Patent Publication Number: US-2021167439-A1

Title: Thermal management system for a battery module

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/654,091, entitled “THERMAL MANAGEMENT SYSTEM FOR A BATTERY MODULE,” filed Apr. 6, 2018, and which is hereby incorporated by reference in its entirety for all purposes. 
    
    
     BACKGROUND 
     The present disclosure relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to a thermal management system for a battery module. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     A vehicle that uses one or more battery systems for providing all or a portion of the motive power for the vehicle can be referred to as an xEV, where the term “xEV” is defined herein to include all of the following vehicles, or any variations or combinations thereof, that use electric power for all or a portion of their vehicular motive force. For example, xEVs include electric vehicles (EVs) that utilize electric power for all motive force. As will be appreciated by those skilled in the art, hybrid electric vehicles (HEVs), also considered xEVs, combine an internal combustion engine propulsion system and a battery-powered electric propulsion system, such as 48 Volt (V) or 130V systems. The term HEV may include any variation of a hybrid electric vehicle. For example, full hybrid systems (FHEVs) may provide motive and other electrical power to the vehicle using one or more electric motors, using only an internal combustion engine, or using both. In contrast, mild hybrid systems (MHEVs) disable the internal combustion engine when the vehicle is idling and utilize a battery system to continue powering the air conditioning unit, radio, or other electronics, as well as to restart the engine when propulsion is desired. The mild hybrid system may also apply some level of power assist, during acceleration for example, to supplement the internal combustion engine. Mild hybrids are typically 96V to 130V and recover braking energy through a belt or crank integrated starter generator. Further, a micro-hybrid electric vehicle (mHEV) also uses a “Stop-Start” system similar to the mild hybrids, but the micro-hybrid systems of a mHEV may or may not supply power assist to the internal combustion engine and operates at a voltage below 60V. For the purposes of the present discussion, it should be noted that mHEVs typically do not technically use electric power provided directly to the crankshaft or transmission for any portion of the motive force of the vehicle, but an mHEV may still be considered as an xEV since it does use electric power to supplement a vehicle&#39;s power needs when the vehicle is idling with internal combustion engine disabled and recovers braking energy through an integrated starter generator. In addition, a plug-in electric vehicle (PEV) is any vehicle that can be charged from an external source of electricity, such as wall sockets, and the energy stored in the rechargeable battery packs drives or contributes to drive the wheels. PEVs are a subcategory of EVs that include all-electric or battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and electric vehicle conversions of hybrid electric vehicles and conventional internal combustion engine vehicles. 
     xEVs as described above may provide a number of advantages as compared to more traditional gas-powered vehicles using only internal combustion engines and traditional electrical systems, which are typically 12V systems powered by a lead acid battery. For example, xEVs may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to traditional internal combustion vehicles and, in some cases, such xEVs may eliminate the use of gasoline entirely, as is the case of certain types of EVs or PEVs. 
     As technology continues to evolve, there is a need to provide improved battery module components that are used in xEVs. For instance, battery modules include one or more battery cells that generate thermal energy (e.g., heat), which may increase a temperature within a housing of the battery module. Existing battery modules may include various features that transfer thermal energy from within the battery module to a heat sink and/or a surrounding environment of the battery module. Unfortunately, existing features may be inefficient at removing thermal energy from the battery module and/or may be expensive and complex to incorporate into the battery module. The present disclosure is generally related to features that improve heat dissipation from within a battery module housing. 
     SUMMARY 
     In an embodiment of the present disclosure, a battery system includes a housing configured to receive a battery cell, where the battery cell is configured to output thermal energy as a byproduct of electrical energy generation and/or consumption, a wall of the housing positioned proximate to the battery cell, and a plurality of fins extending from the wall, where the plurality of fins is configured to absorb thermal energy from the battery cell and dissipate the thermal energy to air, or a heat sink, or both, and where a fin of the plurality of fins comprises a channel configured to facilitate a flow of the air between the fin of the plurality of fins and an adjacent fin of the plurality of fins. 
     In an embodiment of the present disclosure, a battery system includes a housing configured to receive a battery cell, where the battery cell is configured to output thermal energy as a byproduct of electrical energy generation and/or consumption, a wall of the housing positioned proximate to the battery cell, a plurality of fins extending from the wall, where the plurality of fins is configured to absorb thermal energy from the battery cell and dissipate the thermal energy to air, or a heat sink, or both, and a projection extending from the wall and into an opening between adjacent fins of the plurality of fins. 
     In an embodiment of the present disclosure, a battery system includes a housing configured to receive a battery cell, where the battery cell is configured to output thermal energy as a byproduct of electrical energy generation and/or consumption, a wall of the housing positioned proximate to the battery cell, a plurality of fins extending from the wall, wherein the plurality of fins is configured to absorb thermal energy from the battery cell and dissipate the thermal energy to air, or a heat sink, or both, where a fin of the plurality of fins comprises a channel configured to facilitate a flow of the air between the fin of the plurality of fins and an adjacent fin of the plurality of fins, and a projection extending from the wall and into an opening between the fin and the adjacent fin of the plurality of fins. 
    
    
     
       DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is perspective view of a vehicle (an xEV) having a battery system contributing all or a portion of the power for the vehicle, in accordance with an embodiment of the present approach; 
         FIG. 2  is a cutaway schematic view of the xEV of  FIG. 1  in the form of a hybrid electric vehicle (HEV), in accordance with an embodiment of the present approach; 
         FIG. 3  is a perspective view of an embodiment of the battery system of  FIG. 1 , in accordance with an embodiment of the present approach; 
         FIG. 4  is a perspective view of an embodiment of a thermal management system for the battery system of  FIG. 1 , in accordance with an embodiment of the present approach; 
         FIG. 5  is a perspective view of an embodiment of the thermal management system for the battery system of  FIG. 1 , in accordance with an embodiment of the present approach; 
         FIG. 6  is a cross-section of an embodiment of the thermal management system of  FIG. 4 , in accordance with an embodiment of the present approach; and 
         FIG. 7  is a cross-section of an embodiment of the thermal management system of  FIG. 4 , in accordance with an embodiment of the present approach. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     The battery systems described herein may be used to provide power to various types of electric vehicles (xEVs) and other high voltage energy storage/expending applications (e.g., electrical grid power storage systems). Such battery systems may include one or more battery modules, each battery module having a number of battery cells (e.g., lithium-ion (Li-ion) electrochemical cells) arranged and electrically interconnected to provide particular voltages and/or currents useful to power, for example, one or more components of an xEV. As another example, battery modules in accordance with present embodiments may be incorporated with or provide power to stationary power systems (e.g., non-automotive systems). 
     Based on the advantages over traditional gas-power vehicles, manufacturers, which generally produce traditional gas-powered vehicles, may desire to utilize improved vehicle technologies (e.g., regenerative braking technology) within their vehicle lines. Often, these manufacturers may utilize one of their traditional vehicle platforms as a starting point. Accordingly, since traditional gas-powered vehicles are designed to utilize 12 volt battery systems, a 12 volt lithium ion battery may be used to supplement a 12 volt lead-acid battery. More specifically, the 12 volt lithium ion battery may be used to more efficiently capture electrical energy generated during regenerative braking and subsequently supply electrical energy to power the vehicle&#39;s electrical system. 
     As advancements occur with vehicle technologies, high voltage electrical devices requiring voltage higher than 12 volts may also be included in the vehicle&#39;s electrical system. For example, the lithium ion battery may supply electrical energy to an electric motor in a mild-hybrid vehicle. Often, these higher voltage electrical devices utilize voltage greater than 12 volts, for example, up to 48 volts. Accordingly, in some embodiments, the output voltage of a 12 volt lithium ion battery may be boosted using a DC-DC converter to supply power to the high voltage devices. Additionally or alternatively, a 48 volt lithium ion battery may be used to supplement a 12 volt lead-acid battery. More specifically, the 48 volt lithium ion battery may be used to more efficiently capture electrical energy generated during regenerative braking and subsequently supply electrical energy to power the high voltage devices. 
     Thus, the design choice regarding whether to utilize a 12 volt lithium ion battery or a 48 volt lithium ion battery may depend directly on the electrical devices included in a particular vehicle. Nevertheless, although the voltage characteristics may differ, the operational principles of a 12 volt lithium ion battery and a 48 volt lithium ion battery are generally similar. More specifically, as described above, both may be used to capture electrical energy during regenerative braking and subsequently supply electrical energy to power electrical devices in the vehicle. 
     Accordingly, to simplify the following discussion, the present techniques will be described in relation to a battery system with a 12 volt lithium ion battery and a 12 volt lead-acid battery. However, one of ordinary skill in art is able to adapt the present techniques to other battery systems, such as a battery system with a 48 volt lithium ion battery and a 12 volt lead-acid battery. 
     The present disclosure relates to batteries and battery modules. More specifically, the present disclosure relates to features of a battery module housing that are configured to improve dissipation of thermal energy (e.g., heat) generated by one or more battery cells positioned within the battery module housing. Particular embodiments are directed to lithium ion battery modules that may be used in vehicular contexts (e.g., hybrid electric vehicles) as well as other energy storage/expending applications (e.g., energy storage for an electrical grid). 
     With the preceding in mind, the present disclosure describes improved features of a battery module housing that increase dissipation of thermal energy (e.g., heat) from within the battery module housing. As set forth above, one or more battery cells disposed within the battery module housing generate thermal energy as a result or byproduct of chemical reactions that ultimately create electrical energy, which may be supplied to, or consumed by, a load (e.g., a vehicle). The thermal energy increases a temperature within the battery module housing. In some cases, the increased temperature may affect operation of various components (e.g., the battery cells and/or electrical components) within the housing. Embodiments of the present disclosure are related to features of a battery module housing that enhance the dissipation of thermal energy generated within the battery module housing. Specifically, embodiments of the present disclosure are directed to a grid of fins that increase an amount of thermal dissipation through natural convection (e.g., passive transfer of thermal energy). In some embodiments, the fins may include channels or grooves that facilitate a flow of air between openings formed by the fins and/or between the fins and a surrounding environment. Further, the fins may contact a heat sink (e.g., a steel plate, a thermally conductive metal, aluminum, copper, a chassis of a vehicle) that absorbs thermal energy from the fins and further enhances thermal energy dissipation. In some embodiments, the heat sink may include a thermally conductive metal, such as aluminum or copper, that is positioned proximate to, or coupled to, a portion of the battery module housing having the fins. The heat sink may include a shape that conforms to a cross-sectional shape of the battery module housing, which may include a rectangular shape, a triangular shape, a hexagonal shape, or any other suitable shape. 
     The grid of fins is configured to balance an amount of surface area contacting the heat sink, a stiffness of the fins for supporting the battery module housing, and/or an amount of features for facilitating air flow between the openings formed by the fins and/or between the fins and the surrounding environment. In some embodiments, the grid of fins is integral with the battery module housing, thereby facilitating assembly of the battery module and reducing costs. In any case, the grid of fins increases thermal energy dissipation from within the battery module housing, thereby increasing an efficiency of the battery module. 
     To help illustrate,  FIG. 1  is a perspective view of an embodiment of a vehicle  10 , which may utilize a regenerative braking system. Although the following discussion is presented in relation to vehicles with regenerative braking systems, the techniques described herein are adaptable to other vehicles that capture/store electrical energy with a battery, which may include electric-powered and gas-powered vehicles. 
     As discussed above, it would be desirable for a battery system  12  to be largely compatible with traditional vehicle designs. Accordingly, the battery system  12  may be placed in a location in the vehicle  10  that would have housed a traditional battery system. For example, as illustrated, the vehicle  10  may include the battery system  12  positioned similarly to a lead-acid battery of a typical combustion-engine vehicle (e.g., under the hood of the vehicle  10 ). Furthermore, as will be described in more detail below, the battery system  12  may be positioned to facilitate managing temperature of the battery system  12 . For example, in some embodiments, positioning a battery system  12  under the hood of the vehicle  10  may enable an air duct to channel airflow over the battery system  12  and cool the battery system  12 . 
     A more detailed view of the battery system  12  is described in  FIG. 2 . As depicted, the battery system  12  includes an energy storage component  14  coupled to an ignition system  16 , an alternator  18 , a vehicle console  20 , and optionally to an electric motor  22 . Generally, the energy storage component  14  may capture/store electrical energy generated in the vehicle  10  and output electrical energy to power electrical devices in the vehicle  10 . 
     In other words, the battery system  12  may supply power to components of the vehicle&#39;s electrical system, which may include radiator cooling fans, climate control systems, electric power steering systems, active suspension systems, auto park systems, electric oil pumps, electric super/turbochargers, electric water pumps, heated windscreen/defrosters, window lift motors, vanity lights, tire pressure monitoring systems, sunroof motor controls, power seats, alarm systems, infotainment systems, navigation features, lane departure warning systems, electric parking brakes, external lights, or any combination thereof. Illustratively, in the depicted embodiment, the energy storage component  14  supplies power to the vehicle console  20 , a display  21  within the vehicle, and the ignition system  16 , which may be used to start (e.g., crank) an internal combustion engine  24 . 
     Additionally, the energy storage component  14  may capture electrical energy generated by the alternator  18  and/or the electric motor  22 . In some embodiments, the alternator  18  may generate electrical energy while the internal combustion engine  24  is running. More specifically, the alternator  18  may convert the mechanical energy produced by the rotation of the internal combustion engine  24  into electrical energy. Additionally or alternatively, when the vehicle  10  includes an electric motor  22 , the electric motor  22  may generate electrical energy by converting mechanical energy produced by the movement of the vehicle  10  (e.g., rotation of the wheels) into electrical energy. Thus, in some embodiments, the energy storage component  14  may capture electrical energy generated by the alternator  18  and/or the electric motor  22  during regenerative braking. As such, the alternator  18  and/or the electric motor  22  are generally referred to herein as a regenerative braking system. 
     To facilitate capturing and supplying electric energy, the energy storage component  14  may be electrically coupled to the vehicle&#39;s electric system via a bus  26 . For example, the bus  26  may enable the energy storage component  14  to receive electrical energy generated by the alternator  18  and/or the electric motor  22 . Additionally, the bus  26  may enable the energy storage component  14  to output electrical energy to the ignition system  16  and/or the vehicle console  20 . Accordingly, when a 12 volt battery system  12  is used, the bus  26  may carry electrical power typically between 8-18 volts. 
     Additionally, as depicted, the energy storage component  14  may include multiple battery modules. For example, in the depicted embodiment, the energy storage component  14  includes a lead acid (e.g., a first) battery module  28  in accordance with present embodiments, and a lithium ion (e.g., a second) battery module  30 , where each battery module  28 ,  30  includes one or more battery cells. In other embodiments, the energy storage component  14  may include any number of battery modules. Additionally, although the first battery module  28  and the second battery module  30  are depicted adjacent to one another, they may be positioned in different areas around the vehicle. For example, the second battery module  30  may be positioned in or about the interior of the vehicle  10  while the first battery module  28  may be positioned under the hood of the vehicle  10 . 
     In some embodiments, the energy storage component  14  may include multiple battery modules to utilize multiple different battery chemistries. For example, the first battery module  28  may utilize a lead-acid battery chemistry and the second battery module  30  may utilize a lithium ion battery chemistry. In such an embodiment, the performance of the battery system  12  may be improved since the lithium ion battery chemistry generally has a higher coulombic efficiency and/or a higher power charge acceptance rate (e.g., higher maximum charge current or charge voltage) than the lead-acid battery chemistry. As such, the capture, storage, and/or distribution efficiency of the battery system  12  may be improved. 
     To facilitate controlling the capturing and storing of electrical energy, the battery system  12  may additionally include a control module  32 . More specifically, the control module  32  may control operations of components in the battery system  12 , such as relays (e.g., switches) within energy storage component  14 , the alternator  18 , and/or the electric motor  22 . For example, the control module  32  may regulate amount of electrical energy captured/supplied by each battery module  28  or  30  (e.g., to de-rate and re-rate the battery system  12 ), perform load balancing between the battery modules  28  and  30 , determine a state of charge of each battery module  28  or  30 , determine temperature of each battery module  28  or  30 , determine a predicted temperature trajectory of either battery module  28  and  30 , determine predicted life span of either battery module  28  or  30 , determine fuel economy contribution by either battery module  28  or  30 , determine an effective resistance of each battery module  28  or  30 , control magnitude of voltage or current output by the alternator  18  and/or the electric motor  22 , and the like. 
     Accordingly, the control module (e.g., unit)  32  may include one or more processors  34  and one or more memories  36 . More specifically, the one or more processors  34  may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Generally, the processor  34  may perform computer-readable instructions related to the processes described herein. Additionally, the processor  34  may be a fixed-point processor or a floating-point processor. 
     Additionally, the one or more memories  36  may include volatile memory, such as random access memory (RAM), and/or non-volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, or solid-state drives. In some embodiments, the control module  32  may include portions of a vehicle control unit (VCU) and/or a separate battery control module. Additionally, as depicted, the control module  32  may be included separate from the energy storage component  14 , such as a standalone module. In other embodiments, the battery management system (BMS) may be included within the energy storage component  14 . 
     In certain embodiments, the control module  32  or the processor  34  may receive data from various sensors  38  disposed within and/or around the energy storage component  14 . The sensors  38  may include a variety of sensors for measuring current, voltage, temperature, and the like regarding the battery module  28  or  30 . After receiving data from the sensors  38 , the processor  34  may convert raw data into estimations of parameters of the battery modules  28  and  30 . As such, the processor  34  may render the raw data into data that may provide an operator of the vehicle  10  with valuable information pertaining to operations of the battery system  12 , and the information pertaining to the operations of the battery system  12  may be displayed on the display  21 . The display  21  may display various images generated by device  10 , such as a GUI for an operating system or image data (including still images and video data). The display  21  may be any suitable type of display, such as a liquid crystal display (LCD), plasma display, or an organic light emitting diode (OLED) display, for example. Additionally, the display  21  may include a touch-sensitive element that may provide inputs to the adjust parameters of the control module  32  or data processed by the processor  34 . 
     The energy storage component  14  may have dimensions comparable to those of a typical lead-acid battery to limit modifications to the vehicle  10  design to accommodate the battery system  12 . For example, the energy storage component  14  may be of similar dimensions to an H6 battery, which may be approximately 13.9 inches×6.8 inches×7.5 inches. As depicted, the energy storage component  14  may be included within a single continuous housing. In other embodiments, the energy storage component  14  may include multiple housings coupled together (e.g., a first housing including the first battery  28  and a second housing including the second battery  30 ). In still other embodiments, as mentioned above, the energy storage component  14  may include the first battery module  28  located under the hood of the vehicle  10 , and the second battery module  30  may be located within the interior of the vehicle  10 . 
       FIG. 3  is a perspective view of an embodiment of the battery  28  that includes a first battery module terminal  50  and a second battery module terminal  52 . The battery module terminals  50 ,  52  are disposed on a battery module housing  54  and are electrically coupled to one or more battery cells disposed within a cavity of the housing  54 . As such, a load or a power supply may be coupled to the battery module terminals  50 ,  52 , such that the battery  28  supplies and/or receives electrical power. As shown in the illustrated embodiment of  FIG. 3 , the cavity of the housing  54  is sealed via a cover  56 . In some embodiments, the cover  56  is secured to the housing  54  via a weld (e.g., a laser weld), fasteners, another suitable technique, or a combination thereof. In any case, the cavity of the housing is substantially sealed (e.g., air-tight or water-tight) to block gases or fluids within the housing from leaking into an environment  58  surrounding the battery  28  and/or to block water or other contaminants from entering into the housing from the environment  58  surrounding the battery  28 . In some embodiments, the battery module housing  54  and/or the cover  56  may include a polymeric material, such as polypropylene, nylon, or another suitable material. Additionally, the polymeric material of the battery module housing  54  and/or the cover  56  may include an additive, such as a glass fiber additive. However, in other embodiments, the battery module housing  54  and/or the cover  56  may include any suitable material. 
     As discussed above, one or more battery cells disposed within the cavity of the housing  54  generate thermal energy to produce electrical energy, which is ultimately supplied to a load via the battery module terminals  50 ,  52 . Embodiments of the present disclosure are directed to an improved thermal energy management system  70  that increases an amount of thermal energy dissipation from within the battery module housing  54 . For example,  FIG. 4  is a perspective view of an embodiment of the thermal energy management system  70 . As shown in the illustrated embodiment of  FIG. 4 , the thermal energy management system  70  includes a plurality of fins  72  forming a grid-like structure on a portion  74  (e.g., bottom surface) of the battery module housing  54 . For example, the plurality of fins  72  include projections from the portion  74  of the housing  54 . The plurality of fins  72  form openings  76  that are configured to receive and/or otherwise enclose pockets of air. In some embodiments, the openings  76  receive air  78  from the environment  58  (e.g., outside air) surrounding the battery  28 , which may flow through channels or openings  79  formed in the portion  74  of the battery module housing  54  and absorb thermal energy from the fins  72 . Additionally or alternatively, a fan or other suitable device may be utilized to direct air from the environment  58  across the plurality of fins  72  and/or between the openings  76 . In other embodiments, the plurality of fins  72  may be isolated from the environment  58 . In such embodiments, air present within the openings  76  may flow across the plurality of fins  72  to adjacent openings  76 , thereby distributing thermal energy substantially evenly between the each of the openings  76 . 
     In some embodiments, the plurality of fins  72  is integrally formed with the battery module housing  54 . For example, the battery module housing  54 , and thus the plurality of fins  72 , may be formed via an injection molding technique. Integrally forming the plurality of fins  72  with the battery module housing  54  reduces manufacturing costs by eliminating an additional component that is included to dissipate heat from within the battery module housing  54 . Accordingly, the plurality of fins  72  and/or the portion  74  of the battery module housing  54  may include the same material as the battery module housing  54 , such as polypropylene, nylon, or another suitable material. Further as set forth above, the battery module housing  54 , and thus the plurality of fins  72  and/or the portion  74 , may include an additive within the polypropylene, nylon, or another suitable material, such as a glass fiber additive. 
     In some embodiments, the plurality of fins  72  include a plurality of channels  80  (e.g., grooves) that are formed within at least a portion  82  of one or more fins  72  of the plurality of fins  72 . As shown in the illustrated embodiment of  FIG. 4 , the channels  80  are formed on portions  82  of the plurality of fins  72  extending along an axis  84 . Additionally, portions  86  of the plurality of fins  72  extending along an axis  88 , crosswise to axis  84 , may also include the channels  80 . In other embodiments, the portions  86  of the plurality of fins  72  may not include the channels  80  and/or the portions  82  may not include the channels  80 . The number of channels  80  included within the plurality of fins  72  may be based on a desired stiffness of the plurality of fins  72 . For example, forming a large number of the channels  80  within the plurality of fins  72  may reduce the stiffness of the plurality of fins  72 , which may compromise the structural integrity of the battery module housing  54 . Accordingly, the number of channels  80  may be determined based on a stiffness of the plurality of fins  72  to maintain the structural integrity of the battery module housing  54 . 
     As shown, the channels  80  extend across a length  90  of the portions  82  and extend a depth  92  into the portions  82 . In some embodiments, the depth  92  of the channels  80  is between 0.1 millimeters (mm) and 2 mm, between 0.2 mm and 1 mm, or between 0.3 mm and 0.7 mm. In any case, the channels  80  are configured to facilitate a flow of air across each of the plurality of fins  72 . As such, thermal energy within a center  94  of the portion  74  of the housing  54  may be absorbed by ambient air and dissipated into the environment  58  surrounding the battery  28  and/or transferred to openings  76  further away from the center  94  of the portion  74  of the housing  54 . 
     In some embodiments, the battery module housing  54  may further include one or more projections  96  that extend from the portion  74  and into the openings  76 . The projections  96  may increase an amount of surface area exposed to air, thereby increasing an amount of thermal energy dissipated from within the housing  54 . As shown in the illustrated embodiment of  FIG. 4 , the projections  96  may include a substantially cylindrical shape. However, in other embodiments, the projections  96  may include other suitable polygonal shapes that increase a surface area of the thermal management system  70  exposed to air. Additionally or alternatively, the projections  96  may include a length that is less than a length of the plurality of fins  72 . As such, the projections  96  do not block a flow of air across the grid (e.g., between openings  76 ) formed by the plurality of fins  72 , thereby enabling an increased amount thermal energy transfer. In other embodiments, the projections  96  may include substantially the same (e.g., within 10% of, within 5% of, within 1% of) length as the plurality of fins  72 . In still further embodiments, the projections  96  may include another suitable length. 
     While the illustrated embodiment of  FIG. 4  shows the plurality of fins  72  having a substantially square shape (e.g., cross-sectional shape), it should be recognized that the plurality of fins  72  may include other suitable shapes (e.g., cross-sectional shapes). For instance,  FIG. 5  is a perspective view of an embodiment of the battery having the thermal management system  70  with cylindrical shaped fins  100  (e.g., circular cross-sectional shape). In still further embodiments, the plurality of fins  72  may include a cross-sectional shape that is circular, triangular, rectangular, square, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, another suitable polygonal shape, or a combination thereof. 
       FIG. 6  is a cross-section of the battery  28  having the thermal energy management system  70 . As shown in the illustrated embodiment of  FIG. 5 , the plurality of fins  72  extend from a wall  110  (e.g., a pad or the portion  74 ) positioned adjacent to a plurality of battery cells  112 . In some embodiments, the wall  110  may be integrally formed with the battery module housing  54  and include a thickness that is approximately (e.g., within 10% of, within 5% of, or within 1% of) 2 mm. In any case, the wall  110  absorbs thermal energy generated by the plurality of battery cells  112  and ultimately transfers the thermal energy to the plurality of fins  72 . As discussed above, air may flow across the plurality of fins  72  and absorb thermal energy from the plurality of fins  72 . In some cases, the thermal energy is dissipated to the environment  58 , while in other cases, the thermal energy is distributed to adjacent openings  76  formed by the plurality of fins  72 . In some embodiments, the plurality of fins  72  may extend a distance  114  (e.g., a length) from the wall  110 . For example, the distance  114  may be between 2 millimeters (mm) and 6 mm, between 2.5 mm and 5 mm, or between 3 mm and 4 mm. In other embodiments, the distance  114  may be approximately (e.g., within 10% of, within 5% of, or within 1% of) 3.88 mm. 
     Additionally, the plurality of fins  72  may include a thickness  116 . The thickness  116  of the plurality of fins  72  determines a surface area exposed to the ambient air as well as a surface area contacting a heat sink (see, e.g.,  FIG. 7 ). As such, the plurality of fins  72  dissipate thermal energy from within the battery module housing  54  via ambient air and through the heat sink. The thickness  116  of the plurality of fins  72  may be determined by balancing the various surface areas (e.g., a first surface area exposed to ambient air and a second surface area contacting the heat sink) to achieve a threshold amount of thermal energy transfer. Such determination may be made through experimental testing, models of existing data, and/or other suitable techniques. Further, in some embodiments, the thickness  116  of the fins  72  may vary throughout the distance  114  from the wall  110 . For instance, the thickness  116  may taper from the wall  110  toward distal ends  117  of the plurality of fins  72 . In such embodiments, a greater amount of thermal energy may be absorbed from the wall  110  by the plurality of fins  72 , thereby increasing an amount of thermal energy dissipation achieved by the plurality of fins  72 . Additionally or alternatively, the thickness  116  of the plurality of fins  72  may be substantially equal along a cross-section of each fin of the plurality of fins  72 . In other words, sides of the fins  72  that form the cross-sectional shape of the fins  72  may include substantially the same thickness  116  at any point along the distance  114 . 
     As shown in the illustrated embodiment of  FIG. 6 , the grid formed by the plurality of fins  72  may be substantially surrounded by a channel  118  formed around a perimeter of the portion  74  of the battery module housing  54 . In some embodiments, the channel  118  may receive ambient air from the environment  58  surrounding the battery  28  and enable the ambient air to be directed across the plurality of fins  72 , such that thermal energy from within the battery module housing  54  is absorbed and dissipated to the environment  58 . Additionally or alternatively, the channel  118  provide structural support to the battery module housing  54  by providing a buffer between the grid formed by the plurality of fins  72  and a perimeter of the battery module housing  54 . 
       FIG. 7  is a cross-section of an embodiment of the battery  28  having the thermal management system  70 . As shown in the illustrated embodiment of  FIG. 7 , the battery module housing  54  is disposed on a heat sink  140  (e.g., a steel plate, a metallic sheet, a chassis of a vehicle, copper, aluminum, or another conductive material). As such, the plurality of fins  72  contact, or are otherwise adjacent to, the heat sink  140 . The heat sink  140  absorbs thermal energy from the plurality of fins  72  and/or the air flowing across the plurality of fins  72 . Accordingly, the thermal management system  70  enables thermal energy to be transferred to both the heat sink  140  and to air within the openings  76 , thereby increasing an amount of thermal energy dissipation and increasing an efficiency of the battery  28 . 
     One or more of the disclosed embodiments, alone or in combination, may provide one or more technical effects including enhancing thermal energy dissipation from a battery module housing. In particular, a battery module housing includes a grid-like structure formed by a plurality of fins. The fins may include a channel that facilitates air flow between openings formed by the fins, thereby distributing thermal energy throughout the grid-like structure. In some embodiments, ambient air may flow into the openings formed by the plurality of fins to further increase thermal energy dissipation from within the battery module housing. Further, a heat sink may be utilized to absorb thermal energy from the plurality of fins and/or air within the openings formed by the fins. In any case an amount of thermal energy dissipated from within the battery module housing is increased, thereby enhancing an efficiency of the battery module. The technical effects and technical problems in the specification are exemplary and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems. 
     The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.