Method for leaching valuable metal from waste ternary lithium ion battery positive electrode material NCM111

Abstract

The invention relates to a method for leaching valuable metals from a waste ternary lithium ion battery positive electrode material NCM111, and belongs to the technical field of recycling of waste lithium batteries. The preparation method comprises the following steps: adding L-ornithine hydrochloride and ascorbic acid into deionized water, and stirring and reacting at the temperature of 40-70 DEG C to generate a colorless and transparent deep eutectic solvent; the method comprises the following steps: adding the waste ternary lithium ion battery positive electrode material into a deep eutectic solvent, and stirring and leaching for 2-8 minutes at the temperature of 40-70 DEG C to obtain a valuable metal leaching solution; the deep eutectic solvent is used for leaching lithium, manganese, cobalt and nickel from the waste ternary lithium ion battery positive electrode material, leaching is only carried out for 4 min at the leaching temperature of 60 DEG C, and the leaching rate can reach 98% or above.

Description

Technical Field

[0001] The invention relates to a method for leaching valuable metals from NCM111, a positive electrode material of a waste ternary lithium-ion battery, and belongs to the technical field of recycling waste lithium batteries. Background Art

[0002] Lithium-ion batteries are widely used due to their excellent electrochemical properties. With the growing global demand for electric vehicles and portable electronic devices, the production of lithium-ion batteries has increased significantly, and the corresponding treatment and recycling of waste lithium-ion batteries has become increasingly prominent. Waste lithium-ion batteries contain a large amount of valuable metals, such as lithium, manganese, cobalt, and nickel. Recycling valuable metals in lithium-ion batteries is crucial to solving the shortage of metal resources and reducing the manufacturing cost of lithium-ion batteries. At the same time, if they are not handled properly, they will cause serious pollution to the environment.

[0003] At present, the commonly used methods for recycling waste lithium-ion batteries are pyrometallurgy, hydrometallurgy or a combination of the two. Among them, pyrometallurgy requires relatively simple equipment and operations and a short process flow, but it has high energy consumption, serious environmental pollution, and poor metal recovery rate and purity. In contrast, hydrometallurgy has low energy consumption, low cost, environmental friendliness and high metal recovery rate. However, the processing cost and technical requirements of the hydrometallurgical process are high, the process flow is long, and the use of strong acids and alkalis will cause corrosion to the equipment, and a large amount of waste liquid will be generated, causing secondary pollution. Therefore, the development of an environmentally friendly, efficient and economical leaching process is the key to recovering valuable metals from waste ternary lithium-ion batteries. Summary of the invention

[0004] In view of the technical problems of low leaching efficiency and harsh leaching conditions in leaching valuable metals from lithium-ion battery positive electrode materials, the present invention proposes a method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111. In the present invention, L-ornithine hydrochloride and ascorbic acid are synthesized into a deep eutectic solvent by a hydrothermal method. The deep eutectic solvent is used to leach valuable metals such as lithium, manganese, cobalt and nickel from the waste ternary lithium-ion battery positive electrode material. At a leaching temperature of 60°C, the leaching time is only 4 minutes, and the leaching rate can be as high as 98% or more.

[0005] A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111, the specific steps are as follows:

[0006] (1) adding L-ornithine hydrochloride and ascorbic acid into deionized water, stirring and reacting at a temperature of 40 to 70° C. to generate a colorless and transparent deep eutectic solvent;

[0007] (2) Add the waste ternary lithium-ion battery positive electrode material into a deep eutectic solvent, stir and leach for 2 to 8 minutes at a temperature of 40 to 70°C to obtain a valuable metal leachate.

[0008] Preferably, the molar ratio of L-ornithine hydrochloride to ascorbic acid in step (1) is 2:1 to 1:3.

[0009] Preferably, the water content of the deep eutectic solvent in step (1) is 35 to 50 wt.%.

[0010] Preferably, in step (2), the solid-to-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:20 to 50.

[0011] Preferably, the stirring rate in step (2) is 500-800 r / min.

[0012] The present invention uses a deep eutectic solvent to leach valuable metals lithium, manganese, cobalt and nickel from waste ternary lithium-ion battery positive electrode material NCM111:

[0013] The acidic proton hydrogen ions ionized from ascorbic acid in the deep eutectic solvent react with oxygen atoms in the metal oxide to generate water molecules, destroying the layered structure of the positive electrode material of the lithium-ion battery and releasing metal ions; redox reactions occur during the leaching process, converting the high-valent Ni released in the first step to 3+ 、Co 3+ , Mn 4+ Metal ions are reduced to low-valent Ni 2+ 、Co 2 + , Mn 2+ ; The reduced low-valent metal ions form metal chlorate complexes with the chloride ions in L-ornithine hydrochloride. Next, the water generated in the reaction hydrolyzes with part of the chlorine complex to form a hydrated metal ion complex, and finally, the chlorinated metal ion complex and the hydrated metal ion complex reach coordination equilibrium; after leaching is completed, ascorbic acid is oxidized to dehydroascorbic acid, while L-ornithine hydrochloride only serves as a leaching ligand and does not directly participate in the chemical reaction.

[0014] The calculation formula for the leaching rate of valuable metals from the cathode material of waste ternary lithium-ion batteries is:

[0015] η=CV / ωm×100%

[0016] Wherein, C (mg / L): leachate concentration, V (L): leachate volume, ω (%): percentage of each element in the positive electrode material, m (mg): mass of the positive electrode material.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention utilizes a deep eutectic solvent to leach valuable metals such as lithium, manganese, cobalt, and nickel from waste ternary lithium-ion battery cathode materials. Compared with traditional pyrometallurgy and hydrometallurgy, the solvent used in the deep eutectic solvent is organic, which is more biodegradable and reduces environmental pollution.

[0019] (2) The deep eutectic solvent synthesized by the hydrothermal method using ascorbic acid as a hydrogen bond acceptor and L-ornithine hydrochloride as a hydrogen bond donor can achieve high-efficiency extraction of valuable metals in a short time. At a leaching temperature of 60° C., the leaching time is only 4 min, and the leaching rate can be as high as 98% or more, greatly improving the efficiency of the valuable metal recovery process;

[0020] (3) The deep eutectic solvent of the present invention has a low synthesis cost, which helps to reduce the recovery cost. In addition, the use and recovery process are simple and easy to operate, which is conducive to industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the leaching efficiency of L-ornithine hydrochloride and ascorbic acid at different molar ratios in the deep eutectic solvent of Example 1;

[0022] Figure 2 This is a schematic diagram of the leaching efficiency of the deep eutectic solvent at different leaching temperatures of Example 2;

[0023] Figure 3 This is a schematic diagram of the leaching efficiency of the deep eutectic solvent at different leaching times in Example 3;

[0024] Figure 4 This is a schematic diagram of the leaching efficiency of the deep eutectic solvent and the waste ternary lithium-ion battery positive electrode material at different solid-liquid ratios in Example 4;

[0025] Figure 5 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents.

[0027] Example 1: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0028] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 40° C. to generate a colorless and transparent deep eutectic solvent; the molar ratios of L-ornithine hydrochloride and ascorbic acid are 2:1, 1:1, 1:2, and 1:3, respectively; and the water content of the deep eutectic solvent is 40 wt.%;

[0029] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent of different molar ratios of L-ornithine hydrochloride and ascorbic acid, stirring and leaching for 2 minutes at a temperature of 40° C. and a stirring rate of 800 r / min to obtain a valuable metal leachate; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:50;

[0030] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer, and the leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals (see Figure 1 ),from Figure 1 It can be seen that when the molar ratio of L-ornithine hydrochloride to ascorbic acid is 2:1, the leaching rate of lithium is 71%, the leaching rate of manganese is 69.95%, the leaching rate of cobalt is 68.17%, and the leaching rate of nickel is 66.84%; when the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:1, the leaching rate of lithium is 79.33%, the leaching rate of manganese is 77.86%, the leaching rate of cobalt is 76.01%, and the leaching rate of nickel is 75.48%; when the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2, the leaching rate of lithium is 87.09%, the leaching rate of manganese is 86 %, the leaching rate of cobalt is 84.66%, and the leaching rate of nickel is 83.21%; when the molar ratio of L-ornithine hydrochloride and ascorbic acid is 1:3, the leaching rate of lithium is 86.35%, the leaching rate of manganese is 85.88%, the leaching rate of cobalt is 85.02%, and the leaching rate of nickel is 81.9%; it can be seen that when the molar ratio of L-ornithine hydrochloride and ascorbic acid is 1:2, the leaching rates of lithium, manganese, cobalt and nickel are the highest, which shows that the number of hydrogen ions provided by ascorbic acid has a greater influence on the leaching efficiency, and too little or too much hydrogen ions cannot make the leaching efficiency reach the best.

[0031] Example 2: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0032] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 50° C. to generate a colorless and transparent deep eutectic solvent; the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2; and the water content of the deep eutectic solvent is 40 wt.%;

[0033] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent with different molar ratios of L-ornithine hydrochloride and ascorbic acid, respectively, stirring and leaching for 4 min at temperatures of 40° C., 50° C., 60° C. and 70° C. and a stirring rate of 700 r / min to obtain a valuable metal leachate; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:40;

[0034] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer, and the leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals (see Figure 2 ),from Figure 2 It can be seen that the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2. When the leaching temperature is 40°C, the leaching rates of lithium, manganese, cobalt and nickel are 73.82%, 71.64%, 70.82% and 68.36% respectively; when the leaching temperature is 50°C, the leaching rates of lithium, manganese, cobalt and nickel are 80.32%, 78.84%, 76.15% and 74.95% respectively; when the leaching temperature is 60°C, the leaching rates of lithium, manganese and cobalt are 89.21%, 88.73% and 73.8% respectively. %, the leaching rate of cobalt was 87.88%, and the leaching rate of nickel was 85.8%; when the leaching temperature was 70°C, the leaching rates of lithium, manganese, cobalt, and nickel were 86.97%, 81%, 81.64%, and 76.91%; it can be seen that when the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2 and the leaching temperature is 60°C, the leaching rates of lithium, manganese, cobalt, and nickel are the highest, indicating that higher temperatures promote the leaching reaction by increasing the kinetic energy of molecules, resulting in more frequent and more energetic collisions, thereby accelerating the leaching process.

[0035] Example 3: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0036] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 60° C. to generate a colorless and transparent deep eutectic solvent; the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2; and the water content of the deep eutectic solvent is 40 wt.%;

[0037] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent with different molar ratios of L-ornithine hydrochloride and ascorbic acid, respectively, stirring and leaching for 2 min, 4 min, 6 min, and 8 min at a temperature of 60° C. and a stirring rate of 600 r / min to obtain a valuable metal leaching solution; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:30;

[0038] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer, and the leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals (see Figure 3 ),from Figure 3It can be seen that the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2. When the leaching time is 2 minutes, the leaching rates of lithium, manganese, cobalt and nickel are 79%, 77.93%, 77.21% and 75.98% respectively; when the leaching time is 4 minutes, the leaching rates of lithium, manganese, cobalt and nickel are 86.78%, 85.91%, 83.2% and 83.94% respectively; when the leaching time is 6 minutes, the leaching rates of lithium, manganese and cobalt are 96.31%, 94% and 96.97% respectively. When the leaching time was 8 min, the leaching rates of lithium, manganese, cobalt and nickel were 96.47%, 94.96%, 92.99% and 93.46% respectively. It can be seen that when the molar ratio of L-ornithine hydrochloride and ascorbic acid was 1:2 and the leaching time was 6 min, the leaching rates of lithium, manganese, cobalt and nickel were the highest, which illustrates the effectiveness of leaching at different reaction durations. The initial reaction showed a higher rate, which then decreased with the passage of time.

[0039] Example 4: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0040] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 80° C. to generate a colorless and transparent deep eutectic solvent; the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:2; and the water content of the deep eutectic solvent is 40 wt.%;

[0041] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent of different molar ratios of L-ornithine hydrochloride and ascorbic acid, stirring and leaching for 6 min at a temperature of 60° C. and a stirring rate of 600 r / min to obtain a valuable metal leachate; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:20, 1:30, 1:40, and 1:50, respectively;

[0042] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer, and the leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals (see Figure 4 ),from Figure 4It can be seen that when the molar ratio of L-ornithine hydrochloride and ascorbic acid is 1:2, and the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:20, the leaching rate of lithium is 95.33%, the leaching rate of manganese is 96.21%, the leaching rate of cobalt is 93.99%, and the leaching rate of nickel is 95.97%; when the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:30, the leaching rate of lithium is 99.29%, the leaching rate of manganese is 99.72%, the leaching rate of cobalt is 98.79%, and the leaching rate of nickel is 98.32%; when the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:40, the leaching rate of lithium is 94.27%, the leaching rate of manganese is 96.21%, the leaching rate of cobalt is 93.99%, and the leaching rate of nickel is 95.97%. The leaching rate was 94%, the leaching rate of cobalt was 93.01%, and the leaching rate of nickel was 92.99%; when the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent was 1:50, the leaching rate of lithium was 90.17%, the leaching rate of manganese was 88.75%, the leaching rate of cobalt was 87.01%, and the leaching rate of nickel was 87.21%; it can be seen that when the molar ratio of L-ornithine hydrochloride and ascorbic acid was 1:2 and the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent was 1:30, the leaching rates of lithium, manganese, cobalt and nickel were the highest, indicating that during the leaching process, the protons derived from ascorbic acid were consumed, resulting in limited leaching capacity of NCM (111) in a certain amount of deep eutectic solvent.

[0043] Example 5: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0044] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 50° C. to generate a colorless and transparent deep eutectic solvent; the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:1; and the water content of the deep eutectic solvent is 45 wt.%;

[0045] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent of different molar ratios of L-ornithine hydrochloride and ascorbic acid, stirring and leaching for 4 minutes at a temperature of 50° C. and a stirring rate of 700 r / min to obtain a valuable metal leachate; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:40;

[0046] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer. The leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals. The leaching rate of lithium was 78.33%, the leaching rate of manganese was 76.94%, the leaching rate of cobalt was 75.22%, and the leaching rate of nickel was 74%.

[0047] Example 6: A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 (see Figure 5 ), the specific steps are as follows:

[0048] (1) adding L-ornithine hydrochloride and ascorbic acid to deionized water, stirring and reacting at a temperature of 80° C. to generate a colorless and transparent deep eutectic solvent; the molar ratio of L-ornithine hydrochloride to ascorbic acid is 1:3; and the water content of the deep eutectic solvent is 35 wt.%;

[0049] (2) adding the waste ternary lithium-ion battery positive electrode material to a deep eutectic solvent of different molar ratios of L-ornithine hydrochloride and ascorbic acid, stirring and leaching for 8 minutes at a temperature of 70° C. and a stirring rate of 500 r / min to obtain a valuable metal leachate; the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:20;

[0050] The concentrations of lithium, manganese, cobalt and nickel in the leachate were determined using an inductively coupled plasma emission spectrometer. The leaching rates of lithium, manganese, cobalt and nickel were calculated using the leaching rate calculation formula for valuable metals. The leaching rate of lithium was 81.34%, the leaching rate of manganese was 80.01%, the leaching rate of cobalt was 78.93%, and the leaching rate of nickel was 76.74%.

[0051] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111, characterized in that: The specific steps are as follows: (1) adding L-ornithine hydrochloride and ascorbic acid into deionized water, stirring and reacting at a temperature of 40 to 70° C. to generate a colorless and transparent deep eutectic solvent; (2) Add the waste ternary lithium-ion battery positive electrode material into a deep eutectic solvent, stir and leach for 2 to 8 minutes at a temperature of 40 to 70°C to obtain a valuable metal leachate.

2. The method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 according to claim 1, characterized in that: In step (1), the molar ratio of L-ornithine hydrochloride to ascorbic acid is 2:1 to 1:

3.

3. The method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 according to claim 1, characterized in that: The water content of the deep eutectic solvent in step (1) is 35 to 50 wt.%.

4. The method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 according to claim 1, characterized in that: In step (2), the solid-liquid ratio g:L of the waste ternary lithium-ion battery positive electrode material and the deep eutectic solvent is 1:20 to 50.

5. The method for leaching valuable metals from waste ternary lithium-ion battery positive electrode material NCM111 according to claim 1, characterized in that: The stirring rate of step (2) is 500-800 r / min.

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