PROCESS FOR THE RECYCLING OF SPENT LITHIUM ION CELLS

Abstract

Process for the recovery of transition metal from spent lithium ion batteries containing nickel, wherein said process comprises the steps of (a) heating a lithium containing transition metal oxide material to a temperature in the range of from 200 to 900° C. in the presence of H.sub.2, (b) treatment of the product obtained in step (a) with an aqueous medium, (c) solid-solid separation for the removal of Ni from the solid residue of step (b), (d) recovery of Li as hydroxide or salt from the solution obtained in step (b), (e) extraction of Ni and, if applicable, Co from the solid Ni-concentrate obtained in step (c).

Claims

1. A process for recovering transition metals from spent lithium ion batteries containing nickel (Ni), comprising the steps of: (a) heating a lithium containing transition metal oxide material to a temperature ranging from 200° C. to 900° C. in the presence of H.sub.2, wherein the transition metal oxide material is from lithium ion batteries and contains fluorine compounds and/or compounds of phosphorous as impurities; (b) treating the material obtained in step (a) with an aqueous medium to form a solid residue and a solution; (c) removing by solid-solid separation Ni from the solid residue of step (b) forming a solid Ni-concentrate; (d) recovering lithium (Li) as a hydroxide or salt from the solution obtained in step (b); and (e) extracting Ni and/or cobalt (Co) from the solid Ni-concentrate obtained in step (c).

2. A process for recovering transition metals from spent lithium ion batteries containing nickel (Ni), comprising the steps of: (a) heating a lithium containing transition metal oxide material to a temperature ranging from 200° C. to 900° C. in the presence of hydrogen (H.sub.2); (b) treating of the material obtained in step (a) with an aqueous medium to form a solid residue and a solution; (c) removing by solid-solid separation Ni from the solid residue of step (b); (d) recovering lithium (Li) as hydroxide or salt from the solution obtained in step (b) to form a solid Ni-concentrate; and (e) extracting Ni and/or cobalt (Co) from the solid Ni-concentrate obtained in step (c); wherein the lithium containing transition metal oxide material heated in step (a) is from lithium ion batteries and contains fluorine in an amount ranging from 2% to 8% by weight, and/or phosphorous in an amount ranging from 0.2% to 2% by weight, relative to the weight of the lithium containing transition metal oxide material.

3. The process according to claim 1, wherein the temperature in step (a) ranges from 350° C. to 500° C.

4. The process according to claim 1, wherein the lithium containing transition metal oxide material used in step (a) is from lithium ion batteries after mechanic removal of casing, wiring or circuitry and discharging, and wherein the material is not exposed to temperatures of 400° C. or more under oxidizing conditions before the heating of step (a).

5. The process according to claim 1, wherein the extracting of step (e) comprises smelting of the solid Ni-concentrate obtained in step (c).

6. The process according to claim 1, wherein the extracting of step (e) comprises treating the Ni-concentrate obtained in step (c) with a base.

7. The process according to claim 5, wherein the solution containing Ni and/or Co salt, are treated with ammonia or an alkali metal hydroxide to obtain a solution with a pH-value ranging from 2.5 to 8.

8. The process according to claim 5, wherein solution containing Ni and/or Co salts are treated with metallic nickel, metallic cobalt, or metallic manganese or any combination thereof.

9. The process according to claim 1, further comprising removing carbon or organic polymers by a dry solid-solid separation prior to step (b).

10. The process according to claim 1, wherein in step (d), lithium is recovered as lithium hydroxide.

11. The process according to claim 1, wherein in step (d), lithium is recovered by way of precipitation as carbonate.

12. The process according to claim 1, further comprising an additional step (f) of precipitating Ni and/or Co and/or manganese as (mixed) hydroxide, oxyhydroxide or carbonate.

13. The process according to claim 1, wherein step (a) is performed in the presence of steam.

14. The process according to claim 1, wherein step (a) is performed in the presence of lime, quartz, silica, silicate, or any combination thereof.

15. The process according to claim 1, further comprising an additional step before step (a) of contacting the material from spent lithium ion batteries with water and/or organic solvent followed by a solid-liquid separation step.

16. The process according to claim 1, wherein step (e) comprises treating the solid Ni-concentrate obtained in step (c) with an acid.

17. The process according to claim 16, wherein the acid is chosen from sulfuric acid, hydrochloric acid, nitric acid, methane sulfonic acid, oxalic acid, citric acid, and a combination thereof.

18. The process according to claim 1, wherein step (e) comprises treating the Ni-concentrate obtained in step (c) with ammonium bicarbonate or ammonium carbonate.

19. The process according to claim 6, wherein the base is chosen from ammonia; aqueous solutions of amines, ammonia, and/or ammonium carbonate; and a mixture of ammonia and carbon dioxide.

20. The process according to claim 12, wherein step precipitating in (f) comprises adding at least one agent chosen from lithium hydroxide, sodium hydroxide, ammonia, and potassium hydroxide.

21. The process according to claim 12, wherein precipitating in setp (f) is by raising a pH above 8.

22. The process according to claim 3, wherein 35% by volume or more of H.sub.2 is present in step (a) and the temperature in step (a) ranges from 350° C. to 450° C.

Description

EXAMPLE 1

[0161] Step (a.1) Heat-Treatment in the Presence of H.sub.2

[0162] An amount of 60 g mechanically treated battery scrap containing

[0163] 32.8 g spent cathode active material containing nickel, cobalt and manganese in similar molar amounts,

[0164] 17.5 g of organic carbon in the form of graphite and soot and residual electrolyte, and

[0165] 9.7 g of further impurities comprising Al (0.6 g), Cu (0.5 g), F (in total: 2.2 g), Fe (0.55 g), P (0.3 g), Zn (0.04 g), Zr (0.15 g), Mg (2 mg), Ca (6 mg)

[0166] was placed in a graphite crucible in a tube furnace and heated to 400° C. in the course of 45 minutes under a flow of argon (20 NI/h). The temperature was kept constant for 7.5 hours under a flow (22 NI/h) of 10 wt % hydrogen in argon until the flow of hydrogen was stopped and the furnace was left to cool to ambient temperature under a flow of argon. 50.1 g of heat treated material was recovered from the crucible, showing XRD signals of Ni/Co alloy, graphite, and LiOH.

[0167] Step (b.1) Aqueous Treatment of the Product Obtained in Step (a.1)

[0168] 5.5 g of the material obtained in step (a.1) was slurried in 53 mL deionized water and stirred for 30 min at ambient temperature and then filtered. The clear filtrate was found to contain 133 mg Li.sup.+, 212 mg hydroxide anions, 93 mg carbonate ions and 13 mg fluoride ions. This corresponds to a lithium leaching efficiency of 46% with 65% of the lithium being present as LiOH.

[0169] Step (c.1) Solid-Solid Separation for the Removal of Ni from the Solid Residue of Step (b.1)

[0170] An amount of 12 g of the hydrogen treated material obtained from step (a.1) were slurried in 100 ml deionized water and dispersed for 10 minutes with a blade stirrer at 800 rpm under assistance of a sonotrode. The slurry was introduced into a lab-scale high intensity wet magnet separator series L model 4 from Eriez Magnetics Europe Ltd. Steel wool was placed between the poles of the separator in a canister. The feed slurry was pumped to the matrix within 5 min while keeping the matrix magnetized with 1 Tesla. The attached solids were rinsed with deionized water until a clear and colorless solution is obtained from the outlet to fully recover the non-magnetic fraction. After removing the electric field, the magnetic fraction was removed from the canister by again rinsing with deionized water. Both recovered slurries were filtered and dried in an oven giving 9.0 g of a magnetic fraction and 1.25 g of a non-magnetic fraction. The non-magnetic fraction contained 86 wt % carbon and less than 0.2 wt % inorganic and organic fluorine. The Ni, Co and Mn metal content in the magnetic fraction was 52 wt %.

[0171] Step (d.1): Recovery of Li Salt from the Solution Obtained in Step (b.1)

[0172] 31.5 g of the clear filtrate obtained in step (b), containing a total amount of 79 mg lithium ions, was concentrated to dryness under reduced pressure. The flask was refilled with dry nitrogen and transferred into an argon filled glovebox. 215 mg of solid material were recovered, showing X-ray diffraction signals of predominantly LiOH and traces of Li.sub.2CO.sub.3.

[0173] Step (e.1): Acidic Extraction of Ni and Co from the Solid Ni-Concentrate Obtained in Step (c.1)

[0174] In a stirred 250 mL batch reactor, 3.0 g of material obtained as magnetic fraction from step (c.1) were suspended in 50 g deionized water and heated to 40° C. A mixture of 33.4 g H.sub.2SO.sub.4 (96% H.sub.2SO.sub.4) in 20.0 g deionized water was added slowly, followed by a mixture of 3.62 g H.sub.2SO.sub.4 (96% H.sub.2SO.sub.4), 1.2 g aqueous hydrogen peroxide (30% H.sub.2O.sub.2) in 3.47 g deionized water. Slow gas evolution was observed with only minor formation of foam. The resultant slurry was stirred at 60° C. for 3 hours and then cooled to ambient temperature. The resulting mixture was filtered with a glass frit and the solid residue was washed with 62.2 g deionized water. 111.4 g of a red colored clear filtrate were recovered, containing 535 mg Ni, 535 mg Co, 423 mg Mn corresponding to leaching efficiencies of more than 95% for each Ni, Co, and Mn.

[0175] Alternative Step (e.1): Ammoniacal Extraction of Ni and Co from the Solid Ni-Concentrate Obtained in Step (c.1)

[0176] In a stirred 250 mL batch reactor, 3.0 g of material obtained as magnetic fraction from step (c.1) are suspended in a mixture of 117 g of a 25% aqueous ammonia solution and 20 g of ammonium carbonate and 9 g of deionized water, and heated to 60° C. under stirring. 40.1 g of aqueous hydrogen peroxide (30% H2O.sub.2) are added under stirring over a period of 5 h. The reaction is exothermic with evolution of gas. The resultant slurry is stirred at 60° C. for 3 hours and then cooled to ambient temperature. The resulting mixture is filtered with a glass frit and the solid residue is washed with 60.3 g of deionized water. 204.7 g of a dark colored clear combined filtrate are recovered, containing 534 mg Ni, 520 mg Co, 2 mg Mn corresponding to leaching efficiencies of 95% and 94% for Ni and Co respectively, while the leaching efficiency of Mn is only 0.5%. Such ammoniac leaching process may be advantageous in cases where Mn may disturb subsequent separation steps.

EXAMPLE 2: STEP (A.1) HEAT-TREATMENT IN THE PRESENCE OF H2

[0177] An amount of 20 g mechanically treated battery scrap containing 55 wt.-% spent cathode active material containing nickel, cobalt and manganese in similar molar amounts, 29 wt.-% of organic carbon in the form of graphite and soot and residual electrolyte, and 16 wt.-% of further impurities comprising Al (1 wt.-%), Cu (0.8 wt.-%), F (in total: 3.7 wt.-%), Fe (0.9 wt.-%), P (0.5 wt.-%), Zn (0.07 wt.-%), Zr (0.3 wt.-%), Mg (<0.01 wt.-%), Ca (0.01 wt.-%) is placed in a rotary oven and heated to 400, 410, 420, 430, 450, 470, 500° C., respectively, in the course of 45 minutes under a flow of argon (20 NI/h). At the respective temperature, the temperature is kept constant for further 45 min under a flow of hydrogen (100%, 20 NI/h). Afterwards, the flow of hydrogen is stopped, and the furnace left to cool to ambient temperature under a flow of argon. The heat-treated material is recovered from the oven, showing XRD signals of Ni/Co alloy, graphite, and LiOH. The amount of Li within the heated material is determined after each heating experiment.

[0178] Step (b.1) Aqueous Treatment of the Product Obtained in Step (a.1)

[0179] 5 g of the material obtained in step (a.1) is slurried in 50 mL deionized water and stirred for 30 min at ambient temperature and then filtered. The clear filtrate is found to contain lithium, hydroxide, carbonate and fluoride of the below listed concentrations (Tab. 1).

TABLE-US-00001 TABLE 1 Experimental conditions during heat treatment under H2 and analytics of the leached filtrate. Li Lithium Carbonate Fluoride Hydroxide leaching Temperature content content content content efficiency [° C.] [mg] [mg] [mg] [mg] [%] 400 145 105 14 216 55 410 157 70 16 278 58 420 142 75 15 253 52 430 147 80 15 241 55 450 145 100 16 214 52 470 134 120 17 190 51 500 140 115 17 212 48

[0180] Steps (c1), (d1) and (e1) are carried out in analogy to example 1.

EXAMPLE 3: STEP (A.1) HEAT-TREATMENT IN THE PRESENCE OF H2

[0181] An amount of 20 g mechanically treated battery scrap containing 55 wt.-% spent cathode active material containing nickel, cobalt and manganese in similar molar amounts, 29 wt.-% of organic carbon in the form of graphite and soot and residual electrolyte, and 16 wt.-% of further impurities comprising Al (1 wt.-%), Cu (0.8 wt.-%), F (in total: 3.7 wt.-%), Fe (0.9 wt.-%), P (0.5 wt.-%), Zn (0.07 wt.-%), Zr (0.3 wt.-%), Mg (<0.01 wt.-%), Ca (0.01 wt.-%) is placed in a rotary oven and heated to 400° C. in the course of 45 minutes under a flow of argon (20 NI/h). The temperature is kept constant for 15, 30, 45, 60, 150, or 450 min, as noted in Tab. 2, under a flow of hydrogen (100%, 20 NI/h). Afterwards, the flow of hydrogen is stopped, and the furnace left to cool to ambient temperature under a flow of argon. The heat-treated material is recovered from the oven, showing XRD signals of Ni/Co alloy, graphite, and LiOH. The amount of Li within the heated material is determined after each heating experiment.

[0182] Step (b.1) Aqueous Treatment of the Product Obtained in Step (a.1)

[0183] 5 g of the material obtained in step (a.1) is slurried in 50 mL deionized water and stirred for 30 min at ambient temperature and then filtered. The clear filtrate is found to contain lithium, hydroxide, carbonate and fluoride of the below listed concentrations (Tab. 2).

TABLE-US-00002 TABLE 1 Heating duration in H2 atmosphere and analytics of the leached filtrate. Li Heating Lithium Carbonate Fluoride Hydroxide leaching duration content content content content efficiency [min] [mg] [mg] [mg] [mg] [%] 0 18 25 35 50 7 15 134 90 10 208 48 30 146 70 15 246 51 45 145 105 14 216 55 60 149 105 14 212 55 150 147 90 17 251 53 450 146 75 16 252 53

[0184] Steps (c1), (d1) and (e1) are carried out in analogy to example 1.

EXAMPLE 4

[0185] Step (a.3) Solvent Treatment Prior to Heat-Treatment

[0186] An amount of 750 g mechanically treated battery scrap containing 55 wt.-% spent cathode active material containing nickel, cobalt and manganese in similar molar amounts, 29 wt.-% of organic carbon in the form of graphite and soot and residual electrolyte, and 16 wt.-% of further impurities comprising Al (1 wt.-%), Cu (0.8 wt.-%), F (in total: 3.7 wt.-%), Fe (0.9 wt.-%), P (0.5 wt.-%), Zn (0.07 wt.-%), Zr (0.3 wt.-%), Mg (<0.01 wt.-%), Ca (0.01 wt.-%) is mixed with 2.5 L water and stirred for 60 min at ambient temperature and then filtered.

[0187] Step (a.1) Heat-Treatment in the Presence of H2

[0188] An amount of 20 g of the material obtained in step (a.3) is placed in a rotary oven and heated to 400° C. in the course of 45 minutes under a flow of argon (20 NI/h). The temperature is kept constant for several hours under a flow of hydrogen/argon mixture (20 NI/h); the hydrogen concentration is 3, 5, 7, 10, 14, 25, 35, or 100 vol-%, respectively, as noted in the below Tab. 3. Afterwards, the flow of hydrogen is stopped, and the furnace left to cool to ambient temperature under a flow of argon. The heat-treated material is recovered from the oven, showing XRD signals of Ni/Co alloy, graphite, and LiOH. The amount of Li within the heated material is determined after each heating experiment.

[0189] Step (b.1) Aqueous Treatment of the Product Obtained in Step (a.1)

[0190] 5 g of the material obtained in step (a.1) is slurried in 50 mL deionized water and stirred for 30 min at ambient temperature and then filtered. The clear filtrate is found to contain lithium, hydroxide, carbonate and fluoride of the below listed concentrations (Tab. 3).

TABLE-US-00003 TABLE 3 H2 concentration during heating and analytics of the leached filtrate. H2 conc. Li in gas Heating Lithium Carbonate Fluoride Hydroxide leaching mix duration content content content content efficiency [vol-%] [h] [mg] [mg] [mg] [mg] [%]   3 8     97  75 14 147 36   5 8    148  65 13 290 53   7 8    160  60 12 320 57  10 8    141 105 13 260 56  14 4    153 100 14 265 60  25 3    144 100 17 267 57  35 2.5  146 105 16 271 58 100 0.75 166 105 14 289 65

[0191] Steps (c1), (d1) and (e1) are carried out in analogy to example 1.