PROCESS FOR THE RECOVERY OF LITHIUM AND OTHER METALS FROM WASTE LITHIUM ION BATTERIES

Abstract

A process for the recovery of one or more transition metals and lithium from waste lithium ion batteries or parts thereof is disclosed. The process comprising the steps of (a) providing a particulate material containing a transition metal compound and/or transition metal, wherein the transition metal is selected from the group consisting of Ni and Co, and wherein further at least a fraction of said Ni and/or Co, if present, are in an oxidation state lower than +2, e.g. in the metallic state; which particulate material further contains a lithium salt; (b) treating the material provided in step (a) with a polar solvent and optionally an alkaline earth hydroxide; (c) separating the solids from the liquid, optionally followed by a solid-solid separation step; and (d) treating the solids containing the transition metal in a way to dissolve at least part of the Ni and/or Co, typically using a mineral acid, provides good separation of lithium in high purity and of transition metal useful for the production of battery cathode active materials.

Claims

1-16. (canceled)

17. A process for recovering one or more transition metals, and lithium as Li-salt from a particulate material comprising waste lithium ion batteries or parts thereof, wherein the process comprises: (a) providing the particulate material comprises a transition metal compound and/or transition metal, wherein the transition metal is chosen from Ni and Co, and at least a fraction of the Ni and/or Co are in an oxidation state lower than +2 and wherein the particulate material further comprises a lithium salt; (b) treating the particulate material of step (a) with an alkaline earth hydroxide and a polar solvent; (c) separating solid residue comprising the transition metal from liquid of the particulate material of step (b), and optionally, subjecting the solid residue to a solid-solid separation for the removal of the transition metal; and (d) treating the solid residue of step (c) comprising the transition metal to dissolve at least part of the Ni and/or Co.

18. The process according to claim 17, wherein the particulate material of step (a) is from spent lithium ion batteries and/or scrap material from producing lithium ion batteries or lithium ion cathode active materials, and is in a form of a dry powder, wet powder, or suspension of particles in a liquid.

19. The process according to claim 17, wherein the particulate material of step (a) comprises particles having an average particle diameter D50 ranging from 1 μm to 2 mm, when detected in accordance with ISO 13320 EN:2009-10.

20. The process according to claim 17, wherein the transition metal compound and/or transition metal Ni and/or Co in oxidation state lower than +2, comprised in the particulate material of step (a), comprises Ni and/or Co in the metallic state, and wherein the transition metal compound and/or transition metal comprised in the particulate material of step (a) is present in an amount detectable by powder x-ray diffractometry (Cu-k-alpha-1 radiation).

21. The process according to claim 17, wherein the lithium salt comprised in the particulate material of step (a) comprises one or more salts of LiOH, LiF, Li2O, Li2CO3, LiHCO3, lithium aluminates, lithium phosphate salts, and mixed oxides of Li and one or more of Ni, Co, Mn, Fe, Al, Cu.

22. The process according to claim 17, wherein treating in step (b) is carried out in presence of an alkaline earth hydroxide and comprises: i) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising the alkaline earth hydroxide as suspension or solution in a protic solvent, and the particulate material of step (a) simultaneously to the polar solvent, which is a protic solvent; ii) adding the particulate material of step (a) to the polar solvent, which is a protic solvent, to obtain a suspension, followed by adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising alkaline earth hydroxide as suspension or solution in a protic solvent; iii) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid or suspension of solids in a polar solvent, to an aqueous liquid such as water to obtain a mixture comprising alkaline earth hydroxide, and subsequently combining the mixture with the particulate material of step (a); iv) adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, to the particulate material of step (a) to obtain a mixture of solids, followed by adding the polar solvent, which is a protic solvent; or v) adding the particulate material of step (a) to the polar solvent, which is a protic solvent, to obtain a suspension, followed by filtrating to obtain a filtrate, and subsequently adding the alkaline earth hydroxide and/or an alkaline oxide, as a solid, or a mixture comprising alkaline earth hydroxide to the filtrate.

23. The process according to claim 17, wherein the polar solvent of step (b) comprises calcium hydroxide, which is added to the polar solvent, or is formed in situ upon contact of calcium oxide with the polar solvent chosen from protic solvents.

24. The process according to claim 17, wherein the particulate material of step (a) comprises material obtained from waste lithium ion batteries after carrying out a preliminary step (i) of heating under inert or reducing conditions to a temperature ranging from 80° C. to 900° C., wherein the preliminary step (i) is carried out after discharging the lithium ion batteries, dismantling, and/or shredding.

25. The process according to claim 17, wherein treating the solid residue of step (d) comprises treating with a mineral acid chosen from sulfuric acid, hydrochloric acid, nitric acid, methanesulfonic acid, oxalic acid and citric acid, or a combination of at least two of the foregoing.

26. The process according to claim 24, wherein in the preliminary step (i) the temperature ranges from 350° C. to 500° C., and the preliminary step (i) is conducted in the presence of 35% or more by volume of hydrogen; or wherein in the preliminary step (i) the temperature ranges from 500° C. to 850° C., and the preliminary step (i) is conducted in the presence of carbon in an atmosphere containing up to 20% by volume of oxygen.

27. The process according to claim 17, wherein the particulate material of step (a) is obtained from lithium ion batteries after mechanic removal of casing, wiring or circuitry and discharging, and wherein the particulate material is not exposed to temperatures of 400° C. or more under oxidizing conditions before step (a).

28. The process according to claim 17, further comprising subjecting the solids of step (c) to a solid-solid separation.

29. The process according to claim 17, wherein the solids treated in step (d) further comprise one or more of copper, iron, and manganese.

30. The process according to claim 17, further comprising recovering lithium as lithium hydroxyde by crystallization from the liquid obtained in step (c), or recovering lithium as lithium carbonate after adding carbon dioxide to the liquid obtained in step (c) and isolating the lithium carbonate formed.

31. The process according to claim 17, wherein the transition metal obtained in step (d) is subjected to precipitation as hydroxide, and optionally, after removing undesired impurity metals and/or adding missing amounts of metals as corresponding salts, and optionally, followed by calcination to achieve a metal composition of a desired cathode active material.

32. A cathode active precursor material produced by the process according to claim 17.

Description

EXAMPLE 1

Providing a Reduced Mass from Waste Lithium Ion Batteries

[0226] An amount of about 1 t mechanically treated battery scrap containing spent cathode active material containing nickel, cobalt and manganese, organic carbon in the form of graphite and soot and residual electrolyte, and further impurities inter alia comprising fluorine compounds, phosphorous and calcium is treated to obtain a reduced mass according to the process described in Jia Li et al., Journal of Hazardous Materials 302 (2016) 97-104. The atmosphere within the roasting system is air whose oxygen reacts with the carbon in the battery scrap to form carbon monoxide, treatment temperature is 800° C.

[0227] After reaction and cool down to ambient temperature, the heat-treated material is recovered from the furnace, mechanically treated to obtain a particulate material and analyzed by means of X-ray powder diffraction (FIGS. 1 and 2: Mo Ka radiation, FIGS. 3 and 4: Cu Ka radiation), elemental analysis (Tab. 2) and particle size distribution (Tab. 3).

[0228] The Li content is 3.6 wt.-%, which acts as reference for all further leaching examples (see below). Fluorine is mainly represented as inorganic fluoride (88%). Particle sizes are well below 1 mm; D50 is determined to be 17.36 μm.

[0229] Comparing the obtained XRD pattern with calculated reference patterns of Ni (which is identical with that one of CoxNi1−x, x=0-0.6), Co, Li2CO3 and LiAlO2 (see reference patterns in Tab. 1), it can be concluded that Ni is exclusively present as metallic phase, either as pure Ni or as an alloy in combination with Co. For clarity, this result is confirmed by applying two different radiation sources. The presence of metallic nickel is supported by the qualitative observation that the whole sample shows typical ferromagnetic behavior when it gets in touch with a permanent magnetic material. As lithium salts, Li2CO3 as well as LiAlO2 are clearly identified by their characteristic diffraction pattern.

[0230] The composition of the black powder (PM) obtained is shown in Table 2.

TABLE-US-00002 TABLE 2 Composition of reduced black powder (PM) F (ionic F thereof) 2.6 g [i.e. 0.14 mol]/100 g (2.3 g [i.e. 0.12 mol]/100 g) C (inorganic C thereof) 31.3 g/100 g (1.2 g/100 g) Ca 0.16 g [i.e. 0.004 mol]/100 g Co 9.5 g/100 g Cu 3.4 g/100 g Li 3.6 g/100 g Mn 5.8 g/100 g Ni 4.8 g/100 g P 0.36 g/100 g 

TABLE-US-00003 TABLE 3 Results on particle size distribution measurement of reduced mass from waste lithium ion batteries after heat treatment. D10 [μm] D50 [μm] D80 [μm] D90 [μm] 3.46 17.36 33.86 48.92

EXAMPLE 2

Leaching with Ca(OH)2

[0231] An amount of 5 g of the above-mentioned reduced battery scrap material (obtained as shown in Example 1) is filled an a PFA flask and mixed with 5, 1.5, 1.0 and 0.5 g of solid Ca(OH)2, respectively. 200 g of water are added with stirring, and the whole mixture is refluxed for 4 hours.

[0232] After 4 hours, the solid content is filtrated off and filtrate samples are taken and analyzed with regard to Li, F, carbonate, OH, and Ca. Results are compiled in the below Table 4.

TABLE-US-00004 TABLE 4 Analyzed filtrates after Li leaching with Ca(OH)2. Amount of Lithium Fluoride Li leaching Ca(OH).sub.2 content content efficiency [g] [mg] [mg] [%] 0.5 144 46 80 1.0 154 12 84 1.5 156 4 86 5 162 4 90

EXAMPLE 2a

Leaching with Ca(OH)2, Addition of Solids to Liquid

[0233] Example 2 is repeated except that 5 g of the black powder obtained as shown in Example 1, and the designated amount of solid Ca(OH)2, are added simultaneously to 200 g of water with stirring. Results are analogous to those reported in Table 4.

EXAMPLE 3

Higher Solid Content

[0234] An amount of 10, 20 and 30 g, respectively, of the particulate material (PM) described in example 1 is filled an a PFA flask and mixed with solid Ca(OH)2 in a fixed weight ratio of PM:Ca(OH)2=3.3:1. The further treatment with addition of 200 g of water follows example 2 except that each sample is refluxed for 6 hours. Results are shown in Table 5.

[0235] Based on these results, it is concluded that the efficiency of the present leaching process is not affected by the PM solid content.

TABLE-US-00005 TABLE 5 Analyzed filtrates after Li leaching with Ca(OH)2. Amount of Lithium Fluoride Li material from content content leaching example 1 [mg] [mg] efficiency 10 g 322 10 89% 20 g 624 20 86% 30 g 987 30 91%

EXAMPLE 4

Variation of Parameters

[0236] Following the procedure of Example 2a, solid Ca(OH)2 and the particulate material (PM) described in example 1 is added with stirring (3 stages cross-beam stirrer, 60 mm diameter) to 836.8 g of pre-heated water in a glass reactor with baffles. The stirring is continued at constant temperature for the time period (t) indicated in Tab. 6, after which the solid is filtered off and filtrate samples are analyzed. Amounts of Ca(OH)2 and PM, temperatures, stirring parameters, and analysis results (%=g found in 100g of filtrate) are also compiled in Table 6.

TABLE-US-00006 TABLE 6 t Li F.sup.− recovered Li Sample [h] [%] [%] [%] 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.28 0.024 55% T = 70° C., 3 0.28 0.022 55% stir with 525 rpm 4 0.30 0.021 59% (0.85 W/kg) 6 0.33 0.014 65% 24 0.41 0.007 80% 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.41 0.016 80% T = 95° C., 3 0.43 0.015 84% stir with 525 rpm 4 0.44 0.015 86% (0.85 W/kg) 6 0.47 0.014 92% 24 0.48 0.014 94% 125.5 g PM, 0 37.7 g Ca(OH).sub.2 2 0.42 0.014 82% T = 98° C., 3 0.43 0.013 84% stir with 950 rpm 4 0.45 0.013 88% (5 W/kg) 6 0.45 0.013 88% 24 0.48 0.016 94% 167.4 g PM, 0 50.2 g Ca(OH).sub.2 2 0.49 0.019 72% T = 98° C., 3 0.53 0.018 78% stir with 600 rpm 4 0.54 0.018 79% (1.3 W/kg) 6 0.55 0.018 81% 24 0.64 0.029 94%

EXAMPLE 5

Solid LiOH from Leached Lithium Filtrate

[0237] A filtrate obtained from a process according to example 2 is further treated according to the above described step (e1) to yield solid LiOH as monohydrate: 1 L of a filtrate containing 0.21 wt.-% lithium is concentrated by evaporation (40° C., 42 mbar)and finally dried applying 40° C. and a constant flow of nitrogen for 24 h. FIG. 5 shows the obtained LiOH monohydrate with minor impurities of Li2CO3. The latter is due to contact with air during almost all process steps. Next to carbon-based impurities, elemental analysis reveals as main impurities (>200 ppm) F, Na, Ca, K and CI and minor impurities (<200 ppm) of Al and Zn.

EXAMPLE 6

Providing a Reduced Mass from Waste Lithium Ion Batteries (Step a)

[0238] An amount of about 100 t mechanically treated and sieved battery scrap containing spent cathode active material containing nickel, cobalt and manganese, organic carbon in the form of graphite and soot and residual electrolyte, and further impurities inter alia comprising fluorine compounds, phosphorous and calcium is treated to obtain a reduced mass. The composition of this initial material is shown in Tab 7. The reduction is carried out in a rotary kiln applying 450° C. in a 100% hydrogen atmosphere. A residence time of 60 min is achieved by adjusting angle and rotational speed of the kiln. After reaction and cool down to ambient temperature in inert atmosphere, the heat-treated particulate material is analyzed by means of X-ray powder diffraction (results analogous to those shown in FIGS. 1-4), elemental analysis (Tab. 7) and particle size distribution (Tab. 8).

[0239] The Li content is 3.0 wt.-%, which acts as reference for all further leaching examples (see below). fluorine is represented as inorganic fluoride. Particle sizes are well below 1 mm; D50 is determined to be 17 μm.

[0240] Comparing the obtained XRD pattern with calculated reference patterns of Ni (which is identical with that one of CoxNi1−x, x=0-0.6), Co and Li2CO3, it can be concluded that Ni is exclusively present as metallic phase, either as pure Ni or as an alloy in combination with Co. The presence of metallic nickel is supported by the qualitative observation that the whole sample shows typical ferromagnetic behavior when it gets in touch with a permanent magnetic material. As lithium salts, Li2CO3 is clearly identified by its characteristic diffraction pattern. The composition of the black powder (PM) obtained is shown in Table 7 (right column).

TABLE-US-00007 TABLE 7 Composition of the initial and reduced black powder (PM) Initial unreduced black mass Reduced black mass F (ionic 0.92 g [i.e. 0.048 mol]/100 g 1.00 g [i.e. 0.053 mol]/100 g F thereof) (0.58 g [i.e. 0.031 mol]/100 g) (1.00 g [i.e. 0.053 mol]/100 g) C 48.3 g/100 g (0.15 g/100 g) 53 g/100 g (0.77 g/100 g) (inorganic C thereof) Ca 0.26 g [i.e. 0.0065 mol]/100 g 0.29 g [i.e. 0.0072 mol]/100 g Co 7.4 g/100 g 8.2 g/100 g Li 2.9 g/100 g 3.0 g/100 g Mn 3.9 g/100 g 4.2 g/100 g Ni 14.2 g/100 g  16.0 g/100 g  P 0.12 g/100 g  0.11 g/100 g 

TABLE-US-00008 TABLE 8 Results on particle size distribution measurement of reduced mass from waste lithium ion batteries after heat treatment. D10 [μm] D50 [μm] D80 [μm] D90 [μm] 3 17 31 42

EXAMPLE 7

Leaching with Ca(OH)2 (Steps b and c)

[0241] An amount of 30 g of the above-mentioned reduced battery scrap material (obtained as shown in Example 6) is filled an a PFA flask and mixed with 30 g of solid Ca(OH)2. 200 g of water are added with stirring, and the whole mixture is refluxed for 6 hours. After 6 hours, the solid content is filtrated off and washed with water. Filtrate (224.34 g) and dried (12 h, 90° C.) filter cake (37.82 g) are analyzed. The lithium content of the filtrate is determined to be 0.30 g/100 g. Results of the filter cake analysis are shown in Tab. 9. The lithium recovery yield (amount of lithium in liquid phase compared to amount of lithium in liquid+solid phase) is 77%.

TABLE-US-00009 TABLE 9 Analysis of the dried filer cake after lithium leaching Solid residue after Li leaching ionic F 0.64 g/100 g [i.e. 0.034 mol/100 g] Al  1.1 g/100 g Ca 12.4 g/100 g [i.e. 0.31 mol/100 g] Co  6.5 g/100 g Cu 0.63 g/100 g Fe 0.33 g/100 g Li 0.53 g/100 g Mn  3.3 g/100 g Ni 12.6 g/100 g P 0.10 g/100 g

EXAMPLE 8

Acidic Leaching of Obtained Solid Residue in Example 7 (Step d)

[0242] 20 g of the solid obtained after solid liquid separation in step (c) is suspended in 36 g water and heated to 45° C. After reaching this temperature air is bubbled constantly (10 L/h) through the mixture and dosing of 44 g sulfuric acid (50%) is started. Having dosed the whole amount of acid the mixture is kept for another hour at 45° C. and then heated for 4 h at 80° C. After that, the mixture is cooled down and the solid filtered off. The filter cake is washed three times and subsequently dried (12 h, 90° C.). Tab. 10 shows the obtained fractions as well as the corresponding elemental analyses indicating that except for Al all elements can be recovered with a yield >90% by acidic leaching with sulfuric acid in the presence of air. Yields are calculated as ratio of the respective amount in liquid phase and the amount in liquid+solid phase.

TABLE-US-00010 TABLE 10 Results of the acidic leaching. F Al Co Cu Fe Li Mn Ni Filtrate + Washing water - 183.97 g 0.05  0.10 0.60 0.04 0.03 0.04 0.32 1.15 Filter cake - 16.84 g wt.-% 0.052 0.14 0.13 0.05 <0.01  0.03 0.07 0.42 Distribution in fractions Liquid 92% 88% 98% 90% 97% 94% 98% 97% Solid  8% 11%  2%  9%  3%  6%  2%  3%

EXAMPLE 9

Acidic Leaching of Solid Residue Obtained in Step (c)

[0243] 5 g of a solid obtained after solid liquid separation in step (c) is suspended in 50 g water and heated to 45° C. After reaching this temperature a mixture of sulfuric acid (50%, 6.90 g) and hydrogen peroxide (30%, 1.17 g) is dosed while the temperature is kept constant. Having dosed the whole amount, the mixture is kept for another hour at 45° C. and then heated for 4 h at 80° C. After that, the mixture is cooled down and the solid filtered off. The filter cake is washed three times and subsequently dried. Tab. 11 shows the obtained fractions as well as the corresponding elemental analyses.

TABLE-US-00011 TABLE 11 Results of example 9. F Al Co Cu Fe Li Mn Ni Filtrate + Washing water - 175.02 g wt.-% 0.028 0.33 0.008 0.012 0.008 0.11 0.075 Filter cake - 3.83 g wt.-% 1.9  0.58 0.82  Distribution in fractions Filtrate + 89% 90% 81% Washing water Filter cake 11% 10% 19%

EXAMPLE 10

[0244] Each of the solid residues obtained in example 4 after 24 of leaching (see Tab. 6) is treated with sulfuric acid (50%) followed by removal of undissolved residues. The solution obtained is combined with NaOH to precipitate all transition metal from the solution. The precipitate obtained is useful as a precursor for battery cathode active materials.

BRIEF DESCRIPTION OF FIGURES

[0245] FIG. 1: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0246] FIG. 2: X-ray powder diffractogram (Mo Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0247] FIG. 3: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, cobalt, manganese-II-oxide, cobalt oxide, and nickel.

[0248] FIG. 4: X-ray powder diffractogram (Cu Ka) of reduced mass from waste lithium ion batteries after heat/reduction treatment as obtained in example 1 and used in example 2a including reference diffractograms of graphite, lithium aluminate, and lithium carbonate.

[0249] FIG. 5: X-ray powder diffractogram (Cu Ka) of LiOH monohydrate as obtained in example 5.