RECYCLING METHOD FOR MIXED WASTE MATERIAL OF LITHIUM NICKEL MANGANESE COBALT OXIDE AND LITHIUM IRON PHOSPHATE

Abstract

The present disclosure discloses a recycling method for a mixed waste material of lithium nickel manganese cobalt oxide (LNMCO) and lithium iron phosphate (LFP), including: conducting acid-leaching to obtain an acid-leaching liquor with nickel, cobalt, manganese, phosphorus, iron, and lithium; conducting adsorption separation with a resin, washing the resin with sulfuric acid to obtain a mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate, and subjecting the mixed solution to precipitation to obtain an LNMCO cathode material precursor; and subjecting an obtained solution with phosphorus, iron, and lithium to lithium precipitation to obtain a lithium salt precipitate, and subjecting a post-precipitation solution to concentration and electrospinning to obtain a ferric phosphate/carbon material. The process of the present disclosure can achieve comprehensive recycling of a mixed waste material of LNMCO and LFP and the directed circulation of waste LNMCO and LFP materials.

Claims

1. A recycling method for a mixed waste material of lithium nickel manganese cobalt oxide and lithium iron phosphate, comprising the following steps: S1: adding the mixed waste material of lithium nickel manganese cobalt oxide and lithium iron phosphate to an acid solution for acid-leaching, and conducting solid-liquid separation to obtain an acid-leaching liquor; S2: using a resin to adsorb nickel, cobalt, and manganese in the acid-leaching liquor, and washing a resulting saturated resin with sulfuric acid to obtain a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate, and a post-adsorption solution; S3: heating the post-adsorption solution, and adding a lithium-precipitating reagent to obtain a lithium salt precipitate and a post-precipitation solution; and S4: concentrating the post-precipitation solution, adding a carbon source, and stirring to obtain a dispersed mixture; and subjecting the dispersed mixture to electrospinning to obtain a sheet material, and drying and roasting the sheet material to obtain a ferric phosphate/carbon material.

2. The recycling method according to claim 1, wherein in S1, the acid solution is one or more selected from the group consisting of sulfuric acid, nitric acid, and hydrochloric acid.

3. The recycling method according to claim 1, wherein in S1, a mass ratio of the acid solution to the mixed waste material is (4-10):1.

4. The recycling method according to claim 1, wherein in S2, the resin is one or more selected from the group consisting of chelating resin CH-90Na, resin XFS4195, AmberlitelRC748, LonacSR-5, PuroliteS-930, Chelex100, D851, and D402-II.

5. The recycling method according to claim 1, wherein in S2, the obtained mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate is subjected to precipitation to obtain a ternary precursor.

6. The recycling method according to claim 1, wherein in S3, the lithium-precipitating reagent is one or more selected from the group consisting of sodium carbonate, sodium phosphate, potassium phosphate, potassium carbonate, sodium oxalate, potassium oxalate, sodium fluoride, potassium fluoride, and ammonium fluoride; and the heating is conducted at 40° C. to 120° C.

7. The recycling method according to claim 1, wherein in S4, the post-precipitation solution is concentrated until an iron concentration in the post-precipitation solution is 40 g/L to 150 g/L.

8. The recycling method according to claim 1, wherein in S4, the carbon source is one or more selected from the group consisting of polyvinylpyrrolidone, polyvinylidene fluoride, and polyacrylonitrile.

9. The recycling method according to claim 1, wherein in S4, the carbon source is first dissolved in dimethylformamide to obtain a solution, then the solution is poured into a concentrated post-precipitation solution, and a resulting mixture is stirred to obtain the dispersed mixture.

10. The recycling method according to claim 1, wherein in S4, the drying is conducted at 40° C. to 90° C.; and the roasting is conducted at 250° C. to 600° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present disclosure is further described below with reference to accompanying drawings and examples.

[0030] The solethe FIGURE is a process flow diagram of Example 1 of the present disclosure.

DETAILED DESCRIPTION OF ILLUSTRATED EXAMPLES

[0031] The concepts and technical effects of the present disclosure are clearly and completely described below in conjunction with examples, so as to allow the objectives, features and effects of the present disclosure to be fully understood. Apparently, the described examples are merely some rather than all of the examples of the present disclosure. All other examples obtained by those skilled in the art based on the examples of the present disclosure without creative efforts should fall within the protection scope of the present disclosure.

Example 1

[0032] A recycling method for a mixed waste material of LNMCO and LFP was provided, and as shown in the solethe FIGURE, a specific process was as follows: [0033] (1) An LNMCO waste material and an LFP waste material were mixed, crushed, and sieved to obtain a mixed waste material of LNMCO and LFP. [0034] (2) 50 g of the mixed waste material of LNMCO and LFP obtained in step (1) was weighed and added to 250 ml of a sulfuric acid solution with a concentration of 2.5 mol/L in a beaker, then the beaker was placed in a water bath at 80° C., stirring was conducted for 4 h, and a resulting slurry was filtered to obtain a solution with nickel, cobalt, manganese, phosphorus, iron, and lithium and a graphite residue. [0035] (3) A chelating resin CH-90Na was packed in a column, and the solution with nickel, cobalt, manganese, phosphorus, iron, and lithium obtained in step (2) was added dropwise into the resin column using a peristaltic pump; after the resin reached adsorption saturation, a small amount of lithium adhered on a resin surface was washed away with pure water, and then the saturated resin was washed with a 1.5 mol/L sulfuric acid solution to obtain a mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate, where a post-adsorption solution was a solution with phosphorus, iron, and lithium. [0036] (4) The mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate obtained in step (3) was subjected to precipitation to obtain a ternary precursor. [0037] (5) The solution with phosphorus, iron, and lithium was heated to 90° C., a sodium carbonate solution was added dropwise for lithium precipitation, and a resulting mixture was filtered to obtain a filter residue; the filter residue was washed with pure water and dried in an oven for 8 h to obtain lithium carbonate; and a lithium content in a post-lithium-precipitation solution was determined, and a lithium recovery rate was calculated. [0038] (6) The post-lithium-precipitation solution obtained in step (5) was concentrated to an iron concentration of 75 g/L; PVP was dissolved in DMF, a resulting solution was poured into the post-lithium-precipitation solution, and a resulting mixture was subjected to dispersion; and electrospinning was conducted to obtain a sheet material, and the sheet material was dried at 60° C. and then roasted at 500° C. to obtain a ferric phosphate/carbon material.

TABLE-US-00001 Calculation results for each component in Example 1 Item Ni Co Mn P Fe Li Mass of each component in the raw material (g) 1.23 2.55 1.05 3.92 5.56 1.71 Mass of each component in the leaching liquor (g) 1.21 2.51 1.04 3.88 5.51 1.69 Leaching rate (%) 98.37 98.43 99.05 98.98 99.10 98.83 Mass of each component in the solution obtained after nickel, cobalt, and manganese are precipitated (mg) 2.01 23 1.08 - - - Mass of each component in the solution obtained after lithium is precipitated (mg) 1.11 17 0.58 103.86 46.74 0.65 Recovery rate (%) 98.12 97.93 98.89 96.33 98.26 98.45

Example 2

[0039] A recycling method for a mixed waste material of LNMCO and LFP was provided, and a specific process was as follows: [0040] (1) An LNMCO waste material and an LFP waste material were mixed, crushed, and sieved to obtain a mixed waste material of LNMCO and LFP. [0041] (2) 50 g of the mixed waste material of LNMCO and LFP obtained in step (1) was weighed and added to 250 ml of a mixed solution of sulfuric acid and nitric acid that had a concentration of 3.5 mol/L in a beaker, then the beaker was placed in a water bath heated to 90° C., stirring was conducted for 4 h, and a resulting slurry was filtered to obtain a solution with nickel, cobalt, manganese, phosphorus, iron, and lithium and a graphite residue. [0042] (3) A chelating resin CH-90Na was packed in a column, and the solution with nickel, cobalt, manganese, phosphorus, iron, and lithium obtained in step (2) was added dropwise into the resin column using a peristaltic pump; after the resin reached adsorption saturation, a post-adsorption solution was passed through a PuroliteS-930 resin column, a small amount of lithium adhered on a resin surface was washed away with pure water, and then the saturated resin was washed with a 1.5 mol/L sulfuric acid solution to obtain a mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate, where a post-adsorption solution was a solution with phosphorus, iron, and lithium. [0043] (4) The mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate obtained in step (3) was subjected to precipitation to obtain a ternary precursor. [0044] (5) The solution with phosphorus, iron, and lithium was heated to 80° C., a potassium carbonate solution was added dropwise for lithium precipitation, and a resulting mixture was filtered to obtain a filter residue; the filter residue was washed with pure water and dried in an oven for 8 h to obtain lithium carbonate; and a lithium content in a post-lithium-precipitation solution was determined, and a lithium recovery rate was calculated. [0045] (6) The post-lithium-precipitation solution obtained in step (5) was concentrated to an iron concentration of 80 g/L; PVDF was dissolved in DMF, a resulting solution was poured into the post-lithium-precipitation solution, and a resulting mixture was subjected to dispersion; and electrospinning was conducted to obtain a sheet material, and the sheet material was dried at 60° C. and then roasted at 450° C. to obtain a ferric phosphate/carbon material.

TABLE-US-00002 Calculation results for each component in Example 2 Item Ni Co Mn P Fe Li Mass of each component in the raw material (g) 1.23 2.55 1.05 3.92 5.56 1.71 Mass of each component in the leaching liquor (g) 1.22 2.52 1.045 3.84 5.48 1.69 Leaching rate (%) 99.18 98.82 99.52 98.08 98.56 98.84 Mass of each component in the solution obtained after nickel, cobalt, and manganese are precipitated (mg) 4.26 10.62 3.13 - - - Mass of each component in the solution obtained after lithium is precipitated (mg) 3.08 6.04 1.84 41.66 35.64 13.55 Recovery rate (%) 98.59 98.17 99.05 97.02 97.92 98.33

Example 3

[0046] A recycling method for a mixed waste material of LNMCO and LFP was provided, and a specific process was as follows: [0047] (1) An LNMCO waste material and an LFP waste material were mixed, crushed, and sieved to obtain a mixed waste material of LNMCO and LFP. [0048] (2) 50 g of the mixed waste material of LNMCO and LFP obtained in step (1) was weighed and added to 250 ml of a hydrochloric acid solution with a concentration of 4 mol/L in a beaker, then the beaker was placed in a water bath heated to 80° C., stirring was conducted for 6 h, and a resulting slurry was filtered to obtain a solution with nickel, cobalt, manganese, phosphorus, iron, and lithium and a graphite residue. [0049] (4) The mixed solution of nickel sulfate, cobalt sulfate, and manganese sulfate obtained in step (3) was subjected to precipitation to obtain a ternary precursor. [0050] (5) The solution with phosphorus, iron, and lithium was heated to 90° C., a sodium carbonate solution was added dropwise for lithium precipitation, and a resulting mixture was filtered to obtain a filter residue; the filter residue was washed with pure water and dried in an oven for 8 h to obtain lithium carbonate; and a lithium content in a post-lithium-precipitation solution was determined, and a lithium recovery rate was calculated. [0051] (6) The post-lithium-precipitation solution obtained in step (5) was concentrated to an iron concentration of 75 g/L; PVP was dissolved in DMF, a resulting solution was poured into the post-lithium-precipitation solution, and a resulting mixture was subjected to dispersion; and electrospinning was conducted to obtain a sheet material, and the sheet material was dried at 60° C. and then roasted at 400° C. to obtain a ferric phosphate/carbon material.

TABLE-US-00003 Calculation results for each component in Example 3 Item Ni Co Mn P Fe Li Mass of each component in the raw material (g) 1.23 2.55 1.05 3.92 5.56 1.71 Mass of each component in the leaching liquor (g) 1.216 2.52 1.042 3.83 5.51 1.689 Leaching rate (%) 98.86 98.82 99.24 97.70 99.10 98.79 Mass of each component in the solution obtained after nickel, cobalt, and manganese are precipitated (mg) 5.63 17.37 4.21 - - - Mass of each component in the solution obtained after lithium is precipitated (mg) 3.74 7.45 2.49 135.24 83.4 28.38 Recovery rate (%) 98.10 97.85 98.60 96.55 98.50 98.34

[0052] The present disclosure is described in detail with reference to the accompanying drawings and examples, but the present disclosure is not limited to the above examples. Within the scope of knowledge possessed by those of ordinary skill in the technical field, various changes can also be made without departing from the purpose of the present disclosure. In addition, the examples in the present disclosure or features in the examples may be combined with each other in a non-conflicting situation.