Method for recycling lithium battery pole piece membrane material

Abstract

The invention discloses a lithium battery pole piece membrane material recovery method, which comprises the following steps: selecting a specific sol agent to infiltrate a pole piece subjected to embossing pretreatment, then cooperating with spraying to accelerate the stripping of the membrane material, and finally stirring and refining under the action of an NMP organic solvent, thereby ensuring that the membrane material can be effectively dispersed and does not carry too many aluminum foil fragments. And after the aluminum foil is removed through screening, the film material is subjected to vacuum vibration drying to reduce the moisture content. According to the whole technological process, the purity and efficiency of membrane material recovery are improved, non-destructive green recovery is achieved, the value of an original material is reserved to the maximum extent, and meanwhile the problem that the aluminum content exceeds the standard in a traditional method is solved. The recycling method has the characteristics of high automation realization degree and high productivity, can provide effective support for a non-destructive repair technology, and can reduce the recycling cost, maximally realize the value of a regenerated material and realize the closed loop of the lithium battery electrode material compared with a material extraction and recycling technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium battery recycling, and in particular relates to a method for recycling lithium battery pole piece film materials. Background Art

[0002] With the rapid development of the new energy vehicle industry, the production volume of lithium batteries, as a key component of its power source, is also increasing. At the same time, a certain proportion of unfilled positive electrode waste will inevitably be generated during the production process of lithium batteries. These unfilled positive electrode plates usually contain an aluminum foil substrate and an active material film layer (i.e., electrode film material) coated thereon, in which the active material contains valuable metal components such as lithium, cobalt, and nickel. In order to achieve effective recycling of resources and reduce the risk of environmental pollution, how to efficiently and environmentally friendly recycle these unfilled positive electrode plates has become an important issue.

[0003] At present, physical, chemical and biological methods are mainly used for the recycling of unfilled positive electrode plates. The physical method mainly includes steps such as crushing, screening and magnetic separation, and separates aluminum particles and positive electrode material powder by mechanical means, but this method often leads to the mixing of more aluminum foil fragments in the recyclables, which makes the aluminum content in the positive electrode material powder exceed the standard, affecting its recycling rate. In addition, the products obtained by this method are mostly positive electrode material precursors, which need further processing to be prepared into new positive electrode materials, increasing the subsequent processing costs. The chemical method relies on dissolution and precipitation processes to extract valuable metals, while the biological method uses microorganisms to decompose and extract metals. However, both methods have their own limitations: the chemical method may introduce additional chemical elements and increase the risk of pollution; the biological method is not suitable for large-scale industrial applications due to its long cycle and high cost. Summary of the invention

[0004] The purpose of the present invention is to provide a method for recycling lithium battery pole piece film materials, which solves the problem that the pole piece film materials are easily mixed with aluminum foil debris during the stripping process, resulting in excessive aluminum content.

[0005] To achieve the above object, the present invention adopts the following technical solution: a method for recycling lithium battery pole piece film material, comprising the following steps: The uninjected positive electrode plate is embossed to form a surface with a uniformly distributed pattern; a sol agent is selected according to the properties of the plate primer and the binder material, and the embossed plate is immersed in the selected sol agent to accelerate the peeling of the plate film material and the aluminum foil substrate; after the immersion, the plate is sprayed with a spray device to promote the separation of the film material from the aluminum foil; the separated film material enters a refinement tank, and is stirred and refined under the action of NMP organic solvent as a dispersant, so that the film material is refined to a size that can pass through a 150-250 mesh filter; after screening to remove aluminum foil debris, the film material is vacuum-vibrated and dried to reduce the moisture content in the film material.

[0006] Preferably, the embossing process is to cut a diamond pattern with a side length of 4-6 mm on the surface of the pole piece.

[0007] Preferably, the sol agent is selected according to the properties of the pole piece primer and the binder material, including: For water-soluble primer and adhesive, pure water is used as the sol; For oily primer and adhesive, NMP organic solvent is selected as the sol agent.

[0008] Preferably, the infiltration temperature is set to 55°C-65°C, and the time is set to 50-70 seconds for water-soluble primer, while the oily primer is infiltrated for 110-130 seconds at room temperature.

[0009] Preferably, the spraying device uses pure water as the spraying medium to assist the separation of the film material from the aluminum foil with physical force, and simultaneously cuts the film material into the size of the embossed pattern.

[0010] Preferably, in the refinement tank, NMP organic solvent is used as a refiner, the speed of the stirring paddle is set to 90-110 r / min, and the stirring time is adjusted to 10-15 minutes according to the type of the base coating glue.

[0011] Preferably, the method further includes: the dried film material is directly prepared into a directly usable positive electrode material through a lithium supplementation process without extracting lithium elements.

[0012] Preferably, the drying process adopts vacuum vibration drying.

[0013] Preferably, the lithium replenishment process is based on the Li:Fe molar ratio of 1.08 to supplement lithium carbonate as a lithium source, and according to the measured carbon content, sucrose is added to 2.5wt% as a carbon source, and mixed with industrial-grade lithium iron phosphate VC for calcination to repair the crystal structure.

[0014] Preferably, the calcination process is carried out in a natural gas rotary kiln at 650°C-750°C for 9-11 hours, during which inert gas is introduced to prevent oxidation.

[0015] Technical effects and advantages of the present invention: Compared with the prior art, the method for recycling lithium battery pole piece film material proposed by the present invention has the following advantages: The present invention selects a specific sol to wet the electrode after embossing pretreatment, then accelerates the stripping of the film material with spraying, and finally stirs and refines it under the action of NMP organic solvent, ensuring that the film material can be effectively dispersed and does not carry too many aluminum foil fragments. After screening to remove the aluminum foil, the film material is vacuum-vibrated and dried to reduce the moisture content. The entire process not only improves the purity and efficiency of film material recovery, but also realizes non-destructive green recovery, maximizes the value of the original material, and avoids the problem of excessive aluminum content in traditional methods. Therefore, the method has significant technical effects, including but not limited to higher recovery rate, lower impurity content and more environmentally friendly treatment methods. This recycling method has a high degree of automation and high production capacity. It can also provide effective support for non-destructive repair technology. Compared with material extraction and recycling technology, the main advantage of this process is that it can reduce recycling costs, maximize the value of recycled materials, and realize the closed loop of lithium battery electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of a method for recycling lithium battery pole piece film material. DETAILED DESCRIPTION

[0017] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] The present invention provides Figure 1 A method for recycling lithium battery pole piece film material shown includes the following steps: Step 1: emboss the unfilled positive electrode plate to form a surface with a uniformly distributed pattern; the embossing treatment is to cut a diamond pattern with a side length of 4-6 mm on the surface of the plate.

[0019] Specifically, the embossing process significantly enhances the efficiency of subsequent film stripping by cutting a diamond pattern with a side length of 4-6mm on the surface of the pole piece. This specific geometric design not only helps to increase the area of ​​action of the sol on the primer and adhesive, but also provides a more effective separation force during the spraying process, making it easier for the film to fall off the aluminum foil substrate. In addition, the design of the diamond pattern can ensure that the film material maintains a relatively uniform size when it is refined, which is beneficial to the subsequent screening and drying steps, and reduces the possibility of mixing in aluminum foil debris, thereby effectively controlling the aluminum content in the recycled material.

[0020] A non-liquid-injected positive electrode sheet with a size of 30cm x 40cm and a thickness of about 100μm is placed in an embossing device and processed using a special embossing roller. The pattern on the embossing roller is designed as a diamond pattern with a side length of 5mm, evenly distributed on the surface of the electrode. After embossing, the surface of the electrode presents a regularly arranged diamond-shaped concave and convex structure, which increases the surface area of ​​the electrode and also prepares good conditions for the subsequent infiltration process.

[0021] Technical parameters: Embossed pattern: diamond; Side length range: 5mm (can be adjusted to 4-6mm according to actual needs in specific implementation); Pattern distribution: Evenly cover the entire pole surface.

[0022] Step 2: selecting a sol agent according to the properties of the electrode primer and the adhesive material, and placing the embossed electrode in the selected sol agent for soaking to accelerate the peeling of the electrode film material and the aluminum foil substrate; Optionally, pure water is used as the sol for water-soluble primer and adhesive; NMP organic solvent is used as the sol for oily primer and adhesive.

[0023] Specifically, choosing a suitable sol is the key to ensuring efficient separation of the electrode film material from the aluminum foil substrate. For water-soluble primers and adhesives, using pure water as a sol can effectively dissolve these materials without introducing other chemical elements, thus maintaining the purity of the recycled materials. For oily primers and adhesives, NMP (N-methylpyrrolidone) organic solvent is used. This is because NMP has good solubility for such materials and can quickly dissolve the primer and adhesive without destroying the electrode structure, thereby accelerating the peeling process of the film material from the aluminum foil. In addition, as a high-boiling point, low-volatility solvent, NMP is relatively safe and easy to control during the processing process, and can be recycled in subsequent steps, reducing costs.

[0024] By selecting the appropriate sol, this step not only improves the speed and efficiency of film stripping, but also ensures the quality of the recycled material and avoids the introduction of unnecessary impurities. At the same time, since different types of primers and adhesives require different treatment methods, this method can be flexibly adjusted according to the specific material characteristics, enhancing the adaptability and wide applicability of the process.

[0025] Specific implementation method 1: non-liquid-injected positive electrode sheet with water-soluble primer and binder: After embossing, a non-liquid-injected positive electrode plate with a size of 30cm x 40cm and a thickness of about 100μm was immersed in pure water at a temperature of 60°C for 60 seconds. Since the plate uses a water-soluble primer and adhesive, pure water as a sol can effectively dissolve these materials, causing the plate film material to loosen and separate from the aluminum foil substrate. As the immersion time increases, the primer gradually dissolves, and the film material shows a phenomenon of misalignment with the aluminum foil, which prepares for further spray separation.

[0026] Technical parameters: Solvent: pure water; Wetting temperature: 60°C; Immersion time: 60 seconds; Primer and adhesive type: water-soluble; Specific implementation method 2: non-liquid-injected positive electrode sheet with oily primer and adhesive: For a non-liquid-injected positive electrode sheet of the same size but using an oily primer and binder, place it in an NMP organic solvent at room temperature for 120 seconds. As a powerful organic solvent, NMP can quickly dissolve the oily primer and binder, resulting in a significant weakening of the bonding force between the film material and the aluminum foil substrate, thereby accelerating the film material peeling process. Compared with water-soluble materials, oily materials take longer to fully dissolve, so the immersion time is set to 120 seconds to ensure the best effect.

[0027] Technical parameters: Solvent: NMP organic solvent; Wetting temperature: room temperature (about 25°C); Immersion time: 120 seconds; Primer and adhesive type: oily.

[0028] In these two examples, by selecting the most suitable sol for different types of primers and adhesives, efficient film stripping is achieved, while the mixing of impurities is minimized to ensure the high quality of the recycled materials. This step lays a solid foundation for subsequent operations such as spraying, refinement, screening and drying, ensuring the smooth progress of the entire recycling process.

[0029] Step 3: After infiltration, use a spray device to spray the electrode to promote the separation of the film material from the aluminum foil; the infiltration temperature is set to 55°C-65°C, and the time is set to 50-70 seconds for water-soluble primer, and the oily primer is infiltrated at room temperature for 110-130 seconds.

[0030] Furthermore, the spraying device uses pure water as a spraying medium to assist the separation of the film material from the aluminum foil with physical force, and simultaneously cuts the film material into the size of the embossed pattern.

[0031] The spraying step is one of the key links in separating the electrode film from the aluminum foil. By using pure water as the spraying medium, physical force can be provided to assist the film to be completely separated from the aluminum foil. At the same time, the film can be cut into the size of the embossed pattern to ensure that the size of the film is uniform and consistent, which is convenient for subsequent processing. The spraying process not only enhances the effect of film stripping, but also avoids the introduction of additional chemicals, maintaining the purity of the recycled materials. In addition, for water-soluble primers, appropriate infiltration temperature (55°C-65°C) and time (50-70 seconds) can help accelerate the dissolution of the primer, while oily primers can be fully dissolved at room temperature for 110-130 seconds to achieve efficient film stripping.

[0032] The design of the spray device makes the whole process highly automated and easy to operate, and can stably control the quality of film stripping, reducing the uncertainty caused by manual intervention. This technical improvement effectively solves the problem of film materials being easily mixed with aluminum foil debris in traditional methods, reduces the risk of excessive aluminum content in film materials, and improves the purity and value of recycled materials.

[0033] Specific implementation method three: non-liquid-injected positive electrode sheet with water-soluble primer and binder: After the impregnation treatment, the electrode is transferred to the spray device. At this time, the primer on the surface of the electrode has been partially dissolved, and the film material begins to separate from the aluminum foil substrate. The spray device uses pure water as the spray medium to spray the electrode evenly under a certain pressure. During the spraying process, the physical impact force generated by the water flow further promotes the separation of the film material from the aluminum foil and cuts the film material into small pieces that match the embossed pattern. This process effectively prevents the mixing of large pieces of film material and aluminum foil fragments, reducing the risk of excessive aluminum content.

[0034] Technical parameters: Wetting temperature: 60°C (within the recommended range of 55°C-65°C); Immersion time: 60 seconds (within the recommended range of 50-70 seconds); Primer and adhesive type: water-soluble; Spraying medium: pure water; Spray pressure: moderate, enough to provide sufficient physical separation force without damaging the membrane structure.

[0035] Specific implementation method 4: non-liquid-injected positive electrode sheet with oily primer and adhesive: For the pole pieces using oily primer and adhesive, they are also transferred to the spray device after soaking for 120 seconds at room temperature. Although the NMP organic solvent has significantly weakened the bonding force between the film material and the aluminum foil in the soaking step, the role of the spray device is still indispensable. Pure water spraying can not only continue to promote the separation of the film material, but also ensure that the film material is cut into smaller particles that meet the size of the embossed pattern, which is conducive to subsequent refinement and screening operations.

[0036] Technical parameters: Wetting temperature: room temperature (about 25°C); Immersion time: 120 seconds (within the recommended range of 110-130 seconds); Primer and adhesive type: oily; Spraying medium: pure water; Spray pressure: moderate, ensuring separation effect while protecting membrane material integrity.

[0037] In these two examples, the physical force provided by pure water in the spraying step significantly improves the separation efficiency of the membrane material and the aluminum foil, ensures the consistency and uniformity of the membrane material size, and avoids the introduction of unnecessary impurities. This step creates favorable conditions for subsequent operations such as refinement, screening and drying, ensuring that the entire recycling process is efficient, environmentally friendly and economically feasible.

[0038] Step 4: The separated film material enters the refinement tank, where it is stirred and refined under the action of NMP organic solvent as a dispersant, so that the film material can pass through a 150-250 mesh filter; the NMP organic solvent in the refinement tank is used as a refiner, the stirring paddle speed is set to 90-110r / min, and the stirring time is adjusted to 10-15 minutes according to the type of primer.

[0039] The refinement step is the key to ensuring that the recycled film material achieves the ideal particle size distribution and purity. By using NMP organic solvent as a dispersant in the refinement tank, the separated large pieces of film material can be effectively further refined to the point where they can pass through a 150-250 mesh filter. As an efficient organic solvent, NMP can not only dissolve oily primers and binders, but also prevent the reaggregation of film material particles, thereby ensuring uniform dispersion of the film material. The stirring paddle speed is set at 90-110r / min, which can provide sufficient shear force without affecting the structural integrity of the film material, so that the film material is refined into smaller and more uniform particles. In addition, adjusting the stirring time (10-15 minutes) according to the difference in primer type can optimize the refinement process and ensure that pole pieces with different material properties can achieve the best processing effect.

[0040] This technical improvement significantly improves the refinement efficiency and quality of the film material, reduces the mixing of aluminum foil debris and other impurities, and thus reduces the risk of excessive aluminum content in the film material. At the same time, this method also realizes the recycling of NMP solvent, reduces production costs and reduces environmental pollution. Ultimately, the film material after refinement is more suitable for subsequent screening, drying and lithium replenishment processes, improving the efficiency and economic benefits of the entire recycling process.

[0041] Specific implementation method 5: non-liquid-injected positive electrode sheet with water-soluble primer and binder: The film material separated from the spraying device is sent to the refinement tank, during which NMP organic solvent is added as a dispersant. For the film materials of water-soluble primer and adhesive, although they have been partially broken up in the previous infiltration and spraying steps, further stirring and refining in the refinement tank is still necessary. Set the stirring paddle speed to 100r / min and stir for 10 minutes to ensure that the film material is fully refined without destroying its structure. Under this condition, the film material is refined to the extent that it can pass through a 200-mesh filter, which facilitates subsequent screening operations and ensures the uniformity and consistency of the film material particles.

[0042] Technical parameters: Dispersant: NMP organic solvent; Stirring paddle speed: 100r / min (within the recommended range of 90-110r / min); Stirring time: 10 minutes (applicable to water-soluble primer); Screening standard: can pass through 200 mesh filter; Specific implementation method 6: Positive electrode sheet without liquid injection of oily primer and adhesive: For film materials using oily primer and adhesive, NMP organic solvent is also used as a dispersant in the refinement tank. Since the oily material has been well pretreated in the previous infiltration and spraying steps, the main purpose of this step is to ensure that the film material is further refined to the ideal particle size distribution. The stirring paddle speed is set to 100r / min, but considering the characteristics of the oily material, the stirring time is extended to 15 minutes to ensure that all film materials are refined to the extent that they can pass through a 150-250 mesh filter. This step effectively avoids the presence of large pieces of film material, reduces the risk of mixing in aluminum foil debris, and prepares for subsequent screening and drying.

[0043] Technical parameters: Dispersant: NMP organic solvent; Stirring paddle speed: 100r / min (within the recommended range of 90-110r / min); Stirring time: 15 minutes (applicable to oily primer); Screening standard: can pass through 150-250 mesh filter; In these two examples, by precisely controlling the stirring conditions in the refinement tank and the use of NMP solvent, effective refinement of the film material is achieved, ensuring the consistency and uniformity of the particle size. This not only improves the quality of the recycled material, but also lays a good foundation for subsequent processing steps, reflecting the technical advantages of high efficiency, environmental protection and economic feasibility.

[0044] Step 5: After screening to remove the aluminum foil debris, the film material is vacuum-vibrated and dried to reduce the moisture content in the film material.

[0045] The vacuum vibration drying step is a key step to ensure the quality of the recycled film material and the subsequent processing performance. The film material after screening to remove the aluminum foil debris usually contains a certain amount of moisture, which not only affects the storage stability of the film material, but also causes changes or losses in material properties during subsequent lithium replenishment and other heat treatment processes. Through vacuum vibration drying, the moisture content in the film material can be effectively reduced to an extremely low level (for example, ≤1000ppm), thereby: Improve the purity of film materials: The vacuum environment can minimize the mixing of external impurities, maintain the purity of the film materials, and avoid pollutants that may be introduced in traditional drying methods.

[0046] Enhance material stability: After removing moisture, the film material is more stable during storage and transportation, and is not easily affected by moisture and deterioration, which extends the shelf life of the material.

[0047] Optimize subsequent processing conditions: The dried film material is more suitable for subsequent processes such as high-temperature calcination, because the lower moisture content can prevent the material structure from being damaged or the volume expanded due to the rapid evaporation of water at high temperature.

[0048] Improve economic benefits: The efficient and thorough drying process reduces energy consumption, while improving production efficiency and reducing overall recycling costs.

[0049] In addition, the vibration drying method can continuously turn the film material during the drying process to ensure uniform drying and prevent partial over-drying or incomplete drying. This drying method also has a good degree of automation, suitable for large-scale industrial applications, and can adjust the drying time and temperature according to specific needs to adapt to the characteristics of different types of film materials.

[0050] In summary, the vacuum vibration drying step not only significantly improves the drying effect of the membrane material, but also creates favorable conditions for subsequent processes such as lithium replenishment, mixing and calcination, ensuring the efficiency, environmental protection and economy of the entire recycling process.

[0051] Step 6: The dried film material is directly prepared into a positive electrode material that can be used directly through a lithium supplementation process without extracting lithium elements; vacuum vibration drying is used in the drying process.

[0052] Furthermore, the lithium replenishment process is based on the Li:Fe molar ratio of 1.08 to supplement lithium carbonate as a lithium source, and add sucrose to 2.5wt% as a carbon source according to the measured carbon content, and calcine with industrial-grade lithium iron phosphate VC to repair the crystal structure; the calcination process is carried out in a natural gas rotary kiln at 650°C-750°C for 9-11 hours, during which inert gas is introduced to prevent oxidation. This process achieves the following technical effects: No need to extract lithium: This method avoids the complicated lithium extraction steps in the traditional recycling process, simplifies the process, reduces production costs, and reduces the use of chemical reagents, making it more environmentally friendly.

[0053] Direct preparation of finished materials: Through the lithium supplementation process, positive electrode materials with excellent performance can be directly obtained without further processing into precursors to prepare positive electrode materials, which significantly improves the recovery efficiency and economic value of the materials.

[0054] Optimizing material performance: Precisely controlling the Li:Fe molar ratio during lithium replenishment ensures the electrochemical properties of the cathode material, such as capacity, cycle stability, and rate performance. Adding sucrose as a carbon source helps form a conductive network, improve electronic conductivity, and enhance the overall performance of the battery.

[0055] Repairing the crystal structure: Calcination in a natural gas rotary kiln at 650°C-750°C for 9-11 hours, during which inert gas is introduced to prevent oxidation, can effectively repair the crystal structure of the membrane material that may be damaged during the recycling process and restore its original electrochemical activity.

[0056] Reduce the impact of impurities: The entire lithium replenishment and calcination process is carried out under strictly controlled conditions, which minimizes the introduction of external impurities and ensures the purity and consistency of the final product.

[0057] In summary, this lithium replenishment process not only simplifies the recycling process of lithium battery electrode film materials, but also improves the quality and performance of recycled materials, allowing recycled materials to be directly used in new battery manufacturing, realizing effective closed-loop utilization of resources, and has significant economic and environmental benefits.

[0058] In summary, the present invention selects a specific sol to soak the electrode after embossing pretreatment, then accelerates the film stripping by spraying, and finally stirs and refines under the action of NMP organic solvent, ensuring that the film can be effectively dispersed and does not carry too many aluminum foil fragments. After screening to remove the aluminum foil, the film is vacuum-vibrated and dried to reduce the moisture content.

[0059] The entire process not only improves the purity and efficiency of film material recycling, but also realizes non-destructive green recycling, retains the value of the original material to the maximum extent, and avoids the problem of excessive aluminum content in traditional methods.

[0060] Therefore, this method has significant technical effects, including but not limited to higher recovery rate, lower impurity content and more environmentally friendly treatment. This recycling method has a high degree of automation and high production capacity, and can also provide effective support for non-destructive repair technology. Compared with material extraction and recycling technology, the main advantage of this process is that it can reduce recycling costs, maximize the value of recycled materials, and realize the closed loop of lithium battery electrode materials.

[0061] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recycling lithium battery pole piece film material, characterized in that: The following steps are involved: The non-liquid-injected positive electrode plate is subjected to embossing treatment to form a surface with a uniformly distributed pattern; Selecting a sol according to the properties of the electrode primer and the adhesive material, and soaking the embossed electrode in the selected sol to accelerate the peeling of the electrode film material and the aluminum foil substrate; After infiltration, use a spray device to spray the electrode to promote the separation of the film material from the aluminum foil; The separated film material enters the refinement tank, where it is stirred and refined under the action of NMP organic solvent as a dispersant, so that the film material can pass through a 150-250 mesh filter; After screening to remove aluminum foil debris, the film material is vacuum-vibrated and dried to reduce the moisture content in the film material.

2. The method for recycling lithium battery pole piece film material according to claim 1, characterized in that: The embossing process is to cut a diamond pattern with a side length of 4-6 mm on the surface of the pole piece.

3. The method for recycling lithium battery pole piece film material according to claim 1, characterized in that: The method of selecting the sol agent according to the properties of the electrode primer and the adhesive material includes: For water-soluble primer and adhesive, pure water is used as the sol; For oily primer and adhesive, NMP organic solvent is selected as the sol agent.

4. The method for recycling lithium battery pole piece film material according to claim 3, characterized in that: The infiltration temperature is set at 55°C-65°C, and the time is set at 50-70 seconds for water-soluble primer, while the oily primer is infiltrated for 110-130 seconds at room temperature.

5. The method for recycling lithium battery pole piece film material according to claim 1, characterized in that: The spraying device uses pure water as a spraying medium to assist the separation of the film material from the aluminum foil with physical force, and simultaneously cuts the film material into the size of the embossing pattern.

6. The method for recycling lithium battery pole piece film material according to claim 1, characterized in that: In the refinement tank, NMP organic solvent is used as a refiner, the speed of the stirring paddle is set to 90-110 r / min, and the stirring time is adjusted to 10-15 minutes according to the type of the base coating glue.

7. The method for recycling lithium battery pole piece film material according to claim 1, characterized in that: Also includes: The dried film material is directly prepared into a directly usable positive electrode material through a lithium replenishment process without the need to extract lithium elements.

8. The method for recycling lithium battery pole piece film material according to claim 7, characterized in that: The drying process adopts vacuum vibration drying.

9. The method for recycling lithium battery pole piece film material according to claim 8, characterized in that: The lithium replenishment process is based on the Li:Fe molar ratio of 1.08 to supplement lithium carbonate as a lithium source, and according to the measured carbon content, sucrose is added to 2.5wt% as a carbon source, and mixed with industrial-grade lithium iron phosphate VC for calcination to repair the crystal structure.

10. The method for recycling lithium battery pole piece film material according to claim 9, characterized in that: The calcination process is carried out in a natural gas rotary kiln at 650°C-750°C for 9-11 hours, during which inert gas is introduced to prevent oxidation.

Images