Electrical energy storage

Abstract

The invention relates to an electrical energy storage device with a housing in which a number of electrically interconnected individual cells (1) are arranged. According to the invention, a cell housing (4) of at least one individual cell (1) and / or a spacer (8) arranged between adjacent individual cells (1) and / or a predetermined region of the housing are or are provided with a heating lacquer layer (2), wherein the heating lacquer layer (2) is designed to heat the cell housing (4) and / or the spacer (8) and / or the region of the housing when an electrical voltage is applied.

Description

The invention relates to an electrical energy store having a housing in which a number of electrically connected individual cells are arranged.From the Internet site www.thermoheld.global / thermoheld-wand / (called up: at 14.10 am on 28.03.2025), a dry building board is known which is coated with a carbon-containing special paint which can be electrically heated by means of a low-voltage technique.The invention is based on the object of specifying an electrical energy store having a housing.The object is achieved according to the invention by an electrical energy store which has the features specified in claim 1.Advantageous embodiments of the invention are the subject matter of the dependent claims.An electrical energy store has a housing in which a number of electrically connected individual cells are arranged. According to the invention, it is provided that a cell housing of at least one individual cell and / or a spacer arranged between adjacent individual cells and / or a predefined region of the housing are or is provided with a heating lacquer layer, wherein the heating lacquer layer is designed to heat the cell housing and / or the spacer and / or the region of the housing when an electrical voltage is applied.By means of such a heating lacquer layer, it is possible to homogeneously temperature control, in particular heat up, the individual cells of the electrical energy store, such that the individual cells can be operated in their optimized operating temperature range. In particular, the heating takes place when a cell temperature of the individual cell or of the individual cells of the electrical energy store is below a recommended operating temperature.By means of the heating lacquer layer, homogeneous heating of the individual cells of an electrical energy store is possible, so that consistent electrical cell performance and reduced cell aging can be achieved.For the operation of the heating lacquer layer, a low-voltage technique that is essentially electrically non-critical is used, wherein a heating function of the heating lacquer layer is ensured even in the case of a defective heating lacquer layer, in particular scratches.The heating lacquer layer can also be applied to nonmetallic surfaces, for example to plastic, and heats up when an electrical voltage is applied.Exemplary embodiments of the invention are explained in more detail below with reference to drawings.The following are shown: FIG. 1 schematically shows a plan view of an individual cell with a heating lacquer layer, FIG. 2 schematically shows an individual cell with contact elements of the heating lacquer layer arranged in an embodiment, FIG. 3 schematically shows an individual cell with contact elements of the heating lacquer layer arranged in a further embodiment, FIG. 4 schematically shows an individual cell with a spacer with a heating lacquer layer arranged relative to the latter, FIG. 5 schematically shows a plurality of individual cells with a spacer with a heating lacquer layer arranged relative to these, FIG. 6 schematically shows a plan view of an individual cell with spacer with heating lacquer layer, FIG. 7 schematically shows a plan view of a cell composite with spacers with heating lacquer layer, FIG. 8 schematically shows a bottom view of the cell assembly with spacers with heating lacquer layer, FIG. 9 schematically shows a predefined region of a housing of an electrical energy store with heating lacquer layer and contact elements, and FIG. 10 schematically shows a sectional illustration of the housing with individual cells and a plurality of heating lacquer layers of individual cells.Corresponding parts are provided with the same reference numerals in all figures.FIG. 1 shows a plan view of an individual cell 1 with a heating lacquer layer 2.FIG. 2 shows an individual cell 1 with contact elements 3 of the heating lacquer layer 2 arranged in one embodiment, and FIG. 3 shows an individual cell 1 with contact elements 3 of the heating lacquer layer 2 arranged in a further embodiment.Such an electrochemical individual cell 1 is a component of an electrical energy store having a multiplicity of such individual cells 1, which are electrically interconnected with one another and are arranged in a common housing. The electrical energy store is a traction battery of an electric vehicle, of a hybrid vehicle or of a vehicle operated with fuel cells and is usually arranged in a vehicle floor region of the vehicle.The individual cell 1 has a metal sleeve as the cell housing 4, in which an electrode foil arrangement 5, in particular an electrode foil roll, is arranged. The cell housing 4 is closed in a media-tight manner by means of a cell cover, not shown in detail, wherein an electrical pole cap 6 of the individual cell 1 is shown.In particular at temperatures which are below a recommended operating temperature, that is to say below 20° C., of the individual cells 1, it is advisable to condition the individual cells 1. If a temperature is below the recommended operating temperature, a power of the individual cells 1 decreases due to increasing internal electrical resistances, or the individual cells 1 may be damaged at approximately 0° C. during a charging process.In order to condition the individual cells 1 of an electrical energy store to the greatest possible extent and to achieve a substantially homogeneous temperature level when the electrical energy store is heated to its operating temperature in order to avoid inconsistent aging of the individual cells 1, provision is made, according to the exemplary embodiment shown in FIGS. 1 to 3, for the individual cell 1 to be provided with a heating lacquer layer 2.This heating lacquer layer 2 completely covers a lateral surface of the cell housing 4 of an individual cell 1 designed as a round cell. In this case, the heating lacquer layer 2 has a predefined proportion of carbon nanotubes for electrical conductivity and heat resistance, a predefined proportion of binder for required adhesion and flexibility, a predefined proportion of water for optimized processability and a predefined proportion of additives for consistency and stability. It is thus a water-based carbon dispersion which can be applied to various substrates. In the dried state, the heating lacquer layer 2 is highly electrically conductive, so that the heating lacquer layer 2 generates heat with the supply of electric current.For this purpose, the heating lacquer layer 2 is electrically coupled to electrical contact elements 3, wherein one contact element 3 forms an electrical positive pole and a further contact element 3 forms an electrical negative pole when an electrical voltage is applied.In this case, the contact elements 3 according to the exemplary embodiments shown in FIGS. 1 to 3 are configured annularly as contact tab rings and thus completely surround the cell housing 4 on the circumferential side. In particular, the contact elements 3 are arranged opposite one another on the edge side of the heating lacquer layer 2, such that the heating lacquer layer 2 between the contact elements 3 heats up on application of an electrical voltage to the contact elements 3 on account of an electrical resistance of the heating lacquer layer 2. For the electrical coupling of the contact elements 3 to an electrical voltage source or current source, these each have a contact lug 3.1.As shown in FIG. 1, the individual cell 1 can additionally be surrounded by a protective sheath 7, for example in order to protect the heating lacquer layer 2 and / or to avoid electrical contact with the heating lacquer layer 2 and / or the contact elements 3 to the greatest possible extent.According to the embodiment shown in FIG. 2, the contact lugs 3.1 of the contact elements 3 project radially from the cell housing 4 of the individual cell 1, whereas the contact lugs 3.1 project axially with respect to the cell housing 4, that is to say upwards and downwards, in the further embodiment shown in FIG. 3.The heating lacquer layer 2 has a comparatively high electrical resistance at a layer thickness of, for example, 0.1 mm, by means of which the heating lacquer layer 2 heats up, wherein a temperature of up to approximately 40° C. can be reached when an electrical voltage of, for example, 24 volts is applied. This temperature value lies in the range of an optimized operating temperature window of the individual cell 1 and thus of the electrical energy store, the component of which is the individual cell 1.By varying the layer thickness and the electrical voltage, a maximum temperature can be optimally set to the individual cells 1 of the electrical energy store, wherein the heating lacquer layer 2 can also be applied to a cell cover and / or a cell housing base.Alternatively to the heating lacquer layer 2 being applied directly to the cell housing 4 of the individual cells 1, it can be provided that the heating lacquer layer 2 is applied to a self-adhesive film which is then bonded to an object to be heated, for example to the cell housing 4 and / or to the cell cover and / or the cell housing base.In order to set a predetermined distance between adjacently arranged individual cells 1, for example for thermal and / or electrical insulation, a spacer 8 is provided, as is shown in FIGS. 4 to 8.FIG. 4 shows an enlarged detail from FIG. 5, wherein the spacer 8 is arranged between adjacently arranged rows of individual cells 1, that is to say the spacer 8 is assigned to a plurality of individual cells 1.A surface side of the spacer 8 arranged in the direction of an adjacently arranged row of individual cells 1 is provided with a heating lacquer layer 2 and the electrical contact elements 3, so that the surface side is heated upon application of an electrical voltage due to the electrical resistance. It is thus possible to achieve a homogeneous temperature distribution over a comparatively large area with respect to the individual cells 1 of the two rows, between which the spacer 8 is arranged.FIG. 6 shows an embodiment of the spacer 8, in which an individual cell 1 is surrounded completely on the circumference by the spacer 8, wherein the individual cell 1 is arranged in sections in a spacer 8.The spacer 8 is provided on all four outer surfaces with a heating lacquer layer 2 which is electrically coupled to electrical contact elements 3, so that the respective heating lacquer layer 2 heats up on application of an electrical voltage to the contact elements 3 due to an acting electrical resistance.FIGS. 7 and 8 each show a view of a cell assembly comprising a plurality of individual cells 1, which is shown in a plan view in FIG. 7 and in a bottom view in FIG. 8. Each individual cell 1 of the cell assembly is arranged in a spacer 8, so that the predefined distance between respectively adjacent individual cells 1 is set.Each of the spacers 8 is provided on the outside with a heating lacquer layer 2, which is electrically coupled to electrical contact elements 3 in order to heat the heating lacquer layer 2 when an electrical voltage is applied. By means of the respective heating lacquer layer 2 of the spacers 8, the individual cells 1 of the cell assembly can be heated homogeneously in order to operate the individual cells 1 within their optimized operating temperature window.FIG. 9 shows an inner surface of a region of a housing, for example a housing wall 9 of the electrical energy store, wherein a heating lacquer layer 2 or a film provided with a heating lacquer layer 2 is applied to the inner surface. The heating lacquer layer 2 is electrically coupled to the electrical contact elements 3, so that the heating lacquer layer 2 heats up when an electrical voltage is applied.FIG. 10 shows a sectional illustration of a section of a housing of an electrical energy store, wherein a lower housing part 10 and an upper housing part 11 with a number of individual cells 1 are shown.A respective inner surface is provided with a heating lacquer layer 2, which is electrically coupled to electrical contact elements 3, not shown in detail, in order to heat the respective inner surface and the individual cells 1 arranged between the heating lacquer layers 2 when an electrical voltage is applied.A thermal insulation layer 12 is arranged on an outer surface of the upper housing part 11, by means of which thermal insulation layer the housing is thermally insulated at least on one side in order to achieve that the individual cells 1 are heated as homogeneously as possible.In order to provide the electrical voltage which is applied to the contact elements 3 of the respective heating lacquer layer 2, a separate electrical energy store is, for example, kept in stock on the vehicle side.List of reference characters1 Single cell 2 Heating lacquer layer 3 Contact element 3.1 Contact tab 4 Cell housing 5 Electrode foil arrangement 6 Pole cap 7 Protective sleeve 8 Spacer 9 Housing wall 10 Housing lower part 11 Housing upper part 12 Insulation layerReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Cited Non-Patent LiteratureFrom the Internet site www.thermoheld.global / thermoheld-wall / (called: on 28.03.2025 at 14.10 o'clock

[0002]

Claims

Electrical energy store having a housing in which a number of electrically connected individual cells (1) is arranged, characterized in that a cell housing (4) of at least one individual cell (1) and / or a spacer (8) arranged between adjacent individual cells (1) and / or a predefined region of the housing are or is provided with a heating lacquer layer (2), wherein the heating lacquer layer (2) is designed to heat the cell housing (4) and / or the spacer (8) and / or the region of the housing when an electrical voltage is applied.Electrical energy store according to Claim 1, characterized in that an electrically positive contact element (3) and an electrically negative contact element (3) are arranged on the heating lacquer layer (2), which contact elements are arranged spaced apart from one another along a respective edge region of the heating lacquer layer (2) and which contact elements are designed for coupling to an electrical voltage source.Electrical energy store according to Claim 1 or 2, characterized in that an achievable temperature of the heating lacquer layer (2) varies as a function of a thickness of the heating lacquer layer (2) and / or as a function of a magnitude of the applied electrical voltage.Electrical energy store according to one of the preceding claims, characterized in that the heating lacquer layer (2) is applied to a self-adhesive film.

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