, the technology described herein relates to a traction battery assembly that also includes an exhaust duct configured to carry flow from a pressure relief valve.

[0005] In some aspects, the technology described herein relates to a traction battery assembly wherein an exhaust duct includes an inlet end portion that receives flow from a pressure relief valve and an outlet end portion that discharges the flow to an interior exterior of a housing assembly, a first filter is adjacent to the inlet end portion, and a second filter is adjacent to the outlet end portion.

[0006] In some aspects, the technology described herein relates to a traction battery assembly in which a first permeability of a first filter is greater than a second permeability of a second filter.

[0007] In some aspects, the technology described herein relates to a traction battery assembly in which a first filter, a second filter, and an exhaust duct are external to an interior of a housing assembly.

[0008] In some aspects, the technology described herein relates to a traction battery assembly in which a first filter and a second filter span an inner diameter of an exhaust conduit.

[0009] In some aspects, the technology described herein relates to a traction battery assembly wherein first and second filters are disposed within an interior and between at least one battery array and an exhaust port such that flow passes through the first and second filters before the flow passes through a pressure relief valve.

[0010] In some aspects, the technology described herein relates to a traction battery assembly wherein the housing assembly includes a cover and a tray, and a first filter and a second filter span between the cover and the tray.

[0011] In some aspects, the technology described herein relates to a traction battery assembly in which a first permeability of a first filter is greater than a second permeability of a second filter.

[0012] In some aspects, the technology described herein relates to a traction battery assembly wherein a pressure relief valve includes an inlet end portion that receives flow from an interior of a housing assembly and an outlet end portion that discharges the flow to an interior exterior of the housing assembly, a first filter is adjacent to the inlet end portion, and a second filter is adjacent to the inlet end portion.

[0013] In some aspects, the technology described herein relates to a traction battery assembly in which a first permeability of a first filter is greater than a second permeability of a second filter.

[0014] In some aspects, the technology described herein relates to a traction battery assembly wherein the pressure relief valve includes an inlet end portion that receives flow from an interior of a housing assembly and an outlet end portion that discharges the flow to an interior exterior of the housing assembly, with a first filter and a second filter adjacent the inlet end portion.

[0015] In some aspects, the technology described herein relates to a traction battery assembly in which a first permeability of a first filter is greater than a second permeability of a second filter.

[0016] In some aspects, the technology described herein relates to a traction battery assembly in which a first filter has a first permeability configured to block particles of a first size within a flow and a second filter has a second permeability configured to block particles of a second different size within the flow.

[0017] In some aspects, the technology described herein relates to a traction battery assembly exhaust method, comprising: passing an exhaust byproduct stream from an interior of an enclosure assembly housing at least one battery array through a filtration system that filters the stream, the filtration system having at least one first filter and at least one second filter, the at least one first filter having a first permeability and the at least one second filter having a second, different permeability.

[0018] In some aspects, the technology described herein relates to a method in which flow is filtered through a filtration system after the flow is passed through a pressure relief valve that passes the flow from an interior of a housing assembly.

[0019] In some aspects, the technology described herein relates to a method in which a flow is filtered through a filtration system before the flow is passed through a pressure relief valve that passes the flow from an interior of a housing assembly.

[0020] In some aspects, the technology described herein relates to a method wherein a pressure relief valve includes an inlet end portion that receives flow from within a housing assembly and an outlet end portion that discharges the flow to an exterior of the housing assembly, a first filter is adjacent to the inlet end portion, and a second filter is adjacent to the outlet end portion.

[0021] In some aspects, the technology described herein relates to a method wherein a pressure relief valve includes an inlet end portion that receives flow from within a housing assembly and an outlet end portion that discharges the flow to an exterior of the housing assembly, and a first filter and a second filter are disposed adjacent to the inlet end portion.

[0022] In some aspects, the technology described herein relates to a traction battery assembly in which a first filter has a first permeability configured to block particles of a first size within a flow and a second filter has a second permeability configured to block particles of a second different size within the flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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:

[0024] Figure 1 A side view of an electrified vehicle having a traction battery pack with a filtration system is shown.

[0025] Figure 2 yes Figure 1 A perspective view of the traction battery pack.

[0026] Figure 3 Shown through Figure 2 Cross-section of a traction battery pack.

[0027] Figure 4 Shown from Figure 3 A close-up view of the filtration system of the traction battery pack.

[0028] Figure 5A Is from Figure 4 Close-up view of an exemplary filter of a filtration system

[0029] Figure 5B Is from Figure 4A close-up view of another exemplary filter of a filtration system.

[0030] Figure 6 A traction battery pack according to another exemplary aspect of the present disclosure is shown.

[0031] Figure 7 Shown from Figure 6 A close-up view of the filtration system of the traction battery pack.

[0032] Figure 8 A traction battery pack according to yet another exemplary aspect of the present disclosure is shown.

[0033] Fig. 9A Shown from Figure 8 A close-up view of the filtration system of the traction battery pack.

[0034] Fig. 9B Shown from Figure 8 Close-up view of a variation of the filter system of a traction battery pack. DETAILED DESCRIPTION

[0035] The present disclosure generally relates to a filtration system for a traction battery pack. The filtration system can be used to filter a stream of exhaust byproducts (e.g., gases and / or effluent particulates) during a thermal event. In an example, the filtration system includes at least one first filter and at least one second filter, each of which is configured to filter the exhaust byproduct stream before the exhaust byproducts are discharged from the traction battery pack. The first filter can have a first permeability, and the second filter can have a second permeability different from the first permeability. These and other features are discussed in more detail in the following paragraphs of this detailed description.

[0036] refer to Figure 1 , the electrified vehicle 10 includes a traction battery pack 14, an electric motor 18, and wheels 22. The traction battery pack 14 supplies power to the electric motor 18, which converts the electricity into torque to drive the wheels 22.

[0037] The example 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 (instead of or in addition to the electric machine) to drive the wheels. In general, the electrified vehicle 10 can be any type of vehicle having a traction battery pack.

[0038] exist Figure 1 In the example of FIG. 1 , the traction battery pack 14 is secured to the underbody 26 of the electrified vehicle 10 . However, in other examples, the traction battery pack 14 may be located elsewhere on the electrified vehicle 10 .

[0039] Although specific component relationships are shown in the drawings of the present disclosure, the illustrations are not intended to limit the present disclosure. The placement and orientation of the various components of the electrified vehicle 10 are shown schematically and may be varied within the scope of the present disclosure.

[0040] refer to Figure 2 and Figure 3 The traction battery pack 14 includes one or more battery arrays 30 held within an interior area 34 provided by a housing assembly 38. The battery arrays 30 are capable of outputting electrical power to power the motor 18 and / or other electrical loads of the electrified vehicle 10 (see Figure 1 ).

[0041] The housing assembly 38 houses the battery array 30. The housing assembly 38 includes a cover 42 and a tray 46. The cover 42 can be fixed (e.g., bolted, welded, bonded, etc.) to the tray 46 to provide the interior area 34. The cover 42 and the tray 46 can be polymer-based. Alternatively, the cover 42, the tray 46, or both can be metal or metal alloys.

[0042] Each of the example battery arrays 30 includes a plurality of battery cells 50 stacked side by side.

[0043] In this example, the battery cells 50 each include a vent 54. The battery pack 14 may experience a thermal event when the pressure within one of the battery cells 50 increases due to, for example, an overcharge condition or an over discharge condition. The pressure increase may cause the vent 54 to rupture, which may release a vent byproduct stream into the interior region 34. For example, the exhaust byproducts may include gases, effluent particles, and constituent materials such as the internal components of the battery cells and the internal components of the traction battery pack.

[0044] The traction battery pack 14 is equipped with features for venting exhaust byproducts from the enclosure assembly 38 to an area external to the traction battery pack 14 .

[0045] refer to Figures 2 to 5B , the traction battery pack 14 includes at least one pressure relief valve 58. The pressure relief valve 58 is disposed in the wall 62 of the housing assembly 38. The pressure relief valve 58 may be disposed in the cover 42, the tray 46, or both. The pressure relief valve 58 may be secured to the housing assembly 38 with a twist-lock connection.

[0046] The pressure relief valve 58 is configured to transition from a closed position to an open position when the pressure within the interior region 34 increases due to exhaust from one or more battery cells 50 during a thermal event. When in the closed position, the pressure relief valve 58 blocks flow from the interior region 34. When in the open position, the pressure relief valve 58 allows the flow of exhaust byproducts to move from the interior region 34 to an area outside the traction battery pack 14.

[0047] A filter system 66 is provided for filtering the exhaust byproduct stream passing through the pressure relief valve 58. Figure 4 In the example of FIG. 5 , the filter system 66 is external to the housing assembly 38 and includes a first filter 70 and a second filter 74 disposed within an exhaust conduit 78. In other examples, the filter system 66 may include any number of filters, each having a different permeability, as discussed further below. The exhaust conduit 78 conveys the filtered exhaust byproduct stream from the pressure relief valve 58 to an area external to the housing assembly 38.

[0048] An example exhaust conduit 78 is mounted (eg, welded, bolted, etc.) to the wall 62 of the housing assembly 38. The exhaust conduit 78 may direct the flow of exhaust byproducts from the pressure relief valve 58 to a location external to the housing assembly 38.

[0049] In one example, the exhaust conduit 78 is cylindrical, and the first filter 70 and the second filter 74 span the inner diameter of the exhaust conduit 78 .

[0050] The first filter 70 is adjacent to an inlet end portion 82 of the exhaust conduit 78. The inlet end portion 82 receives the exhaust byproduct flow from the pressure relief valve 58. The first filter 70 may be a permeable sheet having a first permeability (see Figure 5A ). The gas G flow exhausted from the battery cell 50 may move through the first filter 70 to the area outside the housing assembly 38. The first filter 70 may block the flow of particles P of the first size, thereby confining the particles of the first size to the interior area 34 of the housing assembly 38.

[0051] The second filter 74 is adjacent to the outlet end portion 86 of the exhaust conduit 78. The outlet end portion 86 discharges the exhaust byproduct flow from the pressure relief valve 58 to an area outside the housing assembly 38. The second filter 74 may be a permeable sheet having a second permeability different from the first permeability of the first filter 70 (see Figure 5B ). The flow of gas G exhausted from the battery cell 50 may move through the second filter 74 to an area outside the housing assembly 38. The second filter 74 may block the flow of particles P of the second size, thereby limiting the particles of the second size to the exhaust duct 78, the interior area 34 of the housing assembly 38, or both.

[0052] The second filter 74 may also prevent ambient particles from moving from outside the housing assembly 38 into the interior area 34 during typical conditions of the battery pack 14 when no thermal events result in venting of the battery cells 50. The second filter 74 may also prevent animals, such as rodents and insects, from entering the exhaust duct 78.

[0053] The first filter 70 and the second filter 74 may also provide a heat sink for the gas G exhausted through the exhaust pipe 78. For example, the first filter 70 and the second filter 74 may be made of a high temperature resistant material including steel and a ceramic material.

[0054] In one example, the first permeability is greater than the second permeability, such that a first size of particles P blocked by the first filter 70 is greater than a second size of particles P blocked by the second filter 74 .

[0055] Throughout this disclosure, like reference numerals refer to like elements where appropriate, and reference numerals incremented by 100 or multiples thereof represent improved elements that are understood to incorporate the same features and benefits of the corresponding elements.

[0056] Figure 6 and Figure 7 Another exemplary traction battery pack 114 is shown. The traction battery pack 114 includes one or more battery arrays 130 held within an interior area 134 provided by a housing assembly 138. Each of the battery arrays 130 includes a plurality of battery cells 150 having exhaust ports 154 for exhausting exhaust byproducts. The traction battery pack 114 includes at least one pressure relief valve 158 that can be moved from a closed position to an open position after certain thermal events of the traction battery pack 114 to pass exhaust byproduct streams exhausted from the battery cells 150. The traction battery pack 114 includes a filter system 166 for filtering the exhaust byproduct stream when the pressure relief valve 158 is in an open position. In this example, the filter system 166 is configured to at least partially filter the exhaust byproduct stream before the exhaust byproduct stream passes through the pressure relief valve 158.

[0057] The filter system 166 includes a first filter 170 and a second filter 174 disposed within the interior area 134 of the housing assembly 138 and between the battery cells 150 and the pressure relief valve 158. The first filter 170 and the second filter 174 span between the lid 142 and the tray 146 of the housing assembly 138. In some examples, the first filter 170 and the second filter 174 may additionally or alternatively span between opposing side walls (not shown) of the housing assembly 138.

[0058] The first filter 170 is a permeable sheet having a first permeability that allows the gas G exhausted from the battery cell 150 to flow to the pressure relief valve 158 while blocking the flow of particles P of a first size exhausted from the battery cell 150. This confines the particles P of the first size to the interior region 134 of the housing assembly 138.

[0059] The second filter 174 is a permeable sheet having a second permeability different from the first permeability. The second permeability allows the gas G exhausted from the battery cell 150 to flow to the pressure relief valve 158, and also blocks the flow of particles P of a second size exhausted from the battery cell 150. This limits the particles P of the second size to the interior area 134 of the housing assembly 138.

[0060] In one example, the first permeability is greater than the second permeability, such that a first size of the particles P blocked by the first filter 170 is greater than a second size of the particles P blocked by the second filter 174 .

[0061] In this example, the first filter 170 and the second filter 174 are directly adjacent to each other. The first filter 170 and the second filter 174 may be attached. In other examples, the first filter 170 and the second filter 174 may be spaced apart from each other.

[0062] Figure 8 , Fig. 9A and Fig. 9B Another exemplary traction battery pack 214 is shown. The traction battery pack 214 includes one or more battery arrays 230 held within an interior area 234 provided by a housing assembly 238. Each of the battery arrays 230 includes a plurality of battery cells 250 having exhaust ports 254 for discharging exhaust byproducts. The traction battery pack 214 includes at least one pressure relief valve 258 that can be moved from a closed position to an open position to pass exhaust byproduct flow from the battery cells 250 after certain thermal events of the traction battery pack 214. The traction battery pack 214 includes a filter system 266 for filtering the exhaust byproduct flow discharged from the battery cells 250 when the pressure relief valve 258 is in the open position. In this example, the filter system 266 is configured to filter the exhaust byproduct flow from the battery cells 250 as the exhaust byproduct flow passes through the pressure relief valve 258.

[0063] The filter system 266 includes a first filter 270 and a second filter 274 disposed within the pressure relief valve 258. The first filter 270 is disposed adjacent to an inlet end portion 290 of the pressure relief valve 258, which receives a flow of exhaust byproducts from the battery cells 250. The example first filter 270 is a permeable sheet having a first permeability that allows the flow of gas G exhausted from the battery cells 250 to reach an area outside the housing assembly 238, and also blocks the flow of first-sized particles P exhausted from the battery cells 250. This limits the first-sized particles P to the interior area 234 of the housing assembly 238.

[0064] The second filter 274 is arranged adjacent to the outlet end portion 294 of the pressure relief valve 258, which discharges the exhaust byproduct flow from the pressure relief valve 58 to an area outside the housing assembly 238. The example second filter 274 is a permeable sheet having a second permeability different from the first permeability. The second permeability allows the gas G flow exhausted from the battery cell 250 to reach the area outside the housing assembly 238, and also blocks the flow of the second size particles P exhausted from the battery cell 250. This limits the second size particles P to the interior area 234 of the housing assembly 238.

[0065] exist Fig. 9B In an exemplary embodiment of the present invention, the first filter 270 and the second filter 274 are arranged adjacent to the inlet end portion 290 of the pressure relief valve 258. The first filter 270 and the second filter 274 are attached. In one example, the first permeability is greater than the second permeability, so that the first size of the particles P blocked by the first filter 270 is greater than the second size of the particles P blocked by the second filter 274.

[0066] The foregoing description is illustrative rather than 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 traction battery assembly, comprising: a housing assembly providing an interior for housing at least one battery array; a pressure relief valve that communicates a flow of exhaust byproducts from the interior of the housing assembly when the pressure relief valve is in an open position; as well as A filtration system having at least one first filter for filtering the flow and at least one second filter for filtering the flow, the first filter having a first permeability and the second filter having a second permeability different from the first permeability.

2. The traction battery assembly of claim 1 further comprising an exhaust conduit configured to convey the flow from the pressure relief valve.

3. The traction battery assembly of claim 2, wherein the exhaust duct includes an inlet end portion that receives the flow from the pressure relief valve and an outlet end portion that discharges the flow to the interior exterior of the housing assembly, the first filter is adjacent to the inlet end portion, the second filter is adjacent to the outlet end portion, and optionally, wherein the first permeability of the first filter is greater than the second permeability of the second filter.

4. The traction battery assembly of claim 2, wherein said first filter, said second filter, and said exhaust duct are external to said interior of said housing assembly.

5. The traction battery assembly of claim 2, wherein the first filter and the second filter span an inner diameter of the exhaust conduit.

6. The traction battery assembly of claim 1 , wherein the first filter and the second filter are disposed within the interior and between the at least one battery array and the exhaust port such that the flow passes through the first filter and the second filter before the flow passes through the pressure relief valve, and optionally wherein the housing assembly includes a cover and a tray and the first filter and the second filter span between the cover and the tray, or wherein the first permeability of the first filter is greater than the second permeability of the second filter.

7. The traction battery assembly of claim 1 , wherein the pressure relief valve includes an inlet end portion that receives the flow from the interior of the housing assembly and an outlet end portion that discharges the flow to the exterior of the interior of the housing assembly, the first filter is adjacent to the inlet end portion, the second filter is adjacent to the inlet end portion, and optionally, wherein the first permeability of the first filter is greater than the second permeability of the second filter.

8. The traction battery assembly of claim 1 , wherein the pressure relief valve includes an inlet end portion that receives the flow from the interior of the housing assembly and an outlet end portion that discharges the flow to the exterior of the interior of the housing assembly, the first filter and the second filter being adjacent the inlet end portion, and optionally, wherein the first permeability of the first filter is greater than the second permeability of the second filter.

9. The traction battery assembly of claim 1 , wherein the first permeability of the first filter is configured to block particles of a first size within the flow, and the second permeability of the second filter is configured to block particles of a second, different size within the flow.

10. A method for exhausting a traction battery assembly, comprising: A flow of exhaust byproducts from within a housing assembly housing at least one battery array is passed through a filtration system that filters the flow, the filtration system having at least one first filter and at least one second filter, the at least one first filter having a first permeability and the at least one second filter having a second, different permeability.

11. The method of claim 10, wherein the flow is filtered through the filtration system after the flow is passed through a pressure relief valve that passes the flow from the interior of the housing assembly.

12. The method of claim 10, wherein the flow is filtered through the filtration system before the flow is passed through a pressure relief valve that passes the flow from the interior of the housing assembly.

13. The method of claim 12, wherein the pressure relief valve includes an inlet end portion receiving the flow from within the housing assembly and an outlet end portion discharging the flow to an exterior of the housing assembly, the first filter being adjacent to the inlet end portion and the second filter being adjacent to the outlet end portion.

14. The method of claim 12, wherein the pressure relief valve includes an inlet end portion receiving the flow from within the housing assembly and an outlet end portion discharging the flow to an exterior of the housing assembly, the first filter and the second filter being disposed adjacent to the inlet end portion.

15. The traction battery assembly of claim 10, wherein the first permeability of the first filter is configured to block particles of a first size within the flow, and the second permeability of the second filter is configured to block particles of a second, different size within the flow.

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