Cooling panel for improving cooling efficiency of prismatic battery cells

Abstract

A cooling panel for regulating the temperature of a prismatic battery cell. The cooling panel includes at least a first laminate and a second laminate, which are heat-sealed together to form a pouch. The pouch is then placed between a first punched sheet and a second punched sheet, which are pressed and fixed together to form a frame. The pouch has an inlet and an outlet for coolant to pass through. The coolant flows into the pouch through the inlet, causing the pouch to expand and thereby communicate with at least one side of the prismatic battery cell, allowing the cooling panel to regulate the temperature of the prismatic battery cell and prevent overheating and thermal runaway events. Subsequently, the coolant flows out of the pouch through the outlet, whereby the coolant can be reused for further temperature regulation.

Description

Technical Field

[0001] This disclosure relates to a cooling panel for a prismatic battery cell. Background Technology

[0002] Electric and hybrid vehicles use high-voltage battery systems that contain multiple battery cells. These electric and hybrid vehicles typically require multiple battery cells to provide sufficient power to meet the vehicle's electrical and energy needs. The battery cells are usually located under the vehicle body, in the middle position between the front and rear wheels.

[0003] Battery cells, especially the high-voltage types mentioned above, generate significant amounts of heat during continuous operation and rapid charging. Over time, this heat can reduce efficiency or trigger thermal runaway events. Therefore, thermal management systems are used to precisely regulate the temperature of the battery pack. In one thermal management system using prismatic battery cells, cooling panels are typically positioned beneath the prismatic battery cells to regulate their temperature and prevent overheating and thermal runaway events.

[0004] Therefore, while current cooling panels have achieved their intended purpose, a new and improved system and method are still needed to cool prismatic battery cells to prevent overheating or thermal runaway events. Summary of the Invention

[0005] In several aspects, this document provides a cooling panel for a prismatic battery cell. The cooling panel may include: a frame including a first stamped sheet and a second stamped sheet, wherein the first stamped sheet is connected to the second stamped sheet. The cooling panel may also include a first outer lamination connected to the first stamped sheet. The cooling panel may further include a second outer lamination connected to the second stamped sheet, wherein the first and second outer laminations are heat-sealed together to form a pouch between the first and second stamped sheets. The cooling panel may further include an inlet communicating with the pouch. The cooling panel may further include an outlet communicating with the pouch, wherein coolant flows into the pouch from the inlet to cause the pouch to expand such that the first lamination contacts the prismatic battery cell, and then the coolant flows out of the pouch through the outlet.

[0006] In another aspect of this disclosure, the soft pack is shaped to match the first and second die-cut pieces, and the first and second die-cut pieces together form a frame to secure the soft pack in place.

[0007] In another aspect of this disclosure, the frame is made of thin aluminum or plastic.

[0008] In another aspect of this disclosure, coolant is introduced into the soft pack through an inlet and discharged from the soft pack through an outlet.

[0009] In another aspect of this disclosure, a cooling panel is disposed within the battery pack housing the prismatic battery cells inside the vehicle.

[0010] In another aspect of this disclosure, the first outer laminate and the second outer laminate are made of flexible laminated stainless steel foil.

[0011] In another aspect of this disclosure, the outer layers of the first and second outer laminates are made of a thermoplastic polymer with a melting point between 250 and 350 degrees Celsius.

[0012] In another aspect of this disclosure, the inner layers of the first outer laminate and the second outer laminate are composed of a thermoplastic polymer with a melting point between 160 and 200 degrees Celsius.

[0013] In another aspect of this disclosure, the pressure generated by the coolant introduced into the pouch through the inlet causes the pouch to expand and communicate with the side of the prismatic battery cell.

[0014] In another aspect of this disclosure, the cooling panel also includes a first inner lamination and a second inner lamination.

[0015] In another aspect of this disclosure, the first inner laminate and the second inner laminate are made of flexible aluminum foil.

[0016] In another aspect of this disclosure, the first inner soft pack within the soft pack is defined by the space between the first outer lamination and the first inner lamination, the central soft pack within the soft pack is defined by the space between the first inner lamination and the second inner lamination, and the second inner soft pack within the soft pack is defined by the space between the second inner lamination and the second outer lamination.

[0017] In another aspect of this disclosure, the outer layers of the first and second outer laminates are made of thermoplastic polymers with melting points between 250 and 350 degrees Celsius, and the inner layers of the first and second outer laminates are made of thermoplastic polymers with melting points between 160 and 200 degrees Celsius.

[0018] In another aspect of this disclosure, the first and third layers of the first and second inner laminates are composed of thermoplastic polymers with melting points between 160 and 200 degrees Celsius.

[0019] In another aspect of this disclosure, the pressure generated by the coolant introduced into the first and second inner pouches through the inlet causes the pouches to expand and communicate with the side of the prismatic battery cell.

[0020] In another aspect of this disclosure, the central soft padding is filled with a thermal barrier material.

[0021] In another aspect of this disclosure, the soft package is heat-sealed with a single serpentine channel, such that the inlet and outlet are located within the same edge of the soft package.

[0022] In another aspect of this disclosure, a plurality of circular seals are heat-sealed within the soft pack to induce turbulence as the coolant flows.

[0023] In several aspects, this document provides a cooling panel for a prismatic battery cell. The cooling panel may include a frame comprising a first stamped sheet and a second stamped sheet, wherein the first stamped sheet is connected to the second stamped sheet. The cooling panel may also include a first outer lamination connected to the first stamped sheet. The cooling panel may also include a second outer lamination connected to the second stamped sheet. The cooling panel may also include a first inner lamination adjacent to the first outer lamination. The cooling panel may also include a second inner lamination adjacent to the second outer lamination, wherein the first outer lamination, the first inner lamination, the second inner lamination, and the second outer lamination are heat-sealed together to form a pouch between the first and second stamped sheets. The cooling panel may also include an inlet communicating with the pouch. The cooling panel may also include an outlet communicating with the pouch, wherein coolant flows into the pouch from the inlet to cause the pouch to expand such that the first lamination contacts the prismatic battery cell, and then the coolant flows out of the pouch through the outlet.

[0024] According to several aspects, a cooling panel for a prismatic battery cell is provided. The cooling panel may include a frame comprising a first stamped sheet and a second stamped sheet, wherein the first stamped sheet is connected to the second stamped sheet. The cooling panel may further include a first laminate connected to the first stamped sheet. The cooling panel may further include a second laminate connected to the second stamped sheet, wherein the first and second laminates are heat-sealed together to form a pouch between the first and second stamped sheets. The cooling panel may further include an inlet communicating with the pouch. The cooling panel may further include an outlet communicating with the pouch. Coolant flows into the pouch from the inlet to cause the pouch to expand, such that the first laminate contacts the prismatic battery cell, and then the coolant flows out of the pouch through the outlet. The cooling panel may further include a plurality of circular seals heat-sealed within the pouch to induce turbulence during coolant flow.

[0025] Further applicability will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0026] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way.

[0027] Figure 1 This is a perspective view of an exemplary vehicle including an exemplary battery pack with a cooling panel, according to an exemplary embodiment.

[0028] Figure 2 This is a schematic top view of an example thermal management system for a battery pack according to an exemplary embodiment;

[0029] Figure 3 This is a perspective view of a cooling panel according to an exemplary embodiment;

[0030] Figure 4 This is a cross-sectional view of a laminated structure according to an exemplary embodiment;

[0031] Figure 5 This is a perspective view of an alternative embodiment of a laminated structure according to an exemplary embodiment;

[0032] Figure 6A This is a perspective view of a cooling panel having a single straight channel according to an exemplary embodiment;

[0033] Figure 6B This is a perspective view of a cooling panel having multiple straight channels according to an exemplary embodiment;

[0034] Figure 6C This is a perspective view of a cooling panel with a serpentine channel according to an exemplary embodiment;

[0035] Figure 6D This is a perspective view of a cooling panel having multiple circular seals according to an exemplary embodiment;

[0036] Figure 7 This is a side view of the frame used to support the cooling panel in a battery pack according to an exemplary embodiment;

[0037] Figure 8A This is a side view of a cooling panel, wherein the laminated structure is composed of four laminates according to an exemplary embodiment, through which coolant flows; and

[0038] Figure 8B This is a side view of a cooling panel, wherein the laminated structure is composed of two laminates, and coolant flows through the cooling panel, according to an exemplary embodiment. Detailed Implementation

[0039] The following description is merely illustrative in nature and is not intended to limit the content, application, or purpose of this disclosure.

[0040] refer to Figure 1An exemplary vehicle 10 is shown, having a battery pack 12 for supplying power to an electric motor 14. While vehicle 10 is shown as a passenger car, it should be understood that the vehicle can be any type of vehicle, including trucks, boats, drones, aircraft, etc., without departing from the scope of this disclosure. The electric motor 14 powers vehicle 10. However, the battery pack 12 can be used in a variety of other electric vehicles and stationary applications, and can be used to power other electrical hardware, without departing from the scope of this disclosure. The battery pack 12 includes a plurality of prismatic battery cells 16 electrically connected to each other. The battery pack 12 is supported by a battery tray 18. Prismatic battery cells 16 typically include a housing 20 encapsulating an electrode stack (not shown) and an electrolyte (not shown) for generating energy. During use and charging, the prismatic battery cells 16 generate heat. The battery pack 12 includes a thermal management system 21 for managing the heat generated by the prismatic battery cells 16.

[0041] refer to Figure 2 A schematic top view of a thermal management system 21 for a battery pack 12 is shown. The thermal management system 21 directs coolant 22 through it to regulate the temperature of the prismatic battery cells 16 within the battery pack 12. In a range of non-limiting examples, the coolant 22 may be water, a glycol-water mixture, mineral oil, a dielectric fluid, an inorganic acid-based coolant, or an organic acid-based coolant. The thermal management system 21 typically includes at least one cooling panel 24 according to the principles of this disclosure, as well as a pump 26, an inlet line 28, an outlet line 30, a heat exchanger 32, and a recovery tank 34. Without departing from the scope of this disclosure, the thermal management system 21 may include various other components, including temperature and humidity sensors, valves, and electronic controllers. Typically, the pump 26 is in fluid communication with the recovery tank 34 and pumps coolant from the recovery tank 34 to the inlet line 28. The inlet line 28 is connected to one or more cooling panels 24 and directs coolant 22 from the pump 26 to the cooling panels 24. The cooling panels 24 are disposed between the individual prismatic battery cells 16, as described in more detail below. Cooling panel 24 contacts the side 36 of the housing 20 of the adjacent prismatic battery cell 16 and provides thermal management. The side 36 of an individual prismatic battery cell 16 is the surface of that individual prismatic battery cell 16 extending along its length. Coolant then returns from cooling panel 24 to outlet line 30 and is conveyed to heat exchanger 32. Heat exchanger 32 removes heat from the coolant, for example using a liquid-to-gas heat exchanger with a fan, but other types of heat exchangers may also be used. Coolant is returned to recovery tank 34.

[0042] refer to Figure 3The diagram shows a perspective view of a cooling panel 24. The cooling panel 24 regulates the temperature of at least one prismatic battery cell 16 in the battery pack 12. The cooling panel 24 is disposed directly next to and parallel to the side 36 of the adjacent prismatic battery cell 16. The cooling panel 24 includes a frame 38 supporting a laminated structure 40. The laminated structure 40 is disposed between the frames 38. The frames 38 are designed to generally conform to one or more end-to-end arranged prismatic battery cells 16, such as... Figure 2 As shown. Frame 38 includes a first punched piece 42 connected to a second punched piece 44, which, when joined together with the second punched piece 44, defines a bottom frame member 45, a top frame member 46, and an end frame member 47. Inlet 48 and outlet 49 communicate with the laminated structure 40.

[0043] Frame 38 includes a first blanked sheet 42 and a second blanked sheet 44, which are blanked into the same shape and arranged parallel to each other. In a non-limiting example, the first blanked sheet 42 and the second blanked sheet 44 are rectangular. The first blanked sheet 42 and the second blanked sheet 44 may be made of plastic or aluminum. The peripheries of the first blanked sheet 42 or the second blanked sheet 44 are then aligned with a thermoplastic polymer adhesive, a laminated structure 40 is disposed between and parallel to the first blanked sheet 42 and the second blanked sheet 44, the two blanked sheets are pressed together, the two blanked sheets are fixed to each other by the thermoplastic polymer adhesive, and the laminated structure 40 is fixed in place.

[0044] Inlet 48 and outlet 49 are located within the edge of laminate 40, with a portion of inlet 48 and outlet 49 protruding outward from laminate 40.

[0045] refer to Figure 4 A cross-sectional view of the laminated structure is shown. The laminated structure is configured to receive and allow coolant 22 to pass through it for thermal conditioning of the prismatic battery cell 16, as described in more detail below. The laminated structure includes a plurality of laminates 50 arranged parallel to each other within a frame. In one embodiment, the plurality of laminates 50 includes a first outer laminate 52, a second outer laminate 54, a first inner laminate 56, and a second inner laminate 58.

[0046] The first outer laminate 52 and the second outer laminate 54 are disposed on the outer side of the coolant panel 20. Therefore, both the first outer laminate 52 and the second outer laminate 54 are configured to contact the side surface 36 of the adjacent prismatic battery cell 16. A first inner laminate 56 and a second inner laminate 58 are disposed between the first outer laminate 52 and the second outer laminate 54. The first outer laminate 52 and the first inner laminate 56 are sealed together along their periphery at the frame 38 to form a first inner soft package 60 between them. The second outer laminate 54 and the second inner laminate 58 are also sealed together along their periphery at the frame 38 to form a second inner soft package 62 between them. One end of the inlet 48 communicates with the first inner soft package 60 and the second inner soft package 62, and the other end of the outlet 49 communicates with the first inner soft package 60 and the second inner soft package 62, as shown below. Figure 3 As shown. A first inner laminate 56 and a second inner laminate 58 are sealed along their periphery at the frame 38 to form a central soft pack 64 between them. The central soft pack 64 may be used to house a thermal barrier material 66, which may be used to minimize heat flow from the prismatic battery cells disposed adjacent to the cooling panel 24 to the remainder of the battery pack 12. In a non-limiting example, the thermal barrier material 66 may be air. In another non-limiting example, the thermal barrier material 66 may be foam, such as a foam board or sprayed foam. In yet another non-limiting example, the thermal barrier material 66 may be some other heat-transfer resistant insulating material, such as glass fiber, cellulose, or silicone aerogel.

[0047] The first outer laminate 52 and the second outer laminate 54 are substantially identical, and both include a central layer 68, an outer layer 70, and an inner layer 72. The outer layer 70 is laminated to a first side 74 of the central layer 68. The outer layer 70 is configured to directly contact the side 36 of the adjacent prismatic battery cell 16. The outer layer 70 is made of a first thermoplastic polymer with a melting temperature between 250 and 350 degrees Celsius. In a non-limiting example, the outer layer 70 is made of polyethylene terephthalate. In another non-limiting example, the outer layer 70 is made of polyamide. The inner layer 72 is laminated to a second side 75 of the central layer 68 opposite the first side 74. The inner layer 72 partially defines a first inner soft case 60 and a second inner soft case 62. The inner layer 72 is made of a second thermoplastic polymer with a melting temperature between 160 and 200 degrees Celsius. In a non-limiting example, the inner layer 72 is made of polypropylene. The central layer 68 is configured to facilitate heat transfer between the first inner pouch 60, the second inner pouch 62, and adjacent prismatic battery cells 16. In a non-limiting example, the central layer 68 is made of flexible stainless steel foil.

[0048] The first inner laminate 56 and the second inner laminate 58 are substantially identical, and both include a first layer 76, a second layer 78, and a third layer 80. The first layer 76 is laminated to the first surface 82 of the second layer 78. The first layer 76 is configured to directly contact the side surface 36 of the adjacent prismatic battery cell 16. The first layer 76 is made of a second thermoplastic polymer. The third layer 80 is laminated to the second surface 84 of the second layer 78 opposite to the first surface 82. The third layer 80 partially defines the central soft pack 64. The inner layer 72 is made of the second thermoplastic polymer. In a non-limiting example, the second layer 78 is made of flexible aluminum foil.

[0049] Inlet 48 and outlet 49 are disposed between the first outer laminate 52 and the second outer laminate 54 along the edge of the laminate, with portions of inlet 48 and outlet 49 protruding outward from the first outer laminate 52 and the second outer laminate 54. The first outer laminate 52 and the second outer laminate 54 are then sealed together at the frame 38 along their periphery to define a soft pack 86 between them. Coolant 22 can be guided into the soft pack 86 through the first inner soft pack 60 and the second inner soft pack 62. In this example, the laminated structure 40 of the soft pack 86 includes four laminates, with portions of inlet 48 and outlet 49 protruding outward from the soft pack 86.

[0050] refer to Figure 5 A perspective view of an alternative embodiment of the laminated structure 40 is shown, and it is generally indicated by reference numeral 88. The laminated structure 88 is similar to... Figure 4 The laminated structure 40 is shown, and therefore the same components are indicated by the same reference numerals. However, the first inner laminate 56 and the second inner laminate 58 are removed, and the first outer laminate 52 and the second outer laminate 54 form the central coolant pouch 90. The laminated structure 88 provides a simpler construction while still allowing coolant 22 to be guided through the central coolant pouch 90 into the pouch 86, wherein the coolant 22 enters the pouch 86 through the inlet 48 and exits the pouch 86 through the outlet 49.

[0051] General Reference Figures 6A-6D The laminated structure 40 can be heat-sealed within the frame 38 in different configurations to provide different coolant flow options. (Reference) Figure 6AThe diagram illustrates a configuration in which a pouch 86 is heat-sealed to form a single straight channel 92 within the pouch 86. This configuration allows coolant 22 to flow from an inlet 48 located within the edge of the pouch 86 to an outlet 49 located within the edge of the pouch 86 opposite to the inlet 48, thus passing through the pouch 86. In this configuration, the coolant 22 flows through the pouch 86 in two streams, which define two distinct spaces within the pouch 86 separated by the single straight channel 92. These two streams help maintain a uniform temperature among the individual prismatic battery cells 16. Inlet lines 24 and outlet lines 26 are arranged along opposite edges of the frame 38.

[0052] refer to Figure 6B The diagram illustrates a configuration in which a pouch 86 is heat-sealed to form a plurality of straight channels 94 within the pouch 86. This configuration allows coolant to flow from an inlet 48 located within the edge of the pouch 86 to an outlet 49 located within the edge of the pouch 86 opposite to the inlet 48, thus passing through the pouch 86. In this configuration, coolant 22 flows through the pouch 86 via a plurality of streams, which define spaces within the pouch 86 separated by the plurality of straight channels 94. The plurality of streams help maintain a uniform temperature among the individual prismatic battery cells 16 in the plurality of prismatic battery cells 16. Inlet lines 24 and outlet lines 26 are arranged along opposite edges of the frame 38.

[0053] refer to Figure 6C The diagram illustrates a configuration in which a flexible pack 86 is heat-sealed to form a single serpentine channel 96 within the flexible pack 86. This configuration allows coolant to flow through the single serpentine channel 96 from an inlet 48 located within the edge of the flexible pack 86 to an outlet 49 located within the same edge of the flexible pack 86 as the inlet 48.

[0054] refer to Figure 6D The diagram illustrates a configuration in which a flexible housing 86 is heat-sealed to form a plurality of circular seals 98 within the housing 86. As coolant 22 enters through the housing 86 from an inlet 48 located within the edge of the housing 86 and exits through an outlet 49 located within the edge of the housing 86 opposite to the inlet 48, the plurality of circular seals 98 allow turbulence to be generated during the flow of coolant 22. Inlet lines 24 and outlet lines 26 are arranged along opposite edges of the frame 38.

[0055] refer to Figure 7 The cooling panel 24 is secured between adjacent prismatic battery cells 16 by a battery tray 18. For example, the battery tray includes a slot designed to receive a bottom frame member 45. The bottom frame member 45 is disposed within the slot. In one embodiment, as... Figure 7 As shown, the bottom frame member is I-shaped, and the slot has a matching I-shape. Therefore, the battery tray 28 secures the cooling panel 24 to the cooling panel 24 in such a way that the cooling panel 24 is perpendicular to the battery tray 28.

[0056] refer to Figure 8A The diagram shows a side view of the cooling panel 24 as coolant 22 flows through it, wherein the laminated structure consists of four laminates. When coolant 22 enters the first pouch 60 and the second pouch 62 through inlet 48, it causes the pouches 60 and 62 to expand, thereby pushing the first outer laminate 52 and the second outer laminate 54 outwards. Each of the first outer laminate 52 and the second outer laminate 54 is in direct contact with the side 36 of the adjacent prismatic battery cell 16. The contact between the laminated structure 40 and the side of the adjacent prismatic battery cell 16 increases the conductivity between them.

[0057] refer to Figure 8B The diagram shows a side view of the cooling panel 24 as coolant 22 flows through it, wherein the laminated structure 40 consists of two laminates. As coolant 22 flows into the central coolant pouch 90 through inlet 48, it causes the pouch 90 to expand, thereby pushing the first outer laminate 52 and the second outer laminate 54 outwards. Each of the first outer laminate 52 and the second outer laminate 54 is in direct contact with the side 36 of the adjacent prismatic battery cell 16. The contact between the laminated structure 40 and the side of the adjacent prismatic battery cell 16 increases conductivity between them.

[0058] The cooling panel 24 of this disclosure offers several advantages. One advantage is the ability to cool the large surface area of ​​a single prismatic battery cell among multiple prismatic battery cells 16 at any given time, thereby making the cooling process of the prismatic battery cells more efficient. This advantage also allows for the use of prismatic battery cells with faster charging rates (i.e., prismatic cells capable of charging at a 3C rate instead of a 2C or 1C rate) without significantly increasing the risk of thermal runaway events. Another advantage of the cooling panel 24, and the entire thermal management system 21, is that the thermal management system 21 does not require thermal interface materials (i.e., thermal paste, thermal adhesive, etc.) during its assembly and operation.

[0059] The descriptions in this disclosure are merely exemplary in nature, and any modifications that do not depart from the spirit and scope of this disclosure are intended to fall within its scope. Such modifications should not be considered as departing from the spirit and scope of this disclosure.

Claims

1. A cooling panel for a prismatic battery cell, the cooling panel comprising: A frame, the frame including a first blanking sheet and a second blanking sheet, wherein the first blanking sheet is connected to the second blanking sheet; A first outer pressure plate, the first outer pressure plate being connected to the first punched sheet; The second outer pressure plate is connected to the second punching sheet; The first outer pressure plate and the second outer pressure plate are heat-sealed together to form a soft package disposed between the first punched sheet and the second punched sheet; The entry point is connected to the soft package; and An outlet, which is in communication with the pouch, wherein coolant flows into the pouch from the inlet to cause the pouch to expand, such that the first laminate contacts the prismatic battery cell, and the coolant flows out of the pouch through the outlet.

2. The cooling panel according to claim 1, wherein, The soft package is shaped to match the first and second die-cut pieces, and the first and second die-cut pieces together form the frame to secure the soft package in place.

3. The framework according to claim 1, wherein, The frame is made of thin aluminum or plastic with a thickness between 0.3 mm and 1 mm.

4. The cooling panel according to claim 1, wherein, The coolant is introduced into the soft pack through the inlet and discharged from the soft pack through the outlet.

5. The cooling panel according to claim 1, wherein, The cooling panel is located inside the battery pack containing the prismatic battery cells within the vehicle.

6. The cooling panel according to claim 5, wherein, The first outer layer and the second outer layer are made of flexible stainless steel foil.

7. The cooling panel according to claim 5, wherein, The outer layers of the first and second outer laminates are made of thermoplastic polymers with a melting point between 250 and 350 degrees Celsius.

8. The cooling panel according to claim 5, wherein, The inner layers of the first outer laminate and the second outer laminate are made of thermoplastic polymers with melting points between 160 and 200 degrees Celsius.

9. The cooling panel according to claim 5, wherein, The pressure generated by the coolant introduced into the pouch through the inlet causes the pouch to expand and connect with the side of the prismatic battery cell, thus eliminating the need for any thermal interface between the cooling plate and the battery surface.

10. The cooling panel according to claim 1, wherein, The cooling panel also includes a first inner pressure plate and a second inner pressure plate.

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