EP4476373A1 - Method and facility for recycling battery cells or parts thereof - Google Patents

Abstract

The invention relates to a method and a facility (20) for recycling rechargeable battery cells (Z) or parts thereof which have electrolyte, lithium, and films provided with coating material, namely cathode films with a coating made of a cathode material and anode films with a coating made of an anode material. According to the method, - the cells (Z) are mechanically pre-comminuted in a shredder stage, in particular in a liquid medium (W), and a shredder fraction (S1) is obtained, - the shredder fraction (S1) is then rinsed in a pre-separation stage using a mechanical separator (24), in particular a stirring element under the effect of mechanical energy and using a liquid medium (W), thereby individualizing the films and rinsing out constituents of the shredder fraction (S1), such as electrolyte, coating material, and lithium, wherein the constituents are accumulated in the liquid medium (W), and a separator fraction (S2) is obtained in the pre-separation stage, and - the separator fraction (S2) is then further prepared in at least one separation stage.

Description

Description

Method and system for recycling battery cells or parts thereof

The invention relates to a method and a system for recycling battery cells or parts thereof. These cells or parts thereof have, among other things, electrolytes and films provided with a coating, namely cathode films with a coating of cathode material, and anode films with a coating of anode material. Depending on the battery type, the cells or parts thereof have additional components, in the case of lithium batteries, lithium, in the case of NiMH batteries, nickel (nickel hydroxide) and a metal hydride.

As the use of lithium batteries in particular for electromobility increases, the focus is increasingly on recycling such batteries, especially in the motor vehicle industry.

DE 10 2019 218 736 A1 discloses a method for material-selective disassembly of lithium-ion batteries, in which the components are placed in a container filled with a liquid and comminuted and separated using an electrohydraulic effect. Here, a pulsed current source is used to generate a shock discharge within the liquid within an underwater spark gap between a ground electrode and a high-voltage electrode. This shock discharge separates the coating material of the foils, i.e. the anode material or the cathode material, at least in sections. In subsequent cutting and separation steps, the films and the coating materials can then be obtained separately from one another and reused. In general, battery cells consist of an anode, a cathode, a separator, an electrolyte and a housing. The anode and cathode are each typically formed by a film provided with a coating. On the anode side, this is typically a copper foil (anode foil) coated with graphite as anode material. On the cathode side, this is typically an aluminum foil (cathode foil), which is typically coated with a coating, for example with a lithium-nickel-cobalt-manganese mixed oxide (NMC) as the cathode material. Alternatively, a coating made of LiCoO, NiCoO, LiFePO4 or other known coating materials is applied. The layer thickness of the film coatings is typically in the range of around 50 pm.

The electrolyte used in a lithium-ion battery (LIB) often consists of a conductive salt and a mixture of highly volatile solvents and less volatile solvents, some of which are also solid at room temperature. The conductive salt only has a proportion of a few percent in the electrolyte, for example only one percent by volume. For example, a LiPF 6 (lithium hexafluorophosphate) is used as the conductive salt.

When the battery is charging, lithium ions migrate from the cathode through the separator foil to the anode and are deposited there. During the discharging process, the lithium ions migrate from the anode to the cathode and are integrated back into the cathode material. While the lithium ions are firmly bound in the cathode material, they are bound on the anode side with only low forces and are largely free in the electrolyte.

When recycling batteries, a rough mechanical disassembly is typically carried out first, which can be done manually. Batteries typically consist of several modules interconnected, which in turn have several of the cells described above. During mechanical pre-shredding, the cells are preserved, which are then fed into the actual recycling process. Based on this, the invention is based on the object of enabling the most efficient recycling of batteries or battery cells, especially lithium-ion batteries (cells) or parts thereof, with the highest possible recovery rate of different valuable materials contained in the cell.

The object is achieved according to the invention by a method and a system for recycling battery cells or parts thereof. The battery cells are in particular cells of a lithium-ion battery. The advantages and preferred configurations listed below with regard to the method can also be applied analogously to the system and vice versa.

If batteries are mentioned here, this refers in particular to accumulator batteries.

The system has a shredding stage, preferably with a mechanical shredder, which ensures mechanical pre-shredding of the cells. This is, in particular, wet shredding using a liquid medium. A (wet) shredder faction is available at the exit of the shredder stage. Through mechanical pre-shredding, especially shredding, the films are exposed and separated from the cell housing. In the present case, shredders are generally understood to mean devices with the help of which mechanical shredding devices, such as grinders, shearing mills, cutting mills, hammer mills, etc. are carried out. In the broader sense, this also includes rotary shears, guillotines, etc.

The films contained in the shredder fraction preferably have a size in the range from 0.3 cm to 10 cm. This size is particularly suitable for the downstream electro-hydraulic separating device.

Following the shredder stage, the system has a pre-separation stage with a mechanical separator, which is designed in particular as a stirrer. The shredder fraction is used in particular together with the liquid Medium in this mechanical separator is flushed under the influence of mechanical energy with the help of a liquid medium, in particular the liquid medium from the shredder stage, which is hereinafter referred to as process water without limiting generality. The mechanical action in combination with rinsing with the process water achieves several advantages: On the one hand, there is an advantageous separation of the films, which are still tightly packed in the cell. This means that the surfaces of the films are more accessible in the subsequent process steps and the subsequent separation and recycling steps can therefore be carried out with less effort and more efficiently.

At the same time, studies have shown that - in addition to washing out the electrolyte - at least part of the anode material, i.e. in particular the graphite, is also advantageously removed from the anode foils and absorbed into the process water. This also results in improved efficiency of the subsequent recycling steps.

Finally, rinsing - in the case of lithium-ion batteries - also absorbs the unbound lithium or ions in the process water. At the end of the mechanical separator there is a wet separator fraction. This contains the process water with the components it contains as well as the shredded films that are at least partially still provided with the coating material.

This separator fraction is subsequently fed to at least one further separation stage and further processed there. Specifically, it is fed to an electro-hydraulic separating device, such as that from

DE 10 2019 218 736 A1 can be found. In this separation stage, in particular, there is a division into one or more coarse fractions, which in particular contain film and housing parts, and into a fine fraction, which has process water with particles floating in it. The system is designed at least for recycling cells or parts thereof. Modules or complete batteries can also be fed into the system for recycling. For this purpose, the shredder stage is preceded by at least one disassembly stage, for example, in which the modules or batteries are disassembled and shredded in advance. Alternatively, larger units, such as modules, are fed to the shredder stage and shredded there.

The mechanical separator is preferably designed as a stirrer which has an agitator. The stirrer generally comprises a container into which the shredder fraction is introduced. The agitator rotates within the container while simultaneously introducing the liquid medium, which is sprayed in, for example. Alternatively or in addition, the container is at least partially filled with the process water, so that the stirring takes place directly in the process water. The stirrer easily introduces mechanical energy, which leads to the desired separation of the anode material from the anode foils. This also supports the washing out of the lithium. Finally, the mechanical movement of the agitator leads to the desired separation of the films in a particularly efficient manner.

As an alternative to a stirrer with an agitator, other combined rinsing and separating devices are also possible, for example a rotating drum can be provided and/or the process water is jetted onto the shredder fraction using high pressure through appropriate nozzles, so that the desired separation and rinsing is achieved by the jet pressure of the water.

The mechanical separator is preferably arranged directly below the shredder, so that the shredder fraction can enter the mechanical separator from above.

The residence time of the shredder fraction within the mechanical separator, i.e. specifically the stirring time, is typically in the range of a few minutes, for example 20 seconds to 5 minutes. In a preferred embodiment, the wet separator fraction is dewatered, for which at least part of the liquid medium with the components contained therein (particles and dissolved substances) is separated off. After dewatering, a dewatered separator fraction is available for further treatment specifically in the electrohydraulic separating device. The particular advantage of this dewatering is that, among other things, the ions contained in the process water, such as lithium ions, are removed, so that the proportion of these conductive elements is reduced for the subsequent process step. Studies have shown that the operation and efficiency of the subsequent electro-hydraulic separating device is impaired as the conductivity increases. The conductivity is generally largely determined by ions dissolved in the process water. In general, this upstream dewatering has particular advantages for subsequent wet separation steps using electrical processes.

For dewatering, for example, a sieve device is used through which the process water can pass and the dewatered separator fraction remains.

In a preferred embodiment, dewatering takes place via a conveyor device, specifically a screw conveyor, via which the separator fraction is transported to the subsequent recycling stage. The conveyor device is in particular inclined so that the process water can drain downwards against the conveying direction and be collected there. This achieves particularly simple and efficient drainage without the need for an additional drainage device.

In a preferred development, components contained therein are recovered from the separated process water (liquid medium). In particular, lithium and/or anode material (graphite) is recovered from the separated process water. This is done in particular in a suitable treatment device for the process water (liquid medium), which is preferably as treated process water is (re)fed to the mechanical separator (e.g. stirrer) and in particular to the shredder stage as the liquid medium. This already achieves a very simple and efficient (partial) recovery of lithium and/or graphite.

For the treatment, for example, a portion of the separated process water is fed to the treatment device either continuously or repeatedly via a branch line. Alternatively, the entire separated process water is continuously fed to the treatment device.

As already stated above, the pre-shredding in the shredder stage is preferably carried out in a liquid medium.

According to an alternative embodiment, only dry pre-shredding takes place without adding a liquid medium. The submission of a correspondingly amended claim 1 without liquid medium in the shredder stage, in which the cells are dry-shredded in the shredder stage, remains reserved.

With the preferred wet shredding, either the liquid medium is sprayed into the pre-shredding system, i.e. specifically the shredder, or it is filled with the liquid medium. This pre-shredding in a liquid medium, generally water or an aqueous solution, has the advantage that the released electrolyte components and, for example, free (lithium) ions are immediately bound. This wet shredding process has the following additional advantages over conventional, dry shredding processes:

- Due to the immersion of the cells or parts thereof to be recycled in the process water, no protective gas atmosphere is initially required and is not intended, as the process water effectively prevents fires from occurring in partially still charged batteries. - This procedure ensures a dust-free shredding process.

- Furthermore, operation preferably takes place at room temperature, whereas dry shredding processes usually require high temperatures of 80 °C or more to separate the electrolytes from the gas phase.

- Due to wet shredding, the electrolytes, the conductive salt contained therein and the (free) lithium ions are absorbed and/or dissolved in the process water during the shredding stage. In contrast to this, in dry shredding processes only volatile gases are separated, whereas the semi-volatile components of the electrolyte and the conductive salts dry out and are passed through the recycling process with the so-called black mass, i.e. the separated solids. This leads to the latent risk of hydrofluoric acid (HF) formation.

- Another advantage of the wet process is that the electrolytes are retained in their chemical structure. They are preferably recycled and reused when necessary.

- A particular advantage is that lithium is absorbed into the process water in an early process step and can therefore be obtained.

- Finally, residual electrical energy contained in the cell can easily be discharged within the process water. On the one hand, this means that, in contrast to conventional processes, a previous discharge of the battery can be dispensed with and is preferably dispensed with. In addition, the heat absorbed by the process water can be used as process heat in the system itself.

The comminution in the shredder stage in a liquid medium - regardless of the use of the mechanical separator, especially in the form of a stirrer - is viewed as an independent invention and the filing of a divisional application in this regard remains reserved. The essential steps here are comminution in a liquid medium to achieve a wet one Shredder fraction, feeding the shredder fraction to a downstream recycling stage, especially an electro-hydraulic separating device, in particular without the interposition of the mechanical separator (stirrer).

A combination of features analogous to claim 1, but in which the feature of the pre-separation stage is not fulfilled, is therefore also considered to be independently inventive. All other advantages and preferred embodiments described here can be combined with this.

These advantages previously described in connection with wet shredding also apply in particular to the previously described wet pre-separation stage using the mechanical separator.

The liquid medium is generally preferably water. This is fed to the shredder stage in particular continuously. The water is preferably removed from the shredder together with the shredder fraction and fed to the mechanical separator as a wet shredder fraction.

If we are talking about water here, this means that at least largely pure water is supplied to the process, i.e. specifically to the shredder stage or the pre-separation stage. The proportion of water is at least 98%, preferably at least 99%. The remainder can be, for example, ions, minerals, etc. contained in the water. The water used is, for example, tap water or deionized or distilled (pure) water. The water supplied preferably has an at least largely neutral pH value, which is therefore preferably in the range between 6.5 and 7.5 and preferably 7.0 +/- 0.2. The process water supplied is therefore not an acid or an alkali. No acid or alkali is added to the water and - in addition to the cells or parts thereof to be shredded - none are added Additions are introduced, for example to react with the water, for example to form an acid or alkali.

The use of normal water allows for a cost-effective, simple process overall.

Shredding and/or pre-separation in the pre-separation stage continue to preferably take place at ambient temperature. Neither active cooling by a cooling device nor active heating by a heating device is provided.

Overall, a large amount of liquid medium, in particular water, is preferably used for the mechanical separator and in particular for the shredder stage. The proportion by weight of the water is preferably at least a factor of 10, more preferably by at least a factor of 30 and in particular by at least a factor of 50 greater than the proportion by weight of the cells or parts of the cells. This large amount means that the above-mentioned advantages of wet treatment are achieved particularly well.

Shredding is preferably carried out under water, i.e. the material to be shredded is completely immersed in a water bath. The same preferably also applies to the further treatment, in particular stirring, in the pre-separation stage.

A total of a wet shredder fraction is removed from the shredder stage and preferably fed directly to the pre-separation stage and the mechanical separator without further treatment. The ratio of water to the shredded portions of the cells is preferably the same as that stated above for the shredding stage. Process water is therefore preferably constantly supplied to the shredder stage and removed again in the same amount together with the shredded portions and fed to the pre-separation stage as the wet shredder fraction. As already stated above, due to the wet treatment, discharging the battery and thus the cells is not necessary and is not provided in a preferred embodiment. This eliminates the need for an otherwise necessary discharge step. In addition, depending on the state of charge, this makes it possible to obtain a high proportion of lithium via the process water.

In order to recover the highest possible lithium content in a simple manner, an expedient design provides that the batteries/cells are brought to a defined state of charge before the battery and cells are shredded, i.e. in particular before the shredding stage. For this purpose, in particular, a charging process for the battery is provided. The defined state of charge is, for example, at least 30%, at least 50%, at least 75% or at least 90% or 100% of a maximum state of charge. The higher the charge level, the more free lithium ions are present and can be washed out with the process water. State of charge (SOC) is generally understood to be the current capacity of a battery as a percentage of its maximum capacity. The maximum capacity of a battery indicates the maximum amount of electrical charge that the battery can store. It is typically given in amp hours (Ah).

This measure for recovering lithium is viewed as an inventive aspect in its own right. The right to file a divisional application based on this remains reserved. The essential procedural steps for this are:

- shredding, especially shredding in a wet environment (in process water)

- -subsequent separation of the process water with subsequent recovery of the lithium.

In a preferred development, this is done in particular with non-discharged batteries and in particular - as described above - the setting of a defined state of charge is provided. All others within the scope of this registration Process steps described are combined with this concept individually or in combination in preferred further training.

As already mentioned several times, the dewatered separator fraction - or in the case of a variant in which the pre-separation stage is omitted, a dewatered shredder fraction - is fed in a (first) separation stage to the already mentioned (first) electro-hydraulic separation device . This generally has a bath filled with a liquid medium (process water) into which the dewatered separator fraction is introduced. The separating device is constructed in particular according to DE 10 2019 218 736 A1. It has a ground electrode and a high-voltage electrode, which are controlled in a suitable manner so that regular shock discharges are generated. In addition to shredding the introduced fraction, these also lead to the separation of the coating material from the film. By setting the process parameters (pulse duration of the shock discharges, pulse energy, etc.), the coating material can be specifically removed either from the anode foil or from the cathode foil. In the first separation stage, the corresponding coating material is therefore typically only separated from one film material. As mentioned above, this is preferably the anode material, specifically graphite. At the end of the first separation stage there is a first separation fraction.

In a preferred development, this first separation fraction, which is in particular a wet fraction, is separated into a coarse fraction and a fine fraction. The coarse fraction has coarse film parts and the fine fraction has the separated coating material as well as other fine parts, such as film parts. These parts of the fine fraction are contained in particular in the process water. The two fractions (coarse fraction and fine fraction) are then further processed separately.

As part of this further processing, the two different film fractions of the coarse fraction, which are obtained in the first separation stage were separated from each other and the film fraction, which still has its coating, i.e. specifically the cathode film with the cathode material (e.g. NMC), is fed to a second separating device in a second separation stage, for which in particular an electrohydraulic (second) separating device is used. This is basically constructed similarly or identically to the first electrohydraulic separating device, with preferably only the process parameters being changed and set in such a way that the cathode material is separated from the cathode foil.

As a result, the cathode material, specifically NMC, is separated from the previously separated cathode foil fraction and preserved in great purity. This is subsequently recovered from the process water.

To separate the different components of the first separation fraction, dewatering, in particular also of the coarse fraction, with subsequent sorting into the two film fractions is preferably provided. In principle, sorting can also be carried out wet without prior drainage. A centrifuge is preferably used to dewater the coarse fraction.

According to a useful further development, parts of the fine fraction in the process water and/or the second separation fraction (i.e. especially anode particles (graphite) and/or cathode particles (NMC)) are fed to a further comminution stage and a (further) comminution device, which is formed in particular by an electro-hydraulic separation device. A crushed fine fraction is obtained.

For example, the parts of the fine fraction or parts of the second separation fraction are again fed to the previous separation stage, in particular to the previous electro-hydraulic separation device. However, these parts are preferably fed to an additional, further shredding device, specifically a further electro-hydraulic separating device. The parts are in particular the rough parts of the respective faction. In order to feed these to the (further) comminution device separately from the finer parts, the respective fraction is preferably first classified into different size classes, especially into a coarse fine fraction, a fine fine fraction and a very fine fraction, in order to then only classify the coarser parts, in particular the coarse ones To feed the fine fraction to the (further) comminution stage and to obtain the shredded fine fraction.

This embodiment is based on the consideration that the fine fraction of the first separation fraction after the first separation stage (after the first electro-hydraulic separation device) or also the second separation fraction after the second separation stage (after the second electro-hydraulic separation device) are still comparatively large parts (greater than 50pm, in particular greater than 250pm ) of the comminuted particles (anode material / cathode material) to which at least some other components still adhere. This is in particular a binder, such as PVDF or CMC, which holds the individual particles of the anode/cathode material together. Alternatively or additionally, this is a so-called carbon black, in particular a type of amorphous graphite, which is electrically conductive and which ensures that the current in the cells is conducted through the coating to the respective film. The proportion of binder or carbon black is, for example, between 2% and 5%.

The comminuted fine fraction then preferably has a homogeneous particle size and generally preferably a particle size of less than 50 pm and in particular of less than 40 pm or less than 30 pm. Through further comminution, the undesirable adhering components (binder and conductive carbon black) are removed and the particles of the coating material (anode material, graphite, cathode material, NMC) are largely kept pure.

In a preferred development, it is provided that one or more of the fractions selected from the fine fraction of the first separation stage, the second separation fraction, the classified fractions obtained or the comminuted fine fraction are fed to a subsequent separation stage. Specifically, the fine fraction, or one or more of the classified fractions obtained from this or the comminuted fraction(s) obtained are fed to the further separation stage. In this, different types of particles, in particular particles of the anode material and particles of the cathode material, are separated and separated from one another.

This is based on the consideration and knowledge that, especially in the first separation stage, the fine fraction obtained is not sufficiently pure, i.e. in the fine fraction there are not only the particles of one coating material (typically the anode material, graphite) but also particles of the other coating material (typically cathode material, NMC contained. The further separation stage therefore results in a further separation of the two coating materials from each other.

The further separation is preferably carried out using a centrifuge or using a so-called flotation process.

It is particularly advantageous if, before this further separation, the fractions were treated with the (further) comminution device and the comminuted fine fraction was produced, which is then fed to the further separation stage.

By means of the further comminution device, the particles are generally comminuted to a size that is as uniform as possible, which simplifies the subsequent separation of the cathode and anode particles.

As already mentioned, a further (third) electro-hydraulic separating device, as already described above, is preferably used as the (further) shredding device.

Such an electro-hydraulic separating device crushes the introduced material using the shock waves and is able to reduce the particle size. division to homogenize or to separate different (interconnected) types of particles from one another. Depending on the treatment duration and/or pulse energy, the fractions vary in size. The preferred aftertreatment described here therefore deliberately exploits this comminution function in order to obtain the most uniform particle size distribution possible. The fine fraction prepared, homogenized and comminuted in this way is then preferably dewatered and the different components (types of particles) are separated and separated from one another.

These aspects, on the one hand the downstream comminution by means of the (further) comminution device and on the other hand the downstream further separation stage and in particular their combination, are in turn viewed as independent inventive aspects and the filing of divisional applications in this regard remains reserved. The essential steps for the further shredding stage are:

- feeding the fine fraction obtained from a separation stage to a comminution device, in particular to a further, preferably electrohydraulic, separation and comminution device for producing a comminuted fine fraction,

- preferably subsequent dewatering and separation of different types of particles in a further separation stage, in particular with the help of a centrifuge or in a flotation or sedimentation process.

The essential steps for the further separation stage are:

- feeding the fine fraction obtained from a separation stage (specifically from the first separation stage) to a further separation stage, in particular after dewatering, the further separation stage being formed in particular by a centrifuge or a flotation process,

- Preferably classifying the fine fraction obtained from the separation stage in advance into several classified fine fractions, with several and / or each of the classified fine fractions being fed to the further separation stage. In a preferred development, the system has several circuits for the liquid medium, which can also be at least partially combined with one another.

In particular, a first circuit is provided in which at least the shredder and/or the mechanical separator (stirrer) are integrated. A portion of the graphite and in particular a portion of the lithium is contained in the process water of the first circuit and is recovered from it.

The second circuit includes in particular the first separation stage with the electro-hydraulic first separation device and the third circuit includes the second separation stage with the second electro-hydraulic separation device.

The latter two circuits are preferably coupled to one another, in particular in such a way that the process water of the third circuit is fed to the second circuit and used there and that the process water is cleaned after passing through the second circuit.

An exemplary embodiment of the invention is explained in more detail below with reference to the figures. These show in simplified representations:

1 shows a partial representation of a system for recycling battery cells in the area of a shredder and a stirrer, which are integrated in a first process water circuit,

2 shows a partial representation of the system in the area of a first electro-hydraulic separating device, which is integrated in a second process water circuit

3 shows a partial representation of the system in the area of a second electro-hydraulic separating device, which is integrated in a third process water circuit

Parts of a coherent system 20 are shown in FIGS. 1-3. 1 shows a first section in which the items to be recycled Cells Z, in particular lithium cells of a lithium-ion battery, are subjected to pre-shredding and pre-separation.

In this first section, the system has a shredder 22, a stirrer 24 and a conveyor 26 as essential components. A liquid medium, referred to here as process water W, is guided in a first circuit K1. Several pumps, valves and collecting or collection containers 28 are arranged in this. Furthermore, a processing device 30 for processing the process water W and in particular for recovering components of the cells Z is shown as a kind of black box in FIG. In particular, this processing device 30 is used to recover lithium and/or graphite. In general, this device is coupled in after sieve and/or filter stages. The sieve or filter stages are preferably used to filter out all particles larger than 5pm, for example, before processing is carried out using the device. In this, the remaining small particles are removed as well as substances dissolved in the process water, especially (lithium) ions.

A wet shredder fraction S1 leaves the shredder 22 together with the process water W, which is fed to the stirrer 24 and then leaves it as the wet separator fraction S2.

This is transported by means of the conveyor device 26 towards the second section, which is shown in FIG. During transport via the conveyor device 26, which is designed in particular as an inclined screw conveyor, the separator fraction S2 is dewatered.

This dewatered separator fraction S2 is fed to a first electrohydraulic separating device 32. In this second section of the system 20, graphite G is separated from the shredded anode foils (copper foils CU). The second section of the system 20 has, following the first electrohydraulic separating device 32, several components for drying/dewatering, sorting and classifying the different fractions. The first separation device 32 is a bath filled with process water W, into which the separator fraction S2 is introduced. In this bath, the separator fraction S2 is treated with shock waves with high pulse energy, with the process parameters being set such that the graphite G is separated from the copper foil. The comminuted and treated separator fraction S2 leaves the first separation device 32 as a first separation fraction T1; specifically, it is pumped out of the bath together with the process water W and fed to a centrifuge 34.

Dewatering and separation of a coarse fraction C from a fine fraction F takes place in the centrifuge 34. The coarse fraction C contains, for example, particles with a diameter greater than or equal to 0.5 cm or greater than or equal to 1 cm. The fine fraction F accordingly has particles smaller than 0.5 cm or smaller than 1 cm.

The fine fraction F is subsequently classified and finally dried. For this purpose, the fine fraction F together with the process water W is fed to a sieve device 36 in the exemplary embodiment. In this, the process water W is separated and a coarse fine fraction F1 and a fine fine fraction F2 are sorted out and classified. The coarse fine fraction F1, for example, has pieces of film with a size of greater than 250 pm and the fine fine fraction has graphite or pieces of film with a size in the range of, for example, 50-250 pm. Even smaller components are fed to a filter device 38 as the finest fraction F3 with the process water W. From this, the finest fraction F3 is finally obtained, which in particular has graphite G with a particle diameter of, for example, less than 50 pm.

The process water W is conducted in the area of this second section of the system 20 in a second circuit K2.

The separated coarse fraction C is fed to the third section, as shown in FIG. This section is used in particular for extraction of NMC i.e. the cathode material. For this purpose, in particular, a second separating device 40 is provided, in which the NMC is separated from the cathode foil (aluminum foil). Beforehand, the coarse fraction C is dried in a drying device 42 and the various foil fractions are subsequently separated from one another, for example in an air classifier 44, namely on the one hand a copper fraction CU which contains copper foils and on the other hand an aluminum fraction which contains the aluminum foils AL, which are still coated with the cathode material (NMC). The copper fraction CU also contains the separator foils.

The aluminum fraction AL is fed to the second electrohydraulic separating device 40, in which the process parameters are now set such that the cathode material, in particular NMC, is separated from the aluminum foils. Depending on the cell type and cathode coating, other materials are also used and separated accordingly, such as NCA, LFP. The comminuted and treated aluminum fraction AL leaves the second separation device 40 as the second separation fraction T2 together with the process water W and is fed to a further filter device 38. In this, the process water W is again separated off together with a very fine fraction F3 and a coarse fine fraction F1 and a fine fine fraction F2 are separated off. The coarse fine fraction F1 in turn contains particles with a diameter of, for example, greater than 250 pm and the fine fine fraction F2 contains particles with a Diameter between 50 and 250 pm. The fine fine fraction F2 typically consists of at least highly enriched NMC. The finest fraction F3 also consists of at least highly enriched NMC. This is in turn fed to a filter device 38 with the process water W and the fine fraction F3 (NMC) is separated there.

In FIG. In a preferred embodiment, this coarse fine fraction F1 is fed to a further comminution device, in particular a third electro-hydraulic separating device 50, in a further comminution stage. In this, further comminution and homogenization of the particles of the coarse fine fraction F1 takes place. At the same time, any remaining binder components or carbon black are separated off. A crushed fine fraction ZF is obtained.

In addition, another of the classified fine fractions F2, F3, in particular the fine fine fraction F2, can also be fed to such a further comminution stage.

This further comminution device is preferably followed (in each case) by a further separation stage, for example in the form of a further centrifuge 52. In this, different types of particles, in particular the cathode material, are separated from those of the anode material. After the first separation device 32, in particular NMC proportions of, for example, 10% to 20% are still contained in the graphite fraction. This further separation stage therefore achieves improved varietal purity.

Such a further separation stage is preferably also provided for one or more or all of the further classified fine fractions F2, F3. These do not necessarily have to be preceded by another shredding stage.

The further comminution stage is alternatively arranged, for example, downstream of the first separating device 32, in particular at a position after a separation of the fine fraction F, which is comminuted (i.e. before classification) and from which the comminuted fine fraction ZF is then obtained

Such a further comminution stage is additionally or alternatively also arranged for the treatment of the second separation fraction T2 after the second separation device 40, either directly for the treatment of the second separation fraction or - preferably - for the treatment of one or more of the classified fine fractions F1, F2, F3, specifically for Treatment (only) of the coarse fine fraction F1 and possibly also for the treatment of the fine fine fraction F2. Since the second separation fraction T2 is generally already largely pure, a further separation stage is preferably dispensed with here.

The process water is pumped in a third circuit K3 and thus continuously through the various components of the third section. In the exemplary embodiment it is provided that the third circuit K3 is coupled to the second circuit K2. For this purpose, the process water W arising in the filter device 38 is fed to the second circuit K2.

In a manner not shown here, used process water W is fed to wastewater treatment.

The following aspects are particularly noteworthy in Appendix 20 described here:

- Through the wet shredding, especially in combination with the wet stirring of the cells Z in the shredder 22 and the stirrer 24, the electrolytes, lithium ions and a portion of the graphite are separated with the process water W at an early stage and are separated in a simple and efficiently obtained from the process water W using the treatment device 30. I.e. Lithium and graphite with a high degree of purity are already being extracted here.

- Preferably - in a manner not shown here - the state of charge of the batteries and thus the cells Z is set in a defined manner, in particular the batteries / cells Z are deliberately electrically charged before shredding. This increases the “free” lithium ion content, so that as much lithium as possible is flushed out with the process water W and recovered.

- It should also be emphasized that by using the stirrer 24, part of the graphite is already removed and is already obtained at this point. In addition, the stirrer 24 separates the otherwise tightly packed films, which is necessary for the subsequent treatment the electro-hydraulic separating devices 32,40 is advantageous. Overall, this improves the separation efficiency with regard to the separation of the coating material from the respective film in the separating devices 32, 40, whereby the degree of recovery is improved. In the system described here, this is typically greater than 90% for NMC.

- Furthermore, the dewatering of the wet separator fraction S2 should be emphasized before it is fed to the first separation device 32. This means that the proportion of free lithium ions in the process water W is reduced, which has a positive effect on the operation of the first separation device 32.

The entire recycling process with the individual process steps (hereinafter A.., B.., C.., D.., E.., W...) as well as the mode of operation, functions and alternatives to the individual components can also be seen from the following, bullet-point detailed description:

A1 Zerlequnq (vehicle) batteries

Vehicle batteries are dismantled (manually, semi-automated or automated), the modules are removed and the remaining components (housing, cables, electronics) are sorted and recycled separately as material streams.

A2 Classifying battery modules

Battery modules are measured and classified (usable for “2nd life applications” vs. recycling). Modules to be recycled are further pre-sorted (e.g. according to types, chemical composition, if necessary remaining charge)

A3 Set the charge status of the battery modules

According to one variant, modules are largely or completely discharged using an unloading device. The electricity is fed back into the grid or used for the recycling plant. Alternatively, entire vehicle batteries may also be discharged without first dismantling the modules.

For the present method, however, the state of charge is ignored because the method allows charged batteries to be recycled, or a defined state of charge is set (e.g. the highest possible charge through charging instead of the usual discharging) in order to be able to extract as much lithium as possible. A4 Dismantling/pre-shredding battery modules manually/semi-automatically/automatically

The battery modules are dismantled with the aim of separating the individual fractions (in particular the cells, housing parts, electronic parts) without mixing them as much as possible. Pure dismantling (dismantling) steps can be used (e.g. unscrewing, prying) as well as separating processes (sawing, cutting). The components (including cells) can remain intact or be damaged; the aim is to avoid mixing. If necessary, loosen existing adhesives, conductive pastes or similar using suitable solvents.

Alternatively, the battery modules can also be shredded, for example, in a liquid medium or shredded with very high pulse energy using an electro-hydraulic separating device (e.g. according to DE10 2019 218 736 A1).

B1 Pre-shredding battery cells Z in liquid medium (essential aspect)

Shredding in Shredder 22:

The cells Z are roughly shredded or cut into strips. This exposes the battery foils (anode, cathode) and, on the one hand, separates them from the housing, and on the other hand, the electrolytes are washed out and mostly bound in the water.

Advantages over dry shredding processes:

(1) No expensive protective gas atmosphere necessary, as any remaining energy in the water is discharged ==> can be used in industrial systems as process heat for later steps.

(2) Operation at room temperature (instead of 80°C or even more) = energy efficient

(3) All electrolytes and conductive salt are safely dissolved in the water (vs. dry process: only the highly volatile gases are separated well, conductive salts and semi-volatile components dry up and become black matter; which results in a permanent risk of hydrofluoric acid (HF) formation.

(4) The electrolytes retain their chemical structure and can later be recycled themselves.

(5) Fully or partially charged cells can also be treated in this way Discharge step can be omitted

(6) Lithium is already dissolved in the water at this point and can be recovered. In other processes, lithium remains in the black mass and can only be recovered much later in the process or is lost (in pyrolytic processes)

(5) + (6) the lithium content in the process water can be specifically adjusted by flow rate and charge status (charged cell Most of the lithium is in graphite as a free ion and dissolves in water; discharged cell: most of the lithium is chemically bound in the NMC and remains in the later black mass). This makes it possible to recycle the lithium in advance by charging it beforehand. As an alternative to the classic shredder, rotary shears or a guillotine can also be used:

Cut or punch through into several large pieces. The goal: to get the largest possible fractions in order to achieve the best possible sorting of the housing parts and to lose as little black mass as possible in this step.

As a further alternative to the classic shredder, the cells are opened automatically by precisely cutting them open on one or more predefined sides.

B2: Pre-sorting of battery cell pieces (optional)

After pre-shredding in step B1, the material flow consists of the following components:

(1) Cathode foils made of aluminum with cathode active material mostly still attached (e.g. NMC, LFP, etc.)

(2) Anode foils made of copper with anode active material still partially or completely adhering (usually graphite mixture)

(3) Separator film

(4) Housing parts

(5) Fine fraction (mainly graphite, with smaller proportions of cathode active material and film particles)

In this step, the resulting fine fraction is firstly removed and sorted/classified (e.g. by sieving, sink-float sorting, centrifugation, magnetic and/or eddy current separation). This happens in steps D1 and D3. Secondly, the coarse housing components are sorted out (e.g. by float-sink sorting, magnetic and/or eddy current separation). Advantage of only coarse shredding in B1 (compared to much finer shredding in other shredding processes): Housing parts can be sorted out in a higher percentage.

C1 Pretreatment of the battery cells (electrolyte, anode stripping)

The shredded or pre-cut cell materials are rinsed or stirred in water for some time (stirrer 24, essential aspect).

Goals are:

(1) the separation of the films (still tightly packed in the cell, through separation the surfaces of the films are more accessible in the following steps)

(2) Solution/flushing of electrolyte

(3) Removal of graphite from the anode foils

(4) Dissolving/rinsing out the lithium

Advantages 1 to 3 and 5 and 6 from B1 also apply here. Steps B1, B2 and C1 are connected by a common first process water circuit K1. This has the largest concentration of electrolytes and possibly also graphite and dissolved lithium. After step C1, partial dewatering takes place through the conveyor device 26 screw conveyor with integrated sieve. As a result, the process water W in the following step C2 contains significantly less electrolytes and is also less conductive (since easily soluble components such as lithium ions and possibly unbound heavy metals) are already absorbed in the first circuit. In addition, the higher concentration of lithium and electrolytes in this first circuit is advantageous for filtering them out

C2 with high

Steps C2 and D1 to D6 are connected by a common second process water circuit K2. Advantages 1 to 3 and 5 and 6 from B1 also apply here. However, due to process steps B1 and C1, the concentration of electrolytes, graphite and lithium in this second circuit K2 is lower. Advantages: The process water W can be circulated for longer without intermediate cleaning; The water cycle represents a second cleaning stage, so that the residual concentration is negligibly low.

D1 Drainage coarse part G

The coarse fraction C from step C2 (mixture of mainly cathode foils, anode foils, separator foils) is conveyed out of the first separating device 32 continuously or discontinuously (and possibly already separated from the fine fraction, but this is not absolutely necessary). The funding is currently using a conveyor belt, but other methods (e.g. screw conveyor, rinsing using process water) are also possible. The coarse fraction C is pre-dewatered in the centrifuge 34 (different types of centrifuges are possible, discontinuous and continuous).

D2 drying coarse fraction C

The coarse fraction C is dried in the drying device 42. The degree of drying is adjustable and is selected according to the subsequent sorting. Heat drying, air drying or other methods can be used (stationary or continuous). Dewatering D1 and drying D2 are advantageous in the case of dry sorting D3. They can be left out during wet sorting.

D3 Sorting coarse fraction (wet or dry)

Wind sifting (dry or largely dry, wind sifting 44). The coarse fraction C is sorted into different fractions (cathode foil, anode foil, separator, housing residues, etc.) in a single or multi-stage process. If necessary, sub-fractions are formed (e.g. different size classes. There may be intermediate steps, e.g. spherification of films, e.g. using an impact mill or similar. Alternatives to wind sifting are optical sorting (dry or largely dry), magnetic separation, eddy current separation (dry or largely dry), wet Sorting processes (sink-swim separation, flotation) as well as magnetic separation, eddy current separation in water.

D4 Pre-sorting/pre-dewatering Fines from pre-treatment

The fines F of step C2 are discharged and classified continuously or discontinuously using the process water W, for example using a sieve with one or more stages.

We carry out wet sieving, but wet separation table(s), dry sieving (if drying is carried out beforehand), centrifugation, hydrocyclone or similar processes are also possible. The sieve stages also serve for pre-drainage. Combinations of magnetic and/or eddy current separation in a wet medium are also possible, as are sedimentation processes. One or more different fractions with different grain sizes and contents are created.

D5 Dewatering/filtering Fines from pretreatment

The various fractions from step D4 are thickened and further dewatered using filter devices 38 (e.g. vacuum, inclined filter, chamber filter press or others). Filter cakes are created per fraction, the consistency of which can vary in terms of residual moisture (i.e. filter cake consists of/contains mostly the active material of the anode (graphite)).

D6 Drying / further treatment of fine particles

The various fractions from step D5 are dried. The degree of drying is adjustable and is selected according to the customer's requirements. Heat drying, air drying or other methods are used (stationary or continuous). If necessary, presses or other processes are used to compact and package the material.

E1 Post-treatment of the cathode foils (cathode stripping)

The “cathode foil” fraction from step D3 is fed to another shock wave system (2nd separation device 40, with low pulse energy), in which the active material (e.g. NMC, LFP, NCO,...) is separated from the electrode carrier (generally aluminum foil).

Steps E1 and F1 to F6 are connected by a common process water circuit. Advantages 1, 2 and 6 from B1 also apply here (3, 4 and 5 are no longer relevant because electrolytes and charge were removed in the previous steps). If process steps B, C and D or parts of them are carried out beforehand, the concentration of electrolytes, graphite and lithium in this 3rd water cycle is very low. Advantage: The process water can be circulated for longer without intermediate cleaning.

E2 sorting After step E1, the materials are discharged in one or more circuits and separated into different fractions. The aim is, on the one hand, to enrich the cathode active material (NMC) as high as possible in one or more fractions and, on the other hand, to enrich the carrier film (typically aluminum) in other fractions. Sieve classification is preferred (wet) and, if necessary, centrifugation. Alternatives to this are sieve classification (dry), float-sink sorting, flotation, magnetic sorting (possibly for LFP).

E3 Pre-drainage/removal of contaminants

With the help of centrifuges or other technologies (sedimentation, sink-swim process, flotation), further impurities are removed from the fractions if necessary and pre-dewatering is carried out in the same or subsequent steps.

To remove contaminants, other auxiliary substances (chemical, mechanical) may also be added (e.g. precipitants, e.g. caustic soda, e.g. catalytically active substances). If necessary, these substances will also be added in a previous step or at the beginning of the overall wet process (B1).

E4 drainage

The various fractions from step D4 are thickened and further dewatered using filter units (e.g. vacuum, inclined filter, chamber filter press or others). Filter cakes are created per fraction, the consistency of which can vary in terms of residual moisture. If necessary, presses or other processes are used to compact and package the material.

E5 Drying / further treatment

The various fractions from step D5 are dried. The degree of drying is adjustable and is selected according to the customer's requirements. Heat drying, air drying or other methods are used (stationary or continuous). If necessary, presses or other processes are used to compact and package the material.

W1 Process water post-treatment

Circuits

Process water W is the medium for many of the aforementioned process steps. This is reused in separate and/or coupled circuits. Preferably, process water W from the second separation device 40 (step (F1, F2...) is then used in the first separation device 32 (step (C2, D..)), and preferably subsequently used in the pre-shredding (B1, B2). in order to be able to use the water for as long as possible.

Part of the process water is controlled from one or more circuits (continuously or discontinuously) in order to remove the dissolved or suspended valuable materials and recover them

W2 process water purification Process water from one or more of the aforementioned circuits K1, K2, K3 is cleaned in a multi-stage process. Goals are:

(1) To make the process water usable again, and/or

(2) To make the process water dischargeable

(3) recover valuable materials

The cleaning is carried out with regard to suspended and dissolved substances, in particular:

(1) Metals and heavy metals (e.g. Li, Al, Cu, Ni, Co, Mn, Fe, etc.)

(2) Other substances (e.g. P, F)

(3) Organic components (electrolytes, electrolyte salts)

Methods in question:

Fine and ultra-fine filtration (ultrafiltration, reverse osmosis, high-performance disc filters, etc.)

Activated carbon filter

Other filter materials, e.g. blotting paper, fiberglass tiles, fabrics

Electrical or electrochemical processes

Mechanical processes

Chemical processes (flocculation and precipitation)

Vacuum evaporation

Adsorption materials of ceramic origin

W3 lithium recovery

Lithium is recovered from the remaining process water W.

Advantages of the procedure:

1. The charge state is used to set how much lithium ends up in the process water W (charged Most of the lithium is present as an ion, ie is dissolved out of graphite and electrolyte; uncharged Most of the lithium is bound in the NMC, less is released)

2. Concentration far higher than in natural Li deposits

Methods:

Possibly ultrafiltration, reverse osmosis

Precipitation

Electrochemical

W4 Exhaust air purification and fabric recovery - wet & dry

The atmosphere above the wet and dry process steps is preferably withdrawn continuously or discontinuously and subjected to measurement and cleaning.

Goals are:

(1) Comply with and monitor emissions requirements

(2) recover valuable materials Methods:

sedimentation

Activated carbon filtering

Electrochemical - Chemical

Reference symbol list

20 facility

22 shredders

24 stirrers

26 conveyor device

28 collection containers

30 processing facility

32 first electro-hydraulic separating device

34 centrifuge

36 screening device

38 filter device

40 second separator

42 drying facility

44 wind classifiers

50 third electro-hydraulic separating device

52 more centrifuges

Z cells

W process water

K1 first circuit

K2 second circuit

K3 third circuit

G graphite

51 Shredder faction

52 Separator faction

T1 first separation fraction

T2 second separation fraction

C coarse fraction

F fine fraction

F1 coarse fine fraction

F2 fine fine fraction

F3 finest fraction

ZF crushed fine fraction

CU copper fraction

AL aluminum fraction

Claims

Claims Method for recycling battery cells (Z) or parts thereof, which have electrolytes, in particular lithium, and films provided with coating material, namely cathode films with a coating of cathode material and anode films with a coating of an anode material, wherein - the cells (Z) are mechanically pre-shredded in a liquid medium (W) in a shredding stage and a wet shredding fraction (S1) is obtained, - then the wet shredder fraction (S1) is rinsed in a pre-separation stage with the aid of a mechanical separator (24), in particular a stirrer under the influence of mechanical energy and using the liquid medium (W), thereby separating the Foils and components of the shredder fraction (S1), such as electrolyte, coating material and lithium, are rinsed out, these components accumulating in the liquid medium (W), with a separator fraction (S2) being obtained in the pre-separation stage, - The separator fraction (S2) is subsequently further processed in at least one separation stage. Method according to the preceding claim, in which the separator is designed as a stirrer (24) with an agitator in which the shredder fraction (S1) is stirred. Method according to one of the preceding claims, in which the wet separator fraction (S2) is dewatered and for this purpose a part of the liquid medium (W) with the components contained therein is separated off and a dewatered separator fraction (S2) is obtained. Method according to the preceding claim, in which the wet separator fraction (S2) is dewatered via a conveyor device (26). is conveyed to the first separation stage and the liquid medium (W) is separated. Method according to one of the two preceding claims, in which components contained therein are recovered from the separated liquid medium (W), in particular lithium and the anode material. Method according to one of the preceding claims, in which the liquid medium is water. Method according to one of the preceding claims, in which the weight fraction of the liquid medium is greater by at least a factor of 10 and preferably by at least a factor of 30 or 50 than the weight fraction of cells or parts of cells which is fed to the shredder stage. Method according to one of the preceding claims, in which the cells (Z) are not discharged before the shredding stage. Method according to one of the preceding claims, in which the cells (Z) are brought to a defined state of charge before the shredding stage, the defined state of charge corresponding to at least 30%, at least 50%, at least 75% or at least 90% of the maximum state of charge. Method according to one of the preceding claims, in which the dewatered separator fraction (S2) is fed in the separation stage to a first electrohydraulic separation device and there at least one of the coatings is detached from the films on which it is applied, in particular the anode material from the anode films and A first separation fraction (T1) is obtained. Method according to the preceding claim, in which the first separation fraction (T1) is separated into a coarse fraction (C) containing coarse film parts and a fine fraction (F) containing the separated coating material and the two fractions are processed separately. Method according to the preceding claim, in which anode foils and cathode foils are separated from one another from the coarse fraction (C) and the one foil fraction from which the coating material was not separated in the first separation stage is fed to a second separation step in which the coating material is separated from the foils of this Film fraction is separated, for this purpose in particular a second electrohydraulic separating device (40) is used and a second separation fraction (T2) is obtained. Method according to one of the two preceding claims, in which at least parts of the fine fraction (F) and / or the second separation fraction (T2) are fed to a further comminution stage, in particular a preferably further electro-hydraulic separation device (50), and a comminuted fine fraction (ZF) is obtained becomes. Method according to one of claims 10 to 12, in which the fine fraction (F) and / or the second separation fraction (T2) is classified into different fine fractions (F1, F2, F3), and at least one of these classified fine fractions (F1, F2, F3) was fed to the further comminution stage in order to obtain the comminuted fine fraction (ZF). Method according to one of claims 10 to 13, in which one of the fractions selected from fine fraction (F), separation fraction (T2), comminuted fine fraction (ZF) or classified fine fraction (F1, F2, F3) is fed to a further separation stage in which different types be separated from each other by the particles they contain. Method according to one of the preceding claims, in which several separate or interconnected circuits (K1, K2, K3) are provided for liquid medium (W), at least lithium and / or graphite being obtained from the liquid medium (W). Method according to one of the preceding claims, in which the liquid medium (W) is returned in a first circuit (K1) via the shredder stage and via a pre-separation stage and again. Method according to the preceding claim, in which at least part of the liquid medium is fed to a processing device (30) in which lithium and / or graphite is deposited. Plant (20) for recycling battery cells (Z) or parts thereof, which have an electrolyte, lithium and films provided with coating material, namely cathode films with a coating of cathode material and anode films with a coating of anode material, wherein - a shredder stage is provided for mechanical pre-shredding of the cells (Z) in order to obtain a shredder fraction (S1), - a pre-separation stage with a separator is subsequently provided, in particular a stirrer (24), for rinsing and separating components of the shredder fraction (S1), such as electrolyte, coating material and for separating the films, - A first separating material is provided, in particular with a first electro-hydraulic separating device (32), in which the separator fraction (S2) obtained in the pre-separation stage is further processed.