Method for efficiently recycling ternary nickel-cobalt-manganese battery positive electrode material

Abstract

The invention belongs to the technical field of lithium batteries, and relates to a method for efficiently recovering a ternary nickel-cobalt-manganese battery positive electrode material, which comprises the following steps: introducing a reducing gas into slurry formed by an NCM positive electrode material and water, and after the leaching reaction is completed, carrying out solid-liquid separation to obtain a leaching solution. According to the method, the leaching rates of lithium, nickel, cobalt and manganese in the leaching solution all reach 87% or above, efficient leaching of valuable metal elements (nickel, cobalt, manganese and lithium) is achieved by introducing the reducing gas into the slurry of the NCM positive electrode material and water for reaction, and compared with traditional acid and reducing agent leaching, the reducing gas is used for leaching under the mild condition, energy consumption is reduced, and the method is suitable for industrial production. Subsequent waste liquid treatment is simplified, and the overall economical efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium batteries, and relates to a method for efficiently recycling positive electrode material of a ternary nickel-cobalt-manganese battery. BACKGROUND

[0002] With the wide application of lithium ion batteries in portable electronic devices, electric vehicles and large-scale energy storage systems, the recycling problem of waste lithium ion batteries has become increasingly prominent and has become an important issue to be solved. Among them, ternary nickel-cobalt-manganese (NCM) material, as one of the mainstream positive electrode materials of lithium ion batteries, is favored due to its excellent characteristics such as high energy density and long cycle life. However, this material system also brings unprecedented challenges to recycling work. On the one hand, the battery positive electrode material is rich in a large amount of noble metal elements such as nickel, cobalt and manganese. These metals not only have a very high value in the economic field, but also occupy a crucial position in the strategic resource reserves of the country. On the other hand, if the waste lithium ion battery is not properly recycled, it will pose a serious pollution threat to the environment. Once the heavy metal elements and harmful substances in the battery leak into the soil, water and other natural environments, they may cause a series of environmental problems such as soil pollution and water pollution, and thus endanger the ecological balance and human health. Therefore, the recycling of metals such as nickel, cobalt and manganese in waste ternary lithium ion battery positive electrode material not only helps to reduce the exploitation of new resources, but also reduces environmental pollution.

[0003] In the treatment of spent ternary lithium-ion battery cathode material by traditional hydrometallurgical process, sulfuric acid and reducing agent (hydrogen peroxide) are mainly used as leaching reagents. In actual operation, the amount of sulfuric acid used is often very large, which not only increases the production cost, but also a large amount of sulfuric acid needs to be treated after use. If not properly treated, it is easy to cause environmental pollution. At the same time, hydrogen peroxide has serious instability problem in the leaching process, it is easy to decompose into water and oxygen. This decomposition phenomenon leads to low effective utilization rate in the leaching reaction. In order to achieve the expected leaching effect, it is necessary to use excessive hydrogen peroxide. This not only further increases the production cost, but also may cause other environmental problems due to the excessive residue of hydrogen peroxide. For example, the method disclosed in Chinese patent CN116970811A discloses a synchronous recovery process of lithium, manganese, nickel and cobalt in spent ternary lithium battery cathode material. By screening special composition of roasting reagent, synchronous and high efficiency recovery of lithium, manganese, nickel and cobalt is realized under the condition of low temperature roasting (≤450℃). Although this process reduces the production energy consumption to some extent, and the leaching rate of lithium, manganese, nickel and cobalt is as high as 95wt% and above, but from the overall process, there are still many problems. The whole process involves complex reagent screening, precise temperature control and multi-step operation process, which undoubtedly consumes a lot of energy to maintain the reaction conditions and drive each process link. In addition, the complex process also means higher equipment investment and operation and maintenance cost, as well as higher requirement for the technical level of the operator. For example, the method disclosed in Chinese patent CN115764036A includes the following steps: (1) dynamic reduction roasting pretreatment: the black powder material recovered from the spent nickel-cobalt-manganese ternary lithium battery is placed in a dynamic roasting furnace in a protective atmosphere; (2) two-stage countercurrent water leaching to extract lithium: after mixing the reduced roasting material with pure water at a liquid-solid mass ratio of 6:8, the mixed slurry is reacted under the conditions of temperature 40-60℃ and reaction time 30-45 minutes; (3) combined two-stage countercurrent leaching of atmospheric leaching and high-pressure acid leaching. That is, by combining roasting pretreatment, two-stage countercurrent water leaching to extract lithium and high-pressure acid leaching, the leaching rate of nickel, cobalt and manganese is improved, but the operation is complex and the production cost is high.

[0004] In summary, the traditional hydrometallurgical process in the treatment of spent ternary lithium-ion battery cathode material has a series of problems such as complex process, large consumption of chemical reagents, serious environmental pollution, etc. These problems seriously restrict the sustainable development of the spent lithium-ion battery recycling industry, and it is urgent to develop a more environmentally friendly and efficient leaching method to break through the current difficulties and achieve the green and sustainable development goal of spent lithium-ion battery recycling. SUMMARY

[0005] The present application aims at the deficiencies in the prior art and provides a method for efficiently recycling ternary nickel-cobalt-manganese battery positive electrode materials, which realizes efficient and green leaching of valuable metal elements (nickel, cobalt, manganese and lithium) by introducing a reducing gas into a mixture of battery positive electrode materials and water.

[0006] The object of the present application is achieved by the following technical solutions.

[0007] The method for efficiently recycling ternary nickel-cobalt-manganese battery positive electrode materials comprises the following steps.

[0008] S1, introducing a reducing gas into a slurry formed by the NCM positive electrode material and water, and after the leaching reaction is completed, performing solid-liquid separation to obtain a leaching solution.

[0009] Preferably, the reducing gas is one or more of H2S, SO2 and SO3.

[0010] Preferably, the reducing gas is introduced into the slurry at a rate of 0.1-10 L / min.

[0011] Preferably, the aeration time is 10 min-6 h.

[0012] Preferably, the slurry temperature during aeration is 5-90℃.

[0013] Preferably, the pH value of the slurry is controlled at 0-7.0 during aeration.

[0014] Preferably, the reducing gas is introduced into the slurry through a gas disperser with a pore size of 5-500 microns.

[0015] Preferably, the NCM positive electrode material and water are mixed to form a slurry at a mass ratio of 1:2-1:100.

[0016] Preferably, the NCM positive electrode material is first crushed to a fine powder with a particle size of ≤100 microns before being mixed with water to form a slurry.

[0017] Preferably, the water is deionized water.

[0018] Preferably, the leaching reaction of step S1 makes the leaching rate of lithium, nickel, cobalt and manganese all reach 87% or above. Further, the leaching reaction of step S1 makes the leaching rate of lithium, nickel, cobalt and manganese all reach 90% or above. More preferably, the leaching reaction of step S1 makes the leaching rate of lithium, nickel, cobalt and manganese all reach 99% or above.

[0019] The method for efficiently recycling ternary nickel-cobalt-manganese battery positive electrode materials of the present application further comprises the following steps:

[0020] S2, adjusting the pH of the leaching solution of step S1, and then obtaining nickel-cobalt-manganese element precipitates and lithium-containing filtrate through solid-liquid separation.

[0021] S3, cooling the lithium-containing filtrate to ≤0℃ to precipitate impurity crystals, and obtaining a filtrate by solid-liquid separation, and obtaining a lithium salt by evaporation crystallization.

[0022] Preferably, the pH of the leaching solution is adjusted to 7-12.

[0023] Preferably, during the adjustment of the pH of the leaching solution, a complexing agent is added, and nickel, cobalt and manganese are co-precipitated under stirring for 1-40 h at 30-70℃ in an inert atmosphere.

[0024] Preferably, the complexing agent is ammonia and / or sodium carbonate.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] 1. In the present application, a reducing gas is introduced into the slurry formed by the NCM positive electrode material and water, the reducing gas is dissolved in water, and the high-valence metal elements in the NCM are reduced to low-valence state, and the low-valence nickel-cobalt-manganese-lithium salt can form a soluble complex, thereby realizing the dissolution of metal ions and effectively improving the leaching efficiency of metal elements. Under the optimal conditions, the leaching rates of nickel, cobalt, manganese and lithium can all reach more than 99%.

[0027] 2. The use of reducing gas instead of the original scheme of sulfuric acid and hydrogen peroxide solves the problem of large amount of acid required in the original scheme, reduces the amount of acid used, reduces the production cost, and also simplifies the subsequent waste liquid treatment process and reduces the pollution risk to the environment.

[0028] 3. The present application can carry out metal element leaching at normal temperature and pressure, greatly reducing the energy consumption, without the need for high-temperature and high-pressure equipment, reducing the equipment investment and operation difficulty, and reducing the safety risk caused by high temperature and high pressure.

[0029] 4. The leaching reaction of the present application can be carried out at room temperature or at high temperature; increasing the temperature helps the dissociation and equilibrium movement of the gas in water, thereby accelerating the leaching reaction; at the same time, the viscosity of the reaction solution is reduced at high temperature, which is further conducive to the diffusion and mass transfer of the reactants.

[0030] 5. The present application can precipitate impurity crystals by cooling the lithium-containing filtrate to ≤0℃, which can effectively remove impurities and improve the purity of lithium salt, and high-content lithium salt can be obtained by evaporation crystallization, providing high-quality products for the recycling of lithium resources. DETAILED DESCRIPTION

[0031] In the following, the embodiments of the method for efficiently recycling ternary nickel-cobalt-manganese positive electrode material of the present application will be described in detail, however, these embodiments are exemplary, and the disclosure of the present application is not limited thereto.

[0032] The application provides a method for efficiently recycling a ternary nickel-cobalt-manganese battery positive electrode material.

[0033] S1, a reducing gas is introduced into a slurry formed by the NCM positive electrode material and water, after the leaching reaction is completed, solid-liquid separation is performed, and a leaching solution is obtained.

[0034] The reducing gas refers to a gas that can provide electrons and cause other substances to undergo a reduction reaction in a chemical reaction. As preferred, the reducing gas is one or more of H2S, SO2 and SO3. Further preferably, the reducing gas is SO2, and when the reducing gas is SO2, the metal leaching effect is better.

[0035] The reducing gas can be obtained by direct or indirect means, for example, heating, heating sulfuric acid to obtain SO3 gas.

[0036] Preferably, the reducing gas is introduced into the slurry at a rate of 0.1-10 L / min; further preferably, the aeration rate is 0.5-5 L / min; and still further preferably, the aeration rate is 1-3 L / min.

[0037] Preferably, the aeration time is 10 min-6 h; further preferably, the aeration time is 0.5-3 h.

[0038] Preferably, the slurry temperature during aeration is 5-90℃; further preferably, the slurry temperature during aeration is 10-80℃. The leaching reaction of step S1 can be carried out at room temperature, greatly reducing energy consumption.

[0039] Preferably, during the aeration process, the pH value of the slurry is controlled at 0-7.0.

[0040] The NCM positive electrode material and water are preferably formed into a slurry at a mass ratio of 1:2-1:100, and further preferably, the NCM positive electrode material and water are formed into a slurry at a mass ratio of 1:5-1:50.

[0041] The NCM positive electrode material is disassembled and collected from a waste lithium ion battery. Preferably, the NCM positive electrode material is first crushed before being mixed with water to form a slurry. The crushing is preferably carried out in a ball mill. Preferably, the crushing is to a fine powder with a particle size of ≤100 microns to increase the surface area of the leaching reaction.

[0042] Preferably, the water is deionized water to avoid interference from other ions.

[0043] The leaching reaction of step S1 is preferably carried out in a container made of corrosion-resistant glass or polytetrafluoroethylene material, and the volume of the container is selected according to the processing scale.

[0044] Preferably, the reducing gas is uniformly introduced into the slurry through a gas disperser with a pore size of 5-500 microns to ensure uniform dispersion of the gas in the slurry.

[0045] The gas disperser is located on the aeration pipe, and the aeration pipe is made of corrosion-resistant material (such as polytetrafluoroethylene or stainless steel).

[0046] After the leaching reaction is completed, a solid-liquid separation method is used to obtain a leaching solution and a solid residue; the solid-liquid separation method in this paper can be filtration, centrifugation, etc. The solid-liquid separation separates the leaching solution from the solid residue, and the solid residue can be further treated or disposed after washing. The leaching solution includes metal ions such as nickel ions, cobalt ions, manganese ions, and lithium ions.

[0047] The leaching rate (E) of the metal can be calculated according to the following formula:

[0048] E(%)=1-(m0×W0) / (m1×W1)×100%

[0049] In the formula: E(%) is the leaching rate of the metal, m0 is the mass of the leaching residue, W0 is the mass fraction of the metal in the leaching residue, m1 is the mass of the NCM positive electrode material, and W1 is the mass fraction of the metal in the NCM positive electrode material.

[0050] The leaching reaction of step S1 of the present application can achieve a leaching rate of 87% or more for lithium, nickel, cobalt, and manganese. Further, the leaching rate of lithium, nickel, cobalt, and manganese can be 90% or more. More preferably, the leaching rate of lithium, nickel, cobalt, and manganese can be 99% or more.

[0051] The method for efficiently recycling ternary nickel-cobalt-manganese battery positive electrode material provided by the present application further comprises the following steps:

[0052] S2, adjusting the pH of the leaching solution of step S1, and then obtaining nickel-cobalt-manganese element precipitate and lithium-containing filtrate through solid-liquid separation;

[0053] S3, cooling the lithium-containing filtrate to ≤0℃ to precipitate impurity crystals, and obtaining lithium salt by evaporation crystallization of the filtrate obtained after solid-liquid separation.

[0054] The step S2 is described in detail as follows:

[0055] Preferably, the pH of the leaching solution is adjusted to 7-12 by adding an alkali solution, and the pH is further adjusted to 8-12.

[0056] The alkali solution can be one or more of NaOH aqueous solution, KOH aqueous solution, and ammonia water, and the concentration of the alkali solution can be 0.05-5 mol / L.

[0057] Preferably, in the process of adjusting the pH of the leaching solution, a complexing agent is added, and the nickel, cobalt and manganese are co-precipitated by stirring for 1-40 hours at 30-70°C in an inert atmosphere.

[0058] The complexing agent can be listed as ammonia, sodium carbonate, etc. The inert atmosphere is nitrogen, argon, etc.

[0059] The molar ratio of the complexing agent to the metal sulfate (metal elements are dissolved in the leaching solution in the form of metal sulfate) is 0.1-5.

[0060] The step S3 is described in detail as follows:

[0061] The lithium-containing filtrate is cooled to ≤0°C to precipitate impurity crystals, and preferably, the lithium-containing filtrate is cooled to -20 to -2°C to precipitate impurity crystals. Further, the lithium-containing filtrate is cooled at a temperature of -15 to -2°C for 2-60 minutes to precipitate impurity crystals.

[0062] After solid-liquid separation, the impurity crystals are removed, and the obtained filtrate is further subjected to evaporation to remove liquid, and the obtained crystals are the lithium salt.

[0063] The technical solutions of the present application are further described and explained below through specific examples, and it should be understood that the specific examples described herein are only used to help understand the present application and are not used to specifically limit the present application. If not specifically stated, the raw materials used in the examples of the present application are all commonly used raw materials in the art, and the methods used in the examples are all conventional methods in the art.

[0064] The NCM positive electrode material (LiMn 0.5 Ni 0.2 Co 0.3 O2) is disassembled and collected from waste lithium-ion batteries, the NCM positive electrode material is crushed to a fine powder with a particle size of less than 100 microns using a ball mill, and the following experiments are performed.

[0065] A vent pipe with a gas disperser is used as a gas inlet device, the pore size of the gas disperser is about 80 microns, and the vent pipe is made of polytetrafluoroethylene.

[0066] Waste gas treatment: the incompletely reacted gas in the leaching process is treated by a tail gas absorption device, the absorption liquid can be an alkaline solution (such as sodium hydroxide solution), and the absorbed solution can be further concentrated or recovered as a byproduct.

[0067] Waste liquid treatment: after neutralization and oxidation treatment, the waste water meeting the discharge standard can be directly discharged, and the concentrated residue can be recovered.

[0068] Example 1

[0069] The method for recycling the ternary nickel-cobalt-manganese battery positive electrode material of the embodiment comprises the following steps:

[0070] S1, the NCM positive electrode material powder and deionized water are placed in a polytetrafluoroethylene reaction container at a mass ratio of 1:12, a stirring system is started (the stirring speed is 300 rpm, and the stirring speed is kept during the whole leaching reaction), so that the slurry is uniformly dispersed; sulfur dioxide gas is passed into the slurry at a flow rate of 2 L / min, the aeration time is 1 hour, the slurry temperature is 30℃ during aeration, and the pH value of the slurry is controlled to be 0-7.0 during the aeration process; after the leaching reaction is completed, the leaching liquid and solid residues are obtained by vacuum filtration.

[0071] The leaching rates of lithium, nickel, cobalt and manganese in the leaching liquid of step S1 are 94.1%, 93.5%, 93.9% and 94.2% respectively after calculation.

[0072] Example 2

[0073] The method for recycling the ternary nickel-cobalt-manganese battery positive electrode material of the embodiment comprises the following steps:

[0074] S1, the NCM positive electrode material powder and deionized water are placed in a polytetrafluoroethylene reaction container at a mass ratio of 1:12, a stirring system is started (the stirring speed is 300 rpm, and the stirring speed is kept during the whole leaching reaction), so that the slurry is uniformly dispersed; sulfur dioxide gas is passed into the slurry at a flow rate of 2 L / min, the aeration time is 1 hour, the slurry temperature is 30℃ during aeration, and the pH value of the slurry is controlled to be 0-7.0 during the aeration process; after the leaching reaction is completed, the leaching liquid and solid residues are obtained by vacuum filtration.

[0075] S2, 1 mol / L NaOH aqueous solution is added to adjust the pH of the leaching liquid to 10, and 2 mol / L ammonia water (the molar ratio of ammonia water to metal sulfate is 1) is added, and the stirring reaction is carried out at 40℃ under argon atmosphere for 90 min, and the nickel-cobalt-manganese element precipitate and lithium-containing filtrate are obtained by vacuum filtration;

[0076] S3, the lithium-containing filtrate is cooled to-5℃ to precipitate sodium impurities, the sodium impurities are removed by vacuum filtration, and the obtained filtrate is further evaporated and crystallized to obtain a lithium salt.

[0077] The leaching rates of lithium, nickel, cobalt and manganese in the leaching liquid of step S1 are 94.1%, 93.5%, 93.9% and 94.2% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of step S3 is 95.3%.

[0078] Example 3

[0079] Example 3 differs from Example 2 in that the aeration time of Step S1 of Example 3 is 0.5 hours, and the slurry temperature during aeration is 60°C; Step S2 adjusts the pH of the leaching solution to 11, and the others are the same as Example 2.

[0080] In the leaching solution of Step S1, the leaching rates of lithium, nickel, cobalt and manganese are 94.0%, 94.3%, 94.2% and 95.3% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of Step S3 is 98.2%.

[0081] Example 4

[0082] Example 4 differs from Example 2 in that the aeration time of Step S1 of Example 4 is 0.5 hours, and the slurry temperature during aeration is 85°C; Step S2 adjusts the pH of the leaching solution to 12, and the others are the same as Example 2.

[0083] In the leaching solution of Step S1, the leaching rates of lithium, nickel, cobalt and manganese are 94.8%, 94.9%, 94.7% and 95.6% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of Step S3 is 99.3%.

[0084] Example 5

[0085] The method for recycling ternary nickel-cobalt-manganese battery cathode material of the embodiment comprises the following steps:

[0086] S1, the NCM cathode material powder and deionized water are placed in a polytetrafluoroethylene reaction container at a mass ratio of 1:8, and the stirring system is started (the stirring speed is 400 rpm, and the stirring speed is maintained throughout the leaching reaction) to make the slurry uniformly dispersed; sulfur dioxide gas is introduced into the slurry at a flow rate of 1 L / min, the aeration time is 1 hour, and the slurry temperature during aeration is 25°C; during the aeration process, the pH value of the slurry is controlled at 0-7.0; after the leaching reaction is completed, the leaching solution and solid residue are obtained by vacuum filtration;

[0087] S2, adjust the pH of the leaching solution to 11 by adding 1 mol / L NaOH aqueous solution, and add 2 mol / L ammonia water (the molar ratio of ammonia water to metal sulfate is 1), stir for 100 min at 45°C under argon atmosphere, and vacuum filter to obtain nickel-cobalt-manganese element precipitate and lithium-containing filtrate;

[0088] S3, the lithium-containing filtrate is cooled to -10°C to precipitate sodium impurities, the sodium impurities are removed by vacuum filtration, and the obtained filtrate is further subjected to evaporation and crystallization to obtain lithium salt.

[0089] In the leaching solution of Step S1, the leaching rates of lithium, nickel, cobalt and manganese are 88.3%, 88.5%, 88.2% and 89.2% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of Step S3 is 99.1%.

[0090] Example 6

[0091] The difference between Example 6 and Example 5 is only that the gas flow rate of Example 6 is 2L / min, and the others are the same as Example 5.

[0092] The leaching rates of lithium, nickel, cobalt and manganese in the leaching solution of step S1 are 92.4%, 91.9%, 92.6% and 92.8% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of step S3 is 99.4%.

[0093] Example 7

[0094] The difference between Example 7 and Example 5 is only that the gas flow rate of Example 7 is 3L / min, and the others are the same as Example 5.

[0095] The leaching rates of lithium, nickel, cobalt and manganese in the leaching solution of step S1 are 99.0%, 99.1%, 99.5% and 99.3% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of step S3 is 99.3%.

[0096] Example 8

[0097] The difference between Example 8 and Example 5 is only that the gas flow rate of Example 8 is 4L / min, and the others are the same as Example 5.

[0098] The leaching rates of lithium, nickel, cobalt and manganese in the leaching solution of step S1 are 99.2%, 99.2%, 99.6% and 99.5% respectively after calculation. The lithium salt content obtained after evaporation and crystallization of step S3 is 99.5%.

[0099] Example 9

[0100] The method for recycling ternary nickel-cobalt-manganese battery cathode material of the present embodiment comprises the following steps:

[0101] S1, the NCM cathode material powder and deionized water are placed in a polytetrafluoroethylene reaction container at a mass ratio of 1:9, and the stirring system is started (the stirring speed is 350 rpm, and the stirring speed is maintained throughout the leaching reaction) to make the slurry uniformly dispersed; H2S gas is passed into the slurry at a flow rate of 1L / min, and the aeration time is 2 hours, the slurry temperature during aeration is 40℃, and the pH value of the slurry is controlled at 0-7.0 during the aeration process; after the leaching reaction is completed, vacuum filtration is performed to obtain a leaching solution and solid residues;

[0102] S2, 1mol / L NaOH aqueous solution is added to adjust the pH of the leaching solution to 11, and 2mol / L ammonia water (the molar ratio of ammonia water to metal sulfate is 1.5) is added, and the stirring reaction is carried out at 50℃ under argon atmosphere for 120min, and vacuum filtration is performed to obtain nickel-cobalt-manganese element precipitate and lithium-containing filtrate;

[0103] S3, cooling the lithium-containing filtrate to -8℃ to precipitate sodium impurities, vacuum filtering to remove the sodium impurities, and further evaporating and crystallizing the obtained filtrate to obtain the lithium salt.

[0104] The leaching rates of lithium, nickel, cobalt and manganese in the leaching solution of step S1 are 88.2%, 87.5%, 88.1% and 87.6% respectively. The content of the lithium salt obtained after the evaporation and crystallization of step S3 is 99.1%.

[0105] From the experimental results of examples 2-4, it can be seen that high temperature is helpful to the dissolution of gas and the improvement of reaction speed, thereby improving the metal leaching efficiency; however, continuously increasing the temperature will increase the energy consumption, and the improvement of leaching efficiency is limited. In addition, increasing the pH of step S2 from 10 to 11 is beneficial to the improvement of the purity of lithium salt, and further increasing the pH to 12 has little effect on the purity of lithium salt.

[0106] From the experimental results of examples 5-8, it can be seen that increasing the gas flow rate of the gas can improve the leaching efficiency; however, too large gas flow rate will result in too large gas bubbles, thereby reducing the uniformity of gas dispersion in the slurry, and thus reducing the leaching efficiency of sulfur dioxide per unit volume.

[0107] The metal leaching efficiency of example 9 is lower than that of SO2 gas.

[0108] Aspects, embodiments, features, of the present application should be considered illustrative of all aspects, embodiments, features, of the present application and are not restrictive of the present application, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art, and the embodiments are not to be construed as limiting the present application to the specific illustrative embodiments, uses and results described herein, but have the intended scope of the claims.

[0109] In the preparation method of the present application, the order of each step is not limited to the order listed, and for those skilled in the art, the order of each step can be changed without creative labor, which is within the protection scope of the present application. In addition, two or more steps or actions can be carried out simultaneously.

[0110] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the embodiments of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, which do not need to be or cannot be fully described here. However, these obvious changes or variations within the spirit of the present application still fall within the protection scope of the present application, and any additional limitation is contrary to the spirit of the present application.

Claims

1. A method for efficiently recycling a positive electrode material of a ternary nickel-cobalt-manganese battery, characterized by, The method comprises the following steps: S1, passing a reducing gas into a slurry formed by the NCM positive electrode material and water, and after the leaching reaction is completed, performing solid-liquid separation to obtain a leaching solution.

2. The method for efficiently recycling the positive electrode material of ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The reducing gas is one or more of H2S, SO2, and SO3.

3. The method for efficiently recycling the positive electrode material of ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The reducing gas is passed into the slurry at a rate of 0.1-10 L / min. And / or, the aeration time is 10 min-6 h. And / or, the slurry temperature during aeration is 5-90℃. And / or, the pH value of the slurry during aeration is controlled to be 0-7.

0. 4.The method of recycling a positive material of a ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The reducing gas is passed into the slurry through a gas disperser with a pore size of 5-500 microns.

5. The method for efficiently recycling the positive electrode material of ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The NCM positive electrode material and water are mixed to form a slurry at a mass ratio of 1:2-1:

100. And / or, the NCM positive electrode material is first crushed into fine powder with a particle size of ≤100 microns before being mixed with water to form the slurry. And / or, the water is deionized water.

6. The method for efficiently recycling the positive electrode material of ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The leaching reaction in step S1 makes the leaching rates of lithium, nickel, cobalt, and manganese all reach 87% or above. And / or, the leaching reaction in step S1 makes the leaching rates of lithium, nickel, cobalt, and manganese all reach 90% or above. And / or, the leaching reaction in step S1 makes the leaching rates of lithium, nickel, cobalt, and manganese all reach 99% or above.

7. The method for efficiently recycling the positive electrode material of ternary nickel-cobalt-manganese battery according to claim 1, characterized in that, The method further comprises the following steps: S2, adjusting the pH of the leaching solution in step S1, and then performing solid-liquid separation to obtain a nickel-cobalt-manganese element precipitate and a lithium-containing filtrate; S3, cooling the lithium-containing filtrate to ≤0℃ to precipitate impurity crystals, and performing solid-liquid separation to obtain a filtrate, and then evaporating and crystallizing the filtrate to obtain a lithium salt. 8.The method of recycling a positive material of a ternary nickel-cobalt-manganese battery according to claim 7, characterized in that, The pH of the leaching solution is adjusted to 7-12. 9.The method of recycling a positive material of a ternary nickel-cobalt-manganese battery according to claim 8, characterized in that, During the adjustment of the pH of the leaching solution, a complexing agent is added, and nickel, cobalt, and manganese are co-precipitated by stirring at 30-70℃ in an inert atmosphere for 1-40 h.

10. The method for efficiently recycling a positive electrode material of a ternary nickel-cobalt-manganese battery according to claim 9, characterized in that, The complexing agent is ammonia water and / or sodium carbonate.