Battery pack vent byproduct shroud assembly and thermal energy management method
By using a shield made of polymer-based materials in the battery pack to establish ventilation channels and contact areas, the problem of ventilation by-product management in the electric vehicle traction battery pack is solved, effective control of thermal events is achieved, and battery is improved Package security.
Patent Information
- Application Number
- CN202410824994.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-01
- Filing Date
- 2024-06-25
- Publication Date
- 2025-01-03
AI Technical Summary
When overcharging or increasing pressure in an electrified vehicle, the towing battery pack may result in the release of ventilation byproducts such as gas and debris, causing cascade of thermal events and the prior art is difficult to effectively manage these byproducts.
A battery pack assembly including a shield is designed, made of polymer-based material with a thickness of less than three millimeters, and a ventilation passage and contact area is established by stamping, across the battery cell stack to receive and guide ventilation byproducts , prevent heat energy transfer.
Effectively manage ventilation by-products in the battery pack, prevent thermal events from cascaded, and improve the safety and reliability of the battery pack.
Smart Images
Figure CN119253172A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to managing ventilation byproducts within a battery pack. Background Art
[0002] An electrified vehicle differs from a conventional motor vehicle in that an electrified vehicle includes a drive train having one or more electric machines. The electric machines may drive the electrified vehicle instead of or in addition to an internal combustion engine. A traction battery pack assembly may power the electric machines. The traction battery pack assembly of an electrified vehicle may include a battery cell pack. Summary of the invention
[0003] In some aspects, the technology described herein relates to a battery pack assembly comprising: a first battery cell stack; a second battery cell stack; a housing having an interior area, wherein the first battery cell stack and the second battery cell stack are contained within the interior area; and a shield spanning the first battery cell stack and the second battery cell stack within the interior area, the shield and the first battery cell stack defining a first channel for receiving ventilation byproducts from at least one battery cell within the first battery cell stack, and the shield and the second battery cell stack defining a second channel for receiving ventilation byproducts from at least one battery cell within the second battery cell stack.
[0004] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield is a polymer-based material.
[0005] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield has a thickness of less than three millimeters.
[0006] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield is a stamped shield.
[0007] In some aspects, the technology described herein relates to a battery pack assembly, wherein the first battery cell stack includes: a plurality of first battery cell vents, a plurality of terminals on a first side of the plurality of first battery cell vents, and a plurality of terminals on a second side opposite to the plurality of first battery cell vents, the shield contacts the first battery cell stack at a first position between the plurality of first battery cell vents and the plurality of terminals on the first side, and the shield contacts the first battery cell stack at a second position between the plurality of first battery cell vents and the plurality of terminals on the second side.
[0008] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield protrudes more from the plurality of terminals than the shield protrudes from the plurality of first battery cell vents.
[0009] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield defines a third channel above the plurality of terminals on the first side and a fourth channel above the plurality of terminals on the second side, wherein the first channel and the second channel are larger than the third channel and the fourth channel.
[0010] In some aspects, the technology described herein relates to a battery pack assembly wherein the shield is sandwiched between a cover of the housing and the first battery cell stack.
[0011] In some aspects, the technology described herein relates to a battery pack assembly wherein the first channel opens at an axial end of the first battery cell stack, wherein the second channel opens at an axial end of the second battery cell stack.
[0012] In some aspects, the technology described herein relates to a battery pack assembly wherein the housing includes a plurality of corrugations that protrude toward the shield.
[0013] In some aspects, the technology described herein relates to a battery pack assembly wherein each of the corrugations within the plurality of corrugations contacts a portion of the shield to provide a terminal clearance channel.
[0014] In some aspects, the technology described herein relates to a battery pack assembly wherein a cover of the housing includes a plurality of corrugations.
[0015] In some aspects, the technology described herein relates to a battery pack assembly wherein each of the corrugations within the plurality of corrugations has a triangular cross-sectional profile.
[0016] In some aspects, the technology described herein relates to a method of managing thermal energy within a battery pack, comprising: positioning a shield within an interior area of a housing, between a wall of the housing and a plurality of battery cells; and using the shield to define a channel of a plurality of vents across the plurality of battery cells, the channel being configured to receive ventilation byproducts ventilated from the plurality of battery cells.
[0017] In some aspects, the technology described herein relates to a method that also includes stamping the shield to create the channel.
[0018] In some aspects, the technology described herein relates to a method wherein the shield is a polymer-based material.
[0019] In some aspects, the technology described herein relates to a method wherein the plurality of battery cells includes: a plurality of terminals on a first side of the plurality of vents, and a plurality of terminals on a second side opposite the plurality of vents, the shield includes a contact area that contacts the plurality of battery cells at a first position between the plurality of vents and the plurality of terminals on the first side, and the shield includes an additional contact area that contacts the plurality of battery cells at a second position between the plurality of vents and the plurality of terminals on the second side.
[0020] In some aspects, the technology described herein relates to a method that also includes stamping the shield in a first direction to provide the channel, and stamping the shield in an opposite second direction to provide the contact area.
[0021] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in conjunction with one embodiment are applicable to all embodiments, unless such features are incompatible. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] 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:
[0023] Figure 1 A side view of an example electrified vehicle is shown.
[0024] Figure 2 Shown from Figure 1 An expanded perspective view of a battery pack for an electrified vehicle.
[0025] Figure 3 Shows Figure 2 Cross-sectional side view of a battery pack.
[0026] Figure 4 shows that when the stamping sheet is Figure 1 and Figure 2 The battery pack is provided with a sheet of material for the shield. DETAILED DESCRIPTION
[0027] The present disclosure details a traction battery pack assembly having a shield that spans a group of one or more battery cells. The shield is configured to contain and direct ventilation byproducts that may be ventilated from within one or more of the battery cells.
[0028] refer to Figure 1, the electrified vehicle 10 includes a traction battery pack assembly 14, an electric motor 18, and wheels 22. The traction battery pack assembly 14 provides power to the electric motor 18, which can convert the electricity into mechanical power to drive the wheels 22. The traction battery pack assembly 14 can be a relatively high voltage battery.
[0029] In an exemplary embodiment, the traction battery pack assembly 14 is secured to an underbody 26 of the electrified vehicle 10. In other examples, the traction battery pack assembly 14 may be located elsewhere on the electrified vehicle 10.
[0030] The 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 (as an alternative or supplement to an electric machine) to drive wheels. In general, the electrified vehicle 10 can be any type of vehicle having a traction battery pack.
[0031] Reference now Figures 2 to 4 , and continue to refer to Figure 1 , the traction battery pack assembly 14 includes a plurality of battery cells 30 held within a housing assembly 34. In the exemplary embodiment, the housing assembly 34 includes a housing cover 38 and a housing tray 42. The housing cover 38 is secured to the housing tray 42 to provide an interior area 44 that accommodates the plurality of battery cells 30.
[0032] A plurality of battery cells (or simply "cells") 30 are used to supply power to various components of the electrified vehicle 10. The battery cells 30 are stacked side-by-side relative to each other as part of a cell stack 46. The battery pack 14 includes four cell stacks 46 located within an interior region 44 of the housing assembly 34.
[0033] Although a specific number of battery cells 30 and battery cell stacks 46 are shown in the various figures of the present disclosure, the traction battery pack assembly 14 may include any number of battery cells 30 and battery cell stacks 46. In other words, the present disclosure is not limited to Figure 2 and Figure 3 The specific configuration of the battery cell 30 and the battery cell stack 46 is shown in FIG.
[0034] In this example, the battery cell 30 is a prismatic lithium-ion cell. However, within the scope of the present disclosure, battery cells having other geometries (cylindrical, pouch, etc.) and / or chemistries (nickel-metal hydride, lead acid, etc.) may alternatively be utilized.
[0035] At times, pressure and heat energy may increase within one or more of the battery cells 30. For example, the increase in pressure and heat energy may be due to an overcharge condition. The increase in pressure and heat energy may cause the associated battery cell 30 to rupture and release ventilation byproducts, such as gases and debris, from within the battery cell 30. The ventilation byproducts may be released from the associated battery cell 30 through the designated cell vents 50.
[0036] In this example, the battery cells 30 each include a battery cell vent 50 and a pair of terminals 54. Bus bars and other electrical connectors (not shown) may electrically connect the terminals 54 to other terminals 54 or other components as desired.
[0037] The battery cell vent 50 is disposed between a pair of terminals 54. The battery cell vent 50 may be within the housing of the battery cell 30. The vent 50 may be a membrane that yields in response to an increase in pressure, or a ruptured region through the associated battery cell 30.
[0038] Sometimes, pressure and heat energy may increase within one or more of the battery cells 30. For example, the increase in pressure and heat energy may be caused by an overcharge condition. The increase in pressure and heat energy may cause the associated battery cell 30 to rupture and release ventilation byproducts V, such as gases and debris, from within the battery cell 30.
[0039] The ventilation byproducts may be released from the associated battery cell 30 through a designated cell vent 50 within the housing of the battery cell 30. The cell vent 50 may be a membrane that yields in response to an increase in pressure, or through a ruptured area of the associated battery cell 30.
[0040] The battery package 14 includes a shield 58 that spans the cell stack 46 within the interior region 44. In some examples, the shield 58 may be referred to as a blanket.
[0041] The shield 58 and one of the battery cell stacks 46 define a first ventilation passage 62A. The shield 58 and the other of the battery cell stacks 46 define a second ventilation passage 62B. The first ventilation passage 62A may receive ventilation byproducts from at least one battery cell 30 within the associated battery cell stack 46. The second ventilation passage 62B may receive ventilation byproducts from at least one battery cell 30 within the second battery cell stack 46.
[0042] Because the example battery pack 14 includes four cell stacks 46, the example shield 58 is stamped to include four raised areas that provide four ventilation channels 62A-62D that can each receive ventilation byproducts from the battery cells 30 in one of the four cell stacks 46. The ventilation channels 62A-62D can help divide the ventilation byproducts within the interior area 44 and can prevent convective heat energy transfer from the ventilation byproducts to adjacent cell stacks 46.
[0043] The ventilation passages 62A to 62D open at the axial ends of the corresponding battery cell stacks 46. The ventilation passages 62A to 62D direct the ventilation byproducts to the outside of the interior area 44 along the axis of the battery cell stack 46. There, the ventilation byproducts can be cooled and then discharged from the housing assembly 34 without adding significant thermal energy to the unventilated battery cells 30, which can help prevent thermal events from cascading to other battery cells 30.
[0044] An example shield 58 is a polymer-based material, such as polypropylene. The thickness T of the shield 58 may be less than three millimeters.
[0045] The example shield 58 is formed from a flat sheet of material 70. The sheet of material 70 is stamped to create raised areas that provide the first ventilation channel 62A and the second ventilation channel 62B. In other examples, the raised areas are established in other ways, such as by injection molding the shield 58 with the raised areas.
[0046] In addition to the four ventilation channels 62A to 62D, the example shield 58 also includes a contact area 74 and terminal clearance channels 78A to 78E. The material sheet 70 can be stamped to form the contact area 74 and the terminal clearance channels 78A to 78E. In the example, the material sheet 70 is stamped in a first direction D1 to establish the four ventilation channels 62A to 62D, and is stamped in an opposite second direction D2 to establish the contact area 74.
[0047] Terminal clearance passages 78A-78E are mounted above terminals 54. Terminal clearance passages 78A-78E are vertically raised a first distance above battery cells 30. Ventilation passages 62A-62D are vertically raised a second distance above battery cells 30 that is greater than the first distance. Thus, ventilation passages 62A-62D are larger than terminal clearance passages 78A-78E. For purposes of this disclosure, vertical is referenced to the ground and the typical orientation of vehicle 10 during operation.
[0048] In this example, the contact area 74 is positioned between the terminal 54 of one of the cell stacks 46 and the vent 50 of the one of the cell stacks 46. In some examples, the contact area 74 is fixed to the cell stack 46. In another example, the contact area 74 rests on the cell stack 46.
[0049] In this example, the shield 58 is sandwiched between the housing cover 38 and the cell stack 46. In this example, the housing cover 38 is a metal or metal alloy. The housing cover 38 can be formed with a plurality of corrugations 78. In this example, the corrugations 78 have a triangular cross-sectional profile. The corrugations 78 protrude downward toward the shield 58 and can contact the shield 58. More specifically, the corrugations 78 each contact one of the terminal gap channels 78A to 78D. Contacting the shield 58 with the corrugations 78 can help maintain the position of the shield 58 within the interior area 44.
[0050] Features of the disclosed example shields can include insulating the cell stack from high temperature ventilation byproducts exhausted from other cell stacks and additionally insulating the battery terminals and bus bars. Another feature is a housing, here a housing cover, having corrugations to help provide structural support. The shield can prevent ventilation byproducts from exiting one of the battery cells and directly impinging on the housing wall.
[0051] The foregoing description is illustrative and non-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 battery pack assembly, comprising: a first battery cell stack; a second battery cell stack; a housing having an interior region in which the first battery cell stack and the second battery cell stack are accommodated; as well as A shield spanning the first battery cell stack and the second battery cell stack within the interior region, the shield and the first battery cell stack defining a first channel for receiving ventilation byproducts from at least one battery cell within the first battery cell stack, and the shield and the second battery cell stack defining a second channel for receiving ventilation byproducts from at least one battery cell within the second battery cell stack.
2. The battery pack assembly of claim 1, wherein the shield is a polymer-based material, and optionally, wherein the thickness of the shield is less than three millimeters.
3. The battery pack assembly of claim 1, wherein the shield is a stamped shield.
4. The battery pack assembly as claimed in claim 1, wherein the first battery cell stack comprises: a plurality of first battery cell vents, a plurality of terminals on a first side of the plurality of first battery cell vents, and a plurality of terminals on a second side opposite the plurality of first battery cell vents, the shield contacting the first battery cell stack at a first position between the plurality of first battery cell vents and the plurality of terminals on the first side, the shield contacting the first battery cell stack at a second position between the plurality of first battery cell vents and the plurality of terminals on the second side, and optionally, wherein the shield protrudes more from the plurality of terminals above the plurality of first battery cell vents than the shield protrudes from the plurality of terminals.
5. The battery pack assembly of claim 4, wherein the shield defines a third channel above the plurality of terminals on the first side and a fourth channel above the plurality of terminals on the second side, wherein the first channel and the second channel are larger than the third channel and the fourth channel.
6. The battery pack assembly of claim 1, wherein the shield is sandwiched between a cover of the housing and the first battery cell stack. 7 . The battery pack assembly of claim 1 , wherein the first passage opens at an axial end of the first battery cell stack, wherein the second passage opens at an axial end of the second battery cell stack.
8. The battery pack assembly of claim 1, wherein the housing comprises a plurality of corrugations protruding toward the shield, and optionally, wherein each of the corrugations within the plurality of corrugations contacts a portion of the shield to provide a terminal gap channel. 9 . The battery pack assembly of claim 8 , wherein the cover of the housing includes the plurality of corrugated portions. 10 . The battery pack assembly of claim 8 , wherein each of the corrugated portions within the plurality of corrugated portions has a triangular cross-sectional profile.
11. A method for managing thermal energy within a battery pack, comprising: positioning a shield within an interior region of the housing between a wall of the housing and a plurality of battery cells; as well as The shield is used to define a channel across a plurality of vents of the plurality of battery cells, the channel being configured to receive ventilation byproducts ventilated from the plurality of battery cells.
12. The method of claim 11 further comprising stamping the shield to create the channel.
13. The method of claim 11, wherein the shield is a polymer-based material.
14. The method of claim 11, wherein the plurality of battery cells comprises: A plurality of terminals on a first side of the plurality of vents, and a plurality of terminals on a second side opposite to the plurality of vents, the shield including a contact area for contacting the plurality of battery cells at a first position between the plurality of vents and the plurality of terminals on the first side, and the shield including an additional contact area for contacting the plurality of battery cells at a second position between the plurality of vents and the plurality of terminals on the second side.
15. The method of claim 14, further comprising stamping the shield in a first direction to provide the channel, and stamping the shield in an opposite second direction to provide the contact area.