All-component closed-loop recycling and recycling method for waste nickel-cobalt-manganese-lithium series battery

Abstract

The invention discloses an all-component closed-loop recycling and recycling method for waste nickel-cobalt-manganese-lithium series batteries, and belongs to the technical field of waste battery recycling. The method comprises the following steps: sequentially carrying out charged crushing, low-temperature volatilization and X-ray sorting on the waste ternary lithium battery to separate a positive plate, a negative plate and a shell; stripping the negative plate to recover the copper sheet, and performing impurity removal and purification on the negative electrode material to obtain high-purity graphite; a positive plate is subjected to sulfuration roasting, valuable metals such as lithium, manganese, iron, aluminum, nickel and cobalt are recycled through step-by-step leaching, and particularly, a nickel-cobalt leaching solution and manganese salt or aluminum salt are subjected to a co-precipitation reaction to prepare a nickel-cobalt-manganese or nickel-cobalt-aluminum ternary battery material precursor and further prepare a regenerated high-nickel ternary positive electrode material. According to the method, the shell, the positive and negative pole pieces, the electrolyte and other components in the waste ternary lithium battery can be efficiently recycled at the same time, the high-added-value product is obtained, the technological process is short, the cost is low, the added value of the product is high, environmental pollution is small, and large-scale industrial production is facilitated.

Description

TECHNICAL FIELD

[0001] The application relates to a waste nickel-cobalt-manganese lithium battery recycling method, in particular to a waste nickel-cobalt-manganese lithium battery full-component closed-loop recycling and recycling method, and belongs to the technical field of waste battery recycling. BACKGROUND

[0002] Lithium ion batteries are the "heart" components of new energy vehicles. With the increasing number of electric vehicles, the use of lithium ion batteries has increased dramatically. With the large-scale use of lithium ion batteries, a large-scale retirement of lithium batteries is inevitable. Retired lithium batteries contain rich valuable metal resources. Taking ternary lithium batteries as an example, the contents of Li, Ni, Co and Mn are 2-5%, 5-12%, 5-20% and 7-10% respectively, and the total metal content is as high as 26-76%. It is a typical key metal secondary resource.

[0003] The existing waste lithium ion battery recycling technology mainly includes pyrometallurgy, hydrometallurgy and direct regeneration. Among them, the pyrometallurgical process is short and has large processing capacity, but the energy consumption is high and the metal recovery selectivity is poor; the hydrometallurgical process has high metal recovery rate, but it usually needs strong acid leaching and solvent extraction, which is easy to produce a large amount of waste liquid; some scholars proposed to use leaching solution as raw material, adjust the element ratio in the leaching solution by removing impurities and adding metal salt, and then directly synthesize the positive electrode material or precursor through sol-gel method or co-precipitation method, which saves the complicated similar metal element separation process. However, due to the difficulty of deep impurity removal and the problem that the regenerated material is difficult to meet the commercial requirements, etc. In addition, the existing waste lithium ion battery recycling process still has deficiencies in tail gas treatment and resource closed-loop utilization. For example, if the sulfur-containing and fluorine-containing waste gas generated in the roasting or pyrolysis process is not effectively recovered, it will cause environmental risk; the lithium salt required in the electrode material regeneration process usually depends on additional purchase, which not only increases the cost, but also the quality fluctuation of lithium salt may affect the performance of the regenerated positive electrode material; the utilization rate of waste negative electrode material is low, and part of it is only used as fuel or low-value filler, which cannot realize high-performance recycling. Therefore, it is urgent to develop a full-component gradient regeneration method which can realize efficient sorting of waste lithium ion battery positive and negative electrodes, high-value recycling of resources, zero emission of tail gas, and direct preparation of high-performance positive and negative electrode materials, so as to improve the resource utilization rate, reduce the environmental impact and take into account the economic benefits.

[0004] Chinese patent application CN118726750A proposes a ternary material full-component recovery process with solid-phase roasting of sulfidizing agent as the core, which first obtains mixed battery powder through crushing and pyrolysis, then sequentially removes aluminum through alkali treatment and copper through ammonia / ammonium salt system, and then adds solid sulfidizing agent for roasting. The roasted material is prepared into ternary precursor through sulfuric acid leaching-nickel cobalt manganese precipitation by alkali-reverse washing-external metal salt proportioning co-precipitation, and lithium is precipitated from the leaching solution by carbonates, and the mother liquor is recycled by MVR to recover the sulfidizing agent. The method has a high recovery rate for ternary materials, but the wet steps of the pretreatment are many, the salt load and waste liquid pressure are large, and the mixing of positive and negative electrode powders easily causes cross contamination. SUMMARY

[0005] In view of the high recovery cost of waste nickel-cobalt-manganese-lithium batteries and the low recovery rate of full components of the batteries, and the secondary pollution caused by the above problems, the purpose of the present application is to provide a method for efficient recovery and regeneration of full components of waste nickel-cobalt-manganese-lithium batteries. The method can recover different types, different batches and different manufacturers of nickel-cobalt-manganese-lithium batteries at the same time, and can also realize efficient recovery of each useful component in the lithium battery, and can also manufacture new high-nickel ternary lithium battery materials and super-fast charging graphite negative electrode materials, realize high-value recovery and efficient sorting of full components of lithium batteries, and also consider environmental protection and economic benefits. The method is simple in process technology, low in cost, small in environmental pollution, and is conducive to large-scale industrial production, and overcomes the problems of cross contamination of impurities caused by mixing of positive and negative electrodes in the existing waste ternary lithium battery recovery process, difficulty in effectively treating tail gas emissions, dependence on external purchase of lithium salt, and low utilization rate of negative electrode materials.

[0006] In order to achieve the above technical purpose, the present application provides a method for closed-loop recovery and recycling of full components of waste nickel-cobalt-manganese-lithium batteries, which comprises the following steps:

[0007] 1) After the waste ternary lithium battery is broken with electricity, low-temperature volatilization is carried out to remove the electrolyte and condense and collect fluorides, and the remaining solids after low-temperature volatilization are separated by X-ray sorting to obtain positive electrode sheets, negative electrode sheets and shells;

[0008] 2) The negative electrode sheet is peeled to obtain a copper foil and a negative electrode material, and the negative electrode material is subjected to gas heat impurity removal and high-temperature purification to obtain high-purity graphite; the high-purity graphite is used as a 6C super-fast charging negative electrode material;

[0009] 3) The positive electrode sheet is placed in a mixed atmosphere containing sulfur dioxide and a reducing gas for sulfidation roasting to obtain a sulfidation roasting product containing lithium sulfate, nickel cobalt sulfide, metallic aluminum and iron manganese oxide, and the tail gas generated during sulfidation roasting is absorbed by alkali liquor to recover sulfur elements in the tail gas and convert them into sulfides and / or sulfates;

[0010] 4) water leaching the sulfidation roasting product to obtain a lithium-containing leaching solution and a water leaching residue, purifying and removing impurities from the lithium-containing leaching solution, and precipitating to obtain a lithium-containing compound;

[0011] 5) obtaining a leaching solution containing manganese, iron and aluminum and an acid leaching residue containing nickel and cobalt sulfides by acid leaching the water leaching residue;

[0012] 6) obtaining a leaching solution containing nickel and cobalt by pressure oxidation leaching the acid leaching residue, purifying and removing impurities from the leaching solution containing nickel and cobalt, adding a manganese salt or an aluminum salt and performing a co-precipitation reaction to obtain a ternary battery material precursor of nickel cobalt manganese or nickel cobalt aluminum;

[0013] 7) obtaining a regenerated high-nickel ternary positive electrode material by oxidizing and roasting the precursor and the lithium-containing compound.

[0014] The recycling method of the abandoned nickel-cobalt-manganese-lithium battery can realize efficient separation and recovery of each component of the lithium ion battery, such as the shell, the positive electrode sheet, the negative electrode sheet and the electrolyte. At the same time, the closed-loop recycling process is adopted to realize high-value utilization of all components, reduce tail gas emission and reduce environmental pollution. After the abandoned nickel-cobalt-manganese-lithium battery is broken with electricity, the organic solvent in the electrolyte can be recovered by low-temperature volatilization. At the same time, the low-boiling-point fluorides volatilized in the electrolyte are recovered by condensation, reducing the harmful substance emission in the subsequent treatment process. The solid obtained by low-temperature volatilization is selected by X-ray, which can efficiently separate the positive electrode sheet, the negative electrode sheet and the shell to avoid the technical problems of cross contamination of impurities caused by mixed treatment of the positive electrode sheet and the negative electrode sheet and difficult effective treatment of tail gas emission. At the same time, the valuable metals are converted into roasting products with different leaching difficulties by selective sulfidation roasting, and the lithium is extracted by water leaching and the nickel and cobalt are recovered by oxidation leaching, which realizes step-by-step leaching, significantly reduces the amount of acid and alkali and salt load.

[0015] The negative electrode material of the waste ternary lithium battery is often accompanied by transition metal impurities (such as Cu, Al, Fe, Ni, Co, Mn, etc.), inorganic lithium salts and fluorine-containing residues (such as Li2CO3, LiF, etc.) from electrolyte / SEI, and a small amount of non-metal oxides such as SiO2 and Al2O3. The above impurities will cause the specific capacity and cycle stability of the regenerated graphite to decrease. For the recovery of the negative electrode sheet, the copper foil is first peeled off, the negative electrode graphite material is removed by gas heating, the metal and its oxides / silicon oxides are converted into volatile chlorides (such as AlCl3, FeCl3, SiCl3, etc.) by fluorine and chlorine gases at high temperature, which are migrated out with the gas phase, realizing efficient removal of impurities in the graphite, and then purified and regenerated at high temperature to obtain a super-fast charging negative electrode material with high rate performance.

[0016] This invention employs a selective sulfurization roasting method for the recycling of positive electrode sheets. The positive electrode sheets do not require pretreatment such as peeling, calcination, or degumming; instead, selective sulfurization roasting is performed directly under a special CO2 / reducing gas atmosphere. In the combined atmosphere of SO2 and CO / H2, sulfur dioxide first generates active sulfur under the action of the reducing gas, and then undergoes a gas-solid reaction with the positive electrode active material on the sheet. This causes preferential phase transformation of Ni, Co, and Li, while Mn remains in the oxidized state within the designated sulfur / oxygen potential region, and the aluminum current collector remains in the metallic state. CO / H2 simultaneously acts as an oxygen potential buffer in the reaction, carrying away oxygen in the form of CO2 and H2O, thus achieving selective sulfurization roasting. After selective sulfurization roasting, lithium is selectively converted into water-soluble lithium sulfate, nickel and cobalt are selectively converted into nickel-cobalt sulfides, while aluminum, iron, and manganese are converted into elemental metals or oxides. This allows for the sequential recovery of lithium through water leaching, aluminum, iron, and manganese through acid leaching, and nickel and cobalt through oxygen-pressure acid leaching. The tail gas generated from sulfur roasting is treated with alkaline solution to recover sulfur, producing reusable sulfides or sulfates, thus achieving closed-loop utilization of sulfur resources. Lithium recovered through water leaching can be converted into lithium carbonate or lithium hydroxide for use as a lithium source in subsequent high-nickel ternary lithium battery cathode material preparation processes. Aluminum, iron, and manganese recovered through acid leaching can be separated using wet methods, while nickel and cobalt recovered through oxygen pressure acid leaching are used as nickel and cobalt sources for nickel-cobalt-manganese or nickel-cobalt-aluminum ternary cathode materials through co-precipitation, ultimately transforming into high-value high-nickel ternary cathode materials.

[0017] As a preferred embodiment, the conditions for the low-temperature volatilization are: an atmosphere of nitrogen and / or inert gas, a temperature of 90~200℃, and a time of 60min~180min. The low-temperature volatilization primarily recovers organic solvents (such as methyl carbonate, ethylene carbonate, etc.) and a small portion of fluorinated compounds and alcohols from the electrolyte. The fluorinated compounds can be collected separately through condensation.

[0018] As a preferred embodiment, the conditions for gas-thermal purification are as follows: at least one of fluorine, chlorine, NH4F or NH3HF2 is used as the purification agent, and the purification temperature is 200~1000℃.

[0019] As a preferred embodiment, the high-temperature purification conditions are: temperature of 2000~3000℃ and time of 60~300min. Under high-temperature conditions above 2000℃, the contained metallic impurities can be volatilized and removed, while the degree of graphitization is improved.

[0020] As a preferred embodiment, the selective sulfurization roasting conditions are as follows: the sum of the volume fractions of SO2 and reducing gas (CO and / or H2) in the mixed atmosphere is 10-40 vol%, the volume ratio of SO2 to reducing gas is 1:(1.5-3.5), the temperature is 600-1000℃, and the time is 60-180 min; the reducing gas includes carbon monoxide and / or hydrogen. Compared with conventional sulfurization roasting, this invention treats the entire positive electrode as the object of treatment, and directly performs gas-solid sulfurization after the electrolyte is volatilized at low temperature. The gas sulfurization method not only has a shorter mass transfer path and a more complete reaction, but also effectively utilizes the residual organic matter on the electrode as an in-situ reducing agent, eliminating the need for a separate pyrolysis stripping process for electrode powder, reducing steps and energy consumption, and reducing dust. Conventional sulfurization processes mostly use solid sulfurizing agents, whose reactions are easily controlled by diffusion, resulting in slow mass transfer, uneven reaction, and incomplete reaction. The ratio of SO2 to reducing gas is a crucial factor affecting the selective sulfurization roasting effect. When the ratio of reducing gas to SO2 is too low, some high-valence metals cannot be reduced and remain in their high-valence metallic state, resulting in low active sulfur content and failing to achieve the goal of efficient nickel and cobalt sulfidation. Conversely, when the ratio is too high, some metals are over-reduced to elemental form, making it difficult to form the target sulfide. In addition to SO2 and reducing gas, the mixed atmosphere of this invention also includes nitrogen or an inert gas (such as Ar). The mixed atmosphere is maintained by continuously introducing a mixture of SO2 diluted with nitrogen or an inert gas and reducing gas, with a total flow rate of 50-1000 mL / min. The tail gas generated during the selective sulfurization roasting process is absorbed by an alkaline solution to generate sulfides or sulfates that can be directly reused as industrial raw materials. The alkaline solution can be at least one of sodium hydroxide solution, potassium hydroxide solution, or sodium carbonate solution, with an absorption temperature of 10-80°C.

[0021] As a preferred embodiment, the water leaching conditions are: temperature of 20~100℃; liquid-to-solid ratio of 10~120mL / g; and leaching time of 30~300min. Since selective sulfidation roasting can control the efficient conversion of lithium to lithium sulfate, a high lithium recovery rate can be obtained by controlling appropriate water leaching conditions.

[0022] As a preferred embodiment, the acid leaching conditions are: temperature of 30~100℃, liquid-to-solid ratio of 5~100mL / g, leaching time of 30~360min, and acid solution of sulfuric acid, hydrochloric acid, or ascorbic acid with a concentration in the range of 0.5~3mol / L. Under these preferred acid leaching conditions, aluminum, iron, and manganese, existing in the form of metals and metal oxides, can be efficiently leached, while nickel and cobalt, existing in the form of sulfides, remain in the slag phase.

[0023] As a preferred embodiment, the oxygen-pressure acid leaching conditions are as follows: the atmosphere inside the pressure vessel is air, the pressure is 1~3 MPa, sulfuric acid with a concentration of 1~4 mol / L is used as the leaching agent, the temperature is 70~180℃, and the time is 30~180 min. Under these preferred acid leaching conditions, efficient leaching of nickel and cobalt sulfides can be ensured.

[0024] As a preferred embodiment, the coprecipitation reaction conditions are: temperature 20-80℃, pH value controlled within the range of 7-11, and time 60-1440 min. Ammonium carbonate, sodium carbonate, ammonium bicarbonate, or ammonia water are used as pH adjusters during the coprecipitation reaction. Both manganese and aluminum salts used in the coprecipitation reaction are sulfates. The amounts of manganese and aluminum salts are quantified according to the chemical composition of the nickel-cobalt-manganese or nickel-cobalt-aluminum ternary battery material precursor, such as Ni... x Co y Mn z (OH)2 or Ni x Co y Al z (OH)2, where x+y+z=1, x is 0.5~0.9, y is 0.01~0.4, and z is 0.01~0.4.

[0025] As a preferred embodiment, the oxidation calcination conditions are as follows: pre-calcination at 400-600℃ for 3-8 hours, followed by calcination at 600-1200℃ for 5-24 hours, in an oxygen-containing gas atmosphere. The oxygen-containing gas can be oxygen, air, or an oxygen-enriched atmosphere. The purpose of pre-calcination is to remove moisture and impurities from the precursor and lithium source, and to promote the gradual conversion of each component into the corresponding transition metal oxides and some intermediate products, thereby facilitating subsequent high-temperature calcination to form a stable and uniform ternary cathode material.

[0026] This invention employs X-ray sorting (XRT), an automated sorting technology based on X-ray transmission (energy dispersive spectroscopy) imaging and deep learning (see CN118572233A for details). The sorting system acquires images of the mixed materials under X-ray projection and distinguishes between copper-rich negative electrode sheets and aluminum-containing positive electrode sheets by extracting the atomic number characteristics of the materials. The equipment consists of a feeding and flattening system with belt conveyor, an X-ray scanning cavity (with X-ray source and linear array detector), an industrial computing platform, and high-speed jet nozzles. During sorting, electrode sheets that have undergone low-temperature volatilization pass through the scanning cavity, where the software identifies the transmission images in real time and generates tags. Upon reaching the sorting position, they are separated by high-speed jet nozzles. This method is fast, non-contact, has high identification accuracy, and a large processing capacity. It is well-suited for waste lithium battery electrode sheets and can achieve long-term stability through production data calibration. The feeding speed of X-ray sorting is 1000 frames / second to 2000 frames / second.

[0027] The purification process of the lithium-containing leachate of the present invention includes the removal of impurity metal ions such as Al, Ca, Mg, Fe, and Cu. This purification process employs conventional techniques found in the prior art.

[0028] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0029] 1) This invention performs low-temperature volatilization and X-ray intelligent sorting on waste nickel-cobalt-manganese lithium batteries after they are broken and charged. This not only achieves efficient separation of positive and negative electrode sheets in retired lithium batteries, which is conducive to the efficient recycling of positive and negative electrode materials, but also achieves simultaneous and efficient treatment of electrolyte, a pollutant.

[0030] 2) This invention uses SO2 as a gaseous sulfur source to directly selectively sulfide-roast the positive electrode of waste nickel-cobalt-manganese-lithium batteries. This not only makes full use of the residual organic matter in the positive electrode to promote the sulfide reaction, but also significantly improves the selective sulfide reaction process. At the same time, the sulfur element in the selective sulfide tail gas is absorbed and recovered by alkaline solution, which can directly prepare sulfides or sulfates, reducing environmental pollution.

[0031] 3) The battery-grade lithium salt recovered through water immersion and impurity removal steps of this invention can be directly used for the regeneration of ternary cathode materials, reducing the cost of purchasing lithium salts and ensuring product performance stability;

[0032] 4) This invention can regenerate waste nickel-cobalt-manganese lithium-ion battery cathode materials into high-nickel ternary cathode materials, and the negative electrode graphite can be purified to prepare ultra-fast charging negative electrode materials with high charge-discharge performance, thereby maximizing the utilization of waste battery resources.

[0033] 5) This invention can significantly reduce the amount of waste liquid and waste gas emissions, reduce the consumption of chemical reagents, and has the potential for industrial-scale promotion. Attached Figure Description

[0034] Figure 1 This is a flow chart of the efficient separation and recycling process for all components of waste nickel-cobalt-manganese-lithium batteries according to the present invention.

[0035] Figure 2 The image shows the XRD phase diagram of the product after selective sulfidation and roasting of the waste nickel-cobalt-manganese-lithium battery cathode sheet in Example 2. Through selective sulfidation and roasting, selective sulfidation of the waste nickel-cobalt-manganese-lithium battery cathode sheet was achieved. Lithium was converted into soluble lithium sulfate, nickel and cobalt were sulfides, manganese was an oxide (manganese sulfide), and aluminum was an element, which is beneficial for subsequent acid leaching and separation treatment. Detailed Implementation

[0036] The following specific embodiments are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the claims.

[0037] Example 1

[0038] The raw material was waste ternary lithium batteries sourced from a new energy company in Hunan Province. The main components and mass content of the waste ternary lithium batteries were as follows: shell 6.05%, separator 5.87%, electrolyte 6.02%, positive electrode 43.69%, and negative electrode 38.37%. The waste ternary lithium batteries were subjected to charged crushing, with a discharge port of 4cm (controlling the discharge particle size to less than 4cm), and nitrogen as the protective gas. The waste ternary lithium batteries were crushed under nitrogen protection, and the resulting mixture was volatilized at 130℃ for 120 minutes in a nitrogen atmosphere. Weighing results showed an electrolyte volatilization rate of 95.43%, and gas chromatography results showed that the volatile organic compounds were mostly organic solvents from the electrolyte (such as methyl carbonate and ethylene carbonate). The mixed electrodes were then identified online in an X-ray intelligent sorting machine at a feed rate of 1800 frames / second, separating the positive and negative electrodes with separation rates of approximately 97.25% and 98.64%, respectively.

[0039] The atmosphere inside the tube furnace was set with a total volume fraction of SO2 and CO of 20%, where the SO2 / CO volume ratio was 1:2, and argon was used as the diluent gas; the total gas flow rate was 100 mL / min; the positive electrode was placed directly inside the tube furnace, and calcination was carried out at 600℃ for 180 min. XRD results were obtained (…). Figure 2 The product mainly consisted of nickel-cobalt sulfides, lithium sulfate, manganese oxide, and elemental aluminum. The calcined product was leached in water at a liquid-to-solid ratio of 10 mL:1 g at room temperature for 120 min, achieving a lithium leaching rate of 98.62%. The lithium-containing solution was then purified by simple hydrolysis precipitation to remove impurities such as Al, Mg, Fe, and Cu, followed by carbonation to convert it into lithium carbonate. The water-leached residue was leached with hydrochloric acid at a concentration of 1.5 mol / L, a liquid-to-solid ratio of 10 mL:1 g, a leaching temperature of 85 °C, and a leaching time of 90 min, yielding nickel-cobalt sulfide leaching residue and leachates containing manganese, iron, and aluminum. The manganese, iron, and aluminum leachates were separated using existing wet separation methods.

[0040] Nickel-cobalt sulfide leaching residue was placed in a pressure vessel, and air was introduced to achieve a pressure of 3 MPa. Leaching was carried out for 120 min at a H₂SO₄ concentration of 2 mol / L and a temperature of 120 °C to obtain a nickel-cobalt sulfate solution. Nickel, cobalt, and manganese sulfates were used as conditioning raw materials, and the feed ratio of Ni:Co:Mn was adjusted to 8.00:1.00:1.00 to prepare the precursor. The precursor preparation conditions were: 1.20 mol / L Na₂CO₃ precipitant, 1.00 mol / L NH₃·H₂O complexing agent, reaction temperature 55 °C, reaction time 120 min, and stirring speed 600 rpm. The obtained material was vacuum dried at 120 °C for 180 min to obtain a lithium source for high-nickel ternary regenerative materials. The lithium source and battery precursor were mixed at a molar ratio of Li:TM = 1.05:1 and then subjected to a mixing treatment. The sample was pre-calcined at 500°C for 5 hours in an air atmosphere and then calcined at 1000°C for 12 hours to obtain a high-nickel recycled ternary material.

[0041] The anode sheets obtained from the intelligent sorting process are physically peeled off to collect the waste graphite anode material. 20.00 wt% NH4F is mixed into the waste graphite material. The mixed sample is placed in a tube furnace and heated to 250°C for 120 min under a nitrogen atmosphere. The calcined product is then leached at room temperature for 60 min at a liquid-to-solid ratio of 15 mL:1 g, followed by filtration and drying to obtain crude recycled graphite with a carbon content of 99.92 wt%. To repair interlayer defects and reduce specific surface area, the crude graphite product is annealed at 2500°C for 90 min under an inert atmosphere, and then cooled to obtain recycled graphite.

[0042] Half-cells were prepared using recycled graphite to evaluate its performance as a negative electrode material. The results showed that the initial capacity of the recycled graphite obtained by this process was 324 mAh / g, the first-cycle coulombic efficiency was 91.32%, and the capacity retention rate after 100 cycles at 0.1C was 99.69%.

[0043] Example 2

[0044] Example 1 was repeated, except that the X-ray sorting feed rate was changed to 1500 frames / second, and the separation rates of the positive and negative electrodes reached 96.44% and 95.33%, respectively. This shows that a suitable feed rate helps to improve the separation rate of the positive and negative electrodes.

[0045] Example 3

[0046] Example 1 was repeated, except that the temperature at which the electrically charged crushed product volatilized at low temperature was 110°C, and all other conditions remained unchanged.

[0047] Under these operating conditions, the volatilized products were analyzed, and the electrolyte volatilization rate was 55.28%, indicating that a suitable heating temperature helps to achieve efficient electrolyte volatilization.

[0048] Example 4

[0049] Example 1 was repeated, except that the selective sulfidation atmosphere of the positive electrode was changed to a mixture of SO2 and H2 with a volume fraction of 12 vol%, wherein the volume ratio of SO2 to H2 was 1:2.5. The composition of the calcination product was still nickel cobalt sulfide, lithium sulfate, manganese oxide and aluminum. The subsequent step-by-step leaching, precursor co-precipitation and battery regeneration were the same as in Example 1. The properties and phases of the obtained material were consistent.

[0050] Comparative Example 1

[0051] Example 1 was repeated, with the only difference being that the selective sulfidation roasting atmosphere was changed to a total SO2 / CO volume of 20 vol%, with a SO2:CO volume ratio of 1:1, the sulfidation temperature was increased to 800℃, and the roasting time was 180 min. NiSO4, CoSO4, and MnSO4 appeared in the sulfidation products, and the lithium leaching rate after water immersion was only 80.34%. This indicates that the excessively high CO proportion leads to the formation of byproducts Li2CO3 and transition metal sulfates in the sulfidation roasting products, increasing the difficulty of separating valuable metals. Therefore, special attention must be paid to the atmosphere control of the selective sulfidation reaction.

[0052] Comparative Example 2

[0053] Example 1 was repeated, with the only difference being that the selective sulfidation roasting atmosphere was changed to a total SO2 / CO volume of 20 vol%, with a volume ratio of SO2:CO = 1:2, the roasting time was 120 min, and the sulfidation temperature was increased to 1200℃. The sulfidation products contained a nickel-cobalt alloy phase and manganese sulfide, and the lithium leaching rate decreased to 55.24% after water immersion. This indicates that excessively high sulfidation temperatures create a strong reducing atmosphere in the reaction system, thereby promoting the transformation of nickel-cobalt sulfides towards the metallic elemental phase. Furthermore, lithium sulfate, under prolonged strong reducing and high-temperature conditions, reacted with molten aluminum to form insoluble lithium aluminate. Therefore, special attention must be paid to the temperature range of the selective sulfidation reaction.

[0054] Example 5

[0055] Example 1 was repeated, except that the negative electrode graphite impurity removal process used chlorine gas as the atmosphere, and was treated at 1000°C for 120 minutes to obtain crude regenerated graphite with a carbon content of 99.51 wt%. This shows that graphite products with a high solid carbon content can still be obtained through chlorination treatment and used in subsequent purification and regeneration processes.

[0056] Comparative Example 3

[0057] Example 1 was repeated, with the only difference being that the graphite purification temperature was 1500℃ and the time was 60 minutes. The resulting graphite, after analysis, was found to contain 3798 µg / g of iron impurities and 558 µg / g of silicon impurities. This indicates that excessively low purification temperatures cannot effectively remove non-volatile metal impurities from graphite; therefore, the temperature range of the graphite purification reaction must be carefully considered.

Claims

1. A closed-loop method for the recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries, characterized in that: Includes the following steps: 1) After the waste ternary lithium battery is crushed while charged, it is volatilized at low temperature to remove the electrolyte and collect the fluoride at the same time. The solid remaining after low temperature volatilization is sorted by X-ray to obtain the positive electrode, negative electrode and shell. 2) The negative electrode sheet is peeled off to obtain copper foil and negative electrode material. The negative electrode material is subjected to gas thermal impurity removal and high temperature purification to obtain high-purity graphite. The high-purity graphite is used as the negative electrode material for 6C ultra-fast charging. 3) The positive electrode is placed in a mixed atmosphere containing sulfur dioxide and reducing gas for selective sulfidation roasting to obtain sulfidation roasting products containing lithium sulfate, nickel cobalt sulfide, metallic aluminum and iron manganese oxide. The tail gas generated during the sulfidation roasting process is absorbed by alkaline solution to recover the sulfur element in the tail gas and convert it into sulfide and / or sulfate. 4) The sulfurized roasting product is subjected to water leaching to obtain a lithium-containing leachate and water leaching residue. The lithium-containing leachate is purified, impurities removed, and precipitated to obtain a lithium-containing compound. 5) The water-leached residue is acid-leached to obtain a leachate containing manganese, iron and aluminum and an acid-leached residue containing nickel-cobalt sulfides; 6) The acid leaching residue is subjected to oxygen pressure acid leaching to obtain a leaching solution containing nickel and cobalt. After purification and impurity removal, manganese salt or aluminum salt is added to the leaching solution and a co-precipitation reaction is carried out to obtain nickel-cobalt-manganese or nickel-cobalt-aluminum ternary battery material precursors. 7) The precursor and the lithium-containing compound are subjected to oxidative roasting to obtain a recycled high-nickel ternary cathode material.

2. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for the low-temperature volatilization are: an atmosphere of nitrogen and / or inert gas, a temperature of 90~200℃, and a time of 60min~180min.

3. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for gas-thermal purification are as follows: at least one of fluorine, chlorine, NH4F or NH3HF2 is used as the purification agent, and the purification temperature is 200~1000℃.

4. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for high-temperature purification are: temperature of 2000~3000℃ and time of 60~300min.

5. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The selective sulfurization roasting conditions are as follows: the sum of the volume fractions of SO2 and reducing gas in the mixed atmosphere is stable in the range of 10~40 vol%, the volume ratio of SO2 to reducing gas is 1:(1.5~3.5), the temperature is 600~1000℃, and the time is 60min~180min; the reducing gas includes carbon monoxide and / or hydrogen.

6. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for water immersion are: temperature of 20~100℃; liquid-to-solid ratio of 10~120mL / g; and immersion time of 30~300min.

7. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The acid leaching conditions are as follows: temperature is 30~100℃, liquid-to-solid ratio is 5~100mL / g, leaching time is 30~360min, and the acid solution is sulfuric acid, hydrochloric acid or ascorbic acid with a concentration in the range of 0.5~3mol / L.

8. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for oxygen pressure acid leaching are as follows: the atmosphere inside the pressure vessel is air, the pressure is 1~3MPa, a sulfuric acid solution with a concentration of 1~4mol / L is used as the leaching agent, the temperature is 70~180℃, and the time is 30~180min.

9. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for the coprecipitation reaction are: temperature of 20~80℃, pH value controlled within the range of 7~11, and time of 60~1440min.

10. The method for closed-loop recycling and reuse of all components of waste nickel-cobalt-manganese-lithium batteries according to claim 1, characterized in that: The conditions for the oxidation roasting are as follows: first, pre-roast at 400~600℃ for 3~8h, then roast at 600~1200℃ for 5~24h, in an oxygen-containing atmosphere.

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