A low-cost and simple method for recycling lithium resources from waste lithium ion battery cathode materials to prepare high-value-added lithium-containing products

Abstract

The application discloses a low-cost and simple method for recycling lithium resources from waste lithium ion battery positive electrode materials to prepare high-value lithium-containing products, which comprises the following steps: mixing the waste lithium ion battery positive electrode materials with elemental iodine in an organic solvent, and reacting at a temperature of 40-100 DEG C; and filtering and drying the filtrate to obtain high-value products including LiI.3H2O. In addition, the filter residue can be directly used as a positive electrode material precursor after drying, and the original structure of the filter residue can be maintained. The method can efficiently recycle lithium resources to prepare high-value products, and the positive electrode material precursor can be directly used as a lithium ion battery, so the method has very high application value and commercial application.

Description

Technical Field

[0001] This invention belongs to the field of waste battery resource recycling technology, and relates to a low-cost and simple method for recovering lithium resources from waste lithium-ion battery cathode materials to prepare high-value-added lithium-containing products. Background Technology

[0002] Lithium-ion batteries are high-energy-density, environmentally friendly, and highly safe batteries, widely used in mobile phones, laptops, electric vehicles, and energy storage systems. However, with the increasing use of lithium-ion batteries, a large number of discarded batteries have led to environmental pollution and resource waste. Improving the recycling and reuse rates of lithium-ion batteries has become an important task for reducing dependence on raw materials and protecting the environment. To address this issue, technologies for recycling and reusing spent lithium-ion batteries have received widespread attention and research. These technologies can not only effectively protect the environment and reduce the impact of harmful substances on ecosystems, but also reduce resource waste and save energy costs, resulting in significant economic and social benefits. Therefore, strengthening investment and research in the recycling and reuse of spent lithium-ion batteries is urgent and of great significance for achieving sustainable development.

[0003] By recycling lithium-containing waste such as used batteries, waste can be transformed into resources, thereby reducing resource waste. This not only reduces raw material costs but also promotes the formation of new industrial chains, supporting industrial upgrading and transformation. Simultaneously, it helps drive the development of the environmental protection industry and promotes sustainable economic development.

[0004] Currently, there are two main types of traditional lithium extraction methods for waste batteries: thermal treatment and chemical methods. Thermal treatment typically involves high-temperature sintering at 800-900℃ to release lithium ions from the batteries for recycling. This method has the advantage of high recycling efficiency, but its disadvantages include high energy consumption (leading to energy and environmental waste), high equipment costs, and the need for specialized process control and operational skills, making it difficult to operate and potentially damaging the material's structure, rendering it unusable. Chemical methods involve adding the material to an acid solution, where the acid dissolves and separates and recovers the lithium ions. This method is simple to operate and yields high-purity lithium compounds, but its disadvantages include high cost, the need for precise operation, complex processes, environmental pollution from the acid used, and the need to treat large amounts of waste. Therefore, traditional lithium recycling methods have certain limitations and need improvement and optimization in terms of recycling efficiency, energy consumption, and environmental pollution. Simultaneously, it is necessary to develop new, more environmentally friendly, low-cost, and efficient recycling technologies. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problems of traditional waste lithium-ion battery cathode material processing technology, such as complex processes, environmental unfriendliness, high cost of lithium resource recycling, and low quality of lithium products. The invention provides a low-cost and simple method for recovering lithium resources from waste lithium-ion battery cathode materials to prepare high-value-added lithium-containing products.

[0006] The objective of this invention is achieved through the following approach:

[0007] A low-cost and simple method for recovering lithium resources from waste lithium-ion battery cathode materials to prepare high-value-added lithium-containing products includes the following steps:

[0008] S1 involves mixing waste lithium-ion battery cathode material with an organic solvent that dissolves elemental iodine to carry out a reaction;

[0009] After the S2 reaction, the reaction solution is filtered to obtain filter residue and filtrate;

[0010] S3 dries the filtrate to obtain lithium-containing products, including LiI·3H2O;

[0011] The amount of lithium ions extracted is controlled by adjusting the amount of elemental iodine added. The molar ratio of elemental iodine to the cathode material is 0.5 or higher, so that lithium can be completely extracted from the cathode material of waste lithium-ion batteries.

[0012] The reaction is a hydrothermal reaction or a condensation reflux reaction.

[0013] The molar ratio of elemental iodine to waste lithium-ion battery cathode material is 0.5 to 1.5.

[0014] The waste lithium-ion battery cathode material includes waste battery cathode material powder or cathode material coated on aluminum foil.

[0015] The lithium-containing products also include AlI3.

[0016] The cathode material is one or more of LiFePO4, a ternary material of nickel, cobalt, and manganese, and lithium cobalt oxide. The molar ratio of nickel, cobalt, and manganese in the ternary material is 5:2:3, 6:2:2, or 8:1:1.

[0017] The waste battery cathode material powder or cathode material attached to aluminum foil is obtained by dismantling, crushing, sorting, fine crushing, and screening waste lithium batteries.

[0018] Before crushing, there is also a discharge process, which involves immersing the waste lithium-ion batteries in a sodium chloride solution for 24 to 72 hours.

[0019] The method also includes drying the filter residue to obtain a lithium-free cathode material precursor.

[0020] The organic solvent for dissolving elemental iodine is one or more of anhydrous ethanol, acetonitrile, ethyl acetate, and dimethyl sulfoxide.

[0021] The reaction temperature is 40-100℃, and the reaction time is 2-8 hours.

[0022] The drying temperature in S3 is 30-100℃, which should be adjusted according to the reaction solvent.

[0023] In S3, drying is performed by rotary evaporation or distillation to recover the organic solvent.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] This invention has a high lithium recovery rate. The amount of lithium ions removed can be controlled by adjusting the amount of elemental iodine added, so that all lithium can be removed from the cathode material powder of waste batteries.

[0026] This invention can produce high-quality lithium products. The lithium solution obtained during its preparation process does not contain any impurity ions such as sodium or potassium. After further purification and drying, high-quality lithium products can be obtained.

[0027] This invention directly produces a cathode material precursor for lithium-ion batteries. The processed material retains its original structure without any damage; lithium ions are simply extracted. After the reaction, the cathode material precursor can be recycled using traditional processes (solid-liquid separation). Alternatively, the cathode material precursor can be directly supplied to the battery industry for direct utilization. This processing method efficiently recycles and utilizes resources from waste materials while maintaining their original structure and performance, making it highly valuable for engineering applications.

[0028] The present invention uses elemental iodine and organic solvents, which are among the most commonly used chemical reagents, to leach lithium ions at relatively low temperatures, while the organic solvents can be recycled and reused. Furthermore, the reagents used in this invention are inexpensive.

[0029] The cathode material powder from waste lithium-ion batteries of this invention does not require acid treatment or high-temperature calcination, and the production process is safe and environmentally friendly.

[0030] In summary, this invention involves reacting waste battery cathode materials with an organic solvent containing elemental iodine. The solid obtained through solid-liquid separation can be directly used as a precursor for lithium-ion battery cathode materials. Most importantly, the filtrate, after purification, can effectively recover lithium resources, yielding LiI·3H2O and AlI3 solid powders. This technology offers significant advantages in solving the problem of waste lithium-ion battery recycling, effectively addressing issues such as the complexity of traditional recycling methods, high lithium recovery costs, high sodium content in the solution, and difficulty in obtaining high-quality lithium products. Furthermore, the production process is simple, energy-efficient, and highly safe and environmentally friendly. This characteristic stems from the green and recyclable nature of the processes and reagents used, minimizing environmental impact and resource waste. It can make a positive contribution to industrial production and environmental protection, possessing significant engineering application value. Attached Figure Description

[0031] Figure 1 The images show the XRD patterns of the waste lithium-ion battery cathode material before and after treatment in Example 1.

[0032] Figure 2 The image shows the XRD pattern of lithium iodide, a lithium-containing product obtained in Example 1.

[0033] Figure 3 This is a constant current charge-discharge curve of the waste lithium-ion battery cathode material after treatment in Example 1 during the first cycle;

[0034] Figure 4 The discharge specific capacity rate performance diagram of the cathode material of the waste lithium-ion battery after treatment in Example 1 is shown.

[0035] Figure 5 This is a graph showing the discharge specific capacity rate performance of the cathode material in a normal lithium-ion battery. Detailed Implementation

[0036] To more clearly describe the technical solutions in the embodiments of the present invention, the present invention will be described in more specific and detailed manner below with reference to the embodiments and accompanying drawings. It should be noted that the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] The waste lithium batteries are disassembled, crushed, sorted, finely crushed and screened to obtain lithium iron phosphate cathode material powder from the waste batteries.

[0039] Weigh 0.45g of elemental iodine and dissolve it in ethanol to prepare an iodine solution. Then add 0.5g of lithium iron phosphate cathode material powder from waste batteries to the above solution, stir evenly, place it in a hydrothermal reactor, and heat at 80℃ for 4 hours.

[0040] The reaction solution was filtered, and the filter residue was dried at 50°C. The resulting powder was then subjected to XRD analysis. Figure 1 The powder obtained is consistent with the ferric phosphate XRD standard card, thus ferric phosphate can be obtained;

[0041] The product obtained after rotary evaporation and drying of the filtrate at 50°C was placed in a forced-air drying oven and dried at 50°C. The resulting powder was then subjected to XRD analysis. Figure 2 As shown, it is consistent with the XRD standard card of LiI·3H2O, that is, the powder obtained after treatment is LiI·3H2O.

[0042] The iron phosphate powder obtained from the filter residue was used as the active material to prepare lithium battery cathode slurry, and its electrochemical performance was tested. Figure 3 As shown, the treated waste lithium-ion battery cathode material has almost no delithiation capacity, indicating that the Li in the material is insufficient. + Completely removed. However, the discharge specific capacity rate performance diagram of the treated waste lithium-ion battery cathode material (as shown in the figure) Figure 4 As shown), the discharge specific capacity rate performance diagram is compared with that of commercially purchased lithium-ion battery cathode materials (e.g.). Figure 5 Compared to the curve shown in the figure, apart from the significant difference in the first constant current charge-discharge curve, the other rate performances did not change significantly, indicating that the material can maintain its original structure and performance.

[0043] Example 2

[0044] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM523 cathode material powder from waste batteries.

[0045] Weigh 0.65g of elemental iodine and dissolve it in dimethyl sulfoxide to prepare an iodine solution. Then add 0.5g of waste battery NCM523 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat it in a 60℃ forced-air drying oven for 6 hours.

[0046] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 5:2:3.

[0047] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0048] Example 3

[0049] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM811 cathode material powder from waste batteries.

[0050] Weigh 0.6g of elemental iodine and dissolve it in acetonitrile to prepare an iodine solution. Then add 0.5g of NCM811 cathode material powder from waste batteries, stir evenly, place in a hydrothermal reactor, and heat at 60℃ for 6 hours.

[0051] After the reaction is complete, the mixture is filtered, and the filter residue is dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 8:1:1.

[0052] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0053] Example 4

[0054] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM622 cathode material powder from waste batteries.

[0055] Weigh 1g of NCM622 cathode material from waste batteries, add 1.23g of elemental iodine dissolved in anhydrous ethanol, stir well and place in a hydrothermal reactor, then heat in a 50℃ forced-air drying oven for 8 hours.

[0056] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 6:2:2.

[0057] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0058] Example 5

[0059] Waste lithium batteries are dismantled, crushed, sorted, finely crushed, and screened to obtain waste battery lithium cobalt oxide cathode powder.

[0060] Weigh 0.5g of lithium cobalt oxide cathode material from waste batteries, add 0.5g of elemental iodine dissolved in ethyl acetate, stir evenly and place in a hydrothermal reactor, then heat in a 60℃ forced-air drying oven for 6 hours.

[0061] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain a cobalt-containing cathode material precursor.

[0062] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0063] Example 6

[0064] Waste lithium batteries are dismantled, crushed, sorted, finely crushed, and screened to obtain waste battery positive electrode sheets.

[0065] Weigh 0.2g of positive electrode sheet (aluminum foil and lithium iron phosphate battery positive electrode material coated on aluminum foil), add 2.8g of elemental iodine dissolved in acetonitrile, stir evenly and place in a hydrothermal reactor, and heat in a 40℃ forced-air drying oven for 8 hours;

[0066] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain the precursor of iron phosphate cathode material.

[0067] After the filtrate is dried by rotary evaporation at 50°C, the resulting product is dried in a forced-air drying oven at 50°C to obtain AlI3·6H2O and LiI·3H2O powders.

[0068] Example 7

[0069] The waste lithium batteries are disassembled, crushed, sorted, finely crushed and screened to obtain waste battery lithium cobalt oxide cathode material powder.

[0070] Weigh 0.9g of elemental iodine and add it to ethyl acetate solution to prepare an iodine solution. Then add 1g of lithium cobalt oxide cathode material powder from waste batteries, stir evenly, place in a hydrothermal reactor, and heat at 90℃ for 6 hours.

[0071] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain a cobalt-containing cathode material precursor.

[0072] The product obtained by evaporating and drying the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0073] Example 8

[0074] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM622 cathode material powder from waste batteries.

[0075] Weigh 1.3g of elemental iodine and dissolve it in ethyl acetate to prepare an iodine solution. Then add 1g of waste battery NCM622 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat it in an 80℃ forced-air drying oven for 8 hours.

[0076] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 6:2:2.

[0077] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0078] Example 9

[0079] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM811 cathode powder from waste batteries.

[0080] Weigh 0.96g of elemental iodine and add it to anhydrous ethanol to prepare an iodine solution. Then add 0.8g of waste battery NCM811 positive electrode material, stir well and place in a hydrothermal reactor. Heat at 60℃ for 6 hours.

[0081] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 8:1:1.

[0082] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0083] Example 10

[0084] The waste lithium batteries are disassembled, crushed, sorted, finely crushed and screened to obtain waste battery lithium cobalt oxide cathode material powder.

[0085] Weigh 4g of elemental iodine and add it to ethyl acetate to prepare an iodine solution. Then add 2g of lithium cobalt oxide cathode material powder from waste batteries, stir evenly, place it in a hydrothermal reactor, and heat it in a 50°C forced-air drying oven for 4 hours.

[0086] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain a cobalt-containing cathode material precursor.

[0087] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0088] Example 11

[0089] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM523 cathode material powder from waste batteries.

[0090] Weigh 2.2g of elemental iodine and add it to anhydrous ethanol to prepare an iodine solution. Then add 1.5g of waste battery NCM523 positive electrode material, stir well and place in a hydrothermal reactor. Heat at 90℃ for 7 hours.

[0091] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 5:2:3.

[0092] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0093] Example 12

[0094] Waste lithium batteries are dismantled, crushed, sorted, finely crushed, and screened to obtain lithium iron phosphate cathode material from waste batteries.

[0095] Weigh 4.5g of elemental iodine and add it to dimethyl sulfoxide solution to prepare an iodine solution. Then add 5g of lithium iron phosphate cathode material from waste batteries, stir well and place in a hydrothermal reactor. Heat at 50°C for 6 hours.

[0096] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain ferric phosphate.

[0097] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0098] Example 13

[0099] Waste lithium batteries are dismantled, crushed, sorted, finely crushed, and screened to obtain waste battery positive electrode sheets.

[0100] Weigh 8g of elemental iodine and add it to ethyl acetate solution to prepare an iodine solution. Then add 0.5g of positive electrode sheet (aluminum foil and lithium iron phosphate positive electrode material coated on aluminum foil), stir evenly and place it in a hydrothermal reactor. Heat the reactor in a 70°C forced-air drying oven for 4 hours.

[0101] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain ferric phosphate.

[0102] The filtrate was dried by rotary evaporation at 50°C to obtain AlI3·6H2O and LiI·3H2O powders.

[0103] Example 14

[0104] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM622 cathode material powder from waste batteries.

[0105] Weigh 8g of elemental iodine and dissolve it in acetonitrile to prepare an iodine solution. Then add 5g of waste battery NCM622 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat the reactor in a 70℃ forced-air drying oven for 6 hours.

[0106] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 6:2:2.

[0107] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0108] Example 15

[0109] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM523 cathode material powder from waste batteries.

[0110] Weigh 9g of elemental iodine and dissolve it in acetonitrile to prepare an iodine solution. Then add 5g of waste battery NCM523 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat the reactor in a 70℃ forced-air drying oven for 6 hours.

[0111] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 5:2:3.

[0112] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0113] Example 16

[0114] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM811 cathode material powder from waste batteries.

[0115] Weigh 4.3g of elemental iodine and dissolve it in ethyl acetate to prepare an iodine solution. Then add 2.5g of waste battery NCM811 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat the reactor in a 60℃ forced-air drying oven for 4 hours.

[0116] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 8:1:1.

[0117] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0118] Example 17

[0119] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM523 cathode powder from waste batteries.

[0120] Weigh 5g of elemental iodine and dissolve it in ethyl acetate to prepare an iodine solution. Then add 3g of waste battery NCM523 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat it in an 80℃ forced-air drying oven for 3 hours.

[0121] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 5:2:3.

[0122] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0123] Example 18

[0124] The waste lithium batteries are disassembled, crushed, sorted, finely crushed and screened to obtain lithium iron phosphate cathode material powder from the waste batteries.

[0125] Weigh 12g of elemental iodine and dissolve it in acetonitrile to prepare an iodine solution. Then add 10g of lithium iron phosphate cathode material from waste batteries, stir well, place in a hydrothermal reactor, and heat in a 40℃ forced-air drying oven for 8 hours.

[0126] The reaction solution is filtered, and the filter residue is dried at 50°C to obtain ferric phosphate.

[0127] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0128] Example 19

[0129] Waste lithium batteries are dismantled, crushed, sorted, finely crushed, and screened to obtain waste battery positive electrode sheets.

[0130] Weigh 5.5g of elemental iodine and dissolve it in dimethyl sulfoxide. Then add 0.35g of NCM811 cathode material coated on aluminum foil, stir evenly and place it in a hydrothermal reactor. Heat it in a 60℃ forced-air drying oven for 5 hours.

[0131] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 8:1:1.

[0132] After the filtrate is dried by rotary evaporation at 50°C, the resulting product is dried in a forced-air drying oven at 50°C to obtain AlI3·6H2O and LiI·3H2O powders.

[0133] Example 20

[0134] Waste lithium batteries are disassembled, crushed, sorted, finely crushed, and screened to obtain NCM811 cathode material powder from waste batteries.

[0135] Weigh 9g of elemental iodine and dissolve it in acetonitrile to prepare an iodine solution. Then add 6g of waste battery NCM811 positive electrode material, stir evenly and place it in a hydrothermal reactor. Heat the reactor in a 60℃ forced-air drying oven for 6 hours.

[0136] The reaction solution was filtered, and the filter residue was dried at 50°C to obtain a cathode material precursor with a nickel, cobalt, and manganese molar ratio of 8:1:1.

[0137] The product obtained by rotary evaporation and drying of the filtrate at 50°C was then dried in a forced-air drying oven at 50°C to obtain LiI·3H2O powder.

[0138] The material treated by this invention does not damage its original structure and can meet the high-quality requirements for precursors. The electrochemical performance of the lithium-ion battery cathode material precursor prepared after treatment is also excellent. It can realize the recycling and reuse of waste materials in the lithium iron phosphate cathode material production process, and can also effectively recover lithium metal, thereby shortening the process flow.

[0139] Before being crushed, the waste lithium-ion batteries also include a discharge process, which is as follows: the waste lithium-ion batteries are immersed in a sodium chloride solution for 24 to 72 hours, and then crushed to separate the positive electrode, negative electrode, separator, and electrolyte; the positive electrode active material on the positive electrode is separated from the current collector aluminum foil to obtain the waste lithium-ion battery positive electrode powder.

[0140] Implementing the above production process allows for complete recycling, which helps reduce operating costs. Furthermore, this process is highly safe and environmentally friendly, as it produces no waste residue, waste gas, or waste liquid emissions. In addition, the resulting product has high purity.

[0141] Although embodiments of the present invention have been shown and described above, it should be noted that these embodiments are merely exemplary and should not be considered as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A low-cost and simple method for recovering lithium resources from waste lithium-ion battery cathode materials to prepare high-value-added lithium-containing products, characterized in that: Includes the following steps: S1 involves mixing waste lithium-ion battery cathode material with an organic solvent that dissolves elemental iodine to carry out a reaction; After the S2 reaction, the reaction solution is filtered to obtain filter residue and filtrate; S3. The filtrate is dried to obtain a lithium-containing product, including LiI•3H2O; The molar ratio of elemental iodine to the cathode material is 0.5 or higher; The cathode material is one or more of LiFePO4, nickel, cobalt, manganese ternary materials, and lithium cobalt oxide.

2. The method as described in claim 1, characterized in that: The reaction is a hydrothermal reaction or a condensation reflux reaction.

3. The method as described in claim 1, characterized in that: The molar ratio of elemental iodine to waste lithium-ion battery cathode material is 0.5~1.

5.

4. The method as described in claim 1, characterized in that: The waste lithium-ion battery cathode material includes waste battery cathode material powder or cathode material coated on aluminum foil.

5. The method as described in claim 1, characterized in that: The lithium-containing products also include AlI3•3H2O.

6. The method as described in claim 1, characterized in that: It also includes drying the filter residue to obtain a cathode material precursor from which lithium is extracted.

7. The method as described in claim 1, characterized in that: The organic solvent for dissolving elemental iodine is one or more of anhydrous ethanol, acetonitrile, ethyl acetate, and dimethyl sulfoxide.

8. The method as described in claim 1, characterized in that: The reaction temperature is 40-100 ℃, and the reaction time is 2-8 h.

9. The method as described in claim 1, characterized in that: In S3, drying is performed by rotary evaporation or distillation.

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