A method for recycling lithium-ion battery cathode materials

Abstract

This invention provides a method for recycling lithium-ion battery cathode materials, comprising the following steps: discharging and disassembling waste lithium-ion batteries to remove battery electrodes; stripping the battery electrodes to obtain aluminum foil and electrode material; crushing and sieving the electrode material to obtain sieved powder; pressing the sieved powder into shape using a mold; placing the pressed material into a vacuum chamber and using laser decomposition technology to cause a decomposition reaction, obtaining soluble lithium salts, metal oxides and / or elemental metals; removing the product after the reaction is complete; using water or a water leaching solution with industrial CO2 gas as the leaching agent, mixing the leaching agent, the laser decomposition product, and the surfactant evenly, leaching, and filtering to obtain a lithium-rich solution and other metal element slag phases; separating and purifying the lithium-rich solution to obtain lithium carbonate product. The lithium-ion battery cathode material recycling method provided by this invention can precisely target and extract lithium, achieving a high lithium element recovery rate and a short process flow.

Description

Technical Field

[0001] This invention relates to the field of lithium battery recycling technology, and specifically to a method for recycling lithium-ion battery cathode materials. Background Technology

[0002] Lithium-ion batteries, with their superior electrochemical performance including high energy density, long cycle life, and high safety, are widely used in various consumer electronics products and new energy vehicles. However, discarded lithium batteries contain many harmful heavy metals and organic substances that endanger the environment and human health. With the increasing market demand for lithium-ion batteries, the environmental pollution and potential safety hazards caused by discarded batteries cannot be ignored.

[0003] Currently, the focus of waste lithium-ion battery recycling is on extracting valuable metal elements from the cathode material. Traditional recycling methods mainly include dry recycling, wet recycling, and biotechnology recycling. Among these, wet recycling is the most commonly used method, which involves crushing and sorting lithium batteries, dissolving and leaching, and then separating and recycling them. This method is increasingly becoming the mainstream technology adopted by enterprises due to its high purity of recycled products, low requirements for operation and equipment, and the ability to reasonably control the feed. However, this process also has disadvantages such as high cost of chemical reagents and slow reaction speed. In comparison, although dry technology has a large recovery volume, its energy consumption and environmental pollution costs are higher, and its purity is also lower, requiring more advanced technology. Biotechnology recycling relies on microbial leaching, but currently, the cultivation of microorganisms is difficult, the leaching environment requirements are high, and it is easy to lead to high research and development costs.

[0004] Therefore, a new, efficient, and environmentally friendly method for recycling waste lithium batteries is needed to solve the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for recycling lithium-ion battery cathode materials, which can accurately target and extract lithium, has a high lithium element recovery rate, and has a short process flow, simple operation, and is environmentally friendly.

[0006] The technical solution of the present invention is as follows:

[0007] A method for recycling lithium-ion battery cathode material, characterized by comprising the following steps:

[0008] Step S1, Disassembly: Discharge and disassemble the used lithium-ion batteries, and remove the battery electrodes;

[0009] Step S2, peeling: After peeling the battery electrode sheets, aluminum foil and electrode material are obtained;

[0010] Step S3, Screening: The electrode material is crushed and screened to obtain sieved powder;

[0011] Step S4, pressing: Press the sieved powder into shape using a mold;

[0012] Step S5, Laser Decomposition: The pressed material is placed in a vacuum chamber and laser decomposition technology is used to decompose the material to obtain soluble lithium salt, metal oxide and / or metal element. The product is taken out after the reaction is completed. The laser power is 1-100W and the scanning rate is 100-1000mm / min. This power condition can prevent the material from overheating and melting locally.

[0013] Step S6, Leaching: Using water or water leaching solution with industrial CO2 gas as leaching agent, mix the leaching agent, the product after laser decomposition, and the surfactant evenly, leach for 30-180 min, and filter to obtain lithium-rich solution and other metal element slag phase; wherein the mass ratio of surfactant to cathode material is 1:10-1:50.

[0014] Step S7, separation and purification: The lithium-rich solution obtained in step S6 is separated and purified to obtain lithium carbonate product.

[0015] Furthermore, in step S2, the binder in the electrode is decomposed by mechanical processing, pyrolysis or chemical decomposition to obtain aluminum foil and peeled electrode material.

[0016] Furthermore, in step S3, the particle size of the sieved powder is 150-400 mesh. The purpose of crushing and sieving is to reduce the particle size of the material, which helps to improve the decomposition efficiency and reduce the instability of the final reaction result.

[0017] Furthermore, in step S4, the sieved powder is pressed into a shape with a thickness of 5-20 mm. This process can improve the thermal conductivity of the material, prevent splashing during laser irradiation and the influence of airflow, and ensure the safety of the entire process and the reliability of the results.

[0018] Furthermore, a certain amount of reducing material is added to the positive electrode powder material, and the mixture is pressed into shape. The mass ratio of the reducing material to the positive electrode powder material is 1:20-1:5. The reducing material is carbon material or sulfuric acid.

[0019] Furthermore, in step S5, an inert gas, such as nitrogen or argon, is introduced into the vacuum chamber. The introduction of the inert gas prevents thermal oxidation of the material.

[0020] Furthermore, in step S5, the laser source used is one of ultraviolet light, visible light, or X-ray.

[0021] Furthermore, in step S5, the liquid-solid ratio of the leaching agent to the product after laser decomposition is 20:1-50:1.

[0022] Further, in step S6, the surfactant is at least one of polyethylene glycol, polypropylene glycol, or sodium dodecyl sulfate.

[0023] Furthermore, the separation and purification process in step S7 is as follows:

[0024] If the leaching agent used is water, the separation and purification process is to heat and concentrate the lithium-rich solution, then pass it through a saturated sodium carbonate solution, then separate and purify it by centrifuge, and finally dry it by a disc dryer to obtain battery-grade lithium carbonate.

[0025] If the leaching agent used is an aqueous leaching solution through which industrial CO2 gas is introduced, the separation and purification process involves vacuum filtration of the lithium-rich solution and evaporation to recover the lithium carbonate product.

[0026] Furthermore, the lithium-ion battery is made of LiNiO2, LiCoO2, LiMnO2, or LiNi x Co y Mn z One of the components of O2.

[0027] The present invention discloses a method for recycling lithium-ion battery cathode materials, which utilizes laser energy to destroy the crystal structure of waste lithium-ion battery cathodes, thereby recovering valuable metal resources therein. During the heating process, the high energy, high power, and high optical density of the laser are used to transfer photon energy to oxygen atoms and metal ions, increasing the energy of the metal-oxygen covalent bonds and placing them in a high-energy state, thereby breaking the covalent bonds between them, ultimately leading to the rupture of chemical bonds and the dissociation of molecules.

[0028] The laser heating process provides energy and momentum. The laser light is absorbed by the lithium-ion battery cathode material powder and converted into heat energy, forming a high-temperature evaporation region on the surface of the metal oxide. This creates a high-temperature and high-pressure environment, further promoting the breakage of chemical bonds between metal and oxygen molecules. Simultaneously, the high optical density and high power of the laser also cause local ionization, forming plasma, which further exacerbates the breaking of chemical bonds.

[0029] For the positive electrode material of calcined lithium batteries, leaching in water is usually required to extract lithium for further recycling of battery raw materials. However, traditional water leaching methods typically have low leaching rates and require long soaking times. Surfactants are compounds with both hydrophilic and lipophilic affinities, which can form a very thin molecular film on the liquid surface, reducing the surface tension of the liquid and enhancing the wettability and permeability of the liquid to the solid. Adding surfactants during water leaching has the following effects: (1) Promoting liquid-solid interface contact: Surfactants can reduce the surface tension of the solution and the solid-liquid interface tension, thereby increasing the contact area and wetting effect between the liquid and solid particles, improving the reaction rate and lithium leaching rate; (2) Enhancing permeability: Adding appropriate types of surfactants helps the liquid penetrate into the interior of solid particles, making the reaction more complete and improving the lithium leaching rate; (3) Preventing particle aggregation: During the water leaching of oxides, particle aggregation affects the uniformity and rate of the reaction, thus affecting the lithium leaching rate. Adding surfactants can prevent particle aggregation, making the particles more uniformly dispersed in the liquid phase, improving the uniformity and rate of the reaction.

[0030] Compared with existing technologies, the method for recycling lithium-ion battery cathode materials provided by this invention has the following advantages:

[0031] I. The lithium-ion battery cathode material recycling method provided by this invention utilizes laser energy to destroy the crystal structure of waste lithium battery cathodes, breaking the metal-oxygen covalent bonds in the cathode material as the core, decomposing it into various low-valence metal oxides and / or elemental metals, and releasing non-toxic gases. Then, a simple water leaching process can achieve selective extraction of lithium. Furthermore, the recycling method of this invention introduces surfactants during the leaching process, changing the surface tension of the solution, thereby increasing the contact area between the liquid and solid, and improving the lithium dissolution rate. In addition, surfactants can be adsorbed on the solid surface to form a protective film, which is beneficial to the penetration of the leaching agent and further promotes lithium leaching. Therefore, the recycling method of this invention can improve the lithium leaching rate, and through selective lithium extraction, the lithium recovery rate can be improved.

[0032] II. The lithium-ion battery cathode material recycling method provided by this invention uses laser decomposition processing. Laser heating rate is fast, which can complete the decomposition of battery cathode material in a shorter time, saving energy and time and greatly improving work efficiency.

[0033] Third, the lithium-ion battery cathode material recycling method provided by this invention, compared with traditional chemical methods, does not involve the use of acid and alkali solutions, organic solvents and reducing agents in the entire recycling process, and the decomposition products are green and environmentally friendly, avoiding the risks and high costs of using toxic solvents, and has high economic and environmental benefits.

[0034] IV. The method for recycling lithium-ion battery cathode materials provided by this invention uses laser decomposition to produce soluble lithium salts and other insoluble metal oxides and their elemental forms. The collection of lithium-containing compounds is relatively easy. This method has the advantages of short process, low energy consumption, simple operation, and high safety. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic flowchart of the lithium-ion battery cathode material recycling method of the present invention;

[0037] Figure 2 This is a schematic diagram of the laser decomposition step in the lithium-ion battery cathode material recycling method of the present invention;

[0038] Figure 3 These are the SEM and XRD images of the waste ternary lithium battery cathode material in Example 3;

[0039] Figure 4 These are SEM and XRD images of the products after laser decomposition treatment of ternary lithium battery raw materials in Example 3. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described below.

[0041] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0042] Please refer to the following: Figure 1 and Figure 2 ,in Figure 1 This is a schematic flowchart of the lithium-ion battery cathode material recycling method of the present invention; Figure 2 This is a schematic diagram of the laser decomposition step in the lithium-ion battery cathode material recycling method of the present invention. A method for recycling lithium-ion battery cathode material includes the following steps:

[0043] Step S1, Disassembly: Discharge and disassemble the used lithium-ion batteries, and remove the battery electrodes;

[0044] Step S2, peeling: After peeling the battery electrode sheets, aluminum foil and electrode material are obtained;

[0045] Specifically, the binder in the electrode is decomposed by mechanical processing, pyrolysis or chemical decomposition to obtain aluminum foil and peeled electrode material;

[0046] Step S3, Screening: The electrode material is crushed and screened to obtain sieved powder;

[0047] Specifically, the sieve mesh size used is 150-400 mesh, and correspondingly, the particle size of the sieved powder is 150-400 mesh.

[0048] Step S4, pressing: Press the sieved powder into shape using a mold;

[0049] Specifically, the sieved powder is pressed into sheet-like structures with a thickness of 5-20 mm. This process improves the material's thermal conductivity, prevents splashing and airflow interference during laser irradiation, and ensures the safety and reliability of subsequent laser decomposition processing. The thickness of the pressed cathode material sheet can be 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, or 20 mm, or other thicknesses within this range. The thickness of the pressed sheet material has a certain impact on the efficiency of laser decomposition.

[0050] As another implementation method, a certain amount of reducing material can be added to the cathode material powder, mixed, and then pressed into shape. The purpose of adding reducing material is to combine the redox reaction of oxides with the cathode material under laser heating, which helps to accelerate the decomposition reaction process of the cathode powder, and the reduced material also meets the water immersion separation conditions. The reducing material is preferably a carbon material or sulfuric acid, with carbon materials such as graphite. The mass ratio of the reducing material to the cathode powder material is 1:20-1:5, such as 1:20, 1:15, 1:10, or 1:5, or other values ​​within this range.

[0051] Step S5, Laser Decomposition: The pressed material is placed in a vacuum chamber, and laser decomposition technology is used to decompose the material to obtain soluble lithium salt, metal oxide and / or metal element. The product is removed after the reaction is completed; wherein the laser power is 1-100W and the scanning rate is 100-1000mm / min.

[0052] Specifically, an inert gas, such as nitrogen or argon, is introduced into the vacuum chamber to prevent thermal oxidation of the material. The laser source used is one of ultraviolet light, visible light, or X-ray, with the laser power designed to be 1-100W and the scanning rate 100-1000mm / min. This prevents localized overheating and melting of the material when the laser power is too high. The laser power can be 1W, 10W, 20W, 30W, 40W, 50W, 60W, 70W, 80W, 90W, or 100W, or other values ​​within this range. The scanning rate can be 100mm / min, 200mm / min, 300mm / min, 400mm / min, 500mm / min, 600mm / min, 700mm / min, 800mm / min, 900mm / min, or 1000mm / min, or other values ​​within this range.

[0053] Step S6, Leaching: Using water or water leaching solution with industrial CO2 gas as leaching agent, mix the leaching agent, the product after laser decomposition, and the surfactant evenly, leach for 30-180 min, and filter to obtain lithium-rich solution and other metal element slag phase; wherein the mass ratio of surfactant to cathode material is 1:10-1:50.

[0054] The surfactant is at least one of polyethylene glycol, polypropylene glycol, or sodium dodecyl sulfate; the mass ratio of the surfactant to the cathode material can be 1:10, 1:20, 1:30, 1:40, or 1:50, or other ratios within this range; the liquid-solid ratio of the leaching agent to the laser decomposition product is 20:1-50:1, such as 20:1, 30:1, 40:1, or 50:1, or other values ​​within this range.

[0055] When the leaching agent is an aqueous leaching solution through which industrial CO2 gas is introduced, the gas flow rate of carbon dioxide is 0.04-0.06 L / min, such as 0.04 L / min, 0.05 L / min, or 0.06 L / min, or other values ​​within this range.

[0056] The leaching time can be 30 min, 50 min, 60 min, 90 min, 120 min, 150 min or 180 min, or other values ​​within this range.

[0057] Step S7, separation and purification: The lithium-rich solution obtained in step S6 is separated and purified to obtain lithium carbonate product;

[0058] Specifically, if the leaching agent used is water, the separation and purification process is to heat and concentrate the lithium-rich solution, then pass it through a saturated sodium carbonate solution, then separate and purify it through a centrifuge, and finally dry it in a disc dryer to obtain battery-grade lithium carbonate.

[0059] If the leaching agent used is an aqueous leaching solution through which industrial CO2 gas is introduced, the separation and purification process involves vacuum filtration of the lithium-rich solution and evaporation to recover the lithium carbonate product.

[0060] The following detailed description of the lithium-ion battery cathode material recycling method of the present invention is illustrated through specific embodiments.

[0061] Example 1: Recycling of LiCoO2 type lithium-ion batteries

[0062] LiCoO2-type waste lithium-ion batteries were discharged and disassembled to remove the LiCoO2 battery electrodes. These electrodes were then mechanically crushed, and the crushed material was filtered through a 200-mesh sieve to obtain sieved powder. 50g of the sieved positive electrode powder was taken, pressed into 10mm sheets, and placed on a sample stage in a vacuum chamber under nitrogen atmosphere. A 10W laser emitter was used, with a scanning rate of 300mm / min, to scan the raw material along a preset path, causing the positive electrode material to undergo a thermal decomposition reaction, yielding Li and Co oxides and releasing oxygen. After the reaction, the product was removed, mixed with polyethylene glycol at a mass ratio of 1:30, and then leached with deionized water for 90 minutes, followed by filtration. ICP testing showed that the lithium leaching rate reached 94.3%, while cobalt leaching was almost nonexistent. Subsequently, the lithium-rich solution was concentrated by heating, then saturated sodium carbonate solution was introduced, and the mixture was stirred at 85°C for 30 minutes. Finally, it was centrifuged for separation and purification. Finally, after drying in a disc dryer, battery-grade lithium carbonate is obtained, with a calculated recovery rate of 91%.

[0063] Example 2: Recycling of LiNiO2 type lithium-ion batteries

[0064] First, waste LiNiO2 batteries were discharged in a 5% NaCl solution for 24 hours. The LiNiO2 electrodes were then disassembled and the positive electrode was placed in a muffle furnace at 400℃ for 60 minutes to decompose the binder, yielding aluminum foil and peeled LiNiO2 positive electrode powder. 30g of the positive electrode powder was sieved using a 300-mesh sieve to obtain sieved material. This material was pressed into 6mm thick sheets and placed in an argon-filled vacuum chamber. The laser power was adjusted to 20W, the scanning rate to 600mm / min, and the laser head was used to heat the material along a preset path, causing decomposition and yielding a mixture of lithium oxide, nickel oxide, and nickel. After the reaction was complete, the product was removed. Polypropylene glycol (1:25 by mass) was mixed with the product, and then a water-based leaching solution with industrial CO2 gas was used as the leaching agent. The CO2 gas flow rate was 0.05L / min, and leaching was carried out for 60 minutes, followed by filtration. The slag sample was tested and found to contain less than 0.1% lithium by mass, resulting in a leaching rate of 98.3%, while the nickel leaching rate was only 0.4%, achieving selective lithium extraction. The lithium-rich solution was then vacuum filtered and evaporated to obtain battery-grade lithium carbonate, with a calculated recovery rate of 95%.

[0065] Example 3, LiNi x Co y Mn z Recycling of O2-type lithium-ion batteries

[0066] LiNi 0.5 Co 0.2 Mn 0.3 O2-type waste lithium-ion batteries were discharged and disassembled. The battery electrodes were removed and soaked in DMF (dimethylformamide) at 80°C for 2 hours to decompose the binder in the electrodes, obtaining aluminum foil and electrode material. After washing and drying, the material was sieved through a 270-mesh sieve to obtain sieved powder. 50g of positive electrode powder was mixed evenly with 10g of graphite material, compacted, and placed on a vacuum chamber platform. The laser power was adjusted to 15W, the scanning rate to 400mm / min, and the laser generator was turned on to cause the material to undergo carbonization and reduction decomposition, yielding a mixture of lithium oxide / lithium carbonate, manganese oxide, cobalt oxide / cobalt, nickel oxide, and nickel. After the reaction was completed, the mixture was mixed with sodium dodecyl sulfate at a mass ratio of 40:1 and leached with deionized water at room temperature with stirring for 100 minutes. After filtration, the residue sample was tested and found to contain less than 0.1% lithium by mass, resulting in a leaching rate of 97.1%. The leaching rates for nickel, cobalt, and manganese were 0.3%, 0.7%, and 0.2%, respectively, achieving selective lithium extraction. The lithium-rich solution was then heated to 90°C, stirred for 30 minutes, and centrifuged. The centrifuged product was washed and dried multiple times to obtain battery-grade lithium carbonate. The calculated recovery rate of the lithium carbonate product was 93%.

[0067] Please refer to the following: Figure 3 and Figure 4 ,in Figure 3 These are the SEM and XRD images of the waste ternary lithium battery cathode material from Example 3. Figure 3 (a) shows the SEM image of the raw material. Figure 3 (b) shows the XRD pattern of the raw material;

[0068] Figure 4 These are SEM and XRD images of the products after laser decomposition treatment of ternary lithium battery raw materials in Example 3. Figure 4 (a) shows the SEM image of the product after laser treatment. Figure 4 (b) shows the XRD pattern of the product after laser treatment. Figure 3 and Figure 4 It can be seen that the diffraction peaks of the waste lithium battery powder correspond one-to-one with those of the standard PDF card (JCPDS: 97-029-1341) of the ternary battery material, and exhibit a distinct spherical morphology. After laser treatment, the layered cathode material has been decomposed and transformed into irregular particles. The bright areas in the SEM image are considered to be fully reduced metallic elements, which are identified by XRD as lithium carbonate, manganese oxide, nickel oxide, nickel-cobalt elements, and residual graphite.

[0069] Comparative Example 1: Recovery of LiNi by Acid Leaching x Co y Mn z O2 type lithium-ion battery

[0070] LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2-type waste lithium-ion batteries were discharged and disassembled. The battery electrodes were removed and soaked in DMF (dimethylformamide) at 80°C for 2 hours to obtain aluminum foil and electrode material. After drying, 40g of positive electrode powder was mixed with 1mol / L sulfuric acid solution and 0.0075mol / L NaHSO3 solution at a liquid-to-solid ratio of 20:1 and leached at 95°C for 240 minutes. After filtration, a residue sample was obtained and analyzed. The leaching rates of nickel, cobalt, manganese, and lithium were calculated to be 96.4%, 91.6%, 87.9%, and 86.6%, respectively. DMG (dimethylglyoxime) was mixed and stirred at 60°C for 40 minutes. After the reaction was complete and the mixture was aged for 30 minutes, it was filtered to obtain a wine-red precipitate, achieving selective nickel recovery. The pH of the filtrate was adjusted, and the mixture was mixed with extractant P204 and stirred for 60 minutes until separation. The upper layer was then back-extracted with sulfuric acid to obtain a manganese sulfate solution. After adjusting the pH of the lower layer solution, it was mixed with extractant P507 and stirred for 60 min, resulting in separation. The upper layer solution was back-extracted to obtain a cobalt sulfate solution, while the lower layer solution was a lithium sulfate solution. The lower layer solution was taken, concentrated by evaporation, mixed with a saturated lithium carbonate solution, heated to 90 °C, stirred for 30 min, and then centrifuged. The centrifuged product was washed and dried multiple times to obtain the lithium carbonate product. The calculated recovery rate of the lithium carbonate product was only 78%.

[0071] It can be seen that the lithium-ion battery cathode material recycling method of the present invention can significantly improve the lithium element recovery rate.

[0072] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and spirit of the present invention still fall within the protection scope of the present invention.

Claims

1. A method for recycling a lithium ion battery cathode material, characterized in that, Includes the following steps: Step S1, Disassembly: Discharge and disassemble the used lithium-ion batteries, and remove the battery electrodes; Step S2, peeling: After peeling the battery electrode sheets, aluminum foil and electrode material are obtained; Step S3, sieving: The electrode material is crushed and sieved to obtain sieved powder with a particle size of 150-400 mesh. Step S4, pressing: A certain amount of reducing material is added to the sieved powder, and after mixing, it is pressed into shape using a mold, with a thickness of 5-20mm; wherein the mass ratio of reducing material to positive electrode powder material is 1:20-1:5; the reducing material is carbon material; Step S5, Laser Decomposition: The pressed material is placed in a vacuum chamber, and laser decomposition technology is used to decompose the material to obtain soluble lithium salt, metal oxide and / or metal element. After the reaction is completed, the product is taken out. The laser source used is one of ultraviolet light, visible light or X-ray, the laser power is 1-100W, and the scanning rate is 100-1000mm / min. Step S6, Leaching: Using water or an aqueous leaching solution infused with industrial CO2 gas as the leaching agent, the leaching agent, the laser decomposition product, and the surfactant are mixed evenly and leached for 30-180 minutes. The solution is then filtered to obtain a lithium-rich solution and a slag phase containing other metal elements. The mass ratio of the surfactant to the cathode material is 1:10-1:50, and the liquid-solid ratio of the leaching agent to the laser decomposition product is 20:1-50:

1. Step S7, separation and purification: The lithium-rich solution obtained in step S6 is separated and purified to obtain lithium carbonate product.

2. The method for recycling lithium-ion battery cathode material according to claim 1, characterized in that, In step S2, the binder in the electrode is decomposed by mechanical processing, pyrolysis or chemical decomposition to obtain aluminum foil and peeled electrode material.

3. The method for recycling lithium-ion battery cathode material according to claim 1, characterized in that, In step S5, an inert gas, namely nitrogen or argon, is introduced into the vacuum chamber.

4. The method for recycling lithium-ion battery cathode material according to claim 1, characterized in that, In step S6, the surfactant is at least one of polyethylene glycol, polypropylene glycol, or sodium dodecyl sulfate.

5. The method for recycling lithium-ion battery cathode material according to claim 1, characterized in that, The separation and purification process in step S7 is as follows: If the leaching agent used is water, the separation and purification process is to heat and concentrate the lithium-rich solution, then pass it through a saturated sodium carbonate solution, then separate and purify it by centrifuge, and finally dry it by a disc dryer to obtain battery-grade lithium carbonate. If the leaching agent used is an aqueous leaching solution through which industrial CO2 gas is introduced, the separation and purification process involves vacuum filtration of the lithium-rich solution and evaporation to recover the lithium carbonate product.

6. The method for recycling lithium-ion battery cathode material according to any one of claims 1-5, characterized in that, LiNiO2, LiCoO2, LiMnO2, LiNi x Co y Mn z O2.

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