Regeneration method of lithium iron phosphate positive electrode material waste

Abstract

The invention discloses a lithium iron phosphate positive electrode material waste regeneration method, which comprises: S1, crushing a disassembled positive electrode plate, and calcining in an inert gas to obtain a pre-treated powder material; s2, putting the pretreated powder into a leaching tank, adding an organic acid and ATMP composite leaching agent, and carrying out a stirring reaction; s3, cooling the leachate to room temperature, adding lithium hydroxide to adjust the pH value, stirring, standing, and filtering to obtain filter residues and filtrate; s4, adding anhydrous sodium carbonate into the filtrate, stirring for reaction, filtering and separating to obtain lithium carbonate precipitate, and cleaning the precipitate to obtain high-purity lithium carbonate; s5, the filter residues and lithium carbonate are mixed, acetylene black is added into the mixture, then the mixture is put into a ball mill, a dispersing agent is added for ball milling, and mixed powder is obtained after spray drying; and S6, roasting the mixed powder under the protection of inert gas, and cooling to room temperature to obtain the regenerated lithium iron phosphate positive electrode material. The method has the advantages of low pollution, high recovery rate, low energy consumption and excellent performance of the regenerated material.

Description

Technical Field

[0001] This invention relates to the field of electronic waste resource utilization technology, and in particular to a method for regenerating lithium iron phosphate cathode material waste. Background Technology

[0002] Lithium-ion batteries, especially lithium iron phosphate batteries, are widely used in new energy vehicles and energy storage systems. However, with their gradual obsolescence, the waste and scrap from lithium iron phosphate batteries are constantly increasing. If these wastes are not effectively recycled, they will not only waste valuable resources such as lithium, iron, and phosphorus, but may also cause environmental pollution problems. Therefore, recycling and reusing lithium iron phosphate cathode material waste is not only conducive to the efficient use of resources, but also of great significance for reducing environmental burden and promoting sustainable development.

[0003] Currently, there are some technologies for recycling waste from lithium iron phosphate cathode materials, but many methods still suffer from high energy consumption, severe pollution, and high costs. For example, the most common traditional recycling technology is hydrometallurgy, which recovers and reuses lithium and iron from lithium iron phosphate. However, hydrometallurgy usually requires the use of strong acid solvents, such as sulfuric acid or hydrochloric acid, which may lead to environmental pollution and increased costs for wastewater treatment. Furthermore, the dissolution and precipitation steps in the hydrometallurgical process are relatively complex, and the recovery efficiency is greatly affected by factors such as temperature and acid concentration, which may lead to the loss of metal elements. At the same time, the process requires a large amount of chemical reagents, resulting in high energy consumption and increased production costs. In addition, the waste and secondary pollution problems generated by hydrometallurgy still need to be further addressed, which limits its large-scale application.

[0004] Therefore, there is an urgent need to develop a method for regenerating lithium iron phosphate cathode waste that is low in pollution, has a high recovery rate, low energy consumption, and produces recycled materials with excellent performance. Summary of the Invention

[0005] The purpose of this invention is to provide a method for regenerating lithium iron phosphate cathode material waste, so as to solve the problems of high energy consumption, serious pollution and high cost of the regeneration methods of lithium iron phosphate cathode material waste mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for regenerating waste lithium iron phosphate cathode material includes the following steps: S1. Crushing the cathode sheets dismantled from waste lithium iron phosphate batteries to a particle size of 50-100 μm, calcining them at 300-400℃ for 1-2 hours under inert gas protection to remove the surface binder, and obtaining pretreated powder; S2. Placing the pretreated powder into a leaching tank, adding an organic acid and ATMP composite leaching agent at a solid-liquid ratio of 1:9-11, and stirring and reacting at 50-70℃ for 2-3 hours to obtain a leachate; S3. [The text abruptly ends here, likely due to an incomplete translation or missing information.] Cool the solution to room temperature, add a 5% (w / w) lithium hydroxide aqueous solution to adjust the pH to 4.5-5.0, stir for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, stir and react at 65-75℃ for 1-2 h, then filter to separate lithium carbonate precipitate, wash the precipitate with deionized water and dry to obtain high-purity lithium carbonate; S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add to it... The mixture is mixed with acetylene black, then placed in a ball mill and a dispersant is added. The mixture is then wet-milled and spray-dried to obtain a mixed powder. S6. Under inert gas protection, the mixed powder is calcined at 650~750℃ for 4~4.5h and cooled to room temperature to obtain a regenerated lithium iron phosphate cathode material.

[0007] As a preferred embodiment of the present invention, the inert gas is either nitrogen or argon.

[0008] As a preferred embodiment of the present invention, the organic acid and ATMP composite leaching agent in S2, wherein the organic acid is any one of 0.5~1.0 mol / L citric acid and oxalic acid, and the amount of ATMP added is 5~8% of the mass of the organic acid.

[0009] As a preferred embodiment of the present invention, the stirring rate in S2 is 200~300 rpm; the stirring rate in S3 is 200~300 rpm.

[0010] As a preferred embodiment of the present invention, the amount of anhydrous sodium carbonate added in step S4 is 1.5 times the mass of the filtrate; the precipitate is washed three times with deionized water, and the amount of deionized water used each time is 5 times the mass of the precipitate; the drying temperature is 120~130℃, and the drying time is 2~2.5h.

[0011] As a preferred technical solution of the present invention, in S5 The addition amount of the additive is 1% to 2% of the mass of the mixture, and the addition amount of the acetylene black is 1% to 3% of the mass of the mixture.

[0012] As a preferred embodiment of the present invention, the dispersant in S5 is anhydrous ethanol, the solid content of the mixture is controlled to be 45-50%, the ball milling speed is 300-500 rpm, and the ball milling time is 3-4 h.

[0013] As a preferred embodiment of the present invention, the inlet air temperature of the dryer in S5 is 180~200℃ and the outlet air temperature is 80~90℃.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, an organic acid is used to provide a mild acidic environment, promoting... The crystal lattice dissolves, thus avoiding corrosion of the equipment, while aminotrimethylenephosphonic acid (ATMP) interacts with the phosphonic acid group in its molecule. Formation of stable complexes, thereby inhibiting The addition of organic acids significantly reduces the impurity content of the leachate, eliminating the need for additional impurity removal processes. The wastewater also meets environmental standards. Furthermore, the use of organic acids not only reduces wastewater treatment costs but also allows for recovery through vacuum distillation, minimizing reagent waste. In addition, the elimination of high-temperature and high-pressure operations significantly reduces energy consumption and production costs. The stability of ATMP and the low toxicity of the organic acids ensure the safety of the production process, reducing the risk of organic solvent leakage and substantially lowering equipment maintenance and safety management costs.

[0015] 2. In this invention, by adding Co-doping modification, with similar ionic radii Embeddable Lattice sites fill vacancies caused by lattice breakage during the regeneration process, reducing lattice distortion rate, improving crystal order, constructing stable channels for lithium-ion diffusion, and significantly improving electronic conductivity. Furthermore, doped ions and... This process forms stronger ionic bonds, reduces the lattice volume expansion rate during charge and discharge, minimizes structural collapse, and simultaneously forms a protective film on the surface to inhibit electrolyte corrosion. This significantly enhances cycle stability. The modification does not require high-temperature sintering. Through a low-temperature regeneration process, it avoids excessive grain growth, ensures uniform grain size, and significantly reduces energy consumption, thus balancing performance and economy.

[0016] 3. This invention constructs an integrated continuous process of pretreatment, leaching, separation, and regeneration, eliminating the need for intermediate material transfer, shortening the process cycle, and significantly improving efficiency compared to traditional processes. Furthermore, the pretreated and recovered binder can be reused, and the leaching agent can be recycled through distillation. The entire process generates no waste residue, achieving a resource recycling rate of over 90%. At the same time, it reduces wastewater treatment costs and energy consumption, significantly lowering the overall product cost compared to traditional methods. It is ready for industrial mass production, achieving a win-win situation for both environmental and economic benefits. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the regeneration process of lithium iron phosphate cathode material waste according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] By using organic acids to provide a mildly acidic environment, it promotes... The crystal lattice dissolves, thus avoiding corrosion of the equipment, while aminotrimethylenephosphonic acid interacts with the phosphonic acid group in its molecule. Formation of stable complexes, thereby inhibiting The addition of organic acids significantly reduces the impurity content of the leachate, eliminating the need for additional impurity removal processes. The wastewater also meets environmental standards. Furthermore, the use of organic acids not only reduces wastewater treatment costs but also allows for recovery through vacuum distillation, minimizing reagent waste. In addition, the elimination of high-temperature and high-pressure operations significantly reduces energy consumption and production costs. The stability of aminotrimethylenephosphonic acid and the low toxicity of the organic acids ensure the safety of the production process, reducing the risk of organic solvent leakage and substantially lowering equipment maintenance and safety management costs.

[0020] By adding Co-doping modification, with similar ionic radii Embeddable Lattice sites fill vacancies caused by lattice breakage during the regeneration process, reducing lattice distortion rate, improving crystal order, constructing stable channels for lithium-ion diffusion, and significantly improving electronic conductivity. Furthermore, doped ions and... This process forms stronger ionic bonds, reduces the lattice volume expansion rate during charge and discharge, minimizes structural collapse, and simultaneously forms a protective film on the surface to inhibit electrolyte corrosion. This significantly enhances cycle stability. The modification does not require high-temperature sintering. Through a low-temperature regeneration process, it avoids excessive grain growth, ensures uniform grain size, and significantly reduces energy consumption, thus balancing performance and economy.

[0021] By constructing an integrated continuous process of pretreatment, leaching, separation, and regeneration, the process cycle is shortened without the need for intermediate material transfer. The efficiency is significantly improved compared to traditional processes. Furthermore, the binder recovered from pretreatment can be reused, and the leaching agent can be recycled through distillation. No waste residue is generated throughout the process, and the resource recycling rate exceeds 90%. At the same time, wastewater treatment costs and energy consumption are reduced, and the overall product cost is significantly lower than that of traditional methods. By controlling the solid content of the mixed slurry during wet ball milling, that is, ensuring the proportion of solids in the solid-liquid mixture after the addition of dispersant, the material is further dispersed evenly during ball milling and high ball milling efficiency is guaranteed. This enables industrial mass production and achieves a win-win situation for both environmental and economic benefits.

[0022] like Figure 1 As shown, a method for regenerating waste lithium iron phosphate cathode material includes the following steps: S1. The positive electrode sheets dismantled from waste lithium iron phosphate batteries are crushed to a particle size of 50-100 μm, and calcined at 300-400℃ for 1-2 hours under inert gas protection to remove the surface binder, obtaining pretreated powder; S2. The pretreated powder is placed in a leaching tank, and organic acid and ATMP composite leaching agent are added at a solid-liquid ratio of 1:9-11. The mixture is stirred and reacted at 50-70℃ for 2-3 hours to obtain a leachate; S3. The leachate is cooled to room temperature, and a mass fraction is added... Adjust the pH of the solution to 4.5-5.0 using a 5% lithium hydroxide aqueous solution, stir for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, stir and react at 65-75℃ for 1-2 h, then filter to separate the lithium carbonate precipitate, wash the precipitate with deionized water and dry to obtain high-purity lithium carbonate; S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add to it... The mixture is mixed with acetylene black, then placed in a ball mill and a dispersant is added. The mixture is then wet-milled and spray-dried to obtain a mixed powder. S6. Under inert gas protection, the mixed powder is calcined at 650~750℃ for 4~4.5h and cooled to room temperature to obtain a regenerated lithium iron phosphate cathode material.

[0023] All raw materials used in this invention are commercially available.

[0024] Example 1: A method for regenerating waste lithium iron phosphate cathode material, comprising the following steps: S1. The positive electrode sheet dismantled from the waste lithium iron phosphate battery is crushed to a particle size of 100μm, and then calcined at 400℃ for 2h under nitrogen protection to remove the surface binder and obtain pretreated powder. S2. Place the pretreated powder into a leaching tank, add organic acid and ATMP composite leaching agent at a solid-liquid ratio of 1:11, wherein the organic acid is 1.0 mol / L citric acid, and the amount of ATMP added is 8% of the mass of citric acid. Stir and react at 70°C for 3 hours, wherein the stirring rate is 300 rpm. S3. Cool the leachate to room temperature, add 5% lithium hydroxide aqueous solution to adjust the pH of the solution to 5.0, stir at 300 rpm for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, wherein the amount of anhydrous sodium carbonate added is 1.5 times the mass of the filtrate, stir and react at 75°C for 2 hours, then filter to separate and obtain lithium carbonate precipitate, wash the precipitate three times with deionized water, wherein the amount of deionized water used each time is 5 times the mass of the precipitate, and then dry it at 130°C for 2.5 hours to obtain high-purity lithium carbonate; S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add 2% of the mass of the mixture to the mixture. Add 3% acetylene black by weight of the mixture, then put it into a ball mill and add anhydrous ethanol as a dispersant. Control the solid content of the mixture to 50%, and perform wet ball milling at a speed of 500 rpm for 4 hours. After ball milling, spray dry to obtain mixed powder, wherein the inlet air temperature of the dryer is 200℃ and the outlet air temperature is 90℃. S6. Under nitrogen protection, the mixed powder was calcined at 750°C for 4.5 hours and then cooled to room temperature to obtain the regenerated lithium iron phosphate cathode material.

[0025] Example 2: A method for regenerating waste lithium iron phosphate cathode material, comprising the following steps: S1. The positive electrode sheet dismantled from the waste lithium iron phosphate battery is crushed to a particle size of 50μm, and then calcined at 300℃ for 1h under nitrogen protection to remove the surface binder and obtain pretreated powder. S2. Place the pretreated powder into a leaching tank, add organic acid and ATMP composite leaching agent at a solid-liquid ratio of 1:9, wherein the organic acid is 0.5 mol / L citric acid, and the amount of ATMP added is 5% of the mass of citric acid. Stir and react at 50°C for 2 hours, wherein the stirring rate is 200 rpm. S3. Cool the leachate to room temperature, add 5% lithium hydroxide aqueous solution to adjust the pH of the solution to 4.5, stir at 200 rpm for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, wherein the amount of anhydrous sodium carbonate added is 1.5 times the mass of the filtrate, stir and react at 65°C for 1 hour, then filter to separate and obtain lithium carbonate precipitate, wash the precipitate three times with deionized water, wherein the amount of deionized water used each time is 5 times the mass of the precipitate, and then dry it at 120°C for 2 hours to obtain high-purity lithium carbonate; S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add 1% of the mass of the mixture to the mixture. Add 1% acetylene black by weight of the mixture, then put it into a ball mill and add anhydrous ethanol as a dispersant. Control the solid content of the mixture to 45%, and perform wet ball milling at a speed of 300 rpm for 3 hours. After ball milling, spray dry to obtain mixed powder, wherein the inlet air temperature of the dryer is 180℃ and the outlet air temperature is 80℃. S6. Under nitrogen protection, the mixed powder was calcined at 650°C for 4 hours and then cooled to room temperature to obtain the regenerated lithium iron phosphate cathode material.

[0026] Example 3: A method for regenerating waste lithium iron phosphate cathode material, comprising the following steps: S1. The positive electrode sheet dismantled from the waste lithium iron phosphate battery is crushed to a particle size of 75μm, and then calcined at 350℃ for 1.5h under nitrogen protection to remove the surface binder and obtain pretreated powder. S2. Place the pretreated powder into a leaching tank, add organic acid and ATMP composite leaching agent at a solid-liquid ratio of 1:10, wherein the organic acid is 0.7 mol / L citric acid, and the amount of ATMP added is 6% of the mass of citric acid. Stir and react at 60°C for 2.5 h, wherein the stirring rate is 250 rpm. S3. Cool the leachate to room temperature, add 5% lithium hydroxide aqueous solution to adjust the pH of the solution to 4.7, stir at 250 rpm for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, wherein the amount of anhydrous sodium carbonate added is 1.5 times the mass of the filtrate, stir and react at 70°C for 1.5 hours, then filter to separate and obtain lithium carbonate precipitate, wash the precipitate three times with deionized water, wherein the amount of deionized water used each time is 5 times the mass of the precipitate, and then dry it at 125°C for 2.3 hours to obtain high-purity lithium carbonate; S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add 1.5% of the mass of the mixture to the mixture. Add 2% acetylene black by weight of the mixture, then put it into a ball mill and add anhydrous ethanol as a dispersant. Control the solid content of the mixture to 47%, and perform wet ball milling at a speed of 400 rpm for 3.5 hours. After ball milling, spray dry the mixture to obtain a powder, with the inlet air temperature of the dryer being 190℃ and the outlet air temperature being 85℃. S6. Under nitrogen protection, the mixed powder was calcined at 700°C for 4.2 hours and then cooled to room temperature to obtain the regenerated lithium iron phosphate cathode material.

[0027] Comparative Example 1: The difference from Example 1 is that the dopant is used... Remove.

[0028] Comparative Example 2: The difference from Example 1 is that the organic acid and ATMP composite leaching agent is replaced with sulfuric acid.

[0029] Comparative Example 3: The difference from Example 1 is that ATMP is removed from the organic acid and ATMP composite leaching agent.

[0030] The lithium iron phosphate cathode materials prepared in Examples 1, 2, and 3, and Comparative Examples 1, 2, and 3 were mixed at room temperature and pressure according to a mass ratio of lithium iron phosphate cathode material: acetylene black: PVDF binder of 90:5:5 to form a slurry. This slurry was then uniformly coated onto a substrate with aluminum foil as the current collector to form an electrode sheet. The resulting film thickness was 30 μm, which served as the cathode. Using lithium metal as the anode, 1 mol of LiPF6 was dissolved in 1 L of a mixed solvent of EC and DEC (where the volume ratio of EC to DEC was 1:1) to form the electrolyte. The cathode and anode sheets, separator, and electrolyte were then prepared in a nitrogen-protected glove box to create a C2032 type battery.

[0031] The electrochemical performance of the prepared battery was tested. At room temperature, the C2032 battery was charged and discharged at 0.1C to measure its charge and discharge capacity. The charging cutoff voltage was 3.8V and the discharging cutoff voltage was 2.5V. The initial charge and discharge capacity was recorded, and the charge and discharge efficiency was calculated (charge and discharge efficiency (%) = discharge capacity ÷ charge capacity × 100%). The C2032 battery was also charged and discharged at 0.1C to measure its charge and discharge capacity. The charging cutoff voltage was 3.8V and the discharging cutoff voltage was 2.5V. This was repeated 100 times, and the capacity retention rate after 100 cycles was calculated. The results are shown in Table 1.

[0032] Table 1: Chemical performance tests of the examples and comparative examples

[0033] As shown in Table 1, Examples 1, 2, and 3 all exhibit high capacity retention and charge / discharge capacity. By using this method to regenerate waste lithium iron phosphate cathode materials, the effective components in lithium iron phosphate are fully recovered, resulting in excellent electrochemical charge / discharge performance and cycle performance.

[0034] In terms of synergistic leaching, traditional strong acids are abandoned in favor of a mild organic acid to provide an acidic environment, avoiding equipment corrosion and the introduction of impurities. Meanwhile, ATMP inhibits corrosion through complexation. Excessive dissolution of impurity ions significantly reduces the impurity content of the leachate, thus facilitating the subsequent preparation of high-purity solutions. Filter residue lays the foundation, reducing lattice defects caused by impurities and ensuring the performance stability of recycled materials from the source. Adding After doping, Due to ionic radius and Similarly, it can be uniformly embedded in the lithium iron phosphate lattice, filling lattice vacancies easily generated in traditional regeneration processes, optimizing crystal structure integrity, reducing lattice distortion rate, and providing a smoother channel for lithium-ion diffusion, thereby improving ion transport efficiency during charging and discharging and enhancing the material's rate charge / discharge performance; at the same time... It can also adjust the distribution of electron clouds in the crystal, enhance electron delocalization, improve the electronic conductivity of the material, reduce polarization during charging and discharging, and further improve the stability of charge and discharge performance. The synergistic effect of high-purity raw materials and optimized crystal structure can enhance the lattice rigidity of the material, reduce the lattice volume expansion and contraction caused by lithium ion insertion or extraction during charge and discharge cycles, suppress structural collapse, and reduce... Reduce oxidation probability, decrease loss of active materials, thereby significantly improving material cycle life and ensuring good capacity retention after long-term cycling, enabling recycled materials to meet the stringent electrochemical performance requirements of power batteries.

[0035] In summary, the present invention provides a low-pollution, high-recovery-rate, and low-energy-consumption method for the regeneration of lithium iron phosphate cathode material waste. The regenerated material not only possesses excellent electrochemical charge-discharge performance but also cycle performance, meeting the stringent requirements of power batteries for electrochemical performance.

[0036] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for regenerating waste lithium iron phosphate cathode material, characterized in that, Includes the following steps: S1. The positive electrode sheet dismantled from the waste lithium iron phosphate battery is crushed to a particle size of 50~100μm, and then calcined at 300~400℃ for 1~2h under inert gas protection to remove the surface binder and obtain pretreated powder. S2. Place the pretreated powder into a leaching tank, add organic acid and ATMP composite leaching agent at a solid-liquid ratio of 1:9~11, stir and react at 50~70℃ for 2~3 hours to obtain leaching solution; S3. Cool the leachate to room temperature, add 5% lithium hydroxide aqueous solution to adjust the pH of the solution to 4.5~5.0, stir for 30 min, let stand for 1 h, and filter to obtain filter residue and filtrate; S4. Add anhydrous sodium carbonate to the filtrate obtained above, stir and react at 65~75℃ for 1~2h, then filter to separate lithium carbonate precipitate, wash the precipitate with deionized water and dry to obtain high-purity lithium carbonate. S5. Mix the filter residue with the lithium carbonate obtained in step S4 at a molar ratio of 1:1.5 to obtain a mixture, and add to it... The mixture is then placed in a ball mill with acetylene black and a dispersant added. The mixture is then wet-milled and spray-dried to obtain a mixed powder. S6. Under inert gas protection, the mixed powder is calcined at 650~750℃ for 4~4.5h, and then cooled to room temperature to obtain regenerated lithium iron phosphate cathode material.

2. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The inert gas is either nitrogen or argon.

3. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The organic acid and ATMP composite leaching agent in S2 is wherein the organic acid is any one of 0.5~1.0 mol / L citric acid or oxalic acid, and the amount of ATMP added is 5~8% of the mass of the organic acid.

4. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The stirring rate in S2 is 200~300 rpm; the stirring rate in S3 is 200~300 rpm.

5. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The amount of anhydrous sodium carbonate added in S4 is 1.5 times the mass of the filtrate; the precipitate is washed three times with deionized water, and the amount of deionized water used each time is 5 times the mass of the precipitate; the drying temperature is 120~130℃, and the drying time is 2~2.5h.

6. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, In S5 The addition amount of the additive is 1-2% of the mass of the mixture, and the addition amount of the acetylene black is 1-3% of the mass of the mixture.

7. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The dispersant in S5 is anhydrous ethanol, the solid content is controlled at 45-50%, the ball milling speed is 300-500 rpm, and the ball milling time is 3-4 h.

8. The method for regenerating lithium iron phosphate cathode material waste according to claim 1, characterized in that, The inlet air temperature of the dryer in S5 is 180~200℃, and the outlet air temperature is 80~90℃.

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