Pressure control of battery cells

Abstract

A pressure management system includes a platen disposed in an initial position relative to a battery cell disposed in a housing, the platen and the housing defining an enclosure, where an increase in an internal pressure of the battery cell causes an expansion force to be applied to the platen. The system includes a mechanical linkage attached to the platen, the mechanical linkage configured to convert an expansive force to a counter force opposite the expansive force; and a rotatable member connected to the mechanical linkage, the rotatable member configured to rotate from a first orientation to a second orientation based on lateral movement of the mechanical linkage to allow the platen to move and increase the volume of the housing.

Description

Technical Field

[0001] The present invention relates to battery systems, and more particularly, to managing pressure of battery cells of a battery system. Background Art

[0002] Battery pouch-type battery cells are used in various applications, such as automotive applications (e.g., in electric and hybrid vehicles). For example, electric and hybrid vehicles include a battery system that includes a battery pack that houses a plurality of battery cells, which may include pouch-type battery cells, such as lithium-ion battery cells. As such battery cells are charged and discharged, and as such batteries age, pressure changes occur, which can be detrimental to charging and power storage capabilities. It is desirable to provide a mechanism that maintains the battery cells at a substantially constant pressure during their operating life. Summary of the invention

[0003] In an exemplary embodiment, a pressure management system includes a pressure plate disposed in an initial position relative to a battery cell disposed in a housing, the pressure plate and the housing defining an enclosure, wherein an increase in internal pressure of the battery cell causes an expansion force to be applied to the pressure plate. The system includes a mechanical linkage attached to the pressure plate, the mechanical linkage configured to convert the expansion force into a reverse force opposite to the expansion force, and a rotatable member connected to the mechanical linkage, the rotatable member configured to rotate from a first orientation to a second orientation based on lateral movement of the mechanical linkage to allow the pressure plate to move and increase the volume of the enclosure.

[0004] In addition to one or more features described herein, the mechanical linkage is configured to laterally move and rotate the rotatable member based on the expansion force being greater than the threshold force.

[0005] In addition to one or more features described herein, the rotatable member is a cam connected to one end of the mechanical linkage via a pivot point, the cam having a shape selected to allow the pressure plate to define a first distance when the cam is in a first orientation and a second distance when the cam is in a second orientation.

[0006] In addition to one or more features described herein, the cam has an eccentric center of gravity selected such that the cam is configured to return to the first orientation when the expansion force is less than a threshold force.

[0007] In addition to one or more features described herein, the cam is configured to maintain contact with the pressure plate during rotation to continuously apply the opposing force as the battery cell expands.

[0008] In addition to one or more features described herein, the mechanical linkage includes a pivot member having a first end and a second end, the first end being attached to the pressure plate at a fixed pivot point having a fixed position relative to the pressure plate.

[0009] In addition to one or more features described herein, the mechanical linkage includes a connecting member having a third end connected to the second end via a second pivot point and a fourth end connected to the rotatable component.

[0010] In addition to one or more features described herein, the pivot member includes a third pivot point between the first end and the second end, the third pivot point configured to move laterally along the guide member.

[0011] In addition to one or more features described herein, the guide member includes a track that moves the third pivot point within a lateral path and moves the fourth end laterally and toward the pressure plate so that the rotatable component applies an opposing force during rotation of the rotatable component.

[0012] In another exemplary embodiment, a method of controlling pressure of a battery cell includes receiving an expansion force at a pressure plate disposed at an initial position relative to the battery cell, the battery cell being disposed in a housing, the pressure plate and the housing defining an enclosure, the expansion force being generated by an increase in internal pressure of the battery cell. The method includes managing the pressure of the battery cell through a pressure management system, the pressure management system including a mechanical linkage attached to the pressure plate, the mechanical linkage connected to a rotatable member, wherein managing the pressure includes: converting the expansion force into a reverse force based on lateral movement of the mechanical linkage, the reverse force being configured to be opposite to the expansion force; and based on the expansion force exceeding a threshold force, causing the mechanical linkage to move laterally and rotate the rotatable member from a first orientation to a second orientation to allow the pressure plate to move and increase the volume of the enclosure.

[0013] In addition to one or more features described herein, the rotatable member is a cam connected to one end of the mechanical linkage via a pivot point, the cam having a shape selected to allow the pressure plate to define a first distance when the cam is in a first orientation and a second distance when the cam is in a second orientation.

[0014] In addition to one or more features described herein, the cam has an eccentric center of gravity selected such that the cam is configured to return to the first orientation when the expansion force is less than a threshold force.

[0015] In addition to one or more features described herein, the cam maintains contact with the pressure plate during rotation to continuously apply an opposing force as the battery cell expands.

[0016] In addition to one or more features described herein, the mechanical linkage device includes a pivot member having a first end and a second end, the first end being attached to the pressure plate at a fixed pivot point, the fixed pivot point having a fixed position relative to the pressure plate, and the mechanical linkage device includes a connecting member having a third end and a fourth end, the third end being connected to the second end via the second pivot point, and the fourth end being connected to the rotatable component.

[0017] In addition to one or more features described herein, the pivot member includes a third pivot point between the first end and the second end, the third pivot point configured to move laterally along the guide member.

[0018] In addition to one or more features described herein, the guide member includes a track that moves the third pivot point within the lateral path and moves the fourth end laterally and toward the pressure plate so that the rotatable component applies an opposing force during rotation.

[0019] In yet another exemplary embodiment, a vehicle system includes a battery system connected to a vehicle electric motor, the battery system including a battery cell disposed in a housing. The vehicle system also includes a pressure management system having a pressure plate disposed at an initial position relative to the battery cell, the battery cell disposed in the housing, the pressure plate and the housing defining an enclosure, wherein an increase in internal pressure of the battery cell causes an expansion force to be applied to the pressure plate. The pressure management system includes a mechanical linkage attached to the pressure plate, the mechanical linkage configured to convert the expansion force into a reverse force opposite to the expansion force, and a rotatable member connected to the mechanical linkage, the rotatable member configured to rotate from a first orientation to a second orientation based on lateral movement of the mechanical linkage to allow the pressure plate to move and increase the volume of the enclosure.

[0020] In addition to one or more features described herein, the mechanical linkage is configured to laterally move and rotate the rotatable member based on the expansion force being greater than the threshold force.

[0021] In addition to one or more features described herein, the rotatable member is a cam connected to one end of the mechanical linkage via a pivot point, the cam having a selected shape to allow the pressure plate to define a first distance when the cam is in a first orientation and a second distance when the cam is in a second orientation, and wherein the cam is configured to maintain contact with the pressure plate during rotation to continuously apply an opposing force as the battery cell expands.

[0022] In addition to one or more features described herein, the cam has an eccentric center of gravity selected such that the cam is configured to return to the first orientation when the expansion force is less than a threshold force.

[0023] The above features and advantages and other features and advantages of the present disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages and details appear, by way of example only, in the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 An energy storage system according to an exemplary embodiment is depicted, the energy storage system including a housing housing one or more battery cells and a pressure management system;

[0026] Figures 2A to 2C is a diagram showing the operation of the Figure 1 A force diagram of various forces generated by the connection mechanism in cooperation with the biasing system;

[0027] Figure 3 A and 3B depict an energy storage system including a pressure management system including one or more mechanical linkages, each mechanical linkage connected to a rotatable member, according to an exemplary embodiment;

[0028] Figure 4 An energy storage system including a pressure management system including one or more mechanical linkages, each mechanical linkage coupled to a rotatable member, is depicted according to an exemplary embodiment;

[0029] Figure 5A and 5B An energy storage system including a pressure management system including one or more mechanical linkages and a biasing system including one or more biasing members is depicted according to an exemplary embodiment;

[0030] Figure 6 An energy storage system according to an exemplary embodiment is depicted, the energy storage system comprising a pressure management system including one or more mechanical linkages and a controllable biasing system including one or more biasing members;

[0031] Fig. 7A and 7B Depicted is a schematic diagram of an exemplary embodiment of the present invention. Figure 6 An adjustment device for the bias system;

[0032] Figure 8 is a flow chart describing a method of managing pressure in a battery system according to an exemplary embodiment; and

[0033] Fig. 9 A computer system according to an exemplary embodiment is depicted. DETAILED DESCRIPTION

[0034] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0035] According to one or more exemplary embodiments, methods, devices, and systems for controlling pressure in battery assemblies and battery systems are provided. Embodiments of the pressure management system include a pressure plate disposed in a housing of a battery assembly (e.g., a battery pack or a battery module), which can move in response to an expansion force generated by the expansion of one or more battery cells in the housing. The pressure management system also includes one or more mechanical linkages that convert a portion of the expansion force into a reaction force or reverse force to maintain or achieve a desired pressure in the battery cell.

[0036] In one embodiment, the mechanical linkage includes a first elongated member (referred to as a "pivoting member") and a second elongated member (referred to as a "connecting member"). The pivoting member is attached to the pressure plate at one end, for example, by a pivot, and is attached to one end of the connecting member at the other end by another pivot. The pivoting member is also connected to a pivot point at a position between the ends of the pivoting member. The pivot point can be coupled to the housing by a fixed attachment, or to a track that allows lateral movement of the pivot point. When an expansion force is applied to the pressure plate, movement of the pressure plate causes one end of the connecting member to move laterally (i.e., along the pressure plate and / or in a direction orthogonal to the direction of the expansion force).

[0037] By limiting the lateral movement to a selected lateral distance, the lateral movement of the connecting member can be limited. The limitation of lateral movement can be achieved by a fixed stop component attached to the pressure plate or a component attached to the connecting member.

[0038] When lateral movement is restricted, the lateral force applied by the connecting member is converted into a reaction force or counterforce proportional to the expansion force. Embodiments of pressure management can be configured to provide a counterforce proportional to the expansion force. The proportion of the expansion force converted into the counterforce can be selected by selecting the parameters of the connection mechanism, such as the length of the pivot member and the connecting member.

[0039] In one embodiment, the lateral movement is limited by a rotatable component that is activated by the lateral movement to rotate along the pressure plate. The rotation of the rotatable component allows the distance between the pressure plate and the housing to be reduced, thereby allowing the pressure plate to move upward and provide space for the expansion of the battery cell. For example, each connecting member is connected to a cam that rests on the pressure plate and establishes an initial distance when the connecting mechanism is in an initial state. When sufficient expansion force (critical expansion force) is applied, the connecting member moves laterally, causing the cam to rotate and reduce the distance between the pressure plate and the housing.

[0040] In one embodiment, the pressure management system includes a biasing system that cooperates with the mechanical linkage and the rotatable component to establish a desired threshold expansion force. The biasing system includes at least one biasing member that is selectable to control the amount of lateral force that must be applied to cause the cam to rotate, thereby calibrating the pressure management system to the desired threshold expansion force (threshold force).

[0041] For example, the biasing system includes a laterally extending spring configured to couple with a cam of a mechanical linkage, which allows control of the threshold force. The spring is operably connected to the cam or connecting member and applies a spring force that resists lateral movement of the connecting member. The magnitude of the spring force can be calibrated or adjusted, for example by selecting a spring with an appropriate spring constant and / or by incorporating a spring adjuster that can be actuated to modify the spring force.

[0042] The embodiments described herein present numerous advantages and technical effects. The embodiments provide improved battery functionality by maintaining a constant force on the battery cell during its life, thereby effectively controlling pressure and avoiding negative effects such as dendrite growth. In addition, the embodiments provide a mechanism that automatically adjusts to allow for expansion and reduces excessive pressure that may occur due to expansion.

[0043] Figure 1 An embodiment of an energy storage device or system 10 is depicted that includes a battery module 12 housing a group (i.e., one or more) of battery cells 14. Each battery cell 14 may be any type of rechargeable battery cell, such as a lithium-based battery cell (e.g., lithium-ion, lithium metal (LMB), etc.). For example, each battery cell 14 is a pouch-type lithium-ion battery cell.

[0044] The module 12 includes a housing 16 in which one or more battery cells 14 are disposed. If multiple battery cells are housed, they may be stacked as shown, with adjacent battery cells 14 separated by support plates 18. Note that the embodiments described herein are not limited to the type or size of the housing 16, the type, size, or number of battery cells shown, or the type of battery cells shown.

[0045] The battery module 12 includes or is coupled to a pressure management system 20 that is configured to provide automatic management of pressure in the battery cells 14. The pressure management system 20 includes a pressure plate 22 disposed above the battery cells 14. The pressure plate 22 has a default position that may be at or near a surface of the uppermost battery cell 14, such as a position where the pressure plate 22 contacts the battery cells 14 (e.g., rests on the uppermost battery cell 14). Alternatively, as Figure 1As shown, the default position can define a gap or clearance that allows a certain amount of battery cell expansion before triggering pressure compensation or management. Note that the pressure plate 22 can be set at any position or location (e.g., below the battery cell 14) so ​​that the expansion of the battery cell causes the movement of the pressure plate 22.

[0046] The pressure compensation device is disposed on the pressure plate 22 or otherwise connected to the pressure plate 22 and is configured to exert a reaction force on the pressure plate 22 to compensate for the expansion of the battery cell 14 and maintain the battery cell 14 at a desired pressure (or within a desired pressure range).

[0047] The pressure compensation device includes a set (i.e., one or more) of mechanical linkages 24 that convert the expansion force on the pressure plate 22 into an opposing force (i.e., in the opposite direction of the expansion force). For example, when the battery cell 14 expands and exerts an upward expansion force on the pressure plate 22, the mechanical linkage 24 operates to exert a proportional downward force. Each linkage 24 can be calibrated to provide a downward force that maintains a constant selected pressure on the battery cell 14 as the battery cell 14 expands.

[0048] like Figure 1 As shown, the pressure compensation device includes two linkage devices 24 located at opposite ends of the pressure plate 22. The pressure plate 22 is oriented so that the surface 23 facing the battery cell 14 defines a plane orthogonal to the expansion direction. For example, the expansion direction is along the z-axis (i.e., in the z-direction), and the surface 23 is parallel to the plane defined by the x-axis and the y-axis (xy plane).

[0049] Each mechanical linkage 24 includes a first member 26 ("pivot member") attached to the pressure plate 22 via a pivot point P1. One end of the pivot member 26 is connected to the pivot point P1, which has a fixed position relative to the pressure plate 22. The other end of the pivot member 26 is attached to one end of a connecting member 28 at a pivot point P2.

[0050] The pivot member 26 further includes a pivot point P0 located between the two ends (eg, at a central position equidistant from the two ends of the pivot member 26 ). When the connecting mechanism moves laterally, the pivot member 26 rotates about the pivot point P0 .

[0051] When the pressure inside the battery cell increases, the force generated by the expansion (called "expansion force" and represented by F e The expansion force (represented by F) can be exerted on the pressure plate 22 in an upward or vertical direction (z direction). One end 30 of the connecting member 28 is connected to the pressure plate 22 so that the mechanical linkage 24 converts a portion of the expansion force into a reaction force (also referred to as a "reverse force", represented by F r ). Reverse force F r The expansion force F ein opposite directions and are selected proportions of the expansion forces.

[0052] If the expansion force F e If the force is sufficient to move the platen 22, the pivot member 26 rotates about the pivot point P0, which in turn causes the end 30 of the connecting member 28 to move laterally (e.g., in the x-direction) or to apply a lateral force toward the center of the platen 22. The "lateral" direction can be a direction orthogonal to the direction of the expansion force (e.g., in the xy plane) or a direction along the surface of the platen 22.

[0053] The lateral movement is restricted so that the lateral force applied by the linkage 24 is redirected to the battery cell 14. This can be achieved, for example, by a stop member 32, which can be a raised structure that blocks the lateral movement of the connecting member 28. When the connecting member 28 engages the stop member 32 or other restriction, the reactive lateral force causes a reverse force F r is applied to the battery cell 14. The opposing force F r and expansion force F e The parameters of the mechanical linkage 24 may be selected to calibrate the mechanical linkage 24 to achieve a desired ratio of opposing forces. Examples of these parameters include the length of the pivot member 26 and the connecting member 28, the height of the pivot point P1, the location of the pivot point P2, the location of the stop member 32, etc.

[0054] Lateral movement may be limited in various ways. For example, as further described herein, lateral movement is limited by a rotatable component. Additionally or alternatively, a biasing system may be included to adjust or calibrate the pressure management system 20.

[0055] Figures 2A-2C FIG. 2 is a force diagram depicting aspects of force transmission using a mechanical linkage 24 and a resistance member (not shown). The resistance member may be a stop member 32 or a cam 40 (e.g., Figure 3 A and 3B). Figures 2A-2C Aspects of calculating forces and selecting connection mechanism parameters to obtain desired opposing forces are also shown.

[0056] In these figures, l1 is the length from point P1 to point P0 on the xz plane, l2 is the length from point P0 to point P2, and l3 is the length from point P2 to point P3. Pivoting member 26 defines an angle θ1 relative to the x-axis (or the lateral direction of movement of end 30), and connecting member 28 defines an angle θ3 relative to the x-axis.

[0057] like Figure 2AAs shown, when force F1 (expansion force) is applied vertically (along the z direction or parallel to the expansion direction) to the pressure plate 22, the pivot member 26 rotates about the pivot point P0, generating a force F2 on the connecting member 28, which in turn causes the connecting member 28 to move along the x direction and generate a lateral force F3.

[0058] like Figure 2B As shown, the connecting member 28 moves a lateral distance d3, and the connecting member 28 pushes the resistance component. The resistance component applies an opposite lateral force f l .

[0059] When the connecting mechanism 24 is in a stable state, the connecting mechanism 24 does not move. Figure 2C As shown, the pivot member 26 and the connecting member 28 can be considered as a rigid body with a fulcrum at point P0. In this case, the connecting mechanism 24 applies a force F4. The force F4 has a normal component F4 N , which represents the reverse force applied to the battery cell 14.

[0060] Under steady-state conditions, the total torque is zero and can therefore be expressed as:

[0061] 11F1+LF4=0

[0062] Where l4 is the length from point P0 to P3 ( Figure 2C ).therefore,

[0063]

[0064] Normal component F4 N That is, the reverse force can be calculated according to the following formula:

[0065]

[0066] The length l4 varies as a function of d3 and as a function of the lengths of the pivot member 26 and the connecting member 28. Thus, the pressure management system 20 can be calibrated by selecting the lengths to produce a reaction force with a desired ratio of the expansion force. The system 20 can also be calibrated based on the locations of the points P0 and P1 to affect the reaction force.

[0067] Figure 3 A and 3B show an embodiment of a pressure management system 20 that includes a rotatable member connected to each mechanical linkage 24. The rotatable member is configured to rotate in response to lateral movement of the linkage 24 and allow the pressure plate 22 to move and provide additional space for the battery cell 14 to expand. In this way, the pressure management system 20 automatically responds to increases in internal pressure, thereby providing a volume buffer.

[0068] In this embodiment, the rotatable member is a cam 40, which may be any object capable of rotating and remaining engaged with the pressure plate 22 during rotation. The cam 40 has a non-circular shape, such as Figure 3 A and 3B show a pear or teardrop shape. The shape may be any suitable shape so that the height h of the cam 40 changes due to the rotation of the cam 40.

[0069] Figure 3 A shows the pressure management system 20 in an initial state, wherein the cam 40 of each mechanical linkage 24 is in a first position. In the first position, the cam 40 defines a distance D between the upper surface 27 of the pressure plate 22 and the top of the housing 16, and the pressure plate 22 and the housing 16 define a volume.

[0070] Figure 3 B shows the pressure management system 20 in an activated state. The activated state is caused by the expansion force F exceeding the threshold force. e In the activated state, the cam 40 has rotated to the second orientation in which the height h is reduced, which allows the pressure plate 22 to move upward and reduce the distance D, and allows the volume to increase to allow the battery cell 14 to expand.

[0071] The cam 40 is connected to the end 30 by a pin 42 or other connection mechanism that allows the cam 40 to rotate about the end 30. For example, as shown, the pin 42 is located at or near the relatively wide end of the cam 40.

[0072] In one embodiment, the cam 40 has a center of gravity 44 that is eccentrically positioned to help the cam 40 return to the first orientation when the internal pressure of the battery cell 14 decreases and the expansion force drops below a threshold. The center of gravity 44 can be established, for example, by increasing the thickness of the cam 40 near the narrower end of the cam 40 (e.g., along the y-axis) or including a higher density material or insert near the narrower end.

[0073] In one embodiment, the pressure management system 20 also includes a mechanical guide or track 46 that limits the movement of the pivot point P0 to a lateral movement path. For example, the track 46 includes an elongated member that can hold a pin 47 or other component at the pivot point P0. The track 46 prevents the pivot point P0 from moving vertically, or otherwise establishes a path so that when the cam 40 rotates, the pivot member 26 forces the connecting member 28 to push the cam 40 laterally and vertically. In this way, when the battery cell 14 expands and the pressure plate 22 moves upward, an opposing force is maintained on the battery cell 14. The track 46 includes an end member or surface 50 that prevents the pivot point P0 from moving toward the side wall of the housing 16 beyond a desired position.

[0074] The pressure management system 20 may include additional features or components to facilitate transitions between the initial state and the activated state. In one embodiment, the pressure plate 22 includes or is attached to an engagement surface 48 that is configured to provide sufficient friction to prevent the cam 40 from slipping. For example, the engagement surface 48 is a portion of the upper surface 27 having increased roughness, or is a separate plate or component attached to the surface 27.

[0075] Additionally, or alternatively, the surface of the cam 40 may have roughness to provide friction. In another example, the surface of the cam 40 and the engagement surface 48 may have features such as grooves or gear teeth that allow the cam 40 to engage the pressure plate and rotate without slipping.

[0076] Track 46 may establish a linear or non-linear path. Figure 4 As shown, track 46 may be a curved track. The curvature of track 48 may be selected so that the end of connecting member 28 moves along a circular or arcuate path to facilitate rotation of cam 40. The curvature may also be selected to affect the opposing force F applied by connecting mechanism 24 when pressure plate 22 is pushed upward by battery cell expansion. r size.

[0077] Note that embodiments are not limited to the number and location of mechanical linkages shown here. For example, the pressure management system 20 can include one connection mechanism 24 on one side of the pressure plate 22. In addition, there can be more than one connection mechanism 24 arranged along the y direction.

[0078] In one embodiment, the pressure management system 20 includes a biasing system that provides one or more components configured to control the opposing force F r The amount (i.e., the expansion force F that controls the redirection toward the battery cell 14) e The biasing system may be a passive or active system which may be designed to maintain and / or adjust the desired ratio.

[0079] The biasing system may also be configured to control the amount of expansion force (ie, threshold force) required to transition the attachment mechanism 24 to the activated state.

[0080] For example, Figure 5A and 5B As shown, the pressure management system 20 includes a stop member 60 that is part of or attached to the pressure plate 22. Laterally extending springs 62 are provided that can be coupled with the connection mechanism 24 to prevent lateral movement of the connection member 28 and prevent rotation of the cam 40. Each spring 62 applies a biasing force that resists lateral movement.

[0081] Figure 5A The pressure plate 22 is shown in an initial or default position, in which the default force Fd applied to the battery cell 14. Each spring 62 is connected or attached to the stop member 60 at one end of the spring 62. The other end of the spring 62 is located laterally away from the stop member 60 and is configured to engage with the corresponding cam 40 and apply a biasing force against rotation.

[0082] The biasing force is a function of the spring constant k of the spring 62. When the battery cell 14 expands and applies an expansion force to the pressure plate 22, the upward movement of the pressure plate 22 causes each pivot member 24 to rotate about the pivot point P0 and causes the pivot point P0 to move along the track 46, which in turn causes the connecting member 28 to move laterally and rotate the cam 40. The rotation of the cam 40 causes the spring 62 to compress, as shown in FIG. Figure 5B By choosing an appropriate spring constant, the amount of lateral force required to rotate the cam and the corresponding expansion force threshold can be selected.

[0083] In one embodiment, the pressure management system 20 includes a bias control system that can be actively controlled at any time to change the relationship between the expansion force and the opposing force. The bias control system can also be used to compress or decompress one or both biasing members to adjust the expansion force threshold.

[0084] Figure 6 An embodiment of a pressure management system 20 is depicted that includes a biasing member adjustment system 80. The adjustment system 80 includes an adjustment device, referred to as a spring adjuster 82. The spring adjuster 82 is coupled to the spring 62 and is controllable to increase or decrease spring compression, thereby controlling the spring force (i.e., the amount of spring force resulting from a given amount of lateral movement).

[0085] In one embodiment, the spring adjuster 82 includes a fixed pinion 84 coupled to at least one linear gear or rack 86 (or other linear actuator). Each linear gear 86 is attached to or engaged with a corresponding spring to adjust the spring force. For example, each linear gear 86 is attached at one end to an interface member 88 (e.g., a plate or disk) that engages a corresponding spring 62.

[0086] The pinion gear is coupled to an actuator 90, such as a low power motor, which is operable to rotate the pinion gear 84 to move the linear gear 86 and compress or decompress the spring 62. The actuator 90 may be manually controlled by an operator, or controlled by a controller 92 or other processing device.

[0087] If you want to adjust the reverse force F r(e.g., maintaining a constant pressure under conditions such as temperature changes, pressure changes, or threshold force changes), the actuator 90 is controlled to rotate the pinion 84 and move the linear gear 86. The pinion 84 can be rotated clockwise to move the linear gear 86 outward and compress the spring 62, which increases the threshold force. In order to decompress the spring 62, thereby reducing the threshold force, the pinion 84 can be rotated clockwise.

[0088] The embodiments are not limited to Figure 6 Configuration shown. Embodiments may include multiple spring force adjusters that are synchronously controlled by a single motor. In other embodiments, multiple independent spring force adjusters are provided, wherein each spring force adjuster is independently controlled.

[0089] Fig. 7A and 7B An example is shown where the biasing system 80 includes two independently controllable spring adjusters 82a and 82b. Each spring adjuster is coupled to a different spring or biasing device and has its own motor. Fig. 7A The biasing system is shown in a first state, wherein the compression on the spring 62 is relatively low, Figure 7B Shown is a state where both spring adjusters 82a and 82b are actuated to compress their respective springs. Since each spring adjuster is independently controllable, different compression amounts can be applied (e.g., spring adjusters 82a and 82b are controlled so that one of springs 62 has a different compression amount than the opposing spring 62).

[0090] Figure 8 An embodiment of a method 100 of managing battery assembly stress is shown. Aspects of the method 100, such as adjustment of the biasing system, may be performed by one or more processors.

[0091] Method 100 includes a number of steps or phases represented by blocks 101-103. Method 100 is not limited to the number or order of steps therein, as some steps represented by blocks 101-103 may be performed in a different order than described below, or less than all steps may be performed in an order.

[0092] For the purpose of illustration, Figure 1 The energy storage device 10 shown in FIG. Figure 2A and 2B Various aspects of method 100 are discussed with reference to pressure management system 20 shown in FIG. Method 100 is not limited thereto and may be used with any type of battery cell and any system having an opposing force linkage as described herein.

[0093] At block 101, a battery assembly is assembled or manufactured. The battery assembly may be a battery module having one or more battery cells, such as module 12. Such battery cells may be lithium metal pouch cells or any other battery cells susceptible to swelling. The manufacture of the battery assembly includes setting up a pressure management system, such as Figure 3 A and 3B stress management system.

[0094] At block 102 , the battery assembly is operated. For example, the battery module 12 is a battery pack of a vehicle and provides power to one or more electric motors of the vehicle.

[0095] At block 103, as the battery cell expands during (or between) operations, the pressure management system 20 controls the pressure of one or more battery cells of the battery assembly. This control includes applying a proportional opposing force in the direction toward the battery cell to compensate for the expansion force and maintain a desired pressure or pressure range. For example, when the battery cell 14 expands, the mechanical linkage 24 and the cam 40 apply the expansion force F e A portion of the force is redirected as a counter force F r .

[0096] For example, the pressure plate 22 applies a default or initial reverse force F d , to maintain the initial pressure in the battery cell 14. As the battery cell 14 cycles, the pressure increases causing the expansion force F e , and the pressure management system 20 responds by providing an opposing force F r When the expansion force F e When a certain threshold is reached, the linkages 24 move laterally and rotate their respective cams 40, allowing the pressure plate 22 to be pushed upward and providing additional volume to accommodate the expansion and reduce pressure. If a spring adjuster 82 is included, control includes operating an actuator 90 to adjust the spring force applied in response to the movement of the linkage 24.

[0097] This pressure control provides the extra volume needed to avoid negative effects, such as separator rupture, dendrite growth, and potential internal shorting. At the same time, when the expansion force is below a threshold, the pressure control can apply an opposing force to maintain the desired pressure range, which can have positive effects, such as preventing dendrite growth.

[0098] Fig. 9 Aspects of an embodiment of a computer system 140 are shown, which can perform various aspects of the embodiments described herein. The computer system 140 includes at least one processing device 142, which typically includes one or more processors, for performing various aspects of the image acquisition and analysis methods described herein.

[0099] Components of the computer system 140 include a processing device 142 (such as one or more processors or processing units), a memory 144, and a bus 146 that couples various system components including the system memory 144 to the processing device 142. The system memory 144 may be a non-transitory computer-readable medium and may include various computer system-readable media. Such media may be any available media that can be accessed by the processing device 142 and includes both volatile and non-volatile media, as well as removable and non-removable media.

[0100] For example, system memory 144 includes nonvolatile memory 148, such as a hard drive, and may also include volatile memory 150, such as random access memory (RAM) and / or cache memory. Computer system 140 may also include other removable / non-removable, volatile / nonvolatile computer system storage media.

[0101] The system memory 144 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, the system memory 144 stores various program modules that generally perform the functions and / or methods of the embodiments described herein. One or more modules 152 may be included to perform functions related to monitoring the battery system. An image analysis module 154 may be included to control various aspects of pressure management, such as controlling an actuator of a spring adjuster as described herein. The system 140 is not limited thereto, as other modules may be included. As used herein, the term "module" refers to a processing circuit, which may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the functionality.

[0102] Processing device 142 may also communicate with one or more external devices 156, which may be keyboards, pointing devices, and / or any device that enables processing device 142 to communicate with one or more other computing devices (e.g., network cards, modems, etc.). Communications with various devices may occur through input / output (I / O) interfaces 164 and 165.

[0103] The processing device 142 may also communicate with one or more networks 166, such as a local area network (LAN), a general wide area network (WAN), a bus network, and / or a public network (e.g., the Internet) via a network adapter 168. It should be understood that, although not shown, other hardware and / or software components may be used in conjunction with the computer system 40. Examples include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc.

[0104] The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced items. The term "or" means "and / or", unless the context clearly indicates otherwise. References to "an aspect" throughout the specification mean that a particular element (e.g., feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in various aspects.

[0105] When an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0106] Unless otherwise indicated herein, all test standards are the most recent standards in effect as of the filing date of the present application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0107] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0108] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope thereof. In addition, many modifications may be made to adapt specific situations or materials to the teachings of the disclosure without departing from the essential scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A stress management system, comprising: a press plate disposed in an initial position relative to the battery cell, the battery cell being disposed in a housing, the press plate and the housing defining an enclosure, wherein an increase in internal pressure of the battery cell causes an expansion force to be applied to the press plate; a mechanical linkage attached to the pressure plate, the mechanical linkage configured to convert the expansion force into a reverse force opposite the expansion force; as well as A rotatable member connected to the mechanical linkage is configured to rotate from a first orientation to a second orientation based on lateral movement of the mechanical linkage to allow the pressure plate to move and increase the volume of the housing.

2. The system according to claim 1, wherein: The mechanical linkage is configured to laterally move and rotate the rotatable member based on the expansion force being greater than a threshold force.

3. The system according to claim 2, wherein: The rotatable member is a cam connected to one end of the mechanical linkage by a pivot point, the cam having a shape selected to allow the pressure plate to define a first distance when the cam is in the first orientation and a second distance when the cam is in the second orientation.

4. The system according to claim 3, wherein: The cam has an eccentric center of gravity selected such that the cam is configured to return to the first orientation when the expansion force is less than the threshold force.

5. The system according to claim 3, wherein: The cam is configured to maintain contact with the pressure plate during rotation to continuously apply the opposing force as the battery cell expands.

6. The system according to claim 1, wherein: The mechanical linkage includes a pivot member having a first end and a second end, the first end being attached to the pressure plate at a fixed pivot point having a fixed position relative to the pressure plate.

7. The system according to claim 6, wherein: The mechanical linkage includes a connecting member having a third end connected to the second end via a second pivot point and a fourth end connected to the rotatable component.

8. The system according to claim 7, wherein: The pivot member includes a third pivot point between the first end and the second end, the third pivot point being configured to move laterally along the guide member.

9. The system according to claim 8, wherein: The guide member includes a track that moves the third pivot point within a transverse path and moves the fourth end laterally and toward the pressure plate so that the rotatable component applies the opposing force during rotation of the rotatable component.

10. A method for controlling pressure of a battery cell, comprising: receiving an expansion force at a pressing plate disposed at an initial position relative to a battery cell, the battery cell being disposed in a housing, the pressing plate and the housing defining an enclosure, the expansion force being generated by an increase in internal pressure of the battery cell; and Managing pressure of the battery cell by a pressure management system, the pressure management system comprising a mechanical linkage attached to a pressure plate, the mechanical linkage connected to a rotatable member, wherein managing pressure comprises: converting an expansion force into a reverse force based on lateral movement of the mechanical linkage, the reverse force being configured to oppose the expansion force; and Based on the expansion force exceeding the threshold force, the mechanical linkage is laterally moved and the rotatable member is rotated from the first orientation to the second orientation to allow the pressure plate to move and increase the volume of the housing.

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