A method and device for stripping and recycling lithium cathode materials in lithium iron phosphate batteries

Abstract

The present invention relates to a method and device for stripping and recycling lithium cathode materials in lithium iron phosphate batteries. The device includes a bottom plate; a first clamping mechanism and a second mechanism provided on the bottom plate for clamping both ends of the lithium battery; the first clamping mechanism includes a first ring, the second clamping mechanism includes two motors, a lead screw shaft is provided at the output shaft end of the motor, and both lead screw shafts are threadedly connected to the same second ring. More than two clamping components are provided on the first ring and the second ring along their respective circumferences. Among them, the clamping components on the second ring can move axially with respect to the second ring and a first return spring is provided between them and the second ring. The whole process of the present invention gets rid of the dependence on acids and alkalis in the previous recycling methods, no waste acid liquid is generated, and the cold shock method and room temperature grinding also excellently achieve the goals of waste liquid reduction and low energy consumption. It is an environmentally friendly, mild and efficient method for stripping the cathode material and recycling lithium.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium battery recycling, and particularly relates to a method and device for stripping and recycling lithium cathode materials in lithium iron phosphate batteries. Background Art

[0002] As the main industry using lithium batteries, the output of new energy vehicles has gradually increased in recent years. With the loss of some market share by nickel-cobalt-manganese ternary (NCM) lithium-ion batteries, the status of lithium iron phosphate batteries has become increasingly prominent. Lithium iron phosphate batteries have the advantages of large working voltage, high energy density, long cycle service life, good safety performance, etc. These advantages have rapidly increased the market share of lithium iron phosphate batteries. The LiFePO4 (LFP) cathode material mainly contains elements such as Li, Fe, and P, and the total lithium content is as high as over 4%. It is the most valuable metal in LFP. Therefore, recycling lithium in LFP is of great significance for saving resources and protecting the environment.

[0003] Currently, the main methods for recycling cathode materials in waste lithium iron phosphate batteries are high-temperature solid-phase regeneration and wet recycling technologies. The high-temperature direct regeneration technology refers to the process of pre-treating waste battery materials through crushing, screening, etc., and oxidizing the recovered LFP cathode material at high temperature to form reaction intermediates, and then re-crystallizing each element in the thermodynamic reaction process to achieve material regeneration. The wet recycling technology is to use specific reagents to leach the metals in the cathode material into the solution for separation and recovery. The wet recycling technology has a mature process, good separation effect for elements, and thorough recovery.

[0004] However, high-temperature solid-phase regeneration requires high energy consumption, releases toxic gases, and is only applicable to treating cathode waste with low impurity content. A large amount of waste liquid (acid solution or alkali solution) will be generated during the wet recycling process, causing greater environmental pollution. Moreover, a large amount of chemical reagents are required during the recycling process, such as acids and bases, reducing agents, oxidizing agents, etc. The reagent consumption is large, and most of them cannot be reused. Summary of the Invention

[0005] The purpose of the present invention is to provide a method and device for stripping and recycling lithium cathode materials in lithium iron phosphate batteries to solve the problems mentioned in the above background art.

[0006] The present invention achieves the above purpose through the following technical solutions:

[0007] A device for stripping and recycling lithium cathode materials in lithium iron phosphate batteries, comprising:

[0008] A bottom plate;

[0009] A first clamping mechanism and a second mechanism disposed on the bottom plate for clamping both ends of a lithium battery; the first clamping mechanism includes a first ring, the second clamping mechanism includes two motors, a lead screw shaft is provided at the output shaft end of the motor, and both lead screw shafts are threadedly connected to the same second ring. The first ring and the second ring are each provided with more than two clamping components along their circumferences. Among them, the clamping components on the second ring can move axially on the second ring and are provided with a first return spring between them and the second ring;

[0010] A rotating ring disposed on the side of the second ring away from the motor;

[0011] More than two cutting components arranged axially along the rotating ring for circumferentially cutting the outer shell of the lithium battery. The cutting components can move axially on the rotating ring and are provided with a second return spring between them and the rotating ring;

[0012] A runner disposed on the lead screw shaft for driving the rotating ring to rotate.

[0013] Preferably, the clamping component includes an electromagnet, a first telescopic rod is provided on the electromagnet, a first spring is wound around the first telescopic rod, and a clamping block is provided at the end of the first telescopic rod away from the electromagnet.

[0014] Preferably, the cutting component includes a moving block, a second telescopic rod is provided on the moving block, a second spring is wound around the second telescopic rod, and a cutting blade is provided at the end of the second telescopic rod away from the moving block.

[0015] Preferably, more than two secondary clamping components are provided along the circumference of the second ring. The secondary clamping component includes a bracket, a clamping plate is provided on the bracket, a third spring for driving the clamping plate to rotate is provided between the bracket and the clamping plate, and an elastic rope for controlling the rotation of the clamping plate is provided between the clamping plate and the runner.

[0016] A method for recycling using the above-mentioned stripping and recycling device, including the following steps:

[0017] S1: Discharge; Immerse the lithium iron phosphate battery in a 5% NaCl solution by mass for 12 - 24 hours, then take it out and dry it, and measure whether the voltage of the lithium battery is less than 1V. If it is less than 1V, it is okay;

[0018] S2: Disassembly; Place both ends of the lithium battery on the first clamping mechanism and the second clamping mechanism respectively. Use the motor to drive the lead screw shaft to rotate, so that the lead screw shaft drives the second ring to move. The runner on the lead screw shaft rotates to drive the rotating ring to rotate. The cutting components on the rotating ring perform circumferential cutting on the middle part of the lithium battery. After the outer shell of the lithium battery is cut off, the clamping components on the second ring drive one end of the outer shell of the lithium battery to move, so that the winding inside the lithium battery is exposed. Pull out the winding from the other outer shell of the lithium battery, and then unfold it along the direction in which the positive and negative electrode plates are wound to separate the positive and negative electrode plates;

[0019] S3: Stripping; Place the positive electrode sheet in a thermal medium at a temperature of 60 - 90°C for 3 - 5 minutes, and then place it in a cold medium at 5 - 20°C for 3 - 5 minutes to strip the active material and the current collector on the positive electrode sheet, obtaining a clean aluminum foil; If the stripping is not complete, repeat the above stripping steps 2 - 3 times;

[0020] S4: High-temperature pyrolysis; Pyrolyze the obtained positive electrode sheet at high temperature to remove the binder, and then cool and grind it to obtain the active positive electrode powder;

[0021] S5: Mechanical grinding; Mix the active positive electrode powder obtained in S4 with a grinding reagent and put it into an instrument to grind at a set speed and time. The metal ions in the grinding reagent replace the lithium in LiFePO4 to generate LiCl, obtaining a solid powder;

[0022] S6: Water leaching; After the grinding reaction is completed, transfer the solid powder to a beaker containing deionized water for leaching. After the leaching is completed, perform vacuum filtration to achieve solid-liquid separation;

[0023] S7: Recycling lithium with carbonate; Add a carbonate reagent with a set molar ratio to the solution obtained in S6 and place it on a constant-temperature magnetic stirrer for reaction. Filter to obtain lithium carbonate precipitation, and the carbonate is recycled. The carbonate used is sodium carbonate or potassium carbonate.

[0024] Preferably, the reaction in S4 is high-temperature pyrolysis at 400 - 600°C for 3 - 5 hours.

[0025] Preferably, the mass ratio of the active positive electrode powder to the grinding reagent in S5 is 1:1 - 1:10, the grinding reagent is NaCl or KCl, the rotation speed is 300 - 600 rpm, and the time is 2 - 8 hours.

[0026] Preferably, the liquid-solid ratio for leaching in S6 is 5 g / L - 50 g / L, the leaching time is 10 - 120 minutes, the temperature is 15 - 90°C, and the rotation speed is 300 - 600 rpm.

[0027] Preferably, the molar ratio of the carbonate in S7 is 1.5:1 - 2:1.

[0028] Preferably, the reaction temperature in S7 is 70 - 90°C, the time is 45 - 90 minutes, and the rotation speed of the constant-temperature magnetic stirrer is 200 - 400 rpm.

[0029] The beneficial effects of the present invention are as follows:

[0030] 1. The present invention separates the positive electrode material and the current collector of waste lithium iron phosphate batteries through cold excitation stripping, and through mechanically induced solid-phase reactions, increases the mechanical energy of the positive electrode material, enhances the reaction activity, rearranges local atoms, enables external metal ions to undergo isomorphic substitution with lithium to form ionic compounds, can leach lithium into the solution, and finally recovers it in the form of lithium carbonate, and NaCl or KCl can be reused. This method completely gets rid of the dependence on acids and alkalis in the previous recovery methods, does not produce waste acid liquid, and the cold excitation method and room-temperature grinding also excellently achieve the goals of waste liquid emission reduction and low energy consumption. It is an environmentally friendly, mild, and efficient method for stripping the positive electrode material and recovering lithium.

[0031] 2. The present invention improves the recycling efficiency of lithium batteries by rapidly stripping them, and also reduces labor costs. Brief Description of the Drawings

[0032] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 is Figure 1 an enlarged schematic diagram of part A in

[0034] Figure 3 is Figure 1 an enlarged schematic diagram of part B in

[0035] Figure 4 is a schematic diagram of the positional relationship between the second ring and the clamping block in the present invention.

[0036] In the figure: 1. Base plate; 2. First ring; 3. Motor; 4. Lead screw shaft; 5. Second ring; 6. First return spring; 7. Rotating ring; 8. Second return spring; 9. Runner; 10. Electromagnet; 11. First telescopic rod; 12. First spring; 13. Clamping block; 14. Moving block; 15. Second telescopic rod; 16. Second spring; 17. Cutting blade; 18. Bracket; 19. Clamping plate; 20. Third spring; 21. Elastic cord. Detailed Embodiments

[0037] The following further describes the present application in detail. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and cannot be understood as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0038] Embodiment 1

[0039] As Figures 1-4 shown, a method and device for stripping and recovering the lithium positive electrode material in a lithium iron phosphate battery include:

[0040] Base plate 1;

[0041] A first clamping mechanism and a second mechanism provided on the bottom plate 1 for clamping both ends of a lithium battery; the first clamping mechanism includes a first ring 2, the second clamping mechanism includes two motors 3, a lead screw shaft 4 is provided at the output shaft end of the motor 3, and both lead screw shafts 4 are threadedly connected to the same second ring 5. The first ring 2 and the second ring 5 are each provided with more than two clamping components along their circumferences. Among them, the clamping components on the second ring 5 can move axially on the second ring 5 and a first return spring 6 is provided between them and the second ring 5;

[0042] A rotating ring 7 provided on the side of the second ring 5 away from the motor 3;

[0043] More than two cutting components arranged axially along the rotating ring 7 for circumferentially cutting the outer shell of the lithium battery. The cutting components can move axially on the rotating ring 7 and a second return spring 8 is provided between them and the rotating ring 7;

[0044] A runner 9 provided on the lead screw shaft 4 for driving the rotating ring 7 to rotate.

[0045] As a further solution of the present invention, the clamping component includes an electromagnet 10, a first telescopic rod 11 is provided on the electromagnet 10, a first spring 12 is wound around the first telescopic rod 11, and a clamping block 13 is provided at the end of the first telescopic rod 11 away from the electromagnet 10.

[0046] As a further solution of the present invention, the cutting component includes a moving block 14, a second telescopic rod 15 is provided on the moving block 14, a second spring 16 is wound around the second telescopic rod 15, and a cutting blade 17 is provided at the end of the second telescopic rod 15 away from the moving block 14.

[0047] In the above embodiment, before the peeling, the electromagnet 10 is activated. The electromagnet 10 generates a magnetic suction force on the clamping block 13 connected thereto, causing the clamping block 13 to approach the electromagnet 10, so that the clamping assemblies at the first ring 2 and the second ring 5 can normally place the lithium battery. Then, both ends of the lithium battery are respectively placed in the middle of the clamping assemblies of the first ring 2 and the second ring 5. The electromagnet 10 stops working, and the first spring 12 drives the clamping block 13 to approach the lithium battery and clamp both ends of the lithium battery. Then the motor 3 is activated to drive the lead screw shaft 4 to rotate. The lead screw shaft 4 drives the second ring 5 to move along the axis direction of the lithium battery. Since the clamping assembly on the second ring 5 can move on the second ring 5, the clamping assembly and the lithium battery remain stationary when the second ring 5 moves. The lead screw shaft 4 drives the rotating wheel 9 to rotate, causing the rotating ring 7 to rotate, and the cutting blade 17 on the rotating ring 7 to rotate, performing circumferential cutting on the outer shell of the lithium battery until the outer shell of the lithium battery is cut open. During the process of cutting the outer shell of the lithium battery, the first return spring 6 is pulled. After the outer shell is cut open, the first return spring 6 pulls the clamping assembly on the second ring 5 to move, separating the two parts of the lithium battery outer shell and exposing the winding inside.

[0048] Among them, the setting of the second telescopic rod 15 enables the cutting blade 17 to have elasticity, enabling the lithium battery to smoothly enter the middle of the cutting assembly and also enabling the cutting blade 17 to smoothly cut the outer shell of the lithium battery.

[0049] As a further solution of the present invention, two or more secondary clamping assemblies are provided along the circumferential direction of the second ring 5. The secondary clamping assembly includes a bracket 18, a clamping plate 19 is provided on the bracket 18, a third spring 20 for driving the clamping plate 19 to rotate is provided between the bracket 18 and the clamping plate 19, and an elastic rope 21 for controlling the rotation of the clamping plate 19 is provided between the clamping plate 19 and the rotating wheel 9.

[0050] In the above embodiment, during the movement of the second ring 5, the secondary clamping assembly is driven to move. When the elastic rope 21 is tightened, the clamping plate 19 rotates, causing the clamping plate 19 to clamp the winding inside the lithium battery. During the process of the clamping plate 19 moving with the second ring 5, the winding inside the lithium battery is completely pulled out from its outer shell.

[0051] Embodiment 2

[0052] A method for recycling using the above peeling and recycling device includes the following steps:

[0053] S1: Discharge; Immerse the lithium iron phosphate battery in a NaCl solution with a mass ratio of 5% for 12 h, then take it out and dry it, and measure whether the voltage of the lithium battery is less than 1 V. If it is less than 1 V, it is okay;

[0054] S2: Disassembly; Place the two ends of the lithium battery on the first clamping mechanism and the second clamping mechanism respectively. Use the motor 3 to drive the lead screw shaft 4 to rotate, so that the lead screw shaft 4 drives the second ring 5 to move. The runner 9 on the lead screw shaft 4 rotates to drive the rotating ring 7 to rotate. The cutting component on the rotating ring 7 performs circumferential cutting on the middle part of the lithium battery. After the outer shell of the lithium battery is cut off, the clamping component on the second ring 5 drives one end of the outer shell of the lithium battery to move, so that the winding inside the lithium battery is exposed. Pull out the winding from the other outer shell of the lithium battery, and then unfold it along the winding direction of the battery positive and negative plates to separate the positive and negative plates;

[0055] S3: Stripping; Place the positive plate in a thermal medium at 60 °C for 3 min, and then place it in a cold medium at 5 °C for 3 min to strip the active material and the current collector on the positive plate to obtain a clean aluminum foil. If the stripping is not complete, repeat the above stripping step 2 times;

[0056] S4: High-temperature pyrolysis; Pyrolyze the obtained positive plate at high temperature to remove the binder, and then cool and grind it to obtain the active positive electrode powder;

[0057] S5: Mechanical grinding; Mix the active positive electrode powder obtained in S4 with the grinding reagent and put it into the instrument to grind at the set speed and time. The metal ions in the grinding reagent replace the lithium in LiFePO4 to generate LiCl to obtain the solid powder. Mix the active positive electrode powder obtained in S4 with the grinding reagent and put it into a zirconia ball mill tank. There are 10 zirconia balls with a diameter of 10 mm in the ball mill tank as the grinding medium to impart mechanical energy to the solid material, and then place the ball mill tank on a high-energy planetary ball mill to grind at the set speed and time;

[0058] S6: Water leaching; After the grinding reaction is completed, transfer the solid powder to a beaker containing deionized water for leaching. After the leaching is completed, perform vacuum filtration to achieve solid-liquid separation;

[0059] S7: Recycling lithium with carbonate; Add a carbonate reagent with a set molar ratio to the solution obtained in S6 and place it on a constant temperature magnetic stirrer for reaction. Filter to obtain lithium carbonate precipitate, and the carbonate is recycled. The carbonate used is sodium carbonate or potassium carbonate. The generated LiCl enters the solution and exists in the form of ions.

[0060] The reaction in S4 is high-temperature pyrolysis at 400 °C for 3 h.

[0061] In S5, the mass ratio of the active positive electrode powder to the grinding reagent is 1:1. The grinding reagent is NaCl or KCl, the rotation speed is 300 rpm, and the time is 2 h.

[0062] In S6, the liquid-solid ratio of leaching is 5 g / L, the leaching time is 10 min, the temperature is 15 °C, and the rotation speed is 300 rpm.

[0063] The molar ratio of carbonate in S7 is 1.5:1.

[0064] The reaction temperature in S7 is 70 °C, the time is 45 min, and the rotation speed of the constant temperature magnetic stirrer is 200 rpm.

[0065] Example 3

[0066] A method for recycling using the above-mentioned peeling and recycling device, comprising the following steps:

[0067] S1: Discharge; Immerse the lithium iron phosphate battery in a NaCl solution with a mass ratio of 5% for 20 h, then take it out and dry it, and measure whether the voltage of the lithium battery is less than 1 V. If it is less than 1 V, it is okay.

[0068] S2: Disassembly; Place the two ends of the lithium battery on the first clamping mechanism and the second clamping mechanism respectively. Use the motor 3 to drive the lead screw shaft 4 to rotate, so that the lead screw shaft 4 drives the second ring 5 to move. The runner 9 on the lead screw shaft 4 rotates to drive the rotating ring 7 to rotate. The cutting assembly on the rotating ring 7 performs circumferential cutting on the middle part of the lithium battery. After the outer shell of the lithium battery is cut off, the clamping assembly on the second ring 5 drives one end of the outer shell of the lithium battery to move, so that the winding inside the lithium battery is exposed. Pull out the winding from the other outer shell of the lithium battery, and then unfold it along the winding direction of the battery positive and negative plates to separate the positive and negative plates.

[0069] S3: Peeling; Place the positive electrode plate in a hot medium at 80 °C for 4 min, and then place it in a cold medium at 10 °C for 4 min to peel the active material and the current collector on the positive electrode plate to obtain a clean aluminum foil. If it is not peeled clean, repeat the above peeling step 3 times.

[0070] S4: High-temperature pyrolysis; Pyrolyze the obtained positive electrode plate at high temperature to remove the binder, and then cool and grind it to obtain active positive electrode powder.

[0071] S5: Mechanical grinding; Mix the active positive electrode powder obtained in S4 with a grinding reagent and put it into an instrument to grind at a set speed and time. The metal ions in the grinding reagent replace the lithium in LiFePO4 to generate LiCl to obtain solid powder; Mix the active positive electrode powder obtained in S4 with a grinding reagent and put it into a zirconia ball mill tank. There are 10 zirconia balls with a diameter of 10 mm in the ball mill tank as grinding media to impart mechanical energy to the solid material, and then place the ball mill tank on a high-energy planetary ball mill to grind at a set speed and time.

[0072] S6: Water leaching; After the grinding reaction is completed, transfer the solid powder to a beaker containing deionized water for leaching. After the leaching is completed, vacuum filtration is carried out to achieve solid-liquid separation.

[0073] S7: Lithium recovery with carbonate; Add carbonate reagent with a set molar ratio to the solution obtained in S6 and react it on a thermostatic magnetic stirrer, then filter to obtain lithium carbonate precipitate, and the carbonate is recovered. The carbonate used is sodium carbonate or potassium carbonate; the generated LiCl enters the solution and exists in ionic form.

[0074] The reaction in S4 is high-temperature pyrolysis at 500 °C for 4 h.

[0075] In S5, the mass ratio of the active cathode powder to the grinding reagent is 1:5. The grinding reagent is NaCl or KCl, the rotation speed is 500 rpm, and the time is 5 h.

[0076] In S6, the liquid-solid ratio of leaching is 40 g / L, the leaching time is 100 min, the temperature is 40 °C, and the rotation speed is 400 rpm.

[0077] In S7, the molar ratio of the carbonate is 1.8:1.

[0078] In S7, the reaction temperature is 80 °C, the time is 60 min, and the rotation speed of the thermostatic magnetic stirrer is 300 rpm.

[0079] Example 4

[0080] A method for recovery using the above-mentioned stripping and recovery device, including the following steps:

[0081] S1: Discharge; Immerse the lithium iron phosphate battery in a 5% NaCl solution by mass for 24 h, then take it out and dry it, and measure whether the voltage of the lithium battery is less than 1 V. If it is less than 1 V, it is okay.

[0082] S2: Disassembly; Place both ends of the lithium battery on the first clamping mechanism and the second clamping mechanism respectively. Use the motor 3 to drive the lead screw shaft 4 to rotate, so that the lead screw shaft 4 drives the second ring 5 to move. The runner 9 on the lead screw shaft 4 rotates to drive the rotating ring 7 to rotate. The cutting component on the rotating ring 7 performs circumferential cutting on the middle part of the lithium battery. After the outer shell of the lithium battery is cut off, the clamping component on the second ring 5 drives one end of the outer shell of the lithium battery to move, so that the winding inside the lithium battery is exposed. Pull out the winding from the other outer shell of the lithium battery, and then unfold it along the winding direction of the battery positive and negative plates to separate the positive and negative plates.

[0083] S3: Stripping; Place the positive plate in a thermal medium at 90 °C for 5 min, and then place it in a cold medium at 20 °C for 5 min to strip the active material and the current collector on the positive plate to obtain a clean aluminum foil; If it is not stripped clean, repeat the above stripping step 3 times.

[0084] S4: High-temperature pyrolysis; Pyrolyze the obtained positive plate at high temperature to remove the binder, then cool and grind it to obtain the active cathode powder.

[0085] S5: Mechanical grinding; Mix the active cathode powder obtained in S4 with a grinding reagent and put it into an instrument to grind at a set speed and time. The metal ions in the grinding reagent replace the lithium in LiFePO4 to generate LiCl, obtaining a solid powder; Mix the active cathode powder obtained in S4 with a grinding reagent and put it into a zirconia ball mill pot. There are 10 zirconia balls with a diameter of 10 mm in the ball mill pot as grinding media to impart mechanical energy to the solid material, and then place the ball mill pot on a high-energy planetary ball mill to grind at a set speed and time;

[0086] S6: Water leaching; After the grinding reaction is completed, transfer the solid powder to a beaker containing deionized water for leaching. After the leaching is completed, perform vacuum filtration to achieve solid-liquid separation;

[0087] S7: Recover lithium with carbonate; Add a carbonate reagent with a set molar ratio to the solution obtained in S6 and place it on a thermostatic magnetic stirrer to react. Filter to obtain lithium carbonate precipitate, and the carbonate is recovered. The carbonate used is sodium carbonate or potassium carbonate; The generated LiCl enters the solution and exists in ionic form.

[0088] The reaction in S4 is high-temperature pyrolysis at 600 °C for 5 h.

[0089] In S5, the mass ratio of the active cathode powder to the grinding reagent is 1:10. The grinding reagent is NaCl or KCl, the rotation speed is 600 rpm, and the time is 8 h.

[0090] In S6, the liquid-solid ratio for leaching is 50 g / L, the leaching time is 120 min, the temperature is 90 °C, and the rotation speed is 600 rpm.

[0091] In S7, the molar ratio of the carbonate is 2:1.

[0092] In S7, the reaction temperature is 90 °C, the time is 90 min, and the rotation speed of the thermostatic magnetic stirrer is 400 rpm.

[0093] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A stripping and recycling device for lithium cathode materials in lithium iron phosphate batteries, characterized in that, Comprising: Base plate (1); A first clamping mechanism and a second clamping mechanism disposed on the base plate (1) for clamping both ends of the lithium battery; the first clamping mechanism includes a first ring (2), the second clamping mechanism includes two motors (3), a lead screw shaft (4) is provided at the output shaft end of the motor (3), and both lead screw shafts (4) are threadedly connected to the same second ring (5). The first ring (2) and the second ring (5) are each provided with more than two clamping components along their circumferences. Among them, the clamping components on the second ring (5) can move axially with respect to the second ring (5) and a first return spring (6) is provided between them and the second ring (5); A rotating ring (7) disposed on the side of the second ring (5) away from the motor (3); More than two cutting components arranged axially along the rotating ring (7) for circumferentially cutting the outer shell of the lithium battery. The cutting components can move axially with respect to the rotating ring (7) and a second return spring (8) is provided between them and the rotating ring (7); A runner (9) disposed on the lead screw shaft (4) for driving the rotating ring (7) to rotate; The clamping component includes an electromagnet (10), a first telescopic rod (11) is provided on the electromagnet (10), a first spring (12) is wound around the first telescopic rod (11), and a clamping block (13) is provided at the end of the first telescopic rod (11) away from the electromagnet (10); The cutting component includes a moving block (14), a second telescopic rod (15) is provided on the moving block (14), a second spring (16) is wound around the second telescopic rod (15), and a cutting blade (17) is provided at the end of the second telescopic rod (15) away from the moving block (14); More than two secondary clamping components are provided along the circumference of the second ring (5). The secondary clamping component includes a bracket (18), a clamping plate (19) is provided on the bracket (18), a third spring (20) for driving the clamping plate (19) to rotate is provided between the bracket (18) and the clamping plate (19), and an elastic cord (21) for controlling the rotation of the clamping plate (19) is provided between the clamping plate (19) and the runner (9).

2. A method of recycling using the peeling and recycling device described in claim 1, characterized in that, Including the following steps: S1: Discharge; Immerse the lithium iron phosphate battery in a 5% mass ratio NaCl solution for 12 - 24 h, then take it out and dry it, and measure whether the voltage of the lithium battery is less than 1 V. If it is less than 1 V, it is okay; S2: Disassembly; Place both ends of the lithium battery on the first clamping mechanism and the second clamping mechanism respectively. Use the motor (3) to drive the lead screw shaft (4) to rotate, so that the lead screw shaft (4) drives the second ring (5) to move. The runner (9) on the lead screw shaft (4) rotates to drive the rotating ring (7) to rotate. The cutting components on the rotating ring (7) perform circumferential cutting on the middle part of the lithium battery. After the outer shell of the lithium battery is cut off, the clamping components on the second ring (5) drive one end of the outer shell of the lithium battery to move, so that the winding inside the lithium battery is exposed. Pull out the winding from the other outer shell of the lithium battery, and then unfold it along the direction in which the positive and negative electrode plates are wound to separate the positive and negative electrode plates; S3: Stripping; Place the positive electrode in a thermal medium at a temperature of 60 - 90 °C for 3 - 5 min, and then place it in a cold medium at 5 - 20 °C for 3 - 5 min to strip the active material and the current collector on the positive electrode to obtain a clean aluminum foil; If it is not stripped cleanly, repeat the above stripping steps 2 - 3 times; S4: High-temperature pyrolysis; Pyrolyze the obtained positive electrode at high temperature to remove the binder, and then cool and grind it to obtain the active positive electrode powder; S5: Mechanical grinding; Mix the active positive electrode powder obtained in S4 with the grinding reagent and put it into an instrument to grind at a set speed and time. The metal ions in the grinding reagent replace the lithium in LiFePO4 to generate LiCl to obtain a solid powder; S6: Water leaching; After the grinding reaction is completed, transfer the solid powder to a beaker containing deionized water for leaching. After the leaching is completed, vacuum filtration is carried out to achieve solid-liquid separation; S7: Recycling lithium with carbonate; Add a carbonate reagent with a set molar ratio to the solution obtained in S6 and place it on a thermostatic magnetic stirrer for reaction, filter to obtain lithium carbonate precipitate, and the carbonate is recycled. The carbonate used is sodium carbonate or potassium carbonate.

3. A method for stripping and recycling the lithium cathode material in a lithium iron phosphate battery according to claim 2, characterized in that, The reaction in S4 is high-temperature pyrolysis at 400 - 600 °C for 3 - 5 h.

4. A method for stripping and recycling the lithium cathode material in a lithium iron phosphate battery according to claim 2, characterized in that, In S5, the mass ratio of the active positive electrode powder to the grinding reagent is 1:1 - 1:10, the grinding reagent is NaCl or KCl, the rotation speed is 300 - 600 rpm, and the time is 2 - 8 h.

5. A method for stripping and recycling lithium cathode materials in lithium iron phosphate batteries according to claim 2, characterized in that, In S6, the liquid-solid ratio for leaching is 5 g / L - 50 g / L, the leaching time is 10 - 120 min, the temperature is 15 - 90 °C, and the rotation speed is 300 - 600 rpm.

6. The stripping and recycling method of the lithium cathode material in a lithium iron phosphate battery according to claim 2, characterized in that, In S7, the molar ratio of the carbonate is 1.5:1 - 2:

1.

7. A method for stripping and recycling the lithium cathode material in a lithium iron phosphate battery according to claim 2, characterized in that, In S7, the reaction temperature is 70 - 90 °C, the time is 45 - 90 min, and the rotation speed of the thermostatic magnetic stirrer is 200 - 400 rpm.

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