CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/351,008, entitled "Cooling Plate Thermal Battery Control", filed June 3, 2010, which is herein incorporated by reference in its entirety.

BACKGROUND

[0002] Disclosed embodiments relate generally to battery systems and methods and, in specific embodiments, to systems and methods for controlling battery temperature.

[0003] Vehicles, such as motor vehicles, utilize an energy source in order to provide power to operate the vehicle. While petroleum based products, such as gasoline, dominate as an energy source in traditional combustion engines, alternative energy sources are available, such as methanol, ethanol, natural gas, hydrogen, electricity, solar, or the like. A hybrid-powered vehicle, referred to as a "hybrid vehicle," utilizes a combination of energy sources in order to power the vehicle. For example, in some embodiments, a battery maybe utilized in combination with the traditional combustion engine to provide power to operate the vehicle. Such vehicles are desirable since they take advantage of the benefits of multiple fuel sources in order to enhance

performance and range characteristics of the hybrid vehicle relative to a comparable gasoline powered vehicle.

[0004] An example of a hybrid vehicle is a vehicle that utilizes a combination of stored electrical energy and a gasoline-powered internal combustion engine to propel the vehicle. An electric vehicle is environmentally advantageous due to its low emissions characteristics and the general availability of electricity as a power source. The battery may be quite large, depending on the energy requirements of the vehicle, and will generate heat that is dissipated using various techniques. Typically, coolant, such as a liquid or a gas, is used as a medium for transferring heat from the battery. Current systems may use air, which may not reject heat fast enough. Other systems using liquid increase the risk of leaks and thus have not reached widespread use. Furthermore, batteries must often be chilled on hot days by either cabin air or through separate chiller units for liquid cooled batteries.

SUMMARY

[0005] As disclosed herein, a battery temperature control system may include (but is not limited to) a base, a battery cell, and a thermal plate. This base has a fluid channel for receiving a thermal fluid that changes a temperature of the base as the thermal fluid flows through the fluid channel. The battery cell is supported on the base. The thermal plate is supported on the base plate. The thermal plate is thermally coupled to the battery cell to change a temperature of the battery cell in response to a change in the temperature of the base.

[0006] Thus, various embodiments provide a temperature control system for a battery. The control system reduces the need for complicated fluid distribution arrangements to manage battery temperature. In various embodiments, the control system provides direct conductive heat transfer. In various embodiments, heat transferred from the battery can be redistributed to other areas of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS [0007] FIG. 1 is a perspective view of a hybrid vehicle.

[0008] FIG. 2 is a perspective view of a hybrid vehicle showing a battery system.

[0009] FIG. 3 illustrates an example battery cell mounted in a thermal base plate.

[0010] FIG. 4A - 4B illustrate a thermal base plate receiving individual thermal veins.

[0011] FIG. 5A - 5C illustrate a plurality of battery cells arranged in a battery pack mounted on a thermal base plate.

[0012] FIG. 6 illustrates a fluid flow channel within a thermal base plate.

[0013] FIG. 7 illustrates a thermal base plate with a plurality of fluid orifices delivering fluid to an internal cavity.

[0014] FIG. 8 illustrates a thermal base plate with fluid channels and a cavity for receiving a thermally active material. [0015] FIG. 9 illustrates a thermal base plate with fluid channels and an open cavity for receiving a thermally active material.

[0016] FIG. 10 illustrates a cooling system using a refrigerant.

[0017] FIGS. 1 lA-1 IB illustrate flow patterns of refrigerant with evaporation.

DETAILED DESCRIPTION

[0018] FIGS. 1 and 2 illustrate a vehicle 10. In the embodiments of FIGS. 1 and 2, the vehicle 10 includes a solar panel 14. The vehicle 10 may be, for instance, a plug- in hybrid vehicle that is solar and electric powered. The vehicle 10 includes a body structure having a frame and outer panels 12 covering the frame that cooperatively form the shape of the vehicle 10. The vehicle 10 includes an interior space 11 referred to as a passenger compartment. For a convertible-style vehicle 10, the passenger compartment 1 1 may be enclosed by a moveable convertible top that covers the passenger compartment 11 in an extended position. The vehicle 10 can also include a storage space 13 referred to as a trunk or luggage compartment 13. The trunk or luggage compartment 13 is typically accessible via a deck lid 15. The deck lid 15 can be a panel member pivotally connected to the body structure of the vehicle 10 such that the deck lid 15 can articulate in multiple positions. For example, the deck lid 15 may pivot about a forward edge 15A in order to provide access to the trunk 13 of the vehicle 10. In a particular example, the deck lid 15 may pivot about a rearward edge 15B in order to stow the folded top within the trunk or luggage compartment 13. The vehicle 10 includes a front compartment 16, which may extend forwardly from the passenger compartment 11. The front compartment 16 is covered from above by a hood 19. The hood 19 can be pivotally mounted at a proximal end 19A of the front compartment 16 adjacent the passenger compartment 11 to allow access to mechanical and electrical components mounted in the front compartment 16.

[0019] The vehicle 10 includes a power source (not shown), such as an engine, that engages a drive shaft (not shown), and in combination with the wheels define a drive train (also referred to as a power train), commonly referred to as a group of components that generate power for delivery to the road surface. In some embodiments, the engine may be located in or below the rear compartment 13. In other embodiments, the engine may be located in the front compartment 16 or at any other suitable location.

[0020] The power train may include an electrically powered motor and motor controller (not shown). The vehicle 10 may also include a gasoline-powered engine that supplements the electric motor when required under certain operating conditions. The electrical energy for the electrically powered motor can be stored in an energy storage device, such as a battery system 18. Various types of batteries are available, such as (but not limited to) lead acid, lithium- ion, and/or the like. It should be appreciated that the vehicle may include more than one type of battery or energy storage system 18. Generally, the battery supplies power in the form of electricity to operate various vehicle components.

[0021] The vehicle 10 may include a low-voltage battery (not shown) (e.g., a typical 12 V lead acid battery) that provides electrical power to the vehicle components and a high-voltage battery, such as (but not limited to) a traction battery (e.g., 9 400 V traction battery) or the like, that provides electrical power to the electrically powered motor. The battery may be in communication with a control system that regulates the distribution of power within the vehicle 10, such as to the electrically powered motor, one or more vehicle components, accessories, and/or the like. In some embodiments, the high voltage battery 18 receives electrical energy from any of (but not limited to) a plug-in source, the low-voltage battery, solar panel 14, or combinations thereof. The hybrid vehicle 10 may include other features conventionally known for a vehicle, such as a gasoline motor, other controllers, a drive train, and/or the like.

[0022] The battery 18 may be a single unit. In other embodiments, the battery 18 may be a plurality of modules arranged in a predetermined manner, such as in a series or the like. Various strategies are available to cool the battery 18. For example, via the circulation of a medium, such as conditioned air, a fluid, and/or the like, in or around the battery case 20.

[0023] The battery 18 is contained within a battery case 20. The case 20 can be constructed of any suitable material. In some embodiments, the vehicle 10 may include more than one type of battery 18 or energy storage device within the case 20. In some embodiments, the vehicle 10 may include more than one case 20.

[0024] As shown in FIGS. 5A - 5C, the battery 18 may include a plurality of individual battery cells 24 arranged or stacked in a series. Non-conductive portions (not shown) can be provided to cover exposed electrically active portions of the individual battery cells 24. In some embodiments, one or more module controllers (not shown) is/are provided and coupled to the individual battery cells 24 to monitor individual voltage of each of the battery cells 24. The controller can further be configured to balance the individual battery cells 24 to achieve desired voltage distribution. For example, if one particular battery cell 24 is delivering a higher voltage than desired, the controller can instruct that cell to bleed some voltage and redistribute the voltage to a cell that is delivering a lower voltage than desired. In further embodiments, the module controller can communicate the voltage

measurements to a full system controller (not shown).

[0025] With reference to FIGS. 1-3, the battery 18 is supported within the vehicle 10 by a tray 22 (refer to FIG. 2). The battery 18 and tray 22 may extend

longitudinally along the length of the vehicle. The tray 22 can be fabricated from a metal material, such as (but not limited to) aluminum and/or the like, and/or any other suitable material. The tray 22 can be secured to the vehicle frame using a fastener, such as (but not limited to) a bolt and/or the like. A seal may be applied between a flange portion of the base member and the frame of the vehicle 10 to prevent the intrusion of elements, such as moisture, dirt, or the like, into the interior of the battery 18. An example of a sealant is (but not limited to) rubber, foam, adhesive, and/or the like.

[0026] Referring to FIGS. 3 - 5C, a thermal control system 21 for adjusting thermal conditions of a battery, such as the battery 18 is illustrated. The thermal control system 21 can also be referred to as a thermal management system or an integrated thermal management system. The battery 18 may include a plurality of the battery cells 24 arranged in a stack. For instance, the battery 18 may include (but is not limited to) about ten to fifty individual battery cells 24. Typically, the battery cells 24 are arranged or stacked together in a predetermined arrangement, for instance, in a vertical or horizontal stack as a series of battery cells 24.

[0027] The battery cells 24 typically define a substantially rectangular geometry having a relatively thin side profile relative to a substantially larger flat surface. The battery cells 24 can be referred to as a "pouch cell" and this geometry can be referred to as a "notebook" configuration. In a vertical stack of the battery cells 24, each individual battery cell 24 lies substantially horizontal and flat and the battery cells 24 can be stacked on top of each other. In other embodiments, the battery cells 24 can be aligned vertically and stacked against each other in a horizontal stack, similar to books in a bookcase.

[0028] Formed around and between the battery cells 24 are openings 24A defined to allow for fitting a thermal vein or thermal plate 23 between the surfaces of the individual battery cells 24. The vein or plate 23 abuts against a surface of the battery cell 24 to provide the heat transfer for cooling and heating of the battery cell 24. In some embodiments, the vein 23 is in direct contact with the surface of the battery cell 24. In other embodiments, an intermediary member (not shown) is provided between the vein 23 and the battery cell 24 in which case the vein 23 provides for heat transfer to the intermediary member, which then provides for heat transfer to the battery cell 24.

[0029] The vein 23 can be constructed of a material that provides thermal conduction to the surface of the battery cells 24 depending on the intended thermal management of the battery cells 24. In some embodiments, the vein 23 can be used to cool the battery cells 24. In other embodiments, the vein 23 can be used to heat the battery cells 24.

[0030] In particular embodiments, the vein 23 is sized and shaped as a flat plate extending along the surface of the battery cell 24. A surface of the vein 23 and the surface of the battery cell 24 can be in physical contact sufficient to provide thermal modification to the battery cell 24 if the surface of the vein 23 is thermally modified. For example, if the vein 23 is cooled to a lower temperature than a portion (e.g., the surface) of the vein 23 that is in contact with the battery cell 24, the contact will cause heat rejection from the surface of the battery cell 24 to lower the temperature of the battery cell 24 through conduction. FIG. 5A shows the vein 23 in contact with the surface of battery cell 24.

[0031] With reference to FIGS. 3-5C, the thermal management system 21 also may include a thermal base plate 26 for supporting the battery cells 24. The base plate 26 can be constructed of any thermally suitable material, such as (but not limited to) aluminum and/or the like, to modify temperature and increase heat transfer between the base plate 26 and other components (e.g., the vein 23). In some embodiments, the individual battery cells 24 can physically connect to the base plate 26 (e.g., FIG. 3). In other embodiments, the individual battery cells 24 abut against the base plate 26 (e.g., FIG. 5C). In some embodiments, the vein 23 can be mounted in the base plate 26 and positioned between the battery cells 24 in the opening 24A. Thus, in various embodiments, a plurality of veins 23 are positioned between a plurality of battery cells 24 in a battery system 18. FIG. 5A is a side profile view of an example vein 23 sandwiched between two battery cells 24.

[0032] Returning to FIGS. 3-5C, the base player 26 may include flow channels 28 for receiving a thermal modifying fluid 25. As the fluid 25 flows through the channels 28, the temperature of the base plate 26 will change (i.e., either decrease or increase). In turn, this changes the temperature of the vein 23 when thermally coupled to (e.g., mounted on) the base plate 26 to absorb (reject) or deliver heat from the surface of the battery cell 24. For instance, in embodiments where cooling is of interest, the fluid 25 may be refrigerant or the like. In such embodiments, as the refrigerant flows through the channels 28, the temperature of the base plate 26 will decrease causing the temperature of the vein 23 to decrease to absorb heat from the surface of the battery cell 24.

[0033] FIGS. 4A-4B show exemplary mounting arrangements of the veins 23 with the base plate 26. The dotted lines represent the fluid 25 within the base plate 26. The base plate 26 can serve as a support structure for the veins 23 and the battery cells 24. In various embodiments example, the base plate 26 defines at least a mounting cavity 40 for mounting the vein 23. In the example of FIG. 4A, the base plate 26 defines a plurality of mounting cavities 40. Each cavity 40 can be sized and shaped to mount a vein 23 in a substantially perpendicular arrangement with respect to the base plate 26.

[0034] With reference to FIGS. 3-5C, the vein 23 may include a flange section 29, extending from a conducting plate section 27 of the vein. In further embodiments, a spring mechanism 41 (or other suitable member) can be disposed between the plate section 27 and the flange section 29 to provide additional fitting support with the battery cells 24. The spring mechanism 41 can be constructed to operatively maintain firm and even contact of the conducting plate 27 with the surface of battery cells 24. This may facilitate efficient heat transfer between the vein 23 and the battery cell 24. In particular embodiments, the flange 29 section extends radially from the plate section 27 and is sized and shaped to securely fit into cavity 40.

[0035] FIG. 5B illustrates the case 20 (having a plurality of veins and battery cells) prior to being mounted to the base plate 26. FIG. 5C illustrates of the case 20 (and the veins 23) mounted to the base plate 26. With reference to FIGS. 3-5C, in some embodiments, the case 20 abuts the base plate 26 to increase contact surface area therebetween. In further embodiments, a high surface area gel or gauze can be provided therebetween to reduce gap effect. In some embodiments, the battery system 18 having the veins 23 placed between battery cells 24 is bolted (or otherwise suitably fastened) to the base plate 26. In particular embodiments, the fastener may allow for thermal conduction between the base plate 26 and the veins 23.

[0036] FIGS. 6-9 illustrate various flow channel configurations for the base plate 26, although other configurations are contemplated. With reference to FIGS. 3-6, the fluid 25 can enter the base plate 26 through the fluid flow channel 28 at an inlet 30A and exit at an outlet 30B. The fluid 25 travels through the base plate 26 in a predetermined pattern operable to modify the temperature of the plate 26. In particular embodiments, the inlet 30A and the outlet 30B are positioned relatively close to one another (e.g., adjacent each other) to minimize temperature difference across the base plate 26. As the temperature of the base plate 26 increases or decreases, the temperature of the vein 23 correspondingly increases or decreases to provide desired heat transfer to or from the battery cell 24. The fluid 25 can be a refrigerant coolant in a cooling example. [0037] FIG. 7 illustrates another example of the base plate 26. In this example, the base plate 26 has an inlet 31 and an outlet 33 positioned close to each other. With reference to FIGS. 3-5C, the fluid 25 can enter the base plate 26 through the inlet 31 into the flow channel 28. In particular embodiments, the flow channel 28 defines at least one orifice or hole 32 sized to disburse the fluid 25 into an internal cavity 34 of the base plate 26. The fluid 25 fills the internal cavity 34, which is generally hollow, thus modifying the temperature of the base plate 26. The fluid 25 exits the cavity 34 through the outlet 33. In some embodiments, a plurality of holes or apertures 32 are defined along the flow channel 28 in a sufficient spacing to ensure even fluid flow and temperature distribution across the base plate 26.

[0038] FIG. 8 illustrates another example of the base plate 26. In this example, the base plate 26 includes the internal cavity 34, one or more of the fluid flow channels 28, and one or more thermal absorption channels 37. With reference to FIGS. 3-5C and 8, in various embodiments, the cavity 34 is filled with an insulating material, such as foam or any other suitable material, to reduce heat loss and maintain even temperature distribution across the base plate 26. The absorption channels 37, shown as rectangular (but not limited to such), in this example can be filled with a heat storage material, phase change material, air, or the like. The absorption channels 37 are operable to absorb or release heat and further stabilize the temperature across the base plate 26. The fluid flow channels 28 provide fluid flow for the thermal fluid 25 to pass through the base plate 26. In some embodiments, the base plate 26 can further include structure support members 35 to provide structural stability.

[0039] FIG. 9 illustrates another example of the base plate 26. With reference to FIGS. 3-5C and 9, the base plate 26 in this example includes a pair of the fluid flow channels 28 through which the thermal fluid flows to modify the temperature of the base plate 26. The cavity 34 can be filled with a phase change material, coolant, air, or the like to maintain the temperature of the base plate. The base plate 26 can further include support members (e.g., 35 in FIG. 8) if needed.

[0040] FIG. 10 illustrates an example cooling or heating system associated with the present disclosure. With reference to FIGS. 1-10, in various embodiments, flow of the thermal fluid 25 into the base plate 26 can be controlled through the vehicle controller based on predetermined thermal thresholds. Temperature sensors (e.g., FIG. 10 at temperature sensor 4) can be placed in and around the battery cells 24 as well as the base plate 26 and the veins 23 to monitor temperatures. The thermal fluid 25 can be delivered to maintain battery temperature within a desired range.

Accordingly, the burden of battery temperature control is reduced as a result of these example systems.

[0041] In various embodiments, the thermal fluid 25 is a refrigerant (or other suitable coolant). A particular property of a refrigerant includes the ability to change phase, which facilitates the desired heat transfer. The refrigerant can be delivered to the base plate 26 through a dedicated stand-alone cooling and heating system or in conjunction with an existing vehicle air conditioning system. Splitting the refrigerant to deliver to both the cabin air conditioner and the battery cooling system reduces the number of physical parts needed to cool the battery 18 or the need for a separate cooling unit dedicated to the battery 18.

[0042] In particular embodiments (e.g., the cooling or heating system of FIG. 10), the battery cooling plate (e.g., the base plate 26) includes a refrigerant inlet and outlet and is coupled to a controller. The controller is further coupled to each of three valves (valve 1, 2, and 3). Valve 1 can be coupled to the in-cabin evaporator (i.e., the air conditioning system of the vehicle 10). The valve 1 can control fluid flow into the air conditioning system of the vehicle 10. The valve 1 can generally be a needle valve (or the like) that allows for expansion to generate a mixed liquid/vapor stream as the inlet into the air conditioning system. Valve 2 functions similarly to the valve 1 but is positioned on the inlet to the base plate 26. The outlet flow from the base plate 26 passes through valve 3, which can function to control many flow characteristics. A temperature sensor 4 can be coupled to the battery cooling plate and deliver temperature readings to the controller.

[0043] The valve 3 can be controlled by the controller to manage (but not limited to) refrigerant flow out of the base plate 26, temperature of the thermal fluid 26, pressure, and/or the like. Based on these flow characteristics and a sensor mounted near or at the outlet, refrigerant quality parameters can be determined, monitored, and modified through the valve 3. For example, vapor/liquid composition is an aspect that effects heat transfer efficiency and capabilities. The vapor/liquid composition can be monitored and adjusted through the valve 3 and measured parameters of the system. For example, in FIGS. 11 A and 1 IB, a simple U-shaped flow pattern for the refrigerant is shown. In FIG. 11 A, the flow rate of a fluid (e.g., the thermal fluid 25 in FIGS. 3 and 4 A) is slower than 1 IB. Accordingly, the fluid can evaporate quickly and therefore only provide desired heat transfer to the first section of the base plate as represented by the oval. In FIG. 1 IB, the flow rate is higher and thus allowing the liquid phase of the refrigerant to evaporate more evenly through the plate.

[0044] Returning to FIGS. 1-10, in some embodiments, the valve 3 provides different control options for desired heat rejection and transfer. Pulse flooding is a one method of improving heat transfer. Pulse flooding includes flowing refrigerant into the base plate 26 until the plate is effectively "flooded" and then turning off the flow. The refrigerant is then allowed to evaporate and the cycle is repeated.

[0045] Another method of improving heat transfer includes evaporation temperature control. The valve 3 can regulate the pressure within the base plate 26 raising the refrigerant evaporation temperature. This can limit heat transfer allowing refrigerant to travel the length of the base plate 26 before being completely evaporated.

[0046] Another method of improving heat transfer includes regulating refrigerant quality. Sensors can estimate gas percentage (i.e., quality) at the outlet of the base plate 26. If 100 percent gas, for example, is detected, the valve can restrict flow, thereby increasing pressure, and reducing heat transfer to allow for the liquid to be present in the entirety of the base plate 26 and transfer heat more uniformly. In a further example, the refrigerant cycle can be reversed to provide heat to the battery when desired. The above methods for improving heat transfer are merely exemplary as any other suitable method may be used in addition to or in alternative of these methods.

[0047] Various embodiments provide for systems and methods of managing thermal conditions of a battery cell 24 or a plurality of battery cells 24 arranged in a battery system 18. Particular systems and methods include positioning a vein 23 in contact with a battery cell 24 to allow the vein 23 to reject heat from or introduce heat to the surface of the battery cell 24; supporting the vein 23 and the battery cell 24 with a thermal base plate 26; and delivering thermal fluid 25 through a channel 28 located in the base plate. In particular embodiments, the thermal fluid may be controlled to either cool or heat the base plate 26, which cools or heats the veins 23, which reject or deliver heat from the battery cells 24.

[0048] The embodiments disclosed herein are to be considered in all respects as illustrative, and not restrictive of the invention. The present invention is in no way limited to the embodiments described above. Various modifications and changes may be made to the embodiments without departing from the spirit and scope of the invention. The scope of the invention is indicated by the attached claims, rather than the embodiments. Various modifications and changes that come within the meaning and range of equivalency of the claims are intended to be within the scope of the invention.