Method and equipment for preparing battery to be recycled

Abstract

The invention relates to a method for producing a battery (100) to be recovered, comprising at least the following steps:-comminuting the provided battery (100) to be recovered in order to obtain a comminuted material (101), the provided battery (100) to be recovered and / or the comminuted material (101) thus obtained being thermally pretreated in a comminuting chamber (3a) by heating to a comminuting temperature (TZ) below 100 DEG C; transferring the comminuted material (101) into the drying container (4a) and heat-treating (ST2) the comminuted material (101) by increasing the actual ambient temperature (TIst) in the drying container (4a) and reducing the actual ambient pressure (pIst) in order to heat the comminuted material (101) in the drying container (4a), the actual ambient temperature (TIst) in the drying container (4a) being set in such a way that the temperature of the comminuted material (101) is increased to no more than 200 DEG C, and the temperature of the comminuted material (101) is increased to no more than 200 DEG C; and setting an actual ambient pressure (pIst) in the drying vessel (4a) in order to separate the low-boiling solvent (LL) and the high-boiling solvent (LH) from the comminuted material (101) by evaporation at a set actual ambient temperature (TIst), the low-boiling solvent (LL) and the high-boiling solvent (LH) being discharged from the same drying vessel (4a) during the heat treatment of the comminuted material (101); and-mechanical production of the heat-treated comminuted material (101).

Description

Technical Field

[0001] The invention relates to a method for preparing a battery to be recycled, such as a lithium-ion battery, and a preparation device for implementing the method. Background Art

[0002] Due to the increasing demand for rechargeable batteries (accumulators), in particular with lithium-ion cells, for off-grid small electronic devices (headphones, mobile phones, etc.) and electric vehicles (traction batteries) or conventional vehicles (starting batteries) or as energy storage, for example in photovoltaic systems or as buffer storage for energy peaks, more and more lithium batteries will be recycled in the future when the batteries reach the end of their service life. This usually occurs after 8-10 years, when the battery capacity has dropped to 80% or less.

[0003] In the case of the preparation of used batteries, mechanical recycling routes are designed and implemented. Within the scope of these preparation schemes, a series of mechanical, electrical and chemical or thermal processes are usually used, which are used to break down the batteries or battery cells into individual components and minimize potential electrical hazards, especially due to fire, explosion and the resulting emission of harmful substances. The electrical processes include in particular the preliminary discharge of the batteries, and the mechanical processes include in particular the preliminary disassembly, mechanical comminution and the subsequent sorting / classification of the components obtained by the corresponding discharge.

[0004] In addition, the thermal process ensures that the chemical substances in the battery to be recycled, in particular the solvents of the electrolyte of the individual battery cells or other electrochemically active substances, evaporate or become inactive, for example by carrying out a preliminary drying step at a corresponding drying temperature. After the above-mentioned thermal pretreatment, these electrochemically active substances will no longer cause greater potential hazards in the subsequent preparation process. As a supplementary solution, pyrolysis at a decomposition temperature of up to 900° C. can be used as a thermal process, in particular to decompose the binder that holds the active material (lithium) of the battery cells, so that the active material can be recovered. This is explained by way of example in DE 102011 110 083B4. However, the pyrolysis process also decomposes other electrochemically active solvents, which also means that these solvents cannot be used later in terms of material.

[0005] It is also known, for example, from ACCUREC / Mühlheim to thermally pretreat spent batteries or the individual cells contained therein in order to evaporate the solvent of the electrolyte, whereby a thermal pretreatment at a drying temperature of about 200° C. is combined with a pyrolysis process in a vacuum furnace. In the pyrolysis process, all organic components of the battery or cells (jacket and separator plastics, electrolyte and other organic components) are converted into pyrolysis gases and pyrolysis coke at a decomposition temperature of 400° C. to 500° C. The components contaminated by the pyrolysis coke can subsequently be cleaned and separated in a conventional mechanical preparation process by means of mechanical comminution and sorting or classification.

[0006] In this case, the disadvantage is that the pyrolysis in a rotary kiln or shaft furnace requires a high decomposition temperature, so the pyrolysis process is relatively complicated and costly, and also generates odors unfavorably. In addition, it is difficult to recover high-quality layer components from the pyrolysis coke, and the pyrolysis coke remaining after sorting / classification is expensive to dispose of as hazardous waste, which makes the entire production process less economical.

[0007] In order to avoid the above situation, DE 10 2015 207 843 B4 proposes, for example, that after discharging and mechanical disassembly, the battery or battery cell is first mechanically shredded in a continuous process in a preparation device (battery processing equipment), and then inactivated by drying in a heat treatment process via a conveyor, wherein a relatively low drying temperature of about 80° C. or less is set. The inactivated battery is then further mechanically prepared in a continuous process via another conveyor.

[0008] In this case, the disadvantage is that only low evaporation temperature or low boiling point solvents of the electrolyte in the battery cells can be separated. In order to also remove other components of the electrolyte from the crushed battery, WO 2021 / 018372 A1 proposes that after the battery is deactivated at 80°C or lower, the inactivated crushed material is transferred to another container in another step, and then the inactivated crushed material is heated to an electrolyte removal temperature of more than 100°C in the container, in particular to more than 150°C. As a supplementary solution, a vacuum can be generated, but this is not necessary. By supplementary heating to more than 100°C, high boiling point solvents of the electrolyte can also be removed. The crushed material is then dissolved with the aid of concentrated sulfuric acid in order to remove fluorine from the crushed material and obtain a dissolved material, from which at least one metal component can then be extracted by a wet chemical method.

[0009] In this case, a disadvantage is that at the electrolyte removal temperature set in the additional container after deactivation given in WO 2021 / 018372 A1, it cannot be ensured that all high-boiling solvents can also be removed from the electrolyte. Very high evaporation temperatures are required to separate all high-boiling solvents. In addition, at such high temperatures, plastic-containing substances in the comminuted material will also begin to melt, thereby changing the comminuted material in an undesirable manner.

[0010] Furthermore, the method of WO 2021 / 018372 A1 is relatively complex, since the comminuted material must be transferred to a plurality of containers adapted to the respective process steps for the prior deactivation of the high-boiling solvents and the subsequent removal of these high-boiling solvents, and thus a corresponding multiple temperature adjustment must be performed, which makes the process relatively complex and slow. The corresponding evaporated solvent fractions are then also discharged separately from one another from the different containers via different fluid connections, which is relatively complex in terms of equipment technology.

[0011] EP 3 312 922 A1 proposes to discharge only low-boiling solvents, wherein only the evaporation of low-boiling solvents is ensured at the above-mentioned ambient temperature below 80° C. and the above-mentioned ambient pressure not exceeding 300 hPa. However, no explicit description is given of evaporating and discharging high-boiling solvents from the dryer for subsequent waste gas treatment.

[0012] Furthermore, EP 3 836 290 A1 proposes to heat treat the battery before comminution and to set an actual ambient temperature of 160° C. to 200° C. and an actual ambient pressure of less than 10 mbar in the drying container in a first process step in order to be able to remove high-boiling and low-boiling solvents from the battery and to convey them to a condenser. Subsequently, in a second process step, the temperature is further increased to 600° C. in order to be able to separate more decomposition products, such as hydrocarbons.

[0013] In this case, disadvantages are that, on the one hand, very high temperatures are required and, on the other hand, the solvents are extracted from the cells which have not yet been comminuted, which makes the process less efficient and less economical overall. Thus, for example, it is not possible to ensure that the solvents can escape completely from the partially closed cells in the drying step before comminution and that the entire cell can be heated uniformly and sufficiently in the first process step in order to safely reach the corresponding boiling point in order to evaporate the corresponding solvents in the entire cell. Summary of the invention

[0014] Therefore, the object of the present invention is to provide a method or a preparation device for preparing batteries to be recycled simply or with less time and design cost and with lower potential risks.

[0015] The invention provides a method and a production device for achieving the above-mentioned object according to the independent claims. The dependent claims describe preferred developments.

[0016] Therefore, according to the present invention, in the method for preparing a battery to be recycled, in particular a lithium-ion battery, at least the following steps are provided:

[0017] - providing at least one battery to be recycled, wherein the battery has preferably been prepared accordingly, in particular disassembled (for example to the module level or the cell level) and / or discharged;

[0018] - comminuting the provided batteries to be recycled to obtain comminuted material, wherein this is preferably carried out in a comminuting chamber under an inert gas and a slightly negative pressure, wherein within the scope of a thermal pretreatment in the comminuting chamber, the provided batteries and / or the comminuted material produced therefrom have been heated to a comminuting temperature of, for example, <100° C., in particular to 50° C. to 70° C., which helps to increase the effectiveness of the subsequent drying step;

[0019] - transferring the pulverized material to a drying container and subjecting the pulverized material to a heat treatment or drying process by increasing the actual ambient temperature and reducing the actual ambient pressure in the drying container, preferably under an inert atmosphere, so as to heat the pulverized material in the drying container and evaporate the solvent contained in the pulverized material, wherein the actual ambient temperature in the drying container is set according to the invention so that the pulverized material is heated to no more than 200° C., and the actual ambient pressure in the drying container is set in a coordinated manner so that low-boiling point solvents and high-boiling point solvents are separated from the pulverized material by evaporation at the set actual ambient temperature, wherein during the heat treatment of the pulverized material these low-boiling point solvents and high-boiling point solvents are discharged from the drying container, at least intermittently discharged together and / or at least intermittently fractionated or separated from each other or discharged successively from the same drying container; and subsequently - mechanical preparation of the heat-treated or dried pulverized material.

[0020] Advantageously, during the (primary) thermal treatment, the actual ambient pressure and the actual ambient temperature in the drying vessel are coordinated in a targeted manner so that the actual ambient temperature in the drying vessel can be kept low, thereby preventing the melting of plastic-containing substances in the comminuted material and separating high-boiling solvents in order to minimize potential hazards for the subsequent preparation. Due to the targeted regulation of the actual ambient pressure, it is possible to work within a temperature range that does not have a negative impact on the preparation process during this and subsequent phases of the thermal treatment.

[0021] Unlike the method in WO 2021 / 018372 A1, according to the present invention, the negative pressure in the drying container is preset and set in a coordinated manner during the heat treatment process so as to ensure that all solvent components in the electrolyte, especially high-boiling solvents, are separated within the above-mentioned temperature range below 200°C. This is based on the following idea: As the actual ambient pressure decreases, the evaporation temperature of high-boiling solvents in the crushed material also decreases. If a lower actual ambient pressure is set in the drying container in a targeted manner, these high-boiling solvents can also evaporate at an actual ambient temperature below 200°C. Preferably, it is assumed that it is sufficient to make the actual ambient temperature reach a preset final ambient temperature of 150°C to 200°C, preferably 150°C, during the heat treatment in the drying container.

[0022] The low-boiling solvents will then also evaporate at these practical ambient temperatures, so that all separated or evaporated solvent fractions can be withdrawn at least intermittently jointly and / or at least intermittently in a fractionated manner (depending on the ambient conditions) from the same drying vessel in just one thermal (main) treatment process and then fed to separate waste gas treatment processes. In this case, high-boiling solvents are solvents which evaporate at a boiling point above 150° C., in particular above 240° C., at atmospheric pressure, and low-boiling solvents are solvents which evaporate at a boiling point below 150° C., in particular below 130° C., at atmospheric pressure.

[0023] It is also preferably provided that during the thermal treatment between separation of the low-boiling solvent and separation of the high-boiling solvent (by evaporation), the comminuted material is not removed from the drying container, so that the low-boiling solvent and the high-boiling solvent can be discharged from the same drying container.

[0024] Overall, the outlay in terms of equipment technology and design of the production plant is reduced, since the main part of the thermal treatment takes place only in one drying vessel, which is suitable for the thermal treatment for the removal of all still present low-boiling and high-boiling solvent fractions, and all these evaporated solvent fractions can be removed intermittently together and / or intermittently separately from one another. It is therefore not necessary to design plant components individually, nor is it necessary to remove individual solvent fractions and other substances produced separately in terms of equipment technology.

[0025] The low-boiling solvent can be separated at least partially in a thermal pretreatment during the comminution process with little effort and without the need for an additional container, wherein this also does not affect the comminution process in this area of ​​the plant, but rather minimizes potential risks. In addition, the effectiveness of the subsequent separation process or the subsequent thermal (main) treatment in the drying container can be increased by this thermal pretreatment, in which the low-boiling (residual) and high-boiling solvent components can then be further evaporated. In particular, the water present in the comminution material can be evaporated earlier by the thermal pretreatment during the comminution process, thereby reducing in particular the damage to the subsequent thermal treatment process in the drying container. In addition, the low-boiling solvent separated in the thermal pretreatment can also be extracted and fed, for example, to an exhaust gas treatment, for example to the same exhaust gas treatment process as the solvent extracted from the drying container.

[0026] Furthermore, the process technology costs are minimized, since the main part of the thermal treatment takes place in only one single drying container, without the need for multiple temperature adjustments to 150°C to 200°C (complete heating and cooling of the drying container or the pulverized material), and multiple pressure treatments (complete evacuation and ventilation of the drying container) and transfer of the pulverized material during this period. Since the pulverizing chamber is already operated under negative pressure and inert gas, the additional process technology and design costs for heating the pulverized material within the scope of the thermal pretreatment are quite low. In this case, the pulverized material is heated, for example, by introducing a correspondingly temperature-controlled air flow into the pulverizing chamber and / or heating the environment in another way. Furthermore, the pulverized material must then be transferred from the pulverizing chamber to the drying container.

[0027] The invention therefore reduces the design and process engineering or time costs. In particular, it is also proposed that the comminuted material is in any case additionally thermally pretreated in the comminution chamber before it is transferred to the drying container and / or that the comminuted material is thermally treated in the drying container and thermally pretreated in the comminution chamber before the mechanical preparation.

[0028] Furthermore, it is preferred that during the thermal treatment of the pulverized material, the actual ambient pressure in the drying container is reduced to a final ambient pressure of 0.01 mbar to 100 mbar, in particular 30 mbar to 100 mbar, preferably 30 mbar. At such a low actual ambient pressure in the drying container, the boiling point or evaporation temperature of the solvent still present in the pulverized material can be reduced to such low values ​​that an actual ambient temperature of at most 200° C., preferably about 150° C., is sufficient to separate or evaporate these solvents from the pulverized material.

[0029] As a supplementary solution, it is preferably also proposed that during the heat treatment of the pulverized material, the actual ambient pressure in the drying container is temporarily increased to a preset intermediate ambient pressure, which is, for example, between 500 mbar and 1000 mbar, preferably 1000 mbar, preferably starting from a previously set final ambient pressure of 0.01 mbar to 100 mbar, in particular 30 mbar to 100 mbar, and after a waiting time, the actual ambient pressure is reduced again from the intermediate ambient pressure, preferably to the final ambient pressure. During this period, the actual ambient temperature in the drying container is preferably not changed, that is, it is kept correspondingly high.

[0030] Advantageously, during this period, gas or air molecules are again "injected" into the drying container by increasing the pressure, so that the comminuted material in the drying container can be heated again during the waiting time, which can cool down slightly again due to the reduced number of gas or air molecules at the lower actual ambient pressure. In this case, the pressure is increased by introducing nitrogen or another inert gas, for example, in order to avoid damage to the drying process. If the actual ambient pressure is then reduced again, the solvent components can separate or evaporate due to the reduction in the boiling point. This ensures that the corresponding solvent evaporates during the entire thermal treatment in the drying container.

[0031] For further optimization, it is preferred that during the thermal treatment of the comminuted material in the drying vessel, the actual ambient pressure in the drying vessel can be temporarily increased to an intermediate ambient pressure several times and then reduced after a waiting time, for example by introducing nitrogen or another inert gas. Thus, the evaporation process is repeatedly "stimulated" in a quasi-pulsed manner or the comminuted material is prevented from cooling down, so that the boiling point or evaporation temperature of the high-boiling solvent is no longer reached. In this way, a continuous separation or evaporation of the solvent is almost ensured, so that after the thermal treatment process in the drying vessel, it can be assumed with a high probability that the comminuted material has only a low chemical hazard potential, because these solvents have ideally evaporated completely.

[0032] Furthermore, preferably, during the increase in the actual ambient temperature in the drying container, the actual ambient pressure in the drying container is reduced only when the actual ambient temperature reaches a preset final ambient temperature (e.g. 150° C. to 200° C.), wherein the actual ambient pressure in the drying container has previously been kept at atmospheric pressure, i.e. in particular about 1000 mbar, preferably under an inert atmosphere. This is because the fewer gas or air molecules there are in the drying container, the slower the energy or heat is transferred to the pulverized material. However, if the actual ambient pressure is reduced or gas and air molecules are extracted from the drying container only when the pulverized material has been heated, the pulverized material can be heated more quickly, so that the thermal treatment process in the drying container is more efficient overall.

[0033] As an alternative, however, it can also be provided that the actual ambient pressure in the drying container is reduced with a preset or pre-settable pressure gradient, while the actual ambient temperature in the drying container reaches a preset final ambient temperature with a certain temperature gradient, wherein the pressure gradient is preferably smaller than the temperature gradient. Thus, when the actual ambient temperature increases, the actual ambient pressure decreases only slowly (compared to the increase in the actual ambient temperature), so that at the beginning there are still enough gas or air molecules in the drying container to heat the pulverized material.

[0034] Furthermore, the comminuted material is preferably heat-treated intermittently in a drying container, wherein for this purpose the comminuted material to be heat-treated is transferred to a drying container and then the drying container is closed in a vacuum-tight manner until the heat-treated comminuted material is conveyed to the mechanical preparation.

[0035] It is also preferred that the comminuted material transferred to the drying container is mixed and / or loosened before and / or during and / or after the heat treatment, preferably by means of a mixing device. This has the advantage that no lumps are formed during the heat treatment and the actual ambient temperature can act uniformly on the entire comminuted material. In addition, free vaporized solvent components can be optimally transferred to the process gas and do not remain in the material, which facilitates the common or fractional extraction of solvent components. In addition, the mixing device is preferably heated in order to avoid the formation of thermal bridges in the drying container during the heat treatment.

[0036] Furthermore, preferably, an inert gas is introduced into the drying container before and / or during the heat treatment of the pulverized material. This allows the heat treatment process to be carried out in a more controlled manner and minimizes other risks during the heat treatment in the drying container.

[0037] Furthermore, according to the present invention, a preparation device is proposed, in particular for carrying out the method according to the present invention, wherein the preparation device has at least:

[0038] A comminution zone including a comminution chamber for processing the provided and optionally prepared batteries to be recycled into comminuted material and for thermal pretreatment;

[0039] - a drying area for thermal (mainly) treatment of the pulverized material, said drying area comprising - a drying container for containing the pulverized material,

[0040] at least one heating device arranged at least partially in or on the drying container for increasing the actual ambient temperature in the drying container, and

[0041] a vacuum pump fluidically connected to the drying container via a corresponding pressure line, which serves to reduce the actual ambient pressure in the drying container;

[0042] - a mechanical processing area for subsequent mechanical preparation of the thermally treated comminuted material; and

[0043] - a control device adapted to control at least one heating device and a vacuum pump in the drying zone so that the pulverized material in the drying container is heated up and the solvent contained in the pulverized material can evaporate,

[0044] According to the present invention, the control device is also suitable for

[0045] - setting the actual ambient temperature in the drying container so that the pulverized material contained therein is heated to no more than 200° C., and - setting the actual ambient pressure in the drying container so that the low-boiling point solvent and the high-boiling point solvent can be separated from the pulverized material by evaporation at the set actual ambient temperature, so that these low-boiling point solvent and the high-boiling point solvent can be discharged from the drying container during the thermal treatment of the pulverized material, at least intermittently discharged together and / or at least intermittently discharged from the same drying container in a fractionated manner or successively.

[0046] Furthermore, preferably, a feed opening for charging the comminuted material and a discharge opening for removing the heat-treated comminuted material are provided on the drying container, wherein the discharge opening is arranged at the bottom side or on the bottom surface of the drying container so that the heat-treated comminuted material can be removed from the drying container in a vertical direction. This simplifies the complete emptying of the drying container, since the comminuted material moves downward to the discharge opening due to gravity and / or an additional overpressure in the drying container.

[0047] Furthermore, a mixing device is preferably arranged in the drying container for mixing and / or loosening the comminuted material during the thermal treatment. This has the advantage that no lumps are formed in the drying container during the thermal treatment and the actual ambient temperature can act uniformly on the entire comminuted material. In addition, free vaporized solvent components can be optimally transferred to the process gas and do not remain in the material, which facilitates the co-extraction of solvent components. Furthermore, the mixing device is preferably designed to be heatable in order to avoid the formation of thermal bridges in the drying container during the thermal treatment.

[0048] Furthermore, the drying container is preferably fluidically connected to the exhaust gas treatment device so that during the thermal treatment of the pulverized material, the low-boiling point solvent and the high-boiling point solvent separated during the thermal treatment of the pulverized material can be transferred at least intermittently together and / or at least intermittently in a fractionated manner from the same drying container to the exhaust gas treatment device. Thus, the solvent evaporated in the same drying container can be discharged intermittently simultaneously or intermittently independently of one another via the same fluid connection without prior process-related separation.

[0049] Furthermore, preferably, a regulating valve is arranged between the drying container and a vacuum pump fluidically connected to the drying container, wherein the regulating valve can be controlled by the control device so that the actual ambient pressure in the drying container approaches a preset nominal ambient pressure. In this way, the pressure regulation can be well controlled, for example within a controllable range. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention is described in detail below with reference to the embodiments.

[0051] Figure 1 is a schematic diagram of a preparation device according to the present invention; and

[0052] Figure 2 A flow chart of a method for preparing batteries for recycling. DETAILED DESCRIPTION

[0053] Figure 1 A preparation device 1 for preparing batteries 100 to be recycled, in particular lithium-ion batteries, is shown highly schematically. The preparation device 1 is divided into a preparation area 2, a crushing area 3, a drying area 4 and a mechanical processing area 5, wherein the batteries 100 to be recycled pass through the preparation device 1 in the order described or shown.

[0054] In the preparation area 2, the batteries 100 to be recycled are prepared for shredding and mechanical processing, i.e., for example, discharging and / or disassembling and / or other preparation steps. If the batteries 100 to be recycled are delivered or provided in the form of battery modules or battery stacks, these batteries to be recycled are moved to the single-cell level in the preparation area 2.

[0055] In the subsequent comminution zone 3, in particular under an inert atmosphere and a slight negative pressure, the prepared battery 100 is mechanically comminuted in a comminution chamber 3a, thereby subsequently producing a comminuted material 101. This is achieved, for example, by shearing or chopping in a pulverizer, or by breaking or crushing or by cutting, shearing or tearing stresses combined with bending and twisting (for example in a granulator). In this case, the comminution chamber 3a is heated to a comminution temperature TZ of, for example, <100° C., so that in a thermal pretreatment, the water and possible low-boiling solvents LS in the produced comminuted material 101 and / or the prepared battery 100 are first at least partially evaporated, thereby increasing the effectiveness of the subsequent drying process.

[0056] The drying container 4a is located in the drying area 4 adjacent to the comminution area, wherein at least one heating device 4b is (at least partially) arranged in or on the drying container 4a, and the drying container 4a is fluidically connected to the vacuum pump 4c. The at least one heating device 4b can be controlled according to the nominal ambient temperature TSoll preset by the control device 8, so that the actual ambient temperature Tist in the drying container 4a is ideally close to the preset nominal ambient temperature Tsoll. This can be done, for example, within the scope of temperature control, wherein for this purpose a temperature sensor 4e is arranged in the drying container 4a, which can detect the current actual ambient temperature Tist in the drying container 4a.

[0057] The at least one vacuum pump 4c can be controlled according to the nominal ambient pressure pSoll which is also preset by the control device 8, so that the actual ambient pressure pIst in the drying container 4a approaches the preset nominal ambient pressure pSoll. This can be done, for example, within the scope of pressure control, wherein for this purpose a pressure sensor 4f is arranged in the drying container 4a, which can detect the current actual ambient pressure pIst in the drying container 4a. However, other methods can also be used to set the preset nominal ambient pressure pSoll.

[0058] Furthermore, in one embodiment, a regulating valve 4g controllable by the control device 8 may be provided between the drying container 4a and the vacuum pump 4c, and the regulating valve may be used to influence the fluid connection between the vacuum pump 4c and the drying container 4a according to circumstances.

[0059] The heat-pretreated pulverized material 101 discharged from the pulverizing area 3 can be conveyed to the drying container 4a through the feed opening 6, and after the pulverized material 101 is subjected to a drying process (main heat treatment) of the heat treatment, the pulverized material can be taken out again through the discharge opening 7. In this case, the discharge opening 7 is preferably arranged at the bottom side of the drying container 4a so that the heat-treated pulverized material 101 can be almost completely removed from the drying container 4a, because the pulverized material will fall vertically downward due to gravity and / or additional overpressure in the drying container 4a. The drying process or the heat (main) treatment process is carried out by correspondingly selectively setting the actual ambient temperature Tist or the actual ambient pressure pIst in the drying container 4a, so that, as will be described in detail below, the pulverized material 101 is heat-treated in the same drying container 4a while separating different solvents L.

[0060] The pulverized material 101 in the drying container 4a can be supplementarily mixed by means of a mixing device 4d with corresponding mixing tools arranged in the drying container 4a, wherein the mixing device 4d is also heated accordingly, so as to avoid the formation of heat bridges in the drying container 4a during the heat treatment. The mixing device 4d ensures that the pulverized material 101 is constantly loosened and does not form lumps. In this way, after the heat treatment, the pulverized material 101, which is ideally free of lumps and flows freely, can be taken out through the discharge port 7, and has a uniformly high degree of sufficient dryness. The well-dried pulverized material 101 can then be moved to the mechanical processing area 5, where it is mechanically processed.

[0061] In order to be able to carry out mechanical processing with comminuted material 101 which has only a low (chemically hazardous) potential, such as Figure 2 By way of example, the described system components are used to carry out a drying process or a thermal (primarily) treatment process.

[0062] In the initial step ST0, the pulverized material 101 is provided by processing the battery 100 (prepared or unprepared) to be recycled as described above into the pulverized material 101 in the pulverizing area 3 and then subjecting it to thermal pretreatment (T<100° C.). In the first step ST1, the pulverized material 101 provided is charged into the drying container 4a through the feed port 6, and then the drying container 4a is closed in a vacuum-tight manner and flushed with nitrogen or an inert gas 10 so that the actual ambient pressure pIst in the drying container 4a can be reliably maintained under an inert atmosphere during the subsequent thermal (main) treatment process that is performed intermittently.

[0063] In the second arrangement ST2, the control device 8 for controlling the drying process or heat treatment process in the drying container 4a presets a nominal ambient temperature Tsoll and controls the at least one heating device 4b as a function of the nominal ambient temperature. For example, a final temperature TE of 150° C. to 200° C., preferably 150° C., is preset as the nominal ambient temperature Tsoll. In addition, the control device 8 also presets a nominal ambient pressure pSoll and controls the vacuum pump 4c and / or the regulating valve 4g (if present) as a function of the nominal ambient pressure. For example, a final pressure pE of 0.01 mbar to 100 mbar, in particular 30 mbar to 100 mbar, preferably 30 mbar, is preset as the nominal ambient pressure pSoll (depending on the vacuum pump 4c used).

[0064] In this case, different implementations can be used to control at least one heating device 4b, vacuum pump 4c and / or regulating valve 4g (if present), as described below:

[0065] According to a first embodiment, at least one heating device 4b and a vacuum pump 4c are controlled simultaneously or in rapid succession, and at the same time a fluid connection is formed between the vacuum pump 4c and the drying container 4a so as to approach a preset nominal value (Tsoll, pSoll). Therefore, when the actual ambient pressure pIst decreases, the drying container 4a will heat up, thereby transferring a certain amount of energy or heat to the pulverized material 101, so that the pulverized material also heats up, ideally to the preset nominal ambient temperature Tsoll.

[0066] According to a second embodiment, at least one heating device 4b is controlled by the control device 8, while the vacuum pump 4c remains switched off and / or the fluid connection between the drying container 4a and the vacuum pump 4c is interrupted by the regulating valve 4g, so that no negative pressure is yet generated in the drying container 4a. As a result, the actual ambient temperature T in the drying container 4a is increased, preferably with a high temperature gradient dT, while the actual ambient pressure pIst remains constant, in particular at atmospheric pressure (approximately 1000 mbar) in an inert atmosphere.

[0067] After a certain time has passed and / or after it has been determined by the temperature sensor 4e that the actual ambient temperature Tist in the drying container 4a has risen to a certain degree, the control device 8 ensures in a first intermediate step ST2.1 that the actual ambient pressure pIst in the drying container 4a is reduced to the nominal ambient pressure pSoll by correspondingly controlling the vacuum pump 4c and / or the regulating valve 4g (if present), thereby generating the desired negative pressure in the drying container 4a.

[0068] In the second embodiment, the transfer of energy or heat to the pulverized material 101 can be optimized by this measure: a reduction in the actual ambient pressure pIst leads to an increasingly slower transfer of energy or heat to the pulverized material 101, since the number of gas or air molecules in the drying container 4a continuously decreases. However, if the actual ambient pressure pIst is only reduced when the pulverized material 101 is already heated, the pulverized material 101 can be brought to the desired nominal ambient temperature Tsoll in a shorter time.

[0069] When the actual ambient temperature Tist in the drying container 4a increases with a correspondingly high temperature gradient dT, instead of first switching off the vacuum pump 4c and / or completely interrupting the fluid connection between the drying container 4a and the vacuum pump 4c by means of the regulating valve 4g (if present), the actual ambient pressure pIst can also be reduced simultaneously (or slightly offset in time) with a small pressure gradient dp (small in relation to the temperature gradient dT) in the direction of the nominal ambient pressure pSoll. The significance of combining the first embodiment with the second embodiment is therefore that when the actual ambient temperature Tist increases rapidly, the actual ambient pressure pIst is only reduced very slowly, so that at the beginning of the heat treatment process in the drying container 4a, when the actual ambient pressure pIst is still high (low negative pressure), a good transfer of energy or heat from the at least one heating device 4b to the comminuted material 101 located in the drying container 4a can be ensured. Only when the comminuted material 101 has been sufficiently heated will the preset nominal ambient pressure pSoll be reached.

[0070] In this case, for example, a smaller pressure gradient dp can be set by means of a control valve 4g, which can also realize an intermediate position, such as a proportional valve or a throttle valve. However, when the control valve 4g is fully open (or when there is no control valve 4g in the fluid connection), the vacuum pump 4c can also be operated at a correspondingly lower power in order to pump less strongly at the drying container 4a, thereby realizing a smaller pressure gradient dp.

[0071] In all the above embodiments, the energy or heat transferred to the pulverized material 101 in the drying container 4a can be optimized by controlling the mixing device 4d by the control device 8 during the drying process or the heat treatment process. Thus, the pulverized material 101 is mixed or loosened during the heating process, so that it can be uniformly and fully dried or heat treated without forming lumps.

[0072] The control device 8 pre-sets the nominal ambient pressure pSoll and the nominal ambient temperature Tsoll in a targeted manner in a coordinated manner so that a specific solvent L can be separated from the pulverized material 101 in the drying container 4a in a targeted manner during the described drying process or heat treatment process. This is based on the following idea: different types of solvents L are contained in the electrolyte as components of the battery 100 to be recycled, and these solvents are still in the pulverized material 101 even after pulverization. The electrolyte contains, in particular, high-boiling solvents LH (e.g., ethylene carbonate (EC), propylene carbonate (PC), etc.) and low-boiling solvents LL (e.g., dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), etc.), which have different boiling points. A given high-boiling solvent LH evaporates at atmospheric pressure when the actual ambient temperature Tist is 240° C. or higher, while a given low-boiling solvent LL evaporates at atmospheric pressure when the actual ambient temperature Tist is 130° C. or lower.

[0073] In the subsequent mechanical preparation process, both solvent components (LL, LH) will cause an increase in potential chemical hazards, so they must be separated in advance, which will be achieved in the drying container 4a during the described drying process or thermal (main) treatment process. However, when the actual ambient temperature Tist exceeds 240°C (this temperature is necessary to evaporate the high-boiling solvent LH), the plastic component in the pulverized material 101 will reach its yield point and will begin to melt during a longer thermal treatment time. Therefore, it should be avoided that such a high actual ambient temperature Tist is reached in the drying container 4a during the drying process or thermal treatment process. Therefore, as mentioned above, the control device 8 specifically presets a nominal ambient temperature Tsoll of 150°C to 200°C, at which the plastic component usually does not reach its yield point.

[0074] In order to make the high boiling point solvent LH also evaporate at a nominal ambient temperature Tsoll of 150° C. to 200° C., the actual ambient pressure pIst is reduced at the same time. This is because the boiling point of the high boiling point solvent LH decreases with the decrease of the actual ambient pressure pIst. In this case, the actual ambient pressure pIst can be greatly reduced, preferably to less than 100 mbar, in particular to about 30 mbar, so that the high boiling point solvent LH has evaporated when the actual ambient temperature Tist is less than 200° C. (for example, 150° C.).

[0075] Since the boiling point of the low-boiling solvents LL is already below the preset 150° C. to 200° C. at atmospheric pressure, these solvents will also evaporate. Therefore, when the nominal ambient temperature Tsoll and the nominal ambient pressure pSoll are specifically preset by the control device 8, the most difficult to evaporate solvent in the electrolyte should be taken into account, because all the more easily evaporated solvents will then automatically evaporate together. By the targeted and coordinated preset of the nominal ambient pressure pSoll and the nominal ambient temperature Tsoll and the subsequent setting in the drying container 4a, all (relevant) liquid solvent components (LL, LH) in the comminuted material 101 can change their aggregate state from liquid to gaseous without simultaneously causing the solid plastic components in the comminuted material 101 to reach their yield point.

[0076] In a second intermediate step ST2.2, the low-boiling and high-boiling solvents LL, LH, which are then at least intermittently co-evaporated and / or at least intermittently evaporated successively, can be withdrawn from the same drying container 4a via the same fluid connection in an intermittently combined and / or intermittently fractionated manner and conveyed to an exhaust gas treatment device 9 which is fluidically connected to the drying container 4a. The exhaust gas treatment can then be carried out in this exhaust gas treatment device.

[0077] In order to further optimize the entire drying process or heat treatment process in the drying container 4a, the actual ambient pressure pIst in the drying container 4a can be increased again in a third intermediate step ST2.3, during which the vacuum pump 4c and / or the regulating valve 4g (if present) are controlled accordingly, wherein for this purpose, for example, an intermediate ambient pressure pZ of 500 mbar or higher is temporarily preset by the control device 8 as the nominal ambient pressure pSoll, while the nominal ambient temperature TSoll is kept between 150° C. and 200° C., preferably at 150° C. In this case, the pressure is increased by introducing, for example, nitrogen or another inert gas, in order not to impair the heat treatment process in the drying container 4a.

[0078] By this pressurization, the number of gas molecules in the drying container 4a is intermittently increased again, thereby improving the energy or heat transfer from the at least one heating device 4b to the pulverized material 101 in a short time and allowing the pulverized material 101, which may have cooled slightly during this period, to be heated up again. Subsequently, in the fourth intermediate step ST2.4, after the waiting time tW, a final ambient pressure pE of 0.01 mbar to 100 mbar, in particular 30 mbar to 100 mbar, preferably 30 mbar, can be preset and set again as the nominal ambient pressure pSoll, so as to reduce the boiling point of all solvent components (LL, LH) in the reheated pulverized material 101 to the preset nominal ambient temperature TSoll or to or below the nominal ambient temperature.

[0079] The third and fourth intermediate steps ST2.3 and ST2.4 can be repeated multiple times during the drying process or heat treatment process in the drying container 4a, wherein the evaporation of the corresponding solvent L is again "stimulated" by the pulse change of the actual ambient pressure pIst, thereby achieving reliable separation of all solvent components (LL, LH) in the crushed material 101.

[0080] In this case, the drying process described in the drying container 4a is carried out within a fixed processing time tB, which processing time may be related to which embodiment or which intermediate steps ST2.1, ST2.2, ST2.3, ST2.4 are implemented. In this case, the processing time tB is determined so that it is assumed that all solvents L (LL, LH) contained in the pulverized material 101 have the possibility of evaporating as completely as possible under given conditions at the current actual ambient temperature TIst and the actual ambient pressure pIst. If a thermal pretreatment is carried out in the pulverizing chamber 3a, the processing time tB can be shortened in some cases.

[0081] After the drying process or heat treatment process in the drying container 4a is completed after the specified treatment time tB, in the third step ST3, the drying container 4a is allowed to reach atmospheric pressure again, and the dried or heat-treated solvent-free crushed material 101 is taken out from the discharge port 7 and transferred to the mechanical processing area 5 for mechanical preparation.

[0082] Reference numerals list

[0083] 1. Preparation equipment

[0084] 2 Preparation area

[0085] 3 Crushing Area

[0086] 3a Crushing room

[0087] 4 Drying area

[0088] 4a Drying container

[0089] 4b Heating device

[0090] 4c vacuum pump

[0091] 4d mixing device

[0092] 4e Temperature Sensor

[0093] 4f pressure sensor

[0094] 4g regulating valve

[0095] 5Machining area

[0096] 6 Feed port

[0097] 7 discharge port

[0098] 8 Control device

[0099] 9 Waste gas treatment device

[0100] 10 Inert Gas

[0101] 100 batteries to be recycled

[0102] 101 Crushing materials

[0103] dp pressure gradient

[0104] dT Temperature gradient

[0105] Solvent

[0106] LL low boiling point solvent

[0107] LH high boiling point solvent

[0108] pE Final ambient pressure

[0109] pIst Actual environmental pressure

[0110] pSoll nominal ambient pressure

[0111] pZ Intermediate ambient pressure

[0112] tBProcessing time

[0113] TE final ambient temperature

[0114] TIst actual ambient temperature

[0115] TSoll nominal ambient temperature

[0116] TZ crushing temperature

[0117] tW Waiting time

[0118] ST1, ST2, ST2.1, ST2.2, ST2.3, ST2.4, ST3 method steps

Claims

1. A method for preparing a battery (100) to be recycled, in particular a lithium-ion battery, comprising at least the following steps: - providing at least one battery (100) to be recycled; - pulverizing the provided battery to be recycled (100) to obtain pulverized material (101) (ST0), wherein the provided battery to be recycled (100) and / or the pulverized material (101) obtained therefrom are subjected to thermal pretreatment in a pulverizing chamber (3a) by heating to a pulverizing temperature (TZ) below 100°C; - transferring the pulverized material (101) to a drying container (4a) (ST1) and subjecting the pulverized material (101) to a heat treatment (ST2) by increasing the actual ambient temperature (TIst) and reducing the actual ambient pressure (pIst) in the drying container (4a) so as to heat the pulverized material (101) in the drying container (4a) and evaporate the solvent (L) contained in the pulverized material (101), wherein the actual ambient temperature (TIst) in the drying container (4a) is set so that the temperature of the pulverized material (101) is increased to no more than 200° C., and the actual ambient pressure (pIst) in the drying container (4a) is set so that a low boiling point solvent (LL) and a high boiling point solvent (LH) are separated from the pulverized material (101) by evaporation at the set actual ambient temperature (TIst), wherein the low boiling point solvent (LL) and the high boiling point solvent (LH) are discharged from the same drying container (4a) during the heat treatment of the pulverized material (101) (ST2.2); and - Mechanically prepare the heat-treated pulverized material (101) (ST3).

2. The method according to claim 1, characterized in that The pulverized material (101) is thermally pretreated in the pulverizing chamber (3a) before mechanical preparation (ST3), and the pulverized material is thermally treated in the drying container (4a).

3. The method according to any one of the preceding claims, characterized in that During the heat treatment of the pulverized material (101) in the drying container (4a), the low-boiling point solvent (LL) and the high-boiling point solvent (LH) are discharged from the same drying container (4a) at least intermittently together and / or at least intermittently independently of each other (ST2.2).

4. The method according to any one of the preceding claims, characterized in that Between the separation of the low boiling point solvent (LL) and the separation of the high boiling point solvent (LH), the crushed material (101) located in the drying container (4a) is not taken out from the drying container (4a), so that the low boiling point solvent (LL) and the high boiling point solvent (LH) can be discharged from the same drying container (4a).

5. The method according to any one of the preceding claims, characterized in that During the heat treatment (ST2) of the pulverized material (101), the actual ambient pressure (pIst) in the drying container (4a) is reduced to a final ambient pressure (pE) of 0.01 mbar to 100 mbar, in particular 30 mbar to 100 mbar, preferably 30 mbar.

6. The method according to claim 5, characterized in that During the heat treatment (ST2) of the pulverized material (101), the actual ambient pressure (pIst) in the drying container (4a) is temporarily increased to a preset intermediate ambient pressure (pZ) (ST2.3), preferably starting from a previously set final ambient pressure (pE), and after a waiting time (tW), the actual ambient pressure (pIst) is reduced again from the intermediate ambient pressure (pZ) (ST2.4), preferably to the final ambient pressure (pE).

7. The method according to claim 6, characterized in that The intermediate ambient pressure (pZ) is, for example, between 500 mbar and 1000 mbar, preferably 1000 mbar.

8. The method according to claim 6 or 7, characterized in that: During the heat treatment (ST2) of the crushed material (101) in the drying container (4a), the actual ambient pressure (pIst) in the drying container (4a) is temporarily increased to the intermediate ambient pressure (pZ) (ST2.3) multiple times and then the actual ambient pressure (pIst) is reduced after the waiting time (tW) (ST2.4).

9. The method according to any one of the preceding claims, characterized in that During the heat treatment (ST2) of the pulverized material (101), the actual ambient temperature (TIst) in the drying container (4a) is brought to a preset final ambient temperature (TE) of 150°C to 200°C, preferably 150°C.

10. The method according to claim 9, characterized in that During the process of increasing the actual ambient temperature (TIst) in the drying container (4a), the actual ambient pressure (pIst) in the drying container (4a) will be reduced only when the actual ambient temperature (TIst) in the drying container (4a) reaches the preset final ambient temperature (TE) (ST2.1), wherein the actual ambient pressure (pIst) in the drying container (4a) is maintained at atmospheric pressure before this.

11. The method according to claim 9, characterized in that The actual ambient pressure (pIst) in the drying container (4a) is reduced by a pressure gradient (dp), while the actual ambient temperature (TIst) in the drying container (4a) reaches a preset final ambient temperature (TE) by a temperature gradient (dT), wherein the pressure gradient (dp) is preferably smaller than the temperature gradient (dT).

12. The method according to any one of the preceding claims, characterized in that The pulverized material (101) is intermittently subjected to heat treatment (ST2) in the drying container (4a), wherein the pulverized material (101) to be heat treated is transferred to the drying container (4a), and then the drying container (4a) is sealed in a vacuum-tight manner until the heat-treated pulverized material (101) is transported to mechanical preparation (ST3).

13. The method according to any one of the preceding claims, characterized in that The pulverized material (101) transferred to the drying container (4a) is preferably mixed and / or loosened by a mixing device (4d) before and / or during and / or after the heat treatment.

14. The method according to claim 13, characterized in that The mixing device (4d) is heated in the drying vessel (4a) at least during the heat treatment.

15. The method according to any one of the preceding claims, characterized in that Before and / or during the heat treatment (ST2) of the pulverized material (101), an inert gas (10) is introduced into the drying container (4a).

16. A production plant (1), in particular for carrying out the method according to any one of the preceding claims, comprising at least: a comminution zone (3) comprising a comminution chamber (3a) for processing the provided batteries to be recycled (100) into comminuted material (101) and for thermally pretreating the provided batteries to be recycled (100) and / or the comminuted material (101) obtained therefrom by heating to a comminution temperature (TZ) below 100° C.; - a drying area (4) for thermally treating the pulverized material (101), the drying area comprising a drying container (4a) for accommodating the crushed material (101), at least one heating device (4b) arranged in the drying container (4a) for increasing the actual ambient temperature (TIst) in the drying container (4a), and a vacuum pump (4c) fluidically connected to the drying container (4a) for reducing the actual ambient pressure (pIst) in the drying container (4a); - a mechanical processing area (9) for mechanically preparing the heat-treated pulverized material (101); and - a control device (8) adapted to control at least one heating device (4b) and a vacuum pump (4c) in the drying area (4) so ​​that the pulverized material (101) in the drying container (4a) is heated and the solvent (L) contained in the pulverized material (101) is evaporated, It is characterized in that The control device (8) is also suitable for - setting the actual ambient temperature (TIst) in the drying container (4a) so that the temperature of the pulverized material (101) contained therein rises to no more than 200°C, and - Setting the actual ambient pressure (pIst) in the drying container (4a) so that the low boiling point solvent (LL) and the high boiling point solvent (LH) can be separated from the pulverized material (101) by evaporation at the set actual ambient temperature (TIst), thereby discharging the low boiling point solvent (LL) and the high boiling point solvent (LH) from the same drying container (4a) during the heat treatment of the pulverized material (101).

17. The preparation device (1) according to claim 16, characterized in that The drying container (4a) is provided with a feed port (6) for loading the crushed material (101) and a discharge port (7) for taking out the heat-treated crushed material (101), wherein the discharge port (7) is arranged on the bottom side of the drying container (4a) so that the heat-treated crushed material (101) can be taken out of the drying container (4a) in a vertical direction.

18. The preparation device (1) according to claim 16 or 17, characterized in that A mixing device (4d) is arranged in the drying container (4a) for mixing and / or loosening the pulverized material (101) during the heat treatment.

19. The preparation device (1) according to any one of claims 16 to 18, characterized in that The drying container (4a) is fluidly connected to the exhaust gas treatment device (7) so that the low boiling point solvent (LL) and the high boiling point solvent (LH) separated during the heat treatment of the pulverized material (101) in the drying container (4a) are transferred from the same drying container (4a) to the exhaust gas treatment device (7) during the heat treatment of the pulverized material (101).

20. The preparation device (1) according to any one of claims 16 to 19, characterized in that A regulating valve (4g) is arranged between the drying container (4a) and a vacuum pump (4c) fluidically connected to the drying container (4a), wherein the regulating valve (4g) is controlled by the control device (8) so that the actual ambient pressure (pIst) in the drying container (4a) is close to a preset nominal ambient pressure (TSoll).

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