Transportation tool, storage assembly, battery cell for storing electrical energy and method for producing same

Abstract

The invention relates to a vehicle, to a storage arrangement, to a method for producing a battery cell (1), and to a battery cell (1) for storing electrical energy. The battery cell comprises: an electrode tab (8); a housing (2) having an opening (3); and an electrical insulator (4); wherein the electrode terminal (8) is arranged in the opening (3) of the housing (2) and is electrically insulated from the housing (2) by means of an electrical insulator (4), which comprises a fiber composite material.

Description

TECHNICAL FIELD

[0001] The invention relates to a storage assembly, a means of transport, a battery cell and a method for the production of such a battery cell for storing electrical energy. The invention relates in particular to an improved short circuit strength of a battery cell for electricity. BACKGROUND

[0002] The electrification of personal means of transport is currently developing rapidly. According to one approach, electrochemical battery cells are produced as round battery cells and are combined in a storage assembly which serves as a traction energy store for a means of transport. The round battery cell comprises a cathode, a separator, an anode, a current collector, an insulator between the current collector and the housing, an external electrode (electrode tab) and a battery cell can. The cathode and the anode are produced as a jellyroll (electrode roll), which is separated by the separator. In order to improve the energy output of the electrical battery cell, a high current strength is pursued. A high current or a high current density occasionally leads to a significant temperature rise during the charging and / or discharging process. When the generated heat is not sufficiently quickly dissipated, the battery cell can be thermally damaged. Therefore, sufficient heat dissipation is an important aspect for the implementation of a battery cell which can be quickly charged. In order to produce a good electrical conductivity, the jellyroll or the tab of the jellyroll is welded to the current collector or to the electrode tab (usually the positive electrode). However, the positive tab of the jellyroll (or the current collector) needs to be electrically insulated with respect to the battery cell housing, since the battery cell housing usually has the opposite polarity (which forms the negative electrode). For this purpose, an insulating disc is installed between the current collector and the housing. In addition, usually a polymer (plastic) is installed as an insulator between the jellyroll and the housing. When the extraction of electrical energy (or the reception of electrical energy during a quick charging process) increases, the heat cannot be dissipated as quickly as desired due to the end-side insulator between the current collector and the housing. Furthermore, there is little area available for the potential welding method of the galvanic connection between the external (mostly positive) tab and the current collector. Depending on the thermal properties of the insulating material used, the heat dissipation can be improved. SUMMARY

[0003] It is the task of the invention to alleviate or eliminate the above-mentioned disadvantages of the prior art.

[0004] The above-mentioned task is solved by the features of the battery cell according to claim 1, the storage assembly according to claim 9, the means of transport according to claim 10 and the method for producing a battery cell according to claim 11. The dependent claims show preferred refinements of the invention.

[0005] The battery cells are used to store electrical energy and are constructed for use, for example, in a memory assembly having multiple (especially identical) battery cells, the memory assembly serving as a traction energy storage device for an electrically driven vehicle. The battery cells include electrode connectors, which are typically positioned as the positive electrode on the outside of the battery cell. The electrode connectors are located in an opening in the housing (battery cell canister or battery cell cover) and are electrically insulated relative to the housing by an electrical insulator. The electrode connectors are located in or extend through the opening in the housing. Electrical contact between one electrode connector and the other housing or the cover of the housing is prevented by a collar of the electrical insulator. Because the electrode connectors can have a wider cross-section inside or outside the housing compared to their intermediate sections, they neither fall into nor out of the housing, and the electrode connector sections inside or outside the housing are also electrically insulated relative to the housing. All of the aforementioned insulating areas can be provided by the same electrical insulator, which can be deformed, particularly during the manufacturing process. According to the invention, and in order to simultaneously associate electrical insulation with sufficiently high thermal conductivity, the electrical insulator is made of or has a fiber composite material. In other words, the electrical insulator contains fibers at least proportionally, which are held together by a material (e.g., a polymer or the like) holding the fibers together. Here, the fibers may have improved thermal conductivity to allow residual heat / process heat generated in the battery cell to be dissipated via the end side / cap of the battery cell, and to prevent melting of the electrical insulator or the polymer material of the electrical insulator. The electrical insulator can here achieve a seal of the battery cell housing, particularly through a polymer material, by pressing the electrical insulator between the electrode connector and the housing, pressing it into an opening. This thus provides reliable electrical insulation, suitable heat dissipation, and simultaneously a durable, airtight seal for the battery cell.

[0006] Fiber composites may, for example, contain glass fibers or carbon fibers, which typically have higher thermal conductivity than polymers, thermoplastics, and / or thermosetting plastics. The three materials just mentioned can be specified as additional components of the fiber composite. Alternative or additional fiber materials may include semiconductor materials, metal particles, metal fibers, or combinations thereof. In particular, with semiconductor materials, metal particles, and metal fibers, it can be additionally guaranteed that they do not establish an electrical short circuit between the electrode terminals and the housing. In principle, the fiber composite can have any combination of the above materials, wherein at least one fiber material is contained with an additional adhesive, particularly a plastic adhesive.

[0007] The fibers of the composite material can preferably be arranged in a predefined orientation or orientation within the electrical insulator. The fiber composite material preferably has sub-regions within which the fibers are predominantly contained in the same orientation. Such orientation provides the possibility of improving the thermal conductivity of the fiber composite material in a preferred direction and using this preferred direction for advantageous properties in the battery cell according to the invention. In particular, the fiber composite material has increased tensile strength in the direction of the preferred orientation of the contained fibers, and tests have shown that this direction is consistent with increased thermal conductivity. Therefore, in particular, fibers oriented from the interior of the battery cell toward the battery cell casing or the environment can advantageously influence the heat dissipation characteristics of the fiber composite material or the electrical insulator.

[0008] The battery cell can be, in particular, a cylindrical battery cell, such that electrical energy is stored in an electrode roll, commonly referred to as a core. A cylindrical battery cell typically has an electrode connector, in the form of a rivet pin, located in the center of the battery cell cover. The rivet pin is also called a rivet pin electrode and is particularly configured as a positive electrode. In this function, the electrode connector needs to be electrically insulated relative to the housing, which typically forms the negative electrode. Because the rivet pin electrode or electrode connector is at least proportionally abutted against the inside and outside of the housing cover (preferably at least approximately fully abutted), the cover needs to be electrically insulated relative to the electrode connector with respect to the opening, the inside, and the outside, and sealed to prevent undesirable leakage of electrolyte. The electrical insulator can be directly or indirectly abutted against the inside, in the area of ​​the opening, and directly or indirectly (indirectly or directly) against the outside of the cover. The electrical insulator can have a collar, which, in the form of a loop or a hollow cylinder, surrounds the electrode connector at least in the area of ​​the opening of the housing. Therefore, the hollow cylinder extends coaxially with the rotational symmetry axis of the circular battery cell in the opening. Within the housing, the electrical insulator can extend as a disc parallel to the end side of the core and parallel to the current collector or the cover of the circular battery cell housing. A particularly thin electrical insulator can be provided here, in which fiber composite materials provide increased strength. This particularly thin electrical insulator allows for the best possible thermal coupling between the core and the end side of the housing at this location. Especially in this region, an increased solid / fiber ratio in the fiber composite material is advantageous. Wherever possible, the fibers can be oriented axially or coaxially to guide heat directly towards the end side of the housing along a direct path. To achieve particularly high strength or tensile strength of the electrical insulator, the fibers, or additional fibers, can be arranged radially between the current collector and the housing cover.

[0009] The neck collar is preferably fiberless so as not to resist deformation of the electrical insulator, thus forming a disc-shaped sub-region between the outer side of the housing cover and the outer flange of the electrode connector. Because heat transfer in the area of ​​the neck collar or in the outer area is not as significant as between the manifold and the inner side of the housing cover, fiber material can be omitted or its proportion can be reduced for reliable or simple manufacturing.

[0010] However, whenever possible and desired, the collar can also have fibers oriented in a predefined manner, which can be coaxial with the main axis of the circular battery cell to ensure good deformability. In other words, the fibers can be oriented in the direction of the main axis of the circular battery cell in the region of the sleeve or later in the region of the outer disk, while they point outward in the radial direction after the electrode joint is pressed. This increases the tensile strength of the outer disk of the electrical insulator and improves heat dissipation from the open area toward a larger radius (the direction of the battery cell periphery).

[0011] Fiber composites can incorporate metal fibers or metallic materials to improve thermal conductivity. To ensure electrical insulation, an additional electrical insulator should be applied to the original electrical insulator. For example, this electrical insulator can be produced through an impregnation or coating process using a simple polymer or similar material. Now, although metal fibers are specified within the electrical insulator, these fibers are not connected to the outside of the insulator. More precisely, they are encased in a non-conductive material around their entire circumference, achieving high thermal conductivity within the interior of the electrical insulator.

[0012] According to a second aspect of the invention, a battery cell assembly is proposed, which can be used, for example, as a traction energy storage device for a transportation vehicle. The battery cell assembly comprises a plurality of battery cells according to the first aspect of the invention, the battery cells being particularly capable of being coaxially arranged with each other, such that passive or active heat dissipation can be achieved through their aligned end faces. The features, combinations of features, and resulting advantages clearly correspond to the features, combinations of features, and advantages described in conjunction with the battery cell according to the invention; to avoid repetition, reference is made to the above description.

[0013] According to a third aspect of the invention, a means of transport is proposed, particularly configured as an electrically driven means of transport. This means of transport includes a battery cell according to the first aspect of the invention and / or a memory assembly according to the second aspect of the invention, for the avoidance of repetition, referring to the description above.

[0014] According to a fourth aspect of the invention, a method for manufacturing a battery cell according to the first aspect of the invention is proposed. The method is exemplarily described using a circular battery cell. In a first step, a housing is provided. Furthermore, an electrode connector (particularly a riveted pin electrode) and an electrical insulator are provided. This insulator can be inserted into an opening in the housing, for example from the outside, but alternatively from the inside. Here, a flange has its abutting surface in the insertion direction, the flange abutting against a cover. Immediately thereafter, the electrode connector is inserted through the electrical insulator. Thus, the electrical insulator reaches between the electrode connector and the housing. If the electrode connector is deformed to form an inner flange and an outer flange in the opening, then the electrical insulator is also deformed in a corresponding manner, and at this time, an inner flange (between the inner flange of the electrode connector and the cover) and an outer flange (between the outer flange of the electrode connector and the cover) are formed. In short, the insulator is inserted into the opening, the electrode connector is inserted into the insulator, and then the electrode connector and the insulator are pressed together in the opening, such that the electrode connector closes the opening in connection with the insulator and electrically insulates the cover relative to the electrode connector. Sufficient thermal coupling between the core and the cover is ensured by employing fiber composite materials in the electrical insulator. Specifically, the portion of the electrical insulator located between the core and the cover is enriched with, constituted with, or incorporating fiber composite materials. This ensures that the electrical insulator in this region possesses high thermal conductivity, high mechanical strength, and simultaneously low electrical conductivity, while also enabling sealing between the battery cell casing and the electrode terminals.

[0015] Electrical insulators can incorporate thermally conductive materials, particularly through a fiber component. The resulting thermal conductivity can range from 0.1 to 2.0 W / mK (through a plane) and from 0.1 to 30.0 W / mK (in a plane). Conventional electrically insulating polymers typically exhibit thermal conductivity between 0.1 and 0.6 W / mK. Attached Figure Description

[0016] Further details, features, and advantages of the invention will become apparent from the following description and the accompanying drawings. The drawings are as follows:

[0017] Figure 1 This is a schematic cross-sectional view of an embodiment of a battery cell constructed according to the present invention;

[0018] Figure 2 This is a schematic cross-sectional view of the connection area of ​​an embodiment of a battery cell constructed according to the present invention;

[0019] Figure 3 This is a schematic cross-sectional view of the connection area of ​​another embodiment of a battery cell constructed according to the present invention;

[0020] Figure 4This is a schematic cross-sectional view of the connection area of ​​a battery cell constructed according to yet another embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of an embodiment of a transport vehicle constructed according to the present invention, having an embodiment of a memory assembly according to the present invention; and

[0022] Figure 6 This is a flowchart describing the steps of an embodiment of a method for manufacturing a battery cell according to the present invention. Detailed Implementation

[0023] Figure 1 The battery cell 1 according to an embodiment of the invention is shown. The battery cell 1 is configured as a circular battery cell and has a rotational symmetry axis X as the winding axis. A rivet pin as an electrode connector 8 is concentrically disposed in the cover of the housing 2. The electrode connector 8 passes through an opening 3, within which the electrode connector is inserted into an electrical insulator 4 and electrically insulated relative to the cover. Within the opening, the electrode connector 8 is surrounded by a collar 5 in the form of a hollow cylinder, which at least proportionally covers the cover of the housing 2 above or outside and below or inside the housing 2. Here, the cover of the housing 2 is electrically insulated relative to the current collector 12 by a plate structure having an internal fiber composite material. The current collector 12 is welded to the terminal piece 11 of the winding core 9 so as to form an electrical connection with the internal flange of the electrode connector 8. This electrical connection may also include a current connection, especially a welded connection.

[0024] Figure 2 The cover region of the battery cell according to the first embodiment is shown, in which the electrical insulator 4 is located in the central region of the neck ring 5 made solely of polymer material, while the plate-shaped structure 7 between the cover of the housing 2 and the current collector 12 comprises a fiber composite material. This results in particularly good thermal conductivity for the electrical insulator 4. The corresponding content applies to the region of the electrical insulator 4 between the cover of the housing 2 and the outer flange of the electrode connector 8. Here, the fibers are oriented only radially so that the fibers do not obstruct the expansion of the electrical insulator 4 during the pressing of the electrode connector 8.

[0025] Figure 3 Another embodiment of the connecting sub-region of the battery cell according to the invention is shown, in which the current collector 12 has a preferred vertical or coaxial orientation with respect to the contained fibrous material. In this way, particularly high thermal conductivity can be achieved in the vertical direction or towards the end of the housing 2. The neck ring 5 is made of only polymer material and therefore has no fibers. The plate-shaped region of the electrical insulator 4 between the outer flange of the electrode connector 8 and the cover of the housing 2 has a fibrous portion oriented in the radial direction, so that expanding this region during the pressing of the electrode connector 8 does not cause difficulty.

[0026] Figure 4 Another embodiment of the connection sub-region of the battery cell 1 according to the invention is shown, in which metallic fibrous material or metal shavings are contained in the electrical insulator 4. However, the proportion of metallic material is not disposed in the surface region of the electrical insulator 4, but only constitutes the internal region of the electrical insulator 4, which is covered outwardly by a simple polymer layer. In this way, the metal fibers 14 are not exposed as electrical conductors between the current collector 12 and the cover of the housing 2. The corresponding metal fiber core is disposed in the collar 5 within the opening 3, and in this region, the protective layer of pure polymer on both sides prevents electrical connection between the cover of the housing 2 and the electrode connector 8. The corresponding content applies to the external flange of the electrical insulator 4, which is formed by expanding the electrode connector 8 between the outer side of the electrode connector 8 and the cover of the housing 2.

[0027] Figure 5 An embodiment of a transport vehicle 10 constructed according to the present invention is shown, the transport vehicle being configured to be electrically driven. An electrochemical memory assembly 13 is provided in the bottom component, which has battery cells arranged coaxially with each other according to an embodiment of the present invention.

[0028] Figure 6 This illustration shows an embodiment of a method for manufacturing a battery cell according to the first aspect of the invention. In step 100, an insulator is introduced into an opening in the housing. The insulator has a fibrous component at least in a sub-region of the insulator disposed within the housing, such that the insulator is configured as a fibrous composite material. In step 200, an electrode connector is introduced into the insulator, such that the electrode connector is disposed, in particular, centrally within the cover of the housing. The electrode connector is now thermally coupled to the cover of the housing, while the electrode connector is electrically insulated relative to the cover. Finally, in step 300, the electrode connector and the insulator are pressed together in the opening. The insulator at this time forms an inner flange and an outer flange, which are disposed between the inner flange of the electrode connector and the cover of the housing, or between the outer flange of the electrode connector and the cover of the housing. Due to the fibrous component in the electrical insulator, the electrical insulator is configured as a fibrous composite material or has a fibrous composite material. The fibrous component significantly improves the thermal conductivity of the electrical insulator, allowing process heat generated during (fast) charging and discharging to be dissipated significantly faster than in the prior art, typically also through the end face of the battery cell, and reducing the degradation of beneficial effects within the battery cell.

[0029] List of reference numerals

[0030] 1 battery cell

[0031] 2 shells

[0032] 3 openings

[0033] 4 Electrical insulators

[0034] 5 neck rings

[0035] 6. External plate structure

[0036] 7. Internal plate structure

[0037] 8-electrode connector

[0038] 9 rolls

[0039] 10 means of transport

[0040] 11 connectors

[0041] 12 manifolds

[0042] 13 Memory Assembly

[0043] 14 Metal Fiber Core

[0044] 100~300 Methods and Steps

[0045] X-wound axis

Claims

1. A battery cell (1) for storing electrical energy, the battery cell comprising: Electrode connector (8); A housing (2) having an opening (3); as well as Electrical insulator (4); The electrode connector (8) is disposed in the opening (3) of the housing (2) and is electrically insulated relative to the housing (2) by means of the electrical insulator (4); characterized in that the electrical insulator (4) comprises a fiber composite material.

2. The battery cell according to claim 1, wherein, The fiber composite material includes glass fiber, and / or carbon fiber, and / or polymer, and / or thermoplastic, and / or thermosetting plastic, and / or semiconductor material, and / or metal particles, and / or metal fiber.

3. The battery cell according to claim 1 or 2, wherein, The fibers of the composite material are arranged in the electrical insulator (4) in a predefined orientation.

4. The battery cell according to any one of the preceding claims, wherein, The battery cell (1) is a circular battery cell, the electrode connector (8) is a riveted pin electrode, and the electrical insulator (4) – preferably at least approximately all-over – is directly or indirectly attached to the inside of the cover of the housing (2) and has a collar (5) that extends at least between the housing (2) and the electrode connector (8) in the opening (3).

5. The battery cell according to claim 4, wherein, The collar (5) has no fibers.

6. The battery cell according to claim 4, wherein, The collar (5) has fibers oriented in a predefined manner in a direction coaxial with the main axis (x) of the circular battery cell.

7. The battery cell according to any one of the preceding claims, wherein, The fiber composite material has metal fibers and is coated with a fiber-free polymer.

8. The battery cell according to any one of the preceding claims, the battery cell further comprising a core (9), the electrical insulator (4) electrically insulating the end side of the core (9) or the current collector (12) relative to the housing (2).

9. A battery cell assembly comprising a plurality of battery cells (1) according to any one of the preceding claims.

10. A means of transport comprising a battery cell (1) according to any one of claims 1 to 8 or a memory assembly according to claim 9.

11. A method for manufacturing a battery cell (1) according to any one of claims 1 to 8, the method comprising the steps of: Provides an electrode connector (8), a housing (2) with an opening (3) and an electrical insulator (4); The insulator (4) is inserted into the opening (3); The electrode connector (8) is inserted into the insulator (4); The electrode connector (8) and the insulator (4) are pressed into the opening (3); characterized in that, The electrical insulator (4) includes a fiber composite material.

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