A method for selectively leaching valuable metals from spent ternary lithium battery cathode materials using amino sugars in a eutectic process.

Abstract

A method for selectively leaching valuable metals from spent ternary lithium-ion battery cathode materials using an amino sugar eutectic solvent relates to the field of hydrometallurgy, providing an efficient method for extracting valuable metals from spent lithium-ion batteries. The hydrophilic eutectic solvent provided in this application comprises D-glucosamine hydrochloride and betaine hydrochloride. Valuable metals in spent ternary lithium-ion battery cathode materials are leached using the aforementioned eutectic solvent. The eutectic solvent of this application uses inexpensive raw materials, is widely available, and has low preparation costs. The leaching method for valuable metals in spent ternary lithium-ion battery cathode materials of this application can replace traditional pyrometallurgical processes and hydrometallurgical processes using strong acids and alkalis as leaching agents, achieving a green and environmentally friendly goal.

Description

Technical Field

[0001] This invention relates to the fields of solid waste recycling and resource utilization technology and hydrometallurgy, specifically to a method for selectively leaching valuable metals from waste ternary lithium battery cathode materials using amino sugars in a low-melting process. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage, the demand for lithium-ion batteries is increasing. Theoretically, the lifespan of lithium-ion batteries in small electronic products is only about 3 years, and in electric vehicles, it's only 5-10 years. After reaching their lifespan, lithium-ion batteries face issues such as failure, disposal, and recycling. It is estimated that by 2030, a cumulative total of 11 million tons of waste lithium-ion batteries will be generated, and by 2040, the annual waste flow from electric vehicle batteries will reach 340,000 tons.

[0003] It is necessary to recycle used lithium-ion batteries to recover heavy metals and reduce resource waste. Furthermore, the failure to promptly recycle and dispose of large quantities of used lithium-ion batteries will cause significant environmental problems and represent a waste of resources. The large number of used lithium-ion batteries generated during use, if not effectively recycled, will cause considerable harm to the environment. Therefore, the recycling and reuse of used lithium-ion batteries is essential.

[0004] Currently, the main methods for recycling spent lithium batteries both domestically and internationally are pyrometallurgy and hydrometallurgy. Compared to pyrometallurgy, hydrometallurgy has advantages such as high recycling efficiency, low pollution, and low cost. The hydrometallurgical process primarily uses inorganic or organic acids to uniformly leach the cathode powder of ternary lithium batteries, followed by extraction and separation. This method typically achieves a high leaching rate, but it has a significant adverse environmental impact. Using strong acids as leaching agents releases Cl2, SO3, and NO during the leaching process. x However, the leaching acid can cause significant environmental damage, and strong acids and alkalis can severely corrode pipelines, leading to substantial costs and waste. Therefore, compared to the methods mentioned above, a method using eutectic melting to selectively leach valuable metals from waste ternary lithium battery cathode materials is a greener, cleaner, and more promising approach.

[0005] Eutectic solvents (DES) are liquids typically composed of two or three inexpensive and safe components that self-associate through hydrogen bonding to form eutectic mixtures with melting points lower than those of the individual components. Eutectic solvents exhibit physicochemical properties similar to ionic liquids, but are more environmentally friendly and relatively cheaper.

[0006] CN115522057A discloses a method for selectively leaching and separating transition metals from waste ternary lithium battery cathode materials using a eutectic solvent. This method uses choline chloride, malonic acid, and deionized water to synthesize a eutectic solvent to effectively and selectively leach lithium, cobalt, and manganese from the waste ternary lithium battery cathode materials. However, ternary lithium batteries contain a higher content of nickel than lithium, cobalt, and manganese, and selective leaching does not effectively recover nickel from waste ternary lithium batteries. Furthermore, subsequent nickel leaching may still require the use of strong acids and alkalis. CN111600090A discloses a process for recycling waste lithium batteries using a eutectic solvent. This involves mixing a quaternary ammonium salt with an amine compound and heating to obtain the eutectic solvent, then leaching the valuable metals from the ternary lithium battery by heating and stirring at 170-200°C for 5-24 hours. However, this method requires a high leaching temperature and a long leaching time. Therefore, it is crucial to develop a "green solvent" that uses inexpensive raw materials, employs a simple leaching method, can completely leach lithium, nickel, cobalt, and manganese, and is environmentally friendly. Summary of the Invention

[0007] This invention addresses the problems of high eutectic viscosity and high leaching temperature in the recycling methods of active components of lithium battery cathodes. It provides a low eutectic solvent to solve the technical problems of high eutectic viscosity, low leaching rate, and environmentally unfriendly leaching process in existing waste lithium battery cathode material leaching methods.

[0008] To achieve the above objectives, the present invention provides the following solution:

[0009] This invention provides a method for recycling valuable metals from waste ternary lithium battery cathode materials using a eutectic solvent, which is carried out according to the following steps:

[0010] 1. Immerse the waste ternary lithium batteries in a 7% sodium chloride solution and discharge for 24 hours. Disassemble the batteries using a tube cutter and pliers to obtain the positive electrode. Cut the positive electrode into a rectangle of approximately 2 x 4 cm and calcine it in a muffle furnace at 500°C for 5 hours. Finally, peel the positive electrode material off the aluminum foil to obtain powdered positive electrode material.

[0011] 2. The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-to-volume ratio of 1:40 g / mL to 1:100 g / mL and leached at room temperature for 48 hours to determine the content of lithium, nickel, cobalt and manganese in the waste ternary lithium battery cathode material.

[0012] 3. Add betaine hydrochloride and D-glucosamine hydrochloride in a molar ratio of 1:(2-5) and 30wt% (accounting for 30% of the total mass of the eutectic solvent after synthesis) of deionized water to a beaker, and then stir at 70℃ for 30 min to obtain the eutectic solvent.

[0013] Fourth, add the eutectic solvent obtained in step one and the waste ternary lithium-ion battery cathode powder into a beaker, and heat and stir in a water bath for 60 to 120 minutes at a temperature of 60°C to 90°C to complete the leaching of valuable metals from the ternary lithium battery cathode material powder.

[0014] 5. Centrifuge the solution obtained in step 2 to obtain a solution containing valence metals.

[0015] Furthermore, the mass-to-volume ratio of the ternary lithium battery cathode material to the eutectic solvent is 1:40 g / mL to 1:100 g / mL.

[0016] The present invention discloses the following technical effects:

[0017] This invention utilizes a ternary eutectic solvent system composed of betaine hydrochloride, D-glucosamine hydrochloride, and deionized water, which has advantages such as low viscosity and low cost. Using this system to leach ternary lithium battery cathode materials has advantages such as low leaching temperature and high metal leaching rate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the process flow for recovering valuable metals from waste ternary lithium battery cathode materials using a eutectic solvent, as per the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to examples. However, the examples below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims.

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should all be covered within the protection scope of this invention.

[0021] Typical but non-limiting embodiments of the present invention are as follows:

[0022] Example 1

[0023] (1) Determination of metal content in ternary lithium battery cathode material: The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-to-volume ratio of 1:40 g / mL and leached at room temperature (about 25°C) for 48 hours.

[0024] (2) Preparation of eutectic solvent: Betaine hydrochloride and D-glucosamine hydrochloride are mixed in a molar ratio of 1:2, and deionized water with a mass ratio of 30wt% (accounting for 30% of the total mass of the synthesized eutectic solvent) is added. The mixture is stirred at 70°C for 30 minutes by water bath heating to obtain a homogeneous solution, which is the eutectic solvent.

[0025] (3) NCM622 leaching: The waste ternary lithium battery NCM622 cathode material was added to the prepared eutectic solvent. The mass-volume ratio of the added ternary lithium battery cathode material to the eutectic solvent was 1:40 g / mL. The reaction was carried out in a constant temperature water bath at 90℃ for 90 min.

[0026] (4) Centrifuge the solution obtained in the above steps at a speed of 9000 rpm.

[0027] (5) The lithium, nickel, cobalt and manganese content of the solution obtained by centrifugation was detected.

[0028] The leaching experiment results of Example 1 are as follows:

[0029] element Metal concentration leached from aqua regia (mg / L) DES leaching metal concentration Leaching rate Li 2.8825 2.7989 97.1％ Ni 1.6700 1.6349 97.9％ Co 2.7025 2.6647 98.6％ Mn 8.9525 8.7914 98.2％

[0030] The calculated input and output rates for lithium, nickel, cobalt, and manganese were 97.1%, 97.9%, 98.6%, and 98.2%, respectively.

[0031] Example 2

[0032] (1) Determination of metal content in ternary lithium battery cathode material: The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-to-volume ratio of 1:80 g / mL and leached at room temperature (about 25°C) for 48 hours.

[0033] (2) Preparation of eutectic solvent: Betaine hydrochloride and D-glucosamine hydrochloride are mixed in a molar ratio of 1:2, and deionized water with a mass ratio of 30wt% (accounting for 30% of the total mass of the synthesized eutectic solvent) is added. The mixture is stirred at 70°C for 30 minutes by water bath heating to obtain a homogeneous solution, which is the eutectic solvent.

[0034] (3) NCM622 leaching: The waste ternary lithium battery NCM622 cathode material was added to the prepared eutectic solvent. The mass-volume ratio of the added ternary lithium battery cathode material to the eutectic solvent was 1:80 g / mL. The reaction was carried out in a constant temperature water bath at 80℃ for 80 min.

[0035] (4) Centrifuge the solution obtained in the above steps at a speed of 9000 rpm.

[0036] (5) The lithium, nickel, cobalt and manganese content of the solution obtained by centrifugation was detected.

[0037] The leaching experiment results of Example 2 are as follows:

[0038] element Metal concentration leached from aqua regia (mg / L) DES leaching metal concentration Leaching rate Li 1.4413 1.4168 98.3％ Ni 0.8350 0.8329 99.75％ Co 1.3513 1.3513 100.0％ Mn 4.4763 4.4763 100.0％

[0039] The calculated import and export rates for lithium, nickel, cobalt, and manganese were 98.3%, 99.75%, 100.0%, and 100.0%, respectively.

[0040] Example 3

[0041] (1) Determination of metal content in ternary lithium battery cathode material: The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-to-volume ratio of 1:100 g / mL and leached at room temperature (about 25°C) for 48 hours.

[0042] (2) Preparation of eutectic solvent: Betaine hydrochloride and D-glucosamine hydrochloride are mixed in a molar ratio of 1:3, and deionized water with a mass ratio of 30wt% (accounting for 30% of the total mass of the synthesized eutectic solvent) is added. The mixture is stirred at 70°C for 30 minutes by water bath heating to obtain a homogeneous solution, which is the eutectic solvent.

[0043] (3) NCM622 leaching: The waste ternary lithium battery NCM622 cathode material was added to the prepared eutectic solvent. The mass-volume ratio of the added ternary lithium battery cathode material to the eutectic solvent was 1:100 g / mL. The reaction was carried out in a constant temperature water bath at 70℃ for 110 min.

[0044] (4) Centrifuge the solution obtained in the above steps at a speed of 9000 rpm.

[0045] (5) The lithium, nickel, cobalt and manganese content of the solution obtained by centrifugation was detected.

[0046] The leaching experiment results of Example 3 are as follows:

[0047] element Metal concentration leached from aqua regia (mg / L) DES leaching metal concentration Leaching rate Li 1.1530 1.0965 95.1％ Ni 0.6680 0.6399 95.8％ Co 1.0810 1.0475 96.9％ Mn 3.5810 3.4807 97.2％

[0048] The calculated import and export rates for lithium, nickel, cobalt, and manganese were 95.1%, 95.8%, 96.9%, and 97.2%, respectively.

[0049] Example 4

[0050] (1) Determination of metal content in ternary lithium battery cathode material: The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-volume ratio of 1:60 g / mL and leached at room temperature (about 25°C) for 48 hours.

[0051] (2) Preparation of eutectic solvent: Betaine hydrochloride and D-glucosamine hydrochloride are mixed in a molar ratio of 1:2, and deionized water with a mass ratio of 30wt% (accounting for 30% of the total mass of the synthesized eutectic solvent) is added. The mixture is stirred at 70°C for 30 minutes by water bath heating to obtain a homogeneous solution, which is the eutectic solvent.

[0052] (3) NCM622 leaching: The waste ternary lithium battery NCM622 cathode material was added to the prepared eutectic solvent. The mass-volume ratio of the added ternary lithium battery cathode material to the eutectic solvent was 1:60 g / mL. The reaction was carried out in a constant temperature water bath at 60℃ for 120 min.

[0053] (4) Centrifuge the solution obtained in the above steps at a speed of 9000 rpm.

[0054] (5) The lithium, nickel, cobalt and manganese content of the solution obtained by centrifugation was detected.

[0055] The leaching experiment results of Example 4 are as follows:

[0056] element Metal concentration leached from aqua regia (mg / L) DES leaching metal concentration Leaching rate Li 1.9217 1.7987 93.6％ Ni 1.1133 1.0276 92.3％ Co 1.8017 1.7206 95.5％ Mn 5.9683 5.7176 95.8％

[0057] The calculated input and output rates for lithium, nickel, cobalt, and manganese were 93.6%, 92.3%, 95.5%, and 95.8%, respectively.

[0058] Example 5

[0059] (1) Determination of metal content in ternary lithium battery cathode material: The stripped waste ternary lithium battery cathode material and aqua regia were added to a plastic bottle at a mass-to-volume ratio of 1:80 g / mL and leached at room temperature (about 25°C) for 48 hours.

[0060] (2) Preparation of eutectic solvent: Betaine hydrochloride and D-glucosamine hydrochloride are mixed in a molar ratio of 1:5, and deionized water with a mass ratio of 30wt% (accounting for 30% of the total mass of the synthesized eutectic solvent) is added. The mixture is stirred at 70°C for 30 minutes by water bath heating to obtain a homogeneous solution, which is the eutectic solvent.

[0061] (3) NCM622 leaching: The waste ternary lithium battery NCM622 cathode material was added to the prepared eutectic solvent. The mass-volume ratio of the added ternary lithium battery cathode material to the eutectic solvent was 1:100 g / mL. The reaction was carried out in a constant temperature water bath at 90℃ for 60 min.

[0062] (4) Centrifuge the solution obtained in the above steps at a speed of 9000 rpm.

[0063] (5) The lithium, nickel, cobalt and manganese content of the solution obtained by centrifugation was detected.

[0064] The leaching experiment results of Example 5 are as follows:

[0065] element Metal concentration leached from aqua regia (mg / L) DES leaching metal concentration Leaching rate Li 1.1530 1.0504 91.1％ Ni 0.6680 0.6092 91.2％ Co 1.0810 1.0129 93.7％ Mn 3.5810 3.3482 93.5％

[0066] The calculated input and output rates for lithium, nickel, cobalt, and manganese were 91.1%, 91.2%, 93.7%, and 93.5%, respectively.

[0067] This invention utilizes betaine hydrochloride, D-glucosamine hydrochloride, and deionized water to prepare a stable eutectic system that is miscible. This system can efficiently leach lithium, nickel, cobalt, and manganese from waste ternary lithium batteries NCM622. It features simple process, easy operation, high leaching rate, and environmental friendliness.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the principles of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for selectively leaching valuable metals from waste ternary lithium battery cathode materials using amino sugars in a eutectic process, characterized in that... The steps are as follows: Step 1: The amino sugar eutectic solvent was prepared by mixing betaine hydrochloride and D-glucosamine hydrochloride in a molar ratio of 1:(2~5) and deionized water accounting for 30% of the total mass of the synthesized amino sugar eutectic solvent, and stirring at 70°C for 30 min. Step 2: Mix the waste ternary lithium battery cathode material with the amino sugar eutectic solvent and leach at a constant temperature; the mass-to-volume ratio of the waste ternary lithium battery cathode material to the amino sugar eutectic solvent is 1:40~1:100 g / mL; the constant temperature stirring leaching temperature in Step 2 is 60~90℃, and the time is 60~120min. Step 3: Centrifuge the solution obtained in Step 2 to obtain a solution containing valence metals.

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