System for battery heat management using vapor chamber and method of them

Abstract

To provide a heat management system for a battery, capable of realizing a heat management to be improved for the battery by using a vapor chamber containing a wicking component in an inner part.SOLUTION: An illustrative heat management system 100 comprises a vapor chamber 110 containing a working fluid 115 and a wicking material 120. A plurality of battery cells 112 is arranged into at least partially the vapor chamber. A cold plate 130 is coupled to the vapor chamber 110, and a heat pump 150 is coupled to the cold plate 130. A capillary tube may be used for facilitating a movement of a vapor in the heat management system 100 and the working fluid 115.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001]

[0001] This application relates to a vapor chamber-based vaporizer, filed on November 18, 2016. This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 424,054, entitled "System and Method for Battery Thermal Management," the entire contents of which are incorporated herein by reference for all purposes.

[0002]

[0002] The present disclosure relates to thermal management, and more particularly, to thermal management of battery packs. [Background technology]

[0003]

[0003] Conventional approaches to thermal management of battery packs and cells, especially in automotive applications, Conventional approaches have attempted to provide rapid and well-controlled heating and / or cooling of battery packs as desired. However, these conventional approaches have been limited in their ability to maintain the battery cells within a desired temperature range during operation, to control maximum and minimum cell temperatures, to achieve an operating set point temperature, or to ensure a limited range of thermal variation between cells within the battery pack. Thus, improved systems and methods for thermal management of battery packs and other electrical devices remain desirable. Summary of the Invention

[0004] In an exemplary embodiment, a thermal management system includes a vapor chamber including a housing, a wicking material, and a working fluid, and a battery including a plurality of battery cells. and a repack, each of the plurality of battery cells being at least partially disposed within the vapor chamber, each battery cell contacting a portion of the wicking material, and the working fluid undergoing a phase change within the vapor chamber to transport heat away from the battery cells.

[0005] In another exemplary embodiment, a method for thermal regulation of a battery pack includes: The method includes at least partially disposing a plurality of battery cells forming a battery pack within a vapor chamber comprising a wicking material and a working fluid, and contacting each of the plurality of battery cells with at least a portion of the wicking material, wherein during charging or discharging of the battery pack, the working fluid changes phase within the vapor chamber to carry heat away from the battery cells.

[0006] In another exemplary embodiment, a thermal management system for an individual battery cell includes a housing. The cold well includes a housing, a wicking material, and a working fluid, and a battery cell disposed at least partially within the cold well such that a bottom of the battery cell contacts the wicking material. An interface between the battery cell and the housing is sealed to retain the working fluid within the housing. The working fluid undergoes a phase change within the cold well to transport heat away from the battery cell.

[0007] In another exemplary embodiment, a thermal management system for a battery pack includes a housing. The thermal management system includes a vapor chamber including a wicking material, a wicking material, and a working fluid, and a cold plate coupling the vapor chamber to the heat pump. The battery pack includes a plurality of battery cells, each of the plurality of battery cells being at least partially disposed within the vapor chamber. The thermal management system also includes a condensation chamber coupled to the cold plate and a capillary connecting the vapor chamber to the condensation chamber. Each battery cell contacts a portion of the wicking material, and the working fluid changes phase in the vapor chamber to transport heat away from the battery cells.

[0008]

[0008] This Summary section should be understood as a simplified introduction to the disclosure. It is not intended to be used to limit the scope of the claims.

[0009]

[0009] Reference is made to the following description, the appended claims, and the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1A] FIG. 1A illustrates an exemplary thermal management system having a cold plate disposed below a vapor chamber that completely surrounds a battery cell, according to an exemplary embodiment. [Figure 1B]

[0011] FIG. 1B illustrates an exemplary thermal management system having a cold plate disposed above a vapor chamber that completely surrounds the battery cells, according to an exemplary embodiment. [Figure 1C]

[0012] FIG. 1C illustrates an exemplary thermal management system having a cold plate disposed below a vapor chamber that completely surrounds the battery cells, according to an exemplary embodiment. [Figure 1D]

[0013] FIG. 1D illustrates an example thermal management system having a cold plate disposed above a vapor chamber that completely surrounds the battery cells, according to an example embodiment. [Figure 1E]

[0014] FIG. 1E illustrates orientation independence for the operation of an exemplary thermal management system in accordance with an exemplary embodiment. [Figure 1F]

[0015] FIG. IF illustrates an example thermal management system that utilizes a common coolant flow path for the battery pack, power electronics, and electric motor, according to an example embodiment. [Figure 2A]

[0016] FIG. 2A shows a honeycomb-like configuration for a wick structure, according to an exemplary embodiment. [Figure 2B]

[0017] FIG. 2B shows a battery cell partially disposed within the wick structure of FIG. 2A, according to an exemplary embodiment. [Figure 2C]

[0018] FIG. 2C illustrates a post-like configuration of a wick structure, according to an exemplary embodiment. [Figure 2D]

[0019] FIG. 2D shows battery cells interspersed among the wick structures of FIG. 2C according to an exemplary embodiment. [Figure 2E]

[0020] FIG. 2E illustrates a serial weave configuration for the wick structure, according to an exemplary embodiment. [Figure 2F]

[0021] FIG. 2F shows a battery cell partially disposed within the wick structure of FIG. 2E. [Figure 2G]

[0022] FIG. 2G shows a battery cell partially disposed within a wick structure having a parallel weave configuration, according to an exemplary embodiment. [Figure 2H]

[0023] FIG. 2H illustrates a tapered wick structure according to an example embodiment. [Figure 2I]

[0024] FIG. 2I illustrates a wick structure having a configuration according to the location of the battery cell within the battery pack, according to an example embodiment. [Figure 2J]

[0025] FIG. 2J illustrates targeted thermal management of battery cells according to their location within a battery pack, according to an example embodiment. [Figure 3A]

[0026] FIG. 3A illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 3B] FIG. 3B illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 3C] FIG. 3C illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 3D] FIG. 3D illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 4A]

[0027] FIG. 4A illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 4B] FIG. 4B illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 4C] FIG. 4C illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 4D] FIG. 4D illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 5A]

[0028] FIG. 5A illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 5B] FIG. 5B illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 5C] FIG. 5C illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 5D] FIG. 5D illustrates a dual layer configuration for a wick structure and the integration of a battery cell therewith, according to various exemplary embodiments. [Figure 6]

[0029] FIG. 6 illustrates a single battery cell and associated coldwell, according to an exemplary embodiment. [Figure 7A]

[0030] FIG. 7A illustrates the use of a vapor chamber and wicking components for cooling of an electronic device, according to various exemplary embodiments. [Figure 7B]FIG. 7B illustrates the use of a vapor chamber and wicking components for cooling of an electronic device, according to various exemplary embodiments. [Figure 7C] FIG. 7C illustrates the use of a vapor chamber and wicking components for cooling of an electronic device, according to various exemplary embodiments. [Figure 8A]

[0031] 8A illustrates an example thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various example embodiments. The capillary has an inlet end and a return end on a common side of the vapor chamber. [Figure 8B] 8B illustrates an example thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various example embodiments. The capillary has an inlet end and a return end on a common side of the vapor chamber. [Figure 8C] 8C illustrates an example thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various example embodiments. The capillary has an inlet end and a return end on a common side of the vapor chamber. [Figure 9A]

[0032] 9A illustrates an example thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various example embodiments. The capillary has an inlet end and a return end on opposite sides of the vapor chamber. [Figure 9B] 9B illustrates an exemplary thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various exemplary embodiments. The capillary has an inlet end and a return end on opposite sides of the vapor chamber. [Figure 9C] 9C illustrates an example thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various example embodiments. The capillary has an inlet end and a return end on opposite sides of the vapor chamber. [Figure 9D]

[0033] FIG. 9D is a diagram illustrating the use of capillaries to achieve the desired circulation of the working fluid in the vapor chamber, according to various exemplary embodiments. [Figure 10A]

[0034] 10A illustrates an exemplary thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various exemplary embodiments. The capillary leads to a condensation chamber, which is coupled to the vapor chamber via a wicking post. [Figure 10B] 10B illustrates an exemplary thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various exemplary embodiments. The capillary leads to a condensation chamber, which is coupled to the vapor chamber via a wicking post. [Figure 11A]

[0035] 11A illustrates an exemplary thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various exemplary embodiments. The capillary leads to a condensation chamber, which is connected to the vapor chamber via a wicking post and a working fluid conduit. [Figure 11B] 11B illustrates an exemplary thermal management system utilizing a capillary in conjunction with a vapor chamber, according to various exemplary embodiments. The capillary leads to a condensation chamber, which is connected to the vapor chamber via a wicking post and a working fluid conduit. [Figure 12A]

[0036] FIG. 12A illustrates the use of wicking posts of various heights in a thermal management system, according to various exemplary embodiments. [Figure 12B] FIG. 12B illustrates the use of wicking posts of various heights in a thermal management system, according to various exemplary embodiments. [Figure 12C] FIG. 12C illustrates the use of wicking posts of various heights in a thermal management system, according to various exemplary embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011]

[0037] The following description relates to various exemplary embodiments only and is not intended to be limiting of the scope of the present disclosure. The present invention is not intended to be limiting in any way, applicability, or configuration. Rather, the following description is intended to provide convenient illustrations for implementing various improved embodiments, including the best mode. As will become apparent, various changes may be made in the function and arrangement of elements described in these embodiments without departing from the scope of the appended description.

[0012]

[0038] For the sake of brevity, the conventional techniques for the construction, configuration and use of battery packs are described. The techniques and conventional techniques for thermal management, operation, measurement, optimization, and / or control will not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and / or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in an actual system or related use, such as a battery pack for an electric vehicle.

[0013]

[0039] Utilizing a battery pack and associated components constructed in accordance with the principles of the present disclosure By using wicking, various shortcomings of conventional battery and / or thermal management systems can be addressed. For example, conventional two-phase cooling approaches typically utilize integral heat pipes and / or battery cells that are fully submerged in fluid, which adds significant weight and reduces energy density. Conventional approaches completely encapsulate each battery cell with wicking material, limiting vapor transport and capillary forces that overcome gravity as cooling is provided underneath the battery pack, increasing cell spacing, and significantly reducing volumetric and gravimetric energy density.

[0014]

[0040] In contrast, the exemplary systems and methods disclosed herein provide a space- and The exemplary system allows for improved energy density at the battery pack level by eliminating limitations on the battery cell geometry and by utilizing lightweight materials. Additionally, the exemplary system utilizes a liquid-vapor phase change mechanism to ensure rapid thermal response and maximum heat transfer. Importantly, the exemplary system provides effective thermal management in all orientations, including gravity-supported, tilted, horizontal, and anti-gravity conditions. Additionally, a wide range of electrically insulating yet thermally conductive materials may be utilized for the wicking material and working fluid. Additionally, the exemplary system enhances and / or targets heat transfer at portions (or specific locations therein) of the battery pack. Additionally, the exemplary system provides for the vapor chamber to be used ... By using a shared working fluid environment among the members, thermal runaway of particular battery cells within the battery pack can be addressed, minimized, and / or prevented.

[0015]

[0041] The thermal management system according to the principles of the present disclosure provides a desired dimensional, mechanical, electrical, chemical, and and / or thermal properties may be provided using any suitable components, structures, and / or elements.

[0016]

[0042] As used herein, a "battery pack" refers to a single, integrated A battery pack represents a set of any number of battery cells interconnected in series or parallel, or a combination of series and parallel, to provide energy storage and / or power to a system. One example of a battery pack is a lithium-ion battery pack in an electric vehicle, which may consist of thousands of cylindrical lithium-ion battery cells.

[0017]

[0043] As used herein, a "battery cell" refers to a device that generates electrical energy from a chemical reaction. A battery cell represents an electrochemical cell that can be charged by introducing an electric current through the cell. Some battery cells may be rechargeable by introducing an electric current through the cell. Battery cells come in a variety of types, such as lead acid, nickel cadmium, nickel metal hydride, nickel metal hydride, lithium ion, nickel sodium chloride (aka "zebra"), etc., based on the chemical reaction used to generate the electric current. Because battery cells generate electricity based on a chemical reaction, the temperature of the cell may affect the efficiency with which electricity is generated. Battery cells may also be fuel cells, such as hydrogen-oxide proton exchange membrane cells, phosphoric acid cells, or solid acid cells. The principles of the present disclosure may be desirably applied to a wide variety of battery cell types and are not limited to a particular battery cell chemistry, size, or configuration.

[0018]

[0044] As used herein, a "heat pump" refers to a device that converts heat from a "heat source" into heat by application of an external power source. "Heat sink" refers to a system that moves thermal energy from one part of the system, known as the heat source, to another part of the system, known as the "heat sink." Typically, heat is transferred by the movement of a fluid circulating between the heat source and the heat sink. Examples include reversible two-phase refrigerant systems and single-phase ethylene-glycol systems.

[0019]

[0045] As used herein, a "vapor chamber" (or "heat pipe") is a combination of two Depicts a heat transfer device that combines the principles of both thermal conductivity and phase change to efficiently manage heat transfer across an interface.

[0020]

[0046] 1A-1D, in various exemplary embodiments, thermal management system 100 comprises vapor chamber 110, cold plate 130, and heat pump 150. Cold plate 130 is disposed between and thermally coupled to vapor chamber 110 and heat pump 150. In some embodiments, cold plate 130 and heat pump 150 are separate components. In other exemplary embodiments, a surface forming portion of heat pump 150 can be considered to function as cold plate 130. In yet other exemplary embodiments, a surface forming portion of vapor chamber 110 can be considered to function as cold plate 130. Thermal management system 100 may comprise any other suitable components, such as sensors, ports, seals, and / or electrical controls, configured to support, guide, modify, and / or otherwise manage and / or control the operation of thermal management system 100 and / or its components. Thermal management system 100 may be utilized to provide isothermal and / or near isothermal conditions for battery cells 112 disposed within (or partially within) vapor chamber 110, for example.

[0021]

[0047] In some exemplary embodiments, the vapor chamber 110 may be any of the components shown in, for example, FIG. 1A and As shown in FIG. 1B, the battery cell 112 is configured to completely house one or more battery cells 112. will be done.

[0022]

[0048] In another exemplary embodiment, the vapor chamber 110 may be any of the configurations shown in, for example, FIGS. 1C and 1D. As shown, the vapor chamber 110 is configured to partially house one or more battery cells 112. In these exemplary embodiments, the vapor chamber 110 is configured with various orifices and / or seals, etc., to at least partially accommodate one or more battery cells 112 while effectively retaining the working fluid 115 within the vapor chamber 110. In these exemplary embodiments, access to one end of each battery cell 112 (e.g., for electrical wiring) is facilitated as compared to an approach in which each battery cell 112 is fully housed within the vapor chamber 110 while still providing sufficient thermal regulation of each battery cell 112. Additionally, in these exemplary embodiments, the vapor chamber 110 may function to at least partially hold, secure, and / or align the battery cells 112 relative to one another, reducing and / or eliminating the need for holding and / or positioning components for the other battery cells 112.

[0023]

[0049] With continued reference to FIGS. 1C and 1D, in one exemplary embodiment, a steam chuck is provided. The vapor chamber 110 is configured with various seals, retention mechanisms, and / or sealants, etc., so that the vapor chamber 110 can accommodate a portion of the multiple battery cells 112 while preventing leakage and / or evaporation of the working fluid 115 from within the vapor chamber 110. For example, in one exemplary embodiment, the vapor chamber 110 comprises a rigid stock material overmolded with an elastomer to provide a compressible seal at the interface where each battery cell 112 is inserted into the vapor chamber 110. In other exemplary embodiments, O-rings or other mechanical sealing techniques can be utilized. Additionally, a suitable potting material can be utilized to seal the joints between the battery cells 112 and the vapor chamber 110. For example, in various exemplary embodiments, the joints between the battery cells 112 and the vapor chamber 110 can be sealed with a flexible or semi-flexible potting material, adhesive, or sealant, epoxy, or hot melt. The sealing material may be silicone, urethane, polyurethane, polyester, or polyamide based, and / or may include any other suitable sealing and / or adhesive material or compound.

[0024]

[0050] The vapor chamber 110 may extend over the length (and / or surface area, In another exemplary embodiment, for each battery cell 112, the vapor chamber 110 may be configured to accommodate between about 10% and about 90% of the length of the battery cell 112. In another exemplary embodiment, for each battery cell 112, the chamber 110 may be configured to accommodate between about 20% and about 50% of the length of the battery cell 112. Furthermore, the vapor chamber 110 may be configured to accommodate different percentages of the battery cells 112 depending, for example, on the location of the battery cells 112 in the battery pack. In an exemplary embodiment, the vapor chamber 110 accommodates about 25% of the length of the battery cells 112 located at the ends of the battery pack and about 50% of the length of the battery cells 112 located approximately in the center of the battery pack. Furthermore, the vapor chamber 110 may be configured to accommodate any suitable percentage of the battery cells 112 based at least in part on the amount of temperature regulation desired for that particular battery cell 112. In this manner, the battery cells 112 requiring greater cooling may be cooled more thoroughly than the other battery cells 112.

[0025]

[0051] In various exemplary embodiments, the vapor chamber 110 is made of a durable material, such as plastic. In some embodiments, vapor chamber 110 comprises one or more of aluminum and / or steel, and the like. Vapor chamber 110 may be formed by any suitable process or combination of processes, such as, for example, overmolding and / or laser welding. do.

[0026]

[0052] The vapor chamber 110 may be, for example, for relieving pressure therefrom and / or In some exemplary embodiments, vapor chamber 110 may be configured with one or more vents and / or access ports, etc., to allow the level of working fluid 115 within vapor chamber 110 to be adjusted. In some exemplary embodiments, vapor chamber 110 is configured with internal temperature and / or pressure sensors to allow the amount of working fluid 115 within vapor chamber 110 to be adjusted (e.g., at intervals, at specific temperature and / or pressure thresholds, in real time, etc.).

[0027]

[0053] The vapor chamber 110 can accommodate one or more items to be thermally managed, such as multiple batteries. The vapor chamber 110 is configured to house (or partially house) the battery cells 112. Although the battery cells 112 are generally configured in a generally cylindrical shape, in various exemplary embodiments, within the vapor chamber 110, the battery cells 112 (or portions thereof) may be configured in any suitable orientation, number, arrangement, size, and / or shape. In some exemplary embodiments, to achieve a high density of battery cells 112 within the vapor chamber 110, the battery cells 112 are packed in offset horizontally and / or vertically. In many exemplary embodiments, the battery cells 112 may be packed in offset horizontally and / or vertically. In this embodiment, the battery cells 112 are configured with positive and negative terminals on a common end of a cylindrical battery structure (e.g., as shown in Figures 1A-1D). In this manner, the thermal management system 100 allows for effective thermal management of the battery cells 112 while facilitating wiring of the battery cells 112.

[0028]

[0054] The vapor chamber 110 contains a selected amount of working fluid 115. Working fluid 115 may include any suitable material or combination of materials, such as, for example, water, methanol, ethanol (ethyl alcohol), acetone, pentane, perfluoromethylcyclohexane, and / or heptane. It is desirable for working fluid 115 to be electrically insulating and / or non-reactive with the components utilized in battery cell 112. Working fluid 115 is selected to enable efficient operation of vapor chamber 110. In various exemplary embodiments, working fluid properties that may be tuned and / or optimized include density, viscosity, surface tension, boiling point, latent heat of vaporization, reactivity with respect to other components of thermal management system 100, and the like.

[0029]

[0055] In the thermal management system 100, the vapor chamber 110 is configured to receive a desired amount of working fluid 1 15, for example, with an amount sufficient to saturate all of the wicking material 120 contained within the vapor chamber 110. Additionally, the vapor chamber 110 may be filled with an amount of working fluid 115 in excess of the amount necessary to saturate the wicking material 120. The amount of working fluid 115 disposed within the vapor chamber 110 may be selected based on a desired level of temperature regulation for the battery cells 112, and / or an expected rate of loss or leakage of working fluid 115 from the vapor chamber 110, etc.

[0030]

[0056] The vapor chamber 110 also contains a number of battery cells 112 and a working fluid 115. The device further comprises a selected amount of a wicking material 120 configured to interact with the

[0031]

[0057] The wicking material 120 may be immersed in the working fluid 115 and may be wicked by capillary action. The porous structure may be mesh-like, porous, or dendritic, or a combination thereof, to provide maximum wetting for evaporation and condensation.

[0032]

[0058] In various exemplary embodiments, the wicking material 120 is compatible with the working fluid 115. For example, the wicking material 120 may be any of a variety of fabrics with microporous structures, such as amorphous silica fibers (of various densities and / or branching configurations), fiberglass, nylon, polytetrafluoroethylene, polypropylene, and the like. and / or polyethylene, etc. Additionally, the wicking material 120 may be comprised of a powder, filaments, fibers, fabric, mesh, mat, and / or film, etc.

[0033]

[0059] In some embodiments, the wicking material 120 is a material that is capable of absorbing liquid-solid and liquid-vapor impingement. The contact angle between the intersections with the interface is less than 90 degrees (i.e., the wicking material 120 is hydrophilic). The contact angle is determined by a combination of factors such as surface tension and gravity. The wicking material 120 also benefits from having a high capillary effect. Small changes in material structure / roughness / texture can result in significant changes in capillary forces. In various exemplary embodiments, properties of the wicking material 120 that can be selected, adjusted, and / or optimized include the effective radius of the wick material, the permeability of the wick material (as a result of both particle size and porosity), the cross-sectional area of ​​the wick material, and / or the effective length of the heat transfer path.

[0034]

[0060] The wicking material 120 is disposed along the battery cells 112 within the vapor chamber 110. 1A , in an embodiment in which cold plate 130 is disposed below vapor chamber 110, wicking material 120 acts to draw working fluid 115 at least partially upwardly and along the sides of battery cells 112 to facilitate the transfer of thermal energy from battery cells 112 to working fluid 115. Additionally, as working fluid 115 returns to a liquid phase through condensation (e.g., along the top and / or sides of vapor chamber 110), wicking material 120 acts to draw working fluid 115 back down the sides of the vapor chamber toward the center of vapor chamber 110.

[0035]

[0061] In various exemplary embodiments, the wicking material 120 is in contact with the working fluid 115. The wicking material 120 is configured to achieve a desired capillary velocity when utilized in conjunction with the battery cells 112. In some embodiments, the wicking material 120 achieves a capillary velocity of up to about 7 mm / s. In other exemplary embodiments, the wicking material 120 achieves a capillary velocity of between about 4 mm / s and about 7 mm / s. Additionally, in the thermal management system 100, the wicking material 120 (along with the working fluid 115) can be configured to provide a sufficient capillary velocity to enable effective thermal conditioning of the battery cells 112 by conveying a sufficient continuous flow of the working fluid 115 into contact with the battery cells 112.

[0036]

[0062] In some exemplary embodiments, the wicking material 120 is disposed in each battery cell 1 In one exemplary embodiment, the wicking material 120 extends less than about 10% of the distance along each battery cell 112. In another exemplary embodiment, the wicking material 120 extends less than about 25% of the distance along each battery cell 112. In yet another exemplary embodiment, the wicking material 120 extends less than about 50% of the distance along each battery cell 112. As will be appreciated, the thermal management system 100 does not require the wicking material 120 to extend completely along each battery cell 112, thereby providing significant weight and cost savings. However, in the thermal management system 100, the wicking material 120 can extend any suitable selected distance along each battery cell 112.

[0037]

[0063] In various exemplary embodiments, the wicking material 120 may be wicked by any suitable process. The wicking material 120 may be constructed by a variety of techniques, such as solvent casting, sheet forming and lateral stretching, and / or injection molding. Additionally, the properties of the wicking material 120 may vary during manufacture and / or when utilized within the vapor chamber 110. For example, in various exemplary embodiments in which the wicking material 120 is injection molded, the properties of the wicking material 120 may vary from injection site to injection site to enable customized and / or targeted thermal performance of the resulting wick structure. For example, a wicking material 120 having a first material (or mixture of materials), density, porosity, and / or level of capillarity, etc. may be injected into a first injection site, and a second material (or mixture of materials), density, porosity, and / or level of capillarity, etc. may be injected into a second injection site. Wicking material 120 having a level of capillarity and / or wicking properties may be injected into the second injection site. Additionally, when manufactured by injection molding, wicking material 120 may be configured with a minimum thickness of about 0.75 mm, thereby allowing wicking material 120 to be positioned between battery cells 112 within vapor chamber 110 while still allowing battery cells 112 to be positioned in close proximity.

[0038]

[0064] The cold plate 130 is disposed between the vapor chamber 110 and the heat pump 150. The cold plate 130 is configured to transfer thermal energy to and from the heat pump 150. For example, when the thermal management system 100 is utilized to cool the battery cells 112 in the vapor chamber 110, the cold plate 130 receives thermal energy from the vapor chamber 110 and transmits the thermal energy to the heat pump 150. Conversely, when the thermal management system 100 is utilized to heat the battery cells 112 in the vapor chamber 110 (e.g., when the thermal management system 100 forms part of a vehicle located in a cold ambient environment), the cold plate 130 receives thermal energy from the heat pump 150 and transmits the thermal energy to the vapor chamber 110. The cold plate 130 may comprise any suitable durable, thermally conductive material, for example, anodized aluminum.

[0039]

[0065] In an exemplary embodiment, the cold plate 130 includes mini-channel cooling and / or or microchannel cooling. The channels formed in and / or on the cold plate 130 may be of any suitable size and / or geometry, such as circular, rectangular, circular with "teeth" or other protrusions, and / or trapezoidal. The cold plate 130 may be configured to have channels for fluid flow only on the side of the cold plate 130 that interfaces with the heat pump 150, only on the side of the cold plate 130 that interfaces with the vapor chamber 110, or on both sides of the cold plate 130. The channels on the cold plate 130 are configured to induce and / or maintain turbulent flow through the cold plate 130 to maximize associated heat transfer.

[0040]

[0066] In various exemplary embodiments, the heat pump 150 may be configured to generate heat by, for example, water, water-glycol The heat pump 150 operates to remove heat from (or provide heat in a heating mode) the cold plate 130 by pumping circulation of a coolant, such as a refrigerant mixture, a hydrofluorocarbon refrigerant liquid, or the like. The heat pump 150 may include any suitable pumps, impellers, valves, hoses, tubes, radiators, etc., as known in the art, for transferring heat to and / or from the cold plate 130.

[0041]

[0067] 1A and 1C, in various exemplary embodiments, a thermal management system 1B and 1D, in various exemplary embodiments, the thermal management system 100 may be configured and / or oriented such that the cold plate 130 is disposed below the vapor chamber 110. Furthermore, in many exemplary embodiments, the relationship between the cold plate 130 and the vapor chamber 110 may be altered, for example, by turning the thermal management system 100 upside down, placing the thermal management system 100 on its side or at an angle relative to a horizontal plane, etc. Thus, as shown in FIG. 1E, the thermal management system 100 is configured to provide adequate cooling and / or heating capacity to items housed within the vapor chamber 100 regardless of the orientation of the thermal management system 100. In other words, the thermal management system 100 does not depend on any particular orientation with respect to gravity to function effectively. In contrast, conventional approaches to vapor-based cooling typically rely heavily on gravity for condensation and fluid return and would not be able to operate properly without gravity assistance. As will be appreciated, the orientation-independent features of the exemplary systems disclosed herein are useful in applications where electrical automation systems often operate in tilted orientations. This is highly desirable in non-stationary energy storage systems such as cars. For example, the thermal management system 100 is configured to function effectively when utilized in electric vehicles, even when the vehicle is moving or parked uphill or downhill. Additionally, the thermal management system 100 is configured to function effectively when utilized in electric aircraft, drones, and the like, even when the orientation of the thermal management system 100 is changing, such as by ascending, descending, tilting while turning, and the like.

[0042]

[0068] During operation of the thermal management system 100, at least two thermal A transfer path is operable. The first heat transfer is accomplished by an external heat pump 150 that transfers heat to or from the battery cells 112 via a fluid (e.g., water-glycol fluid, etc.). Within the vapor chamber 110, heat transfer is facilitated by a liquid-gas phase change within the voids and / or cavities covered and / or formed by the wicking material 120. During the cooling mode of the thermal management system 100, a rapid thermal response is established by the latent heat of vaporization, and the working fluid 115 within the wicking material 120 evaporates into the vapor space 117 (as used herein, "vapor space" refers to the space within the vapor chamber 110 that is not occupied by a solid or liquid). The heat pump 150 that carries the heat away condenses the vapor, and the wicking material 120 exerts capillary forces to draw the condensate back to the evaporation site, thereby repeating the cycle. During the battery pre-heat mode of the thermal management system 100, the heat pump 150 serves as a heat source that supplies heat to the vapor chamber 110. The vapor space within the vapor chamber 110 acts as one or more thermosiphons that transfer heat to the walls of the battery cells 112. The large latent heat of vaporization facilitates the pre-heating process and is beneficial in cold climates.

[0043]

[0069] Referring briefly to FIG. 1F, the principles of the present disclosure also include a battery pack, a power electronics An integrated thermal management system for an electric vehicle is envisioned in which the battery pack, power electronics, and motor or generator may be cooled or heated via an integrated system employing two-phase cooling for the battery pack, power electronics, and motor or generator. In some exemplary embodiments, the heat pump 150 circulates a fluid (such as propylene glycol, etc.) through the battery pack 151, power electronics 152, and electric motor 153 (note that the battery pack 151, power electronics 152, and electric motor 153 may be arranged in any order relative to one another with respect to the fluid circulated by the heat pump 150). In still other exemplary embodiments, the battery pack 151, power electronics 152, and electric motor 153 are each coupled to the heat pump 150 via a dedicated fluid line, but share a common fluid reservoir. In various exemplary embodiments, each of the battery pack 151, power electronics 152, and electric motor 153 is at least partially cooled by two-phase cooling utilizing a working fluid and / or a wicking material as disclosed herein.

[0044]

[0070] The thermal management system 100 may be configured to provide, for example, a particular level of thermal performance, volumetric energy density, Wicking material 120 can be configured as desired to achieve mechanical retention and / or fixation, etc. of battery cells 112. For example, wicking material 120 may be configured to at least partially hold battery cells 112 in particular positions within vapor chamber 110 and / or relative to one another.

[0045]

[0071] With further reference to FIGS. 2A and 2B, in some exemplary embodiments, The wicking material 120 is configured in a honeycomb-like structure. In these exemplary embodiments, the wicking material 120 is configured as contact rings 210 having heat flow contact areas 220 that conduct heat from the battery cells 112 (wherein the battery cells 112 are individually disposed within each contact ring 210) to a vapor path 230 between the contact rings 210. In FIG. 2A, the contact areas 220 are configured as contact rings 210 having heat flow contact areas 220 that conduct heat from the battery cells 112 (wherein the battery cells 112 are individually disposed within each contact ring 210) to a vapor path 230 between the contact rings 210. Although shown as segments of contact rings 210, continuous surfaces within the contact rings 210 may also be utilized. Contact rings 210 of shapes other than circular may be used, especially if the battery cells 212 are not cylindrical (e.g., rectangular cells). The contact area between the contact area 220 and the battery cells 112 may be adjusted by varying the shape of the contact rings 210 for optimal heat transfer. FIG. 2B shows a wicking material 120 with cylindrical battery cells 112 arranged within several contact rings 210. In many cases of practical use, every contact ring 210 has a corresponding battery cell 112 inserted therein. The contact rings 210 may be formed from straight wall segments as shown, or may be smoothly circular without corners. The vapor path 230 may be triangular or any other suitable shape for efficient stacking arrangement of the contact rings 210. Additionally, the thickness of the wicking material 120 within the contact rings 210 may vary within the contact rings 210 and / or from ring to ring. For example, the portions of the contact ring 210 located directly between adjacent battery cells 112 may be thin, while the portions of the contact ring 210 that form the edges of the vapor path 230 may be thicker. In this manner, the battery cells 112 may be positioned in close proximity to one another, with a sufficient amount of the wicking material 120 remaining in contact with (or in close proximity to) each battery cell 112 to provide a desired level of thermal performance.

[0046]

[0072] 2C and 2D, in various exemplary embodiments, a wiki The wicking material 120 is configured as a plurality of post-like structures. In some embodiments, the posts 211 are formed in a three-sided post shape in the wicking material 120 and patterned such that there is a vapor space 231 between the posts 211 and between the battery cells 112. The posts 211 may include indentations or other shapes to fit securely to the shape of the battery cells 112. The three-sided shape of the posts 211 allows for efficient stacking arrangement of the battery cells 112. However, any suitable shape for the posts 211 may be utilized. Additionally, the posts 211 may vary in size, shape, material, or other characteristics from post 211 to post 211 to provide a selected level of thermal performance at a particular location within the vapor chamber 110.

[0047]

[0073] Additionally, any suitable number of posts 211 may be utilized in the vapor chamber 110. For example, in vapor chamber 110, each battery cell 112 may be in contact with at least one post 211, or at least two posts 211, or at least three posts 211, or at least four posts. Additionally, in vapor chamber 110, certain posts 211 (and / or all of posts 211) may extend all the way from an inner surface of vapor chamber 110 to a corresponding inner surface on the opposite side of vapor chamber 110 to facilitate effective movement of working fluid 115 regardless of the orientation of vapor chamber 110.

[0048]

[0074] In some exemplary embodiments (e.g., the battery cells 112 are generally circular in shape), In some cases, the posts 211 may be sized and / or configured to fit entirely within the spaces that exist between the battery cells 112 when the battery cells 112 are packed as geometrically close as possible. In this manner, the thermal management system 100 is configured to achieve improved thermal control of the battery cells 112 without adding any volume to the spaces between the battery cells 112.

[0049]

[0075] 2E and 2F, in various exemplary embodiments, a wiki The wicking material 120 is configured in a serial weave pattern. The cereal weave wall 212 of the wicking material 120 is patterned to partially contact each battery cell 112 while leaving a vapor space 232 for vapor return. The cereal weave pattern can be from a single continuous strip of wicking material 120 or from separate strips. Additionally, the thickness or other characteristics of the cereal weave wall 212 can be adjusted to suit the application, e.g., vapor chamber 232. may vary depending on the position of the battery cell 112 within the member 110.

[0050]

[0076] Referring now to FIG. 2G, in various exemplary embodiments, the wicking material 120 The wicking material 120 is configured in a parallel weave pattern. The parallel woven wall 213 is patterned to partially contact each battery cell 112 while leaving a vapor space 232 for vapor return. The parallel woven pattern can be from a single continuous strip of wicking material 120 or from separate strips. Additionally, the thickness or other characteristics of the parallel woven wall 213 can vary depending on, for example, the location of the battery cell 112 within the vapor chamber 110.

[0051]

[0077] Now referring to FIG. 2H, in various exemplary embodiments, a wicking material 1 20 may be configured with a tapered and / or variable thickness. For example, the wicking material 120 may vary in thickness as it extends along the battery cell 112. In some exemplary embodiments, the wicking material 120 may decrease in thickness as it extends from the base of the battery cell 112 toward the distal end of the battery cell. In this manner, the amount of wicking material 120 used within the vapor chamber 110 may be reduced, resulting in weight and cost savings. The wicking material 120 may be evenly tapered. Alternatively, the wicking material 120 may be tapered in a stepped or non-uniform manner, as desired. Additionally, the wicking material 120 may be tapered to provide a desired balance between providing a particular amount of capillarity near the battery cell 112 while providing a desired amount of available vapor space.

[0052]

[0078] In addition to the variable thickness, the wicking material 120 may be arranged along the battery cell 112. Other properties may change as it stretches. For example, portions of the wicking material 120 disposed near the base of the battery cell 112 may be configured to efficiently transfer the working fluid 115 along the battery cell 112 by capillary action, while portions of the wicking material 120 disposed further along the battery cell 112 may be configured to promote efficient evaporation of the working fluid 115.

[0053]

[0079] In the thermal management system 100, the wicking material 120 is disposed within the vapor chamber 110. 2I, in some exemplary embodiments, wicking material 120 is non-uniformly positioned within vapor chamber 110 and / or relative to a particular battery cell 112. For example, wicking material 120-A may extend a first distance along a side of battery cell 112 adjacent a sidewall of vapor chamber 110. Wicking material 120-B may extend a second, longer distance along a side of battery cell 112 adjacent to another battery cell 112 within vapor chamber 110 (and / or positioned away from an edge of vapor chamber 110). In other words, vapor chamber 110 may be configured to provide additional wicking material 120 to battery cells 112 (and / or sides of battery cells 112) that are at least partially surrounded by other battery cells 112 within vapor chamber 110.

[0054]

[0080] Moreover, in various exemplary embodiments, characteristics other than shape and size may be present in a particular The porosity of the wicking material 120 in relation to the battery cells 112 may vary. For example, the porosity of the wicking material 120 in contact with a first battery cell 112 may be different than the porosity of the wicking material 120 in contact with a second battery cell 112. In this manner, the battery cells 112 are provided with different cooling and / or heating rates that are better tailored to their particular locations within the vapor chamber 110, ensuring more uniform thermal conditions throughout the battery 112. In other words, the thermal management system 100 is able to provide a targeted The amount, shape, and properties of the wicking material 120 may be varied with the thermal profile of a particular battery pack, to vary the available heat removal rate in particular portions of the battery pack, etc.

[0055]

[0081] Now referring to FIG. 2J, in various exemplary embodiments, a thermal management system 100 is configured to provide different heat transfer rates to the battery cells 112 depending at least in part on the location of the particular battery cell 112 within the battery pack. For example, with reference to FIG. 2J, in an exemplary battery pack, a particular battery cell 112, e.g., a battery cell 112 disposed at least partially adjacent to a side of the battery pack (and / or having a path to the side of the battery pack unobstructed by other battery cells 112), is considered an "end" cell. Further, in an exemplary battery pack, a particular battery cell 112, e.g., a battery cell 112 that is adjacent to at least one end cell but not adjacent to a side of the battery pack, is considered an "inner" cell. Still further, in an exemplary battery pack, a particular battery cell 112, e.g., a battery cell 112 disposed adjacent only to inner cells and / or other center cells, is considered a "center" cell. In various exemplary embodiments, the thermal management system 100 is configured to provide a higher rate of heat transfer to the center battery cells 112 compared to the inner battery cells 112 and / or the end battery cells 112 (e.g., by using additional wicking material 120, using wicking material 120 that facilitates more efficient vaporization of the working fluid 115, deeper insertion of the battery cells 112 into the vapor chamber 110, etc.). Additionally, the thermal management system 100 may be configured to provide a higher rate of heat transfer to the inner battery cells 112 compared to the end battery cells 112. Additionally, the system 110 may be configured to provide different rates of heat transfer between two particular center battery cells 112, or between two particular inner battery cells 112, and / or between two particular end battery cells 112. Of course, the above examples of targeted thermal management of the battery cells 112 are merely illustrative, and in the thermal management system 100, battery cells 112 requiring additional heating and / or cooling may be provided with additional heat transfer to provide conditions that more closely approximate isothermal conditions within the vapor chamber 110.

[0056]

[0082] Additionally, the thermal management system 100 may include a thermal management system for controlling the flow of thermal fluid associated with the cold plate 130. The heat pump 150 may be configured to provide different rates of heat transfer to the battery cells 112 based at least in part on the direction and / or path of flow. For example, during operation of the heat pump 150, the thermal fluid is pumped across the cold plate 130, for example, in a serpentine path. When the thermal management system 100 is operating in a cooling mode, the thermal fluid gains heat as it traverses the cold plate 130. Thus, the thermal fluid is hotter when it leaves contact with the cold plate 130 compared to when it began contacting the cold plate 130. Thus, battery cells 112 located at or near the area where the thermal fluid begins contacting the cold plate 130 ("inlet" cells) relative to the cold plate 130 may be provided with a different configuration of associated wicking material 120 relative to battery cells 112 located at or near the area where the thermal fluid leaves contact with the cold plate 130 ("outlet" cells). This is because the inlet cells may obtain a higher degree of direct conductive cooling from the cold plate 130 than the outlet cells. In this manner, through operation of the thermal management system 100, the battery cells 112 within the battery pack may achieve conditions that more closely resemble true isothermal conditions.

[0057]

[0083] In some exemplary embodiments, the thermal management system 100 includes a wicking The wicking material 120 includes a single type, layer, and / or configuration of material. In other exemplary embodiments, the wicking material 120 may be configured as multiple layers and / or segments or portions. The wicking material 120 of a first portion may be configured as a wicking material of a second portion. The wicking material 120 may have different materials and / or properties from the wicking material 120. For example, the properties of the wicking material 120, such as pore size, material density, fiber thickness, etc., may vary from one portion to the next. In various exemplary embodiments, the pore size of the wicking material 120 may range from about 1 micrometer (μm) to about 100 μm. In this manner, the wicking action may be increased in certain portions of the vapor chamber 110 while promoting the phase change action in other certain portions. In this manner, the distribution of the working fluid 115 in the vapor chamber 110 may be optimized to more effectively cool the battery cells 112.

[0058]

[0084] 3A-3D, in some exemplary embodiments, The wicking material 120 is comprised of a first layer and a second layer (more generally a first wicking portion 322 and a second wicking portion 326). The first wicking portion 322 may be configured to rapidly and / or effectively direct the working fluid 115 to the second portion 326 (e.g., laterally to the series of battery cells 112, i.e., in the case of generally cylindrical battery cells 112, generally perpendicular to the cylindrical axis). The first wicking portion 322 may be configured to have holes or openings 323 therethrough to fit between the battery cells 112. In these illustrative examples, the ends of the battery cells 112 may be in direct contact with the cold plate 130 without a wicking material disposed therebetween. In this manner, conductive heat transfer from the ends of the battery cells 112 to the cold plate 130 may be promoted while still allowing for efficient distribution of the working fluid 115 within the vapor chamber 110 via the action of the wicking material 120.

[0059]

[0085] The second wicking portion 326 is adapted to absorb the electrical current in a second direction (e.g., The second wicking portion 326 may be configured to primarily facilitate distribution of the working fluid 115 (along the length of the wicking portion 112) and / or to more effectively facilitate vaporization of the working fluid 115. In some exemplary embodiments, the second wicking portion 326 may be configured as a series of approximately triangular posts 327 each having an opening 328 therethrough to act as a vapor path. The posts 327 may also have spaces 329 between the individual posts 327 to provide additional vapor paths. By utilizing a wicking material 120 configured in multiple portions, improved distribution of the working fluid 115 may be achieved, resulting in better heat distribution within the vapor chamber 110.

[0060]

[0086] 4A-4D, in some exemplary embodiments, First wicking portion 422 of wicking material 120 is configured to pass under battery cells 112 and / or be disposed between battery cells 112 and the side, top, or bottom of vapor chamber 110. In these approaches, first wicking portion 422 is configured to have no holes or openings for battery cells 112 to pass through, and second wicking portion 426 may be configured in any suitable manner, for example, similar to second wicking portion 326 (i.e., having posts 427 and openings 428). Additionally, first wicking portion 422 may be configured to roughly approximate the contours of a group of battery cells 112, as depicted.

[0061]

[0087] In yet another exemplary embodiment, the first wicking of the wicking material 120 As shown in FIGS. 5A - 5D, the wicking portion 522 can be configured as a sheet or plane of continuous material. The second wicking portion 526 can be configured in the same manner as the second wicking portions 326 and / or 426. Further, the first wicking materials 322 / 422 / 522 and the corresponding second wicking portions 326 / 426 / 526 may be manufactured separately from each other. Alternatively, the first wicking portions 322 / 422 / 522 and the corresponding second wicking portions 326 / 426 / 526 may be manufactured together, for example, by injection molding.

[0062]

[0088] As will be appreciated, the multi - part approach described in FIGS. 3A - 5D is compatible with and can be used in conjunction with the various configurations and shapes for the wicking material 120 described in connection with the discussion of FIGS. 2A - 2J. Further, as will be appreciated, during operation of the thermal management system 100, particularly when the vapor chamber 110 is tilted with respect to gravity and / or oriented laterally, the first wicking portions 322 / 422 / 522 function to more uniformly distribute the working fluid 115 within the vapor chamber 110.

[0063]

[0089] Compared to conventional thermal management approaches, the principles of the present disclosure have various advantages, such as ​3A-3D, the density of a single post 327 is less than one-quarter the density of aluminum, while still achieving at least three times the thermal performance. Furthermore, the unique arrangement of the posts 327 allows the spacing of the battery cells 112 to be controlled by the manufacturability of the cell retainer, rather than the posts 327. Furthermore, the posts 327 may even accommodate the minimum spacing achieved when adjacent battery cells 112 contact each other. In other words, in the thermal management system 100, the battery cells 112 may be arranged to achieve a maximum possible volumetric efficiency of 90.69% (for cylindrical batteries) while still allowing for effective thermal management of the battery cells 112 by operation of the vapor chambers 110, wicking materials, etc. Furthermore, in the thermal management system 100, the battery cells 112 may be arranged to achieve a volumetric efficiency of between 80% and 90.69%, more preferably between 85% and 90.69%, and even more preferably between 88% and 90.69%.

[0064]

[0090] In various exemplary embodiments, a particular battery cell 11 within the vapor chamber 110 The mass of posts 327 associated with 2 is less than 0.5% of the mass of battery cells 112, allowing for extremely high energy density. In some exemplary embodiments, the mass of all wicking material 120 within vapor chamber 110 is less than 0.5% of the mass of all battery cells 112 that are thermally managed by operation of vapor chamber 110. The mass of all wicking material 120 within vapor chamber 110 is between about 0.1% and about 1% of the mass of all battery cells 112 that are thermally managed by operation of vapor chamber 110.

[0065]

[0091] Referring now to FIG. 6, in various exemplary embodiments, the principles of the present disclosure include: The present invention may be applied at the level of an individual battery cell 112, rather than at the level of a pack of battery cells 112. For example, to provide thermal management of the battery cells 112, in an exemplary embodiment, a two-phase thermal management system is coupled to an end of a single battery cell 112. In an exemplary embodiment, a "coldwell" 610 is coupled to the end of the battery cell 112, forming a completely enclosed space between an outer wall of the coldwell 610 and the end of the battery cell 112. The coldwell 610 includes a wicking material 120 disposed at least partially along its bottom and end, within the coldwell 610, the wicking material 120 also contacts the end of the battery cell 112. The coldwell 610 contains a selected amount of working fluid 115. During operation, the working fluid 115 vaporizes at or near the interface between the battery cell 112 and the wicking material 120, and generally condenses in a "condensation region" as shown in FIG. 6. Depending on the orientation of the battery cells 112 and cold well 610, capillary action (and / or gravity) draws the condensed working fluid 115 back toward the surface of the battery cells 112 through the wicking material 120, and the cycle repeats. The cold well 610 may be coupled to any suitable additional components (e.g., heat pumps, fans, etc.) to remove heat therefrom or to apply heat thereto. As will be appreciated, a cold well 610 may be coupled to each battery cell 112 in a battery pack (or only a portion of the battery cells 112 in a battery pack) to provide thermal regulation, and further, the characteristics of the associated cold well 610 may vary between battery cells 112 in a battery pack.

[0066]

[0092] 7A-7C, in various exemplary embodiments, the present disclosure The two-stage cooling principle shown can be utilized to provide thermal management to power stage components such as a battery pack controller circuit, a motor or generator electronic control system, etc. FIGS. 7A-7C show an example of a two-stage cooling system utilized to cool a power stage component 730 such as a battery pack controller circuit or a motor / generator electronic control system, etc. An external heat pump 750 provides cooling to the entire power stage system. The power stage component 730 is at least partially surrounded by a wicking material 720 that wicks working fluid to the power stage component 730 to provide cooling. A channel 760 can be incorporated into the wicking material 720 to act as a vapor chamber connecting the power stage component 730 to the external heat pump 750, allowing capillary action through the wicking material 720 to cool and condense vapor by the external heat pump 750 for liquid phase return to the power stage component 730.

[0067]

[0093] During operation, the vapor chamber 110 undergoes thermal expansion that is governed by one or more factors. has an upper limit to its transport capacity. In some exemplary embodiments, the operation of the vapor chamber 110 may be affected by the following factors: capillary limit, entrainment limit, boiling limit, sonic limit, and / or viscosity limit. The capillary limit indicates the ability of the wicking material 120 to transport the working fluid 115 by the driving pressure of the liquid circulation, i.e., capillary action. Entrainment limit: During operation, the vapor velocity increases with temperature and can be high enough to create a shear force effect on the return flow of the liquid working fluid 115 from the condensation region to the evaporation region, which causes entrainment of the liquid by the vapor, resulting in a lack of fluid flow and ultimately drying out of some of the wicking material 120. Boiling limit: The point reached when the temperature difference exceeds the degree of superheat that can be sustained for nucleate boiling conditions, and the onset of boiling within the wicking material 120 can disrupt the liquid circulation of the working fluid 115 and cause drying out of some of the wicking material 120. Sonic Limit: At temperatures above the vapor pressure limit, the vapor velocity may be comparable to the speed of sound (i.e., Ma is close to, equal to, and / or greater than 1), causing the vapor flow to be "choked off" and preventing further increases in heat transfer capacity. The viscous limit typically occurs at low temperatures and represents a measure of the cold start capability of the vapor chamber 110. In various exemplary embodiments, the operation of the thermal management system 100 is governed by the associated capillary limit, in other words, the thermal management system 100 may reach the capillary limit before it reaches any other limit.

[0068]

[0094] The following Table 1 shows the results when the cold plate 130 is placed under the vapor chamber 110. 1A and 1C . At lower operating temperatures, viscous limitations dominate, limiting vapor flow. The saturation temperature of the vapor chamber 110 is optimally designed, such that capillary limitations become the limiting factor during operation. In the thermal management system 100, the components are configured to not only overcome gravity, but also to impart sufficient force to pull the working fluid 115 back along the battery cells 112 to a desired height. As shown in Table 1, in this exemplary embodiment, the maximum performance of the vapor chamber 110 ranges from about 9.26 W to about 28.03 W of heat loss at the battery cell 112 level, depending on different configurations and operating conditions. Thus, in various exemplary embodiments, the thermal management system 100 can achieve a thermal resistance of about 0.018 K / W to about 0.054 K / W (or an effective thermal conductivity of about 617.33 Watts per meter Kelvin (W / mK) to about 5,606 W / mK) within the vapor chamber 110 at approximately isothermal temperature.

[0069]

[0095] [Table 1]

[0070]

[0096] Compared with conventional battery thermal management systems, the thermal management system 100 Achieve extremely high levels of cooling at the cell 112 level. In some exemplary embodiments, the thermal management system 100 provides a heat transfer of about 1500 W / mK at the battery cell 112 level (i.e., a heat transfer rate comparable to direct contact with diamond). In other exemplary embodiments, the thermal management system 100 provides a heat transfer of about 500 W / mK at the battery cell 112 level (i.e., a level of heat transfer slightly higher than that of direct contact with copper) to about 2000 W / mK (i.e., a level of heat transfer that is about 500% of that of direct contact with copper). Furthermore, as will be appreciated, in various exemplary embodiments, the thermal management system 100 provides a heat transfer level at the battery 112 level that is about three to about five times greater than that of direct contact with various solid materials commonly utilized for conductive heat transfer, such as aluminum, copper, etc.

[0071]

[0097] Moreover, compared to conventional approaches, the principles of the present disclosure provide This allows for high energy density at the battery pack level. For example, the vapor chamber 110 can be configured to be lightweight. This contributes to a much higher energy density at the battery pack level. For example, the mass of the vapor chamber 110 at the battery pack level in various exemplary embodiments ranges from about 1.45 kg to about 2.9 kg (for a 98 kWh battery pack) depending on the configuration of the wicking material 120 in the vapor chamber 110. As can be seen, the posts of the wicking material 120 do not occupy additional space, so that total volumetric energy density can be maximized in a high energy density cylindrical cell. As a result, there is no loss of volumetric energy density. Compared to various existing approaches, when utilizing the same battery cell of the same capacity, the exemplary embodiment of the thermal management system 100 achieves at least an additional 56 Wh / L volumetric energy density (an increase of more than 12%), and the advantage of the principles of the present disclosure only increases the higher capacity to the pack.

[0072]

[0098] For example, with a volume of approximately 105 L, an exemplary battery pack can store over 55 kWh of battery. While a typical thermal management system 100 may achieve approximately 46 kWh of power per second, a conventional approach utilizing the same battery chemistry and battery cell dimensions may achieve only approximately 46 kWh. In various exemplary embodiments, in the thermal management system 100, the battery cells 112 may be arranged with a cell spacing between approximately 0 mm (i.e., adjacent battery cells 112 touch each other) and approximately 2 mm. In contrast, conventional cooling approaches often require that the battery cells be at least 2 mm apart.

[0073]

[0099] Additionally, the exemplary thermal management system 100 provides a In some exemplary embodiments, the improvement in gravitational energy density may range from about 0.5% to about 15%. In exemplary embodiments, the gravitational energy density improvement can range from about 5% to about 15%. In yet other exemplary embodiments, the gravitational energy density improvement can range from about 8% to about 12%. Moreover, compared to conventional conductively coupled single-phase cooling solutions, the exemplary systems disclosed herein provide significantly higher gravitational and volumetric energy densities.

[0074]

[0100] In accordance with the principles of the present disclosure, the exemplary battery thermal management system is desirably utilized in connection with items such as electric vehicles or mobile industrial equipment, e.g., cars, tractors, trucks, trolleys, trains, vans, quads, golf carts, scooters, boats, airplanes, drones, forklifts, telehandlers, backhoes, and the like.

[0075]

[0101] In various exemplary embodiments, the thermal management system 100 may utilize additional structures and / or components to facilitate the movement and / or distribution of the vapor and working fluid 115. With reference to FIGS. 8A through 8C, in various exemplary embodiments, the thermal management system 100 may be configured to use one or more capillaries 114. The capillaries 114 facilitate the condensation of the working fluid 115 from a vapor to a liquid state. In addition, the capillaries 114 facilitate a more uniform distribution of the working fluid 115 within the thermal management system 100. The capillaries 114 also provide improved heat transfer from (and / or to) the battery cells 112 by vibrations resulting from the movement of the working fluid 115 through the capillaries 114. In other words, the capillaries 114 facilitate forced convection in addition to phase change heat transfer. Additionally, the capillaries 114 convert a portion of the thermal energy generated from the battery cells 112 into kinetic energy of the slugs and vapor bubbles of the working fluid 115. Additionally, the capillaries 114 facilitate a more uniform distribution of the working fluid 115 within the thermal management system 100. During the thermal management system 100, the capillaries promote a stable and / or approximately uniform vapor pressure. In other words, in the thermal management system 100, the capillaries promote a reduced pressure drop from the evaporator to the condenser.

[0076]

[0102] In various exemplary embodiments, the capillary 114 comprises a thermally conductive material, such as aluminum, copper, or the like. The capillary 114 may be electrically insulated and / or isolated via a dielectric coating, such as aluminum oxide. In some exemplary embodiments, the capillary 114 may comprise a durable material, such as plastic. In general, the capillary 114 may be formed from a material that is compatible and / or non-reactive with the working fluid 115. The capillary 114 may comprise a circular tube. Alternatively, the capillary 114 may have an elliptical cross-section, a rectangular cross-section, or other suitable shape. The capillary 114 may have multiple inlet portions that lead to a common main portion (i.e., in an arrangement similar to tributaries connecting a river). Additionally, the capillary 114 may have a common main portion that leads to multiple return portions (i.e., in an arrangement similar to a river that spreads into multiple paths in a delta). Stated differently, the capillary 114 may have a single inlet end and / or return end. Alternatively, the capillary 114 may have multiple inlet ends and / or return ends. Additionally, the capillary 114 may vary in diameter, wall thickness, or other properties along its path, as desired.

[0077]

[0103] The particular capillary 114 diameter, particular capillary 114 wall thickness, and / or number of capillaries 114 utilized in a particular thermal management system 100 may be selected based on one or more of the following: the particular thermal load within the thermal management system 100, the length of the capillaries 114, the surface tension of the working fluid 115, the inclination angle of the capillaries 114, the vapor pressure within the vapor chamber 110, the number of bends in the capillaries 114, the desired horizontal and / or vertical flow rates through the capillaries 114, the number of battery cells 112 at least partially contained within the vapor chamber 110, etc. Additionally, the capillaries 114 may be configured with internal and / or external components, e.g., textured internal and / or external surfaces, to facilitate condensation of vapor within the capillaries 114 and / or transport of the working fluid 115 through the capillaries 114.

[0078]

[0104] In an exemplary embodiment, the capillary tube 114 comprises a copper tube having an inner diameter of 3 mm. In another exemplary embodiment, the capillary tube 114 comprises a copper tube having an inner diameter of 5 mm. In various exemplary embodiments, the capillary tube 114 comprises a metal tube having an inner diameter not exceeding 12 mm. In yet another exemplary embodiment, in which the working fluid 115 includes ethanol and the interior of the vapor chamber 110 is exposed to a vapor pressure of 0.18 bar (resulting in a boiling point of ethanol of approximately 40° C.), the capillary tube 114 is configured to have an inner diameter of 3.6 mm.

[0079]

[0105] During operation of the thermal management system 100, condensation within the capillaries 114 results in the formation of "slugs" of working fluid 115 separated by vapor / air bubbles. The formation of bubbles and slugs within the capillaries 114 leads to perturbations in the operation of the fluid flow therethrough. Thus, in a thermal management system 100 configured with capillaries 114, the configuration of the capillaries 114 can be adjusted to obtain a desired "fill ratio," i.e., the ratio of the amount of working fluid 115 to vapor / air within the capillaries 114. A higher ratio of bubbles to slugs (i.e., a lower total amount of working fluid 115 within the capillaries 114) is typically achieved by reducing the diameter of the capillaries 114, resulting in a lower mass flow rate of working fluid 115 for sensible heat transfer. A higher ratio of slugs to bubbles (i.e., a higher total amount of working fluid 115 within the capillaries 114) is typically achieved by a larger diameter of the capillaries 114, resulting in less vibration while reducing pumping action and heat transfer. Thus, the capillaries 114 may be sized to obtain a desired tradeoff, for example a desired balance between pumping action and mass flow rate, to optimize the operation of the thermal management system 100 .

[0080]

[0106] The capillaries 114 can be arranged in the thermal management system 100 in a variety of ways. In an exemplary embodiment, the thermal management system 100 utilizes one or more capillaries 114 having inlet and return ends disposed on a common side of the vapor chamber 110. The capillaries 114 are thermally coupled into, through, and / or to the vapor chamber 110. When the thermal management system 100 is operating, the vapor in the capillaries 114 condenses into a liquid form of working fluid 115, resulting in alternating vapor / air bubbles in the capillaries 114 and slugs of working fluid 115. The vapor pressure generated in the vapor chamber 110 pushes the slugs through the capillaries 114 and forces the working fluid 115 out of the return ends of the capillaries 114, resulting in a deposition of condensed working fluid 115 at the base of the post 211.

[0081]

[0107] 9A-9C, in some exemplary embodiments, the thermal management system 100 utilizes one or more capillaries 114 having an inlet end on a first side of the vapor chamber 110 and a return end on an opposite side (or orthogonal side, or generally any different side) of the vapor chamber 100. For example, as shown in FIG. 9C, a thermal management system 100 having a generally rectangular vapor chamber 110 may be configured with two capillaries 114. The inlet end of the first capillary 114 and the return end of the second capillary 114 may be located on one side of the generally rectangular vapor chamber 110. On the opposite side of the rectangle, the return end of the first capillary 114 and the inlet end of the second capillary 114 are located. In this manner, a supply of freshly condensed working fluid 115 is introduced to the two opposite sides of the vapor chamber 110.

[0082]

[0108] As will be appreciated, in various exemplary embodiments, multiple capillaries 114 may be utilized to direct the flow of the working fluid 115 within the thermal management system 100. Such configurations may be symmetrical, asymmetrical, looped, or otherwise configured to distribute the working fluid 115 within the thermal management system 100 as desired. For example, and with momentary reference to FIG. 9D, in one exemplary embodiment, the thermal management system 100 is configured with a four-sided vapor chamber 110 and utilizes four capillaries 114. A first capillary 114-A has an inlet end on side S1 of the vapor chamber 110 and a return end on adjacent side S2. A second capillary 114-B has an inlet end on side S2 and a return end on adjacent side S3, a third capillary 114-C has an inlet end on side S3 and a return end on adjacent side S4, and a fourth capillary 114-D has an inlet end on side S4 and a return end on adjacent side S5. Capillary 114-D has an inlet end at side S4 and a return end at adjacent side S1. During operation of thermal management system 100, working fluid 115 circulates in a round robin manner through the four capillaries 114, resulting in a more even distribution of working fluid 115 within thermal management system 100 and thus enabling more balanced thermal management of the batteries utilized therein.

[0083]

[0109] 10A and 10B, in some exemplary embodiments, the thermal management system 100 is configured with capillaries 114 and vapor / fluid passages or pathways between the vapor chamber 110 and the condensation chamber 140. In these configurations, vapor is collected via the capillaries 114 and introduced into a common pool of working fluid 115 in the condensation chamber 140. Within the condensation chamber 140, the working fluid 115 pools throughout the condensation chamber 140 via the action of gravity and the surface tension of the working fluid 115 (i.e., similar to liquid spreading across the sides of a container as the container fills), and further, the working fluid 115 may be distributed within the condensation chamber 140 in response to the acceleration of the condensation chamber 140 or the tilt of the condensation chamber 140 from the horizontal. The posts 211 extend into the pool of working fluid 115 contained within the condensation chamber 140 and wick up the working fluid 115 via capillary action, lifting the working fluid 115 into the vapor chamber 110. The working fluid 115 then evaporates to cool the battery cells 112 as described in the various embodiments above.

[0084]

[0110] In these exemplary embodiments, cold plate 130 is configured with a number of openings 131 to allow posts 211 to pass through cold plate 130 to access working fluid 115 in condensation chamber 140. In other words, in these exemplary embodiments, cold plate 130 is configured as a perforated barrier disposed between vapor chamber 110 and condensation chamber 140. However, as will be appreciated, cold plate 130 remains sealed around openings 131 to allow coolant to pass through cold plate 130 without leaking into vapor chamber 110 and / or mixing with working fluid 115.

[0085]

[0111] In various exemplary embodiments, opening 131 is sized to correspond to the space between battery cells 112 within vapor chamber 110. In other words, opening 131 can be sized in a manner that does not require expansion space between battery cells 112 so that the exemplary battery pack can maintain a desired energy density.

[0086]

[0112] In various exemplary embodiments, the openings 131 are configured as generally circular holes when viewed perpendicular to the plane of the cold plate 130. In other exemplary embodiments, the openings 131 are configured as one or more shapes of one or more triangles, Reuleaux triangles, pseudotriangles, squares, rectangles, ellipses, and / or combinations thereof. In various exemplary embodiments, the opening 131 is configured with a diameter (and / or longest dimension) not exceeding 6 mm. In one exemplary embodiment, the opening 131 comprises a circular hole with a diameter of 4 mm.

[0087]

[0113] As will be appreciated, in the thermal management system 100, the openings 131 may be configured with different shapes and / or sizes. For example, in the thermal management system 100, a first opening 131 having a post 211 disposed therein may be configured as a circular hole having a diameter of 4 mm. A second opening 131 having no post 211 disposed therein may be configured as a circular hole having a diameter of 2 mm. In another example, the first opening 131 having a post 211 disposed therein may be configured as a generally pseudo-triangular hole having a distance between vertices of about 5 mm. In this example, the second opening 131 having no post 211 disposed therein may be configured as a circular hole having a diameter of 3 mm. Additionally, in the thermal management system 100, the openings may be configured with different shapes and / or sizes, such as a checkerboard, striped, staggered, or other suitable pattern, to provide for circulation of the working fluid 115 and vapor within the thermal management system 100. Any suitable combination of sizes and shapes of 131 may be utilized.

[0088]

[0114] In various exemplary embodiments, the post 211 is configured to be approximately flush with the edge of the corresponding opening 131. In other words, the post 211 may completely fill or occupy the corresponding opening 131 in which it is disposed. In some exemplary embodiments, the post 211 may only partially fill or occupy the opening 131. For example, the post 211 may be configured as a hollow cylinder such that it occupies all edges of the corresponding circular opening 131 while leaving a small cylindrical area of ​​the opening 131 free. Additionally, the post 211 may be configured as a cylinder with a notch in its side such that the post 211 occupies a majority of the circular opening 131 while leaving a small void along one edge of the opening 131. In this manner, the flow of the vapor and / or working fluid 115 in either direction through the opening 131 is encouraged, for example, to encourage a more consistent vapor pressure (and therefore a more consistent saturation temperature point) at all relevant locations in the thermal management system 100.

[0089]

[0115] In some exemplary embodiments, the post 211 is configured to be approximately flush with both the edges of the corresponding opening 131 and the edges of one or more associated battery cells 112. For example, the post 211 may have a generally cylindrical shape element for a first portion of the post 211 (i.e., the portion intended for insertion into the opening 131) and a pseudo-triangular shape element with a truncated end for a second portion of the post 211 (i.e., the shape element intended to fit into the space between closely packed cylindrical battery cells 112, e.g., as shown in FIG. 2C ). In these embodiments, the length of the first portion of the post 211 may determine the distance the post 211 is insertable through the corresponding opening 131.

[0090]

[0116] In various exemplary embodiments, the posts 211 may extend through the openings 131 such that the bottoms of the posts 211 contact the distal side of the condensation chamber 140 (i.e., a portion of each post 211 traverses from one side of the condensation chamber 140 to the other). In this manner, the posts 211 may siphon the working fluid 115 that has pooled to any depth within the condensation chamber 140. In other exemplary embodiments, the posts 211 may extend through the openings 131 such that the bottoms of the posts 211 do not traverse completely within the condensation chamber 140 but only reach partway through the condensation chamber 140. In these configurations, when the condensation chamber 140 is positioned horizontally, a minimum pool depth of the working fluid 115 will exist within the condensation chamber 140 before the pool of working fluid 115 contacts the bottoms of the posts 211. This configuration promotes uniform distribution of the working fluid 115 within the condensation chamber 140, as it allows the working fluid 115 to flow laterally in all directions. In contrast, in some embodiments where the posts 211 extend all the way to the opposing wall of the condensation chamber 140, the posts 211 may wick up and transport the working fluid 115 vertically at a rate that is faster than the rate at which the working fluid 115 flows laterally through the condensation chamber 140. This leads to "dry" or "drier" posts 211 (i.e., posts 211 with reduced access to the working fluid 115; typically such posts may occur in a central region of an array of posts 211 in the thermal management system 100).

[0091]

[0117] Additionally, in some exemplary embodiments, combinations may be utilized in which some posts 211 extend only partially into the condensation chamber 140 and other posts 211 extend completely across the condensation chamber 140. For example, alternating posts 211 may be arranged in an alternating manner, such as a checkerboard pattern. In another example, every third post 211 in a row of posts 211 may extend completely across the condensation chamber 140. In yet another example, every third post 211 in a row of posts 211 may extend only part way into the condensation chamber 140. In yet other examples, the posts 211 that extend completely across the condensation chamber 140 and the posts 211 that extend only part way into the condensation chamber 140 may be arranged in any other configuration, such as stripes, spirals, concentric geometries, etc. These combined approaches provide unimpeded lateral flow of working fluid 115 within condensation chamber 140 while ensuring sufficient upward transport velocity of working fluid 115 into vapor chamber 110. Additionally, thermal management system 100 may utilize any suitable arrangement of posts 211 that extend completely across condensation chamber 140 and posts 211 that extend only partway through condensation chamber 140.

[0092]

[0118] 11A and 11B, in some exemplary embodiments, in the thermal management system 100, certain openings 131 are not filled partially or completely with posts 211, but instead are left as unobstructed passages or pathways connecting the vapor chamber 110 and the condensation chamber 140. In one example, alternating openings 131 may be left empty, for example in a checkerboard pattern. In another example, every third opening 131 in a row of openings 131 may be left empty. In yet another example, the cold plate 130 may be configured with an array of openings 131 such that the empty openings 131 and the openings 131 occupied by posts 211 form concentric circles or contours centered approximately in the middle of the cold plate 130. In yet another example, the empty openings 131 may be arranged in alternating rows or stripes with the openings 131 occupied by posts 211. Furthermore, the selection of apertures 131 that are left empty and the selection of apertures 131 that are occupied by posts 211 may be in any suitable pattern, for example to achieve a desired circulation of the vapor and working fluid 115 within the thermal management system 100.

[0093]

[0119] As will be appreciated, in various exemplary embodiments, the thermal management system 100 may utilize both unobstructed (and / or partially obstructed) openings 131 and capillaries 114. In yet other exemplary embodiments, the thermal management system 100 may be configured to utilize only unobstructed (and / or partially obstructed) openings 131 and not have capillaries 114. In yet other exemplary embodiments, the thermal management system 100 may be configured to utilize capillaries 114 and not have unobstructed (and / or partially obstructed) openings 131.

[0094]

[0120] In various exemplary embodiments, in the thermal management system 100, the capillaries 114 may be positioned, shaped, and / or otherwise configured based at least in part on the direction and / or path of coolant (or more generally, thermal fluid) flow in the associated cold plate 130. For example, during operation of the heat pump 150, the thermal fluid is pumped across the cold plate 130, for example, in a serpentine path. When the thermal management system 100 is operating in a cooling mode, the thermal fluid gains heat as it traverses the cold plate 130. Thus, the thermal fluid is at a higher temperature when it leaves contact with the cold plate 130 compared to when it begins contact with the cold plate 130. Thus, in some exemplary embodiments, the thermal management system 100 is configured with one or more capillaries 114 having return ends disposed generally on a common side of the vapor chamber 110 as the portion of the cold plate 130 where the thermal fluid exits the cold plate 130 (i.e., the portion that is the “hottest” portion of the cold plate 130 when the thermal management system 100 is operating in a cooling mode). In this manner, the supply of working fluid 115 can be increased to an area in the vapor chamber 110 where direct cooling of the battery cells 112 by the cold plate 130 is minimal, thus further cooling the battery cells 112 in that area via a phase change of the working fluid. Furthermore, in some exemplary embodiments, the dimensions, length, path, number of inlet ends, number of return ends, and / or other characteristics of the capillaries 114 in the thermal management system 100 can be selected based on the characteristics of the flow of the thermal fluid in the cold plate 130. For example, a particular capillary 114 can traverse and / or be disposed along a portion of the cold plate 130 in a direction that is generally parallel to the flow of the thermal fluid in the cold plate 130. Another particular capillary 114 may traverse and / or be disposed along a portion of the cold plate 130 in a direction generally opposite or counter to the direction of thermal fluid flow within the cold plate 130. Thus, the thermal management system 100 may utilize the capillaries 114 to more closely approximate isothermal conditions within the vapor chamber 110 and / or provide approximately equal cooling capacity to each battery cell 112 within the thermal management system 100 (e.g., the cooling capacity of the battery cells 112 does not vary by more than 10% from highest capacity to lowest capacity).

[0095]

[0121] 12A-12C, in various exemplary embodiments, the thermal management system 100 may utilize an array of posts 211 where the length, thickness, material, or other properties of a particular post 211 vary at least in part depending on the location of that particular post 211 in the array. For example, with reference to FIG. 12A, which illustrates a view along the length of the thermal management system 100, it can be seen that a particular post 211-A located near the outer edge of the array of posts 211 is configured with a lower height than another post 211-B located near the center of the array of posts 211. Posts 211 closer to the center of the array 211 may be configured with a higher height, for example, to provide increased cooling capacity to an associated battery cell 112. Similarly, with reference to FIG. 12B, which illustrates a view along the width of the thermal management system 100, it can be seen that post 211-C is shorter than post 211-D, which is shorter than post 211-E. 12A and 12B, it can be seen that variations in the height of the posts 211 can be applied across both the length and width of the thermal management system 100. In this manner, the posts 211 in the thermal management system 100 can be configured to provide appropriate cooling capacity to the associated battery cells 112, particularly those battery cells 112 in an area generally centrally located in the thermal management system 100 that tend to experience the greatest thermal loads.

[0096]

[0122] The height of the posts 211 may vary linearly, curved, stepped, or in any other suitable manner. For example, the height of the posts 211 may have a first value in a first annular region disposed generally along the outer edge of the array of posts 211, and a second, higher value in an inner region bounded by the first annular shape. In another example, moving along the length of the thermal management system 100, the posts 211 may gradually increase in height, reach a maximum, and then gradually decrease at a point, and may be triangular and / or trapezoidal in cross-section (i.e., as shown in FIGS. 12A and 12B ).

[0097]

[0123] As will be appreciated, the embodiments of Figures 8A-12B are compatible with, and may be used in any suitable combination with, the various system configurations and orientations disclosed in connection with the description of Figures 1A-1E.

[0098]

[0124] In an exemplary embodiment, a vapor chamber for transferring heat between the vapor chamber and a heat pump includes an outer housing, a wicking material contained within the outer housing, and a working fluid at least partially wicked by the wicking material. The vapor chamber is configured with a plurality of openings for receiving a portion of a plurality of battery cells therein. The vapor chamber facilitates close packing of the plurality of battery cells. The battery cells may be disposed less than 1 mm apart from one another. The vapor chamber operates to cool the battery cells regardless of the orientation of the vapor chamber relative to gravity. A battery cell of the plurality of battery cells has a first end and a second end distal from the first end, the first end and the second end having a length therebetween. The wicking material may be in contact with 10% to 50% of the length of the battery cell. The wicking material may be in contact with the battery cell beginning at the first end and extending along 5% to 50% of the length of the battery cell. The wicking material may vary in thickness along the length of the battery cell. The wicking material may vary in porosity along the length of the battery cell. The wicking material may be configured as contact rings having a honeycomb shape. The wicking material may be configured in a parallel weave configuration. The wicking material may be configured in a serial weave configuration. The battery cells may be conductively coupled to a cold plate that forms an edge of the vapor chamber. The vapor chamber may be coupled to a heat pump through the cold plate.

[0099]

[0125] In another exemplary embodiment, a method for cooling a battery pack including a plurality of battery cells includes identifying a set of battery cells in the battery pack that are end cells. The method further includes identifying a set of battery cells in the battery pack that are interior cells. The method further includes identifying a set of battery cells in the battery pack that are center cells. The method further includes coupling the plurality of battery cells to a vapor chamber, disposing a working fluid in the vapor chamber, and disposing a wicking material in the vapor chamber. The method further includes coupling a first amount of wicking material to the end cells, coupling a second amount of wicking material to the interior cells that is different from the first amount, and coupling a third amount of wicking material to the center cells that is different from the first amount or the second amount. The method may further include identifying a set of battery cells in the battery pack that are inlet cells, and identifying a set of battery cells in the battery pack that are outlet cells. The method may further include configuring the wicking material such that an amount of wicking material coupled to the inlet cells is different from an amount of wicking material coupled to the outlet cells. The method may further include bonding a first amount of wicking material having a first wicking property to the end cells, bonding a second amount of wicking material having a second wicking property different from the first wicking property to the inner cells, and bonding a third amount of wicking material having a third wicking property different from the first wicking property or the second wicking property to the central cell.

[0100]

[0126] In an exemplary embodiment, a method for thermal regulation of a battery pack includes disposing a plurality of battery cells at least partially within a vapor chamber, the plurality of battery cells forming a battery pack, the vapor chamber comprising a housing, a wicking material, and a working fluid. The method also includes contacting each of the plurality of battery cells with at least a portion of the wicking material. During charging or discharging of the battery pack, the working fluid changes phase within the vapor chamber to transfer heat away from the battery cells. The method may further include coupling a heat pump to the vapor chamber via a cold plate. The vapor chamber may operate to transfer heat away from the battery cells regardless of an orientation of the vapor chamber relative to gravity. The method may further include monitoring at least one of a temperature or a pressure within the vapor chamber during charging or discharging of the battery pack, and adding or removing an amount of working fluid to the vapor chamber in response to the monitoring.

[0101]

[0127] In another exemplary embodiment, a thermal management system for an individual battery cell includes a cold well containing a housing, a wicking material, and a working fluid, and a battery cell disposed at least partially within the cold well such that a bottom of the battery cell contacts the wicking material, an interface between the battery cell and the housing is sealed to retain the working fluid within the housing, and the working fluid undergoes a phase change within the cold well to transport heat away from the battery cell.

[0102]

[0128] In another exemplary embodiment, a thermal management system for a battery pack includes a vapor chamber including a housing, a wicking material, and a working fluid, a cold plate coupling the vapor chamber to a heat pump, a battery pack including a plurality of battery cells, each of the plurality of battery cells being at least partially disposed within the vapor chamber, a condensation chamber coupled to the cold plate, and a capillary connecting the vapor chamber and the condensation chamber, each battery cell contacting a portion of the wicking material, and the working fluid undergoing a phase change in the vapor chamber to transfer heat away from the battery cells.

[0103]

[0129] The wicking material may be configured as a set of posts disposed between the battery cells. The cold plate may be disposed between the vapor chamber and the condensation chamber. The cold plate may be configured with a plurality of openings for connecting the vapor chamber and the condensation chamber. A first portion of the plurality of openings may be occupied by the wicking material and a second portion of the plurality of openings may not be occupied by the wicking material. A portion of the wicking material may include a post, the post passing through the opening completely across the condensation chamber. A portion of the wicking material may include a post, the post partially occupying one of the plurality of openings. The capillary may be configured with a plurality of inlet ends leading to a common portion of the capillary. The capillary may have an inlet end on a first side of the vapor chamber and a return end on an opposite side of the vapor chamber. The capillary may be configured with an inner diameter between 1 mm and 12 mm. Evaporation of the working fluid from the wicking material may cause vapor to flow into the capillary. The wicking material may be configured as an array of posts, the array of posts differing in height from one another. The array of posts may have graduated heights when viewed along the length of the array of posts.

[0104]

[0130] Although the principles of the present disclosure have been illustrated in various embodiments, numerous modifications of the structure, arrangement, proportions, elements, materials, and components specifically adapted to the particular environment and operational requirements of the actual application may be used without departing from the principles and scope of the present disclosure. These and other changes or modifications are intended to be included within the scope of the present disclosure and may be expressed in the appended claims.

[0105]

[0131] The present disclosure has been described with reference to various embodiments. However, those skilled in the art will appreciate that various modifications and changes can be made without departing from the scope of the present disclosure. Therefore, the present specification should be considered in an illustrative rather than a limiting sense, and all such modifications are intended to be included within the scope of the present disclosure. Similarly, benefits, other advantages, and solutions to problems have been described above with respect to various embodiments. However, benefits, advantages, solutions to problems, and elements by which the benefits, advantages, or solutions may occur or become more pronounced should not be construed as critical, necessary, or essential features or elements in any or all of the claims.

[0106]

[0132] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to include a non-exclusive inclusion and include no listing of elements. A process, method, article, or apparatus comprising a component may not include only those elements, but may include other elements not expressly recited or inherent to such process, method, article, or apparatus. Also, as used herein, the terms "coupled," "coupling," or any other variation thereof may refer to a physical connection, electrical connection, or other connection. This is intended to include electrical, magnetic, optical, communicative, functional, thermal, and / or any other connection. When "at least one of A, B, or C" or similar terms such as "at least one of A, B, and C" are used in this specification or claims, the phrase means any of the following: (1) at least one A. (2) at least one B. (3) at least one C. (4) at least one A and at least one B. (5) at least one B and at least one C. (6) at least one C and at least one A. (7) at least one A, at least one B, and at least one C.

Claims

1. a vapor chamber comprising a housing, a wicking material, and a working fluid; a battery pack comprising a plurality of battery cells, each battery cell disposed at least partially within the vapor chamber; Each battery cell contacts a portion of the wicking material; the working fluid undergoes a phase change in the vapor chamber to carry heat away from the battery cells. Thermal management system.

2. The system of claim 1 , further comprising a heat pump coupled to the vapor chamber.

3. 10. The system of claim 1, wherein the wicking material comprises posts disposed at least partially between the battery cells.

4. The system of claim 3 , wherein the post is configured with an internal opening to allow steam to pass therethrough.

5. The system of claim 3 , wherein the post extends from a first side of the vapor chamber to an opposite second side of the vapor chamber.

6. 4. The system of claim 3, wherein the battery cells of the battery pack contact one another and the wicking material comprises a set of posts disposed in spaces between the battery cells.

7. 10. The system of claim 1, wherein the wicking material is configured in at least one of a honeycomb pattern, a serial weave pattern, or a parallel weave pattern.

8. 10. The system of claim 1, wherein the wicking material contacts less than 90% of a surface area of ​​a battery cell disposed within the vapor chamber.

9. 10. The system of claim 1, wherein the wicking material extends along less than 90% of a length of a battery cell disposed within the vapor chamber.

10. 2. The system of claim 1, wherein the wicking material extends partially along a length of a battery cell disposed within the vapor chamber, the wicking material tapering as it extends along the length of the battery cell.

11. 2. The system of claim 1, wherein a first set of battery cells in the plurality of battery cells are partially accommodated in the vapor chamber at a first ratio, and a second set of battery cells in the plurality of battery cells are partially accommodated in the vapor chamber at a second ratio that is higher than the first ratio.

12. The system of claim 1 , wherein the thermal management system operates to provide heat transfer at a level of greater than or equal to 500 Watts per meter Kelvin (W / mK) and less than or equal to 2000 W / mK.

13. The system of claim 1 , wherein the wicking material is injection moldable, hydrophilic, and stretchable.

14. The system of claim 2 , wherein the thermal management system operates regardless of orientation of the thermal management system relative to gravity.

15. 2. The system of claim 1, wherein the battery cell is cylindrical and the wicking material comprises a first wicking portion and a second wicking portion, the first wicking portion configured to transport the working fluid in a direction generally perpendicular to a cylindrical axis of the battery cell and the second wicking portion configured to promote evaporation of the working fluid.

16. 10. The system of claim 1, further comprising a capillary having an inlet end at a first elevation within the vapor chamber and a return end at a lower second elevation within the vapor chamber, the working fluid condensing from a gas to a liquid form within the capillary.

17. The system of claim 16 , wherein evaporation of the working fluid from the wicking material provides a force that urges the working fluid out of the capillary at the return end.

18. a condensation chamber coupled to the cold plate; a capillary having an inlet end at a first location within the vapor chamber and a return end at a second location different within the vapor chamber, the capillary at least partially extending through the condensation chamber; The system of claim 2 further comprising:

19. a condensation chamber coupled to the cold plate; the cold plate is configured with a plurality of openings connecting the vapor chamber and the condensation chamber; a portion of the wicking material passes through one or more of the plurality of openings into the condensation chamber; The system of claim 2.

20. 20. The system of claim 19, wherein the wicking material comprises a series of posts, a first portion of the series of posts extending completely across the condensation chamber and a second portion of the series of posts extending partially across the condensation chamber.

Images