METHOD AND DEVICE FOR PRODUCING AN ELECTRODE STACK

Description

[0001] The invention relates to a method and a device for producing an electrode stack for a lithium-ion battery.

[0002] Such a lithium-ion battery has at least one battery cell containing an electrode stack with a number of sheet-like cathodes (cathode sheets) and sheet-like anodes (anode sheets). The cathodes and anodes are stacked, for example, one above the other. Depending on the battery design, a separator or—in the case of a solid-state lithium-ion battery—a solid electrolyte is arranged between the cathodes and anodes, separating the anodes and cathodes from each other.

[0003] The electrode stack with stacked anodes and cathodes is manufactured, for example, using so-called single-sheet stacking. Typically, the individual anodes and cathodes are moved using a gripper system. Using a gripper of this gripper system, the anodes and cathodes are alternately picked up, transported to a stacking location, and placed there.

[0004] Alternatively, such an electrode stack can be manufactured using a process known as Z-folding. In this process, a separator strip is folded in a Z-shape (zigzag pattern), with an anode and a cathode being alternately placed on the Z-leg of the separator strip after each folding process using a gripper system.

[0005] However, such gripper systems are comparatively slow. Furthermore, the alternating stacking of the anodes and cathodes requires a relatively long time, making the manufacturing process of such an electrode stack comparatively time-consuming.

[0006] EP 2 648 263 A2 discloses a battery cell manufacturing device. This device comprises a unit cell stacking unit into which unit cells are inserted from above and in which the unit cells are sequentially stacked, as well as a packaging unit for wrapping an outer side of the unit cell stack with a release film.

[0007] JP 2018 006216 A and WO 2017 / 073677 A1 each disclose a laminating device in which anodes and cathodes are conveyed from opposite sides into a laminating area.

[0008] WO 2020 / 120109 A1 discloses a method for producing an electrode stack, in which cathodes are conveyed into a chamber in a first direction without the use of a gripper, and in which anodes are conveyed into the chamber in a second direction without the use of a gripper.

[0009] The invention is based on the object of providing a particularly suitable method and device for producing an electrode stack for a lithium-ion battery. In particular, the method and / or device are intended to enable the electrode stack to be manufactured as quickly as possible.

[0010] With regard to the method, the stated object is achieved according to the invention by the features of claim 1, and with regard to the device by the features of claim 5. Advantageous further developments and refinements are the subject of the dependent claims. The statements made in connection with the device also apply mutatis mutandis to the method, and vice versa.

[0011] The process is used to produce an electrode stack consisting of anodes and cathodes. The electrode stack is intended for a lithium-ion battery (Li-ion battery), in particular for a lithium-ion battery for powering an electrically powered motor vehicle.

[0012] The anodes and cathodes are sheet-like. The anodes and cathodes, collectively referred to as electrodes, have a comparatively small dimension in one spatial direction; in other words, the electrodes are flat. The electrodes are also referred to as electrode sheets, and the anodes and cathodes are referred to as anode sheets and cathode sheets, respectively.

[0013] According to the process, the anodes and cathodes are first conveyed into a production area, also referred to as a stacking compartment or stacking chamber. Each of the anodes or cathodes is expediently provided with a separator. In particular, each of the anodes or cathodes is laminated on both sides with a separator film. If the anodes and cathodes are intended for a solid-state lithium-ion battery, each of the anodes and / or cathodes is expediently provided with a solid electrolyte.

[0014] Alternatively, a number of monocells are conveyed to the production area. Each of the monocells has one (single) anode and one (single) cathode. Advantageously, each of the monocells has a first separator arranged between the anode and the cathode, as well as a second separator arranged on the side of the cathode facing away from the anode or on the side of the anode facing away from the cathode. Suitably, the anode, the cathode, and the two separators are joined together using a lamination process. However, if the monocells are intended for a solid-state lithium-ion battery, the anode and / or the cathode of each monocell is advantageously provided with a solid electrolyte.

[0015] According to the method, the anodes and cathodes or monocells are conveyed into the production area at a vertical (Z) direction, spaced from the floor of the production area. Thus, the anodes and cathodes or monocells leave a conveyor system designed and configured for this conveying process at a distance from the floor. Consequently, after being conveyed into the production area, the anodes and cathodes or monocells sink toward the floor due to gravity, counter to the vertical direction.

[0016] Furthermore, an air flow is generated within the production area by introducing air. The air flow is generated in such a way that it has a flow strength and / or a flow direction such that the anodes and cathodes, or alternatively the mono cells, are aligned with each other or with respect to a predetermined target position as they descend toward the floor of the production area.

[0017] In summary, an air flow is generated within the production area in such a way that the anodes and cathodes, or the monocells, are aligned relative to each other and / or relative to a target position as they descend. As a result, the anodes and cathodes, or the monocells, are stacked on top of each other in alignment after their descent, forming the electrode stack. Advantageously, the electrode stack therefore has aligned anodes and cathodes, or the monocells, respectively. Thus, a specified (target) stacking accuracy is easily achieved.

[0018] In addition, the alignment of the anodes and cathodes, or the monocells, using the airflow is comparatively fast, especially compared to the stacking methods using a gripper system mentioned above. Another advantage is that the risk of damage to the anodes and cathodes, or the monocells, caused by the airflow is comparatively low.

[0019] Suitably, the anodes and cathodes are conveyed into the production area alternately (in time) one after the other, so that the anodes and cathodes of the electrode stack are stacked alternately on top of one another. In the alternative embodiment of the method with monocells instead of separate anodes and cathodes, the monocells are conveyed into the production area in a similar manner (in time) one after the other. For a comparatively high stacking rate, the cathodes and the anodes or the monocells are preferably conveyed into the production area while the previous anode or cathode or the previous monocell is still sinking. The production area has a corresponding height for this purpose, i.e. a corresponding extension in the vertical direction. Consequently, several anodes and cathodes or several monocells are sinking simultaneously.

[0020] As an alternative to the conveying process according to which the anodes and cathodes or the monocells are conveyed into the production area one after the other, according to a suitable further development the anodes and the cathodes or a portion of the anodes and the cathodes are placed on top of one another, preferably alternately, before they are conveyed into the production area and then conveyed into the production area lying on top of one another. In the variant of the process with monocells instead of separate anodes and cathodes, the monocells or a portion of the monocells are placed on top of one another before they are conveyed into the production area and then conveyed into the production area lying on top of one another. In this case it is not necessary for the anodes and the cathodes or the monocells to be placed on top of one another in alignment before the conveying process, since the alignment of the anodes and the cathodes orThe monocells are fed using the airflow within the production area. This advantageously allows a comparatively large number of anodes and cathodes, or a comparatively large number of monocells, to be conveyed into the production area per unit of time, thus reducing the production time of the electrode stack.

[0021] According to the method, in order to align the anodes and cathodes or to align the monocells using the air flow, air is introduced, in particular blown in, from two opposite sides of the production area underneath each of the anodes conveyed and lowered into the production area and underneath each of the cathodes conveyed and lowered into the production area or underneath each of the monocells conveyed and lowered into the production area. Since, if more than one electrode or more than one monocell are descending in the production area at the same time, these are spaced apart from one another in the vertical direction, air is preferably introduced underneath each of the electrodes or monocells at a distance corresponding to their vertical distance from one another. Alternatively, the air is introduced at a (single) height relative to the floor, so that air is introduced successively underneath each of the anodes and under each of the cathodes or monocells.is introduced under each of the mono cells.

[0022] To generate the airflow and align the anodes and cathodes or monocells, the air is introduced into the production area either parallel to the floor of the production area or only slightly inclined relative to the floor, particularly upwards (i.e., vertically). Slightly inclined means that the angle between the floor and the air inlet direction is no more than 30°.

[0023] Preferably, the introduced air is ionized. Due to the at least slight conductivity of the air, electrostatic charging of the electrodes or the monocells is prevented or at least reduced. This advantageously prevents the anodes and cathodes or the monocells from sticking together due to electrostatic charging. Furthermore, contamination of the electrodes or monocells by electrostatically attracted dust particles is prevented.

[0024] By introducing the air from the opposing alignment units, preferably directed at each other, a vortex is created beneath the respective electrode or monocell. The introduced air temporarily remains beneath the respective anode or cathode or monocell. This acts like a kind of air cushion, slowing the descent accordingly.

[0025] The air introduced beneath the electrodes or monocells flows out of the production area, particularly vertically, from the side of the electrodes or monocells, i.e., through a gap between the electrodes or monocells and the lateral boundary of the production area. Due to the lateral flow, a force acts on the respective anode or cathode or monocell, whereby the force aligns the respective anode or cathode or monocell toward a central axis of the production area.

[0026] In addition, a (frictional) force acts on the respective anode or the respective cathode or the respective monocell, which is caused by the introduction of the air and also aligns the respective anode or the respective cathode or the respective monocell towards a central axis of the production area.

[0027] When the air is introduced at an upward angle towards the floor, there is an additional component of the air flow in the vertical direction, so that the sinking of the anodes and cathodes or the monocells is further slowed down.

[0028] Advantageously, a comparatively easy alignment of the anodes and cathodes or the mono cells is possible, since the counteracting friction force of the air cushion is comparatively low.

[0029] In summary, although the descent of the anodes and cathodes is slowed due to the air cushion and / or the inclined air introduction, such a stacking process is comparatively fast, especially compared to the stacking processes using a gripper system mentioned above.

[0030] According to an advantageous embodiment of the method, the air is introduced into the production area at a constant time, i.e., constant flow rate, in terms of direction and flow rate. This type of air introduction is relatively simple.

[0031] Particularly preferably, air is introduced at several points spaced apart from one another in the vertical direction as shown above. The flow rate of the air to be introduced is preferably lower the closer it is introduced to the ground. In other words, a gradient with decreasing flow rate of the air to be introduced is preferably provided or set against the vertical direction. The descending anodes and cathodes or the descending monocells are increasingly aligned the closer they are to the ground. Consequently, a lower current strength is required for alignment due to the air flow. This achieves a comparatively efficient alignment process.

[0032] Alternatively, the flow rate and / or the direction of the air introduced to generate the air flow can be adjusted. This allows the air flow to be varied during the descent of the anodes and cathodes or monocells and / or, in particular, to be adapted to a descent speed and / or a position of the anodes and cathodes or monocells within the production area. As a result, the alignment of the individual electrodes or monocells is relatively quick.

[0033] The device is designed and suitable for producing an electrode stack comprising anodes and cathodes for a lithium-ion battery, for example, for a (traction) battery of an electrically powered motor vehicle. The electrode stack is produced using the device according to one of the variants of the method described above.

[0034] For this purpose, the device comprises a conveyor system. This conveyor system serves to convey the anodes and cathodes, or the monocells, each comprising one of the anodes and one of the cathodes, into a production area. The conveyor system is arranged vertically spaced from the floor of the production area, so that the anodes and cathodes, or the monocells, are spaced from the floor in the production area immediately after leaving the conveyor system and, as a result, sink toward the floor in the opposite direction to the vertical direction.

[0035] Furthermore, the device has at least two alignment units. Each of the alignment units, in turn, has at least one air outlet, by means of which an air flow can be generated for aligning the anodes and cathodes or for aligning the monocells. Preferably, each of the alignment units has a plurality of air outlets arranged next to one another in the vertical direction and / or in a direction transverse to the vertical direction. For example, the air outlets are each designed as an air nozzle or as a diffuser. The air outlets are expediently fluidically connected to a fan, a compressor, or the like.

[0036] The alignment units delimit the production area, at least in sections, in or against a direction oriented perpendicular to the vertical direction (X-direction). For example, the alignment units are designed as a plate into which the air outlets are incorporated, with the normal to the plane spanned by the plate pointing into the production area.

[0037] Thus, one of the alignment units defines the production area in the X direction, and the other defines it in the opposite direction. In other words, the production area is located between the two alignment units.

[0038] Particularly preferably, the device comprises at least two additional alignment units with air outlets, which define the production area in a similar manner in or against the Y direction, which is oriented perpendicular to the vertical direction and perpendicular to the X direction. Thus, air can also be introduced in or against the Y direction for aligning the electrodes or monocells.

[0039] Particularly preferably, the air flow is configured such that the anodes and cathodes or the monocells do not touch the alignment units as they descend, thus avoiding the risk of damage. In the event of a fault, for example, a failure of the air flow or a part thereof, the alignment units prevent the anodes and cathodes or the monocells from escaping from the production area.

[0040] According to an advantageous embodiment, the alignment units are movable transversely to the vertical direction of the production area. In particular, the opposing alignment units are movable toward and away from each other.

[0041] In this way, the gap (space) between the outer edges of the descending anodes and cathodes, or the descending monocells, and the alignment units that define the production area can be adjusted. Depending on the (spatial) size of the gap, the air introduced under the respective electrode or monocell flows faster or slower along the sides of the electrode or monocell, through the gap, and out of the production area. Consequently, the larger the gap, the greater the descent speed.

[0042] In summary, the descent speed can be adjusted using the alignment unit method. Furthermore, the device can also be used to produce electrode stacks with different external dimensions.

[0043] According to an advantageous development, the device comprises a braking unit with an air outlet for generating a braking air flow, which decelerates the anodes and cathodes or the monocells conveyed into the production area in the opposite direction to the conveying direction, i.e., the direction in which the anodes and cathodes or the monocells are conveyed into the production area. The braking air flow thus prevents impact on the alignment unit opposite the conveyor and thus the risk of damage.

[0044] According to a suitable embodiment, the device comprises a horizontal alignment unit. This is arranged in the region of the conveyor and defines the vertical direction of the production area. The horizontal alignment unit comprises an air outlet, preferably several air outlets, by means of which a vertical air flow flowing essentially counter to the vertical direction can be generated.

[0045] Depending on the design of the conveyor system, for example if it is designed as a conveyor belt, the front end of the anodes and cathodes or monocells, with respect to the conveying direction along which the anodes and cathodes or monocells are conveyed into the production area, leaves the conveyor system before the rear end. As a result, the front end begins to sink earlier than the rear end of the respective electrode or monocell. After leaving the rear end, i.e. after completely leaving the conveyor system, the respective electrode or monocell is aligned horizontally using the vertical air flow. In particular, the vertical air flow acts on the rear end of the respective electrode or monocell, so that the rear end is pushed towards the floor.

[0046] Alternatively or additionally, the electrodes or monocells are conveyed into the production area at an angle to the floor, so that the electrodes are essentially horizontal after completely leaving the conveyor. For example, the conveyor belt is inclined accordingly; in other words, the conveying direction is inclined toward the floor.

[0047] For example, the horizontal alignment unit can also be moved to the floor of the production area. This allows the electrode stack arranged on the floor to be compacted, i.e., the gaps between the electrodes or between the monocells can be reduced.

[0048] According to an advantageous embodiment, the surfaces of the alignment units delimiting the production area are inclined against the vertical direction.

[0049] If several alignment units are arranged one above the other in the vertical direction, the upper end of the lower alignment unit preferably rests against the lower end of the alignment unit arranged above it. The two alignment units arranged one above the other are therefore preferably not spaced apart from each other in the vertical direction.

[0050] At most, the upper end of the respective alignment unit, with respect to the vertical direction, is advantageously tilted outward, in other words, away from the alignment unit opposite it. The production area delimited by the alignment units (at least in sections) is thus funnel-shaped. In other words, the production area tapers in the opposite direction.

[0051] The surface bordering the production area forms a, in particular flat, guide surface for the air flow and / or, if the anodes and cathodes touch the alignment unit during their descent, for the anodes and cathodes or for the monocells.

[0052] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. In the drawings: Fig. 1a schematically shows a side view of an apparatus for producing an electrode stack, the apparatus having a conveyor device which conveys monocells, each with an anode and a cathode, spaced from a floor into a production area, and the apparatus having alignment units by means of which the monocells are aligned, Fig. 1b schematically shows the apparatus, the conveyor device being used to convey a stack of anodes and cathodes placed on top of one another but not aligned with one another into the production area, Fig. 2 schematically shows a plan view of the apparatus, the alignment units circumferentially delimiting the production area in a plane perpendicular to the vertical direction, and Fig. 3 shows a flow diagram of a process sequence for producing the electrode stack.

[0053] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0054] In the Figuren 1a and 1b a device 2 is shown which serves to produce an electrode stack 4 which is formed from anodes 6 and cathodes 8.

[0055] For this purpose, the device 2 comprises a conveyor device 12. According to this exemplary embodiment, the device 2 is formed by two conveyor belts. These are oriented parallel to each other, with the two conveyor belts having opposite directions of rotation. The conveyed material is introduced between the two conveyor belts, with both conveyor belts touching the material. At correspondingly high conveying speeds of the conveyed material, unwanted lifting of the material due to buoyancy by the ambient air is thus avoided.

[0056] Using the conveyor device 12, monocells 10 ( Fig. 1a ) are conveyed one after the other into a production area 14. Each of the monocells 10 has a single anode 6 and a single cathode 8. A separator 16 is arranged both between the anode 6 and the cathode 8 and on the side of the cathode 8 facing away from the anode 6, wherein the anode 6, the cathode 8 and the separators 16 are joined together by means of a lamination process. The separator is in Fig. 2 displayed transparently.

[0057] According to the alternative design of the Fig. 1b Separate anodes 6 and cathodes 8 are conveyed into the production area 14 by means of the conveyor device. The cathodes 8 are provided with a separator 16 on both sides. A portion of the anodes 6 and cathodes 8 are placed on top of one another prior to their conveyance into the production area 14, so that the superimposed anodes 6 and cathodes 8 are conveyed into the production area 14 simultaneously by the conveyor device 12.

[0058] According to two alternatives not further illustrated, either the anodes 6 and the cathodes 8 are conveyed into the production area 14 alternately and sequentially, or alternatively, monocells 10 placed one on top of the other but not aligned with each other. The following explanations apply analogously.

[0059] Here, the conveyor device 12 is arranged in the vertical direction Z at a distance from the floor 18 of the production area 14, so that the individual anodes 6 and cathodes 8 or the monocells 10 sink towards the floor 18 due to gravity after leaving the conveyor device 12.

[0060] The production area 14, which is also referred to as a stacking compartment or stacking chamber, is delimited in a plane perpendicular to the vertical direction Z by plate-shaped and opposing alignment units 20. In other words, the alignment units 20 delimit the production area 14 circumferentially in two directions X, Y perpendicular to each other and to the vertical direction Z.

[0061] Several alignment units 20 are arranged one above the other in the vertical direction Z. The upper end of the lower alignment unit 20 preferably rests against the lower end of the alignment unit 20 arranged above it. The two alignment units arranged one above the other are therefore preferably not spaced apart from one another in the vertical direction Z.

[0062] For the purpose of better clarity, the Fig. 1 the alignment units 20 which delimit the production area 14 in or against the Y-direction are not shown further.

[0063] Each of the alignment units 20 has a plurality of air outlets 22, by means of which an air flow can be generated within the production area 14. For this purpose, the air outlets 22 are fluidly connected to a blower or a compressor or the like in a manner not shown in detail. The air outlets 22 are designed as an air nozzle. For the sake of clarity, only some of the air outlets 22 are provided with a reference symbol. According to an alternative not shown in detail, the air outlets 22 are designed as diffusers.

[0064] The air outlets 22 serve to generate an air flow L, which is fed into the Figuren 1a and 1b is shown only in sections, namely below two of the monocells 10 and below two of the cathodes 8. Based on the air flow L, the anodes 6 and the cathodes 8 ( Fig. 1b ) or the mono cells 10 ( Fig. 1a ), to each other and / or to a predetermined target position, for example with respect to the central axis of the production area 14.

[0065] For this purpose, preferably ionized air is blown from opposing alignment units 20 under each of the anodes 6 conveyed into and descending from the production area 14 and under each of the cathodes 8 conveyed into and descending from the production area 14 or under each of the monocells 10 conveyed into and descending from the production area 14.

[0066] The air inlet direction is either parallel to the floor of the production area or only slightly inclined upwards (i.e., in the vertical direction Z). Slightly inclined means that the angle between the floor 18 and the air inlet direction is a maximum of 30°.

[0067] In this way, under each of the anodes 6 and under each of the cathodes ( Fig. 1b ) or under each of the monocells 10 ( Fig. 1a ) a turbulence, so that the sinking of the electrodes 6, 8 or the monocells 10 is slowed down.

[0068] A gap 24 is formed between the descending electrodes 6, 8 or between the monocells 10 and the alignment units 20, through which the air introduced under the respective electrode 6, 8 or under the respective monocell 10 flows in the vertical direction Z. Due to this lateral flow, a force acts on the respective anode 6 or the respective cathode 8 or on the respective monocell 10, so that it is aligned towards a central axis of the production area 14.

[0069] The alignment units 20 can also be moved transversely to the vertical direction Z, i.e. in the direction or in the Y direction, which is Figuren 1a , 1b and 2is represented by a double arrow. Consequently, the extent of the gap 16 can be adjusted in the plane spanned by the X-direction and the Y-direction. In addition, a gap forms between the alignment units 20 in this plane, through which gap air can also escape from the production area 14. By adjusting the gap size in this way, the flow velocity and / or the amount of air laterally applied to the respective anode 6 or the respective cathode 8 of the respective monocell 10 and, consequently, their sinking speed can be adjusted.

[0070] The alignment units 20, arranged at a distance from the floor 18, are inclined relative to the vertical direction Z. In other words, the angle between the vertical direction Z and that of the plate-shaped alignment unit is greater than zero. The upper end of each of these alignment units 20 is inclined outwards, i.e., away from the alignment unit opposite it. The production area 14 is thus funnel-shaped in the Z direction. The surfaces 25 of these alignment units 20 that border the production area 14 form a guide surface for the air flow and for the anodes 6 and the cathodes 8, or for the monocells 10, if they touch the alignment unit 20 during their descent.

[0071] Furthermore, the device 2 has a braking unit 26. This also comprises a plurality of air outlets 22 designed as air nozzles for generating a braking air flow BL. This brakes the monocells 10 conveyed into the production area 14 in the opposite direction to the conveying direction in which the monocells 10 are introduced into the production area, thus preventing the monocells 10 from striking the alignment unit 20 opposite the conveying device 12 in the conveying direction.

[0072] Furthermore, a horizontal alignment unit 28 of the device 2 is arranged in the area of the conveyor device 12. This unit is arranged above the floor 18 and, in the vertical direction, above the conveyor device 12. To generate a vertical air flow VL oriented counter to the vertical direction Z, the horizontal alignment unit 28 has a plurality of air outlets 22 in a manner analogous to the alignment units 20.

[0073] As particularly in the Fig. 2 As can be seen, the anodes 6 and the cathodes 8 of the monocell each have an electrical contact 30, also referred to as a tab. The contacts 30 protrude beyond the separator 16 in or against the Y direction in the plane spanned by the respective anode 6 or by the respective cathode 8. According to an exemplary embodiment not shown in detail, the contacts 30 of the anodes 6 and the contacts 30 of the cathodes 8 protrude beyond the separator 16 on the same side, wherein they are spaced from one another in the direction of the edge of this side, i.e. in the X direction.

[0074] At most, the corresponding alignment units 20, according to the Fig.2 Those which delimit the production area in or against the Y-direction each have a recess 32 extending in the Z-direction for the contacts 30. Consequently, damage to the contacts 30 during the sinking of the monocell 10 is avoided.

[0075] This applies analogously to the case where the cathodes 8 and the anodes 6 are conveyed individually, i.e. separately from each other, into the production area.

[0076] In the Fig. 2 For the purpose of better clarity, the braking unit 26, the horizontal alignment unit 28 and the alignment units 20 arranged in the vertical direction Z above or below the alignment units 20 shown are not shown further.

[0077] The floor 18 is formed by a height-adjustable conveyor belt. This is shown in the Figuren 1a and 1bindicated by a double arrow. The electrode stack 4 can thus be easily moved out of the production area by lowering the conveyor belt, i.e., by adjusting the conveyor belt counter to the vertical direction Z. For example, the electrode stack 4 is conveyed to a storage area by means of the conveyor belt and, if necessary, by means of additional conveyor belts, or is made available for a further manufacturing process of the lithium-ion battery.

[0078] The Fig. 3 The flowchart shown represents the process related to the Figuren 1a , 1b and 2 already described method for producing an electrode stack 4 from anodes 6 and cathodes 8 or from monocells 10.

[0079] In summary, the anodes 6 and the cathodes 8 or the monocells 10 are conveyed into the production area 14 by means of the conveyor device 12 at a distance from the bottom 18 thereof (step I). Subsequently, the anodes 6 and the cathodes 8 or the monocells 10 are braked counter to the conveying direction by means of the braking unit 26 and aligned horizontally by means of the horizontal alignment unit 28 (step II).

[0080] The anodes 6 and cathodes 8 or the descending monocells 10 sinking in the production area 14 opposite to the vertical direction Z are aligned to one another and to a desired position using an air flow L generated in the production area 14 (step III), so that the anodes 6 and the cathodes 8 or the monocells 10 are stacked on the floor in alignment with one another or are placed on top of one another in alignment with one another (step IV) to form the electrode stack 4.

[0081] For this purpose (for step III), the air is introduced from two opposite sides of the production area 14 under each of the anodes 6 and under each of the cathodes 8 or under each of the monocells 10. To generate the air flow L, the air is blown into the production area 14 either parallel to the floor 18 of the production area 14 or only slightly inclined against the floor 18. The air is either introduced into the production area 14 at a constant rate over time with regard to its introduction direction and its flow rate, or alternatively, the flow rate and / or the introduction direction of the air to be introduced to generate the air flow L is adjusted or varied.

[0082] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments can also be combined with one another in other ways, within the scope of the appended claims. List of reference symbols

[0083] 2Device 4Electrode stack 6Anode 8Cathode 10Monocell 12Conveyor 14Production area 16Separator 18Floor of the production area 20Alignment unit 22Air outlet 24Gap 25Surface of the alignment unit 26Braking unit 28Horizontal alignment unit 30Contact 32Recess LAirflow BLBrake airflow VLVertical airflow XDirection YDirection ZUpward direction I. Conveying the anodes and cathodes or monocells II. Braking the anodes and cathodes or monocells III. Aligning the anodes and cathodes or monocells IV. Forming the electrode stack

Claims

1. Method for producing an electrode stack (4) comprising anodes (6) and cathodes (8) for a lithium-ion battery, in particular an electrically driven motor vehicle, - in which the anodes (6) and the cathodes (8) or a number of monocells (10), each of which has one of the anodes (6) and one of the cathodes (8), are conveyed into a production region (14), wherein the anodes (6) and the cathodes (8) or the monocells (10) are conveyed into the production region at a distance from a floor (18) of the production region (14) in the vertical direction (Z), so that the anodes (6) and the cathodes (8) or the monocells (10) drop towards the floor (18), - in which an air flow (L) is generated within the production region (14) by introducing air, and - in which the anodes (6) and the cathodes (8) or the monocells (10) are aligned with each other by means of the air flow (L) as they fall, - wherein, for alignment by means of the air flow (L), the air is introduced beneath each of the anodes (6) and beneath each of the cathodes (8) or beneath each of the monocells (10) from two opposite sides of the production region (14), wherein the air for generating the air flow (L) is introduced into the production region (14) parallel to the floor (18) of the production region (14) or inclined in relation to the floor (18) at an angle between the floor (18) and the introduction direction of air of at most 30°.

2. Method according to Claim 1, characterized - in that the anodes (6) and the cathodes (8) or some of the anodes (6) and the cathodes (8) are placed one on the other before the process of conveying them into the production region (14) and are conveyed into the production region (14) lying one on the other, or - in that the monocells (10) or some of the monocells (10) are placed one on the other before the process of conveying them into the production region (14) and are conveyed into the production region (14) lying one on the other.

3. Method according to Claim 1 or 2, characterized - in that the air is ionized, and / or - in that the air is introduced into the production region (14) in a constant manner in terms of its introduction direction and in terms of its flow strength over time.

4. Method according to any of Claims 1 to 3, characterized in that the flow strength and / or introduction direction of the air to be introduced for generating the air flow (L) can be adjusted.

5. Apparatus (2) for producing an electrode stack (4) comprising anodes (6) and cathodes (8) for a Li-ion battery in line with the method according to any of Claims 1 to 4, comprising - a conveying device (12) for conveying the anodes and cathodes or for conveying monocells, each of which comprises one of the anodes (6) and one of the cathodes (8), into a production region (14), wherein the conveying device (12) is arranged at a distance from a floor (18) of the production region (14) in the vertical direction (Z), and - at least two alignment units (20) each with at least one air outlet (22) for generating an air flow (L) for aligning the anodes (6) and the cathodes (8) or for aligning the monocells (10), - wherein the alignment units (20) delimit the production region (14) in or opposite to a direction (X) oriented transversely to the vertical direction (Z) at least in sections.

6. Apparatus (2) according to Claim 5, characterized in that the alignment units (20) can be moved transversely to the vertical direction (Z) of the production region (14).

7. Apparatus (2) according to Claim 5 or 6, characterized by a braking unit (26) with an air outlet (22) for generating a braking air flow (BL), which decelerates the anodes (6) and cathodes (8) conveyed into the production region (14) or the monocells (10) conveyed into the production region (14) counter to the conveying direction.

8. Apparatus (2) according to any of Claims 5 to 7, characterized by a horizontal alignment unit (28), which is arranged in the region of the conveying device (12) and delimits the production region (14) in the vertical direction (Z), wherein the horizontal alignment unit (28) has an air outlet (22), by means of which a vertical air flow (VL) which flows substantially counter to the vertical direction (Z) can be generated.

9. Apparatus (2) according to any of Claims 5 to 8, characterized in that the surfaces (25) of the alignment units (20) delimiting the production region (14) are inclined in relation to the vertical direction (Z).