A method for directly regenerating a positive electrode material of a waste lithium ion battery by room temperature lithiation
By using lithiation reagents to regenerate the cathode material of spent lithium-ion batteries at room temperature, the high energy consumption and pollution problems of existing lithium-ion battery recycling technologies are solved, achieving efficient and low-energy lithium resource recycling and performance restoration.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- STATE GRID JIANGXI ELECTRIC POWER CO LTD RES INST
- Filing Date
- 2026-06-03
- Publication Date
- 2026-07-10
AI Technical Summary
Existing lithium-ion battery recycling technologies suffer from high energy consumption, severe pollution, resource waste, and low recycling rates, especially in the inability to effectively recycle lithium resources.
Using lithium-ion battery cathode materials, lithium-ion battery cathode materials are regenerated by solution-based lithium replenishment using lithium-ion reagents such as lithium-naphthalene solution, lithium-biphenyl solution, lithium-dimethylfluorene solution, or lithium triethylborohydride solution at room temperature, including solid-liquid separation and drying steps.
It achieves efficient regeneration of cathode materials from spent lithium-ion batteries, with fast reaction rate, low energy consumption, less waste liquid, and significantly improved capacity, solving the problems of high temperature, high energy consumption, and insufficient performance recovery in traditional regeneration processes.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of battery recycling and regeneration, specifically to a method for direct regeneration of waste lithium-ion battery cathode materials by room temperature lithiation. Background Technology
[0002] With the rapid development of the new energy vehicle industry, the global installed capacity of lithium-ion batteries continues to climb, and the first large-scale retirement wave will arrive in the next few years. However, the current global recycling rate of waste lithium-ion batteries is less than 5%. If efficient and green recycling cannot be achieved, it will cause serious waste of resources (loss of key metals such as lithium, cobalt, and nickel) and environmental pressure (heavy metal pollution, organic electrolyte leakage).
[0003] Current mainstream recycling technologies are mainly pyrometallurgy and hydrometallurgy, which have obvious drawbacks. Pyrometallurgy requires high-temperature calcination to extract transition metals, resulting in high energy consumption, large carbon emissions, and the inability to directly recover lithium resources, requiring secondary processing. Hydrometallurgy relies on strong acid and strong base solvents to extract metals, which is cumbersome, prone to secondary pollution, and has high recycling costs. Summary of the Invention
[0004] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide a method for direct regeneration of waste lithium-ion battery cathode materials by room temperature lithiation.
[0005] The technical solution of the present invention is as follows: A method for direct regeneration of waste lithium-ion battery cathode materials at room temperature by lithiation involves first peeling and collecting the cathode active material from the waste cathode sheet, then immersing it in a lithiation reagent to regenerate and repair the waste lithium iron phosphate material at room temperature, followed by solid-liquid separation, cleaning, and drying to obtain the regenerated cathode material. The lithiation reagent is at least one of the following: lithium-naphthalene solution, lithium-biphenyl solution, lithium-dimethylfluorene solution, and triethyl borohydride solution.
[0006] Preferably, it includes the following steps: S1: Completely discharge, disassemble, wash, and dry the waste lithium batteries to obtain waste positive electrode sheets; S2: Place the waste positive electrode sheet into deionized water to separate the positive electrode active material from the aluminum current collector and obtain the positive electrode active material; dry the positive electrode active material to obtain waste positive electrode active material powder; S3: Prepare the lithiumization reagent; S4: Add waste positive electrode active material powder and lithium reagent according to the lithium deficiency in the powder, stir at room temperature for 2-20 minutes, filter the solution after reaction to achieve solid-liquid separation, wash the solid phase with organic solvent, and then dry in an oven to obtain the repaired and regenerated positive electrode active material.
[0007] Preferably, the temperature of the deionized water is 40-80℃, and the time for immersion in the deionized water is 50-70 seconds.
[0008] Preferably, in step S2, the drying temperature is 70-90°C.
[0009] Preferably, in step S3, the concentration of the lithium reagent is 0.05-1M.
[0010] Preferably, in step S3, the method for preparing the lithium-ionizing agent is as follows: The solution is prepared by stirring naphthalene, biphenyl, dimethylfluorene, or lithium flakes in a solvent for 3-10 hours.
[0011] Preferably, in step S4, the drying temperature is 50-70°C.
[0012] Preferably, in step S1, the waste lithium battery is at least one of waste lithium iron phosphate batteries, waste lithium cobalt oxide batteries, and waste ternary lithium batteries.
[0013] The beneficial effects of this invention are: This invention achieves efficient regeneration of waste lithium iron phosphate, lithium cobalt oxide and other cathode materials through solution-based lithium replenishment. The lithium-ion reagent used has strong reducing properties, fast reaction rate and short lithium replenishment time. It has the advantages of room temperature reaction, low energy consumption, less waste liquid, recyclable solution and significantly improved regeneration capacity, and solves the problems of high temperature and high energy consumption and insufficient performance recovery in traditional regeneration processes. Attached Figure Description
[0014] Figure 1 XRD patterns of waste lithium iron phosphate (SLFP) and regenerated lithium iron phosphate (RLFP) lithified by different lithiation reagents; Figure 2 The molar ratio of Li to Fe in SLFP and RLFP; Figure 3 The first charge-discharge curves are for waste lithium iron phosphate (SLFP), recycled lithium iron phosphate (RLFP) from Example 1, and commercial lithium iron phosphate (CLFP). Detailed Implementation
[0015] A method for direct regeneration of waste lithium-ion battery cathode materials at room temperature by lithiation involves first peeling and collecting the cathode active material from the waste cathode sheet, then immersing it in a lithiation reagent to regenerate and repair the waste lithium iron phosphate material at room temperature, followed by solid-liquid separation, cleaning, and drying to obtain the regenerated cathode material. The lithiation reagent is at least one of the following: lithium-naphthalene solution, lithium-biphenyl solution, lithium-dimethylfluorene solution, and triethyl borohydride solution.
[0016] The reaction equations involved are as follows: .
[0017] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.
[0018] Example 1 This embodiment directly regenerates waste lithium iron phosphate powder to obtain recycled lithium iron phosphate powder, specifically including the following steps: (1) Collection of positive electrode sheets: waste lithium iron phosphate batteries are completely discharged, disassembled, washed and dried to obtain waste lithium iron phosphate positive electrode sheets; (2) Separation: The above positive electrode sheet is placed in deionized water at 60℃ for 60s to separate the positive electrode active material from the aluminum current collector. The lithium iron phosphate positive electrode active material is dried in an oven at 80℃.
[0019] (3) Preparation of lithium reagent: Weigh the corresponding amount of naphthalene-lithium flakes in the glove box at a molar ratio of 1:1, place the naphthalene and lithium flakes in DME solvent and stir for 3 h to prepare a 0.1 M lithium-naphthalene (Li-Naph) solution.
[0020] (4) Lithification regeneration: Waste lithium iron phosphate powder and lithiation reagent are prepared according to the ratio of missing lithium in powder to lithium in lithiation reagent = 1:2. Stir for 10 min in a glove box at room temperature. The solution after reaction is filtered to achieve solid-liquid separation and washed with DME solvent. Then it is dried in an oven at 60℃ to obtain the repaired and regenerated lithium iron phosphate.
[0021] Example 2 The difference from Example 1 is that the lithiation reagent is a lithium-dimethylfluorene (Li-DiMF) solution, and the rest is the same as in Example 1.
[0022] Preparation method of lithiation reagent Li-DiMF solution: Weigh the corresponding amounts of lithium sheet and DiMF in a glove box at a molar ratio of 1:1. First, place DiMF in DME solvent and stir for 3 h. Then, place the lithium sheet in the solution and react for 3 h to obtain a 0.1 M Li-DiMF solution.
[0023] Example 3 The difference from Example 1 is that the lithiation agent is lithium-biphenyl (Li-Bip), otherwise it is the same as in Example 1.
[0024] Preparation method of Li-Bip solution: Weigh the corresponding amounts of lithium sheet and biphenyl (Bip) in a glove box at a molar ratio of 1:1. First, place Bip in DME solvent and stir for 3 h. Then, place the lithium sheet in the solution and react for 3 h to obtain a 0.1 M Li-Bip solution.
[0025] Example 4 Unlike Example 1, the lithiation reagent was a Li-TBH solution, otherwise it was the same as in Example 1; the LiTBH solution was purchased directly from Aladdin.
[0026] X-ray diffraction analysis was performed on the recycled lithium iron phosphate (RLFP) and spent lithium iron phosphate (SLFP) from Examples 1-4. The results are shown in the figure. Figure 1 As can be seen from the figure, the diffraction peaks of the lithium-deficient FePO4 phase in the regenerated lithium iron phosphate cathode material were eliminated, confirming that the solution lithium replenishment method successfully inserted lithium ions into the iron phosphate lattice.
[0027] Elemental analysis was performed on the recycled lithium iron phosphate (RLFP) and spent lithium iron phosphate (SLFP) from Example 1. The test results are shown in [Figure 1]. Figure 2 As can be seen from the figure, the Li / Fe molar ratio in waste lithium iron phosphate is 0.74, resulting in a loss of approximately 26% of active lithium. In contrast, the Li / Fe molar ratio in regenerated lithium iron phosphate is 1, indicating that the missing active lithium has been replenished.
[0028] First-cycle charge-discharge tests were conducted on recycled lithium iron phosphate (RLFP), spent lithium iron phosphate (SLFP), and commercial lithium iron phosphate (CLFP) from Example 1. The test results are shown in [Figure 1]. Figure 3 As shown in the figure, waste lithium iron phosphate has a low charging capacity due to the lack of active lithium. After lithium replenishment with chemical lithiation reagent, the charging capacity of regenerated lithium iron phosphate is restored and is comparable to that of commercial lithium iron phosphate (CLFP).
[0029] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of the present invention.
Claims
1. A method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials, characterized in that, First, the positive electrode active material is stripped and collected from the waste positive electrode sheet, then it is soaked in the lithiumization reagent to complete the regeneration and repair of the waste lithium iron phosphate material at room temperature. Subsequently, solid-liquid separation, cleaning and drying are performed to obtain the regenerated positive electrode material. The lithiation reagent is at least one of the following: lithium-naphthalene solution, lithium-biphenyl solution, lithium-dimethylfluorene solution, and triethyl borohydride solution.
2. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 1, characterized in that, Includes the following steps: S1: Completely discharge, disassemble, wash, and dry the waste lithium batteries to obtain waste positive electrode sheets; S2: Place the waste positive electrode sheet into deionized water to separate the positive electrode active material from the aluminum current collector and obtain the positive electrode active material; dry the positive electrode active material to obtain waste positive electrode active material powder; S3: Prepare the lithiumization reagent; S4: Add waste positive electrode active material powder and lithium reagent according to the lithium deficiency in the powder, stir at room temperature for 2-20 minutes, filter the solution after reaction to achieve solid-liquid separation, wash the solid phase with organic solvent, and then dry in an oven to obtain the repaired and regenerated positive electrode active material.
3. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S2, the temperature of the deionized water is 40-80℃, and the time for immersing the deionized water is 50-70 seconds.
4. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S2, the drying temperature is 70-90℃.
5. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S3, the concentration of the lithium reagent is 0.05-1M.
6. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S3, the method for preparing the lithium-ionizing reagent is as follows: The solution is prepared by stirring naphthalene, biphenyl, dimethylfluorene, or lithium flakes in a solvent for 3-10 hours.
7. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S4, the drying temperature is 50-70℃.
8. The method for direct room-temperature lithiation regeneration of waste lithium-ion battery cathode materials according to claim 2, characterized in that, In step S1, the waste lithium battery is at least one of waste lithium iron phosphate battery, waste lithium cobalt oxide battery, and waste ternary lithium battery.