Battery

Abstract

Battery (10), comprising a plurality on battery cells connected in series or parallel (12), each having a cell envelope (13) and an anode region (16) emerging from the cell envelope (13) and have a cathode region (18) emerging from the cell envelope (13), wherein the anode regions (16) emerging from the cell envelope (13) and the cathode regions (18) emerging from the cell envelope (13) the majority of battery cells (12) at least partially are embedded in a casting compound (20), and furthermore within the casting compound (20) at least an anode region (16) and a cathode region (18), an anode region (16) and an anode region (16) and / or a cathode region (18) and a cathode region (18) are placed one above the other and connected to each other, wherein the casting compound (20) can be tempered by a tempering element (28).

Description

The present invention relates to a battery having a plurality of battery cells, wherein effective temperature control of the battery cells is permitted and, furthermore, simple mullability is permitted.Prior ArtA wide variety of energy stores, such as lithium-based energy stores or lithium-ion batteries, are hardly to be considered away from today's life. Fields of application include, in addition to fully electrically driven vehicles or hybrid vehicles, also electrical tools, electrical entertainment electronics, computers, mobile telephones and further applications.In order to ensure the safety of battery cells, such as lithium ion cells, battery modules or battery packs, and to optimize the performance and service life, it is often necessary to operate the battery cells within a defined temperature range which is optimum for operation or storage. In particular with high power consumption or power output, the heating of the battery cells above the optimum operating temperature should be avoided and heat should be dissipated in order to avoid damage to the system or a reduction in the service life.Furthermore, battery concepts are being followed which provide for the operation of batteries at temperatures which are above room temperature, such as, for example, in a range of 60-80° C. Such batteries should optionally be heated during operation, wherein cooling can be partly dispensed with. Heating can be realized, for example, by heating foils which are placed on or between the cells.The document DE 10 2011 104 000 A1 describes an apparatus for heating a battery and a battery with an apparatus for heating. Such a battery comprises in detail a heating means, such as a heating wire, a heating band, a heating strand and / or a fluid channel, which is arranged or integrated in a flexible enveloping element. The enveloping element is formed in particular from a textile mat or a woven cloth. Furthermore, the individual cells which are connected in series are thermally coupled to the heating element via their electrical contact elements.Furthermore, a high-voltage battery is known from document DE 10 2011 109 969 A1. The high-voltage battery comprises a number of cell blocks having a plurality of cells, wherein a frame and a cooling and / or heating plate are furthermore provided. This document teaches that the edge portion of the cooling / heating plate is electrically insulating. Furthermore, a heat-conducting film is arranged adjacent to the cooling and / or heating plate.The document DE 10 2010 052 514 A1 describes a battery pack having a housing for accommodating a plurality of battery cells. For the electrical connection of the cells to one another, a cathode arrester of a first battery cell and an anode arrester of an adjacent battery cell are electrically connected to one another via a contact device. The contact device consists of a spacer element lying between arresters and a clamping element which engages over the arresters and the spacer element and holds the arresters on the side surfaces of the spacer element in an electrically connecting manner, wherein an element of a first contact device is formed integrally with a connection pole of the battery block.Document US 2013 / 0 323 572 A1 describes a cell unit for a secondary battery. Such a cell unit comprises two adjacent battery cells each having a cell housing. At least one cell housing has a recessed area for disposing a thermal transfer element such as a metal.The document DE 10 2011 109 306 A1 describes a modular arrangement for receiving battery cells. In this case, a plurality of U-shaped elements with cooling fluid channels are provided, which are fastened to one another in a stacked manner. Furthermore, carrier plates can be fastened to the elements, to which battery cells are in turn fixed.The document DE 10 2012 112 294 A1 describes an electrical energy store. Such an energy store has battery cells designed as pouch cells, between which a film containing graphite particles is arranged for cooling. furthermore, a cooling duct is provided in the region of at least one cell terminal, which cooling duct is connected to the cell terminal and the film in a heat-transferring manner.Furthermore, the documents DE 10 2010 002 289 A1, DE 10 2008 059 955 A1 and U.S. Pat. No. 7,993,776 B2 are also prior art in this regard.Disclosure of the InventionThe present invention relates to a battery comprising a plurality of series- or parallel-connected battery cells, each of which has a cell casing and an anode region emerging from the cell casing and a cathode region emerging from the cell casing. The anode regions emerging from the cell casing and the cathode regions emerging from the cell casing of the plurality of battery cells are at least partially embedded in a potting compound, wherein the potting compound can be temperature-controlled by a temperature-control element. Furthermore, within the potting compound, at least one anode region and one cathode region, one anode region and one anode region and / or one cathode region and one cathode region are placed one above the other and are connected to one another.A battery described above thus achieves the object of allowing efficient temperature control of battery cells along with advantageous mullability in a simple and cost-effective manner.The present invention thus relates to a battery. A battery may be a primary battery or advantageously a secondary battery, i.e. a rechargeable battery. For example, the battery can be a lithium-based battery, in particular a lithium-ion battery.Such a battery includes a plurality of battery cells, such as lithium ion cells. The battery cells can form a battery module in a manner known per se and can be connected in series or in parallel in a suitable manner in order to achieve the desired specifications of the battery module.The battery cells each have a cell casing and an anode region emerging from the cell casing and a cathode region emerging from the cell casing. Such battery cells can thus be configured in a manner known per se.For example, the battery cells can be designed as so-called pouch cells or pouch cells and have a plurality of cell units placed one above the other, which are arranged in a flexible casing. The battery cells can be configured in a manner known per se as a film structure with applied active materials. In this embodiment, the envelope can have a sealed film structure, wherein the arresters of the anode and of the cathode can each be present from the envelope as an anode region emerging from the cell envelope or as a cathode region emerging from the cell envelope. The arresters of the individual cell units of the pouch cell can be in electrically conductive contact and thus each together form the anode region or cathode region emerging from the cell envelope.Alternatively, the cell casing can be formed by a rigid cell casing, also referred to as a hardcase casing, for example made of plastic or of metal, wherein the battery cell can be, for example, a prismatic cell. In this configuration, the battery cell can have an in particular flat-wound film winding, which is also referred to as a jelly roll, which has, for example, an aluminum foil and a copper foil, which are coated with reactive cathode materials or anode materials. Furthermore, two plastic films, which are designed for example as diaphragms, can be provided, which separate the anode and the cathode. The remaining region within the cell envelope can be filled with an electrolyte, for example.In order to realize electrical contacting of the cathode or the anode of the film roll, the two films designed as a cathode or as an anode, for example, cannot be placed against one another with an exact fit, but rather can be slightly offset in the direction of the roll axis. As a result, the negative voltage can be tapped off on one open narrow side of the winding, and the positive voltage of the respective foil or electrode on the other, opposite narrow side, by the foils projecting or protruding from the casing as arresters of the anode or the cathode.In order to reduce thermal runaway or counteract its effects, a rupture membrane can be provided in the case of a rigid housing and a predetermined breaking point can be present in the case of a flexible casing, for example in the case of a pouch cell.In the case of a battery described above, it is furthermore provided that the anode regions emerging or protruding from the cell casing and the cathode regions emerging or protruding from the cell casing are at least partially embedded in a potting compound. In the context of the present invention, this can mean, in particular, that at least a part of the respective anode region or of the cathode region located outside the cell envelope is not exposed, but is embedded in, i.e., preferably cast around, a potting material or in a potting compound.This can be realized, for example, by placing the arrangement of a plurality of battery cells in a mold, which is filled with a curable compound at the corresponding regions, whereupon the compound is cured, for example, by the action of temperature or radiation. Alternatively, the plurality of battery cells can already be placed in a module housing which has corresponding regions which are filled with a castable compound, whereupon the compound can be cured. This makes it possible to achieve a very tight and intimate contact between the embedded component, that is to say in particular the arresters or the anode region emerging or protruding from the cell cladding and the cathode region emerging or protruding from the cell cladding and the potting compound.In the context of the present invention, a potting compound or a potting material is to be understood as meaning, in particular, a material of this type which, at least in one production step, in particular under normal conditions, that is to say 22° C. and 1bar, has a pourable consistency and is optionally curable. In particular, the casting compound can be pourable when embedding the anode regions or the cathode regions and can subsequently be curable, for example by the action of radiation or heat.In the case of a battery described above, temperature control of the battery or of the module can be made possible in a simple manner. Because the potting compound can be temperature-controlled by a temperature-control element, i.e. one or more than one temperature-control element, very effective temperature control of the battery cells can be made possible in a simple manner. In detail, the potting compound can be temperature-controlled, which is in particularly close thermal contact with anode regions or cathode regions, preferably of all battery cells of the battery module, with the result that heat can be supplied directly to the anodes and / or the cathodes in a particularly effective manner or can be dissipated therefrom. A temperature control can thus be integrated and effected directly, which brings about a particularly effective temperature control at the positions significant for a temperature control, namely within the battery cells.Additional elements, such as heat conducting foils or the like, can be dispensed with, so that particularly simple and cost-effective production and furthermore good durability can be made possible.The potting compound can be tempered in a manner known per se by the use of fundamentally known tempering agents or tempering units which act on the potting compound.In the case of a battery described above, moreover, secure fixing of the anode regions or of the cathode regions can be made possible in a simple manner, and therefore production can be particularly simple and stable. In particular, when pouch cells are provided, a standardized, favorable module structure can be made possible in a simple manner. This allows a simple design of different battery systems with regard to the geometry. It is also possible to show dimensions and peripheries, such as connections, as are otherwise known for prismatic cells with an inflexible housing.Furthermore, a connection of a temperature control can be standardized, since essentially no consideration need be taken of the geometry of the battery cells when the temperature control elements are provided. This is because the anode regions or cathode regions protruding from the cell casing can be very effectively tempered with the potting compound being interposed, wherein a tempering element can act on the potting compound, the final geometry of which can be selected substantially freely and can be adapted to existing or standardized elements.In summary, a battery described above enables improved mikroability in a simple and cost-effective manner, associated with effective temperature control of the battery cells.Within the scope of one embodiment, the temperature control element can be arranged within the potting compound. In this configuration, the potting compound and thus also the battery cells can be tempered particularly effectively and thus with a particularly low energy input. This is because in this embodiment, the potting compound can be tempered from the inside, which can keep losses particularly low, which can be advantageous in particular when supplying heat. Such a configuration can be easily formed because the corresponding, for example standardized, temperature control medium can be encapsulated in a simple manner by the potting compound, for example together with the corresponding anode regions or cathode regions, during the production of the battery. The production can thus be particularly simple.Within the scope of a further embodiment, the temperature control element can be provided adjacent to the potting compound and thermally coupled thereto. In this embodiment, substantially standardized temperature control elements can be used, which only need to be arranged adjacent to the potting compound and in thermal contact therewith. For example, in this embodiment, the temperature control element can be arranged in an approximately plate-shaped carrier, for example an adapter plate, which is arranged adjacent to the potting compound and in thermal contact therewith. Such carriers can be formed, for example, from a plastic, metal or a combination thereof.Within the scope of a further embodiment, the temperature control element can have a line structure for conducting a fluid temperature control medium. The provision of such a temperature control medium or coolant structure is known per se to the person skilled in the art and can serve in particular to guide a fluid suitable for temperature control, such as in particular a liquid, through the temperature control element in order thus, for example, to dissipate heat from the battery cells or to supply it to the battery cells. The temperature control element is thus in particular an active temperature control element in which a temperature control effect is based on a temperature control medium and which can equally serve for cooling and heating. The temperature control medium, in particular temperature control fluid, to be used in connection with the temperature control element is in principle not restricted. As temperature control agents, for example, but not by way of limitation, air, water, glycol or water / glycol mixture or else refrigerant, such as, for example, the agent known under the designation R1234yf, can be used in order, for example, to dissipate heat. In this way, the potting compound or the battery cells can be kept in a suitable temperature range which, for example and in no way limiting, can lie in a range from greater than or equal to 30° C. to less than or equal to 40° C., although values outside this range, such as from greater than or equal to 60° C. to less than or equal to 80° C., can also be suitable. In principle, however, essentially any desired temperature can be set by adjusting the temperature control medium.A battery system comprising the battery can have, for example, a temperature control medium circuit which is of known design and is connected to the temperature control medium structure.Within the scope of a further embodiment, the temperature control element can have a heating conductor. In this configuration, the heating conductor, such as the heating wire or a heating element with a sufficient electrical resistance, can be connected to a current source, which can be an external current source or the above-described battery itself, and thereby heat the potting compound or the battery cells. This embodiment offers the advantage of particularly cost-effective mikroability. Furthermore, such a temperature control element requires only a very small space requirement, so that implementation into existing systems is possible in a particularly simple manner. This configuration is suitable in particular for systems of this type which operate at an elevated temperature, for example at greater than or equal to 60° C. to less than or equal to 80° C., so that cooling can be dispensed with under certain circumstances.Within the scope of a further embodiment, the potting compound can comprise a resin, in particular an epoxy resin or a polyurethane resin. Resins in particular are distinguished in that they can be well suited as casting compound and are subsequently curable without problems. Epoxy resins or polyurethane resins can also be used without problems in the above-described application in batteries and can also be stable over long periods of time. Furthermore, these already have sufficient thermal conductivity, so that further additions can be dispensed with under certain circumstances and depending on the respective application. In a manner which is obvious to the skilled person, a curing agent may optionally be added to the resins during production in order to cure them. The selection of the specific resins used can be made in a manner that is obvious to the skilled person by specifying the desired properties.Within the scope of a further embodiment, the potting compound can have an additive for increasing the thermal conductivity. In other words, a substance can be provided in the casting compound in such a way that the thermal conductivity of the casting compound with this substance is higher than without this substance. In this embodiment, an even more free selection of the potting compound can be effected, since it does not necessarily have to be selected on the basis of its thermal conductivity. Thus, substantially independently of the choice of the potting compound, a particularly effective temperature control of the battery cells can be made possible.Non-limiting examples of such additives include, for example, boron nitride and / or aluminum oxide, which may be stable and durable under the operating conditions of a battery.According to the invention, the anode regions emerging from the cell casing and / or the cathode regions emerging from the cell casing of two adjacent battery cells are placed one above the other and connected to one another. In this configuration, the arresters or the anode regions and cathode regions can each be angled and connected to one another, for example welded. In this configuration, a corresponding circuit, in series or in parallel, of the individual battery cells can be effected in a particularly simple and reliable manner, which can further improve the mullability. Depending on the circuit of the battery cells, in particular in the case of a parallel circuit, a collector for a module terminal can be provided on each side. This collector can extend, for example, between the cell casings and the arresters or anode regions or cathode regions. An electrically conductive connection to the arresters and also to the arresters among one another can be effected, for example, by laser welding, ultrasonic welding or clinching. Furthermore, the collector can be at least partially embedded in the potting compound.Within the scope of a further embodiment, a means for determining a cell voltage can be provided. This embodiment allows an advantageous check of the performance of the battery or of the module over its service life. For example, an electronic connection element can be provided, which is electrically connected, for example, to the protruding anode regions or cathode regions. In this case, a separate connection element can be present for each desired measurement position, or a common connection element can preferably be present as a component for all measurement positions. For example, the connection element can likewise be at least partially embedded in the potting compound and / or electrically contactable, for example by forming a plug connection or by coupling to an electrical plug. Thus, voltages of individual, several or all battery cells can be determined or calculated on the basis of data that can be determined in this way, as is known in principle to the person skilled in the art.In this embodiment, it can be advantageous if the arresters or the anode regions emerging from the cell casing and the cathode regions emerging from the cell casing are not completely embedded in the potting compound but only partially embedded in the potting compound, such that they can easily be contacted by the electrical connection element.DRAWINGSFurther advantages and advantageous configurations of the subject matters according to the invention are illustrated by the drawings and explained in the following description, wherein the described features, individually or in any combination, can be a subject matter of the present invention, insofar as the opposite is not clearly evident from the context. It should be noted that the drawings are merely descriptive in nature and are not intended to limit the invention in any form. They show FIG. 1 shows a schematic view of an embodiment of a battery from obliquely above; FIG. 2 shows a schematic view of the battery from FIG. 1 from above; FIG. 3 is a partial sectional view of a further embodiment of a battery from above; FIG. 4 is a partial sectional view of another embodiment of a battery from above; FIG. 5 is a partial sectional side view of another embodiment of a battery; and FIG. 6 shows an enlarged region of the connection element from FIG. 1.FIGS. 1 and 2 show a configuration of a battery 10. The battery 10 includes a plurality of battery cells 12 that are disposed in a housing 14 that may serve as a module housing. The battery cells 12 arranged in the housing 14 are thus interconnected to form a battery module and can be mechanically connected to one another, for example by using an adhesive tape. Bores 15 are provided in the housing 14 in order to enable fixing of the module. Furthermore, the battery cells 12 each have a cell casing 13 and an anode region 16 emerging from the cell casing 13 and a cathode region 18 emerging from the cell casing 13. The battery cells 12 can be configured, for example, as pouch cells or as prismatic cells.Depending on the design of the battery cell 12, a potential can be present on the cell casing 13, which is why, if it is formed from an electrically conductive material, for example, it can be provided with an electrically insulating coating, such as a paint system.The battery cells 12 of the battery module can be connected, for example, in series or in parallel. For example, the battery cells 12 may be fully connected in parallel or in series, or a certain number of battery cells 12 may be connected in parallel and the corresponding blocks of battery cells 12 connected in parallel may in turn be connected in series.In the case of the battery 10, it is furthermore provided that the anode regions 16 emerging from the cell casing 13 and the cathode regions 18 of the plurality of battery cells 12 emerging from the cell casing 13 are at least partially embedded in a potting compound 20. The potting compound 20 can comprise, for example, a resin, in particular an epoxy resin or a polyurethane resin. Furthermore, the potting compound 20 can have an additive for improving the thermal conductivity of the potting compound 20.It is also shown in FIGS. 1 and 2 that a means for determining cell voltages is provided. In detail, FIGS. 1 and 2 show a connection element 22, which at least partially accommodates the arresters or the anode regions 16 emerging from the cell casing 13 and the cathode regions 18 of the plurality of battery cells 12 emerging from the cell casing 13. For example, interconnected arresters of the same polarity and possibly adjacent battery cells 12 can be accommodated, as will be explained in detail below.For this purpose, the connection element 22 can have, for example, a comb structure with a main strand 25 and with a plurality of secondary strands 24, wherein the secondary strands can be aligned as an extension of the battery cells 12 or their anode regions 16 or cathode regions 18 emerging from the cell casing 13, and the main strand 25 can run substantially at right angles thereto along the plurality of battery cells 12. For example, the arresters can run into the secondary strings 24 and be connected to one another in the main string 25 at connecting regions 19. Furthermore, the arresters of the same polarity and of approximately adjacent battery cells 12 can be accommodated without an electrical connection. For this purpose, these may run, for example, into the secondary strings 24, but there may be no electrical connection of the arresters in the main string 25 between the respective secondary strings 24. This is shown purely schematically and by way of example in FIG. 6. As a result, an freely selectable interconnection of the battery cells 12 can be made possible.At corresponding positions of the connection element 22, which can be formed for example from plastic, connections can be provided, which can be contacted, for example, with electrical plugs for voltage measurement. Depending on the circuit of the battery cells 12, the corresponding terminals can be contacted at different positions for voltage measurement, in order thus to measure individual voltages or total voltages or to determine them computationally on the basis of measured values. For example, if two battery cells 12 are connected in parallel, a voltage tap can be made at the connection regions 19 on the cathode side and on the anode side, respectively, in order to thus determine the voltages of these battery cells 12.For example, the connection element 22 can be present in a region of the arresters not embedded in potting compound 20, or the connection element 22 can likewise be at least partially embedded in the potting compound 20.In the case of a battery described above, the potting compound 20 can furthermore be temperature-controlled. For this purpose, for example, temperature control agents not shown in FIGS. 1 and 2 can be provided in the potting compound 20, as shown by way of example and not by way of limitation in FIGS. 3 and 4.FIG. 3 shows an embodiment of a battery 10 in which in each case two battery cells 12 according to FIG. 3 are connected to one another on the cathode side. In detail, it is shown that the anode regions 16 emerging from the cell casing 13 and / or the cathode regions 18 of adjacent battery cells 12 emerging from the cell casing are placed one above the other at a connecting region 19 and are connected to one another. In the case of a parallel connection, a collector connecting the battery cells 12 can be provided, which collector runs along the battery cells 12 or along the connecting regions 19. Furthermore, in the case of a series circuit, there may be a corresponding shifted interconnection on the anode side, not shown.With respect to the temperature control medium, it is shown in FIG. 3 that the temperature control element 28 is provided adjacent to the potting compound 20 and thermally coupled thereto. The temperature control element 28 according to FIG. 3 is present in a plate-shaped carrier 26 and is designed as a heating conductor 30 with a corresponding connection 31. The plate-shaped carrier 26 can have bores 27 for a suitable fixing, for example for screwing. Furthermore, the carrier 26 can be fixed in one step with the casting around of the arresters, or it can be subsequently connected to the casting compound 20, for example by pressing.In the embodiment according to FIG. 4, the temperature control element 28 is again provided adjacent to the potting compound 20 and thermally coupled thereto. In this case, the temperature control element 28 according to FIG. 4 is likewise present in a plate-shaped carrier 26. However, the temperature control element 28 according to FIG. 4 has a line structure 32 for conducting a fluid temperature control medium. The temperature control element 28 can likewise be directly embedded in the casting compound, so that an additional carrier 26 can be dispensed with.FIG. 5 also shows a part of a pouch cell purely schematically. It can be seen here that the anode regions 16 emerging from the cell casing 13 and the cathode regions 18 of the plurality of battery cells 12 emerging from the cell casing 13 are not completely embedded in the potting compound 20, but still offer free space for contacting, for example for voltage measurement. The temperature control element 28 can likewise be directly embedded in the casting compound, so that an additional carrier 26 can be dispensed with.

Claims

Battery (10), having a plurality of series- or parallel-connected battery cells (12), each of which has a cell casing (13) and an anode region (16) emerging from the cell casing (13) and a cathode region (18) emerging from the cell casing (13), wherein the anode regions (16) emerging from the cell casing (13) and the cathode regions (18) of the plurality of battery cells (12) emerging from the cell casing (13) are at least partially embedded in a potting compound (20), and furthermore, within the potting compound (20), at least one anode region (16) and a cathode region (18), an anode region (16) and an anode region (16) and / or a cathode region (18) and a cathode region (18) are placed one above the other and are connected to one another, wherein the potting compound (20) can be temperature-controlled by a temperature-control element (28).Battery (10) according to Claim 1, characterized in that the temperature-control element (28) is arranged within the potting compound (20).Battery (10) according to Claim 1, characterized in that the temperature-control element (28) is provided adjacent to the potting compound (20) and thermally coupled thereto.Battery (10) according to one of Claims 1 to 3, characterized in that the temperature-control element (28) has a line structure (32) for conducting a fluid temperature-control medium.Battery (10) according to one of Claims 1 to 3, characterized in that the temperature-control element (28) has a heating conductor (30).Battery (10) according to one of Claims 1 to 5, characterized in that the potting compound (20) comprises a resin, in particular an epoxy resin or a polyurethane resin.Battery (10) according to one of Claims 1 to 6, characterized in that the potting compound (20) has an additive for increasing the thermal conductivity.Battery (10) according to one of Claims 1 to 7, characterized in that the anode regions (16) emerging from the cell casing (13) and / or the cathode regions (18) emerging from the cell casing (13) of two adjacent battery cells (12) are placed one above the other and are connected to one another.Battery (10) according to one of Claims 1 to 8, characterized in that a means for determining a cell voltage is provided.Battery (10) according to one of Claims 1 to 9, characterized in that the battery cells (12) each comprise a pouch cell or a prismatic cell.

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