A lithium ion battery recycling pre-treatment method

Abstract

This invention discloses a pretreatment method for the recycling and crushing of lithium-ion batteries. Before crushing, the lithium-ion batteries to be recycled are immersed in a discharge solution for discharge treatment. The key feature is that after discharge, the lithium-ion batteries are cleaned and dried before crushing and separation. During cleaning, the pH of the discharge solution is first detected, and then the cleaning solution is adjusted to a neutral pH, ensuring that the cleaning solution neutralizes any residual discharge solution on the battery surface. This invention has the advantages of improving the discharge treatment effect, increasing processing efficiency, and reducing the impact of the treatment process on subsequent lithium-ion battery processing procedures.

Description

Technical Field

[0001] This invention relates to the field of waste lithium battery recycling technology, specifically to a method for pre-treatment of lithium-ion batteries before crushing and recycling. Background Technology

[0002] Today, lithium-ion batteries are widely used in various devices and applications, ranging from portable electronic products to electric vehicles. Electric vehicle batteries typically need to be replaced every 3 to 5 years. Discarded lithium-ion batteries contain high levels of recyclable materials, such as rare metals like cobalt and nickel, making them highly valuable for recycling. Therefore, used lithium batteries are usually recycled.

[0003] In the recycling of waste lithium-ion battery materials, the lithium batteries must first be completely discharged before subsequent dismantling and crushing processes can proceed. Otherwise, short circuits between the positive and negative electrodes during dismantling and crushing may occur, potentially causing fires or explosions. The discharge process typically involves immersing the lithium batteries in a salt solution, using sodium chloride or similar solutions as the electrolyte. The positive and negative electrode metals of the battery serve as the anode and cathode, respectively, and the charge is consumed through electrolytic reactions occurring at the anode and cathode. After discharge, the lithium-ion batteries undergo further dismantling, crushing, heat treatment, and magnetic separation to ultimately obtain a mixture of positive and negative electrode materials of different particle sizes for subsequent processing.

[0004] Current waste lithium-ion battery discharge treatment technologies typically rely on manual immersion in a salt solution for discharge, followed by crushing, screening, and selective recycling of the discharged lithium batteries. This method is not only inefficient, but also results in excessive residual discharge solution on the lithium batteries. If these solutions are not cleaned and dried before subsequent crushing and screening, they can easily mix with the crushed powder, creating a large amount of agglomerates and negatively impacting subsequent processing. Simultaneously, the discharge of waste lithium-ion batteries causes electrolytic reactions in the salt substances (such as sodium chloride) in the discharge solution, releasing different types of electrolytic reaction gases (such as chlorine and hydrogen) from the electrode surface. The battery casing and electrode terminals may also be corroded and damaged, leading to electrolyte leakage. Consequently, the pH of the discharge solution changes (① low discharge volume: the lithium battery hardly undergoes any discharge reaction, and the pH remains relatively constant; ② high discharge volume: due to battery discharge, damage to the battery casing and electrodes, acidic substances are generated, and the discharge solution gradually becomes acidic; ③ due to battery discharge, damage to the battery casing and electrodes, alkaline substances are generated after discharge, and the discharge solution gradually becomes alkaline). Therefore, as the discharge treatment of waste lithium batteries continues, the pH of the discharge solution may change under different circumstances, ultimately leading to a deterioration in the discharge effect of the lithium batteries and a reduction in discharge efficiency. Manual replacement of the discharge solution or adjustment of its pH is required before the next batch of batteries can be discharged.

[0005] Therefore, how to improve the discharge efficiency of existing lithium batteries, enhance the discharge effect, reduce the impact of discharge treatment on subsequent processing procedures, and reduce recycling costs has become a problem that needs to be considered and solved by those skilled in the art. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a lithium-ion battery recycling pre-crushing treatment method that can quickly and efficiently realize the discharge treatment before crushing lithium batteries and improve crushing efficiency.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A method for pretreatment before crushing and recycling lithium-ion batteries involves immersing the lithium-ion batteries to be recycled in a discharge solution for discharge treatment before crushing. The method is characterized by cleaning and drying the lithium-ion batteries after discharge before crushing and separation.

[0009] This is because, as described in the background section, during the discharge process of lithium-ion batteries, the discharge phenomenon and damage to the battery casing and electrodes can easily cause the originally neutral discharge solution to become alkaline or acidic. In the subsequent crushing and separation process, the residual acidic or alkaline solution can cause agglomeration, affecting the efficiency and effectiveness of the crushing and separation. Therefore, cleaning and drying the lithium-ion battery after discharge treatment before crushing and separation can avoid the influence of residual discharge solution and better improve the efficiency and effectiveness of subsequent crushing and separation.

[0010] Furthermore, during cleaning, the pH of the discharge solution is first tested, and then the cleaning solution is adjusted to a pH that can neutralize it, so that the cleaning solution can neutralize the discharge solution on the battery surface during the cleaning process.

[0011] This process effectively neutralizes and removes residual acidic or alkaline discharge solution from the battery surface, resulting in a better cleaning effect. Simultaneously, the cleaning solution flows into the discharge solution, neutralizing its pH and restoring balance, allowing the discharge solution to better maintain its discharge effect and improve discharge efficiency.

[0012] Furthermore, this method relies on a lithium-ion battery discharge device, which includes a discharge box located at the bottom, containing a discharge solution for discharging, and a battery holder inside the discharge box. The battery holder is characterized in that it is vertically and vertically installed inside the discharge box via a lifting mechanism, and a cleaning device is provided above the discharge box for cleaning and drying the battery after discharge.

[0013] In this way, when the device is working, the battery is first immersed in the discharge solution (salt solution) and placed on the battery holder for discharge treatment. After the discharge is completed for a period of time, the battery holder is controlled to rise out of the liquid surface, and then the cleaning device is controlled to clean and dry it. This washes away the residual discharge solution on the battery surface and completes the drying process, better avoiding the impact of residual discharge solution on subsequent crushing and separation operations.

[0014] Furthermore, the lifting mechanism includes two racks vertically arranged at intervals on the outer sides of both ends of the discharge box. The upper ends of each rack are connected to both ends of the battery holder through a set of fixedly connected horizontal connecting plates located above the discharge box and vertical connecting plates located inside the discharge box. It also includes two gears that mesh with the two racks respectively. The gears are connected to the lifting control motor.

[0015] In this way, the lifting control motor controls the gear to rotate, which in turn drives the battery holder to move up and down through the rack. This has the advantages of simple structure, smooth movement, and reliable control.

[0016] Furthermore, a U-shaped baffle is provided on the outer side of the rack.

[0017] This arrangement, with the rack positioned inside the baffle, better protects the transmission structure.

[0018] Furthermore, limit sleeves are fixedly installed on the upper inner sides of both ends of the discharge box, and the vertical connecting plate can slide up and down through the limit sleeves. In this way, the limit sleeves can be used to limit the upper limit position of the battery placement component.

[0019] Furthermore, a limit switch is provided on the lower surface of the limit sleeve, and the limit switch is connected to the control circuit of the lifting control motor. This allows for better automatic control of the lifting operation.

[0020] Furthermore, the battery holder includes a grid plate.

[0021] In this way, using a grating plate can achieve rapid liquid leakage, making it easier to clean and dry the liquid after it rises to the surface.

[0022] Furthermore, the discharge box is also equipped with a discharge device, which includes discharge plates located at the upper end of the side plates on both sides of the discharge box and inclined outward and downward. The upper end of the side plates on both sides of the discharge box is lower than the upper end of the side plates at both ends. The upper end of the discharge plate has a limiting section extending upward into the discharge box.

[0023] In this way, when the battery holder is raised to contact the limiting section of the discharge plate, it is convenient for the discharged lithium battery to be discharged from the discharge material on both sides.

[0024] Furthermore, the discharge device also includes a triangular plate located in the middle of the discharge box and arranged along both ends of the discharge box (the vertical connecting plate and the triangular plate are fixed to connect the lifting mechanism and the battery holder). The triangular plate is fixedly connected to one side of two symmetrical elongated base plates to form a triangle with a convex center. The lower surfaces of both sides of the triangular plate have fixed downward mounting ears. Each mounting ear is rotatably connected to two grid plates on both sides that are initially horizontal through a horizontal rotating shaft. The inner ends of the two grid plates each have a rotating rod groove facing each other on both sides. A supporting rotating rod is arranged in the rotating rod groove along the direction of both sides of the discharge box. The connecting end of the supporting rotating rod is installed on one of the grid plates through a vertical rotating shaft. Inside the rotating rod groove of the plate, a rotating rod torsion spring is also provided between the supporting rotating rod and the vertical rotating shaft. The rotating rod torsion spring keeps the free end of the supporting rotating rod in the rotating rod groove of another grid plate when it is not under force. The discharge device also includes a striking block located at the middle of the upper inner side of the side panel at both ends of the discharge box. The lower surface of the striking block is an impact surface that is inclined outward and downward. There is a space for the striking block to be inserted in the middle between the two grid plates. When the triangular plate and the grid plate move up to the upper end, the impact surface of the striking block can contact the supporting rotating rod and push it to rotate horizontally. When the grid plate moves up to the outer side and contacts or contacts the limiting section of the discharge plate, the striking block can push the free end of the supporting rotating rod out of the rotating rod groove of the grid plate where it is located.

[0025] Initially, the two grid plates are horizontal, and the supporting rotating rods maintain a large load-bearing capacity to accommodate the lithium batteries. After the lithium batteries have discharged in the discharge tank, the lifting mechanism controls the triangular plate to move the grid plates on both sides upward. Before the outer side of the grid plate contacts the limiting section of the discharge plate, the battery is removed from the discharge solution surface, completing the cleaning and drying process. Then, the grid plates continue to move upward. When the outer side of the grid plate is about to contact the limiting section of the discharge plate, the impact surface below the impact block first contacts the supporting rotating rod and pushes it to rotate horizontally. When the grid plate moves upward to the point where the outer side contacts or touches the limiting section of the discharge plate, the impact block can push the free end of the supporting rotating rod out of the rotating rod groove of the grid plate. At this time, the triangular plate continues to move upward, while the grid plates on both sides rotate under their own weight and the limiting section of the discharge plate, changing to a downward tilted state on the outside, until the upper side of the grid plate rotates to contact the lower surface of the triangular plate and can no longer rotate (the structural design of the triangular plate and the mounting lugs limits the rotation angle range of the grid plates). At this point, the grid plates on both sides are tilted, facilitating the downward sliding of the cleaned batteries onto the discharge plate, and then outward and downward from the discharge plate. After all the batteries have slid out, the lifting mechanism drives the triangular plate and grid plates downward until they contact the lower surface of the discharge box. Under the action of the lower surface of the discharge box, the grid plates return to their initial horizontal state. The free end of the supporting rotating rod, under the action of the rotating rod torsion spring, re-enters the rotating rod groove of the corresponding side of the grid plate to provide support force for the next discharge operation. Therefore, this greatly improves the convenience and efficiency of discharge.

[0026] Furthermore, the tilt angle of the two base plates in the triangular plate is greater than the tilt angle of the discharge plate.

[0027] This allows the grating to rotate to a greater tilt angle than the discharge plate during discharge, avoiding dead corners and improving discharge effect and efficiency.

[0028] Furthermore, a clearance groove is vertically provided in the middle of the side panel that is in contact with the vertical connecting plate and the side panels at both ends of the discharge box, and the impact block is located in the clearance groove. This not only better avoids interference and ensures the effectiveness of the impact block, but also protects the impact block and extends its service life.

[0029] In one embodiment, the cleaning device includes multiple cleaning nozzles positioned above the discharge box and facing downwards, with each cleaning nozzle connected to a corresponding cleaning fluid supply tank. It also includes multiple airflow nozzles positioned above the discharge box and facing downwards, with each airflow nozzle connected to an air source device. The cleaning nozzles and airflow nozzles are installed side by side.

[0030] In this way, after the discharge is completed, the battery is cleaned by the cleaning fluid sprayed from the cleaning nozzle, and then dried by the air jet nozzle. This allows for convenient and quick cleaning of the battery, facilitating subsequent crushing and screening operations.

[0031] Furthermore, the air source device is a warm air blower, which enables the drying operation to be completed more quickly.

[0032] Furthermore, the cleaning fluid supply tank includes an acidic cleaning fluid control tank and an alkaline cleaning fluid control tank. Each of the acidic and alkaline cleaning fluid control tanks is connected to a cleaning nozzle via a cleaning fluid flow control valve. The discharge box is also equipped with an acid-base level detection probe, and the acid-base level detection probe and the cleaning fluid flow control valve are respectively connected to the control center.

[0033] This is because, as described in the background section, the applicant discovered that during the discharge process of used lithium batteries, the discharge solution may gradually become acidic or alkaline. Therefore, before cleaning, the pH change of the discharge solution is monitored. If it becomes alkaline, an acidic cleaning solution is used; if it becomes acidic, an alkaline cleaning solution is used; if there is no change, a portion of the acidic and alkaline cleaning solutions are neutralized to form a neutral cleaning solution before cleaning. A flow control valve is used to control the mixing of different proportions of acidic and alkaline cleaning solutions at different pH levels, thus improving the cleaning effect. Therefore, this not only improves the cleaning effect but also allows the cleaning solution to adjust its pH after entering the discharge solution, better ensuring the sustainability of the discharge effect.

[0034] Alternatively, the cleaning device includes multiple cleaning nozzles positioned above the discharge box and facing downwards. The cleaning nozzles are generally tubular and arranged in an array in the horizontal direction. The upper end of the cleaning nozzles is connected to a pressure box, which is connected to an air supply pipe and a blower. The end of the pressure box is also provided with a liquid inlet pipe, the other end of which is connected to the outlet pipe of the cleaning fluid supply box through a liquid inlet control structure.

[0035] During cleaning, the cleaning solution is first added through the inlet pipe, allowing it to enter the pressure tank. Under the pressure of the blower, it is then sprayed out from the cleaning nozzle to clean the battery. After cleaning, the blower continues to blow air, causing it to be sprayed out from the cleaning nozzle to dry the battery. Therefore, it can simultaneously clean and dry the battery, completing the cleaning work efficiently and conveniently.

[0036] Furthermore, the liquid inlet control structure includes vertically arranged and parallel liquid storage pipes outside the pressure tank. The liquid storage pipes are positioned directly above the horizontal connecting plate of the lifting mechanism. A piston is installed inside the liquid storage pipe. A piston rod is connected to the lower end of the piston via a vertical pipe. The lower end of the piston rod is fixed to the horizontal connecting plate of the lifting mechanism of the battery holder. A horizontal liquid inlet pipe is provided in the upper part of the liquid storage pipe and communicates with the pressure tank. The lower part of the liquid storage pipe is connected to the outlet pipe of the cleaning fluid supply tank arranged parallel to the side.

[0037] In this way, after discharge, the cleaning fluid flows from the outlet pipe of the cleaning fluid supply tank into the storage pipe. Then, the lifting mechanism controls the battery holder to move the battery upward, while the piston moves upward in conjunction, pushing the cleaning fluid flowing into the storage pipe into the inlet pipe and then into the pressure tank. Under the pressure in the pressure tank, the cleaning fluid is sprayed from the cleaning nozzle onto the battery surface to clean it. After cleaning, the blower continues to dry the battery by spraying air through the pressure tank and the cleaning nozzle. Therefore, the above structure can achieve linkage control between the liquid inlet cleaning at the top of the equipment and the battery discharge lifting operation at the bottom, thus improving the control effect of battery cleaning.

[0038] Furthermore, a push rod is provided at the upper end of the piston, and an arc-shaped sealing pad that matches the inner cavity of the liquid storage tube is provided on the side of the push rod facing the end of the pressure box. The sealing pad is larger than the inlet of the liquid inlet of the pressure box and can block the inlet of the liquid inlet when the liquid storage tube is in the liquid inlet state.

[0039] This ensures that the inlet pipe is blocked when liquid is introduced into the storage pipe, preventing the cleaning fluid from entering the pressure tank prematurely. This improves the accuracy of cleaning fluid dispensing control.

[0040] Furthermore, the upper end of the liquid storage tube is provided with an opening and has a matching top cover, and the upper end of the push rod is fixedly connected to the top cover.

[0041] In this way, as the piston moves upward, the top cover is pushed open to the same pressure as atmospheric pressure, ensuring the flow of liquid in the reservoir. After the piston moves downward, the top cover can cover the reservoir to provide protection and prevent dust and other contaminants from falling in.

[0042] Furthermore, the piston is a double-sealed piston, and the distance between the two sealing rings is greater than the diameter of the liquid inlet pipe at the end of the pressure tank.

[0043] After the piston moves upward and pushes all the cleaning fluid in the reservoir into the pressure tank, the piston can block the inlet pipe of the pressure tank, ensuring that there is no leakage from the inlet pipe during subsequent air jet cleaning, thus better guaranteeing the cleaning effect.

[0044] Furthermore, a cleaning fluid flow control valve is installed on the outlet pipe of the cleaning fluid supply tank. This allows for control of the outflow and flow rate of the cleaning fluid, facilitating better control of the pressure tank's inlet operation.

[0045] Furthermore, the inlet pipe, inlet control structure, and cleaning fluid supply tank are arranged in two sets, located at opposite ends of the pressure tank; one cleaning fluid supply tank contains acidic cleaning fluid to form an acidic cleaning fluid control tank, and the other cleaning fluid supply tank contains alkaline cleaning fluid to form an alkaline cleaning fluid control tank; cleaning fluid flow control valves are installed on the outlet pipes of both cleaning fluid supply tanks; an acid-base level detection probe is also installed in the discharge box, and the acid-base level detection probe and the cleaning fluid flow control valve are respectively connected to the control center.

[0046] This is because, as described in the background section, the applicant discovered that during the discharge process of used lithium batteries, the discharge solution may gradually become acidic or alkaline. Therefore, before cleaning, the pH change of the discharge solution is monitored. If it becomes alkaline, an acidic cleaning solution is used; if it becomes acidic, an alkaline cleaning solution is used. If there is no change (the battery is completely depleted and undamaged, so the discharge solution will not change pH), then a portion of the acidic cleaning solution and a portion of the alkaline cleaning solution can be introduced into a pressure tank for thorough mixing and neutralization to form a neutral cleaning solution before cleaning. A flow control valve is used to control the mixing of different proportions of acidic and alkaline cleaning solutions at different pH levels, thus improving the cleaning effect. Therefore, this not only improves the cleaning effect but also compensates for and adjusts the pH of the discharge solution after the cleaning solution enters, better ensuring the sustainability of the discharge effect.

[0047] Furthermore, the blower is a hot air blower, which further improves the drying effect.

[0048] In summary, the present invention has the advantages of improving the discharge treatment effect, increasing the processing efficiency, and reducing the impact of the treatment process on subsequent lithium-ion battery processing procedures. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of a lithium-ion battery discharge device used in the implementation of the present invention.

[0050] Figure 2 for Figure 1 A sectional view.

[0051] Figure 3 for Figure 1 Schematic diagram of the three-dimensional structure.

[0052] Figure 4 for Figure 1 A schematic diagram of the structure of a separate discharge box from another direction, after removing the side panel at one end.

[0053] Figure 5 for Figure 2 An enlarged schematic diagram of the local structure at point A alone.

[0054] Figure 6 for Figure 4 An enlarged schematic diagram of the local structure at point B.

[0055] Figure 7 This is a schematic diagram of another lithium-ion battery discharge device used in the implementation of the present invention. Detailed Implementation

[0056] The present invention will now be described in further detail with reference to the accompanying drawings.

[0057] Detailed implementation method: A method for pretreatment of lithium-ion battery recycling and crushing, wherein the lithium-ion battery to be recycled is immersed in a discharge solution for discharge treatment before crushing, characterized in that the lithium-ion battery is cleaned and dried after discharge before crushing and separation.

[0058] This is because, as described in the background section, during the discharge process of lithium-ion batteries, the discharge phenomenon and damage to the battery casing and electrodes can easily cause the originally neutral discharge solution to become alkaline or acidic. In the subsequent crushing and separation process, the residual acidic or alkaline solution can cause agglomeration, affecting the efficiency and effectiveness of the crushing and separation. Therefore, cleaning and drying the lithium-ion battery after discharge treatment before crushing and separation can avoid the influence of residual discharge solution and better improve the efficiency and effectiveness of subsequent crushing and separation.

[0059] During implementation, the pH of the discharge solution is first tested during cleaning, and then the cleaning solution is adjusted to a pH that can neutralize the discharge solution in the discharge box, so that the cleaning solution can neutralize the discharge solution in the discharge box during the cleaning process.

[0060] This process effectively neutralizes and removes charged ions from the battery surface, resulting in a better cleaning effect. Simultaneously, the cleaning solution flows into the discharge solution, neutralizing its pH and restoring balance, allowing the discharge solution to better maintain its discharge performance.

[0061] This method relies on a lithium-ion battery discharge device for implementation, such as... Figure 1-6 As shown, the lithium-ion battery discharge device includes a discharge box 1 located at the bottom, which contains a discharge solution for discharging. A battery holder is also provided inside the discharge box 1. The battery holder is installed in the discharge box 1 in a lifting manner via a lifting mechanism. A cleaning device is also provided above the discharge box 1 to clean and dry the battery after discharge.

[0062] In this way, when the device is working, the battery is first immersed in the discharge solution (salt solution) and placed on the battery holder for discharge treatment. After the discharge is completed for a period of time, the battery holder is controlled to rise out of the liquid surface, and then the cleaning device is controlled to clean and dry it. This washes away the residual discharge solution on the battery surface and completes the drying process, better avoiding the impact of residual discharge solution on subsequent crushing and separation operations.

[0063] The lifting mechanism includes two racks 2 vertically arranged at intervals on the outer sides of both ends of the discharge box. The upper ends of each rack 2 are connected to both ends of the battery holder through a set of fixedly connected horizontal connecting plates 3 located above the discharge box and vertical connecting plates 4 located inside the discharge box. It also includes two gears 5 that mesh with the two racks 2 respectively. The gears 5 are connected to the lifting control motor (not shown in the figure) for transmission.

[0064] In this way, the lifting control motor controls the gear to rotate, which in turn drives the battery holder to move up and down through the rack. This has the advantages of simple structure, smooth movement, and reliable control.

[0065] Among them, the outer side of the rack 2 is surrounded by a baffle 6 with a U-shaped cross-section.

[0066] This arrangement, with the rack positioned inside the baffle, better protects the transmission structure.

[0067] In this device, a limiting sleeve 7 is fixedly installed on the upper inner side of both ends of the discharge box 1, and the vertical connecting plate 4 can slide up and down through the limiting sleeve 7. In this way, the limiting sleeve can be used to limit the upper limit position of the battery placement component.

[0068] The lower surface of the limit sleeve 7 is equipped with a limit switch, which is connected to the control circuit of the lifting control motor. This allows for better automatic control of the lifting operation.

[0069] The battery holder includes a grid plate 8.

[0070] In this way, using a grating plate can achieve rapid liquid leakage, making it easier to clean and dry the liquid after it rises to the surface.

[0071] The discharge box is also equipped with a discharge device, which includes a discharge plate 9 located at the upper end of the side plates on both sides of the discharge box and inclined outward and downward. The upper end of the side plates on both sides of the discharge box is lower than the upper end of the side plates at both ends. The upper end of the discharge plate 9 has a limiting section 10 extending upward into the discharge box.

[0072] In this way, when the battery holder is raised to contact the limiting section of the discharge plate, it is convenient for the discharged lithium battery to be discharged from the discharge material on both sides.

[0073] The discharge device also includes a triangular plate 11 located in the middle of the discharge box and arranged along both ends of the discharge box (the vertical connecting plate and the triangular plate are fixed to connect the lifting mechanism and the battery holder). The triangular plate 11 is fixedly connected to one side of two symmetrical elongated base plates to form a triangle with a convex center. The lower surfaces of both sides of the triangular plate 11 have fixed downward mounting ears. Each mounting ear is rotatably connected to two grid plates 8 on both sides, which are initially horizontal, through a horizontal rotating shaft. The inner ends of the two grid plates 8 are each provided with a rotating rod groove 12 facing each other on both sides. A supporting rotating rod 13 is arranged in the rotating rod groove 12 along the direction of both sides of the discharge box. The connecting end of the supporting rotating rod 13 is mounted on a vertical rotating shaft. Inside the rotating rod groove of the grating plate, a rotating rod torsion spring is also provided between the supporting rotating rod 13 and the vertical rotating shaft. The rotating rod torsion spring keeps the free end of the supporting rotating rod in the rotating rod groove of another grating plate when it is not under force. The discharge device also includes a striking block 14 located at the middle of the upper inner side of the side panel at both ends of the discharge box. The lower surface of the striking block is an impact surface that is inclined outward and downward. There is a space for the striking block to be inserted in the middle between the two grating plates. When the triangular plate 11 and the grating plate 8 move up to the upper end, the impact surface of the striking block 14 can contact the supporting rotating rod and push it to rotate horizontally. When the grating plate moves up to the outer side and contacts or contacts the limiting section of the discharge plate, the striking block 14 can push the free end of the supporting rotating rod out of the rotating rod groove of the grating plate where it is located.

[0074] Initially, the two grid plates are horizontal, and the supporting rotating rods maintain a large load-bearing capacity to accommodate the lithium batteries. After the lithium batteries have discharged in the discharge tank, the lifting mechanism controls the triangular plate to move the grid plates on both sides upward. Before the outer side of the grid plate contacts the limiting section of the discharge plate, the battery is removed from the discharge solution surface, completing the cleaning and drying process. Then, the grid plates continue to move upward. When the outer side of the grid plate is about to contact the limiting section of the discharge plate, the impact surface below the impact block first contacts the supporting rotating rod and pushes it to rotate horizontally. When the grid plate moves upward to the point where the outer side contacts or touches the limiting section of the discharge plate, the impact block can push the free end of the supporting rotating rod out of the rotating rod groove of the grid plate. At this time, the triangular plate continues to move upward, while the grid plates on both sides rotate under their own weight and the limiting section of the discharge plate, changing to a downward tilted state on the outside, until the upper side of the grid plate rotates to contact the lower surface of the triangular plate and can no longer rotate (the structural design of the triangular plate and the mounting lugs limits the rotation angle range of the grid plates). At this point, the grid plates on both sides are tilted, facilitating the downward sliding of the cleaned batteries onto the discharge plate, and then outward and downward from the discharge plate. After all the batteries have slid out, the lifting mechanism drives the triangular plate and grid plates downward until they contact the lower surface of the discharge box. Under the action of the lower surface of the discharge box, the grid plates return to their initial horizontal state. The free end of the supporting rotating rod, under the action of the rotating rod torsion spring, re-enters the rotating rod groove of the corresponding side of the grid plate to provide support force for the next discharge operation. Therefore, this greatly improves the convenience and efficiency of discharge.

[0075] Among them, the tilt angle of the two base plates in the triangular plate 11 is greater than the tilt angle of the discharge plate 9.

[0076] This allows the grating to rotate to a greater tilt angle than the discharge plate during discharge, avoiding dead corners and improving discharge effect and efficiency.

[0077] The vertical connecting plate 4 and the side panels at both ends of the discharge box are vertically fitted with a clearance groove 15 in the middle of their respective sides, and the impact block 14 is located within the clearance groove 15. This design not only better avoids interference and ensures the effectiveness of the impact block, but also protects the impact block and extends its service life.

[0078] In this embodiment, the cleaning device includes a plurality of cleaning nozzles 16 located above the discharge box and facing downwards. The cleaning nozzles 16 are generally tubular and arranged in an array in the horizontal direction. The upper end of the cleaning nozzles is connected to a pressure box 17. An air supply pipe is connected to the pressure box 17 and a blower 18. A liquid inlet pipe 19 is also provided at the end of the pressure box 17. The other end of the liquid inlet pipe is connected to the outlet pipe of the cleaning fluid supply box 20 through a liquid inlet control structure.

[0079] During cleaning, the cleaning solution is first added through the inlet pipe, allowing it to enter the pressure tank. Under the pressure of the blower, it is then sprayed out from the cleaning nozzle to clean the battery. After cleaning, the blower continues to blow air, causing it to be sprayed out from the cleaning nozzle to dry the battery. Therefore, it can simultaneously clean and dry the battery, completing the cleaning work efficiently and conveniently.

[0080] The liquid inlet control structure includes a vertically arranged liquid storage pipe 21 arranged in parallel outside the pressure box. The liquid storage pipe 21 is positioned above the horizontal connecting plate of the lifting mechanism. A piston 22 is installed inside the liquid storage pipe 21. A piston rod 23 is connected to the lower end of the piston 22 via a vertical pipe. The lower end of the piston rod 23 is fixed to the horizontal connecting plate of the lifting mechanism of the battery holder. A horizontal liquid inlet pipe 19 is provided in the upper part of the liquid storage pipe 21 and is connected to the pressure box 17. The lower part of the liquid storage pipe 21 is connected to the outlet pipe of the cleaning fluid supply tank 20 arranged in parallel on the side.

[0081] In this way, after discharge, the cleaning fluid flows from the outlet pipe of the cleaning fluid supply tank into the storage pipe. Then, the lifting mechanism controls the battery holder to move the battery upward, while the piston moves upward in conjunction, pushing the cleaning fluid flowing into the storage pipe into the inlet pipe and then into the pressure tank. Under the pressure in the pressure tank, the cleaning fluid is sprayed from the cleaning nozzle onto the battery surface to clean it. After cleaning, the blower continues to dry the battery by spraying air through the pressure tank and the cleaning nozzle. Therefore, the above structure can achieve linkage control between the liquid inlet cleaning at the top of the equipment and the battery discharge lifting operation at the bottom, thus improving the control effect of battery cleaning.

[0082] Among them, a push rod 24 is provided on the upper end of the piston 22. An arc-shaped sealing pad 25 matching the inner cavity of the liquid storage tube is provided on the side of the push rod 24 facing the end of the pressure box. The sealing pad 25 is larger than the inlet of the liquid inlet pipe of the pressure box and can block the inlet of the liquid inlet pipe 19 when the liquid storage tube is in the liquid inlet state.

[0083] This ensures that the inlet pipe is blocked when liquid is introduced into the storage pipe, preventing the cleaning fluid from entering the pressure tank prematurely. This improves the accuracy of cleaning fluid dispensing control.

[0084] The liquid storage tube 21 has an opening at its upper end and a matching top cover 26, and the upper end of the top rod 24 is fixedly connected to the top cover 26.

[0085] In this way, as the piston moves upward, the top cover is pushed open to the same pressure as atmospheric pressure, ensuring the flow of liquid in the reservoir. After the piston moves downward, the top cover can cover the reservoir to provide protection and prevent dust and other contaminants from falling in.

[0086] Among them, piston 22 is a double-sealed piston, and the distance between the two sealing rings is greater than the diameter of the liquid inlet pipe at the end of the pressure box.

[0087] After the piston moves upward and pushes all the cleaning fluid in the reservoir into the pressure tank, the piston can block the inlet pipe of the pressure tank, ensuring that there is no leakage from the inlet pipe during subsequent air jet cleaning, thus better guaranteeing the cleaning effect.

[0088] The cleaning fluid supply tank is equipped with a cleaning fluid flow control valve 27 on its outlet pipe. This allows for control of the cleaning fluid outflow and flow rate, facilitating better control of the pressure tank's fluid intake.

[0089] The inlet pipe 19, the inlet control structure, and the cleaning fluid supply tank 20 are arranged in two sets and located at both ends of the pressure tank 17 respectively; one cleaning fluid supply tank contains acidic cleaning fluid to form an acidic cleaning fluid control tank, and the other cleaning fluid supply tank contains alkaline cleaning fluid to form an alkaline cleaning fluid control tank; a cleaning fluid flow control valve 27 is installed on the outlet pipe of both cleaning fluid supply tanks; an acid-base detection probe (not shown in the figure) is also installed in the discharge box, and the acid-base detection probe and the cleaning fluid flow control valve are respectively connected to the control center (not shown in the figure).

[0090] This is because, as described in the background section, the applicant discovered that during the discharge process of used lithium batteries, the discharge solution may gradually become acidic or alkaline. Therefore, before cleaning, the pH change of the discharge solution is monitored. If it becomes alkaline, an acidic cleaning solution is used; if it becomes acidic, an alkaline cleaning solution is used. If there is no change (the battery is completely depleted and undamaged, so the discharge solution will not change pH), then a portion of the acidic cleaning solution and a portion of the alkaline cleaning solution can be introduced into a pressure tank for thorough mixing and neutralization to form a neutral cleaning solution before cleaning. A flow control valve is used to control the mixing of different proportions of acidic and alkaline cleaning solutions at different pH levels, thus improving the cleaning effect. Therefore, this not only improves the cleaning effect but also compensates for and adjusts the pH of the discharge solution after the cleaning solution enters, better ensuring the sustainability of the discharge effect.

[0091] Among them, blower 18 is a hot air blower, which better improves the drying effect.

[0092] This method can also be implemented using another lithium-ion battery discharge treatment device. This device differs from the aforementioned lithium-ion battery discharge device only in its cleaning mechanism; the rest of the structure is the same. (See [link to relevant documentation]). Figure 7In this lithium-ion battery discharge treatment device, the cleaning device includes a plurality of cleaning nozzles 31 located above the discharge box and facing downwards. The cleaning nozzles 31 are connected to the corresponding cleaning fluid supply tanks 32. The device also includes a plurality of airflow nozzles 33 located above the discharge box and facing downwards. The airflow nozzles 33 are connected to an air source device 34. The cleaning nozzles and airflow nozzles are installed side by side.

[0093] In this way, after the discharge is completed, the battery is cleaned by the cleaning fluid sprayed from the cleaning nozzle, and then dried by the air jet nozzle. This allows for convenient and quick cleaning of the battery, facilitating subsequent crushing and screening operations.

[0094] The air source device 34 is a heater, which enables the drying process to be completed more quickly.

[0095] The cleaning fluid supply tank 32 includes an acidic cleaning fluid control tank and an alkaline cleaning fluid control tank. Each of the acidic and alkaline cleaning fluid control tanks is connected to a cleaning nozzle via a cleaning fluid flow control valve. The discharge box is also equipped with an acid-base level detection probe. The acid-base level detection probe and the cleaning fluid flow control valve are respectively connected to the control center.

[0096] This is because, as described in the background section, the applicant discovered that during the discharge process of used lithium batteries, the discharge solution may gradually become acidic or alkaline. Therefore, before cleaning, the pH change of the discharge solution is monitored. If it becomes alkaline, an acidic cleaning solution is used; if it becomes acidic, an alkaline cleaning solution is used; if there is no change, a portion of the acidic and alkaline cleaning solutions are neutralized to form a neutral cleaning solution before cleaning. A flow control valve is used to control the mixing of different proportions of acidic and alkaline cleaning solutions at different pH levels, thus improving the cleaning effect. Therefore, this not only improves the cleaning effect but also allows the cleaning solution to adjust its pH after entering the discharge solution, better ensuring the sustainability of the discharge effect.

Claims

1. A method for pre-treatment of lithium-ion batteries before recycling and crushing, wherein the lithium-ion batteries to be recycled are immersed in a discharge solution for discharge treatment before crushing, characterized in that, After discharge, the lithium-ion battery is cleaned and dried before being crushed and separated. During cleaning, the pH of the discharge solution is first tested, and then the cleaning solution is adjusted to a pH that can neutralize it, so that the cleaning solution can neutralize the residual discharge solution on the battery surface during the cleaning process. This method relies on a lithium-ion battery discharge device, which includes a discharge box located at the bottom, containing a discharge solution for discharge, and a battery holder inside the discharge box. The battery holder is installed in the discharge box in a lifting manner via a lifting mechanism. A cleaning device is also provided above the discharge box to clean and dry the battery after discharge. The lifting mechanism includes two racks that are vertically arranged at intervals on the outer sides of both ends of the discharge box. The upper ends of each rack are connected to both ends of the battery holder through a set of fixedly connected horizontal connecting plates located above the discharge box and vertical connecting plates located inside the discharge box. It also includes two gears that mesh with the two racks respectively. The gears are connected to the lifting control motor. The battery holder includes a grid plate; The discharge box is also equipped with a discharge device, which includes a discharge plate located at the upper end of the side plates on both sides of the discharge box and inclined outward and downward. The upper end of the side plates on both sides of the discharge box is lower than the upper end of the side plates at both ends. The upper end of the discharge plate has a limiting section extending upward into the discharge box. The discharge device also includes a triangular plate located in the middle of the discharge box and arranged along both ends of the discharge box. A vertical connecting plate and the triangular plate are fixedly connected to the lifting mechanism and the battery holder. The triangular plate is formed by two symmetrical elongated base plates fixedly connected on one side, creating a triangle with a convex center. The lower surfaces of both sides of the triangular plate have fixed, downward-facing mounting ears. Each mounting ear is rotatably connected to two initially horizontal grid plates via a horizontal rotating shaft. The inner ends of the two grid plates each have a rotating rod groove facing each other on both sides. Supporting rotating rods are arranged in the rotating rod grooves along the direction of both sides of the discharge box. The connecting ends of the supporting rotating rods are mounted on the rotating shaft of one of the grid plates. Inside the rod groove, a torsion spring is also provided between the supporting rotating rod and the vertical rotating shaft. The torsion spring keeps the free end of the supporting rotating rod in the rod groove of another grid plate when it is not under force. The discharge device also includes a striking block located at the middle of the upper inner side of the side panel at both ends of the discharge box. The lower surface of the striking block is an impact surface that is inclined outward and downward. There is a space for the striking block to be inserted in the middle between the two grid plates. When the triangular plate and the grid plate move up to the upper end, the impact surface of the striking block can contact the supporting rotating rod and push it to rotate horizontally. When the grid plate moves up to the outer side and contacts or contacts the limiting section of the discharge plate, the striking block can push the free end of the supporting rotating rod out of the rod groove of the grid plate where it is located.

2. The lithium-ion battery recycling and pre-processing method as described in claim 1, characterized in that, The rack has a U-shaped baffle on its outer side; Limiting sleeves are also fixedly installed on the upper inner sides of both ends of the discharge box, and the vertical connecting plate can slide up and down through the limiting sleeves.

3. The lithium-ion battery recycling and pre-processing method as described in claim 1, characterized in that, The cleaning device includes multiple cleaning nozzles located above the discharge box and facing downwards, each cleaning nozzle being connected to a corresponding cleaning fluid supply tank. It also includes multiple airflow nozzles located above the discharge box and facing downwards, each airflow nozzle being connected to an air source device. The cleaning nozzles and airflow nozzles are installed side by side. The cleaning fluid supply tank includes an acidic cleaning fluid control tank and an alkaline cleaning fluid control tank. Each of the acidic and alkaline cleaning fluid control tanks is connected to a cleaning nozzle via a cleaning fluid flow control valve. The discharge box is also equipped with an acid-base level detection probe. The acid-base level detection probe and the cleaning fluid flow control valve are respectively connected to the control center.

4. The lithium-ion battery recycling and pre-processing method as described in claim 1, characterized in that, The cleaning device includes multiple cleaning nozzles positioned above the discharge box and facing downwards. The cleaning nozzles are tubular in shape and arranged in an array in the horizontal direction. The upper end of the cleaning nozzles is connected to a pressure box, which is connected to an air supply pipe and a blower. The end of the pressure box is also provided with a liquid inlet pipe, the other end of which is connected to the outlet pipe of the cleaning fluid supply box through a liquid inlet control structure.

5. The lithium-ion battery recycling and pre-treatment method as described in claim 4, characterized in that, The liquid inlet control structure includes vertically arranged and parallel liquid storage pipes outside the pressure tank, with the liquid storage pipes positioned directly above the lifting mechanism. A piston is installed inside the liquid storage pipe, with a piston rod connected to the lower end of the piston via a vertical pipe. The lower end of the piston rod is fixed to the lifting mechanism of the battery holder. A horizontal liquid inlet pipe is provided in the upper part of the liquid storage pipe and communicates with the pressure tank. The lower part of the liquid storage pipe is connected to the liquid outlet pipe of the cleaning fluid supply tank arranged parallel to the side. A push rod is installed at the upper end of the piston. An arc-shaped sealing pad that matches the inner cavity of the liquid storage tube is installed on the side of the push rod facing the end of the pressure box. The sealing pad is larger than the inlet of the liquid inlet of the pressure box and can block the inlet of the liquid inlet when the liquid storage tube is in the liquid inlet state. The upper end of the liquid storage tube is open and has a matching top cover, and the upper end of the top rod is fixedly connected to the top cover.

6. The lithium-ion battery recycling and pre-processing method as described in claim 4, characterized in that, The inlet pipe, inlet control structure, and cleaning fluid supply tank are arranged in two sets, located at opposite ends of the pressure tank. One cleaning fluid supply tank contains acidic cleaning fluid, forming an acidic cleaning fluid control tank, while the other contains alkaline cleaning fluid, forming an alkaline cleaning fluid control tank. Cleaning fluid flow control valves are installed on the outlet pipes of both cleaning fluid supply tanks. The discharge box is also equipped with an acid-base level detection probe, and the acid-base level detection probe and the cleaning fluid flow control valve are respectively connected to the control center.

7. The lithium-ion battery recycling and pre-processing method as described in claim 4, characterized in that, The blower is a hot air blower.

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