Regeneration method of waste ternary material and regenerated ternary material

Abstract

The invention discloses a regeneration method of a waste ternary material and a regenerated ternary material, and belongs to the technical field of recovery and regeneration of waste lithium ion batteries. According to the waste ternary material regeneration method, the mode of mechanical and physical separation, liquid phase recovery and heterogeneous flocculation combined coating is adopted, high-yield recovery of the ternary material is achieved on the premise that the intact structure of the material is guaranteed, aluminum and binder impurities can be effectively removed through the mode, the use amount of a washing solvent is reduced, and the recycling efficiency of the waste ternary material is improved. And a point-surface / point-line / point-line-surface type network-shaped coating structure can be formed on the surface of the material at the same time, so that the performance of the material is enhanced. The whole preparation process is simple, environment-friendly, low in cost, low in energy consumption and suitable for industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling and regeneration of waste lithium-ion batteries, and particularly relates to a regeneration method for waste ternary materials and regenerated ternary materials. Background Art

[0002] With the continuous development of new energy vehicles and the replacement of electronic products, the recycling of lithium-ion batteries has become an indispensable part of the entire battery industrial chain layout. The recycling of nickel, cobalt, and manganese metal elements in waste lithium-ion batteries will generate considerable economic benefits. In particular, for Co-Ni-Mn and Co-Ni-Al lithium-ion batteries, which have excellent safety, the recycling and regeneration of such ternary materials have important economic and environmental significance.

[0003] However, waste ternary electrode materials contain components such as aluminum foil, PVDF binder, and carbon black conductive agent, which severely limit the repair and regeneration of waste ternary materials. The existing recycling technologies for waste ternary electrode materials mainly include: (1) Through high-temperature heat treatment at 450-550°C, crushing and sorting processes, etc., to recycle the ternary electrode materials. However, during the high-temperature heat treatment process, the PVDF binder will undergo pyrolysis, releasing a large amount of HF gas. The acidic gas HF is prone to react with the ternary material at high temperature to form metal fluorides, resulting in damage and failure of the ternary material during the recycling process. Subsequently, it can only be repaired by methods such as re-lithiation and high-temperature sintering again, leading to high costs, high energy consumption, and a long process; (2) Crushing and disassembling the ternary electrode, sorting, adding alkali and / or acid to leach nickel, cobalt, and manganese ions, but the reagents used in acid-base soaking are numerous and in large quantities, the process is complex, and the recycling is difficult.

[0004] How to provide a regeneration method for waste ternary materials with high recovery rate and capable of ensuring the integrity of the material structure is an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the applicant of the present invention provides a regeneration method for waste ternary materials and regenerated ternary materials. The present invention realizes high-recovery rate recycling of ternary materials and ensures the integrity of the material structure by means of mechanical physical separation, liquid-phase recovery, and heterogeneous flocculation coating. At the same time, there is no need for re-lithiation and long-time high-temperature sintering, with low cost and low energy consumption.

[0006] The technical solution of the present invention is as follows: A regeneration method for waste ternary materials, comprising the following steps: S1. Crushing and sorting waste ternary electrodes to obtain primary ternary powder and primary aluminum powder; soaking the primary aluminum powder in an organic solvent, performing primary screening, filtration, and rinsing the screen residue to obtain a screening solution, a rinsing solution, and secondary aluminum powder; S2. Mix the screening liquid, eluent and primary ternary powder, soak them, and perform secondary screening to obtain tertiary aluminum powder and ternary slurry; S3. Mix the carbon nanomaterials with the ternary slurry and stir to disperse them to obtain a dispersed slurry; S4. Add a cationic polymer solution to the dispersed slurry and stir for t hours to obtain a flocculated slurry; S5. Filter press the flocculated slurry, wash the filter cake and disperse it in an organic solvent, then filter press and dry it; S6. Heat-treat the dried material, sort it, and demagnetize it to obtain a recycled ternary material.

[0007] Preferably, in S1, the mass ratio of the primary aluminum powder to the organic solvent is 1:(1 - 2); And / or, both the organic solvent and the eluent used in elution include at least one of NMP, DMF, and DMSO; And / or, the purity of the organic solvent is ≥99.5%, and the water content is ≤1000 ppm; And / or, the soaking time is 5 - 8 h; And / or, the screen aperture of the primary screening is 200 - 300 meshes; And / or, the mass ratio of the primary aluminum powder to the eluent used in elution is 1:(2 - 3).

[0008] Preferably, in S2, the soaking time is 8 - 16 h; And / or, the screen aperture of the secondary screening is 500 - 700 meshes.

[0009] Preferably, in S3, the addition amount of the carbon nanomaterials is 1.5 - 3 wt% of the solid content in the ternary slurry in S2; And / or, the carbon nanomaterials include at least one of graphene oxide, oxidized carbon nanotubes, and carboxylated carbon nanotubes; And / or, the stirring and dispersing speed is 5000 - 8000 rpm, and the time is 1 - 2 h.

[0010] Preferably, the graphene oxide is monolayer or multilayer; And / or, the lateral size of the graphene oxide is ≥10 μm; And / or, the oxidized carbon nanotubes are single-walled or multi-walled; And / or, the carboxylated carbon nanotubes are single-walled or multi-walled; And / or, the length of the oxidized carbon nanotubes is ≥10 μm; And / or, the length of the carboxylated carbon nanotubes is ≥10 μm.

[0011] Preferably, in S4, the solute of the cationic polymer solution includes polymers that can dissolve in strongly polar aprotic solvents; the solute includes at least one of modified polyacrylamine, polyamide, polyimide, polyamine, polyvinylamine, and polyethyleneimine; and / or, the solvent of the cationic polymer solution includes at least one of NMP, DMF, and DMSO; and / or, the solid content of the cationic polymer solution is 5 - 10 wt%; and / or, the mass ratio of the solute to the carbon nanomaterial in the cationic polymer solution is 1:(0.8 - 1.2).

[0012] Preferably, in S4, the cationic polymer solution is added under the stirring state of the dispersion slurry, the addition time is 30 - 60 min, and the stirring speed is 1000 - 2000 rpm; and / or, the stirring time t is 20 - 30 min.

[0013] Preferably, in S5, the ratio of the total mass of the organic solvents used for washing and dispersion to the mass of the solids in the ternary slurry in S2 is (1.5 - 2):1; and / or, the organic solvent includes at least one of NMP, DMF, and DMSO; and / or, the drying temperature is 105 - 115 °C.

[0014] Preferably, in S6, the heat treatment temperature is 600 - 700 °C, and the heat treatment time is 2 - 5 h; and / or, the heat treatment is carried out in a protective atmosphere. Preferably, the protective atmosphere includes at least one of argon or nitrogen.

[0015] The present invention also provides a regenerated ternary material, which is prepared by the regeneration method of the above-mentioned waste ternary material.

[0016] The beneficial technical effects of the present invention are as follows: (1) The regeneration method of the waste ternary material of the present invention realizes the high-yield recovery of the ternary material on the premise of ensuring the integrity of the material structure by adopting mechanical physical separation, liquid-phase recovery, and heterogeneous flocculation coating methods; at the same time, the combination of physical mechanical separation and liquid-phase recovery can reduce the generation of micron-sized aluminum chips, and through precise sieving, aluminum impurities can be effectively removed, without the need for strong alkali washing, the preparation process is simple, environmentally friendly, and applicable to industrial production.

[0017] (2) The regeneration method of the waste ternary material of the present invention adopts the scheme of heterogeneous flocculation coating, which not only solves the problem that the PVDF binder in the waste ternary material cannot be removed efficiently, quickly, without damage and at low cost, but also forms a network carbon coating structure of point-plane / point-line / point-line-plane type with the original Super P conductive agent in the material while removing the binder. This network coating structure can avoid side reactions on the material surface, significantly improve the conductivity of the material, and reduce the amount of conductive agent used in the subsequent pole piece manufacturing process. At the same time, there is no need for lithium supplementation and long-time high-temperature sintering process, with low cost and low energy consumption. Detailed implementation mode

[0018] The present invention will be specifically described below in conjunction with embodiments.

[0019] The first aspect of the present invention provides a regeneration method for waste ternary materials, comprising the following steps: S1. Crushing and sorting waste ternary pole pieces to obtain primary ternary powder and primary aluminum powder; soaking the primary aluminum powder in an organic solvent, performing primary screening, filtration and rinsing of the oversize material to obtain screening liquid, rinsing liquid and secondary aluminum powder; S2. Mixing and soaking the screening liquid, rinsing liquid with the primary ternary powder, and performing secondary screening to obtain tertiary aluminum powder and ternary slurry; S3. Mixing carbon nanomaterials with the ternary slurry and stirring for dispersion to obtain a dispersed slurry; S4. Adding a cationic polymer solution to the dispersed slurry and stirring for t time to obtain a flocculated slurry; S5. Filter-pressing the flocculated slurry, washing the filter cake and dispersing it in an organic solvent, then filter-pressing and drying; S6. Heat-treating the dried material, sorting and demagnetizing to obtain the regenerated ternary material.

[0020] In addition to the ternary material, the waste ternary pole piece material also contains components such as aluminum foil, PVDF binder, carbon black conductive agent, etc. The method of the present invention can recover the ternary material without damage and with high yield by combining physical peeling and liquid-phase peeling, and remove aluminum impurities through precise screening.

[0021] It can be understood that when the waste ternary pole piece material is peeled and recovered by chemical method or high-temperature method, the aluminum foil will be partially dissolved and denatured, the texture becomes brittle, and too many tiny aluminum chips are easily generated. While the present invention adopts pure physical collision, friction sorting and then combines with the liquid-phase peeling method, so that the aluminum foil can maintain good toughness and ductility, reduce the generation of tiny aluminum chips while obtaining aluminum powder, facilitate subsequent aluminum removal and sorting, and reduce the aluminum impurities in the regenerated ternary material.

[0022] For the ternary material obtained by liquid-phase exfoliation, due to the dissolution of the ultra-high molecular weight PVDF binder, a viscous solution is formed. It is extremely difficult to separate the solid from the liquid for this highly viscous solution, and it requires high dilution + multiple washings to separate and extract the ternary material. In the present invention, by adding carbon nanomaterials and cationic polymers, the cationic polymers combine with the negatively charged carbon nanomaterials to form flocs that wrap the ternary material, promoting the aggregation of the ternary material, reducing the hindrance of viscosity in the solution, and facilitating the rapid sedimentation and filtration of solid particles during separation.

[0023] This heterogeneous flocculation coating solution not only solves the problem of the inefficient, rapid, and non-destructive removal of the PVDF binder in waste ternary materials, but also forms a network-like carbon coating on the material surface while removing the binder, achieving the rapid and low-cost regeneration of waste ternary materials. Moreover, the carbon black conductive agent in the waste ternary electrode material does not need to be removed, and it can form a stable network-like carbon coating structure of point-plane / point-line / point-line-plane type with the carbon nanomaterials and cationic polymers. This coating structure can prevent the surface of the positive electrode material from contacting with trace moisture and HF in the battery, reducing side reactions, and can significantly improve the conductivity of the positive electrode material, reducing the amount of conductive agent used in the subsequent electrode manufacturing process.

[0024] In some embodiments, in S1, the mass ratio of the primary aluminum powder to the organic solvent is 1:(1 - 2), including but not limited to 1:1, 1:1.5, 1:2.

[0025] In some embodiments, in S1, both the organic solvent and the eluent used during elution include at least one of NMP, DMF, and DMSO.

[0026] In some embodiments, in S1, the purity of the organic solvent ≥ 99.5%, and the water content ≤ 1000 ppm.

[0027] In some embodiments, in S1, the soaking time is 5 - 8 h, including but not limited to 5 h, 6 h, 7 h, 8 h.

[0028] In some embodiments, in S1, the screen aperture of the primary screening is 200 - 300 mesh, including but not limited to 200 mesh, 250 mesh, 300 mesh.

[0029] In some embodiments, in S1, the mass ratio of the primary aluminum powder to the eluent used during elution is 1:(2 - 3), including but not limited to 1:2, 1:2.5, 1:3.

[0030] In some embodiments, in S2, the soaking time is 8 - 16 h, including but not limited to 8 h, 10 h, 12 h, 14 h, 16 h.

[0031] In some embodiments, in S2, the aperture of the sieve during the secondary screening is 500 - 700 mesh, including but not limited to 500 mesh, 600 mesh, and 700 mesh.

[0032] It can be understood that the primary aluminum powder and the secondary aluminum powder will contain ternary powder that has not been separated, so it is necessary to perform multiple screenings on them to improve the yield of the ternary material.

[0033] In some embodiments, in S3, the addition amount of the carbon nanomaterial is 1.5 - 3 wt% of the solid content in the ternary slurry in S2, including but not limited to 1.5 wt%, 2 wt%, 2.5 wt%, and 3 wt%.

[0034] In some embodiments, in S3, the carbon nanomaterial includes at least one of graphene oxide, oxidized carbon nanotubes, and carboxylated carbon nanotubes.

[0035] In some embodiments, in S3, the stirring and dispersion speed is 5000 - 8000 rpm, including but not limited to 5000 rpm, 6000 rpm, 7000 rpm, and 8000 rpm, and the time is 1 - 2 h, including but not limited to 1 h, 1.5 h, and 2 h.

[0036] In some embodiments, in S3, the graphene oxide is monolayer or multilayer.

[0037] In some embodiments, in S3, the lateral size of the graphene oxide ≥ 10 μm.

[0038] In some embodiments, in S3, the oxidized carbon nanotubes are single-walled or multi-walled.

[0039] In some embodiments, in S3, the carboxylated carbon nanotubes are single-walled or multi-walled.

[0040] In some embodiments, in S3, the length of the oxidized carbon nanotubes ≥ 10 μm.

[0041] In some embodiments, in S3, the length of the carboxylated carbon nanotubes ≥ 10 μm.

[0042] If the size of the carbon nanomaterial is too small, it will result in poor sedimentation effect of the ternary material during the solid-liquid separation process; it will also lead to poor continuity of the carbon network structure formed by coating, thereby affecting the performance of the cathode material.

[0043] In some embodiments, in S4, the solute of the cationic polymer solution includes polymers that can be dissolved in strongly polar aprotic solvents, including but not limited to at least one of modified polyacrylamine, polyamide, polyimide, polyamine, polyvinylamine, and polyvinylimine.

[0044] In some embodiments, in S4, the solvent of the cationic polymer solution includes at least one of NMP, DMF, and DMSO.

[0045] In some embodiments, in S4, the solid content of the cationic polymer solution is 5-10 wt%, including but not limited to 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%.

[0046] In some embodiments, in S4, the mass ratio of the solute in the cationic polymer solution to the carbon nanomaterial is 1:(0.8-1.2), including but not limited to 1:0.8, 1:1.0, 1:1.2.

[0047] It can be understood that during the stirring process, after the dispersed carbon nanomaterials encounter the cationic polymer, they can bind on the surface of the ternary material and form a network-like coating structure.

[0048] The addition amounts of the carbon nanomaterials and the cationic polymer solution should be appropriate. If the addition amount of the carbon nanomaterials is too low, the sedimentation effect of the ternary material and the coating effect will be poor; if the addition amount of the carbon nanomaterials is too high, the coating amount will be too high, which will cause the capacity of the positive electrode material to decrease; if the addition amount of the cationic polymer solution is too low or too high, the sedimentation effect will be poor, which will lead to difficult solid-liquid separation and affect the recycling utilization rate of the recycled ternary material.

[0049] In some embodiments, in S4, the cationic polymer solution is added under the stirring state of the dispersion slurry, the addition time is 30-60 min, including but not limited to 30 min, 40 min, 50 min, 60 min; the stirring speed is 1000-2000 rpm, including but not limited to 1000 rpm, 1500 rpm, 2000 rpm.

[0050] In some embodiments, in S4, the stirring time t is 20-30 min, including but not limited to 20 min, 25 min, 30 min.

[0051] In some embodiments, in S5, the ratio of the total mass of the organic solvents used for washing and dispersion to the solid mass in the ternary slurry in S2 is (1.5-2):1; including but not limited to 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1.

[0052] In some embodiments, in S5, the organic solvent includes at least one of NMP, DMF, and DMSO.

[0053] In some embodiments, in S5, the drying temperature is 105 - 115 °C, including but not limited to 105 °C, 110 °C, and 115 °C.

[0054] In some embodiments, in S6, the heat treatment temperature is 600 - 700 °C, including but not limited to 600 °C, 650 °C, and 700 °C, and the heat treatment time is 2 - 5 h, including but not limited to 2 h, 3 h, 4 h, and 5 h.

[0055] During the heat treatment process, the oxygen-containing functional groups in the carbon nanomaterials are decomposed, forming a point-plane / point-line / point-line-plane network-like carbon coating structure with the original carbon black conductive agent in the material. The heat treatment temperature should not be too high or too low. Too high will cause the ternary material to melt, and too low will result in incomplete carbonization coating.

[0056] In some embodiments, in S6, the heat treatment is carried out in a protective atmosphere. Preferably, the protective atmosphere includes at least one of argon or nitrogen.

[0057] It can be understood that in S6, the purpose of demagnetization is to remove magnetic metal impurities such as iron and nickel in the ternary material, avoid internal short circuits in the battery, and improve battery safety.

[0058] The second aspect of the present invention provides a regenerated ternary material, which is obtained by the regeneration method of the waste ternary material described in the first aspect.

[0059] Example 1 A regeneration method for waste ternary materials includes the following steps: S1. Cut and crush 200 kg of waste 622-type ternary electrode sheets (with an aluminum current collector content of 10 wt%), sort them according to weight and particle size to obtain 105 kg of first-grade ternary powder and 95 kg of first-grade aluminum powder. Put the first-grade aluminum powder into a reaction kettle, add 171 kg of NMP solution, stir and soak for 6 h, then screen through a 250-mesh vibrating screen, and wash the oversize material with 273 kg of NMP to obtain a screening solution, a washing solution, and second-grade aluminum powder.

[0060] S2. Transfer the screening solution, washing solution, and first-grade ternary powder in step S1 to a reaction kettle for mixing, stir and soak for 11 h, then screen through a 600-mesh ultrasonic vibrating screen to obtain third-grade aluminum powder and 618 kg of ternary slurry; after testing, the solid content of this slurry is 28.7%, containing 177 kg of ternary material. After calculation, the yield of the ternary material is 98.3%.

[0061] S3. First add 5.2 kg of graphene oxide with a transverse size > 10 μm to the reaction kettle, and then add the ternary slurry, and stir and disperse at 6000 rpm for 1.5 h to obtain a dispersed slurry.

[0062] S4. Add 50 kg of a 10 wt% polyethyleneimine NMP solution to the dispersion slurry, complete the feeding within 40 min at a rotation speed of 1500 rpm, and continue stirring for 20 min after the feeding is completed to obtain a flocculated slurry.

[0063] S5. After pressure-filtering the flocculated slurry, rinse it with 70 kg of NMP, disperse the filter cake in 200 kg of NMP, perform pressure-filtering again, and then flash-dry it at 110 °C.

[0064] S6. Place the dried material in a roller hearth furnace and heat-treat it in nitrogen at 650 °C for 3 h, perform sorting according to particle size, and demagnetize it to obtain 167 kg of recycled ternary material, with a recycling utilization rate of 94.3%.

[0065] In the above step S2: Yield = (mass of ternary material recovered from the positive electrode sheet / theoretical mass of ternary material in the positive electrode sheet) × 100%; In the above step S6: Recycling recovery rate = (mass of recycled ternary material / mass of ternary material recovered from the positive electrode sheet) × 100%.

[0066] Example 2 A regeneration method for waste ternary materials includes the following steps: S1. Cut, crush 155 kg of waste 523-type ternary electrode sheets (with an aluminum current collector content of 10 wt%), perform sorting according to weight and particle size to obtain 85 kg of first-grade ternary powder and 70 kg of first-grade aluminum powder. Put the first-grade aluminum powder into a reaction kettle, add 70 kg of DMF solution, stir and soak for 5 h, then screen it through a 300-mesh vibrating screen, and wash the oversize material with 210 kg of DMF to obtain a screening liquid, a washing liquid, and second-grade aluminum powder.

[0067] S2. Transfer the screening liquid, washing liquid, and first-grade ternary powder in step S1 to a reaction kettle for mixing, stir and soak for 16 h, and then screen it through a 500-mesh ultrasonic vibrating screen to obtain third-grade aluminum powder and 410 kg of ternary slurry; after testing, the solid content of this slurry is 33.5%, containing 137 kg of ternary material. After calculation, the yield of the ternary material is 98.2%.

[0068] S3. First add 2.7 kg of carbon nanotubes with a length > 10 μm to the reaction kettle, and then add the ternary slurry, and stir and disperse it at 5000 rpm for 2.0 h to obtain a dispersion slurry.

[0069] S4. Add 55 kg of a 5 wt% polyamide DMF solution to the dispersion slurry, complete the feeding within 60 min at a rotation speed of 1000 rpm, and continue stirring for 20 min after the feeding is completed to obtain a flocculated slurry.

[0070] S5. After pressure filtering the flocculated slurry, rinse it with 50 kg of DMF, disperse the filter cake in 185 kg of DMF, perform pressure filtering again, and then flash dry at 105 °C.

[0071] S6. Place the dried material in a roller hearth furnace and heat-treat it in nitrogen at 700 °C for 3 h, sort it according to particle size, remove magnetism, to obtain 130 kg of recycled ternary material, and the recycling utilization rate is 94.8%.

[0072] Example 3 A recycling method for waste ternary materials, comprising the following steps: S1. Cut and crush 320 kg of waste 811-type ternary pole pieces (aluminum current collector content 8 wt%), sort them according to weight and particle size, to obtain 162 kg of first-grade ternary powder and 158 kg of first-grade aluminum powder. Put the first-grade aluminum powder into a reaction kettle, add 316 kg of DMSO solution, stir and soak for 5 h, then screen it through a 250-mesh vibrating screen, and rinse the oversize material with 316 kg of DMSO to obtain a screening solution, a rinsing solution, and second-grade aluminum powder.

[0073] S2. Transfer the screening solution, rinsing solution, and first-grade ternary powder in step S1 to a reaction kettle for mixing, stir and soak for 8 h, then screen through a 700-mesh ultrasonic vibrating screen to obtain third-grade aluminum powder and 905 kg of ternary slurry; after testing, the solid content of this slurry is 31.9%, containing 289 kg of ternary material. After calculation, the yield of the ternary material is 98.1%.

[0074] S3. First add 5.5 kg of carboxylated carbon nanotubes with a length > 10 μm to the reaction kettle, and then add the ternary slurry, stir and disperse at 8000 rpm for 1.0 h to obtain a dispersed slurry.

[0075] S4. Add 91 kg of a DMSO solution of 6 wt% butyl acrylate copolymer-modified polyacrylamide to the dispersed slurry, complete the feeding within 30 min at a rotation speed of 2000 rpm, and continue to stir for 30 min after the feeding is completed to obtain a flocculated slurry.

[0076] S5. After pressure filtering the flocculated slurry, rinse it with 120 kg of DMSO, disperse the filter cake in 330 kg of DMSO, perform pressure filtering again, and then flash dry at 110 °C.

[0077] S6. Place the dried material in a roller hearth furnace and heat-treat it in nitrogen at 600 °C for 3 h, sort it according to particle size, remove magnetism, to obtain 273 kg of recycled ternary material, and the recycling utilization rate is 94.5%.

[0078] Comparative Example 1 150 kg of waste 622-type ternary cathode sheets (with 10 wt% aluminum current collector content) were heat-treated at 450 °C in air for 1.5 h, and then mechanically peeled and sorted to obtain 131 kg of ternary black powder. The ternary black powder was placed in 1 mol / L sodium hydroxide with a solid content of 20%, reacted for 30 - 60 min, washed with water until the pH was 7 - 8 to remove aluminum impurities in the ternary black powder, and after drying, lithium carbonate fine powder was added according to the lithium loss in the material. After mixing, it was sintered in oxygen at 800 °C for 10 h, and the sintered product was crushed and sorted to obtain 120 kg of recycled ternary material.

[0079] Comparative Example 2 Basically the same as Example 1, except that the addition amount of graphene oxide in S3 was 10.0 kg.

[0080] Comparative Example 3 Basically the same as Example 1, except that the addition amount of the NMP solution of 10 wt% polyethyleneimine in S4 was 20 kg.

[0081] Comparative Example 4 Basically the same as Example 1, except that the lateral size of the graphene oxide used in S3 was about 3 microns.

[0082] Comparative Example 5 Basically the same as Example 1, except that the heat treatment temperature in S6 was 500 °C.

[0083] Comparative Example 6 Basically the same as Example 1, except that the heat treatment temperature in S6 was 800 °C.

[0084] Test Example: (1) Yield of the material The aluminum impurity content, the yield of the ternary material, the recycling utilization rate of the recycled ternary material, and the results of the aluminum impurity content in the above examples and some comparative examples were detected by inductively coupled plasma atomic emission spectrometry (ICP) method, as shown in Table 1.

[0085] Table 1: Yield table of examples and comparative examples

[0086] It can be seen from Table 1 that the method of the present invention can recover ternary materials from waste ternary materials with a high yield, realize recycling utilization, and has a high recycling utilization rate, and reduces the aluminum impurity content in the recycled ternary material.

[0087] (2) Electrochemical performance test of the battery The recycled ternary materials prepared in the above examples and comparative examples were assembled into batteries according to the following steps, and the following electrochemical performance tests were carried out. The test results are shown in Table 2.

[0088] The prepared recycled ternary material of the present invention is mixed with a binder and a conductive agent, then pulped, coated, roll-pressed, and cut. Then, a lithium sheet is used as the counter electrode to prepare a button battery. The battery is cycled twice at a rate of 0.1C within a voltage range of 3.0 - 4.3V, and its specific capacity is measured. The test method for the capacity retention rate is as follows: The prepared recycled ternary material is mixed with a binder and a conductive agent, then pulped, coated, roll-pressed, and cut. Then, a graphite electrode sheet is used as the counter electrode to prepare a single-cell battery. The battery is cycled 500 times at a rate of 1C at room temperature within a voltage range of 3.0 - 4.3V.

[0089] Table 2: Performance Test Table of Examples and Comparative Examples

[0090] Comparing Examples 1 - 3 with Comparative Example 1 and combining Tables 1 and 2, it can be seen that the recycling method of the waste ternary material of the present invention has the advantages of high yield and high recycling utilization rate, and the prepared recycled ternary material has excellent electrochemical performance, indicating that the integrity of the material structure can be ensured when using the method of the present invention for recycling; in addition, this method does not require lithium supplementation and long-time high-temperature sintering, with low cost and low energy consumption.

[0091] Comparing Example 1 with Comparative Example 2 and combining Table 2, it can be seen that when the addition amount of the carbon nanomaterial is too high, it will cause the capacity of the recycled ternary material to decrease. The possible reason for the analysis is that too high an addition amount leads to too high a coating amount, thus affecting the capacity.

[0092] Comparing Example 1 with Comparative Example 3 and combining Tables 1 and 2, it can be seen that when the addition amount of the cationic polymer solution is too low, it has little effect on the electrochemical performance of the recycled ternary material, mainly affecting the recycling utilization rate of the material. The possible reason for the analysis is that when the addition amount of the cationic polymer solution is too low, the sedimentation effect will be poor, thus affecting the utilization rate of the recyclable material.

[0093] Comparing Example 1 with Comparative Example 4 and combining Tables 1 and 2, it can be seen that when the size of the carbon nanomaterial is too small, it will have a negative impact on both the recycling utilization rate and the electrochemical performance of the recycled ternary material. The possible reason for the analysis is that too small a size will lead to poor sedimentation effect of the material, reducing the recycling utilization rate of the material. In addition, it will also lead to poor continuity of the carbon network structure formed by coating, thus affecting the electrochemical performance.

[0094] Comparing Example 1 with Comparative Examples 5 and 6 and combining Tables 1 and 2, it can be seen that too low or too high heat treatment temperature will have a negative impact on the recycling utilization rate and the electrochemical performance of the recycled ternary material. The possible reason for the analysis is that too high heat treatment temperature will cause the recycled ternary material to melt and agglomerate, while too low temperature will lead to incomplete carbonization coating, thus affecting the electrochemical performance.

[0095] In summary, the regeneration method of waste ternary materials of the present invention can recycle ternary materials with a high yield and ensure the integrity of the material structure, so that it has good electrochemical properties. At the same time, during recycling, there is no need for multiple washing with the aid of strong alkali, etc., which reduces the amount of detergent used, and there is no need for lithium supplementation and long-term high-temperature sintering, with low cost and low energy consumption.

[0096] The above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and changes directly derived or associated by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the protection scope of the present invention.

Claims

1. A regeneration method for waste ternary materials, characterized in that, It includes the following steps: S1. Crush and sort the waste ternary electrode sheets to obtain primary ternary powder and primary aluminum powder; soak the primary aluminum powder in an organic solvent, perform primary screening, filtration, and rinse the oversize material to obtain a screening solution, a rinsing solution, and secondary aluminum powder; S2. Mix the screening solution, the rinsing solution with the primary ternary powder and soak them, then perform secondary screening to obtain tertiary aluminum powder and a ternary slurry; S3. Mix the carbon nanomaterials with the ternary slurry and stir to disperse them to obtain a dispersed slurry; S4. Add a cationic polymer solution to the dispersed slurry and stir for t time to obtain a flocculated slurry; S5. Filter the flocculated slurry under pressure, wash the filter cake, disperse it in an organic solvent, filter it under pressure, and dry it; S6. Heat-treat the dried material, sort it, and demagnetize it to obtain a recycled ternary material.

2. The regeneration method of waste ternary materials according to claim 1, characterized in that In S1, the mass ratio of the primary aluminum powder to the organic solvent is 1:(1 - 2); and / or, both the organic solvent and the rinsing agent used for rinsing include at least one of NMP, DMF, and DMSO; and / or, the purity of the organic solvent is ≥99.5%, and the water content is ≤1000 ppm; and / or, the soaking time is 5 - 8 h; and / or, the screen aperture of the primary screening is 200 - 300 mesh; and / or, the mass ratio of the primary aluminum powder to the rinsing agent used for rinsing is 1:(2 - 3).

3. The regeneration method of waste ternary materials according to claim 1, characterized in that In S2, the soaking time is 8 - 16 h; and / or, the screen aperture of the secondary screening is 500 - 700 mesh; 4. The regeneration method of waste ternary materials according to claim 1, characterized in that, In S3, the addition amount of the carbon nanomaterials is 1.5 - 3 wt% of the solid content in the ternary slurry in S2; and / or, the carbon nanomaterials include at least one of graphene oxide, oxidized carbon nanotubes, and carboxylated carbon nanotubes; and / or, the stirring and dispersing speed is 5000 - 8000 rpm, and the time is 1 - 2 h.

5. The regeneration method of waste ternary materials according to claim 4, characterized in that, The graphene oxide is monolayer or multilayer; and / or, the lateral size of the graphene oxide is ≥10 μm; and / or, the oxidized carbon nanotubes are single-walled or multi-walled; and / or, the carboxylated carbon nanotubes are single-walled or multi-walled; and / or, the length of the oxidized carbon nanotubes is ≥10 μm; and / or, the length of the carboxylated carbon nanotubes is ≥10 μm.

6. The regeneration method of waste ternary materials according to claim 1, characterized in that, In S4, the solute of the cationic polymer solution includes polymers that can dissolve in strongly polar aprotic solvents; the solute includes at least one of modified polyacrylamine, polyamide, polyimide, polyamine, polyvinylamine, and polyvinylimine; and / or, the solvent of the cationic polymer solution includes at least one of NMP, DMF, and DMSO; and / or, the solid content of the cationic polymer solution is 5 - 10 wt%; and / or, the mass ratio of the solute in the cationic polymer solution to the carbon nanomaterials is 1:(0.8 - 1.2).

7. The regeneration method of the waste ternary material according to claim 1, characterized in that, In S4, the cationic polymer solution is added under the stirring state of the dispersed slurry, the addition time is 30 - 60 min, and the stirring speed is 1000 - 2000 rpm; and / or, the stirring time t is 20 - 30 min.

8. The regeneration method of the waste ternary material according to claim 1, wherein In S5, the ratio of the total mass of the organic solvents used for washing and dispersion to the mass of the solids in the ternary slurry in S2 is (1.5 to 2):1; and / or, the organic solvent includes at least one of NMP, DMF, and DMSO; and / or, the drying temperature is 105 to 115 °C.

9. The regeneration method of the waste ternary material according to claim 1, characterized in that, In S6, the heat treatment temperature is 600 to 700 °C, and the heat treatment time is 2 to 5 h; and / or, the heat treatment is carried out in a protective atmosphere. Preferably, the protective atmosphere includes at least one of argon or nitrogen.

10. A regenerated ternary material, characterized in that, It is prepared by the regeneration method of the waste ternary material according to any one of claims 1 to 9.

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