Battery with composite structure

Abstract

Battery (60), comprising, - a battery cell (50), - a thermal element (40), - a composite structure (30) for contacting the battery cell (50) with the thermal element (40), wherein the composite structure (30) is arranged at a contact point directly between the battery cell (50) and the thermal element (40), wherein the composite structure (30) comprises a first component (1) which is electrically insulating and non-elastic, and a second component (2) which is electrically insulating and thermally conductive, wherein the second component (2) is arranged in the composite structure (30) such that it establishes thermal contact between the battery cell (50) and the thermal element (40), characterized in that the first component (1) is designed as a plate with recesses, wherein the recesses are filled by the second component (2).

Description

[0001] The present invention relates to a battery comprising a battery cell, a thermal element and a composite structure for contacting the battery cell with the thermal element, wherein the composite structure is arranged at a contact point directly between the battery cell and the thermal element, wherein the composite structure comprises a first component which is electrically insulating and non-elastic, and a second component which is electrically insulating and thermally conductive, wherein the second component is arranged in the composite structure such that it establishes thermal contact between the battery cell and the thermal element.

[0002] To ensure the safety of batteries or battery packs, two essential requirements must be met, especially when these batteries or battery packs contain lithium-ion battery cells. First, the battery cells of these battery packs must be operated within a specified temperature range. Second, the battery cells of the battery pack must be electrically insulated from the remaining components of the respective battery pack.

[0003] For this reason, so-called heat sinks or heat sources are installed within battery packs in the state of the art, which influence the temperature properties of the battery pack. Various variants for the implementation of heat sinks or heat sources are known in the state of the art. For example, battery packs exist in the state of the art which have fluid-flowing plates that are in thermal contact with the battery cells within the battery pack, i.e. which function as cooling or heating plates. Gaps which form due to unevenness on the contact surfaces between the fluid-flowing plates and the battery cells must be avoided to enable good thermal contact. Furthermore, it must be ensured that the battery cells of the battery pack are electrically insulated from the fluid-flowing plate.

[0004] For example, DE 10 2009 014 954 A1 discloses a device for thermally connecting an energy storage device and / or a cooling plate, which device comprises a contact element with a heat transfer surface for providing the thermal connection. The contact element comprises a first region with a first thermal conduction property and at least one further region with a further thermal conduction property, wherein the first region and the at least one further region are arranged adjacent to one another with respect to the heat transfer surface.

[0005] Furthermore, DE 10 2007 010 745 A1 discloses a battery with a heat-conducting plate for controlling the temperature of the battery. The battery cells are connected to this heat-conducting plate in a heat-conducting manner. The heat-conducting plate has a channel structure arranged in the heat-conducting plate through which a heat-conducting medium can flow.

[0006] The state of the art in this regard is also the document DE 10 2007 063 179 A1.

[0007] The object underlying the invention is to improve the batteries known from the prior art with regard to their thermal properties.

[0008] This object is achieved according to the invention by providing a battery which comprises a battery cell, a thermal element, and a composite structure for contacting the battery cell with the thermal element. The composite structure is arranged at a contact point directly between the battery cell and the thermal element. According to the invention, the composite structure comprises a first component which is electrically insulating and non-elastic, and a second component which is electrically insulating and thermally conductive. The second component is arranged in the composite structure such that it establishes thermal contact between the battery cell and the thermal element.

[0009] In the battery according to the invention, improved thermal contact between the battery cells and a thermal element, for example a cooling plate or a heating plate, is achieved through the use of a composite structure compared to the prior art. The first, non-elastic component of the composite structure ensures that the distance between the surface of the battery cell and the thermal element does not become smaller than the distance predetermined by the dimensions or height of the first component itself. The second component ensures a good thermal connection between the surface of the battery cell and the surface of the thermal element.

[0010] Preferably, the second component is embedded in the first component. Such an embodiment allows the first and second components to be connected or combined in a space-saving manner.

[0011] According to the invention, the first component is designed as a plate with recesses, wherein the recesses are filled by the second component. With such an embodiment of the composite structure, the composite structure can also be very well arranged between, for example, a plurality of battery cells and, for example, a heating plate or a cooling plate. The functions of the first and second components described above can also be particularly well fulfilled by the first and second components with such an embodiment of the composite structure.

[0012] In a preferred embodiment, the first component of the composite structure is a plastic. Plastics are among the lightest materials available and are also particularly cost-effective. Furthermore, plastics are good insulators of electrical current and can be molded easily and inexpensively.

[0013] The material for the second component is preferably selected from a group comprising thermal pastes, gels optimized with thermally conductive additives, and potting compounds. Thermal pastes are highly thermally conductive materials which, in contrast to, for example, thermal pads, are particularly well suited, among other things, for filling existing cavities or recesses, for example, within the composite structure described above. Potting compounds exhibit very good flow properties and can be cured in various ways.

[0014] In a preferred embodiment, the composite structure is at least partially coated with the second component on the side in contact with the battery cell.

[0015] The battery is preferably a lithium-ion battery. Advantages of such batteries include their comparatively high energy density and high thermal stability. Another advantage of lithium-ion batteries is that they are not subject to the memory effect.

[0016] Furthermore, a motor vehicle is provided with a battery according to the invention, wherein the battery is connected to a drive system of the motor vehicle.

[0017] Advantageous developments of the invention are specified in the subclaims and described in the description.

[0018] Embodiments of the invention are explained in more detail with reference to the drawings and the following description. They show: Fig. 1 a schematic section of an embodiment of a battery according to the invention, Fig. 2 a possible design of a composite structure in a plan view, and Fig. 3 another possible design of a composite structure in a top view.

[0019] In the Fig. 1 shows a schematic section of an embodiment of a battery 60 according to the invention. The section of this battery 60 schematically shows a battery cell 50, a composite structure 30, and a thermal element 40 in a side view. The arrangement of these components relative to one another and their design is shown in Fig. 1 is chosen purely as an example. Furthermore, the components are shown in simplified form for better understanding.

[0020] The battery cell 50, which in this embodiment is arranged purely by way of example in a prismatic battery cell housing, the dimensions of which are shown in a side view in Fig. 1, is in contact with the composite structure 30 via the base plate of the battery cell housing. In this exemplary embodiment, the composite structure 30 is designed purely as an example as a plate which rests on the thermal element 40. The thermal element 40 is also designed purely as an example as a plate in this exemplary embodiment, or more precisely, purely as an example as a cooling plate. In other exemplary embodiments of batteries 60 according to the invention, the thermal element 40 can, however, also be a heating plate or another cooling or heating element, which also does not have to be designed as a plate. In other words, the battery cell 50 within the battery 60 is in indirect contact with the cooling plate via the composite structure 30. The composite structure 30 is therefore arranged directly at the contact point between the battery cell 50 and the thermal element 40.The composite structure 30 comprises a first component 1, which is electrically insulating and non-elastic. Furthermore, the composite structure 30 has a second component 2, which is electrically insulating and thermally conductive. The second component 2 is arranged in the composite structure 30 such that it establishes thermal contact between the battery cell 50 and the thermal element 40, which in this exemplary embodiment is designed as a cooling plate.

[0021] In the Fig. 1, the second component 2 is embedded purely by way of example in the first component 1. In other words, the first component 1 in this exemplary embodiment is designed purely by way of example as a plate which has cutouts or recesses which are filled or filled by the second component 2. In this exemplary embodiment, the second component 2 is embedded in a columnar manner in the plate of the composite structure 30, which in this exemplary embodiment is formed by the first component 1. Both components 1, 2 are therefore in direct contact with the battery cell 50 or with its battery cell housing or with the thermal element 40.Furthermore, in this exemplary embodiment, the composite structure 30 is optionally coated with the second component 2 on the side in contact with the battery cell 50 at the locations where it is not in contact with the battery cell 50.

[0022] Since the first component 1 is not elastic or deformable, or is only deformable under mechanical stress, which is not present or expected within the battery 60 according to the invention, the first component 1 ensures that the distance 5 between the battery cell 50 and the thermal element 40 is not less than the height of the first component 1 in the unloaded state. In other words, the distance 5 between the battery cell 50 and the thermal element 40 is predetermined by the height or dimensions of the first component 1 in the unloaded state. As a result, the composite structure, and in particular the first component 1, is designed to be mechanically stable and does not deform, for example, under compressive stress.

[0023] Thermal contact is established between the battery cell 50 and the thermal element 40 via the second component 2. In other words, the surface of the battery cell 50 or the battery cell housing is thermally connected to the surface of the thermal element 40, in particular via the second component 2 of the composite structure 30. The battery cell 50 is thus thermally connected to the thermal element 40, in particular via the second component 2.

[0024] In this exemplary embodiment, the first component 1 is embodied as a plastic purely by way of example. However, the choice of plastic for the realization of the first component 1 of the composite structure 30 within a battery 60 according to the invention is merely a purely exemplary embodiment. Other materials can therefore also be selected for the realization of the first component 1 that have the properties of the first component 1 described above. The second component 2 is embodied as a thermally conductive paste purely by way of example in this exemplary embodiment. The use of thermally conductive paste is also chosen purely by way of example in this exemplary embodiment.For example, batteries 60 according to the invention can also be realized in which the second component 2 of the composite structure 30 is designed as a potting compound or as a gel optimized with heat-conducting additives or even as a completely different material which has the properties of the second component 2 described above.

[0025] The Fig. Figure 2 shows a possible design of a composite structure 30 in a plan view. In other words, Fig. 2 is a plan view of a possible embodiment of a composite structure 30 as used in a battery 60 according to the invention. Fig. The composite structure 30 shown in Figure 2 is the one shown in Fig. 1 composite structure 30 shown in section, which in Fig. 2 without the coating with the second component 2. The second component 2 of the composite structure 30 is in this embodiment purely by way of example embedded in the first component 1, which in this embodiment purely by way of example is designed as a plate, in the form of alternating rows of columns, each with a round base. Fig. 1, these columns have a constant diameter along their length.

[0026] The Fig. Figure 3 shows a further possible embodiment of a composite structure 30 in a plan view. This is essentially identical to the one shown in Fig. 2. The components with the same designation in Fig. 3 correspond to those of the embodiment of the Fig. 2, so that what is said there regarding these components also applies to the second embodiment of the Fig. 2. In contrast to the Fig.In the composite structure 30 shown in Figure 2, the base areas of the columns that partly make up the second component 2 are not round, but rectangular.

[0027] In all of the exemplary embodiments presented here, multiple battery cells 50 within a battery 60 according to the invention can also be in indirect contact with a thermal element 40 via a composite structure 30. Furthermore, the shape or design of the composite structure 30 in batteries 60 according to the invention can also differ fundamentally from the shapes or designs shown here. For example, the second component 2 does not have to be embedded in the first component 1. Furthermore, the first component 1 does not have to be designed as a plate, but can also have a completely different geometric shape.

Claims

[1] Battery (60), comprising, - a battery cell (50), - a thermal element (40), - a composite structure (30) for contacting the battery cell (50) with the thermal element (40), wherein the composite structure (30) is arranged at a contact point directly between the battery cell (50) and the thermal element (40), wherein the composite structure (30) comprises a first component (1) which is electrically insulating and non-elastic, and a second component (2) which is electrically insulating and thermally conductive, wherein the second component (2) is arranged in the composite structure (30) such that it establishes thermal contact between the battery cell (50) and the thermal element (40), characterized by that the first component (1) is designed as a plate with recesses, wherein the recesses are filled by the second component (2). [2] Battery (60) according to the preceding claim, wherein the first component (1) of the composite structure (30) is a plastic. [3] Battery (60) according to one of the preceding claims, wherein the material for the second component (2) is selected from a group comprising thermally conductive pastes, gels optimized with thermally conductive additives and potting compounds. [4] Battery (60) according to one of the preceding claims, wherein the composite structure (30) is at least partially coated with the second component (2) on the side in contact with the battery cell (50). [5] Battery (60) according to one of the preceding claims, wherein the battery (60) is designed as a lithium-ion battery. [6] Motor vehicle with a battery (60) according to one of claims 1 to 5, wherein the battery (60) is connected to a drive system of the motor vehicle.

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