Battery module with coolant flow control

Abstract

A battery module includes: a plurality of battery cells configured to store and supply electrical power; a battery cell holder configured to support the battery cells; a preformed insert comprising 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 passage.

Description

Technical Field

[0001] The present disclosure relates to cooling battery cells included in a battery module, such as but not limited to, cooling battery cells configured to store and supply electrical power for a vehicle. Background Art

[0002] A rechargeable energy storage system (RESS) can be configured to store and supply electrical power for various applications, and one of the more common types of RESS includes a plurality of battery cells arranged into one or more battery modules. Such a RESS can be included on a vehicle to store and supply electrical power for a main or high voltage (HV) bus and / or an auxiliary or low voltage (LV) bus. Because battery cells tend to generate heat when storing and supplying electrical power, it can be advantageous for an associated battery module to utilize a cold plate or other external element of a cooling system to operate to conduct thermal energy away from the battery cells. Such a cooling system can include a static epoxy filler or other cured fluid to provide a fixed heat path of immovable material, thereby facilitating the conduction of thermal energy away from the battery cells. The immobility of such a filler can operate to substantially provide a type of fixed heat sink, whereby heat generated by the battery cells can be conducted through the static material in an attempt to dissipate the accompanying thermal energy to the cold plate or other external cooling element, which can be relatively inefficient. Summary of the Invention

[0003] One aspect of the present disclosure relates to a battery module configured to dissipate heat from battery cells in a relatively efficient manner, such as by utilizing the thermodynamic benefits of a moving coolant flow to conduct heat away from the battery cells or otherwise transfer heat from the battery cells in a thermal manner.

[0004] One aspect of the present disclosure relates to a battery module. The battery module can include a plurality of battery cells configured to store and supply electrical power, a battery cell holder configured to support the battery cells, a preformed insert disposed relative to the battery cell holder and the battery cells, and a flow control system, wherein the preformed insert optionally includes a potting material shaped to define a plurality of coolant channels for the battery cells, and the flow control system is operable to control the coolant flow through the coolant channels.

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

[0006] The flow diverters can be configured to contract from a nominal state to a smaller state in response to the coolant temperature of the coolant flow there exceeding a nominal temperature threshold.

[0007] The diverter can be configured to contract from a nominal state to a minimum state in response to the coolant temperature there exceeding a nominal temperature threshold by a predetermined amount.

[0008] The nominal state can cause the diverter to block a greater portion of the coolant passage than when in the minimum state, such that the nominal state restricts coolant flow more than the minimum state.

[0009] The preformed insert can include a plurality of cell cavities fluidly interconnected with the coolant passage, optionally the cell cavities being formed within a potting material to receive a respective one of the cells.

[0010] The coolant passage can be formed to have a spiral shape around the cell cavities, wherein the spiral shape guides coolant flow in a circular manner from the top to the bottom or from the bottom to the top of a respective one of the cell cavities.

[0011] The flow control system can include a coolant container configured to enclose the preformed insert and the cells within a sealed housing, optionally the sealed housing being operable to direct coolant flow through the coolant passage and around the cells to provide immersion cooling.

[0012] The coolant container can include a pressure relief valve configured to release coolant flow to the exterior of the sealed housing in response to the pressure within the sealed housing exceeding a pressure threshold.

[0013] The preformed insert can include a plurality of thermal channels for the cells, wherein the thermal channels are configured to keep a thermal fluid separated from the coolant flow when the 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 can include a flow manifold operable to direct a coolant input having coolant into the coolant passage to create a coolant flow therethrough.

[0015] The flow control system can include: an input and an output for each respective coolant passage in the coolant passage; and a diverter operable to selectively meter coolant through the input and the output and thereby meter the coolant flow through the respective coolant passage.

[0016] The flow control system can include a plurality of temperature sensors disposed relative to the cells and / or the coolant passage, optionally the diverter being operable to meter the coolant based on the temperature measured using the temperature sensors.

[0017] One aspect of the present disclosure relates to a battery module. The battery module may include: a plurality of battery cells configured to store and supply electrical power; a preformed insert including a potting material shaped to define a plurality of battery cell cavities for holding the battery cells and a plurality of cooling channels for guiding a coolant flow relative to the battery cell cavities; a coolant container configured to enclose the preformed insert and the battery cells within a sealed housing; and an immersion flow control system operable to circulate the coolant through the cooling channels and the coolant container to cool the battery cells in an immersion manner.

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

[0019] The diverter may be configured to contract from a nominal state to a minimum state in response to the coolant temperature there exceeding a nominal temperature threshold by a predetermined amount. Optionally, the nominal state causes the diverter to block a greater portion of the coolant channel than when in the minimum state.

[0020] The cooling channels may be formed in a spiral shape that guides the coolant flow in a circular manner from the top to the bottom or from the bottom to the top of a respective one of the battery cell cavities.

[0021] One aspect of the present disclosure relates to a vehicle including: an electric motor configured to convert electrical power into mechanical power suitable for use in propelling the vehicle; and a rechargeable energy storage system (RESS) having one or more energy modules configured to store and supply electrical power. Each energy module may respectively include: a plurality of energy cells configured to store and supply electrical power; a preformed insert including a potting material shaped to define a plurality of energy cell cavities for holding the energy cells and a plurality of cooling channels for guiding a coolant flow relative to the energy cell cavities; a coolant container configured to enclose the preformed insert and the energy cells within a sealed housing; and an immersion flow control system operable to circulate the coolant through the cooling channels and the coolant container to cool the energy cells in an immersion manner.

[0022] Each energy module may include a bus bar configured to electrically interconnect the energy cells of the energy module. Optionally, the bus bars are respectively connected to portions of the energy cells above the preformed insert and within the coolant container such that the bus bars are cooled in an immersion manner.

[0023] An immersion flow control system may include a plurality of diverters disposed within a coolant passage. Optionally, the diverters are configured to expand and contract based on the coolant temperature of the coolant flow there, such that the diverters contract from a nominal state to a minimum state in response to the coolant temperature there exceeding a nominal temperature threshold by a predetermined amount, and thereafter expand back to the nominal state when the coolant temperature drops below the nominal temperature threshold.

[0024] The present invention also includes the following solutions:

[0025] Solution 1. A battery module, comprising:

[0026] A plurality of battery cells configured to store and supply electric power;

[0027] A battery cell holder configured to support the battery cells;

[0028] A preformed insert disposed relative to the battery cell holder and the battery cells, the preformed insert including a potting material formed to define a plurality of coolant passages for the battery cells; and

[0029] A flow control system operable to control the coolant flow through the coolant passages.

[0030] Solution 2. The battery module according to Solution 1, wherein:

[0031] The flow control system includes a plurality of diverters disposed within the potting material, wherein the diverters are configured to meter the coolant flow through a respective one of the coolant passages.

[0032] Solution 3. The battery module according to Solution 2, wherein:

[0033] The diverters are configured to contract from a nominal state to a smaller state in response to the coolant temperature of the coolant flow there exceeding a nominal temperature threshold.

[0034] Solution 4. The battery module according to Solution 3, wherein:

[0035] The diverters are configured to contract to a minimum state less than the nominal state in response to the coolant temperature there exceeding the nominal temperature threshold by a predetermined amount.

[0036] Solution 5. The battery module according to Solution 4, wherein:

[0037] The nominal state causes the diverter to block a greater portion of the coolant passage than when in the minimum state, such that the nominal state restricts the coolant flow more than the minimum state.

[0038] Aspect 6. The battery module according to aspect 1, wherein:

[0039] The preformed insert includes a plurality of cell cavities that are fluidly interconnected with the coolant passage, wherein the cell cavities are formed within the potting material to receive a respective one of the cells.

[0040] Aspect 7. The battery module according to aspect 6, wherein:

[0041] The coolant passage is formed in a helical shape around the cell cavity, wherein the helical shape guides the coolant flow in a circular manner from the top to the bottom or from the bottom to the top of a respective one of the cell cavities.

[0042] Aspect 8. The battery module according to aspect 1, wherein:

[0043] The flow control system includes a coolant container that is configured to enclose the preformed insert and the cells within a sealed housing, wherein the sealed housing is operable to direct the coolant flow through the coolant passage and around the cells to provide immersion cooling.

[0044] Aspect 9. The battery module according to aspect 8, wherein:

[0045] The coolant container includes a pressure relief valve that is configured to release the coolant flow to the exterior of the sealed housing in response to the pressure within the sealed housing exceeding a pressure threshold.

[0046] Aspect 10. The battery module according to aspect 1, wherein:

[0047] The preformed insert includes a plurality of thermal channels for the cells, wherein the thermal channels are configured to keep a thermal fluid separated from the coolant flow when the 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.

[0048] Aspect 11. The battery module according to aspect 1, wherein:

[0049] The flow control system includes a flow manifold that is operable to direct a coolant input having coolant into the coolant passage to create a coolant flow therethrough.

[0050] Solution 12. The battery module according to Solution 11, wherein:

[0051] The flow control system includes: inputs and outputs for each respective coolant channel in the coolant channels; and a diverter, the diverter being operable to selectively meter the coolant passing through the inputs and outputs and thereby meter the coolant flow through the respective coolant channels.

[0052] Solution 13. The battery module according to Solution 12, wherein:

[0053] The flow control system includes a plurality of temperature sensors disposed relative to the battery cells and / or the coolant channels; and

[0054] The diverter is operable to meter the coolant based on the temperature measured by the temperature sensors.

[0055] Solution 14. A battery module, comprising:

[0056] A plurality of battery cells configured to store and supply electrical power;

[0057] A preformed insert including a potting material formed to define a plurality of battery cell cavities and a plurality of cooling channels, wherein the battery cell cavities are configured to hold the battery cells and the cooling channels are configured to direct coolant flow relative to the battery cell cavities;

[0058] A coolant container configured to enclose the preformed insert and the battery cells within a sealed housing; and

[0059] A flow control system operable to circulate coolant through the coolant channels and the coolant container to submerge-cool the battery cells.

[0060] Solution 15. The battery module according to Solution 14, wherein:

[0061] The immersion flow control system includes a plurality of splitters disposed within the coolant channels, wherein the splitters are configured to expand and contract based on the coolant temperature of the coolant flow therein.

[0062] Solution 16. The battery module according to Solution 15, wherein:

[0063] The splitter is configured to contract from a nominal state to a minimum state in response to the coolant temperature therein exceeding a nominal temperature threshold by a predetermined amount, wherein the nominal state causes the splitter to block a greater portion of the coolant channel than when in the minimum state.

[0064] Solution 17. The battery module according to Solution 14, wherein:

[0065] The coolant passage is formed in a spiral shape, which guides the coolant flow in a circular manner from the top to the bottom or from the bottom to the top of a respective one of the battery cell cavities.

[0066] Solution 18. A vehicle, comprising:

[0067] An electric motor configured to convert electrical power into mechanical power suitable for propelling the vehicle; and

[0068] A rechargeable energy storage system (RESS) having one or more energy modules configured to store and supply the electrical power, wherein the energy modules each include:

[0069] A plurality of energy cells configured to store and supply electrical power;

[0070] A preformed insert including a potting material shaped to define a plurality of energy cell cavities and a plurality of cooling channels, wherein the energy cell cavities are configured to receive the energy cells, and the cooling channels are configured to guide a coolant flow relative to the energy cell cavities;

[0071] A coolant container configured to enclose the preformed insert and the energy cells within a sealed housing; and

[0072] An immersion flow control system operable to circulate coolant through the coolant channels and the coolant container to immerse-cool the energy cells.

[0073] Solution 19. The vehicle according to Solution 18, wherein:

[0074] Each of the energy modules includes a bus bar configured to electrically interconnect the energy cells of the energy module, wherein the bus bars are respectively connected to portions of the energy cells above the preformed insert and within the coolant container such that the bus bars are immersion-cooled.

[0075] Solution 20. The vehicle according to Solution 19, wherein:

[0076] The immersion flow control system includes a plurality of diverters disposed within the coolant channels, wherein the diverters are configured to expand and contract based on the coolant temperature of the coolant flow there, such that the diverters contract from a nominal state to a minimum state in response to the coolant temperature there exceeding a nominal temperature threshold by a predetermined amount, and thereafter expand back to the nominal state when the coolant temperature drops below the nominal temperature threshold.

[0077] These features and advantages, along with other features and advantages of the present teachings, will be apparent from the following detailed description of the modes for carrying out the present teachings when considered in conjunction with the accompanying drawings. It should be understood that although the following drawings and examples may be described separately, their individual features may be combined into additional embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The drawings, which can be incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0079] Figure 1 A vehicle is shown in accordance with a non - limiting aspect of the present disclosure.

[0080] Figure 2 A partial exploded view of a battery module is shown in accordance with a non - limiting aspect of the present disclosure.

[0081] Figure 3 A partial cross - sectional perspective view of a pre - formed insert is shown in accordance with a non - limiting aspect of the present disclosure.

[0082] Figure 4 A perspective view of a battery module is shown in accordance with a non - limiting aspect of the present disclosure.

[0083] Figure 5 A schematic side view taken from Figure 4 is shown to illustrate a pre - formed insert having a split configuration in accordance with a non - limiting aspect of the present disclosure.

[0084] Figure 6 A cross - sectional view taken from Figure 4 is shown to illustrate a pre - formed insert having an integral configuration in accordance with a non - limiting aspect of the present disclosure.

[0085] Figure 7 A cross - sectional view taken from Figure 4 is shown to illustrate a pre - formed insert having an integral configuration with a diverter in accordance with a non - limiting aspect of the present disclosure.

[0086] Figure 8 A cross - sectional view taken from Figure 4 is shown to illustrate a pre - formed insert having an integral configuration with a helical channel in accordance with a non - limiting aspect of the present disclosure.

[0087] Figure 9 A side schematic view of a helical channel is shown in accordance with a non - limiting aspect of the present disclosure, the helical channel guiding a coolant flow relative to the surface of a respective one of the battery cells.

[0088] Figure 10A perspective schematic view of a helical channel is shown in accordance with a non - limiting aspect of the present disclosure, the helical channel guiding a coolant flow relative to a surface of a respective one of the battery cells.

[0089] Figure 11 A flowchart of a method for manufacturing a battery module is shown in accordance with a non - limiting aspect of the present disclosure. Detailed Description

[0090] As needed, detailed embodiments of the present disclosure may be disclosed herein; however, it is understood that the disclosed embodiments may be merely examples of the present disclosure, which may be implemented in various and alternative forms. The drawings may not necessarily be to scale; some features may be exaggerated or minimized to show details of particular components. Thus, the specific structural and functional details disclosed herein may not be construed as limiting, but merely as a representative basis for teaching one of ordinary skill in the art to use the present disclosure in various ways.

[0091] Figure 1 Vehicle 12 is shown in accordance with a non - limiting aspect of the present disclosure. Vehicle 12 may be interchangeably referred to as an electric vehicle 12 and may include a traction motor 14 that is operable to convert electrical power into mechanical power for work purposes, such as mechanically powering a powertrain 16 to propel the vehicle. Since the powertrain 16 optionally includes an internal combustion engine (ICE) 18 for generating mechanical power, vehicle 12 is shown as a hybrid type. Vehicle 12 may alternatively omit the electric motor 14 and instead be propelled only by the ICE 18. The powertrain 16 may include components to facilitate the transfer of rotational force from the traction motor 14 and / or the ICE 18 to one or more of the wheels 20, 22, 24, 26. Vehicle 12 may include a rechargeable energy storage system (RESS) 30 to store and supply electrical power for the traction motor 12 and / or other components, systems, etc. 32 on the vehicle 12, which is achieved, for example, via a first bus 34 (e.g., a main bus or HV bus) and a second bus 36 (e.g., an auxiliary bus or LV bus). Vehicle 12 may include a vehicle controller 38 to facilitate monitoring, controlling, measuring, and otherwise directing operations, performance, etc. on vehicle 12, which may include performing measurements, taking readings, or otherwise collecting data to facilitate operation. The vehicle controller 38 may include additional controllers (not shown), and the associated operations may optionally be performed by one or more processors executing corresponding non - transitory instructions stored in one or more computer - readable storage media.

[0092] Figure 2A partial exploded view of a battery module 44 in accordance with a non - limiting aspect of the present disclosure is shown. The battery module 44 may be included as part of the RESS 30 to house a plurality of battery cells 46, which may in turn be operable to store and supply electrical power. For simplicity of presentation, the RESS is shown as including a single battery module 44, as the present disclosure fully contemplates that the RESS 30 includes additional battery modules 44, including battery modules 44 having more or fewer battery cells 46 than shown. The battery module 44 may include additional components for electrically interconnecting the battery cells 46 to each other and / or to other systems on the vehicle 12. The battery cells 46 may include a variety of components operable to store and supply electrical power. The battery cells 46 may include lithium - ion materials or other material chemistries suitable for storing and supplying electrical power. Optionally, some of the battery cells 46 have a mixed or different chemistry compared to some of the other battery cells 46. However, the use of the battery cells 46 is presented for non - limiting purposes, as the present disclosure fully contemplates that the battery cells 46 are other types of energy cells capable of storing and / or supplying electrical power, such as, but not limited to, energy cells partially or fully constituted by capacitors, supercapacitors, fuel cells, and / or other types of energy components.

[0093] The battery module 44 may include a battery cell holder 50 configured to support the battery cells 46. The battery cell holder 50 may be formed as a rigid structure, such as made of a plurality of stamped or molded materials assembled into a housing or other structure adapted to enclose the battery cells 46. The battery cell holder 50 is shown for non - limiting purposes as including four side members 52, 54, 56, 58 and opposing top member 60 and bottom member 62, which may be interconnected, welded, fastened, or otherwise attached to each other. The bottom member 62 has a lower side that abuts or otherwise mates with a cooling plate 66 or other element of the cooling system (not shown). One aspect of the present disclosure relates to a pre - formed insert 68 included within the battery module 44. The pre - formed insert 68 may be operable to facilitate the conduction of thermal energy away from the battery cells 46 without having to pour a filler or other curing material into the associated battery module or otherwise undertake a labor - and time - consuming manufacturing process. As Figure 3As shown in the partial cross-sectional perspective view, the preformed insert 68 can be formed of a potting material that is shaped to define a cavity 70 for receiving the battery cell 46 and a coolant passage 72 for circulating a dielectric or other suitable coolant relative to the battery cell 46. The battery cell 46 can be press-fitted or otherwise inserted into the cavity 70, and the coolant can thereafter be circulated through the coolant passage 72 to conduct thermal energy away from the battery cell 46. Since the circulation of the coolant tends to provide greater heat distribution and efficiency, the ability to circulate the coolant through the coolant passage 72 (which is not individually labeled but is instead shown by representative dashed lines for simplicity of presentation) can be advantageous relative to a thermal path having a fixed or immovable filler.

[0094] The preformed insert 68 can include battery cell cavities 70 arranged in a plurality of rows and columns, and optionally, the coolant passages 72 in each row are fluidly interconnected. The preformed insert 68 can include a coolant inlet 76 and a coolant outlet 78 for each coolant passage 72, which can optionally include tapered or other shaped expansion elements 80, 82 for dispersing the coolant passing therethrough. The preformed insert 68 can optionally include a coolant band 90 disposed within one or more of the coolant passages 72. The coolant band 90 can be a rigid structure for defining a coolant path for the coolant to flow through the coolant passage 72. The coolant band 90 can be divided into an upper portion 92 and a lower portion 94 such that coolant fluid can be conveyed through a respective one of the coolant inlets 76 to communicate through the upper portion 92, where the coolant then travels to the rear end of the associated coolant band 90, at which point the coolant can reverse direction to flow back toward the respective coolant outlet 78 positioned adjacent the associated lower portion 94. The material for forming the preformed insert 68 can consist of a thermally conductive material having a closed-cell foam structure or other types of materials suitable for conducting energy away from the battery cell 46. The potting material can be semi-rigid or less rigid than the housing 50 and / or the coolant band 90. The potting material can be dense and / or hard enough to facilitate a press fit with the battery cell 46 and / or otherwise support the battery cell 46 in the manner contemplated herein.

[0095] Returning to Figure 2, the coolant inlets and outlets 76, 78 may cooperate with the inlet and outlet coolant ports 86, 88 included within the battery cell retainer 50 to facilitate fluid connection of the coolant inlets and outlets 80, 82 with the flow control system 95. The flow control system 95 may include a flow manifold 97 operable to direct a coolant input 99 having coolant into the coolant channels 72 for creating a coolant flow therethrough. The flow control system 95 may include a diverter 101 operable to selectively meter the coolant passing through the input and output and thus the coolant flow through the respective coolant channels. For simplicity of presentation, the diverter 101 is shown as including two conduits 103, 105 for fluid interconnection with the inlets and outlets 76, 78 of the preformed insert 68, as the present disclosure fully contemplates the diverter 101 including additional conduits, optionally providing a separate conduit 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 diverter 101 may be operable to meter the coolant exchange with the inlets and outlets 76, 78 based on the temperature measured by the temperature sensors 107. Although some temperature sensors 107 are shown for simplicity of presentation, more diverse temperature sensors may be utilized to facilitate separately measuring the temperature at the battery cells 46, within the coolant channels 72, and / or elsewhere within the module 44. The flow control system 95 may include a flow controller (flow regulator) 109 operable to use the temperature measurements (optionally utilizing other vehicle-related metrics such as state of charge (SOC), mileage, motor demand, etc.) to correspondingly adjust the rate, amount, and / or other metering options of the coolant circulating through the coolant channels 72. This ability to selectively meter the coolant flow may be beneficial in enabling the flow control system 95 to affect the cooling of the battery cells in a manner that can be customized to maximize performance, efficiency, life, etc.

[0096] Figure 4A perspective view of a battery module 44A in accordance with a non-limiting aspect of the present disclosure is shown. The battery module 44A may be similar to the battery module described above with respect to including a battery cell holder 50 and a plurality of battery cells 46 positioned within a preformed insert 68. The battery module 44A is shown as including fewer battery cells 46 than in the battery module 44 described above, in order to demonstrate the advantageous ability of the present disclosure to support a modular construction, whereby a plurality of battery modules 44A may be joined together to form a RESS 30, such as a plurality of modules operating in series and / or in parallel together. The ability to selectively interconnect a plurality of battery modules 44A may be advantageous in customizing the size, capacity, etc. of the RESS 30 to fit a vehicle and / or other device employing its use. One aspect of the present disclosure contemplates that the preformed insert 68 may have different configurations depending on the desired manner in which coolant is circulated through the coolant channels 72. The ability to circulate coolant through the coolant channels 72 may be advantageous in providing an immersion cooling environment, whereby the coolant may be circulated relative to, and optionally in contact with, the battery cells 46 in order to optimize heat conduction and cooling. While the battery module 44A may include an inlet 86 and an outlet 88 leading to the coolant channels 72 in the manner described above, as an exemplary alternative, the battery module 44A may include a coolant inlet 86 at one end of the battery cell holder 50 and a coolant outlet 88 at the other end, such that the coolant flows through the preformed insert 68 in a front-to-back direction. As will be appreciated by those skilled in the art, the ability to circulate coolant, and thereby improve cooling on static or immovable fillers and heat sinks, is advantageous in restricting the operating temperature of the RESS 30, which may in turn improve the performance, efficiency, life, etc. of the battery cells 46.

[0097] Figure 5 A perspective view of a battery module 44A in accordance with a non-limiting aspect of the present disclosure is shown. The battery module 44A may be similar to the battery module described above with respect to including a battery cell holder 50 and a plurality of battery cells 46 positioned within a preformed insert 68. The battery module 44A is shown as including fewer battery cells 46 than in the battery module 44 described above, in order to demonstrate the advantageous ability of the present disclosure to support a modular construction, whereby a plurality of battery modules 44A may be joined together to form a RESS 30, such as a plurality of modules operating in series and / or in parallel together. The ability to selectively interconnect a plurality of battery modules 44A may be advantageous in customizing the size, capacity, etc. of the RESS 30 to fit a vehicle and / or other device employing its use. One aspect of the present disclosure contemplates that the preformed insert 68 may have different configurations depending on the desired manner in which coolant is circulated through the coolant channels 72. The ability to circulate coolant through the coolant channels 72 may be advantageous in providing an immersion cooling environment, whereby the coolant may be circulated relative to, and optionally in contact with, the battery cells 46 in order to optimize heat conduction and cooling. While the battery module 44A may include an inlet 86 and an outlet 88 leading to the coolant channels 72 in the manner described above, as an exemplary alternative, the battery module 44A may include a coolant inlet 86 at one end of the battery cell holder 50 and a coolant outlet 88 at the other end, such that the coolant flows through the preformed insert 68 in a front-to-back direction. As will be appreciated by those skilled in the art, the ability to circulate coolant, and thereby improve cooling on static or immovable fillers and heat sinks, is advantageous in restricting the operating temperature of the RESS 30, which may in turn improve the performance, efficiency, life, etc. of the battery cells 46. Figure 4Schematic side view of an intercepted section to show a preformed insert 68A having a split configuration. The split configuration may correspond to a preformed insert 68A having a two-piece structure, where an upper portion 90 is preformed separately from a lower portion 92, and an interlock 94 is configured to attach the upper portion 90 to the lower portion 92. The interlock 94 may include features adapted to seal, connect, or otherwise attach the upper and lower portions together such that coolant flowing through the respective coolant channels 72 can be retained therein. The interlock 94 may be operable to allow the lower portion 92 to be inserted into the battery cell holder 50 such that the battery cell 46 can be inserted into one of the corresponding battery cavities 70, after which the upper portion 90 can be assembled thereon. The interlock 94 may also be operable to allow the lower portion 90 to be inserted into the battery cell holder 50 such that the upper portion 90 can be assembled thereon, after which the battery cell 46 can be fitted into the battery cell cavity 70 after the preformed insert 68A is assembled. The battery cell cavity 70 may include an upper end 98 near the top of the battery cell 46 and a lower end 100 near the bottom of the battery cell 46. The preformed insert 68A may include an upper protrusion 102 and a lower protrusion 104, which are configured to provide an upper interference fit between the upper end 98 and the top of the battery cell 46 and a lower interference fit between the lower end 100 and the middle of the battery cell 46. The interference fit may be operable to retain the coolant within the respective coolant channels 72. The upper and lower ends 98, 100 of the battery cell cavity 70 may be narrower than the middle portion 106 such that the middle portion 106 can 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 cell 46 such that the battery cell cavity 70 can be dispersed relative to the coolant channels 72. The battery cell cavity 70 may be interconnected with the coolant channels 72 or formed as part of the coolant channels 72 such that the coolant circulating through the coolant channels 72 can physically contact the sides of the battery cell 46 before being conveyed through a tunnel portion connected to another one of the battery cell cavities 70. A bus bar or other circuit components 120 may be included for electrically interconnecting the battery cells 46 to each other.

[0098] The separate structure may also include a plurality of heat channels 121 that are preformed in the potting material to be operable independently of the coolant channel 72. The heat channels 121 may be separated from the coolant channel 72 by a separator or other feature 123 that is adapted to provide an interference fit, gasket, O-ring, or other seal capable of isolating the coolant flow from the hot fluid contained within the heat channels 121. The heat channels 121 may be configured to maintain the hot fluid independently of the coolant flow when the coolant temperature of the coolant flow is below a thermal threshold, which may be based, for example, on a temperature associated with a thermal event. The separator or other component 123 for sealingly isolating the coolant channel 72 from the heat channels 121 may be configured to automatically change shape, break down, or otherwise alter its structure or material structure when the coolant temperature there exceeds the thermal threshold. In such a case, the separator 123 may be configured to release the hot fluid into the coolant flow in an attempt to provide additional auxiliary cooling. The hot fluid may have cooling properties different from those of the coolant and may optionally have additional additives for providing chemical inhibitors, which may contribute to providing additional cooling beyond that provided by the coolant. The separator 123 may be a sacrificial type of component, whereby the release of the hot fluid may be irreversible as long as the separator cannot thereafter fluidically isolate the heat channels 121 from the associated coolant channel 72.

[0099] Module 44A may optionally include a coolant container 127 that is configured to enclose the preformed insert 68A and the battery cell 46 within a sealed housing. The flow control system 95 may include the coolant container 127 to facilitate additional circulation of the coolant external to the coolant channel 72, thereby providing additional immersion cooling of the battery cell 46. The coolant container 127 may be provided with sealed joints 129, 131 between the top member 60 and the bottom member 62 of the battery cell holder 50, or may be provided in the manner shown with a container top member 133 and a container bottom member 135, and used as an alternative or supplement thereto. The coolant container 127 may be formed and configured in such a way as to enclose the preformed insert 68A and the battery cell 46 within a sealed housing such that the coolant can circulate through the coolant channel 72 and auxiliary channels or spaces that are defined in relation to the preformed insert 68A, the bus bar 120, and other parts of the module 44A within the sealed housing. The diverter 101 may optionally be configured to meter the coolant through the auxiliary space independently of the cooling channels, for example via associated inlets and outlets (not labeled). The coolant container 127 may include a pressure relief valve 137 that is configured to release the coolant flow to the exterior of the sealed housing in response to the pressure within the sealed housing exceeding a pressure threshold. For example, the pressure relief valve 137 may be configured to automatically open the valve or release itself from the container top member when the pressure threshold is exceeded.

[0100] Figure 6 A cross-sectional view taken from Figure 4 is shown to illustrate a preformed insert 68B having an integral construction. The integral construction may be characterized in that the preformed insert 68B has a one-piece structure. Although the present disclosure contemplates an integral construction including a heat channel 121, the illustrated construction shows the heat channel 121 omitted in order to enlarge or provide a greater cross-sectional area for the coolant channel 72. The container top member and the container bottom members 133, 135 may similarly include container seals 129, 131 such that coolant may circulate through the coolant channel 72 and onto an auxiliary space to provide immersion cooling. Due to the immersion cooling, i.e., using coolant outside the coolant channel 72, the fit between the upper and lower ends of the preformed insert and the corresponding battery cells 46 may allow coolant to pass therethrough, which may facilitate the manufacture of the preformed insert 68B and the insertion of the battery cells 46 into the battery cell cavities 70. In cases where it may be desirable to separate the coolant channel 72 from the auxiliary space, seals (not shown) may be used to provide an upper interference fit between the upper end 98 and the top of the battery cell 46 and a lower interference fit between the lower end 100 and the bottom of the battery cell 46. The seals may be formed of rubber or other materials different from the potting material and are used to replace the above-described upper and lower protrusions to improve tolerance requirements, forming control, and / or other processes required to form the protrusions.

[0101] Figure 7 A cross-sectional view taken from Figure 4 is shown to illustrate a preformed insert 68C having an integral construction with a diverter 143. The diverter 143 may be part of a flow control system 95 and is disposed within the potting material for metering the coolant flow through a respective one of the coolant channels 72. The diverter 143 may be configured to contract from a nominal state to a smaller state in response to the coolant temperature in there exceeding a nominal temperature threshold. The diverter 143 may thus be configured to contract from a nominal state to a minimum state in response to the coolant temperature in there exceeding the nominal temperature threshold by a predetermined amount such that the nominal state causes the diverter 143 to block a greater portion of the coolant channel 72 than when in the minimum state, such that the nominal state restricts the coolant flow more than the minimum state. The diverter 143 may be constructed in this manner to serve as a temperature-driven component capable of changing its shape and dimensions or size in accordance with the temperature associated therewith. This ability to perform such self-regulation may be advantageous in enabling the diverter 143 to individually regulate the metering of the coolant circulating therethrough without the need for instructions or control from a flow controller. As shown, this ability may result in some diverters 143 having different dimensions relative to other diverters 143 depending on the corresponding temperature differences in there.

[0102] Figure 8 shows a cross-sectional view taken from Figure 4 to illustrate a preformed insert 68D having an integral construction with a helical channel 72A. The helical channel 72A can be configured to circulate coolant relative to the battery cell 46 in a circular manner, whereby the coolant flows from the top to the bottom or from the bottom to the top of a respective one of the battery cell cavities. The helical or circular movement of the coolant can be beneficial in providing a convective type of action that can be operative to facilitate cooling by guiding the coolant around the battery cell 46 through a plurality of loops or windings included with the potting material. The loops or windings can correspond to recesses etched in the battery cell cavity relative to other bumps 145 such that the potting material can intermittently press against or be in close proximity to the battery cell 46 from the top to the bottom. The helical channel 72A can optionally include seals, protrusions, or other elements to facilitate sealing the bumps 148 onto the respective battery cells 46 in order to maintain the desired directionality of the coolant flow. However, the present disclosure fully contemplates omitting the seals or the seals not being necessary since the helical action of the coolant can still be achieved even if some coolant is able to pass between the bumps 148 and the battery cells 46. Figure 9 shows a schematic side view of the helical channel 72A that guides the coolant flow relative to the surface of a respective one of the battery cells 46. The battery cells 46 can correspond to battery cells 46 aligned within the same row such that the coolant inlet 86 can be used to guide the coolant from the bottom to the top through the helical channel 72A of the first battery cell 46A, through the tunnel-like other structure 147 in the potting material to the second battery cell 46B, and then exchanged through the coolant outlet 88 from the top to the bottom relative to the second battery cell 46B. Figure 10 shows a perspective schematic view of the helical channel 72A that guides the coolant flow relative to the surface of a respective one of the battery cells 46.

[0103] Figure 11FIG. 140 is a flow chart of a method for manufacturing a battery module 44 in accordance with a non-limiting aspect of the present disclosure. Block 142 relates to a forming process in which a preformed insert 68 may be formed. The forming process may include: forming the preformed insert 68 such that the battery cell cavity 70 includes an upper end, a lower end, and an intermediate portion between the upper end and the lower end, wherein the upper end and the lower end are narrower than the intermediate portion and the intermediate portion defines a coolant passage 72. The forming process may include: forming the preformed insert 68C such that the battery cells 46 are arranged in multiple rows and the intermediate portions of the cavities 70 in each respective row are fluidly interconnected with each other to define the coolant passage 72. The forming process may include: forming the preformed insert 68 from a thermally conductive material having a closed cell foam structure. Block 144 relates to a process for receiving and / or manufacturing a battery cell holder 50. Block 146 relates to a process for receiving a plurality of battery cells 46. Block 148 relates to an assembly process for positioning the preformed insert 68 within the battery cell holder 50 and thereafter or therewith press-fitting or otherwise inserting the battery cells 46 into respective ones of the battery cell cavities 70. The assembly process may optionally be performed by securing the battery cells 46 within the preformed insert 68 and securing the preformed insert 68 within the battery cell holder 50 without using a potting epoxy or fluid adhesive.

[0104] As described above, the present disclosure relates to a preformed cell-to-cell barrier potting material that is molded with built-in channels having active and / or passive flow control valves, the built-in channels providing a direct cooling function for the cells in a battery module. The cell-to-cell barrier material can be formed as a part that can be assembled during battery module manufacturing to reduce manufacturing costs and cycle time by eliminating the need for an injection machine, inventory for potting cure times in an assembly line, etc. The potting material can be formed with built-in channels for dielectric coolant flow to enable immersion cooling without significant loss of a large coolant volume within the battery module. The potting material can be a preformed closed-cell foam material that provides thermal and electrical barriers between cells. The potting material can be shaped to surround coolant flow channels that replace cold plates and / or cooling straps and interface directly with the rest of the cooling system (pump, filter, hose, heat exchanger). The potting material can be shaped to form cavities for receiving cells and / or other types of energy units having cylindrical, prismatic, pouch-shaped, or other shapes and / or dimensions, with the coolant channels shaped relative thereto. Sensors and flow control valves (molded into the potting material at critical locations or placed externally) can be used to provide temperature information about the cells and coolant and direct the coolant to the hottest cells. A coolant containment plate can be used to seal the coolant within the cell retainer, cool the cells and bus bars, and include a pressure relief valve to vent gases released during a thermal event. A coolant channel having a passive bimetallic valve can be used as a diverter along the entire length of the channel and can be molded into the preformed potting and control flow (when the valve opens the channel, the hotter cells receive more flow; while when the valve partially closes the channel, the cooler cells receive less flow). Flow to different parts of the coolant channel can be actively controlled via an active flow control valve at the inlet manifold. The flow control valve can operate according to a logic based on information from temperature sensors, optionally where the flow control valve redirects more coolant flow to the hotter parts of the module and / or away from the cooler parts of the module.

[0105] Although various embodiments have been described, the description is intended to be exemplary rather than restrictive, and it will be apparent to those of ordinary skill in the art that more embodiments and implementations within the scope of the embodiments are possible. Unless specifically restricted, any feature of any embodiment may be used in combination with or substitute for any other feature or element in any other embodiment. Thus, the embodiments are not restricted except in accordance with the appended claims and their equivalents. Moreover, various modifications and changes can be made within the scope of the appended claims. Although several modes for carrying out many aspects of the teachings have been described in detail, those skilled in the art of the teachings will recognize various alternative aspects for practicing the teachings, which are within the scope of the appended claims. It is therefore intended that all content included in the foregoing description or shown in the accompanying drawings should be construed as illustrative and exemplary for the entire scope of alternative embodiments, and those of ordinary skill in the art will recognize that these alternative embodiments are implied by the content included, are structurally and / or functionally equivalent to the content included, or otherwise become apparent based on the content included, and should not be limited solely to those embodiments explicitly depicted and / or described.

Claims

1. A battery module, comprising: a plurality of battery cells configured to store and supply electric power; a battery cell holder configured to support the battery cells; a preformed insert disposed relative to the battery cell holder and the battery cells, the preformed insert including a potting material shaped to define a plurality of coolant channels for the battery cells; and a flow control system operable to control the coolant flow through the coolant channels.

2. The battery module according to claim 1, wherein: the flow control system includes a plurality of diverters disposed within the potting material, wherein the diverters are configured to meter the coolant flow through a respective one of the coolant channels.

3. The battery module according to claim 2, wherein: the diverters are configured to contract from a nominal state to a smaller state in response to the coolant temperature of the coolant flow therein exceeding a nominal temperature threshold.

4. The battery module according to claim 3, wherein: the diverters are configured to contract to a minimum state smaller than the nominal state in response to the coolant temperature of the coolant flow therein exceeding the nominal temperature threshold by a predetermined amount.

5. The battery module according to claim 4, wherein: the nominal state causes the diverters to block a greater portion of the coolant channels than when in the minimum state, such that the nominal state restricts the coolant flow more than the minimum state.

6. The battery module according to claim 1, wherein: the preformed insert includes a plurality of battery cell cavities fluidly interconnected with the coolant channels, wherein the battery cell cavities are shaped within the potting material to receive a respective one of the battery cells.

7. The battery module according to claim 6, wherein: the coolant channels are formed in a spiral shape around the battery cell cavities, wherein the spiral shape guides the coolant flow in a circular manner from the top to the bottom or from the bottom to the top of a respective one of the battery cell cavities.

8. The battery module according to claim 1, wherein: the flow control system includes a coolant container configured to enclose the preformed insert and the battery cells within a sealed housing, wherein the sealed housing is operable to direct the coolant flow through the coolant channels and around the battery cells to provide immersion cooling.

9. The battery module according to claim 8, wherein: the coolant container includes a pressure relief valve configured to release the coolant flow to the exterior of the sealed housing in response to the pressure within the sealed housing exceeding a pressure threshold.

10. The battery module according to claim 1, wherein: The preformed insert includes a plurality of thermal channels for the battery cells, wherein the thermal channels are configured to keep the thermal fluid separated from the coolant flow when the 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.

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