Patent Publication Number: US-2021175563-A1

Title: Thermal management system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/593,706, filed on Dec. 1, 2017, the entire contents of which are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present application relates to thermal management systems, and in particular to thermal management systems for battery packs (e.g., formula-E battery packs). 
     BACKGROUND OF THE INVENTION 
     Battery packs used within high end clusters, such as electric vehicle battery packs, require advanced thermal management to combat challenges associated with non-uniform temperature profiles or operating temperatures that are too high or too low. Such problems can cause issues such as reduced lifetime of the battery pack, battery fade, and reduced discharge current/operational time. These challenges are amplified within high-discharge rate and varying transient discharge applications, such as motorsport electric vehicle applications. Ambient temperatures also affect the performance of the battery pack. To maximize the electrical performance and lifetime of a battery pack, it is sometimes required to maintain an isothermal temperature across the surface of each cell, across all cells within the pack, or to cool or heat the entire pack to maintain the isothermal temperature within a specific temperature range. 
     Current formula-E battery packs use individually formed microchannel cold flow plates that are connected to a relatively bulky polymer chassis. The polymer component incorporates through-holes and o-rings that when stacked next to one another are compressed to form a seal between adjacent cold plates and the polymer frames. By stacking multiple frames/pouch cells, inlet and outlet plenums are formed enabling a single liquid inlet and outlet port to be deployed. A major issue with these current systems, however, is that there are hundreds of seals in the battery pack (2 per pouch cell) that are prone to leaking. Additionally, these types of devices have a relatively large mass due to the bulky polymer chassis. 
     SUMMARY OF THE INVENTION 
     In one embodiment, the invention provides a device for removal of heat from a plurality of heat sources. The device includes a first manifold to receive a working fluid, and a plurality of elongated intermediate frame members each in thermal communication with at least one of the plurality of heat sources. Each intermediate frame member includes a microchannel in fluid communication with the first manifold to receive the working fluid from the first manifold. Each elongated intermediate frame member includes a slot extending along a longitudinal axis of the heat transfer device. The device further includes a second manifold spaced from the first manifold and in fluid communication with the plurality of intermediate frame members to receive the working fluid from each microchannel in the plurality of intermediate frame members. The second manifold is configured to transfer the working fluid away from the plurality of heat sources. 
     In another embodiment, the invention provides a heat transfer system that includes a plurality of battery pouches, and a framework disposed adjacent the battery pouches along one side of the plurality of battery pouches, the framework having an inlet and an outlet for working fluid to enter and exit the framework, respectively. The heat transfer system further includes a plurality of thermal conducting devices coupled to the framework and extending parallel to one another and away from the framework. Each of the thermal conducting devices is a plate of encapsulated graphite having a first end coupled to the framework, and a second, opposite free end that is disposed between two of the battery pouches. The plates extend away from the framework along a direction that is perpendicular to a direction of movement of working fluid within the framework. 
     In another embodiment, the invention provides a device for removal of heat from a plurality of heat sources. The device includes a first frame member having a first channel configured to direct the flow of working fluid to a plurality of intermediate frame members, each intermediate frame member comprising a channel in fluid communication with the first channel. The device further includes a second frame member spaced from the first frame member, the second frame member having a second channel in fluid communication with the plurality of intermediate frame members to receive the working fluid from the plurality of intermediate frame members, the second channel configured to transfer the working fluid away from the plurality of heat sources. The device further includes a plurality of heat conducting devices each in thermal communication with one of the plurality of intermediate frame members. Each heat conducting device is positioned to receive heat from one of the plurality of heat sources. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a thermal management system according to one embodiment. 
         FIG. 2A  is a front view of the thermal management system of  FIG. 1 . 
         FIG. 2B  is a side view of the thermal management system of  FIG. 1 . 
         FIG. 2C  is a top view of the thermal management system of  FIG. 1 . 
         FIG. 3A  is a perspective view of a pouch cell of the thermal management system of  FIG. 1 . 
         FIG. 3B  is a side view of the pouch cell of  FIG. 3A . 
         FIG. 4A  is a perspective view of a framework of the thermal management system of  FIG. 1 , the framework including an inlet manifold, an outlet manifold, and a plurality of intermediate frame members extending therebetween. 
         FIG. 4B  is a top view of the framework of  FIG. 4A   
         FIG. 4C  is a cross-sectional view of the framework of  FIG. 4A   
         FIG. 5  is a perspective view of one of the intermediate frame members of  FIG. 4A . 
         FIG. 6  is a cross-sectional view of the intermediate frame member of  FIG. 5 . 
         FIG. 7  is an enlarged perspective view of a portion of the framework of  FIG. 4A , illustrating (with a clear view of the interior of the framework) one of the intermediate frame members in fluid communication with the inlet manifold. 
         FIG. 8  is a perspective view of a portion of the inlet manifold of  FIG. 7 . 
         FIG. 9A  is a cross-sectional view of another embodiment of the intermediate frame member, the intermediate frame member having four protrusions. 
         FIG. 9B  is a cross-sectional view of another embodiment of the intermediate frame member, the intermediate frame member having eight protrusions. 
         FIGS. 10A-10D  are cross-sectional views of the intermediate frame member of  FIG. 9A , illustrating different shaped microchannels. 
         FIG. 11  is a perspective view of two of the thermal management systems of  FIG. 1 , stacked together. 
         FIG. 12A  is a perspective view of the stacked thermal management systems of  FIG. 11 , without the plurality of pouch cells. 
         FIG. 12B  is a side view of the stacked thermal management systems of  FIG. 12A . 
         FIG. 13  is an enlarged perspective view of a portion of the stacked thermal management systems of  FIG. 12A . 
     
    
    
     Before any constructions of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other constructions and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limited. 
     DETAILED DESCRIPTION 
     The term “thermal management system” used herein refers to any system that is arranged to remove heat from one or more heat sources and to move the heat to a separate location. The term “spreader” used herein refers for example to a plate, sheet, disk, enclosure, chamber, or other structure that receives heat and spreads or otherwise moves the heat from one location to another (e.g., linearly or generally within a plane defined by the spreader). The term “k-Core” used herein refers to Thermacore&#39;s k-Core technology (k-Core® material, available from Thermacore, Inc. of Lancaster, Pa. 17601), which uses encapsulated graphite to move heat (e.g., in avionic applications). One example of k-Core technology material is encapsulated annealed pyrolytic graphite (APG) which creates high-conductivity thermal spreading (e.g., up to three times the conductivity of solid copper with lower mass than aluminum). The term “encapsulated” or “encapsulating material” or “encapsulant” used herein refers, for example, to material (e.g., an aluminum foil, copper alloy, ceramic, composite, or other material) that forms an enclosure or covering or in some instances a chamber and that encapsulates or otherwise encloses and contains material therein, such as k-Core material. 
     In one exemplary embodiment, as shown in  FIG. 1 , a thermal management system  10  may be used in any application where multiple heat dissipating devices, such as battery packs or other electrical components, including a closely-packed or stacked heat source, require temperature control within a specific temperature range or an isothermal temperature profile throughout the device. The present embodiment can be applied in thermal management of electric vehicle battery packs using flat or generally flat pouch cells  14  stacked in multiple banks of cells that are installed into an overall battery pack chassis. Each bank of pouch cells  14  is directly coupled to or otherwise is in communication with one or more of the thermal management systems  10  described herein. The term “pouch cell” used herein refers to a heat source, and in the illustrated embodiment, to a heat source having a structure that acts as a fuel cell or battery cell of a battery pack. The pouch cell  14  defines an enclosure or chamber therein for generation of energy.  FIGS. 3A and 3B  illustrate a single pouch cell  14 . 
     Other cell formats, including, but not limited to cylindrical cells, are also envisioned. Cylindrical cells represent a common type of battery format (e.g., for an AA battery) typically for consumer use. The interior of a typical cylindrical battery includes three concentric layers of film/foil (copper, polymer isolation layer and aluminum foil) that are rolled up inside the battery cylinder and that define the current and voltage. One foil (e.g., aluminum) has a carbon coating that stores the charge. An electrolyte fills the voids between the layers. In some embodiments, rather than rolling up the adjacent foil and polymer layers into a cylinder, multiple separate sheets of foil and polymer are stacked on top of one-another. The foil layers may be vacuum sealed within a polymer film container (typically used in the food industry) that forms a flat rectangular pack. The laminated layers forming the positive and negative terminals are exposed. The rectangular shape increases packing density into the pack chassis. 
     In some embodiments, the thermal management system  10  described herein includes three main components (see  FIGS. 1, 2A-2C, and 7 ): 
     1. a thermal conduction device  22 ; 
     2. a thermal regulation system  26 A,  26 B; and 
     3. a thermal extraction interface  30 . 
     With reference to  FIGS. 1 and 2A , the thermal management system  10  includes a first thermal regulation system  26 A disposed on one side of the pouch cells  14  (e.g., above the pouch cells  14 ) and a second thermal regulation system  26 B disposed on an opposite side of the pouch cells  14  (e.g., below the pouch cells  14 ). Thermal conduction devices  22  extend from each of the thermal regulation systems  26 A,  26 B toward one another, and are disposed adjacent to the pouch cells  14 , including in between adjacent pouch cells  14 . 
     The thermal conduction device  22  may be any heat transfer device (e.g., a heat spreader) that receives heat from one or more of the pouch cells  14  (or other heat sources) and transfers the heat away from the pouch cell  14  and to one of the thermal regulation systems  26 A,  26 B. In the illustrated embodiment, each thermal conduction device  22  includes a flat or generally flat conduction plate  34  (e.g., a flexible sheet) made of graphite (e.g., encapsulated graphite). The conduction device  22  contacts a surface  38  ( FIG. 3A ) of the pouch cell  14  or is otherwise closely positioned or spaced relative to the surface  38  of the pouch cell  14  for thermal communication with the pouch cell  14 . In some embodiments, the thermal conduction device  22  may be positioned proximate the surface  38  of the pouch cell  14  such that there is a gap between the thermal conduction device  22  and the pouch cell  14 . In this configuration, the thermal conduction device  22  still receives heat from the pouch cell  14  even though the thermal conduction device  22  is spaced from the pouch cell  14 . 
     The thermal conduction plate  34  has relatively high thermal conductivity to produce uniform heat distribution across the surfaces of the pouch cell  14 , smoothing out hot spots and creating a more isothermal temperature profile across the surface  38  of the pouch cell  14 . In some embodiments, and as described further herein, an edge of the plate  34  extends past the pouch cell surface  38  and thermally interfaces with a secondary heat extraction system (e.g., one of the thermal regulation systems  26 A,  26 B). The secondary heat extraction systems extract heat from the thermal conduction device  22  (e.g., from the plate  34 ) to control and to maintain the pouch cell  14  within a required operating temperature range. High thermal conductivity materials other than graphite, including but not limited to aluminum and copper, may be used in alternative embodiments of the thermal conduction device  22 . 
     One feature of the illustrated thermal conduction device  22  is the use of an encapsulated graphite material for heat transfer. For example, a graphite material core with very high in-plane thermal conductivity in comparison to copper and aluminum, may be protected (e.g., encapsulated) within a protective skin (metal foil, polymer, composite sheet, carbon fiber etc.) to provide good thermal transfer capability. The very high in-plane thermal conductivity of the graphite core minimizes the thermal gradient between the high temperature regions of the pouch cell  14  and the interface with the thermal regulation system  26 A,  26 B, resulting in a lower operating temperature and a temperature profile across the pouch cell surface  38  that is close to or approaching isothermal conditions. 
     With continued reference to  FIGS. 1 and 2A , the use of the conduction plate  34  as a graphite spreader may provide further increased flexibility in comparison to solid metal plates. This flexibility accommodates expansion and contraction of the pouch cell  14  caused by expansion and contraction of the electrolyte solution contained within the pouch cell  14  in response to changes in temperature. To benefit from the increased flexibility of the graphite-based conduction plate  34 , and as illustrated in  FIG. 1 , a configuration of the thermal conduction device  22  may incorporate separate conduction plates  34  that are connected independently to the upper and lower thermal regulation systems  26 A,  26 B, respectively. The upper and lower thermal regulation systems  26 A,  26 B are fixed rigidly in position. By separating the thermal conduction devices  22 , increased flexibility is achieved. 
     A further embodiment of the thermal conduction device  22  uses graphene sheets or films as an alternative to graphite. As graphene has excellent barrier properties, there is no need to encapsulate the graphene, providing an improvement in thermal performance versus that of an encapsulated graphite device. In addition, the 2D-like configuration or flat nature of the graphene sheets has a very small thickness and gives a very high level of flexibility. 
     In some embodiments the grains of the graphene or graphite flakes are all aligned along a common direction in a plane of the thermal conducting device, such that heat is directed in the common direction. 
     It should be noted that the surface of the graphene may be functionalized, potentially by the addition of a copper flash or polymerization. Functionalization achieves benefits such as improved through-plane thermal conductivity and increased adhesion of the individual graphene layers. Although true graphene should be one atom thick (2D), commercially available materials can be manufactured from using flakes with up to 20 layers. The surface of the flakes is functionalized by, for example, polymerization which helps protect the graphene and helps the flakes adhere to one another during consolidation. Copper flash does the same but has a higher thermal conductivity and is more difficult to consolidate into bulk material. 
     In a further embodiment of the thermal management system  10 , the pouch cell  14  directly incorporates the thermal conduction device  22  within the pouch cell  14 , eliminating or reducing thermal resistance between the thermal conduction device  22  and the pouch cell surface  38  in the thermal path. As such, in this configuration, the heat source or pouch cell  14  is directly coupled to the thermal regulation system  26 A,  26 B. In addition, by the addition of one or more layers between the cell sheet layers, the thermal conductivity through the thickness (width) of the pouch cell  14  can be made isothermal (i.e., a 3D isothermal temperature profile). In a case where graphite or graphene based thermal conduction materials are used, the material may replace the existing graphitic layer and perform both the electrical and thermal functions within the pouch cell  14 . 
     With reference to the exemplary embodiment of  FIGS. 4A-4C , each of the thermal regulation systems  26 A,  26 B is formed in the nature of a framework of manifolds (i.e., frame members), including pipes, tubes, etc. that are coupled to one or more of the thermal conduction devices  22 . In the illustrated embodiment, as shown in  FIG. 4A-4C , each thermal regulation systems  26 A,  26 B includes a first frame member  46  having an inlet  50  to receive a working fluid A (e.g., coolant/refrigerant/two-phase flow, as illustrated in  FIG. 4C ). Each of the thermal regulation systems  26 A,  26 B also includes a second frame member  54  that is spaced from the first frame member  46 . In the illustrated embodiment, the second frame member  54  extends parallel to the first frame member  46 . The second frame member  54  includes an outlet  58  for the working fluid A to exit the thermal regulation system  26 A,  26 B. As illustrated in  FIG. 4C , the working fluid A may enter the inlet  50  in one direction, and exit the outlet  58  in the same direction. The thermal regulation system  26 A,  26 B further includes a plurality of intermediate frame members  62  that extend between the first and second frame members  46 ,  54 . For example, as shown in  FIGS. 4A-4C , the intermediate frame members  62  extend perpendicularly relative to the first and second frame members  46 ,  54  and parallel to one another. The thermal conduction devices  22  are coupled to the intermediate frame members  62  (e.g., see  FIG. 13 ). More specifically, the thermal conduction devices  22  are releasably coupled to the intermediate frame members  62 . 
     The thermal regulation systems  26 A,  26 B extract heat generated by the pouch cells  14  (or other heat sources) that has been transferred to the thermal conduction devices  22 , and thermally regulate the operating temperature of the overall thermal management system  10 . In the illustrated embodiment, and as described above, the thermal management system  10  includes an upper thermal regulation system  26 A and a lower thermal regulation system  26 B. In other embodiments, the thermal management system  10  may include only one thermal regulation system  26 , or more than two thermal regulation systems. The upper and lower thermal regulation systems  26 A,  26 B, as shown in  FIGS. 1, 2A-2C , are configured to form the structure of a rigid chassis  70 , or more particularly, a low mass rigid chassis, to which the thermal conduction devices  22  and/or pouch cells  14  are coupled. The intermediate frame members  62  of the chassis  70  incorporate fluid flow channels  66  (e.g., microchannels) that enable the working fluid A to pass through the chassis  70 . By controlling the flowrate and inlet temperature of the working fluid A, heat extraction from the thermal conduction devices  22  and the temperatures of the thermal conduction devices  22  and pouch cells  14  are controlled. 
       FIGS. 4A-4C  illustrate one of the upper or lower thermal regulation systems  26 A,  26 B. The thermal regulation system  26 A,  26 B in the illustrated embodiment includes two elements (i.e., the first frame member  46  and the second frame member  54 ) that form the outer framework of the chassis  70 . The first and second frame members  46 ,  54  are interconnected by the intermediate frame members  62 . The intermediate frame members  62  are a series of parallel structural elements that act as struts or cross-struts. As noted above, the intermediate frame members  62  extend, in some embodiments, perpendicularly between the first frame member  46  and the second frame member  54  (see  FIGS. 4A-4C ). 
     With continued reference to  FIGS. 4A-4C , the outer framework elements  46 ,  54  (i.e., the first and second frame members) are hollow, forming large inlet and outlet conduits  74 ,  78 . The conduit  74  of the first frame member  46  of the outer framework elements  46 ,  54  provides an inlet manifold to supply the working fluid A through inlet ports  82  ( FIG. 8 ) to the intermediate frame members  62 . The intermediate frame members  62  are also hollow, but in contrast to the large conduit  74  of the first frame member  46 , each of the intermediate frame members  62  includes at least one microchannel  66 . More specifically, the microchannels  66  provide relatively high thermal efficiency flow passages that enhance the collection of heat from the parallel thermal conduction devices  22  and transfer the collected heat into the working fluid A flowing through the microchannels  66 . The conduit  78  of the second frame member  54  of the outer framework elements  46 ,  54  acts as an outlet manifold to receive the working fluid A from the microchannels  66  of the intermediate frame members  62  through outlet ports  84  ( FIG. 4C ) of the second frame member  54 . 
     Each of the intermediate frame members  62  includes one of the microchannels  66  ( FIG. 5 ) to transfer working fluid A from the first frame member  46  to the second frame member  54 . In other embodiments, the intermediate frame members  62  may be formed with relatively larger channels. The intermediate frame members  62  thus are configured to conduct the working fluid A along the heated ends of the thermal conduction devices  22  coupled to the intermediate frame members  62  so that heat generated by the thermal conduction devices  22  is absorbed by the working fluid A as the working fluid flows through the second frame member  54 . The heat absorbed from the thermal conduction devices  22  by the working fluid A is then transferred out of each of the thermal regulation systems  26 A,  26 B when the working fluid A exits the outlet  58  of second frame member  54 . 
     With reference to  FIGS. 4C, 7, and 8 , in the illustrated embodiment, the intermediate frame members  62  are joined to the first and second frame members  46 ,  54  to create an interconnected fluid flow passage network ( FIG. 4C ) in a parallel flow configuration (other configurations may be used) that balances the pressure drop and/or the flow rate through each microchannel  66 . This fluid flow passage network may facilitate a uniform heat transfer coefficient within each parallel microchannel  66 . In particular,  FIGS. 7 and 8  illustrate the inlet conduit  74 , the inlet ports  82 , and the microchannels  66  in fluid communication. The illustrated outlet conduit  78  and outlet ports  84  are similarly configured to interact with the microchannels  66  to move the working fluid A. In the illustrated embodiment, the thermal conduction devices  22  extend away from the framework or chassis  70  along a direction that is perpendicular to a direction of movement of working fluid within the framework of the thermal regulation systems  26 A,  26 B. 
     With reference to  FIGS. 5 and 6 , the thermal extraction interface  30  corresponds to the connections between the thermal conduction devices  22  and the thermal regulation systems  26 A,  26 B. In particular, it refers to the connections between ends of the thermal conductions devices  22  (e.g., edges of the plates  34 ) and the intermediate frame members  62  (e.g., slots described below). For example, as illustrated in the embodiments of  FIGS. 5 and 6 , the profile of each of the plurality of intermediate frame members  62  includes two main features. The first feature is a circular (or other shape) tube portion  86  within which the circular microchannel passage  66  runs along the longitudinal axis of the intermediate frame member  62 . As shown, The tube portions  86  are in fluid communication with the inlet and outlet ports  82 ,  84  of the conduits  74 , 78 , respectively. The second feature is a pair of parallel spaced-apart protrusions  90  (e.g., fingers, elongate arms, or other extending structural features, etc.) extending outwardly from and along the length of the circular tube portions  86 . The protrusions  90  form a slot  94  (e.g., groove, crease, etc.) therebetween that extends along a longitudinal axis of the intermediate frame member  62 . 
     A portion of each of the thermal conduction devices  22  is received and held in the slot  94  formed by each pair of spaced-apart protrusions  90  to form the thermal extraction interface  30  between the thermal conduction device  22  and the tube  86 . In particular, heat generated by the thermal conduction devices  22  and received by the pair of spaced-apart parallel protrusions  90  is conducted through the circular tube portion  86  where the heat is then absorbed by the working fluid A flowing through the microchannel  66 . The wall thicknesses of the parallel protrusions  90  and the microchannel tube  86  may be varied to optimize heat transfer and minimize the mass of the thermal conduction devices  22 . For example, the height and width of the slot  94  may be varied to accommodate various configurations and types of the thermal conduction devices  22  to optimize heat transfer between the thermal conduction devices and the working fluid A flowing through the microchannels of the intermediate frame members  62 . An interface material such as solder or epoxy or any other suitable alternative filler material may be used to minimize thermal resistance and maximize thermal conduction across the joint between the thermal conduction devices  22  and the associated intermediate frame members  62 . 
     With reference to  FIG. 5 , in the illustrated embodiment the intermediate frame members  62  each have a constant cross-sectional profile along the length of its entire length to enable manufacture by extrusion. Alternatively, the cross-sectional profile along the length of the intermediate frame members  62  may be varied by using additional or alternative manufacturing processes. 
     In some embodiments, a mechanical device may be used to hold the thermal conduction device  22  in position on the intermediate frame member  62 . For example, a wedge and/or a plate may be used to clamp or otherwise secure a thermal conduction device  22  to an intermediate frame member. In some embodiments, the intermediate frame member  62  may only include one protrusion  90  instead of a pair of spaced-apart protrusions, and a flat plate may be used to clamp the thermal conduction device  22  to the protrusion  90 . The protrusion and separate flat plate thus act as a capture feature. The terms “capture feature” or “capture features” refer to any structural features or structures that are used to “capture” (i.e., receive, retain, hold, secure, encompass, etc.) another component, such as the thermal conduction device  22  or one of the first, second, or intermediate frame members  46 ,  54 ,  62 , respectively, to hold them in place. 
     As shown in the embodiment of  FIGS. 7-8 , the first and/or second frame member  46 ,  54  includes capture features that are formed as recessed regions  98  (e.g., keyed regions) sized and shaped to receive an end of an intermediate frame member  62 . In the illustrated embodiment, each of the first and second frame members  46 ,  54  includes multiple recesses each dimensioned to correspond to the cross-sectional profile of the intermediate frame members  62  ( FIGS. 7 and 8 ). The recesses  98  of the first and second frame members  46 ,  54  align the orientation of the intermediate frame members  62  relative to the first and second frame members  46 ,  54  and the microchannels  66  with the inlet and outlet ports  82 ,  84  provided along the lengths of the first and second frame members  46 ,  54  ( FIG. 8 ). In other embodiments, the capture features may be protrusions, fingers, or any other surfaces or structures that are sized and shaped to securely hold one component in position with respect to another component. 
     In some embodiments, the interfaces between the intermediate frame members  62  and the first and second frame members  46 ,  54  are sealed by brazing, welding or using an epoxy. In some embodiments, the end of the first frame member  46  opposite the inlet  50  and/or the end of the second frame member  54  opposite the outlet  58  are sealed using a cap  102  ( FIG. 4A ). 
     With reference to  FIGS. 9A-10D , the cross-sectional profile of each of the illustrated microchannels  66  may be designed to minimize mass (i.e., weight) of the framework, and/or to minimize thermal resistance and improve thermal conduction. For example, the single microchannel  66  may be replaced with a multi-channel configuration ( FIGS. 10C-10D ) to increase heat transfer. The channel shape and size also may varied. For example, the cross-sectional profile of microchannel  66  may be shaped as a square, triangle or any other desired shape to provide a capillary action. Examples of such different cross-sectional profiles for microchannels  66  are shown in  FIGS. 10A-10D , including multi-channel configurations. In addition, more than one thermal conduction device  22  may be thermally associated with each intermediate frame member  62 . For example, intermediate frame members  62  provided with more than one capture feature (e.g., two or more pairs of spaced-apart protrusions  90 ) to hold more than one thermal conduction device  22  are shown in  FIGS. 9A and 9B . 
     In some embodiments, intermediate frame members  62  with two capture features (e.g., two pairs of spaced-apart parallel protrusions  90 ) may be used, for example, to thermally manage two battery cells as shown, for example, in  FIGS. 11-12B . In the illustrated embodiment, the mass of the entire thermal transfer device  10  is reduced in that two sets of battery cells are thermally managed by three thermal regulation systems  26 A,  26 B,  26 C instead of four systems with a separate pair of thermal regulations systems  26 A,  26 B for each set of battery cells. In this configuration, the intermediate frame members  62  of the thermal management system  26 B are configured as having the cross-section profile as shown in  FIG. 9A  (the intermediate frame members  62  including two pairs of spaced-apart parallel protrusions  90 ). In other embodiments, the thermal management system  10  may include multiple sets of battery cells such that the intermediate frame members  62  of the thermal management system  26 B are configured as having the cross-section profiles as shown in  FIG. 9B  (the intermediate frame members  62  including four pairs of spaced-apart parallel protrusions  90 A). A close-up view of the assembled components of the thermal management system  10  of  FIG. 12A , in particular the thermal regulation system  26 B, is shown in  FIG. 13 . The overall assembly with the pouch cells  14  in position is also shown in  FIG. 11 . 
     In some embodiments, the chassis  70  may be formed as a light-weight chassis framework, manufactured from brazed aluminum extrusion profiles (or material other than aluminum) to form parallel flow liquid cold plates or frame members including, for example, the intermediate frame members  62 . Each parallel intermediate frame member  62  and flow channel  66  connects to a k-Core foil encapsulated spreader (e.g., conduction device  22 ) that is installed between two adjacent pouch cells  14 . During use, the pouch cells  14  (or other heat sources) generate heat. That heat is transferred to the associated or adjacent thermal conduction device(s)  22  (e.g., to the k-Core plates  34 ). The thermal conduction devices  22  extend parallel to one another, and extend into spaces or gaps between the pouch cells  14  (e.g., like fingers). Thus, the thermal conduction devices  22  pick up the heat from the pouch cells  14  and move the heat away from the pouch cells  14  toward the thermal regulation system  26 A,  26 B. As illustrated in  FIG. 1 , and as described above, a first upper thermal regulation system  26 A and a second lower thermal regulation system  26 B are provided. The thermal conduction devices  22  extend from both the first thermal regulation system  26 A and the second thermal regulation system  26 B (e.g., toward each other). Once the heat reaches the ends or edges of the thermal conduction devices  22  (which are captured or otherwise held by the protrusions  90  of the intermediate frame members  62 ), the heat moves into the microchannels  66  in the intermediate frame members  62 . From there the heat is picked up by the working fluid A passing through the microchannels  66 , and is moved to the second frame member  54  and then out of the thermal management system  10 . 
     The thermal management systems  10  described herein may be used in electric vehicle (EV) thermal management. In particular, in some embodiments they are directed for use with Formula-E battery packs and other high performance EV applications, although they could be used on vehicles other than electric vehicles, or could be used in systems other than vehicles (e.g., in stationary systems that have heat sources, such as electronics) to remove heat. In some embodiments, the thermal management systems  10  described herein may be used in high performance electric vehicle battery pack applications and low volume and niche EV automotive applications (e.g. busses, excavators, tractors, trucks, etc.). 
     In some embodiments, the thermal management systems  10  include (1) use of K-Core as a thermal spreader to regulate and even out pouch cell temperature, (2) a K-Core thermal transport to a liquid cooling system and integration with the cooling system, (3) a method or arrangement of interconnections between K-Core material and a cooling system, and/or (4) a design of a liquid cooling system to be a structural chassis framework  70 . 
     Although the invention has been described in detail with reference to certain preferred constructions, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described. Various features and advantages of the invention are set forth in the following claims.