Electrode for a battery cell of an electrical energy storage device, battery cell, electrical energy storage device and method for filling a battery cell

Abstract

The invention relates to an electrode (14, 16) for a battery cell (10) of an electrical energy storage device of an at least partially electrically powered motor vehicle, wherein the electrode (14, 16) has at least one through-opening (24) which is designed for the passage of an electrolyte (26). The invention further relates to an electrical energy storage device and a method for filling a battery cell (10).

Description

[0001] The invention relates to an electrode for a battery cell of an electrical energy storage device of an at least partially electrically operated motor vehicle according to the applicable patent claim 1. Furthermore, the invention relates to a battery cell, an electrical energy storage device and a method for filling a battery cell.

[0002] Especially in lithium-ion battery cells, after the active material has been inserted, one of the final steps is to fill the cells with an electrolyte. The goal is to completely impregnate the entire active material within the cell with the electrolyte. This process is complex and time-consuming because, despite filling in a vacuum, the electrolyte can only diffuse into the active material along the electrodes. There is also a risk of incomplete penetration, which reduces the performance of the battery cell.

[0003] In the current state of the art, the electrolyte is introduced into the battery cell through a filling opening in the housing. The electrolyte can only move within the separator foils or along the boundary layers between the separator foils and the active materials, thus diffusing into the active materials. Transverse diffusion is not possible because the anodes and cathodes, constructed as metal foils, represent an impermeable barrier to the electrolyte. This has the disadvantage that the internal structure of the battery cell hinders the even distribution of the electrolyte in the active material. Furthermore, the process is very time-consuming. Furthermore, there is a risk of incomplete filling.

[0004] EP2 754 194 A1 describes an electrochemical cell comprising an anode, a semi-solid cathode, and a separator disposed therebetween. The semi-solid cathode contains a porous current collector and a suspension of an active material and a conductive material disposed in a non-aqueous liquid electrolyte. The porous current collector is at least partially disposed within the suspension, such that the suspension essentially encapsulates the porous current collector.

[0005] EP 3 332 436 A1 relates to a battery and a method for its production. An example method comprises forming a substrate with a first surface, wherein the first surface has a plurality of pores. The pores may be configured to receive lithium metals. The method comprises introducing lithium metal into at least a portion of the plurality of pores. The lithium metal may be introduced into the pores by a pre-alloying process, which may comprise electroplating lithium metal into the porous substrate. The method also comprises forming an electrolyte disposed between the first surface of the substrate and a cathode. The electrolyte is configured to reversibly transport lithium ions by diffusion between the substrate and the cathode. The method also comprises forming the cathode.In some embodiments, the substrate can simultaneously serve as the active material of the anode or as an electrically conductive current collector.

[0006] The object of the present invention is to provide an electrode, a battery cell, an electrical energy storage device and a method for filling a battery cell, by means of which an electrolyte can be introduced into a battery cell in an improved manner.

[0007] This object is achieved by an electrode, a battery cell, an electrical energy storage device, and a method according to the independent patent claims. Advantageous embodiments are specified in the subclaims.

[0008] One aspect of the invention relates to an electrode for a battery cell of an electrical energy storage device of an at least partially electrically powered motor vehicle. It is provided that the electrode has at least one through-opening designed for the passage of an electrolyte.

[0009] In particular, an electrode foil with fine pores is formed. The metallic electrodes according to the prior art form an impermeable barrier for the electrolyte. Spreading transversely across the electrode layers is therefore not possible in the prior art. The pores or through openings now make it possible to support the transverse spread of the electrolyte. This shortens the diffusion paths and promotes a uniform distribution of the electrolyte.

[0010] According to an advantageous embodiment, the electrode is designed as an anode. The positive electrode, in particular, can also be considered an anode. In particular, a battery cell, for example, can thus be provided with a plurality of anodes, which in turn are connected to an active material. The anode thus serves as a current collector for the active material.

[0011] A further advantageous embodiment provides for the electrode to be designed as a cathode. In particular, the electrode can thus be considered a negative collector. In particular, the cathode is coupled to the active material and can form the negative current collector for the battery cell. In particular, a plurality of electrodes or cathodes can be formed in the battery cell, for example.

[0012] Preferably, for example, at least one separator film can be formed between an anode and a cathode in order to separate the corresponding poles of a battery cell.

[0013] It is also advantageous if the electrode has a plurality of through-openings. In particular, a plurality of through-openings is thus provided within an electrode, in particular an electrode foil. The plurality of through-openings can preferably be distributed substantially regularly. In particular, however, the active material of a battery cell is designed accordingly without a through-opening, so that, for example, no loss of capacity is recorded. The through-opening is formed only in the electrode, or the through-openings are preferably formed only within the electrode foils, so that the active materials can then be reliably impregnated with the electrolyte subsequently.

[0014] It is also advantageous if the electrode is connected to a continuous active material. This ensures that there is no loss of performance within a battery cell, while the electrolyte is still reliably distributed via the corresponding through-hole within the electrode.

[0015] A further aspect of the invention relates to a battery cell with at least one electrode according to the preceding aspect. In particular, the battery cell has at least two electrodes according to the preceding aspect. For example, a first electrode can be designed as an anode and a second electrode as a cathode. Preferably, the battery cell has a plurality of electrodes, in particular a plurality of cathodes and anodes.

[0016] According to an advantageous embodiment of the battery cell, the active material is provided as graphite and / or lithium. In particular, a reliable battery cell, in particular a lithium-ion battery cell, can thus be provided.

[0017] It has also proven advantageous if an electrolyte is introduced via a filler opening on the top side of the battery cell. For example, the battery cell can be designed as a round cell. The round cell can, in turn, have a filler opening, through which the electrolyte is introduced into the filler opening from above. It is now advantageous that the corresponding electrolyte can also be distributed transversely through the active material through the through-opening. This ensures that the electrolyte is reliably distributed within the battery cell, allowing for faster and more reliable electrolyte filling.

[0018] Yet another aspect of the invention relates to an electrical energy storage device for an at least partially electrically powered motor vehicle having at least one battery cell according to the preceding aspect. In particular, the electrical energy storage device can have a plurality of battery cells.

[0019] The invention further relates to a motor vehicle with an electrical energy storage device according to the preceding aspect. The motor vehicle is at least partially electrically operated, in particular fully electric.

[0020] Furthermore, the invention also relates to a method for filling a battery cell with an electrolyte. The battery cell is provided with at least two electrodes according to the preceding aspect and with active material. The battery cell is filled with the electrolyte via a filling opening in the battery cell.

[0021] Advantageous embodiments of the electrode are to be regarded as advantageous embodiments of the battery cell, the electrical energy storage device and the method.

[0022] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0023] Showing: Fig. 1 is a schematic sectional view of an embodiment of a battery cell; and Fig. 2 shows another schematic sectional view of the battery cell from Fig. 1 during a filling process.

[0024] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0025] Fig. Figure 1 shows a schematic sectional view of an embodiment of a battery cell 10 for an electrical energy storage device (not shown). The electrical energy storage device is, in turn, designed for an at least partially electrically powered motor vehicle or a fully electrically powered motor vehicle.

[0026] The battery cell 10 has an interior space 12. In the present case, four electrodes 14, 16 are formed in the interior space 12. In the present exemplary embodiment, two anodes 14 and two cathodes 16 are shown. The anodes 14 and the cathodes 16 are, in particular, metallic electrode foils. In the present exemplary embodiment, the anode 14 is surrounded, in particular, by graphite 8 as the active material 18, 20. The cathode 16 is surrounded, in particular, by lithium 20 as the active material.

[0027] In particular, separator films 22 are formed between the respective active materials, which can, for example, electrically separate a housing of the battery cell 10 from the active material 18, 20 and the active material 18, 20 itself from one another.

[0028] In particular, how Fig. 1, a respective electrode 14, 16 has at least one through-opening 24, in particular a plurality of through-openings 24. The through-openings 24 are in particular designed for the penetration of an electrolyte 26 ( Fig. 2) trained.

[0029] Fig. 2 shows a further schematic sectional view of the battery cell 10 according to Fig. 1. In particular, the Fig. 2 shows a filling process or method for filling the battery cell 10 with the electrolyte 26. The electrolyte 26 can be reliably distributed within the active material 18, 20 through the corresponding through-openings 24. This is illustrated here in particular by corresponding arrows.

[0030] For this purpose, the battery cell 10 has a filling opening 28, particularly before final production of the battery cell 10. The filling opening 28 is formed, in particular, on an upper side 30 of the battery cell 10.

[0031] In particular, the Fig. 1 and Fig. 2 that the anode 14 and the cathode 16 have respective through-openings 24, for example in the form of pores. The active materials 18, 20, such as in particular graphite 18 and lithium 20, cover the through-openings 24. Consequently, the volume of the active material 18, 20 is not reduced by the through-openings 24. The performance of the battery cell 10 remains unchanged.

[0032] When filling the battery cell 10 with the electrolyte 26, the electrolyte cannot flow through the separator foil 22 or along the boundary layers between the separator foils 22 and the active material 18, 20, but rather diffuses transversely through the anodes 14 and the cathodes 16 into the active material 18, 20, graphite 18, or lithium 20, respectively. Diffusion paths are significantly shortened, thus enabling a homogeneous distribution of the electrolyte 26 in the battery cell 10.

[0033] This has the particular advantage that the battery cell 10 can be filled with the electrolyte 26 in a short time. Furthermore, the risk of uneven distribution of the electrolyte 26 is avoided. List of reference symbols 10 battery cells 12 Interior 14 Anode 16 Cathode 18 Graphit 20 lithium 22 Separator film 24 passage opening 26 Electrolyte 28 Filling opening 30 Top QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 754 194 A1

[0004] EP 3 332 436 A1

[0005]

Claims

[1] Electrode (14, 16) for a battery cell (10) of an electrical energy storage device of an at least partially electrically operated motor vehicle, characterized by that the electrode (14, 16) has at least one through-opening (24) which is designed for the penetration of an electrolyte (26). [2] Electrode (14, 16) according to claim 1, characterized by that the electrode (14, 16) is designed as an anode (14). [3] Electrode (14, 16) according to claim 1, characterized by that the electrode (14, 16) is designed as a cathode (16). [4] Electrode (14, 16) according to one of the preceding claims, characterized by that the electrode (14, 16) has a plurality of through openings (24). [5] Electrode (14, 16) according to one of the preceding claims, characterized by that the electrode (14, 16) rests against a continuously formed active material (18, 20). [6] Battery cell (10) with at least one electrode (14, 16) according to one of claims 1 to 5. [7] Battery cell (10) according to claim 6, characterized by that graphite (18) and / or lithium (20) is provided as the active material (18, 20). [8] Battery cell (10) according to one of claims 6 or 7, characterized by that an electrolyte (26) is introduced via a filling opening (28) on an upper side (30) of the battery cell (10). [9] Electrical energy storage device for an at least partially electrically operated motor vehicle with at least one battery cell (10) according to one of claims 6 to 8. [10] Method for filling a battery cell (10) with an electrolyte (26), comprising the steps: - Providing a battery cell (10) with at least two electrodes (14, 16) according to one of claims 1 to 5 and with active material (18, 20); and - Filling the battery cell (10) with the electrolyte (26) via a filling opening (28) of the battery cell (10).

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