DE102018117237A1 - Hydrometallurgical recycling process of lithium-ion traction batteries - Google Patents

Abstract

The invention relates to a hydrometallurgical recycling process of lithium-ion traction batteries comprising the following steps: a) Generation of an aqueous solution containing lithium, cobalt, nickel and manganese (Li, Co, Ni, Mn) starting from solid battery material to be recycled by adding an aqueous one Acid to the solid battery material, hereinafter b) optional separation of insoluble constituents, the process comprising the following further steps: c) precipitation of the transition metals Ni, Co, Mn from the solution of step a) or b), d) separation of the precipitation precipitate, optionally washing the precipitate, e) obtaining lithium carbonate from the liquid phase and the optional washing solutions, f) gradually dissolving the individual transition metals Mn, Ni and Co in such a way that solutions are formed which contain only one transition metal Mn, Ni or Co, andg) galvanostatic deposition of elemental Ni and elemental Co from the respective solution obtained from step f). The process according to the invention not only enables the transition metals and the lithium to be recovered separately, the transition metals are also obtained in elemental form and the lithium as carbonate, which enables reuse in a wide variety of applications.

Description

The present invention relates to a hydrometallurgical recycling process of lithium-ion traction batteries, in particular for electric vehicles, with the features of the preamble of patent claim 1.

In the prior art, hydrometallurgical recycling processes of lithium-ion traction batteries are known, which in particular recover the lithium in the form of various salt compounds. Various processing steps are also described in the art with regard to the transition metals contained in the respective battery material, but in principle the transition metals are also recovered as salt compounds or oxides or the solutions are discarded.

From the US 2004/0028585 A1 A pyrometallurgical and hydrometallurgical process for the reprocessing of used lithium metal gel batteries or solid polymer electrolyte batteries is known, in which the battery material is first cooled and thus hardened, then optionally treated thermally and the ash or mass obtained in this way is taken up in an acid , Vanadium compounds are first extracted from this mother solution, then further transition metals and aluminum are separated therefrom and finally lithium carbonate is precipitated from the remaining solution. The vanadium is obtained as vanadium pentoxide. Both the step of thermal treatment to convert the battery mass to ash and the step of oxidizing the vanadium compounds contained in the mother liquor into pentavalent vanadium are very energy-intensive.

A further development of this method is from the DE 10 2013 016 671 A1 known, which relates to the hydrometallurgical recovery of lithium from the lithium transition metal oxide-containing fraction of used galvanic cells, in which a lithium transition metal oxide-containing fraction, wherein the transition metals are nickel, cobalt and / or manganese, with an aluminum content of up to 5 % By weight or those of the metals nickel, cobalt and / or aluminum and a particle size of up to 500 μm. It is proposed, based on the oxide content of the lithium transition metal oxide-containing fraction, to introduce at least a stoichiometric amount of sulfuric acid or hydrochloric acid with a concentration of 0.5 to 4 mol / l and a solid to liquid ratio in the range from 10 to 300 g / l with the addition of the at least stoichiometric amount of hydrogen peroxide, based on the transition metal content of the fraction containing lithium transition metal oxide, to be digested at temperatures of 35 to 70 ° C. The lithium salts formed and the salts of the transition metal-containing solution are separated off and the remaining residue is washed at least twice, the separated salts and the salt-containing washing solutions are combined, the transition metals in the pH range from 9 to 11 are precipitated as hydroxides, separated and washed. The remaining lithium sulfate-containing solutions are then combined and converted into lithium hydroxide by means of electrodialysis with bipolar membranes. In this process, too, the transition metals are not separated from one another, but are precipitated together as hydroxides. Lithium is obtained in the form of lithium hydroxide.

From the US 2007/0196725 A1 A further possibility for a hydrometallurgical treatment of cells and batteries is known which has at least one lithium-based anode, a salt dissolved in an electrolyte and a cathode which comprises at least one metal or a compound composed of metals, which consists of cobalt, nickel, manganese and iron are selected to recover the recyclable fractions. The procedure of US 2007/0196725 A1 is characterized in that it comprises dry grinding at ambient temperature under an inert atmosphere, treatment by at least magnetic separation and table readers, followed by aqueous hydrolysis to at least the lithium in the form of carbonate or lithium phosphate, an anion of the said salt of the electrolyte and a concentrate on the basis of at least one metal of said cathode. The lithium can be obtained as lithium carbonate in the process mentioned. However, here too the metals of the cathode are obtained as a concentrate of their salts or their oxides. In addition, the method provides for at least one magnetic separation and table reader in four fractions, which in practice could be difficult to carry out on an industrial scale in a continuous process.

The object of the present invention is therefore to provide a hydrometallurgical recycling process for lithium-ion traction batteries by means of which the transition metals and the lithium can not only be recovered separately. It is also desirable that the transition metals be obtained in an elemental form by a recycling process and at the same time the lithium as carbonate, which enables reuse in a wide variety of applications. In addition, the process should also be able to be used on an industrial scale.

According to the invention, this object is achieved by a hydrometallurgical recycling process of lithium-ion traction batteries with the features of claim 1.

1. a) Erzeugung einer Lithium, Kobalt, Nickel und Mangan (Li, Co, Ni, Mn) enthaltenden wässrigen Lösung ausgehend von zu recycelndem festen Batteriematerial durch Zugabe einer wässrigen Säure zu dem festen Batteriematerial, nachfolgend
2. b) optionale Abtrennung von unlöslichen Bestandteilen,

wobei das Verfahren die folgenden weiteren erfinderischen Schritte umfasst:

• c) Fällung der Übergangsmetalle Ni, Co, Mn aus der Lösung des Schritts a) oder b),
• d) Abtrennung des Fällungsniederschlags, optional Waschen des Fällungsniederschlags,
• e) Gewinnung von Lithiumcarbonat aus der flüssigen Phase und den optionalen Waschlösungen,
• f) schrittweises Lösen der einzelnen Übergangsmetalle Mn, Ni und Co derart, dass jeweils Lösungen entstehen, die nur noch ein Übergangsmetall Mn, Ni oder Co enthalten, und
• g) galvanostatische Abscheidung von elementarem Ni und elementarem Co aus der jeweiligen aus Schritt f) gewonnenen Lösung.

The hydrometallurgical recycling process of lithium-ion traction batteries according to the invention has the following steps:

1. a) Generation of an aqueous solution containing lithium, cobalt, nickel and manganese (Li, Co, Ni, Mn) starting from solid battery material to be recycled by adding an aqueous acid to the solid battery material, hereinafter
2. b) optional separation of insoluble constituents,

the method comprising the following further inventive steps:

• c) precipitation of the transition metals Ni, Co, Mn from the solution of step a) or b),
• d) separation of the precipitate, optionally washing the precipitate,
• e) obtaining lithium carbonate from the liquid phase and the optional washing solutions,
• f) gradually dissolving the individual transition metals Mn, Ni and Co in such a way that solutions are formed which contain only one transition metal Mn, Ni or Co, and
• g) galvanostatic deposition of elemental Ni and elemental Co from the respective solution obtained from step f).

In step a), solid battery material to be recycled is dissolved by adding an aqueous acid. The battery material to be recycled can be, for example, cathode material such as LCO, LMO and / or NMC, but also any other battery material that contains compounds of the elements Li, cobalt, nickel and manganese as components. It is also possible for the battery material to be recycled to be lithium-based and to contain only cobalt and nickel or only cobalt and manganese or only nickel and manganese or only one of the transition metals mentioned as a compound, in particular as oxides, as a constituent. Likewise, the battery material to be recycled can be a mixture of cathode material as described above and anode material. Then it also contains graphite and / or a Si-C nanocomposite. The battery material to be recycled can also have been pretreated thermally or mechanically, for example by crushing.

The aqueous acid can preferably be concentrated or dilute hydrochloric acid or concentrated or dilute sulfuric acid, but other mineral acids can also be used. A 1-5 molar hydrochloric acid, in particular a 3 molar hydrochloric acid, may be mentioned here as examples of acids which are particularly preferably used to dissolve the battery material to be recycled. Similarly, it is also possible to use 0.5 molar to 4.0 molar sulfuric acid to dissolve the battery material.

In step b) of the present method, any undissolved constituents of the battery material to be recycled that are contained are separated from the solution from step a). This is, for example, essentially graphite and / or Si-C nanocomposite made from possibly included anode material. The separation can take place, for example, by filtration.

In step c), the transition metals Ni, Co and / or Mn are precipitated from the solution obtained from step a) or b). For this purpose, for example, the pH of the solution is first adjusted to the selected precipitation reaction using a buffer solution, in particular an ammonia / ammonium chloride buffer solution. In step c), the transition metals Mn, Ni and / or Co contained are preferably precipitated by adding hydrogen sulfide (H ₂ S) and settle out as a solid precipitate. In the subsequent step d), the precipitate which now comprises the sulfides of the transition metals Mn, Co and / or Ni contained, for example by filtration or centrifuging, is separated from the remaining aqueous solution. The lithium remains in the aqueous solution as a dissolved salt compound. In other words, steps c) and d) separate the transition metals Ni, Co and / or Mn from the lithium-containing fraction on the one hand. The precipitation precipitate of the transition metals is optionally washed one or more times and the washing solutions are combined with the aqueous, lithium-containing fraction.

In step e), the lithium is obtained as lithium carbonate from the optionally combined aqueous solution from steps c) and d). This can be done in various ways known to those skilled in the art. For example, the pH of the solution can be adjusted to a basic range by adding a base and sodium carbonate or potassium carbonate can then be added so that the lithium contained precipitates as lithium carbonate. Lithium carbonate has the advantage that it can be cleaned very well and serves both in aluminum production and as a starting material for many other lithium compounds. It is the most important lithium compound.

In step f) of the present method, the individual transition metals Mn, Ni and Co are dissolved step by step in such a way that solutions are formed which only have one Mn, Ni or Co contain transition metal. In other words, in this step, a wet chemical separation process is carried out in such a way that, for example, due to the different solubilities in different solvents, only one transition metal precipitates as a solid precipitate and the other transition metals or the remaining transition metal remain in the solution. Alternatively, the solubilities can be chosen so that two or one transition metal (s) are precipitated and only one transition metal remains in the solution. In a second subsequent step, the transition metals remaining in a fraction can then be separated from one another in a similar manner. A preferred example of such a separation in solutions with only one transition metal Co, Ni or Mn is described in more detail below in the context of a possible embodiment of the method according to the invention.

Finally, in step g) of the present method, the transition metal Ni, Co and Mn is electrodeposited from their respective aqueous solution from step f).

The advantages of this step are the simple device technology and the quick implementation. The main advantage, however, is that the transition metals are obtained in their elementary form. This means that they can be reused in a wide range of applications and the value they had before the traction battery was manufactured is fully recovered.

In one embodiment of the present invention, the transition metals Mn, Ni, and Co are precipitated as sulfides in step c). This precipitation reaction can be carried out reliably and has excellent turnover rates. The transition metals can thus be completely and safely separated from the lithium-containing fraction. For example, the solution obtained from step a) or b) can be adjusted in a basic range by adding a buffer solution, in particular by adding an ammonia / ammonium chloride buffer solution in a molar ratio of 1: 1, in particular at pH values between 7.5 and 9.0, particularly preferably at pH 8.5. H ₂ S is added to the resulting basic solution in at least stoichiometric amounts. The solid sulfide deposits of the transition metals, that is to say MnS, Ni ₂ S ₃ and / or Co ₂ S _3, are separated off by filtration and optionally washed one or more times, as provided in step d). The wash solutions are combined with the remaining liquid phase, which contains the lithium. The precipitation reaction of step c) can be carried out at room temperature.

In one embodiment of the method according to the invention, the liquid phase is adjusted to a basic pH in step e). To obtain the lithium carbonate, it is precipitated by adding potassium carbonate.

Due to the different solubilities of the two alkali salts, it is easily possible to obtain lithium carbonate in this way. As described above, lithium carbonate is industrially the most important lithium salt used in a variety of applications. Purification, for example by dissolving and reprecipitating, can be carried out very easily, and an extremely pure product can be obtained in this way.

In contrast to the addition of sodium carbonate, which is also possible within the scope of the invention, the addition of potassium carbonate has the advantage that the solubilities and the dissolving behavior of the two competing salts have greater differences and therefore precipitation of lithium carbonate is made even easier.

For example, the liquid phase obtained from step d) can first be brought to a pH of by adding NaOH 11 be adjusted and then the potassium carbonate is added. The precipitation reaction to obtain the lithium carbonate can preferably be carried out at an elevated temperature, in particular at a temperature of 85 ° C-100 ° C.

In one embodiment of the invention, the manganese sulfide is first dissolved in acetic acid in step f) and separated from the remaining solid residue. For this purpose, the residues obtained from the sulfide precipitation are taken up in an acetic acid solution. For example, a solid: acetic acid ratio of 1:20 can be set. The solution process can be carried out at room temperature. Advantageously, only the manganese sulfide is brought into solution by this, the sulfides of nickel and / or cobalt remain as undissolved solids. The solids are separated from the solution, for example using a sediment separator.

In one embodiment of the process according to the invention, the solution containing Mn obtained in step f) is treated with hydrochloric acid and a pH of less than 4 is set. Elemental manganese is obtained from this by means of galvanostatic deposition. The pH can be adjusted in particular by adding 0.5-2.0 molar hydrochloric acid solution, in particular by adding 1 molar hydrochloric acid solution. This additionally facilitates the subsequent electrochemical deposition.

In one embodiment of the invention, after the Mn-containing solution has been separated off, the residue containing Ni and Co is dissolved with acetic acid and hydrogen peroxide. The aqueous acetic acid solution can first be mixed with the hydrogen peroxide solution and added to the separated solid residues from step f), which comprises nickel and / or cobalt sulfides, preferably in a ratio of 1:20 solid to solution. An aqueous solution is formed which contains the two remaining transition metals Ni and Co. The solution step can be carried out at room temperature.

In one embodiment of the present invention, a solution of 2-ethylhexyl hydrogen phosphonate (EHPNA) in toluene and ammonium solution is added to the solution containing Ni and Co, and the organic and aqueous phases are then extracted and separated.

For example, an approximately 3-4 molar aqueous ammonium solution can first be prepared, to which a 20% solution of EHPNA in toluene is added. This mixture is added to the solution containing Ni and / or Co, preferably in a volume ratio of 3: 1, mixture of ammonium-EHPNA / toluene solution to Ni-Co solution. The organic phase is then extracted and separated from the aqueous phase. The extraction is preferably carried out at elevated temperature, in particular at 50 ° C. The aqueous phase thus obtained contains Ni in dissolved form. The organic phase obtained by extraction contains Co.

The extraction step advantageously makes it possible to separate the valuable transition metals nickel and cobalt from one another so that they can be separated and fed purely to a subsequent electrochemical deposition. As a result, the metals nickel and cobalt, which are already in great demand at the present time, can be obtained separately from one another in elementary form. The type of extraction shown can be carried out very easily, so that this step of the method according to the invention is also suitable for large-scale use.

In one embodiment of the present method, Ni is deposited in elemental form from the aqueous phase after the addition of hydrochloric acid. For example, a 1 molar hydrochloric acid solution can first be added to the aqueous Ni-containing solution obtained from the extraction in a volume ratio of approximately 1: 1. The aqueous solution thus obtained is subsequently subjected to electrochemical deposition to obtain elemental nickel.

In one embodiment of the present invention, the organic phase of the preceding extraction step is treated with hydrochloric acid and back-extracted, after which Co is deposited in an elementary form from the back-extracted solution. For example, a 1 molar hydrochloric acid solution in a volume ratio of approximately 1: 2, based on the organic phase to the hydrochloric acid solution, can be added to the organic phase of the previous extraction. An extraction is carried out, after which the aqueous, hydrochloric acid phase contains Co. This aqueous solution containing hydrochloric acid Co obtained in this way can then be subjected directly to an electrochemical deposition to obtain elemental Co.

• i) Zerkleinern des festen Batteriematerials,
• ii) thermische Behandlung, gegebenenfalls unter Zuführung von Sauerstoff,
• iii) Entfernung von organischen Bestandteilen, und/oder
• iv) Abtrennung von unlöslichem Graphit.

In one embodiment of the method of the present invention, the solid battery material to be recycled is pretreated before step a) by at least one of the following steps:

• i) crushing the solid battery material,
• ii) thermal treatment, if appropriate with the addition of oxygen,
• iii) removal of organic components, and / or
• iv) separation of insoluble graphite.

The pretreatment steps mentioned serve individually or in combination to increase the efficiency of the process and ensure that an optimal solution of the valuable components can be achieved.

For example, the solid battery material to be recycled can be crushed in a first pretreatment. This can be done by suitable methods generally known to the person skilled in the art. In particular, particles with an average size of approximately 500 μm can be obtained in this way.

Furthermore, the material which may have been comminuted can be pretreated thermally. For example, a calcination step can be carried out in an oven at about 500 ° C-650 ° C, especially at 560 ° C. The calcination can be supported by the addition of oxygen. It is possible, among other things, to remove organic components from the material by means of thermal treatment. The calcination is advantageously exothermic, so that only a small amount of energy is required for this.

1. 1) Zerkleinern des festen Batteriematerials,
2. 2) thermische Behandlung unter Zuführung von Sauerstoff,
3. 3) Entfernung von organischen Bestandteilen,
4. 4) Erzeugung einer Lithium, Kobalt, Nickel und Mangan (Li, Co, Ni, Mn) enthaltenden wässrigen Lösung ausgehend von zu recycelndem festen Batteriematerial durch Zugabe einer wässrigen Säure zu dem festen Batteriematerial,
5. 5) Abtrennung von unlöslichem Graphit,
6. 6) Fällung der Übergangsmetalle Ni, Co, Mn aus der Lösung des Schritts 5) durch Zusatz von Schwefelwasserstoff,
7. 7) Abtrennung des Fällungsniederschlags, optional Waschen des Fällungsniederschlags,
8. 8) Gewinnung von Lithiumcarbonat aus der flüssigen Phase und den optionalen Waschlösungen durch Zugabe von Kaliumcarbonat oder Natriumcarbonat bei einem basischen pH-Wert und erhöhter Temperatur, insbesondere bei 85°C-100°C,
9. 9) Lösen der MnS-Salze durch Aufnahme der festen Fällungsrückstände in Essigsäurelösung,
10. 10) elektrochemische Abscheidung von elementarem Mangan aus der Essigsäurelösung aus Schritt 9) unter Zusatz von Salzsäurelösung,
11. 11) Lösen der Ni und/oder Co Rückstände nach Abtrennung der Mn-Essigsäurelösung in einer Essigsäure/Wasserstoffperoxidlösung,
12. 12) Zugabe von EHPNA/Toluol- und Ammoiniumhydroxidlösung zur Lösung aus Schritt 11),
13. 13) Extraktion und Trennung der wässrigen Phase, welche Ni enthält, von der organischen Phase, welche Co enthält.
14. 14) elektrochemische Abscheidung von elementarem Nickel aus der wässrigen Extraktionsphase aus Schritt 13) unter Zusatz von Salzsäure,
15. 15) Rückextraktion des Co-Anteils aus der organischen Phase aus Schritt 13) durch Zugabe von verdünnter Salzsäurelösung,
16. 16) elektrochemische Abscheidung von elementarem Kobalt aus der wässrigen Phase aus Schritt 15), und
17. 17) optional Wiederverwendung der organischen Phase aus Schritt 15) in Schritt 12).

In a preferred embodiment of the method according to the invention, the recycling method is characterized by the steps:

1. 1) shredding the solid battery material,
2. 2) thermal treatment with the addition of oxygen,
3. 3) removal of organic components,
4. 4) generation of an aqueous solution containing lithium, cobalt, nickel and manganese (Li, Co, Ni, Mn) starting from solid battery material to be recycled by adding an aqueous acid to the solid battery material,
5. 5) separation of insoluble graphite,
6. 6) Precipitation of the transition metals Ni, Co, Mn from the solution of the step 5 ) by adding hydrogen sulfide,
7. 7) separation of the precipitation, optional washing of the precipitation,
8. 8) Obtaining lithium carbonate from the liquid phase and the optional washing solutions by adding potassium carbonate or sodium carbonate at a basic pH and elevated temperature, in particular at 85 ° C.-100 ° C.,
9. 9) dissolving the MnS salts by taking up the solid precipitation residues in acetic acid solution,
10. 10) electrochemical deposition of elemental manganese from the acetic acid solution from step 9 ) with the addition of hydrochloric acid solution,
11. 11) dissolving the Ni and / or Co residues after separating the Mn-acetic acid solution in an acetic acid / hydrogen peroxide solution,
12. 12) Add EHPNA / toluene and ammonium hydroxide solution to the solution from step 11 )
13. 13) Extraction and separation of the aqueous phase, which contains Ni, from the organic phase, which contains Co.
14. 14) Electrochemical deposition of elemental nickel from the aqueous extraction phase from step 13 ) with the addition of hydrochloric acid,
15. 15) Back extraction of the Co portion from the organic phase from step 13 ) by adding dilute hydrochloric acid solution,
16. 16) Electrochemical deposition of elemental cobalt from the aqueous phase from step 15 ), and
17. 17) optional reuse of the organic phase from step 15 ) in step 12 ).

Regarding the possible and preferred further details of the steps 1 ) to 17 ) may be referred to the above information, which are also applicable to the steps mentioned here and equally preferred.

• 1 in einem stark schematisierten Fließschema ein erfindungsgemäßes Verfahren in einer bevorzugten Ausgestaltung.

There are a multitude of options for designing and developing the recycling process. For this purpose, reference may first be made to the claims subordinate to claim 1. A preferred embodiment of the invention may be explained in more detail below with reference to the drawing and the associated description. The drawing shows:

• 1 a method according to the invention in a preferred embodiment in a highly schematic flow diagram.

(I)

The mixture of cathode material such as LCO, LMO and / or NMC, organic components and graphite ( 1 ) first thermally with the addition of oxygen ( 2 ) treated to remove the organic matter ( 3 ). For example, a calcination step can be carried out in an oven at about 500 ° C-650 ° C, especially at 560 ° C. The calcination can be supported by the addition of oxygen. The calcination is advantageously exothermic, so that only a small amount of energy is required for this.

(II)

Then we mix the mixture of cathode material and graphite ( 5 ) in hydrochloric acid ( 6 ) in a stirred tank ( 7 ) solved. The aqueous acid can preferably be concentrated or dilute hydrochloric acid or concentrated or dilute sulfuric acid, but other mineral acids can also be used. A 1-5 molar hydrochloric acid, in particular a 3 molar hydrochloric acid, may be mentioned here as examples of acids which are particularly preferably used to dissolve the battery material to be recycled. Similarly, it is also possible to use 0.5 molar to 4.0 molar sulfuric acid to dissolve the battery material. The insoluble graphite can be separated from the solution ( 8th ). Then the pH value ( 9 ) using an NH3 / NH4Cl buffer solution ( 11 ) adjusted, especially by adding an ammonia / ammonium chloride buffer solution in a molar ratio 1 : 1, can be set in a basic range, in particular at pH values between 7.5 and 9.0, particularly preferably at pH 8.5.

(III)

The transition metals nickel, cobalt and manganese ( 13 ) precipitated as sulfides from the solution by introducing H ₂ S (12). H ₂ S is added to the basic solution in at least stoichiometric amounts.

(IV)

The solution ( 15 ) is from the precipitation ( 20 ) Cut. The solid sulfide precipitates of the transition metals, that is to say MnS, Ni ₂ S ₃ and / or Co ₂ S _3, are separated off by filtration and optionally washed one or more times. The solution turns lithium into carbonate ( 19 ) by adding K2CO3 ( 16) like. The solution is made up by the addition of NaOH ( 14 ) to a basic pH value ( 18 ) of about 11 set. The precipitation is preferably carried out at elevated temperatures, preferably at about 100 ° C.

(V)

The sulfides are gradually dissolved again after separation from the solution. First the manganese sulfide ( 22 ) with acetic acid ( 21 ) dissolved and separated from the residue, treated with hydrochloric acid ( 24 ) and galvanostatically deposited. The pH of the solution should be less than 4 ( 23 ) and can be adjusted to this value with dilute hydrochloric acid.

(VI)

The residue containing nickel and cobalt ( 25 ) with acetic acid and hydrogen peroxide ( 26 ) solved. Residues are filtered off from the solution ( 28 ).

(VII)

The solution is then washed with 20% EHPNA in toluene ( 31 ) which ammonium solution ( 30 ) was added, extracted ( 32 ). The extraction can be carried out at approx. 50 ° C to increase efficiency. The extraction can also be carried out at room temperature. Cobalt accumulates in the organic phase ( 35 ) and nickel in the aqueous phase ( 33 ) on. After phase separation, hydrochloric acid is added to the aqueous phase and galvanostatically deposited to obtain nickel ( 34 ). The organic phase is washed with hydrochloric acid ( 37 ) treated to back extract the cobalt from the organic phase ( 39 ).
The back-extracted solution is galvanostatically deposited to obtain cobalt ( 40 ) and the organic phase can be used for re-extraction ( 38 ).

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2004/0028585 A1 [0003]
• DE 102013016671 A1 [0004]
• US 2007/0196725 A1 [0005]

Claims (11)

Hydrometallurgical recycling process of lithium-ion traction batteries comprising the following steps: a) Generation of an aqueous solution containing lithium, cobalt, nickel and manganese (Li, Co, Ni, Mn) starting from the solid battery material to be recycled by adding an aqueous acid to the solid Battery material, hereinafter b) optional separation of insoluble constituents, characterized in that the method comprises the following further steps: c) precipitation of the transition metals Ni, Co, Mn from the solution of step a) or b), d) separation of the precipitation precipitate, optionally washing the precipitation, e) obtaining lithium carbonate from the liquid phase and the optional washing solutions, f) gradually dissolving the individual transition metals Mn, Ni and Co in such a way that solutions are formed which contain only one transition metal Mn, Ni or Co, and g) galvanostatic deposition of elemental Ni and elemental C. o from the respective solution obtained from step f). Recycling process according to Claim 1 , characterized in that in step c) the transition metals Mn, Ni, and Co are precipitated as sulfides. Recycling process according to Claim 1 or 2 , characterized in that in step e) the liquid phase is adjusted to a basic pH and for recovery the lithium carbonate is precipitated by adding potassium carbonate. Recycling process according to one of the Claims 1 to 3 , characterized in that in step f) the manganese sulfide is first dissolved with acetic acid and separated from the residue. Recycling process according to one of the preceding claims, characterized in that the solution containing Mn obtained in step f) is treated with hydrochloric acid and a pH value of less than 4 is set and elemental manganese is obtained therefrom by means of galvanostatic deposition. Recycling process according to Claim 4 , characterized in that after the separation of the solution containing Mn, the residue containing Ni and Co is dissolved with acetic acid and hydrogen peroxide. Recycling process according to Claim 6 , characterized in that a solution of 2-ethylhexyl hydrogen phosphonate (EHPNA) in toluene and ammonium solution is added to the solution containing Ni and Co and then extraction and separation of the organic and the aqueous phase takes place. Recycling process according to Claim 7 , characterized in that Ni is precipitated in elemental form from the aqueous phase after addition of hydrochloric acid. Recycling process according to Claim 7 , characterized in that the organic phase is treated with hydrochloric acid and back-extracted, after which Co is deposited from the back-extracted solution galvanostatically in elemental form. Recycling process according to Claim 1 , characterized in that the solid battery material to be recycled is pretreated before step a) by at least one of the following steps: i) crushing the solid battery material, ii) thermal treatment, optionally with the addition of oxygen, iii) removal of organic constituents, and / or iv) separation of insoluble graphite. Recycling process according to one or more of the preceding claims, characterized by the steps: 1) crushing the solid battery material, 2) thermal treatment with the addition of oxygen, 3) removal of organic constituents, 4) generation of lithium, cobalt, nickel and manganese (Li , Co, Ni, Mn) containing aqueous solution starting from solid battery material to be recycled by adding an aqueous acid to the solid battery material, 5) removal of insoluble graphite, 6) precipitation of the transition metals Ni, Co, Mn from the solution of step 5) by adding hydrogen sulfide, 7) separating the precipitate, optionally washing the precipitate, 8) recovering lithium carbonate from the liquid phase and the optional washing solutions by adding potassium carbonate or sodium carbonate at a basic pH and elevated temperature, in particular at 85 ° C. -100 ° C, 9) Dissolve the MnS salts by taking up the solid precipitation residues in acetic acid solution, 10) electrochemical separation of elemental manganese from the acetic acid solution from step 9) with the addition of hydrochloric acid solution, 11) dissolving the Ni and / or Co residues after separation of the Mn-acetic acid solution in an acetic acid / hydrogen peroxide solution, 12) adding EHPNA / toluene and ammonium hydroxide solution for the solution from step 11), 13) Extraction and separation of the aqueous phase, which contains Ni, from the organic phase, which contains Co. 14) electrochemical deposition of elemental nickel from the aqueous extraction phase from step 13) with the addition of hydrochloric acid, 15) back extraction of the Co portion from the organic phase from step 13) by adding dilute hydrochloric acid solution, 16) electrochemical deposition of elemental cobalt from the aqueous phase from step 15), and 17) optionally reusing the organic phase from step 15) in step 12).

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