Insulating and cooling assembly for a battery cell

Abstract

The invention relates to an insulating and cooling assembly for at least one battery cell, comprising at least one cooling plate with a first main side for thermal contact with the at least one battery cell, and with a first and an opposing second end side, and comprising an insulating element for electrical insulation on a first end side of the cooling plate, wherein a first side surface of the insulating element lies substantially in the same plane as the first main side of the cooling plate.

Description

[0001] Description

[0002] Insulation and cooling arrangement for a battery cell

[0003] The invention relates to an insulation and cooling arrangement for a battery cell and a battery cell arrangement with an insulation and cooling arrangement, which is used in particular in traction batteries.

[0004] In many technical fields, the term "battery" has also become established for accumulators and is used as such in this application. This applies particularly to applications in vehicles and aircraft, for example, motor vehicles or rail vehicles.

[0005] These batteries utilize traction batteries that require cooling to ensure their performance and sufficient service life. Various battery cell designs are known for such batteries, particularly prismatic, round, and pouch cells. For cooling purposes, water-cooled cooling plates made of aluminum alloys are typically used for high performance requirements. By connecting the battery cells in series, the desired voltage is achieved, which for traction batteries is in the kV range. Appropriate insulation from the cooling system must be ensured, otherwise short circuits and battery damage will occur. Furthermore, a compact and lightweight design of the traction battery is required, while simultaneously meeting stringent mechanical and environmental requirements over a long service life.

[0006] Reliable insulation of the battery cells from the cooling plates is also complicated by the fact that, in the case of leakage currents, the affected system components are difficult to access via air and creepage distances. Furthermore, from a physical perspective, the insulating properties of materials are usually at odds with mechanical flexibility and good thermal conductivity, the latter being necessary to transfer heat from the battery cells to the cooling plates.

[0007] It is known to bond a thin insulating film, such as Kapton or polyester, to the battery cells. However, these films are mechanically very sensitive, and their thinness poses a risk of partial discharge. The insulation is often inadequate at corners and edges. The same applies to silicone-based films with or without glass fiber reinforcement. Although tolerance compensation (i.e., compensation for manufacturing tolerances in the battery components) is possible depending on the hardness of the material used, this material is also difficult to apply over corners and edges, and the edges of the insulation are critical with regard to clearance and creepage distances.

[0008] An insulating coating can also be applied to the cooling surfaces. However, it is difficult to ensure long-lasting, good adhesion to the surface, and cracks, pores, or detachments, as well as corners, edges, and holes, pose a risk. Tolerance compensation is not possible.

[0009] Finally, it is also known to implement only low-voltage insulation in the battery area and to install high-voltage insulation elsewhere, for example, between load-bearing components and the vehicle chassis. However, this involves a complex design, as both the coolant and the connection points (load-bearing component to vehicle chassis) must be highly insulating permanently and under all conditions. Adequate insulation is often not achievable as a result.

[0010] The object of the invention is to provide a cooling arrangement for a battery cell that enables effective cooling while simultaneously providing reliable insulation. This object is achieved by an insulation and cooling arrangement and by a battery cell arrangement having the respective features of the independent patent claims. Advantageous embodiments of the invention are specified in the respective dependent patent claims.

[0011] A first aspect of the invention relates to an insulation and cooling arrangement for at least one battery cell, which has at least one cooling plate with a first main side for thermal contact with the at least one battery cell and with a first and an opposite second end side and an insulation element for electrical insulation on a first end side of the cooling plate, wherein a first side surface of the insulation element lies substantially in a plane with the first main side of the cooling plate.

[0012] The invention provides for an insulating element to be provided on a first end face of a cooling element, the side face of which element lies essentially in a plane with a side face of the cooling plate. This is the side face of the cooling plate which is intended for thermal contact with a battery cell and is referred to as the first main face. The insulating element essentially enlarges the first main face of the cooling plate beyond its first end face. Because the side faces lie essentially in a plane, an essentially flat base is provided for an insulating layer so that it does not have to be routed around an edge or corner. Possible creepage distances to the cooling plate are significantly increased, thereby also improving the insulation.The term "cooling plate" encompasses various forms of cooling devices and not just plate-shaped structures in the narrow sense. In particular, the side surfaces do not have to be strictly flat. The cooling plate is preferably heated by a coolant, for example, a heat sink.

[0013] Water, flows through. A second aspect of the invention relates to a battery cell arrangement having at least one battery cell and an insulation and cooling arrangement according to the invention, wherein a first main side of the battery cell is in thermal contact with the first main side of the cooling plate (4) and an insulation layer is arranged between these first main sides, and wherein the insulation layer extends over substantially the entire first main side of the cooling plate and substantially the entire first side surface of the insulation element.

[0014] The invention thus also encompasses a battery cell arrangement with one or more battery cells and the insulating and cooling arrangement. A first main side of the battery cell is in thermal contact with the first main side of the insulating and cooling arrangement. An insulating layer is arranged between the first main side of the cooling plate and the first main side of the battery cell, said insulating layer having sufficient electrical insulation properties and, at the same time, sufficient thermal conductivity. The insulating layer extends over substantially the entire first main side of the cooling plate and over at least part of the first side surface of the insulating element. Because the side surfaces of the cooling plate and the insulating element lie essentially in one plane, the insulating layer is applied to a flat surface, which is simple in terms of production and reduces the risk of weak points or damage.Furthermore, a certain tolerance compensation can be made.

[0015] The battery cell can be of a standard design type. In particular, it can be a prismatic cell, a pouch cell, or a round cell.

[0016] According to one embodiment, a first end face of the battery cell lies substantially in a plane with the first end face of the cooling plate. In other words, these parts are "equal in height," and the insulation element protrudes beyond them. Alternatively, the first end face of the cooling plate can be higher or lower than the end face of the battery cell, with cooling being improved in the first case (larger cooling plate). With a smaller cooling plate, if the first end face of the cooling plate is lower than the end face of the battery cell, the space requirement can be reduced. For example, it is possible for the side of the insulation element facing away from the cooling plate to lie in a plane with the first end face of the battery cell, so that the insulation element does not protrude beyond the battery cell, resulting in a particularly compact arrangement.

[0017] The insulating layer preferably covers the entire first side surface of the insulating element, but it may also leave a part free if sufficient insulation is ensured in the area of ​​the first end face of the cooling plate.

[0018] The insulation element can be at least partially covered with an electrically insulating fastening element. The fastening element can serve, in particular, to fasten the insulation element to the cooling plate and / or to sufficiently fix the battery cell. The fastening element can at least partially cover the battery cell, thereby achieving fixation in the corresponding direction. The fastening element can be connected to the insulation element, for example, due to its shape, in particular by interlocking or intermeshing, or a screw connection can be provided.

[0019] The first end face of the cooling plate can be flat, but it can also have a bulge or a projection that projects into the insulating element. This improves the insulating effect. A further insulating element can be present on a second end face of the cooling plate opposite the first end face, with its first side surface also lying essentially in a plane with the first main face of the cooling plate. The advantageous effects also occur here, since the insulating layer is applied on an essentially smooth plane and it is not necessary to guide the insulating layer around corners or edges for good insulation. In the case of minor deviations from a completely smooth plane, for example due to manufacturing tolerances, the insulating layer can provide the necessary compensation.

[0020] In principle, the same variants are possible for the additional insulation element as for the insulation element. It is particularly advantageous if the additional insulation element also forms a holder or support for the battery cell or for the battery cell adjacent to it. Depending on the arrangement of the battery cells, the battery cell adjacent to the additional insulation element can be different from the battery cell adjacent to the insulation element. The additional insulation element can have a T-shaped or angular cross-section and extend at least partially beneath the adjacent battery cell. Furthermore, the second end face of the cooling plate can have a bulge or a projection as described in connection with the first end face.

[0021] In general, several battery cells, referred to here as a module, are arranged between two insulation and cooling assemblies and interconnected in the desired manner to generate the required voltage and current. The geometric arrangement of the battery cells in the module depends on the type of battery cells. Preferably, several such modules are arranged side by side, with an insulation and cooling assembly being present between each two modules and these quasi-internal insulation and cooling assemblies also having an insulating layer on a second main side opposite the first main side. The internal insulation and cooling assemblies are preferably constructed symmetrically.

[0022] A thermal conduction structure may be present between some or all of the battery cells of a module. This structure is preferably thermally and electrically conductive, whereby the electrical conductivity can be used, in particular, to interconnect the battery cells.

[0023] Particularly preferably, the battery cell arrangement is designed as a traction battery of a vehicle, in particular a rail vehicle.

[0024] The invention is explained in more detail below using exemplary embodiments. They show a schematic representation

[0025] Fig.1 shows a first embodiment of a battery cell arrangement according to the invention with an insulating and cooling arrangement according to the invention,

[0026] Fig. 2 shows an arrangement with several battery cell arrangements of a second embodiment,

[0027] Fig.3 a third embodiment,

[0028] Fig.4 a fourth embodiment,

[0029] Fig.5 shows a part of the insulating and cooling element of the fourth embodiment with a tolerance compensation,

[0030] Fig.6 a fifth embodiment,

[0031] Fig.7 and 8 a sixth embodiment, and

[0032] Fig.9 and 10 show a seventh embodiment, wherein a cross section is shown in each figure, but for reasons of clarity the internal structure of the individual components such as the cooling plate and battery cell is not shown.

[0033] Fig. 1 shows, in a first embodiment, a battery cell arrangement 1 with an insulating and cooling arrangement 2 and a battery cell 3. The insulating and cooling arrangement 2 comprises a cooling plate 4 with a first main side 4a and a first end face 4b. An insulating element 5 is arranged on the first end face 4b, which has a first side surface 5a. The first side surface 5a and the first main side 4a lie in one plane, so that a continuous, smooth support surface for an insulating layer 6 is formed here. The insulating layer 6 extends over the entire first main surface 4a of the cooling plate and over the entire first side surface 5a of the insulating element. The battery cell 3 is electrically insulated from the cooling plate on its first main side 3a by the insulating layer 6, but is thermally connected. For the insulating layer, for example, a glass fiber reinforced silicone material can be used, e.g.with a ceramic filler for improved thermal conductivity, with a thickness in the range of 0.1 mm - 5 mm, or another material used in the state of the art, such as Kapton or polyester. A combination of such a glass fiber-reinforced silicone material with a curing, initially liquid silicone material is also possible.

[0034] In this exemplary embodiment, a first end face 3b of the battery cell lies in the same plane as the first end face 4b of the cooling plate. However, the first end faces 3b, 4b can also lie in different planes.

[0035] Typically, several battery cells are arranged one behind the other, i.e., in front of or behind the plane of the drawing, and are suitably interconnected to form a module. The insulation and cooling arrangement then extends accordingly over the length of the module, in front of and behind the plane of the drawing. In this embodiment, a prismatic battery cell is provided.

[0036] Fig. 2 shows adjacent battery cell arrangements with battery cells 3, 30, 31 and intermediate insulating and cooling arrangements with cooling plates 4, 40 and insulating elements 5, 50. The insulating layer 6 is applied or arranged on the first main side 4a, 40a of the cooling plates and on the opposite second main side 4c, 40c. The insulating layer 6 can each have a greater length, wherein the length projecting beyond the respective first end face 3b, 30b, 31b of the battery cells 3, 30, 31 or beyond the respective insulating element 5, 50 can be transferred to the adjacent battery cell or the insulating element. Even if damage should occur in this area, the creepage distance is not shortened as a result, since this is still ensured by the insulating element.In this embodiment, the side 5b, 50b of the insulating element 5, 50 facing away from the cooling plate is flush with the first end face 3b, 30b, 31b of the battery cells. This uniform height results in a particularly space-saving design. It is advisable to provide a further insulating element in the same way on the side opposite the first end face 4b of the cooling plate, i.e., the cooling plate 4 is correspondingly shorter, and the further insulating element is flush with the underside of the battery cell. This results in a very space-saving design while simultaneously providing very reliable electrical insulation.

[0037] Fig. 3 shows a third exemplary embodiment in which the insulating element 5 is covered with an electrically insulating fastening element 7. The fastening element 7 also extends over the insulating layer 6 and a portion of the adjacent battery cells 3, 31. The battery cells are fixed in place in this way. Fixing or support in the opposite direction is achieved by a further insulating element 8 on the second end face 4d of the cooling plate, which is opposite the first end face. This further insulating element 8 has a T-shaped cross-section and extends partially beneath the adjacent battery cells, i.e. beneath a second end face 3c, 31c, which is opposite the first end face 3a. Its side surfaces lie in a plane with the first or second main side 4a, 4c of the insulating and cooling arrangement.In one variant, the additional insulation element 8 can have a rectangular cross-section, i.e., it does not extend beneath the adjacent battery cells and does not serve for fixing or support. It then preferably terminates at the second end face 3c, 31c, as already explained in the description of Fig. 2. The fastening element 7 can be connected to the insulation element 5 and, if applicable, the cooling plate, for example, by a screw connection. The insulation element 5 and the fastening element 7 can also be shaped such that they are connected to one another by interlocking. In the third embodiment, the insulation is also improved in the lower region of the battery cell by the additional insulation element 8, since possible creepage distances are significantly extended.The lower insulation element can be covered only with an insulation material and its core can consist of another material, for example a thermally conductive material and preferably of the material of the cooling plate.

[0038] Fig. 4: In this embodiment, the first end face 4b of the cooling element has a projection that extends into the insulation element 5. This allows the cooling plate 4 to be enlarged while maintaining virtually no reduction in insulation effect.

[0039] Fig. 5 shows the upper part of the insulation and cooling arrangement in the case where the first or second main side 4a, 4c of the cooling plate 4 and the corresponding side surface 5a of the insulation element 5 are not completely in one plane. The resulting slight step can be compensated by the insulation layer 6 if an insulation layer 6 with sufficiently plastic properties is selected.

[0040] Fig. 6 shows an embodiment in which a projection of the cooling plate 4 extends into the further insulation element 8, and the insulation element 5 is flush with the first end face 3b, 31b of the battery cell. These measures achieve a very good insulation and cooling effect while simultaneously maintaining a compact design. It is also possible for the cooling plate to extend even further into the further insulation element and also under the battery cell, with the further insulation element partially enclosing the cooling plate here. This can be advantageous for stability, since the cooling plate 4 is usually made of an electrically conductive metal. Such a sheathing is preferably provided at locations where an extension of the creepage distance is required. This can be the case, for example, at the interfaces between the insulation element 8, the insulating layer 6, and the battery cell 3, 31.

[0041] 7 and 8 show an embodiment with battery cells 3, 32, 33, 34, wherein Fig. 8 shows a cross-section in the plane shown in dashed lines in Fig. 7, i.e. at the level of the insulation element 5. In Fig. 8, the battery cells 32, 33, 34, which are arranged one behind the other and are designed as pouch cells, can be seen. For better heat dissipation, a heat-conducting structure 9 is inserted after every three cells, for example. On one side, the right-hand side in Fig. 8, this structure extends to the insulation layer 6 and can be connected there, so that it has a comb-shaped or repeating L-shaped structure. The heat-conducting structure 9 can also extend in sections alternately on one side and on the other side to the insulation layer, i.e. the repeating L-shaped structures are each stacked in a mirror image to the one below. Cover plates 10 are provided at the front and rear ends of the module as a closure.If these cover plates 10 are made of an electrically conductive material, they must additionally be electrically insulated from the battery cell 32 adjacent to the respective cover plate 10 or the heat-conducting structure 9. For this purpose, plates or blocks made of an electrically insulating material can be provided, which, according to the example in Fig. 8, are arranged above the upper battery cell 32 or below the lower prong of the heat-conducting structure 9. The plates or blocks have a respective thickness corresponding to the required extension of the creepage distance.

[0042] 9 and 10 show an embodiment with round cells, wherein Fig. 10 shows a cross-section in the plane shown in dashed lines in Fig. 9, i.e. parallel and closely adjacent to the insulating layer 6. The battery cells 32, 33, 34 are arranged horizontally and suitably connected at their poles by means of the electrically conductive heat conduction structure; in the example, fourteen cells are connected in series, as can be seen in Fig. 10. The heat conduction structure 9 also serves to thermally connect to the insulating layer 6 on both sides of the module. The cooling plates 4 border on the insulating element 5 and the further insulating element 8. The first side surfaces 5a, 8a of the insulating elements 5, 8 and the first main side 4a of the cooling plate lie in one plane, so that the insulating layer 6 does not have to be guided around edges or corners.

[0043] The features and aspects of the invention described in the exemplary embodiments can, of course, be combined with one another in various ways. In particular, the features can be used not only in the described combinations, but also in other combinations or on their own. List of reference symbols

[0044] 1 Battery cell arrangement

[0045] 2 Insulation and cooling arrangement

[0046] 3, 30, 31, 32, 33, 34 battery cell

[0047] 3a first main side of the battery cell

[0048] 3b first end face of the battery cell

[0049] 3c second end face of the battery cell

[0050] 4, 40 cooling plate

[0051] 4a, 40a first main side of the cooling plate

[0052] 4b first front side of the cooling plate

[0053] 4c, 40c second main side of the cooling plate

[0054] 4d second front side of the cooling plate

[0055] 5 Insulation element

[0056] 5a first side surface of the insulation element

[0057] 5b opposite side surface of the insulation element

[0058] 6 Insulating layer

[0059] 7 Fastening element

[0060] 8 additional insulation element.

[0061] 8a first side surface of the further insulation element

[0062] 9 Thermal conduction structure

[0063] 10 Cover plate

Claims

CHANGED CLAIMS received at the International Bureau on 17 October 2023 (17.10.2023) 1. Insulation and cooling arrangement (2) for at least two battery cells (3, 31), comprising at least - a cooling plate (4) with a first main surface (4a) for thermal contact with one battery cell (3), with a second main surface (4c, 40c) opposite the first main surface for thermal contact with the second battery cell (31) and with a first (4b) and a second opposite end surface (4d), and - an insulating element (5) for electrical insulation on a first end face (4b) of the cooling plate (4), - wherein a first side surface (5a) of the insulating element (5) is essentially in the same plane as the first main surface (4a, 40a) of the cooling plate.

2. Insulation and cooling arrangement according to claim 1, characterized in that it further comprises an insulating layer (6) for electrical insulation, which is applied to the first main surface (4a) of the cooling plate (4) and at least a part of the first side surface (5a) of the insulating element (5).

3. Battery cell arrangement (1) comprising at least one battery cell (3) and an insulating and cooling arrangement according to claim 2, - wherein a first main surface (3a) of the battery cell (3) is in thermal contact with the first main surface (4a) of the cooling plate (4) and the insulating layer (6) is arranged between these first main surfaces (3a, 4a), and - wherein the insulating layer (6) extends over substantially the entire first main surface (4a) of the cooling plate (4) and at least part of the first side surface (5a) of the insulating element (5).

4. Battery cell arrangement (1) according to claim 3, characterized in that a first end face (3b) of the battery cell (3) is substantially in one plane with the AMENDED SHEET (ARTICLE 19) first end face (4b) of the cooling plate (4) or with the side (5b) of the insulation element (5) facing away from the cooling plate (4).

5. Battery cell arrangement (1) according to claim 3 or 4, characterized in that the insulating element (5) is at least partially covered by an electrically insulating fastening element (7), wherein the insulating fastening element (7) fixes the battery cell (3).

6. Battery cell arrangement (1) according to one of claims 3 to 5, characterized in that the first end face (4b) of the cooling plate (4) has a protrusion or projection which extends into the insulating element (5).

7. Battery cell arrangement (1) according to one of claims 3 to 6, characterized in that a further insulating element (8) is arranged on the second end face (4d) of the cooling plate (4), wherein a side surface (8a) of the further insulating element (8) is substantially in a The level with the first main side (4a, 40a) of the cooling plate (4) is located.

8. Battery cell arrangement (1) according to the preceding claim, characterized in that the further insulating element (8) has a T- or angle-shaped cross-section and extends at least partially under the second end face (3c) of the battery cell (3) opposite the first end face (3b).

9. Battery cell arrangement (1) according to the preceding Claim, characterized in that the further insulating element (8) consists of a thermally conductive material and is combined with an insulating material for electrical The insulation is at least partially encased.

10. Battery cell arrangement (1) according to one of claims 3 to 9, characterized in that a thermal conductivity structure AMENDED SHEET (ARTICLE 19) (9) is arranged between two battery cells (3, 30, 31, 32, 33, 34) and / or between the battery cell (3, 30, 31, 32, 33, 34) and the insulating layer (6).

11. Battery cell arrangement (1) according to one of claims 3 to 10, characterized in that it is designed as a traction battery of a vehicle, in particular a rail vehicle. AMENDED SHEET (ARTICLE 19)

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