Patent Description:
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. 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. 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. 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'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 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.

In addition to use in vehicles (e.g., vehicles, boats, trucks, motorcycles, and airplanes), advances in battery technology and rechargeable batteries are more frequently being used in what may be referred to as stationary battery applications. Applications for stationary batteries, which are often used in backup or supplemental power generation, are becoming more widespread with improvements in rechargeable aspects of batteries and with the lowering of prices for such technology. For example, stationary batteries may be utilized for industrial and/or household applications. Such applications may include DC power plants, substations, back-up power generators, transmission distribution, solar power collection, and grid supply.

Batteries, such as lithium ion batteries, are sensitive to low and high temperatures. Thus, it is important to regulate the cells and battery packs to remain in a desired temperature range for optimum performance and life. It is also important to reduce uneven distribution of temperature throughout a battery pack, which could lead to reduced performance. Likewise, it is important to eliminate or reduce the potential for uncontrolled temperature buildup or thermal runaway. Accordingly, a device or system for thermal management is desired.

One common device for use in thermal management is a heat sink. Current devices use screws or other fixation devices or over-molding a heat sink in order to capture the heat sink in a plastic battery housing. Unfortunately, screws and fixation devices risk damaging the cell should an overheating event or impact event occur. Further, in known over-molding processes issues arise during the manufacturing process, namely, trying to retain a heat sink in place while over-molding the plastic battery housing. For example, molding pressures may cause the heat sink to shift in the molding tool.

For example, <CIT> relates to such a conventional Lithium ion battery module comprising a heat sink overmolded by a container such that the heat sink is retained in a portion of the container and exposed along a bottom portion of the container. The container includes an electrically non-conductive polymeric material with a nanomaterial enhancing the impermeability applied to the polymeric material. The inside of the container may comprise a metalized coating for increasing the thermal conductivity.

<CIT> is directed to a conventional battery pack with a heat sink, which is received within and secured to an inner surface of the bottom wall. Specifically, the heat sink is fixed or embedded in the bottom wall.

<CIT> relates to a conventional battery module having a radiation plate that is set between stacked battery cells to discharge heat radiated from a battery cell to the outside. The radiation plate is fixed by injection molding.

<CIT> is directed to an injection-molded battery case comprising a casing frame structure, a high-heat-conducting heat sink fixed to the casing frame structure by injection molding. The casing frame structure and the high-heat-conducting heat sink are both made from plastic material.

Therefore, a need exists for a battery module, battery housing, and system having a heat sink, as well as a method of manufacturing or installation of a heat sink which meets the needs of thermal management and overcomes one or more of the deficiencies of prior devices and processes.

For example, the disclosed heat sink and fixation method allow for the battery housing material to melt over the heat sink for robust connection between the heat sink and battery housing. Further, the disclosed in various embodiments allow for ease of manufacture. In addition, the disclosed allows for no extraneous fixation devices such as screws to be introduced into the battery housing, preventing risks of puncture and damage to battery cells (which may be a particular risk when the battery used is in a vehicle and an accident or impact occurs).

These and other features and advantages of devices, systems, and methods are described in, or are apparent from, the following detailed descriptions and drawings of various examples of embodiments.

Various examples of embodiments of the systems, devices, and methods will be described in detail, with reference to the following figures, wherein:.

In certain instances, details that are not necessary to the understanding of the invention or render other details difficult to perceive may have been omitted. For ease of understanding and simplicity, common numbering of elements within the numerous illustrations is utilized when the element is the same in different Figures. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

Referring to the Figures, a heat sink, a battery housing, a battery module, a system, and a method for fixation of a heat sink in a battery and a battery housing are disclosed.

The battery, battery module, and 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 a 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-powered vehicles, manufactures, 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. In accordance with aspects of the present disclosure, since traditional gas-powered vehicles are designed to utilize <NUM> volt battery systems, a <NUM> volt or <NUM> volt lithium ion battery may be used to supplement a <NUM> volt lead-acid battery. More specifically, the <NUM> volt or <NUM> 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's electrical system.

As advancements occur with vehicle technologies, high voltage electrical devices may also be included in the vehicle's electrical system. For example, the lithium ion battery may supply electrical energy to an electric motor in a mild-hybrid vehicle. Often, these high voltage electrical devices utilize voltage greater than <NUM> volts, for example, up to <NUM> volts. Accordingly, in some embodiments, the output voltage of a <NUM> volt lithium ion battery may be boosted using a DC-DC converter to supply power to the high voltage devices. Additionally or alternatively, a <NUM> volt lithium ion battery may be used to supplement a <NUM> volt lead-acid battery. More specifically, the <NUM> 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.

To help illustrate, <FIG> is a perspective view of an embodiment of a vehicle <NUM>. As discussed above, it would be desirable for a battery system <NUM> to be largely compatible with traditional vehicle designs. Accordingly, the battery system <NUM> may be placed in a location in the vehicle <NUM> that may house a traditional battery system. For example, as illustrated, the vehicle <NUM> may include the battery system <NUM> positioned similarly to a lead-acid battery of a typical combustion-engine vehicle (e.g., under the hood of the vehicle <NUM>). Furthermore, as will be described in more detail below, the battery system <NUM> may be positioned to facilitate managing temperature of the battery system <NUM>. For example, in some embodiments, positioning a battery system <NUM> under the hood of the vehicle <NUM> may enable an air duct to channel airflow over the battery system <NUM> and cool the battery system <NUM>. While specific examples of locations are described, one of skill in the art will appreciate that variations thereon would also be acceptable for the purposes provided.

In other words, the battery system <NUM> may supply power to components of the vehicle'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 <NUM> supplies power to the vehicle console <NUM> and the ignition system <NUM>, which may be used to start (e.g., crank) the internal combustion engine <NUM>.

Additionally, the energy storage component <NUM> may capture electrical energy generated by the alternator <NUM> and/or the electric motor <NUM>. In some embodiments, the alternator <NUM> may generate electrical energy while the internal combustion engine <NUM> is running. More specifically, the alternator <NUM> may convert the mechanical energy produced by the rotation of the internal combustion engine <NUM> into electrical energy. Additionally or alternatively, when the vehicle <NUM> includes an electric motor <NUM>, the electric motor <NUM> may generate electrical energy by converting mechanical energy produced by the movement of the vehicle <NUM> (e.g., rotation of the wheels) into electrical energy. Thus, in some embodiments, the energy storage component <NUM> may capture electrical energy generated by the alternator <NUM> and/or the electric motor <NUM> during regenerative braking. As such, the alternator <NUM> and/or the electric motor <NUM> are generally referred to herein as a regenerative braking system.

To facilitate capturing and supplying electric energy, the energy storage component <NUM> may be electrically coupled to the vehicle's electric system via a bus <NUM>. For example, the bus <NUM> may enable the energy storage component <NUM> to receive electrical energy generated by the alternator <NUM> and/or the electric motor <NUM>. Additionally, the bus <NUM> may enable the energy storage component <NUM> to output electrical energy to the ignition system <NUM> and/or the vehicle console <NUM>. Accordingly, when a <NUM> volt battery system <NUM> is used, the bus <NUM> may carry electrical power typically between <NUM>-<NUM> volts.

Additionally, as depicted, the energy storage component <NUM> may include multiple battery modules. For example, in the depicted embodiment, the energy storage component <NUM> includes a lithium ion (e.g., a first) battery module <NUM> in accordance with present embodiments, and a lead-acid (e.g., a second) battery module <NUM>, where each battery module <NUM>, <NUM> includes one or more battery cells <NUM>. In other embodiments, the energy storage component <NUM> may include any number of battery modules. Additionally, although the lithium ion battery module <NUM> and lead-acid battery module <NUM> are depicted adjacent to one another, they may be positioned in different areas around the vehicle. For example, the lead-acid battery module <NUM> may be positioned in or about the interior of the vehicle <NUM> while the lithium ion battery module <NUM> may be positioned under the hood of the vehicle <NUM>.

In some embodiments, the energy storage component <NUM> may include multiple battery modules to utilize multiple different battery chemistries. For example, when the lithium ion battery module <NUM> is used, performance of the battery system <NUM> 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 <NUM> may be improved.

To facilitate controlling the capturing and storing of electrical energy, the battery system <NUM> may additionally include a control module <NUM>. More specifically, the control module <NUM> may control operations of components in the battery system <NUM>, such as relays (e.g., switches) within energy storage component <NUM>, the alternator <NUM>, and/or the electric motor <NUM>. For example, the control module <NUM> may regulate amount of electrical energy captured/supplied by each battery module <NUM> or <NUM> (e.g., to de-rate and re-rate the battery system <NUM>), perform load balancing between the battery modules <NUM> and <NUM>, determine a state of charge of each battery module <NUM> or <NUM>, determine temperature of each battery module <NUM> or <NUM>, control voltage output by the alternator <NUM> and/or the electric motor <NUM>, and the like.

Accordingly, the control unit <NUM> may include one or more processor <NUM> and one or more memory <NUM>. More specifically, the one or more processor <NUM> 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. Additionally, the one or more memory <NUM> 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 unit <NUM> may include portions of a vehicle control unit (VCU) and/or a separate battery control module.

In accordance with the present disclosure, the housing <NUM> of the battery module <NUM> includes one or more covers <NUM>, <NUM> configured to seal or cover the housing <NUM>. For example, referring to <FIG>, the housing <NUM> may include a lateral cover <NUM> that fits over a lateral side <NUM> of the housing <NUM>, where the lateral side <NUM> of the housing <NUM> retains, for example, a printed circuit board (PCB) and other electrical components (not shown) of the battery module <NUM>. An upper cover <NUM> may be disposed over the upper side <NUM> of the housing <NUM> to seal or cover the upper side <NUM> of the housing <NUM>. The upper cover <NUM> of the housing <NUM> may include various features, such as but not limited to, a handle for transport and/or a vent path which allows the scape of gases or fluids, and the like (not shown).

In accordance with embodiments of the present disclosure, the battery module <NUM> may include a housing <NUM> (e.g., plastic housing) configured to retain electrochemical cells <NUM> (e.g., prismatic lithium-ion [Li-ion] electrochemical cells) within an inside of the housing <NUM> (see <FIG>). The housing <NUM> illustrated and described herein may contain multiple stacks of prismatic lithium-ion (Li-ion) electrochemical cells <NUM>. The battery module <NUM> may include any number of electrochemical cells <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more electrochemical cells), any type of electrochemical cell (e.g., Li-ion, lithium polymer, lead-acid, nickel cadmium, or nickel metal hydride, prismatic, and/or cylindrical), and any arrangement of the electrochemical cells <NUM> (e.g., stacked, separated, or compartmentalized).

As will be discussed herein, battery elements or electrochemical cells <NUM> may be provided atop a heat sink <NUM>. The electrochemical cells <NUM> may include terminals <NUM>. The electrochemical cells <NUM> may be inserted into the housing <NUM> through the openings <NUM> in the upper side <NUM> of the housing <NUM>, and positioned within the housing <NUM> such that the terminals <NUM> of the electrochemical cells <NUM> are disposed in the opening. A bus bar carrier (not shown) may be disposed into the opening and may retain bus bars (not shown) disposed thereon, where the bus bars are configured to interface with the terminals <NUM> of the electrochemical cells <NUM>. For example, the bus bars may interface with the terminals <NUM> to electrically couple adjacent electrochemical cells <NUM> together. Depending on the embodiment, the bus bars may couple the electrochemical cells <NUM> in series, in parallel, or some of the electrochemical cells <NUM> in series and some of the electrochemical cells <NUM> in parallel. Further, certain of the bus bars may be configured to electrically couple the electrically interconnected group of electrochemical cells <NUM> with major terminals <NUM> of the battery module <NUM>, where the major terminals <NUM> are configured to be coupled to a load (e.g., component(s) of the vehicle <NUM>) to power the load. The electrochemical cells <NUM> may also include vents <NUM> configured to enable gases from within the electrochemical cells <NUM> to vent into the inside of the housing <NUM> in certain operating conditions (e.g., if a pressure within one or more individual electrochemical cell exceeds a cell venting pressure threshold of the corresponding one or more individual electrochemical cells).

The use of plastics may be desirable for use in lithium ion battery modules. For instance, plastics are usually considered lightweight, water resistant, and may be constructed to have strengths that approach or even exceed certain metal constructions. Thermoplastics are a type of plastic material that becomes pliable when subjected to a temperature above a predefined threshold (based on the particular thermoplastic material) to allow plastic deformation and melting. This temperature may be referred to as the glass transition temperature (Tg). When a thermoplastic is below its Tg, it is solid. Thermoplastics are generally considered to be resistant to shrinkage, durable, and strong. Accordingly, in one or more examples of embodiments, the battery module <NUM> may include a housing <NUM> that is constructed of thermoplastic.

Referring to <FIG>, one or more examples of a battery housing <NUM> are shown. The battery housing <NUM> comprises an enclosure having a plurality of exterior walls <NUM>, e.g., four exterior walls, and a base <NUM> or bottom. In some examples of embodiments, the battery housing <NUM> may be divided into a plurality of battery compartments or sections <NUM>. In the illustrated embodiment, the battery housing <NUM> is divided into four internal sections <NUM> by a number of interior walls <NUM>. As shown, an internal section <NUM> is made up of at least two interior walls <NUM> or interior wall segments <NUM>, and an interior surface or portion <NUM> of the at least two exterior walls <NUM> or exterior wall segments. While four internal sections <NUM> are shown, it is understood that any number of internal sections may be provided, namely, one or more, without departing from the disclosure herein. The battery housing <NUM> may be comprised of material such as, but not limited to, polypropylene.

A heat sink <NUM> is provided on the base <NUM> or bottom surface <NUM> of an internal section <NUM> of the housing <NUM>. To this end, one or more heat sinks <NUM> may be provided in the battery housing <NUM>. In the illustrated examples, a heat sink <NUM> is shown along a bottom surface <NUM> of each internal section <NUM>. As shown in <FIG>, the heat sink <NUM> illustrated in the examples of embodiments shown in <FIG> is generally a planar, flat plate having a width (w) and length (l) corresponding to the width and length of the internal section <NUM>, such that the heat sink <NUM> extends to the walls <NUM>, <NUM>, <NUM>, <NUM> forming the internal section <NUM>. That is, when installed in the housing <NUM> the heat sink(s) <NUM> are positioned along a bottom interior surface <NUM> of the battery housing <NUM> and span from and between the interior walls <NUM> and exterior walls <NUM>. The heat sink <NUM> may be constructed of known materials capable of delivering the functions of a heat sink. For example, the heat sink <NUM> may be an aluminum plate. However, it is understood that various materials may be used to accomplish these functions and the foregoing is presented as an example only.

In one or more examples of embodiments, the battery housing <NUM> may further comprise one or more, or a plurality of ribs <NUM> (see <FIG>). In one or more examples of embodiments, the ribs <NUM> are formed integral with the housing <NUM> and may be formed of the same material as the housing <NUM>. A rib <NUM> extends along the bottom interior edge of one or more of the exterior walls <NUM> and bottom edge of one or more of the interior walls <NUM>. In the illustrated embodiment, a plurality of ribs <NUM> are provided in each internal section <NUM>. In one example, the ribs <NUM> are provided on opposing wall surfaces such that they are spaced apart and may be generally parallel to each other on opposite sides of the internal section <NUM>. However, it is understood that the ribs <NUM> may be provided at any location and orientation suitable for accomplishing the intended purposes. The ribs <NUM> retain or assist in retaining a heat sink <NUM> in place on the bottom surface <NUM> of the housing <NUM>. More specifically, the ribs <NUM> are plastically deformed ribs which retain the heat sink <NUM> in position. Namely, when the heat sink <NUM> is installed, the ribs <NUM> may generally have a partial "mushroom" shape which connects to the bottom surface <NUM> of the housing <NUM>, surrounds an edge (or both edges) of the heat sink <NUM>, and extends over a portion of the top surface of the heat sink <NUM>. In this manner, the ribs <NUM> fix the heat sink <NUM> completely to the housing <NUM>.

While specific examples of shapes and materials and locations are described, variations and combinations of suitable materials, shapes and configurations, should likewise be understood as within the scope of the disclosure.

As discussed herein, one or more battery cells <NUM> may be provided into each internal section <NUM> (see example shown in <FIG>). In one or more examples of embodiments, the battery cells <NUM> may be provided seated above or on top of the heat sink <NUM>. In some examples of embodiments, the cells <NUM> may also be electrically isolated from the heat sink <NUM>, for example, using an isolation component <NUM>. In <FIG>, an isolation component <NUM> is illustrated in cross-section. Generally, the isolation component <NUM> may be sheet or other device providing a separation between the battery cells <NUM> and the bottom surface <NUM> of the housing <NUM> and/or the attached heat sink <NUM>. This isolation sheet <NUM> may also impart certain structural advantages such as, but not limited to, more consistent attachment to the battery housing <NUM>.

Referring to <FIG>, a system and method of installation of the heat sink <NUM> into the battery housing <NUM> described in <FIG> will be discussed. Accordingly, a battery housing <NUM> may be provided. First, the heat sink <NUM>, which may be a planar plate, may be installed onto or attached to a heating fixture <NUM>. In various embodiments, the heating fixture <NUM> is a fixture or heater suitably sized and configured to deliver heat to sufficiently heat the heat sink <NUM> for the purposes disclosed herein. The heating fixture <NUM> may be heated to a suitable temperature to heat the heat sink <NUM> plate to a temperature which may induce at least partial melting or plastic deformation of the housing material in the internal section <NUM> (such as for example a rib <NUM> or surface <NUM> or wall <NUM>, <NUM>). The melting temperature may be a temperature sufficient to heat the plastic or thermoplastic but not warp the heat sink <NUM>. For example, in various embodiments, the heating element may be at least <NUM> degrees Celsius. The heat sink <NUM> is placed on the heating fixture <NUM>. In one or more examples of embodiments, the heating fixture <NUM> may be comprised of a tool-grade stainless steel block, although variations thereon which accomplish the purposes provided would also be acceptable. While specific examples are provided, one of skill in the art will appreciate variations thereon may also be acceptable.

Next, the heating fixture <NUM> and the plate or heat sink <NUM> may be provided into (e.g., lowered) into the battery housing <NUM>. The plate <NUM> and fixture <NUM> are provided together into a battery housing <NUM> and pressed into the battery housing <NUM>. As shown in the illustrated example of <FIG>, the heat sink <NUM> remains attached to the fixture <NUM> when inserted into the battery housing <NUM>. Insertion is made into an internal section <NUM> of the battery housing <NUM>. The heat from the fixture <NUM> may then transfer through the plate (heat sink <NUM>) and into the battery housing <NUM>, melting the plastic (for example, but not limited to, polypropylene or thermoplastic), and creating a robust joint between the heat sink plate <NUM> and battery housing <NUM>. That is, the heating fixture <NUM> may at least partially melt the battery housing <NUM> in the internal section <NUM>, for example, the battery housing ribs <NUM> and/or bottom surface. As the heat sink <NUM> is provided in the battery housing <NUM>, the battery housing material may be understood to melt slightly, allowing for the plastic material, such as the rib, to "mushroom" over a portion of the top surface of the heat sink <NUM> or plastically deform and fasten the heat sink <NUM> in place. In some examples of embodiments, an amount of force may be applied by the fixture <NUM> and heat sink <NUM> plate being pressed into the battery housing <NUM>, toward the bottom of the housing <NUM>, which, along with the application of heat presses the plate into the bottom surface plastic and causes the melting rib to mushroom over the heat sink <NUM>. After a predetermined amount of time, the fixture <NUM> is then raised or removed from the housing <NUM>, leaving the heat sink <NUM> attached to the bottom of the battery housing <NUM>. In some examples of embodiments, an isolation component or sheet <NUM> may subsequently be provided to separate the heat sink <NUM> and battery element or cell(s) <NUM>.

The assembly of heat sink <NUM> to housing <NUM> described hereinabove, in various embodiments, simplifies the joint between the battery housing <NUM> and heat sink <NUM>. The consistent interface between the heat sink <NUM> and battery housing <NUM> also optimizes heat transfer from the heat sink <NUM> to the battery housing <NUM> and out to the external environment.

One or more alternative examples of embodiments are shown in <FIG> with like elements including like reference numerals. In the alternative embodiments shown, a battery housing <NUM> having exterior walls <NUM> and a base <NUM> or bottom is illustrated. One or more interior walls <NUM> may also be provided, forming one or more internal sections <NUM>. In various embodiments, the battery housing <NUM> may also optionally include one or more ribs <NUM>, for example, but not limited to, bottom ribs <NUM>.

In <FIG>, one or more alternative examples of a heat sink <NUM> are provided within the battery housing <NUM>, and in particular within the internal sections <NUM>. As illustrated, one or more heat sink(s) <NUM> are aligned along a bottom surface <NUM> of housing <NUM> or internal sections <NUM>. Referring to <FIG>, the heat sink(s) <NUM> may have a first wall segment <NUM> and an opposing second wall segment <NUM>, each segment extending at an angle from and spaced apart by a bottom segment <NUM>. Each wall segment <NUM>, <NUM> and the bottom segment <NUM> may be generally planar. The first wall segment <NUM> and second wall segment <NUM> may extend generally perpendicularly from the bottom segment <NUM>. In some examples, the respective segments <NUM>, <NUM>, <NUM> may be integrally connected; that is, formed as a single unit. Accordingly, the heat sink <NUM> may be generally U-shaped. As a result, when the heat sink <NUM> is inserted into the housing <NUM> as shown in <FIG>, that first wall segment <NUM> and second wall segment <NUM> on the two sides of the heat sink <NUM> may abut or be positioned adjacent to the walls of the housing <NUM> making up an internal section <NUM> of the battery housing <NUM>. In the illustrated embodiment the first wall segment <NUM> is positioned against or abuts an interior portion <NUM> of the exterior wall <NUM> and the second wall segment <NUM> is positioned against or abuts a surface of segment <NUM> of the interior wall <NUM>. The first wall segment <NUM> and second wall segment <NUM> of the heat sink <NUM> may extend along at least a portion of the interior of each wall <NUM>, <NUM>. The first wall segment <NUM> and second wall segment <NUM> have a height which is shorter than the height of the exterior wall <NUM>. <FIG> illustrates four U-shaped heat sinks <NUM> provided into a battery housing <NUM>.

Referring to <FIG>, a system and method of installation of the alternative examples of embodiments of a heat sink <NUM> into the battery housing <NUM> described in <FIG> will be discussed. Accordingly, a battery housing <NUM> may be provided. Similar to the embodiments described in reference to <FIG>, in step (A) first the heat sink <NUM>, which may be a U-shaped plate, may be installed onto or attached to a heating fixture <NUM>. Next, the heating fixture <NUM> and the heat sink <NUM> plate may be provided into (e.g., lowered) into the battery housing <NUM>. The heat sink <NUM> plate and fixture <NUM> are provided together into a battery housing <NUM> and pressed into the battery housing <NUM>. As shown in the illustrated example of <FIG>, the heat sink <NUM> remains attached to the heating fixture <NUM> when inserted into the battery housing <NUM>. Insertion is made into an internal section <NUM> of the battery housing <NUM>. The heat from the fixture <NUM> may then transfer through the plate (heat sink <NUM>) and into the battery housing <NUM>, melting the plastic (for example, but not limited to, polypropylene), plastically deforming the material and at least partially affixing the heat sink <NUM> plate and battery housing <NUM>. In other words, the heating fixture <NUM> presses the bottom of the heat sink <NUM> into the plastic battery housing <NUM>. The heat transfer from the fixture <NUM> through the heat sink <NUM> melts the battery housing plastic to create a solid joinder or bond between the battery housing <NUM> and heat sink <NUM>.

However, unlike the embodiment shown in <FIG>, in the presently described examples, as shown in step (B) a second heating fixture <NUM> may be introduced into the battery housing <NUM>. The second heating fixture <NUM> with a tapered profile is moved into the internal section <NUM> of the housing <NUM> and the heat sink <NUM> and forces the vertical walls or wall segments <NUM>, <NUM> of the heat sink <NUM> outwards through the same pressure and heat transfer method described above. As shown in <FIG>, the second heating fixture <NUM> may have a larger width than the first heating fixture <NUM>. The second heating fixture <NUM> may also have tapered sidewalls <NUM> which taper inwardly toward the insertion end <NUM> of the heating fixture. In the illustrated embodiment, only a portion of each sidewall <NUM> is tapered. The second heating fixture <NUM> taper and increased width enables the fixture <NUM> to press against the first and second segments <NUM>, <NUM> of the heat sink <NUM>, which are generally vertical walls in the illustrated examples, when the second fixture <NUM> is inserted (Note: <FIG> illustrates this concept in an exaggerated manner and shows the heat sink and fixture <NUM> elevated from the bottom of the internal section <NUM> for ease of visibility). Because of the taper, width, and heat, the fixture <NUM> forces the heat sink <NUM> first and second segments <NUM>, <NUM> outwards into battery housing material. That is, insertion of the second heating fixture <NUM>, while heated, presses the sidewalls or first wall segment <NUM> and second wall segment <NUM> of the heat sink <NUM> into the walls <NUM>, <NUM> of the battery housing <NUM>, e.g., the exterior wall <NUM> and interior wall <NUM>, allowing for plastic to plastically deform and spread or mushroom over a portion of the heat sink <NUM>. The heat sink <NUM> may then be attached or at least partially embedded into the walls of the battery housing <NUM>. The second heating fixture <NUM> may then be removed (see <FIG>). Finally, in some examples of embodiments, an isolation component or sheet <NUM> may be provided to separate the housing <NUM> and/or heat sink <NUM> from an inserted battery element or cell <NUM> (see <FIG>).

The heating fixture <NUM>, <NUM> carries the heat sink <NUM> and transfers heat into the battery housing <NUM> through the heat sink <NUM>. The heating fixture <NUM>, <NUM>, in various embodiments, may therefore comprise a block having two dimensions (w) (l) which are the same approximate dimensions as the heat sink <NUM>, or slightly larger than the heat sink <NUM>. In one or more examples of embodiments, the heating fixture <NUM> may have a varied profile (for example, the second heating fixture <NUM> as shown in <FIG> may have a tapered profile). The heating fixture <NUM>, <NUM> may comprise a solid steel block; however, other materials accomplishing the purposes provided should be contemplated as within the scope of this disclosure.

Accordingly, a battery housing <NUM> for a battery module <NUM> is provided. The battery housing <NUM> has a plurality of exterior walls <NUM> surrounding a base <NUM> forming an internal section <NUM> which is configured to receive one or more battery cells <NUM>. The internal section <NUM> has a bottom surface <NUM>. A heat sink <NUM> or <NUM> is joined to the bottom surface <NUM> of the battery housing <NUM> by a plastic deformation of a portion of the housing <NUM>. A cover encloses the internal section <NUM> of the battery housing <NUM>. The heat sink <NUM> or <NUM> being provided between the battery cells <NUM> and the housing base <NUM>.

In one or more examples of embodiments, the housing <NUM> comprises a plurality of interior walls <NUM>, wherein one or more exterior walls <NUM> and one or more interior walls <NUM> form the internal section <NUM>. In this regard, the housing <NUM> may also comprise a plurality of internal sections <NUM>, and a plurality of heat sinks <NUM> or <NUM> joined to the battery housing <NUM> in the plurality of internal sections <NUM>.

In one or more examples of embodiments, the heat sink <NUM> or <NUM> is joined to the bottom surface <NUM> by one or more plastically deformed ribs <NUM>. The one or more plastically deformed ribs <NUM> may extend over an edge and a portion of a surface of the heat sink <NUM>. In the examples of embodiments described herein the heat sink may be a planar plate <NUM> or alternatively may be a U-shaped plate <NUM>. In the examples of embodiments in which a U-shape heat sink <NUM> is provided a first wall segment <NUM> and a second wall segment <NUM> of the U-shape plate are at least partially embedded in a respective first sidewall <NUM> and second sidewall <NUM> of the internal section <NUM> of the battery housing <NUM>.

A battery module <NUM> is also disclosed. The battery module <NUM> comprises a battery housing <NUM> having a plurality of exterior walls <NUM> surrounding a base <NUM> forming an internal section <NUM> which receives one or more battery cells <NUM>. The internal section <NUM> has a bottom surface <NUM>. A heat sink <NUM> or <NUM> is joined to the bottom surface <NUM> of the battery housing <NUM> by a plastic deformation of a portion of the housing <NUM>. A plurality of battery cells <NUM> are seated on top of the heat sink <NUM> or <NUM> in the internal section <NUM>. A cover <NUM> encloses the internal section <NUM> and plurality of battery cells <NUM>. In one or more examples of embodiments, an isolation component <NUM> may be provided between the plurality of battery cells <NUM> and the heat sink <NUM> or <NUM>.

A method of installation of a heat sink <NUM> or <NUM> in a battery housing <NUM> for a battery module <NUM> is also disclosed. The method includes the steps of: providing a battery housing <NUM> comprised of plastic and having an internal section <NUM> formed by a plurality of exterior walls <NUM> surrounding a base <NUM>, the internal section <NUM> having a bottom surface <NUM>; installing a heat sink <NUM> or <NUM> on a heating fixture <NUM>; moving a heating fixture <NUM> with installed heat sink <NUM> or <NUM> into the internal section <NUM> of the battery housing <NUM>; pressing the heat sink <NUM> or <NUM> into the bottom surface <NUM> while heating with the heating fixture <NUM> to at least partially melt the plastic and affix the heat sink <NUM> or <NUM> to the housing <NUM>; and removing the heating fixture <NUM> from the housing <NUM>.

In one or more examples of embodiments, the internal section <NUM> of the battery housing <NUM> has one or more ribs <NUM>, and wherein the heating fixture <NUM> plastically deforms the one or more ribs <NUM>. In one or more alternative examples of embodiments, the heat sink <NUM> has a U-shape profile and further comprising the steps of: introducing a second heating fixture <NUM> into the battery housing <NUM>, the second heating fixture <NUM> having a tapered profile; wherein movement of the second heating fixture <NUM> into the battery housing <NUM> and heating presses first and second sidewalls <NUM>, <NUM> of the heat sink <NUM> into first and second walls <NUM>, <NUM> of the internal section <NUM> of the battery housing <NUM>, and at least partially embeds the heat sink <NUM> in the housing <NUM>; and removing the second heating fixture <NUM> from the housing <NUM>.

Accordingly, a heat sink and fixation method for a battery is provided which solves one or more of the deficiencies with existing devices. The heat sink and fixation method provides improved consistency of fixation of the heat sink to the battery housing. For example, the disclosed heat sink and fixation method may allow for the battery housing material to melt over the heat sink for robust connection between the heat sink and battery housing. Further, the disclosed in various embodiments may allow for ease of manufacture. In addition, the disclosed may allow for no extraneous fixation devices such as screws to be introduced into the battery housing, preventing risks of puncture and damage to battery cells (which may be a particular risk when the battery used is in a vehicle and an accident or impact occurs).

The disclosed system and method may have a number of additional advantages. For example, traditional methods of installing a heat sink include introducing undercuts into the interior walls of the battery housing, and installing an aluminum heat sink into the undercuts. In this traditional method, the heat sink is manufactured in a size which is larger than the internal section and must be flexed during insertion so that it can seat into the undercuts. In comparison, in the method described herein, there is no reliance on heat sink sheet flexing or the complication of introducing undercuts in the plastic battery housing. Therefore, the disclosed system and method may be understood as an improvement upon traditional methods which rely on aluminum flexing to engage with an undercut in the battery housing. The heat sink described herein does not require the use of additional fastening hardware or complicated over-molding. Moreover, the heat sink becomes integral with the plastic battery housing. The system disclosed also may ensure maximum heat transfer between the heat sink and the battery housing, and out to the external environment.

Accordingly, the battery module, battery housing, and system having a heat sink, as well as the method of manufacturing or installation of a heat sink described herein meet the needs of thermal management and overcome one or more of the deficiencies of prior devices and processes.

As utilized herein, the terms "approximately," "about," "substantially", and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

It should be noted that references to relative positions (e.g., "top" and "bottom") in this description are merely used to identify various elements as are oriented in the Figures. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used.

For the purpose of this disclosure, the term "coupled" means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.

Claim 1:
A battery housing (<NUM>) for a battery module (<NUM>) comprising:
- a plurality of exterior walls (<NUM>) surrounding a base (<NUM>) forming an internal section (<NUM>) which is configured to receive one or more battery cells (<NUM>);
- a bottom surface (<NUM>) in the internal section (<NUM>);
- a heat sink (<NUM>, <NUM>) joined to the bottom surface (<NUM>) of the battery housing (<NUM>) by a plastic deformation of a portion of the housing (<NUM>) due to application of heat to the heat sink (<NUM>, <NUM>), melting of the portion of the housing (<NUM>) and pressing the heated heat sink (<NUM>, <NUM>) into the bottom surface (<NUM>); and
- a cover (<NUM>, <NUM>) enclosing the internal section (<NUM>).