Cell housing for a battery cell of an energy storage device, in particular for a motor vehicle, battery cell, energy storage device, motor vehicle and method

Abstract

The invention relates to a cell housing for a battery cell of an energy storage device, in particular for a motor vehicle; the cell housing having a sheet metal body; the sheet metal body having an end side and a lateral side; the cell housing having an opening opposite the end side for inserting a cell coil; the sheet metal body having an inner side circumferentially enclosed by the lateral side; the inner side defining an installation space for the cell coil; and the cell housing having an insulator applied to the inner side for electrically insulating the cell coil with respect to the sheet metal body.

Description

[0001] Battery cell housing for a battery cell of an energy storage device, in particular for a motor vehicle, battery cell, energy storage device, motor vehicle, method

[0002] The present disclosure relates to a cell housing for a battery cell of an energy storage device, in particular for a motor vehicle. The disclosure also relates to a battery cell for an energy storage device, in particular for a motor vehicle, an energy storage device, in particular for a motor vehicle, a motor vehicle, and a method for assembling a battery cell.

[0003] Such an energy storage device typically comprises a plurality of battery cells connected in parallel and / or series, thus forming a high-voltage storage system for the vehicle, also known as a traction battery. The energy storage device is designed to discharge the battery cells and provide electrical energy to operate the vehicle and / or to supply electrical energy externally, for example via a charging station, and to be supplied with electrical energy via the charging station and / or through recuperation during driving in order to charge the battery cells of the energy storage device.

[0004] The production of such a battery cell can be divided into three main process steps: electrode manufacturing, cell assembly, and cell finalization. For the cell assembly of cylindrical battery cells, so-called cell cans are used as cell housings. During cell assembly, a cell coil (jelly roll), to whose anode and cathode a so-called conductor tab or contact disc (dies) is welded, is placed into the cell housing.

[0005] Such a cell assembly process is described in "PRODUCTION PROCESS OF A LITHIUM-ION BATTERY CELL", January 2023, self-published by PEM of RWTH Aachen & VDMA, 4th edition, ISBN: 978-3-947920-26-6. An insulator ring is placed on the top of the winding (i.e., the anode tab side). The cell can is then placed over the winding so that the insulator ring rests on the bottom of the can. The anode tab is then attached to the bottom of the can by resistance welding. Another insulator ring is placed on the top of the winding (the cathode tab side). A bead is pressed into the casing by crimping. The lid assembly is then welded to the cathode tab. After the electrolyte filling, the lid assembly is crimped onto the flared cell cup, thus sealing the cylindrical cell.

[0006] The cell cups are made of an electrically conductive material, such as a metal. Since the battery cell being manufactured has an anode and a cathode, and the cell cup is typically designed as the negative electrode (cathode), the cell cup is electrically insulated from the positive electrode (anode) of the cell winding by inserting an electrically insulating insulator ring. Furthermore, the cell winding is laterally insulated from the cell cup by wrapping insulating tape around the end face and casing of the cell winding in the anode area, around the terminal tab.

[0007] The application of the insulating tape is a separate process step in cell assembly. This assembly can be prone to errors. Furthermore, friction between the insulating tape and the cell casing during the insertion of the cell winding into the cell housing can lead to damage and / or displacement of the insulating tape. An inaccurate placement of the insulating tape can result in inadequate electrical insulation. This can be particularly relevant if the battery cell is subjected to mechanical stress, for example, in the event of an accident.

[0008] Against the background of this prior art, one objective of the present disclosure is to provide a device and a method, each of which is suitable for enriching the prior art and improving at least the aforementioned aspects of the prior art. In particular, the objective of the disclosure is to achieve reliable insulation during cell assembly and to be able to provide a cost-effective battery cell.

[0009] The problem is solved by the features of the independent claims. The dependent claims contain further developments of the disclosure.

[0010] The problem is then solved according to one aspect of the disclosure by a cell housing for a battery cell of an energy storage device, in particular for a motor vehicle; wherein the cell housing has a sheet metal body; the sheet metal body has an end face and a shell side; the cell housing has an opening opposite the end face for inserting a cell winding; the sheet metal body has an inner side enclosed by the shell side; the inner side defines a space for the cell winding; and the cell housing has an insulator applied to the inner side for electrically insulating the cell winding from the sheet metal body.

[0011] It was recognized that the insulating tape rolled around the cell winding can be dispensed with if electrical insulation is provided by other means. Therefore, it is proposed that the cell housing incorporate an insulator that isolates the cell winding from the sheet metal body. Specifically, the insulator can be provided for electrical insulation between an anode-side drain tab of the cell winding and the cell housing.

[0012] The insulator can be applied during the manufacturing of the cell casing and is therefore independent of the cell assembly itself. This allows for more efficient cell assembly. The electrical insulation provided in the cell casing reduces the susceptibility to errors in the insulator's placement and minimizes the risk of the insulator slipping when the cell winding is inserted into the casing. This results in more reliable cell assembly, and by reducing the number of assembly and, if necessary, testing steps, the battery cell can be manufactured more cost-effectively.

[0013] Optionally, the insulator is arranged on the inside of the end face and at least partially on the casing side. This effectively provides electrical insulation between the anode-side leakage tab of the cell winding and the cell casing, since the anode-side leakage tab is typically located on the end face and makes contact with the end face and, in the area of ​​the end face, also with the casing side.

[0014] Optionally, the cell housing has a pole on its end face for electrical contact by a positive electrode of the cell winding that can be inserted into the cell housing; and the insulator has a recess for contacting the pole by the positive electrode. This ensures that the anode of the cell winding can be electrically contacted via the pole on the end face.

[0015] Optionally, the insulator includes a plastic insulating layer and / or insulating tape applied to the sheet metal body. The insulating layer can be applied in a particularly cost-effective, homogeneous, and durable manner. The insulating tape can also be applied in a particularly cost-effective manner. For example, the insulator is made of a polymer, in particular polypropylene (PP) and / or polyimide (PI).

[0016] According to one aspect of the disclosure, a battery cell is provided for an energy storage device, particularly for a motor vehicle, comprising a cell casing as described in the disclosure and a cell winding arranged in the cell casing. Optionally, the cell casing has one or more of the features described herein as optional and / or advantageous in order to achieve an associated technical effect.

[0017] According to one aspect of the disclosure, an energy storage device, particularly for a motor vehicle, is provided, comprising a battery cell as described in the disclosure. Optionally, the battery cell and / or its cell casing may have one or more of the features described herein as optional and / or advantageous in order to achieve an associated technical effect.

[0018] According to one aspect of the disclosure, a motor vehicle is provided, comprising the energy storage device according to the disclosure. Optionally, the energy storage device, its battery cells and / or its cell casing, may have one or more of the features described herein as optional and / or advantageous in order to achieve an associated technical effect.

[0019] According to one aspect of the disclosure, a method for assembling a battery cell is provided, comprising: providing a cell casing and a cell winding as described in the disclosure; inserting the cell winding into the cell casing; and completing the cell assembly of the battery cell, in particular by electrical contacting, electrolyte filling, and / or sealing the cell casing. Optionally, the method is carried out such that one or more of the features described herein as optional and / or advantageous are implemented to achieve a related technical effect.

[0020] One embodiment of each is described below with reference to the figures.

[0021] Fig. 1 schematically shows a motor vehicle according to one aspect of the disclosure;

[0022] Fig. 2 shows a cell casing and a cell winding according to the prior art;

[0023] Fig. 3 shows a cell casing according to the disclosure and a cell coil;

[0024] Fig. 4 schematically shows a flowchart of a method according to one aspect of the disclosure. Figure 1 schematically shows a motor vehicle 50 with an energy storage device 55 having a battery cell 56 with an electrode 60a, which was manufactured by a method 200 according to one aspect of the disclosure.

[0025] Motor vehicle 50 is a land vehicle. Motor vehicle 50 is a passenger car.

[0026] The motor vehicle 50 has an energy storage device 55, also referred to as a traction battery, and an electric drive 52. The energy storage device 55 has a plurality of battery cells 56, the number of which is shown only schematically. The energy storage device 55, or the battery cells 56, are configured to be supplied with electrical energy in order to charge the battery cells 56, i.e., to increase the state of charge of the battery cells 56. The energy storage device 55, or the battery cells 56, are configured to provide electrical energy for operating the motor vehicle 50 and / or the electric drive 52, whereby the battery cells 56 are discharged, i.e., the state of charge of the battery cells 56 decreases.

[0027] Each of the battery cells 56 has a cell housing 57 and a cell winding 58 arranged therein. Features of such battery cells 56 and such cell housings 57 are described with reference to Figure 3.

[0028] Figure 2 shows a cell casing 57 and a cell winding 58 according to the prior art.

[0029] Figure 2 illustrates a longitudinal section of a cell housing 57. The cell housing 57 is a cell housing 57 for a cylindrical battery cell 56 and thus defines an axis A. The cell housing 57 has a sheet metal body 570. The sheet metal body 570 has an end face 571 and a shell side 572. The end face 571 extends perpendicular to the axis A, i.e., radially. The shell side 572 extends coaxially to the axis A, i.e., circumferentially. The sheet metal body 570 has an inner surface 573 that is circumferentially enclosed by the shell side 572. The inner surface 573 defines a space 574 for a cell winding 58.

[0030] The cell housing 57 has an opening 575 opposite the end face 571 for inserting the cell winding 58. The cell winding 58, which is inserted during cell assembly, has a current collector tab 582 and an associated positive electrode 581. The current collector tab 582 is welded to the cell winding 58 and facilitates charge transport to and from the positive electrode 581 of the cell winding 57. In the area of ​​the positive electrode 581, the cell winding 58 is completely and partially wrapped on its end face with an insulating tape 585.

[0031] During cell assembly, the cell winding 58 is pushed along axis A. A spacer 579 is arranged at the end face inside the cell housing 57. The cell winding 58 is pushed up to the spacer 579. The positive electrode 581 thereby contacts the pole 577 of the cell housing 57. The insulating tape 585 provides electrical insulation between the cell winding 58, in particular the anode-side current collector tab 582, and the cell housing 57.

[0032] Figure 3 shows a cell housing 57 according to the disclosure and a cell winding 58. The cell housing 57 according to Figure 3 is a cell housing 57 for a battery cell 56 of an energy storage device 55, in particular for a motor vehicle 50. Such a motor vehicle 50, such an energy storage device 55, such a battery cell 56, and features thereof are described with reference to Figure 1. Figure 3 is described with reference to Figure 1.

[0033] Figure 3 illustrates a longitudinal section of a cell housing 57. The cell housing 57 is a housing for a cylindrical battery cell 56 and thus defines an axis A. The cell housing 57 has a sheet metal body 570. The sheet metal body 570 is manufactured, for example, by deep drawing, a tensile-compressive forming process in which sheet metal blanks are pressed into a hollow body open at one end. The raw material of the sheet metal body 570 is pressed through a die with a punch, resulting in a round or, alternatively, prismatic housing. After a final of several deep-drawing steps, excess material is removed and the sheet metal body 570 is cleaned.

[0034] The sheet metal body 570 has an end face 571 and a shell side 572. The end face 571 and the shell side 572 form the one-piece sheet metal body 570. The end face 571 extends perpendicular to the axis A, i.e., radially. The shell side 572 extends coaxially to the axis A, i.e., circumferentially. The sheet metal body 570 has an inner surface 573 that is circumferentially enclosed by the shell side 572. The inner surface 573 is also formed axially by the end face 571. The inner surface 573 defines a space 574 for a cell winding 58. The space 574 is cylindrical.

[0035] The cell housing 57 has an opening 575 opposite the end face 571 for inserting the cell winding 58. The outer shell 572 extends along axis A from the end face 571 to the opening 575. The cell housing 57 has an insulator 576 applied to its inner surface 573 for electrically insulating the cell winding 58 from the sheet metal body 570. The insulator 576 is located on the inner surface 573 of the end face 571 and on the outer shell 572. The insulator 576 can thus cover the entire surface of the end face 571 and the outer shell 572 and surround the cylindrical installation space 574.

[0036] The insulator 576 comprises an insulating layer made of plastic and / or an insulating tape applied to the sheet metal body 570. An insulating layer can be applied, for example, by coating the sheet metal body 570 after its manufacture. This can be done, for instance, by spraying a coating onto the sheet metal body 570 and / or by dipping the sheet metal body 570 into a coating. Alternatively or additionally, an insulating tape (not shown) can be inserted into the sheet metal body 570 and attached to the inner surface 573 of the sheet metal body 570, for example, by gluing. Due to the end-face arrangement of the insulator 576, an end-face spacer (see Figure 2) is unnecessary.

[0037] The cell housing 57 has a pole 577 on its end face 571 for electrical contact by a positive electrode 581 of the cell winding 58, which can be inserted into the cell housing 57. The pole 577 extends concentrically to axis A from a center point on the end face 571 outwards. The insulator 576 has a recess 578 for contacting the pole 577 by the positive electrode 581. The recess 578 is located on the end face of the insulator 576. The recess 578 extends concentrically to axis A from a center point on the end face 571 outwards. The recess 578 and the size of the pole 577 are matched so that the pole 577 can protrude through the recess 578.

[0038] The cell winding 58, which is inserted during cell assembly, has a current collector tab 582 and an associated positive electrode 581. The current collector tab 582 is welded to the cell winding 58 and facilitates charge transport to and from the positive electrode 581 of the cell winding 57. An insulating tape wrapped around the cell winding 57 (see Figure 2) is unnecessary, as the electrical insulation is provided by the insulator 576.

[0039] During cell assembly, the cell winding 58 is pushed along axis A. The cell winding 58 is pushed until it reaches the insulator 576. The positive electrode 581 contacts the terminal 577 of the cell housing 57. The insulator 576 provides electrical insulation between the cell winding 58, in particular the anode-side current collector tab 582, and the cell housing 57. Figure 4 schematically shows a flowchart of a method 100 according to one aspect of the disclosure. The method 100 according to Figure 4 is a method 100 for assembling a battery cell 56 according to the disclosure. Such a battery cell 56, or a cell housing 57 of such a battery cell 56, is described with reference to Figures 1 and 3. Figure 4 is described with reference to Figures 1 and 3.

[0040] The method 100 according to Figure 4 comprises: providing 110 the cell casing 57 and a cell winding 58.

[0041] Method 100 consists of: inserting 120 of the cell coil 58 into the cell housing 57.

[0042] Method 100 according to Figure 4 comprises: completing 130 the cell assembly of the battery cell 56, in particular by electrical contacting, electrolyte filling and / or sealing the cell housing 57. Further steps may be necessary for this, which are known from the prior art. For example, the cell housing 57 together with the cell winding 58 may need to be rotated so that it can be filled with electrolyte.

[0043] The person skilled in the art recognizes that the method 100 according to Figure 2 can also be carried out in a different sequence than the one shown. In particular, it is possible that steps of the method 100 can be exchanged, shifted, repeated and / or carried out simultaneously.

[0044] Reference symbol (part of the description)

[0045] 50 motor vehicles

[0046] 52 electric drive

[0047] 55 Energy storage device

[0048] 56 battery cells

[0049] 57 cell casings

[0050] 570 sheet metal bodies

[0051] 571 Front

[0052] 572 Page

[0053] 573 Inside

[0054] 574 Construction space

[0055] 575 Opening

[0056] 576 Insulator

[0057] 577 Pole

[0058] 578 Exclusion

[0059] 579 spacers

[0060] 58 cell wraps

[0061] 581 positive electrode

[0062] 585 Insulation tape

[0063] 100 procedures

[0064] 110 Provide

[0065] 120 Insert

[0066] 130 completions

[0067] Axis

Claims

Claims 1. Cell housing (57) for a battery cell (56) of an energy storage device (55) in particular for a motor vehicle (50); wherein - the cell casing (57) has a sheet metal body (570); - the sheet metal body (570) has an end face (571) and a side face (572); - the cell casing (57) has an opening (575) opposite the front face (571) for inserting a cell coil (58); - the sheet metal body (570) has an inner side (573) completely enclosed by the outer side (572); - the inner side (573) defines a construction space (574) for the cell winding (58); and - the cell housing (57) has an insulator (576) applied to the inside (573) for electrically insulating the cell winding (58) from the sheet metal body (570).

2. Cell housing (57) according to claim 1 , wherein - the insulator (576) is arranged on the inside (573) of the end face (571) and at least partially on the outer side (572).

3. Cell housing (57) according to claim 1 or 2, wherein - the cell housing (57) has a pole (577) on its end face (571) for electrical contact by a positive electrode (581) of the cell winding (58) which can be inserted into the cell housing (57); and - the insulator (576) has a recess (578) for contacting the pole (577) by the positive electrode (581).

4. Cell housing (57) according to one of the preceding claims, wherein the insulator (576) comprises an insulating layer of plastic and / or an insulating tape applied to the sheet metal body (570).

5. Battery cell (56) for an energy storage device (55) in particular for a motor vehicle (50), comprising a cell housing (57) according to one of the preceding claims and a cell winding (58) arranged in the cell housing (57).

6. Energy storage device (55) in particular for a motor vehicle (50), comprising a battery cell (56) according to claim 5.

7. Motor vehicle (50) comprising an energy storage device (55) according to claim 6.

8. Method (100) for cell assembly of a battery cell (56) according to claim 5, wherein the method (100) comprises: - Providing (110) a cell housing (57) according to one of claims 1 to 4 and a cell winding (58); - Inserting (120) the cell coil (58) into the cell casing (57); - Completing (130) the cell assembly of the battery cell (56), in particular by electrical contacting, electrolyte filling and / or sealing the cell housing (57).

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