Battery cell swelling restriction with hot melt fixation

Abstract

A battery module is described herein. An example battery module includes a housing, a plurality of battery cells, and at least one battery cell swelling limiting feature. An example battery cell swelling limiting feature includes a cradle, a sidewall, and a heat stake feature. An example battery module also includes an isolation feature positioned between the limiting feature and the battery cell to provide electrical isolation.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 964,463, filed on January 22, 2020, entitled “CELL SWELLING RESTRAINT WITH HEAT STAKED FIXATION,” the entire contents of which are incorporated herein by reference in their entirety. Background Art

[0003] The present disclosure relates generally to the field of batteries and battery modules. More particularly, the present disclosure relates to a housing for a battery or battery module.

[0004] This section is intended to introduce the reader to various aspects of the prior art that may be relevant to the various aspects of the present disclosure described 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. Therefore, it should be understood that these statements should be interpreted in this light and not as admissions of the prior art.

[0005] The vehicle uses one or more battery systems. In particular, vehicles (e.g., electric vehicles, hybrid vehicles) can use lithium-ion (Li-ion) batteries instead of or in addition to more traditional lead-acid batteries. As will be understood by those skilled in the art, a hybrid electric vehicle (HEV) (also considered an EV) combines an internal combustion engine propulsion system with a battery-powered electric propulsion system (such as a 48 volt (V) or 130V system). In some electric vehicles, the lithium-ion battery supplies most or all of the electricity used to propel the vehicle. Some hybrid electric vehicles can recover braking energy through a belt or crank-integrated starter generator. This energy is stored in the lithium-ion battery cells. Therefore, in addition to storing the typical charge collected from another power source (e.g., AC power) when the car is not in use, the lithium-ion battery is also used to store regenerative energy when the vehicle is in use.

[0006] There are many design aspects to consider when using lithium-ion batteries. For example, it may be beneficial to fit a lithium-ion battery in a space similar to that of a lead-acid battery. Other design considerations may include weight, compression resistance, heat transfer from the lithium-ion battery cells to prevent overheating, material cost, manufacturing cost, and ease of manufacturing. Since different vehicle applications may use lithium-ion batteries of different sizes, capacities, or types, designing a battery system that can be used in a wide variety of vehicles (as well as non-vehicle applications) may be beneficial to increase the ease of manufacturing a range of lithium-ion battery systems.

[0007] As technology continues to advance, there is a need to provide improved power sources, particularly battery modules, for such vehicles. SUMMARY

[0008] Accordingly, a battery system and method are disclosed. A summary of various aspects is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of the disclosure. Indeed, the disclosure can encompass a variety of aspects that can not be set forth below. The present disclosure relates to batteries and battery modules. More particularly, the present disclosure relates to lithium ion battery cells that can be used in vehicles and other energy storage / consumption applications (e.g., energy storage for the power grid).

[0009] The present disclosure relates to a battery module including a housing having a containment feature with a thermal fuse feature. The battery module also includes a battery cell assembly disposed within an interior space of the housing. The housing further includes a spacer feature positioned between the containment feature and the battery cell to electrically insulate the battery cell from the containment feature, a metal base plate to act as a heat sink to draw heat away from the battery cell assembly. The metal base plate can be coupled to a plastic portion of the housing using an adhesive dispensed in a groove of the housing.

[0010] The present disclosure also relates to a method for manufacturing a battery module. The method includes positioning a containment feature in a housing, positioning an adhesive on a bottom surface of the containment feature, inserting a spacer feature within the containment feature, and then inserting a battery cell assembly. BRIEF DESCRIPTION OF DRAWINGS

[0011] Various examples of embodiments of systems, apparatuses, and methods in accordance with the present application will be described in detail with reference to the following drawings.

[0012] Figure 1 is a perspective view of a vehicle having a battery system in accordance with embodiments of the present application that contributes all or a portion of the electrical power for the vehicle.

[0013] Figure 2 is Figure 1 is a cross-sectional schematic view of a vehicle in the form of a hybrid electric vehicle (HEV) employing a battery module.

[0014] Figure 3 is Figure 2 is an isometric view of an example battery module used in

[0015] Figure 4 is Figure 3 is an isometric view of a portion of the battery module of

[0016] Figure 5 is Figure 4a partial exploded view of a portion of a battery module.

[0017] It should be understood that the drawings are not necessarily to scale. In certain instances, details that are not necessary for an understanding of the application or that render other details difficult to perceive can have been omitted. It should be understood that the application is not necessarily limited to the particular embodiments illustrated herein. DETAILED DESCRIPTION

[0018] 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 can be 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 can be made that are specific to the implementation in question, such as specific selection of materials, specific

[0019] The battery systems described herein can be used to provide power to various types of electric vehicles (e.g., EVs) and other high-voltage energy storage / consumption applications (e.g., grid power storage systems). Such battery systems can include one or more battery modules, each having a housing and a plurality of battery cells (e.g., lithium-ion (Li-ion) electrochemical cells) disposed within the housing that provide a particular voltage and / or current that can be used to power, for example, one or more components of a vehicle. As another example, battery modules according to the present embodiments can be incorporated in or provide power for stationary power systems (e.g., non-automotive systems).

[0020] The present embodiments include physical battery module features, assembly components, manufacturing and assembly techniques, etc., that facilitate the manufacture of battery modules and systems in a manner that can allow for wider tolerance ranges for battery cell sizes, greater variation within the tolerance, and potential reductions in the size and weight of the battery modules and systems. Indeed, using the methods described herein, certain advanced battery modules (e.g., lithium-ion battery modules) can be designed to have a desired form factor.

[0021] Likewise, battery modules configured according to the present embodiments can be used in any number of energy consumption systems (e.g., vehicle environments (such as electric vehicles, fuel-powered vehicles) and stationary power environments (such as commercial applications, power grids, generators, etc.). To facilitate the discussion, the construction of the battery modules described herein is presented in the context of advanced battery modules used in vehicles (e.g., xEVs). In light of the foregoing, Figure 1is a perspective view of such a vehicle 10 that can utilize a regenerative braking system. As used herein, the terms "battery" and "battery module" can be used interchangeably.

[0022] It can be desirable for the battery system 12 to be largely compatible with conventional vehicle designs. For example, as illustrated, the vehicle 10 can include the battery system 12 in a similar location as a lead-acid battery of a typical combustion engine vehicle (e.g., under the hood of the vehicle 10).

[0023] Figure 2 A more detailed view of the battery system 12 is described in FIG. 2. As illustrated, the battery system 12 includes an energy storage component 14. The energy storage component is 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 can capture / store electrical energy generated in the vehicle 10 and output the electrical energy to electrical devices in the vehicle 10.

[0024] The battery system 12 can power components of the vehicle electrical system, which can include a radiator cooling fan, a climate control system, an electric power steering system, an active suspension system, an automatic parking system, an electric oil pump, an electric super / turbocharger, an electric water pump, a heated windshield / defroster, a window lift motor, a vanity light, a tire pressure monitoring system, a sunroof motor controller, electric seats, an alarm system, an infotainment system, a navigation feature, a lane departure warning system, an electric park brake, an exterior light, or any combination thereof. In the illustrated configuration, the energy storage component 14 powers the vehicle console 20 and the ignition system 16, which can be used to start (e.g., crank) the internal combustion engine 24.

[0025] Additionally, the energy storage component 14 can capture electrical energy generated by the alternator 18 and / or the electric motor 22. In some implementations, the alternator 18 generates electrical energy when the internal combustion engine 24 is running. More specifically, the alternator 18 can convert mechanical energy generated by the rotation of the internal combustion engine 24 into electrical energy. Additionally or alternatively, when the vehicle 10 includes the electric motor 22, the electric motor 22 can generate electrical energy by converting mechanical energy generated by movement of the vehicle 10 (e.g., rotation of the wheels) into electrical energy. Thus, the energy storage component 14 can capture electrical energy generated by the alternator 18 and / or by the electric motor 22 functioning as a generator during regenerative braking. Accordingly, the electric motor 22 is generally referred to herein as a regenerative braking system.

[0026] To facilitate the capture and supply of electrical energy, the energy storage component 14 can be electrically coupled to the electrical system of the vehicle via a bus 26. For example, the bus 26 enables the energy storage component 14 to receive electrical energy generated by the alternator 18 and / or the electric motor 22. Additionally, the bus 26 can enable the energy storage component 14 to output electrical energy to the ignition system 16 and / or the vehicle console 20. Thus, when using a 12-volt (V) battery system 12, the bus 26 can carry electrical power that is typically between 8 and 18 volts.

[0027] Additionally, as illustrated, the energy storage component 14 includes multiple battery modules. For example, in the illustrated embodiment, the energy storage component 14 includes a lithium-ion (e.g., first) battery module 28 and a lead-acid (e.g., second) battery module 30, where each battery module includes one or more battery cells 31. In other configurations, the energy storage component 14 includes any number of battery modules. Additionally, while the lithium-ion battery module 28 and the lead-acid battery module 30 are illustrated as being adjacent to one another, they can be positioned in different areas around the vehicle. For example, the lead-acid battery module can be positioned in or around the interior of the vehicle 10, while the lithium-ion battery module 28 can be positioned under the hood of the vehicle 10.

[0028] In some implementations, the energy storage component 14 includes multiple battery modules to take advantage of multiple different battery chemistries. For example, when using the lithium-ion battery module 28, the performance of the battery system 12 can be improved because lithium-ion battery chemistries generally have a higher coulombic efficiency and / or a higher charge acceptance (e.g., a higher maximum charge current or charge voltage) than lead-acid battery chemistries. Thus, the capture, storage, and / or distribution efficiency of the battery system 12 can be improved.

[0029] To facilitate controlling the capture and storage of electrical energy, the battery system 12 can additionally include a control module 32. More specifically, the control module 32 can control the operation of components in the battery system 12, such as relays (e.g., switches) within the energy storage component 14, the alternator 18, and / or the electric motor 22. The control module 32 can adjust the amount of electrical energy captured / supplied by each battery module 28 or 30 (e.g., derate and re-determine the rating of the battery system 12), perform load balancing between the battery modules 28 and 30, determine the state of charge of each battery module 28 or 30, determine the temperature of each battery module 28 or 30, control the voltage output of the alternator 18 and / or the electric motor 22, etc.

[0030] As Figure 2As shown, the control module 32 includes one or more processors 34 and one or more memories 36. More specifically, the one or more processors 34 can 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 memories 36 can include volatile memory (such as random access memory (RAM)), and / or non-volatile memory (such as read only memory (ROM), optical drives, hard drives, or solid state drives). In some embodiments, the control module 32 can include a portion of a vehicle control unit (VCU) and / or a separate battery control module. Moreover, as illustrated, the lithium-ion battery module 28 and the lead-acid battery module 30 are connected in parallel through their terminals. In other words, the lithium-ion battery module 28 and the lead-acid module 30 can be coupled in parallel to the electrical system of the vehicle via the bus 26.

[0031] The lithium-ion battery module 28 can have any of a variety of different shapes, sizes, output voltages, capacities, etc., and the present disclosure is generally intended to apply to variations from the shape and size of the module illustrated in the figures. Note that, Figure 3 is a front top perspective view of one configuration of the battery module 28.

[0032] The battery module 28 includes a first terminal 38 (e.g., a negative terminal) and a second terminal 40 (e.g., a positive terminal) that can be coupled to an electrical load (e.g., an electrical circuit). In other configurations, the battery module has more than two terminals to provide different voltages for different loads via connections across different combinations of terminals.

[0033] Figure 3 An example configuration of the lithium-ion battery module 28 is depicted. The battery module 28 includes a housing 42 for packaging or containing a plurality of battery cells 31 and other components of the battery module. The battery cells 31 can be spaced apart from one another by a separator 43 (see Figure 5 As will be described in greater detail below, the housing 42 packages a plurality of prismatic battery cells 31. The housing 42 includes two end portions 44, two side portions 46, a top portion 48 (e.g., fitted with a top cover), and a bottom portion (not shown). Figure 3 One of the two end portions 44 and one of the two side portions 46 are shown. The housing can also include one or more partition walls that separate the battery cells. The housing 42 can be a polymer (e.g., polypropylene, acrylonitrile butadiene styrene (ABS), polystyrene (PS), polyimide (PI), or other suitable polymer or plastic or combination thereof), or other suitable housing material or combination of materials.

[0034] Figure 4 isFigure 3 isometric view of the battery module 28 without the housing 42, thus showing a pair of containment features 50. Reference is made to Figure 4 A plurality of battery cells 31 can be seen in the example embodiment of the containment features 50. The containment features 50 can be understood to fit within the battery housing 42 with the lid 48. Additionally, battery management systems and electrical components (not shown) can be coupled to the battery cells - for example, disposed on top of the battery cells.

[0035] As can be seen in Figure 4 The containment features 50 enclose one or more groups of battery cells 31. The containment features 50 help provide sufficient containment against swelling for the battery cells 31 housed within the battery housing 42. The thickness of each wall 52 of the containment features 50 can vary. Further, the containment features 50 can advantageously act as a heat sink. A heat sink can be understood as a feature that takes heat away from one or more battery cells 31. The battery cell swelling containment features 50 can be an aluminum structure that is fixed within the battery housing 42. The battery cell swelling containment features 50 and assembly physically constrain the battery cells 31 to optimize battery cell performance. The disclosed containment features can also constrain the battery cells 31 in the event of a thermal runaway. In various embodiments, the containment features 50 can withstand the pressure caused by battery cell swelling. Additionally, the structure of the disclosed containment features 50 can take heat away from the battery cells 31 and expel it from the battery module 28 to reduce internal temperatures. The disclosed containment features 50 can have a further advantage for heat dissipation: allowing heat dissipation on the bottom face of the shelf, and also allowing indirect heat dissipation on the sides of the battery cells 31, as well as on the front and back faces.

[0036] In the illustrated example, the limiting feature includes a heat stake 54 feature (e.g., tab) at the top 56 of each wall 52 for heat staking one or more posts within the housing. The heat stake feature 54 can be integrally formed with the limiting feature 50. The illustrated heat stake feature 54 is generally rectangular. The heat stake 54 feature includes a first portion 54a and a second portion 54b that act as connecting tabs. The first portion of the heat stake feature 54 positioned on a first limiting feature 50 can interlock with a corresponding second portion of the heat stake feature 54 positioned on a second limiting feature 50. The first heat stake portion 54a includes an opening 55 and the second portion 54b includes a protrusion 57. The protrusion 57 is sized to correspond with the size of the opening 55 in order to ensure the connection between the first portion 54a and the second portion 54b of each interlocked heat stake feature 54. The heat stake feature 54 is sized to account for the mechanical and thermal loads expected to occur during the life of the battery module 30. The protrusion 57 and the corresponding opening 55 of the heat stake feature 54 have corresponding shapes and are shaped in a manner that facilitates automatic alignment of these parts when assembled, even if the initial placement of the limiting feature 50 within the housing 42 is imperfect. The heat stake feature 54 is advantageous over other fasteners because the formation of the heat stake feature 54 accounts for tolerance in the overall height, whereas other types of fasteners (such as snaps) tend to have no adjustability. In some examples, similar heat stake features 54 can be included on the housing 42 such that the limiting feature 50 (e.g., aluminum disc) is secured within the housing 42. The heat stake can provide advantages over known connection mechanisms, allowing for secure connections across a moving axis while advantageously not using fasteners. It is preferable to avoid the use of fasteners because the use of fasteners can introduce other features in the housing that can risk damage to the battery cells.

[0037] Figure 5 An example is shown having Figure 4FIG. 6 is an exploded view of the battery module 28 of the battery unit expansion limiting feature 50. The limiting feature 50 (e.g., battery unit expansion limiting feature) can be constructed of a suitable material, which can be metal, such as but not limited to aluminum. The aluminum can be advantageously adhered to the housing 42 via an adhesive (e.g., epoxy) 58. An isolation feature 60 can be provided between the battery unit expansion limiting feature 50 and the battery unit 31. The isolation feature 60 is positioned above the adhesive layer 58. The isolation feature 60 can have an aperture 62 at the bottom that exposes the adhesive 58 to the bottom of the battery unit 31 (i.e., allows the adhesive 58 to contact the battery unit 31 to secure the battery unit within the housing 42). The isolation feature 60 can advantageously provide electrical insulation between the battery unit 31 and the limiting feature 50, which also acts as a heat sink. The adhesive layer 58 can secure the battery unit 31 to the limiting feature 50 and can have sufficient thermal conductivity to draw heat to the limiting feature 50, which can act as a heat sink. Additionally, the limiting feature 50 includes a U-shaped bracket 64 and two end walls 66 to trap both sides of the battery unit stack. Thus, the limiting feature 50 can provide more structure than a common drawn aluminum sheet.

[0038] It can also be understood to disclose a method for providing a mechanism (e.g., limiting feature 50) for battery unit expansion limiting. In various embodiments, a plastic U-shaped sheet with a large aperture at the bottom is disposed within the battery unit expansion limiting feature 50. An adhesive 58 is disposed in the aperture 62, and a battery unit 31 is positioned above the adhesive 58 and isolation feature (60). The battery unit expansion limiting feature 50 can then be staked into the housing 42 via the stake feature 54. A busbar carrier (not shown) can be attached above the aluminum structure instead of being staked to the housing 42.

[0039] One or more disclosed embodiments, alone or in combination, can provide one or more technical effects including manufacturing a battery module with battery units (e.g., prismatic battery units). The disclosed designs enable the use of battery unit stacks that can be disposed within a housing of a battery module and can be kept below a maximum operating temperature using a heat sink. Accordingly, the disclosed battery module designs can provide better flexibility and performance compared to other battery module designs. The technical effects and technical problems in this specification are exemplary and non-limiting. It should be noted that the embodiments described in this specification can have other technical effects and can address other technical problems.

[0040] As used herein, the terms "about," "approximately," "substantially" and similar terms are intended to have a broad meaning in harmony with the common and accepted usage of these terms by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It is to be understood that such terms are intended to be employed as specified herein and are used to describe approximations which are near the value being described, but are not intended to be a precise identification of something as being exactly upon a particular value. It is therefore to be understood that such terms are to be interpreted in the broadest sense and used in a manner that is intended to be consistent with the principles of the present disclosure.

[0041] It should be noted that references in the specification to "top," "bottom," "y-axis," etc., are merely intended to indicate orientation in the figures. It is to be understood that a particular device can be flipped or inverted, and / or the orientation of the device can be changed, and that the orientation of the device can be changed.

[0042] For purposes of this disclosure, the term "coupled" means the joining of two members directly or indirectly to one another. Such joining can be stationary or moveable in nature. Such joining can be achieved by integral formation, by affixing the two members to one another, by insertion of at least a portion of one member into the other, or by a combination thereof. Such joining can be permanent in nature, or can be removable or releasable.

[0043] It is also important to note that the construction and arrangement of the systems, methods, and devices shown in the various examples of embodiments is illustrative only and not restrictive. Although several embodiments have been described in detail above, those with ordinary skill in the art will be able to make modifications and / or alterations to the embodiments without departing from the scope of the disclosure, which is defined by the appended claims and their equivalents. For example, the size, dimensions, structural configurations, shapes and proportions of the various elements, the values of the parameters, the mounting arrangements, the use of materials, the colors, the orientations, etc. can be varied. For example, elements shown as integrally formed can be constructed of multiple parts or elements shown as multiple parts can be integrally formed, the operation of the interfaces can be reversed or otherwise varied, the length or width of the structures and / or members or connector or other elements of the system can be varied, the nature or number of adjustment positions provided between the elements can be varied (e.g., by varying the number of engagement slots or the size or type of engagement), and the order or sequence of any process or method steps can be varied or re-sequenced. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions and arrangement of the various examples of the embodiments without departing from the spirit of the present disclosure or the scope of the claims. Accordingly, the present disclosure is intended to embrace all alternatives, modifications, variations, improvements, and / or substantial equivalents that are within the spirit and scope of the claims.

[0044] The technical effects and technical problems in the specification are exemplary and not restrictive. It should be noted that the embodiments described in the specification can have other technical effects and can solve other technical problems.

Claims

1. A battery cell swelling limit feature for a battery housing, comprising: a bracket; a sidewall; and a heat stake feature positioned on top of the sidewall, wherein the battery cell swelling limit feature is secured in the battery housing by the heat stake feature. The material of the battery cell swelling limit feature comprises a metal.

2. The battery cell expansion limiting feature of claim 1, wherein, The material of the battery cell swelling limit feature comprises aluminum.

3. The battery cell expansion limiting feature of claim 1, wherein, The bracket is U-shaped.

4. The battery cell expansion limiting feature of claim 1, wherein, 5. A battery module, comprising: a battery housing; a plurality of battery cells; and a battery cell swelling limit feature according to one of claims 1 to 4.

6. The battery module of claim 5, further comprising an isolation feature for providing electrical isolation between the battery cells and the battery cell swelling limit feature.

7. The battery module of claim 5, further comprising an adhesive layer coupling the plurality of battery cells to the battery cell swelling limit feature. The isolation feature surrounds the plurality of battery cells.

8. The battery module of claim 6, wherein, The battery cell swelling limit feature is a heat sink.

9. The battery module of claim 5, wherein, The second battery cell swelling limit feature is substantially identical to the battery cell swelling limit feature, wherein the second battery cell swelling limit feature is positioned in the battery housing alongside the battery cell swelling limit feature.

10. The battery module of claim 5, further comprising a second plurality of battery cells and a second battery cell swelling limiting feature, wherein, 11. A battery module, comprising: a battery housing; a plurality of battery cells; and a battery cell swelling limit feature having a bracket, a sidewall, and a heat stake feature positioned on top of the sidewall, the heat stake feature comprising a first interlocking portion and a second interlocking portion, wherein the battery cell swelling limit feature is secured in the battery housing by the heat stake feature.

12. The battery module of claim 11, further comprising an isolation feature for providing electrical isolation between the battery cells and the battery cell swelling limit feature.

13. The battery module of claim 11, further comprising an adhesive layer coupling the plurality of battery cells to the battery cell swelling limit feature. The isolation feature surrounds the plurality of battery cells.

14. The battery module of claim 12, wherein, The battery cell swelling limit feature is a heat sink.

15. The battery module of claim 11, wherein, The second battery cell swelling limit feature is substantially identical to the battery cell swelling limit feature, wherein the second battery cell swelling limit feature is positioned in the battery housing alongside the battery cell swelling limit feature.

16. The battery module of claim 11, further comprising a second plurality of battery cells and a second battery cell swelling limiting feature, wherein, The heat stake feature of the battery cell swelling limit feature interlocks with the heat stake feature of the second battery cell swelling limit feature.

17. The battery module of claim 16, wherein, The first interlocking portion of the battery cell swelling limit feature comprises an opening and the second interlocking portion of the battery cell swelling limit feature comprises a protrusion.

18. The battery module of claim 11, wherein, ​

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