High-efficiency stripping device for lithium iron phosphate positive electrode material and working method of high-efficiency stripping device

Abstract

The invention relates to an efficient stripping device for a lithium iron phosphate positive electrode material and a working method thereof.The efficient stripping device comprises a stripping kettle, a feeding pipe is installed on the side wall of the stripping kettle, a discharging valve is installed at the bottom of the stripping kettle, and a first stirring shaft is installed in the center of the interior of the stripping kettle; the first stirring shaft is connected with a charging barrel and a plurality of stirring arms through connecting arms, a plurality of filtering holes are formed in the outer side of the charging barrel, a bearing seat is mounted in the charging barrel through a supporting arm, and a second stirring shaft is rotatably mounted in the bearing seat in a penetrating manner; according to the double-shaft collaborative stirring system, a first stirring shaft drives a charging barrel to revolve, meanwhile, an inner gear ring is meshed with rotating teeth to achieve autorotation of a second stirring shaft, planetary stirring is formed, the mixing efficiency of pole piece fragments and a solvent is greatly improved, dissolution of a binder is accelerated, the modular charging barrel design is achieved, and a detachable barrel base at the bottom of the charging barrel is matched with a pneumatic cylinder to control opening and closing. Automatic solid-liquid separation is achieved, manual intervention is reduced, and the treatment efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium iron phosphate battery recycling, and in particular to a high-efficiency stripping device for lithium iron phosphate positive electrode materials and a working method thereof. Background Art

[0002] At present, the recycling of waste lithium iron phosphate batteries mainly adopts mechanical crushing + wet leaching process, but the traditional method has the following problems: low stripping efficiency, slow dissolution rate of binder, resulting in incomplete separation of positive electrode material and aluminum foil, solvent waste: large consumption of organic solvent, high recycling cost, complex equipment, and mostly adopts multi-stage crushing + stirring + centrifugal separation, which has a long process and high energy consumption. During solid-liquid separation, the solid content is high, resulting in excessive load on the solid-liquid separation process. Summary of the Invention

[0003] The problem solved by the present invention is to provide an efficient stripping device for lithium iron phosphate positive electrode materials and a working method thereof, which solves the technical problems of low stripping efficiency and slow binder dissolution rate, which lead to incomplete separation of positive electrode material and aluminum foil, solvent waste, large organic solvent consumption, high recovery cost, complex equipment, and multi-stage crushing + stirring + centrifugal separation, which has a long process and high energy consumption. During solid-liquid separation, the solid content is high, which leads to excessive load in the solid-liquid separation process.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A high-efficiency stripping device for lithium iron phosphate positive electrode materials includes a stripping kettle, a feeding pipe is installed on the side wall of the stripping kettle, a discharge valve is installed on the bottom of the stripping kettle, a first stirring shaft is installed at the center of the stripping kettle, the first stirring shaft is connected to the barrel and several stirring arms through a connecting arm, several filter holes are opened on the outside of the barrel, a bearing seat is installed in the barrel through a support arm, a second stirring shaft is rotatably installed in the bearing seat, several stirring rods are installed on the outside of the second stirring shaft, and a barrel seat is detachably installed on the bottom end of the barrel.

[0006] Preferably, a reducer is installed on the top side of the stripping kettle, the reducer input end is connected to the motor output end, and the reducer output end is connected to the first stirring shaft.

[0007] Preferably, an inner gear ring is installed on the top of the inner wall of the stripping kettle, and a rotating tooth is installed on the top of the second stirring shaft, and the rotating tooth is engaged with the inner gear ring.

[0008] Preferably, an inner rod is installed through the center of the second stirring shaft and the rotating teeth, the bottom end of the inner rod is connected to the cylinder seat, and the top side of the cylinder seat is configured to be conical.

[0009] Preferably, a stopper is installed at the top end of the inner rod, and a spring is sleeved on the outside of the inner rod and located between the stopper and the rotating tooth.

[0010] Preferably, a pneumatic cylinder is installed on the top side of the stripping kettle, and the movement of the inner rod is achieved through the extension and retraction of the pneumatic cylinder.

[0011] A working method of a high-efficiency stripping device for lithium iron phosphate positive electrode materials, the specific operating steps of the working method are as follows:

[0012] Step 1: Discharge the waste lithium iron phosphate battery to a safe voltage, disassemble the battery shell mechanically or manually, remove the positive electrode sheet, use a shear crusher or roller press to break the positive electrode sheet into 5-10mm fragments, and preliminarily separate the aluminum foil fragments and lithium iron phosphate powder through a vibrating screen. Put the broken electrode fragments into a stripping kettle, add an organic solvent and stir to make the solvent fully contact with the electrode to promote the dissolution of the binder. Use a centrifuge or filter press to separate the solid and liquid. The dissolved binder and solvent enter the recovery system and are recycled after distillation. The aluminum foil fragments and lithium iron phosphate powder enter the next step of cleaning. Wash the aluminum foil fragments and lithium iron phosphate powder with deionized water or ethanol multiple times to remove residual solvent and impurities. Vacuum dry the lithium iron phosphate powder at 80-100°C for 4-6 hours, and obtain lithium iron phosphate material through air flow classification or vibrating screen;

[0013] Step 2: The motor drives the first stirring shaft to rotate, and then drives the stirring arm and the barrel to rotate through the connecting arm, and rotates the barrel to correspond to the feeding tube. At this time, the electrode fragments and organic solvent are added to the barrel, and the organic solvent enters the stripping kettle through the filter hole. The organic solvent is mixed by the rotating stirring arm and the barrel, and when the barrel rotates, the rotating teeth at the top of the second stirring shaft are driven to rotate around the inner gear ring to realize the rotation of the stirring shaft. The electrode fragments and organic solvent inside the barrel are stirred and mixed by the stirring rod, and after the stirring is completed, the liquid is discharged from the stripping kettle through the discharge valve, and then the telescopic end of the pneumatic cylinder acts on the block to drive the inner rod to move downward and compress the spring until the barrel seat is separated from the barrel. At this time, the solid in the barrel seat falls into the stripping kettle and is discharged through the discharge valve after rinsing.

[0014] The beneficial effects of the present invention are as follows: the dual-shaft coordinated stirring system drives the barrel to revolve through the first stirring shaft, and simultaneously utilizes the internal gear ring to mesh with the rotating gear to realize the second stirring shaft to rotate, thereby forming planetary stirring, greatly improving the mixing efficiency of the electrode fragments and the solvent, and accelerating the dissolution of the binder;

[0015] Modular barrel design, with a detachable barrel seat at the bottom of the barrel and a pneumatic cylinder to control opening and closing, to achieve automated solid-liquid separation, reduce manual intervention and improve processing efficiency;

[0016] Dynamic filtration function: the filter holes on the side wall of the barrel achieve dynamic solvent penetration during rotation to avoid clogging, while the stirring rod continuously stirs the debris to prevent accumulation

[0017] By combining mechanical stirring with chemical dissolution, the binder stripping time is significantly shortened, the recovery rate of lithium iron phosphate is improved, and the organic solvent can be distilled and recycled, reducing processing costs; staged solid-liquid separation ensures high-purity recovery of aluminum foil and lithium iron phosphate powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 It is a cross-sectional view of the present invention;

[0020] Figure 3 Schematic diagram of the internal structure of the present invention;

[0021] Figure 4 For the present invention Figure 3 A partial enlarged view of area A in the middle;

[0022] Figure 5 For the present invention Figure 3 A partial enlarged view of area B in the middle.

[0023] Legend:

[0024] 1. Stripping kettle; 2. Feeding pipe; 3. Discharge valve; 4. Reducer; 5. Motor; 6. First stirring shaft; 7. Connecting arm; 8. Stirring arm; 9. Barrel; 10. Filter hole; 11. Support arm; 12. Bearing seat; 13. Second stirring shaft; 14. Stirring rod; 15. Rotating gear; 16. Internal gear ring; 17. Inner rod; 18. Stopper; 19. Spring; 20. Barrel seat; 21. Pneumatic cylinder. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] Specific examples are given below.

[0027] See also Figures 1 to 5A high-efficiency stripping device for lithium iron phosphate positive electrode materials includes a stripping kettle 1, a feeding pipe 2 is installed on the side wall of the stripping kettle 1, a discharge valve 3 is installed at the bottom of the stripping kettle 1, a first stirring shaft 6 is installed at the center of the stripping kettle 1, the first stirring shaft 6 is connected to the barrel 9 and a plurality of stirring arms 8 through a connecting arm 7, a plurality of filter holes 10 are opened on the outside of the barrel 9, a bearing seat 12 is installed in the barrel 9 through a supporting arm 11, a second stirring shaft 13 is rotatably installed in the bearing seat 12, a plurality of stirring rods 14 are installed on the outside of the second stirring shaft 13, and a barrel seat 20 is detachably installed at the bottom end of the barrel 9.

[0028] A reducer 4 is installed on the top side of the stripping kettle 1. The input end of the reducer 4 is connected to the output end of the motor 5. The output end of the reducer 4 is connected to the first stirring shaft 6. The motor 5 drives the first stirring shaft 6 to rotate, and then drives the stirring arm 8 and the barrel 9 to rotate through the connecting arm 7.

[0029] An inner gear ring 16 is installed on the top of the inner wall of the stripping kettle 1, and a rotating tooth 15 is installed on the top of the second stirring shaft 13, and the rotating tooth 15 is engaged with the inner gear ring 16. When the barrel 9 rotates, the rotating tooth 15 on the top of the second stirring shaft 13 is driven to rotate around the inner gear ring 16, thereby realizing the rotation of the stirring shaft 13, and the electrode fragments and organic solvent inside the barrel 9 are stirred and mixed through the stirring rod 14.

[0030] An inner rod 17 is installed through the center of the second stirring shaft 13 and the rotating tooth 15. The bottom end of the inner rod 17 is connected to the cylinder seat 20. The top side of the cylinder seat 20 is set to a cone. A stopper 18 is installed on the top of the inner rod 17. A spring 19 is installed on the outside of the inner rod 17 and between the stopper 18 and the rotating tooth 15. A pneumatic cylinder 21 is installed on the top side of the stripping kettle 1. The movement of the inner rod 17 is achieved by the telescopic operation of the pneumatic cylinder 21. The telescopic end of the pneumatic cylinder 21 acts on the stopper 18 to drive the inner rod 17 downward, compressing the spring 19 until the cylinder seat 20 is separated from the barrel 9. At this time, the solid in the cylinder seat 20 falls into the stripping kettle 1, and after the pneumatic cylinder 21 contracts, the spring 19 returns to its original state and drives the cylinder seat 20 to move upward.

[0031] Working principle: discharge the waste lithium iron phosphate battery to a safe voltage, disassemble the battery shell mechanically or manually, take out the positive electrode sheet, use a shear crusher or roller press to break the positive electrode sheet into 5-10mm fragments, and use a vibrating screen to preliminarily separate the aluminum foil fragments and lithium iron phosphate powder. Put the broken electrode fragments into the stripping kettle 1, add an organic solvent and stir to make the solvent fully contact with the electrode to promote the dissolution of the binder. Use a centrifuge or filter press to separate the solid and liquid. The dissolved binder and solvent enter the recovery system and are recycled after distillation. The aluminum foil fragments and lithium iron phosphate powder enter the next step of cleaning. Wash the aluminum foil fragments and lithium iron phosphate powder with deionized water or ethanol multiple times to remove residual solvents and impurities. Vacuum dry the lithium iron phosphate powder at 80-100℃ for 4-6 hours, obtain lithium iron phosphate material through air flow classification or vibrating screen, and drive the first stirring by motor 5. The mixing shaft 6 rotates, and then drives the stirring arm 8 and the barrel 9 to rotate through the connecting arm 7, and rotates the barrel 9 to correspond to the feeding pipe 2. At this time, the electrode fragments and organic solvent are added to the barrel 9, and the organic solvent enters the stripping kettle 1 through the filter hole 10. The organic solvent is mixed by the rotating stirring arm 8 and the barrel 9, and when the barrel 9 rotates, the rotating teeth 15 at the top of the second stirring shaft 13 are driven to rotate around the inner gear ring 16 to realize the rotation of the second stirring shaft 13, and the electrode fragments and organic solvent inside the barrel 9 are stirred and mixed by the stirring rod 14. After the stirring is completed, the liquid is discharged from the stripping kettle 1 through the discharge valve 3, and then the telescopic end of the pneumatic cylinder 21 acts on the stopper 18, driving the inner rod 17 to move downward, compressing the spring 19 until the barrel seat 20 is separated from the barrel 9. At this time, the solid in the barrel seat 20 falls into the stripping kettle 1, and is discharged through the discharge valve 3 after being rinsed.

[0032] The dual-shaft coordinated stirring system drives the barrel 9 to orbit through the first stirring shaft 6, while the second stirring shaft 13 rotates by meshing the internal gear ring 16 with the rotating gear 15, forming planetary stirring, greatly improving the mixing efficiency of the electrode fragments and the solvent, and accelerating the dissolution of the binder;

[0033] The modular barrel 9 is designed with a detachable barrel seat 20 at the bottom of the barrel 9 and a pneumatic cylinder 21 to control the opening and closing, realizing the automation of solid-liquid separation, reducing manual intervention and improving processing efficiency;

[0034] Dynamic filtration function: the filter holes 10 on the side wall of the barrel 9 realize dynamic solvent penetration during rotation to avoid clogging, while the stirring rod 14 continuously stirs the debris to prevent accumulation

[0035] By combining mechanical stirring with chemical dissolution, the binder stripping time is significantly shortened, the recovery rate of lithium iron phosphate is improved, and the organic solvent can be distilled and recycled, reducing processing costs; staged solid-liquid separation ensures high-purity recovery of aluminum foil and lithium iron phosphate powder.

[0036] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A high-efficiency stripping device for lithium iron phosphate positive electrode material, characterized in that: The invention comprises a stripping kettle (1), wherein a feeding pipe (2) is installed on the side wall of the stripping kettle (1), a discharge valve (3) is installed on the bottom of the stripping kettle (1), a first stirring shaft (6) is installed at the center of the interior of the stripping kettle (1), the first stirring shaft (6) is connected to a barrel (9) and a plurality of stirring arms (8) through a connecting arm (7), a plurality of filter holes (10) are provided on the outside of the barrel (9), a bearing seat (12) is installed in the barrel (9) through a supporting arm (11), a second stirring shaft (13) is rotatably installed in the bearing seat (12), a plurality of stirring rods (14) are installed on the outside of the second stirring shaft (13), and a barrel seat (20) is detachably installed at the bottom end of the barrel (9).

2. The high-efficiency stripping device for lithium iron phosphate cathode material according to claim 1, characterized in that: A reducer (4) is installed on the top side of the stripping kettle (1), the input end of the reducer (4) is connected to the output end of the motor (5), and the output end of the reducer (4) is connected to the first stirring shaft (6).

3. The efficient stripping device for lithium iron phosphate cathode material according to claim 2, characterized in that: An inner gear ring (16) is installed on the top of the inner wall of the stripping kettle (1), and a rotating tooth (15) is installed on the top of the second stirring shaft (13), and the rotating tooth (15) is meshed with the inner gear ring (16).

4. The high-efficiency stripping device for lithium iron phosphate cathode material according to claim 3, characterized in that: An inner rod (17) is installed through the center of the second stirring shaft (13) and the rotating tooth (15), and the bottom end of the inner rod (17) is connected to the cylinder seat (20), and the top side of the cylinder seat (20) is set to be conical.

5. The high-efficiency stripping device for lithium iron phosphate cathode material according to claim 4, characterized in that: A stopper (18) is installed on the top end of the inner rod (17), and a spring (19) is sleeved on the outside of the inner rod (17) and located between the stopper (18) and the rotating tooth (15).

6. The high-efficiency stripping device for lithium iron phosphate cathode material according to claim 5, characterized in that: A pneumatic cylinder (21) is installed on the top side of the stripping kettle (1), and the movement of the inner rod (17) is achieved through the expansion and contraction of the pneumatic cylinder (21).

7. The working method of the high-efficiency stripping device for lithium iron phosphate cathode material according to claim 6, characterized in that: The specific steps of this working method are as follows: Step 1: Discharge the waste lithium iron phosphate battery to a safe voltage, disassemble the battery shell mechanically or manually, remove the positive electrode sheet, use a shear crusher or roller press to break the positive electrode sheet into 5-10mm fragments, and preliminarily separate the aluminum foil fragments and lithium iron phosphate powder through a vibrating screen. Put the broken electrode fragments into a stripping kettle, add an organic solvent and stir to make the solvent fully contact with the electrode to promote the dissolution of the binder. Use a centrifuge or filter press to separate the solid and liquid. The dissolved binder and solvent enter the recovery system and are recycled after distillation. The aluminum foil fragments and lithium iron phosphate powder enter the next step of cleaning. Wash the aluminum foil fragments and lithium iron phosphate powder with deionized water or ethanol multiple times to remove residual solvent and impurities. Vacuum dry the lithium iron phosphate powder at 80-100°C for 4-6 hours, and obtain lithium iron phosphate material through air flow classification or vibrating screen; Step 2: The motor (5) drives the first stirring shaft (6) to rotate, and then drives the stirring arm (8) and the barrel (9) to rotate through the connecting arm (7), and rotates the barrel (9) to correspond to the feeding pipe (2). At this time, the pole piece fragments and the organic solvent are added into the barrel (9), and the organic solvent enters the stripping kettle (1) through the filter hole (10). The organic solvent is subjected to the organic solvent by the rotating stirring arm (8) and the barrel (9), and when the barrel (9) rotates, the rotating teeth (15) at the top of the second stirring shaft (13) are driven to rotate around the inner gear ring (16 ) rotates to realize the rotation of the stirring shaft (13), and the electrode fragments and the organic solvent inside the barrel (9) are stirred and mixed through the stirring rod (14). After the stirring is completed, the liquid is discharged from the stripping kettle (1) through the discharge valve (3), and then the telescopic end of the pneumatic cylinder (21) acts on the stopper (18), driving the inner rod (17) to move downward, compressing the spring (19) until the barrel seat (20) is separated from the barrel (9). At this time, the solid in the barrel seat (20) falls into the stripping kettle (1), is rinsed, and is discharged through the discharge valve (3).

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