Configuration of interface between battery array and heat exchange plate

Abstract

The present disclosure relates generally to motorized vehicles, and more particularly to a configuration of an interface between a battery array and a heat exchange plate. In one example, a battery pack may include a battery array, a heat exchange plate, and an interface between the battery array and the heat exchange plate. The interface is configured to reduce capacitance between the battery array and the heat exchange plate.

Description

Technical Field

[0001] This disclosure generally relates to electrified vehicles, and more specifically to the configuration of the interface between the battery array and the heat exchange plate. Background Technology

[0002] High-voltage traction battery packs typically power the electric motor and other electrical loads of electrified vehicles. A traction battery pack comprises multiple battery cells. Summary of the Invention

[0003] In some respects, the technology described herein relates to a battery pack comprising: a battery array; a heat exchange plate; and an interface between the battery array and the heat exchange plate, the interface being configured to reduce the capacitance between the battery array and the heat exchange plate.

[0004] In some respects, the technology described herein relates to a battery pack, wherein the interface includes: a thermal interface material layer disposed between the battery array and the heat exchange plate; and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer.

[0005] In some respects, the technology described herein relates to a battery pack in which the dielectric material layer is provided by a coating applied to the heat exchange plate.

[0006] In some respects, the technology described herein relates to a battery pack in which: the interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and the dielectric material layer exhibits a thickness and dielectric constant configured to reduce the capacitance between the battery array and the heat exchange plate.

[0007] In some respects, the technology described herein relates to a battery pack in which the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3.

[0008] In some respects, the technology described herein relates to a battery pack in which the dielectric constant is in the range of 3 to 7 and the thickness is greater than 250 μm.

[0009] In some respects, the technology described herein relates to a battery pack in which the dielectric material layer is provided by a coating applied to the heat exchange plate.

[0010] In some respects, the technology described herein relates to a battery pack in which the interface does not include any thermal interface material.

[0011] In some respects, the technology described herein relates to a battery pack in which the interface is composed of the dielectric material layer.

[0012] In some respects, the technology described herein relates to a battery pack in which: the battery array includes a plurality of battery cells, each of the plurality of battery cells including a housing having a bottom wall, and the interface is between the bottom wall of the battery cell and the heat exchange plate.

[0013] In some respects, the technology described herein relates to a battery pack, wherein the battery array is one of a plurality of battery arrays within the battery pack.

[0014] In some respects, the technology described herein relates to a battery pack, wherein the battery pack is a battery pack for an electrified vehicle.

[0015] In some aspects, the technology described herein relates to an electrified vehicle comprising: a battery pack including a battery array, a heat exchange plate, and an interface between the battery array and the heat exchange plate, wherein the interface comprises: (i) a thermal interface material layer disposed between the battery array and the heat exchange plate, and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer, or (ii) a dielectric material layer disposed between the battery array and the heat exchange plate, wherein the dielectric material layer exhibits a thickness and dielectric constant according to one of the following: (a) the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3, or (b) the dielectric constant is in the range of 3 to 7 and the thickness is greater than 250 μm.

[0016] In some respects, the technology described herein relates to an electrified vehicle, wherein the interface comprises: a thermal interface material layer disposed between the battery array and the heat exchange plate; and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer.

[0017] In some respects, the technology described herein relates to an electrified vehicle in which: the interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and the dielectric material layer exhibits a thickness in the range of 25 μm to 250 μm and also exhibits a dielectric constant of less than 3.

[0018] In some respects, the technology described herein relates to an electrified vehicle in which: the interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and the dielectric material layer exhibits a dielectric constant in the range of 3 to 7 and also exhibits a thickness greater than 250 µm.

[0019] In some respects, the technology described herein relates to an electrified vehicle in which the interface does not include any thermal interface material.

[0020] In some respects, the technology described herein relates to an electric vehicle, wherein the interface is composed of the dielectric material layer.

[0021] In some aspects, the technology described herein relates to a method comprising: establishing an interface between a battery array and a heat exchange plate, wherein the interface comprises: (i) a thermal interface material layer disposed between the battery array and the heat exchange plate, and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer, or (ii) a dielectric material layer disposed between the battery array and the heat exchange plate, wherein the dielectric material layer exhibits a thickness and dielectric constant according to one of the following: (a) the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3, or (b) the dielectric constant is in the range of 3 to 7 and the thickness is greater than 250 μm.

[0022] In some respects, the technology described herein relates to an electrified vehicle, wherein the interface comprises the dielectric material layer, and wherein the dielectric layer is provided by a coating applied to the heat exchange plate. Attached Figure Description

[0023] Figure 1 The powertrain system of an electric vehicle is shown schematically.

[0024] Figure 2 The battery pack of the electric vehicle is shown.

[0025] Figure 3 A first exemplary configuration of the interface between the battery array and the heat exchange plate is shown.

[0026] Figure 4 A second exemplary configuration of the interface between the battery array and the heat exchange plate is shown. Detailed Implementation

[0027] This disclosure generally relates to electrified vehicles, and more specifically to the configuration of the interface between a battery array and a heat exchange plate. An exemplary interface between the battery array and the heat exchange plate is configured to reduce the capacitance between the battery array and the heat exchange plate (such capacitance may be referred to as parasitic or stray capacitance). These and other benefits will be understood from the description below.

[0028] Figure 1The powertrain 10 for the electrified vehicle 12 is schematically shown. Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and can be extended to other electrified vehicles, including but not limited to plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), fuel cell vehicles, etc.

[0029] In this embodiment, the powertrain 10 is a power-split powertrain employing a first drive system and a second drive system. The first drive system includes a combination of an engine 14 and a generator 18 (i.e., a first motor). The second drive system includes at least a motor 22 (i.e., a second motor), the generator 18, and a battery pack 24. In this example, the second drive system is considered to be the electric drive system of the powertrain 10. Both the first and second drive systems are capable of generating torque to drive one or more sets of vehicle drive wheels 28 of the electrified vehicle 12. Although... Figure 1 The power distribution configuration is described, but this disclosure extends to any hybrid or electric vehicle, including strong hybrid, parallel hybrid, series hybrid, mild hybrid, or micro hybrid.

[0030] Engine 14 (which may be an internal combustion engine) and generator 18 can be connected via power transmission unit 30 (such as a planetary gear set). Of course, other types of power transmission units (including other gear sets and transmissions) can be used to connect engine 14 to generator 18. In a non-limiting embodiment, power transmission unit 30 is a planetary gear set including a ring gear 32, a center gear 34, and a gear carrier assembly 36.

[0031] The generator 18 can be driven by the engine 14 via the power transmission unit 30 to convert kinetic energy into electrical energy. Alternatively, the generator 18 can be used as a motor to convert electrical energy into kinetic energy, thereby outputting torque to the shaft 38 connected to the power transmission unit 30. Since the generator 18 is operatively connected to the engine 14, the rotational speed of the engine 14 can be controlled by the generator 18.

[0032] The ring gear 32 of the power transmission unit 30 can be connected to a shaft 40, which is connected to the vehicle drive wheels 28 via a second power transmission unit 44. The second power transmission unit 44 may include a gear set having a plurality of gears 46. Other power transmission units may also be suitable. The gears 46 transmit torque from the engine 14 to a differential 48 to ultimately provide traction to the vehicle drive wheels 28. The differential 48 may include a plurality of gears that enable the transmission of torque to the vehicle drive wheels 28. In a non-limiting embodiment, the second power transmission unit 44 is mechanically coupled to the axle 50 via the differential 48 to distribute torque to the vehicle drive wheels 28.

[0033] Motor 22 can also be used to drive vehicle drive wheels 28 by outputting torque to shaft 52, which is also connected to the second power transmission unit 44.

[0034] Battery pack 24 is an exemplary battery for an electrified vehicle. Battery pack 24 may be a high-voltage traction battery comprising multiple battery arrays 25 (i.e., battery assemblies or battery cell groups) capable of outputting power to operate motor 22, generator 18, and / or other electrical loads of the electrified vehicle 12 to provide power to propel wheels 28. Other types of energy storage and / or output devices may also be used to power the electrified vehicle 12.

[0035] In this embodiment, the electrified vehicle 12 has two basic operating modes. The electrified vehicle 12 can operate in electric vehicle (EV) mode, where the motor 22 is used for vehicle propulsion (typically without assistance from the engine 14), thereby depleting the state of charge of the battery pack 24 up to its maximum permissible discharge rate in certain driving modes / cycles. EV mode is an example of the charge-consuming operating mode of the electrified vehicle 12. The engine 14 is generally off in the default EV mode, but may be operated as needed based on the vehicle system status or with operator permission.

[0036] The electrified vehicle 12 can also operate in a hybrid electric vehicle (HEV) mode, in which both the engine 14 and the motor 22 are used for vehicle propulsion. The HEV mode is an example of a charge-maintenance operating mode for the electrified vehicle 12. During HEV mode, the electrified vehicle 12 can reduce the use of the motor 22 for propulsion in order to maintain the state of charge of the battery pack 24 at a constant or substantially constant level by increasing the propulsion of the engine 14. Within the scope of this disclosure, the electrified vehicle 12 can operate in other operating modes besides EV mode and HEV mode.

[0037] Figure 2 A battery pack 24 that can be used in an electrified vehicle is schematically shown. For example, the battery pack 24 can be incorporated as... Figure 1 It is part of the powertrain system 10 of the electric vehicle 12. Figure 2 This is an assembled perspective view of battery pack 24.

[0038] Battery pack 24 may include battery system 54. Battery system 54 of battery pack 24 includes a plurality of battery cells 56 that store energy to power various electrical loads of the electrified vehicle 12. Within the scope of this disclosure, battery system 54 may include any number of battery cells. Therefore, this disclosure is not limited to the exact battery system configuration shown in the accompanying drawings.

[0039] Battery cells 56 can be stacked side-by-side to form a group of battery cells 56, sometimes referred to as a battery array. In an embodiment, battery cells 56 are prismatic lithium-ion cells.

[0040] Figure 2 The battery system 54 depicted includes a first battery array 25A, a second battery array 25B, a third battery array 25C, a fourth battery array 25D, a fifth battery array 25E, and a sixth battery array 25F. Arrays 25A to 25F are arranged within a housing 58. Although the battery system 54 is depicted as including six battery arrays, the battery pack 24 may include more or fewer battery arrays and still fall within the scope of this disclosure.

[0041] Figure 3 The arrangement of the first battery array 25A relative to the heat exchange plate 60 is shown. It should be understood that any additional arrays of the battery pack 24 can be arranged similarly.

[0042] The heat exchange plate 60 may be part of the housing 58, or it may be a component separate from the housing 58. The battery cells 56 of the first battery array 25A are distributed along the longitudinal axis A. In this example, each battery cell 56 is represented as a housing including a top wall 62, a bottom wall 64, side walls 66, 68 located in a plane substantially parallel to axis A, and end walls 70, 72 located in a plane substantially perpendicular to axis A. The terms "top" and "bottom" are used with reference to... Figure 3 It is used according to the orientation.

[0043] In this example, the heat exchange plate 60 is spaced downward relative to the first battery array 25A, and specifically spaced downward relative to the bottom wall 64 of the battery cell 56. The term "downward" refers to... Figure 3 It is used according to the orientation.

[0044] In one example, the heat exchange plate 60 is configured as a cold plate or part of a cold plate assembly. Alternatively, the heat exchange plate 60 may be configured as a hot plate. The heat exchange plate 60 may be part of a liquid cooling system associated with the battery system 54 and is configured for thermal management of the battery cells 56 of each battery array.

[0045] In this disclosure, the battery cell 56 is adjacent to the heat exchange plate 60, but not in direct contact with it. Instead, an interface is provided between the battery array 25A and the heat exchange plate 60. This disclosure includes various configurations for the interface, each configured to reduce the capacitance between the battery array and the heat exchange plate 60.

[0046] exist Figure 3 The text indicates the configuration of the first interface. Figure 3In this configuration, interface 74 is disposed between the battery array 25A and the heat exchange plate 60, and specifically between the bottom wall 64 of the battery cell 56 and the top wall 76 of the heat exchange plate 60. The top wall 76 of the heat exchange plate 60 is the wall of the heat exchange plate 60 directly facing the battery array 25A. Although interface 74 is located between the bottom wall 64 and the top wall 76, the heat exchange plate 60 may alternatively or additionally be arranged on the side, end, or top of the battery array 25A, and in such cases, an interface substantially similar to interface 74 may be disposed at the corresponding location.

[0047] Interface 74 includes a thermal interface material (TIM) layer 78 disposed between the battery array 25A and the heat exchange plate 60, and particularly between the battery array 25A and the dielectric material layer 80. Interface 74 also includes a dielectric material layer 80 disposed between the heat exchange plate 60 and the thermal interface material layer 78. In one example, the dielectric material layer 80 is provided by a coating applied to the heat exchange plate 60, and particularly to the top wall 76. In one example, the dielectric material layer 80 may be provided by a Sipiol® coating. Before applying the thermal interface material layer 78 between the dielectric material layer 80 and the battery array 25A, the dielectric material layer 80 may be coated onto the top wall 76 and allowed to cure, such as by UV curing.

[0048] The thermal interface material layer 78 may be made of any known thermally conductive material. In one embodiment, the thermal interface material layer 78 comprises epoxy resin. In another embodiment, the thermal interface material layer 78 comprises a silicon-based material. Other materials, including thermal grease, may alternatively or additionally constitute the thermal interface material layer 78.

[0049] exist Figure 4 The text indicates the second interface configuration. Figure 4 In this configuration, interface 82 is disposed between battery array 25A and heat exchange plate 60, and specifically between bottom wall 64 of battery cell 56 and top wall 76 of heat exchange plate 60. Interface 82 includes a dielectric material layer 84. In one aspect, interface 82 does not include any thermal interface material (TIM) layer. In another aspect, interface 82 is composed of dielectric material layer 84.

[0050] The dielectric material layer 84 exhibits a thickness T and a dielectric constant (ɛ) configured to reduce the capacitance between the heat exchange plate 60 and the battery array 25A. In one example, the thickness T is in the range of 25 μm to 250 μm, and the dielectric constant (ɛ) is less than 3. In another example, the dielectric constant (ɛ) is in the range of 3 to 7, and the thickness T is greater than 250 μm. This combination of thickness T and dielectric constant (ɛ) has been found to reduce the capacitance between the heat exchange plate 60 and the battery array 25A.

[0051] It should be understood that terms such as “about” and “substantially” are not intended to be unbounded terms and should be interpreted in accordance with the manner in which those skilled in the art would interpret these terms. Directional terms such as “above,” “over,” “below,” and “bottom” are used with reference to the arrangement of corresponding parts in the accompanying drawings and are not intended to be restrictive in any other way.

[0052] Although the different examples have the specific components shown in the illustrations, the embodiments of this disclosure are not limited to those particular combinations. Some of the components or features from one of the examples may be used in combination with features or components from another of the examples.

[0053] Those skilled in the art will understand that the embodiments described above are exemplary and not restrictive. That is, modifications to this disclosure will fall within the scope of the claims. Therefore, the appended claims should be studied to determine their true scope and content.

[0054] According to the present invention, an electric vehicle is provided, comprising: a battery pack including a battery array, a heat exchange plate, and an interface between the battery array and the heat exchange plate, wherein the interface comprises: (i) a thermal interface material layer disposed between the battery array and the heat exchange plate, and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer, or (ii) a dielectric material layer disposed between the battery array and the heat exchange plate, wherein the dielectric material layer exhibits a thickness and dielectric constant according to one of the following: (a) the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3, or (b) the dielectric constant is in the range of 3 to 7 and the thickness is greater than 250 μm.

[0055] According to an embodiment, the interface includes: a thermal interface material layer disposed between the battery array and the heat exchange plate; and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer.

[0056] According to an embodiment, the interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and the dielectric material layer exhibits a thickness in the range of 25 μm to 250 μm and also exhibits a dielectric constant of less than 3.

[0057] According to an embodiment, the interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and the dielectric material layer exhibits a dielectric constant in the range of 3 to 7 and also exhibits a thickness greater than 250 µm.

[0058] According to an embodiment, the interface does not include any thermal interface material.

[0059] According to an embodiment, the interface is composed of the dielectric material layer.

[0060] According to the present invention, a method includes: establishing an interface between a battery array and a heat exchange plate, wherein the interface comprises: (i) a thermal interface material layer disposed between the battery array and the heat exchange plate, and a dielectric material layer disposed between the heat exchange plate and the thermal interface material layer, or (ii) a dielectric material layer disposed between the battery array and the heat exchange plate, wherein the dielectric material layer exhibits a thickness and dielectric constant according to one of the following: (a) the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3, or (b) the dielectric constant is in the range of 3 to 7 and the thickness is greater than 250 μm.

[0061] In one aspect of the invention, the interface is composed of the dielectric material layer, and wherein the dielectric layer is provided by a coating applied to the heat exchange plate.

Claims

1. A battery pack comprising: Battery array; Heat exchange plate; as well as The interface between the battery array and the heat exchange plate is configured to reduce the capacitance between the battery array and the heat exchange plate.

2. The battery pack according to claim 1, wherein the interface comprises: A thermal interface material layer is disposed between the battery array and the heat exchange plate; as well as A dielectric material layer is disposed between the heat exchange plate and the thermal interface material layer.

3. The battery pack of claim 2, wherein the dielectric material layer is provided by a coating applied to the heat exchange plate.

4. The battery pack according to claim 1, wherein: The interface includes a dielectric material layer disposed between the battery array and the heat exchange plate, and The dielectric material layer exhibits a thickness and dielectric constant configured to reduce the capacitance between the battery array and the heat exchange plate.

5. The battery pack of claim 4, wherein the thickness is in the range of 25 μm to 250 μm and the dielectric constant is less than 3.

6. The battery pack of claim 4, wherein the dielectric constant is in the range of 3 to 7, and the thickness is greater than 250 μm.

7. The battery pack of claim 4, wherein the dielectric material layer is provided by a coating applied to the heat exchange plate.

8. The battery pack of claim 4, wherein the interface does not include any thermal interface material.

9. The battery pack of claim 4, wherein the interface is composed of the dielectric material layer.

10. The battery pack according to claim 1, wherein: The battery array includes multiple battery cells. Each of the plurality of battery cells includes a housing with a bottom wall, and The interface is between the bottom wall of the battery cell and the heat exchange plate.

11. The battery pack of claim 1, wherein the battery array is one of a plurality of battery arrays within the battery pack.

12. The battery pack of claim 1, wherein the battery pack is a battery pack for an electric vehicle.

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