Method and cutting device for cutting electrode films

Abstract

A method for cutting an electrode film (1) by means of a particle stream (2) is proposed. A cutting device (4) for cutting an electrode film (1) is also described, the electrode film being provided for use in a battery cell, the cutting device comprising at least a nozzle (5) with an outlet (6), a cutting tool (7), an oscillating device (8) for exciting at least the cutting tool (7) to oscillate (14), a particle feed line (9) for conveying at least particles (13), and a gas feed line (10) for conveying a first gas stream (12), wherein the particles (13) and the first gas stream (12) can be mixed in the cutting device (4) to form a particle stream (2) and can be conveyed to the outlet (6) via the nozzle (5), wherein the cutting tool (7) and the outlet (5) can be arranged above the electrode film (1) at a distance (11) from a surface (3) of the electrode film (1), and the electrode film (1) can be cut at least by the particle stream (2) and by means of the oscillation (14) of the cutting tool (7).

Description

Technical Field

[0001] The invention relates to a method and a cutting device for cutting electrode films, in particular coated electrode films. Background Art

[0002] Batteries, especially lithium-ion batteries, are increasingly used to drive motor vehicles. Batteries are usually composed of battery cells, wherein each single cell has a stack of anode membranes, cathode membranes and separator membranes, which are optionally present in the form of layers or material layers. At least a portion of the anode membrane and cathode membrane is designed as a current collector for conducting the current provided by the battery cell to electrical consumers arranged outside the battery cell. The individual elements of the stack are also referred to below as electrodes or membranes.

[0003] The individual films are provided in particular as a continuous material, are coated, if necessary, with, for example, an active material, and are at least partially trimmed. The uncoated regions of the coated films can be used as arresters.

[0004] Perform the following steps when cutting electrodes:

[0005] Slit: The cutting line extends along the extension direction (x direction) of the continuous material so as to divide the wider starting material into multiple narrower continuous material strips;

[0006] Grooving: The formation of an arrester from a continuous material by means of a cutting line; the cutting line extends longitudinally and transversely relative to the extension direction of the continuous material;

[0007] • Debonding: The cutting line is transverse to the extension direction of the continuous material; by debonding the electrode film is cut off from the continuous material and forms an individual layer of the stack.

[0008] The current state of the art for cutting lithium-ion battery electrodes uses a shearing principle, where an upper tool (above the layer to be cut) contacts a lower tool (below the layer to be cut). This contact results in high friction, which leads to faster tool wear. High kerf speeds amplify this problem. Therefore, cutting speeds are currently limited to a maximum of 120 m / min [meters per minute].

[0009] The slitting is carried out in particular by means of upper and lower circular knives made of tungsten carbide. These knives need to be re-sharpened after approximately 200 km [kilometers] of cutting line. Such frequent re-sharpening of the knives results in high operating costs.

[0010] Grooving and stripping are carried out in particular as separate processes after slitting. This can be done mechanically or by laser. Since the machines for slitting and groove cutting are separate, greater investment and space are required.

[0011] Laser cutting is a very energy-intensive process (the power requirement of the facility is about 6 kW [kilowatts]) and produces a heat-affected zone. The active material of the coated electrode in this heat-affected zone is burned, thus reducing the cell capacity. In addition, the laser process is inefficient because most of the concentrated light beam is reflected by the copper or aluminum surface of the electrode. In particular, special green lasers are required to achieve better light absorption. However, lasers of this type are expensive and do not allow speeds above 80 m / min.

[0012] Mechanical grooving has high tool wear. In addition, the electrode feed must be stopped regularly to carry out process steps. This leads to a reduction in cutting speed. The movement of the electrode in the z direction (thickness direction) during the grooving process causes waviness at the grooving edge or cutting line. Since there is no corresponding tool, this waviness cannot be monitored.

[0013] In particular, no limitation is provided for the movement of the electrodes in the y-direction (width direction). This results in waviness in the y-direction.

[0014] Due to the lack of counterforce during slitting and mechanical grooving, burrs can form. This can lead, in particular, to short circuits in the battery cells. Active material from the cut-out electrodes can get caught on the cutting edge. This requires extensive cleaning of the cutting edge and the tool. Particles larger than 10 μm [micrometers] adhering to the cutting edge can also lead to short circuits in the battery cells.

[0015] In short, cutting using a tool (mechanical cutting) and / or cutting using energy (laser) may result in reduced cutting speed, increased cost, reduced battery capacity, and / or reduced safety of the battery cells.

[0016] These disadvantages can be reduced as follows:

[0017] Use a solution of alcohol and paraffin oil to thoroughly clean the blade while cutting;

[0018] Cleaning of the cutting edge by contact and non-contact cleaning in mechanical cutting; in non-contact cleaning, ionized air is blown onto the cutting edge in order to neutralize the static electricity on the non-conductive particles; the particles thus neutralized can subsequently be blown off or sucked away;

[0019] Use green laser because it has the lowest reflectivity on the metal surface of the electrode;

[0020] Reduce cutting speed to reduce tool wear;

[0021] • Increasing cutting edge tolerances (in terms of allowed burr size and particle adhesion), which in fact reduces battery safety.

[0022] The main disadvantages of the known facilities in use are as follows:

[0023] High wear of the slitting knives; the slitting knives must be reground every 200 km; tungsten carbide and other hard metals as well as ceramics as tool materials reduce this wear rate, but are very expensive;

[0024] · Extensive cleaning stations are required during cutting; possibly electrode cleaning stations are required after slitting and laser cutting to remove particulate contamination from the electrodes; this increases machine costs, cycle time and / or space requirements;

[0025] Mechanical longitudinal cutting (kerf cutting) is very sensitive to cutting parameters such as cutting angle, cutting speed, force between upper and lower cutters, cutter surface roughness and machine vibration; slight changes lead to burr formation and additional particle contamination;

[0026] There is currently no achievable solution for continuous grooving and stripping; this means that during the grooving and stripping process, the electrode movement is temporarily stopped; this reduces the grooving and stripping speed; the maximum speed during grooving and stripping is 60m / min.

[0027] The following techniques are known to overcome some of the disadvantages mentioned:

[0028] Use hard materials such as high-chrome steel, ceramics and tungsten carbide as tool materials to reduce wear;

[0029] The minimum radius when cutting grooves is set to 2 mm [millimeters]; a smaller radius between the two cutting edges (at the intersection of the longitudinal and transverse cuts) cannot be achieved;

[0030] Continuous movement of the electrode during the grooving and stripping process can only be implemented by a few manufacturing experts; meaning that the laser gun moves at an angle while cutting so that the final cut edge is "perfectly" straight; this requires very precise control of the laser gun's travel path and the electrode movement;

[0031] Using different cutting principles, such as rotary cutting for slitting and grooving; in rotary cutting, the quality of the transverse cut is poorer than that of the longitudinal cut;

[0032] Cutting anodes using green laser and high power (6kW);

[0033] Use cooling plates when laser cutting electrodes to achieve rapid cooling and reduce heat affected zones.

[0034] This therefore means that cutting battery electrodes using mechanical tools or using energy (laser) will always remain a flawed, high tolerance, expensive and / or unreliable process.

[0035] A device for treating a surface by honing is known from US Pat. No. 6,379,858 B1. A honing agent is thrown onto the surface of the material to be treated by a horn. Alternatively, the honing agent is arranged on the surface and the tool is excited to vibrate and contacts the surface with the honing agent.

[0036] A method for producing panels using an ultrasonic oscillation unit as a processing tool is known from DE 2 329 932 A2.

[0037] A polishing device for treating a surface is known from JP 2009-274181 A. There, a nozzle is set into vibration, through which a polishing agent is applied to the surface. Summary of the invention

[0038] The technical problem to be solved by the present invention is to at least partially solve the problems mentioned in the prior art. In particular, a method and a cutting device for cutting electrode films are proposed, by which high-quality cutting can be performed at high speed and with as little wear as possible.

[0039] The technical problem is solved according to the invention by a method for cutting an electrode film at least by a particle stream, the electrode film being provided for use in a battery cell; wherein the method is implemented by a cutting device, the cutting device comprising at least one nozzle with an outlet, a cutting tool, an oscillating device, a particle feed line and a gas feed line, and the method comprises at least the following steps:

[0040] a) providing an electrode film having a surface;

[0041] b) arranging the cutting tool and the outlet above the electrode membrane at a distance relative to the surface;

[0042] c) introducing a first gas flow from the gas input pipeline into the cutting device;

[0043] d) introducing particles from at least the particle input line into a cutting device;

[0044] e) mixing the first gas stream and at least the particles into a particle stream in the cutting device;

[0045] f) exciting at least the cutting tool or additionally the nozzle to vibrate by means of the oscillation device;

[0046] g) applying a particle flow flowing out of an outlet to the electrode membrane, thereby dividing the electrode membrane, and

[0047] h) applying vibration of the cutting tool to the electrode film by at least one particle arranged between the cutting tool and the electrode film, thereby dividing the electrode film.

[0048] The technical problem is also solved according to the present invention by a cutting device for cutting an electrode membrane, wherein the electrode membrane is configured to be applied to a battery cell, and the cutting device comprises at least a nozzle having an outlet, a cutting tool, an oscillation device for at least exciting the cutting tool to vibrate, a particle input pipeline for conveying at least particles, and a gas input pipeline for conveying a first gas flow, wherein the particles and the first gas flow can be mixed into a particle flow in the cutting device and can be conveyed to the outlet through the nozzle, wherein the cutting tool and the outlet can be arranged above the electrode membrane at a distance relative to the surface of the electrode membrane, and the electrode membrane can be divided at least by the particle flow and by the vibration of the cutting tool.

[0049] Advantageous further developments are apparent from the description. The features mentioned individually in the description can be combined with one another in a technically meaningful manner and can be supplemented by explanatory facts in the description and / or details in the drawings, which show further embodiments of the invention.

[0050] The method for cutting an electrode film described below contributes to this. The electrode film is provided or intended in particular for use in a battery cell. The method is implemented by at least one cutting device. The cutting device comprises at least the following components: a nozzle with an outlet, a cutting tool, an oscillating device, a particle input line and a gas input line. The cutting is performed by a particle flow, i.e., by applying a particle flow to the electrode film. The cutting is also achieved by vibration of the cutting tool, wherein the cutting tool contacts the electrode film by arranging the particle flow and at least one particle between the cutting tool and the electrode film.

[0051] The method comprises at least the following steps:

[0052] a) providing an electrode film having a surface;

[0053] b) arranging the outlet above the electrode membrane at a distance relative to the surface;

[0054] c) introducing a first gas flow from a gas input line into the cutting device,

[0055] d) introducing at least particles from a particle feed line into a cutting device,

[0056] e) mixing the first gas stream and at least the particles into a particle stream in a cutting device;

[0057] f) exciting at least the cutting tool or additionally the nozzle to vibrate by means of an oscillating device;

[0058] g) applying a particle flow flowing out of an outlet to the electrode membrane, thereby dividing the electrode membrane; and

[0059] h) applying vibration of the cutting tool to the electrode film through at least one particle arranged between the cutting tool and the electrode film, thereby dividing the electrode film.

[0060] The above (non-exhaustive) division of method steps a) to d) should primarily serve only to distinguish, but not to impose a sequence and / or dependency. The number of method steps can also be varied. It is also possible that the method steps overlap with each other at least partially in time. Very particularly preferably, steps c) to h) occur at least sometimes in time parallel to each other. Steps c) to h) are in particular carried out after step a) and step b).

[0061] The battery cell comprises in particular a housing enclosing a volume and arranged in the volume at least one first electrode film of a first electrode type, a second electrode film of a second electrode type and a separator material arranged between the first and second electrode films as well as an electrolyte, for example a liquid or solid electrolyte.

[0062] The battery cells are in particular pouch-shaped battery cells (or soft pack battery cells, which have a deformable housing made of a pouch film) or prismatic battery cells (which have a dimensionally stable housing). Pouch films are known deformable housing parts that serve as housings for so-called pouch-shaped battery cells. Pouch films are composite materials that include, for example, plastic and aluminum.

[0063] The battery cells are especially lithium-ion battery cells.

[0064] The individual membranes of the plurality of electrode membranes are arranged one above the other and in particular form a stack. These electrode membranes are respectively assigned to different electrode types, ie are designed as anodes or cathodes. Here, the anodes and cathodes are arranged alternately and separated from each other by separator materials.

[0065] A battery cell is an electrical storage device which is used, for example, in a motor vehicle to store electrical energy. In particular, for example, a motor vehicle has an electric machine (traction drive) for driving the motor vehicle, wherein the electric machine can be driven by the electrical energy stored in the battery cell.

[0066] According to step a), an electrode film having a surface is provided in particular. The electrode film is provided in particular as a continuous material. The electrode film comprises in particular a carrier material, in particular a carrier material made of a metallic material, which carrier material is, if necessary and in this case, designed to be at least partially coated, for example with an active material. The electrode film has two largest side surfaces, which have a theoretically infinite length in the x-direction, and also has a width in the y-direction and a thickness in the z-direction. The extension in the z-direction is the smallest. In this case, one of the two side surfaces of the electrode film constitutes the surface.

[0067] A cutting device is provided, which comprises at least a nozzle having an outlet, a cutting tool and an oscillating device. In addition, the outlet is arranged above the electrode membrane at a distance relative to the surface (step b)). The nozzle is used to align the particle flow with the surface. The particle flow flows out of the cutting device through the outlet of the nozzle and flows to the surface. The nozzle is arranged at such a distance from the surface that there is no direct mechanical contact between the nozzle and the surface. The cutting tool can have an outlet or be arranged adjacent to the outlet. The cutting tool is excited by the oscillating device and vibrates.

[0068] The cutting tool does not in particular contact or does not directly contact the surface. The cutting tool in particular contacts the surface via at least one particle arranged between the cutting tool and the surface. The cutting tool thus in particular contacts the particles and moves the particles due to the vibrations. The particles thus excited produce a cutting action on the electrode film. The distance between the cutting tool and the surface can therefore in particular be bridged by individual particles.

[0069] A particle input line and a gas input line are also provided. These input lines are used, in particular, to transport particles and the first gas flow.

[0070] According to step c), in particular a first gas flow from a gas feed line is introduced into the cutting device. According to step d), at least particles from a particle feed line are introduced into the cutting device. Furthermore, according to step e), the first gas flow and at least the particles are mixed in the cutting device to form a particle stream. The first gas flow is used in particular to transport and accelerate the particles so that the particles are transported to the surface together with the gas flow, i.e. as a particle stream, through the nozzle.

[0071] According to step f), at least the cutting tool or additionally the nozzle is excited to vibrate, in particular by means of an oscillation device. Due to the vibration, at least the cutting tool is moved, in particular in a plane oriented perpendicularly to the surface.

[0072] According to step g), the particle stream flowing out of the outlet is applied to the electrode membrane and the electrode membrane is cut. The electrode membrane is cut continuously by the impact of the particles on the surface. In this case, the particles are thrown onto the surface in particular, so that material of the surface or the electrode membrane is displaced by the particles.

[0073] According to step h), the electrode film is divided by applying vibrations of the cutting tool to the electrode film, in particular by means of at least one particle arranged between the cutting tool and the electrode film.

[0074] Step g) and step h) can be designed to respectively (at least sometimes) individually or jointly realize a (partial) segmentation process of the electrode film.

[0075] In particular, the nozzle is an ultrasonic oscillation unit (or sonotrode) or is designed as an ultrasonic oscillation unit, wherein the outlet is excited by the oscillation device to vibrate. Due to the vibration, the outlet and the cutting tool move in a plane oriented perpendicular to the surface.

[0076] A sonotrode is a tool that is set into resonant vibration by introducing high-frequency mechanical vibrations (for example ultrasound, but also lower frequencies). The amplitude of the excitation can be increased by means of a sonotrode.

[0077] As an alternative to mechanical cutting (using the shearing principle by means of a cutting tool) or slitting and groove cutting by means of energy (laser), cutting is carried out here by means of a rapidly vibrating gas medium, a first gas stream carrying the abrasive particles, and by means of a cutting tool that is excited to vibrate. The cutting action of the particles or the cutting tool can be intensified by high-frequency excitation of the particle stream or the cutting tool by means of an ultrasonic oscillation unit.

[0078] The proposed method can achieve high cutting speeds in particular. Moreover, tool wear occurs only on the cutting tool. Furthermore, no burrs are generated on the separating edge and there is no heat-affected zone. The method is particularly suitable for slitting. However, the method can also be used for grooving and stripping.

[0079] The cutting is carried out by a combination of two operating principles: one by a throwing mechanism (bombardment) and the other by a hammering action ("hammering") of the hammering method.

[0080] In the case of the first principle of action, the throwing mechanism, the first air flow, which may vibrate, in particular the high-speed air flow, carries the abrasive particles. The particles begin to vibrate, in particular, in the first air flow. Both the first air flow and the particles are thrown onto the cutting area of ​​the surface in the form of a sharp abrasive air knife. In this case, the focus of the abrasive air knife can be designed to be very small. The cutting is achieved in particular by the kinetic energy of the particles transported by the first air flow and, if necessary, the vibration energy.

[0081] In the case of the second principle of action, the hammering method, cutting is achieved by vibrationally excited and abrasive particles. Here, the abrasive is distributed over the cutting area (here the surface) and is set into vibration by the vibrating cutting tool. Thus, there is an interaction between the cutting tool and the electrode film. Here, cutting is achieved in particular by the vibration energy of the cutting tool and by the abrasive action of the particles arranged between the cutting tool and the surface and moved by the cutting tool. The particles are conveyed to the cutting tool by the gas stream.

[0082] The sonotrode is in particular designed with a cavity and the particle flow is conveyed through the cavity to the outlet.

[0083] The outlet of the nozzle is particularly configured on the cutting tool. Therefore, the particle flow flows out particularly from the outlet arranged at the tip of the cutting tool. The cutting tool is therefore particularly designed to be hollow and is particularly connected to the cavity of the ultrasonic oscillation unit. The particle flow is guided to the surface by the cavity in the ultrasonic oscillation unit and the hollow cutting tool. The tip of the cutting tool is oriented toward the surface of the electrode film and is arranged to be closest to the surface. Therefore, the cutting tool extends away from the surface from the tip.

[0084] The outlet is particularly configured adjacent to the cutting tool. The particle flow is particularly introduced through the cavity of the ultrasonic oscillation unit and subsequently transported to an input area arranged adjacent to the cutting tool. The particle flow is guided to the cutting area through the input area. The cutting tool is particularly designed as a solid component, i.e., not hollow. The input area is particularly connected to the ultrasonic oscillation unit and is excited by the ultrasonic oscillation unit.

[0085] Especially at least

[0086] The vibration has an amplitude, especially at the outlet, of at most 80 μm, preferably at most 60 μm or at most 50 μm; or

[0087] The frequency of the vibration is between 5 kHz [kilohertz] and 50 kHz, preferably between 10 kHz and 25 kHz; or

[0088] The outlet has a diameter or maximum width of up to 1.0 mm, in particular 0.2 to 0.8 mm, preferably 0.4 to 0.6 mm.

[0089] The cutting tool has in particular a closed tip facing the electrode membrane, which has a minimum width of 0.2 to 1.5 mm, preferably 0.5 to 1.2 mm. The open tip with the outlet has in particular a minimum width of at most 2 mm. The minimum width is in particular the minimum extension of the width. If, for example, the ultrasonic oscillation unit or the nozzle is designed as a rectangle, the tip extends along a length parallel to the surface of the electrode membrane. Therefore, this much larger length should not be understood as a width.

[0090] The oscillation device preferably comprises a transducer (piezoelectric or magnetostrictive), to which the high-frequency electrical signal is transmitted. The transducer converts the electrical signal into a low-frequency mechanical vibration with a small amplitude. Basically, the transducer converts electrical energy into mechanical vibrations. The mechanical vibrations are then transmitted to the hollow ultrasonic oscillation unit.

[0091] These mechanical vibrations have a small amplitude in the region of the transducer. The main function of the sonotrode is to amplify these vibrations.

[0092] A piezoelectric transducer or crystal generates a small electric current when it is squeezed. When the current passes through the crystal, it expands. When the current is removed, the crystal returns to its original size and shape. Such transducers can deliver up to 900 watts of power. Piezoelectric crystals have a high conversion efficiency of 95%. In the case of such a transducer, an electrical signal is introduced into the transducer and the resulting mechanical vibrations are transmitted to the ultrasonic oscillator.

[0093] The magnetostrictive acoustic transducer changes its length when subjected to a strong magnetic field. This transducer is made of nickel or nickel alloy plates. Its conversion efficiency is about 20-30%. This transducer can provide up to 2000 watts of power. The maximum length change that can be achieved is about 25 microns. When using this transducer, a magnetic field is provided in the transducer, and the mechanical vibrations generated thereby are then transmitted to the ultrasonic oscillation unit.

[0094] Piezoelectric transformers can be preferred due to their high conversion efficiency. Low frequencies of approximately 10 kHz and amplitudes of approximately 50 micrometers have proven to be particularly suitable for cutting electrode films. The ultrasonic oscillator receives an input amplitude of approximately 20 to 25 micrometers, wherein the output amplitude at the output end is then amplified to 50 micrometers, for example.

[0095] The converter is provided in particular in the form of a ring and is arranged in the inlet region of the sonotrode. In particular, only the sonotrode is excited by the converter.

[0096] The ultrasonic oscillation unit or nozzle is made of titanium or a titanium alloy, for example Ti6Al4V. The cavity extends from the inlet to the outlet as a channel through the ultrasonic oscillation unit or nozzle and is made of tungsten carbide. The cavity or channel and the ultrasonic oscillation unit can be designed in two parts and connected to each other by extrusion.

[0097] The cavity or channel through the nozzle or the sonotrode extends in particular conically or exponentially. The outlet has in particular a smaller diameter than the inlet.

[0098] The particle stream can be further focused by the nozzle / ultrasonic oscillation unit so that the maximum diameter of the particle stream on the surface is approximately 10% of the maximum diameter of the outlet.

[0099] Calculating the required length of the sonotrode, i.e. between the inlet and the outlet, is one of the most important parts of the sonotrode design. In order to minimize losses and transfer the maximum energy of the ultrasonic probe or the converter to the sonotrode, the sonotrode should resonate with the operating frequency of the ultrasonic probe of the oscillation device. The length of the sonotrode, in particular up to the tip of the cutting tool, should be equal to an odd multiple of half the wavelength (λ / 2) of the vibration of the converter. It should be noted in particular that the amplitude of the vibration is maximum at the outlet. The vibration node is in particular arranged at the inlet of the sonotrode, and the antinode is arranged at the outlet or at the tip of the cutting tool.

[0100] The distance between the surface and the outlet should in particular be equal to a multiple of the wavelength of the vibration of the transducer. The amplitude of the vibration is therefore maximum at the focus of the particle flow on the surface. In particular, the inlet of the channel of the sonotrode receives the amplitude of the acoustic transducer.

[0101] In particular, a mixture of at least the particles and anhydrous liquid is conveyed via the particle feed line.

[0102] The proportion of the liquid in the mixture is in particular at most 25% by weight, preferably 4 to 15% by weight, particularly preferably at least 2% by weight.

[0103] The liquid comprises, in particular, a component of a carbonate-based electrolyte or a paraffin-based oil.

[0104] The liquid comprises in particular a component of a carbonate-based electrolyte, for example ethylene carbonate (C3H4O3) or diethyl carbonate (C5H 10 If the electrolyte component is used as a liquid, adhesion of the electrolyte component to the electrode membrane is not harmful and is also not harmful to the subsequent operation of the battery cell produced in this way.

[0105] In particular, ethylene carbonate can be supplemented with polypropylene carbonate so that the liquid does not assume a solid state even at relatively low temperatures.

[0106] In contrast to the known hammering methods, the proposed method in particular does not use any water for producing the mixture.

[0107] The liquid can be fed to the particles in the mixing device. The liquid and particles are mixed in particular and then provided, for example as a so-called "slurry" for feeding to the cutting device. The mixture consisting of particles and liquid can then be fed through the particle feed line.

[0108] The gas flow is conveyed to the nozzle in particular via a Venturi nozzle.

[0109] The gas flow comprises in particular (only) air. The air is compressed in particular upstream of the gas feed line, in particular to a pressure of at least 2 bar, preferably at least 5 bar; particularly preferably at most 10 bar.

[0110] A gas compressor in the form of a radially constructed centrifugal compressor can be used for this compression. Here, a dry gas (e.g. dry air) is sucked into the center of a rotating impeller with radial blades and compressed by centrifugal force. The rotation speed of the centrifugal compressor controls the gas pressure.

[0111] The gas flow is delivered to the cutting device via a gas feed line and introduced into the inlet of the Venturi nozzle (into the converging first section).

[0112] Venturi nozzles are generally known. A Venturi nozzle generally comprises a converging first section, a second section with a minimum flow cross section and a diverging third section. The Venturi nozzle has an inlet upstream of the first section and an outlet downstream of the third section. The Venturi nozzle extends over the entire length in the flow direction between the inlet and the outlet. The individual sections each extend over a length.

[0113] The Venturi nozzle consists in particular of a smooth-walled tube with a constriction of the cross section, for example by means of two cones pointing towards each other which meet at the point of their smallest diameter. When a fluid flows through the Venturi nozzle, the dynamic pressure (dynamic head) is at a maximum and the static pressure of the fluid is at a minimum at the narrowest point of the tube.

[0114] In the first section, the first air flow is accelerated to a high speed (Mach number in the range of 0.5 to 1) and expands in the diverging region of the nozzle. The speed of the first air flow at the outlet should be approximately Mach number 0.5 to 1. The pressure at the outlet is in particular equal to the ambient pressure.

[0115] The (dry) first air flow moves through the Venturi nozzle toward the outlet, wherein the pressure at the inlet is converted into a higher velocity at the outlet. The accelerated air flow is in particular delivered to the inlet of the nozzle or the ultrasonic oscillation unit.

[0116] The particle feed line opens into the first section or the third section, in particular at the inlet of the venturi nozzle, downstream of the inlet. The individual flows are regulated in particular by valves. Through the particle feed line, in particular only particles can be conveyed, if necessary supported by the gas flow, or a mixture of particles and liquid can be conveyed.

[0117] If the particle feed line opens upstream of the second section, the particles can at least be accelerated to the same velocity as the first gas flow. However, the Venturi nozzle will have a shorter service life because the fast-moving particles have an abrasive effect on the second section.

[0118] If the particle feed line opens downstream of the second section, the first gas stream has its highest velocity in the third section. The velocity of the particles is significantly lower than if it opens further upstream. However, the service life of the Venturi nozzle is longer.

[0119] In particular, the particle flow has a flow velocity of at least Mach 0.15, preferably between Mach 0.15 and 0.5, at least at the outlet.

[0120] Aluminum oxide is used in particular as particles. Aluminum oxide is ceramic, electrically non-conductive and may be present in battery cells, for example as a coating for separators. Aluminum oxide also has high hardness and high electrical resistance.

[0121] The particles have in particular a maximum diameter of at most 40 micrometers. The quality of the separating edge produced by cutting can be improved by smaller particles. The particles preferably have a maximum diameter of 10 to 30 micrometers.

[0122] The cutting device has in particular a suction device, by which particles that at least bounce back from the surface to the nozzle or particles that pass through the electrode membrane are sucked away. The suction device can be arranged at least partially adjacent to the nozzle or the ultrasonic oscillation unit. Particles that bounce back from the surface can thus be sucked away. Alternatively or additionally, at least a portion of the suction device can be arranged spaced apart from the nozzle / ultrasonic oscillation unit by the electrode membrane. Therefore, the suction device can be arranged opposite to the nozzle / ultrasonic oscillation unit, wherein the electrode membrane is arranged between the suction device and the nozzle / ultrasonic oscillation unit. In this case, particles that pass through the electrode membrane can be sucked away.

[0123] The electrode film is guided in particular on tensioning rollers and / or conveyor rollers, so that the position of the electrode film relative to the cutting device is defined. The cutting line extends in particular such that there is no support from the rollers in this region.

[0124] The roller can be designed with a surface structure such that the electrode film is tensioned both in the longitudinal direction (x direction) and in the width direction (y direction).

[0125] The electrode membrane can be supported in particular by the support device, so that in particular the distance between the outlet of the nozzle / ultrasonic oscillation unit and the surface can be set accurately. The suction device can in particular be at least partially integrated in the support device, so that the suction device is arranged opposite the outlet below the cutting line and in particular at any time during the separation.

[0126] The cutting device comprises in particular a heating device, by means of which the electrode film acted upon by the particle stream is dried. The heating device comprises in particular at least one infrared radiator, by means of which the electrode film can be heated, in particular to 105 to 125 degrees Celsius, preferably to approximately 120 degrees Celsius.

[0127] The use of a heating device makes it possible in particular to remove liquid from the mixture from the dividing edge.

[0128] The cutting device has in particular a cleaning device in which adhering particles are removed from at least one dividing edge of the electrode membrane at least by mechanical contact, for example by a brush or roller or by an ionized second air flow. Possibly electrostatically charged particles can be neutralized by the ionized second air flow and can subsequently be sucked away or blown off more easily.

[0129] The particles can be reused in particular. For this reason, the particles can be collected and sent back so that the particles can be supplied to the method again via the particle feed line.

[0130] Furthermore, a cutting device is proposed for cutting electrode films which are provided for use in battery cells. The cutting device is designed in particular for carrying out the described method.

[0131] The cutting device comprises at least one nozzle with an outlet, a cutting tool, an oscillating device for exciting at least the cutting tool to vibrate, a particle input line for conveying at least particles, and a gas input line for conveying a first gas flow. The particles and the first gas flow can be mixed in the cutting device to form a particle flow and can be conveyed to the outlet through the nozzle. The cutting tool and the outlet of the nozzle can be arranged above the electrode membrane at a distance relative to the surface of the electrode membrane, and the electrode membrane can be divided at least by the particle flow and by the vibration of the cutting tool.

[0132] In particular, a mixture of at least the particles and anhydrous liquid is conveyed via the particle feed line. The liquid is used in particular to wet the particles. As a result, the particles are more closely bound together and a rebound of particles thrown onto the surface can be reduced or prevented.

[0133] The nozzle is in particular an ultrasonic oscillation unit, wherein the cutting tool and the outlet can be excited to vibrate by the oscillating device of the cutting device. Due to the vibration, the outlet and the cutting tool move in a plane oriented perpendicularly to the surface.

[0134] Furthermore, a battery cell is proposed, which comprises at least a housing and an electrode film stack arranged in the housing, the electrode films being produced in particular by the described method and / or by the described cutting device.

[0135] Furthermore, a motor vehicle is proposed, which comprises at least a traction drive and a battery having at least one battery cell as described, wherein the traction drive can be supplied with energy by the at least one battery cell.

[0136] The method can be implemented in particular by a system for data processing, such as a controller, wherein the system has a device that is appropriately equipped, configured or programmed to implement the steps of the method or to implement the method. By means of the system, at least

[0137] · regulation of at least one first air flow;

[0138] · regulation of at least one particle flow;

[0139] Adjustment of cutting speed;

[0140] · regulation of the velocity of the particle flow; and / or

[0141] Adjustment of the oscillating device.

[0142] The cutting device comprises in particular the above-described system.

[0143] The device comprises, for example, a processor and a memory in which commands to be executed by the processor are stored, and data lines or transmission means enabling the transmission of commands, measured values, data etc. between the mentioned elements.

[0144] Also proposed is a computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out the described method or the steps of the described method.

[0145] Also proposed is a computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to carry out the described method or the steps of the described method.

[0146] The description of the method can be transferred in particular to a cutting device, a battery cell, a motor vehicle, a system for data processing and a computer-implemented method (ie a computer or a processor, a computer-readable storage medium) and vice versa.

[0147] The following advantages are achieved:

[0148] The proposed separation of the electrode film by particles enables in particular burr-free cutting;

[0149] ·No heat affected zone is produced like laser cutting;

[0150] An electrolyte component, for example ethylene carbonate (EC), can be used as liquid for the mixture; that is, even if ethylene carbonate is present at the dividing edge after drying, this is harmless;

[0151] Aluminum oxide is particularly recommended for the particles; aluminum oxide is not an electrical conductor and therefore does not cause a short circuit if the particles remain on the dividing edge;

[0152] Instead of ethylene carbonate, optionally with additives, dimethyl carbonate or paraffinic oils, optionally with additives, can be used; paraffinic oils can be mixed with alcohol for faster evaporation; using a heating device, the entire paraffinic oil can be evaporated;

[0153] The ultrasonic oscillation unit and the Venturi nozzle can be designed in an integrated manner; the component generates high speed and vibration of the particles; it can be provided as a very compact component; the Venturi nozzle can be arranged at the inlet of the nozzle / ultrasonic oscillation unit; the Venturi nozzle and the ultrasonic oscillation unit can be manufactured from tungsten carbide as a single component; the Venturi nozzle can be fixed to the inlet of the ultrasonic oscillation unit by bolts and a vibration-damping membrane if necessary; this enables good flexibility in fixing the Venturi nozzle and the ultrasonic oscillation unit; in this case, the Venturi nozzle is not excited by the ultrasonic oscillation unit;

[0154] Since the airflow is cleaning the edges at high speed, no particles can adhere to the cutting edges; the cutting edges and surfaces can be further cleaned before rolling up;

[0155] The method can be run at very high cutting speeds of about 150 m / min;

[0156] Tool wear occurs only on the cutting tools which can be easily replaced; therefore, the method is very economical;

[0157] No gas is generated like laser cutting; therefore no costly extraction is required; nor is cooling of the electrode film to reduce the heat affected zone necessary;

[0158] The method can be used for both slitting and grooving and stripping;

[0159] Produce very thin dividing edges, since fine particles with a maximum diameter of about 12 microns can be used and the vibration amplitude of the outlet can be set to about 50 microns;

[0160] By reducing speed and vibration, the same cutting device can be used to cut a variety of different electrode film materials;

[0161] Since cutting, drying and cleaning can be integrated in one machine, the cutting device requires less space;

[0162] The method is economical because the particles can be reused multiple times;

[0163] The required pressure of the first gas stream may be 6 bar, which is commonly available in the industry; therefore, there is no need to provide dry high-pressure air;

[0164] The sonotrode has two main functions: amplifying the vibration amplitude and reducing the diameter of the particle stream that hits the surface; in this way a sharp and small focus can be provided and the sonotrode gives the particles a large amplitude, so that the particle cutting action is enhanced;

[0165] The ultrasonic oscillation unit can be manufactured simply; the internal channel of the ultrasonic oscillation unit in contact with the particles can be made of tungsten carbide; this makes the welding head have good wear resistance and a long service life;

[0166] The combination of the vibration of the cutting tool and the kinetic energy of the particle stream can generate more cutting energy, for example to cut hard ceramic coatings;

[0167] The combination of the action principle (throwing mechanism or hammering action) prevents particles from bouncing back from the surface of the electrode membrane, so that no additional arrangement for collecting or sucking away the bouncing particles is required;

[0168] For the slitting, in particular a cylindrical sonotrode with a correspondingly cylindrical or conical cutting tool is used.

[0169] For cutting and detaching, in particular rectangular sonotrode units with correspondingly rectangular cutting tools are used;

[0170] When a solid cutting tool is used, the gas flow and the particles are directed to the surface via an inlet region arranged adjacent to the cutting tool, the cutting tool and the sonotrode being connected in particular via a slide valve mechanism; the sonotrode and the inlet region being connected in particular via a screw and, if necessary, a nut;

[0171] In the variant using a solid cutting tool, hammering is the more dominant cutting mechanism;

[0172] When a hollow cutting tool is used, in particular no input region is provided; the cutting tool and the ultrasonic oscillation unit are connected in particular via a slide valve mechanism; the particle flow flows out via an outlet configured on the cutting tool;

[0173] In the variant using a hollow cutting tool, the throwing mechanism is the more dominant cutting mechanism.

[0174] In particular, the use of indefinite articles ("a", "an") in the specification should be understood as such and not as a numeral. Accordingly, the terms or components introduced accordingly should be understood as occurring at least once and in particular also occurring multiple times.

[0175] It should be noted that the numbers used here ("first", "second", etc.) are primarily (only) used to distinguish between multiple identical objects, dimensions or processes and are therefore not in particular mandatory for the correlation and / or order of these objects, dimensions or processes with each other. If correlation and / or order is required, this will be explicitly stated here or will be obvious to a person skilled in the art when studying the specifically described design. If a component can appear multiple times ("at least one"), the description of one of these components can also apply to all or most of these components, but this is not mandatory. BRIEF DESCRIPTION OF THE DRAWINGS

[0176] The present invention and the technical environment are described in more detail below with reference to the accompanying drawings. It should be noted that the present invention should not be limited by the embodiments listed. In particular, if not explicitly stated otherwise, parts of the facts described in the drawings can also be extracted and combined with other components and understandings in the specification.

[0177] In particular, it should be pointed out that the drawings and in particular the dimensional ratios shown are only schematic. In the drawings:

[0178] Figure 1 A cutting device for implementing the method is shown;

[0179] Figure 2 The first working principle of the cutting device is shown;

[0180] Figure 3 The second working principle of the cutting device is shown;

[0181] Figure 4 Show according to Figure 1 A first embodiment variant of the cutting device;

[0182] Figure 5 Show according to Figure 4 A partial stereoscopic view of a cutting device;

[0183] Figure 6 Show according to Figure 4 and Figure 5 A stereoscopic diagram of an ultrasonic oscillation unit and a cutting tool of a cutting device;

[0184] Figure 7 Show according to Figure 1 A second embodiment of the cutting device;

[0185] Figure 8 Show according to Figure 7 A three-dimensional diagram of a rectangular ultrasonic oscillation unit and a cutting tool of a cutting device;

[0186] Fig. 9 Show according to Figure 7 and Figure 8 a cutting tool of a cutting device;

[0187] Fig.10 Show according to Figure 7 A perspective view of a cylindrical ultrasonic oscillation unit and a cutting tool of a cutting device; and

[0188] Fig.11 Show Fig.10 details. DETAILED DESCRIPTION

[0189] Figure 1 A cutting device 4 for carrying out the method is shown. The cutting device 4 comprises a nozzle 5 with an outlet 6, a cutting tool 7, an oscillating device 8, a particle feed line 9 for conveying at least particles 13, and a gas feed line 10 for conveying a first gas stream 12. The particles 13 and the first gas stream 12 are mixed in the cutting device 4 to form a particle stream 2 and conveyed to the outlet 6 via the nozzle 5. The outlet 6 is arranged above the electrode film 1 at a distance 11 relative to the surface 3 of the electrode film 1, and the electrode film 1 is also divided by the particle stream 2.

[0190] According to step a), an electrode film 1 having a surface 3 is provided. The electrode film 1 is provided as a continuous material. The electrode film 1 has two largest side surfaces, which have a theoretically infinite length in the x-direction, and also has a width in the y-direction and a thickness in the z-direction. The extension in the z-direction is the smallest. Here, one of the two side surfaces of the electrode film 1 constitutes the surface 3.

[0191] Furthermore, a cutting device 4 is provided, which comprises a nozzle 5 with an outlet 6, and the outlet 6 is arranged above the electrode film 1 at a distance 11 relative to the surface 3 (step b)). The nozzle 5 is used to direct the particle flow 2 toward the surface 3. The particle flow 2 flows out of the cutting device 4 through the outlet 6 of the nozzle 5 and flows toward the surface 3. The nozzle 5 is arranged at such a distance 11 from the surface 3 that there is no direct mechanical contact between the nozzle 5 and the surface 3. The cutting tool 7 can have the outlet 6, or the outlet 6 can be arranged adjacent to the cutting tool 7. The cutting tool 7 is excited to vibrate 14 by the oscillation device 8.

[0192] The cutting tool 7 contacts the surface 3 via at least one particle 13 arranged between the cutting tool 7 and the surface 3. The cutting tool 7 thus contacts the particle 13 and moves the particle 13 due to the vibration 14. The particles 13 thus excited produce a cutting action on the electrode film 1. The distance 11 between the cutting tool 7 and the surface 3 can thus be bridged by individual particles 13.

[0193] Furthermore, a particle supply line 9 and a gas supply line 10 are provided. These supply lines 9 , 10 serve to transport particles 13 and a first gas flow 12 .

[0194] According to step c), in particular a first gas flow 12 from a gas feed line 10 is introduced into the cutting device 4. According to step d), at least particles 13 from a particle feed line 9 are introduced into the cutting device 4. Further, according to step e), the first gas flow 12 and at least the particles 13 are mixed in the cutting device 4 to form the particle flow 2. The first gas flow 12 serves to transport and accelerate the particles 13, so that the particles are transported together with the gas flow 12, i.e. as a particle flow 2, through the nozzle 5 to the surface 3.

[0195] According to step f), the cutting tool 7 and the nozzle 5 are excited to perform vibrations 14 by the oscillation device 8. Due to the vibrations 14, the cutting tool 7 and the outlet 6 are moved in a plane oriented perpendicularly to the surface 3.

[0196] According to step g), the particle stream 2 flowing out of the outlet 6 is applied to the electrode film 1 and the electrode film 1 is cut. The electrode film 1 is cut continuously by the impact of the particles 13 on the surface 3. In this case, the particles 13 are thrown onto the surface 3, so that the material of the surface 3 or the electrode film 1 is squeezed out by the particles 13.

[0197] According to step h), vibrations 14 of the cutting tool 7 are applied to the electrode film 1 by means of at least one particle 13 arranged between the cutting tool 7 and the electrode film 1 in order to divide the electrode film 1 .

[0198] The nozzle 5 is an ultrasonic oscillator or is designed as an ultrasonic oscillator, wherein the outlet 6 and the cutting tool 7 are excited by an oscillation device 8. The ultrasonic oscillator as the nozzle 5 is designed to be hollow.

[0199] A mixture 19 of particles 13 and anhydrous liquid 20 is conveyed from the mixing device 28 via the particle feed line 9 by means of a pump 41 .

[0200] The first gas flow 12 is delivered to the nozzle 5 via the venturi nozzle 21. For this purpose, the first gas flow 12 is compressed upstream of the gas supply line 10. A compressor 30, for example a gas compressor in the form of a radially configured centrifugal compressor, is used for this compression. The first gas flow 12 is delivered to the cutting device 4 via the gas supply line 10 and introduced into the inlet 31 of the venturi nozzle 21 into the converging first section 33.

[0201] The venturi nozzle 21 comprises a converging first section 33, a second section 34 with a minimum flow cross section and a diverging third section 35. The venturi nozzle 21 has an inlet 31 upstream of the first section 33 and an outlet 32 ​​downstream of the third section 35. The venturi nozzle 21 extends over the entire length in the flow direction between the inlet 31 and the outlet 32.

[0202] The (dry) first air flow 12 moves through the venturi nozzle 21 towards the outlet 32, wherein the pressure at the inlet 31 is converted into a higher velocity at the outlet 32. The accelerated first air flow 12 is fed to the inlet 36 of the nozzle 5 or of the sonotrode.

[0203] The particle feed line 9 opens into the first section 33 downstream of the inlet 31. If the particle feed line 9 opens upstream of the second section 34, the particles 13 can be accelerated to the same speed as the first gas flow 12.

[0204] The individual flows, ie the flow of the first gas flow 12 and the flow of the mixture 19 , are regulated by means of valves 39 .

[0205] The cutting device 4 has a suction device 24, through which the particles 13 that bounce back from the surface 3 to the nozzle 5 and the particles 13 that pass through the electrode film 1 are sucked away. The suction device 24 is partially arranged adjacent to the nozzle 5 or the ultrasonic oscillation unit. Therefore, the particles 13 that bounce back from the surface 3 can be sucked away. In addition, a part of the suction device 24 is arranged with the nozzle 5 spaced apart by the electrode film 1. Therefore, the suction device 24 is also arranged opposite to the nozzle 5, wherein the electrode film 1 is arranged between the suction device and the nozzle. In this case, the particles 13 that pass through the electrode film 1 can be sucked away.

[0206] The electrode film 1 is guided on the tensioning roller 37 and the transport roller 37, so that the position of the electrode film 1 relative to the cutting device 4 is defined. The cutting line extends in such a way that there is no support from the roller 37 in this region.

[0207] The electrode film 1 is supported by the support device 29 so that the distance 11 between the outlet 6 of the nozzle 5 and the surface 3 can be set accurately. The suction device 24 is designed to be at least partially integrated in the support device 29 so that the suction device 24 is arranged opposite the outlet 6 below the cutting line and at any time during the separation.

[0208] The cutting device 4 comprises a heating device 22, by means of which the electrode film 1 acted upon by the particle stream 2 is dried. The heating device 22 can be used to remove the liquid 20 in the mixture 19 from the dividing edge 26 (see Figure 4 ) removed.

[0209] The cutting device 4 has a cleaning device 25, in which adhering particles 13 are removed from the separating edge 26 of the electrode film 1 by mechanical contact, for example by a brush or roller or by an ionized second gas flow 27. Possibly electrostatically charged particles 13 can be neutralized by the ionized second gas flow 27 and can then be sucked away or blown off more easily.

[0210] The particles 13 are reused. To this end, the particles 13 are collected at least by means of a suction device 24 and fed back to a mixing device 28 for the mixture 19 so that they can be conveyed again via the particle feed line 9 to the Venturi nozzle 21.

[0211] Certain components of the cutting device 4 may be controlled by the controller 38 .

[0212] Figure 2 The first principle of action of the cutting device 4 is shown. Figure 1 Description.

[0213] In the case of the first principle of action, the throwing mechanism, the first air flow 12, which may vibrate, carries the particles 13 that have an abrasive effect. The particle flow 2 flows through the cavity 15 of the nozzle 5 designed as an ultrasonic oscillation unit and is excited by the vibration 14 of the excited ultrasonic oscillation unit. The particles 13 begin to vibrate in the first air flow 12. Both the first air flow 12 and the particles 13 are thrown onto the cutting area of ​​the surface 3 in the form of a sharp abrasive air knife. Here, the focus of the abrasive air knife can be designed to be very small. Cutting is achieved by the kinetic energy of the particles 13 transported by the first air flow 12 and the vibration energy when necessary.

[0214] Figure 3 A second operating principle of the cutting device 4 is shown. Figure 1 and Figure 2 Description.

[0215] In the case of the second principle of action, the hammering method, cutting is achieved by vibration excitation and abrasive particles 13. Here, the abrasive is distributed over the cutting area (here the surface 3) and is set into vibration 14 by the vibrating cutting tool 7. Therefore, there is an interaction between the cutting tool 7 and the electrode film 1. Cutting is achieved by the vibration energy of the cutting tool 7 and by the abrasive action of the particles 13 arranged between the cutting tool 7 and the surface 3 and moved by the cutting tool 7.

[0216] Figure 4 Show according to Figure 1 A first embodiment variant of the cutting device 4 is provided. Figure 5 Show according to Figure 4 A partial three-dimensional view of the cutting device 4. Figure 6 Show according to Figure 4 and Figure 5 The following is a three-dimensional diagram of the ultrasonic oscillation unit and the cutting tool 7 of the cutting device 4. Figures 4 to 6 . Please refer to Figures 1 to 3 Description.

[0217] The nozzle 5 is an ultrasonic oscillation unit or is designed as an ultrasonic oscillation unit, wherein the outlet 6 and the cutting tool 7 are excited by the oscillation device 8. The ultrasonic oscillation unit is designed as a hollow nozzle 5. The outlet 6 is constructed adjacent to the cutting tool 7. The particle flow 2 is introduced through the cavity 15 of the ultrasonic oscillation unit and then transported to the input area 23 arranged adjacent to the cutting tool 7. The particle flow 2 is guided to the cutting area through the input area 23. The cutting tool 7 is designed as a solid component, that is, not hollow. The input area 23 is connected to the ultrasonic oscillation unit and is excited by the ultrasonic oscillation unit.

[0218] The cavity 15 of the sonotrode is formed by a plurality of channels, through which the first gas flow 12 and the particles 13 together as a particle flow 2 can be conveyed to the cutting region.

[0219] The ultrasonic oscillator is designed in a rectangular shape, wherein the cutting tool 7 as a solid component is also designed in a rectangular shape. The cutting tool 7 and the ultrasonic oscillator can be connected to each other via a slide valve mechanism. The cutting tool 7 has a closed tip 17 facing the electrode membrane 1.

[0220] The oscillation device 8 comprises a transducer (piezoelectric or magnetostrictive) to which a high-frequency electrical signal is transmitted. The transducer converts the electrical signal into a low-frequency mechanical vibration 14 with a small amplitude 16. Basically, the transducer thus converts electrical energy into mechanical vibration 14. The mechanical vibration 14 is then transmitted to the hollow ultrasonic oscillation unit.

[0221] The mechanical vibrations have a small amplitude 16 in the region of the converter (see diagram on the right). The main function of the sonotrode is to amplify these vibrations 14.

[0222] The (sound wave) converter is provided in the form of a ring and is arranged in the region of the nozzle 5 or the inlet 36 of the sonotrode. Only the sonotrode is excited by the converter. The inlet 36 of the cavity 15 of the nozzle 5 or the sonotrode thus receives the amplitude 16 of the sound wave converter of the oscillation device 8.

[0223] Calculating the required length 40 of the sonotrode, i.e. between the inlet 36 and the outlet 6, is one of the most important parts of the sonotrode design. In order to minimize losses and transfer the maximum energy of the ultrasonic probe or the transducer to the sonotrode, the sonotrode should resonate with the operating frequency of the ultrasonic probe of the oscillation device 8. The length 40 of the sonotrode should be equal to an odd multiple of half the wavelength (λ / 2) of the vibration 14 of the transducer. The length 40 is set so that the amplitude 16 of the vibration 14 is maximum at the outlet 6 or the tip 17 of the cutting tool 7, i.e. there should be an antinode of the vibration 14. The node of the vibration 14 is arranged at the inlet 36.

[0224] The distance 11 between the surface 3 and the outlet 6 should in particular be equal to a multiple of the wavelength of the transducer's vibrations 14. The amplitude 16 of the vibrations 14 is therefore greatest at the focus of the particle flow 2 on the surface 3.

[0225] Figure 7 Show according to Figure 1 A second embodiment variant of the cutting device 4 is provided. Figure 8 Show according to Figure 7 A three-dimensional view of a rectangular ultrasonic oscillation unit and a cutting tool 7 of a cutting device 4 is shown. Fig. 9 Show according to Figure 7 and Figure 8 The cutting tool 7 of the cutting device 4 is described below together Figures 7 to 9 . Please refer to Figures 1 to 6 Description.

[0226] The nozzle 5 is an ultrasonic oscillation unit or is designed as an ultrasonic oscillation unit, wherein the outlet 6 and the cutting tool 7 are excited by the oscillation device 8. The ultrasonic oscillation unit is designed as a hollow nozzle 5. The outlet 6 of the nozzle 5 is constructed on the cutting tool 7. The particle flow 2 flows out from the outlet 6 arranged at the tip 17 of the cutting tool 7. The tip 17 has a width 18. The cutting tool 7 is designed to be hollow and connected to the cavity 15 of the ultrasonic oscillation unit. The particle flow 2 is introduced to the surface 3 through the cavity 15 in the ultrasonic oscillation unit and the hollow cutting tool 7. The tip 17 of the cutting tool 7 is oriented toward the surface 3 of the electrode film 1 and is arranged closest to the surface 3. The cutting tool 7 extends away from the surface 3 from the tip 17.

[0227] The ultrasonic oscillation unit is designed in a rectangular shape, wherein the cutting tool 7 is also designed in a rectangular shape. The cutting tool 7 and the ultrasonic oscillation unit can be connected to each other via a slide valve mechanism.

[0228] Fig.10 Show according to Figure 7 A three-dimensional view of the cylindrical ultrasonic oscillation unit and the cutting tool 7 of the cutting device 4. Fig.11 Show Fig.10 The following describes the details together Fig.10 and Fig.11 . Please refer to Figures 7 to 9 Description.

[0229] Here, the ultrasonic oscillation unit and the cutting tool 7 are designed to be cylindrical or conical. The cutting tool 7 and the ultrasonic oscillation unit can be connected to each other through a slide valve mechanism. The cutting tool 7 is designed to be hollow and connected to the cavity 15 of the ultrasonic oscillation unit.

[0230] Reference numerals list

[0231] 1 Electrode membrane

[0232] 2 Particle Flow

[0233] 3 Surface

[0234] 4 Cutting device

[0235] 5 Nozzle

[0236] 6 Exit

[0237] 7 Cutting tools

[0238] 8 Oscillating device

[0239] 9 Particle input line

[0240] 10 Gas input pipeline

[0241] 11 Distance

[0242] 12 First Airflow

[0243] 13 particles

[0244] 14 Vibration

[0245] 15 Cavity

[0246] 16 Amplitude

[0247] 17 Tip

[0248] 18 Width

[0249] 19 Mixture

[0250] 20 Liquid

[0251] 21 Venturi nozzle

[0252] 22 Heating device

[0253] 23 Input Area

[0254] 24 Suction device

[0255] 25 Cleaning device

[0256] 26 Split Edge

[0257] 27 Second Airflow

[0258] 28 Mixing device

[0259] 29 Support device

[0260] 30 Compressor

[0261] 31 Entrance

[0262] 32 Exit

[0263] 33 First Segment

[0264] 34 Second Section

[0265] 35 Section 3

[0266] 36 Entrance

[0267] 37 rollers

[0268] 38 Controller

[0269] 39 valve

[0270] 40 Length

[0271] 41 Pump

Claims

1. A method for cutting an electrode film (1) at least by a particle flow (2), wherein the electrode film is arranged to be applied to a battery cell; wherein: The method is implemented by a cutting device (4), which comprises at least one nozzle (5) with an outlet (6), a cutting tool (7), an oscillating device (8), a particle feed line (9) and a gas feed line (10), and comprises at least the following steps: a) providing an electrode film (1) having a surface (3); b) arranging the cutting tool (7) and the outlet (6) above the electrode membrane (1) at a distance (11) from the surface (3); c) introducing a first gas flow (12) from the gas input pipeline (10) into the cutting device (4); d) introducing at least the particles (13) from the particle feed line (9) into the cutting device (4); e) mixing the first gas flow (12) and at least the particles (13) into a particle flow (2) in the cutting device (4); f) exciting at least the cutting tool (7) or additionally the nozzle (5) to vibrate (14) via the oscillation device (8); g) applying a particle flow (2) flowing out of an outlet (6) to the electrode membrane (1), thereby dividing the electrode membrane (1), and h) applying vibration (14) of the cutting tool (7) to the electrode film (1) through at least one particle (13) arranged between the cutting tool (7) and the electrode film (1), thereby dividing the electrode film (1).

2. The method according to claim 1, wherein: The nozzle (5) is an ultrasonic oscillation unit, wherein the outlet (6) is excited to vibrate by the oscillation device (8).

3. The method according to claim 2, characterized in that The ultrasonic oscillation unit is designed with a cavity (15), and the particle flow (2) is conveyed to the outlet (6) through the cavity (15).

4. The method according to claim 2 or 3, wherein: The outlet (6) is formed on the cutting tool (7).

5. The method according to claim 2 or 3, wherein: The outlet (6) is configured adjacent to the cutting tool (7).

6. The method according to claim 1, wherein: The vibration (14) has an amplitude (16) of at most 80 micrometers, or the frequency of the vibration (14) is between 5 kHz and 50 kHz.

7. The method according to claim 1, characterized in that The cutting tool (7) has a closed tip (17) facing the electrode film (1) and having a minimum width (18) of 0.2 to 1.5 millimeters.

8. The method according to claim 1, wherein: A mixture (19) consisting of at least the particles (13) and a water-free liquid (20) is conveyed through the particle feed line (9).

9. The method according to claim 8, characterized in that The proportion of the liquid (20) in the mixture (19) is at most 25% by weight.

10. The method according to claim 8 or 9, wherein: The liquid (20) includes a carbonate-based electrolyte component or a paraffin-based oil.

11. The method according to claim 1, wherein: At least the first gas flow (12) is conveyed through a Venturi nozzle (21) of the nozzle (5).

12. The method according to claim 1, wherein: The particle flow (2) has a flow velocity of at least Mach 0.15 at least at the outlet (6).

13. The method according to claim 1, wherein: The cutting device (4) comprises a heating device (22) by means of which the electrode film (1) acted upon by the particle flow (2) is dried.

14. A cutting device (4) for cutting an electrode film (1), the electrode film being arranged to be applied to a battery cell, the cutting device comprising at least a nozzle (5) having an outlet (6), a cutting tool (7), an oscillating device (8) for at least exciting the cutting tool (7) to vibrate (14), a particle input pipeline (9) for conveying at least particles (13), and a gas input pipeline (10) for conveying a first gas flow (12), wherein: The particles (13) and the first air flow (12) can be mixed in the cutting device (4) to form a particle flow (2) and can be conveyed to an outlet (6) through the nozzle (5), wherein the cutting tool (7) and the outlet (6) can be arranged above the electrode film (1) at a distance (11) from the surface (3) of the electrode film (1) and are designed in such a way that the electrode film (1) can be divided at least by the particle flow (2) and by the vibration (14) of the cutting tool (7), wherein the vibration of the cutting tool is applied to the electrode film by at least one particle arranged between the cutting tool and the electrode film.

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