PROCESS FOR THE RECOVERY OF LITHIUM AND TRANSITION METAL USING HEAT

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 400 to 1200° C., (b) treating said heat-treated material with water, (c) treating the solid residue from step (b)with an acid selected from sulfuric acid, hydrochloric acid, nitric acid, methanesulfonic acid, oxalic acid and citric acid, (d) adjusting the pH value to 2.5 to 8, (e) removing compounds of Al, Cu, Fe, Zn or combinations of at least two of the foregoing from the solution or slurry obtained in step (d).

Claims

1.-13. (canceled)

14. 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 400 to 1200° C., (b) treating said heat-treated material with water, (c) treating the solid residue obtained in step (b) with an acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, methanesulfonic acid, oxalic acid and citric acid, (d) adjusting the pH value to 2.5 to 8, (e) removing compounds of Al, Cu, Fe, Zn or combinations of at least two of the foregoing from the solution or slurry obtained in step (d).

15. Process according to claim 14 comprising an additional step (f), wherein step (f) includes precipitating nickel and, if applicable, cobalt and/or manganese as (mixed) hydroxide, oxyhydroxide or carbonate.

16. Process according to claim 14 wherein step (e) comprises the removal of precipitates of carbonates, oxides, phosphates, hydroxides or oxyhydroxides of Al, Cu, Fe, Zn, or combinations of at least two of the foregoing.

17. Process according to claim 14 wherein the lithium containing transition metal oxide material is present in form of complete batteries, battery modules, battery cells, or battery scraps.

18. Process according to claim 14 wherein step (b) is performed under CO.sub.2 at a pressure in the range of from 10 to 150 bar.

19. Process according to claim 14 wherein step (b) is performed at a temperature in the range of from 5 to 100° C.

20. Process according to claim 14 wherein step (b) has a duration in the range of from 20 minutes to 10 hours.

21. Process according to claim 14 wherein step (a) is performed under inert atmosphere, under an atmosphere that contains oxygen, or the atmosphere is changed during step (a) from inert to oxygen containing atmosphere.

22. Process according to claim 14 wherein prior to step (c) a solid-solid separation step is performed to separate non-soluble components like carbon and polymers from the metallic or metal oxide components.

23. Process according to claim 22 wherein said solid-solid separation step is a magnetic separation step.

24. Process according to claim 14 wherein step (d) is performed by the addition of at least one of lithium hydroxide, sodium hydroxide, ammonia and potassium hydroxide.

25. Process according to claim 15 wherein in step (f) the precipitation of nickel and, optionally, cobalt or manganese as hydroxide, oxyhydroxide or carbonate is performed by raising the pH value above 8.

26. Process according to claim 14 including recovering the lithium by way of precipitation as carbonate.

Description

EXAMPLES

[0101] The metal impurities and phosphorous were determined by elemental analysis using ICP-OES (inductively coupled plasma—optical emission spectroscopy) or ICP-MS (inductively coupled plasma—mass spectrometry). Total carbon was determined with a thermal conductivity detector (CMD) after combustion. Fluorine was detected with an ion sensitive electrode (ISE) after combustion for total fluorine or after H.sub.3PO.sub.4 distillation for ionic fluoride. Phase compositions of solids were determined with powder x-ray diffractometry (PXRD).

Step (a) Heating

[0102] An amount of 192.7 g simulated spent battery scrap containing

78.8 g cathode active material containing nickel, cobalt and manganese in similar molar amounts, approximate formula Li(Ni.sub.0.34Co.sub.0.33Mn.sub.0.33)O.sub.2,
62.2 g of organic carbon in the form of graphite and soot
47.0 g of organic electrolyte mixture (containing LiPF.sub.6)
7.4 g polyvinylidene fluoride as binder,
2.4 g aluminum powder,
0.2 g iron powder,
2.0 g copper metal
was placed into a 500-mL quartz round bottom flask and attached to a rotary evaporator in a way that the flask was immersed in an oven. Within 4.5 hours the rotating flask was heated to 800° C. under a flow of argon (20 l/h) and held at this temperature for 1 hour. An amount of 173.3 g heat treat material were obtained. 102.7 g of this powder were again heated to 800° C. under a flow of Argon (20 l/h) to 350° C. and above 350° C. under a flow of air (20 l/h) and held at 800° C. under air for 1 hour. From this 99.0 g heat treated material were obtained comprising a phase composition of Ni/Co-alloy, iron manganese oxide, Li.sub.2CO.sub.3, LiF, and graphite.
Step (b): Treating with Water/CO.sub.2

[0103] 30.0 g of the material obtained after the treatment under air described in Step (a) was slurried into 100 mL deionized water and subjected to a CO.sub.2 atmosphere of 50 bar CO.sub.2 in a stirred pressure autoclave. The suspension was stirred for three hours at ambient temperature. After releasing the pressure, the slurry was recovered from the autoclave and filtered. 100 g of a clear non-diluted LiHCO.sub.3 solution were recovered as filtrate. The lithium content in the filtrate was determined to 0.85 wt % corresponding to a leaching efficiency of 61% referred to the full amount of water employed for extraction. The filter cake was washed with 350 g water and dried in an oven. PXRD of the remaining solid indicated no residual traces of Li.sub.2CO.sub.3.

[0104] 17.7 g of the recovered non-diluted filtrate were heated to 95° C. and filtered hot. An amount of 0.37 g of pure Li.sub.2CO.sub.3 was recovered as solids, corresponding to a recovery rate of 46% of the Li, calculated as Li.sub.2CO.sub.3.

Step (c): Treatment with Acid

[0105] 19.96 g of heat treated powder from step (b) were added to 201 g H.sub.2SO.sub.4 (96% H.sub.2SO.sub.4) in a 4 necked 1 L round bottom flask. The resultant slurry was stirred at 60° C. for 4 hours and then slowly added to 103 g ice placed in a 500 ml beaker while keeping the temperature below 50° C. Another 208 g ice-water were used to wash the residual slurry from the flask into the beaker. The resulting mixture was filtered with a glass frit and the solid residue was washed with 301 g water. 844 g of a clear and red colored filtrate were obtained, containing 2.19 g Ni, 2.19 g Co, 2.16 g Mn, less than 1 ppm Cu, 0.12 g Fe, and 0.13 g Al. This corresponds to leaching efficiencies >97% for Ni, Co, and Mn, as well as a separation efficiency for Cu of 100%.

Step (d): Adjusting the pH

[0106] The pH value of 200 g of the filtrates from step (c.1) was adjusted to a pH value of 6.5 by gradually adding 315 g of a 4 molar caustic soda solution under stirring, followed by 2.7 g of 1 molar caustic soda solution.

Step (e): Removing Compounds

[0107] Precipitate formation could be observed. After stirring for 12 hours, the solids were removed by suction filtration. The filtrate (515 g) so obtained contained impurity levels of Al and Fe below 15 ppm and of Cu <1 ppm.

[0108] It was excellently suited for high-yield recovery of Ni, Co and Mn at very low impurity level.