Housing part for a battery housing of a traction battery, battery housing, traction battery, and method for manufacturing a housing part

Abstract

The invention relates to a housing part (10), in particular a housing lower part, for a battery housing (100) of a traction battery (200) of an electrically operable vehicle, wherein a plurality of battery cells can be arranged in a housing interior space (40) of the battery housing (100), for connection to a second housing part (12) of the battery housing (100), the housing part comprising a layer composite (20) composed of a plurality of layers (22, 24, 26) made of different materials, at least comprising: an outer layer (22) made of a fibre-reinforced plastic; a metal layer (24), in particular made of steel or aluminium; and a bonding layer (26) between the outer layer (22) and the metal layer (24), wherein the layer composite (20) is formed by means of compression. The invention also relates to: a battery housing (100) for a traction battery (200); a traction battery (200); and a method for manufacturing a housing part (10) for a battery housing (100).

Description

[0001] Housing part for a battery housing of a traction battery, battery housing, traction battery and method for producing a housing part

[0002] The invention relates to a housing part, in particular a housing lower part, for a battery housing of a traction battery of an electrically operated vehicle, as well as a battery housing, a traction battery and a method for producing a housing part.

[0003] DE 10 2020 101 039 A1 discloses a housing cover for a battery housing of a traction battery of an electrically driven motor vehicle, which housing cover serves to be placed on a lower housing part of the battery housing. The housing cover has a covering layer for closing off, in particular for sealing, an interior space of the battery housing. The interior space is designed to accommodate at least one battery cell. Furthermore, the housing cover has a protective layer that overlaps the covering layer at least in some areas to withstand thermal stress caused by heat exposure to the housing cover during emergency degassing of the at least one battery cell.The protective layer is mechanically connected to the cover layer in connection areas and is arranged at a distance from the cover layer in protection areas, forming a gap intended to increase a thermal contact resistance between the protective layer and the cover layer.

[0004] Typically, in battery housings for electrically powered motor vehicles, metallic EMC (electromagnetic compatibility) shields such as metal foils, metal sheets, or electrically conductive paints are applied to a plastic component in a subsequent processing step, e.g., by gluing or painting. Crash reinforcements or fire protection reinforcements, such as mica mats or metal reinforcements, are also usually incorporated into the finished component in a separate joining step. One object of the invention is to provide an improved housing part, in particular a housing base, for a battery housing of a traction battery of an electrically powered vehicle.

[0005] A further object is to create an improved battery housing for a traction battery of an electrically operated vehicle.

[0006] Another task is to create an improved traction battery for an electrically powered vehicle.

[0007] A further object is to provide an improved method for producing a housing part for a battery housing of a traction battery of an electrically operated vehicle.

[0008] The above-mentioned objects are solved by the features of the independent claims.

[0009] Advantageous embodiments and advantages of the invention emerge from the further claims, the description and the drawing.

[0010] According to one aspect of the invention, a housing part, in particular a housing lower part, for a battery housing of a traction battery of an electrically operated vehicle is proposed, wherein a plurality of battery cells can be arranged in a housing interior of the battery housing, for connection to a second housing part of the battery housing, with a layered composite of several layers with different materials, at least comprising an outer layer made of a fiber-reinforced plastic, a metal layer, in particular made of steel or aluminum, and a connecting layer between the outer layer and the metal layer. The layered composite is formed by pressing.

[0011] The proposed housing part is a part of a battery housing made of fiber-reinforced plastics, such as duroplast or thermoplastic, with integrated metallic EMC shielding and with additional metallic crash structure and / or fire protection structure.

[0012] To provide EMC shielding and crash reinforcement or fire protection, a metal layer in the form of a metallic tub, for example made of steel or aluminum, is inserted into a pressing tool and pressed directly onto the plastic material of the outer layer. The base material for the outer layer can be a thermoset or thermoplastic with a high glass fiber content and flame-retardant additives. For example, a so-called sheet molded compound (SMC) based on an unsaturated polyester resin can be used as the fiber-reinforced plastic. The fiber content can preferably be at least 20%, particularly preferably at least 30%. Additional flame-retardant additives can preferably be added to the resin. The sheet thickness of the steel metal layer can be, for example, 1 mm. Alternatively, an aluminum sheet with a material thickness of at least 1 mm can also be used.The material thickness depends on the geometry of the housing part. However, the formability and mechanical properties of aluminum tend to be greater than those of steel.

[0013] A bonding layer is applied to the metal tray, which promotes a permanent bond between the metal layer and the outer layer. This allows the outer layer and metal layer to be firmly bonded together without the need for adhesive.

[0014] By incorporating the additional functions during the pressing step, subsequent processing steps can be eliminated. This makes the production of the battery housing more cost-effective and shortens production cycle times.

[0015] The semi-finished plastic parts and process parameters are advantageously designed to achieve optimal, flat adhesion between the plastic and the reinforcement tray. The metal insert serves as a ductile layer that ensures the integrity of the housing part even in the event of significant deformation or impact with a sharp object.

[0016] Downstream joining steps can be eliminated in this manufacturing process. The EMC shielding, crash reinforcement, and fire protection reinforcement are integrated directly into the housing component. Corrosion protection of the metal shell can be achieved with a plastic coating. For example, the edges of the metal shell can be pressed and / or overmolded with the plastic material of the outer layer.

[0017] According to an advantageous embodiment of the housing part, the connecting layer can form a chemical bond with the outer layer and / or the metal layer under pressure and / or close contact. This advantageously enables a permanent bond between the metal layer and the outer layer. According to an advantageous embodiment of the housing part, the metal layer can be encased by the outer layer at an outer peripheral edge, in particular in the radially outward direction, in particular embedded in the outer layer. Thus, the metallic insert can be completely encased by the outer layer as a plastic layer and / or overmolded, thus providing permanent protection against corrosion.

[0018] According to an advantageous embodiment of the housing part, the outer layer can have flame-retardant properties. This allows for effective fire protection to be achieved in a cost-effective manner.

[0019] According to an advantageous embodiment of the housing part, the connecting layer can comprise a lacquer, in particular a powder lacquer. The connecting layer can thus be applied to the metal layer in a simple and cost-effective manner and, during pressing, enable a permanent bond between the outer layer and the metal layer. The lacquer can be applied to the metal layer, which is designed, for example, as a steel tray, as a bonding agent and baked on. The semi-finished plastic products are then pressed together in the form of a mat, with the lacquer providing the adhesion between the two components, the metal layer and the outer layer.

[0020] A powder coating primer, for example, can be applied as a bonding layer. The binder base can be an epoxy resin. The density can be, for example, 1.2-1.7 g / cm 3 an application quantity of approximately 0.3 kg / m 2, with a layer thickness of 200pm.

[0021] According to an advantageous embodiment of the housing part, at least one electrical contact element can be electrically connected to the metal layer, which, when the second housing part is properly assembled, is electrically connected to a metallic cover of the second housing part. This advantageously allows for effective EMC shielding.

[0022] According to an advantageous embodiment of the housing part, the outer layer can have, at least in some areas, radially outwardly projecting ribbing. Alternatively or additionally, the metal layer can have, at least in some areas, raised portions, in particular beads, directed toward the housing interior. The ribbing can advantageously stiffen the battery housing against lateral forces. The raised portions, in particular beads, stiffen the housing part, as the lower housing part of a battery housing, against deflection when accommodating heavy battery modules.

[0023] According to a further aspect of the invention, a battery housing for a traction battery of an electrically operated vehicle is proposed, wherein a plurality of battery cells can be arranged in a housing interior of the battery housing, with a first housing part, in particular a lower housing part, and with a second housing part, in particular an upper housing part, wherein the first housing part has a layer composite made of several layers with different materials, at least comprising an outer layer made of a fiber-reinforced plastic, a metal layer, in particular made of steel or aluminum, and a connecting layer between the outer layer and the metal layer. The layer composite is formed by pressing. The second housing part is tightly connected to a peripheral edge of the first housing part. In particular, the second housing part is electrically connected via electrical contact elements.

[0024] The proposed battery housing with the housing part described above provides a cost-effective and production-friendly solution for a battery housing for a traction battery.

[0025] The battery housing advantageously features integrated EMC shielding, crash reinforcement, and fire protection reinforcement. The battery housing is permanently protected against corrosion.

[0026] According to a further aspect of the invention, a traction battery for an electrically operated vehicle is proposed, comprising a plurality of battery cells and a battery housing, wherein the battery cells are arranged in a housing interior of the battery housing.

[0027] The proposed traction battery, which comprises a battery housing with the housing part described above, provides a cost-effective and production-friendly solution for a traction battery.

[0028] The traction battery advantageously has integrated EMC shielding, crash reinforcement, and fire protection reinforcement. The battery housing is permanently protected against corrosion. According to a further aspect of the invention, a method for producing a housing part for a battery housing of a traction battery of an electrically operated vehicle is proposed, at least comprising providing a metal layer, in particular made of steel or aluminum, providing an outer layer made of a fiber-reinforced plastic, applying a bonding layer, in particular a paint, in particular a powder paint, to the metal layer, inserting the metal layer into a mold, placing the outer layer onto the metal layer, and pressing the outer layer with the metal layer to form a layered composite.

[0029] The proposed method enables the production of a housing part as part of a battery housing made of fiber-reinforced plastics, such as duroplast or thermoplastic, with integrated metallic EMC shielding and with additional metallic crash structure and / or fire protection structure.

[0030] To provide EMC shielding, crash reinforcement, or fire protection, a metal layer in the form of a metallic tub, for example, made of steel or aluminum, is inserted into a pressing tool and pressed directly into the plastic material of the outer layer. The base material for the outer layer can be a thermoset or thermoplastic with a high glass fiber content and flame-retardant additives. For example, a so-called sheet molded compound (SMC) based on an unsaturated polyester resin can be used as the fiber-reinforced plastic. The fiber content can preferably be at least 20%, particularly preferably at least 30%. The sheet thickness of the steel metal layer can be, for example, 1 mm. Alternatively, an aluminum sheet with a material thickness of at least 1 mm can also be used. The material thickness depends on the geometry of the housing part.However, the formability and mechanics of aluminum tend to be greater than those of steel.

[0031] A bonding layer is applied to the metal tray, which promotes a permanent bond between the metal layer and the outer layer. This allows the outer layer and metal layer to be firmly bonded together without the need for adhesive.

[0032] The paint can be applied to the metal layer, which is formed, for example, as a steel tray, as a bonding agent and baked on. The semi-finished plastic parts are then pressed together in the form of a mat, with the paint providing the adhesion between the two components: the metal layer and the outer layer.

[0033] A powder coating primer, for example, can be applied as a bonding layer. The binder base can be an epoxy resin. The density can be, for example, 1.2-1.7 g / cm 3an application quantity of approximately 0.3 kg / m 2 , with a layer thickness of 200pm.

[0034] By incorporating the additional functions during the pressing step, subsequent processing steps can be eliminated. This makes the production of the battery housing more cost-effective and shortens production cycle times.

[0035] The semi-finished plastic parts and process parameters are advantageously designed to achieve optimal, flat adhesion between the plastic and the reinforcement tray. The metal insert serves as a ductile layer that ensures the integrity of the housing part even in the event of significant deformation or impact with a sharp object.

[0036] Downstream joining steps can be eliminated in this manufacturing process. EMC shielding, crash reinforcement, and fire protection reinforcement are integrated directly into the housing component. Corrosion protection of the metal shell can be achieved with a plastic coating. For example, the edges of the metal shell can be pressed and / or overmolded with the plastic material of the outer layer.

[0037] Further advantages will become apparent from the following description of the drawings. The drawings illustrate an exemplary embodiment of the invention. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into useful further combinations.

[0038] Showing:

[0039] Fig. 1 is an isometric view of a first housing part, the lower housing part, of a battery housing of a traction battery of an electrically operated vehicle according to an embodiment of the invention;

[0040] Fig. 2 shows a longitudinal section in the edge region of the housing part; and Fig. 3 shows a longitudinal section through a battery housing of a traction battery according to an embodiment of the invention.

[0041] In the figures, identical or similar components are numbered with the same reference numerals. The figures show only examples and are not to be understood as limiting.

[0042] Figure 1 shows an isometric view of a first housing part 10, the lower housing part, of a battery housing 100 of a traction battery 200 of an electrically operated vehicle according to an embodiment of the invention.

[0043] Figure 2 shows a longitudinal section in the edge region 28 of the first housing part 10, the lower housing part.

[0044] The first housing part 10, the housing base, has a layered composite 20 made of several layers 22, 24, 26 made of different materials. The layered composite 20 comprises an outer layer 22 made of a fiber-reinforced plastic, a metal layer 24, in particular made of steel or aluminum, and a connecting layer 26 between the outer layer 22 and the metal layer 24. The layered composite 20 is formed by pressing.

[0045] The method for producing the housing part 10 comprises at least providing the metal layer 24, in particular made of steel or aluminum. Furthermore, the outer layer 22 is provided from a fiber-reinforced plastic. Subsequently, the bonding layer 26, in particular a paint, in particular a powder coating, is applied to the metal layer 24 and baked. The metal layer 24 is placed in a mold, and the outer layer 22 is placed onto the metal layer 24.

[0046] Subsequently, the outer layer 22 is pressed together with the metal layer 24 to form a layered composite 20. The connecting layer 26 forms a chemical bond with the outer layer 22 and / or the metal layer 24 under pressure and / or due to the close contact caused by the pressing. In this way, the outer layer 22 and the metal layer 24 can be firmly bonded together without the use of adhesive.

[0047] The outer layer 22 can expediently have flame-retardant properties, allowing a fire protection structure to be implemented. As can be seen in Figure 1, the outer layer 22 can have, at least in some areas, ribbing 34 projecting radially outward. The metal layer 24, on the other hand, can have, at least in some areas, protrusions 36, in particular beads, directed toward the housing interior 40.

[0048] Figure 2 shows that the metal layer 24 is encased by the outer layer 22 at an outer peripheral edge 28, particularly in the radially outward direction, and is particularly embedded in the outer layer 22. The metal layer 24, as a metallic insert, can be pressed around by the fiber-reinforced plastic material of the outer layer 22. In Figure 2, one of the protruding ribs 34 is cut. In this area, the outer layer 22 is therefore considerably thicker than, for example, in the base area.

[0049] The continuous connecting layer 26 is arranged between the metal layer 24 and the outer layer 22.

[0050] Figure 3 shows a longitudinal section through a battery housing 100 of a traction battery 200 according to an embodiment of the invention.

[0051] The battery housing 100 has a first housing part 10, the lower housing part, and a second housing part 12, the upper housing part, which are connected in the region of the edge 28 of the first housing part 10. The first housing part 10 can, for example, be formed from a layered composite 20, as shown in Figures 1 and 2. The second housing part 12 can, as shown in the exemplary embodiment in Figure 3, have a frame element 38 in the edge region, which can serve to connect to the vehicle and / or as a crash structure for absorbing laterally acting forces.

[0052] A plurality of battery cells, not shown, can be arranged in a housing interior 40 of the battery housing 100.

[0053] The first housing part 10 comprises the layered composite 20, as previously described, with an outer layer 22 made of a fiber-reinforced plastic, a metal layer 24, in particular made of steel or aluminum, and a connecting layer 26 between the outer layer 22 and the metal layer 24. The layered composite 20 is formed by pressing.

[0054] The second housing part 12 is tightly connected to the peripheral edge 28 of the first housing part 10. The second housing part 12 has a metallic cover on its side facing the housing interior 40. In the first housing part 10, electrical contact elements 30 are arranged on the edge 28 and are electrically connected to the metal layer 24. When the battery housing 100 is closed, these electrical contact elements 30 are electrically connected to the metallic cover 32 of the second housing part 12. This provides effective EMC shielding for the battery housing 100.

[0055] The sectional view in Figure 3 shows a base part 42, which has elevations 44, in the housing interior 40 above the metal layer 24. The elevations 44 serve as spacers for the battery cells or battery modules (not shown) arranged above it, from the housing base. A so-called venting channel is formed here between the battery cells and the base part 42, through which gases generated by a thermal event can be discharged from the battery housing 100 at defined locations.

[0056] Furthermore, Figure 3 shows a crash absorber 46, which protects the battery cells from intrusion in the event of a mechanical impact.

[0057] List of reference symbols

[0058] 10 Housing part

[0059] 12 second housing part

[0060] 20 layer composite

[0061] 22 Outer layer

[0062] 24 metal layer

[0063] 26 Connection layer

[0064] 28 Rand

[0065] 30 electrical contact element

[0066] 32 metallic cover

[0067] 34 ribbing

[0068] 36 Emphasis

[0069] 38 frame element

[0070] 40 Housing interior

[0071] 42 Base part

[0072] 44 Survey

[0073] 46 crash absorbers

[0074] 100 battery cases

[0075] 200 traction battery

Claims

Patent claims 1. Housing part (10), in particular a housing lower part, for a battery housing (100) of a traction battery (200) of an electrically operated vehicle, wherein a plurality of battery cells can be arranged in a housing interior (40) of the battery housing (100), for connection to a second housing part (12) of the battery housing (100), with a layer composite (20) made of several layers (22, 24, 26) with different materials, at least comprising an outer layer (22) made of a fiber-reinforced plastic, a metal layer (24), in particular made of steel or aluminum, a connecting layer (26) between the outer layer (22) and the metal layer (24), wherein the layer composite (20) is formed by pressing.

2. Housing part according to claim 1, wherein the connecting layer (26) has a chemical bond with the outer layer (22) and / or the metal layer (24) under pressure and / or close contact.

3. Housing part according to claim 1 or 2, wherein the metal layer (24) is enveloped by the outer layer (22) at an outer peripheral edge (28), in particular in the radial outward direction, in particular is embedded in the outer layer (22).

4. Housing part according to one of the preceding claims, wherein the outer layer (22) has flame-retardant properties.

5. Housing part according to one of the preceding claims, wherein the connecting layer (24) comprises a lacquer, in particular a powder lacquer.

6. Housing part according to one of the preceding claims, wherein at least one electrical contact element (30) is electrically conductively connected to the metal layer (24), which, when the second housing part (12) is mounted as intended, is electrically connected to a metallic cover (32) of the second housing part (12).

7. Housing part according to one of the preceding claims, wherein the outer layer (22) has at least in some regions a ribbing (34) projecting radially outwards and / or wherein the metal layer (24) has at least in some regions protrusions (36), in particular beads, directed towards the housing interior (40).

8. A battery housing (100) for a traction battery (200) of an electrically operated vehicle, wherein a plurality of battery cells can be arranged in a housing interior (40) of the battery housing (100), comprising a first housing part (10), in particular a lower housing part, according to one of the preceding claims, and a second housing part (12), in particular an upper housing part, wherein the first housing part (10) has a layered composite (20) made of several layers (22, 24, 26) with different materials, at least comprising an outer layer (22) made of a fiber-reinforced plastic, a metal layer (24), in particular made of steel or aluminum, a connecting layer (26) between the outer layer (22) and the metal layer (24), wherein the layered composite (20) is formed by pressing, wherein the second housing part (12) is tightly connected to a peripheral edge (28) of the first housing part (10),in particular via electrical contact elements (30) is electrically connected., 9. Traction battery (200) for an electrically operated vehicle, comprising a plurality of battery cells and a battery housing (100) according to claim 8, wherein the battery cells are arranged in a housing interior (40) of the battery housing (100).

0. Method for producing a housing part (10) according to one of claims 1 to 7 for a battery housing (100) of a traction battery (200) of an electrically operable vehicle, at least comprising Providing a metal layer (24), in particular made of steel or aluminum, Providing an outer layer (22) made of a fiber-reinforced plastic, - applying a connecting layer (26), in particular a lacquer, in particular a powder lacquer, to the metal layer (24), inserting the metal layer (24) into a tool mould, - Placing the outer layer (22) on the metal layer (24), pressing the outer layer (22) with the metal layer (24) to form a layer composite (20).

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