Traction battery pack exhaust system for protecting coated area

Abstract

The present disclosure provides a traction battery pack exhaust system for protecting a coated region. A traction battery pack venting system includes one or more battery cells and a venting chamber adjacent the one or more battery cells. The one or more battery cells are configured to vent air to the vent chamber. The exhaust chamber has an inner wall and an outer wall. The outer wall may include an outer wall vent opening. Each of the outer wall exhaust openings is configured to receive an exhaust by-product emitted from one of the one or more battery cells. The inner wall may include inner wall inlets each configured to receive an exhaust by-product emitted from one of the one or more battery cells.

Description

Technical Field

[0001] This disclosure generally relates to a venting system for a battery pack, and more specifically to a venting system for a battery pack that protects the coated areas of the battery pack from the effects of venting byproducts. Background Technology

[0002] Electrified vehicles differ from conventional motor vehicles because they can be selectively driven by one or more electric motors powered by a traction battery pack. The electric motors propel the electrified vehicle as an alternative to or in combination with an internal combustion engine. The traction battery pack discharges while supplying power to one or more of the electric vehicle's motors and other loads. Summary of the Invention

[0003] In some respects, the technology described herein relates to a traction battery pack venting system comprising: one or more battery cells; and a venting chamber adjacent to the one or more battery cells, the one or more battery cells being configured to vent to the venting chamber, the venting chamber having an inner wall and an outer wall.

[0004] In some aspects, the technology described herein relates to an exhaust system, wherein the outer wall includes a plurality of outer wall exhaust openings, each of which is configured to receive exhaust byproducts emitted from one of the one or more battery cells, wherein the inner wall includes a plurality of inner wall inlets, each of which is configured to receive exhaust byproducts emitted from one of the one or more battery cells.

[0005] In some respects, the technology described herein relates to an exhaust system in which one or more battery cells are immersed in cooling.

[0006] In some respects, the technology described herein relates to an exhaust system, wherein one or more battery cells are cylindrical battery cells.

[0007] In some respects, the technology described herein relates to an exhaust system in which the outer wall is at least partially electrocoated.

[0008] In some aspects, the technology described herein relates to an exhaust system in which at least the outer wall is coated with metal or a coated metal alloy.

[0009] In some respects, the technology described herein relates to an exhaust system in which the exhaust chamber is sealed relative to a cell chamber surrounding the one or more battery cells, such that liquid flowing through the cell chamber as part of an immersion thermal management system is blocked from entering the exhaust chamber.

[0010] In some respects, the technology described herein relates to an exhaust system in which the inner wall is a folded sheet of material.

[0011] In some respects, the technology described herein relates to an exhaust system in which the inner wall is angled relative to the outer wall to provide a gap between the inner wall and the outer wall.

[0012] In some respects, the technology described herein relates to an exhaust system in which the inner wall has an inner wall base plate adjacent to an outer wall base plate of the outer wall, the inner wall base plate being inclined relative to the outer wall base plate to provide an air gap between the inner wall base plate and the outer wall base plate.

[0013] In some respects, the technology described herein relates to an exhaust system in which the air gap has a triangular profile.

[0014] In some respects, the technology described herein relates to an exhaust system in which the inner wall has a wavy profile.

[0015] In some respects, the technology described herein relates to an exhaust system in which an inner wall is disposed within the exhaust chamber opposite an outer wall exhaust opening, the outer wall exhaust opening receiving exhaust byproducts from one or more of the one or more battery cells, the outer wall exhaust opening being located within the outer wall.

[0016] In some respects, the technology described herein relates to an exhaust system in which exhaust byproducts are contained in the exhaust chamber via the inner wall on the bottom side, via the outer wall on the opposite horizontal side, and via the outer wall on the top side.

[0017] In some respects, the technology described herein relates to an exhaust system in which the inner wall overlaps only with the base plate of the outer wall.

[0018] In some aspects, the technology described herein relates to a traction battery pack venting system comprising: a housing assembly having a housing interior; a partition within the housing interior separating a cell chamber within the housing interior from one or more venting chambers within the housing interior; a thermal management system having a liquid configured to circulate the liquid through the cell chamber; and one or more battery cells disposed within the cell chamber, the one or more battery cells being configured to vent into the one or more venting chambers, each of the one or more venting chambers having an inner wall and an outer wall.

[0019] In some aspects, the technology described herein relates to an exhaust system, wherein the outer wall includes a plurality of outer wall exhaust openings, each of the plurality of outer wall exhaust openings being configured to receive exhaust byproducts emitted from one of the one or more battery cells, wherein the inner wall includes a plurality of inner wall inlets, each of the plurality of inner wall inlets being configured to receive exhaust byproducts emitted from one of the one or more battery cells.

[0020] In some respects, the technology described herein relates to an exhaust system in which the thermal management system circulates the liquid through the cell chamber without allowing the liquid to pass through the one or more exhaust chambers.

[0021] In some respects, the technology described herein relates to an exhaust system in which the inner wall is angled relative to the outer wall to provide a gap between the inner wall and the outer wall.

[0022] In some aspects, the technology described herein relates to an exhaust system in which at least the outer wall is coated with metal or a coated metal alloy.

[0023] Embodiments, examples, and alternatives, including any of their various aspects or respective individual features, may be adopted independently or in any combination of the foregoing paragraphs, claims, or the following description and drawings. Features described in connection with one embodiment are applicable to all embodiments unless such features are incompatible. Attached Figure Description

[0024] According to specific embodiments, the various features of the disclosed examples and advantage This will become apparent to those skilled in the art. The accompanying drawings, which detail specific embodiments, can be briefly described as follows:

[0025] Figure 1 A side view of an electrified vehicle with a battery pack is shown.

[0026] Figure 2 Showing from Figure 1 A perspective view of the battery cells in the battery pack.

[0027] Figure 3 It shows Figure 2 Another perspective view of the battery cell.

[0028] Figure 4 Exemplary embodiments of the present disclosure are shown. Figure 1 A perspective view of the battery pack of an electric vehicle.

[0029] Figure 5 It shows Figure 4 An expanded view of the battery pack.

[0030] Figure 6 It shows along Figure 4 The cross-sectional view taken by line 6-6 in the figure.

[0031] Figure 7 It shows along Figure 4 The cross-sectional view taken by line 7-7 in the figure.

[0032] Figure 8 An exemplary embodiment is shown. Figure 7 A close-up view of the area and an end view of the inner wall are shown.

[0033] Figure 8A An example of another exemplary embodiment is shown. Figure 8 The same area shows the inner wall.

[0034] Figure 9 It is shown to be foldable to provide for use Figure 4 The material sheet on the inner wall of the battery pack.

[0035] Figure 10 A cross-sectional view of a battery pack with an inner wall is shown during assembly according to another exemplary embodiment.

[0036] Figure 11 The assembly process is shown. Figure 10 A cross-sectional view. Detailed Implementation

[0037] This disclosure details an exemplary traction battery pack having a venting system. The venting system may include a venting chamber. During a thermal event, the battery cells may vent into the venting chamber, which has inner and outer walls. The inner wall prevents venting byproducts emitted from one or more battery cells from directly impacting the coatingable outer wall.

[0038] refer to Figure 1 The electrified vehicle 10 includes a battery pack 14, a motor 18, and wheels 22. The battery pack 14 supplies power to the motor 18, which converts electrical energy into mechanical power to drive the wheels 22. Therefore, the battery pack 14 is a traction battery pack.

[0039] In an exemplary embodiment, the battery pack 14 is fixed to the bottom 26 of the electric vehicle 10. In other examples, the battery pack 14 may be located elsewhere on the electric vehicle 10.

[0040] Electrified vehicle 10 is a purely electric vehicle. In other examples, electrified vehicle 10 is a hybrid electric vehicle that selectively uses torque provided by an internal combustion engine (as a replacement or supplement to the electric motor) to drive the wheels. In general, electrified vehicle 10 can be any type of vehicle with a traction battery pack.

[0041] Now for reference Figure 2 – Figure 7 The exemplary embodiment of the battery pack 14 includes a plurality of battery cells 34. In this example, the battery cells 34 are cylindrical battery cells. In particular, each of the example battery cells 34 has a jelly-rolled electrode structure housed within a casing 38. The cylindrical battery cells 34 are each arranged along a respective battery cell axis A.

[0042] The cap 42 of the casing 38 provides a positive terminal at a first axial end of each cell 34. The cap 42 rises above a ring 44, which provides a negative terminal at the first axial end of each cell 34. A venting side 46 of the casing 38 is located at the opposite second axial end of each cell 34. A venting passage 48 extends through the venting side 46. If a thermal event causes one of the cells 34 to vent, the venting passage 48 provides a path for the discharge of venting byproducts from that cell in the cell 34. The venting passage 48 may be covered, for example, by a membrane until the cell 34 begins to vent. Increased pressure within one of the cells 34 can cause the membrane to rupture, allowing venting byproducts to pass through the venting passage 48.

[0043] The busbar can be connected to terminals provided by the cap 42 and ring 44 of the cell 34 to electrically connect the cell 34 to other cells 34, to other components of the battery pack 14, or both. The busbar is omitted in the figure.

[0044] Example battery pack 14 houses battery 34 within interior 52 of housing assembly 56. In an exemplary embodiment, housing assembly 56 includes housing cover 60 and housing tray 64. Housing cover 60 is secured to housing tray 64 to provide interior 52 for housing battery 34. Housing cover 60 may be secured to housing tray 64 using, for example, mechanical fasteners (not shown).

[0045] Inside the interior 52, the battery 34 is supported on the platform 72. Support legs 76 extend downwards from the platform 72 to the base plate 80 of the housing tray 64, raising the platform 72 above the base plate 80 within the interior 52. The platform 72 divides the interior 52 into a cell chamber 84 and an exhaust chamber 88.

[0046] Example battery pack 14 uses liquid to manage the thermal energy of battery cells 34 and other components of battery pack 14. Cells 34 and other components of battery pack 14 are at least partially immersed in the liquid. Therefore, an immersion thermal management system is used to manage the thermal energy within battery pack 14.

[0047] In this example, the liquid cools the battery cell 34 and other components of the battery pack 14. In another example, the liquid may alternatively or additionally be used to heat the battery cell 34 and other components. For example, the liquid may be a dielectric coolant.

[0048] In this example, pump 92 circulates liquid through cell chamber 84. Platform 72 prevents liquid from entering vent chamber 88. Battery cell 34 is enclosed within cell chamber 84.

[0049] Within the cell chamber 84, the liquid moves above the battery cells 34 and other components, absorbing heat energy from them. The liquid then moves from the battery pack 14 to the heat exchange device 96, where the heat energy can be transferred away from the liquid.

[0050] Liquid moves from heat exchange device 96 to liquid supply device 100. Liquid is drawn from liquid supply device 100 as needed, and the liquid is circulated back to battery pack 14 by pump 92.

[0051] In this example, the battery pack 14 includes three exhaust chambers 88, one below each row of battery cells 34. Support legs 76 separate the exhaust chambers 88 from each other within the interior 52. Typically, the housing tray 64, support legs 76, and platform 72 form the perimeter of the exhaust chambers 88. In this example, the housing tray 64, support legs 76, and platform 72 provide an outer wall for each of the exhaust chambers 88.

[0052] The exhaust chamber 88 is sealed by the platform 72 relative to the cell chamber 84 inside the interior 52, so that the liquid transported through the cell chamber as part of the immersion thermal management system is prevented from entering the exhaust chamber 88.

[0053] The battery pack 14 includes a vent 104 within the housing tray 64. The support leg 76 is spaced apart from the side of the housing tray 64 having the vent 104 to provide a clearance G with that side. Figure 6 Exhaust byproducts in either of the exhaust chambers 88 may exit the housing assembly 56 through the exhaust port 104. Exhaust byproducts received in the exhaust chamber 88 may flow to the gap G through the exhaust port 104.

[0054] Platform 72 includes multiple outer wall vent openings 108. Each outer wall vent opening 108 is aligned with a vent passage 48 for each of the battery cells 34. When one of the battery cells 34 experiences a thermal event, exhaust byproducts can be discharged through the vent passage 48, through the outer wall vent opening 108, and into one of the exhaust chambers 88.

[0055] The housing assembly 56 may be a metal or metal alloy, such as steel. The housing assembly 56 may be coated, such as a coating to prevent rust. Both the outer and inner surfaces of the housing assembly 56 may be coated; in some examples, the coating is an electrophoretic coating. In some examples, the platform 72 and the legs 76 may also be coated.

[0056] To protect the coated areas from exhaust byproducts, the example battery pack 14 includes an inner wall 112 in each of the exhaust chambers 88. Each of the inner walls 112 is constructed as follows: Figure 9 The material sheet 116 shown is provided. To provide the example inner wall 112, a notch 120 is cut out in the material sheet 116. Next, along... Figure 9 The dashed lines shown indicate that the material sheet 116 bends until the inner wall 112 has... Figure 8 The shape shown. Therefore, the inner wall 112 is provided by folded sheets of material. Figure 8 An inner wall 112A according to another exemplary aspect of this disclosure is shown, wherein the material sheet 116 is bent slightly differently.

[0057] Refer again Figure 4 – Figure 8 The exhaust byproducts that have moved through the exhaust opening 108 on the outer wall move through the recess 120 in the inner wall 112, such as Figure 8 As indicated by the arrows, the notch 120 creates an internal venting opening. The internal wall 112 protects the housing tray 64 from exhaust byproducts by preventing them from directly impacting the housing tray 64. Therefore, the coated area of ​​the housing tray 64 heated by exhaust byproducts will not be heated to the same degree as if the exhaust byproducts were directly impacting the housing tray 64. If the platform 72 or the legs 76 are also coated, the internal wall 112 also protects these areas.

[0058] Due to the angle at which the inner wall 112 is inclined or bent relative to the outer wall, a large portion of the inner wall 112 is angled and spaced apart from the outer casing tray 64, legs 76, and platform 72 to create an air gap 124 within the exhaust chamber 88. The air gap 124 is located within the exhaust chamber 88 but outside the inner wall 112. The air gap 124 further isolates and reduces heat transfer to the outer casing tray 64, legs 76, and platform 72. In this example, each air gap 124 has a triangular profile.

[0059] refer to Figure 10 and Figure 11 In another exemplary embodiment, the inner wall 112A is positioned within the exhaust chamber 88A along the bottom plate 80 of the outer casing tray 64, but not adjacent to the support leg 76 or platform 72. The inner wall 112A is opposite to the outer wall exhaust opening 108.

[0060] In the example, the inner wall 112A can be a mica sheet. During assembly, such as Figure 10 As shown, the inner wall 112A can be fitted into the outer shell tray 64 before the positioning platform 72 and the support leg 76. The inner wall 112A may have an arcuate profile.

[0061] Next, platform 72 and legs 76 are positioned within housing tray 64. Inner wall 112A is sandwiched between base plate 80 and legs 76. Inner wall 112A has a small arcuate profile in each exhaust chamber 88A to provide an air gap 124A between base plate 80 and inner wall 112A in each exhaust chamber 88A. This gives inner wall 112A a wavy profile. Inner wall 112A and air gap 124A reduce heat transfer to base plate 80 and any coatings on base plate 80.

[0062] In this example, the inner wall 112A overlaps only with the bottom plate 80 of the exhaust chamber 88A. Exhaust byproducts are contained within the exhaust chamber 88A via the inner wall 112A on the bottom side, via the support leg 76 (i.e., the outer wall) on the opposite horizontal side, and via the platform (i.e., the outer wall) on the top side. For the purposes of this disclosure, bottom and top refer to the general orientation of the ground and battery pack 14 when installed within the vehicle 10.

[0063] The foregoing description is exemplary in nature and not restrictive. Variations and modifications made to the disclosed examples will become apparent to those skilled in the art, and such variations and modifications do not necessarily depart from the spirit of this disclosure. Therefore, the scope of protection accorded to this disclosure can only be determined by studying the following claims.

[0064] According to an embodiment, the thermal management system circulates the liquid through the cell chamber without allowing the liquid to pass through the one or more exhaust chambers.

Claims

1. A traction battery pack venting system, comprising: One or more battery cells; as well as An exhaust chamber is provided adjacent to one or more battery cells, the one or more battery cells being configured to exhaust gas into the exhaust chamber, the exhaust chamber having an inner wall and an outer wall.

2. The exhaust system of claim 1, wherein the outer wall includes a plurality of outer wall exhaust openings, each of the outer wall exhaust openings being configured to receive exhaust byproducts emitted from one of the one or more battery cells, wherein the inner wall includes a plurality of inner wall inlets, each of the plurality of inner wall inlets being configured to receive exhaust byproducts emitted from one of the one or more battery cells.

3. The exhaust system of claim 1, wherein the one or more battery cells are immersed in cooling, and optionally, wherein the one or more battery cells are cylindrical battery cells.

4. The exhaust system of claim 1, wherein at least the outer wall is coated with metal or coated with a metal alloy, and optionally, wherein the outer wall is at least partially electrocoated.

5. The exhaust system of claim 1, wherein the exhaust chamber is sealed relative to the cell chamber surrounding the one or more battery cells, such that liquid flowing through the cell chamber as part of the immersion thermal management system is blocked from entering the exhaust chamber.

6. The exhaust system of claim 1, wherein the inner wall is a folded sheet of material.

7. The exhaust system of claim 1, wherein the inner wall is angled relative to the outer wall to provide a gap between the inner wall and the outer wall.

8. The exhaust system of claim 1, wherein the inner wall has an inner wall base plate adjacent to an outer wall base plate of the outer wall, the inner wall base plate being inclined relative to the outer wall base plate to provide an air gap between the inner wall base plate and the outer wall base plate, and optionally, wherein the air gap has a triangular profile.

9. The exhaust system of claim 1, wherein the inner wall has a wavy profile.

10. The exhaust system of claim 1, wherein the inner wall is disposed in the exhaust chamber opposite to the outer wall exhaust opening, the outer wall exhaust opening receiving exhaust byproducts from one or more of the one or more battery cells, the outer wall exhaust opening being in the outer wall, and optionally, wherein the inner wall overlaps only with the base plate of the outer wall.

11. The exhaust system of claim 1, wherein exhaust byproducts are contained in the exhaust chamber via the inner wall on the bottom side, via the outer wall on the opposite horizontal side, and via the outer wall on the top side.

12. A traction battery pack exhaust system, comprising: A housing assembly having a housing interior; The partition inside the housing separates the cell chamber inside the housing from one or more exhaust chambers inside the housing; A liquid thermal management system is provided, the thermal management system being configured to circulate the liquid through the cell chamber; as well as One or more battery cells are disposed in the cell chamber, the one or more battery cells being configured to vent gas into the one or more exhaust chambers, each of the one or more exhaust chambers having an inner wall and an outer wall.

13. The exhaust system of claim 12, wherein the outer wall includes a plurality of outer wall exhaust openings, each of the plurality of outer wall exhaust openings being configured to receive exhaust byproducts emitted from one of the one or more battery cells, wherein the inner wall includes a plurality of inner wall inlets, each of the plurality of inner wall inlets being configured to receive exhaust byproducts emitted from one of the one or more battery cells.

14. The exhaust system of claim 12, wherein the inner wall is angled relative to the outer wall to provide a gap between the inner wall and the outer wall.

15. The exhaust system of claim 12, wherein at least the outer wall is coated with metal or coated with a metal alloy.

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