WO2024165501A1

WO2024165501A1 - Process for recycling lithium ion battery material

Info

Publication number: WO2024165501A1
Application number: PCT/EP2024/052791
Authority: WO
Inventors: Marc DUCHARDT; Maximilian RANG; Wolfram WILK; Bernard Muller; Vincent Smith; Fabian Seeler; Wolfgang Rohde; Kerstin Schierle-Arndt; Simon Schroedle; Anne-Marie Caroline ZIESCHANG
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2023-02-07
Filing date: 2024-02-05
Publication date: 2024-08-15
Anticipated expiration: 2025-08-07
Also published as: TW202441838A; KR20250143338A; CN120584206A

Abstract

The present disclosure relates to processes for recycling lithium ion battery materials and for recovering lithium from such materials.

Description

Process for recycling lithium ion battery material

Field of the invention

Background

Lithium ion battery materials are complex mixtures of various elements and compounds. For example, many lithium ion battery materials contain valuable metals such as lithium, aluminum, copper, nickel, cobalt, and/or manganese. It may be desirable to recover various elements and compounds from lithium ion battery materials. For example, it may be advantageous to recover lithium, aluminum, copper, nickel, cobalt, and/or manganese. Accordingly, there is a need for processes for recycling lithium ion battery materials.

High purity lithium is a valuable resource. Many sources of lithium, such as lithium ion batteries, lithium ion battery waste, lithium containing water, e.g. ground water, and raw lithium containing ores, are complex mixtures of various elements and compounds. The removal and purification of lithium from a material, such as a lithium ion battery material, are exemplary steps in the recycling of lithium ion batteries. Accordingly, there is a need for processes for recovering lithium from lithium ion battery materials.

WO 2021 / 018 372 A1 discloses a method for recycling lithium ion batteries comprising the steps: (a) digesting down a ground material containing ground components of electrodes of lithium batteries with concentrated sulfuric acid at a digestion temperature of at least 100 ° C, in particular at least 140 ° C, so that exhaust gas and a digested material are produced, (b) discharging the exhaust gas (14) and (c) wet-chemically extracting at least one metal component of the digested material.

US 2022 / 017 989 A1 discloses a method for the recovery of metals from a feed stream containing one or more value metals and lithium. The method comprises subjecting the feed stream to a sulfuric acid leach to form a slurry comprising a pregnant leach solution of soluble metal salts and a solid residue; separating the pregnant leach solution and the solid residue; subjecting the pregnant leach solution to one or more separate solvent extraction steps, wherein each solvent extraction step recovers one or more value metals from the pregnant leach solution, the remaining pregnant leach solution comprising lithium; and recovery of lithium from the pregnant leach solution.

JP 7 100 211 B1 discloses a method for recovering metal from lithium ion battery waste which includes a wet process for using acid to leach metal including lithium in the lithium ion battery waste and extracting the metal from the metal-containing solution in which the metal is dissolved, where the lithium extracted in the wet process is used as a pH adjuster used in the wet process.

WO 2022 /009 004 A1 discloses a process for generating a metal sulfate that involves crystallizing a metal sulfate from an aqueous solution to form a crystallized metal sulfate in a mother liquor with uncrystallized metal sulfate remaining in the mother liquor; separating the crystallized metal sulfate from the mother liquor; basifying a portion of the mother liquor to convert the uncrystallized metal sulfate to a basic metal salt; and using the basic metal salt upstream of crystallizing the metal sulfate.

WO 2018 / 223 193 A1 discloses a process for the recovery of cobalt, lithium and associated metals from lithium-ion batteries, comprising (i) shredding and pulverizing the batteries under an inert atmosphere, (ii) leaching the batteries with sulfuric acid and sulfur dioxide under reducing conditions with a sub- stoichiometric amount of acid, (iii) recovery of copper by cementation, (iv) purification of the leach filtrate to precipitate iron and aluminum, along with some of the manganese and nickel if they are at low levels in the feed battery, (v) ion exchange to remove residual copper, nickel and manganese, (vi) precipitation of the purified solution with soda ash to recover all of the cobalt, and (vii) recovery of lithium as carbonate.

In a method for the production of cathode active materials (CAM) for lithium ion batteries, a precursor material (pCAM), e.g., a compound corresponding to formula Ni_xCOyMni._x-y(OH)2, is mixed with LiOH and/or U2CO3, and the mixture is calcinated to produce LiNi_xCo_yMni._x.yO2. The product is washed with water to remove excess lithium salts.

WO 2022 / 128 805 A2 discloses a process for making an electrode active material (cathode active material) comprising the following steps: (a) Providing a hydroxide TM(OH)₂ or an oxyhydroxide of TM wherein TM is one or more metals and contains Mn and, optionally, Co, and from 85 to 95 mol% Ni, referring to the sum of Ni, Co and Mn, (b) Drying said hydroxide TM(OH)₂ or oxyhydroxide of TM at a temperature in the range of from 400 to 600°C, thereby obtaining an oxide or oxyhydroxide of TM with a residual moisture content of from 200 to 500 ppm, (c) mixing said oxide or oxyhydroxide from step (b) with a source of lithium and with at least one compound of Mg or Al and with at least one compound of Ti or Zr, (d) treating the mixture obtained from step (c) thermally at a temperature in the range of from 550 to 875°C. The material obtained from step (d) is treated with an aqueous medium, preferably with water, followed by a liquid-solid separation step.

In the production of cathode active materials (CAM) for lithium ion batteries, wastewater is produced which contains significant amounts of Li₂CO₃ and LiOH. The wastewater needs to either be disposed of directly, or a costly dedicated Li retrieval step has to be used to remove lithium from the wastewater.

Summary of the invention

In processes for the recycling of lithium ion battery materials and for recovering valuable elements such as lithium, aluminum, copper, nickel, cobalt, and/or manganese from the lithium ion battery materials, the addition of alkaline solutions, e.g., sodium hydroxide (NaOH) solution, is required at multiple stages for pH adjustment of the reaction mixture. It has been found that part of the alkaline solution can be substituted by alkaline wastewater from the production of cathode active materials (CAM) for lithium ion batteries.

This dispenses with the need for a dedicated step for Li retrieval from the wastewater in CAM production. Lithium is recovered from the alkaline wastewater, alkali consumption in the recycling process of lithium ion battery materials and sodium concentration in the reaction mixture are reduced,

Brief description of the drawings

Fig. 1 shows an exemplary process for recycling lithium ion battery material according to the present disclosure;

Fig. 2 shows selected process steps of another exemplary process for recycling lithium ion battery material according to the present disclosure.

Detailed description of the drawings

Fig. 1 shows an exemplary process for recycling lithium ion battery material according to the present disclosure. Lithium ion battery material 10 comprising lithium, copper, cobalt, and nickel is provided to leaching step 100. In leaching step 1000, the lithium ion battery material 10 is leached with sulfuric acid 11 to obtain an acidic aqueous solution 12 comprising lithium, copper, cobalt, and nickel, and a leach residue 13. In a first solvent extraction step 2000, copper 23 is recovered from the solution 12 by solvent extraction and a solution 22 depleted of copper is obtained. The solvent extraction involves the addition of an alkaline solution 21 to the solution 12. In subsequent first precipitation step 3000, impurities 33 are precipitated from the solution 22, and a solution 32 depleted of impurities is obtained. The precipitation of impurities 33 involves the addition of an alkaline solution 31 to the solution 22. In a second solvent extraction step 4000, manganese sulfate 43 is recovered from the solution 32 by solvent extraction and a solution 42 depleted of manganese is obtained. The solvent extraction involves the addition of an alkaline solution 41 to the solution 32. In a third solvent extraction step 5000, cobalt sulfate 53 is recovered from the solution 42 by solvent extraction and a solution 52 depleted of cobalt is obtained. The solvent extraction involves the addition of an alkaline solution 51 to the solution 42. In a fourth solvent extraction step 6000, nickel sulfate 63 is recovered from the solution 52 by solvent extraction and a solution 62 depleted of nickel is obtained. The solvent extraction involves the addition of an alkaline solution 61 to the solution 52. In an evaporating step 7000, water is removed from the solution 62 by evaporation, and a concentrated solution 72 is obtained. In a second precipitation step 8000, lithium carbonate 83 is precipitated from the solution 72 by addition of sodium bicarbonate 81. The mother liquor 82 comprising residual lithium is transferred to a third precipitation step 9000, and sodium phosphate 91 is added to precipitate lithium phosphate 93. shows selected process steps of another exemplary process for recycling lithium ion battery material according to the present disclosure. Steps 1000 through 6000 are similar to the process shown in Fig.1. Solution 62 then is fed to a precipitation step 10000, where magnesium hydroxide 103 is precipitated from the solution 62, and a solution 102 depleted of magnesium is obtained. The precipitation of magnesium hydroxide 103 involves the addition of an alkaline solution 101 to the solution 62. In a fifth solvent extraction step 11000, lithium is recovered from the solution 102 by solvent extraction. The solvent extraction involves the addition of an alkaline solution 11 1 to the solution 102.

From the loaded stripping liquid 1 12, lithium sulfate 1 13 can be crystallized.

Detailed description

The present disclosure provides a process for recycling lithium ion battery material comprising a) providing lithium ion battery material comprising lithium, copper, cobalt, and nickel; b) leaching the lithium ion battery material with an acid to obtain an acidic aqueous solution comprising lithium, copper, cobalt, and nickel, c) recovering copper from the solution obtained in step b) by solvent extraction, the solvent extraction involving the addition of an alkaline solution to the solution obtained in step b), d) precipitating impurities from the solution obtained in step c), the precipitation involving the addition of an alkaline solution to the solution obtained in step c), e) recovering impurities from the solution obtained in step d) by solvent extraction, the solvent extraction involving the addition of an alkaline solution to the solution obtained in step d), f) recovering cobalt from the solution obtained in step e) by solvent extraction, the solvent extraction involving the addition of an alkaline solution to the solution obtained in step e), g) recovering nickel from the solution obtained in step f) by solvent extraction, the solvent extraction involving the addition of an alkaline solution to the solution obtained in step f), h) recovering lithium from the solution obtained in step g).

It is a characteristic feature of the process that at least one of the alkaline solutions added in steps c) through g) comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate has a pH value in the range of from 12 to 13. In some embodiments of the process, the alkaline solution comprising sodium, lithium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH and/or Li₂CO₃ with water. Said solution contains large amounts of lithium as well as hydroxide, carbonate, and sulfate. In some embodiments, the solution obtained by washing a reaction product of pCAM and UOH/U2CO3 comprises from 3 to 4 percent by weight, relative to the total weight of the solution, of dissolved salts. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 0.25 to 1 percent by weight, e.g., from 0.4 to 0.7 percent by weight, relative to the total weight of the solution, of lithium. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 0.01 to 0.15 percent by weight, e.g., from 0.03 to 0.1 percent by weight, relative to the total weight of the solution, of sodium. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 0.005 to 0.03 percent by weight, e.g., from 0.025 to 0.02 percent by weight, relative to the total weight of the solution, of potassium. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 0.5 to 1 percent by weight, relative to the total weight of the solution, of hydroxide. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 0.2 to 0.5 percent by weight, relative to the total weight of the solution, of carbonate. In some embodiments, the solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃ comprises from 1 .5 to 2.5 percent by weight, relative to the total weight of the solution, of sulfate.

In the context of the present disclosure, the term "pCAM" refers to a precursor material of cathode active materials (CAM) for lithium ion batteries. In some embodiments, the precursor material corresponds to formula Ni_xCOyMni._x.y(OH)₂ with 0 < x < 0.9 and 0 < y 0.5 and (1 -x-y) > 0. In some embodiments, the precursor material corresponds to formula (Ni_aCo_bMn_c)_1.dM1_d(OH)₂ with a being in the range of from 0.85 to 0.95, b being zero or in the range of from 0.01 to 0.14, c being in the range of from 0.01 to 0.15, and d being in the range of from zero to 0.05, M1 is at least one of Al and Mg, and a + b + c = 1 .

The process for recycling lithium ion battery material of the present disclosure comprises a) providing lithium ion battery material comprising lithium, copper, cobalt, and nickel. In some embodiments, the lithium ion battery material comprises lithium, copper, cobalt, nickel, manganese, aluminum, iron, carbon, phosphorus, or combinations thereof. In some embodiments of the process, the lithium ion battery material comprises at least one chosen from a lithium ion battery, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, black mass, lithium ion cathode active material, cathodes, cathode active material precursors, and combinations thereof.

“Black mass” refers to materials comprising lithium derived from, for example, a lithium ion battery, lithium ion battery waste, lithium ion battery production scrap, lithium ion cell production scrap, lithium ion cathode active material, and/or combinations thereof by mechanical processes such as mechanical comminution. For example, black mass may be derived from battery scrap by mechanically treating the battery scrap to obtain the active components of the electrodes such as graphite and cathode active material and may include impurities from the casing, electrode foils, cables, separator, and electrolyte. In some examples, the battery scrap may be subjected to a heat treatment to pyrolyze organic (e.g. electrolyte) and polymeric (e.g. separator and binder) materials. Such a heat treatment may be performed before or after mechanical comminution of the battery material. In some embodiments, the black mass is subjected to a heat treatment.

Lithium ion batteries may be disassembled, punched, milled, for example in a hammer mill, rotor mill, and/or shredded, for example in an industrial shredder. From this kind of mechanical processing, the active material of the battery electrodes may be obtained. A light fraction such as housing parts made from organic plastics and aluminum foil or copper foil may be removed, for example, in a forced stream of gas, air separation or classification or sieving.

Battery scraps may stem from, e.g., lithium ion batteries or from production waste such as off-spec material. In some embodiments a material is obtained from mechanically treated battery scraps, for example from battery scraps treated in a hammer mill a rotor mill or in an industrial shredder. Larger parts of the battery scrap like the housings, the wiring and the electrode carrier films may be separated mechanically such that the corresponding materials may be excluded from the lithium ion battery material employed in the process of the present disclosure. In some embodiments, the separation is done by manual or automated sorting. For example, magnetic parts can be separated by magnetic separation; non-magnetic metals can be separated by eddy-current separators. Other techniques may comprise jigs and air tables.

In some embodiments, the lithium ion battery material comprises carbon, nickel, cobalt, manganese, copper, aluminum, lithium, iron, phosphorus, or combinations thereof.

In some embodiments, the lithium ion battery material comprises from 1 to 50 wt.-%, e.g., from 20 to 45 wt.-%, for instance, from 30 to 40 wt.-% carbon, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 0.1 to 10 wt.-%, e.g., from 1 to 7 wt.-%, for instance, from 2 to 4 wt.-% aluminum, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 0.5 to 7 wt.-%, e.g., from 1 to 5 wt.-%, for instance, from 1 .5 to 3 wt.-% copper, relative to the total weight of the lithium ion battery material.

In some embodiments, the ion battery material comprises from 0 to 45 wt.-%, e.g., from 1 .5 to 30 wt.-%, for instance, from 3 to 10 wt.-% manganese, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 0.01 to

65 wt.-%, e.g., from 2 to 12 wt.-%, for instance, from 3 to 5 wt.-% cobalt, relative to the total weight of the lithium ion battery material. In some embodiments, the lithium ion battery material comprises from 0.01 to 60 wt.-%, e.g., from 5 to 40 wt.-%, for instance, from 10 to 20 wt.-% nickel, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 1 to 7 wt.-%, e.g., from 1 .5 to 5 wt.-%, for instance, from 2 to 4 wt.-% lithium, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 0 to 10 wt.-%, e.g., from 0.05 to 1 wt.-%, for instance, from 0.1 to 0.2 wt.-% iron, relative to the total weight of the lithium ion battery material.

In some embodiments, the lithium ion battery material comprises from 0.1 to 1 .4 wt.-%, e.g., from 0.2 to 1 wt.-%, for instance, from 0.4 to 0.6 wt.-% phosphorus, relative to the total weight of the lithium ion battery material.

The sum of the weight fractions of C, Al, Cu, Mn, Co, Ni, Li, Fe, P of the lithium ion battery material is less than or equal to 100 wt.-%.

In some embodiments, the lithium ion battery material has a weight ratio ranging from 0.01 to 10, 0.01 to 5, 0.01 to 2, or 0.01 to 1 of lithium to a total weight of nickel, cobalt, manganese, copper, aluminum, iron, and phosphorus.

In some embodiments, the lithium ion battery material comprises lithiated nickel cobalt manganese oxide of formula Li_{1 +x}(Ni_aCO Mn_cM1_d)_1.xO₂, wherein: M1 is chosen from Mg, Ca, Ba, Al, Ti, Zr, Zn, Mo, V and Fe, zero < x < 0.2, 0.1 < a < 0.95, zero < b < 0.9, or 0.05 < b < 0.5, zero < c < 0.6, zero < d < 0.1 , and a + b + c + d = 1 .

In some embodiments, the lithium ion battery material comprises lithiated nickel-cobalt aluminum oxides of formula Li[NihCo lj]O2_+r, wherein h ranges from 0.8 to 0.95, i ranges from 0.1 to 0.3, j ranges from 0.01 to 0.10, and r ranges from zero to 0.4. In some embodiments, the material comprises lithiated nickel-cobalt aluminum oxides of formula Li[NihCoiAlj]O2+r, wherein: h ranges from 0.8 to 0.90, i ranges from 0.1 to 0.3, j ranges from 0.01 to 0.10, and r ranges from zero to 0.4.

In step b) of the process of the present disclosure, the lithium ion battery material is leached with an acid to obtain an acidic aqueous solution comprising lithium, copper, cobalt, and nickel.

In some embodiments, the acid comprises at least one acid chosen from HCI, H₂SO₄, CH3SO3H, and HNO3. In some embodiments, the acid is sulfuric acid.

In some embodiments, leaching the lithium ion battery material with an acid in step b) comprises a sequence of acid leach, followed by oxidative leach, followed by reductive leach.

In some embodiments, the acid leach comprises leaching the lithium ion battery material under inert gas atmosphere with an acid comprising sulfuric acid.

In some embodiments, the oxidative leach comprises leaching the lithium ion battery material with an acid comprising sulfuric acid while sparging air through the acid.

In some embodiments, the reductive leach comprises leaching the lithium ion battery material with an acid comprising sulfuric acid while sparging sulfur dioxide through the acid.

In step c) of the process of the present disclosure, copper is recovered from the acidic aqueous solution comprising lithium, copper, cobalt, and nickel obtained in step b) by a first solvent extraction. The first solvent extraction involves the addition of an alkaline solution to the solution obtained in step b). In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃.

Solvent extraction is a useful method for separating and purifying metal ions from an aqueous solution or leachate. This can be difficult when purifying metal ions present in a hydrated form in an aqueous solution, since it is difficult to move the ions to an organic solvent layer having a low polarity. In order to move hydrated metal ions to the organic phase, the metal ions should be in a form of an uncharged complex and the metal ions should be able to remove water molecules from the hydrated complex.

A solvent extracting agent allows the metal ions to form a non-charged complex and remove water molecules. The extraction efficiency depends on, e.g., the type of solvent extracting agent, the equilibrium pH, and the metal ions in the aqueous solution. The extraction efficiency may also be affected by, e.g., the concentration of the solvent extracting agent, the ratio of the solvent extracting agent to the aqueous solution, and the composition and concentration of the stripping solution. In some embodiments of the process, the solvent extracting agent is LIX984N, a 1 :1 mixture of 5-nonyl salicylaldoxime and 2-hydroxy-5- nonyl acetophenone.

In some embodiments, the first solvent extraction comprises

• adding an alkaline solution to the solution obtained in step b) to adjust the pH value of the solution to 2.0±0.2;

• adding a solvent extracting agent to the acidic aqueous solution obtained in step b),

• homogenizing the mixture of acidic aqueous solution obtained in step b) and solvent extracting agent,

• allowing the mixture to separate into a layer of an acidic aqueous solution depleted of Cu and a layer of solvent extracting agent comprising Cu,

• separating the layer of solvent extracting agent comprising Cu from the layer of acidic aqueous solution depleted of Cu, • mixing the separated solvent extracting agent comprising Cu with a second aqueous acidic solution,

• homogenizing the mixture,

• allowing the mixture to separate into a layer of a second aqueous solution comprising copper and a layer of solvent extracting agent, and

• separating the aqueous solution comprising Cu from the layer of solvent extracting agent.

In some embodiments, the solvent extraction is a two-step process (or even a three-step process if impurities need to be scrubbed before the stripping). The optional step of scrubbing (step 2), if necessary, is carried out in-between the extraction of the target species into the organic phase (step 1 ) and the stripping (step 3).

In a first step, a solvent extracting agent (a non-polar weak acid) is dissolved in an organic liquid (diluent), such as kerosene. This mixture forms the extracting agent solution. This solution is brought into contact/mixed with the acidic aqueous solution comprising lithium, copper, cobalt, and nickel, from which the extracting agent selectively extracts copper cations.

In a second optional step, impurities are removed from the organic phase (the extracting agent solution) by scrubbing.

Subsequently, the extracting agent solution, which now comprises copper cations, is brought into contact with an acid solution (strong acid), which causes the copper cations to be replaced by H+. In return, the copper cations transfer into the acidic aqueous solution. This solution is then called loaded stripping solution. The process of transferring the copper cations back into an aqueous phase is called stripping.

The acidic aqueous solution depleted of Cu obtained after the first solvent extraction is further processed in step d). In step d) of the process of the present disclosure, impurities are precipitated from the acidic aqueous solution depleted of Cu obtained in step c). The precipitation involves the addition of an alkaline solution to the solution obtained in step c). In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH and/or Li₂CO₃.

The impurities comprise one or more selected from iron, aluminum, magnesium, calcium, titanium, manganese, residual copper, fluoride, and phosphate. The precipitation involves the addition of an alkaline solution to the solution obtained in step c), thereby adjusting the pH value of the solution to 3.4±0.2 in a first step d1 ), and to 4.5±0.2 in a second step d2). Iron, aluminum, magnesium, titanium, and copper precipitate from the solution as hydroxides and/or oxide-hydroxides and/or carbonates, fluorides and/or phosphates, and are removed from the mother liquor after each step by solid-liquid separation, e.g., filtration. In some embodiments of the process, manganese also is precipitated as manganese carbonate. The mother liquor is further processed in step e). In some embodiments of the process, step e) is omitted and the mother liquor is further processed in step f).

In step e) of the process of the present disclosure, residual impurities, e.g., manganese, calcium, and/or zinc, are recovered from the mother liquor obtained in step d) by a second solvent extraction. The second solvent extraction involves the addition of an alkaline solution to the mother liquor obtained in step d), thereby adjusting the pH value of the mother liquor to 5.0±0.2. In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃. In some embodiments of the process, the solvent extracting agent is bis(2- ethylhexyl)phosphate (D2EHPA). In some embodiments, a further solvent extraction step is performed on the loaded stripping solution obtained, using bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex® 272) as solvent extraction agent. After solvent extraction, the mother liquor is further processed in step f).

In step f) of the process of the present disclosure, cobalt is recovered from the mother liquor obtained in step e) by solvent extraction. The solvent extraction involves the addition of an alkaline solution to the mother liquor obtained in step e), thereby adjusting the pH value to 5.8±0.2. In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃.

In some embodiments of the process, the solvent extracting agent is bis(2,4,4- trimethylpentyl)phosphinic acid (Cyanex® 272). After solvent extraction, the mother liquor is further processed in step g).

In step g) of the process of the present disclosure, nickel is recovered from the mother liquor obtained in step f) by solvent extraction. The solvent extraction involves the addition of an alkaline solution to the solution obtained in step f), thereby adjusting the pH value of the mother liquor to 6.5±0.2. In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃.

In some embodiments of the process, the solvent extracting agent is neodecanoic acid (Versatic™ acid 10). After solvent extraction, the mother liquor is further processed in step h). In step h) of the process of the present disclosure, lithium is recovered from the solution obtained in step g). In some embodiments of the process, recovering lithium from the solution obtained in step g) involves precipitation of Li₂CO₃ by addition of at least one carbonate to the solution obtained in step g). In some embodiments of the process, the mother liquor obtained after separation of precipitated lithium carbonate from the solution and containing residual lithium ions is further processed to recover lithium by solvent extraction or precipitation of lithium salts.

In some embodiments of the process, recovering lithium from the solution obtained in step g) involves precipitation of Li₃PO₄. In some embodiments of the process, lithium phosphate is precipitated from the mother liquor obtained after precipitation of lithium carbonate from the solution obtained in step g). Precipitation of lithium phosphate is caused by addition of sodium phosphate to the solution obtained in step g) or the mother liquor obtained after precipitation of lithium carbonate. In some embodiments, precipitation of lithium phosphate is effected at a pH value of 10.0±0.2.

In some embodiments of the process, recovering lithium from the solution obtained in step g) involves solvent extraction. The solvent extraction involves the addition of an alkaline solution to the solution obtained in step g), thereby adjusting the pH value of the mother liquor to 12.5±0.2. In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃.

In some embodiments, the solvent extracting agent comprises 1 ,3-diketones. In some embodiments, the solvent extracting agent is thenoyl trifluoroacetone. In some embodiments, the solvent extracting agent comprises benzoyl acetone. In some embodiments, the solvent extracting agent comprises benzoyl acetone and kerosene. In some embodiments, the solvent extracting agent is 4,4,4- trifluoro-1 -2(2-furyl)-1 ,3-butanedione. In some embodiments, the solvent extracting agent comprises at least one phosphorus-based compound. In some embodiments of the process, the solvent extracting agent is a phosphorus- based extractant (Cyanex® 936P). In some embodiments, the solvent extracting agent comprises 3-benzoyl-1 ,1 ,1 -trifluoroacetone (HBTA) and trioctylphosphineoxide (TOPO) in kerosene. In some embodiments, the ratio of HBTA:TOPO:Kerosene is about 13:10:77 wt.%.

In some embodiments of the process, solvent extraction is preceded by precipitation of magnesium hydroxide. The precipitation of magnesium hydroxide involves the addition of an alkaline solution to the solution obtained in step g). In some embodiments of the process, the alkaline solution added comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate contains a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃.

In some embodiments of the process, solvent extraction is followed by crystallization of lithium sulfate monohydrate from the loaded stripping liquid (LSL) obtained from the solvent extraction step.

At least one of the alkaline solutions added in steps c) through g) comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate. In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate is added in only one of steps c) through g). In some embodiments of the process, the alkaline solution comprising sodium, lithium, hydroxide, carbonate, and sulfate is added in two or more of steps c) through g). In some embodiments of the process, the alkaline solution comprising sodium, lithium, hydroxide, carbonate, and sulfate is added in each and every one of steps c) through g). In some embodiments of the process, the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate is added in step c). When the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate is a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃, addition in this early stage of the process makes sure that other metals present in the alkaline solution, such as cobalt and/or nickel, are also recovered in the course of the process

By the addition of the alkaline solution comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate to the reaction mixture and the at least partial substitution of sodium hydroxide used for pH adjustment in the process, lithium concentration in the reaction mixture is increased and overall sodium concentration in the reaction mixture is reduced. Both factors facilitate recovery of lithium in step h) of the process of the present disclosure.

The present disclosure also pertains to the use of a solution obtained by washing a reaction product of pCAM and LiOH and/or Li₂CO₃ in a process for recycling lithium ion battery material and/or for recovering valuable materials from lithium ion battery material. Examples of valuable materials include copper, manganese, cobalt, nickel, lithium, and magnesium, as well as salts comprising these elements, e.g., manganese sulfate, manganese carbonate, cobalt sulfate, nickel sulfate, lithium sulfate, lithium phosphate, lithium carbonate, magnesium hydroxide, or magnesium carbonate.

Examples

Table 1 shows an exemplary composition of a solution obtained by washing a reaction product of pCAM and LiOH/Li₂CO₃. The alkaline aqueous solution comprises 3.88 percent by weight, relative to the total weight of the solution, of dissolved salts.

Table 1

Table 2 summarizes process parameters of an exemplary continuous process of the present disclosure. Flow rates, pH values, and temperatures are listed for the individual steps of the process as well as for the different product streams. For the solvent extraction steps, the ratio of organic phase to aqueous phase (0:A) based on the outflows of the solvent extraction, the proportion of extractant used, relative to the total volume, and the extractant are listed. Table 2

Lithium ion battery material is leached in a three-stage leaching process comprising acid leach, followed by oxidative leach, followed by reductive leach. The pregnant leach solution (PLS) is depleted of copper by solvent extraction, yielding a Cu SX Raffinate. Impurities are precipitated from the Cu SX Raffinate, and the mother liquor (Impurity Precipitation Filtrate) is subjected to solvent extraction to remove residual impurities, and the Impurity SX LSL obtained by solvent extraction is subjected to a further solvent extraction step to recover manganese sulfate. Cobalt and nickel are recovered from the solution depleted of copper and impurities (Impurity SX Raffinate) by subsequent solvent extraction steps. From the solution depleted of copper, impurities, cobalt, and nickel (Ni SX Raffinate), lithium is recovered, e.g., by precipitation. From the mother liquor (Li SX Pre-treatment Filtrate), residual lithium is recovered by solvent extraction and subsequent crystallization of lithium sulfate.

List of reference siqns

10 lithium ion battery material

11 sulfuric acid

12 aqueous solution comprising lithium, copper, cobalt, and nickel

13 leach residue

21 alkaline solution

22 solution depleted of copper

23 copper

24 H₂SO₄

31 alkaline solution

32 solution depleted of impurities

33 impurities

41 alkaline solution

42 solution depleted of manganese

43 manganese sulfate

44 H2SO4

51 alkaline solution

52 solution depleted of cobalt

53 cobalt sulfate

54 H2SO4

61 alkaline solution

62 solution depleted of nickel

63 nickel sulfate

64 H2SO4

72 concentrated solution

81 sodium bicarbonate

82 mother liquor

83 lithium carbonate

91 sodium phosphate

93 lithium phosphate

94 sodium sulfate

101 alkaline solution

102 solution depleted of magnesium 103 magnesium hydroxide

11 1 alkaline solution

112 H₂SO₄

113 loaded stripping liquid

114 lithium sulfate

1000 Leaching step

2000 First solvent extraction step

3000 First precipitation step

4000 Second solvent extraction step 5000 Third solvent extraction step 6000 Fourth solvent extraction step

7000 Evaporation step

8000 Second precipitation step

9000 Third precipitation step

10000 Precipitation step

10100 Mg precipitation

10200 Solids/liquid separation 11000 Solvent extraction step 11 100 Li solvent extraction 11200 Li solvent stripping

Claims

1 . A process for recycling lithium ion battery material (10) comprising a) providing lithium ion battery material (10) comprising lithium, copper, cobalt, and nickel; b) leaching (1000) the lithium ion battery material (10) with an acid (11 ) to obtain an acidic aqueous solution (12) comprising lithium, copper, cobalt, and nickel, c) recovering copper (23) from the solution (12) obtained in step b) by a first solvent extraction (2000), the first solvent extraction (2000) involving the addition of an alkaline solution (21 ) to the solution (12) obtained in step b), d) precipitating impurities (33) selected from iron, aluminum, magnesium, calcium, titanium, manganese, residual copper, fluoride, and phosphate from the solution (22) obtained in step c), the precipitation (3000) involving the addition of an alkaline solution (31 ) to the solution (22) obtained in step c), e) recovering impurities (43) selected from manganese, calcium, and zinc from the solution (32) obtained in step d) by a second solvent extraction (4000), the second solvent extraction (4000) involving the addition of an alkaline solution (41 ) to the solution (32) obtained in step d), f) recovering cobalt (53) from the solution (42) obtained in step e) by a third solvent extraction (5000), the third solvent extraction (5000) involving the addition of an alkaline solution (51 ) to the solution (42) obtained in step e), g) recovering nickel (63) from the solution (52) obtained in step f) by a fourth solvent extraction (6000), the fourth solvent extraction (6000) involving the addition of an alkaline solution (61 ) to the solution (52) obtained in step f), h) recovering lithium from the solution (62) obtained in step g), characterized in that at least one of the alkaline solutions (21 , 31 , 41 , 51 , 61 ) added in steps c) through g) comprises lithium, sodium, potassium, hydroxide, carbonate, and sulfate.

2. The process of claim 1 , wherein the alkaline solution (21 , 31 , 41 , 51 , 61 ) comprising lithium, sodium, potassium hydroxide, carbonate, and sulfate contains wastewater obtained by washing a reaction product of a precursor material of cathode active materials (CAM) for lithium ion batteries and LiOH and/or Li₂CO₃.

3. The process of claim 2, wherein wastewater obtained by washing a reaction product of a precursor material of cathode active materials (CAM) for lithium ion batteries and LiOH and/or Li₂CO₃ is present in the alkaline solution (21 ) added in step c).

4. The process of any one of claims 1 to 3, wherein wastewater obtained by washing a reaction product of a precursor material of cathode active materials (CAM) for lithium ion batteries and LiOH and/or Li₂CO₃ is added in step h).

5. The process of any one of claims 1 to 4, wherein recovering lithium from the solution (62) obtained in step g) involves precipitation (8000) of Li₂CO₃ (83).

6. The process of any one of claims 1 to 5, wherein recovering lithium from the solution (62) obtained in step g) involves precipitation (9000) of Li₃PO₄ (93).

7. The process of any one of claims 1 to 4, wherein recovering lithium from the solution (62) obtained in step g) involves solvent extraction (1 1000).

8. The process of claim 7, wherein the solvent extraction (11000) involves the addition of an alkaline solution (111 ) comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate, to the solution (62) obtained in step g).

9. The process of claim 7 or 8, wherein the solvent extraction (11000) is preceded by precipitation (10000) of magnesium hydroxide (103).

10. The process of claim 9, wherein the precipitation (10000) of magnesium hydroxide (103) involves the addition of an alkaline solution (101 ) comprising lithium, sodium, potassium, hydroxide, carbonate, and sulfate, to the solution (62) obtained in step g).

11. The process of any one of claims 7 to 10, wherein solvent extraction (11000) is followed by precipitation of lithium sulfate (1 13).

12. The process of any one of claims 1 to 11 , wherein leaching (1000) the lithium ion battery material (10) with an acid (11 ) in step b) comprises a sequence of acid leach, followed by oxidative leach, followed byreductive leach.

13. The process of claim 12, wherein the oxidative leach comprises leaching the lithium ion battery material (10) with an acid (1 1 ) comprising sulfuric acid while sparging air through the acid.

14. The process of claims 12 or 13, wherein the reductive leach comprises leaching the lithium ion battery material (10) with an acid (11 ) comprising sulfuric acid while sparging sulfur dioxide through the acid.

15. Use of alkaline wastewater obtained by washing a reaction product of a precursor material of cathode active materials (CAM) for lithium ion batteries and LiOH and/or Li₂CO₃ in a process for recycling lithium ion battery material (10) and/or for recovering valuable materials (23, 43, 53, 63, 83, 93, 103, 113) from lithium ion battery material (10).