Patent ID: 12211984

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

The present disclosure provides a thermal device to heat battery modules at cold start and during start/stop operations and to prevent the battery modules from overheating during operation. The thermal device comprises a first layer of a non-metallic material that is a good conductor of heat and electricity, a pair of metal wires disposed on the first layer, and two layers of a plastic material that is a good conductor of heat enclosing the first layer and the metal wires. The metal wires and the first layer are sandwiched between the two layers of the plastic material. The plastic layers comprising the metal wires and the first layer are disposed around one or more cells of a battery module and/or around one or more battery modules.

To heat the battery module at cold start and during start/stop operations, the first layer is connected to the battery module through a switch. When the switch is closed (turned on), the battery module supplies power to the first layer. The first layer heats due to Joule heating, which heats the metal wires and causes the metal wires to generate infrared radiation. The plastic layers conduct the Joule heat and heat from the infrared radiation to heat the cells of the battery module. The switch is opened (turned off) when temperature of the battery module reaches a threshold.

Conversely, when the battery module becomes hot during operation, heat from hot spots in the cells of the battery module is distributed across the first layer, which prevents formation of the hot spots. The thermal device can be implemented in low-voltage battery modules to allow use of a wide range of cells (e.g., low-cost LFP cells, solid-state batteries, etc.) for high power battery modules. These and other features of the thermal device of the present disclosure are described below in detail. Throughout the present disclosure, while a vehicle is used as an example for illustrative purposes, the teachings of the present disclosure are also applicable to non-vehicle implementations.

The present disclosure is organized as follows. Examples of a thermal device and of a system that uses the thermal device are shown and described with reference toFIGS.1A and1B. Examples of a thermal device are shown and described with reference toFIGS.2A and2B. Examples of a battery module and a thermal device disposed around cells of the battery module are shown and described with reference toFIGS.3A and3B. The heating and heat distribution performed by the thermal device is shown and described with reference toFIGS.4A-4C. Additional examples of a battery module and a thermal device disposed around cells of the battery module are shown and described with reference toFIGS.5A-6C.

Examples of a plurality of interconnected battery modules and a thermal device disposed around cells of the battery modules are shown and described with reference toFIGS.7A and7B. Examples of a bipolar cell and a thermal device disposed around the bipolar cell are shown and described with reference toFIGS.8A-8D. Additional examples of the bipolar cell and a thermal device disposed around the bipolar cells are shown and described with reference toFIGS.9A-9C. Examples of a dual thermal device are shown and described with reference toFIGS.10A and10B. Examples of battery modules and the dual thermal device disposed around cells of the battery modules are shown and described with reference toFIGS.11A and11B.

FIG.1Ashows a system100comprising a thermal device according to the present disclosure. The system100comprises a battery module102, a thermal device104, a battery management module (BMM)106, a startup module108, and a communication module110. A shunt111is connected in series with the battery module102and is connected to the BMM106to measure current supplied by the battery module102. The BMM106, the startup module108, and the communication module110are connected to and communicate via a controller area network (CAN) bus112in a vehicle (now shown). Additional control modules that control other subsystems of the vehicle (e.g., an engine control module, a motor control module, a transmission control module, an infotainment subsystem control module, and so on; all not shown) may be connected to the CAN bus112.

For example only, the battery module102is shown to include only four cells103-1,103-2,103-3, and103-4(collectively cells103) connected in series. Alternatively, the battery module102can include any number of cells. For example, the battery module102can include N cells, where N is a positive integer. Further, the cells in the battery module102can be interconnected in various series/parallel configurations (e.g., seeFIG.3Aonwards). The positive and negative terminals of the battery module102are connected to a load (e.g., a motor of an electric vehicle, not shown) to be powered by the battery module102.

The battery module102may include one or more temperature sensors located proximate to one or more cells103of the battery module102. For example only, four temperature sensors116-1,116-2,116-3, and116-4(collectively temperature sensors116) are shown. Alternatively, the battery module102may include N temperature sensors, where N is a positive integer. The temperature sensors116sense temperature of one or more cells103of the battery module102. Any of the battery module modules shown and described below with reference toFIG.3Aonwards can be used (along with one or more of the temperature sensors116) in place of the battery module102in the system100.

FIG.1Bshows a schematic of an example of the thermal device104. The thermal device104is described below in detail with reference toFIGS.2A and2B. The thermal device104is disposed around the cells103of the battery module102. The thermal device104includes two terminals that are connected across the first layer in the thermal device104(see elements156and158inFIGS.2A and2B). A first terminal of the thermal device104is directly connected to a first terminal of the battery module102. A second terminal of the thermal device104is connected to a second terminal of the battery module102via a switch114. Alternatively, while not shown, the first terminal of the thermal device104can be connected to the first terminal of the battery module102via the switch114, and the second terminal of the thermal device104can be directly connected to a second terminal of the battery module102. For example, the switch114may include a relay, a field effect transistor, or any other switching device.

During cold start, the startup module108closes (turns on) the switch114and connects the thermal device104to the battery module102. Alternatively, the communication module110can receive a signal from a remote device (e.g., a key fob equipped with a remote starter, not shown), and in response to receiving the signal from the remote device, the communication module110can close the switch114and connect the thermal device104to the battery module102. The startup module108and the communication module110may communicate with the thermal device104and/or the switch114directly, via the BMM106, or via another controller.

When the switch114is closed, the battery module102supplies power to the thermal device104. Specifically, the battery module102supplies power to the first layer in the thermal device104. The first layer in the thermal device104heats due to the power received from the battery module102(i.e., due to the current flowing through the first layer upon receiving the power from the battery module102). Due to the heat generated by the first layer, the metal wires in the thermal device104(seeFIGS.2A and2B) become hot and generate infrared radiation105. The infrared radiation105heats the cells of the battery module102. The temperature sensors116sense the temperature of the cells103of the battery module102and communicate the temperature to the BMM106. When the temperature of the cells103or the battery module102reaches a threshold, the BMM106opens (turns off) the switch114and disconnects the thermal device104from the battery module102.

A similar procedure is performed when the vehicle operates in a start/stop mode. In the start/stop mode, the power supply from the battery module102to the load (e.g., a motor in the vehicle) is shut off when the vehicle stops (e.g., at a traffic light or in a congested traffic) and is resupplied when the vehicle operator decides to move the vehicle. The temperature of the battery module102may drop below the threshold when the vehicle is temporarily stopped in the start/stop mode. The startup module108connects the thermal device104to the battery module102when the temperature of the battery module102drops below the threshold in the start/stop mode and disconnects the thermal device104from the battery module102when the temperature of the battery module102reaches the threshold.

During operation, the temperature of the battery module102increases. The first layer in the thermal device104conducts heat from one or more hot spots of the battery module102. The heat from the hot spots is distributed across the first layer in the thermal device104. Thus, the thermal device104prevents formation of hot spots in the battery module102.

FIG.2Ashows a first example of the thermal device104. For example, the thermal device104comprises a first layer150of a material that is non-metallic and that is a good conductor of heat and electricity, a pair of metal wires152-1and152-2(collectively metal wires152) disposed on the first layer150, and two layers of a thermally conductive plastic material154-1and154-2(collectively plastic layers154) enclosing the first layer150and the metal wires152. The first layer150includes two terminals (or tabs)156and158to receive power. For example, the terminals156and158of the first layer150can be respectively connected to the positive and negative terminals (or to the negative and positive terminals) of a cell or a battery module (e.g., the battery module102). The plastic layers154are good conductors of heat. As used herein, the phrase good conductor of heat used with reference to the first layer150and the plastic layers154indicates that the thermal conductivity of these layers is suitable to transfer a desirable amount of heat from these layers to cells and/or battery modules and that the thermal conductivity of these layers is synchronous with mechanical properties of these layers.

FIG.2Bshows a second example of the thermal device104, which is shown as element104-1. The only difference between the thermal device104shown inFIG.2Aand the thermal device104-1shown inFIG.2Bis that the layout of metal wires152-3,152-4in the thermal device104-1differs from the layout of the metal wires152-1,152-2and that terminals156-1,158-1in the thermal device104-1are on the same side of the first layer150instead of being on the opposite sides as shown inFIG.2A.

Throughout the present disclosure, except where specifically identified, generally, the thermal devices104and104-1are collectively called the thermal device104; the metal wires152-1,152-2,152-3, and152-4are collectively called the metal wires152; the terminals156and156-1are called the first terminal156of the thermal device104; and the terminals158and158-1are called the second terminal158of the thermal device104.

The following description applies to bothFIG.2AandFIG.2B. While a pair of metal wires152is shown, any number of metal wires can be used. For example, N metal wires can be used, where N is a positive integer. Further, the layout of the metal wires152shown is for example only, and any other layout may be used instead. The layout of the metal wires152can have any shape so long as the metal wires152are spread and distributed across the first layer150. Further, while shown as wires, the metal wires152need not be continues. That is, the metal wires152can include multiple discontinuous segments. Furthermore, the metal wires152can include a mesh of a metallic material. For example, the mesh can be in the form of a grid, or the mesh can have an irregular shape. In any of these forms, the metal wires152generate infrared radiation when heated.

For example, the first layer150may be made of a material such as graphite, graphene, carbon nanotubes, pressed graphite or carbon powder, a polymer that is a good conductor of heat and electricity, a phase change material, and so on. Due to the composition and properties of the material, the first layer150comprises a complex resistive network or array of randomly arranged resistive elements. Consequently, the first layer150heats due to Joule heating when power is applied from the battery module102across the first layer150and current flows through these resistive elements. Additionally, these resistive elements provide a uniform thermal path. Consequently, the first layer150provides passive or resistive cooling, draws heat from the cells of the battery module102, and distributes the heat throughout the first layer150, which reduces or eliminates hotspots in the cells of the battery module102. The phase change material can act as a heat capacitor. That is, the phase change material can store the heat generated while current flows through the first layer150and can supply the stored heat to cells and/or battery modules after the first layer150is disconnected from power.

The plastic layers154can be made of a thermally conductive plastic such as but not limited to polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), liquid-crystal polymer (LCP), polycarbonate (PC), polyamide such as PA6, PA46, and so on. In some implementations, both plastic layers154-1and154-2can be made of the same material and can have the same thickness. Alternatively, the plastic layers154-1and154-2can be made of the same material and can have different thicknesses. In some implementations, the plastic layers154-1and154-2can be made of different materials and can have the same thickness. In some implementations, the plastic layers154-1and154-2can be made of different materials and can have different thicknesses. The metal wires152and the terminals156,158can be made of any metallic material such as but not limited to copper, aluminum, nickel, nickel coated with copper, stainless steel, aluminum alloys, etc.

The first layer150, the metal wires152, and the plastic layers154can be homogenous or can comprise multiple layers. The thicknesses of the first layer150, the metal wires152, and the plastic layers154can be selected depending on the number of cells in the battery modules, the size and shape of the cells and the battery modules, the voltages of the cells and the battery modules, the types of cells in the battery modules, and so on. For example, the thickness of the first layer150may range from 1 micrometer to 10 millimeters.

The thermal device104can also reduce electromagnetic interference (EMI). For example, the first layer150can reflect EMI while the metal wires152can absorb EMI.

As shown and described with reference toFIG.3Aonwards, the thermal device104can be arranged between each cell in a battery module. Alternatively, the thermal device104can be arranged around the battery module without being arranged between the cells of the battery module. Further, when battery modules are connected in a cascaded arrangement (e.g., seeFIG.7A), the cells or battery modules in a center portion of the cascaded arrangement may take longer to heat. Accordingly, in the cascaded arrangement, the thermal device104may be arranged between each cell in battery modules located near the center portion of the cascaded arrangement and may be arranged around the battery modules located at the periphery of the cascaded arrangement without being arranged between the cells of the battery modules located at the periphery of the cascaded arrangement.

In some implementations, in the cascaded arrangement, the thermal device104may not be used with the battery modules at the periphery of the cascaded arrangement; rather, the thermal device104may be arranged only between each cell in the battery modules located near the center portion of the cascaded arrangement, or the thermal device104may be arranged only around the battery modules located near the center portion of the cascaded arrangement.

FIGS.3A and3Bshow examples of a battery module and a thermal device disposed around cells of the battery module.FIG.3Ashows an example of a lithium iron phosphate (LFP) battery module200comprising four cells connected in series to form a 12V battery module. The four cells are shown as202-1,202-2,202-3, and202-4and are collectively called the cells202. For example, each cell202in the battery module200may be a liquid electrolyte based lithium-ion battery (LIB). The voltage of each cell202may be less than or equal to 5V. For example, the battery module200can be used in the system100shown inFIG.1A.

FIG.3Bshows an example of the thermal device104shown inFIG.2Aarranged between and around each cell202of the battery module200shown inFIG.3A. In the perspective view shown, only the plastic layer154-1of the thermal device104is visible.

In the battery module200, the first terminal156of the thermal device104is connected to a positive terminal of the first cell202-1of the battery module200. A negative terminal of the first cell202-1is connected to a positive terminal of the second cell202-2of the battery module200. A negative terminal of the second cell202-2is connected to a positive terminal of the third cell202-3of the battery module200. A negative terminal of the third cell202-3is connected to a positive terminal of the fourth cell202-4of the battery module200. A negative terminal of the fourth cell202-4is connected to the second terminal158of the thermal device104via the switch114. The first and second terminals156,158of the thermal device104are on opposite sides of the battery module200. The thermal device104can be operated as described above with reference toFIGS.1A and1B.

FIGS.4A-4Cshow the heating and heat distribution performed by the thermal device104in the battery module200shown inFIGS.3A and3B.FIG.4Ashows an example of how the thermal device104heats the fourth cell202-4when the switch114is closed. While other cells202of the battery module200are not shown for simplicity of illustration, it is understood that the other cells202are similarly heated by the thermal device104. Arrows210-1,210-2, and210-3show the direction of current flow through the first layer150of the thermal device104, which heats the metal wires152in the thermal device104, which in turn generates infrared radiation105that heats the cells202of the battery module200.

FIG.4Bshows how the thermal device104draws and distributes heat from the cells202of the battery module200. While only the fourth cell202-4is shown for simplicity of illustration, it is understood that the thermal device104similarly draws and distributes heat from the other cells202of the battery module200. Element212shows an example of a hot spot212in the fourth cell202-4, and arrows214-1and214-2show directions of heat flow and heat distribution from the hot spot212through the first layer150of the thermal device104.

FIG.4Cshows a graph of temperature versus time for the cells202of the battery module200. Graph216shows how the hot spot212is transformed into a warm spot when the thermal device104is used in the battery module200. Graph218shows formation of the hot spot212in the cells202when the thermal device104is not used in the battery module200.

FIGS.5A-6Cshow additional examples of arrangements200-1and200-2of the battery module200and the thermal device104disposed around the cells202of the battery module200. The arrangement200-1of the battery module200and the thermal device104shown inFIG.5Ais the same as inFIG.3Bexcept that inFIG.5A, the switch114is located between first terminal156of the thermal device104and the positive terminal of the first cell202-1, and the negative terminal of the fourth cell202-4is directly connected to the second terminal158of the thermal device104. The battery module200shown in the arrangement200-1can be used in the system100shown inFIG.1A, and the thermal device104can be operated as described above with reference toFIGS.1A and1B.

FIG.5Bshows an arrangement200-2of the battery module200with the thermal device104-1shown inFIG.2B. The arrangement200-2is the same as the arrangement shown inFIG.3Bexcept that inFIG.5B, the first and second terminals156-1,158-1of the thermal device104-1are located on the same side of the battery module200; the first terminal156-1of the thermal device104-1is connected to the positive terminal of the first cell202-1of the battery module200; and the second terminal158-1of the thermal device104-1is connected to the negative terminal of the fourth cell202-4via the switch114.

While not shown, another arrangement is also possible where the first and second terminals156-1,158-1of the thermal device104-1are located on the same side of the battery module200; the first terminal156-1of the thermal device104-1is connected to the positive terminal of the first cell202-1of the battery module200via the switch114; and the second terminal158-1of the thermal device104-1is directly connected to the negative terminal of the fourth cell202-4of the battery module200. The battery module200shown in the arrangement200-2can be used in the system100shown inFIG.1A, and the thermal device104-1can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIGS.6A-6Cshow arrangements of a battery module220and the thermal devices104,104-1shown inFIGS.2A and2B. These arrangements can be used in the system100shown inFIGS.1A and1B.FIG.6Ashows the battery module220including four cells222-1,222-2,222-3, and222-4(collectively the cells222). The cells222are similar to the cells202of the battery module200shown inFIGS.3A-5Bexcept that each cell222includes positive and negative terminals on opposite sides of the cell instead of on the same side of the cell.

FIG.6Bshows an example of the thermal device104shown inFIG.2Aarranged between and around each cell222of the battery module220shown inFIG.6A. In the perspective view shown, only the plastic layer154-1of the thermal device104is visible.

In the battery module220, the first terminal156of the thermal device104is connected to a positive terminal of the first cell222-1of the battery module220. A negative terminal of the first cell222-1is connected to a positive terminal of the second cell222-2(not visible) of the battery module220. A negative terminal of the second cell222-2is connected to a positive terminal of the third cell222-3of the battery module220. A negative terminal of the third cell222-3(not visible) is connected to a positive terminal of the fourth cell222-4(not visible) of the battery module220. A negative terminal of the fourth cell222-4is connected to the second terminal158of the thermal device104via the switch114.

The first and second terminals156,158of the thermal device104are on opposite sides of the battery module220. The battery module220can be used in the system100shown inFIG.1A, and the thermal device104can be operated as described above with reference toFIGS.1A and1B.

FIG.6Cshows an example of the thermal device104-1shown inFIG.2Barranged between and around each cell222of the battery module220shown inFIG.6A, which is shown as arrangement220-1. The arrangement220-1is the same as the arrangement shown inFIG.6Bexcept that inFIG.6C, the first and second terminals156-1,158-1of the thermal device104-1are located on the same side of the battery module220; the first terminal156-1of the thermal device104-1is connected to the positive terminal of the first cell222-1of the battery module220via the switch114; and the second terminal158-1of the thermal device104-1is connected to the negative terminal of the fourth cell222-4.

While not shown, another arrangement is also possible where the first and second terminals156-1,158-1of the thermal device104-1are located on the same side of the battery module220; the first terminal156-1of the thermal device104-1is directly connected to the positive terminal of the first cell202-1of the battery module220; and the second terminal158-1of the thermal device104-1is connected to the negative terminal of the fourth cell222-4via the switch114. The battery module220shown in the arrangement220-2can be used in the system100shown inFIG.1A, and the thermal device104-1can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIGS.7A and7Bshow an example of a plurality of interconnected (cascaded) battery modules and a thermal device disposed around the cells of the cascaded battery modules. For example, inFIG.7A, four battery modules250-1,250-2,250-3, and250-4(collectively battery modules250) are connected in series. Each battery module250is similar to the battery module200except that the battery module250includes three cells252-1,252-2, and252-3(collectively cells252) connected in parallel instead of four cells202connected in series as shown inFIGS.3A-5B. The cells252are similar to the cells202.

Each battery module250includes a respective (i.e., separate) thermal device104. In each battery module250, a separate thermal device104is arranged between the cells252and around the battery module250. An example of the thermal device104for the battery module250including three cells252is shown inFIG.7B. The cascaded battery modules250can be used in the system100shown inFIG.1A, and the thermal device104of each battery module250can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

InFIG.7A, in each battery module250, the positive terminals of the cells252are connected to each other, and the negative terminals of the cells252are connected to each other. In the first and third battery modules250-1,250-3, the positive terminals of the cells252are directly connected to the first terminal156of the respective thermal device104, and the negative terminals of the cells252are connected to the second terminal158of the respective thermal device104via a respective switch114. In the second and fourth battery modules250-2,250-4, the negative terminals of the cells252are directly connected to the second terminal158of the respective thermal device104, and the positive terminals of the cells252are connected to the first terminal156of the respective thermal device104via a respective switch114.

The positive terminals of the first battery module250-1are connected to the negative terminals of the second battery module250-2. Consequently, the first terminal156of the thermal device104of the first battery module250-1, the positive terminals of the cells252of the first battery module250-1, the second terminal158of the thermal device104of the second battery module250-2, and the negative terminals of the cells252of the second battery module250-2are connected to each other.

The positive terminals of the third battery module250-3are connected to the negative terminals of the fourth battery module250-4. Consequently, the first terminal156of the thermal device104of the third battery module250-3, the positive terminals of the cells252of the third battery module250-3, the second terminal158of the thermal device104of the fourth battery module250-4, and the negative terminals of the cells252of the fourth battery module250-4are connected to each other.

Additionally, the positive terminals of the second battery module250-2are connected to the negative terminals of the third battery module250-3. While not shown, the thermal devices104need not be powered by the respective battery modules250; instead, power from one of the battery modules250can be supplied to other thermal devices104of the other battery modules250.

One or more switches114associated with the four battery modules250can be opened or closed. For example, one or more switches114can be closed at cold start and/or during start/stop operations (i.e., auto-start mode). Further, one or more switches114can be closed during charging mode, regeneration mode, power boost mode, test mode, dual/auxiliary battery mode, and other modes of operation of a electric/hybrid vehicle (or any other system/application).

The thermal devices104,104-1are bidirectional; that is, their first and second terminals do not have specific polarities; rather, any terminal of the thermal devices104,104-1can be connected to a positive or negative terminal of a cell or a battery module. Current flows through the thermal device104,104-1from a terminal, which is connected to a positive terminal of a cell or a battery module, to a terminal, which is connected to a negative terminal of the cell or the battery module.

While not shown, arrangements similar to those shown and described with reference toFIGS.6A-6Ccan be used with the cells252and the battery modules250shown inFIGS.7A and7B. In other words, the cells252can include positive and negative terminals on opposite sides of each cell252instead of on the same side of each cell252. Further, while not shown, the thermal device104-1shown inFIG.2Bcan be used with the cells252and the battery modules250shown inFIGS.7A and7Binstead of the thermal device104.

Additional permutations and combinations of the various features and configurations of the cells, battery modules, and thermal devices described with reference toFIGS.3A-7Bare feasible and contemplated. Further, the thermal device104may be used in various locations (e.g., between one or more cells of a battery module, around the battery module without being arranged between the cells of the battery module, etc.) as described below with reference toFIGS.11A and11B.

FIGS.8A-8Dshow examples of a bipolar cell and a thermal device disposed around the bipolar cell. For example,FIG.8Ashows a 12V bipolar cell300having positive and negative terminals on the same side of the bipolar cell300. The thermal device104shown inFIG.8Bsurrounds the bipolar cell300. In the perspective view shown, only the plastic layer154-1of the thermal device104is visible.

The first terminal156of the thermal device104is connected to the positive terminal of the bipolar cell300. The second terminal158of the thermal device104is connected to the negative terminal of the bipolar cell300via the switch114. Alternatively, while not shown, the first terminal156of the thermal device104can be connected to the positive terminal of the bipolar cell300via the switch114, and the second terminal158of the thermal device104can be directly connected to the negative terminal of the bipolar cell300.

The first and second terminals156,158of the thermal device104are located on opposite sides of the bipolar cell300. The bipolar cell300can be used in the system100shown inFIG.1A, and the thermal device104can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIG.8Cshows an example of a bipolar cell300-1with positive and negative terminals on the opposite sides of the bipolar cell300-1. The thermal device104shown inFIG.8Bsurrounds the bipolar cell300-1. In the perspective view shown, only the plastic layer154-1of the thermal device104is visible.

The first terminal156of the thermal device104is connected to a positive terminal of the bipolar cell300-1via the switch114. The second terminal158of the thermal device104is directly connected to a negative terminal (not visible) of the bipolar cell300-1. Alternatively, while not shown, the first terminal156of the thermal device104can be directly connected to the positive terminal of the bipolar cell300-1, and the second terminal158of the thermal device104can be connected to the negative terminal (not visible) of the bipolar cell300-1via the switch114.

The first and second terminals156,158of the thermal device104are located on opposite sides of the bipolar cell300-1. The bipolar cell300-1can be used in the system100shown inFIG.1A, and the thermal device104can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIG.8Dshows an example of the bipolar cell300with the thermal device104-1shown inFIG.2Bsurrounding the bipolar cell300. In the perspective view shown, only the plastic layer154-1of the thermal device104-1is visible. The first terminal156-1of the thermal device104-1is connected to the positive terminal of the bipolar cell300via the switch114. The second terminal158-1of the thermal device104-1is directly connected to the negative terminal of the bipolar cell300. Alternatively, while not shown, the first terminal156-1of the thermal device104-1can be directly connected to the positive terminal of the bipolar cell300, and the second terminal158-1of the thermal device104-1can be connected to the negative terminal of the bipolar cell300via the switch114.

The first and second terminals156-1,158-1of the thermal device104-1are located on the same side of the bipolar cell300. The bipolar cell300can be used in the system100shown inFIG.1A, and the thermal device104-1can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIGS.9A-9Cshow examples of other arrangements of multiple bipolar cells and the thermal devices104,104-1. For example,FIG.9Ashows two bipolar cells310-1,310-2connected in series. The bipolar cells310-1,310-2are identical to the bipolar cell300shown inFIG.8A. A negative terminal of the first bipolar cell310-1is connected to a positive terminal of the second bipolar cell310-2.FIG.9Bshows an example of the thermal device104that can be used with the two bipolar cells310-1,310-2.

InFIG.9A, the thermal device104is arranged between and around the two bipolar cells310-1,310-2. In the perspective view shown, only the plastic layer154-1of the thermal device104is visible. The first terminal156of the thermal device104is connected to a positive terminal of the first bipolar cell310-1. A negative terminal of the second bipolar cell310-2is connected to the second terminal158of the thermal device104via the switch114. Alternatively, while not shown, the first terminal156of the thermal device104can be connected to the positive terminal of the first bipolar cell310-1via the switch114, and the negative terminal of the second bipolar cell310-2can be directly connected to the second terminal158of the thermal device104.

The first and second terminals156,158of the thermal device104are located on opposite sides of the two bipolar cells310-1,310-2. The bipolar cells310-1,310-2can be used in the system100shown inFIG.1A, and the thermal device104can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIG.9Cshows the two bipolar cells310-1,310-2connected in series as shown inFIG.9A. Each of the first and second bipolar cells310-1,310-2is enclosed in (i.e., covered or surrounded by) a respective (i.e., separate) thermal device104-1. A first terminal156-1of the first thermal device104-1covering the first bipolar cell310-1is connected to the positive terminal of the first bipolar cell310-1. A second terminal158-1of the first thermal device104-1covering the first bipolar cell310-1is connected to the negative terminal of the first bipolar cell310-1via a first switch114. Alternatively, while not shown, the first terminal156-1of the first thermal device104-1can be connected to the positive terminal of the first bipolar cell310-1via the first switch114, and the second terminal158-1of the first thermal device104-1can be directly connected to the negative terminal of the first bipolar cell310-1.

Additionally, a first terminal156-1of the second thermal device104-1covering the second bipolar cell310-2is connected to the positive terminal of the second bipolar cell310-2. A second terminal158-1of the second thermal device104-1covering the second bipolar cell310-2is connected to the negative terminal of the second bipolar cell310-2via a second switch114. Alternatively, while not shown, the first terminal156-1of the second thermal device104-1can be connected to the positive terminal of the second bipolar cell310-2via the second switch114, and the second terminal158-1of the second thermal device104-1can be directly connected to the negative terminal of the second bipolar cell310-2.

FIGS.10A and10Bshow examples of a dual thermal device.FIG.10Ashows an example of a dual thermal device350-1. The dual thermal device350-1is similar to the thermal device104shown inFIG.2Aexcept that the dual thermal device350-1includes two first layers150(shown as150-1,150-2and called the first layer150-1and the second layer150-2, respectively), two sets of the metal wires152-1,152-2, and two sets of the first and second terminals156,158arranged between the plastic layers154.

A first set of the first and second terminals156,158is connected to the first layer150-1, and a second set of the first and second terminals156,158is connected to the second layer150-2. The first layer150-1, a first set of the metal wires152-1,152-2arranged on the first layer150-1, and a first set of the first and second terminals156,158connected to the first layer150-1form a first thermal device of the dual thermal device350-1. The second layer150-2, a second set of the metal wires152-1,152-2arranged on the second layer150-2, and a second set of the first and second terminals156,158connected to the second layer150-2form a second thermal device of the dual thermal device350-1.

FIG.10Bshows an example of a dual thermal device350-2. The dual thermal device350-2is similar to the thermal device104-1shown inFIG.2Bexcept that the dual thermal device350-2includes two first layers150(shown as150-1,150-2and called the first layer150-1and the second layer150-2, respectively), two sets of the metal wires152-3,152-4, and two sets of the first and second terminals156-1,158-1arranged between the plastic layers154.

A first set of the first and second terminals156-1,158-1is connected to the first layer150-1, and a second set of the first and second terminals156-1,158-1is connected to the second layer150-2. The first layer150-1, a first set of the metal wires152-3,152-4arranged on the first layer150-1, and a first set of the first and second terminals156-1,158-1connected to the first layer150-1form a first thermal device of the dual thermal device350-2. The second layer150-2, a second set of the metal wires152-3,152-4arranged on the first layer150-2, and a second set of the first and second terminals156-1,158-1connected to the second layer150-2form a second thermal device of the dual thermal device350-2.

The dual thermal device350-1can be used instead of the thermal device104inFIGS.3A-9C. The dual thermal device350-2can be used instead of the thermal device104-1inFIGS.3A-9C. When used, one or both of the first and second thermal devices in the dual thermal devices350-1,350-1can be turned on to heat one or more portions of the cells and battery modules. The first and second thermal devices in the dual thermal devices350-1,350-1can be turned on and off at varying duty cycles (e.g., by the system100shown inFIG.1A, using PWM for example).

In some implementations, the first layer150-1and the second layer150-2can include different nonmetallic materials that are good conductors of heat and electricity. Further, the first layer150-1and the second layer150-2can have different thicknesses. Furthermore, the metal wires disposed on the first layer150-1can include different material and/or can have different thicknesses and different layout (i.e., pattern) than the metal wires disposed on the second layer150-2.

FIGS.11A and11Bshow examples of battery modules and the dual thermal device disposed around cells of the battery modules.FIG.11Ashows the dual thermal device350-1used with the battery module200shown inFIG.3A. The first terminals156of the first and second thermal devices in the dual thermal device350-1are connected to the positive terminal of the first cell202-1of the battery module200. The second terminals158of the first and second thermal devices in the dual thermal device350-1are connected to the negative terminal of the fourth cell202-1of the battery module200via respective switches114. Alternatively, while not shown, the first terminals156of the first and second thermal devices in the dual thermal device350-1can be connected to the positive terminal of the first cell202-1via respective switches114, and the second terminals158of the first and second thermal devices in the dual thermal device350-1can be directly connected to the negative terminal of the fourth cell202-1.

One or both of the first and second thermal devices in the dual thermal device350-1can be turned on to heat one or more portions of the cells202of battery module200. The battery module200and the dual thermal device350-1can be used in the system100shown inFIG.1A, and each of the first and second thermal devices in the dual thermal device350-1can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

FIG.11Bshows the dual thermal device350-1used with the bipolar cell300shown inFIG.8A. The first terminals156of the first and second thermal devices in the dual thermal device350-1are connected to the positive terminal of the bipolar cell300. The second terminals158of the first and second thermal devices in the dual thermal device350-1are connected to the negative terminal of the bipolar cell300via the switch114. Alternatively, while not shown, the first terminals156of the first and second thermal devices in the dual thermal device350-1can be connected to the positive terminal of the bipolar cell300via the switch114, and the second terminals158of the first and second thermal devices in the dual thermal device350-1can be directly connected to the negative terminal of the bipolar cell300.

One or both of the first and second thermal devices in the dual thermal device350-1can be turned on to heat one or more portions of the bipolar cell300. The bipolar cell300and the dual thermal device350-1can be used in the system100shown inFIG.1A, and each of the first and second thermal devices in the dual thermal device350-1can be operated similar to the thermal device104described above with reference toFIGS.1A and1B.

In some implementations, in any of the arrangements of battery modules and cells shown and described throughout the present disclosure, the thermal devices104,104-1,350-1,350-2can cover the entire surface area of the cells or the battery modules as shown inFIG.3Aonwards. For example, the thermal devices104,104-1,350-1,350-2may cover a portion of the surface area of the cells or the battery modules. For example, the thermal devices104,104-1,350-1,350-2may cover only a center portion of the cells or the battery modules, or a portion proximate to one of the edges of the cells or the battery modules. For example, the first and second thermal devices in the dual thermal devices350-1,350-2may cover portions proximate to the edges of the cells or the battery modules.

In some implementations, the thermal devices104,104-1,350-1,350-2may be arranged between alternate cells of a battery module, between alternate battery modules (in cascaded battery modules), between each cell in all except first and last battery modules and around the first and last battery modules (in cascaded battery modules), and so on. Any combination of the various arrangements of the thermal devices104,104-1,350-1,350-2described throughout the present disclosure may be used.

Throughout the present disclosure, the battery modules shown and described herein can include, without limitation, cells of the following types: liquid based lithium ion batteries, hybrid cells (liquid plus polymer, liquid plus ceramic particles), or any other types of cells. The cell format can be, without limitation, pouch, prismatic, or cylindrical. Further, the voltage range that can be achieved using the battery modules shown and described herein can be 12V to 150V.

The battery modules and the cells described throughout the present disclosure can include other arrangements of positive and negative terminals. For example, the cells and the battery modules can include multiple positive and negative terminals. These multiple terminals can be located at multiple locations on the cells and the battery modules. The thermal devices described throughout the present disclosure can be operated with these other arrangements.

Further, throughout the present disclosure, the thermal devices are shown and described as being powered by the respective cells or battery modules that the thermal devices heat. However, other sources of power can be used to supply power to the thermal devices instead. For example, in an electric vehicle, a high voltage battery can be used to power the thermal devices (e.g., via a DC-to-DC converter). Alternatively, power from a charger that charges the battery modules can be used to power the thermal devices (e.g., via a DC-to-DC converter). In other examples, a power supply connected to a wall outlet (AC mains) can be used to supply power to the thermal devices. Power from these sources can be supplied to the thermal devices using a remote control such as a key fob. While the vehicle is being driven, power from a generator in the vehicle can be used to power the thermal devices. Many other alternate or additional sources of power to supply the power to the thermal devices are contemplated.

The foregoing description is merely illustrative in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.

In this application, including the definitions below, the term “module” or the term “controller” may be replaced with the term “circuit.” The term “module” may refer to, be part of, or include: an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that are connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules that are connected via interface circuits. For example, multiple modules may allow load balancing. In a further example, a server (also known as remote, or cloud) module may accomplish some functionality on behalf of a client module.

The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, data structures, and/or objects. The term shared processor circuit encompasses a single processor circuit that executes some or all code from multiple modules. The term group processor circuit encompasses a processor circuit that, in combination with additional processor circuits, executes some or all code from one or more modules. References to multiple processor circuits encompass multiple processor circuits on discrete dies, multiple processor circuits on a single die, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the above. The term shared memory circuit encompasses a single memory circuit that stores some or all code from multiple modules. The term group memory circuit encompasses a memory circuit that, in combination with additional memories, stores some or all code from one or more modules.

The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used herein, does not encompass transitory electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory, tangible computer-readable medium are nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

The apparatuses and methods described in this application may be partially or fully implemented by a special purpose computer created by configuring a general purpose computer to execute one or more particular functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications, which can be translated into the computer programs by the routine work of a skilled technician or programmer.

The computer programs include processor-executable instructions that are stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may encompass a basic input/output system (BIOS) that interacts with hardware of the special purpose computer, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, etc.

The computer programs may include: (i) descriptive text to be parsed, such as HTML (hypertext markup language), XML (extensible markup language), or JSON (JavaScript Object Notation) (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. As examples only, source code may be written using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.