Systems and methods related to controlling battery temperature are generally described.
Batteries can be used to provide power to a wide variety of devices, from portable consumer electronics to electric motor vehicles. In many cases, batteries can exhibit reduced performance when they are operated outside a predetermined range of temperatures. For example, when some batteries are too hot, undesirable chemical reactions can occur and/or components of the battery can be structurally compromised, both of which can damage the battery. In some cases, when the battery temperature is too cold, power output can be diminished and, at sufficiently low temperatures, batteries will not charge or discharge. Moreover, thermal gradients within a battery and/or from one battery to another within a pack of batteries can lead to unpredictable power output, among other adverse effects. For these reasons, among others, the ability to control the temperature of batteries is desirable.
The embodiments described herein generally relate to systems and methods for controlling battery temperature. The subject matter of the present invention involves, in some cases, interrelated products, alternative solutions to a particular problem, and/or a plurality of different uses of one or more systems and/or articles.
In one aspect, a system for controlling temperature within a battery pack is described. In some embodiments, the system can comprise a battery pack comprising at least one electrochemically rechargeable battery cell; a source of temperature control gas; and a temperature control gas distribution and heat transfer system. In some cases, the temperature control gas distribution and heat transfer system can comprise at least one gas delivery section delivering temperature control gas to the battery pack, and downstream from the gas delivery section, at least one heat exchange section substantially parallel to a surface of the battery pack and having a direction of flow, wherein the heat exchange section passes only across a portion of the pack that is shorter than the dimension of the pack as measured in a direction substantially parallel to the direction of flow of the heat exchange section.
The system can comprise, in some embodiments, a battery pack comprising at least one electrochemically rechargeable battery cell; a source of temperature control gas; and a temperature control gas distribution and heat transfer system constructed and arranged such that at least a portion of the temperature control gas is not transported from one boundary of the battery pack to an opposed boundary of the battery pack.
In some instances, the system can comprise a battery pack comprising electrochemically rechargeable battery cells; a source of temperature control gas; and a temperature control gas distribution and heat transfer system comprising a flow path comprising a first portion that is directed at a first boundary portion of the battery pack and is deflected proximate the first boundary portion such that the flow path changes direction, the battery pack lying within the reflex angle defined by the direction of the flow path, and a second portion that is deflected proximate a second boundary portion of the battery pack such that the flow path changes direction and enters the battery pack through the second boundary portion.
The system can comprise, in some cases, a battery pack comprising electrochemically rechargeable battery cells; a source of temperature control gas; and a temperature control gas distribution and heat transfer system comprising a flow path comprising a first portion that is deflected proximate a boundary of the battery pack such that the flow path changes direction and enters the volume of the battery pack through the boundary, and a second portion that is deflected within the battery pack such that the flow path changes direction.
In another aspect, a method of controlling temperature within a battery pack is described. In some embodiments, the method can comprise establishing the flow of a temperature control gas across at least a portion of a surface of a battery pack, wherein at least a portion of the temperature control gas is not transported from one boundary of the battery pack to an opposed boundary of the battery pack.
Other advantages and novel features of the present invention will become apparent from the following detailed description of various non-limiting embodiments of the invention when considered in conjunction with the accompanying figures. In cases where the present specification and a document incorporated by reference include conflicting and/or inconsistent disclosure, the present specification shall control. If two or more documents incorporated by reference include conflicting and/or inconsistent disclosure with respect to each other, then the document having the later effective date shall control.
Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention. In the figures:
Systems and methods are provided for controlling battery temperature, for example those used in electric vehicles. In some embodiments, a temperature control gas is used to heat or cool a battery pack to establish and/or maintain a relatively uniform temperature distribution within the pack. The temperature control gas can also be used to adjust and/or maintain the temperature of the battery pack such that it falls within a pre-selected range of temperatures. In some cases, the temperature control gas can be transported through a temperature control gas distribution and heat transfer system including a gas pathway constructed and arranged such that the temperature control gas exchanges heat with the battery pack only over a portion of the cross-sectional length of the pack. The use of relatively short gas pathways can ensure that the temperature control gas is not heated or cooled to an extent that renders the gas ineffective as a heat exchange medium prior to reaching downstream portions of the battery pack.
Many traditional temperature control systems for batteries have operated by transporting a temperature control gas from one boundary of the battery pack to an opposed boundary of the battery pack. This can lead to relatively large thermal gradients within the battery pack. Briefly, when a temperature control gas is used to control battery pack temperature, the temperature of the gas changes as the gas exchanges heat with the battery pack. For example, when a cooling gas is transported along a battery pack, the cooling gas becomes hotter as it travels along a surface of the battery pack. As the temperature control gas is transported along the pack, the temperature difference between the pack and the gas becomes smaller, relative to the temperature difference between the pack and the gas at the gas inlet. In such cases, more heat can be transferred from the portion of the battery pack near the temperature control gas entry (where a relatively large thermal gradient exists) than can be transferred toward the end of the temperature control gas pathway (where a relatively small thermal gradient exists). This effect can produce an uneven temperature distribution within the battery pack.
The inventors have discovered, within the context of the invention, that the temperature within a battery pack can be more effectively controlled by manipulating the flow pathway of the temperature control gas such that it spans relatively short lengths. In some embodiments, the systems and methods described herein can employ temperature control gas distribution and heat transfer systems including gas pathways that lead to reduced temperature gradients (and hence, reduced disparities in heat flux across the surfaces of the batteries) within the battery pack. For example, in some cases, the temperature control gas distribution and heat transfer system can be constructed and arranged such that at least a portion of the temperature control gas is not transported from one boundary of the battery pack to an opposed boundary of the battery pack.
The systems and methods described herein can be used to control the temperature of battery packs in a wide variety of applications. For example, the temperature of a battery pack of an electric motor vehicle (e.g., to power the drive train and/or electronics systems) can be controlled, in some embodiments. In some cases, the temperature of a battery pack in a portable electronic device (e.g., laptops, cellular phones, and the like) can be controlled. In some cases, the temperature of a battery pack in a stationary energy power storage application (e.g., utility power storage, windmill storage packs, and the like) can be controlled.
As mentioned, temperature control can be achieved using a temperature control gas. As used herein, a “temperature control gas” refers to a gas that is used to exchange heat with a component of the battery pack to alter the temperature of the component. In some embodiments, the temperature control gas can act as a cooling gas by removing heat from a portion of a battery pack component. The temperature control gas can act as a heating gas, in some cases, by supplying heat to a portion of a component of the battery pack. The temperature control gas can be used to maintain a substantially consistent temperature throughout the battery pack and/or to ensure that the minimum and maximum temperatures of the battery pack lie within a predetermined temperature range.
In
System 100 can also include a temperature control gas distribution and heat transfer system. The temperature control gas distribution and heat transfer system can be constructed and arranged to establish the flow of the temperature control gas across at least a portion of a surface of the battery pack. As the temperature control gas is transported across the portion of the surface of the battery pack, it can exchange heat with the battery pack such that the portion of the battery pack surface that is contacted is heated or cooled. In some embodiments, the temperature control gas can be transported across an interior surface within the battery pack. For example, the temperature control gas can be used to heat or cool an exterior surface of a battery cell that lies within the boundaries of the battery pack, such as surface 114 in
In some embodiments, the temperature control gas distribution and heat transfer system can include at least one gas delivery section that can be used to deliver temperature control gas to the battery pack. As shown in
In
The temperature control gas distribution and heat transfer system can also include, in some embodiments, at least one heat exchange section downstream from the gas delivery section. In some embodiments, the gas delivery section can be constructed and arranged to deliver temperature control gas to the heat exchange section(s), where the gas can be used to exchange heat with the battery cells in the battery pack. A heat exchange section can, in some embodiments, comprise a branch (e.g., a channel or other suitable fluid passageway) fluidically connected to, and extending from the gas delivery section. In some embodiments, multiple heat exchanges sections can extend from the gas delivery section. For example, in
In some embodiments, the heat exchange section(s) within the battery pack can be relatively short. In some embodiments, one or more heat exchange sections pass only across a portion of the battery pack that is shorter than the dimension of the pack as measured in a direction substantially parallel to the direction of flow of the heat exchange section. For example, in
The use of short heat exchange sections can ensure that the surface area over which the temperature control gas contacts the surface(s) of the battery cells is relatively small. When the area of contact between the temperature control gas and the battery cells is relatively small, it is relatively easy to ensure that the temperature control gas is not excessively heated or cooled as it is transported through the system, compared to systems in which large contact areas are employed. Relatively short contact areas can allow for effective heat transfer while using relatively low temperature control gas flow rates and/or relatively small temperature differences between the temperature control gas and the battery cells.
In some embodiments, the gas delivery section(s) and heat exchange section(s) can be constructed and arranged such that relatively little heat transfer occurs in the gas delivery section(s) and a relatively large amount of heat transfer occurs in the heat exchange section(s). For example, in some embodiments, at least about 75%, at least about 90%, at least about 95%, or at least about 99% of the heat transferred between the temperature control gas and the cells within the battery pack is transferred within heat exchange sections of the temperature control gas distribution and heat transfer system within the battery pack. One of ordinary skill in the art would be capable of determining the amount of heat transferred within various parts of the passageways within the battery pack by, for example, measuring the temperature of the gas within the battery pack at various positions within the temperature control gas distribution and heat transfer system and on the surfaces of the cells, and calculating the amount of heat transferred based upon the enthalpy of the temperature control gas.
In some embodiments, at least a portion of the temperature control gas is not transported from one boundary of the battery pack to an opposed boundary of the battery pack. Temperature control gas is said to be transported from one boundary of a battery pack to an opposed boundary of the battery pack when it enters the pack through a first boundary and exits the pack through a second, opposed boundary. In
The temperature control gas can be, in some embodiments, transported over a relatively short length. In some instances, at least a portion of the temperature control gas is transported along a length that is substantially equal to or less than about 75%, substantially equal to or less than about 50%, substantially equal to or less than about 25%, or substantially equal to or less than about 10% of the dimension of the pack as measured in a direction substantially parallel to the direction of flow of the temperature control gas at the temperature control gas inlet. For example, in
In some cases, a relatively large portion of the temperature control gas that is transported through the boundary pack is not transported from one boundary of the battery pack to an opposed boundary of the battery pack. For example, in some instances, at least about 50%, at least about 75%, at least about 90%, at least about 95%, at least about 99%, or substantially all of the temperature control gas that is transported through the battery pack is not transported from one boundary of the battery pack to an opposed boundary of the battery pack. In
In some cases, the temperature control gas distribution and heat transfer system can include a flow path comprising multiple turns.
In some embodiments, the temperature control gas distribution and heat transfer system includes a flow path comprising a first portion that is directed at a first boundary portion of the battery pack and is deflected proximate the first boundary portion such that the flow path changes direction. In such cases, the battery pack can lie within the reflex angle defined by the direction of the flow path. For example, in the set of embodiments illustrated in
The flow path of the temperature control gas can include, in some instances, a portion in which the temperature control gas is deflected proximate a boundary portion of the battery pack such that the flow path changes direction and enters the battery pack through the boundary portion. For example, in
The temperature control gas flow path can also include, in some embodiments, one or more portions within the battery pack at which the temperature control gas changes direction. For example, in
The temperature control gas can, in some cases, be transported into the battery pack through a relatively small portion of a battery pack boundary. For example, in some cases, substantially all of the temperature control gas can be transported into the battery pack through a portion (or multiple portions) of a battery pack boundary that occupies less than about 50%, less than about 25%, less than about 10%, or less than about 5% of the surface area of the battery pack boundary. As a specific example, in the set of embodiments illustrated in
In some cases, the portion of the boundary of the battery pack through which the temperature control gas enters the battery pack can include the geometric center of the boundary. Transporting the temperature control gas through the geometric center of a battery pack boundary can provide for a substantially even distribution of temperature control gas within the battery pack, which can lead to uniform and more controllable heat transfer, in some cases. In some instances, the geometric centers of the portion through which the gas enters and the boundary in which the entry portion is located are substantially aligned (i.e., the portion of the boundary through which the temperature control gas enters is centered on the geometric center of that boundary). For example, in the set of embodiments illustrated in
While embodiments have been described in which the battery pack includes a plurality of electrochemically rechargeable battery cells, other embodiments might make use of a battery pack that includes a single electrochemically rechargeable battery cell. For example, in the set of embodiments illustrated in
In the systems and methods described herein, the flow of temperature control gas can be established using any suitable method. In some cases, the temperature control gas can be transported using a pump and/or a vacuum. In some cases, the temperature control gas can be transported relative to the battery pack due to the movement of the battery pack relative to the temperature control gas. For example, in some cases, the temperature control gas can comprise ambient air that is transported through an air intake manifold upon movement of an automobile.
The temperature control gas distribution and heat transfer system can include, in some embodiments, one or more channels (e.g., from the temperature control gas source to the battery pack, between battery cells in the battery pack, etc.). A “channel,” as used herein, refers to a feature on or in an article or substrate, or between two articles, that at least partially directs the flow of a fluid. A channel can have any cross-sectional shape (circular, semi-circular, oval, semi-oval, triangular, irregular, square or rectangular, or the like) and can be covered or uncovered. In embodiments where it is completely covered, at least one portion of the channel can have a cross-section that is completely enclosed, or the entire channel can be completely enclosed along its entire length with the exception of its inlet(s) and outlet(s). A channel can also have an aspect ratio (length to average cross sectional dimension) of at least 2:1, more typically at least 3:1, 5:1, or 10:1 or more.
The direction of fluid flow within a temperature control gas flow pathway can be controlled using any suitable device. In some embodiments, the surfaces of the batteries within the battery pack can be arranged to obtain the desired flow profile. In some cases, the flow profile can be controlled using one or more fins within the system (e.g., within the battery pack). For example,
U.S. Provisional Patent Application No. 61/325,063, filed Apr. 16, 2010, and entitled “Battery Temperature Control” is incorporated herein by reference in its entirety for all purposes.
While several embodiments of the present invention have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present invention. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the invention may be practiced otherwise than as specifically described and claimed. The present invention is directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present invention.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of” or “exactly one of” “Consisting essentially of” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/325,063, filed Apr. 16, 2010, and entitled “Battery Temperature Control,” which is incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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61325063 | Apr 2010 | US |