Pressure relief of vehicle battery cells

Abstract

A battery assembly of a vehicle includes a battery cell and a cell holder in which the battery cell is located. The cell holder includes a holder base and one or more holder legs extending downwardly from the holder base. A plurality of cell vent holes extend through the holder base. The plurality of cell vents are configured to release the pressure of the battery cell when a thermal event occurs.

Description

Technical Field

[0001] The present disclosure relates to vehicles, and in particular to cooling of a battery pack of a vehicle. Background Art

[0002] High capacity battery packs are used in many consumer and industrial sectors, including transportation and grid applications. High capacity battery packs are known to include multiple battery modules, allowing flexibility in configuration and adaptation to application requirements.

[0003] When placed under load, such battery packs generate heat and internal pressure. Heat can have an adverse effect on battery efficiency and / or battery life, and the buildup of internal pressure during a thermal event in the battery can lead to failure of the battery pack. Therefore, removing heat and reducing internal pressure can provide benefits to battery operation. Summary of the invention

[0004] In an exemplary embodiment, a battery assembly for a vehicle includes a battery cell and a cell holder in which the battery cell is located. The cell holder includes a holder base and one or more holder legs extending downwardly from the holder base. A plurality of cell vents extend through the holder base. The plurality of cell vents are configured to release pressure from the battery cell when a thermal event occurs.

[0005] In addition to one or more features described herein, a cell vent hole of the plurality of cell vent holes extends through a retainer leg of the one or more retainer legs.

[0006] In addition to one or more features described herein, a battery cell includes an electrode stack, a cell housing in which the electrode stack is positioned, and one or more stack supports extending from a stack base of the electrode stack.

[0007] In addition to one or more features described herein, one or more stack supports define a cell gap between the electrode stack and a case base of the cell case.

[0008] In addition to one or more features described herein, a cell vent hole of the plurality of cell vent holes is positioned between the stack support and a lateral end of the battery cell.

[0009] In addition to one or more features described herein, the battery cell has a vertical height greater than a lateral width.

[0010] In addition to one or more features described herein, the battery cell is a lithium-ion battery cell.

[0011] In addition to one or more of the features described herein, the battery cell holder also includes one or more holder side walls extending upwardly from the holder base.

[0012] In addition to one or more features described herein, one or more side cell vents are positioned in one or more retainer side walls.

[0013] In addition to one or more features described herein, the one or more battery cell vent holes are one or more of circular, oval, square, rectangular, or hexagonal.

[0014] In another exemplary embodiment, a vehicle includes a body, one or more wheels connected to the body, and a propulsion system operably connected to the one or more wheels, the propulsion system configured to propel the vehicle. The propulsion system includes at least one battery assembly. The battery assembly includes a battery cell and a cell holder in which the battery cell is positioned. The cell holder includes a holder base and one or more holder legs extending downwardly from the holder base. A plurality of cell vents extend through the holder base. The plurality of cell vents are configured to release pressure from the battery cells when a thermal event occurs.

[0015] In addition to one or more features described herein, a cell vent hole of the plurality of cell vent holes extends through a retainer leg of the one or more retainer legs.

[0016] In addition to one or more features described herein, a battery cell includes an electrode stack, a cell housing in which the electrode stack is positioned, and one or more stack supports extending from a stack base of the electrode stack.

[0017] In addition to one or more features described herein, one or more stack supports define a cell gap between the electrode stack and a case base of the cell case.

[0018] In addition to one or more features described herein, a cell vent hole of the plurality of cell vent holes is positioned between the stack support and a lateral end of the battery cell.

[0019] In addition to one or more features described herein, the battery cell has a vertical height greater than a lateral width.

[0020] In addition to one or more features described herein, the battery cell is a lithium-ion battery cell.

[0021] In addition to one or more of the features described herein, the battery cell holder also includes one or more holder side walls extending upwardly from the holder base.

[0022] In addition to one or more features described herein, one or more side cell vents are positioned in one or more retainer side walls.

[0023] In addition to one or more features described herein, the one or more battery cell vent holes are one or more of circular, oval, square, rectangular, or hexagonal.

[0024] The above features and advantages and other features and advantages of the present disclosure are apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, advantages and details appear, by way of example only, from the following detailed description, which refers to the accompanying drawings, in which:

[0026] Figure 1 is a schematic diagram of an embodiment of a vehicle;

[0027] Figure 2 is a schematic diagram of an embodiment of a battery assembly;

[0028] Figure 3 is a diagrammatic representation of an embodiment of a battery cell of a battery assembly;

[0029] Figure 4 is a diagrammatic representation of an embodiment of a battery cell in a cell holder;

[0030] Figure 5 is a diagrammatic representation of another embodiment of a battery cell in a cell holder; and

[0031] Figure 6 is a diagrammatic representation of yet another embodiment of a battery cell in a cell holder. DETAILED DESCRIPTION

[0032] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0033] According to an exemplary embodiment, a vehicle according to a non-limiting example is Figure 1 10. The vehicle 10 includes a body 12 supported on a plurality of wheels 16. In a non-limiting example, two of the plurality of wheels 16 are steerable. The body 12 partially defines a passenger compartment 20 having a seat 22 positioned behind an instrument panel 26. A steering controller 30 is disposed between the seat 22 and the instrument panel 26. The steering controller 30 is operated to control the orientation of the steerable wheels. The vehicle 10 includes an electric motor 34 connected to a transmission that provides power to one or more of the plurality of wheels 16. A rechargeable energy storage system (RESS) or battery assembly 38 provides power to the electric motor 34.

[0034] Reference now Figure 2, an embodiment of a battery assembly 38 is shown. In some embodiments, the battery assembly 38 is a lithium ion battery, but those skilled in the art will readily appreciate that other suitable types of batteries may be utilized. The battery assembly 38 includes one or more battery cells 40 disposed in a cell holder 42. In some embodiments, each battery cell 40 is located in its own cell holder 42, such as Figure 1 As shown, in other embodiments, two or more battery cells 40 may reside in a common cell holder 42 .

[0035] In some embodiments, the battery cell 40 is a "tall" prismatic can battery cell 40. In this configuration, as Figure 3 As shown, the battery cell 40 has a vertical cell height 44 that is greater than both the cell width 46 and the cell depth 48. In some embodiments, the aspect ratio of the cell height 44 to the cell width 46 is greater than 2:1. The battery cell 40 includes an electrode stack 47 disposed in a cell housing 50. The electrode stack 47 is supported in the cell housing 50 by one or more stack supports 52 extending between a stack bottom surface 54 and a housing base 56 of the cell housing 50. The stack supports 52 define a vertical offset of the stack bottom surface 54 from the housing base 56, which is referred to herein as a cell gap 58.

[0036] like Figure 4 As shown, the cell holder 42 includes a holder base 60 from which a holder sidewall 62 extends upward. In some embodiments, a holder leg 64 extends downward from the holder base 60. In the event of a thermal event such as thermal runaway of the battery cell 40, the internal gas pressure in the battery cell 40 increases, and as the internal pressure continues to increase, the battery cell 40 is at risk of failure. To reduce the internal pressure, a plurality of cell vents 66 defined as openings in the cell holder 42 are located in the holder base 60. In one configuration, as shown in FIG. Figure 4As shown, three cell vents 66 are located in the holder base 60, wherein the first cell vent 66a is located at the lateral center of the holder base 60, and two second cell vents 66b are located at or near the lateral ends 68 of the holder base 60. In some embodiments, as shown, the second cell vent 66b extends through the holder legs 64 of the cell holder 42. The use of the cell vent 66 improves the removal of high-pressure gas from the battery cell 40 to prevent the battery cell 40 from rupturing during a thermal event. Although three cell vents 66 are shown and described herein, it will be readily understood by those skilled in the art that other numbers of cell vents 66 may be used. Positioning the second cell vent 66b near the lateral end 68 can quickly direct the hot gas flow 76 out of the cell holder 42, thereby effectively and quickly limiting the internal pressure increase of the battery cell 40 during a thermal event. In some embodiments, the vent 66 includes a pressure-sensitive vent cover 78 above the vent 66 opening. When the internal pressure exceeds a predetermined threshold, the vent cap 78 opens, thereby opening the vent 66, thereby allowing the pressure to be released.

[0037] In some embodiments, the shape of the cell vent 66 is circular, but it is contemplated within the scope of the present disclosure that other cross-sectional shapes (e.g., oval, square, rectangular, hexagonal, or other shapes) of the cell vent 66 may be used. In addition, while in some embodiments, the shape and / or size of the cell vent 66 are the same, in other embodiments, the size and / or shape of the cell vent 66 of the cell holder 42 may be varied to meet the pressure relief requirements of the battery cell 40.

[0038] In another embodiment, Figure 5 As shown, the cell holder 42 may include one or more side cell vents 70 disposed in the cell holder 42, particularly in one or more of the holder side walls 62. The side cell vents 70 may be used in addition to or in place of the cell vents 66. Similar to the cell vents 66, in some embodiments, the side cell vents 70 are circular in shape, but it is contemplated within the scope of the present disclosure to use side cell vents 70 of other cross-sectional shapes, such as elliptical, square, rectangular, hexagonal, or other shapes. In addition, while in some embodiments, the shape and / or size of the side cell vents 70 are the same, in other embodiments, the size and / or shape of the side cell vents 70 of the cell holder 42 may be varied to meet the pressure relief requirements of the battery cell 40.

[0039] In yet another embodiment, Figure 6As shown, the cell holder 42 may include one or more top cell vents 72 disposed in a top plate 74 of the cell holder 42. The top cell vents 72 may be used in addition to or in place of the cell vents 66 and / or the side cell vents 70. Similar to the cell vents 66, the top cell vents 72 are circular in some embodiments, but it is contemplated within the scope of the present disclosure to use top cell vents 72 having other cross-sectional shapes (e.g., elliptical, square, rectangular, hexagonal, or other shapes). In addition, while in some embodiments, the shape and / or size of the top cell vents 72 are the same, in other embodiments, the size and / or shape of the top cell vents 72 of the cell holder 42 may be varied to meet the pressure relief requirements of the battery cell 40.

[0040] The term "one" does not indicate a limitation of quantity, but rather indicates the presence of at least one of the referenced items. Unless the context clearly indicates otherwise, the term "or" means "and / or". References to "aspects" throughout the specification mean that a particular element (e.g., a feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in the various aspects.

[0041] When an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

[0042] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0043] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from its scope. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the disclosure without departing from the basic scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A battery assembly for a vehicle, comprising: Battery cells; A cell holder, in which the battery cell is arranged, and the cell holder comprises: retainer base; one or more retainer legs extending downwardly from the retainer base; and A plurality of cell vent holes extend through the holder base, wherein the plurality of cell vent holes are configured to relieve pressure from the battery cells.

2. The battery assembly of claim 1, wherein a cell vent hole among the plurality of cell vent holes extends through a retainer leg among the one or more retainer legs.

3. The battery assembly according to claim 1, wherein the battery cell comprises: Electrode stack; A battery cell shell, wherein the electrode stack is arranged in the battery cell shell; as well as One or more stack supports extend from a stack base of the electrode stack. 4 . The battery assembly of claim 3 , wherein the one or more stack supports define a cell gap between the electrode stack and a case base of the cell case.

5. The battery assembly of claim 3, wherein a cell vent hole of the plurality of cell vent holes is disposed between a stack support and a lateral end of the battery cell.

6. The battery assembly of claim 1, wherein the battery cell has a vertical height greater than a lateral width.

7. The battery assembly according to claim 1, wherein: The battery cell is a lithium-ion battery cell.

8. The battery assembly of claim 1, wherein the cell holder further comprises one or more holder side walls extending upwardly from the holder base.

9. The battery assembly of claim 8, further comprising one or more side cell vents disposed in the one or more retainer side walls.

10. A vehicle comprising: Car body; one or more wheels connected to the vehicle body; as well as A propulsion system operably connected to the one or more wheels, the one or more wheels being configured to propel the vehicle, the propulsion system comprising at least one battery assembly according to any one of the preceding claims.

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