Regeneration method and application of nickel-cobalt-manganese ternary material precursor based on raw material recycling

Abstract

The invention provides a regeneration method and application of a nickel-cobalt-manganese ternary material precursor based on raw material recycling. The regeneration method comprises the following steps: crushing a nickel cobalt lithium manganate positive plate disassembled from a waste battery, and screening to obtain positive powder; calcining the positive electrode powder in a hydrogen atmosphere, and dissolving a calcined solid product in water to obtain a leachate and a solid mixture; mixing the solid mixture with dilute sulphuric acid, and reacting at a certain temperature to obtain leachate and hydrogen; adding ammonia water into the leachate to obtain a chelate, adjusting the pH value through sodium hydroxide to precipitate the chelate, and performing solid-liquid separation to obtain a precursor and a waste liquid; distilling the waste liquid to collect ammonia gas and water vapor; and (5) electrolyzing the residual liquid in the distillation in the step (5), collecting sodium hydroxide in a cathode chamber after electrolysis, and collecting dilute sulfuric acid in an anode chamber. The regeneration method not only has a high regeneration rate, but also can ensure the cyclic utilization of the raw materials, so that no medicine waste or waste water tail treatment process exists.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling and utilization of lithium-ion batteries, in particular to the recycling and utilization of positive electrode materials, and more particularly to a regeneration method and application of nickel-cobalt-manganese ternary material precursors based on raw material recycling. Background Art

[0002] With the rapid industrialization of new energy vehicles, sales are expected to soar, and the number of lithium-ion power batteries in use will also increase exponentially. At the same time, the environmental pollution and resource recycling issues of spent lithium-ion power batteries have become widespread concerns in the industry and are urgently needed to address them. Solving this issue not only benefits environmental protection but also promotes resource recycling, and is of great practical significance.

[0003] Currently, the recycling of spent lithium-ion power batteries typically involves first recovering various valuable materials from the spent batteries and then reusing them. For example, the positive electrode active material is recovered from the spent batteries and then used to prepare the corresponding precursor.

[0004] The recovery of positive electrode active materials is generally simple, primarily involving wet and pyrometallurgical processes. The wet process utilizes a liquid medium to separate metal ions. It operates under mild conditions and consumes minimal energy, primarily involving pretreatment, leaching, and recovery. The pyrometallurgical process typically involves incinerating battery electrodes at high temperatures, burning away carbon and organic matter from the broken electrodes. The remaining ash, which cannot be burned, is then screened to yield a fine powder containing metals and metal oxides.

[0005] The process of recovering the positive electrode active material and regenerating it into a precursor is relatively more complicated, and the traditional precursor regeneration step still requires the use of a large amount of chemicals, which leads to a large amount of drug waste and wastewater tail treatment costs, greatly increasing the system recovery cost. Summary of the Invention

[0006] Based on the above problems, the purpose of the present invention is to provide a regeneration method and application of nickel-cobalt-manganese ternary material precursor based on raw material recycling. This regeneration method not only has a high regeneration rate, but also can ensure the recycling of raw materials in the regeneration method. The input-output is fully closed in the entire system, so there is no waste of drugs and wastewater tail treatment process.

[0007] To achieve the above objectives, the present invention provides a first aspect of a regeneration method for a nickel-cobalt-manganese ternary material precursor based on raw material recycling, comprising: (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets disassembled from waste batteries are crushed and screened to obtain positive electrode powder; (2) Calcination and leaching calcining the positive electrode powder in a hydrogen atmosphere, and dissolving the calcined solid product in water to obtain a leachate and a solid mixture; (3) Acid leaching The solid mixture and dilute sulfuric acid are mixed and reacted at a certain temperature to obtain a leachate and hydrogen, and the hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2); (4) Sedimentation adding ammonia water to the leachate to obtain a chelate, adjusting the pH value with sodium hydroxide to precipitate the chelate, and then performing solid-liquid separation to obtain a precursor and a waste liquid; (5) Distillation The waste liquid is distilled to collect ammonia gas and water vapor, which can be used as the ammonia water in the precipitation of step (4) after cooling; (6) Electrolysis The liquid remaining in the distillation of step (5) is electrolyzed. The device used for the electrolysis uses graphite plates as cathode plates and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. After the electrolysis, sodium hydroxide that can be used for precipitation in step (4) is collected in the cathode chamber, and dilute sulfuric acid that can be used for acid leaching in step (3) is collected in the anode chamber.

[0008] In the regeneration method adopted by the present invention, the positive electrode powder is calcined under a hydrogen atmosphere, and the nickel-cobalt-manganese ternary material in the positive electrode powder is decomposed into Li2O and other metal elements or oxides (Ni, Co, cobalt oxide, manganese oxide). After calcination, Li2O is leached with water and converted into LiOH solution, thereby achieving the separation of lithium and nickel-cobalt-manganese metal. The water-insoluble metal elements or oxides are leached with dilute sulfuric acid to obtain a leachate containing various sulfates, and the hydrogen generated by the reaction of the metal elements and dilute sulfuric acid can be used as the hydrogen atmosphere in the calcination and leaching in step (2), thereby achieving the recycling of hydrogen. The leachate reacts with ammonia water to form a stable metal-ammonium complex, thereby increasing the solubility of the metal ions. The formed metal-ammonium complex is then added with sodium hydroxide for precipitation, so that the metal ions can be more evenly distributed in the solution during the precipitation process, thereby reducing aggregation and unevenness during the precipitation process, thereby helping to obtain precursor particles with uniform particle size and good morphology, thereby improving the electrochemical performance of the final battery material. The waste liquid is distilled to collect ammonia and water vapor to be used as ammonia water in the precipitation of step (4) to achieve the recycling of ammonia. The remaining liquid in the distillation is electrolyzed. Due to the effect of the anion exchange membrane, SO4 in the cathode chamber is 2-H2SO4 is generated in the anode chamber through an anion exchange membrane, while NaOH is generated in the cathode chamber itself. The H2SO4 and NaOH generated in the two chambers can be recycled to the acid leaching and precipitation steps respectively. Therefore, the regeneration method adopted in the present invention can not only obtain a nickel-cobalt-manganese ternary material precursor with a high regeneration rate, but also ensure the recycling of hydrogen, ammonia, H2SO4 and NaOH. The input-output of the whole system is a complete closed loop, so there is no drug waste and wastewater tail treatment process.

[0009] As a technical solution of the present invention, the lithium nickel cobalt manganese oxide-based positive electrode sheet includes a positive electrode active material, a binder and a conductive agent. The chemical formula of the positive electrode active material is LiNi x Co y Mn z M (1-x-y-z) O2, where M is at least one of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, 0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z ≤ 1. The binder includes PVDF, and the conductive agent includes at least one of conductive carbon black, conductive graphite, carbon fiber, carbon nanotube and graphene.

[0010] As a technical solution of the present invention, the lithium nickel cobalt manganese oxide-based positive electrode sheet is mechanically crushed to a particle size of 70-90 μm, and then the screening is carried out by coupling a sieve and a vibration stirrer.

[0011] As a technical solution of the present invention, the temperature of the calcination is 450-650 °C and the time is 1-2 h.

[0012] As a technical solution of the present invention, the concentration of the dilute sulfuric acid is 3-5 mol / L, and the liquid-solid ratio of the dilute sulfuric acid and the positive electrode powder is 8-12 L / Kg.

[0013] As a technical solution of the present invention, the certain temperature is 90-100 °C, and the time of the reaction is 50-80 min.

[0014] As a technical solution of the present invention, the molar ratio of the total molar amount of all metals in the leaching solution and the molar amount of ammonia water is 1:1.0-1.5, the concentration of sodium hydroxide is 2-4 mol / L, and the adjusted pH value is 8-10.

[0015] As a technical solution of the present invention, the temperature of the distillation is 90-100 °C.

[0016] As a technical solution of the present invention, the concentration of the remaining liquid is adjusted to 0.8-1.2 mol / L before the electrolysis, and the voltage applied in the electrolysis is 3.5-5.0 V.

[0017] In the second aspect of the present invention, there is provided a nickel-cobalt-manganese ternary material precursor obtained by the aforementioned regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling, and the regeneration rate is at least 90%. Detailed implementation manners

[0018] The present invention provides a regeneration method and application of a nickel-cobalt-manganese ternary material precursor based on raw material recycling, which can prepare a nickel-cobalt-manganese ternary material precursor with a high regeneration rate, and can ensure the recycling of hydrogen, ammonia, H2SO4 and NaOH. The input-output of the whole system is fully closed-loop, so there is no waste of drugs and wastewater tail treatment process.

[0019] The lithium nickel cobalt manganese oxide-based positive electrode sheet of the present invention refers to a positive electrode sheet containing a lithium nickel cobalt manganese oxide-based positive electrode active material. The lithium nickel cobalt manganese oxide-based positive electrode sheet includes a positive electrode active material, a binder and a conductive agent. The positive electrode active material includes a lithium nickel cobalt manganese oxide-based positive electrode active material, and its chemical formula is LiNi x Co y Mn z M (1-x-y-z) O2, where M is at least one of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V and Ti, 0 < x < 1, 0 < y < 1, 0 < z < 1, and x + y + z ≤ 1. The binder includes PVDF. The conductive agent includes at least one of conductive carbon black, conductive graphite, carbon fiber, carbon nanotube and graphene. The mass ratio of the positive electrode active material, the binder and the conductive agent can be, but is not limited to, 85-98:0.5-3.0:0.5-3.0. The positive electrode active material, the binder and the conductive agent are made into a slurry by a solvent and coated on the positive electrode current collector and dried, rolled, etc. to obtain the positive electrode sheet.

[0020] The regeneration method of the nickel-cobalt-manganese ternary material precursor based on raw material recycling of the present invention includes the steps of: (1) preparing positive electrode powder, (2) calcining and leaching, (3) acid leaching, (4) precipitation, (5) distillation and (6) electrolysis.

[0021] Among them, the step (1) of preparing the positive electrode powder includes crushing the lithium nickel cobalt manganese oxide-based positive electrode sheet disassembled from the waste battery and screening to obtain the positive electrode powder. The particle size of the positive electrode powder obtained after crushing and screening is 70-90 μm. As an example, the particle size can be, but is not limited to, 70 μm, 72 μm, 74 μm, 76 μm, 78 μm, 80 μm, 82 μm, 84 μm, 86 μm, 88 μm, 90 μm. The lithium nickel cobalt manganese oxide-based positive electrode sheet is mechanically crushed and then screened by coupling a sieve and a vibration stirrer.

[0022] Step (2) calcination and leaching includes calcining the positive electrode powder under a hydrogen atmosphere, and dissolving the calcined solid product in water to obtain a leachate and a solid mixture. The calcination temperature is 450-650°C. As an example, the temperature can be, but is not limited to, 450°C, 480°C, 500°C, 520°C, 550°C, 580°C, 600°C, 620°C, and 650°C. The time is 1-2 hours. As an example, the time can be, but is not limited to, 1 hour and 2 hours. The positive electrode powder is calcined under a hydrogen atmosphere to produce Li2O and other metal elements or oxides (Ni, Co, cobalt oxide, manganese oxide) as shown in Formula 1. After calcination, Li2O is leached with water to convert it into a LiOH solution (as shown in Formula 2). Subsequently, the LiOH solution can be converted into a LiOH·H2O solid by further crystallization and recovered (as shown in Formula 3).

[0023] Reaction of positive electrode powder and hydrogen: LiNi x Co y Mn (1-x-y) O2(s)+H2(g)→ Li2O(s)+Ni(s)+Co(s)+CoO(s)+MnO(s)+H2O(g) Formula 1 Li2O water leaching: Li2O(s)+H2O(l)→2LiOH(aq) Crystallization reaction: LiOH(aq)+H2O(l)→LiOH·H2O(s) Formula 3 Step (3) acid leaching involves mixing the solid mixture with dilute sulfuric acid and reacting them at a certain temperature to produce a leachate and hydrogen. The reactions of other metal elements or oxides (Ni, Co, cobalt oxide, manganese oxide) with dilute sulfuric acid are shown in Equations 4 to 6. The resulting hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2).

[0024] Ni(s)+H2SO4(aq)→Ni 2+ (aq)+SO4 2- (aq)+H2(g) Co(s)+CoO(s)+2H2SO4(aq)→2Co 2+ (aq)+2SO4 2- (aq) + H2(g) + H2O(l) Formula 5 MnO(s)+H2SO4(aq)→Mn 2+ (aq)+SO4 2- (aq) + H2O(l) formula six Meanwhile, the concentration of dilute sulfuric acid is 3-5 mol / L. As an example, the concentration can be, but is not limited to, 3 mol / L, 4 mol / L, or 5 mol / L. The liquid-to-solid ratio of dilute sulfuric acid to positive electrode powder is 8-12 L / Kg. As an example, the liquid-to-solid ratio can be, but is not limited to, 8 L / Kg, 9 L / Kg, 10 L / Kg, 11 L / Kg, or 12 L / Kg. The constant temperature is 90-100°C. As an example, the temperature can be, but is not limited to, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, or 100°C. The reaction time is 50-80 minutes. As an example, the reaction time can be, but is not limited to, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, or 80 minutes. Heating can accelerate the acid leaching process.

[0025] Step (4) precipitation includes adding ammonia water to the leachate to obtain a chelate, and then adjusting the pH value with sodium hydroxide to precipitate the chelate, followed by solid-liquid separation to obtain a precursor and a waste liquid.

[0026] The leachate and ammonia water can react as shown in Formula 7 to form a stable metal-ammonium complex, thereby increasing the solubility of the metal ions. The metal-ammonium complex then reacts with sodium hydroxide as shown in Formula 8 to form a hydroxide precipitate, which is a nickel-cobalt-manganese ternary material precursor. In addition, the ratio of the total molar amount of all metals in the leachate to the molar amount of ammonia water is 1:1.0~1.5. As an example, the mass ratio can be, but is not limited to, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.04, 1:1.5. The concentration of sodium hydroxide is 2~4 mol / L. As an example, the concentration can be, but is not limited to, 2 mol / L, 3 mol / L, and 4 mol / L. The adjusted pH value is 8~10. As an example, the pH value can be, but is not limited to, 8, 9, or 10.

[0027] xNi 2+ (aq)+yCo 2+ (aq)+(1-xy)Mn 2+ (aq)+nNH3(l)→[Ni x Co y Mn (1-x-y) (NH3) n ] 2+ (aq) formula seven [Ni x Co y Mn (1-x-y) (NH3) n ] 2+ (aq)+2OH - (aq)→Ni x Co y Mn (1-x-y)(OH)2(s)+nNH3(l) Step (5) distillation includes distilling the waste liquid to collect ammonia and water vapor. The distillation temperature is 90-100°C. As an example, the temperature can be, but is not limited to, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, and 100°C. The ammonia and water vapor in the waste liquid can be collected by distillation and then cooled to be used as ammonia water in the precipitation of step (4). The remaining liquid can be diluted or concentrated to adjust the concentration to 0.8-1.2 mol / L for electrolysis.

[0028] Step (6) electrolysis includes electrolyzing the liquid remaining from the distillation in step (5). The electrolysis apparatus uses graphite plates as cathode and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. During electrolysis, the reactions shown in Formula 9 and Formula 10 occur in the cathode chamber and the anode chamber, respectively.

[0029] Cathode chamber: 2H2O(l)+2e-→2OH - (aq)+H2(g) formula 9 Anode chamber: 2H2O(l)→O2(g)+4H + (aq)+4e - Style 10 Due to the effect of the anion exchange membrane, SO4 2- The H is combined in the anode chamber through the exchange membrane + H2SO4 is generated, while NaOH is generated in the cathode chamber until the reaction charge balance stops. Therefore, after electrolysis, sodium hydroxide is collected in the cathode chamber and dilute sulfuric acid is collected in the anode chamber. The collected sodium hydroxide can be used for precipitation in step (4), and the collected dilute sulfuric acid can be used for acid leaching in step (3). The voltage applied during electrolysis is 3.5~5.0V. As an example, the voltage can be, but is not limited to, 3.5V, 3.7V, 4.0V, 4.2V, 4.4V, 4.6V, 4.8V, and 5.0V.

[0030] In order to better illustrate the purpose, technical solutions and beneficial effects of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be noted that the following implementation method is a further explanation of the present invention and should not be used as a limitation of the present invention.

[0031] Example 1 This embodiment is a method for regenerating a nickel-cobalt-manganese ternary material precursor based on raw material recycling, and the steps are as follows.

[0032] (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets disassembled from the No. 1 waste battery are mechanically crushed to a particle size of 80 μm, and then screened using a screen coupled with a vibrating agitator to obtain positive electrode powder.

[0033] (2) Calcination and leaching The positive electrode powder is calcined at 500° C. for 2 hours in a hydrogen atmosphere, and the calcined solid product is dissolved in water to obtain a leachate and a solid mixture.

[0034] (3) Acid leaching The solid mixture is mixed with dilute sulfuric acid having a concentration of 4 mol / L (the liquid-to-solid ratio of the two is 9 L / Kg) and reacted at 95°C for 65 min to obtain a leachate and hydrogen. The hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2).

[0035] (4) Sedimentation Ammonia water was added to the leachate (the ratio of the total molar amount of all metals in the leachate to the molar amount of ammonia water was 1:1.2) to obtain a chelate. The pH value was then adjusted to 9 with 4 mol / L sodium hydroxide to precipitate the chelate. After solid-liquid separation, the precursor and waste liquid were obtained. The regeneration rate of the precursor was calculated to be 91.5%.

[0036] (5) Distillation The waste liquid is distilled at 90°C to collect ammonia gas and water vapor, which can be used as ammonia water in the precipitation of step (4) after cooling.

[0037] (6) Electrolysis The liquid remaining from the distillation in step (5) is concentrated to a concentration of 1.0 mol / L and then electrolyzed. The electrolysis apparatus uses graphite plates as cathode and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. Electrolysis is performed at 3.5-5.0 V. After electrolysis, sodium hydroxide is collected in the cathode chamber for use in the precipitation in step (4), and dilute sulfuric acid is collected in the anode chamber for use in the acid leaching in step (3).

[0038] Example 2 This embodiment is a method for regenerating a nickel-cobalt-manganese ternary material precursor based on raw material recycling, and the steps are as follows.

[0039] (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets disassembled from the No. 2 waste battery are mechanically crushed to a particle size of 90 μm, and then screened using a screen coupled with a vibrating agitator to obtain positive electrode powder.

[0040] (2) Calcination and leaching The positive electrode powder was calcined at 600° C. for 1.5 h in a hydrogen atmosphere, and the calcined solid product was dissolved in water to obtain a leachate and a solid mixture.

[0041] (3) Acid leaching The solid mixture is mixed with dilute sulfuric acid having a concentration of 5 mol / L (the liquid-to-solid ratio of the two is 10 L / Kg) and reacted at 100°C for 60 min to obtain a leachate and hydrogen. The hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2).

[0042] (4) Sedimentation Ammonia water was added to the leachate (the ratio of the total molar amount of all metals in the leachate to the molar amount of ammonia water was 1:1.5) to obtain a chelate. The pH value was then adjusted to 10 with 3 mol / L sodium hydroxide to precipitate the chelate. After solid-liquid separation, the precursor and waste liquid were obtained. Calculation showed that the regeneration rate of the precursor was 90.8%.

[0043] (5) Distillation The waste liquid is distilled at 100°C to collect ammonia gas and water vapor, which can be used as ammonia water in the precipitation of step (4) after cooling.

[0044] (6) Electrolysis The liquid remaining from the distillation in step (5) is concentrated to a concentration of 1.0 mol / L and then electrolyzed. The electrolysis apparatus uses graphite plates as cathode and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. Electrolysis is performed at 3.5-5.0 V. After electrolysis, sodium hydroxide is collected in the cathode chamber for use in the precipitation in step (4), and dilute sulfuric acid is collected in the anode chamber for use in the acid leaching in step (3).

[0045] Example 3 This embodiment is a method for regenerating a nickel-cobalt-manganese ternary material precursor based on raw material recycling, and the steps are as follows.

[0046] (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets disassembled from the 3# waste battery are mechanically crushed to a particle size of 80μm, and then screened using a screen coupled with a vibrating agitator to obtain positive electrode powder.

[0047] (2) Calcination and leaching The positive electrode powder is calcined at 650° C. for 4 hours in a hydrogen atmosphere, and the calcined solid product is dissolved in water to obtain a leachate and a solid mixture.

[0048] (3) Acid leaching The solid mixture is mixed with dilute sulfuric acid having a concentration of 4 mol / L (the liquid-to-solid ratio of the two is 12 L / Kg) and reacted at 95°C for 65 minutes to obtain a leachate and hydrogen. The hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2).

[0049] (4) Sedimentation Ammonia water was added to the leachate (the ratio of the total molar amount of all metals in the leachate to the molar amount of ammonia water was 1:1.3) to obtain a chelate. The pH value was then adjusted to 9 with 2.5 mol / L sodium hydroxide to precipitate the chelate. After solid-liquid separation, the precursor and waste liquid were obtained. The regeneration rate of the precursor was calculated to be 90.4%.

[0050] (5) Distillation The waste liquid is distilled at 95°C to collect ammonia gas and water vapor, which can be used as ammonia water in the precipitation of step (4) after cooling.

[0051] (6) Electrolysis The liquid remaining from the distillation in step (5) is concentrated to a concentration of 1.2 mol / L and then electrolyzed. The electrolysis apparatus uses graphite plates as cathode and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. Electrolysis is performed at 3.5-5.0 V. After electrolysis, sodium hydroxide is collected in the cathode chamber for use in the precipitation in step (4), and dilute sulfuric acid is collected in the anode chamber for use in the acid leaching in step (3).

[0052] Comparative Example 1 This comparative example is a regeneration method of a nickel-cobalt-manganese ternary material precursor based on raw material recycling, and the steps are as follows.

[0053] (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets disassembled from the No. 1 waste battery are mechanically crushed to a particle size of 80 μm, and then screened using a screen coupled with a vibrating agitator to obtain positive electrode powder.

[0054] (2) Calcination and leaching The positive electrode powder is calcined at 500° C. for 2 hours in a hydrogen atmosphere, and the calcined solid product is dissolved in water to obtain a leachate and a solid mixture.

[0055] (3) Acid leaching The solid mixture is mixed with dilute sulfuric acid having a concentration of 4 mol / L (the liquid-to-solid ratio of the two is 9 L / Kg) and reacted at 95°C for 65 min to obtain a leachate and hydrogen. The hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2).

[0056] (4) Sedimentation The pH value of the leaching solution was adjusted to 9 by adding 4 mol / L sodium hydroxide to precipitate, and then the precursor and waste liquid were obtained by solid-liquid separation. The regeneration rate of the precursor was calculated to be 68.5%.

[0057] (5) Electrolysis The waste liquid is concentrated to a concentration of 1.0 mol / L and then electrolyzed. The device used for electrolysis uses graphite plates as cathode plates and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. Electrolysis is carried out at 3.5-5.0 V. After electrolysis, sodium hydroxide that can be used for precipitation in step (4) is collected in the cathode chamber, and dilute sulfuric acid that can be used for acid leaching in step (3) is collected in the anode chamber.

[0058] The precursors prepared in Examples 1-3 and Comparative Example 1 were mixed with lithium carbonate (the molar ratio of lithium to the total metal content of the precursor was 1.05:1) and ground, followed by sintering at 780°C for 15 hours to produce a ternary cathode material. The resulting ternary cathode material was assembled into button cells and subjected to electrochemical performance testing. The performance test results are shown in Table 1.

[0059] Table 1 Electrochemical performance test results

[0060] As can be seen from the results in Table 1, the nickel-cobalt-manganese ternary material precursor obtained by the regeneration method of the present invention has better electrochemical performance when used as a ternary positive electrode material. In addition, after acid leaching, ammonia chelation is first used and then sodium hydroxide precipitation is used. The obtained nickel-cobalt-manganese ternary material precursor has better electrochemical performance when used as a ternary positive electrode material. This is because the leachate and ammonia reaction can form a stable metal-ammonium complex, thereby increasing the solubility of the metal ions. The metal-ammonium complex formed is then added with sodium hydroxide for precipitation. During the precipitation process, the metal ions can be more evenly distributed in the solution, thereby reducing aggregation and unevenness during the precipitation process. Therefore, it is helpful to obtain precursor particles with uniform particle size and good morphology, thereby improving the electrochemical performance of the final battery material.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for regenerating a nickel-cobalt-manganese ternary material precursor based on raw material recycling, characterized in that: include: (1) Preparation of positive electrode powder The nickel-cobalt-manganese-oxide lithium positive electrode sheets removed from waste batteries are crushed and screened to obtain positive electrode powder; (2) Calcination and leaching calcining the positive electrode powder in a hydrogen atmosphere, and dissolving the calcined solid product in water to obtain a leachate and a solid mixture; (3) Acid leaching The solid mixture and dilute sulfuric acid are mixed and reacted at a certain temperature to obtain a leachate and hydrogen, and the hydrogen can be used as the hydrogen atmosphere in the calcination leaching in step (2); (4) Sedimentation adding ammonia water to the leachate to obtain a chelate, adjusting the pH value with sodium hydroxide to precipitate the chelate, and then performing solid-liquid separation to obtain a precursor and a waste liquid; (5) Distillation The waste liquid is distilled to collect ammonia gas and water vapor, which can be used as the ammonia water in the precipitation of step (4) after cooling; (6) Electrolysis The liquid remaining in the distillation of step (5) is electrolyzed. The device used for the electrolysis uses graphite plates as cathode plates and anode plates, and is divided into a cathode chamber and an anode chamber using an anion exchange membrane. The remaining liquid is placed in the cathode chamber, and an equal amount of water is injected into the anode chamber. After the electrolysis, sodium hydroxide that can be used for precipitation in step (4) is collected in the cathode chamber, and dilute sulfuric acid that can be used for acid leaching in step (3) is collected in the anode chamber.

2. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The lithium nickel cobalt manganese oxide-based positive electrode sheet includes a positive electrode active material, a binder, and a conductive agent. The chemical formula of the positive electrode active material is LiNi x Co y Mn z M (1-x-y-z) O2, where M is at least one of Mg, Cu, Zn, Al, Sn, B, Ga, Cr, Sr, V, and Ti, 0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z ≤ 1. The binder includes PVDF, and the conductive agent includes at least one of conductive carbon black, conductive graphite, carbon fiber, carbon nanotube, and graphene.

3. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The lithium nickel cobalt manganese oxide positive electrode sheet is mechanically crushed to a particle size of 70-90 μm, and then screened using a sieve coupled with a vibrating stirrer.

4. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The calcination temperature is 450-650° C. and the calcination time is 1-2 hours.

5. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The concentration of the dilute sulfuric acid is 3-5 mol / L, and the liquid-to-solid ratio of the dilute sulfuric acid to the positive electrode powder is 8-12 L / Kg.

6. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The certain temperature is 90-100° C., and the reaction time is 50-80 min.

7. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The ratio of the total molar amount of all metals in the leachate to the molar amount of the ammonia water is 1:1.0-1.5, the concentration of the sodium hydroxide is 2-4 mol / L, and the adjusted pH value is 8-10.

8. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The distillation temperature is 90-100°C.

9. The regeneration method of nickel-cobalt-manganese ternary material precursor based on raw material recycling according to claim 1, characterized in that: The concentration of the remaining liquid is adjusted to 0.8-1.2 mol / L before the electrolysis, and the voltage applied during the electrolysis is 3.5-5.0 V.

10. The nickel-cobalt-manganese ternary material precursor obtained by the regeneration method of the nickel-cobalt-manganese ternary material precursor based on raw material recycling according to any one of claims 1 to 9, characterized in that: The regeneration rate is at least 90%.

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