Active pressure control piezoelectric mechanism for improving battery performance

Abstract

A vehicle, a pressure control apparatus, and a method for controlling a pressure within a battery of the vehicle. The pressure control device includes a support plate, a pressure plate, and an actuator. The pressure plate is configured to move relative to the support plate. The battery is arranged between the supporting plate and the pressure plate. The actuator changes between a first shape and a second shape to move the pressure plate relative to the support plate to control the pressure within the battery.

Description

Technical Field

[0001] The present disclosure relates to improving the performance of a battery, and in particular, to controlling the pressure applied to a battery operating under high pressure conditions to improve its performance. Background Art

[0002] Lithium metal batteries (LMBs) can be used to provide power in electric vehicles. When the LMB is operated under low voltage conditions, dendrites can grow between the anode and cathode of the battery. These dendrites limit the life and effectiveness of the LMB. However, by operating the LMB under high voltage conditions, dendrite growth can be reduced. Therefore, it is desirable to provide a method and apparatus for applying high voltage to a battery during battery operation. Summary of the invention

[0003] In an exemplary embodiment, a pressure control device for controlling pressure in a battery is disclosed. The pressure control device includes a support plate, a pressure plate, and an actuator. The pressure plate is configured to move relative to the support plate. The battery is disposed between the support plate and the pressure plate. The actuator is configured to change between a first shape and a second shape to move the pressure plate relative to the support plate, thereby controlling the pressure in the battery.

[0004] In addition to one or more features described herein, the actuator includes a strip of piezoelectric material extending from a first end to a second end, the strip of piezoelectric material coupled to the control board at the first end by a first support and coupled to the control board at the second end by a second support.

[0005] In addition to one or more features described herein, the first end is fixed to the first support and the second end is fixed to one of the second supports, the first end is fixed to the first support and the second end is slidable relative to the second support, and the first end is slidable relative to the first support and the second end is slidable relative to the second support.

[0006] In addition to one or more features described herein, the actuator includes a steel bar coupled to the piezoelectric material.

[0007] In addition to one or more features described herein, the steel strip is biased toward one of the first shape and the second shape.

[0008] In addition to one or more features described herein, the control plate is stationary relative to the support plate.

[0009] In addition to one or more features described herein, the pressure control device also includes a pressure sensor configured to measure pressure within the battery and a controller configured to control current through the actuator based on the pressure.

[0010] In another exemplary embodiment, a method of controlling pressure within a battery is disclosed. The method includes disposing a battery between a support plate and a pressure plate configured to move relative to the support plate, and activating an actuator to change between a first shape and a second shape to move the pressure plate relative to the support plate, thereby controlling the pressure within the battery.

[0011] In addition to one or more features described herein, the actuator includes a strip of piezoelectric material extending from a first end to a second end, the strip of piezoelectric material coupled to the control board at the first end by a first support and coupled to the control board at the second end by a second support.

[0012] In addition to one or more features described herein, the first end is fixed to the first support and the second end is fixed to one of the second supports, the first end is fixed to the first support and the second end is slidable relative to the second support, and the first end is slidable relative to the first support and the second end is slidable relative to the second support.

[0013] In addition to one or more features described herein, the actuator includes a steel bar coupled to the piezoelectric material.

[0014] In addition to one or more features described herein, the steel strip is biased toward one of the first shape and the second shape.

[0015] In addition to one or more features described herein, the control plate is stationary relative to the support plate.

[0016] In addition to one or more features described herein, the method also includes measuring pressure within the battery using a pressure sensor and controlling current through the actuator based on the pressure.

[0017] In yet another exemplary embodiment, a vehicle is disclosed. The vehicle includes a battery and a pressure control device. The pressure control device includes a support plate, a pressure plate configured to move relative to the support plate, wherein the battery is disposed between the support plate and the pressure plate, and an actuator configured to change between a first shape and a second shape to move the pressure plate relative to the support plate to control pressure within the battery.

[0018] In addition to one or more features described herein, the actuator includes a strip of piezoelectric material extending from a first end to a second end, the strip of piezoelectric material coupled to the control board at the first end by a first support and coupled to the control board at the second end by a second support.

[0019] In addition to one or more features described herein, the first end is fixed to the first support and the second end is fixed to one of the second supports, the first end is fixed to the first support and the second end is slidable relative to the second support, and the first end is slidable relative to the first support and the second end is slidable relative to the second support.

[0020] In addition to one or more features described herein, the actuator includes a steel bar coupled to the piezoelectric material.

[0021] In addition to one or more features described herein, the steel strip is biased toward one of the first shape and the second shape.

[0022] In addition to one or more features described herein, the vehicle also includes a pressure sensor configured to measure pressure within the battery and a controller configured to control current through the actuator based on the pressure.

[0023] The above features and advantages and other features and advantages of the present disclosure are 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, from the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 An electric vehicle according to an exemplary embodiment is shown;

[0026] Figure 2 A battery system for a battery in an exemplary embodiment is shown;

[0027] Figure 3 shows a close-up side view of the actuator in a non-actuated state;

[0028] Figure 4 shows a close-up side view of the actuator in an energized state;

[0029] Figure 5 shows a perspective view of the actuator in a first embodiment in a non-energized state;

[0030] Figure 5A showing a second support member and slot of the actuator;

[0031] Figure 6 shows a perspective view of the actuator in the first embodiment in an energized state;

[0032] Figure 7 shows a perspective view of an actuator in a second embodiment;

[0033] Figure 8 A side view of a pressure control device in another embodiment is shown. 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 an exemplary embodiment, Figure 1 An electric vehicle 100 is shown. The electric vehicle 100 includes an electric motor 102, a battery system 104, and a controller 106. The battery system 104 includes a battery 108, which includes an anode 110 and a cathode 112, which are susceptible to forming dendrites during operation at standard pressure or ambient pressure. Dendrites reduce the operating quality of the battery 108. In various embodiments, the battery 108 is any battery that requires high pressure conditions to operate, such as a lithium metal battery (LMB). The battery system 104 includes a device that applies pressure to the battery 108 and is capable of regulating or controlling the pressure as needed.

[0036] The controller 106 may include processing circuitry that may include an application specific integrated circuit (ASIC), electronic circuitry, a processor (shared, dedicated, or group) and memory executing one or more software or firmware programs, combinatorial logic circuitry, and / or other suitable components that provide the described functionality. The controller 106 may include a non-transitory computer readable medium storing instructions that, when processed by one or more processors of the controller 106, implement a method of operating the battery system 104 to apply pressure to the battery 108 as desired.

[0037] Figure 2 A battery system 200 for a battery 108 in an exemplary embodiment is shown. The battery system 200 includes a housing 202 that accommodates the battery 108. The housing 202 may have a bottom surface 204, a top surface 206, and a sidewall 208. A pressure control device 210 for the battery 108 is disposed inside the housing 202. The pressure control device 210 includes a support plate 212 on which the battery 108 is disposed, a pressure plate 214 that is movable relative to the support plate, and a column 216 that guides the movement of the pressure plate in a direction toward or away from the support plate. The support plate 212 may be the same as the bottom surface of the housing 202. The support plate 212 is placed against a first side of the battery 108, and the pressure plate 214 is placed against a second side of the battery 108 that is opposite to the first side. The pressure plate 214 may move toward the support plate 212 to increase the pressure applied to the battery 108. The pressure plate 214 may move away from the support plate 212 to reduce the pressure applied to the battery 108.

[0038] The actuator 218 is disposed at a position above the pressure plate 214. The actuator 218 includes a piezoelectric material that changes shape when an electric current is applied. The piezoelectric material can change between a first shape (when no current is applied to the piezoelectric material) and a second shape (when full current is applied to the piezoelectric material). When the current is applied, the piezoelectric material can be referred to as being excited, and when the current is not applied, the piezoelectric material can be referred to as being non-excited. The current can be provided from a voltage source (not shown) that applies a voltage across the piezoelectric material. The first shape can be a planar shape, and the second shape is an arc shape that occupies a larger space than the first shape. The actuator 218 can be coupled to or fixed to a control board 220 that is held in a fixed position relative to the support plate 212. In various embodiments, the control board 220 can be the top surface 206 of the housing 202. When in the first shape (i.e., the planar shape), the actuator 218 applies little or no force on the pressure plate 214. When electrically excited to assume the second shape (ie, the arcuate shape), the piezoelectric material expands out of plane to exert a force on the pressure plate 214 , thereby increasing the pressure within the battery 108 .

[0039] The pressure sensor 240 is configured to measure the pressure within the battery 108. The pressure may be sent to the controller 106 or other suitable processor. The controller 106 may control the operation of the electric motor based on the detected pressure within the battery 108 by controlling the amount of current flowing through the piezoelectric material.

[0040] Figure 3 A close-up side view 300 of the actuator 218 in a non-actuated state is shown. The actuator 218 includes a strip 302 of piezoelectric material extending from a first end 304 to a second end 306. The first end 304 is coupled to a first support 308, and the second end 306 is coupled to a second support 310. The first support 308 is coupled to the control board 220 at a first location, and the second support 310 is coupled to the control board at a second location. The first end 304 can be fixed in place by the first support 308, and the second end 306 can be fixed in place by the second support 310. Without any current flowing through the piezoelectric material, the strip 302 is formed into a planar first shape.

[0041] In one embodiment, the strip 302 has a bi-state layer that includes two layers of different piezoelectric materials that expand at different rates when energized by electrical current, thereby creating a bend or arc in the strip 302. Alternatively, the strip 302 may include a layer of steel or steel strip or other material that forms a spring that amplifies the displacement of the strip 302 when electrically energized. The steel layer may be biased toward the arc shape.

[0042] In another embodiment, the strip 302 may include a layer of steel or other material forming a spring that is biased toward a flat or planar shape. In this embodiment, the strip 302 naturally (i.e., when no current is applied) resides in an arc shape. The piezoelectric material pulls back the spring when electrically excited.

[0043] Figure 4 A close-up side view 400 of the actuator 218 in an energized state is shown. As current flows through the piezoelectric material, the strip 302 assumes a second shape. The second shape comprises an arc in which a middle portion of the material bends away from the control plate 220 and toward the platen 214. In this shape, the strip 302 exerts a force on the platen 214 to move the platen 214 away from the control plate 220 and toward the support plate 212. The amount of current passing through the strip 302 of piezoelectric material can be controlled to adjust the amount of arc created in the strip 302, thereby adjusting the force exerted on the platen 214.

[0044] Figure 5 A perspective view 500 of the actuator 218 in a non-activated state in the first embodiment is shown. The first end 304 of the strap 302 is fixed in place by the first support 308. The second support 310 includes a slot 502 through which the second end 306 of the strap 302 is free to move or slide. Figure 5A The second support 310 and the slot 502 are shown. When the strip 302 is in a planar shape, the second end 306 extends completely through the slot 502. The second end 306 may have a flange portion 504.

[0045] Figure 6 A perspective view 600 of the actuator 218 in the first embodiment is shown in an energized state. As the strip 302 changes to an arcuate shape, the second end 306 is pulled inwardly through the slot 502. The flange portion 504 limits the extent to which the second end 306 can be withdrawn through the slot 502.

[0046] Figure 7A perspective view 700 of the actuator 218 in a second embodiment is shown. The first support 308 includes a first slot 702 through which the first end 304 of the strip 302 is free to move or slide. The second support 310 includes a second slot 704 through which the second end 306 of the strip 302 is free to move or slide. When the strip 302 is in a planar shape, the first end 304 extends through the first slot 702 and the second end 306 extends through the second slot 704. When the strip 302 changes to an arcuate shape, the first end 304 is pulled inward through the first slot 702 and the second end 306 is pulled inward through the second slot 704. The first end 304 can have a first flange section 706 and the second end 306 can have a second flange section 708, each of which limits the extent to which their respective ends can be withdrawn through their respective slots.

[0047] Figure 8 A side view 800 of a pressure control device 210 in another embodiment is shown. The pressure control device 210 includes a plurality of actuators. For illustrative purposes, three actuators 218a, 218b, 218c are shown. Each actuator can be independently energized using an independently controlled current. Thus, different forces can be applied at different locations along the surface of the pressure plate 214, which results in a pressure differential within the battery 108.

[0048] The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced item. Unless the context clearly indicates otherwise, the term "or" means "and / or". References to "aspects" throughout the specification mean that a particular element (e.g., a 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 the various aspects.

[0049] 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.

[0050] Unless otherwise indicated herein, all test standards are the most current standards in effect as of the filing date of this application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0051] 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.

[0052] 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 its scope. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings of the disclosure without departing from the basic 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 pressure control device for controlling the pressure in a battery, comprising: Support plate; a pressure plate configured to move relative to the support plate, wherein the battery is disposed between the support plate and the pressure plate; as well as An actuator is configured to change between a first shape and a second shape to move the pressure plate relative to the support plate to control pressure within the battery.

2. The pressure control device according to claim 1, wherein: The actuator includes a strip of piezoelectric material extending from a first end to a second end, the strip of piezoelectric material being coupled to a control board at the first end by a first support and coupled to the control board at the second end by a second support.

3. A pressure control device according to claim 2, wherein one of the following: (i) the first end is fixed to the first support member and the second end is fixed to the second support member; (ii) the first end is fixed to the first support member and the second end is capable of sliding relative to the second support member; and (iii) the first end is capable of sliding relative to the first support member and the second end is capable of sliding relative to the second support member.

4. The pressure control device according to claim 2, wherein: The actuator also includes a steel bar coupled to the piezoelectric material.

5. The pressure control device of claim 1, further comprising a pressure sensor and a controller, the pressure sensor being configured to measure pressure within the battery, the controller being configured to control current through the actuator based on the pressure.

6. A method for controlling pressure within a battery, comprising: disposing the battery between a support plate and a pressure plate, the pressure plate being configured to move relative to the support plate; as well as An actuator is energized to change between a first shape and a second shape to move the pressure plate relative to the support plate to control pressure within the battery.

7. The method according to claim 6, wherein: The actuator includes a strip of piezoelectric material extending from a first end to a second end, the strip of piezoelectric material being coupled to a control board at the first end by a first support and coupled to the control board at the second end by a second support.

8. A method according to claim 7, wherein one of the following: (i) the first end is fixed to the first support member and the second end is fixed to the second support member; (ii) the first end is fixed to the first support member and the second end is capable of sliding relative to the second support member; and (iii) the first end is capable of sliding relative to the first support member and the second end is capable of sliding relative to the second support member.

9. The method according to claim 7, wherein: The actuator also includes a steel bar coupled to the piezoelectric material.

10. The method according to claim 6, further comprising: A pressure sensor is used to measure the pressure within the battery, and the current through the actuator is controlled based on the pressure.

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