PRESSURE RELIEF OF A VEHICLE BATTERY CELL

Abstract

A vehicle battery assembly comprises 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 feet extending downwards from the holder base. A multitude of cell vents extends through the holder base. These vents are designed to provide pressure relief from the battery cell in the event of a thermal event.

Description

INTRODUCTION

[0001] The subject matter of the disclosure relates to vehicles and, in particular, to the cooling of vehicle battery packs.

[0002] High-capacity battery packs are used in many consumer and industrial sectors, particularly in transportation and power grids. High-capacity battery packs are known to include a variety of battery pack modules, allowing flexibility in configuration and adaptation to application requirements.

[0003] Such battery packs generate heat and internal pressure when subjected to load. Heat can adversely affect battery efficiency and / or service life, and a buildup of internal pressure during a thermal event within the battery can lead to battery pack failure. Dissipating heat and reducing internal pressure are therefore beneficial to battery operation. SUMMARY

[0004] In an exemplary embodiment, 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 feet extending downwardly from the holder base. A plurality of cell vents extend through the holder base. The plurality of cell vents are configured to provide pressure relief of the battery cell in the event of a thermal event.

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

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

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

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

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

[0010] In addition to one or more of the 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 cell support further includes one or more support side walls extending upwardly from the support base.

[0012] In addition to one or more of the features described herein, one or more side cell vents are mounted in the one or more support side walls.

[0013] In addition to one or more of the features described herein, the one or more cell vents are round, oval, square, rectangular, or hexagonal.

[0014] In another exemplary embodiment, a vehicle includes a vehicle body, one or more wheels connected to the vehicle body, and a propulsion system operatively connected to the one or more wheels to propel the vehicle. The propulsion system includes at least one battery assembly. The battery assembly includes a battery cell and a cell mount in which the battery cell is disposed. The cell mount includes a mount base and one or more mount feet extending downwardly from the mount base. A plurality of cell vents extend through the mount base. The plurality of cell vents are configured to provide pressure relief of the battery cell in the event of a thermal event.

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

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

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

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

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

[0020] In addition to one or more of the 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 cell support further includes one or more support side walls extending upwardly from the support base.

[0022] In addition to one or more of the features described herein, one or more side cell vents are mounted in the one or more support side walls.

[0023] In addition to one or more of the features described herein, the one or more cell vents are round, oval, square, rectangular, or hexagonal.

[0024] The foregoing features and advantages, as well as other features and advantages of the disclosure, will be readily apparent from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features, advantages and details are listed only as examples in the following detailed description, which refers to the drawings in which: Fig. 1 shows a schematic representation of a vehicle, Fig. 2 shows a schematic representation of a battery assembly, Fig. 3 shows a representation of an embodiment of a battery cell of a battery arrangement, Fig. 4 shows a representation of an embodiment of a battery cell in a cell holder, Fig. 5 shows a representation of another embodiment of a battery cell in a cell holder, and Fig. 6 shows a representation of a further embodiment of a battery cell in a cell holder. DETAILED DESCRIPTION

[0026] The following description is merely exemplary and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference characters designate like or corresponding parts and features.

[0027] According to an exemplary embodiment, a vehicle according to a non-limiting example is generally designated 10 in Fig. 1 marked.

[0028] The vehicle 10 includes a body 12 resting on a plurality of wheels 16. In one non-limiting example, two of the plurality of wheels 16 are steerable. The body 12 partially defines a passenger compartment 20 having seats 22 disposed behind an instrument panel 26. A steering wheel 30 is disposed between the seats 22 and the instrument panel 26. The steering wheel 30 is actuated to control the orientation of the steerable wheel or wheels. The vehicle 10 includes an electric motor 34 connected to a transmission that drives 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.

[0029] With reference now to Fig. 2, one embodiment of a battery assembly 38 is shown. In some embodiments, the battery assembly 38 is a lithium-ion battery, but it will be apparent to one skilled in the art that other suitable battery types may be used. The battery assembly 38 includes one or more battery cells 40 arranged in a cell holder 42. In some embodiments, each battery cell 40 is located in its own cell holder 42, as shown in Fig. 1, while in other embodiments two or more battery cells 40 may be located in a common cell holder 42.

[0030] In some embodiments, the battery cell 40 is a “large” prismatic can battery cell 40. In such a structure, the battery cell 40 has, as shown in Fig. 3, a vertical cell height 44 that is greater than the cell width 46 and the cell depth 48. In some embodiments, the aspect ratio of cell height 44 to cell width 46 is greater than 2:1. The battery cell 40 includes an electrode stack 47 disposed within a cell housing 50. The electrode stack 47 is supported within the cell housing 50 by one or more stack supports 52 that extend between a stack bottom surface 54 and a housing bottom 56 of the cell housing 50. The stack supports 52 form a vertical offset of the stack bottom surface 54 relative to the housing bottom 56, referred to herein as a cell gap 58.

[0031] As in Fig. 4, the cell holder 42 includes a holder base 60 from which the side walls 62 of the holder extend upwardly. In some embodiments, the holder feet 64 extend downwardly from the holder base 60. In the event of a thermal event, e.g., a thermal runaway of the battery cell 40, the internal gas pressure in the battery cell 40 increases, and if the internal pressure of the battery cell 40 continues to rise, there is a 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. As shown in Fig. 4, in one configuration, three cell vents 66 are located in the bracket base 60, with a first cell vent 66a located at the lateral center of the bracket base 60 and two second cell vents 66b located at or near the lateral ends 68 of the bracket base 60. In some embodiments, the second cell vents 66b extend through the bracket feet 64 of the cell bracket 42, as shown. The use of the cell vents 66 enhances the removal of high-pressure gases from the battery cell 40 to prevent rupture of the battery cell 40 during a thermal event. Although three cell vents 66 are shown and described herein, it will be apparent to those skilled in the art that a different number of cell vents 66 may be used.The placement of the second cell vent 66b near the lateral ends 68 quickly directs the hot gas flow 76 out of the cell support 42, thus effectively and quickly limiting the increase in internal pressure of the battery cell 40 during a thermal event. In some embodiments, the vents 66 include pressure-sensitive vent covers 78 over the vent openings 66. When the internal pressure exceeds the predetermined threshold, the vent covers 78 open, allowing the vents 66 to open and the pressure to be released.

[0032] The cell vents 66 are circular in some embodiments, but the use of cell vents 66 with other cross-sectional shapes, such as oval, square, rectangular, hexagonal, or other shapes, is contemplated within the scope of the present disclosure. While in some embodiments the cell vents 66 have an identical shape and / or size, in other embodiments the size and / or shape of the cell vents 66 of the cell support 42 can be varied to meet the pressure relief requirements of the battery cell 40.

[0033] In a different configuration, as in Fig. 5, the cell holder 42 may include one or more side cell vents 70 disposed within the cell holder 42, and more particularly, within one or more of the holder sidewalls 62. The side cell vents 70 may be used in addition to or instead of the cell vents 66. Similar to the cell vents 66, the side cell vents 70 are circular in some embodiments, but the use of side cell vents 70 with other cross-sectional shapes, such as oval, square, rectangular, hexagonal, or other shapes, is contemplated within the scope of the present disclosure. While in some embodiments the side cell vents 70 have an identical shape and / or size, 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.

[0034] In a further development, as in Fig.6, the cell support 42 may include one or more side cell vents 72 disposed in a top plate 74 of the cell support 42. The top cell vents 72 may be used in addition to or instead 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 the use of top cell vents 72 with other cross-sectional shapes, such as oval, square, rectangular, hexagonal, or other shapes, is contemplated within the scope of the present disclosure. While in some embodiments the top cell vents 72 have an identical shape and / or size, in other embodiments the size and / or shape of the top cell vents 72 of the cell support 42 may be varied to meet the pressure relief requirements of the battery cell 40.

[0035] The terms "a" and "an" do not imply a limitation of quantity, but rather the presence of at least one of the items mentioned. The term "or" means "and / or" unless the context clearly indicates otherwise. Whenever this specification refers to "an aspect," it means that a particular element (e.g., a feature, structure, step, or property) described in connection with the aspect is included in at least one of the aspects described herein and may or may not be present in other aspects. It is understood that the described elements in the various aspects may be combined in any suitable manner.

[0036] When an element such as a layer, overlay, region, or substrate is described as being "on" another element, it may be directly on top of the other element, or there may be intervening elements. In contrast, when an element is described as being "directly on" another element, no intervening elements are present.

[0037] Unless otherwise defined, 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.

[0038] While 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 equivalent elements may be substituted without departing from the scope of the disclosure. Furthermore, many changes may be made to adapt a particular situation or material to the teachings of the disclosure without departing from its essential scope. Therefore, the present disclosure is not intended to be limited to the particular embodiments disclosed, but is intended to include all embodiments falling within its scope.

Claims

[1] Battery assembly for a vehicle, comprising: a battery cell, a cell holder in which the battery cell is arranged, the cell holder comprising: a bracket base, one or more support feet extending downwards from the support base, and a plurality of cell vents extending through the support base, the plurality of cell vents configured to provide pressure relief of the battery cell. [2] The battery assembly of claim 1, wherein a cell vent of the plurality of cell vents extends through a support leg of the one or more support legs. [3] Battery assembly according to claim 1, wherein the battery cell comprises: an electrode stack, a cell housing in which the electrode stack is arranged, and one or more stack supports extending 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 housing bottom of the cell housing. [5] The battery assembly of claim 3, wherein a cell vent of the plurality of cell vents 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 of 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 support side walls. [10] Vehicle comprising: a vehicle body, one or more wheels connected to the vehicle body, and a drive system operatively connected to the one or more wheels and configured to drive the vehicle, the drive system comprising at least one battery assembly according to any one of the preceding claims.

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