Manufacturing device for cylindrical battery cells with particle protection

Abstract

The present invention relates to a manufacturing device (1) for cylindrical battery cells. The manufacturing device (1) comprises a transport device for a conductor foil (2) which is coated with an electrode material (4) on one side in a central region (3). The manufacturing device (1) also comprises a cutting device (7) for creating incisions (6) in an edge region (5) of the conductor foil (2) that is not coated with the electrode material (4). The manufacturing device (1) also comprises a protective device (10), that is arranged in the region of the cutting device (7), for preventing particles produced during the creation of the incisions (6) from reaching the electrode material (4).

Description

[0001] Manufacturing device for cylindrical battery cells with particle protection

[0002] The present invention relates to a manufacturing device for cylindrical battery cells.

[0003] Battery cells are used in a wide variety of applications today. Increasingly stringent requirements are being placed on them, for example, with regard to the greatest possible capacity, the most effective cooling, the greatest possible reliability and robustness, and particularly simple and cost-effective production. Accordingly, various improvement measures already exist, although there is still a need for further improvements. As one approach to improving conventional battery cells, US 2020 / 0 144676 A1 describes a battery cell with a so-called table-like electrode, which is not connected to an external contact of the battery cell via a single tab. Here, too, the electrodes are wound cylindrically in an electrode coil (jelly roll).

[0004] As a further approach, WO 2020 / 192845 A1 describes a device for providing electrode strands from a separator web and electrodes fixed thereon for the large-scale production of cell assemblies for batteries. In order to improve process reliability and speed, the electrodes are to be separated from a web-shaped electrode substrate on a moving carrier of a conveyor device in such a way that at least two edges of the electrodes are cut in a cutting process and / or that carrier segments of the carrier that are movable relative to one another are brought closer together for cutting and spaced further apart for fixing the then separated electrodes. As a further approach, WO 2019 / 145337 A1 describes a method for producing an electrode for a battery.At the same time, a solvent is used to remove a pore former for forming pores in the electrode and to remove dirt particles and / or foreign particles from the electrode.

[0005] The object of the present invention is to improve the reliability and safety of cylindrical battery cells with an electrode angle.

[0006] This object is achieved by the subject matter of the main claim. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matters of the independent claims are to be regarded at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matters of the independent claims, optionally in conjunction with one or more of the subclaims.

[0007] The manufacturing device according to the invention serves for the production, or at least for a production step, of cylindrical battery cells. For this purpose, the manufacturing device has a holding and / or transport device for an electrode or conductor foil, which is coated or covered on one side in a central region with an electrode material. Depending on the requirements or the specific cell chemistry used, different materials can be used for this purpose. The conductor foil can be a copper foil, for example. The conductor foil can serve in the respective finished battery cell to collect and conduct electrons to an external or connection contact. The conductor foil coated with the electrode material can, for example, be in the form of a continuous web or as a web section intended for each battery cell, or can be transported by means of the transport device.For this purpose, the transport device can comprise, for example, a conveyor belt and / or one or more transport rollers or rollers or the like. By means of the transport device, the conductor foil can be transported or moved in a predetermined transport direction. This transport direction can in particular correspond to the longitudinal direction of the conductor foil, i.e., if appropriate, a corresponding web direction. Furthermore, the production device comprises a cutting device for producing incisions in an edge region of the conductor foil that is not coated or covered with the electrode material. These incisions can run from an outer edge or an outer edge of the conductor foil towards the central region, i.e., in the direction of the electrode material, in particular at least substantially perpendicular to the web or longitudinal direction, i.e., in the transverse direction of the conductor foil.The incisions can be limited to the edge region, i.e., they can extend from the outer edge of the conductor foil to at most the central region or at most to the electrode material. During production, i.e., during the intended operation of the production device, the conductor foil can be transported past the cutting device in the transport direction, in particular in the path or longitudinal direction of the conductor foil. In this case, a plurality of incisions extending transversely and arranged parallel to one another can be successively created in the edge region of the conductor foil by means of the cutting device.These incisions allow a corresponding number of contact tabs to be created along the edge area, which are folded or bent in a subsequent production step, particularly after the conductor foil has been rolled or wound into an electrode coil, to form a corresponding electrical contact surface. This allows a so-called table-like electrode or connection design to be realized.

[0008] According to the invention, the manufacturing device also comprises a protective device arranged in the region of the cutting device. This protective device is arranged and configured to prevent particles generated during the creation of the incisions from reaching the electrode material. The protective device can thus, for example, intercept or capture or block or deflect or redirect such particles, or the like.

[0009] Such particles originating from the conductor foil can damage other components of the battery cells, particularly the electrodes or a separator arranged between them. This can lead to short circuits in the battery cell and thus potentially pose safety risks, such as overheating or even explosion, or at least reduce the efficiency of current flow in the respective battery cell. The particles could also contaminate the electrode material. This, in turn, can change or influence its chemical composition, which can lead to reduced performance and potentially accelerated degradation of the respective battery cell over time. The particles can also interfere with the battery cell formation process, during which the battery cell is charged and discharged to establish its capacity and performance characteristics.Any foreign particles present in or on the electrode material, especially from the conductor foil, can disrupt the flow of electrons and thus lead to inconsistent performance and an overall reduced efficiency of the battery cell.

[0010] All of these problems can be avoided or at least significantly reduced by the protective device provided according to the invention. This can be achieved particularly simply and efficiently by the protective device. For example, the protective device can be or comprise a simple component serving as a barrier, which can be arranged, for example, between the cutting device or the edge region in which the incisions are created, and the electrode material. This means that neither a process for manufacturing the battery cells needs to be fundamentally changed, nor does the process or the cutting device for creating the incisions, or the material of the conductor foil, or the electrode material need to be adapted. If necessary, a cleaning step for cleaning the electrode material of particles can then even be omitted.

[0011] In one possible embodiment of the present invention, the protective device is or comprises a plate-shaped component impermeable to the particles, for example a solid plate or a curtain or the like. This plate-shaped component extends in the longitudinal direction of the conductor foil and - on an upper side and / or an underside of the conductor foil - perpendicular or obliquely or tilted to its main extension plane away from the conductor foil. Such a plate-shaped component can therefore serve or be arranged, for example, as a barrier between the electrode material and the cutting device or the edge region or at least a section of the edge region in which the cutting device is arranged or the incisions are created. This makes it possible to prevent the particles created when the incisions are created from reaching the electrode material in a particularly simple and effective manner.Depending on the application or requirements, the plate-shaped component can be formed, for example, from a metallic or ceramic material, a plastic material, a rubber material, or the like. In a possible further development of the present invention, the plate-shaped component is arranged such that, during normal operation of the production device, it rests on the conductor foil and / or the electrode material, at least on the side of the conductor foil covered with the electrode material, in the edge region thereof. A side or edge of the plate-shaped component facing the conductor foil can then, for example, slide along the conductor foil and / or the electrode material during normal operation when the conductor foil is transported or conveyed relative to the cutting device.For this purpose, the plate-shaped component can be made, for example, from a correspondingly conductive material, such as PTFE (polytetrafluoroethylene) or POM (polyoxymethylene) or the like, or can be coated with such a lubricious material on its side, narrow side, or edge facing the conductor foil. The direct mechanical contact of the plate-shaped component with the conductor foil and / or the electrode material proposed here can particularly reliably prevent the particles from reaching the electrode material, since there is then no corresponding gap through which the particles could pass. The plate-shaped component can, for example, slide or be guided along an outer edge of the electrode material facing the edge region.This allows, on the one hand, the electrode material to be effectively protected from the particles and, on the other hand, sufficient space to create the incisions is available in the edge area.

[0012] In another possible development of the present invention, the protective device has a plurality of rollers, for example wheels or rollers or the like, which extend at least partially beyond the conductor foil, and a belt guided around these rollers. The rollers can therefore be arranged above and / or below the conductor foil perpendicular to the main extension plane of the conductor foil or can extend from an area next to the conductor foil in the transverse direction to above or below the conductor foil. The protective device is then designed to roll the belt, in particular without slippage, continuously in the transport direction of the conductor foil along the edge region of the conductor foil and / or along an outer region of the electrode material facing the edge region of the conductor foil, by rotating the rollers in a manner corresponding to the transport movement of the conductor foil.The plurality of rollers can be spaced apart from one another, in particular in the transport direction, i.e., for example, in the path or longitudinal direction of the conductor foil. Likewise, the rollers can be arranged at a distance from one another and / or from at least one other roller of the protective device, for example perpendicular to the main extension plane of the conductor foil. The rollers and the belt can be arranged or act at least substantially analogously to a caterpillar or chain drive, whereby the belt can roll along the surface of the conductor foil and / or the electrode material. By appropriately adapting the rotational speed of the rollers to the movement or transport speed of the conductor foil, a grazing relative movement of the belt on the conductor foil or the electrode material can be avoided. This can prevent corresponding damage or the formation of furrows in the electrode material or the like.At the same time, however, the direct physical contact between the belt and the conductor foil or the electrode material can prevent a gap there, so that the particles can be kept away from the electrode material particularly effectively.

[0013] In one possible development of the present invention, the plate-shaped component is arranged such that it covers or fills an area between the rollers and the belt. In other words, the plate-shaped component can fill or cover the area that is delimited or surrounded by the rollers and an inner side of the belt. The belt can slide between the rollers, for example, along the upper and lower narrow sides of the plate-shaped element. Likewise, the plate-shaped component can be arranged, for example, on the side of the belt and / or rollers facing the electrode material and / or the edge region. The plate-shaped component can then at least partially cover or cover the rollers and / or the belt. This can be particularly effective in preventing particles from getting onto the electrode material.

[0014] In a further possible embodiment of the present invention, the protective device has at least one spring element. This spring element is designed and arranged to press a part of the protective device against the conductor foil and / or the electrode material during normal operation of the production device. For example, at least one of the rollers mentioned elsewhere and / or the belt mentioned elsewhere and / or the plate-shaped component mentioned elsewhere can be spring-loaded or spring-mounted accordingly by means of the spring element. The spring element can thus ensure permanent and reliable direct contact between the protective device and the conductor foil or the electrode material.This makes it possible to particularly effectively and reliably prevent gaps through which particles could reach the electrode material, even if there are changes in position or position deviations or movements of the conductor foil perpendicular to its main plane of extension.

[0015] In a further possible embodiment of the present invention, the protective device is or comprises a suction device. This suction device is arranged and configured to generate, during normal operation of the production device, an air flow directed at least primarily parallel to the main extension plane of the conductor foil and away from the electrode material at the edge region of the conductor foil in order to suction away the particles. By means of such a suction device or an air flow directed in this way, the particles created in the edge region can be deflected or sucked away from the electrode material without generating a significant load on the conductor foil perpendicular to its main extension plane. The latter could be the case, for example, when using a conventional air curtain flow perpendicular to the main extension plane of the conductor foil.The embodiment of the present invention proposed here makes it possible to avoid damage to or deformation of the conductor foil and to produce the incisions particularly reliably and precisely, while at the same time preventing contamination of the electrode material by the particles. The extraction device can comprise, for example, a fan or a blower or a turbine or the like to generate the air flow. The extraction device can also comprise an air guiding element, for example a nozzle or an air guiding duct or the like. This air guiding element can be arranged next to the conductor foil or next to the edge region of the conductor foil and can be open towards the conductor foil. The fan or blower and / or the air guiding element can, for example, be arranged perpendicular to the main plane of extension of the conductor foil on both sides, i.e. upwards and downwards, over the conductor foil orprotrude beyond their main extension plane. This allows the air flow to be generated particularly simply and effectively both above and below the conductor foil. This also prevents particles from being deposited on the underside of the conductor foil, which may not be coated or covered with the electrode material. This can ultimately also benefit the reliability and safety of the battery cells. The aforementioned extraction device can also be referred to as the first extraction device. In a possible development of the present invention, the protective device then also comprises a second extraction device.The first extraction device is arranged and configured to generate the air flow at least primarily on or at the top side of the conductor foil, while the second extraction device is arranged and configured to generate a corresponding, equally directed air flow at least primarily on or at the bottom side of the conductor foil. During normal operation of the production device, the conductor foil can then, for example, be guided between the two extraction devices. By using two extraction devices as proposed here, these can each be arranged and aligned in an optimized manner in order to enable particularly effective and efficient extraction of the particles only from the top side or only from the bottom side of the conductor foil.This allows for improved flexibility in the design of the extraction device and / or the production device as a whole and ultimately a particularly reliable prevention of contamination by the particles.

[0016] In a further possible embodiment of the present invention, the cutting device is enclosed, i.e. shielded or sealed off, for example by the protective device or an additional housing, at least in the intended position of the electrode material and viewed perpendicular to the main extension plane of the conductor foil, upwards and downwards, as well as on both sides in the longitudinal direction or in the intended transport direction of the conductor foil. When the incisions are made, particles created can move primarily in the transverse direction of the conductor foil, i.e. along the shortest path in the direction of the electrode material. However, some of the particles created can also move in other directions or reach the electrode material along other paths. The enclosure of the cutting device proposed here, orBy blocking an action or effective area of ​​the switching device in which the incisions are created, not only the primary path for particle contamination but also secondary particle paths to the electrode material can be blocked. This ultimately makes it particularly reliable to prevent particles from reaching the electrode material. In order to enable particularly easy accessibility to the cutting device or the action or effective area of ​​the cutting device, for example for monitoring and / or maintenance purposes or the like, the housing provided here can be open, for example, in the transverse direction of the conductor foil in the direction pointing away from it. The suction device mentioned elsewhere can also be arranged there, for example.

[0017] In a further possible embodiment of the present invention, the cutting device comprises a laser for laser cutting the conductor foil or is configured as such a laser. In other words, the incisions can then be created contactlessly by laser cutting, i.e., by means of a corresponding laser beam generated by the switching device. This enables the incisions to be created particularly quickly, precisely, and without wear, largely avoiding deformation or mechanical stress on the conductor foil.

[0018] Further features of the invention may emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures alone, 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.

[0019] The drawing shows:

[0020] Fig. 1 is a partial schematic plan view of a manufacturing device for cylindrical battery cells with an electrode track;

[0021] Fig. 2 is a partial schematic cross-sectional view of the manufacturing device;

[0022] Fig. 3 is a partial schematic side view of the manufacturing device;

[0023] Fig. 4 is a partial schematic cross-sectional view of the manufacturing device with a suction device in a first variant; and

[0024] Fig. 5 shows a partial schematic cross-sectional view of the production device with the extraction device in a second variant. In the figures, identical and functionally identical elements are provided with the same reference numerals. For the sake of clarity, where identical or similar elements are present in multiple copies, only a representative selection is explicitly marked in the figures, at least in part.

[0025] Fig. 1 shows a partial schematic top view of a manufacturing device 1 for cylindrical battery cells. It also shows part of a material web for an electrode coil. This material web comprises an electrically conductive conductor foil 2, which is coated or covered with an electrode material 4 in a central region 3. In an edge region 5 adjacent to the central region 3, however, the conductor foil 2 is free of the electrode material 4.

[0026] The manufacturing device 1 is intended here for the manufacture of battery cells in a so-called fabless design. In this case, a plurality of incisions 6 are created in the edge region 5. For this purpose, the manufacturing device 1 comprises a corresponding cutting device 7, which can create the incisions 6 using a cutting beam 8, indicated schematically here, for example using a laser beam. During production, the conductor foil 2 is transported past the cutting device 7 in a transport direction 9, indicated here. This transport direction 9 can correspond to the web or longitudinal direction of the conductor foil 2. The incisions 6, however, can run in a transverse direction of the conductor foil 2 or be longitudinally extended.

[0027] When creating the incisions 6, particles can be created that could potentially get onto the electrode material 4 and then cause damage or impairment. To prevent this, the production device 1 has a corresponding protective device 10. This protective device 10 here comprises a protective plate 11 that is impermeable to the particles. This protective plate 11 is located in the area of ​​the cutting device 7, perpendicular to the conductor foil 2 in the edge region 5, in particular between a part of the edge region 5, in which the incisions 6 are created, and the central region 3. The protective plate 11 extends in and against the transport direction 9 on both sides of the switching device 7 or on both sides of its effective area in which the cutting beam 8 strikes the conductor foil 2.The protective plate 11 thus serves as a barrier for the particles created when the incisions 6 are created, preventing the particles from reaching the electrode material 4. The protective device 10 can also be designed differently and / or comprise other or additional elements. Optionally, the protective device 10 can, for example, comprise side walls 12, which is indicated here by their dashed representation. The side walls 12 can, for example, extend on both sides of the cutting device 7 or the effective area of ​​the cutting device 7 from the protective plate 11 perpendicular to the transport direction 9, i.e. in the transverse direction of the conductor foil 2 away from the electrode material 4. The side walls 12 can thus serve as barriers for intercepting particles that have a movement or speed component directed in or against the transport direction 9.

[0028] For further illustration, Fig. 2 shows a partial schematic representation of the production device 1 in a cross-sectional view. The transport direction 9 can therefore be perpendicular to the plane of the drawing. It can be seen that the protective plate 11 can extend both above and below the conductor foil 2 or that a protective plate 11 can be arranged both above and below the conductor foil 2. In addition, the protective device 10 can also have cover elements 13 for further enclosing the switching device 7 or the effective area of ​​the cutting device 7 or the cutting beam 8. With a limited height of the protective plate 11, it can be prevented that particles in an arc-shaped trajectory pass over the protective plate 11 onto the electrode material 4 or onto the underside of the conductor foil 2 opposite it.The cover elements 13 can therefore extend, for example, parallel to the main extension plane of the conductor foil 2, for example from the respective protective plate 11 to the respective side walls 12.

[0029] Fig. 3 shows a partial schematic representation of the production device 1 with a further possible variant or a further possible part of the protective device 10. The protective device 10 here comprises a plurality of rollers 14. These rollers 14 are each rotatably mounted about an axis of rotation perpendicular to the plane of the drawing, so that they can rotate in a respective direction of rotation 15 indicated here. The protective device 10 also comprises belts 16, which are each guided around the rollers 14 arranged above or below the conductor foil 2. The belts 16 can therefore run along or be unrolled on the respective side of the conductor foil 2 during a movement of the conductor foil 2 in the transport direction 9 and simultaneous corresponding rotation of the rollers 14 in the respective direction of rotation 15. An area lying between the rollers 14 and the respective belt 16 is covered by a respective protective plate 11.

[0030] Fig. 4 shows a partial schematic cross-sectional view of the production device 1 to illustrate further possible design details, in particular of the protective device 10. The protective device 10 here comprises an extraction device 17 for generating a directed air flow 18. A primary flow direction of this air flow 18 corresponds here to the transverse direction of the conductor foil 2, i.e. runs in or parallel to its main extension plane and in particular perpendicular to the longitudinal or transport direction 9. Particles generated when creating the incisions 6 by means of the cutting beam 8 can thus be transported away from the electrode material 4.

[0031] The extraction device 17 is arranged perpendicular to the main extension plane of the conductor foil 2, approximately at the height of the conductor foil 2. This allows the air flow 18 to be generated both above and below the conductor foil 2.

[0032] Fig. 5 shows a further possible design of the production device 1 or the protective device 10 analogous to Fig. 4. Here, the protective device 10 comprises two separate suction devices 17. One of these suction devices 17 is arranged above the conductor foil 2, while the other suction device 17 is arranged below the conductor foil 2. Thus, corresponding air flows 18 can be generated in a targeted or primary manner by means of one suction device 17 above and by means of the other suction device 17 below the conductor foil 2 in order to suction the particles in the transverse direction.

[0033] Overall, the examples described demonstrate how a particle shield—for example, designed as a physical barrier and / or as an air flow—can be realized and applied for battery cell production prior to a production step for rolling up corresponding electrode coils for cylindrical battery cells.

[0034] 1 manufacturing device

[0035] 2 conductor foil

[0036] 3 central area

[0037] 4 Electrode material

[0038] 5 Marginal area

[0039] 6 incision

[0040] 7 Cutting device

[0041] 8 Cutting beam

[0042] 9 Transport direction

[0043] 10 Protective device

[0044] 11 Protective plate

[0045] 12 side wall

[0046] 13 Cover element

[0047] 14 rolls

[0048] 15 Direction of rotation

[0049] 16 belts

[0050] 17 Extraction device

[0051] 18 Airflow

Claims

Patent claims 1. Manufacturing device (1) for cylindrical battery cells, comprising - a transport device for a conductor foil (2) which is covered on one side in a central region (3) with an electrode material (4), - a cutting device (7) for producing incisions (6) in an edge region (5) of the conductor foil (2) not covered with the electrode material (4), - a protective device (10) arranged in the region of the cutting device (7) to prevent particles created during the production of the incisions (6) from reaching the electrode material (4).

2. Manufacturing device (1) according to claim 1, characterized in that the protective device (10) comprises a plate-shaped component (11) which is impermeable to the particles and which extends in the longitudinal direction (9) of the conductor foil (2) and perpendicular or obliquely to its main extension plane away from the conductor foil (2).

3. Manufacturing device (1) according to claim 2, characterized in that the plate-shaped component (11) is arranged such that, during normal operation of the manufacturing device (1), it rests on the side of the conductor foil (2) covered with the electrode material (4) in the edge region (5) of the conductor foil (2) and / or on the electrode material (4).

4. Production device (1) according to claim 1 or 2, characterized in that the protective device (10) has a plurality of rollers (14) at least partially projecting beyond the conductor foil (2) and a belt (16) guided around said rollers and is designed to, during normal operation of the production device (1), continuously guide the belt (16) in the transport direction (9) of the conductor foil (2) onto the edge region (5) thereof and / or onto a to roll along the outer region of the electrode material (4) facing the edge region (5) of the conductor foil (2).

5. Manufacturing device (1) according to claims 4 and 2, characterized in that the plate-shaped component (11) covers an area between the rollers (14) and the belt (16).

6. Manufacturing device (1) according to one of the preceding claims, characterized in that the protective device (10) has a spring element for pressing a part of the protective device (10) against the conductor foil (2) and / or the electrode material (4) during normal operation of the manufacturing device (1).

7. Manufacturing device (1) according to one of the preceding claims, characterized in that the protective device (10) comprises a suction device (17) which is designed to generate an air flow (18) for sucking off the particles at the edge region (5) of the conductor foil (2), said air flow being directed at least primarily parallel to the main extension plane of the conductor foil (2) and away from the electrode material (4).

8. Manufacturing device (1) according to claim 7, characterized in that the protective device (10) also comprises a second suction device (17) and the suction device (17) is designed to generate the air flow (18) at least primarily on the upper side of the conductor foil (2), while the second suction device (17) is designed to generate a corresponding directed air flow (18) at least primarily on the opposite underside of the conductor foil (2).

9. Manufacturing device (1) according to one of the preceding claims, characterized in that the cutting device (7) is arranged at least to the intended position of the electrode material (4) and perpendicular to the main extension plane of the conductor foil (2) upwards and downwards and in the longitudinal direction of the conductor foil (2) on both sides.

10. Manufacturing device (1) according to one of the preceding claims, characterized in that the cutting device (7) comprises a laser for laser cutting the conductor foil (2).

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