BATTERY CELL ARRANGEMENT AND METHOD FOR PRODUCING A BATTERY CELL ARRANGEMENT

Abstract

A battery cell arrangement comprises at least one battery cell plane (11) with a plurality of battery cells (20). At least the space (12) between adjacent battery cells (20) is filled with a filler (40). The battery cells (20) have a substantially cylindrical housing (21). The housing (21) further has a surface provided with a specific surface structure (30) to facilitate improved adhesion with the filler.

Description

[0001] The following description relates to a battery cell arrangement and a method for manufacturing a battery cell arrangement. State of the art

[0002] A battery cell is the smallest unit in a battery system and typically comprises a cathode, anode, and electrolyte, all housed within a casing. The battery cell (also called an accumulator) is a chemical energy storage device capable of delivering electrical energy. When describing an accumulator, the operation and characteristics of a single battery cell are often explained. A battery array is formed when several individual battery cells are electrically connected. This connection creates a larger unit known as a battery array. Battery arrays can have various configurations, such as series or parallel connections of the cells, to achieve a desired overall voltage and capacity. A battery, also called a battery module, is created when one or more battery arrays are assembled into a larger system.It typically comprises a large number of battery cells or battery assemblies that are electrically interconnected. A battery can thus have a higher overall voltage and capacity and is used in various applications such as electric vehicles, energy storage systems, or portable devices, for example as a high-voltage storage device.

[0003] In modern high-voltage energy storage systems, two-component materials such as silicone, silicone foam, epoxy, epoxy foam, and polyurethane foam are increasingly mixed and filled into the cavities between individual battery cells. This foaming process reduces thermal expansion, mechanical shocks, and vibrations under normal operating conditions. These improvements enhance the battery's safety, mechanical stability, and lifespan. The structural foam performs mechanical functions such as load distribution and shock absorption. However, the foam does not adhere sufficiently well to the cells, necessitating additional measures to ensure mechanical stability. To improve the adhesion of the fillers, the battery cell casings currently undergo complex pretreatment processes, such as plasma treatment or full-surface mechanical roughening of the casing surfaces.In addition to the effort and associated costs, it is disadvantageous that environmental influences such as moisture can weaken the adhesion of the filling materials to the battery cells and lead to mechanical failure.

[0004] The task is to specify a battery cell arrangement and a method for manufacturing a battery cell arrangement that allows improved adhesion of filler materials.

[0005] These problems are solved by the battery cell arrangement and the method for manufacturing a battery cell arrangement with the features of the independent and dependent claims. Advantageous embodiments and further developments of the invention are described in the dependent claims. Summary

[0006] It is hereby assumed that each feature described in relation to any embodiment may be used alone or in combination with other features described herein, and may be used in combination with one or more features of any other embodiment, or in any combination of any other embodiment, unless explicitly described as an alternative. Furthermore, equivalents and modifications not described below may be used without departing from the scope of the claimed subject matter.

[0007] The following describes a battery cell arrangement. According to one embodiment, the battery cell arrangement comprises one or more battery cell levels with a plurality of electrically interconnected battery cells. At least the space formed by adjacent battery cells is filled with a filler material. The battery cells have a substantially cylindrical housing, wherein the housings have at least one surface provided with a specific surface structure to facilitate improved adhesion with the filler material.

[0008] The improved concept presented here is based in particular on the considerations outlined below. To increase the adhesion of filler materials, such as structural foam, to a surface of the battery cell, the cell has a structured surface. This surface structuring can be, for example, in the form of threads or any other perforations, such as tire tread patterns. In another embodiment, the top surface of the cell is also surface-structured.

[0009] Surface structuring can improve adhesion with the filler through various effects. One such effect is increasing the contact area between the two materials. Increasing the contact area creates a greater number of binding sites where the molecules of the two materials can interact, thereby strengthening adhesion. Another effect that can improve adhesion is increasing surface roughness. A rough surface offers more opportunities for mechanical bonding between the materials, resulting in stronger adhesion. This effect can be achieved by using microstructures or grooves on the surface. Furthermore, surface structuring can also improve the surface's wetting properties.Overall, surface structuring can help improve adhesion between materials by increasing the contact area, roughness, and wetting properties of the surface.

[0010] The term "surface texture" is used here in contrast to "roughening." The difference between roughening and structuring a surface lies in the way the surface is treated to create a specific texture or finish. Roughening involves processing the surface to create irregularities. This can be done through various methods such as grinding, brushing, sandblasting, or chemical etching. Structuring, as it is understood here, involves intentionally applying defined patterns, shapes, or relief structures to the surface. This can be achieved through various methods such as embossing, engraving, laser processing, or mechanical machining.

[0011] According to one embodiment, the surface structure is designed to create an increased contact area between the housing and the filler, thereby improving adhesion. This increased contact area can be achieved in various ways. In one embodiment, the surface structure on the housing surface is designed as microstructures or grooves. In another embodiment, the surface structure on the housing surface is designed as raised relief patterns or protruding structures. In principle, both designs can also be combined.

[0012] According to one embodiment, the surface structure provides mechanical anchoring between the housing and the filler. The resulting increase in the contact area allows for the formation of more bonding points between the housing and the filler. Furthermore, the surface structure can also be at least partially irregular, such as a toothed structure. Such structures can take various forms, for example, a sawtooth-shaped structure with evenly spaced teeth, an irregular toothed structure with teeth of varying sizes or uneven spacing, or even an asymmetrical toothed structure. These "teeth," or more generally, these odd sections, can further increase the contact area and improve adhesion.

[0013] According to one embodiment, the surface structure is arranged along the lateral surface of the cylindrical housing.

[0014] According to one embodiment, the housing comprises a substantially circular lid. Alternatively, or in combination, the housing comprises a substantially circular base opposite the lid. The surface structure is arranged on a surface of the lid and / or the base. The aspects proposed here can also be applied to the lid and / or base, thus increasing the contact area and improving adhesion.

[0015] According to one embodiment, the surface structure extends in a thread-like fashion along the longitudinal direction of the cylindrical housing, for example along the cylinder axis of the housing.

[0016] According to one embodiment, the surface structure is designed according to a profile pattern. The term "profile pattern" refers to a specific surface structure or pattern created on a surface. For example, a profile pattern has repeating elements or patterns arranged on the surface that have a specific geometric shape or texture. Profile patterns can have different shapes and properties. For example, they can have geometric patterns such as grooves, diamonds, lines, or dots. They can also create a specific texture or feel, such as a rough, smooth, structured, or relief-like surface.

[0017] According to one embodiment, the surface structure has at least partially parallel substructures.

[0018] Furthermore, a method for manufacturing a battery assembly is proposed. According to one embodiment, the method comprises the following steps: - Providing a large number of battery cells, wherein the battery cells have an essentially cylindrical casing, - Structuring the cylindrical housings with a specific surface structure to increase the contact area between a filler and the housing, - Arranging the battery cells in at least one battery cell plane, and - Filling the spaces between adjacent battery cells with the filler material

[0019] The following describes exemplary embodiments with reference to the accompanying drawings. Further details, preferred embodiments, and refinements will be derived from these. Identical or functionally equivalent components are identified by the same reference numerals in the figures. The components shown, as well as their relative sizes, are not to be considered to scale. Where components and parts function identically across different figures, their descriptions will not necessarily be repeated for each subsequent figure. Brief description of the drawings

[0020] Specifically, we show: Fig. 1 an embodiment of a battery cell arrangement, Fig. 2A to 2D different embodiments of battery cells with surface structures, and Fig. 3A to 3C further examples of battery cells with surface structures. Detailed description

[0021] Fig. Figure 1 shows an embodiment of a battery cell arrangement. The battery cell arrangement 10 comprises a plurality of battery cells 20, each of which has a substantially cylindrical housing 21. The housings 21 have at least one surface provided with a specific surface structure 30. In this example, the battery cells 20 are arranged side by side in a plane, thus forming a battery cell plane 11 with a plurality of battery cells 20. For the sake of simplicity, only this battery cell plane 11 is considered in the following, without being restrictive. Further planes are derived analogously with regard to the following description.

[0022] As a result of the cylindrical shape of the battery cells 20 and their arrangement in the battery cell plane 11, gaps 12 are formed between adjacent battery cells 20. The gaps 12 are at least partially or completely filled with a filler material 40. Two-component materials containing silicone, silicone foam, epoxy, epoxy foam and / or polyurethane foam can be used as the filler material 40 and are filled into the gaps 12 between individual battery cells 20.

[0023] The specific surface structure 30 of the housing 21 provides improved adhesion with the filler 40. This improvement is achieved, for example, compared to a hypothetical housing 21 surface without surface structure 30 (such as a smooth housing). The surface structure 30 creates an increased contact area between the housing 21 and the filler 40, thus increasing the adhesion between the battery cells 20 and the filler 40. For example, the surface structure 30 is designed to provide mechanical anchoring between the housing 21 and the filler 40. The surface structure 30 can be designed on the surface of the housing 21 in the form of recesses, such as microstructures or grooves. Alternatively, or additionally, the surface structure 30 can be designed in the form of elevations on the surface of the housing 21, such as raised relief patterns or structures protruding from the surface.The terms “recess” and “raised” refer, for example, to the level given by an imaginary surface of the housing 21 without surface structure 30 (such as a smooth housing).

[0024] The Fig. Figures 2A to 2D show different embodiments of battery cells with surface structures. The drawings show surface structures 30 arranged along the outer surface 21 of the cylindrical housings 21. The surface structure 30 in Fig. 2A is designed in a threaded form. The pitch, diameter, profile shape, and number of threads can be determined by the specific cylindrical housing 21, for example, by its height and diameter. The thread extends along the cylinder axis. Alternatively, or additionally, the surface structure 30 can have other structures, such as a profile pattern, perhaps like a tire, or other perforations. Another possibility is in Fig. Figure 2B shows the surface structure 30, which consists of concentric circles around the cylinder axis, essentially parallel to the base and top of the cell. This design allows for better force transmission in the z-direction, i.e., along the cylinder axis. Another possibility is shown in Fig. Figure 2C shows the surface structure 30 as indentations or protrusions parallel to the cylinder axis. This has the effect of improved torque transmission in the z-direction, as indicated by the arrow in the drawing. Furthermore, this design offers the advantage of better force transmission in the x / y direction, i.e., perpendicular to the cylinder axis (see Figure 2C). Fig. 2D). The embodiment with the thread form made of Fig. 2A is a superposition of the individual solutions from the Fig. 2B to 2D and allows a superposition of the force directions.

[0025] The Fig. Figures 3A to 3C show further embodiments of battery cells with surface structures. In addition to or supplementing the outer surfaces of the cylindrical battery cells, the respective covers 23 and / or bottoms 24 of the housings 21 can also be designed with the surface structure 30. Fig. Figure 3A shows a surface structure 30 with individual structural elements 31, which are arranged on the lid in the manner of a tire tread. In the Fig. 3B and Fig. 3C is the surface structure 30 star-shaped on the cylinder axis ( Fig. 3B) or parallel to the cylinder axis ( Fig. 3C). The surface structure 30 of the lid and / or base can be related to and extend the surface structure 30 of the lateral surface.

[0026] Although the improved concept has been illustrated and described in detail using exemplary embodiments, it is not limited by these embodiments. Rather, other variations of the improved concept can be derived by a person skilled in the art without departing from the scope of protection defined by the claims. Reference symbol list 10 battery cell arrangement 11 Battery cell level 12 spaces 20 battery cells 21 cases 22 Surface area 23 lids 24 floor 30 Surface structure 40 Filler

Claims

[1] A battery cell arrangement comprising at least one battery cell plane (11) with a plurality of battery cells (20), wherein: - at least the space (12) between adjacent battery cells (20) is filled with a filler material (40), - the battery cells (20) have an essentially cylindrical housing (21), and - the housing (20) has a surface which is provided with a specific surface structure (30) to provide improved adhesion with the filler (40). [2] The battery cell arrangement according to claim 1, wherein the surface structure (30) on the surface of the housing (21) is designed in the form of microstructures or grooves. [3] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) on the surface of the housing (21) is designed in the form of raised relief patterns or protruding structures. [4] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) creates an increased contact area between the housing (21) and the filler (40) to improve adhesion. [5] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) provides a mechanical anchoring between the housing (21) and the filler (40). [6] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) is arranged along the lateral surface of the cylindrical housing (21). [7] The battery cell arrangement according to one of the preceding claims, wherein - the housing (21) comprises a substantially circular lid (23), and / or - the housing (21) comprises a substantially circular base (24) opposite the lid (23), and - the surface structure (30) is arranged on a surface of the lid (23) and / or the base (24). [8] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) extends thread-like along the longitudinal direction of the cylindrical housing (21) and / or wherein the surface structure (30) is designed according to a profile pattern. [9] The battery cell arrangement according to one of the preceding claims, wherein the surface structure (30) has at least sectionally parallel substructures (31). [10] A method for manufacturing a battery cell assembly comprising the steps: - Providing a plurality of battery cells (20), wherein the battery cells (20) have a substantially cylindrical housing (21), - Structuring the cylindrical housings (21) with a specific surface structure (30) to increase a contact area between a filler (40) and the housing (21), - Arranging the battery cells (20) in at least one battery cell plane (11), and - Filling the spaces (12) between adjacent battery cells (20) with the filler (40).

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