Method for recycling rechargeable batteries and equipment for treating rechargeable batteries

Abstract

The present invention relates to a method for recycling rechargeable batteries, in particular lithium and / or sodium rechargeable batteries, which consist of at least one galvanic element, each having two poles, and which contains a conductive salt dissolved in a conductive salt solvent, comprising: The present invention relates to a method comprising the steps of: (a) short-circuiting a rechargeable battery until at least 75% of the galvanic elements have a regenerative cell voltage of at most 0.3 volts, in particular at most 0.2 volts; and (b) then pulverizing the rechargeable battery to obtain pulverized material.

Description

[Technical field]

[0001] The present invention relates to a method for recycling rechargeable batteries, in particular lithium or sodium rechargeable batteries, which contain a conductive salt dissolved in a conductive salt solvent, the rechargeable batteries in particular consisting of at least one galvanic element, each having two poles.

[0002] According to a second aspect, the present invention relates to a rechargeable battery treatment facility, in particular a lithium rechargeable battery treatment facility, comprising: (a) a rechargeable battery crushing facility for crushing rechargeable batteries to obtain crushed material; and (b) a cleaning device for washing the crushed material with a cleaning solvent to obtain a cleaning liquid. [Background technology]

[0003] When rechargeable batteries are no longer usable, they need to be recycled, where the substances or chemical elements present in the rechargeable battery are separated so that they can be used again to manufacture rechargeable batteries or for other purposes.

[0004] In recycling, also known as regeneration, it is desirable to produce as few unwanted by-products as possible, and in particular to produce as few greenhouse gases as possible, since the desire to reduce the amount of greenhouse gases produced in the energy supply is one of the reasons for the increased use of rechargeable batteries.

[0005] A number of methods are known for recycling rechargeable batteries, particularly lithium rechargeable batteries, but they have a relatively large CO2 footprint.

[0006] In particular, it is desirable to recycle as many components of a rechargeable battery as possible so that they can be used to manufacture rechargeable batteries again. This has proven difficult. Summary of the Invention

[0007] The invention is based on the problem of improving the recycling of rechargeable batteries, in particular lithium rechargeable batteries.

[0008] The present invention solves this problem by a method for recycling rechargeable batteries, in particular lithium and / or sodium rechargeable batteries, which consist of at least one galvanic element, each with two poles, and which contains a conductive salt dissolved in a conductive salt solvent, comprising: (a) short-circuiting the rechargeable battery until at least 75% of the galvanic elements have a regeneration cell voltage of at most 0.4 volts, in particular at most 0.3 volts, preferably at most 0.2 volts, in particular at most 0.15 volts, and (b) then grinding the rechargeable battery to obtain a ground material. Preferably, the method comprises: (a) grinding the rechargeable battery to obtain a ground material, and (b) washing the conductive salt from the ground material with a washing solvent to obtain a washed ground material.

[0009] The present invention further solves this problem by a method for recycling rechargeable batteries, in particular lithium rechargeable batteries containing a conductive salt dissolved in a conductive salt solvent, comprising the steps of (a) pulverizing the rechargeable battery to obtain a pulverized material, and (b) washing the conductive salt from the pulverized material with a washing solvent to obtain a washed pulverized material. Preferably, the method comprises the steps of (a) short-circuiting the rechargeable battery until at least 75% of the galvanic elements have a regenerative cell voltage of up to 0.2 volts, in particular up to 0.15 volts, and (b) then pulverizing the rechargeable battery to obtain a pulverized material.

[0010] The advantageous embodiments described below relate to both inventions.

[0011] According to a second aspect, the present invention solves this problem by means of an attributed rechargeable battery treatment installation comprising a washing device for washing the ground material with a washing solvent to obtain a washing liquid.

[0012] Short-circuiting of rechargeable batteries leads to the recovery of conductive salts with particularly high purity. It is not fully understood why short-circuiting increases the purity of the recovered conductive salts. Presumably, the regenerative cell voltage significantly above 0 V generates localized heat during grinding, which can promote the decomposition of conductive salts and / or the production of hydrogen fluoride.

[0013] It should be noted that deep discharge alone does not result in a regenerative cell voltage of up to 0.2 V. Deep discharge is understood to mean that current is drawn from a rechargeable battery until the capacity is almost completely exhausted, in particular below the final discharge voltage. After deep discharge, the amount of energy in the rechargeable battery becomes very small, since on the one hand the cell voltage drops significantly and on the other hand the achievable discharge current is very small. Therefore, in the methods according to the prior art, only deep discharge is performed.

[0014] However, even after deep discharge, the energy content was found to be high enough to produce hydrogen fluoride. Although the amount of hydrogen fluoride produced when grinding a deeply discharged but unshorted rechargeable battery is relatively small, it has been found that even minor contamination of the conductive salt with decomposition products can compromise the suitability of the conductive salt and / or electrolyte for manufacturing new rechargeable batteries.

[0015] By regeneration cell voltage is meant the cell voltage present at the respective galvanic element after a certain regeneration time during which the poles of the rechargeable battery are not electrically connected. The feature that the poles of the rechargeable battery are not electrically connected is meant that the poles are insulated from one another, i.e. in particular that there is a resistance of at least 1 megaohm between the two poles. In other words, during the regeneration time no electrical energy is extracted from the galvanic element. In particular, during the regeneration time the poles of the galvanic element of the rechargeable battery are not electrically connected.

[0016] During the regeneration time, the cell voltage will increase. For example, discharging a rechargeable battery to a cell voltage below 0.2V will result in a regenerative cell voltage above 0.2V if the discharge is not continued for a long enough period of time.

[0017] A Samsung rechargeable battery INR18650-25R manufactured in February 2022 was found to have a cell voltage of 0V after 1 hour of short circuit. The regenerative cell voltage was 1V. After 3 hours of short circuit, the cell voltage was 0V and the regenerative cell voltage was 0.8V. After 5 hours of short circuit, the cell voltage was 0V and the regenerative cell voltage was 0.6V. After 24 hours of short circuit, the cell voltage was 0V and the regenerative cell voltage was 0.2V.

[0018] A long-term short circuit of the rechargeable battery, in which the regenerative cell voltage is a maximum of 0.4 V, in particular a maximum of 0.3 V, in particular a maximum of 0.2 V, can also be called an anti-regeneration short circuit, i.e. it is advantageous if the comminution of the rechargeable battery is carried out only after the anti-regeneration short circuit of the rechargeable battery.

[0019] Whether or not an anti-regenerative short circuit has been performed can be verified by storing the corresponding rechargeable battery at 1013 hPa and 23 °C during the regeneration time without any external electrical load and in particular without any short circuit. In other words, if the rechargeable battery is crushed or otherwise handled before the end of the regeneration time, a short circuit of the rechargeable battery may also occur until at least 75% of the galvanic elements are at the specified maximum regeneration cell voltage. The only determining factor is whether or not they have been short-circuited in such a way that the specified regeneration cell voltage is not exceeded after the end of the regeneration time.

[0020] The regenerative time is 12 hours. Note that this does not indicate how long the rechargeable battery will be shorted. In particular, a 12 hour short on a rechargeable battery may still cause the regenerative cell voltage to exceed 0.2 volts.

[0021] Preferably, the rechargeable battery is short-circuited for a short-circuit time of at least 8 hours, particularly at least 10 hours, preferably at least 12 hours, particularly at least 15 hours, particularly at least 18 hours. A short-circuit time of at least 20 hours, for example 24 hours, is particularly preferred. A short-circuit time of less than 120 hours is preferred. In this way, it is possible to achieve, as contemplated by the preferred embodiment, that at least 90 weight percent, particularly at least 95 weight percent of the conductive salt of the rechargeable battery does not decompose during grinding.

[0022] It is advantageous if the short circuit is effected by means of a metallic conductor, which connects the poles of the rechargeable battery, i.e. the negative and positive poles, in an unloaded manner, meaning that the metallic conductor does not connect the poles of the rechargeable battery to an electrical resistance or to other power consumers. It is particularly advantageous if the connection of the negative and positive poles is effected without the use of liquids, in particular without salt solutions.

[0023] Preferably, during short circuit, the electrical resistance between the positive pole of the rechargeable battery and the negative pole of the rechargeable battery is at most 10 ohms, in particular at most 1 ohm, preferably at most 0.3 um.

[0024] It is possible, but not essential, to transport the rechargeable battery after the anti-regenerative short circuit, in particular over a distance of at least 1 km, in particular at least 5 km. The anti-regenerative short circuit particularly reduces the risk of fire from the rechargeable battery and thus the dangerous impact on the environment. It is preferable not to transport the rechargeable battery after the anti-regenerative short circuit over a distance of more than 1 km. Such transportation may pose a safety risk.

[0025] Preferably, the method comprises drying the ground material at a temperature of at most 80°C, in particular at most 70°C, particularly preferably at most 60°C, for example at most 50°C, and a pressure of at most 300 hPa, in particular at most 50 hPa, to obtain a dried ground material.

[0026] Preferably, at least 40% by weight, in particular at least 50% by weight, preferably at least 60% by weight, particularly preferably at least 70% by weight of the electrolyte solvent is removed by drying. Preferably, at most 95% by weight, in particular at most 90% by weight, particularly preferably at most 85% by weight of the electrolyte solvent is removed. Since washing away the conductive salt with a washing solvent leads to a relatively high CO2 footprint of the method, it is advantageous to remove only the solvent part of the electrolyte that cannot be removed well by drying.

[0027] It is advantageous if the conductive salts are washed away from the dried ground material thus obtained using a washing solvent.

[0028] Preferably, before washing off the conductive salt, the black mass is separated and the conductive salt is washed off from the black mass. Preferably, the separation of the black mass is carried out after drying.

[0029] By screening is understood the process of separating the black mass from the other constituents of the ground material. The separation of heavy substances and / or foils, in particular from the dried ground matter, means screening the black mass.

[0030] It may be advantageous if the rechargeable battery is short-circuited during grinding, which results in particularly low losses of conductive salts.

[0031] An advantage of the present invention is that, if the rechargeable battery contains fluorine, washing off the conductive salts removes most of the fluorine from the ground material, which can react to form hydrogen fluoride and / or organic fluorine species that can be highly toxic and / or cause significant wear to rechargeable battery processing equipment.

[0032] In order for the conductive salt and / or the conductive salt solvent to be able to be used again in the manufacture of rechargeable batteries without complex cleaning, it must be highly pure, which proves difficult to achieve by simply short-circuiting the rechargeable battery, washing off the conductive salt with a cleaning solvent and / or drying under vacuum at up to 80° C. However, by combining the two methods, particularly pure conductive salts and / or conductive salt solvents can be obtained.

[0033] At least when lithium rechargeable batteries are also being treated, most of the lithium can be removed relatively simply by washing away the conductive salts, which can potentially facilitate subsequent wet chemical extraction.

[0034] If the conductivity salt solvent contains a component with a boiling point higher than that of the washing solvent of a preferred embodiment of the present invention, washing away the conductivity salt will usually remove most of this component as well, and in the subsequent drying step contemplated by a preferred embodiment, little or no removal of this component is required, which facilitates drying.

[0035] Within the scope of this specification, a lithium rechargeable battery is understood to be a rechargeable battery in which useful electrical energy is provided by an electrochemical reaction with lithium. Lithium rechargeable batteries contain an electrolyte, which is a conductive salt solvent.

[0036] By grinding material is meant the product of the grinding of rechargeable batteries. The grinding material can be altered or divided into various fractions by further mechanical separation steps. The grinding material does not exist after chemical transformation, i.e. chemical reactions, such as combustion or mixing with acids, which are not carried out solely to adjust the pH value.

[0037] Washing is understood in particular to mean adding and removing a washing solvent to the ground material, whereby the conductive salt is transferred into the washing solvent. Washing can include continuous addition and removal of the washing solvent, in which case it is referred to as continuous washing. Washing can also include a one-time addition and a one-time release of the washing solvent, in which case it is referred to as intermittent washing. Washing can also include several discontinuous additions and releases of the washing solvent, in which case it is referred to as semi-continuous washing. Thus, in the following, "washing" or "washing" always means adding and removing the washing solvent.

[0038] The washing solvent is preferably an organic solvent. Preferably, the washing solvent is a pure substance, i.e. it is not a mixture. The characteristic that the washing solvent is a pure substance is understood in particular to mean that at least 85 weight percent, in particular at least 90 weight percent of the washing solvent is made up of a pure substance. However, a mixture of several pure substances can also be used. The mixture preferably contains a maximum of three components.

[0039] For example, the washing solvent is acetone, acetoacetate, ethyl acetate, methyl ethyl ketone and / or tetrahydrofuran. Preferably, the washing solvent does not contain N-methyl-2-pyrrolidone.

[0040] The washing solvent may also be a supercritical fluid, such as supercritical carbon dioxide, or a fluid that is gaseous at 1013 hPa and 30° C., such as liquid carbon dioxide, which results in a particularly high purity of the recovered solvent of the recovered conductive salt and / or electrolyte.

[0041] By black mass is meant the graphite-containing fraction of the ground material which is produced by separating housing parts and metal parts, such as connecting electrodes, and foils, such as separator foils or conductor foils of components, from the ground material.

[0042] By foils in particular are understood parts of separator foils and conductor foils.

[0043] According to a preferred embodiment, the conductive salt is a fluorine compound and / or contains at least 5 weight percent of a fluorine compound, which is preferably LiPF6 or NaPF6. In this case, it is advantageous if the flushing is carried out until the amount of conductive salt (measured by weight) is reduced by at least 80%, in particular by at least 90%.

[0044] Preferably, the conductive salt is a lithium compound or contains at least 50 weight percent of a lithium compound. In that case, it is preferable to remove a large portion, particularly at least half, of the total lithium in the ground material by removing the conductive salt. The conductive salt, and therefore the lithium, can be more easily removed from the washing solvent than from the ground material.

[0045] Preferably, the conductive salt is a chloride compound or contains at least 50% by weight of a chloride compound. Preferably, the conductive salt is a boron compound, such as sodium tetraborate, or contains at least 50% by weight of a boron compound. Such conductive salts are particularly sensitive to localized heating that may occur if a rechargeable battery is not short-circuited for a sufficiently long time.

[0046] Preferably, the rinsing is carried out until at least 80% of ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and / or diethyl carbonate (DEC) is removed. Alternatively or additionally, the rinsing is preferably carried out until at least 80% of fluorobenzene, methanol; ethanol, propylene carbonate, phenylcyclohexane (cyclohexylbenzene) and / or trimethyl(trifluoromethyl)silane is removed.

[0047] Preferably, the method includes the step of removing the wash solvent from the ground material, which can be done, for example, by siphoning, filtering, draining or allowing to run off.

[0048] Preferably, the method includes the step of separating the wash solvent from a wash liquid produced by washing the conductive salt from the ground material with the wash solvent.

[0049] This results in a regenerated washing solvent. In this way, as contemplated by the preferred embodiment, the washing solvent can be reused, i.e. added again to the ground material. It is preferred to circulate the washing solvent, i.e. use it repeatedly.

[0050] The separation of the washing solvent from the washing liquid is carried out, for example, by distillation, in particular continuous distillation. Alternatively or additionally, the separation may involve gravity separation and / or centrifugation and / or filtration.

[0051] Advantageously, the method comprises a step of wet-chemical extraction of at least one metal component from the ground material, the wet-chemical extraction preferably comprising the addition of a mineral acid, in particular sulphuric acid or hydrochloric acid.

[0052] The wet chemical extraction preferably includes the step of adding concentrated sulfuric acid, which removes at least 80%, particularly at least 90%, of the remaining fluorine. By pre-washing out the conductive salts, less sulfuric acid should be used to remove the fluorine. This leads to less waste and reduced resource consumption.

[0053] The conductive salt solvent has a maximum boiling point, which is the temperature at which at least 99 weight percent of one liter of the conductive salt solvent will evaporate after one hour at 1013 hpa and at this temperature. If the conductive salt solvent is composed of pure substances, as contemplated by a preferred embodiment, the maximum boiling point corresponds to the boiling point of the conductive salt solvent. If the conductive salt solvent is a mixture of pure substances, each having a boiling point, as contemplated by an alternative embodiment, the maximum boiling point is the boiling point of the highest boiling component.

[0054] Preferably, the maximum boiling point of the cleaning solvent is lower than the maximum boiling point of the conductive salt solvent. Preferably, the maximum boiling point of the cleaning solvent is at least 10 Kelvin lower than the maximum boiling point of the conductive salt solvent, preferably at least 20 Kelvin lower, particularly preferably at least 30 Kelvin lower.

[0055] It is advantageous if the washing solvent has a maximum boiling point of at most 90° C., preferably at most 80° C., particularly preferably at most 70° C., in particular at most 60° C., very particularly preferably at most 50° C. This facilitates the removal of the washing solvent in a subsequent drying step, which is preferably present. Furthermore, in the case of drying at such low temperatures, the generation of dangerous fluorine compounds, in particular hydrogen fluoride, is reduced or prevented.

[0056] The conductive salt in the cleaning solvent has a solubility expressed in grams of conductive salt per liter of cleaning solvent when the cleaning solvent is maximally saturated with the conductive salt. According to a preferred embodiment, the solubility of the conductive salt in the cleaning solvent is at least half of the solubility of the conductive salt in the electrolyte. It is particularly advantageous if the solubility of the conductive salt in the cleaning solvent is greater than the solubility in the conductive salt solvent.

[0057] Preferably, the washing off of the conductive salt is carried out using explosion-proof machinery and / or in an explosion-proof atmosphere.

[0058] Preferably, the washing solvent is a solvent for PVDF (polyvinylidene fluoride). PVDF is a binder often used in lithium batteries and contains fluorine. The appropriate washing solvent can also dissolve and remove the binder, which further reduces the fluorine concentration in the washed ground material.

[0059] Preferably, washing away the conductive salt further dissolves the binder. According to one preferred embodiment, washing with a washing solvent is performed until at least 70 weight percent, preferably at least 80 weight percent, in particular at least 90 weight percent of the binder is removed.

[0060] Preferably, the method includes the steps of (a) drying the washed ground material and, preferably, (b) thereafter separating foil, in particular metal foil and / or heavy substances from the washed ground material to obtain a black mass.

[0061] Alternatively, the method may include the steps of (a) separating foil, particularly metal foil and / or heavy materials, from the washed ground material, and (b) thereafter drying the washed ground material.

[0062] Drying is preferably carried out under negative pressure. For example, during drying, the pressure is at most 700 hPa, in particular at most 600 hPa, preferably at most 500 hPa. In particular, the pressure is at least 100 hPa, preferably at least 200 hPa, in particular at least 300 hPa. During drying, the temperature is preferably at most 90°C, preferably at most 80°C, particularly preferably at most 70°C, in particular at most 60°C, and very particularly preferably at most 50°C.

[0063] According to a preferred embodiment, drying is terminated when so much washing solvent has been removed that a flammable atmosphere cannot form at 23° C. and 1013 hPa in a 50 liter barrel half-filled with dried material.

[0064] If the metal foil is separated, according to a preferred embodiment, it is also dried after washing and / or the black mass adhering to the metal foil is separated, for example by air jet sieving.

[0065] Preferably, the method includes a step of drying the ground material after grinding, in particular without prior washing. Drying is preferably carried out at a temperature of at most 80°C, in particular at a temperature of at most 70°C, preferably at a temperature of at most 60°C, particularly preferably at a temperature of at most 50°C. In this way, a dried ground material is obtained. Preferably, drying is carried out under negative pressure, the pressure being preferably at most 600hPa, in particular at most 300hPa.

[0066] Drying is preferably carried out so that at most 30 weight percent, in particular at most 20 weight percent, of the high-boiling components, whose vapor pressure at 50° C. is less than 10 hPa, in particular less than 5 hPa, is removed. Further removal of these components requires a lot of time and energy. Subsequent washing of the ground product allows the high-boiling components to be washed away and removed.

[0067] Alternatively or additionally, drying is terminated before more than 95 weight percent, particularly more than 90 weight percent, of the conductive salt solvent is removed. Electrolyte components remain in the ground material, which are particularly difficult to remove. These components can then be simply washed out of the ground material in a process contemplated by preferred embodiments in which a wash solvent is used to wash out the conductive salt.

[0068] From the dried ground material, in a process contemplated according to a preferred embodiment, the weights, in particular the ground parts of the housing, and / or the foils, in particular the metal foils, are separated out, thus obtaining ground material in the form of a black mass.

[0069] The separation of heavy objects, in particular plastic housing parts, prevents these objects from being dissolved by the cleaning solvent during any subsequent cleaning, which could lead to contamination of the cleaning solvent.

[0070] According to a preferred embodiment, the method includes a step of separating the foil from the possibly dried ground material into a plastic foil and a metal foil. The metal foil is often coated with black mass, which often does not peel completely off from the metal foil. In contrast, the plastic foil is usually not coated with black mass, but may be dissolved or swollen by the washing solvent, which is often undesirable. By separating the foil into the plastic foil and the metal foil, which is performed, for example mechanically, the two types of foil can be processed separately.

[0071] Preferably, the metal foil is washed with a washing solvent after separation from the plastic foil. This can be done together with the separated black mass or separately. If, as contemplated by the preferred embodiment, the metal foil is not washed off (also together with other foils) before being separated from the plastic foil, the metal foil is preferably washed off together with the black mass that is not attached to the metal. Alternatively or additionally, the metal foil is washed separately. The latter has the advantage that, for most types of lithium batteries, a black mass containing cobalt in particular is obtained when washing off.

[0072] The black mass is in the form of ground material. According to a preferred embodiment, the conductive salts are washed out of the ground material using a washing solvent.

[0073] Preferably, the washed black mass thus obtained is then dried. Drying is preferably carried out at a temperature of at most 70° C., preferably at a temperature of at most 60° C., particularly preferably at a temperature of at most 50° C. In this way, a dried ground material is obtained. Preferably, drying is carried out under negative pressure, the pressure being preferably at most 600 hPa, in particular at most 300 hPa.

[0074] However, drying can also be carried out at temperatures above 80°. In that case, fluorine compounds such as hydrogen fluoride can be formed. However, by washing off the conductive salt beforehand, the amount of hydrogen fluoride formed is reduced.

[0075] The rechargeable battery treatment plant according to the invention preferably comprises a washing solvent regeneration plant, which separates the washing solvent from the washing liquid and returns the washing solvent to the washing plant. The washing solvent regeneration system comprises, for example, a distillation plant.

[0076] Preferably, the rechargeable battery treatment facility has a dryer designed to dry the dried ground material, which is arranged downstream or upstream of the washing device in the material flow direction. In particular, the dryer is arranged immediately after or immediately before the washing device, which means that the dryer is directly connected to the washing device. This connection is preferably dust-proof, in particular airtight.

[0077] According to a preferred embodiment, the rechargeable battery treatment plant has a separation device for separating heavy substances and / or foils, in particular plastic and / or metal foils, of the material to be ground. This separation device can be arranged upstream or downstream of the cleaning device in the material flow direction. It is also possible for the rechargeable battery treatment plant to have two separation devices, one of which is arranged upstream of the cleaning device in the material flow direction and the other downstream of the cleaning device.

[0078] It is possible, but not essential, that the separating apparatus forms part of or shares a housing with the cleaning apparatus, however it is preferred that the separating apparatus is located separately from the cleaning apparatus.

[0079] Preferably, the rechargeable battery treatment facility comprises a wet chemical treatment facility for wet chemical extraction of at least one metal component from the washed black mass. The wet chemical treatment facility preferably comprises at least one reactor designed to mix the washed black mass with a mineral acid, in particular concentrated sulfuric acid. For this purpose, the reactor comprises a sulfuric acid supply line and a sulfuric acid vessel, which is preferably filled with sulfuric acid.

[0080] The treatment facility preferably includes an exhaust gas purification facility for purifying exhaust gas generated when the washed black mass is mixed with concentrated sulfuric acid. The exhaust gas purification facility includes, for example, a hydrogen fluoride precipitator for precipitating hydrogen fluoride. For this purpose, for example, a liquid containing calcium ions can be used.

[0081] The rechargeable battery processing equipment is preferably designed to be explosion-proof. If, as contemplated by a preferred embodiment, a solvent having a flash point below 250° C. is used, there may be a risk of explosion without protective measures. Therefore, in particular, the lines leading from the cleaning device 22 are preferably designed to be explosion-proof. Particularly preferably, all lines in the material flow path between the rechargeable battery crushing equipment and the dryer are designed to be explosion-proof.

[0082] The present invention will now be described in detail with reference to the accompanying drawings. [Brief description of the drawings]

[0083] among them [Figure 1] 1 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out a method according to the invention according to a first embodiment.

[0084] [Diagram 2] 2 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a second embodiment.

[0085] [Diagram 3]3 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a third embodiment.

[0086] [Figure 4] 4 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a fourth embodiment.

[0087] [Diagram 5] 5 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a fifth embodiment.

[0088] [Figure 6] 6 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a sixth embodiment.

[0089] [Figure 7] 7 shows a schematic diagram of a rechargeable battery treatment installation according to the invention for carrying out the method according to the invention according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0090] Figure 1 shows a rechargeable battery treatment installation 8 for treating rechargeable batteries 10.1, 10.2, .... The rechargeable batteries may for example be present in the form of battery systems each comprising a number of galvanic cells and a charge controller.

[0091] The rechargeable battery is first deeply discharged in the discharge station 12. In that case, the voltage between the electrodes of the rechargeable battery is, for example, less than 0.1 V.

[0092] After deep discharge, the rechargeable batteries 10.1, 10.2, ... are short-circuited using a metal wire, preferably a copper wire. The resistance of the copper wire is, for example, 1 ohm. The short-circuit time T k In this case, T k = 20 hours. As a result, the regenerative cell voltage U regis U reg =0.2V.

[0093] After discharging, the individual battery cells are removed from the battery system at an optional dismantling station 14 .

[0094] The rechargeable battery treatment facility 8 comprises a rechargeable battery crushing facility 16 for crushing the rechargeable batteries 10.1, 10.2, ... to obtain crushed material 18. The rechargeable battery crushing facility 16 is designed, for example, to shred, crush or grind the rechargeable batteries 10.1, 10.2, ....

[0095] Downstream of the rechargeable battery crushing installation 16 in the material flow direction, an optional (and therefore shown in dashed lines, like all optional components) separation device 20 can be arranged. With the separation device 20, the crushed material 18 is separated into a black mass 58 and a residual fraction. The residual fraction comprises housing parts, usually crushed plastic parts, metal parts, e.g. connection electrodes, and foils, e.g. separator foils or conductive foils of the parts. In the case of lithium rechargeable batteries, the black mass 58 comprises graphite, substances contained in the graphite, e.g. metal salts, conductive salt solvents, and conductive salts. If the separation device 20 is present, it is preferably connected to the rechargeable battery crushing installation 16 via a dust-proof, in particular gas-tight line.

[0096] A washing device 22 is arranged downstream of the rechargeable battery crushing installation 16 in the material flow direction and downstream of the separating device 20, if present. The washing device 22 can also be called a washer. In the washing device 22, the crushed material is mixed with a washing solvent 24. It is advantageous, but not essential, for the washing device 22 to have a mixer, for example an agitator or a rotatably supported drum.

[0097] Upon contact with the ground material 18, the wash solvent 24 becomes a wash liquid 26. The wash liquid 26 contains conductive salts and is regenerated by an optional wash solvent regeneration facility 28 and fed back to the washer 22.

[0098] If a separation device 20 is present, then there can also be an optional foil separator 31, by means of which the metal foil 61 is separated from the residual fraction. The metal foil 61 thus obtained can also be fed to the washing device 22.

[0099] Downstream of the washer 22 in the material flow direction is a dryer 30 for drying the washed grinding material, in particular the washed black mass 58. The dryer 30 is separated from the washer 22 by a gate 32.1. The components not separated by the foil separator 31 are dried in the dryer 30 or in a separate dryer. If the components not separated by the foil separator 31 are dried in the dryer 30, this is preferably done at a time offset from the black mass 58.

[0100] A gate 32.2 can also be arranged between the rechargeable battery crushing plant 16 and the washing device 22. If a separating device 20 is present, a gate 32.3 can also be arranged between the separating device 20 and the washing device 22.

[0101] The dryer 30 optionally comprises a mixer 34, which may be, for example, a vermixer. The mixer 34, and in particular the mixing elements of the mixer, can be cooled or heated.

[0102] The pressure p30 in the dryer 30 is preferably p30≦700 hPa, in particular p30≦600 hPa. The temperature T30 in the dryer is in particular at most 70° C., in particular at most 50° C.

[0103] If the separating device 20 is not present, the dried ground material can be separated into black mass and a residual fraction in an optional separating device 36 arranged downstream of the dryer 30 in the material flow direction. The residual fraction consists, for example, of heavy substances and metal foils. Typically, the rechargeable battery treatment plant 8 only has one separating device 20, 36.

[0104] If a separator is present and metal foil is fed to the washer 22, the dried ground material can be separated into black mass and washed metal foil in the optional separator 36.

[0105] The dried ground material, in particular the dried black mass 58, is either filled into transport containers 38 or fed to a wet-chemical treatment plant 40. In the treatment plant 40, the metal components of the black mass 58 (in the form of metal salts) are put into solution. For this purpose, the black mass is mixed, for example, with a mineral acid, in particular concentrated sulfuric acid, and is leached, in particular with water. The exhaust gas 42 which is then generated is fed to an exhaust gas purification plant 44, where, for example, hydrogen fluoride is removed and, for example, precipitated.

[0106] The wash solvent regeneration facility 28 comprises, for example, a distillation column. First, the wash liquid 26 is converted to a gaseous state, for example by a heating device 46 or by applying a negative pressure using a vacuum pump 48. The resulting gaseous components are fractionated and condensed.

[0107] The fraction whose boiling temperature corresponds to the boiling temperature of the washing solvent 24 is returned to the washing device 22 .

[0108] The high boiling point component 50 and the low boiling point component 52 are further processed, for example distilled again, so that the components of the electrolyte of the rechargeable battery 10 can be reused. The non-condensable components 54, mainly air, are purified in an exhaust gas purification system 56 and then released into the environment. The high boiling point components 50 are components whose boiling point is higher than the maximum boiling point of the washing solvent.

[0109] However, the wash solvent regeneration facility 28 is not necessary. Alternatively, the wash solvent 24 can be supplied to the wash device 22 from a storage vessel and the wash liquid 26 can be conducted to the storage vessel. Optional treatment of the wash liquid 26 can then be carried out in a remote wash solvent regeneration facility.

[0110] 2 shows an alternative embodiment of a rechargeable battery treatment installation 8 according to the invention. The cleaning device 22 is arranged immediately after the rechargeable battery crushing installation 16 in the material flow direction. This is understood to mean that no associated treatment of the crushed material 18 takes place downstream of the rechargeable battery crushing installation 16 and upstream of the cleaning device 22 in the material flow direction. The crushed material 18 is fed to the cleaning device 22 by means of a dust-proof, in particular airtight and / or explosion-proof line and via an optional gate 32.2.

[0111] After cleaning of the ground material 18, the black mass 58 is separated from the cleaned ground material in the separator 20 and reaches the dryer 30 via a line that is also dust-proof, in particular airtight and / or explosion-proof. In addition to the black mass 58, heavy material and foil are obtained, which can be dried in a separate dryer or in the dryer 30 if the latter is operated intermittently.

[0112] It is advantageous if the metal foil 61 is separated from the heavy material and foil in an optional foil separator 31. The metal foil 61 can be dried in the dryer 30 or in a separate dryer. If the metal foil 61 is dried in the dryer 30, this can be done together with the black mass 58 or staggered in time.

[0113] The pressure p30 in the dryer 30 located downstream of the washing device 22 in the material flow direction, which is a preferred feature regardless of the features otherwise described in connection with the figures, is preferably below the vapor pressure of the washing solvent 24 at 60° C., in particular at 50° C. The dried black mass 58 can be filled into a transport container 38 or fed directly to a wet-chemical treatment plant 40.

[0114] Figure 3 shows a third embodiment of a rechargeable battery treatment installation 8 according to the invention. The washing device 22 is again arranged immediately after the rechargeable battery crushing installation 16. The washed crushed material reaches a dryer 30. In an optional separation device 36 arranged immediately after the dryer 30, black mass 58 is separated from the dried crushed material. The fraction separated from the black mass 58 is treated as described above for Figure 2.

[0115] FIG. 4 shows a fourth embodiment of a rechargeable battery treatment installation 8 according to the invention, in which the ground material 18 from the rechargeable battery grinding installation 16 is led directly to a dryer 30 .

[0116] After drying, the black mass 58 is separated in a separator 36 and washed in a washer 22. The washed black mass is dried in a second dryer 60.

[0117] It is advantageous if the metal foil 61 is separated in the separating device 36 and then introduced into the washing device 22. The metal foil 61 and the black mass 58 can be washed together or one after the other. As a further alternative, the metal foil 61 can also be washed in a separate washing device. If the metal foil 61 and the black mass 58 are washed together, it is preferred to separate them from one another afterwards.

[0118] If the metal foil 61 is washed separately from the black mass, the rechargeable battery treatment equipment 8 preferably includes a separator to remove the black mass 58' adhering to the metal foil 61.

[0119] When the metal foil 61 and the black mass 58 are washed together and dried in the dryer 60, the rechargeable battery treatment equipment 8 preferably has a separation device for separating the metal foil 61 and the black mass 58 and a separator for peeling off the black mass 58' adhering to the metal foil 61.

[0120] According to a preferred embodiment, the heavy materials and / or plastic foils can be washed in the washing device 22 or in a separate washing device. The heavy materials and / or foils can be dried in the dryer 60 and / or in a separate dryer.

[0121] The final pressure p30,end in the dryer 30, i.e. the pressure at the end of the drying process, is preferably p30≦300 hPa, in particular p30≦50 hPa. The temperature T30 in the dryer is preferably at most 60° C., in particular at most 50° C.

[0122] 5 shows a fifth embodiment of a rechargeable battery treatment installation 8 according to the invention, in which the separating device 20 is arranged immediately after the washing device 22 in the material flow direction. The separated heavy materials and foils are dried out of time with respect to the black mass 58 in the dryer 60. Alternatively, the separating device 20 can also be arranged downstream of the second dryer 60 in the material flow direction.

[0123] 6 shows a further embodiment of a rechargeable battery treatment plant 8 according to the invention, in which downstream of the washing device 22 a separation device 20 separates the black mass 58 from the residual fraction comprising heavy substances and foil. Downstream of the separation device 20 in the material flow direction is arranged a foil separator 31 which removes the metal foil and sends it to a further dryer 62. The black mass 58 adhering to the metal foil often contains more cobalt than the black mass 58 not adhering to it. Instead of the further dryer 62, the metal foil can also be dried in a dryer 60. Downstream of the dryer 60 in the material flow direction is arranged a separator 64, for example an air jet sieve, for separating the black mass from the dried metal foil.

[0124] 7 shows a schematic diagram of a further embodiment of a rechargeable battery treatment installation 8 according to the invention, in which supercritical carbon dioxide is used as the cleaning solvent 24, which can be understood as both liquid and gas. The cleaning solvent is removed via a pressure line 66 and evaporated in an evaporator 68. The gaseous carbon dioxide is brought to the supercritical state by a high-pressure pump 70 and reaches the cleaning device 22 again. [Explanation of symbols]

[0125] 8. Rechargeable battery processing equipment 10 rechargeable batteries 12 Discharge Station 14 Dismantling Station 16 Rechargeable battery crushing equipment 18 Crushed materials 20 Separation device 22 Cleaning Equipment 24 Cleaning Solvent 26 Cleaning Solution 28 Cleaning solvent regeneration equipment 30 Dryer 31 Foil separator 32 Gate 34 Mixer 36 Separation device 38 Transport containers 40 Wet chemical processing equipment 42 Exhaust Gas 44 Exhaust gas purification equipment 46 Heating device 48 Vacuum Pump 50 High boiling point components 52 Low boiling point components 54 Non-condensable components 56 Exhaust gas purification 58 Black Mass 60 Dryer 62 Dryer 64 Separator 66 Pressure Line 68 Evaporator 70 High Pressure Pump T k Short circuit time U reg Regenerative cell voltage

Claims

1. A method for recycling rechargeable batteries, in particular lithium and / or sodium rechargeable batteries, which consist of at least one galvanic element, each having two poles, and which contains a conductive salt dissolved in a conductive salt solvent, comprising: (a) shorting the rechargeable battery until at least 75% of the galvanic elements have a regenerative cell voltage of up to 0.4 volts, the regenerative cell voltage being the cell voltage after a 12 hour regeneration period during which the poles of the rechargeable battery are not electrically connected; (b) then pulverizing the rechargeable battery to obtain pulverized material; The method includes:

2. The short circuit is (a) performed without load using metallic conductors; and / or (b) The short circuit is performed so that the electrical resistance between the negative electrode of the rechargeable battery and the positive electrode of the rechargeable battery is a maximum of 10 Ω.

2. The method according to claim 1 .

3. The short circuit between the negative electrode and the positive electrode is performed without the use of a liquid, in particular a salt solution.

4. A method according to any one of the preceding claims.

4. (a) drying the ground material at a temperature of up to 80° and a pressure of up to 300 hPa to obtain a dried ground material; (b) then washing the conductive salt from the dried ground material with an organic wash solvent to obtain a washed ground material; 10. The method according to any one of the preceding claims, characterized in that

5. (a) screening the black mass before washing off said conductive salt, in particular after drying; (b) washing the conductive salt from the black mass; The method according to claim 3, characterized in that

6. The rechargeable battery is short-circuited during the crushing process.

4. A method according to any one of the preceding claims.

7. A method for recycling rechargeable batteries, in particular lithium and / or sodium rechargeable batteries, containing a conductive salt dissolved in a conductive salt solvent, comprising the steps of: (a) crushing the rechargeable battery to obtain crushed material; (b) washing the conductive salt from the ground material with a wash solvent to obtain a washed ground material.

8. (a) separating the washing solvent, in particular by distillation, from a washing solution resulting from washing the conductive salt from the ground material with the washing solvent to obtain a regenerated washing solvent; (b) reusing the regenerated wash solvent to wash away conductive salts; 10. The method according to any one of the preceding claims, characterized in that

9. Separating said conductive salt from said washing solvent, in particular by distillation. The method according to claim 8, characterized in that

10. wet chemical extraction of at least one metal component from said washed ground material.

10. The method according to any one of the preceding claims, characterized in that

11. (a) the conductive salt solvent has a maximum boiling point, the maximum boiling point being the temperature at which at least 99 weight percent of one liter of conductive salt solvent evaporates after one hour at this temperature at 1013 hPa; (b) the cleaning solvent has a maximum boiling point that is less than the maximum boiling point of the conductive solvent.

4. A method according to any one of the preceding claims.

12. 10. The method according to any one of the preceding claims, characterized in that the washing solvent is a solvent for PVDF.

13. (a) drying the washed ground material; and then (b) separating foil, particularly metal foil, from the washed ground material; 10. The method according to any one of the preceding claims, characterized in that

14. (a) crushing the rechargeable battery and then drying the crushed material to obtain a dried crushed material; (b) washing the conductive salt from the dried ground material with the wash solvent; (c) drying the ground material; 10. The method according to any one of the preceding claims, characterized in that

15. (d) crushing the rechargeable battery and drying the crushed material to obtain a dried crushed material, from said dried ground material Heavy substances and / or - separating the foil, in particular the plastic foil, to obtain a black mass; (e) washing the conductive salt from the dried black mass with the wash solvent; (f) drying the black mass; The method according to claim 14, characterized in that

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