A lithium battery positive electrode active material stripping and recycling device

Abstract

The utility model discloses a lithium battery positive pole active material stripping recovery unit relates to lithium battery recovery technical field, including stripping mechanism and screening mechanism, stripping mechanism includes cabin, and the front end of cabin is equipped with feed hopper, and the rear end is equipped with drive motor and discharge channel, and the top is equipped with exhaust channel, and the bottom is equipped with drain channel, is equipped with water mist sprinkler system, cylinder, hot -blast drying system, dust receiving drawer and water tank in cabin, and the cylinder rotation is established in cabin, and from front to back is inclined downward, and the through -hole is evenly distributed on its body, and the cylinder is driven and rotates by drive motor, and the output of water mist sprinkler system points to the cylinder, and the output of hot -blast drying system points to the cylinder, and dust receiving drawer slidingly is established in cabin, and is equipped with heating device in water tank, the utility model discloses the cooperation of stripping mechanism and screening mechanism, need not high temperature calcination and chemical reagent processing, also can easily separate positive pole active material and current collector aluminum foil, and the environmental protection is good, and the economy is high.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery recycling technology, specifically to a lithium battery positive electrode active material stripping and recycling device. Background Technology

[0002] The cathode plates of spent lithium iron phosphate batteries contain abundant valuable metal resources (Li, Cu, Al, Fe). Recycling them can not only reduce pollution risks but also supplement metal sources and alleviate resource pressure.

[0003] Currently, there are two main methods for recycling cathode materials from spent lithium iron phosphate batteries:

[0004] One method involves high-temperature calcination of the positive electrode sheets from spent lithium iron phosphate batteries. This process decomposes and degrades the binder, causing the positive electrode active material to separate from the current collector aluminum foil. The resulting powder can then be obtained by sieving. However, high-temperature calcination consumes enormous amounts of energy, reduces the positive electrode active material to alloys or slag, results in low purity of separated valuable metals, and generates a large amount of harmful waste gas.

[0005] Another method involves directly immersing the positive electrode sheets of spent lithium iron phosphate batteries in a sodium hydroxide solution for alkaline leaching to remove aluminum. The filtered material after aluminum removal is then dried to obtain the positive electrode active material. However, this recycling method generates a large amount of alkaline wastewater, and the filtrate contains sodium aluminate, increasing the need for secondary aluminum metal recovery.

[0006] Existing technologies for recycling waste lithium iron phosphate battery cathode materials are insufficient to meet environmental and economic requirements, severely restricting the industrial application of green lithium battery recycling technologies. Utility Model Content

[0007] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides a lithium battery positive electrode active material stripping and recycling device. Through the cooperation of the stripping mechanism and the screening mechanism, the positive electrode active material and current collector aluminum foil can be easily separated without high-temperature calcination and chemical reagent treatment. It is environmentally friendly and economical.

[0008] This utility model provides a lithium battery positive electrode active material stripping and recycling device, including a stripping mechanism and a screening mechanism connected in sequence from front to back;

[0009] The stripping mechanism includes a first frame and a chamber mounted on the first frame; the front end of the chamber is provided with a feed hopper with a feed valve, the rear end of the chamber is provided with a drive motor and a discharge channel with a discharge gate, the top of the chamber is provided with an exhaust channel with a filter, and the bottom of the chamber is provided with a drainage channel; the interior of the chamber, from top to bottom, is provided with a water mist spraying system, a roller, a hot air drying system, a dust collection drawer, and a water tank.

[0010] The roller is rotatably mounted inside the chamber, and the roller is inclined downward from front to back. The roller body has through holes evenly distributed on it. The inner wall of the chamber closes the front and rear ends of the roller. The feed hopper and the discharge channel are both connected to the internal cavity of the roller. The roller is driven to rotate by the drive motor. The output end of the water mist spraying system points to the roller, and the output end of the hot air drying system points to the roller.

[0011] The ash collection drawer is slidably disposed in the cabin, and the outer periphery of the ash collection drawer matches the inner periphery of the cabin; a heating device is provided in the water tank, and the drainage channel is connected to the water tank.

[0012] Specifically, the diameter of the through hole ranges from 0.25 to 1.7 mm, and the density of the through hole ranges from 10 to 60 per square inch.

[0013] Specifically, the water mist spraying system includes several spray pipes, which are fixed to the inner wall of the chamber and extend along the length of the roller. Each spray pipe is provided with multiple spray heads at intervals, and the multiple spray heads point towards the axis of the roller.

[0014] Specifically, the plurality of spray pipes are a first spray pipe, a second spray pipe and a third spray pipe, the first spray pipe is located directly above the roller, and the second spray pipe and the third spray pipe are respectively arranged on both sides of the first spray pipe;

[0015] With the axis of the roller as the center, a first angle is formed between the second spray pipe and the first spray pipe, and a second angle is formed between the third spray pipe and the first spray pipe. The angle range of the first angle is 30° to 60°, and the angle range of the second angle is 30° to 60°.

[0016] Specifically, a rotating support is provided inside the cabin, and the roller is placed on the rotating support;

[0017] The rotating bracket includes a first rotating shaft and a second rotating shaft that are rotatably mounted. The first rotating shaft and the second rotating shaft extend along the length direction of the roller and are parallel to each other. A first rotating wheel is fixedly mounted at both ends of the first rotating shaft, and a second rotating wheel is fixedly mounted at both ends of the second rotating shaft. The output end of the drive motor is fixedly connected to the first rotating shaft.

[0018] The roller includes two screen cylinder mounting seats arranged opposite each other, and a screen cylinder installed between the two screen cylinder mounting seats. The through holes are evenly distributed on the screen cylinder. An annular track is formed on the surface of each screen cylinder mounting seat. The annular track of each screen cylinder mounting seat is simultaneously engaged with a first rotating wheel and a second rotating wheel.

[0019] Specifically, a first sealing ring protrudes from the inner wall of the front end of the cabin, and a second sealing ring protrudes from the inner wall of the rear end of the cabin. The front and rear ends of the roller are respectively rotatably disposed in the first sealing ring and the second sealing ring.

[0020] Specifically, the hot air drying system includes multiple hot air pipes, which are fixed to the side wall of the chamber and are spaced apart along the length of the drum, pointing towards the axis of the drum.

[0021] Specifically, the chamber is equipped with a sliding track, which is located above the water tank and below the hot air drying system; a dust removal window is provided at the front end of the chamber, which exposes the sliding track; the dust collection drawer is slidably disposed in the dust removal window and on the sliding track.

[0022] The front end of the ash receiving drawer is provided with a blocking section, and the outer periphery of the blocking section matches the inner periphery of the ash cleaning window.

[0023] Specifically, the screening mechanism includes a second frame and a screen frame mounted on the second frame, the screen frame being mounted on the second frame based on spring support;

[0024] The sieve frame is equipped with a sieve mesh, and the space within the sieve frame is divided into an upper space and a lower space based on the sieve mesh. The upper space has an upper discharge port, which is connected to an upper discharge channel. The lower space has a lower discharge port, which is connected to a lower discharge channel. The discharge channel leads to the upper space.

[0025] The bottom of the screen frame is provided with a vibration support, and a vibration motor is installed on the vibration support.

[0026] Specifically, the mesh size of the sieve ranges from 4 to 5 mesh.

[0027] Compared with the prior art, the beneficial effects of this utility model are:

[0028] In the lithium battery positive electrode active material stripping and recycling device of this utility model, the stripping mechanism mainly uses a water mist spraying system, a hot air drying system and a water tank in conjunction with a roller to strip the positive electrode active material and current collector aluminum foil of the lithium iron phosphate battery positive electrode sheet. Then, after screening by the screening mechanism, the individual lithium iron phosphate active material and the individual aluminum foil can be obtained. The recovery rate of lithium iron phosphate active material is high (≥98wt%), and the aluminum content in the lithium iron phosphate active material is low (≤0.5wt%).

[0029] The system includes a water mist spraying system to generate water mist for wetting the positive electrode sheet in the drum; a hot air drying system to output hot air for drying the positive electrode sheet in the drum; a water tank to heat and generate atmospheric pressure steam for peeling the positive electrode active material and current collector aluminum foil from the positive electrode sheet, and the water in the water tank can be recycled; the drum is driven by a drive motor to rotate, which not only fully agitates the positive electrode sheet so that it can be fully exposed to the action of water mist, hot air or steam, but also provides gentle mechanical force to promote the peeling of the positive electrode active material and current collector aluminum foil.

[0030] This utility model's lithium battery positive electrode active material stripping and recycling device allows the positive electrode sheet to be sequentially treated by water mist, water vapor, and hot air under the tumbling of the drum, thereby achieving the wetting, stripping, and drying of the positive electrode sheet, which can then enter the screening mechanism for screening. Using this utility model's lithium battery positive electrode active material stripping and recycling device to process lithium iron phosphate battery positive electrode sheets results in a high recovery rate, and it eliminates the need for high-temperature calcination and the use of chemical reagents, reducing energy consumption, the use of chemical reagents, and the emission of waste gas, wastewater, and solid waste. It is not only environmentally friendly but also highly economical. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the lithium battery positive electrode active material stripping and recycling device in this embodiment of the utility model;

[0033] Figure 2 This is a schematic diagram of the overall structure of the peeling mechanism in an embodiment of this utility model;

[0034] Figure 3 This is a schematic diagram of the internal structure of the peeling mechanism in an embodiment of this utility model;

[0035] Figure 4 This is a schematic diagram of the structure of the spray pipe in an embodiment of this utility model;

[0036] Figure 5 This is a schematic diagram of the layout of the first spray pipe, the second spray pipe and the third spray pipe in an embodiment of this utility model;

[0037] Figure 6 This is a schematic diagram of the rotating bracket in an embodiment of this utility model;

[0038] Figure 7 This is a schematic diagram of the structure of the first and second closed rings in an embodiment of this utility model;

[0039] Figure 8 This is a schematic diagram of the overall structure of the hot air duct, sliding track, and dust collection drawer in this embodiment of the utility model;

[0040] Figure 9 This is a cross-sectional structural diagram of the water tank in an embodiment of this utility model;

[0041] Figure 10 This is a schematic diagram of the overall structure of the screening mechanism in an embodiment of this utility model.

[0042] In the attached diagram: 1. Stripping mechanism; 2. Screening mechanism; 10. First frame; 20. Cabin; 21. Feed hopper; 22. Drive motor; 23. Discharge channel; 24. Exhaust channel; 25. Drainage channel; 30. Second frame; 40. Screen frame; 41. Screen mesh; 50. Spring; 61. Upper discharge channel; 62. Lower discharge channel; 71. Vibrating support; 72. Vibrating motor; 210. Water mist spraying system; 211. Spray pipe; 2111. First spray pipe; 2112. Second spray pipe; 2113. Third spray pipe ; 212, Spray head; 220, Drum; 221, Screen cylinder mounting base; 2211, Circular track; 222, Screen cylinder; 230, Hot air drying system; 231, Hot air pipe; 240, Ash receiving drawer; 241, Sliding track; 242, Ash cleaning window; 243, Sealing section; 250, Water tank; 251, Heating device; 260, Rotating bracket; 261, First rotating shaft; 2611, First rotating wheel; 262, Second rotating shaft; 2621, Second rotating wheel; 271, First closed ring; 272, Second closed ring. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0044] This invention provides a device for stripping and recycling positive electrode active materials of lithium batteries. Figure 1 A schematic diagram of the overall structure of the lithium battery positive electrode active material stripping and recycling device in an embodiment of the present invention is shown. The device includes a stripping mechanism 1 and a screening mechanism 2 connected sequentially from front to back.

[0045] Figure 2 A schematic diagram of the overall structure of the peeling mechanism in an embodiment of the present invention is shown. The peeling mechanism 1 includes a first frame 10 and a chamber 20 disposed on the first frame 10. The front end of the chamber 20 is provided with a feed hopper 21 with a feed valve, the rear end of the chamber 20 is provided with a drive motor 22 and a discharge channel 23 with a discharge gate, the top of the chamber 20 is provided with an exhaust channel 24 with a filter, and the bottom of the chamber 20 is provided with a drainage channel 25.

[0046] Figure 3 The diagram shows the internal structure of the stripping mechanism in an embodiment of the present invention. The interior of the chamber 20 is provided with, from top to bottom, a water mist spraying system 210, a roller 220, a hot air drying system 230, a dust collection drawer 240, and a water tank 250.

[0047] The roller 220 is rotatably disposed within the chamber 20. The roller 220 is inclined downward from front to back, and through holes are evenly distributed on the body of the roller 220. The inner wall of the chamber 20 seals the front and rear ends of the roller 220. The feed hopper 21 and the discharge channel 23 are both connected to the internal cavity of the roller 220. The roller 220 is driven to rotate by the drive motor 22. The output end of the water mist spraying system 210 points towards the roller 220, and the output end of the hot air drying system 230 points towards the roller 220.

[0048] The ash collection drawer 240 is slidably disposed in the cabin 20, and the outer periphery of the ash collection drawer 240 matches the inner periphery of the cabin 20; a heating device 251 is provided in the water tank 250, and the drainage channel 25 is connected to the water tank 250.

[0049] In the lithium battery positive electrode active material stripping and recycling device of this utility model, the stripping mechanism 1 mainly uses a water mist spraying system 210, a hot air drying system 230 and a water tank 250 in conjunction with a roller 220 to strip the positive electrode active material and current collector aluminum foil of the lithium iron phosphate battery positive electrode sheet. Then, after screening by the screening mechanism 2, separate lithium iron phosphate active material and separate aluminum foil can be obtained. The recovery rate of lithium iron phosphate active material is high (≥98wt%), and the aluminum content in lithium iron phosphate active material is low (≤0.5wt%).

[0050] The water mist spraying system 210 can generate water mist to wet the positive electrode sheet in the drum 220; the hot air drying system 230 can output hot air to dry the positive electrode sheet in the drum 220; the water tank 250 can heat to generate atmospheric pressure steam to peel off the positive electrode active material and current collector aluminum foil from the positive electrode sheet, and the water in the water tank 250 can be recycled; the drum 220 is driven by the drive motor 22 to rotate, which can not only fully turn the positive electrode sheet so that the positive electrode sheet can fully receive the action of water mist, hot air or steam, but also provide gentle mechanical force to promote the peeling off of the positive electrode active material and current collector aluminum foil.

[0051] The lithium battery positive electrode active material stripping and recycling device of this invention allows the positive electrode sheet to be treated sequentially by water mist, water vapor and hot air under the tumbling of the drum 220, thereby achieving the wetting, stripping and drying of the positive electrode sheet, and then it can enter the screening mechanism 2 for screening. Using the lithium battery positive electrode active material stripping and recycling device of this invention to process lithium iron phosphate battery positive electrode sheets has a high recovery rate, and it does not require high-temperature calcination or the use of chemical reagents, thus reducing energy consumption, reducing the use of chemical reagents, and reducing the emission of waste gas, wastewater and solid waste. It is not only environmentally friendly, but also highly economical.

[0052] In some specific embodiments, the chamber 20, the roller 220, and the ash collection drawer 240 are all made of stainless steel, which is sturdy and durable. Specifically, the surface of the roller 220 is provided with a protective coating to prevent vapor corrosion.

[0053] In some specific embodiments, the diameter of the through hole ranges from 0.25 to 1.7 mm. If the diameter of the through hole is less than 0.25 mm, it is not conducive to water mist, steam, and hot air entering the drum 220; if the diameter of the through hole is greater than 1.7 mm, the lithium iron phosphate active material is prone to leaking out of the drum 220. Optionally, the diameter of the through hole can be 0.25 mm, 0.5 mm, 0.8 mm, 1.2 mm, or 1.7 mm; preferably, the diameter of the through hole is 0.8 mm, which not only facilitates the flow of water mist, steam, and hot air, but also makes it less likely for the lithium iron phosphate active material to leak out.

[0054] Specifically, the density of the through holes ranges from 10 to 60 per square inch. If the density is less than 10 per square inch, it will hinder the entry of water mist, steam, and hot air into the roller 220; if the density is greater than 60 per square inch, it will weaken the structural strength of the roller 220 and shorten its service life. Optionally, the density of the through holes can be 10, 20, 30, 40, 50, or 60 per square inch; preferably, the density is 30 per square inch, which not only facilitates the flow of water mist, steam, and hot air, but also ensures excellent structural strength and a long service life for the roller 220.

[0055] Figure 4 A schematic diagram of the spray pipe structure in an embodiment of this utility model is shown. The water mist spraying system 210 includes a plurality of spray pipes 211, which are fixed to the inner wall of the chamber 20. The spray pipes 211 extend along the length of the roller 220. Each spray pipe 211 is provided with a plurality of spray heads 212 at intervals, and the spray heads 212 point towards the axis of the roller 220. This facilitates the rapid generation of a large amount of water mist, allowing the water mist to quickly enter and fill the internal space of the roller 220, thus wetting the positive electrode sheet. The spray pipes 211 and spray heads 212 are both made of stainless steel, making them sturdy and durable.

[0056] Specifically, the water mist sprayed by any of the spray heads 212 has a particle size range of 50–100 μm. Water mist within this particle size range easily adheres to the surface of the positive electrode sheet, completing the wetting of the positive electrode sheet. This not only improves the wetting efficiency of the positive electrode sheet but also helps reduce water consumption. Optionally, the particle size range of the water mist sprayed by the spray head 212 can be 50–60 μm, 60–70 μm, 70–80 μm, 80–90 μm, or 90–100 μm; preferably, the particle size range of the water mist sprayed by the spray head 212 is 50–60 μm, resulting in high efficiency in entering the drum 220.

[0057] Figure 5A schematic diagram of the layout of the first spray pipe, the second spray pipe, and the third spray pipe in an embodiment of the present invention is shown. The plurality of spray pipes 211 are respectively the first spray pipe 2111, the second spray pipe 2112, and the third spray pipe 2113. The first spray pipe 2111 is located directly above the roller 220. The second spray pipe 2112 and the third spray pipe 2113 are respectively arranged on both sides of the first spray pipe 2111. With the axis of the roller 220 as the center, the second spray pipe 2112 and the first spray pipe 2111 form a first included angle α, and the third spray pipe 2113 and the first spray pipe 2111 form a second included angle β. The angle range of the first included angle α is 30° to 60°, and the angle range of the second included angle β is 30° to 60°. The first spray pipe 2111 at the top mainly covers the top area of ​​the drum 220, while the second spray pipe 2112 and the third spray pipe 2113 on both sides (with an angle of 30° to 60°) significantly extend the spray range to the sides of the drum 220. This combination of coverage forms a wider and more three-dimensional spray area, which not only helps to reduce spray dead angles and improve spray uniformity, but also helps to enhance the penetration effect of water mist into the drum 220, ultimately improving the wetting effect of the positive electrode sheet.

[0058] Optionally, the angle of the first included angle α can be 30°, 45°, or 60°, and the angle of the second included angle β can be 30°, 45°, or 60°; preferably, the angle of the first included angle α is 45° and the angle of the second included angle β is 45°, which helps to reduce the number of droplets bounced off the surface of the roller 220 and can effectively increase the efficiency of water mist entering the roller 220.

[0059] Figure 6 A schematic diagram of the rotating bracket in an embodiment of the present invention is shown. A rotating bracket 260 is disposed inside the cabin 20, and the roller 220 is placed on the rotating bracket 260. The rotating bracket 260 includes a first rotating shaft 261 and a second rotating shaft 262 rotatably disposed thereon. The first rotating shaft 261 and the second rotating shaft 262 extend along the length direction of the roller 220 and are parallel to each other. A first rotating wheel 2611 is fixedly disposed at both ends of the first rotating shaft 261, and a second rotating wheel 2621 is fixedly disposed at both ends of the second rotating shaft 262. The output end of the drive motor 22 is fixedly connected to the first rotating shaft 261.

[0060] Please see Figure 6The roller 220 includes two screen cylinder mounting seats 221 arranged opposite to each other, and a screen cylinder 222 installed between the two screen cylinder mounting seats 221. The through holes are evenly distributed on the screen cylinder 222. An annular track 2211 is formed on the surface of any screen cylinder mounting seat 221. The annular track 2211 of any screen cylinder mounting seat 221 is simultaneously engaged with a first rotating wheel 2611 and a second rotating wheel 2621.

[0061] In this way, the rotating bracket 260 supports the rotation of the roller 220 without obstructing both ends of the roller 220, ensuring that the roller 220 can smoothly feed and discharge materials.

[0062] Figure 7 The diagram shows the structure of the first and second sealing rings in an embodiment of the present invention. The first sealing ring 271 protrudes from the inner wall of the front end of the chamber 20, and the second sealing ring 272 protrudes from the inner wall of the rear end of the chamber 20. The front and rear ends of the roller 220 are respectively rotatably disposed in the first sealing ring 271 and the second sealing ring 272, which helps to prevent material from leaking out from both ends of the roller 220.

[0063] Figure 8 This diagram illustrates the overall structure of the hot air ducts, sliding rails, and dust collection drawer in an embodiment of the present invention. The hot air drying system 230 includes multiple hot air ducts 231, which are fixed to the side wall of the chamber 20. These ducts are spaced apart along the length of the drum 220 and point towards the axis of the drum 220. This design facilitates a large output of hot air, allowing it to quickly enter the drum 220 and dry the materials. The hot air ducts 231 are made of stainless steel, making them sturdy and durable.

[0064] For details, please refer to Figure 8 Multiple hot air pipes 231 are symmetrically distributed on both sides of the drum 220, which can quickly dry the material inside the drum 220. Moreover, when the hot air pipes 231 output hot air, the exhaust duct 24 at the top of the chamber 20 will exhaust air at the same time to balance the pressure inside the chamber 20; the exhaust duct 24 is connected to an exhaust fan, which can quickly remove air, water vapor and other substances inside the chamber 20.

[0065] Figure 9 A cross-sectional view of the water tank in an embodiment of this utility model is shown. A sliding track 241 is provided inside the chamber 20, located above the water tank 250 and below the hot air drying system 230. A dust removal window 242 is provided at the front end of the chamber 20, exposing the sliding track 241. Please refer to [link to relevant documentation]. Figure 8 and Figure 9 The ash-receiving drawer 240 is slidably disposed within the ash-cleaning window 242 and on the sliding track 241. The ash-receiving drawer 240 can collect material powder and debris leaking from the roller 220, preventing large amounts of material powder and debris from falling into the water tank 250. Furthermore, the ash-receiving drawer 240 can also serve as a cover for the water tank 250; by adjusting the extension length of the ash-receiving drawer 240, the exposed area of ​​the water tank 250 can be adjusted, thereby controlling the output of water vapor. The ash-receiving drawer 240 is made of stainless steel, making it sturdy and durable.

[0066] For details, please refer to Figure 8 The front end of the ash collection drawer 240 is provided with a blocking section 243. The outer periphery of the blocking section 243 matches the inner periphery of the ash cleaning window 242. The blocking section 243 can precisely block the ash cleaning window 242, reducing water vapor leakage. Moreover, the blocking section 243 has a certain length, so that when the ash collection drawer 240 is pulled out to a certain length, the ash cleaning window 242 can still be blocked, which is convenient to reduce water vapor leakage when adjusting the exposed area of ​​the water tank 250.

[0067] Furthermore, the overall length of the ash receiving drawer 240 is L1, and the length of the blocking section 243 is L2. The constraint relationship between L1 and L2 is: 0.1L1≤L2≤0.15L1.

[0068] Figure 10 A schematic diagram of the overall structure of the screening mechanism in this embodiment of the present invention is shown. The screening mechanism 2 includes a second frame 30 and a screen frame 40 disposed on the second frame 30. The screen frame 40 is mounted on the second frame 30 based on the support of a spring 50. A screen mesh 41 is disposed in the screen frame 40. The space inside the screen frame 40 is divided into an upper space and a lower space based on the screen mesh 41. The upper space has an upper discharge port, which is connected to an upper feeding channel 61. The lower space has a lower discharge port, which is connected to a lower feeding channel 62. The discharge channel 23 leads to the upper space. A vibration support 71 is disposed at the bottom of the screen frame 40, and a vibration motor 72 is mounted on the vibration support 71. During screening, the lithium iron phosphate active material is discharged from the lower feeding channel 62, and the aluminum foil is discharged from the upper feeding channel 61.

[0069] Specifically, the mesh size of the sieve 41 is in the range of 4 to 5 mesh, which is suitable for separating lithium iron phosphate active material and aluminum foil; when the mesh size of the sieve 41 is 4 mesh, the aluminum content in the obtained lithium iron phosphate active material is less than 0.36 wt%; when the mesh size of the sieve 41 is 5 mesh, the aluminum content in the obtained lithium iron phosphate active material is less than 0.5 wt%.

[0070] Furthermore, the screening mechanism 2 is tilted at a 2° to 5° angle from front to back, which facilitates material flow. Optionally, the screening mechanism 2 is tilted at a 2°, 3°, 4°, or 5° angle from front to back. Preferably, the screening mechanism 2 is tilted at a 4° angle from front to back, balancing separation efficiency and separation effect.

[0071] The working process of the lithium battery positive electrode active material stripping and recycling device of this utility model is as follows:

[0072] First, the lithium iron phosphate battery positive electrode sheet enters the drum 220 through the feed hopper 21, and the drive motor 22 is started to drive the drum 220 to rotate. The water mist spraying system 210 is activated to generate water mist, and the heating device 251 of the water tank 250 is activated to heat the water (the heating temperature can be set to 50-100℃). The ash collection drawer 240 is pulled out to a certain length (keeping the ash cleaning window 242 blocked). The drum 220 rotates slowly (the speed can be set to 5-15 rpm), turning the lithium iron phosphate battery positive electrode sheet, so that the positive electrode sheet is fully wetted by the water mist, which is conducive to the subsequent steam penetration into the interior of the positive electrode sheet.

[0073] Once the positive electrode sheet is fully wetted, the water in the water tank 250 is heated to a certain temperature, generating a significant amount of water vapor. At this point, the water mist spray system 210 is shut off, and the positive electrode sheet in the drum 220 is treated solely using water vapor. The binder (usually PVDF) of the lithium iron phosphate positive electrode sheet swells, softens, and plasticizes in the steam environment, resulting in a significant decrease in its bonding strength, which is crucial for peeling. Simultaneously, the rotating drum 220 provides gentle mechanical force to help the positive electrode active material layer, which has lost its bonding strength, loosen, break, and peel off from the aluminum foil.

[0074] Next, after the steam treatment is completed, the heating device 251 of the water tank 250 is turned off, and the ash collection drawer 240 is completely pushed into the chamber 20 to cover the water tank 250. Then, the hot air drying system 230 is started to dry the material in the drum 220, and the exhaust fan connected to the exhaust channel 24 is started to exhaust the air. At this time, the rotation speed of the drum 220 can be increased (the rotation speed can be set to 16-50 rpm), which can not only improve the drying efficiency of the material, but also promote the further separation of lithium iron phosphate active material and aluminum foil.

[0075] Then, after drying is completed, the hot air drying system 230 and the exhaust fan are turned off, the drum 220 is kept rotating, and the discharge gate of the discharge channel 23 is opened. Under the combined action of the tilting and rotation of the drum 220, the dried material is automatically transported to the screening mechanism 2 through the discharge channel 23. The screen 41 of the screening mechanism 2 vibrates under the drive of the vibrating motor 72, which can disperse and screen the lithium iron phosphate active material and aluminum foil. The lithium iron phosphate active material is discharged from the lower discharge channel 62, and the aluminum foil is discharged from the upper discharge channel 61.

[0076] In the lithium battery positive electrode active material stripping and recycling device of this utility model, the stripping mechanism 1 integrates the water mist spraying system 210, the hot air drying system 230, the ash receiving drawer 240, the water tank 250 and the roller 220 into the chamber 20. It creatively integrates the scattered and independent processing units in the recycling process into a single functional module, which not only saves space but also facilitates the realization of fully automated processing of "spray wetting - steam stripping - hot air drying" with one click.

[0077] The lithium battery positive electrode active material stripping and recycling device of this invention is used to process lithium iron phosphate battery positive electrode sheets without high-temperature calcination. Moreover, the process only uses water mist, water vapor and hot air, without the use of chemical reagents. This can effectively reduce energy consumption and the use of chemical reagents, and at the same time reduce the emission of waste gas, wastewater and solid waste. It is not only environmentally friendly, but also highly economical.

[0078] Furthermore, the recovery rate of lithium iron phosphate active material is high (≥98wt%), and the aluminum content in lithium iron phosphate active material is low (≤0.5wt%). In addition, after long-term use, the water in the tank 250 will enrich some of the lost lithium, which can be recycled as a lithium-rich solution, and the product is nearly 100% resource-based.

[0079] The above provides a detailed description of a lithium battery positive electrode active material stripping and recycling device provided by the embodiments of this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A device for stripping and recycling positive electrode active materials of lithium batteries, characterized in that, This includes a stripping mechanism and a screening mechanism connected sequentially from front to back; The stripping mechanism includes a first frame and a chamber mounted on the first frame; the front end of the chamber is provided with a feed hopper with a feed valve, the rear end of the chamber is provided with a drive motor and a discharge channel with a discharge gate, the top of the chamber is provided with an exhaust channel with a filter, and the bottom of the chamber is provided with a drainage channel; the interior of the chamber, from top to bottom, is provided with a water mist spraying system, a roller, a hot air drying system, a dust collection drawer, and a water tank. The roller is rotatably mounted inside the chamber, and the roller is inclined downward from front to back. The roller body has through holes evenly distributed on it. The inner wall of the chamber closes the front and rear ends of the roller. The feed hopper and the discharge channel are both connected to the internal cavity of the roller. The roller is driven to rotate by the drive motor. The output end of the water mist spraying system points to the roller, and the output end of the hot air drying system points to the roller. The ash collection drawer is slidably disposed in the cabin, and the outer periphery of the ash collection drawer matches the inner periphery of the cabin; a heating device is provided in the water tank, and the drainage channel is connected to the water tank.

2. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The diameter of the through holes ranges from 0.25 to 1.7 mm, and the density of the through holes ranges from 10 to 60 per square inch.

3. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The water mist spraying system includes several spray pipes, which are fixed to the inner wall of the chamber and extend along the length of the roller. Each spray pipe is provided with multiple spray heads at intervals, and the multiple spray heads point towards the axis of the roller.

4. The lithium battery positive electrode active material stripping and recycling device as described in claim 3, characterized in that, The plurality of spray pipes are a first spray pipe, a second spray pipe and a third spray pipe. The first spray pipe is located directly above the roller, and the second spray pipe and the third spray pipe are respectively arranged on both sides of the first spray pipe. With the axis of the roller as the center, a first angle is formed between the second spray pipe and the first spray pipe, and a second angle is formed between the third spray pipe and the first spray pipe. The angle range of the first angle is 30° to 60°, and the angle range of the second angle is 30° to 60°.

5. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The cabin is equipped with a rotating support, and the roller is placed on the rotating support. The rotating bracket includes a first rotating shaft and a second rotating shaft that are rotatably configured. The first rotating shaft and the second rotating shaft extend along the length direction of the drum and are parallel to each other. A first rotating wheel is fixedly provided at both ends of the first rotating shaft, and a second rotating wheel is fixedly provided at both ends of the second rotating shaft; the output end of the drive motor is fixedly connected to the first rotating shaft. The roller includes two screen cylinder mounting seats arranged opposite each other, and a screen cylinder installed between the two screen cylinder mounting seats. The through holes are evenly distributed on the screen cylinder. An annular track is formed on the surface of each screen cylinder mounting seat. The annular track of each screen cylinder mounting seat is simultaneously engaged with a first rotating wheel and a second rotating wheel.

6. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The front inner wall of the cabin has a protruding first sealing ring, and the rear inner wall of the cabin has a protruding second sealing ring. The front and rear ends of the roller are respectively rotatably disposed in the first sealing ring and the second sealing ring.

7. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The hot air drying system includes multiple hot air pipes, which are fixed to the side wall of the chamber. The multiple hot air pipes are spaced apart along the length of the drum and point towards the axis of the drum.

8. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The chamber is equipped with a sliding track, which is located above the water tank and below the hot air drying system; a dust removal window is provided at the front end of the chamber, which exposes the sliding track. The dust collection drawer is slidably disposed in the dust removal window and on the sliding track; The front end of the ash receiving drawer is provided with a blocking section, and the outer periphery of the blocking section matches the inner periphery of the ash cleaning window.

9. The lithium battery positive electrode active material stripping and recycling device as described in claim 1, characterized in that, The screening mechanism includes a second frame and a screen frame mounted on the second frame, the screen frame being mounted on the second frame based on spring support; The sieve frame is equipped with a sieve mesh, and the space within the sieve frame is divided into an upper space and a lower space based on the sieve mesh. The upper space has an upper discharge port, which is connected to an upper discharge channel. The lower space has a lower discharge port, which is connected to a lower discharge channel. The discharge channel leads to the upper space. The bottom of the screen frame is provided with a vibration support, and a vibration motor is installed on the vibration support.

10. The lithium battery positive electrode active material stripping and recycling device as described in claim 9, characterized in that, The mesh size of the sieve ranges from 4 to 5 mesh.

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