Thermal management configuration for battery pack

Abstract

The present disclosure provides a thermal management configuration for a battery pack. A battery assembly for an electrically powered vehicle may include a battery array having a first battery cell, a second battery cell, and a thermal barrier between the first battery cell and the second battery cell. The thermal barrier has a size greater than a corresponding size of the first battery cell and the second battery cell.

Description

Technical Field

[0001] The present disclosure relates to thermal management arrangements and corresponding methods for battery packs, such as battery packs for electrified vehicles. Background Art

[0002] The need to reduce automotive fuel consumption and emissions is well known. As a result, vehicles are being developed that reduce or completely eliminate reliance on internal combustion engines. Electrified vehicles are one type of vehicle being developed for this purpose. Generally, electrified vehicles differ from conventional motor vehicles in that they are selectively driven by an electric motor powered by a battery. In contrast, conventional motor vehicles rely solely on an internal combustion engine to propel the vehicle.

[0003] A high-voltage battery pack typically powers the electric motor and other electrical loads of an electrified vehicle. The battery pack includes multiple battery cells and various other battery internal components that support the electric propulsion of the electrified vehicle. Summary of the invention

[0004] In some aspects, the technology described herein relates to a battery assembly for an electrified vehicle, the battery assembly comprising: a battery array having a first battery cell, a second battery cell, and a thermal barrier between the first battery cell and the second battery cell, wherein a size of the thermal barrier is larger than corresponding sizes of the first battery cell and the second battery cell.

[0005] In some aspects, the technology described herein relates to a battery assembly that also includes: an array cover; and a layer vertically located between the top of the first and second battery cells and the array cover, wherein the layer includes a narrow groove that receives a top section of the thermal barrier.

[0006] In some aspects, the technology described herein relates to a battery assembly in which the slot is aligned with a vent of the array cover relative to a length of the battery array.

[0007] In some aspects, the technology described herein relates to a battery assembly wherein the slot is sized and shaped to receive the top section of the thermal barrier and allow gas to flow to a vent of the array cover.

[0008] In some aspects, the technology described herein relates to a battery assembly wherein the layer includes another slot aligned with the vent of the array cover, wherein the another slot is spaced apart from the slot that receives the top section of the thermal barrier relative to the length of the battery array.

[0009] In some aspects, the technology described herein relates to a battery assembly wherein a topmost surface of the thermal barrier is disposed vertically above the layer.

[0010] In some aspects, the technology described herein relates to a battery assembly wherein the topmost surface of the thermal barrier is spaced below the bottommost surface of the array cover.

[0011] In some aspects, the technology described herein relates to a battery assembly wherein the topmost surface of the thermal barrier contacts the bottommost surface of the array cover.

[0012] In some aspects, the technology described herein relates to a battery assembly wherein the thermal barrier includes mica and aerogel.

[0013] In some aspects, the technology described herein relates to a battery assembly wherein the thermal barrier includes a mica-aerogel-mica interlayer.

[0014] In some aspects, the technology described herein relates to a battery assembly wherein the thermal barrier comprises an aerogel-mica-aerogel interlayer.

[0015] In some aspects, the technology described herein relates to a battery assembly in which the thermal barrier includes an asymmetric arrangement of material layers.

[0016] In some aspects, the technology described herein relates to a battery assembly in which the thermal barrier includes layers of aerogel, fiberglass, and polyurethane foam.

[0017] In some aspects, the technology described herein relates to a battery assembly in which at least a portion of the thermal barrier protrudes through a slot in the array cover.

[0018] In some aspects, the technology described herein relates to a battery assembly, which also includes: an array cover; wherein the thermal barrier includes a baffle that is adjacent to and protrudes from a top section of the thermal barrier, and the baffle can be deflected from a neutral position to a deflected position wherein the baffle contacts the array cover.

[0019] In some aspects, the technology described herein relates to a battery assembly wherein the dimension of the thermal barrier is a height, and the corresponding dimension of the first battery cell and the second battery cell is a height.

[0020] In some aspects, the technology described herein relates to an electrified vehicle, comprising: a battery assembly, the battery assembly comprising: a battery array, the battery array having a first battery cell, a second battery cell, and a thermal barrier between the first battery cell and the second battery cell, wherein a size of the thermal barrier is larger than a corresponding size of the first battery cell and the second battery cell.

[0021] In some aspects, the technology described herein relates to an electrified vehicle that also includes: an array cover; and a layer vertically located between the top of the first and second battery cells and the array cover, wherein the layer includes a narrow slot that receives a top section of the thermal barrier.

[0022] In some aspects, the technology described herein relates to an electrified vehicle in which the thermal barrier protrudes through a slot in an array cover.

[0023] In some aspects, the technology described herein relates to a method comprising: sealing a compartment of a battery array of a battery assembly of an electrified vehicle using a thermal barrier disposed between the first battery cell and the second battery cell, wherein a size of the thermal barrier is larger than corresponding sizes of the first battery cell and the second battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A powertrain system for an electrified vehicle is schematically shown.

[0025] Figure 2 is a partial cross-sectional view of an exemplary battery array.

[0026] Figure 3 yes Figure 2 An enlarged view of a portion of an exemplary battery array.

[0027] Figure 4 yes Figure 2 A top view of a portion of a layer of a battery array of FIG. The layer includes an alternating arrangement of slots of different sizes.

[0028] Figure 5 yes Figure 4 Top view of a layer of battery cells and thermal barriers arranged relative to the slots.

[0029] Figure 6 is a cross-sectional view of a portion of an exemplary battery array and particularly illustrates an embodiment in which the cover includes a baffle in contact with a thermal barrier.

[0030] Figure 7 is a cross-sectional view of a portion of an exemplary battery array and particularly illustrates an embodiment in which the thermal barrier includes a deflectable baffle.

[0031] Fig. 8A is a cross-sectional view of a portion of an exemplary battery array and particularly illustrates an embodiment in which a layer includes slots configured to receive a thermal barrier and also provide ventilation functionality.

[0032] Figure 8B yes Fig. 8AA top view of a portion of a layer.

[0033] Fig. 9 is a partial cross-sectional view of another exemplary battery array. DETAILED DESCRIPTION

[0034] The present disclosure relates to thermal management configurations for battery packs, such as those used in electrified vehicles, and corresponding methods. The disclosed arrangements seal adjacent compartments, each of which contains one or more battery cells, thereby reducing heat transfer between adjacent compartments and promoting ventilation.

[0035] Figure 1 A powertrain 10 for an electrified vehicle 12 ("vehicle 12") is schematically illustrated. Although depicted as a hybrid electric vehicle (HEV), it should be understood that the concepts described herein are not limited to HEVs and may be extended to other electrified vehicles including, but not limited to, plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs).

[0036] In one embodiment, the powertrain 10 is a power-split powertrain that employs 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), a generator 18, and a battery assembly 24. In this example, the second drive system is considered to be an electric drive system of the powertrain 10. The first drive system and the second drive system generate torque to drive one or more sets of vehicle drive wheels 28 of the vehicle 12. Although a power-split configuration is shown, the present disclosure extends to any hybrid or electric vehicle, including a strong hybrid, a parallel hybrid, a series hybrid, a mild hybrid, or a micro hybrid.

[0037] The engine 14, which in one embodiment is an internal combustion engine, and the generator 18 may be connected via a power transfer unit 30, such as a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine 14 to the generator 18. In one non-limiting embodiment, the power transfer unit 30 is a planetary gear set that includes a ring gear 32, a sun gear 34, and a carrier assembly 36.

[0038] The generator 18 may be driven by the engine 14 through the power transfer unit 30 to convert kinetic energy into electrical energy. The generator 18 may alternatively be used as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft 38 connected to the power transfer unit 30. Since the generator 18 is operatively connected to the engine 14, the speed of the engine 14 may be controlled by the generator 18.

[0039] The ring gear 32 of the power transfer unit 30 can be connected to the shaft 40, which is connected to the vehicle drive wheels 28 through the second power transfer unit 44. The second power transfer unit 44 can include a gear set having a plurality of gears 46. Other power transfer units may also be suitable. The gears 46 transfer torque from the engine 14 to the differential 48 to ultimately provide traction to the vehicle drive wheels 28. The differential 48 can include a plurality of gears that enable the torque to be transferred to the vehicle drive wheels 28. In one embodiment, the second power transfer unit 44 is mechanically coupled to the axle 50 through the differential 48 to distribute the torque to the vehicle drive wheels 28.

[0040] The motor 22 can also be used to drive the vehicle drive wheels 28 by outputting torque to the shaft 52, which is also connected to the second power transfer unit 44. In one embodiment, the motor 22 and the generator 18 can be used as a motor to output torque. For example, the motor 22 and the generator 18 can each output power to the battery assembly 24.

[0041] The battery assembly 24 is an exemplary electrified vehicle battery. The battery assembly 24 may be a high voltage traction battery pack including a plurality of battery arrays 25 or other groups of battery cells capable of outputting electrical power to operate the motor 22 , the generator 18 , and / or other electrical loads of the vehicle 12 .

[0042] The vehicle 12 may additionally 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-maintaining operating mode of the vehicle 12. During the HEV mode, the vehicle 12 may reduce propulsion use of the motor 22 in order to maintain the state of charge of the battery assembly 24 at a constant or approximately constant level by increasing propulsion use of the engine 14. The vehicle 12 may also operate in other operating modes in addition to the EV mode and the HEV mode within the scope of the present disclosure.

[0043] Figure 2 Additional details of some components of an example battery assembly 24 are shown in cross-section. The battery assembly 24 includes at least one array 25. The array 25 includes a plurality of compartments 60, each compartment including structures that follow the same pattern along the length L of the array 25. For example, with respect to one of the compartments 60, the compartment 60 includes two cells 62A, 62B that are in direct contact with each other within the single compartment 60. The compartments 60 are separated by a barrier 64, which may be referred to as a thermal barrier. Reference Figure 2 , the barrier 64 is a vertically extending wall and also extends between the side walls of the battery assembly 24, relative to Figure 2 Each barrier 64 may be made of a mica-aerogel-mica sandwich, wherein the layers of the sandwich are arranged relative to the length L (i.e., Figure 2In another embodiment, the barrier 64 includes a 0.5 mm thick mica layer, a 3.5 mm thick aerogel layer, and a 0.5 mm thick mica layer.

[0044] Alternatively, barrier 64 may be provided by a sandwich of aerogel-mica-aerogel. Still further, barrier 64 may be provided by a sandwich of aerogel-fiberglass-aerogel. Instead of aerogel, other materials may be used, such as alkaline earth silicate (AES) insulators. In some embodiments, barrier 64 may also include an asymmetric arrangement of material layers in the left-to-right direction. For example, barrier 64 may be provided by an arrangement including aerogel-fiberglass-polyurethane foam layers, such as in Figure 2 Move from left to right.

[0045] The barrier 64 exhibits a height H1 greater than the height H2 of the cells 62A, 62B, which serves to direct the exhaust gases away from the adjacent compartments 60, and instead generally in a vertically upward direction (relative to the Figure 2 ) to direct those exhaust gases. The heights H1, H2 are measured from the bottom surface 63 of the battery assembly 24, which can be the bottom of the tray, and the cells 62A, 62B and the barriers 64 are directly supported on the bottom surface. In this embodiment, the top section of each barrier 64 including the topmost surface 65 is arranged adjacent to the array cover 66, which is here the top cover and is generally arranged opposite the bottom surface 63. More specifically, the topmost surface 65 of each barrier 64 protrudes into and passes through the narrow slot 68 in the layer 70. The layer 70 is vertically below the array cover 66, as shown in FIG. Figures 2 to 5 In one embodiment, layer 70 may include mica flakes and polyurethane foam.

[0046] Common Reference Figures 2 to 5 , the topmost surface 65 can directly contact the bottom 69 of the array cover 66. In this embodiment, the layer 70 includes an alternating arrangement of slots, including slots 72 that align with the vents in the array cover 66 and slots 68 for receiving the barrier 64. The slots 68 exhibit at least one dimension that is different from the slots 72. In this example, the slots 68 exhibit a dimension D1 that is larger than the dimension D2 of the slots 72. In this example, the dimensions D1, D2 are the length dimensions of the slots 68, 72, and are measured relative to the width of the battery assembly 24.

[0047] In this example, slots 68 are sized and shaped so that layer 70 directly contacts barrier 64. Contact between barrier 64 and layer 70 seals each compartment 60. Contact between layer 70 and array cover 66 and / or barrier 64 and array cover 66 further seals each compartment 60.

[0048] In this example, the array cover 66 includes a vent baffle 74 ( Figure 3 ), the vent baffle being configured to selectively flap open when subjected to a relatively high pressure from within a corresponding one of the compartments 60. In this example, the vent baffle 74 covers a corresponding vent opening 75 of the array cover 66. In other embodiments, the vent baffle 74 may cover two or more vent openings 75 of the array cover 66. The vent baffle 74 may be configured to be attached to the array cover 66, or to be formed by scoring the array cover 66, such as by scoring three edges of the rectangular shape of the array cover 66. The vent baffle 74 may be covered by a layer of mica or another material.

[0049] exist Figure 6 In the embodiment of FIG. 1 , the barrier 64 protrudes into and through the ventilation opening 75 in the array cover 66. The baffle 76 (which may be made of mica) protrudes into contact with the barrier 64. The baffle 76 may be attached to the array cover 66 using tape or another type of adhesive. Figure 6 In FIG. 6 , two baffles 76 protrude into each ventilation opening 75 in the array cover 66. In addition, in Figure 6 In the embodiment, the outer layers of the sandwich forming the barrier 64 protrude above the array cover 66. Although not shown, the layer 70 may be present Figure 6 Alternatively, layer 70 is not required.

[0050] like Figure 7 As shown, a hinged baffle 78 protrudes from the barrier 64 and is disposed adjacent to the array cover 66 to establish a seal between adjacent compartments 60 in the event of release of exhaust gas. In this example, the hinge point 79 of the hinged baffle 78 is adjacent to the topmost surface 65 of the barrier 64. Figure 7 , baffle 78 is shown in a standby or neutral position. Baffle 78 can be moved to a deflected position. The deflected position is shown in phantom relative to the right baffle 78. In the deflected position, exhaust gas deflects baffle 78 so that baffle 78 contacts array cover 66 to establish a seal between adjacent compartments 60 and direct airflow through vent baffle 74. Although not shown, layer 70 may be present Figure 7 Alternatively, layer 70 is not required.

[0051] like Fig. 8A and Figure 8B As shown, the slots 68 of the layer 70 are sized and shaped to receive the barrier 64 and allow fluid to flow to the vent baffles 74 of the array cover 66 (one example vent baffle 74 is shown). Figure 8B, each of the slots 68 exhibits a dimension D3 that is greater than the thickness of the barrier 64. Dimension D3 is the width of the slot 68 and is measured parallel to the length L. The slots 68 are aligned with the vent baffles 74 relative to the length L of the array 25. Fig. 8A and Figure 8B Each compartment has a battery cell.

[0052] Although in the embodiments discussed above, the cells 62A, 62B are supported relative to their respective bottom surfaces, in other embodiments, the cells 62A, 62B may be supported from another surface, such as a top surface or a side surface. Fig. 9 64. In the embodiment of the present invention, the cells 62A, 62B are supported relative to the top barrier 80 of the array 25. In this configuration, each compartment 60 includes two cells 62A, 62B separated by a barrier 64. As in the previous embodiment, the barrier 64 exhibits a height dimension H1 that is greater than the height dimension H2 of the cells 62A, 62B. The barrier 64 protrudes vertically downward relative to the top barrier 80 through corresponding slots in the cover 66, which is the bottom cover 66 in this example. The vent baffle 74 is configured to direct gas through the channel 72. In examples in which the cells 62A, 62B are supported relative to their sides, the dimensions of the cells in the side-to-side direction can be smaller than the corresponding side-to-side dimensions of the barrier 64.

[0053] It should be understood that terms such as "about," "substantially," and "generally" are not intended to be open-ended terms, and should be interpreted consistent with the manner in which those skilled in the art would interpret those terms. It should also be understood that directional terms such as "upper," "top," "vertical," "forward," "rearward," "side," "above," "below," etc., are used herein with respect to the normal operating posture of the vehicle for purposes of explanation only, and should not be considered limiting.

[0054] Although different examples have specific components shown in the drawings, embodiments of the present disclosure are not limited to those specific 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. In addition, the various drawings of the present disclosure are not necessarily drawn to scale, and some features may be enlarged or minimized to show certain details of a particular component or arrangement.

[0055] Those skilled in the art will appreciate that the above embodiments are exemplary and not restrictive. That is, modifications of the present disclosure will fall within the scope of the claims. Therefore, the appended claims should be studied to determine their true scope and content.

[0056] According to the present invention, an electric vehicle is provided, which includes: a battery assembly, wherein the battery assembly includes: a battery array, wherein the battery array has a first battery cell, a second battery cell, and a thermal barrier between the first battery cell and the second battery cell, wherein the height of the thermal barrier is greater than the height of the first battery cell and the second battery cell.

[0057] According to one embodiment, the invention is further characterized by: an array cover; and a layer vertically located between the top of the first and second battery cells and the array cover, wherein the layer includes a slot that receives a top section of a thermal barrier.

[0058] According to one embodiment, the thermal barrier protrudes through a slot in the array cover.

[0059] According to the present invention, a method includes: sealing a compartment of a battery array of a battery assembly of an electrified vehicle using a thermal barrier arranged between the first battery cell and the second battery cell, wherein the height of the thermal barrier is greater than the height of the first battery cell and the second battery cell.

[0060] In one aspect of the invention, the battery assembly includes: an array cover; and a layer vertically located between the tops of the first and second battery cells and the array cover, wherein the layer includes a slot to receive a top section of a thermal barrier.

Claims

1. A battery assembly for an electric vehicle, comprising: A battery array having a first battery cell, a second battery cell, and a thermal barrier between the first battery cell and the second battery cell, wherein a size of the thermal barrier is larger than corresponding sizes of the first battery cell and the second battery cell.

2. The battery assembly according to claim 1, further comprising: array cover, and A layer is vertically positioned between the tops of the first and second battery cells and the array cover, wherein the layer includes a slot that receives a top section of the thermal barrier.

3. The battery assembly of claim 2, wherein the slot is aligned with a vent of the array cover relative to a length of the battery array.

4. The battery assembly of claim 3, wherein the slot is sized and shaped to receive the top section of the thermal barrier and allow gas to flow to the vent of the array cover.

5. The battery assembly of claim 2, wherein the layer includes another slot aligned with the vent of the array cover, wherein the other slot is spaced apart from the slot that receives the top section of the thermal barrier relative to the length of the battery array.

6. The battery assembly of claim 2, wherein a topmost surface of the thermal barrier is disposed vertically above the layer.

7. The battery assembly of claim 6, wherein the topmost surface of the thermal barrier is spaced below the bottommost surface of the array cover.

8. The battery assembly of claim 6, wherein the topmost surface of the thermal barrier contacts the bottommost surface of the array cover.

9. The battery assembly of claim 1, wherein the thermal barrier comprises mica and aerogel.

10. The battery assembly of claim 9, wherein the thermal barrier comprises a mica-aerogel-mica interlayer.

11. The battery assembly of claim 9, wherein the thermal barrier comprises an aerogel-mica-aerogel interlayer.

12. The battery assembly of claim 1, wherein the thermal barrier comprises an asymmetric arrangement of material layers.

13. The battery assembly of claim 12, wherein the thermal barrier comprises layers of aerogel, fiberglass, and polyurethane foam.

14. The battery assembly of claim 1, wherein at least a portion of the thermal barrier protrudes through a slot in the array cover.

15. The battery assembly as claimed in claim 1, further comprising: array cover; The thermal barrier includes a baffle adjacent to and protruding from a top section of the thermal barrier, and the baffle is deflectable from a neutral position to a deflected position wherein the baffle contacts the array cover.

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