Lithium manganese iron phosphate cathode material prepared from waste batteries, its preparation method and application
Patent Information
- Application Number
- CN202610611988.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-07
- Publication Date
- 2026-08-14
AI Technical Summary
[0003]现有电池再生工艺多采用湿法冶金路线，需要使用大量酸碱试剂，并且工艺流程较为复杂，对设备要求较高，增加了回收成本和环境处理压力
[0015] In existing technologies, after dismantling waste batteries, waste lithium iron phosphate is typically calcined under an inert atmosphere, and waste lithium manganese oxide is typically calcined under an oxygen atmosphere to remove binders and organic residues. Then, liquid-phase treatment methods such as acid leaching are used to break down the original structure and convert the metal elements into reusable resources. These methods typically suffer from problems such as high consumption of acidic reagents, cumbersome separation and extraction steps, significant element loss, and waste acid and wastewater discharge, limiting resource utilization efficiency and environmental friendliness. In this application, by controlling the calcination atmosphere and temperature conditions of different cathode materials during the pretreatment stage, elements such as lithium, iron, manganese, and phosphorus in waste lithium iron phosphate and lithium manganese oxide are effectively activated, achieving synergistic utilization of these elements. Therefore, complex steps such as acid-base leaching are unnecessary, allowing direct entry into the subsequent solid-phase reaction process to prepare lithium manganese iron phosphate cathode materials. This method significantly simplifies the process flow, improves the utilization rate of elements such as lithium, iron, manganese and phosphorus, avoids acid and alkali consumption and equipment requirements, and greatly enhances the universality and environmental friendliness of the system's upgrade, recycling and regeneration route, with good environmental benefits and industrial application prospects.
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Abstract
Description
Technical Field
[0001] This application relates to the field of waste battery recycling, and more specifically, to a lithium manganese iron phosphate cathode material prepared from waste batteries, its preparation method, and its application. Background Technology
[0002] Lithium iron phosphate (LFP) batteries are widely used in electric vehicles and energy storage due to their high safety, long cycle life, and low cost. Lithium manganese oxide (LMO) batteries are widely used in two-wheeled electric vehicles and portable electronic devices due to their lower cost and better rate performance. With the large-scale application of these batteries, the quantity of waste LFP and LMO batteries is increasing year by year. Co-utilizing the metal resources in waste LFP and LMO cathode materials and upgrading them into higher energy density LMO cathode materials is considered a promising resource utilization method.
[0003] Existing battery regeneration processes mostly employ hydrometallurgical routes, requiring large amounts of acid and alkali reagents, and are relatively complex, demanding high-end equipment, thus increasing recycling costs and environmental impact. Therefore, developing a simple regeneration method that does not require large amounts of acid and alkali reagents, enabling efficient regeneration from spent batteries to lithium manganese iron phosphate cathode materials, is of great significance. Summary of the Invention
[0004] This invention provides a lithium manganese iron phosphate cathode material prepared from waste batteries, its preparation method, and its application. The preparation process of this invention is simple and does not require a large amount of acid and alkali reagents, realizing the efficient regeneration and application of lithium manganese iron phosphate cathode material from waste batteries.
[0005] This invention discloses a method for preparing lithium manganese iron phosphate cathode material from waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, and calcine it in an oxygen-containing atmosphere for 1-3 hours. The calcination product is recorded as sample A. Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and pre-treat and calcine it under an inert atmosphere for 1-3 hours. The calcination product is recorded as sample B. Step 3: Without adding any additional iron or manganese sources, according to the molar ratio Fe:Mn:P:Li = (0.4~0.8):(0.2~0.6):1:(1.0~1.1), weigh appropriate amounts of sample A, sample B, ammonium dihydrogen phosphate, lithium carbonate, and glucose, and mix them with water to form a slurry. Then, mill the slurry, spray dry it, and calcine it at high temperature to obtain lithium manganese iron phosphate cathode material.
[0006] Preferably, the calcination temperature in step 1 is 500-700°C.
[0007] Preferably, the calcination temperature in step 1 is 600°C.
[0008] Preferably, the calcination temperature in step 2 is 600-900°C.
[0009] Preferably, the calcination temperature in step 2 is 800°C.
[0010] Preferably, the inert atmosphere in step 2 is argon or nitrogen.
[0011] Preferably, in step 3, Fe:Mn:P:Li = 0.6:0.4:1:1.05.
[0012] Preferably, in step 3, the total amount of sample A and sample B added is 45-60% of the solid content in the slurry.
[0013] The present invention also provides a lithium manganese iron phosphate cathode material prepared by the above method.
[0014] The present invention also provides the application of the lithium manganese iron phosphate cathode material prepared by the above method, which is used to prepare lithium manganese iron phosphate / lithium half-cells.
[0015] In existing technologies, after dismantling waste batteries, waste lithium iron phosphate is typically calcined under an inert atmosphere, and waste lithium manganese oxide is typically calcined under an oxygen atmosphere to remove binders and organic residues. Then, liquid-phase treatment methods such as acid leaching are used to break down the original structure and convert the metal elements into reusable resources. These methods typically suffer from problems such as high consumption of acidic reagents, cumbersome separation and extraction steps, significant element loss, and waste acid and wastewater discharge, limiting resource utilization efficiency and environmental friendliness. In this application, by controlling the calcination atmosphere and temperature conditions of different cathode materials during the pretreatment stage, elements such as lithium, iron, manganese, and phosphorus in waste lithium iron phosphate and lithium manganese oxide are effectively activated, achieving synergistic utilization of these elements. Therefore, complex steps such as acid-base leaching are unnecessary, allowing direct entry into the subsequent solid-phase reaction process to prepare lithium manganese iron phosphate cathode materials. This method significantly simplifies the process flow, improves the utilization rate of elements such as lithium, iron, manganese and phosphorus, avoids acid and alkali consumption and equipment requirements, and greatly enhances the universality and environmental friendliness of the system's upgrade, recycling and regeneration route, with good environmental benefits and industrial application prospects. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 The image shows the XRD pattern of sample A prepared in Examples 1, 2, 3 and Comparative Example 1.
[0018] Figure 2 The image shows the XRD pattern of sample B prepared in Examples 1, 2, 3 and Comparative Example 1.
[0019] Figure 3 The image shows the XRD pattern of lithium manganese iron phosphate prepared in Example 3.
[0020] Figure 4 The image shows the SEM image of lithium manganese iron phosphate prepared in Example 3.
[0021] Figure 5 The images show the first charge-discharge cycle (0.1C) of the lithium manganese iron phosphate / lithium half-cells prepared in Examples 1, 2, 3, and Comparative Example 1.
[0022] Figure 6 The graph shows the cycle performance of lithium manganese iron phosphate / lithium half-cells prepared in Examples 1, 2, 3 and Comparative Example 1.
[0023] Figure 7 The graph shows the mass percentage of recovered raw materials to total input for Examples 1, 2, 3 and Comparative Example 1.
[0024] Figure 8 This is a comparison diagram between the patent process and the conventional process. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0026] Example 1
[0027] A method for preparing lithium manganese iron phosphate cathode material using waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, calcine it in air atmosphere for 3 hours, the calcine temperature is 500°C, and the calcine product is recorded as sample A. Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and pre-treat and calcine it for 3 hours under an argon atmosphere at a calcination temperature of 600°C. The calcination product is recorded as sample B. Step 3: Without adding any additional iron or manganese sources, according to the molar ratio Fe:Mn:P:Li = 0.4:0.6:1:1, weigh appropriate amounts of sample A, sample B, ammonium dihydrogen phosphate, lithium carbonate, and glucose, and mix them with water to form a slurry. The total amount of sample A and sample B added to the slurry has a solid content of 45%. The slurry is then milled, spray-dried, and calcined at high temperature to obtain lithium manganese iron phosphate cathode material.
[0028] The above-mentioned lithium iron phosphate cathode material and lithium sheet are assembled to obtain lithium iron phosphate / lithium half-cell.
[0029] Example 2
[0030] A method for preparing lithium manganese iron phosphate cathode material using waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, calcine it for 1 hour in an oxygen atmosphere at a calcine temperature of 700°C, and record the calcine product as sample A. Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and pre-treat and calcine it for 1 hour under a nitrogen atmosphere at a calcination temperature of 900°C. The calcination product is recorded as sample B. Step 3: Without adding any additional iron or manganese sources, according to the molar ratio Fe:Mn:P:Li = 0.8:0.2:1:1.1, weigh appropriate amounts of sample A, sample B, ammonium dihydrogen phosphate, lithium carbonate, and glucose, and prepare a slurry with water. The total amount of sample A and sample B added to the slurry is 60% of the solid content. The slurry is then sand-milled, spray-dried, and calcined at high temperature to obtain lithium manganese iron phosphate cathode material.
[0031] The above-mentioned lithium iron phosphate cathode material and lithium sheet are assembled to obtain lithium iron phosphate / lithium half-cell.
[0032] Example 3
[0033] A method for preparing lithium manganese iron phosphate cathode material using waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, and calcine it in air atmosphere for 2 hours at a calcine temperature of 600°C. The calcine product is recorded as sample A. Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and pre-treat and calcine it for 2 hours under an argon atmosphere at a calcination temperature of 800°C. The calcination product is recorded as sample B. Step 3: Without adding any additional iron or manganese sources, according to the molar ratio Fe:Mn:P:Li = 0.6:0.4:1:1.05, weigh appropriate amounts of sample A, sample B, ammonium dihydrogen phosphate, lithium carbonate, and glucose, and prepare a slurry with water. The total amount of sample A and sample B added to the slurry has a solid content of 56.8%. The slurry is then milled, spray-dried, and calcined at high temperature to obtain lithium manganese iron phosphate cathode material.
[0034] The above-mentioned lithium iron phosphate cathode material and lithium sheet are assembled to obtain lithium iron phosphate / lithium half-cell.
[0035] Comparative Example 1 A method for preparing lithium manganese iron phosphate cathode material using waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, and calcine it at 600°C for 2 hours under an argon atmosphere to obtain sample A; Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and calcine it at 800°C for 2 hours in an oxygen atmosphere to obtain sample B; Step 3: Use 2 mol / L nitric acid to leach sample A from step 1 to obtain leachate A; Step 4: Use 2 mol / L nitric acid and 5 vol% H2O2 to leach sample B from step 2 to obtain leachate B.
[0036] Step 5: According to the molar ratio Fe:Mn:P:Li = 0.6:0.4:1:1.05, weigh appropriate amounts of leachate A, leachate B, ammonium dihydrogen phosphate, lithium carbonate and citric acid to carry out sol-gel reaction, and then dry them (in the dried material, the total solid content of samples A and B is 29%). After sand milling and spray drying, high-temperature calcination is carried out to obtain the target product lithium manganese iron phosphate cathode material.
[0037] The above-mentioned lithium iron phosphate cathode material and lithium sheet are assembled to obtain lithium iron phosphate / lithium half-cell.
[0038] The lithium iron phosphate / lithium half-cells prepared in Examples 1-3 and Comparative Example 1 were subjected to charge-discharge cycle tests at 30 °C. The test results are shown in the table below:
[0039] Figure 1 The images show the XRD patterns of samples A prepared in Examples 1, 2, 3 and Comparative Example 1. In Comparative Example 1, sample A still has the crystal structure of lithium iron phosphate (LiFePO4), making it difficult to directly incorporate manganese. However, in Examples 1, 2, and 3, an oxidation reaction occurred in an oxygen atmosphere, which destroyed the original structure and formed Li3Fe2(PO4)3, which is easier to introduce manganese later. The samples at 600 °C did not have the characteristic peak of LiFePO4 and had Li3Fe2(PO4)3 with good peak intensity. Figure 2 The images show the XRD patterns of sample B prepared in Examples 1, 2, 3, and Comparative Example 1. In Comparative Example 1, sample B still exhibits the crystal structure of lithium manganese oxide, making direct incorporation into lithium iron phosphate difficult. In Examples 1, 2, and 3, a high-temperature decomposition reaction occurs under an oxygen-free atmosphere, resulting in MnO samples with good peak intensity at 800 °C. Samples A and B respectively achieve the transformation from their original crystal structure to usable products at this calcination temperature. The optimal calcination temperature for waste lithium iron phosphate is 600 °C, and the optimal calcination temperature for waste lithium manganese oxide is 800 °C. Figure 3 The image shows the XRD pattern of lithium manganese iron phosphate prepared in Example 3. Figure 4 The image shows a SEM image of lithium manganese iron phosphate prepared in Example 3. This lithium manganese iron phosphate material has a pure crystal structure and a regular morphology. Figure 5 The first charge-discharge curves at 0.1C for the lithium manganese iron phosphate / lithium half-cells prepared in Examples 1-3 and Comparative Example 1 show that the specific capacity of the sample in Comparative Example 1 is significantly lower than that of the process in this patent, while the sample in Example 3 has the highest specific capacity of 151.2 mAh / g under the process conditions of Example 3. Figure 6 The graph shows the cycle performance of lithium manganese iron phosphate / lithium half-cells prepared in Examples 1-3 and Comparative Example 1. It can be observed that the sample in Example 3 has the highest specific capacity, the samples in Examples 1 and 2 have slightly lower capacities, and the sample in Comparative Example 1 has the lowest capacity.
[0040] Figure 7 The graph shows the mass ratio of recycled raw materials to total input for Examples 1, 2, 3 and Comparative Example 1. Using the preparation method of lithium manganese iron phosphate cathode material prepared from waste batteries according to the present invention, the recycling rate of waste batteries in Examples 1, 2, and 3 is much higher than that in Comparative Example 1.
[0041] Figure 8This is a comparison diagram of the process flow of this patent and the conventional process flow, namely, a comparative schematic diagram of the process flow of Examples 1, 2, 3 and Comparative Example 1. This invention effectively activates elements such as lithium, iron, manganese, and phosphorus in waste lithium iron phosphate and lithium manganese oxide by controlling the calcination atmosphere and temperature conditions of different cathode materials during the pretreatment stage, and achieves synergistic utilization of these elements. Therefore, it eliminates the need for complex steps such as acid-base leaching, allowing direct entry into the subsequent solid-phase reaction process to prepare lithium manganese iron phosphate cathode materials.
[0042] Tables 1 and 2 detail the production costs of the patented process and the conventional process. The calculations assume the recovery of 0.73 tons of waste lithium iron phosphate cathode material and 0.27 tons of waste lithium manganese oxide cathode material. Theoretically, the patented process can yield 1213.8 kg of recycled lithium manganese iron phosphate cathode material, requiring only 238.6 thousand yuan in reagent costs. In contrast, the conventional process can theoretically yield 1092.5 kg of recycled lithium manganese iron phosphate cathode material, requiring 636 thousand yuan in reagent costs.
[0043] Table 1. Detailed breakdown of costs for the patent recycling process.
[0044] Table 2. Cost Breakdown of Routine Recycling Process
[0045] In summary, this invention effectively activates lithium, iron, manganese, and phosphorus elements in waste lithium iron phosphate and lithium manganese oxide by controlling the calcination atmosphere and temperature conditions of different cathode materials during the pretreatment stage, achieving synergistic utilization of these elements. This eliminates the need for complex steps such as acid-base leaching, allowing direct entry into the subsequent solid-state reaction process to prepare lithium manganese iron phosphate cathode materials. This method significantly simplifies the process flow, improves the utilization rate of lithium, iron, manganese, and phosphorus elements, avoids acid and alkali consumption and equipment requirements, and greatly enhances the universality and environmental friendliness of the system's upgrade, recycling, and regeneration route, demonstrating good environmental benefits and promising prospects for industrial application.
[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing lithium manganese iron phosphate cathode material from waste batteries, the method comprising: Step 1: Disassemble the waste lithium iron phosphate soft-pack battery, separate the waste lithium iron phosphate cathode material, place the obtained cathode material in a tube furnace, and calcine it in an oxygen-containing atmosphere for 1-3 hours. The calcination product is recorded as sample A. Step 2: Disassemble the waste lithium manganese oxide soft-pack battery, separate the waste lithium manganese oxide positive electrode material, place the obtained positive electrode material in a tube furnace, and pre-treat and calcine it under an inert atmosphere for 1-3 hours. The calcination product is recorded as sample B. Step 3: Without adding any additional iron or manganese sources, according to the molar ratio Fe:Mn:P:Li = (0.4~0.8):(0.2~0.6):1:(1.0~1.1), weigh appropriate amounts of sample A, sample B, ammonium dihydrogen phosphate, lithium carbonate, and glucose, and mix them with water to form a slurry. Then, mill the slurry, spray dry it, and calcine it at high temperature to obtain lithium manganese iron phosphate cathode material.
2. The preparation method according to claim 1, characterized in that, The calcination temperature in step 1 is 500-700°C.
3. The preparation method according to claim 1, characterized in that, The calcination temperature in step 1 is 600°C.
4. The preparation method according to claim 1, characterized in that, The calcination temperature in step 2 is 600-900°C.
5. The preparation method according to claim 1, characterized in that, The calcination temperature in step 2 is 800°C.
6. The preparation method according to claim 1, characterized in that, In step 2, the inert atmosphere is argon or nitrogen.
7. The preparation method according to claim 1, characterized in that, In step 3, Fe:Mn:P:Li = 0.6:0.4:1:1.
05.
8. The preparation method according to claim 1, characterized in that, In step 3, the total amount of sample A and sample B added is 45-60% of the solid content in the slurry.
9. A lithium iron phosphate cathode material, characterized in that, The lithium manganese iron phosphate cathode material is prepared by the preparation method described in any one of claims 1 to 9.
10. The application of the lithium iron phosphate cathode material as described in claim 9, characterized in that, The lithium manganese iron phosphate cathode material of claim 9 is used to prepare lithium manganese iron phosphate / lithium half-cells.