BATTERY MODULE WITH COOLANT FLOW CONTROL

Abstract

A battery module comprising a plurality of battery cells configured to store and deliver electrical energy, a cell holder configured to support the battery cells, a pre-molded insert containing a potting material shaped to define a plurality of coolant channels for the battery cells, and a flow control system operable to control a flow of coolant through the coolant channels.

Description

INTRODUCTION

[0001] This description relates to the cooling of battery cells included in a battery module, such as, but not necessarily limited to, the cooling of battery cells configured to store and deliver electrical energy to a vehicle.

[0002] A rechargeable energy storage system (RESS) can be configured to store and deliver electrical energy for a variety of applications, with one of the more common types of RESS comprising a plurality of battery cells arranged in one or more battery modules. Such a RESS can be installed onboard a vehicle to store and deliver electrical energy for a main or high-voltage (HV) bus and / or an auxiliary or low-voltage (LV) bus. Because the battery cells generate heat when storing and delivering electrical energy, it may be advantageous for the associated battery module to be operated with a cold plate or other external element of a cooling system to dissipate the thermal energy from the battery cells.Such a cooling system may incorporate a static epoxy filler or other solidifying fluid to create rigid thermal pathways of immobile material that facilitate the dissipation of thermal energy from the battery cells. The immobility of such fillers can serve to essentially provide a stationary heat sink, allowing the heat generated by the battery cells to be conducted through the static material in an attempt to dissipate the associated thermal energy to the cold plate or other external cooling element, which can be relatively inefficient. DESCRIPTION

[0003] One aspect of the present description relates to a battery module configured to dissipate heat from the battery cells in a relatively efficient manner, e.g., by exploiting the thermodynamic advantages of a moving coolant flow to conduct or otherwise thermally dissipate heat from the battery cells.

[0004] One aspect of the present description relates to a battery module. The battery module may include a plurality of battery cells configured to store and deliver electrical energy, a cell holder configured to support the battery cells, a pre-molded insert disposed relative to the cell holder and the battery cells, the pre-molded insert optionally including a potting material shaped to define a plurality of coolant channels for the battery cells, and a flow control system operable to control coolant flow through the coolant channels.

[0005] The flow control system may include a plurality of flow diverters disposed within the encapsulating material, wherein the flow diverters are optionally configured to meter the coolant flow through one of the respective coolant channels.

[0006] The flow diverters may be configured to contract from a nominal state to a smaller state when the coolant temperature of the coolant flow there exceeds a nominal temperature threshold.

[0007] The flow diverters can be configured to transition from a nominal state to a minimum state when the coolant temperature there exceeds a nominal temperature threshold by a predefined value.

[0008] The nominal state may cause the flow diverters to block a larger portion of the coolant channels than in the minimum state, so that the nominal state restricts the coolant flow more than the minimum state.

[0009] The preformed insert may include a plurality of cell cavities in fluid communication with the coolant channels, wherein the cell cavities are optionally shaped within the encapsulating material to each receive one of the battery cells.

[0010] The coolant channels can be formed spirally around the cell cavities, with the spiral shape directing the coolant flow in a circular manner from top to bottom or from bottom to top into one of the cell cavities.

[0011] The flow control system may include a coolant reservoir configured to enclose the preformed insert and the battery cells in a sealed housing, wherein the sealed housing is optionally operable to direct the coolant flow through the coolant channels and around the battery cells to provide immersive cooling.

[0012] The coolant reservoir may include a pressure relief valve configured to allow coolant flow outside the sealed enclosure when the pressure within the sealed enclosure exceeds a pressure threshold.

[0013] The preformed insert may include a plurality of thermal channels for the battery cells, the thermal channels being configured to retain a thermal fluid separate from the coolant flow when a coolant temperature of the coolant flow is below a thermal threshold and to release the thermal fluid into the coolant flow when the coolant temperature exceeds the thermal threshold.

[0014] The flow control system may include a flow manifold configured to direct a coolant inlet containing a coolant to the coolant channels to create the coolant flow therethrough.

[0015] The flow control system may include an inlet and an outlet for each of the coolant channels and a flow controller that selectively meters the coolant through the inlets and outlets and thus the coolant flow through the respective coolant channel.

[0016] The flow control system may include a plurality of temperature sensors arranged relative to the battery cells and / or the coolant channels, wherein the flow controller may optionally be used to meter the coolant based on the temperatures measured by the temperature sensors.

[0017] One aspect of the present description relates to a battery module. The battery module may include a plurality of battery cells configured to store and deliver electrical energy, a pre-molded insert having a potting material shaped to define a plurality of cell cavities for holding the battery cells and a plurality of cooling channels for directing coolant flow relative to the cell cavities, a coolant reservoir configured to enclose the pre-molded insert and the battery cells within a sealed housing, and a submerged flow control system operable to cyclically flow coolant through the coolant channels and the coolant reservoir to submergedly cool the battery cells.

[0018] The immersive flow control system may include a plurality of flow diverters disposed within the coolant channels, wherein the flow diverters are optionally configured to expand and contract based on a coolant temperature of the coolant flow.

[0019] The flow diverters may be configured to contract from a nominal state to a minimum state when the coolant temperature there exceeds a nominal temperature threshold by a predefined amount, wherein the nominal state optionally results in the flow diverters blocking a larger portion of the coolant channels than in the minimum state.

[0020] The coolant channels can be spiral-shaped so that the coolant flow is directed in a circular manner from top to bottom or from bottom to top into the respective cell cavity.

[0021] One aspect of the present description relates to a vehicle having an electric motor configured to convert electrical energy into mechanical energy suitable for propulsion of the vehicle and a rechargeable energy storage system (RESS) having one or more energy modules configured to store and deliver the electrical energy.The energy modules may each include a plurality of energy cells configured to store and deliver electrical energy, a pre-molded insert containing a potting material shaped to define a plurality of cell cavities for holding the energy cells and a plurality of cooling channels for directing coolant flow relative to the cell cavities, a coolant reservoir configured to enclose the pre-molded insert and the energy cells within a sealed housing, and a submerged flow control system operable to cyclically flow coolant through the coolant channels and the coolant reservoir to submergedly cool the energy cells.

[0022] The energy modules may each comprise a bus bar configured to electrically interconnect the energy cells, wherein the bus bars are optionally each connected to a portion of the energy cells above the preformed insert and within the coolant reservoir such that the bus bars are immersion cooled.

[0023] The immersive flow control system may include a plurality of flow diverters disposed within the coolant channels, the flow diverters optionally configured to expand and contract based on a coolant temperature of the coolant flow therein, such that the flow diverters contract from a nominal state to a minimum state in response to a coolant temperature therein exceeding a nominal temperature threshold by a predefined amount, and thereafter expand back to the nominal state when the coolant temperature falls below the nominal temperature threshold.

[0024] These features and advantages, as well as other features and advantages of the present teachings, will be readily apparent from the following detailed description of the embodiments of the present teachings, taken in conjunction with the accompanying figures. It should be understood that, although the following figures and embodiments may be described separately, individual features thereof may be combined to form additional embodiments. BRIEF DESCRIPTION OF THE CHARACTERS

[0025] The accompanying figures, which may be incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. Fig. Figure 1 shows a vehicle according to a non-limiting aspect of the present description. Fig. Figure 2 shows a partially exploded view of a battery module in accordance with a non-limiting aspect of the present description. Fig. Figure 3 shows a partial perspective view of a preformed insert in accordance with a non-limiting aspect of the present description. Fig. 4 shows a perspective view of a battery module in accordance with a non-limiting aspect of the present description. Fig. 5 shows a schematic side view of Fig. 4 illustrating a preformed insert having a split configuration in accordance with a non-limiting aspect of the present description. Fig. 6 shows a cross-sectional view of Fig. 4 to illustrate a preformed insert having a uniform configuration according to a non-limiting aspect of the present description. Fig. 7 shows a cross-sectional view of Fig. 4 to illustrate a preformed insert having a unitary configuration with flow diverters according to a non-limiting aspect of the present description. Fig. 8 shows a cross-sectional view of Fig. 4 to illustrate a preformed insert having a uniform configuration with spiral channels according to a non-limiting aspect of the present description. Fig. Figure 9 shows a schematic side view of the spiral channels that direct the coolant flow relative to a surface of one of the battery cells, in accordance with a non-limiting aspect of the present description. Fig. Figure 10 shows a perspective, schematic view of the spiral channels that direct the coolant flow relative to a surface of one of the battery cells, according to a non-limiting aspect of the present description. Fig. 11 shows a flow diagram of a method of manufacturing a battery module in accordance with a non-limiting aspect of the present description. DETAILED DESCRIPTION

[0026] Where appropriate, detailed embodiments of the present description may be disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or reduced in size to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for showing one skilled in the art how to variously apply the present description.

[0027] Fig. 1 shows a vehicle 12 in accordance with one non-limiting aspect of the present description. The vehicle 12, which may be interchangeably referred to as an electric vehicle 12, may include a traction motor 14 operable to convert electrical energy into mechanical energy for the purpose of performing work, such as mechanically driving a drivetrain 16 to propel the vehicle. The vehicle 12 is depicted as a hybrid vehicle because the drivetrain 16 optionally includes an internal combustion engine (ICE) 18 for generating mechanical energy. The vehicle 12 may alternatively dispense with the electric motor 14 and instead be powered solely by the internal combustion engine 18. The drivetrain 16 may include components that facilitate the transfer of rotational power from the traction motor 14 and / or the internal combustion engine 18 to one or more of the wheels 20, 22, 24, 26.The vehicle 12 may include a rechargeable energy storage system (RESS) 30 to store and supply electrical energy to the traction motor 12 and / or other components, systems, etc. 32 onboard the vehicle 12, for example, via a first bus 34 (e.g., main or high-voltage bus) and a second bus 36 (e.g., auxiliary or low-voltage bus). The vehicle 12 may include a control unit 38 to facilitate monitoring, controlling, measuring, and otherwise controlling the operation, performance, etc. onboard the vehicle 12, which may include taking measurements, taking readings, or otherwise collecting data to facilitate operation.The vehicle control unit 38 may include additional control units (not shown), the associated operations of which are optionally performed according to one or more processors executing corresponding non-transitory instructions stored on one or more computer-readable storage media.

[0028] Fig. 2 shows a partially exploded view of the battery module 44 in accordance with one non-limiting aspect of the present description. The battery module 44 may be included as part of the RESS 30 to house a plurality of battery cells 46, which in turn may be operated to store and deliver electrical energy. The RESS is illustrated with a single battery module 44 for simplicity, as the present description fully contemplates the RESS 30 with additional battery modules 44, including battery modules 44 with more or fewer than the number of battery cells 46 shown. The battery module 44 may include additional components for electrically connecting the battery cells 46 to each other and / or to other systems on board the vehicle 12. The battery cells 46 may include a variety of components suitable for storing and delivering electrical energy.The battery cells 46 may include a lithium-ion material or other material chemistry suitable for storing and delivering electrical energy, and some of the battery cells 46 may have a mixed or different chemistry than some of the other battery cells 46. However, the use of battery cells 46 is not presented in a limiting manner, as the present description also contemplates other types of energy cells capable of storing and / or delivering electrical energy, such as, but not necessarily limited to, energy cells partially or entirely comprising capacitors, supercapacitors, fuel cells, and / or other types of energy components.

[0029] The battery module 44 may include a cell holder 50 for receiving the battery cells 46. The cell holder 50 may be formed as a rigid structure, e.g., from a variety of stamped or formed materials assembled into a case or other structure suitable for enclosing the battery cells 46. The cell holder 50 is illustrated, for non-limiting purposes, as including four side panels 52, 54, 56, 58 and opposing top and bottom panels 60, 62 that may be bonded, welded, fastened, or otherwise secured together. The bottom panel 62 has a bottom surface that abuts or otherwise cooperates with a cold plate 66 or other element of a cooling system (not shown). One aspect of the present description relates to a preformed insert 68 included within the battery module 44.The preformed insert 68 may serve to facilitate the dissipation of thermal energy from the battery cells 46 without the need to mold a filler or other strengthening material into an associated battery module or otherwise perform labor- and time-consuming manufacturing processes. As shown in the partial cross-sectional perspective view of FIG. Fig. 3, the preformed insert 68 may be made of a potting material shaped to define cavities 70 for receiving the battery cells 46 and coolant channels 72 for circulating a dielectric or other suitable coolant relative to the battery cells 46. The battery cells 46 may be press-fitted or otherwise inserted into the cavities 70, and the coolant may then circulate through the cooling channels 72 to remove thermal energy from the battery cells 46. The ability to circulate the coolant through the cooling channels 72 (which are not individually labeled and are instead shown with representative dashed lines for simplicity) may be advantageous compared to heat paths with solid or immobile fillers, as the circulating coolant tends to provide better heat distribution and efficiency.

[0030] The preformed insert 68 may include the cell cavities 70 arranged according to a plurality of rows and columns, with the coolant channels 72 in each row optionally fluidly connected. The preformed insert 68 may include a coolant inlet 76 and a coolant outlet 78 for each of the coolant channels 72, which may optionally include a cone or other shaped expansion element 80, 82 for distributing the coolant therethrough. The preformed insert 68 may optionally include a coolant band 90 disposed within one or more of the coolant channels 72. The coolant bands 90 may be rigid structures that form coolant passages to allow coolant to flow through the coolant channels 72.The coolant bands 90 may be divided into an upper portion 92 and a lower portion 94 such that coolant liquid may be supplied through a respective one of the coolant inlets 76 for communication through the upper portion 92, with the coolant then flowing to a rear end of the associated coolant band 90, where it may reverse direction to flow back to a respective coolant outlet 78 located proximate the associated lower portion 94. The material used to fabricate the preformed insert 68 may comprise a thermally conductive material having a closed-cell foam structure or another material suitable for conducting energy away from the battery cells 46. The potting material may be semi-rigid or less rigid than the housing 50 and / or the cooling bands 90.The potting material may be sufficiently dense and / or rigid to facilitate interference fit with the battery cells 46 and / or to otherwise support the battery cells 46 in the manner contemplated herein.

[0031] Back to Fig. 2: The coolant inlets and outlets 76, 78 may cooperate with coolant inlet and outlet openings 86, 88 contained in the cell holder 50 to facilitate fluid communication of the coolant inlets and outlets 80, 82 with a flow control system 95. The flow control system 95 may include a flow manifold 97 for directing a coolant inlet 99 containing a coolant to the coolant channels 72 to establish coolant flow therethrough. The flow control system 95 may include a flow regulator 101 for selectively metering the coolant through the inlets and outlets and thus the coolant flow through the respective coolant channel.The flow regulator 101 is illustrated for simplicity as including two conduits 103, 105 for fluid communication with the inlets and outlets 76, 78 of the preformed insert 68; however, this description fully contemplates the flow regulator 101 including additional conduits, optionally with separate conduits for each of the inlets and outlets 76, 78. The flow control system 95 may include a plurality of temperature sensors 107 disposed relative to the battery cells 46 and / or the coolant channels 72. The flow regulator 101 may be used to meter the coolant exchange with the inlets and outlets 76, 78 based on the temperatures measured by the temperature sensors 107.For simplicity, some of the temperature sensors 107 are shown, however, a larger number of temperature sensors may be used to facilitate the individual measurement of temperatures at the battery cells 46, in the coolant channels 72, and / or elsewhere in the module 44. The flow control system 95 may include a controller 109 that uses the temperature measurements, optionally with other vehicle-related measurements, e.g., state of charge (SOC), range, engine demand, etc., to adjust the rate, quantity, and / or other dosing options for the coolant flowing through the coolant channels 72 accordingly. This ability to selectively measure coolant flow may be advantageous in enabling the flow control system 95 to influence the cooling of the battery cells in a manner that may be tailored to maximize performance, efficiency, longevity, etc.

[0032] Fig. 4 shows a perspective view of a battery module 44A in accordance with one non-limiting aspect of the present description. The battery module 44A may be similar to that described above and include a cell holder 50 and a plurality of battery cells 46 arranged in a pre-molded insert 68. The battery module 44A is shown including fewer battery cells 46 than the battery module 44 described above to demonstrate the advantageous capabilities of the present description to support a modular construction, wherein multiple battery modules 44A may be connected together to form the RESS 30, for example, with multiple modules that can be operated together in series and / or parallel. The ability to selectively connect multiple battery modules 44A together may be advantageous to vary the size, capacity, etc.of the RESS 30 to the vehicle and / or other device in which it is used. One aspect of the present description contemplates that the pre-formed insert 68 may have different configurations depending on the desired manner of coolant circulation through the coolant channels 72. The ability to circulate coolant through the cooling channels 72 may be advantageous for creating an immersive type of cooling environment, wherein a coolant may be circulated relative to the battery cells 46 and optionally in contact with the battery cells 46 to optimize thermal conductivity and cooling.While the battery module 44A may include the inlets and outlets 86, 88 to the coolant channels 72 in the manner described above, as an exemplary alternative, the battery module 44A may include the coolant inlets 86 at one end of the cell holder 50 and the coolant outlets 88 at the other end, such that the coolant flows in a front-to-back direction through the preformed insert 68. As those skilled in the art will appreciate, the ability to circulate the coolant and thereby improve cooling over static or immobile fillers and heat sinks may be advantageous for limiting the operating temperatures of the RESS 30, which in turn may improve the performance, efficiency, longevity, etc., of the battery cell 46.

[0033] Fig. 5 shows a schematic side view of Fig. 4 illustrates a preformed insert 68A having a split configuration in accordance with one non-limiting aspect of the present description. The split configuration may correspond to the preformed insert 68A having a two-piece construction, with an upper portion 90 preformed separately from a lower portion 92, and a latch 94 configured to secure the upper portion 90 to the lower portion 92. The latch 94 may include features suitable for sealing, connecting, or otherwise securing the upper and lower portions together so that coolant flowing through the respective coolant channels 72 may be retained therein.The latch 94 can be actuated to allow insertion of the lower portion 92 into the cell holder 50 so that the battery cells 46 can be inserted into one of the respective battery cavities 70, after which the upper portion 90 can be mounted thereover. The latch 94 can also be actuated to allow insertion of the lower portion 90 into the cell holder 50 so that the upper portion 90 can be mounted thereover, after which the battery cells 46 can be inserted into the cell cavities 70 after the preformed insert 68A is installed. The cell cavities 70 can have an upper end 98 near a top of the battery cells 46 and a lower end 100 near a bottom of the battery cells 46.The preformed insert 68A may include upper and lower protrusions 102, 104 configured to form an upper interference fit between the upper end 98 and the top of the battery cells 46 and a lower interference fit between the lower end 100 and the center of the battery cells 46. The interference fits may serve to retain the coolant in the respective cooling channels 72. The upper and lower ends 98, 100 of the cell cavities 70 may be narrower than a central portion 106 such that the central portion 106 may be used to define the respective coolant channels 72. The preformed potting material forming the preformed insert 68A may be shaped to at least partially or completely laterally surround the battery cells 46 such that the cell cavities 70 may be distributed relative to the cooling channels 72.The cell cavities 70 may be connected to or form part of the coolant channels 72, so that the coolant flowing through the coolant channels 72 may physically contact the sides of the battery cell 46 before flowing through a tunneled section leading to another of the cell cavities 70. A bus bar or other circuit components 120 may be provided to electrically connect the battery cells 46 to one another.

[0034] The split configuration may additionally include a plurality of thermal channels 121 preformed in the potting material and operable independently of the coolant channels 72. The thermal channels 121 may be separated from the coolant channels 72 by a partition or other feature 123 adapted to provide an interference fit, gasket, O-ring, or other seal capable of isolating the coolant flow from a thermal fluid contained within the thermal channels 121. The thermal channels 121 may be configured to retain the thermal fluid independent of the coolant flow when the coolant temperature of the coolant flow is below a thermal threshold, which may be based, for example, on temperatures associated with a thermal event.The splitter or other component 123 used to seal the coolant channels 72 from the heat channels 121 may be configured to change shape, dissolve, or otherwise automatically alter its configuration or material construction when the coolant temperature therein exceeds the thermal threshold. In such a case, the splitter 123 may be configured to release the thermal fluid into the coolant stream to provide additional assistive cooling. The thermal fluid may have different cooling properties than the coolant and optionally contain additional additives to provide chemical suppressors that may be helpful in providing additional cooling beyond that of the coolant.The partition wall 123 may be a sacrificial component, wherein the release of the thermal fluid may be irreversible in that the partition wall is subsequently no longer able to isolate the thermal channels 121 from the associated coolant channels 72.

[0035] The module 44A may optionally include a coolant reservoir 127 configured to enclose the preformed insert 68A and the battery cells 46 within a sealed housing. The flow control system 95 may include the coolant reservoir 127 to facilitate additional circulation of the coolant outside the coolant channels 72 to provide additional immersion cooling of the battery cells 46. The coolant reservoir 127 may be provided with sealing connections 129, 131 between the top and bottom portions 60, 62 of the cell holder 50, or, as shown, with a reservoir top 133 and a reservoir bottom 135 used in place of or added to them.The coolant reservoir 127 may be shaped and configured to enclose the preformed insert 68A and the battery cells 46 within the sealed enclosure, allowing coolant to circulate through the coolant channels 72 and auxiliary channels or spaces defined with respect to the preformed insert 68A, the bus bar 120, and other portions of the module 44A within the sealed enclosure. The flow regulator 101 may optionally be configured to meter the coolant through the auxiliary spaces independently of the cooling channels, for example, via inlets and outlets connected thereto (not labeled). The coolant reservoir 127 may include a pressure relief valve 137 configured to relieve the flow of coolant to the exterior of the sealed enclosure when the pressure within the sealed enclosure exceeds a pressure threshold.For example, the pressure relief valve 137 may be configured to automatically open a valve or detach from the container top when the pressure threshold is exceeded.

[0036] Fig. 6 shows a cross-sectional view of Fig. 4 to illustrate the preformed insert 68B having a unitary configuration in accordance with a non-limiting aspect of the present description. The unitary configuration may be characterized in that the preformed insert 68B has a one-piece construction. While the present description contemplates the unitary configuration with the heat channels 121, the illustrated configuration shows that the heat channels 121 have been omitted to expand the coolant channels 72 or to provide larger cross-sectional areas. The upper and lower container parts 133, 135 may similarly be provided with the container seals 129, 131 so that the coolant can circulate through the cooling channels 72 and the auxiliary spaces to ensure immersive cooling. Due to the immersion cooling, i.e.When using the coolant outside of the cooling channels 72, a fit between the upper and lower ends of the preformed insert and the respective battery cell 46 may allow the passage of the coolant, which may facilitate the manufacture of the preformed insert 68B and the insertion of the battery cells 46 into the cell cavities 70. In the event that it is desirable to separate the coolant channels 72 from the auxiliary spaces, gaskets (not shown) may be used to create an upper interference fit between the upper end 98 and the top of the battery cells 46 and a lower interference fit between the lower end 100 and the bottom of the battery cells 46.The seals may be made of rubber or another material different from the potting material and may be used in place of the upper and lower bosses described above to improve tolerance requirements, mold control, and / or other processes required to form the bosses.

[0037] Fig. 7 shows a cross-sectional view of Fig. 4 illustrates the preformed insert 68C having a unitary configuration with flow diverters 143 according to one non-limiting aspect of the present description. The flow diverters 143 may be part of the flow control system 95 and disposed within the potting material to meter the coolant flow through a corresponding one of the coolant channels 72. The flow diverters 143 may be configured to contract from a nominal state to a smaller state when the coolant temperature of the coolant flow therein exceeds a nominal temperature threshold.The flow diverters 143 can be configured to contract from a nominal state to a minimum state when a coolant temperature there exceeds a nominal temperature threshold by a predefined amount, such that the nominal state causes the flow diverters 143 to block a larger portion of the coolant channels 72 than in the minimum state, such that the nominal state restricts the coolant flow more than the minimum state. The flow diverters 143 can be configured to act as temperature-controlled components that can change their shape and size depending on the respective temperature. This self-regulating capability can be advantageous because it allows the flow diverters 143 to individually adjust the dosage of coolant flowing through them without requiring instructions or controls from the flow control unit.As shown, this ability may result in some of the flow diverters 143 having different sizes relative to other flow diverters 143 depending on the respective temperature differences.

[0038] Fig. 8 shows a cross-sectional view of Fig. 4 illustrates the preformed insert 68D having a uniform configuration with spiral channels 72A in accordance with one non-limiting aspect of the present description. The spiral channels 72A may be configured to circulate the coolant relative to the battery cells 46 in a circular manner, with the coolant flowing from top to bottom or bottom to top within the respective cell cavities. The spiral or circular movement of the cooling fluid may be advantageous to achieve a convective effect that facilitates cooling by directing the cooling fluid around the battery cells 46 through multiple loops or turns contained within the potting material.The loops or turns may correspond to depressions machined into the cell cavities relative to other bumps 145 so that, from top to bottom, portions of the potting material may be intermittently pressed against or near the battery cells 46. The spiral channels 72A may optionally include gaskets, projections, or other elements to facilitate sealing the bumps 148 against the respective battery cells 46 to maintain the desired direction of coolant flow. However, in the present description, it is entirely contemplated that the gaskets may be omitted or not required, since the spiraling action of the cooling fluid can be achieved even if some of the cooling fluid is allowed to pass between the bumps 148 and the battery cells 46. Fig. 9 shows a schematic side view of the spiral channels 72A that direct coolant flow relative to a surface of one of the battery cells 46 in accordance with a non-limiting aspect of the present description. The battery cells 46 may correspond to battery cells 46 aligned within the same row, such that a coolant inlet 86 may be used to direct the coolant through the spiral channels 72A from the bottom to the top of a first battery cell 46A, through a tunnel or other construct 147 in the potting material to a second battery cell 46B, and then from the top to the bottom relative to the second battery cell 46B for exchange through a coolant outlet 88. Fig. Figure 10 shows a perspective schematic view of the spiral channels 72A that direct coolant flow relative to a surface of one of the battery cells 46 in accordance with a non-limiting aspect of the present description.

[0039] Fig.11 shows a flowchart 140 of a method of manufacturing a battery module 44 in accordance with one non-limiting aspect of the present description. Block 142 refers to a molding process by which the pre-formed insert 68 may be formed. The molding process may include forming the pre-formed insert 68 such that the cell cavities 70 include a top end, a bottom end, and a middle portion between the top and bottom ends, wherein the top and bottom ends are narrower than the middle portions, and the middle portions define the coolant channels 72. The molding process may include forming the pre-formed insert 68C such that the battery cells 46 are arranged in a plurality of rows and the middle portions of the cavities 70 in each respective row are in fluid communication with one another to define the cooling channels 72.The molding process may include molding the preformed insert 68 from a thermally conductive material having a closed-cell foam structure. Block 144 refers to a method of receiving and / or manufacturing a cell holder 50. Block 146 refers to a method of receiving a plurality of battery cells 46. Block 148 refers to an assembly method for positioning a preformed insert 68 within the cell holder 50 and thereafter, or in conjunction therewith, for press-fitting or otherwise inserting the battery cells 46 into a corresponding one of the cell cavities 70. The assembly process may optionally be performed by securing the battery cells 46 in the preformed insert 68 and securing the preformed insert 68 in the cell holder 50 without using a poured epoxy or a liquid adhesive.

[0040] As supported above, the present description relates to a preformed cell-to-cell barrier encapsulant molded with built-in channels with active and / or passive flow control valves that provide a directional cooling function for the cells within the battery module. The cell-to-cell barrier material can be molded as a part that can be assembled during battery module manufacturing to reduce manufacturing costs and cycle time by eliminating the need for injection molding machines, inventory for encapsulant curing time on the assembly line, etc. The encapsulant can be molded with built-in channels for the dielectric cooling fluid to enable immersion cooling without compromising the bulk of the large volume of coolant within the battery module.The potting material may be a preformed closed-cell foam that forms a thermal and electrical barrier between the cells. The potting material may be shaped to enclose coolant flow channels that replace cooling plates and / or cooling belts and connect directly to the rest of the cooling system (pumps, filters, hoses, heat exchangers). The potting material may be shaped to form cavities for receiving battery cells and / or other types of energy cells of cylindrical, prismatic, pouch-like, or other shapes and / or sizes, with the coolant channels shaped relative thereto.

[0041] Sensors and flow control valves (either molded into the potting material at key locations or mounted externally) can be used to provide temperature information about the cells and coolant and direct the coolant to the hottest cells. Coolant reservoir plates can be used to seal the coolant within the cell holder, cool cells and busbars, and contain pressure relief valves to vent gases released during thermal events. Coolant channels with passive bimetallic strip valves can act as flow diverters along the entire length of the channel and be molded into preformed potting compound, controlling flow (hotter cells receive more flow when the valves open the channels, while cooler cells receive less flow when the valves partially close the channels).The flow to the various sections of the coolant channels can be actively controlled at the inlet manifold via an active flow control valve. The flow control valve can operate according to logic based on information from temperature sensors, with the flow control valve optionally diverting a larger coolant flow to the hotter parts of the module and / or away from the cooler parts of the module.

[0042] While various embodiments have been described, the description is intended to be exemplary and not restrictive, and it will be apparent to those skilled in the art that many other embodiments and implementations are possible that fall within the scope of the embodiments. Any feature of one embodiment may be used in combination with, or in place of, another feature or element in another embodiment, unless expressly limited. Accordingly, the embodiments are to be limited only in light of the appended claims and their equivalents. Also, various modifications and changes may be made within the scope of the appended claims.Although various modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the prior art to which these teachings relate will recognize various alternative aspects for carrying out the present teachings that fall within the scope of the appended claims. It is intended that everything contained in the above description or shown in the accompanying drawings be considered illustrative and exemplary of the entire range of alternative embodiments that one of ordinary skill in the art would recognize as being implied, structurally and / or functionally equivalent, or otherwise obvious based on the content contained therein, and not as limited solely to the embodiments expressly shown and / or described.

Claims

[1] A battery module comprising: a plurality of battery cells configured to store and deliver electrical energy; a cell holder configured to support the battery cells; a preformed insert disposed relative to the cell holder and the battery cells, the preformed insert containing a potting material shaped to define a plurality of cooling channels for the battery cells; and a flow control system for controlling the coolant flow through the coolant channels. [2] The battery module of claim 1, wherein the flow control system comprises a plurality of flow diverters disposed within the encapsulating material, the flow diverters configured to meter the flow of coolant through a respective one of the coolant channels. [3] The battery module of claim 2, wherein the flow diverters are configured to contract from a nominal state to a smaller state when a coolant temperature of the coolant flow therein exceeds a nominal temperature threshold. [4] The battery module of claim 3, wherein the flow diverters are configured to contract to a minimum state less than the nominal state when the coolant temperature therein exceeds the nominal temperature threshold by a predefined amount. [5] The battery module of claim 4, wherein the nominal state results in the flow diverters blocking a larger portion of the coolant channels than in the minimum state, so that the nominal state restricts the coolant flow more than the minimum state. [6] Battery module according to claim 1, wherein: the preformed insert has a plurality of cell cavities in fluid communication with the coolant channels, the cell cavities being shaped within the potting material to each receive one of the battery cells. [7] The battery module of claim 6, wherein the coolant channels are formed spirally around the cell cavities, the spiral shape directing the coolant flow in a circular manner from top to bottom or from bottom to top of a respective one of the cell cavities. [8] The battery module of claim 1, wherein the flow control system comprises a coolant reservoir configured to enclose the pre-formed insert and the battery cells within a sealed enclosure, the sealed enclosure operable to direct the flow of coolant through the coolant channels and around the battery cells to provide immersive cooling. [9] Battery module according to claim 1, wherein: the preformed insert includes a plurality of heat channels for the battery cells, the heat channels being configured to retain a heat fluid separate from the coolant flow when a coolant temperature of the coolant flow is below a heat threshold and to release the heat fluid into the coolant flow when the coolant temperature exceeds the heat threshold. [10] Battery module according to claim 1, wherein: the flow control system comprises a flow manifold operable to direct a coolant input having a coolant to the coolant channels to generate the coolant flow therethrough.

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