Thermal management system for efficient heat dissipation

Abstract

The present disclosure relates to a thermal management system for a battery. The system includes a solid component and a liquid-transport component for efficient heat dissipation in a battery having multiple cells housed in a casing. The solid component is a powder mixture of organic and inorganic compounds in an optimal ratio for heat exchange with the multiple cells. The liquid cooling component is composed of multiple liquid-transport components arranged to allow a coolant to flow through the solid component for heat exchange with the solid component and transport heat to the outside of the battery.

Description

[Technical Field]

[0001] The present disclosure relates generally to a thermal management system for a battery, and more particularly to a thermal management system including powdered solid components, liquid-transporting components, one or more sensors, a pump, and a heat exchanger for maintaining the temperature of cells within a battery within a predetermined temperature range. [Background technology]

[0002] Electric vehicles (EVs) mostly use lithium-ion battery cells to power their drivetrains. The optimal operating temperature for these cells is between 10 and 50°C. Heat buildup in the battery can lead to thermal runaway. At the same time, temperatures below the recommended limit affect cell performance. Maintaining temperatures within the optimal operating range requires a thermal management system that cools or heats the cells within the battery system as needed. This system can be an active solution that uses a pump or radiator to remove heat from the cells, or a passive system such as an extended fin surface that utilizes convection cooling. This system also needs to be as efficient as possible to reduce the load on the battery storage and maximize the vehicle's range.

[0003] The most common technology used to maintain thermal balance in EVs is liquid cooling. This involves creating multiple fluid lines and pathways from each cell to a radiator, which can be cooled by atmospheric or vehicle-powered chillers. When cells need to be heated, heaters are used to heat fluid, which then flows through the battery to warm the cells when the ambient temperature is below the battery's optimal performance range. Another method involves using phase-change materials (PCMs) surrounding the cells. These materials have a high latent heat, allowing them to absorb large amounts of heat as they undergo a phase change. PCMs range from organic to synthetic chemicals. These materials can become fully fluid or semi-solid, depending on the temperature they are exposed to. However, while using PCMs as a heat transfer element can rapidly remove heat corresponding to their latent heat, PCM materials also experience stresses in all directions as they expand with increasing temperature.

[0004] Therefore, there is a need for a thermal management system that can be effectively used with batteries to maintain the temperature of the cells within the battery within a predetermined range. Summary of the Invention

[0005] To overcome or mitigate at least some of the problems in the art, the present disclosure provides a thermal management system for a battery having a plurality of cells housed in a casing, the thermal management system comprising: a powdered solid component contacting outer surfaces of the plurality of cells and substantially filling interstices between the plurality of cells; a liquid-transport component configured to exchange heat with the solid component, the surfaces of the cells, or both; one or more sensors configured to sense a temperature of any one of the one or more cells, the solid component, and the liquid-transport component; a pump for circulating a coolant through the liquid-transport component; and a heat exchanger disposed outside the battery and in fluid communication with the liquid-transport component for heat exchange, for maintaining a temperature of cells within the battery within a predetermined temperature range. [Problem to be solved by the invention]

[0006] A primary objective of the present disclosure is to provide a thermal management system for heat dissipation. Another objective of the present disclosure is to provide a thermal management system for efficient heat dissipation of a battery. [Brief explanation of the drawings]

[0007] These and other features, aspects, and advantages of the exemplary embodiments can be better understood when the following detailed description is read in conjunction with the accompanying drawings, in which like characters represent like parts throughout. [Figure 1] Figure 1 is an isometric view of the thermal management system for a Type A battery. [Figure 2] Figure 2 is a top view of the thermal management system for a Type A battery. [Figure 3] Figure 3 is an isometric view of the thermal management system for a Type B battery. [Figure 4] FIG. 4 is a top view of the thermal management system of a Type B battery. [Figure 5] Figure 5 is an isometric view of the thermal management system for a Type C battery. [Figure 6] FIG. 6 is a cross-sectional view of the thermal management system of a Type C battery. [Figure 7] Figure 7 is an isometric view of the thermal management system for a Type D battery. [Figure 8] FIG. 8 is a top view of the thermal management system of a Type D battery. [Figure 9] Figure 9 is an isometric view of the thermal management system for a Type E battery. [Figure 10] FIG. 10 is a top view of the thermal management system of a Type E battery. [Figure 11] FIG. 11 is an isometric view of a plate-type heat exchanger. [Figure 12] FIG. 12 is a cross-sectional view of a plate-type heat exchanger. [Figure 13] FIG. 13 shows a comparative graph of thermal performance of a battery without a thermal management system, with a solid component powder mix, with a solid component powder mix and an air-cooled arrangement with fins, and with a solid component powder mix and heat-dissipating liquid-transporting components, as measured using a particular type of cell with an allowable peak discharge of 20C (where the C rating is numerically equal to the ampere-hour (Ah) rating of the battery; i.e., a 20C discharge rate of a 1 Ah battery is 20 Amps), in accordance with one embodiment of the present disclosure. [Figure 14] FIG. 14 is a comparative graph of thermal performance of a battery without a thermal management system, with a solid component powder mix, with a solid component powder mix and an air-cooled arrangement with fins, and with a solid component powder and heat-dissipating liquid-transporting components, as measured using a particular type of cell with an allowable peak discharge of 4C, in accordance with one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] In order to facilitate understanding of the principles of the present disclosure, reference will now be made to embodiments, and specific terms will be used to describe the same.Nevertheless, it will be understood that the scope of the present disclosure is not intended to be limited thereby, and that such changes and further modifications in the exemplified compositions, and such further applications of the principles of the present disclosure as exemplified therein, are contemplated as would normally occur to those skilled in the art in the field to which the present disclosure pertains.Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure pertains.The compositions, methods, and examples provided herein are merely illustrative and are not intended to be limiting.

[0009] The articles "a", "an" and "the" are used to refer to one or to more than one (ie to at least one) of the grammatical object of the article.

[0010] The terms "comprise" and "comprising" are used in an inclusive and open sense, meaning that additional elements may be included. They are not intended to be interpreted as "consists of only." Throughout this specification, unless the context clearly indicates otherwise, the word "comprise" and variations such as "comprises" and "including" are understood to mean the inclusion of stated elements or steps, or groups of elements or steps, but not the exclusion of other elements or steps, or groups of elements or steps.

[0011] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the teachings of this disclosure, the preferred methods and materials are now described.

[0012] The terms and structures used herein are intended to describe, teach, and clarify some embodiments and their particular features and elements, and are not intended to limit, restrict, or narrow the spirit and scope of the present disclosure.

[0013] In a typical arrangement, solid and liquid cooling components are co-located within the battery for thermal regulation. The various portions of the bi-directional thermal management system are as defined herein.

[0014] The solid component is "DiCo" and is the primary thermal management material used in this disclosure, filling the gaps between the battery cells and the liquid-carrying components. The solid component is a mixture of specific amounts of multiple compounds manufactured in a controlled process for optimal performance.

[0015] As used herein, the term "DiCo" refers to a compound containing various inorganic components and at least one organic component, namely C, which belongs to the sesquiterpenoid family and is commonly known by the name isocaryophyllene. 15 H 24 and, although other nomenclature may be used, the contents of which are fully disclosed in Indian Patent Application No. 202121024470, the contents of which are incorporated herein by reference.

[0016] The solid component "DiCo" is a specially formulated synergistic powder mixture for heat dissipation that has both organic and inorganic compounds as its constituents. The organic constituent material is C 15 H 24 The inorganic constituent materials of the powder mixture include at least one carbonate, at least one oxide, and at least one oxalate. These may be selected from calcium carbonate, silicon dioxide, and neodymium praseodymium oxalate, and two or more materials may be selected from the group consisting of, but not limited to, ammonium chloride, zirconium dioxide, zirconium sulfate, zirconium carbide, metallic zirconium, iron oxide, and carbonyl iron. While calcium carbonate, silicon dioxide, and praseodymium neodymium oxalate are specifically mentioned, other carbonates, oxides, and oxalates may be used in combination with these materials. Furthermore, other similar or dissimilar materials may be included in addition to the two or more selected materials to impart properties to the powder mixture depending on the application.

[0017] The DiCo powder is a thermal management solution that also acts as a filler around the cells, providing structural support and protection from thermal runaway.

[0018] Liquid transport components are used to move a suitable coolant, such as water or a water-glycol mixture, through the battery to remove heat from the multiple cells. The coolant flowing through these liquid transport components dissipates heat very quickly. Pumps are used to create and regulate the flow of the coolant. Radiators are used as heat sinks to transfer the heat to the outside. They are made of metal, for example aluminum.

[0019] Cells come in a variety of shapes and sizes. These cells can be cylindrical, pouch-shaped, prismatic, rectangular, etc. The primary function of these cells is to store electrical energy in chemical form and release it when needed. This reversible reaction occurs with every charge and discharge cycle. The conversion efficiency is highly temperature dependent. A large amount of heat is generated during the charging and discharging of the cell, and this heat must be removed for optimal cell operation.

[0020] The casing is the enclosure that holds the entire assembly of cells together and provides structural support.

[0021] According to one embodiment, the present disclosure discloses a battery thermal management system having a unique structural arrangement that efficiently dissipates excess heat generated by the battery. The thermal management system broadly comprises a configuration of solid and liquid cooling components that work together to dissipate heat. The thermal management system is particularly useful in extreme conditions where a single solid cooling component is insufficient, and the liquid cooling component works in parallel to assist in heat dissipation. This unique combination of solid and liquid cooling components provides higher cooling efficiency for the battery compared to other existing solutions. The solid cooling component is the main part of the system and functions throughout operation. Meanwhile, the liquid cooling component is activated only when the thermal load is such that the solid cooling alone cannot dissipate the generated heat. The system is configured to rely primarily on passive cooling by the solid components to minimize the operation of power-consuming liquid-transporting components and increase energy efficiency.

[0022] The two-component heat dissipation systems described herein can be effectively used in any heat-generating device, including electronic and electrochemical devices. Specifically, the two-component heat dissipation systems developed and described herein are effective in cooling and preventing thermal runaway, explosion, and thermal overload in various types of modular battery systems for electric vehicles.

[0023] The figures show various types of battery configurations, the different components of which are numbered 1: solid cooling element DiCo, 2: lithium ion cylindrical cell, 3: lithium ion prismatic cell, 4: casing, 5: cooling plate, 6: liquid cooling channels, 7. thermal pad, 8: compression pad, 9: metal casing with fins, 10: fins, 11A: top cover lid, 11: outlet for terminals, 12: handle, 13: modular plastic casing, 14: ribs, 15: outlet for removable terminals, 16: coolant inlet, 17: refrigerant inlet, 18: coolant outlet, 19: refrigerant outlet, 20: separator plate, 22: metal casing for heat exchanger, 23: separator tube, and various embodiments will be described below.

[0024] The present disclosure provides a thermal management system for a battery having a plurality of cells housed in a casing, the thermal management system comprising: a powdered solid component in contact with outer surfaces of the plurality of cells and substantially filling gaps between the plurality of cells; a liquid transport component configured to exchange heat with the solid component, the surfaces of the cells, or both; one or more sensors configured to sense the temperature of any one of the one or more cells, the solid component, and the liquid transport component; a pump for circulating a coolant through the liquid transport component; and a heat exchanger disposed outside the battery and in fluid communication with the liquid transport component for heat exchange, for maintaining the temperature of cells within the battery within a predetermined temperature range.

[0025] According to one embodiment of the present disclosure, the fluid transfer component includes one or more tubes for circulating fluid through the battery.

[0026] According to another embodiment of the present disclosure, the liquid-transporting component is a metal block configured to contact at least one of a surface of the battery, the solid component, or both, the block having a passage for transporting the coolant within the metal block.

[0027] According to another embodiment of the present disclosure, the coolant is any one of water, glycol, and a mixture of water and glycol in a predetermined ratio.

[0028] According to another embodiment of the present disclosure, the heat exchanger is selected from any one of a radiator, a chiller, a heater, and a chiller heater.

[0029] According to another embodiment of the present disclosure, the outer surface of the battery casing is configured with one of a ribbed surface or fins to improve heat dissipation.

[0030] According to another embodiment of the present disclosure, the casing is constructed from one of aluminum or an aluminum composite.

[0031] According to another embodiment of the present disclosure, the flow of the liquid conveyed through the liquid conveying component is controlled by one or more flow control valves.

[0032] According to another embodiment of the present disclosure, the one or more tubes are positioned either in a position where they pass close to each of the plurality of cells or in a position where they contact the bottom surface of each of the plurality of cells.

[0033] According to another embodiment of the present disclosure, one or more sensors arranged to measure one or more temperatures associated with the battery and its cells are communicatively connected to a controller configured to process one or more signals from the one or more sensors and to perform one or more of the following: control the flow of the liquid through the liquid transfer component; and control one of a heater, a chiller, or a chiller heater.

[0034] According to one embodiment of the present invention, the battery is a lithium ion battery.

[0035] According to one embodiment of the present invention, the plurality of cells are interconnected in one of a series, parallel, and series-parallel configuration.

[0036] According to one embodiment of the present disclosure, a thermal management system for a Type A battery is shown in FIGS. 1 and 2, which includes multiple cells 2 each in contact with a liquid-transport component 6 housed within a casing 4. In this type of battery, electrical connections are either on the top side of the cells or on a side perpendicular to the longitudinal axis of the cells within the battery, depending on the busbar configuration. The liquid-transport component 6 radially contacts the outer surfaces of the cells 2. This battery configuration ensures a sufficient contact area with the cells. The gaps between the cells 2 and the liquid-transport component 6 can be filled with a powdered solid component 1, which functions as a thermal management system and simultaneously promotes efficient cell sealing within the casing 4. Additionally, a coolant circulating through the liquid-transport component 6 can be used to further cool the battery depending on temperature conditions.

[0037] According to another embodiment of the present disclosure, a thermal management system for a Type B battery having multiple cells 2 housed in a casing 4 is shown in FIGS. 3 and 4. In this battery, the bus bars and all electrical connections are located above the multiple cells, as shown in FIG. 1. As shown in FIG. 1, the bottom surfaces of the multiple cells are in contact with a thermal pad 7. One side of the thermal pad is in direct contact with the base of the cells 2, and the other side is in contact with a cooling plate 5. The cooling plate 5 is configured to allow a coolant to flow through a liquid-transporting element 6 provided therein to remove heat. Excess heat from the cells 2 flows to the surrounding solid components 1, then passes through the thermal pad 7 and is removed through the liquid-transporting element 6 present within the cooling plate 5. This configuration is suitable for any cylindrical cell standard.

[0038] In conventional batteries, the gaps between cells are primarily hollow or filled with structural foams such as polyurethane (PU). PU only provides structural support and increases the stiffness of the battery, but is not useful as a thermal material. The same is true when the gaps are filled with air. Introducing solid components into the interstitial spaces of these batteries solves two problems: the solid components function as thermal management materials while also providing structural stiffness. Therefore, batteries with solid-filled interstitial spaces are more efficient both thermally and electrically, as they require less cooling power to maintain optimal temperatures.

[0039] According to another embodiment of the present disclosure, a thermal management system for a Type C battery, comprising multiple prismatic cells 3 housed within a casing 4, is shown in Figures 5 and 6. In this type of cell 3, both terminals are located on top of the cell. The outer cell cover is made of a thermally conductive metal material for heat dissipation. Due to its rectangular parallelepiped shape, no gaps exist. Compression pads 8 are used between the cells 3 to provide rigidity and allow room for expansion of the cells over time due to degradation. All of these cells rest on a thermal pad 7 that is in direct contact with the cooling plate 5. Several gaps are created near the thermal pad by shortening the length of the compression pad 8. In this type of battery configuration, solid components 1 can be introduced into the gaps created by shortening the length of the compression pad 8, solving several problems. Typically, these gaps are filled with thermally conductive resin to increase thermal contact between the cells and the thermal pad. However, cost-effective solid components, which are also compressible powders with thermal properties, can replace both the compression pad and the thermal resin and are a better alternative to the thermal resin in this type of battery.

[0040] According to another embodiment of the present disclosure, a thermal management system for a Type D battery comprising multiple cylindrical cells 2 is shown in Figures 7 and 8. The cell terminals are at the ends of the cells adjacent a top cover 11A having an outlet 11. The battery casing 4 is constructed of a lightweight, processable material such as aluminum. It has an extended, finned surface profile for improved heat convection. A compression pad material similar to that described for the Type C battery above is also used here, but is optional.

[0041] Typically, the gaps between the cells 2 are filled with a thermal resin or any type of epoxy adhesive or foam to provide structural stability as well as a thermal path between the cells and the casing.

[0042] In this type of battery, solid components are also introduced instead of thermal resins and epoxies or foams. The solid components act as a thermal interface as well as a filler. Depending on the requirements, different cell types are introduced into this type of battery configuration. The use of solid components in this type of battery increases the overall effectiveness of passive air cooling through the fins.

[0043] According to another embodiment of the present disclosure, the battery is a Type E replaceable battery with cells 2 housed in a modular plastic casing 13 with a ribbed connector 14, as shown in Figures 9 and 10, and the cover is equipped with a handle 12. The battery can be easily removed for external charging, allowing for instantaneous power replenishment for the vehicle. Figures 9 and 10 are schematic diagrams of the replaceable battery. The battery casing is durable and designed to be repeatedly removed from the vehicle, attached to a charger, and then attached to the vehicle. All casings have a uniform shape and energy storage capacity. The ribbed connector 14 is positioned on the casing to perfectly align the battery with the vehicle connector, ensuring seamless power transfer. This type of battery is most popular for motorcycles with short driving distances and continuous driving requirements. This configuration can withstand multiple insertions and removals from the vehicle. The battery has a removable terminal with a removable terminal outlet 15 that connects the full power of the pack to the vehicle system. The connector between the battery and the vehicle is designed to ensure seamless power coupling between the battery and the vehicle. This type of battery generally does not include a cooling system. The solid component 1 is introduced as a passive thermal management system surrounding the cells of this type of battery, acting as a thermal interface material and as a packaging agent.

[0044] According to another embodiment of the present disclosure, a thermal management system for a battery includes cells 2, 3 packed in a casing 4 and a refrigerant system operating in a vapor compression cycle (VCC), in which a compressed liquid refrigerant is circulated to carry heat away from the battery. The refrigerant can be circulated through a liquid-transporting element 5 provided on the casing 4 in direct contact with the cells.

[0045] This battery incorporates solid components to enhance the overall system effectiveness and provide efficient cooling. The solid components are arranged to surround cells 2 and 3 on all sides. Plate-type heat exchangers, as shown in Figures 11 and 12, are used to exchange heat between the refrigerant and coolant flowing through the battery. Type A, Type B, and Type C batteries can all operate with this type of arrangement along with the plate-type heat exchangers.

[0046] This thermal management system is useful for batteries with any type of lithium-ion cell in a casing, where the battery is used in adverse environments and requires faster and more intensive cooling.

[0047] According to one embodiment of the present invention, the plate-type heat exchanger comprises a coolant inlet 16, a refrigerant inlet 17, a coolant outlet 18, a refrigerant outlet 19, a separator plate 20, a metal heat exchanger casing 22, and a separator tube 23. Figure 13 is a graph showing curves illustrating the thermal performance of a battery without a thermal management system 24, with a solid component powder mixture 25, with air cooling and fins 26, and with a solid component powder mixture and liquid cooling 27, as measured using a particular type of cell with an allowable peak discharge of 20C. The stepped curves are due to the minimum deviation of 1°C for the temperature sensors used.

[0048] The curves in the graph are plotted for a simulated test cycle of an automobile operating condition in which the battery module described above is used under similar driving conditions. The simulated test conditions are the same as those disclosed above. The test cycle used here discharges a complete cell from 100% SoC to 10% SoC in approximately 13 minutes. For an efficient thermal management system, the cell temperature must not exceed 60°C, because improper cooling can lead to thermal runaway and shorten the cell's lifespan. The results clearly show that even under these extremely high-power conditions, the cell temperature of the batteries using only the solid component powder mixture, the solid component powder mixture and air-cooled fins, and the solid component powder mixture and liquid cooling as the heat dissipation medium does not exceed the operating limit of 60°C. For the batteries using the solid component powder mixture and liquid cooling as the heat dissipation medium, the temperature remains below 45°C. FIG. 14 is a graph showing curves illustrating the thermal performance of a battery without a thermal management system 28, with a solid component powder mixture 29 and air cooling and fins 30, and with a solid component powder mixture and liquid cooling 31, as measured using a particular type of cell with an allowable peak discharge of 4C.

[0049] Again, the cell temperature will not exceed the operating limit of 60°C for batteries with only solid powder mixture, solid powder mixture with air cooling and fins, and solid powder mixture with liquid cooling as a heat dissipation medium. For batteries with solid powder mixture and liquid cooling as a heat dissipation medium, the temperature will remain below 40°C.

[0050] The results of the following tests, however, clearly show that the solid component powder mixture is useful in controlling the battery's operating temperature within a predetermined range, and that although its efficiency can be further improved by adding air cooling and fins to the battery casing, placing liquid components in the battery along with the solid component powder mixture most efficiently maintains the operating temperature within a predetermined range.

[0051] Although specific language has been used to describe this disclosure, no limitations are intended thereby. Those skilled in the art will appreciate that various operational modifications can be made to the method in order to implement the inventive concepts taught herein.

[0052] The figures and the foregoing description illustrate exemplary embodiments. Those skilled in the art will appreciate that one or more of the described elements may be combined into a single functional element. Alternatively, certain elements may be divided into multiple functional elements. Elements of one embodiment may be added to another embodiment. For example, the order of the steps described herein may be changed and is not limited to the aspects described herein. Furthermore, the actions in any flow diagram need not be performed in the order shown, and not all actions necessarily need to be performed. Furthermore, actions that are independent of other actions may be performed in parallel with other actions. The scope of the embodiments is in no way limited by these specific examples. Numerous variations, such as differences in structure, dimensions, and use of materials, are possible, whether or not explicitly shown herein.

Claims

1. 1. A thermal management system for a battery having a plurality of cells housed in a casing, comprising: a powdered solid component contacting the outer surfaces of the plurality of cells and substantially filling the gaps between the plurality of cells; a liquid-transporting component configured to exchange heat with the solid component, a surface of the cell, or both; one or more sensors configured to sense a temperature of any one of the one or more cells, the solid component, and the liquid transfer component; a pump for circulating coolant through the fluid transport component; a heat exchanger disposed outside the battery and in fluid communication with the fluid-transporting component for heat exchange, for maintaining a temperature of cells within the battery within a predetermined temperature range; A thermal management system comprising:

2. The thermal management system of claim 1 , wherein the fluid transfer component comprises one or more tubes for circulating fluid through the battery.

3. 2. The thermal management system of claim 1, wherein the liquid-transporting component is a metal block configured to contact at least one or more of a surface of the battery, the solid component, or both, the block having a passageway for transporting the coolant within the metal block.

4. The thermal management system of claim 1 , wherein the coolant is one of water, glycol, and a mixture of water and glycol in a predetermined ratio.

5. The thermal management system of claim 1 , wherein the heat exchanger is selected from one of a radiator, a chiller, a heater, and a chiller heater.

6. The thermal management system of claim 1 , wherein an outer surface of the battery casing is configured as one of a ribbed surface or fins to enhance heat dissipation.

7. The thermal management system of claim 1 , wherein the casing is constructed from one of aluminum or an aluminum composite.

8. The thermal management system of claim 1 , wherein the flow of the liquid conveyed through the liquid-transporting component is controlled by one or more flow control valves.

9. The thermal management system of claim 2 , wherein the one or more tubes are positioned either in a position where they pass closely through each of the plurality of cells or in a position where they contact a bottom surface of each of the plurality of cells.

10. 10. The thermal management system of claim 1, wherein the one or more sensors are communicatively connected to a controller configured to process one or more signals from the one or more sensors and to perform one or more of: controlling the flow of the liquid through the liquid transfer component; and controlling one of a heater, a chiller, or a chiller heater.

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