METHOD FOR SAFE RECOVERY OF A WASTE ANODE PIECE OF A LITHIUM ION BATTERY AND APPLICATION THEREOF

Abstract

The invention discloses a method and application for a safe recovery of waste anode pieces of lithium ion batteries. The method comprises the following steps: crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; mixing the crushed aluminum slag with an acid solution, stirring under ultrasound, and then performing wet sieving to obtain an aluminum slag and a battery powder; the obtained aluminum slag is washed with water, then rinsed with an explosion suppressant, centrifuging to obtain an explosion suppressing aluminum slag, and then packed and compressed to obtain an aluminum slag block; connecting the two ends of the aluminum slag block to a positive plate and a negative plate of a DC electrode respectively, applying a current to melt the aluminum slag block, and cooling to obtain a safe aluminum slag block.

Claims

1. A method for a safe recovery of a waste anode piece of a lithium ion battery, comprising the following steps: (1) crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; (2) mixing the crushed aluminum slag with an acid solution, stirring under ultrasound, and then performing wet sieving to obtain an aluminum slag and a battery powder; (3) washing the aluminum slag obtained in step (2) first with water, then with an explosion suppressant; centrifuging to obtain an explosion suppressing aluminum slag, and then packaging and compressing the explosion suppressing aluminum slag to obtain an aluminum slag block; (4) connecting two ends of the aluminum slag block to a positive plate and a negative plate of a DC electrode respectively, applying a current to melt the aluminum slag block, and cooling to obtain a safe aluminum slag block; wherein in step (3), the explosion suppressant is a saturated calcium hydroxide solution; in step (4), the positive plate or the negative plate is a circulating liquid-cooled hollow metal plate.

2. The method according to claim 1, wherein step (2) further comprises the following steps: filtering the battery powder and washing a resulting filter residue to obtain an anode powder B; mixing the anode powder A and the anode powder B, soaking and stirring a resulting mixture in an aluminum-dissolving solution, filtering, washing a resulting residue to obtain an anode powder.

3. The method according to claim 2, wherein the aluminum-dissolving solution is at least one selected from the group consisting of a sodium hydroxide solution, a potassium hydroxide solution and a calcium hydroxide solution.

4. The method according to claim 2, wherein a volume concentration of the aluminum-dissolving solution is 0.003-2 mol/L; and a temperature of the aluminum-dissolving solution is 15-45° C.

5. The method according to claim 1, wherein in step (2), the acid is one selected from the group consisting of sulfuric acid, hydrochloric acid and nitric acid.

6. The method according to claim 1, wherein in step (2), a solid-to-liquid ratio of the crushed aluminum slag to the acid solution is 1: (0.3-5) kg/L; wherein in step (2), a concentration of the acid solution is 0.1-2 mol/L.

7. The method according to claim 1, wherein in step (3), the aluminium slag is washed with water for 0.5-5 min and washed with the explosion suppressant for 0.5-5 min.

8. The method according to claim 1, wherein in step (4), the current is 80-500 A, and the current is applied for 0.5-5 s.

9. The method according to claim 1, wherein in step (4), the metal is one selected from the group consisting of copper, silver, gold, copper-plated gold and copper-plated silver.

10. Use of the method of claim 1 in metal recovery.

11. Use of the method of claim 2 in metal recovery.

12. Use of the method of claim 3 in metal recovery.

13. Use of the method of claim 4 in metal recovery.

14. Use of the method of claim 5 in metal recovery.

15. Use of the method of claim 6 in metal recovery.

16. Use of the method of claim 7 in metal recovery.

17. Use of the method of claim 8 in metal recovery.

18. Use of the method of claim 9 in metal recovery.

Description

DETAILED DESCRIPTION OF ILLUSTRATED EXAMPLES

[0041] Hereinafter, the concept of the present invention and the technical effects produced by it will be described clearly and completely with reference to the embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present invention.

Example 1

[0042] The method for a recovery of a waste anode piece of lithium-ion batteries in this embodiment comprises the following specific steps: [0043] (1) Crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; [0044] (2) Mixing the crushed aluminum slag with 0.1 mol/L sulfuric acid at a solid-to-liquid ratio of 1:5 kg/L, stirring under ultrasound at a stirring speed of 500 r/min for 60 min, to obtain a crushed aluminum slag after acid washing; [0045] (3) preforming wet sieving to screen the crushed aluminum slag after acid washing, and the oversize from the acid solution is mainly an aluminum slag, and the undersize is mainly battery powder; filtering the undersize and washing with water to obtain an anode powder B; [0046] (4) Mixing the anode powder A and anode powder B, adding 0.003 mol/L calcium hydroxide solution according to a solid-liquid ratio of 1:0.5 kg/L, soaking for 120 min, filtering, washing a resulting filter residue with water to obtain a safe type anode powder; [0047] (5) Washing the aluminum slag obtained in step (3) with water for 0.5 min, then with saturated calcium hydroxide solution for 0.5 min, and drying a resulting product by centrifuging to obtain an explosion suppressing aluminum slag; [0048] (6) Placing the explosion suppressing aluminum slag into a metal baler, packaging and compressing under a pressure of 5 MPa to obtain the aluminum slag block; [0049] (7) Connecting two ends of the aluminum slag block to two DC electrode plates (hollow liquid-cooled copper plates) respectively, as a positive plate and a negative plate; applying 80 A current between the positive and negative plates for 5 s, and cooling to obtain a safe type aluminum slag block.

Example 2

[0050] The method for a safe recovery of a waste anode piece of lithium-ion batteries in this embodiment comprises the following specific steps: [0051] (1) Crushing and sieving the waste anode piece with a screen with an aperture size of 0.3 mm to obtain an anode powder A and a crushed aluminum slag; [0052] (2) Mixing the crushed aluminum slag with 1 mol/L sulfuric acid at a solid-to-liquid ratio of 1:1 kg/L, stirring under ultrasound at a stirring speed of 500 r/min for 5 min, to obtain a crushed aluminum slag after acid washing; [0053] (3) performing wet sieving to screen the crushed aluminum slag after acid washing, and the oversize from the acid solution is mainly an aluminum slag, and the undersize is mainly battery powder; filtering the undersize and washing with water to obtain an anode powder B; [0054] (4) Mixing the anode powder A and anode powder B, adding 0.5 mol/L sodium hydroxide solution according to a solid-liquid ratio of 1:0.5 kg/L, soaking for 30 min, filtering, washing a resulting filter residue with water to obtain a safe type anode powder; [0055] (5) Washing the aluminum slag obtained in step (3) with water for 1 min, then with saturated calcium hydroxide solution for 1 min, and drying a resulting product by centrifuging to obtain an explosion suppressing aluminum slag; [0056] (6) Placing the explosion suppressing aluminum slag into a metal baler, packaging and compressing under a pressure of 10 MPa to obtain the aluminum slag block; [0057] (7) Connecting two ends of the aluminum slag block to two DC electrode plates (hollow liquid-cooled copper plates) respectively, as a positive plate and a negative plate; applying 200 A current between the positive and negative plates for 2 s, and cooling to obtain a safe type aluminum slag block.

Example 3

[0058] The method for a safe recovery of a waste anode piece of lithium-ion batteries in this embodiment comprises the following specific steps: [0059] (1) Crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; [0060] (2) Mixing the crushed aluminum slag with 2 mol/L sulfuric acid at a solid-to-liquid ratio of 1:0.3 kg/L, stirring under ultrasound at a stirring speed of 500 r/min for 60 min, to obtain a crushed aluminum slag after acid washing; [0061] (3) preforming wet sieving to screen the crushed aluminum slag after acid washing, and the oversize from the acid solution is mainly an aluminum slag, and the undersize is mainly battery powder; filtering the undersize and washing with water to obtain an anode powder B; [0062] (4) Mixing the anode powder A and anode powder B, adding 2 mol/L potassium hydroxide solution according to a solid-liquid ratio of 1:2 kg/L, soaking for 1 min, filtering, washing a resulting filter residue with water to obtain a safe type anode powder; [0063] (5) Washing the aluminum slag obtained in step (3) with water for 5 min, then with saturated calcium hydroxide solution for 5 min, and drying a resulting product by centrifuging to obtain an explosion suppressing aluminum slag; [0064] (6) Placing the explosion suppressing aluminum slag into a metal baler, packaging and compressing under a pressure of 30 MPa to obtain the aluminum slag block; [0065] (7) Connecting two ends of the aluminum slag block to two DC electrode plates (hollow liquid-cooled copper plates) respectively, as a positive plate and a negative plate; applying 500 A current between the positive and negative plates for 0.5 s, and cooling to obtain a safe type aluminum slag block.

Comparative Example 1

[0066] The method for a safe recovery of waste anode pieces of lithium ion batteries of this comparative example comprises the following specific steps: [0067] (1) After crushing the anode piece of the waste lithium-ion battery, sieving with a screen having an aperture of 0.5 mm, a resulting under-sieve is an anode powder; [0068] (2) Mixing the oversize with 1 mol/L sulfuric acid for 1 min according to a solid-to-liquid ratio of 1:1 kg/L, filtering, washing with water and drying to obtain an aluminum slag of this comparative example.

Comparative Example 2

[0069] The method for a safe recovery of a waste anode piece of lithium-ion batteries in this embodiment comprises the following specific steps: [0070] (1) Crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; [0071] (2) Mixing the crushed aluminum slag with 0.1 mol/L sulfuric acid at a solid-to-liquid ratio of 1:5 kg/L, stirring under ultrasound at a stirring speed of 500 r/min for 60 min, to obtain a crushed aluminum slag after acid washing; [0072] (3) Preforming wet sieving to screen the crushed aluminum slag after acid washing, and the oversize from the acid solution is mainly an aluminum slag, and the undersize is mainly battery powder; filtering the undersize and washing with water to obtain an anode powder B; [0073] (4) Mixing the anode powder A and anode powder B, adding 0.003 mol/L calcium hydroxide solution according to a solid-liquid ratio of 1:0.5 kg/L, soaking for 120 min, filtering, washing a resulting filter residue with water to obtain a safe type anode powder; [0074] (5) Washing the aluminum slag obtained in step (3) with water for 0.5 min, then with saturated sodium hydroxide solution for 0.5 min, and drying a resulting product by centrifuging to obtain an explosion suppressing aluminum slag; [0075] (6) Placing the explosion suppressing aluminum slag into a metal baler, packaging and compressing under a pressure of 5 MPa to obtain the aluminum slag block; [0076] (7) Connecting two ends of the aluminum slag block to two DC electrode plates (hollow liquid-cooled copper plates) respectively, as a positive plate and a negative plate; applying 80 A current between the positive and negative plates for 5 s, and cooling to obtain a safe type aluminum slag block.

Comparative Example 3

[0077] The method for a safe recovery of a waste anode piece of lithium-ion batteries in this embodiment comprises the following specific steps: [0078] (1) Crushing and sieving the waste anode piece to obtain an anode powder A and a crushed aluminum slag; [0079] (2) Mixing the crushed aluminum slag with 0.1 mol/L sulfuric acid at a solid-to-liquid ratio of 1:5 kg/L, stirring under ultrasound at a stirring speed of 500 r/min for 60 min, to obtain a crushed aluminum slag after acid washing; [0080] (3) Preforming wet sieving to screen the crushed aluminum slag after acid washing, and the oversize from the acid solution is mainly an aluminum slag, and the undersize is mainly battery powder; filtering the undersize and washing with water to obtain an anode powder B; [0081] (4) Mixing the anode powder A and anode powder B, adding 0.003 mol/L calcium hydroxide solution according to a solid-liquid ratio of 1:0.5 kg/L, soaking for 120 min, filtering, washing a resulting filter residue with water to obtain a safe type anode powder; [0082] (5) Washing the aluminum slag obtained in step (3) with water for 0.5 min, then with saturated calcium hydroxide solution for 0.5 min, and drying a resulting product by centrifuging to obtain an explosion suppressing aluminum slag; [0083] (6) Placing the explosion suppressing aluminum slag into a metal baler, packaging and compressing under a pressure of 5 MPa to obtain the aluminum slag block; [0084] (7) Connecting two ends of the aluminum slag block to two solid copper electrode plates respectively, as a positive plate and a negative plate; applying 80 A current between the positive and negative plates for 5 s, and cooling to obtain an aluminum slag block.

Comparative Results

[0085] (1) The aluminum and battery powder recovered in the above-mentioned examples and comparative examples were used to calculate the metal recovery rate before and after the comparison treatment. The results are shown in Table 1. The small amount of metal aluminum that may be brought in by the crushing and sieving is selectively dissolved and separated, while avoiding the dissolution of other valuable metal elements such as nickel, cobalt, manganese, and lithium. This invention can also ensure a high recovery rate of valuable metals such as nickel, cobalt, manganese, lithium, etc., while eliminating the hidden dangers of battery powder. [0086] (2) The aluminum slag recovered in the above examples and comparative examples were letting stand for 7 days to determine the hydrogen release rate per unit time; the battery powder recovered in the above examples and comparative examples were added to sulfuric acid to determine the hydrogen release rate per unit time per unit weight of the material. The results are shown in Table 2, indicating that when the aluminum slag was packed and compressed into blocks as in Examples 1-3, the gaps between the aluminum slags were greatly compressed, and the specific surface area of the aluminum slags were reduced. The reaction rate of the aluminum slag with residual alkali or with water was reduced so as to effectively reduce the inhibit hydrogen release and make the aluminum slag intrinsically safe. Comparative example 1 exhibits more higher hydrogen release. Comparative example 2 replaces saturated calcium hydroxide solution with saturated sodium hydroxide solution as an explosion suppressant, the aluminum slag still releases hydrogen. [0087] (3) At a room temperature of 25° C., the aluminum slag recovered from the above examples and comparative examples was put into a ton bag and allowed to stand for 1 hour and 24 hours, respectively, and the temperature inside the aluminum slag was measured. The results are shown in Table 3. [0088] (4) In Example 1-3, the two ends of the aluminum slag block were connected to two DC electrode plates (hollow liquid-cooled metal plates) respectively, and an electric current was applied. After cooling, a safe aluminum slag block was obtained. In Comparative Example 3, the two ends of the aluminum slag block were connected to two solid copper electrode plates respectively, and a current was applied. After cooling, an aluminum slag block was obtained. Measure the surface temperature of the aluminum slag and observe the adhesion between the electrode plate and the aluminum slag block. The results are shown in Table 4.

TABLE-US-00001 TABLE 1 Metal recovery rate Comparative Example1 Example 2 Example 3 Example1 recovery recovery recovery recovery Metal rate rate rate rate Al 98.8% 98.2% 99.1% 83.6% Ni 99.2% 98.5% 98.1% 80.3% Co 99.5% 99.6% 99.2% 82.7% Mn 98.7% 99.2% 98.8% 76.9% Li 97.9% 98.3% 98.6% 72.6%

TABLE-US-00002 TABLE 2 Hydrogen release rate during the aluminum slag storage and the battery powder leaching Compar- Compar- ative ative Example 1 Example 2 Example 3 Example 1 Example 1 hydrogen hydrogen hydrogen hydrogen hydrogen release release release release release Material rate rate rate rate rate Alumi- 0 0 0 0.5 0.13 num mg/(h .Math. kg) mg/(h .Math. kg) slag Battery 0 0 0 3.3 0 powder g/(min .Math. kg)

TABLE-US-00003 TABLE 3 Temperature during the aluminum slag storage Comparative Example 1 Example 2 Example 3 Example 1 temperature temperature temperature temperature Material 1 h 24 h 1 h 24 h 1 h 24 h 1 h 24 h Aluminum 32° C. 26° C. 35° C. 25° C. 30° C. 25° C. 85° C. 72° C. slag

TABLE-US-00004 TABLE 4 Surface temperature and adhesion of the aluminum slag Comparative Item Example 1 Example 2 Example 3 Example 3 Surface 88 92 81 156 temperature of the aluminum slag/° C. Adhesion No adhesion No adhesion No adhesion Part of the between the between the between the aluminum aluminum aluminum aluminum slag adhere slag and slag and slag and to the the plates the plates the plates plates

[0089] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above-mentioned embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the purpose of the present invention. Variety. In addition, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.