DE102012112063A1 - Battery housing portion for battery case of traction battery of electric vehicle, has second layer that is made of second material, which is constant than first material, which is media-resistant to electrolyte of traction battery - Google Patents

Abstract

The portion (10) has a side open cavity (14) in which a traction battery (12) is received. A wall (16) is provided with two layers (18, 20). The first layer is provided with a cavity and side (22). The second layer is provided with a side (24) facing the vicinity of a battery housing portion main portion and facing away from the cavity. The first layer is made of a first material (26), which is media-resistant to an electrolyte of the traction battery. The second layer is made of a second material (28), which is constant than the first material.

Description

Background of the invention

The present invention relates to a battery case part for a battery case of a traction battery of an electric vehicle.

Battery housing parts of the type mentioned are often exposed to external influences during use, which can lead to damage of the battery housing part. This is the case in particular in the case of high outside temperatures in the summer, where melting of the plastic material can often occur as a result of these high outside temperatures, from which the battery housing parts usually at least partially exist. Another problem that arises in the manufacture of the battery housing part is the production of media resistance to the electrolytes of the traction battery. Thus, known battery housing parts often result in damage or degradation of the battery housing part material due to contact with electrolytes leaking from the traction battery.

Underlying task

The present invention has for its object to provide a battery housing part for a battery case of a traction battery of an electric vehicle, which has a high media resistance to expiring from the traction battery electrolyte in conjunction with a high temperature resistance, and to provide a method for producing such a battery housing part.

Inventive solution

This object is achieved with a battery housing part for a battery case of a traction battery of an electric vehicle having the features of claim 1 and a method for producing such a battery housing part with the features of claim 9.

According to the invention, it is provided that the first layer consists at least partially of a first material that is resistant to media to the electrolytes of the traction battery, and that the second layer at least partially consists of a second material, which is creep resistant than the first material.

The provision of the first and the second layer advantageously realizes high media resistance to electrolytes leaking from the traction battery, in conjunction with high temperature resistance. For this purpose, there is the first layer, which comes in contact with the electrolyte during the discharge of electrolyte from the traction battery in contact or come, at least partially or entirely from a media-resistant to the first material. The second layer, on the other hand, which can be exposed to higher heat than the first layer, especially in the summer especially by thermal radiation, consists at least partially of a second material, which is creep resistant to achieve a high temperature resistance or to achieve a higher temperature resistance than the first layer as the first material of the first layer.

The first or second material of which the layers at least partially consist can preferably be an electrolyte-resistant plastic material or polymer material.

In a preferred embodiment, the first material is a thermoplastic material, preferably polypropylene. Of the thermoplastic materials in particular polypropylene is characterized by a high media resistance to the electrolyte. In addition, polypropylene is characterized in particular by a very good processability and low acquisition costs. An alternative for an electrolyte-resistant plastic material is polybutylene terephthalate (PBT).

In a further preferred embodiment, the second material is a thermoplastic material, preferably polyamide or polyethylene terephthalate. Of these materials, in particular polyamide is characterized by a high creep resistance, which is particularly greater than the creep resistance of polypropylene, along with a high temperature resistance.

Preferably, the second material may also be a glass fiber material or a glass fiber reinforced plastic material, which in addition to a high creep resistance advantageously also characterized by a high strength.

In a practical embodiment of the battery housing part according to the invention the first and the second material is a thermoplastic material, wherein the first layer of the first material and first reinforcing fibers, wherein the first reinforcing fibers are at least partially embedded in the first material, and / or wherein the second Layer of the second material and second reinforcing fibers, wherein the second reinforcing fibers are at least partially embedded in the second material. By providing the reinforcing fibers may advantageously be the strength or the mechanical Resilience of the battery case part be substantially increased or substantially increased.

The reinforcing fibers are preferably mineral fibers, in particular glass fibers, and / or carbon fibers, and / or aramid fibers and / or polymeric fibers, and / or synthetic fibers and / or fibers of renewable raw materials. In this case, the first layer and / or the second layer can in particular be unidirectionally fiber-reinforced by means of the reinforcing fibers, in particular in order to advantageously make it possible to adapt to forces acting in later use of the battery housing part and resulting load paths. Furthermore, the reinforcing fibers may be short fibers and / or long fibers and / or continuous fibers.

In another practical embodiment, at least one third layer is provided between the first and second layers. The third layer may in this case in particular consist at least partially or entirely of an adhesion-promoting material. By providing this view, a firm connection can be created between the first and second layers. The adhesion-promoting material may in this case be, in particular, a glass fiber fleece material or a continuous fiber material. A particularly strong connection can be created or provided in that the adhesion-promoting material is a mixture of the first and the second material. The adhesion-promoting material is then formed in the form of a blend or polymer blend of the first and second material, along with a very high adhesion.

Preferably, the third layer can also consist at least partially or wholly of a heat-insulating material. By providing the heat insulating material, excessive cooling of the traction battery during operation of the electric vehicle can be effectively avoided at low outside temperatures. The heat insulating material may preferably be a polymeric foam material.

• (A) Bereitstellen einer Mehrzahl von Matten, die im wesentlichen flächig ausgebildet sind, wobei die Mehrzahl der Matten wenigstens eine Teilanzahl von ersten Matten und zweiten Matten umfasst, wobei jede erste Matte wenigstens teilweise aus dem ersten Material besteht, und wobei jede zweite Matte wenigstens teilweise aus dem zweiten Material besteht,
• (B) Ausbilden einer Matten-Anordnung, wobei die Matten-Anordnung wenigstens eine erste Matte und wenigstens eine zweite Matte umfasst, die über die ersten Matte angeordnet ist, und
• (C) Ausbilden des Batteriegehäuseteils durch Verformen und/oder Konsolidieren der Matten-Anordnung.

The method according to the invention comprises the following steps:

• (A) providing a plurality of mats that are substantially planar, wherein the plurality of mats comprises at least a portion of first mats and second mats, each first matte being at least partially made of the first material, and each second matte being at least partly made of the second material,
• (B) forming a mat assembly, the mat assembly comprising at least a first mat and at least one second mat disposed over the first mat, and
• (C) forming the battery case by deforming and / or consolidating the mat assembly.

By means of the method according to the invention, a battery housing part according to the invention can be produced in a practical manner using the flat-shaped mats.

In step C, the battery housing part is formed by deforming and / or consolidating the mat arrangement, wherein the mats or the material of the mats or the material of the first and second mats is deformable. Depending on the material used or depending on the used first and second material of the mats, which may preferably be in particular a plastic material or a polymer material, it may be necessary or advantageous for providing the deformability of the mats or the deformability of the first and second mats to warm them up.

Under consolidation according to the invention is a compacting or compaction of the mats to understand. During consolidation, air taken in through the compartments, in particular in the mats, can escape from the mats due to compacting or compaction. By forming and / or consolidating further at least partially the formation of cohesive connections between the individual mats, accompanied by the creation of a stable and coherent first and second layer.

In step B, the mat assembly is formed, wherein the mat assembly includes at least a first mat and at least one second mat disposed over the first mat.

Preferably, in step B, provided that a plurality of first mats and a plurality of second mats are provided in step A, the second mats are overlaid on the mats to form the mat assembly to be deformed in step C and / or juxtaposed with each other; arranged first mats and stacked in arranging and / or contiguous and / or juxtaposed. For producing a battery housing part, the wall of which is formed from the first layer and the second layer or whose wall (without providing an intermediate layer) consists of the first layer and the second layer, can be stacked to form the mat arrangement to be deformed in step C. and / or to each other and / or juxtaposition of the first mats, the second mats placed on the first mats and placed on the laying on and / or applied to each other and / or juxtaposed.

In step A, there is provided a plurality of mats that are substantially planar, the plurality of mats comprising at least a portion of first mats and second mats, the first mat (if the number of parts is one) or each first mat at least partially made of the first material, and wherein the second mat (if the number of parts is one) or every other mat at least partially made of the second material. In particular, in step A, the plurality of mats may not only comprise a part number of first mats and second mats but the plurality of mats or all provided mats may exclusively comprise only first and second mats or may be exclusively only first and second mats. The latter is intended for producing a battery housing part whose wall is formed from the first layer and the second layer or whose wall (without provision of an intermediate layer) consists of the first layer and the second layer, in which case the formation of the mat Arrangement takes place such that the at least one second mat is placed on the at least one first mat.

In a practical embodiment of the method according to the invention, the first and second material is a thermoplastic material, of the mats provided in step A, the first mat or first mat consists of the first material and first reinforcing fibers at least partially embedded in the first material wherein the second mat or second mat is comprised of the second material and second reinforcing fibers at least partially embedded in the second material, and prior to step C, the thermoplastic material of all mats of the mat assembly is at least partially fluidized by heating is transferred, and wherein after step C, the battery housing part is cooled.

By means of this practical embodiment of the method according to the invention is advantageously a battery housing part according to the invention can be produced, in which the first and the second layer are reinforced by the reinforcing fibers, accompanied by a high mechanical strength and a high mechanical stability.

The heating of the mats is preferably carried out by convection heating and / or infrared radiation. Further preferably within a convection and / or infrared continuous furnace. The heating by infrared radiation or by convection heating allows a uniform heating of the mats.

By naming the steps with the letters A to C no binding or exclusive binding to a chronological order is pursued. The letters merely serve to designate or identify the steps and therefore in particular facilitate the reference. Thus, step B may preferably be performed after step A. Alternatively, step B can also take place during step A or at the same time or substantially simultaneously with step A. Step C is carried out according to the invention after step B.

As with the above practical embodiment of the battery housing part according to the invention, the reinforcing fibers may preferably be mineral fibers, in particular glass fibers, and / or carbon fibers, and / or aramid fibers and / or polymeric fibers, and / or synthetic fibers and / or fibers of renewable raw materials act. The first and / or second mats can be unidirectionally fiber-reinforced in particular by the reinforcing fibers, in particular in order to advantageously make it possible to adapt to forces acting in later use of the battery housing part and resulting load paths. Furthermore, the reinforcing fibers may be short fibers and / or long fibers and / or continuous fibers.

In a further practical embodiment of the method according to the invention, in step B, the mats are placed on a rough contour of the battery housing part predetermining workpiece carrier and constructed into a mat arrangement in the form of a three-dimensional preform, wherein during or after completion of the construction of the preform a positional fixation of at least two Mats is made to each other and wherein after fixing the preform placed in a final shape of the battery housing part forming mold and formed in step C by providing a mold internal pressure from the preform, the battery housing part by deforming the preform and / or by consolidating the preform.

The inclusion of the rough contour predetermining tool carrier allows in a practical way a precise production of a battery housing part. In particular, the provision of the tool carrier advantageously produces a precise production of a multiplicity of identically constructed or substantially identical battery housing parts, e.g. possible as part of a series production.

By preforming the fiber reinforced mats into a preform can ever Be disregarded from the application of a pronounced deformation, so that no significant forming or flow processes must be performed. In this case, according to step C, only by consolidating the training or the final design of the battery case part can be done. The provision of the mold internal pressure can be carried out within the mold by injection-molding of the preform with plastic. The provision or adjustment of the mold internal pressure can also by additional insertion of GMT pieces (GMT: Abbreviation for glass mat reinforced thermoplastic), more preferably by a ShotPot technique or by inserting sealing cords in the mold or by inserting a sealing film in the Mold done. Furthermore, the aforementioned possibilities can be used in any combination.

By adjusting a mold internal pressure by the aforementioned possibilities it is achieved that there are no uncontrolled flow processes of the thermoplastic material of the mats within the mold, which leads to an unwanted displacement of embedded in the thermoplastic matrix fiber material or the reinforcing fibers. In addition, a uniform internal pressure of the preform is achieved by a mold internal pressure.

The intended position fixation of at least two of the mats, wherein preferably a position fixation of all mats takes place to one another, can e.g. be made by welding or by means of a welding process at least one or more cohesive connections between the mats. Preferably, the position fixing of the mats takes place by an ultrasonic and / or heating element and / or laser welding process. The positional fixing of the mats to each other during or after completion of the construction or the formation of the preform offers the advantage that the preform has a significantly improved handling. For fixing the position of the mats to one another, it is also possible to use textile-technical methods, preferably needling and / or sewing. If the mat arrangement comprises a plurality of first and a plurality of second mats, it is preferable to fix the position of all the mats to one another.

In a further practical embodiment, in step C the battery housing part is formed by deep drawing of the mat arrangement. Also, by a deep-drawing process can be made in a practical and simple way, a design of the battery case part, especially if the design of the battery case part is a particular suitable for the deep drawing process design.

In a preferred embodiment of the method according to the invention, to produce a battery housing part having at least a third layer provided between the first and second layers, in step A, in addition to a number of first mats and second mats, at least one third mat may be provided at least partially made of a third material, and wherein in step B, the third mat is disposed between the at least one first mat and the at least one second mat.

The third material may preferably be an adhesion-promoting material, so that the third layer of the produced battery-housing part consists at least partially or wholly of an adhesion-promoting material. By providing this layer, a strong bond can be created between the first and second layers. In this case, the adhesion-promoting material may in particular be a fiberglass nonwoven material or an endless fiber material or an unreinforced material. A particularly strong connection can be created or provided in that the adhesion-promoting material is a mixture of the first and the second material. The adhesion-promoting material is then formed in the form of a blend or polymer blend of the first and second material, along with a very high adhesion.

The third material may also preferably be a heat-insulating material, so that the third layer of the produced battery-housing part consists at least partially or wholly of a heat-insulating material. By providing the heat insulating material, excessive cooling of the traction battery during operation of the electric vehicle can be effectively avoided at low outside temperatures. The heat insulating material may preferably be a polymeric foam material.

Brief description of the drawings

Embodiments of the invention will be explained in more detail with reference to the accompanying drawings. It shows:

1 a schematic sectional view of an embodiment of a battery housing part according to the invention, and

2 a schematic sectional view of an embodiment of a mat arrangement.

That in the 1 in a sectional view schematically illustrated battery housing part according to the invention 10 for a battery case of a traction battery 12 an electric vehicle has a one-sided open cavity 14 in which the traction battery 12 (shown only schematically) is receivable. The battery case part 10 has a wall 16 with two layers 18 . 20 on, with a first layer 18 or first inner layer 18 a the cavity 14 facing side 22 and wherein a second layer 20 or second outer layer 20 a page 24 that surrounds the battery case part 10 facing and from the cavity 14 turned away.

The first shift 18 consists of a first material 26 , which is opposite to the electrolytes of the traction battery 12 is resistant to media, and first reinforcing fibers in the first material 26 are embedded (not shown here). At the first material 26 it is preferably very media-resistant polypropylene.

The second layer 20 consists of a second material 28 which is more resistant to creep than the first material 26 , and second reinforcing fibers incorporated in the second material 28 are embedded (not shown here). For the second material 28 it is preferably very creep-resistant polyamide with a high temperature resistance.

The 2 shows a schematic sectional view of an embodiment of a trained according to step B of the method according to the invention mat arrangement 30 , The mat arrangement 30 includes several first mats 32 which have been stacked and / or attached to each other and several second mats 34 that on the first mats 32 placed on top of each other and placed on top of each other and / or attached to each other.

The mats 32 . 34 the illustrated mat arrangement 30 were previously provided in step A of the process of the invention. From the mat arrangement 30 can according to step C of the method according to the invention a battery housing part according to the invention by deforming and / or consolidating the mat arrangement 30 be trained or produced.

Claims (13)

Battery housing part ( 10 ) for a battery housing of a traction battery ( 12 ) of an electric vehicle, wherein the battery housing part ( 10 ) a cavity open on one side ( 14 ), in which the traction battery ( 12 ) is receivable, wherein the battery housing part ( 10 ) a wall ( 16 ) with at least two layers ( 18 . 20 ), wherein a first layer ( 18 ) a the cavity ( 14 ) facing side ( 22 ), and wherein a second layer ( 20 ) a page ( 24 ), which surrounds the battery housing part ( 10 ) and from the cavity ( 14 ), the first layer ( 18 ) at least partially made of a first material ( 26 ), which is opposite to the electrolyte of the traction battery ( 12 ) is media-resistant, and wherein the second layer is at least partially made of a second material ( 28 ), which is more resistant to creep than the first material ( 26 ). Battery housing part ( 10 ) according to claim 1, characterized in that the first material ( 26 ) is a thermoplastic plastic material, preferably polypropylene. Battery housing part ( 10 ) according to claim 1 or 2, characterized in that the second material ( 28 ) is a thermoplastic material, preferably polyamide or polyethylene terephthalate. Battery housing part ( 10 ) according to one of the preceding claims, characterized in that the first and the second material is a thermoplastic material, the first layer ( 18 ) from the first material ( 26 ) and first reinforcing fibers, wherein the first reinforcing fibers are at least partially incorporated into the first material ( 26 ) and / or wherein the second layer ( 20 ) from the second material ( 28 ) and second reinforcing fibers, said second reinforcing fibers being at least partially submerged in said second material ( 28 ) are embedded. Battery housing part ( 10 ) according to one of the preceding claims, characterized in that between the first and the second layer ( 18 . 20 ) at least a third layer is provided. Battery housing part ( 10 ) according to claim 5, characterized in that the third layer consists at least partially or wholly of an adhesion-promoting material. Battery housing part ( 10 ) according to claim 6, characterized in that the adhesion-promoting material is a mixture of the first and the second material ( 26 . 28 ). Battery housing part ( 10 ) according to claim 5, characterized in that the third layer consists at least partially or wholly of a heat-insulating material. Method for producing a battery housing part ( 10 ) for a battery housing of a traction battery of an electric vehicle according to claim 1, the method comprising the following steps: (A) providing a plurality of mats ( 32 . 34 ), which are formed substantially flat, wherein the majority of mats ( 32 . 34 ) at least a part number of first mats ( 32 ) and second mats ( 34 ), each first mat ( 32 ) at least partially from the first material ( 26 ) and each second mat ( 34 ) at least partially from the second material ( 28 ), (B) forming a mat arrangement ( 30 ), wherein the mat arrangement ( 30 ) at least a first mat ( 32 ) and at least one second mat ( 34 ), which over the first mat ( 32 ), and (C) forming the battery case part (10) 10 by deforming and / or consolidating the mat arrangement ( 30 ). Method according to claim 9, characterized in that the first and the second material ( 26 . 28 ) is a thermoplastic material that of the provided in step (A) mats ( 32 . 34 ) every first mat ( 32 ) from the first material ( 26 ) and first reinforcing fibers at least partially into the first material ( 26 ) are embedded, that every second mat ( 34 ) from the second material ( 28 ) and second reinforcing fibers at least partially into the second material ( 28 ), that before step (C) the thermoplastic material of all mats ( 32 . 34 ) of the mat arrangement ( 30 ) is converted by heating at least partially into a flowable state, and that after step (C) the battery housing part ( 10 ) is cooled. A method according to claim 10, characterized in that in step (B) the mats ( 32 . 34 ) on a rough contour of the battery housing part ( 10 ) can be placed and formed into a mat arrangement in the form of a three-dimensional preform, during or after completion of the construction of the preform, a positional fixation of at least two mats ( 32 . 34 ) and wherein after the fixing of the position the preform is brought into a molding die forming the final shape of the battery housing part and in step (C) the battery housing part is provided by providing a mold internal pressure from the preform ( 10 ) is formed by deforming the preform and / or consolidating the preform. A method according to claim 9 or 10, characterized in that in step (C) the battery housing part ( 10 ) by deep drawing the mat arrangement ( 30 ) is formed. Method according to one of claims 9 to 12, characterized in that for producing a battery housing part with at least one third layer, which is provided between the first and the second layer, in step (A) in addition to a part number of first mats ( 32 ) and second mats ( 34 ) at least one third mat is provided, which consists at least partially of a third material, and wherein in step (B) the third mat between the at least one first mat ( 32 ) and the at least one second mat ( 34 ) is arranged.

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