Patent ID: 12191518

The present disclosure is amenable to various modifications and alternative forms, and some representative embodiments are shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the above-enumerated drawings. Rather, this disclosure covers all modifications, equivalents, combinations, subcombinations, permutations, groupings, and alternatives falling within the scope of this disclosure as encompassed, for example, by the appended claims.

DETAILED DESCRIPTION

This disclosure is susceptible of embodiment in many different forms. Representative embodiments of the disclosure are shown in the drawings and will herein be described in detail with the understanding that these embodiments are provided as an exemplification of the disclosed principles, not limitations of the broad aspects of the disclosure. To that extent, elements and limitations that are described, for example, in the Abstract, Introduction, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise.

For purposes of the present detailed description, unless specifically disclaimed: the singular includes the plural and vice versa; the words “and” and “or” shall be both conjunctive and disjunctive; the words “any” and “all” shall both mean “any and all”; and the words “including,” “containing,” “comprising,” “having,” and the like, shall each mean “including without limitation.” Moreover, words of approximation, such as “about,” “almost,” “substantially,” “generally,” “approximately,” and the like, may each be used herein in the sense of “at, near, or nearly at,” or “within 0-5% of,” or “within acceptable manufacturing tolerances,” or any logical combination thereof, for example. Lastly, directional adjectives and adverbs, such as fore, aft, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, front, back, left, right, etc., may be with respect to a motor vehicle, such as a forward driving direction of a motor vehicle when the vehicle is operatively oriented on a horizontal driving surface.

Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views, there is shown inFIG.1a representative motor vehicle, which is designated generally at10and portrayed herein for purposes of discussion as a sedan-style, electric-drive automobile. The illustrated automobile10—also referred to herein as “motor vehicle” or “vehicle” for short—is merely an exemplary application with which novel aspects of this disclosure may be practiced. In the same vein, incorporation of the present concepts into an FEV powertrain should be appreciated as a non-limiting implementation of disclosed features. As such, it will be understood that aspects and features of this disclosure may be applied to other powertrain architectures, incorporated into any logically relevant type of motor vehicle, and utilized for both automotive and non-automotive applications alike. Moreover, only select components of the motor vehicles, battery assemblies, and thermal systems are shown and described in additional detail herein. Nevertheless, the vehicles and systems discussed below may include numerous additional and alternative features, and other available peripheral components, for carrying out the various methods and functions of this disclosure.

The representative vehicle10ofFIG.1is originally equipped with a vehicle telecommunications and information (“telematics”) unit14that wirelessly communicates, e.g., via cell towers, base stations, mobile switching centers, satellite service, etc., with a remotely located or “off-board” cloud computing host service24(e.g., ONSTAR®). Some of the other vehicle hardware components16shown generally inFIG.1include, as non-limiting examples, an electronic video display device18, a microphone28, audio speakers30, and assorted user input controls32(e.g., buttons, knobs, pedals, switches, touchpads, joysticks, touchscreens, etc.). These hardware components16function, in part, as a human/machine interface (HMI) that enables a user to communicate with the telematics unit14and other components resident to and remote from the vehicle10. Microphone28, for instance, provides occupants with a means to input verbal or other auditory commands; the vehicle10may be equipped with an embedded voice-processing unit utilizing audio filtering, editing, and analysis modules. Conversely, the speakers30provide audible output to a vehicle occupant and may be either a stand-alone speaker dedicated for use with the telematics unit14or may be part of an audio system22. The audio system22is operatively connected to a network connection interface34and an audio bus20to receive analog information, rendering it as sound, via one or more speaker components.

Communicatively coupled to the telematics unit14is a network connection interface34, suitable examples of which include twisted pair/fiber optic Ethernet switches, parallel/serial communications buses, local area network (LAN) interfaces, controller area network (CAN) interfaces, and the like. Other appropriate communication interfaces may include those that conform with ISO, SAE, and/or IEEE standards and specifications. The network connection interface34enables vehicle hardware16to send and receive signals with one another and with various systems and subsystems both onboard and off-board the vehicle body12. This allows the vehicle10to perform assorted vehicle functions, such as modulating powertrain output, governing operation of a vehicle transmission, activating friction and regenerative brake systems, controlling vehicle steering, regulating charge and discharge of a vehicle battery pack, and other automated functions. For instance, telematics unit14may receive and transmit signals to/from a Powertrain Control Module (PCM)52, an Advanced Driver Assistance System (ADAS) module54, an Electronic Battery Control Module (EBCM)56, a Steering Control Module (SCM)58, a Brake System Control Module (BSCM)60, and assorted other vehicle ECUs, such as a transmission control module (TCM), engine control module (ECM), Sensor System Interface Module (SSIM), etc.

With continuing reference toFIG.1, telematics unit14is an onboard computing device that provides a mixture of services, both individually and through its communication with other networked devices. This telematics unit14is generally composed of one or more processors40, each of which may be embodied as a discrete microprocessor, an application specific integrated circuit (ASIC), or a dedicated control module. Vehicle10may offer centralized vehicle control via a central processing unit (CPU)36that is operatively coupled to a real-time clock (RTC)42and one or more electronic memory devices38, each of which may take on the form of a CD-ROM, magnetic disk, IC device, a solid-state drive (SSD) memory, a hard-disk drive (HDD) memory, flash memory, semiconductor memory (e.g., various types of RAM or ROM), etc.

Long-range vehicle communication capabilities with remote, off-board devices may be provided via one or more or all of a cellular chipset/component, a navigation and location chipset/component (e.g., global positioning system (GPS) transceiver), or a wireless modem, all of which are collectively represented at44. Close-range wireless connectivity may be provided via a short-range wireless communication device46(e.g., a BLUETOOTH® unit or near field communications (NFC) transceiver), a dedicated short-range communications (DSRC) component48, and/or a dual antenna50. It should be understood that the vehicle10may be implemented without one or more of the above listed components or, optionally, may include additional components and functionality as desired for a particular end use. The communications devices described above may provision data exchanges as part of a periodic broadcast in a vehicle-to-vehicle (V2V) communication system or a vehicle-to-everything (V2X) communication system, e.g., Vehicle-to-Infrastructure (V2I), Vehicle-to-Pedestrian (V2P), Vehicle-to-Device (V2D), etc.

CPU36receives sensor data from one or more sensing devices that use, for example, photo detection, radar, laser, ultrasonic, optical, infrared, or other suitable technology, including short range communications technologies (e.g., DSRC) or Ultra-Wide Band (UWB) radio technologies, e.g., for executing an automated vehicle operation or a vehicle navigation service. In accord with the illustrated example, the automobile10may be equipped with one or more digital cameras62, one or more range sensors64, one or more vehicle speed sensors66, one or more vehicle dynamics sensors68, and any requisite filtering, classification, fusion, and analysis hardware and software for processing raw sensor data. The type, placement, number, and interoperability of the distributed array of in-vehicle sensors may be adapted, singly or collectively, to a given vehicle platform for achieving a desired level of automation and concomitant autonomous vehicle operation.

To propel the motor vehicle10, an electrified powertrain is operable to generate and deliver tractive torque to one or more of the vehicle's drive wheels26. The powertrain is generally represented inFIG.1by a rechargeable energy storage system (RESS), which may be in the nature of a chassis-mounted traction battery pack70, that is operatively connected to an electric traction motor (M)78. The traction battery pack70is generally composed of one or more battery modules72each having a stack of battery cells74, such as lithium-class, zinc-class, nickel-class, or organosilicon-class battery cells of the pouch, can, or prismatic type. One or more electric machines, such as traction motor/generator (M) units78, draw electrical power from and, optionally, deliver electrical power to the battery pack70. A power inverter module (PIM)80electrically connects the battery pack70to the motor(s)78and modulates the transfer of electrical current therebetween. Disclosed concepts are similarly applicable to HEV and ICE-based powertrains.

The battery pack70may be configured such that module management, cell sensing, and module-to-module or module-to-host communication functionality is integrated directly into each battery module72and performed by an integrated electronics package, such as a wireless-enabled cell monitoring unit (CMU)76. The CMU76may be a microcontroller-based, printed circuit board (PCB)-mounted sensor array. Each CMU76may have a GPS transceiver and RF capabilities and may be packaged on or in a battery module housing. The battery module cells74, CMU76, housing, coolant lines, busbars, etc., collectively define the cell module assembly.

FIG.2presents a more detailed depiction of select components of a representative battery pack100assembly, which may be incorporated into the automobile10ofFIG.1, e.g., for powering the traction motor78, or implemented for a non-automotive application, e.g., for powering a residential or commercial power pack. In this non-limiting example, a rectangular array of battery modules120, each containing a stack of battery cells (e.g., battery cells74ofFIG.1), is enclosed within a protective battery case102(FIG.3). The battery case102may be constructed of a metallic, polymeric, or fiber-reinforced polymer material, including combinations thereof, to satisfy various mechanical and/or thermal design specifications. The battery pack100may have a relatively flat and generally rectangular shape, as shown, or may be arranged in a T-configuration or other application-specific shape. Likewise, the battery pack100may contain stacks of lithium-ion polymer pouch cells that are segregated into discrete battery modules120, as shown, or may contain prismatic or can-type battery cells, may employ any suitable battery technology, and/or may be stored in a shared compartment inside the battery case102.

Under anomalous operating conditions, the battery pack100may become damaged or may malfunction in a manner that causes excessive heat (e.g., 400-500+° C.) to be generated by cells inside the battery modules120.FIG.3schematically illustrates the battery pack100with an active thermal management (ATM) system104that helps to regulate the operating temperatures of the battery modules120during normal charge and discharge of the pack100and during such high-heat thermal events. The ATM system104ofFIG.3includes a coolant line106with coolant inlet and outlet ports101and103, respectively, that penetrate the outer perimeter of the battery case102. In the illustrated example, the ATM system104employs one or more liquid injection valves110that are passively or actively actuated to inject a dielectric immersion coolant liquid111(also referred to as “liquid immersion cooling fluid” or “coolant” for brevity) into the battery case102. Each valve110may spray dielectric immersion coolant liquid111onto a respective battery module120to partially or fully submerge the module in the coolant111, e.g., responsive to a temperature within the battery case102exceeding a pack-calibrated maximum temperature threshold. This temperature threshold may be a memory-stored TR temperature at which thermal runaway is predicted to occur within the battery pack100.

The coolant line106ofFIG.3may be biased towards the periphery of the battery case102, as shown, may be biased towards the center of the battery case102, or may take various other routes throughout the battery case102. Rather than spray coolant liquid111onto and at least partially submerge the battery modules120, as shown inFIG.3, the ATM system104may fill the individual battery modules120with coolant liquid111, as described below forFIG.4, or may altogether omit the individual module housings such that spraying coolant liquid111into the case102will partially/fully submerge the battery cells. The coolant line106may additionally circulate coolant through assorted components packaged in or on the battery pack100. For example, battery pack100contains a backplane assembly130that is positioned between select rows of battery modules120in contact with an electrical busbar134appurtenant each of the battery modules120. The backplane assembly130may provide a “drop in” module racking structure with quick-connect electrical contacts for physically attaching the modules120to the battery case102and electrically coupling the modules210with the busbar134. Coolant111may be diverted from coolant line106into one or more internal conduits132of the backplane130, for example, to facilitate cooling or heating of the battery pack100.

Turning next toFIG.4, there is shown another representative example of a battery assembly, namely a rechargeable battery module200assembly, with an active thermal management system, portrayed as a liquid immersion cooling system204, for maintaining an operating temperature of the assembly within a predefined “acceptable” temperature range. While differing in appearance, it is envisioned that any of the features and options described above with respect to the battery pack100and ATM system104ofFIGS.2and3may me incorporated, singly and in any combination, into the battery module200and LIC system204ofFIG.4, and vice versa. As a non-limiting point of similarity, the battery module200contains a stack of lithium-ion polymer battery cells274that is operatively housed within a protective outer case202. In addition, both thermal management systems104and204ofFIGS.3and4use direct liquid cooling techniques to cool the heat-generating electrochemical cells encased within the respective battery assemblies100,200. Within the battery module case202ofFIG.4, for example, is a liquid-tight immersion compartment201that holds a pool of dielectric liquid coolant and encloses the battery cells274such that they are kept partially or completely submerged in the dielectric liquid coolant during operation of the module200.

The LIC system204ofFIG.4is equipped with a main coolant reservoir240(also referred to as “vehicle dielectric reservoir”) for stowing a dielectric liquid immersion cooling fluid211. In accord with the illustrated example, the main coolant reservoir240is a fluid-tight polymeric container that stores and disseminates LIC fluid211to the battery module200and, for automotive applications, other heat-generating components distributed throughout the vehicle (e.g., CMU/battery electronics package76and traction motor78). As shown, the main coolant reservoir240ofFIG.4may be manufactured with a single-piece or bipartite reservoir body that is defined by a reservoir basin241and a reservoir cover243adjoining the basin241. The reservoir basin241collects and retains the LIC fluid211, whereas the reservoir cover243extends across and closes off the reservoir basin241such that vent gases213are trapped between the pooled LIC fluid213and the cover243. To selectively heat and/or cool the LIC fluid211, a heating element or a heat sink (collectively represented at244inFIG.4) may be disposed inside the main coolant reservoir240, as shown, or may be mounted to or separately fluidly coupled with the main coolant reservoir240. An electronic liquid pump242is fluidly coupled to the coolant reservoir240and selectively activated (e.g., via EBCM56or CMU/integrated electronics package76ofFIG.1) to circulate LIC fluid211to and from the reservoir240and, concomitantly, into and out of the battery module case202in order to partially or fully submerge the Li—Po battery cells274in the LIC fluid211.

A thermal fluid loop—typified by an interconnected network of pipes, hoses, channels, and/or other fluid conduits—facilitates the distribution of LIC fluid211throughout the LIC system204. Located fluidly downstream from the main coolant reservoir240, for example, are a coolant inlet manifold246and a coolant inlet conduit248that, together, fluidly connect the coolant reservoir240to the battery module case202. When the pump242is activated, LIC fluid211is transferred from the reservoir240, through the coolant inlet conduit248, and into the coolant inlet manifold246, which then disseminates the coolant211throughout the immersion compartment201inside the battery module case202. Located fluidly upstream from the main coolant reservoir240are a coolant outlet manifold250and a coolant outlet conduit252that, together, fluidly connect the battery module case202to the coolant reservoir240. By activating the pump242, LIC fluid211is pushed out of the battery case's internal immersion compartment201and accumulates in the coolant outlet manifold250. From there, the LIC fluid211passes through the coolant outlet conduit252and into the reservoir240. While portrayed inFIG.4as bipartite sections of the thermal fluid loop, the inlet section (i.e., coolant inlet manifold and conduit246,248) and outlet section (i.e., coolant outlet manifold and conduit250,252) may each be fabricated as a single-piece component or, alternatively, may be assembled from three or more individual parts.

During a thermal runaway event, vent gases released by overheating electrochemical cells will mix with and, in so doing, heat and expand the dielectric liquid immersion coolant inside the immersion compartment201. To mitigate thermal runaway using liquid immersion cooling, the LIC system204expels these vent gases from the immersion compartment201without allowing leakage of the LIC fluid211. Upon occurrence of any such thermal event, an auxiliary vent manifold254(also referred to as “hot gas manifold”) selectively fluidly connects the battery module case202to the main coolant reservoir240to thereby transfer the heated and expanding LIC fluid211with any entrained vent gases213out of the immersion compartment201and into the coolant reservoir240. In this instance, the battery module case202may be characterized by a lack of air exhaust vents that allow vent gases to escape directly from the battery module200assembly to the surrounding environment. Were the battery module cases202to include air exhaust vents, like those incorporated into passively cooled and indirect liquid cooled battery assemblies, the heated and expanding vent gases and LIC fluid may violently erupt from the battery assembly200to the surrounding environment.

The auxiliary vent manifold254ofFIG.4may be structurally configured to slow and cool the cell-generated vent gases213before these gases213are ejected from the LIC system204. By way of example, and not limitation, the coolant outlet manifold250is fabricated with an outlet manifold body251(also referred to herein as “first cylindrical manifold body”) that has a cylindrical shape and a respective (first) diameter D1. Contrastingly, the auxiliary vent manifold254is fabricated with a vent manifold body255(also referred to herein as “second cylindrical manifold body”) that has a cylindrical shape and a respective (second) diameter D2. The diameter D2of the vent manifold body255is markedly larger (e.g., 2×-3×+ greater) than the diameter D1of the outlet manifold body251to allow the LIC fluid211and vent gases213exiting the battery module case202to expand and, thus, depressurize and cool before transfer to the reservoir240.

To increase fluid cooling prior to vent gas expulsion from the LIC system104, the auxiliary vent manifold254provides a supplemental exit route with an extended route length that expends LIC fluid and vent gas thermal energy before arriving at the reservoir240. Thermal fluid loop's primary coolant outlet section, for example, has a total (first) conduit length L1, e.g., an end-to-end length of the coolant outlet manifold and conduit250,252, that extends from the battery case202to the coolant reservoir240. Thermal fluid loop's secondary coolant outlet section, on the other hand, has a total (second) conduit length L2, e.g., an end-to-end length of the auxiliary vent manifold254and auxiliary vent conduit256, that extends from the battery case202to the coolant reservoir240. The secondary coolant outlet section's total conduit length L2is markedly larger (e.g., 50-100%+ greater) than the primary coolant outlet section's total conduit length L1such that thermal energy of the LIC fluid211and vent gases213is lost to conductive heat transfer, turbulent flow and friction before reaching the main coolant reservoir240.

In order to maintain a default internal fluid pressure for immersion cooling during ordinary use of the battery module200, the LIC system204may limit or outright preclude fluid flow through the secondary coolant outlet section unless and until onset of a predefined thermal event. According to the illustrated example, the auxiliary vent manifold254is fabricated with one or more burst vents, an example of which is shown at258within inset view IV1, that physically restrict fluid flow through the auxiliary vent manifold254prior to a thermal runaway event. Each burst vent258may include or, if desired, may consist essentially of a metallic, or polymer frangible burst disc259that is sealingly connected to a fluid port257of the auxiliary vent manifold254. As shown, a series of mutually parallel exhaust runners265originate at the battery case202and terminate at fluid inlet ports257on the vent manifold body255, selectively fluidly coupling the immersion compartment201with the auxiliary vent manifold254. These fluid inlet ports257may each be blocked by a respective burst disc259that is sealed over the port's opening. The frangible burst disc259is scored, slotted, notched, thinned, or otherwise structurally configured to fail at a predefined internal compartment pressure of the immersion compartment201. By way of non-limiting example, the frangible burst disc259may be a thin aluminum foil that is designed to rip open at a predefined thermal runaway pressure (e.g., a 3-bar TR onset pressure) inside the immersion compartment201. When the burst discs259fail, LIC fluid211and vent gases213are allowed to flow into and through the auxiliary vent manifold254to the coolant reservoir240. It is also within the scope of this disclosure to utilize other fluid flow restrictions and obstructions, which may be located at any functionally suitable location within the LIC system204.

Packaged downstream from the auxiliary manifold254and battery case202are one or more gas valves260, each of which is fluidly connected to the main coolant reservoir240and actively/passively activated to evacuate vent gases from the LIC system204. In the representative LIC architecture ofFIG.4, a passive-type, spring-biased gas release valve260is mounted onto the coolant reservoir240and opened by gas pressures at or above a predefined internal pressure within the reservoir240to thereby expel vent gases213to the surrounding environment. At least one gas valve260may be fastened directly to the reservoir cover243, at least partially disposed within a reservoir gas vent245that extends through the cover243, as best seen in the inset view IV2. The gas valve260may be a pressure-activated flapper valve with a flapper diaphragm261that seats onto an exterior surface of the coolant reservoir cover243; when seated, the diaphragm261circumscribes and fluidly seals the gas vent245. The flapper diaphragm261is biased closed by a helical expansion spring263or other functionally suitable biasing mechanism. When fluid pressure inside the main coolant reservoir240exceeds the spring force of the expansion spring263, the flapper diaphragm261is unseated from the reservoir cover243to expose the gas vent245. Unseating the gas valve260opens the gas vent245, which allows vent gases213to empty from the main coolant reservoir240and, for automotive applications, expel from the vehicle body. In addition, the auxiliary vent conduit256fluidly connects a fluid outlet port of the auxiliary vent manifold254to an upper portion of the reservoir body such that the LIC fluid211separates from the vent gases213and drains into the reservoir basin241.

Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; those skilled in the art will recognize, however, that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined, for example, by the appended claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and features.