Layer material for thermal insulation

Abstract

The invention relates to a layer material for thermally and / or electrically insulating an electric device (8), comprising: a middle layer (2) made from a resilient and compressible material; a first insulation layer (3) on a first side (2a) of the middle layer (2); and a second insulation layer (4) on a second side (2b) of the middle layer (2), wherein the second side (2b) is opposite the first side (2a), wherein a first adhesion-promoting layer (5) is located between the first insulation layer (3) and the middle layer (2), and wherein a second adhesion-promoting layer (6) is located between the second insulation layer (4) and the middle layer (2).

Description

[0001] Layered material for thermal insulation

[0002] Description

[0003] The present invention relates to a layer material for thermal insulation for an electrical device, in particular a battery module, and to an electrical device, in particular an energy storage device with a battery cell, with a layer material according to the invention.

[0004] Due to thermal processes, battery cells can expand, for example, in battery modules. In extreme cases, such expansion processes can lead to damage to the battery module, a housing of the battery module, or neighboring battery cells. For example, DE 102021 132 072 A1 describes a two-layer system with a contact layer and an insulation layer to ensure the longest possible service life of a battery module.

[0005] The object of the present invention is to provide a layered material for thermal insulation of electrical devices, in particular battery modules, which can extend the service life of the electrical device while being simple in design and easy and cost-effective to manufacture. Furthermore, the object of the present invention is to provide an electrical device with improved thermal properties.

[0006] This object is achieved by a layer material having the features of claim 1 and an electrical device having the features of claim 15. The subclaims each contain preferred developments of the invention.

[0007] The layer material according to the invention for the thermal and / or electrical insulation of electrical devices, in particular battery modules, has the advantage that thermally induced expansion processes of components of the electrical device can be absorbed and compensated for by the layer material according to the invention. As a result, damage to the electrical device due to thermal expansion processes can be virtually prevented over the service life of the electrical device. The layer material according to the invention can be produced very simply and cost-effectively. Furthermore, the layer material according to the invention has particularly high thermal insulation properties, so that essentially constant temperatures can be maintained within the electrical device, in particular within a battery cell of an energy storage device.

[0008] This is achieved according to the invention in that the layer material for thermal and / or electrical insulation comprises a middle layer made of an elastic and compressible material. The layer material further comprises a first and a second insulation layer. The first insulation layer is arranged on a first flat side of the middle layer, and the second insulation layer is arranged on a second flat side, which is arranged opposite the first flat side of the middle layer. Furthermore, a first and a second adhesion-promoting layer are provided between the first insulation layer and the middle layer, and between the second insulation layer and the middle layer. The first and second adhesion-promoting layers on the middle layer ensure that the two insulation layers can be applied directly to the middle layer.The adhesion-promoting layers serve to provide direct chemical bonds between the middle layer and the insulation layers. This ensures a strong bond between the insulation layers and the middle layer, preventing any dissolution processes between the middle layer and the insulation layers, even at high temperatures. Thus, the layer material according to the invention can have a very long service life, particularly a service life appropriate to the application, for example, an energy storage device.

[0009] Thus, the first and second insulation layers are not applied directly to the middle layer, but rather, adhesion-promoting layers are provided between the insulation layers and the middle layer. This enables particularly good durability of the layer material according to the invention.

[0010] In addition to a thermal insulation function, the thermal insulation layers preferably also have an electrical insulation function.

[0011] Preferably, the middle layer also has an electrical insulation function.

[0012] For ease of application, the layered material is preferably provided as a planar layered material. This allows the layered material to be easily stacked, for example, and, particularly in the case of prismatic battery modules, to be easily arranged on the side walls of the battery cells of the battery module.

[0013] Further preferably, in the initial state, a thickness D0 of the middle layer is greater than a first thickness D1 of the first insulation layer and greater than a second thickness D2 of the second insulation layer. The first thickness D1 and the second thickness D2 are preferably of equal thickness. This results in a symmetrical structure, so that no thermal influences due to different thicknesses of the layer material occur on the electrical device.

[0014] More preferably, the first and second insulation layers are made of the same material. This allows the same adhesion-promoting layer to be used on both sides of the middle layer. This keeps manufacturing costs low.

[0015] More preferably, the first and / or second adhesion-promoting layer comprises a carrier element. The carrier element preferably comprises a plurality of fibers, in particular short inorganic or organic fibers, whose orientation is in particular parallel to a flat side of the middle layer.

[0016] For particularly good elasticity and compressibility, the middle layer preferably has gas-filled regions. The gas-filled regions are preferably evenly distributed throughout the middle layer.

[0017] The gas-filled regions are preferably closed regions filled with a gas, preferably air. The closed regions are preferably closed pores. The middle layer is particularly preferably made of a silicone foam.

[0018] Alternatively or additionally, the gas-filled regions further comprise gas channels that are open at a first and a second end face of the layer material. This can further improve the deformability of the middle layer. Particularly preferably, only a plurality of parallel gas channels are provided. The middle layer can then be produced, for example, as an extruded component. In this case, a mat-like precursor can be produced, which can then be divided into smaller pieces according to an application.

[0019] Preferably, in the initial state of the layer material, the gas-filled regions are arranged such that the gas-filled regions occupy approximately 60 vol.% of the volume of the middle layer, and a material of the middle layer occupies approximately 40 vol. Preferably, the volume fraction of the gas-filled regions is in a range of 50-70 vol.%, and the remaining vol.% is then the material of the middle layer.

[0020] According to a further preferred embodiment of the invention, the gas channels are provided such that the gas channels are open to the first and / or second insulation layer and are only covered by the first and / or second insulation layer. Thus, the gas channels of the middle layer are practically provided as grooves in the middle layer.

[0021] Particularly preferably, the middle layer comprises an inner central layer and a plurality of webs which protrude on both flat sides of the central layer. The webs are then connected to the first or second insulation layer, such that the layer material is produced with continuous gas channels. Thus, a connection between the middle layer and the two insulation layers only exists in the region of the webs. Preferably, the webs on the first flat side of the middle layer are offset from the webs on the second flat side. This results in better compressibility of the middle layer in the application. In particular, when the electrical device expands, the layer material can have a meander shape for thermal insulation, wherein in particular the central layer is deformed into a meander shape.

[0022] The present invention further relates to an electrical device having a layer material according to the invention. The electrical device is particularly preferably an energy storage device comprising at least one battery cell, wherein the layer material is arranged on at least one wall side of the battery cell. The battery cell is preferably a prismatic battery cell. The layer material is particularly preferably arranged on both flat sides of a prismatic battery cell. Further preferably, a plurality of prismatic battery cells are combined to form a battery module, wherein the layer material according to the invention is arranged on the exposed sides of the battery module. For example, four or five battery cells are combined, and the layer material according to the invention is arranged on the two exposed flat sides of the combined battery cells.

[0023] The layer material according to the invention preferably completely covers an entire flat side of the prismatic battery cell.

[0024] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing:

[0025] Fig. 1 is a schematic, partially sectioned view of an electrical

[0026] Device with a layer material in an undeformed initial state according to a first embodiment of the invention,

[0027] Fig. 2 is a schematic, partially sectioned view of an electrical

[0028] Device with a layer material in an undeformed

[0029] Initial state according to a second embodiment of the

[0030] invention, Fig. 3 is a schematic sectional view of Fig. 2 with a partially deformed

[0031] Layer material and

[0032] Fig. 4 is a schematic sectional view of Fig. 2 with a fully deformed layer material.

[0033] An electrical device 8 having a layer material 1 according to a first preferred embodiment of the invention will be described in detail below with reference to Fig. 1.

[0034] The electrical device 8 is a battery module comprising a plurality of battery cells 7. The battery cells 7 of this exemplary embodiment are prismatic battery cells.

[0035] The layer material 1 according to the invention is arranged between the two battery cells 7. The layer material 1 is a planar layer material and completely covers one flat side of each of the two battery cells 7.

[0036] The planar layer material 1 has several layers which are arranged flatly one above the other.

[0037] The layer material 1 comprises a middle layer 2, a first insulation layer 3, and a second insulation layer 4. The first insulation layer 3 is arranged on a first flat side 2a of the middle layer 2. The second insulation layer 4 is arranged on a second flat side 2b of the middle layer 2, which is opposite the first flat side 2a.

[0038] A first adhesion-promoting layer 5 is arranged between the middle layer 2 and the first insulation layer 3. A second adhesion-promoting layer 6 is arranged between the middle layer 2 and the second insulation layer 4.

[0039] The middle layer 2 is made of an elastic and compressible material, preferably silicone foam. The silicone foam contains enclosed, gas-filled areas that improve the compressibility of the middle layer 2.

[0040] In this embodiment, the first insulation layer 3 and the second insulation layer 4 are also somewhat compressible. Alternatively, however, the first and second insulation layers 3, 4 can also be provided incompressibly.

[0041] The first and second insulation layers 3, 4 are made of the same material and have the same thickness D1 and D2. The middle layer 2 has a first thickness D0 and, in the undeformed state shown in Fig. 1, is approximately twice as large as the thicknesses D1, D2 of the first and second insulation layers 3, 4. The first and second adhesion-promoting layers 5, 6 are also made of the same materials. Preferably, carrier materials, in particular inorganic fibers, are also arranged in the first and second adhesion-promoting layers.

[0042] During operation of the electrical device 8, expansion of the battery cells 7 may occur, e.g., due to thermal factors. Since the layer material 1 is arranged between the battery cells 7, thermally induced expansions can be absorbed by deformation of the middle layer 2. If the first and second insulation layers 3, 4 are also compressible, the compressibility of the middle layer is greater than the compressibility of the first and second insulation layers 3, 4.

[0043] In particular, if the middle layer 2 has gas-filled regions, a high degree of compressibility can be achieved. Should the thermally induced expansion of the battery cell 7 decrease again, the elasticity of the middle layer 2 ensures that the layer material 1 remains pressed against the walls of the battery cells 7, preventing any undesirable gaps from forming. This is particularly advantageous if, for example, a thermally induced volume change of the battery cells 7 occurs during charging, which then decreases again after charging is complete.

[0044] However, the layer material 1 according to the invention is also designed in particular to compensate for remaining deformations of the battery cells 7.

[0045] Figures 2 to 4 show an electrical device 8 with a layer material 1 according to a second preferred embodiment of the invention.

[0046] Fig. 2 shows a layered material 1 between two battery cells 7 in an undeformed initial state. Fig. 3 shows the layered material 1 of Fig. 2 in a partially deformed state, and Fig. 4 shows the layered material 1 of Fig. 2 in a fully deformed state.

[0047] As can be seen from Fig. 2, which shows a cross-sectional view through the layer material 1, in contrast to the first embodiment, the middle layer 2 is designed differently in the second embodiment. The middle layer 2 has a central layer

[0048] 20, on which webs 21 are arranged on both flat sides. The webs

[0049] 21 are, as can be seen from Fig. 2, arranged offset from one another in the direction of expansion of the central layer 20. This creates gas-filled channels 22.

[0050] The first insulation layer 3 and the second insulation layer 4 are thus each connected to the middle layer 2 at the free ends 21a of the webs 21. The first and second adhesion-promoting layers 5, 6 are thus each arranged only at the free ends 21a of the webs 21.

[0051] Thus, only in the area of ​​the webs 21 is there a connection between the middle layer 2 and the first and second insulation layers 3, 4.

[0052] The layered material 1 of the second embodiment can be manufactured as an extruded profile. The gas-filled channels 22 are then open on both ends of the layered material 1.

[0053] If, as indicated in Fig. 3, a thermal increase in volume of one or both battery cells 7, between which the layer material 1 is arranged, occurs, a partial deformation of the middle layer 2 results. Thus, the middle layer 2 is compressed, resulting in a partially compressed layer material T (cf. Fig. 3).

[0054] Fig. 4 shows a layered material 1" that is completely deformed. Here, the middle layer 2 has been deformed by forming such that virtually no gas-filled regions remain in the middle layer 2. As a result, the central layer 20 takes on a meandering shape. The webs 21 may be partially bent. In extreme cases, there are no gas-filled regions at all in the middle layer 2.

[0055] Depending on the choice of material for the first and second insulation layers 3, 4, deformation of the insulation layers 3, 4 may also occur, which is indicated schematically in Fig. 4.

[0056] As can be seen from the undeformed state shown in Fig. 2, the webs 21 have a neck 21b and a slightly widened head 21c at the free end of the webs in cross-section. However, the webs can also have a different, in particular rectangular, cross-section.

[0057] However, the neck 21b of the webs 21 positively supports the deformability of the middle layer 2. The head 21c provides a larger contact surface for the insulation layers 3, 4.

[0058] In addition to the above written description of the invention, reference is hereby explicitly made to the graphic representation of the invention in the figures for its supplementary disclosure.

Claims

Patent claims 1. Layer material for thermal and / or electrical insulation of an electrical device (8), comprising: - a middle layer (2) made of an elastic and compressible material, - a first insulation layer (3) on a first side (2a) of the middle layer (2), and - a second insulation layer (4) on a second side (2b) of the middle layer (2), the second side (2b) being opposite to the first side (2a), - wherein a first adhesion-promoting layer (5) is arranged between the first insulation layer (3) and the middle layer (2), and - wherein a second adhesion-promoting layer (6) is arranged between the second insulation layer (4) and the middle layer (2).

2. Layer material according to claim 1, wherein the layer material is a sheet-like layer material.

3. Layer material according to one of the preceding claims, wherein Initial state, a thickness (D1) of the first insulation layer (3) is equal to a thickness (D2) of the second insulation layer (4).

4. Layer material according to claim 3, wherein in the initial state a thickness (DO) of the middle layer (2) is greater than a thickness (D1) of the first insulation layer (3) and a thickness (D2) of the second insulation layer (4).

5. Layer material according to one of the preceding claims, wherein the first insulation layer (3) and the second insulation layer (4) are made of the same material and / or the first adhesion-promoting layer (5) and the second adhesion-promoting layer (6) are made of the same material.

6. Layer material according to one of the preceding claims, wherein the first adhesion-promoting layer (5) and the second adhesion-promoting layer (6) comprise a carrier material, in particular inorganic fibers.

7. Layer material according to one of the preceding claims, wherein the middle layer (2) has gas-filled regions (22).

8. Layer material according to claim 7, wherein the gas-filled regions are closed regions, in particular closed pores.

9. Layer material according to claim 7, wherein the gas-filled regions are gas-filled channels (22) which are open at a first and a second end face.

10. Layer material according to claim 9, wherein the gas-filled channels (22) are parallel to each other.

11. Layer material according to claim 9 or 10, wherein the middle layer (2) is an extruded component.

12. Layer material according to one of claims 7 to 11, wherein in the initial state of the layer material the gas-filled regions occupy approximately 60 vol.% of the middle layer (2) and a material of the middle layer (2) occupies approximately 40 vol.%.

13. Layer material according to one of claims 9 to 12, wherein the gas-filled channels (22) are open to the first insulation layer (3) and / or to the second insulation layer (4) and are covered by the first or second insulation layer.

14. Layered material according to one of claims 9 to 13, wherein the middle layer (2) comprises an inner central layer (20) and a plurality of webs (21), wherein the webs (21) are arranged on both sides of the central layer (20) and wherein the webs (21) are connected to the first or second insulation layer (3, 4) and wherein in particular the webs (21) on the first side of the central layer (20) are offset from the webs (21) on the second side of the central layer (20).

15. Electrical device, in particular energy storage device, comprising a layer material according to one of the preceding claims, wherein the layer material (1) is arranged on a wall side of the electrical device.

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