Method for reusing alkaline metal batteries and battery reprocessing equipment

Abstract

The present invention relates to a method for reusing an alkali metal battery (12), particularly a Li battery or a Na battery, comprising an active material, a carrier foil on which the active material is arranged, a binder connecting the active material to the carrier foil, a liquid electrolyte, a conductive salt (38), and a housing surrounding the active material, the carrier foil, and the binder, the method comprising the steps of: pulverizing the alkali metal battery (12) to produce pulverized material containing black mass (30) containing the active material and the binder, the method comprising the steps of: washing the pulverized material with a washing solvent (36) to wash away the conductive salt (38) but not the binder, thereby obtaining pulverized material and washing liquid (40) with a low conductive salt content; regenerating the washing solvent (36) from the washing liquid (40), and particularly by distillation; and washing the pulverized material with at least a portion of the regenerated washing solvent (36). The present invention also relates to battery reprocessing equipment for reusing alkali metal batteries (12), particularly Li batteries or Na batteries.

Description

[Technical Field]

[0001] The present invention relates to a method for reusing an alkali metal battery, particularly a Li battery or a Na battery, comprising (a) an active material, particularly graphite or silicon, (b) a carrier foil on which the active material is arranged, (c) a binder connecting the active material to the carrier foil, (d) an electrolyte, particularly a liquid electrolyte, and (e) a conductive salt. Preferably, the alkali metal battery further includes a housing, but it may also be without a housing. The method comprises the step of grinding the alkali metal battery to produce a pulverized material having a black mass containing the active material and binder.

[0002] According to a second aspect of the present invention, (a) the present invention relates to a battery reprocessing facility for reusing alkaline metal batteries, particularly Li batteries or Na batteries, which is equipped with a grinding facility for grinding alkaline metal batteries. [Background technology]

[0003] Alkali metal batteries are widely used to supply energy to power-consuming devices, and their use is increasing. In particular, alkaline metal batteries are used as traction batteries in electric vehicles. Electric vehicles are becoming increasingly popular, especially because they can reduce CO2 emissions during use. To reduce the CO2 footprint of electric vehicles, it is desirable to reprocess alkaline metal batteries as efficiently and resource-savingly as possible.

[0004] Chinese Patent Application Publication No. 103825064 describes a method for flushing out electrolytes from undamaged batteries. After distilling the electrolyte, a portion of the distillate is reused to flush out the electrolyte.

[0005] After removing the electrolyte, the top of the housing is sawn open to extract the electrodes. The electrodes are stripped and separated into the positive electrode, separator, and negative electrode. This method is complex and imposes very high process engineering requirements, especially when processing batteries of many different structures.

[0006] Chinese Patent Application Publication No. 110380150 describes a method in which a battery is first disassembled. Next, the electrolyte is rinsed away with an organic solvent and an organosiloxane, and the resulting mixture is heated to react the conductive salt with the organosiloxane to precipitate it. Therefore, it becomes difficult to recover the conductive salt.

[0007] From Chinese Patent Application Publication No. 113322380, a method of discharging and pulverizing a battery is known. The electrolyte is separated from the pulverized material by filtration, and lime milk is added to precipitate the fluorine component as calcium fluoride.

[0008] International Publication No. 2014 / 208597 describes a method of rinsing away the electrolyte from an undamaged battery. The resulting solution is mixed with water or an acid and evaporated under vacuum to expel the fluorine component as hydrogen fluoride.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0010] An object of the present invention is to improve the recycling of alkali metal batteries.

Means for Solving the Problems

[0011] The present invention solves the problem by a method that is attribute-corresponding and includes the steps of (ii) washing the pulverized material with a washing solvent so that conductive salts are washed away but the binder is not washed away, thereby obtaining pulverized material and washing liquid with fewer conductive salts; (iii) regenerating the washing solvent from the washing liquid; and (iv) washing the pulverized material using at least a portion of the regenerated washing solvent.

[0012] According to a second aspect, the present invention solves the problem with an attribute-corresponding battery reprocessing facility comprising: (b) a washing device designed and arranged to wash at least one fraction of a pulverized material, particularly black mass, using a washing solvent, thereby obtaining a pulverized material and washing solution with fewer conductive salts; and (c) a regenerator, which is (i) designed to automatically regenerate the washing solvent from the washing solution, (ii) a supply conduit connected to the washing device for sending the washing solution from the washing device to the regenerator, and (iii) a return conduit connected to the washing device for sending the washing solvent from the regenerator to the washing device.

[0013] An advantage of the present invention is that conductive salts can usually be recovered in large quantities. These recovered conductive salts can then be reused in alkali metal batteries. For this purpose, it may be advantageous to separate the conductive salts from the cleaning solution or a portion of the cleaning solution. It is even more advantageous to subsequently purify the conductive salts, for example, by crystallization and / or purification. Preferably, the washing of the pulverized material and / or the regeneration of the washing solvent is carried out so that at least 50 mol%, particularly at least 70 mol%, particularly at least 80 mol%, preferably at least 90 mol%, and especially preferably at least 95 mol%, of at least one conductive salt and / or anions of at least one conductive salt, or anions of at least one conductive salt, are retained unchanged and separated, especially during regeneration. For example, preferably, a small amount of water and / or a small amount of acid is added to the electrolyte and / or pulverized material such that the amount of conductive salt and / or anions of conductive salt remains unchanged to at least 80 mol%, preferably at least 90 mol%, and especially preferably at least 95 mol%.

[0014] Furthermore, it is advantageous that this method can be carried out such that substantially no hydrogen fluoride is formed during the rinsing and / or regeneration of the conductive salt, and that it is carried out according to a preferred embodiment. Thereafter, according to a preferred embodiment, a large amount of fluorine bound to the conductive salt can be recovered, preferably at least 95% by weight, particularly at least 97% by weight, and especially preferably at least 99% by weight.

[0015] The characteristic that hydrogen fluoride is substantially not formed is understood to mean that, in particular, during the rinsing and / or regeneration of the conductive salt, up to 5 mol%, particularly up to 2 mol%, preferably up to 1 mol%, particularly preferably up to 0.1 mol%, and particularly preferably up to 0.05 mol%, of the fluorine in the alkali metal battery react to form hydrogen fluoride.

[0016] Electrolytes are generally understood to refer specifically to conductive salt solvents and solutions of conductive salts dissolved in them.

[0017] Furthermore, it is advantageous that the electrolyte can be recovered with relatively high purity. It has been shown that a pure electrolyte can be recovered that can be reused in the manufacture of alkali metal batteries and used according to preferred embodiments.

[0018] Within the scope of this specification, an alkali metal battery is understood to be a battery in which an alkali metal, particularly sodium or lithium, or a compound of an alkali metal, moves from one electrode to the other when releasing electrical energy. In this case, oxidation and / or a change in charge of the alkali metal is possible but not essential.

[0019] Alkaline metal batteries are also understood as alkaline metal storage batteries. A storage battery is understood as a rechargeable battery. Li batteries are also understood as lithium storage batteries, i.e., rechargeable batteries.

[0020] Examples of alkaline metal batteries include lithium-ion batteries such as lithium cobalt dioxide batteries, lithium polymer batteries, lithium manganese batteries, lithium nickel cobalt manganese batteries, lithium iron phosphate batteries, lithium yttrium iron phosphate batteries, lithium titanate batteries, lithium metal polymer batteries, and lithium batteries containing metallic lithium. Furthermore, lithium-air batteries, lithium sulfur batteries, sodium nickel chloride high-temperature batteries, sodium sulfur batteries, and sodium-ion batteries are also included.

[0021] The term "pulverized material" is understood to refer to the material produced by pulverizing alkali metal batteries.

[0022] Black mass is understood to be the graphite- and / or silicon-containing fraction of the pulverized material. In particular, black mass contains at least 30 weight percent, and especially at least 40 weight percent, of graphite. Black mass preferably contains at least 10 weight percent of transition metals and / or their compounds. For example, black mass contains at least 5 weight percent of nickel and / or 3 weight percent of cobalt, although this is not mandatory. This weight information refers to the weight of nickel or cobalt and corresponds to the weight percentage obtained when all nickel or cobalt atoms are present in elemental form, i.e., not in compound form.

[0023] Black mass is a material obtained by separating plastic particles, particularly the crushed housing and / or crushed separator foil of an alkali metal battery, from the crushed material. The separator foil is understood to be the foil that separates the anode from the cathode.

[0024] Washing of pulverized materials is understood to involve contacting the pulverized material directly, or a portion of it, particularly black mass, with a washing solvent so that the conductive salts are at least partially dissolved by the washing solvent. Dissolving the conductive salts generates a washing solution from the washing solvent.

[0025] The characteristic of the conductive salt being washed away is particularly understood as the removal of at least a portion, particularly at least half (in mole percent, particularly at least 60 mole percent, particularly preferably at least 70 mole percent, particularly preferably at least 80 mole percent, particularly preferably at least 90 mole percent) of the anions of the conductive salt. Regenerating the washing solvent from the washing solution is particularly understood as treating the washing solution so that the washing solvent can be obtained again. In particular, regeneration includes separating the conductive salt from the washing solvent.

[0026] The characteristic that the cleaning solvent is a component of the electrolyte is understood, in particular, to be that it is the same substance. Preferably, at least a portion of the cleaning solvent is pre-included in the alkali metal battery pulverized within the scope of the method. Preferably, cleaning solvent that is not included in, or was not included in, the alkali metal battery, and recovered is used at the start of the method according to the present invention. In the course of the method, the conductive salt solvent is washed away from the pulverized material and partially regenerated as the cleaning solvent. Preferably, a portion of the conductive salt solvent is discharged during regeneration, so that the proportion of conductive salt solvent in the cleaning solvent increases continuously.

[0027] In other words, the pulverized material is preferably washed using its own conductive salt solvent components.

[0028] Grinding is understood, in particular, in the sense of mechanical process engineering. That is, grinding is understood as shifting the size distribution of an object into a finer size range. In particular, grinding is the irreversible reduction in size of an object, such as an alkali metal battery. Grinding is, in particular, the dissolution of material composites of an object, not along seams. In particular, grinding is not dismantling.

[0029] The grinding is preferably (a) pressure grinding in which the object is crushed between two tool surfaces, (b) impact grinding in which the object is placed on a tool surface and shattered by striking with a second movable tool, (c) friction grinding in which the object is loaded by two tool surfaces moving in opposite directions, (d) cutting grinding in which the object is cut into two parts by at least two cutting blades, and / or (e) impact grinding in which the object is thrown against a wall, bounced off a moving tool, or two objects collide.

[0030] Grinding, particularly cutting grinding, has the advantage of producing a relatively small proportion of very small plastic particles when the housing is ground. Preferably, cutting grinding is performed such that the weight proportion (number, not particularly weight percentage) of plastic particles produced when the housing is ground is less than one-tenth of the average weight of the plastic particles produced when the housing is ground, is at most one-third, and especially at most one-tenth, of the weight proportion of plastic particles produced when the housing is ground and have a weight greater than the average weight. Cutting grinding methods such as sawing produce many small plastic particles, which are often difficult to separate by other methods.

[0031] Grinding is preferably carried out using a fixed grinding tool. This is advantageous because it minimizes contamination of the grinding material. For example, when a liquid grinding tool such as water in waterjet cutting is used, the grinding material becomes contaminated.

[0032] Preferably, at least half (by weight percent) of the electrode, and especially at least 90 percent by weight, is cut during grinding.

[0033] When electrodes are cut, the materials that were normally separated within the battery, particularly the cathode and anode coatings, mix together. However, surprisingly, it was found that the degree of separation of the individual components could be greatly increased, thereby making the mixing an acceptable drawback.

[0034] Preferably, during grinding, at least half (by number), and especially at least 90 percent, of the carrier foil and / or separator foil are cut at least once, particularly in half. Indeed, smaller carrier foil particles are heavier than the other components of the grinding material.

[0035] In particular, the pulverized material includes both pulverized electrodes and pulverized housing and / or pulverized separator foil particles. The housing is a structure that surrounds the electrodes and shields them from the surrounding environment. Preferably, the housing is pulverized by the same pulverizing equipment as the other components of the alkali metal battery and / or at the same time. Preferably, the housing and carrier foil are pulverized simultaneously, i.e., using the same tools and at the same time. In particular, the housing and carrier foil are finely chopped, and in the chopping process, both the housing and / or separator foil and the carrier foil are finely chopped, respectively.

[0036] Alternatively or additionally, regeneration may include, for example, separating the conductive salt by lowering the temperature.

[0037] The characteristic of washing the grinding material with at least a portion of the recycled washing solvent is understood to mean that the recycled washing solvent is brought into contact with the grinding material again, at least partially, to wash away the conductive salts. In other words, the washing solvent is recycled at least partially.

[0038] Preferably, the washing of the pulverized material with the washing solvent is carried out at a temperature of up to 80°C, particularly up to 70°C, preferably up to 60°C, particularly preferably up to 55°C, particularly preferably up to 50°C, particularly preferably up to 45°C, and particularly preferably up to 40°C. At lower temperatures, the washing away of conductive salts is slower, but the breakdown of conductive salts and / or the formation of hydrogen fluoride are significantly reduced.

[0039] The electrolyte contains a conductive salt solvent for dissolving the conductive salt. The conductive salt solvent can be a pure substance. Alternatively, the conductive salt solvent is a mixture of at least two pure substances. The electrolyte also contains the conductive salt.

[0040] Electrolytes are generally understood to be liquids or solids that contain ions, specifically ions of conductive salts.

[0041] A conductive salt is understood to be a compound composed of anions and cations, dissolved in a conductive salt solvent. The anions are particularly alkali metal anions, which are released or absorbed by the cathode and / or anode during charging and discharging. Alkali metal batteries can contain several substances that act as conductive salts. In this case, the conductive salt is understood to be the sum total of all these substances.

[0042] Preferably, the conductive salt solvent includes ethylmethyl carbonate, i.e., ethylmethyl carbonate (EMC), and / or dimethyl carbonate, i.e., dimethyl carbonate (DMC).

[0043] When the pulverized material is washed in batch mode, as intended by the preferred embodiment, the pulverized material is washed, each time, preferably at least twice, particularly at least three times, preferably at least four times, and particularly at least five times, using a fresh washing solvent. Preferably, it is washed up to 1000 times.

[0044] It was found that the purity of the recovered graphite and / or conductive salts was often insufficient after at least one wash.

[0045] If the pulverized material is washed continuously or semi-continuously, as intended by an alternatively preferred embodiment, the washing solvent is preferably supplied such that at the end of washing, the concentration of the conductive salt in the washing solvent is the same as if the pulverized material had been washed at least two times, particularly at least three times, preferably at least four times, particularly at least five times, using a fresh washing solvent in batch mode.

[0046] According to a preferred embodiment, the method includes a step of separating the black mass from the residue fraction, particularly by sieving or sieving. Preferably, the obtained black mass is washed with a washing solvent. Alternatively or additionally, the separation of black mass may also include foam flotation. Further alternative or additionally, the separation may include preparing a suspension and centrifugation of the suspension. It is necessary to maximize the proportion of graphite, which is typically the anode coating, in the black mass, and since this graphite usually consists of particles smaller than the particles of the housing and / or carrier foil, sieving, particularly air-jet sieving, has proven advantageous.

[0047] A step is performed to separate the black mass from the residue fraction of the pulverized material, particularly the dry pulverized material. The residue fraction is the material that remains after the separation of the black mass. In particular, the residue fraction and the black mass form the pulverized material, particularly the dry pulverized material. Preferably, the residue fraction includes particles of the pulverized housing and / or pulverized separator foil, and / or particles of the pulverized carrier foil.

[0048] Preferably, the separation of black mass from the residue fraction is carried out such that the weight proportion of plastic particles in the black mass is no more than one-fifth of the weight proportion of plastic in the residue fraction. This ensures that the washing solvent does not come into contact with the plastic, i.e., synthetic resin or paper, or comes into very little contact with it during washing of the pulverized material, especially the black mass. Otherwise, the expansion of the plastic and / or contamination of the washing solvent by the plastic or plastic components, which frequently occurs, are avoided. Expansion can increase the stickiness of the plastic, which can make it difficult to separate the black mass from the plastic after washing.

[0049] In particular, the separation of black mass from the residue fraction includes, or is the separation of black mass from plastic particles. Plastic particles include, in particular, particles generated by the grinding of the housing when grinding alkali metal batteries.

[0050] The separation of pulverized materials, particularly black mass, from the washing solvent is carried out, for example, by filtration.

[0051] Accordingly, the present invention also includes a method comprising: (i) grinding an alkali metal battery to produce a pulverized material containing black mass containing the active material and binder; (ii) subsequently separating the black mass from the pulverized material, particularly by sieving or sieving; (iii) washing the black mass of the pulverized material with a washing solvent so that conductive salts are washed away but the binder is not, thereby obtaining black mass and washing solution with less conductive salts; (iv) regenerating the washing solvent from the washing solution, particularly by distillation; and (v) washing the black mass with at least a portion of the regenerated washing solvent. In this way, conductive salts can usually be recovered with particularly high purity. Preferred embodiments described herein also apply to this invention. Preferably, this method includes steps referred to in other methods according to the present invention.

[0052] Preferably, the washing solvent is a component of the electrolyte.

[0053] Preferably, the washing solvent consists of one or more compounds in which at least 50% by weight, preferably at least 70% by weight, more preferably at least 85% by weight, particularly preferably at least 95% by weight, and particularly preferably at least 98% by weight, are components of an electrolyte.

[0054] It is advantageous if the cleaning solvent contains at least substantially no diluent. This can be understood in particular as up to 20% by weight, especially up to 15% by weight, especially preferably up to 10% by weight, and preferably up to 5% by weight of the cleaning solvent consisting of a substance not simultaneously present in the electrolyte of the alkali metal battery.

[0055] It is advantageous to keep the washing solvent from coming into substantially contact with water. This characteristic of keeping the washing solvent from coming into substantially contact with water is understood to mean that, in particular, contact with water that would lead to the reaction of at least 5 mol%, particularly more than 1 mol%, and especially preferably more than 0.1 mol of the conductive salt does not occur. In particular, water is not added to the washing solvent.

[0056] It is advantageous if the washing solvent contains at least two different solvents. This can increase the solubility of the conductive salt.

[0057] Preferably, the washing solvent comprises at least 5% by weight, particularly at least 10% by weight, particularly preferably at least 15% by weight, particularly at least 20% by weight, and particularly preferably at least 25% by weight of a first pure substance (first washing solvent pure substance) and at least 5% by weight, particularly at least 10% by weight, particularly preferably at least 15% by weight, particularly at least 20% by weight, and particularly preferably at least 25% by weight of a second pure substance (second washing solvent pure substance). The first pure substance is preferably ethyl methyl carbonate. The second pure substance is preferably dimethyl carbonate.

[0058] Preferably, the concentration of the main component of the cleaning solvent (measured in weight percent) differs from the concentration of the main component of the conductive salt solvent by up to 10 times, particularly up to 9 times, particularly up to 8 times, particularly up to 7 times, particularly up to 6 times, particularly up to 5 times, particularly up to 4 times, particularly up to 3 times, and particularly up to 2 times.

[0059] This multiple is calculated by determining the maximum value from the concentration of the main component of the cleaning solvent and the concentration of the main component of the conductive salt solvent. The multiple is the quotient of this maximum value (numerator) and the minimum value (denominator) of the specified amount. The main component is the pure substance that accounts for the largest weight percentage of the cleaning solvent or conductive salt solvent.

[0060] Conductive salt solvents are optimized to dissolve conductive salts as well as possible. Therefore, washing solvents can dissolve conductive salts particularly well if their main components match the main components of the conductive salt solvent as closely as possible.

[0061] Preferably, the concentration (measured in weight percentage) of the secondary main component of the washing solvent differs from the concentration of the secondary main component of the conductive salt solvent by up to 10 times, particularly up to 9 times, particularly up to 8 times, particularly up to 7 times, particularly up to 6 times, particularly up to 5 times, particularly up to 4 times, particularly up to 3 times, and particularly up to 2 times. The secondary main component is the pure substance that accounts for the second largest proportion by weight percentage of the washing solvent or conductive salt solvent. This further improves the solubility of the conductive salt in the washing solvent.

[0062] Preferably, the washing solvent is selected so as not to react with the conductive salt during washing.

[0063] Preferably, the washing solvent is selected so as not to form compounds with lithium during washing.

[0064] Preferably, when washing the pulverized material, especially black mass, the pulverized material, especially black mass, is moved, for example, agitated, or rotated in a rotatable drum.

[0065] The cleaning process can be performed continuously, discontinuously (i.e., in batch mode), or semi-continuously.

[0066] Washing of the crushed material, especially black mass, is preferably carried out until at least 70% by weight of the conductive salt, especially at least 75% by weight, especially at least 80% by weight, especially at least 85% by weight, especially at least 90% by weight, and especially at least 95% by weight is removed.

[0067] This can be determined, for example, by regularly taking samples of the pulverized material, particularly black mass, and measuring the content of conductive salts. This can be done, for example, by nuclear magnetic resonance (NMR) measurement.

[0068] Alternatively, the concentration of conductive salts in the washing solution is continuously monitored, for example, by (NMR) measurement. This concentration follows an extraction curve plotting the concentration of conductive salts against the total amount of washing solvent used. The extraction curve decreases strictly monotonically. The measured values ​​are fitted to a parameterized model function (curve fitting), in which case the parameters of the model function are selected so that the original concentration can be determined from it. From this model function, the concentration at which a specified percentage of conductive salts are removed is calculated. If a measured value lower than this concentration is obtained, the washing is terminated.

[0069] Alternatively, preliminary tests can be used to determine how frequently and / or for how long the washing solvent needs to be introduced and removed in order to remove a specified proportion of conductive salts.

[0070] According to a preferred embodiment, the regeneration of the washing solvent includes distilling the washing solution, particularly by vacuum distillation.

[0071] Vacuum distillation is performed at the regeneration temperature. The regeneration temperature is preferably up to 100°C, particularly up to 80°C, particularly up to 70°C, particularly up to 60°C, particularly up to 55°C, particularly up to 52°C, particularly up to 50°C, particularly up to 48°C, and particularly up to 45°C.

[0072] Preferably, the regeneration of the washing solvent is carried out in such a way that at least 80 mol%, particularly at least 90 mol%, of the conductive salt, lithium hexafluoride phosphate, and / or the anions of the conductive salt do not decay and / or chemically react.

[0073] In particular, the calcium compound is substantially not added, and / or fluorine does not precipitate as calcium fluoride. The characteristic of substantially not adding a calcium compound is understood to mean that, in particular, a maximum of 5% by weight, especially a maximum of 1% by weight, and especially preferably a maximum of 0.1% by weight, of the calcium compound is added to the washing solvent.

[0074] Preferably, the regeneration of the washing solvent is carried out so that the conductive salt is recovered. Alternatively or additionally, the regeneration of the washing solvent is carried out so that at least 80 mol%, particularly at least 85 mol%, particularly preferably at least 90 mol%, particularly preferably at least 95 mol%, of the anions of the conductive salt are separated without change in the compound. In other words, preferably during regeneration, a substance containing the same anions as the conductive salt is separated, but which may, but does not necessarily, contain other cations.

[0075] The regeneration temperature is the highest temperature reached at the point of contact with the conductive salt (dissolved or undissolved) within the vacuum distillation apparatus.

[0076] Vacuum distillation is preferably performed at a regeneration temperature and at a pressure lower than the vapor pressure of the washing solvent.

[0077] According to a preferred embodiment, the distillation pressure p 42 The solution is selected so that both ethyl methyl carbonate (EMC, ethyl methyl carbonate) and dimethyl carbonate (DMC, dimethyl carbonate) evaporate.

[0078] Preferably, the distillation pressure p 42 Its boiling point is at atmospheric pressure (1013 hPa) and its separation boiling point is T trenn It is selected so that substances with a higher boiling point than T do not evaporate. trennA substance having a boiling point corresponding to is called a low-boiling substance.

[0079] Separation boiling point T trenn The higher it is, the more components of the electrolyte of the alkali metal battery, which is part of the cleaning solvent, there are. Preferably, the separation boiling point T trenn is selected such that at most 5 components of the electrolyte, particularly at most 4 components, preferably at most 3 components, particularly preferably at most 2 components evaporate.

[0080] Preferably, the separation boiling point T trenn is selected such that at least 1 component of the electrolyte, particularly at least 2 components, preferably at least 3 components, particularly preferably at least 4 components evaporate.

[0081] One component of the electrolyte is a pure substance whose proportion in the electrolyte of the alkali metal battery is at least 0.5 mol%.

[0082] Preferably T trenn > 108 °C, for example T trenn = 110 °C.

[0083] Preferably, the method includes a step of separating the conductive salt from the cleaning liquid. A separation residue is generated when the cleaning solvent is regenerated. When the regeneration is vacuum distillation, a distillation bottom residue occurs. Preferably, the conductive salt is separated from the separation residue, particularly the distillation bottom residue. For example, the conductive salt is separated by crystallization.

[0084] It is advantageous if the separated conductive salt is used in the manufacture of a new alkali metal battery.

[0085] Preferably, the cleaning solvent consists of one compound or a plurality of compounds in which at least 50 weight percent is a component of the electrolyte. It is advantageous if the method includes a step of discharging the cleaning solvent from the cleaning solvent circuit through which the cleaning solvent is led.

[0086] It is advantageous if the discharged cleaning solvent can be used in the manufacture of new alkali metal batteries.

[0087] According to a preferred embodiment, this method includes a step of grinding (Mahlen) a low-conductive salt material. This can be done, for example, using a turbo mill, impact mill, or ball mill. Preferably, the low-conductive salt material still contains foil components, particularly portions of the carrier foil and / or metal foil components. Preferably, the low-conductive salt material contains at least one-third of the weight percentage of metal foil components in the material immediately after grinding, and in particular, all metal foil components are still present.

[0088] After grinding, black mass is separated. Black mass is the fraction with the smallest particle size. From the remaining fraction, components, preferably the copper foil portion and / or aluminum foil portion, are separated. This is done, for example, by a fluidized bed separator or a sieve separator. From the black mass thus obtained, the binder is eluted, preferably using a binder solvent, as described below.

[0089] According to a preferred embodiment, the method comprises the step of removing, in particular eluting, the binder from a low-conductive salt pulverized material, especially a low-conductive salt black mass, using a binder solvent, thereby obtaining a low-binder pulverized material, especially a low-binder black mass. In particular, the binder solvent is not a washing solvent. High purity is required so that the active material, especially graphite, can be reused in the manufacture of alkali metal batteries. It has been found that this purity can be easily achieved by eluting the binder.

[0090] While it is theoretically desirable to completely remove the binder, this is not practically possible. Preferably, at least 50 weight percent of the binder, especially at least 60 weight percent, especially at least 70 weight percent, especially at least 80 weight percent, and especially at least 90 weight percent, is removed. Preferably, up to 99 weight percent of the binder is removed.

[0091] Alternatively, the binder solvent is a component of the conductive salt solvent. Although the conductive salt solvent does not appear to dissolve the binder at operating temperatures, surprisingly, it has been found that the conductive salt solvent can dissolve the binder, especially at high temperatures.

[0092] Alternatively or additionally, the method preferably includes the step of eluting a solid electrolyte from a pulverized material with low conductive salt content, particularly black mass with low conductive salt content, using a solvent, thereby obtaining a pulverized material with low solid electrolyte content, particularly black mass with low solid electrolyte content.

[0093] The binder solvent is preferably acetone, γ-butyrolactone (GBL), diethyl carbonate (DEC), dimethylacetamide (DMA), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 3-heptanone, 3-hexanone, methyl ethyl ketone (MEK), methyl ethyl ketone (MEK), methyl octanoate, supercritical carbon dioxide, or a mixture of two, three, four or more of the above compounds.

[0094] Preferably, the binder is eluted using at least one diluent. Preferably, the diluent is γ-butyrolactone (GBL), dimethyl sulfoxide (DMSO), 3-heptanone, or 3-octanone. The diluent is used to elute the binder together with the binder solvent. For example, the binder solvent is mixed with the diluent. However, the use of a diluent is not always necessary.

[0095] The elution of the binder and / or solid electrolyte is preferably carried out at a temperature of at least 70°C, particularly at least 90°C, particularly at least 110°C, particularly at least 130°C, particularly at least 150°C, particularly at least 175°C, particularly at least 200°C, particularly at least 240°C, particularly at least 260°C, particularly at least 280°C, and particularly at least 290°C.

[0096] Preferably, this temperature is lower than the boiling point of the binder solvent at the pressure used.

[0097] It is advantageous when the binder elution occurs at a temperature up to 30 Kelvin, particularly up to 20 Kelvin, and preferably up to 10 Kelvin, lower than the boiling point of the binder solvent at each process pressure.

[0098] Preferably, the binder elution is carried out under an overpressure of, for example, at least 100 hPa, particularly at least 200 hPa, at least 500 hPa, at least 1000 hPa, at least 2000 hPa, or at least 3000 hPa. Preferably, the overpressure is a maximum of 10 MPa. This overpressure is the process pressure.

[0099] Before the binder dissolution, the pulverized material with few conductive salts, especially black mass with few conductive salts, is preferably not subjected to high-temperature metallurgical oxidation and / or heated to temperatures above 300°C, especially above 250°C.

[0100] Before the binder is dissolved, pulverized materials with low conductive salt content, especially black mass with low conductive salt content, are preferably not heated in a hydrogen-containing atmosphere.

[0101] According to a preferred embodiment, the method includes a step of post-washing a low-binder pulverized material, particularly a low-binder black mass, with a post-washing solvent, thereby washing away the binder solvent. The post-washing solvent is preferably an organic solvent. The boiling point of the post-washing solvent is preferably less than the boiling point of the binder solvent, preferably less than 100°C at atmospheric pressure, particularly less than 90°C, particularly less than 80°C, and preferably less than 70°C. For example, the post-washing solvent is acetone.

[0102] Preferably, the method includes a step of regenerating the post-wash solvent. This can be done, for example, by distillation, particularly by vacuum distillation. Regeneration separates the post-wash solvent from the binder solvent, which is preferably reused for post-washing.

[0103] The washing solvent preferably contains up to 5% by weight, more preferably up to 3% by weight, and most preferably up to 1% by weight, alkaline earth metal hydroxides, and most preferably substantially absent. The characteristic of substantially absent alkaline earth metal hydroxides is understood to mean that, if alkaline earth metal hydroxides are present, the amount is negligible.

[0104] Preferably, the washing solvent is selected such that a maximum of 20 mol%, a maximum of 10 mol%, a particularly preferably 5 mol%, and a particularly preferably 1 mol%, of lithium reacts during washing to form lithium hydroxide. Preferably, the washing solvent is selected so that lithium hydroxide is not formed during washing.

[0105] Before binder elution, pulverized materials with low conductive salt content, especially black mass with low conductive salt content, are non-degradable, i.e., not treated with mineral acids.

[0106] According to a preferred embodiment, the method includes the step of separating, in particular, a low-binder pulverized material, especially a low-binder black mass, and sieving it so as to obtain a graphite fraction and a transition metal fraction in which at least one transition metal is concentrated relative to the graphite fraction.

[0107] However, separation of the pulverized material with less binder is not required.

[0108] According to one embodiment, the method comprises first step (i) as described in claim 1, then pre-drying, then separating the plastic particles, particularly separating the particles from the crushed housing and / or crushed carrier foil, so as to obtain black mass, then steps (ii), (iii), (iv) according to claim 1, then optionally drying the black mass, and then sieving the black mass, optionally the dried black mass.

[0109] In this case, drying is preferably carried out so that at least 70 percent by weight, particularly at least 80 percent by weight, particularly preferably at least 90 percent by weight, and particularly at least 95 percent by weight of the washing solvent contained in the black mass is removed.

[0110] Alternatively or additionally, pre-drying is preferably carried out so that at least 50% by weight, particularly at least 60% by weight, preferably at least 70% by weight, particularly preferably at least 80% by weight, and particularly preferably at least 90% by weight of the electrolyte and / or electrolyte solvent is removed.

[0111] Transition metals are understood to be elements that have an incomplete d-subshell or form ions that have an incomplete d-subshell. In particular, cobalt and / or nickel in the transition metal fraction are concentrated relative to the graphite fraction by a concentration factor of at least 3 (meaning that the concentration of the corresponding transition metal in the transition metal fraction is at least 3 times greater than the concentration of the corresponding transition metal in the graphite fraction), especially 4, especially 5, and preferably 6.

[0112] It has been found that a particularly good concentration factor can be achieved when as much binder as possible is removed. The exact reason is not fully understood. It is hypothesized that the binder adheres individual graphite particles to each other and to particles containing transition metals or salts of transition metals, thereby enabling separation.

[0113] Separation may be by flotation, particularly foam flotation, or may include this method. However, it has been found that a higher concentration factor can be achieved by sieving.

[0114] Preferably, the sieving is fine sieving. It is advantageous when the sieving is performed by a fine sieving machine having a sieving wheel. The sieving wheel may also be called a classification wheel. The sieving wheel has recesses, particularly slots. The recesses preferably have an inner width, particularly a slot width, of at least 0.1 mm, particularly 1 mm and / or up to 25 mm, particularly up to 15 mm, and particularly preferably up to 10 mm.

[0115] Preferably, the fine sieve splitter is designed to rotate the sieve wheel at a sieve wheel rotation frequency of 500 to 20,000 revolutions per second. The higher the sieve wheel rotation frequency, the smaller the aerodynamic diameter of the fraction removed.

[0116] Preferably, the recess and rotation frequency are selected such that the graphite fraction has a graphite fraction particle size distribution, and 80 volume percent of the graphite has a particle size of less than 20 μm.

[0117] Alternatively or additionally, the recesses and rotational frequencies are selected such that the transition metal fraction has a transition metal fraction particle size distribution, with 90% of the particles having a particle size of less than 35 μm, particularly less than 30 μm. Preferably, at least 50% of the particles have a particle size of less than 25 μm, particularly less than 20 μm. In this way, it has been found that particularly high enrichment factors can be achieved. The particle size is determined according to DIN ISO 13320:2009.

[0118] In a preferred embodiment, the method includes washing the pulverized material, particularly black mass, with a washing solvent, followed by drying the pulverized material, particularly black mass, which has a low conductive salt content. This drying is preferably carried out at a maximum temperature of 80°C, particularly 70°C, particularly 60°C, particularly 50°C, and preferably 45°C. In this way, the generation of hydrogen fluoride is substantially prevented. This feature of substantially preventing the generation of hydrogen fluoride is particularly evident when the hydrogen fluoride concentration during drying in a gaseous atmosphere is less than 1 mg / m³. 3 It is understood to be that.

[0119] Alternatively, drying is performed at a temperature above the boiling point of the washing solvent. This is advantageous when washing is carried out with the washing solvent until the conductive salt content is very low and at least substantially no hydrogen fluoride is generated during subsequent drying. For example, drying is performed at a temperature of at least 80°C, especially at least 100°C, and especially at least 120°C.

[0120] Preferably, the method includes a step of washing, after drying, the pulverized material with a low conductive salt content, particularly black mass with a low conductive salt content, using a second solvent having a boiling point lower than that of the washing solvent. If the washing solvent contains two or more components, the second solvent preferably has a boiling point lower than that of all components of the washing solvent combined. Preferably, the pulverized material thus treated, particularly black mass thus treated, is then dried again.

[0121] After drying, particularly after pre-drying, separation of particles from the foil components, especially plastic components and / or metal foil components and / or the crushed housing is performed. This is done especially before the binder is eluted. Preferably, the separation is performed such that the weight ratio of the foil components after separation is at most one-fifth of the weight ratio of the foil before separation. This ensures that the binder solvent does not come into contact with the plastic or metal foil, or comes into very little contact, during the binder elution.

[0122] Preferably, pulverized materials with low binder content, especially black mass with low binder content, are dried before binder elution. Drying is preferably carried out at a pressure of up to 300 hPa, particularly up to 10 hPa. This reduces contamination of the binder solvent.

[0123] It is advantageous when the graphite in the graphite fraction is used in the manufacture of new alkaline metal batteries.

[0124] It is advantageous if the method includes the following step, namely, the step of separating the foil portion from the pulverized material before washing the pulverized material. The pulverized material thus obtained, which can also be called a pulverized material with less foil, can be well washed using a washing solvent. The foil can be a carrier foil, in particular a plastic foil and / or a metal foil. For example, this is a separator foil and / or a portion of an aluminum foil and / or a copper foil.

[0125] According to a preferred embodiment, the method includes the following steps: pre-drying the pulverized material after pulverization, preferably after separation of the foil portion, or before separation of the foil portion and / or particles from the pulverized housing, and before washing the pulverized material. Pre-drying is preferably carried out so as to remove at least 50% by weight, particularly at least 60% by weight, preferably at least 70% by weight, particularly preferably at least 80% by weight, and particularly preferably at least 90% by weight of the electrolyte and / or electrolyte solvent. Pre-drying can also be generally referred to as drying.

[0126] In particular, the method comprises the steps of (a) drying the pulverized material so that a dry pulverized material is produced, (b) separating plastic particles from the dried pulverized material, especially from the pulverized housing and / or the pulverized carrier foil and / or the pulverized separator foil, thereby obtaining a black mass, and (c) washing the black mass with a washing solvent. The plastic particles are preferably not washed with the washing solvent. This avoids contamination of the washing solvent with the components of the plastic. Furthermore, swelling of the plastic particles is avoided.

[0127] Preferably, pre-drying is carried out at a pressure of up to 300 hPa and / or at a temperature of up to 70°C, particularly up to 60°C, and especially up to 50°C. Preferably, pre-drying is carried out at a low temperature such that up to 5 mole percent, particularly up to 1 mole percent, of fluorine in the pulverized material reacts to form hydrogen fluoride.

[0128] According to a preferred embodiment, the method includes the step of short-circuiting the battery before grinding until at least 75% of the galvanic elements have a regenerated cell voltage of up to 0.4 volts, particularly up to 0.3 V, preferably up to 0.2 volts, particularly up to 0.15 volts, particularly preferably up to 0.1 volts, particularly up to 0.05 V.

[0129] By short-circuiting the battery, conductive salts can be recovered with particularly high purity. The reason why short-circuiting increases the purity of the recovered conductive salts is not fully understood. It is likely that a regeneration cell voltage much higher than 0V generates localized heat during pulverization, which accelerates the breakdown of conductive salts and / or the generation of hydrogen fluoride.

[0130] It should be noted that deep discharge alone does not result in a regenerated cell voltage of at least 0.2V. Deep discharge is understood as drawing electricity from a battery until its capacity is almost completely depleted, particularly until the final discharge voltage falls below a certain level. The final discharge voltage can be, for example, 0.1 volts. After deep discharge, the cell voltage drops significantly, while the achievable discharge current becomes very small, resulting in a very small energy capacity for the battery. Therefore, conventional methods only perform deep discharge.

[0131] However, it was found that even after deep discharge, the energy capacity was large enough to generate hydrogen fluoride. Although the amount of hydrogen fluoride generated when a deeply discharged but non-short-circuited battery is crushed is relatively small, it was found that even slight contamination of the conductive salt by decay products can impair the suitability of the conductive salt and / or electrolyte for the manufacture of new batteries.

[0132] The regenerated cell voltage is understood to be the cell voltage present in each galvanic element after a predetermined regeneration time during which the battery's terminals are not electrically connected. The characteristic of the battery's terminals not being electrically connected is understood to mean that the terminals are insulated from each other, that is, there is at least 1 megaohm of resistance between two terminals in particular. In other words, no electrical energy is extracted from the galvanic elements during the regeneration time. Specifically, during the regeneration time, the terminals of the battery's galvanic elements are not electrically connected.

[0133] During regeneration, the cell voltage increases. Even if the battery is discharged to a final cell voltage of, for example, less than 0.2V, or even 0V, the regenerated cell voltage will be higher than the final cell voltage.

[0134] A Samsung INR18650-25R battery manufactured in February 2022 was found to have a cell voltage of 0V after a 1-hour short circuit. The regenerated cell voltage was 1V. After a 3-hour short circuit, the regenerated cell voltage was 0.8V. After a 5-hour short circuit, the regenerated cell voltage was 0.6V. After a 24-hour short circuit, the regenerated cell voltage was 0.2V.

[0135] A short circuit in a battery with a long short-circuit duration, where the regenerated cell voltage is a maximum of 0.2V, especially a maximum of 0.15V, and especially a maximum of 0.1V, can also be called a regenerative safety short circuit. In other words, it is advantageous for the battery to be shredded only after a regenerative safety short circuit has occurred.

[0136] Whether a safe short circuit for regeneration has occurred can be determined by storing the corresponding battery without an external electrical load for the regeneration time, especially at 1013 hPa and 23°C, without any short circuits, and then measuring the cell voltage. In other words, even if the battery is crushed or otherwise disposed of before the regeneration time has elapsed, a short circuit in the battery may exist until at least 75% of the galvanic elements reach the maximum regeneration cell voltage mentioned above. The only crucial factor is whether the short circuit was applied after the regeneration time so as not to exceed the regeneration cell voltage mentioned above.

[0137] The regeneration time is 12 hours. It should be noted that this does not describe how long the battery is short-circuited. Rather, the regeneration time is the amount of time the battery remains in a non-contact, and especially non-short-circuited, state after discharge, particularly after a short circuit. In particular, even if a battery is short-circuited for 12 hours, the regeneration cell voltage may exceed 0.2 volts.

[0138] Preferably, the 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, and particularly at least 18 hours. A short-circuit time of at least 20 hours, for example 24 hours, is particularly advantageous. Preferably, the short-circuit time is less than 120 hours. In this way, as intended by the preferred embodiment, it is possible to achieve that at least 90 percent by weight, particularly at least 95 percent by weight, of the conductive salts of the battery do not collapse upon pulverization.

[0139] Preferably, the steps prior to washing the black mass are carried out so that the conductive salts of the alkali metal battery decay to a maximum of 10 weight percent, particularly a maximum of 5 weight percent, particularly a maximum of 3 weight percent, particularly a maximum of 1 weight percent, particularly a maximum of 0.5 weight percent, particularly a maximum of 0.1 weight percent.

[0140] Short circuits are advantageous when they are performed using metal conductors. In this case, the metal conductors connect the terminals of the battery, i.e., the negative and positive terminals, without any load. This means that the metal conductors do not connect the terminals of the battery to electrical resistors or other electrical devices. It is particularly advantageous if the connection between the negative and positive terminals is not made by a liquid, especially a salt solution.

[0141] Preferably, during a short circuit, the electrical resistance between the positive and negative terminals of the battery is a maximum of 10 ohms, particularly a maximum of 1 ohm, preferably a maximum of 0.3 ohms, and especially preferably a maximum of 0.1 ohms.

[0142] After regenerative safety short-circuiting, it is possible, but not required, to transport the battery over distances of at least 1 km, and especially at least 5 km. Regenerative safety short-circuiting significantly reduces the risk of battery fire and thus environmental damage. Preferably, after regenerative safety short-circuiting, the battery is not transported over distances exceeding 1 km due to the potential for safety hazards.

[0143] According to a preferred embodiment, the pulverized material is not substantially contacted with water before washing. The characteristic of not substantially contacting the pulverized material with water is understood to mean that, in particular, there is no contact with water that would lead to a reaction of at least 5 mol%, particularly more than 1 mol%, and especially more preferably more than 0.1 mol% of the conductive salt.

[0144] In particular, the grinding is carried out without introducing water, and is not carried out by waterjet cutting.

[0145] Preferably, the pulverized material is at least substantially free of organic cations. This is understood to mean that the content of organic cation-containing material is at most 0.1 weight percent.

[0146] Particularly preferable, the pulverized material does not contain organic cations and / or double-layer capacitors.

[0147] Preferably, the active material and / or electrolyte should not be substantially contacted with water before and during grinding. This is understood to mean that contact with water that would lead to a reaction of more than 5 mol%, particularly more than 1 mol%, and particularly more than 0.1 mol% of the conductive salt or electrolyte should not occur.

[0148] Preferably, the active material and / or electrolyte should not be substantially contacted with water during washing. This is understood to mean that contact with water that would lead to a reaction of more than 5 mol%, particularly more than 1 mol%, and particularly more than 0.1 mol% of the conductive salt or electrolyte is not made.

[0149] Preferably, the grinding is carried out at a low temperature such that a maximum of 2.5 mole percent, particularly a maximum of 1 mole percent, and especially preferably a maximum of 0.5 mole percent, of the fluorine relative to the grinding material decomposes.

[0150] Preferably, low-binder pulverized material, especially low-binder black mass, is decomposed in concentrated sulfuric acid and then leached out. Because it contains very little binder, the amount of sulfuric acid consumed is small. Therefore, graphite with low metal ion content is easily obtained. In some cases, this can be reused in the manufacture of alkali metal batteries.

[0151] The battery reprocessing equipment according to the present invention preferably includes a separation device designed and arranged to separate black mass from the residue fraction. For example, the separation device is a sieve or a sieve.

[0152] According to the present invention, the following method, namely (a) Active material, especially graphite and, (b) A carrier foil on which the active material is arranged, (c) A binder that connects the active material to the support foil, (d) Liquid electrolyte, (e) Conductive salt and, (f) A method for reusing an alkali metal battery, particularly a Li battery or a Na battery, comprising an active material, a carrier foil, and a housing surrounding a binder, (i) A step of optionally discharging and short-circuiting so that the regeneration voltage is less than 0.2V, especially 0.1V, (ii) A step of crushing an alkali metal battery to produce a crushed material containing black mass, active material and binder, (iii) optionally drying the pulverized material, particularly at a temperature of less than 70°C and / or at a maximum pressure of less than 300 hPa, (iv) A step of optionally separating black mass, particularly by sieving, (v) A process in which the pulverized material, especially black mass, is washed with a washing solvent, thereby washing away conductive salts but not the binder, and thereby obtaining pulverized material with fewer conductive salts, especially black mass with fewer conductive salts, The washing solvent is a component of the electrolyte, preferably, and is washed until a maximum of 10% by weight of the conductive salt remains, particularly a maximum of 5% by weight, particularly preferably a maximum of 1%, particularly a maximum of 1% by weight, particularly a maximum of 0.1%, particularly a maximum of 0.1%, particularly a maximum of 1%, particularly a maximum of 0.1%. The washing solvent is recovered. From the residue generated during the recovery of the washing solvent, conductive salts and / or substances having the same anion as the conductive salts are separated. The process involves separating at least one solvent, which is an electrolyte component and not a cleaning solvent, from the residue and reusing it, particularly for reuse in new batteries. (vi) Optionally, a step of drying the pulverized material with low conductive salt content, especially black mass with low conductive salt content (this can be done at a temperature higher than the boiling temperature of the washing solvent, preferably below the binder decomposition temperature), Optionally, a step of washing with a second washing solvent having a lower boiling point than the washing solvent, (vii) A step in which a binder is optionally eluted from black mass with low conductive salt content using a binder solvent (not a washing solvent), thereby obtaining a pulverized material with low binder content, (viii) Optionally, a step of drying the crushed material with a small amount of binder, (ix) Optionally, a step of separating the pulverized material with a low binder content, particularly by sieving, thereby obtaining a graphite fraction and a transition metal fraction in which at least one transition metal is concentrated relative to the graphite fraction, (x) A method may be summarized that optionally includes the steps of manufacturing a new battery, in particular an alkaline metal battery, from graphite fraction and / or washing solvent and / or separated conductive salts of graphite.

[0153] Preferably, the method includes a step of washing away the binder solvent. This is done using an organic solvent, which may be called a binder washing solvent. The binder washing solvent preferably has a boiling point lower than the boiling point of the binder solvent. Preferably, the boiling point at atmospheric pressure is less than 100°C, particularly less than 90°C, particularly less than 80°C, particularly less than 70°C, and particularly less than 60°C.

[0154] In the battery reprocessing equipment according to the present invention, the regenerator is preferably a vacuum distiller designed to automatically distill and remove the low-boiling fraction of the cleaning solution, and the low-boiling fraction forms the cleaning solution.

[0155] Preferably, the battery reprocessing equipment includes a binder removal unit designed to automatically elute the binder from pulverized material with low conductive salt content, particularly black mass with low conductive salt content, using a binder solvent. The binder removal unit is preferably located behind the washing unit in the material flow direction. A dryer and / or separation unit may, but is not required, be located before the binder removal unit in the material flow direction.

[0156] The binder removal equipment preferably uses pulverized material with low conductive salt content, particularly black mass with low conductive salt content, to decompose the binder at a temperature T BZ Designed to heat to a higher temperature than the binder decomposition temperature T. BZ This is the temperature at which half of the binder will decompose after 30 minutes. In this way, the binder residue is further reduced, resulting in a higher concentration factor for subsequent separation.

[0157] Preferably, the battery reprocessing equipment has a binder removal system designed to automatically elute the binder using a binder solvent, particularly the pulverized material with low conductive salt content, especially black mass with particularly low conductive salt content.

[0158] If binder removal equipment is present, the battery reprocessing equipment preferably has a postwasher designed to wash away the binder solvent from the low-binder pulverized material, especially the low-binder black mass, using a postwashing solvent.

[0159] The present invention will be described in detail below with reference to the attached drawings. [Brief explanation of the drawing]

[0160] [Figure 1] This is a flowchart of the battery reprocessing equipment of the present invention. [Figure 2] This is a flowchart of a battery reprocessing facility according to a second embodiment of the present invention. [Figure 3] This is a flowchart of a battery reprocessing facility according to a third embodiment of the present invention. [Figure 4] This is a flowchart of a battery reprocessing facility according to a fourth embodiment of the present invention. [Modes for carrying out the invention]

[0161] Figure 1 shows a battery reprocessing facility 10 for reusing lithium in the form of an alkali metal battery 12, in this example a lithium-ion battery, according to the present invention. While it is preferable, the alkali metal battery 12 is discharged by a discharge device 14, this is not necessarily required. In that case, the electrical energy can be sent to a power grid such as the public power grid, but this is not essential.

[0162] It is preferable, but not necessarily, to short-circuit the alkali metal battery 12 after discharge. In other words, the positive electrode 16 and the negative electrode 18 are connected to each other. In that case, the electrical resistance between the positive electrode 16 and the negative electrode 18 is preferably less than one-fifth, and especially less than one-tenth, of the internal resistance of the corresponding alkali metal battery.

[0163] Short circuit occurs during the short circuit time T. K It is executed over a short-circuit time T. K The regenerated cell voltage U reg U regThe length is selected so that the voltage is less than 0.15V. For example, T s = 12 hours.

[0164] The alkali metal battery 12 is crushed in the crushing equipment 20 to obtain crushed material 22. The crushing equipment 20 is preferably designed so that up to 5 mass percent of the crushed material 22 has a sphere diameter greater than 4 cm. The sphere diameter is the diameter of the smallest virtual sphere that completely encloses the corresponding object.

[0165] The crushed material 22 is preferably sent to an optional separator 26 by an airtight conduit 24.1. A lock 28.1 may be placed between the crushing equipment 20 and the separator in the material flow direction M, but is not required. The separator 26 separates the black mass 30 from the residue fraction 32. The residue fraction 32 includes, for example, plastic components of the housing or separator that may be present.

[0166] Although the separation device 26 is shown as a sieve divider, it can also be a sieving system, a combination of a sieving system and a sieve divider, or a separation device based on other separation principles, not only in general and in relation to the embodiment according to D1.

[0167] The black mass 30 (or, if the separation device 26 is not present, the pulverized material 22) enters the washing device 34 through a preferably airtight conduit 24.2, where it is brought into contact with the washing solvent 36. The washing solvent 36 dissolves the conductive salt 38 from the black mass 30, thereby generating the washing solution 40.

[0168] The washing solution 40 enters a regenerator 42, which in this example can be designed as a vacuum distiller. The term vacuum distillation apparatus can also be used instead of vacuum distiller. The regenerator 42 has a temperature control device 43 and separates the washing solution 40 into at least one low-boiling fraction and a high-boiling fraction 44 that form the washing solvent 36.

[0169] The highest temperature at the point in contact with the conductive salt inside the vacuum distillation apparatus 42 is the regeneration temperature T. r It is called T.r <60℃, for example T r =50℃. The temperature control device 43 sets the regeneration temperature T r Set it.

[0170] The inside of the vacuum distiller 42 is the distiller pressure p 42 It is under pressure. Distiller pressure p 42 Preferably, the solution is selected so that both ethyl methyl carbonate (EMC) and dimethyl carbonate (DMC) evaporate.

[0171] Preferably, the distillation pressure p 42 Its boiling point is at atmospheric pressure (1013 hPa) and its separation boiling point is T trenn Selected so that substances with a higher concentration do not evaporate. Preferably T trenn >108℃, for example T trenn = 110℃.

[0172] In this embodiment, gaseous EMC and DMC are condensed by the condenser 46 and returned to the washing device 34 as washing solvent 36. In the gas flow direction G, the temperature in front of the condenser 46 is the separation boiling point T. trenn The temperature can be within this range. It is advantageous to monitor this temperature with a thermometer 47.

[0173] A portion of the cleaning solvent 36 can be discharged, for example, through a discharge conduit 48.1 and supplied to the electrolyte container 50. The cleaning solvent 36 may, in some cases, be further reprocessed and then used in the manufacture of new alkali metal batteries.

[0174] The high-boiling fraction 44 containing conductive salts remains in the vacuum distiller 42. The components of the high-boiling fraction 44 have separate boiling points T trenn It has a higher boiling point. The high-boiling-point fraction 44 can be discharged, for example, from a second discharge conduit 48.2 and supplied to a transport container 52.

[0175] distiller pressure p 42The pressure is preferably less than 286 hPa, particularly less than 233 hPa, particularly preferably less than 188 hPa, and particularly less than 150 hPa.

[0176] In this embodiment, the low-boiling-point fraction includes substances with a boiling point of 85°C, particularly 88°C to 109°C, at atmospheric pressure. When the alkali metal battery is a lithium-ion battery, the low-boiling-point fraction particularly includes dimethyl carbonate and ethylmethyl carbonate.

[0177] In this embodiment, the high-boiling-point fraction 44 includes a substance whose boiling point at atmospheric pressure exceeds 110°C.

[0178] In this embodiment, the cleaning device 34 operates in batch mode. The predetermined limit concentration C of the conductive salt in the cleaning solution 40 grenz Washing is carried out until the threshold is below a certain level. In this case, black mass 30 is called black mass 30', which has fewer conductive salts. Preferably, the threshold concentration C grenz The conductive salt is selected such that at least 95% by weight of it is washed away from the black mass 30.

[0179] The black mass 30' with low conductive salt content enters an optional dryer 54 through an optional lock 28.3. The dryer 54 can be designed as a vacuum dryer, as in this example, but this is not mandatory. In that case, the inside of the dryer 54 is, for example, p 54 Dryer pressure p ≤ 300 hPa 54 It is applied. Dryer temperature T inside dryer 54 54 Preferably T 54 The temperature is below 60°C. Therefore, the washing solvent 36 present in the black mass 30', which has a low concentration of conductive salts, evaporates and is completely condensed in the condenser 56.

[0180] The dryer 54 preferably includes a mixer 57 to improve contact between the washing solvent 36 and the black mass 30, thereby improving the discharge of conductive salts and electrolyte components that do not form the washing solvent 36.

[0181] In the material flow direction M, the binder removal equipment 58 is located behind the washing device 34 and, in this example, behind the dryer 54. The black mass 30' with low conductive salt content enters the binder removal equipment 58 preferably through an airtight conduit 24.4 and, optionally, a lock 28.4, where it is mixed with a binder solvent 60, such as dimethyl sulfoxide.

[0182] If the binder solvent 60 contains supercritical carbon dioxide, as intended in a preferred embodiment, the temperature and pressure in the binder removal equipment are selected so that the carbon dioxide becomes supercritical.

[0183] Preferably, the binder removal temperature T inside the binder removal equipment 58. 58 The boiling point T of the binder solvent 60 should be as high as possible, especially. s,60 It is close to. Preferably, the binder removal temperature is at least T S,60 = 170℃. Preferably, T S,60 = ≤ 400℃, especially T S,60 = ≤ 375℃. To achieve the highest possible binder removal temperature, process pressure p in binder removal equipment 58 58 It is advantageous when the pressure is higher than the ambient pressure. Preferably, p 58 ≥1200 hPa, especially p 58 It is ≥2000 hPa. In particular, p 58 The pressure is ≤12MPa.

[0184] The binder removal equipment 58 preferably includes a stirrer 60 for introducing mechanical energy into the black mass 30' which has a low concentration of conductive salts. It is advantageous if the pH value in the binder removal equipment 58 is a maximum of 9.

[0185] The binder removal equipment 58 operates, for example, in batch mode. The binder solvent 60 is frequently replaced until at least 40%, preferably at least 50%, of the binder is removed from the black mass 30'' with low conductive salt content. The resulting black mass 30'' with low binder content is then dried in a dryer 54.2, for example, via a conduit 24.5. The temperature in the second dryer T54.2 Binder decomposition temperature T BZ Higher levels are possible but not required. The exhaust gases 62 that may be generated are purified by the exhaust gas purification equipment 64, particularly with hydrogen fluoride, and then released into the surrounding environment.

[0186] The binder-free black mass 30'' enters a separation device 66 designed as a microsieve separator in this case. The microsieve separator 66 has a sieve wheel 68, which is powered by a motor 70, for example, f 68 = 1501 / s sieve wheel rotation frequency f 68 To be made to.

[0187] The coarse fraction 74 exits the fine sieve separator 66 through the coarse fraction outlet 72, and the fine fraction 78 exits through the fine fraction outlet 76. The coarse fraction 74 contains significantly more graphite than the fine fraction 78, and can therefore be called the graphite fraction. In contrast, the fine fraction 78 contains significantly more transition metals than the coarse fraction 74, and can therefore be called the transition metal fraction.

[0188] Figure 2 shows a second embodiment of the battery reprocessing equipment according to the present invention, in which the vacuum distiller 42 is designed as a rectification apparatus, i.e., a fractional distillation apparatus.

[0189] In this case, it is advantageous to use the fraction with the lowest boiling point as the washing solvent 36, or to use the fraction with the highest weight percentage of the washing solvent 36.

[0190] Figure 3 shows a third embodiment of the battery reprocessing equipment 10 according to the present invention for reusing alkali metal batteries 12, particularly Li batteries or Na batteries, the battery reprocessing equipment 10 comprising (a) a grinding equipment 20 that grinds the batteries to obtain a grinding material 22 which is black mass 30, particularly black mass containing active material and binder; (b) a washing device 34 located behind the grinding equipment 20 in the material flow direction and designed to wash at least one portion of the grinding material 22, particularly black mass 30, with a washing solvent 36 to obtain a grinding material 22 with fewer conductive salts and a washing liquid 40; and (c) a regenerator 42 which (i) is designed to automatically regenerate the washing solvent 36 from the washing liquid 40, (ii) has a supply conduit connected to the washing equipment 34 to send the washing liquid 40 from the washing equipment 34 to the regenerator 42, and (iii) has a return conduit connected to the washing equipment 34 to send the washing solvent 36 from the regenerator 42 to the washing equipment 34.

[0191] The battery reprocessing equipment 10 has a pre-dryer 80 located behind the crushing equipment 20 and in front of the separation device 26 in the material flow direction M. The pressure p inside the pre-dryer 54’ It can reach up to 300 hPa, for example, p 54’ This results in a negative pressure of 100 hPa. This negative pressure is generated by the vacuum pump 82.

[0192] A condenser 56' for condensing the conductive salt solvent 86 can optionally be placed before (or alternatively, behind) the vacuum pump 82 in the gas flow direction G. The conductive salt solvent 84 can be used, for example, as a washing solvent 36, or can be used directly.

[0193] A particle filter 88 can be optionally placed before the condenser 84 in the gas flow direction G. An activated carbon filter 90 can be optionally placed after the vacuum pump 82 in the gas flow direction G. The gas thus purified can then be further purified or released directly into the surrounding environment.

[0194] The pre-dryer 80 can be connected to the separation device 26 via a lock 28.5 and preferably a particle-dense conduit 24.6.

[0195] In the separation unit 26, the black mass 30 is separated from the residue fraction 32. The residue fraction includes, in particular, heavy materials, i.e., particles generated by crushing the housing, and crushed carrier foil and / or crushed separator foil. Behind the separation unit 26 in the material flow direction, a washing unit 34 is located to wash away the conductive salt washing solvent 36.

[0196] The battery reprocessing equipment 10 may optionally have a dryer 54 positioned behind the washing device 34 in the material flow direction.

[0197] The battery reprocessing equipment 10 may optionally have a binder removal unit 58 located behind the washing unit 34 in the material flow direction, and especially behind the dryer 54 if present.

[0198] If the battery reprocessing equipment 10 has a binder removal equipment 58, it may optionally have a post-washer 92, which washes the binder solvent 60 from the black mass 30'' with a binder-washing solvent 94, thereby obtaining a cleaning solution 96. Preferably, the battery reprocessing equipment has a cleaning solution regenerator 98 for separating the binder-washing solvent 94 from the cleaning solution 96.

[0199] Optionally, the battery reprocessing equipment 10 may have sieves, in particular a fine sieve 66, to generate graphic fractions and transition metal fractions from black mass 30''' with less binder, if applicable.

[0200] Optionally, the battery reprocessing facility 10 may have a discharge device 14.

[0201] The battery reprocessing equipment 10 may have all the components shown in Figure 3, but this is not mandatory.

[0202] Figure 4 shows another embodiment of the battery reprocessing equipment 10 according to the present invention for reusing alkali metal batteries 12, particularly Li batteries or Na batteries, the reprocessing equipment 10 comprising (a) a grinding equipment 20 for grinding batteries to obtain a pulverized material 22 containing black mass 30 containing active material and binder; (b) a washing device 34 located behind the grinding equipment 20 in the material flow direction and designed to wash at least one portion of the pulverized material 22, particularly the black mass 30, with a washing solvent 36 to obtain a pulverized material 22 with fewer conductive salts and a washing solution 40; and (c) a regenerator 42 having (i) a design for automatically regenerating the washing solvent 36 from the washing solution 40, (ii) a supply conduit connected to the washing equipment 34 for sending the washing solution 40 from the washing equipment 34 to the regenerator 42, and (iii) a return conduit connected to the washing equipment 34 for sending the washing solvent 36 from the regenerator 42 to the washing equipment 34.

[0203] Furthermore, the battery reprocessing equipment 10 has a dryer 54 located behind the washing device 34 in the material flow direction M. The dryer 54 operates under process pressure p 54 For example, maximum p 54 = 300 hPa and / or dryer temperature T 54 For example, maximum T 54 It can be a vacuum dryer that reaches 70°C. The preferred dryer temperature mentioned above also applies here.

[0204] Alternatively, the dryer 54 may operate at atmospheric pressure or overpressure, and / or at a dryer temperature T exceeding 70°C, particularly exceeding 80°C, for example, exceeding 90°C. 54 It can operate at the boiling temperature T of the washing solvent 36. For example, the oven temperature is set to the boiling temperature T of the washing solvent 36. S,36 It's higher than that.

[0205] Behind the dryer 54 in the material flow direction, a separation device 26 is positioned to separate the black mass 30 from the residue fraction 32. The residue fraction includes, in particular, heavy materials, i.e., particles generated by grinding the housing, and the ground carrier foil and / or ground separator foil.

[0206] Optionally, the battery reprocessing facility 10 includes a binder removal unit 58 in which a binder solvent 60 is used to elute the binder in the black mass 30. Optionally, the battery reprocessing facility 10 includes another dryer 54.2 for drying the black mass 30'' with less binder.

[0207] If the battery reprocessing equipment 10 has a binder removal equipment 58, it may optionally have a post-washer 92, which washes the binder solvent 60 from the black mass 30'' with a binder-washing solvent 94, thereby obtaining a cleaning solution 96. Preferably, the battery reprocessing equipment has a cleaning solution regenerator 98 for separating the binder-washing solvent 94 from the cleaning solution 96.

[0208] Optionally, the battery reprocessing equipment 10 may have sieves, in particular a fine sieve 66, to generate graphic fractions and transition metal fractions from black mass 30''' with less binder, if applicable.

[0209] The battery reprocessing equipment 10 may have all the components shown in Figure 4, but this is not mandatory.

[0210] For example, the battery reprocessing facility 10 does not have a dryer and / or separation device in front of the binder removal facility 58 in the material flow direction. [Explanation of Symbols]

[0211] 10 Battery reprocessing facility 12 Alkaline metal batteries 14 Discharge device 16 positive electrode 18 negative electrode 20. Grinding equipment 22. Crushing materials 24 Conduit 26 Separation device 28 Rock 30 Black Mass 32 Residue fraction 34 Washing device 36 Washing solvent 38 Conductive salts 40 Cleaning solution 42 Regenerator 43 Temperature control device 44 High boiling point fraction 46 Condenser 47 Thermometer 48 Discharge conduit 50 electrolyte container 52 Transport containers 54, 54' dryer 56 Condenser 57 Mixer 58 Binder removal equipment 60 Binder solvent 62 Exhaust gas 64 Exhaust gas purification equipment 66 Fine sieve separator 68 sieve wheel 70 Motor 72 Crude fraction outlet 74 rough sketch 76. Detailed output 78 fine divisions 82 Vacuum pump 84 Condenser 86 Conductive salt solvents 88-particle filter 90 Activated Carbon Filter 92 Rear Wash 94 Binder rinsing solvent 96 Cleaning Solution C grenz Limit concentration f 68 Sieve wheel rotation frequency G Gas flow direction M Material flow direction p 42 distiller pressure p 54 Process pressure p 58 Process pressure of binder removal equipment T S,36 Boiling temperature of the washing solvent T 54 dryer temperature TK Short circuit time T r regeneration temperature U reg Regenerated cell voltage.

Claims

1. (a) Active material and, (b) A carrier foil on which the active material is arranged, (c) A binder for connecting the active material to the carrier foil, (d) Liquid electrolyte, (e) Conductive salt (38) (f) A method for reusing an alkali metal battery (12), particularly a Li battery or a Na battery, comprising a housing surrounding the active material, carrier foil, and binder, (i) A method comprising the step of crushing the alkali metal battery (12) to produce a crushed material containing the active material and the binder, black mass (30), (ii) A step of washing the pulverized material with a washing solvent (36) so that the conductive salt (38) is washed away, but the binder is not washed away, thereby obtaining pulverized material and washing liquid (40) with less conductive salt, (iii) A step of regenerating the cleaning solvent (36) from the cleaning solution (40) and especially by distillation, (iv) A step of washing the pulverized material using at least a portion of the regenerated washing solvent (36), (v) A method characterized by a step in which the washing solvent (36) is a component of the electrolyte.

2. The method according to claim 1, wherein, after the pulverization of the alkali metal battery (12), the black mass (30) is separated from the residue fraction (32) by sieving or sieving, the black mass (30) is washed using the washing solvent (36).

3. The concentration of the main component of the cleaning solvent (36), measured in weight percent, differs by up to 10 times from the concentration of the main component of the conductive salt solvent. A method according to any one of the prior claims, characterized in that

4. (a) The washing solvent (36) is not substantially combined with water, (b) The regeneration of the washing solvent (36) includes distilling and separating the conductive salt (38) from the washing liquid (40). A method according to any one of the prior claims, characterized in that

5. The regeneration of the washing solvent (36) includes vacuum distillation, and the vacuum distillation is Maximum regeneration temperature of 70°C (T ｒ ) and / or the regeneration temperature (T ｒ ) is carried out at a pressure less than the vapor pressure of the washing solvent (36). The method according to claim 4, characterized in that

6. (i) A step of drying the pulverized material at a maximum temperature of 60°C and a maximum pressure of 300 hPa, (ii) A step of separating the foil components, particularly the plastic components and / or metal foil components, before the washing, A method according to any one of the prior claims, characterized by the above.

7. A step of pre-drying the pulverized material after the pulverization, preferably before or after separating the foil portion, and before washing the pulverized material, The pre-drying is performed such that at least 50 weight percent of the electrolyte solvent is removed. A method according to any one of the preceding claims, characterized by a process.

8. (a) A step of drying the pulverized material so that a dried pulverized material is produced, (b) A step of separating plastic particles from the dried pulverized material, particularly from the pulverized housing and / or pulverized carrier foil, thereby obtaining black mass, (c) The black mass is washed using the washing solvent (36), step A method according to any one of claims 1 to 6, characterized by the above.

9. After washing the pulverized material, the binder is dissolved from the pulverized material with a low concentration of conductive salt using the binder solvent (60), thereby obtaining pulverized material with a low concentration of binder. A method according to any one of the preceding claims, characterized by a process.

10. (i) Separate the pulverized material, especially the pulverized material with a low binder content, and sieve it finely, thereby obtaining a graphic fraction and a transition metal fraction in which at least one transition metal is concentrated relative to the graphite fraction. A method according to any one of the preceding claims, characterized by a process.

11. Before the aforementioned battery is crushed, at least 75% of the galvanic elements are regenerated to a maximum cell voltage of 0.2 volts, particularly 0.15 volts (U ｒｅｇ Short-circuit the battery until it has been set to A method according to any one of the preceding claims, characterized by a process.

12. The step prior to cleaning the black mass (30) is performed such that the conductive salt (38) of the alkali metal cell (12) decays by up to 2 weight percent. A method according to any one of the prior claims, characterized in that

13. (a) Do not allow the crushed material (22) to come into contact with water before washing. (b) The conductive salt (38) is not disintegrated, in particular not in contact with water, not heated, and not reacted with the washing solvent (36). (c) Before and during grinding, the active material and / or electrolyte present in the alkali metal battery (12) shall not come into contact with water. (d) The alkali metal battery (12), the crushed material, and / or the black mass (30) are not subjected to high-temperature metallurgical treatment before the washing, and are not heated above 300°C, and (e) The grinding is carried out at a low temperature such that a maximum of 2.5 mole percent of fluorine is disintegrated from the grinding material (22). A method according to any one of the prior claims, characterized in that

14. A battery reprocessing facility (10) for reusing alkali metal batteries (12), particularly Li batteries or Na batteries, (a) A grinding apparatus (20) for grinding the battery to obtain a grinding material (22) containing black mass (30) containing the active material and binder, (b) A washing apparatus (34) designed and arranged to wash at least one portion of the pulverized material (22), particularly the black mass (30), using a washing solvent (36), thereby obtaining pulverized material (22) and washing solution (40) with fewer conductive salts, (c) Regenerator (42), (i) The cleaning solvent (36) is designed to be automatically regenerated from the cleaning solution (40), (ii) A supply conduit connected to the cleaning device (34) for sending the cleaning solution (40) from the cleaning device (34) to the regenerator (42), (iii) A return conduit connected to the cleaning device (34) for sending the cleaning solvent (36) from the regenerator (42) to the cleaning device (34) A regenerator (42) having, A battery reprocessing facility (10) equipped with the following:

15. The regenerator (42) is a vacuum distiller designed to automatically distill and remove the low-boiling fraction of the washing liquid (40), the low-boiling fraction forming the washing liquid (40). The battery reprocessing equipment (10) according to claim 14, characterized in that...

16. (a) A separator (26) positioned behind the grinding equipment (20) in the material flow direction (M), and / or designed and positioned to separate the black mass (30) from the residue fraction (32), and / or (b) A dryer (54) positioned behind the washing device (34) in the material flow direction (M) A battery reprocessing apparatus (10) according to claim 14 or 15, characterized by the above.

17. A pre-dryer (80) is positioned behind the crushing equipment (20) and in front of the washing device (34) in the material flow direction (M). A battery reprocessing apparatus (10) according to claim 14 or 15, characterized by the above.

18. A binder removal device (58) is positioned behind the washing device (34) in the material flow direction (M) and is designed to automatically dissolve the binder from the pulverized material (22) with a low conductive salt content using a binder solvent (60). A battery reprocessing apparatus (10) according to any one of claims 14 to 16, characterized by the above.

19. A sieve for separating black mass with few binders in order to produce a graphite fraction and a transition metal fraction enriched with at least one transition metal relative to the graphite fraction, the sieve being a fine sieve (66) having a sieve wheel (68). A battery reprocessing apparatus (10) according to any one of claims 14 to 18, characterized by the above.

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