Patent Application
20120141851
1. Technical Field
The subject matter disclosed herein relates to an enclosure for an energy storage device.
2. Discussion of Art
Energy storage devices may have challenges with leakage and manufacturability. Multiple welded seams may increase the number of discontinuities in the packaging, which may increase inefficient thermal management.
It may be desirable to have a battery package that differs from those packages that are currently available.
Presently disclosed is an enclosure for an energy storage device. In an embodiment, the enclosure includes a cell housing having a base portion, and at least one side portion seamlessly extending from the base portion to define a volume and having a peripheral edge defining an aperture distal from the base portion through which an electrochemical cell may be disposed within the volume. A cover is securable to the peripheral edge of the cell housing over the aperture. The cell housing and cover are configured to house at least one electrochemical cell at an operating temperature that is greater than about 100 degrees Celsius.
A method to package an energy storage device is provided. In an embodiment, the method includes securing a cover to a peripheral edge of a cell housing having a base portion and at least one side portion seamlessly extending from the base portion, and placing the cell housing containing an electrochemical cell into an environmental housing volume through an aperture of the environmental housing.
An energy storage device is provided in one embodiment. The energy storage device includes a deep drawn monolithic housing defining a volume. The deep drawn monolithic housing has one or more corners, and at least one of the corners has a profile that is rounded. A cover engages the housing and at least partially encloses the volume. A plurality of electrochemical cells are disposed in the volume in an array configured to prevent any of the plurality of electrochemical cells from being disposed in the at least one corner with the rounded profile.
Reference is made to the accompanying drawings in which particular embodiments and further benefits of the invention are illustrated as described in more detail in the description below, in which:
The subject matter disclosed herein relates to an enclosure for an energy storage device. Referring to
In an embodiment, the enclosure for an energy storage device includes a cell housing having a base portion, and at least one side portion seamlessly extending from the base portion to define a volume. The housing also has a peripheral edge defining an aperture distal from the base portion through which at least one electrochemical cell may be disposed within the volume. The aperture is configured to receive one or more electrochemical cells during assembly. The enclosure also includes a cover that is securable to the peripheral edge of the cell housing. The housing and cover are configured to house at least one electrochemical cell at an operating temperature that is greater than about 100 degrees Celsius. In some embodiments, the housing and cover are configured to house electrochemical cells operating at temperatures greater than about 250 degrees Celsius, or greater than about 400 degrees Celsius.
Referring now to
As illustrated, the side portions 24 extend upward from the base portion 22. The side portions may be substantially straight or may be curved or stepped as desired. In some embodiments, the environment in which the energy storage device will be used imposes restrictions on the dimensions of the enclosure and the housing is configured to accommodate these dimensions. The base portion 22 is substantially planar as illustrated, but other configurations are also contemplated. In an alternative embodiment, the base portion includes ridges or alignment features to facilitate the installation and/or support of the electrochemical cells within the housing. In an embodiment, the ridges are integrally formed with the base portion of the housing. In an alternative embodiment, the guides are attached to the housing, such as by welding on L-brackets. In another embodiment, a sump portion 104 is provided to elevate and position the electrochemical cells and provide a reservoir to receive electrolyte fluid in the event an electrochemical cell is damaged. As shown in
In another embodiment, the housing 20 is provided with guides or rails to mate with the device or system with which the energy storage device will be used and to facilitate installation. For example, in one embodiment, rails 110 are attached to the side portions 24 of the housing 20 as illustrated in
The housing also has a peripheral edge 26 defining an aperture distal from the base portion 22 through which at least one electrochemical cell 106 may be disposed within the volume. The peripheral edge 26 is configured such that a cover (not shown in
In an embodiment, the cell housing 20 includes a base portion 22 and at least one side portion 24 extending seamlessly from the base portion 22 to define a volume 28. The term “seam” as used herein refers to a boundary or joint between two discrete pieces of material that are welded, bonded, or otherwise joined together. As such, the cell housing may be understood as having a continuous surface lacking in seams, joints or similar discontinuities in material between the base portion and the at least one side portion. In one embodiment, the cell housing is a seamless housing having a continuous surface lacking in seams, joints, or other discontinuities in material in the portion of the housing defining the volume.
Referring to
In another alternative, the cell housing 20 is a seamless housing lacking boundaries or joints between discrete pieces of material that are welded, bonded, or otherwise joined together, where the discrete pieces of material are purposed for defining the volume 28 of the housing 20. As such, a seamless housing has a continuous surface lacking in discontinuities of joined sections of materials, but for possible discontinuities of other materials provided for purposes other than defining the volume of the cell housing. A port for an electrical connector is one example of a discontinuity provided for purposes other than defining the volume. The purpose of a port is to provide access to the interior region of the cell housing and not for defining the volume of the housing, even though the port may fill the opening 78 and therefore define the volume in an incidental sense. In another embodiment, an opening 78 may be filled with a plug of material that is removeable for installing a connector or other component.
In another embodiment, the cell housing 20 is a seamless housing lacking boundaries or joints between discrete pieces of material that are welded, bonded, or otherwise joined together, where the discrete pieces form a non-circumscribed junction. The openings 78 or ports described above are examples of circumscribed junctions, laterally surrounded by continuous material of the housing.
In yet another embodiment, the cell housing 20 includes a base portion 22 and at least one side portion 24 extending seamlessly from the base portion to define a volume 28, and the cell housing 20 is seamless in a region encompassing a portion of the volume 28 defined by a second plane 116 that intersects at least a portion of the peripheral edge 26 and at least one side portion 24. As illustrated, the portion of the cell housing 20 that defines a portion of the volume 28 defined by the second plane 116 is seamless, where the portion of the volume 28 is less than the entirety of the volume.
In another embodiment, the cell housing 20 includes a base 22 with a periphery; the periphery defines an area of the base. All or a portion of the base 22 may be planar. Around the entire periphery of the base, a peripheral side wall extends up from and is seamlessly attached to (e.g., integral with) the base portion. Additionally, around the entire periphery, the peripheral side wall is disposed at a non-zero degree angle to the base portion, and has a height (distance greater than zero). The peripheral side wall defines at least part of a volume 28 of the housing 20. In an embodiment, at least part of the peripheral side wall is disposed at a ninety degree angle to the base. In another embodiment, the entire portion of the base and side wall below the volume defined by the side wall is seamless.
In various embodiments, the seamless housing is formed from sheet metal that is stamped, drawn, extruded, or pressed into the desired shape to form the housing without seams. In one embodiment, the cell housing is a deep drawn monolithic housing. A deep drawn housing is formed from material, such as a section of sheet metal, that is press formed one or more times to achieve the desired configuration. In one embodiment, press forming includes stamping a section of steel metal using a die to alter the shape of the metal. The resulting deep drawn housing retains the continuity of the original material avoiding the formation of seams or other discontinuities. A deep drawn housing is a monolithic structure consisting of a single unbroken component. After the housing is formed, one or more openings may be cut into the housing to accommodate ports. In an embodiment, a deep drawn monolithic housing is a seamless housing formed from one piece of material. A deep drawn housing may be provided in multiple configurations, such as the cell housing 20 illustrated in
In various embodiments, the cell housing is formed of stainless steel, other corrosion resistant alloy, or other suitable material that can provide structural support at the operating temperature of the energy storage device. The material of the housing may be selected to avoid undesired reactions with the chemistry of the electrochemical cells in the event that an electrochemical cell is damaged or leaks within the enclosure. Other factors in the material selection include environmental conditions, operating conditions, electrical and thermal insulation factors, and other application specific parameters. In one embodiment, the housing is formed of non-metallic materials such as molded plastic or fiberglass. In each instance, the housing may be understood to form a continuous structure for housing the electrochemical cells disposed within the volume of the cell housing. Additionally, since seams, such as weld joints, have been known to degrade over time, the housing may provide improved reliability and resistance to breakage, leakage or other deterioration. Further, since weld joints may have discontinuities, there may result relatively short paths for thermal loss and management that are undesirable. The enclosure described herein may be useful in applications where the energy storage device is subjected to high temperature, vibration, or both.
The cell housing of the enclosure for an energy storage device may be formed in a variety of shapes and sizes to accommodate specific electrochemical cells. The energy storage capacity of an energy storage device is correlated to the number of electrochemical cells utilized in the device, and the enclosure may be sized to house one, two, or any number of electrochemical cells to achieve a desired energy storage capacity. Additionally, the enclosure may be adapted to mate with the shape or mounting features of an existing application. In this manner, the enclosure may be utilized with replacement energy storage devices with minimal impact to the system or device with which it is to be used.
In another embodiment, the housing for use with an enclosure for an energy storage device is a substantially cylindrical housing 30 as illustrated in
Referring now to
The non-metallic core 52 may or may not be adapted to prevent leakage from the energy storage device or prevent the ingress of air or moisture. In one embodiment, the composite housing 50 has a seamless outer layer 54 at least partially covering the non-metallic core 52. The outer layer 54 may be capable of inhibiting the ingress of air or moisture into the enclosure. In an embodiment, the non-metallic core 52 is formed with seams and the outer layer 54 is seamless such that the composite housing 50 is a seamless housing as described above. In another embodiment, the non-metallic core 52 is also seamless. As illustrated in
In an embodiment, the composite housing 50 permits the selection of a first material for the non-metallic core 52 based upon the structural properties of the material, and permits the selection of a second material for the outer layer 54 based upon non-structural characteristics, such as the ability to inhibit the ingress of air or moisture into the enclosure. As such, the composite housing 50 may provide flexibility for certain applications of the enclosure.
Referring now to
The cover 40 may be secured to the peripheral edge 26 of the cell housing in a variety of methods. In one embodiment, the cover 40 is welded to the peripheral edge 26. The peripheral edge 26 may be configured to facilitate welding of the cover 40. In an embodiment, the peripheral edge 26 is weldable to the cover 40 to provide a single continuous seam securing the cover 40 to the housing. A single continuous weld seam may improve the reliability of the enclosure by reducing the number of welds and the number of discontinuities in the weld seam. A single continuous weld or full perimeter weld surface also may provide a longer path for thermal loss in the system. By reducing the number of weld seams, the opportunity for variation in weld quality is reduced increasing the likelihood of a high quality weld securing the cover 40 to the cell housing.
In other embodiments, the cover 40 is welded to the peripheral edge 26 of the housing by a weld process suitable to the materials selected for the cover and housing. In various embodiments, the weld seam is created by a laser weld process, a resistance weld process, an electron beam weld process, a plasma arc weld process, a tungsten inert gas weld process, a wire weld process, a solder weld process, or any other appropriate welding technique. Additionally, the connection between the cover 40 and the peripheral edge 26 of the housing may be any suitable weld joint geometry, such as butt joint, lap joint, corner joint, edge joint, or T-joint. The cover 40 may be welded to any portion of the peripheral edge 26 as desired to secure the cover to the housing. The peripheral edge 26 may thus be understood as the portion of the housing to which the cover 40 is secured. In some embodiments, the cover 40 is secured to a portion of the side portions 24 and this portion would also be properly understood as part of the peripheral edge 26 of the housing.
Referring now to
In other embodiments, a combination of fasteners and welds are utilized. For example, the cover 40 may be secured to the housing by a hinge during the assembly of the energy storage device to prevent the cover 40 from being separated from the housing and to allow the cover 40 to be opened and closed during the assembly process. After the electrochemical cells are placed within the volume of the housing, the cover 40 may be secured to the peripheral edge of the housing by a weld as previously described.
In yet another embodiment, the enclosure for an energy storage device further includes a flange extending from the peripheral edge of the housing to support the cover. Referring to
The flange 46 may provide a larger surface to facilitate attachment of the cover 40, and may improve the ability to weld the cover 40 to the housing by providing increased access to the weld area. A single continuous weld or full perimeter weld surface also may provide a longer path for thermal loss in the system.
In one embodiment, the cover 40 is secured to the flange 46 by a lap weld. In another embodiment, a gasket 48 is disposed between the cover 40 and the housing. As illustrated in
As illustrated in
In yet another alternative embodiment, the cover 40 has a curvature that is either convex or concave by a determined amount. A concave cover may extend towards the base portion of the housing. Alternatively, the cover may be convex and may extend away from the base portion of the housing. A convex cover may be convex by a sufficient amount that a vacuum applied to the volume after the cover is secured to the housing biases the cover from convex into a substantially planer configuration.
As described above, the base portion and cover may be formed to provide additional benefits or features to the enclosure. For example, the cover may have one or more raised portions to accommodate cables, connectors, or other components used in connection with the electrochemical cells of the energy storage device. In yet another embodiment, the cover is substantially similar to the housing, including a cover portion, side portions seamlessly extending from the cover portion, and a peripheral edge capable of being secured to the peripheral edge of the housing. Such an embodiment may substantially increase the size of the volume of the housing thereby increasing the capacity of the energy storage device by enabling the inclusion of a larger number of electrochemical cells.
In another embodiment, the enclosure for an energy storage device includes a first insulation element 72 configured to nestingly receive the cell housing 20 as illustrated in
Suitable insulating materials may be selected for use with the presently disclosed enclosure. In an embodiment, the first and second insulation elements are formed of the same insulating materials. In an alternative embodiment, the first and second insulation elements are formed of different materials. The insulation elements may be formed of one or more insulating materials, or combinations of material, to provide the desired amount of thermal insulation. In alternative embodiments, the insulation materials are foamed, woven, or non-woven insulation. In alternative embodiments, the insulation materials include zirconium, aluminum, magnesium, calcium-silicate, phase change materials or other suitable insulating materials or combinations of multiple materials.
Referring now to
As shown in
The environmental housing may provide an external or outer housing of the enclosure for an energy storage device. In an embodiment, the environmental or outer housing is constructed in substantially the same fashion as described above in connection with the cell housing including the seamless transition between the base portion and the at least one side portions. In one embodiment, the environmental housing 60 is a deep drawn monolithic housing. In another embodiment, the environmental housing 60 is larger, but otherwise identical to the cell housing. In other embodiments, the environmental housing 60 has seams and is constructed of one or more discrete parts joined together by welds, fasteners, or other attachments.
In an embodiment, the environmental housing 60 inhibits the ingress of air and moisture into the enclosure. In some embodiments, the environmental housing 60 and the housing combine to render the enclosure about impervious to moisture or leakage. The environmental housing 60 also provides structural support for the enclosure. For example, the environmental housing 60 may provide rigidity to the enclosure for protecting the electrochemical cells from damage.
Referring now to
In some embodiments, the operating temperature of the electrochemical cells of the energy storage device is greater than 100 degrees Celsius. In one embodiment, an energy storage device utilizing a sodium-halide chemistry has an operating temperature between 250 degrees Celsius and 300 degrees Celsius. Alternatively, an energy storage device may have an operating temperature greater than 300 degrees Celsius, and in some embodiments, may have an operating temperature between 400 degrees Celsius and 700 degrees Celsius. Although energy storage devices have high internal operating temperatures, it may be desired to employ an energy storage device in an environment with a substantially lower ambient temperature.
In various embodiments, the enclosure for an energy storage device also includes at least one first insulation element 72 configured to nestingly receive the cell housing 20, and a second insulation element 74 configured to engage the first insulation element and be positioned adjacent to the cover 40. In one embodiment, the housing is enveloped by the first insulation element 72 and the second insulation element 74 prior to installation in an environmental housing. As illustrated in
In another embodiment, the enclosure includes the first insulation element nestingly receiving the cell housing and the second insulation element, without the use of an environmental housing, such as illustrated in
In another embodiment, the enclosure for an energy storage device includes a vacuum between the environmental housing and the cell housing to provide thermal insulation. A vacuum applied to the space between the environmental housing and the cell housing may increase the thermal resistance of the enclosure thereby reducing the transfer of heat from the enclosure to the surrounding environment. In one embodiment, after the environmental cover is secured to the environmental housing, a negative pressure may be applied to a sealable aperture in a side portion of the environmental housing to establish a vacuum or reduced pressure within the enclosure.
The enclosure for an energy storage device may also include one or more openings configured to provide access to the volume of the housing and the electrochemical cells disposed within the enclosure. In one embodiment, the enclosure for an energy storage device includes a sealable port extending from the exterior of the enclosure through at least one side portion and into the volume of the cell housing to provide external electrical access to the at least one electrochemical cell disposed within the housing. In one embodiment, the sealable port provides an airtight seal between the side portions of the environmental housing and the housing to maintain a vacuum or reduced pressure between the environmental housing and cell housing as previously discussed. The sealable port may also be adapted to provide an electrical connection pathway to the at least one electrochemical cell disposed within the housing, such as by installing an electrical connector in the sealable port. In another embodiment, the sealable port is hermetically sealed and a hermetically sealed electrical connector provides the electrical pathway. In an embodiment, the connector is selected to reduce the ingress of air or moisture that could interfere with the operation of the energy storage device, and is selected to accommodate the electrical current and voltage to be produced by the energy storage device.
Referring again to
Referring now to
In addition, when the environmental housing 60 is secured to a system or other device by the flange 68, the flange 68 may provide an effective pathway for thermal loss or electrical grounding of the enclosure. In various embodiments, the flange 68 may be smaller or larger as desired and may be sized and configured to meet the requirements of a given installation or application.
One or more electrochemical cells may be disposed within the enclosure presently disclosed to form an energy storage device. In an embodiment, an electrical storage device includes a cell housing nestingly received in an environmental housing with an insulating material disposed between the cell housing and the environmental housing. The orientation of the electrochemical cells disposed within the volume of the cell housing may be varied as desired. In one embodiment, an array of electrochemical cells is provided in the cell housing. The array of electrochemical cells may be connected in series or parallel as necessary to provide the desired current and voltage for a given application.
To facilitate installation and maintenance, the electrochemical cells may be disposed within the housing such that the electrical connections of the electrochemical cells are accessible when the cover is removed. However, the orientation of the electrochemical cells disposed within the volume of the housing is not restricted and the arrangement of the electrochemical cells may be tailored for specific applications.
In another embodiment, the plurality of electrochemical cells are disposed in the volume of the cell housing in an array configured to prevent any of the plurality of electrochemical cells from being disposed in the at least one corner with a rounded profile. As previously discussed, the transition between the base portion 22 and the at least one side portion 24 of the cell housing 20 may have a rounded profile or corner that interferes with the placement of electrochemical cells immediately adjacent the side portion 24. In other embodiments, transitions between the at least one side portions 24 have a rounded profile that interferes with the placement of electrochemical cells. As shown in
Referring now to
In an embodiment, the controller is in communication with the sensor, and the sensor is further capable of monitoring one or more conditions or parameters of the electrochemical cells in the energy storage device and communicating information related to the monitored conditions to the controller. For example, the sensor may be capable of detecting the charge level of the electrochemical cells and identifying a low power condition when the power output of the electrochemical cells is depleted. Similarly, for a rechargeable system, the sensor may be capable of reporting a full charge condition allowing the controller to discontinue charging the electrochemical cells to avoid potential damage or degradation of the cells. In some embodiments, the controller and sensor are co-located, or one device may provide both the sensing and controlling capability for the energy storage device.
In another embodiment, the enclosure for an energy storage device includes an inlet port 92 that fluidically couples an internal region of the enclosure to an external source of heat transfer fluid such as a cooling fluid, an outlet port 94 fluidically coupled to the internal region of the enclosure which allows emission of a fluid from the internal region of the enclosure, and a displacement unit 90 fluidically coupled to the inlet port which pushes the fluid through the inlet port into the internal region of the enclosure through the outlet port and out of the enclosure. The inlet port 92 and outlet port 94 include inner connectors 96 and outer connectors 98. In an embodiment, the inner connectors 96 may be connected to pipes within the enclosure adapted to absorb heat from the electrochemical cells. The outer connectors 98 are connected to the displacement unit 90 as shown, or may be connected to other external plumbing as desired. In one embodiment, displacement unit 90 dissipates excess heat and the heat transfer fluid remains in a closed system circulating through the enclosure of the energy storage device.
In an embodiment, the displacement unit 90 is controlled by a temperature regulation system configured to monitor and control the operating temperature of the energy storage device within a predetermined temperature range. In another embodiment, the energy storage device includes a heating system disposed within the enclosure configured to raise the temperature of the electrochemical cells to the desired operating temperature. In one embodiment, the internal operating temperature of the energy storage device is maintained between approximately 200 degrees Celsius and 300 degrees Celsius. In one embodiment, the sensor 84 is further capable of detecting the temperature of the electrochemical cells within the enclosure and communicating the monitored temperature to the controller 80. The controller 80 may implement a temperature regulation system by controlling the operation of a heating system and the displacement unit 90 to heat or cool the electrochemical cells as required to maintain the desired operating temperature.
Referring now to
In another embodiment, the enclosure for an energy storage device includes a cell housing and a cover. The cell housing has a base portion, and at least one side portion extending from the base portion to define a volume. The side portion has a peripheral edge defining an aperture distal from the base portion through which at least one electrochemical cell may be disposed within the volume. The cover is securable to the peripheral edge of the cell housing. The housing and cover are configured to house the at least one electrochemical cell at an operating temperature equal to or greater than approximate 100 degrees Celsius. “Approximate” a given value of degrees Celsius (e.g., 100 degrees Celsius) means +/−2% of the given value. In another embodiment, the housing and cover are configured to house the at least one electrochemical cell at an operating temperature at or above 100 degrees Celsius. In another embodiment, the housing and cover are configured to house the at least one electrochemical cell at an operating temperature that is above 200 degrees Celsius.
This written description uses examples to disclose the invention, including the best mode, and also to enable one of ordinary skill in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not different from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
