Tamper-proof water access connection for a vehicle's rechargeable energy storage system

Abstract

A vehicle battery assembly comprises one or more battery cells, a battery housing in which the one or more battery cells are positioned, and a fire suppression line extending from the battery housing and designed to deliver a flow of fire suppression medium to the one or more battery cells. An activation element is designed to block the fire suppression line and activate it when pressure exceeding a preselected threshold pressure is applied to the activation element, thereby allowing a flow of fire suppression medium to enter the battery housing.

Description

INTRODUCTION

[0001] The present disclosure relates to vehicles and vehicles having high capacity battery assemblies.

[0002] High-capacity battery assemblies are widely used in many consumer and industrial sectors, including transportation and power grid applications. High-capacity battery packs are known to incorporate a variety of battery assembly modules, allowing flexibility in configuration and adaptation to application requirements. Such battery assemblies generate heat and internal pressure when placed under load. Heat can adversely affect battery efficiency and / or service life, and an increase in internal temperature and pressure can lead to battery assembly failure.

[0003] When a thermal event occurs that exceeds the design conditions, it is desirable to direct a fire extinguishing agent, such as water, onto the battery assembly. However, since the battery assembly is typically embedded inside the vehicle structure, it is difficult to direct the water directly onto the battery assembly. One solution is to provide a line open to the exterior of the vehicle through which the water can be directed directly to the battery assembly. However, such lines can be subject to tampering, allowing liquids or other foreign matter to be directed through the line into the battery assembly. SUMMARY

[0004] In an exemplary embodiment, a battery assembly of a vehicle includes one or more battery cells, a battery housing in which the one or more battery cells are positioned, and an extinguishing agent conduit extending from the battery housing and configured to deliver an extinguishing agent flow to the one or more battery cells. An activation element is configured to block and activate the extinguishing agent conduit when a pressure exceeding a preselected threshold pressure is applied to the activation element, thereby allowing an extinguishing agent flow into the battery housing.

[0005] In addition to one or more of the features described herein, a conduit connector is attached to the battery housing, and the extinguishing agent conduit is operatively connected thereto. The activation element is positioned inside the conduit connector.

[0006] In addition to one or more of the features described herein, the activation element is secured in the conduit connector by one of welding, soldering, crimping, or sealing.

[0007] In addition to one or more of the features described herein, the activation element is designed to be activated at a pressure of 50 psi or greater.

[0008] In addition to one or more of the features described herein, the thrust washer is designed to be activated at a temperature greater than 1200 degrees Celsius.

[0009] In addition to one or more of the features described herein, the activation element includes one or more localized thickness reductions to enable activation at the preselected threshold pressure.

[0010] In addition to one or more of the features described here, the activation element is made of a metallic material.

[0011] In addition to one or more of the features described herein, the extinguishing agent line extends from the battery enclosure to a flood opening located on the exterior of the vehicle.

[0012] In another exemplary embodiment, a vehicle includes a vehicle body defining a passenger compartment and a battery assembly located on the vehicle body. The battery assembly includes one or more battery cells, a battery enclosure in which the one or more battery cells are disposed, and an extinguishing agent conduit extending from the battery enclosure and configured to deliver an extinguishing agent flow to the one or more battery cells. An activation element is configured to block the extinguishing agent conduit and be activated when a pressure exceeding a preselected threshold pressure is applied to the activation element, thereby allowing the extinguishing agent flow to flow into the battery enclosure.

[0013] In addition to one or more of the features described herein, a conduit connector is attached to the battery housing, and the extinguishing agent conduit is operatively connected thereto. The activation element is positioned inside the conduit connector.

[0014] In addition to one or more of the features described herein, the activation element is secured in the conduit connector by one of welding, soldering, crimping, or sealing.

[0015] In addition to one or more of the features described herein, the activation element is designed to be activated at a pressure of 50 psi or greater.

[0016] In addition to one or more of the features described herein, the activation element is designed to be activated at a temperature greater than 1200 degrees Celsius.

[0017] In addition to one or more of the features described herein, the activation element includes one or more localized thickness reductions to enable activation at the preselected threshold pressure.

[0018] In addition to one or more of the features described here, the activation element is made of a metallic material.

[0019] In addition to one or more of the features described herein, the extinguishing agent line extends from the battery enclosure to a flood opening positioned on an exterior of the vehicle.

[0020] In a further exemplary embodiment, a method comprises positioning an activation element between an extinguishing agent line and a battery arrangement of a vehicle, directing an extinguishing agent flow along the extinguishing agent line in the direction of the battery arrangement, activating the activation element via the extinguishing agent pressure on the activation element and introducing the extinguishing agent into the battery arrangement.

[0021] In addition to one or more of the features described herein, the activation element is designed to be activated at a pressure of 50 psi or greater.

[0022] In addition to one or more of the features described herein, a conduit connector is attached to the battery assembly, and the extinguishing agent conduit is operatively connected thereto. The activation element is positioned inside the conduit connector, and the activation element is secured within the conduit connector by one of welding, soldering, crimping, or sealing.

[0023] In addition to one or more of the features described herein, the extinguishing agent flow along the extinguishing agent line is directed via a flood opening on the exterior of the vehicle.

[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 when 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. Figure 1 is a schematic representation of an embodiment of a vehicle; Fig. Figure 2 is a schematic representation of an embodiment of a battery assembly; Fig. 3 is a schematic representation of an embodiment of an extinguishing agent line connection to a housing of a battery arrangement; Fig. 4 is a schematic representation of a further embodiment of an extinguishing agent line connection to a housing of a battery arrangement; Fig. 5 is a perspective view of an embodiment of a thrust washer; and Fig. 6 is a schematic representation of a method of assembling a battery assembly. 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. The vehicle 10 includes a body 12 supported on a plurality of wheels 16. By way of 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 controller 30 is disposed between the seats 22 and the instrument panel 26. The steering controller 30 is actuated to control the orientation of the steerable wheel(s). 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.

[0028] With reference now to Fig. 2, the battery assembly 38 comprises a plurality of battery cells 40 arranged in a battery housing 42. An extinguishing agent line (44) is fluidly connected to the battery assembly (38) via a line opening (46) in the battery housing (42). In some embodiments, the extinguishing agent line 44 is a tubular element made of, for example, a plastic or rubber material. Referring again to Fig. 1, the extinguishing agent line 44 extends from the battery assembly 38 at a first line end 48 to an outer location of the body 12 and terminates at a flood opening 50 at the outer location of the body 12 at a second line end 52. In some embodiments, the flood opening 50 is located at a rear portion of the body 12, for example, at a rear bumper cover 54 of the body 12. In some embodiments, a movable or removable opening cover 56 is installed over the flood opening 50.

[0029] With further reference to Fig. 2, the extinguishing agent line 44 provides access to the battery assembly 38 from outside the vehicle 10 to inject a fire extinguishing agent, such as water or the like, directly into the battery assembly 38 in the event of a thermal runaway event that exceeds design conditions. However, an open line from the exterior of the body 12 to the battery assembly 38 may allow the extinguishing agent line 44, and thus the battery assembly 38, to be tampered with and may also prevent the battery assembly 38 from being sealed within the battery housing 42.

[0030] With reference now to Fig. 3, illustrates the connection of the extinguishing agent line 44 to the battery housing 42 at the line opening 46. This connection is made via a line connector 58. The line connector 58, in some embodiments, is a flared nipple that is attached to the battery housing 42 at the line opening 46, for example, by welding, soldering, crimping, or the like. A line sleeve 60 is installed over the line connector 58 and, in some embodiments, is a tubular member having a first sleeve portion 62 attached to the line connector 58. In some embodiments, a sealant is used to seal the connection of the first connector portion 62 to the line connector 58.The extinguishing agent line 44 is installed on a second sleeve portion 64 of the line sleeve 60 and fastened thereto, for example, by a plurality of barbs 66 that extend radially inward from the second sleeve portion 64 and engage an outer conduit surface 68 of the extinguishing agent line 44. This connection of the extinguishing agent line 44 to the second sleeve portion 64 is only exemplary, however, and one skilled in the art will readily recognize that the extinguishing agent line 44 may be fastened to the line sleeve 60 by other means, such as clamps or the like. Further, while in the embodiment of . Fig. 3 the extinguishing agent line 44 is installed in an inner sleeve surface 70 of the second sleeve section 64, in other embodiments the extinguishing agent line 44 is installed on an outer side of the second sleeve section 64 on an outer sleeve surface 72.

[0031] To prevent tampering with the battery assembly 38 and to seal the battery housing 42, an activating element 74, such as a disk or the like, is installed inside the cable sleeve 60, for example, on an inside of the cable connector 58, as shown in Fig. 3, or alternately at an input 71 of the line connector 58 or at another location, as in Fig. 4, or within the second sleeve portion 64. The activation element 74 is actuated based on one or more of a pressure exceeding a pressure threshold or a temperature exceeding a temperature threshold. The activation element 74 may be made of, for example, a metallic or non-metallic material, and in some embodiments is made of an aluminum material. The activation element 74 may be attached to the interior of the conduit connector 58 or the conduit sleeve 60, for example, by soldering, welding, crimping, caulking, or the like, and provides a pressure barrier for sealing the interior space 41 of the battery housing 42.The activation element 74 may be sized so that the thermal inertia of the activation element 74 does not decrease to the point of causing rupture during a design thermal event, but under extreme failure modes where access for first responders is required, it would open.

[0032] In some embodiments, the activation element 74 includes one or more features that enable rupture of the activation element 74 when pressure within a preselected pressure range is applied to the activation element 74. In some embodiments, the activation element 74 is constructed from an aluminum material, while in other embodiments, the activation element 74 may be constructed from other metal or plastic materials designed to provide the required fracture characteristics while withstanding the temperatures and pressures associated with a design-related thermal runaway event. Further, alternatively to soldering or welding the rupture disk 74 into position within the conduit fitting 58 or conduit sleeve 60, a sealant or rubber gasket may be used to secure the activation element 74 in position.

[0033] With reference now to Fig. 5, as mentioned above, the activation element disk 74 includes one or more features that enable the activation element 74 to rupture at the preselected pressure. In the illustrated embodiment, the activation element 74 includes one or more grooves 78 or other areas of localized reduced thickness in the activation element 74 to enable activation at the preselected pressure. In other embodiments, the activation element 74 as a whole has a material thickness such that the activation element 74, for example, ruptures, folds over, collapses, or the like, at the preselected pressure. The preselected pressure is greater than the pressure of a design-related thermal runaway event and also greater than a standard pressure test to which the battery assembly 38 is subjected during assembly and testing of the battery assembly 38.The preselected pressure is selected to correspond to the water pressure of a standard fire hose that uses the extinguishing agent line 44 accessible through the flood opening 50 to direct a flow of extinguishing agent, such as water, into the battery assembly 38.

[0034] A typical thermal runaway event might exhibit a pressure of approximately 6.52 psi gauge (21.03 absolute) or higher during the event, or alternatively, an overpressure increase of 2 psi or greater during a thermal runaway event. The activation element 74 is designed to activate at a pressure much greater than such an event pressure. The fire hose would discharge water at a preselected pressure significantly higher than the pressure during the thermal runaway event. In some embodiments, the preselected pressure is in the range of approximately 50-200 psi, and in some embodiments, the preselected pressure is 100 psi or higher, allowing the flow of water to be directed into the battery assembly 38.Furthermore, the thrust washer 74 may be designed to fracture or melt during an exceptional thermal event when temperatures exceed those of a design thermal runaway, which is in the range of approximately 500-1200 degrees Celsius. This temperature failure threshold, in some embodiments, is based on one or more absolute maximum temperatures to which the thrust washer 74 is exposed, or alternatively, may be based on a dynamic temperature over time.

[0035] With reference now to Fig.6 illustrates a method for assembling a battery assembly 38. In step 100, the thrust washer 74 is secured within the conduit connector 58, for example, by welding or soldering. In one embodiment, the attachment of the thrust washer 74 is achieved by furnace brazing. In step 102, the conduit connector 58 is installed on the battery housing 42 and secured to the battery housing 42, in particular to the conduit opening 46, for example, by a welding or soldering process. In some embodiments, a sealant is installed at the junction between the conduit connector 58 and the conduit opening 46. The assembly is now a sealed pressure vessel and can be pressure and / or leak tested in step 104. In step 106, the extinguishing agent line 44 is installed on the conduit connector 58 and secured thereto, for example, via the conduit sleeve 60.

[0036] The use of the thrust washer 74 in the line connector 58 prevents the battery assembly 38 from being tampered with via the fire suppression line 44, but allows for activation or rupture, for example, if a first responder uses a fire hose to direct a stream of water through the fire suppression line 44 onto the battery assembly 38. The thrust washer 74 will only rupture at a pressure far exceeding that of a design-related thermal runaway event and / or at a temperature far exceeding that of a design-related thermal runaway event. Furthermore, the installation and sealing of the thrust washer 74 in the line connector 68 helps facilitate leak testing of the battery assembly 38.

[0037] The terms "a / an" do not imply a quantity limitation, but denote the presence of at least one of the referenced subject matter. The term "or" means "and / or" unless the context clearly indicates otherwise. References throughout this specification to "an aspect" mean that a particular element (e.g., a feature, structure, step, or property) described in connection with that aspect is included in at least one of the aspects described herein and may or may not be present in other aspects. Furthermore, it is understood that the described elements in the various aspects may be combined in any suitable manner.

[0038] When an element, such as a layer, film, 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. Conversely, when an element is described as being "directly on" another element, there are no intervening elements.

[0039] 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.

[0040] 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 its scope. 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] A battery assembly of a vehicle, comprising: one or more battery cells; a battery housing in which the one or more battery cells are arranged; an extinguishing agent line extending from the battery housing and configured to deliver an extinguishing agent flow to the one or more battery cells; and an activating element configured to block the extinguishing agent line and to be activated when a pressure exceeding a preselected threshold pressure is applied to the activating element, thereby allowing the extinguishing agent stream to flow into the battery enclosure. [2] The battery assembly of claim 1, further comprising a conduit connector secured to the battery housing and operatively connected to the extinguishing agent conduit; wherein the activation element is disposed inside the conduit connector. [3] The battery assembly of claim 2, wherein the activation element is secured in the lead connector by one of welding, soldering, crimping, or sealing. [4] The battery assembly of claim 1, wherein the activation element is configured to be activated at a pressure of 50 psi or greater. [5] The battery assembly of claim 1, wherein the thrust washer is configured to be activated at a temperature greater than 1200 degrees Celsius. [6] The battery assembly of claim 1, wherein the activation element includes one or more localized thickness reductions to enable activation at the preselected threshold pressure. [7] Battery assembly according to claim 1, wherein the activation element is made of a metallic material. [8] Battery assembly according to claim 1, wherein the extinguishing agent line extends from the battery housing to a flood opening arranged on the outside of the vehicle. [9] Vehicle comprising: a vehicle body defining a passenger compartment; and a battery assembly according to any one of claims 1-8, arranged on the vehicle body. [10] Method comprising: Positioning an activation element between an extinguishing agent line and a battery assembly of a vehicle; Directing a flow of extinguishing agent along the extinguishing agent line towards the battery arrangement; Activating the activation element via the extinguishing agent pressure on the activation element; and Introducing the extinguishing agent into the battery arrangement.

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