Recovery Method and Device for Battery Electrode Sheet Powder

Abstract

The present invention relates to a method and device for recycling battery electrode sheet powder materials, which comprises the following steps carried out in sequence: S1, humidifying the powder materials on the surface of the battery electrode sheet to a first set humidity by using a first humidifying medium; S2, performing a first pressurization on the surface of the battery electrode sheet by a first roller under a first preset pressure to enable the first humidifying medium to fully infiltrate the powder materials on the surface of the battery electrode sheet; S3, humidifying the powder materials on the surface of the battery electrode sheet to a second set humidity by using a second humidifying medium; S4, performing a second pressurization on the surface of the battery electrode sheet by a second roller under a second preset pressure to enable the powder materials on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder materials on the surface of the battery electrode sheet from the current collector; S5, removing and collecting the powder materials adhered to the surface of the second roller. The present invention improves the stripping rate of the powder materials on the surface of the battery electrode sheet, and the recycled powder materials have been evaluated by laboratory coin cell testing, and the recycled powder materials have reusability.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a method and device for recycling battery pole piece powder. Background Art

[0002] Lithium-ion batteries have the advantages of long cycle life, high specific energy, stable discharge voltage, small size, and no memory effect. Lithium-ion batteries can be used in portable mobile devices, electric vehicles, power tools and other fields, and have broad development prospects. Lithium-ion battery negative electrode materials (graphite) are an important component of lithium-ion batteries, accounting for about 20-30% of the cost of lithium-ion batteries. The secondary recycling of waste produced during lithium-ion battery production is of great significance, which is not only beneficial to environmental protection, but also more conducive to the recycling of resources. How to improve the stripping rate of battery pole sheet powder and make the recycled battery pole sheet powder reusable is a technical problem that needs to be solved in this field. Summary of the invention

[0003] To this end, the present invention provides a method and a device for recycling battery pole piece powder, which improve the pole piece powder stripping rate and make the recycled battery pole piece powder reusable.

[0004] In order to solve the above technical problems, the present invention provides a method for recycling battery pole piece powder, comprising the following steps performed in sequence:

[0005] S1, using a first humidifying medium to humidify the powder on the surface of the battery electrode to a first set humidity;

[0006] S2, the first roller pressurizes the surface of the battery pole piece once at a first preset pressure, so that the first humidifying medium fully infiltrates the powder on the surface of the battery pole piece and the powder on the surface of the battery pole piece does not stick to the roller;

[0007] S3, using a second humidifying medium to humidify the powder on the surface of the battery electrode to a second set humidity;

[0008] S4, the second roller applies secondary pressure to the surface of the battery electrode sheet at a second preset pressure, so that the powder on the surface of the battery electrode sheet adheres to the second roller, and the powder and the current collector on the surface of the battery electrode sheet are separated;

[0009] S5. The powder adhering to the surface of the second roller is removed and collected.

[0010] Furthermore, one of the first humidifying medium and the second humidifying medium is deionized water, and the other is alcohol.

[0011] Specifically, the first humidifying medium is alcohol and the second humidifying medium is deionized water. First, the surface of the battery electrode is humidified with alcohol, and then the surface of the battery electrode is humidified with deionized water. First, after the alcohol humidifies the battery electrode for the first time, the alcohol can reduce the adhesion strength between the powder material of the battery electrode and the current collector, facilitating the subsequent peeling of the powder material on the battery electrode, and can prevent the pre-rolled battery electrode from wrinkling after humidification (when the battery electrode wrinkles, the contact surface with the second roller decreases, which will affect the peeling rate of the powder material on the battery electrode); second, after the deionized water humidifies the battery electrode for the second time, it can improve the absorption rate of the powder material on the battery electrode surface to the deionized water, further improving the humidifying effect of the deionized water. Third, the alcohol can volatilize subsequently and will not affect the composition of the powder material on the battery electrode surface.

[0012] Specifically, the first humidifying medium is deionized water and the second humidifying medium is alcohol. First, the surface of the battery electrode is humidified with deionized water, and then the surface of the battery electrode is humidified with alcohol. First, after the deionized water humidifies the battery electrode for the first time, the deionized water infiltrates the powder material on the surface of the battery electrode, enabling the powder material on the surface of the battery electrode to be more easily separated from the current collector of the battery electrode, and the deionized water only increases the humidity of the powder material on the surface of the battery electrode and will not affect the composition of the powder material on the surface of the battery electrode; second, after the alcohol humidifies the battery electrode for the second time, the alcohol can reduce the adhesion strength between the powder material of the battery electrode and the current collector, facilitating the subsequent peeling of the powder material on the battery electrode. Third, the alcohol can volatilize subsequently and will not affect the composition of the powder material on the surface of the battery electrode.

[0013] Further, both the first humidifying medium and the second humidifying medium are deionized water. The deionized water infiltrates the powder material on the surface of the battery electrode, enabling the powder material on the surface of the battery electrode to be more easily separated from the current collector of the battery electrode, and the deionized water only increases the humidity of the powder material on the surface of the battery electrode and will not affect the composition of the powder material on the surface of the battery electrode.

[0014] Further, the first roller is tensioned on the surface of the battery electrode to apply a primary pressure to the surface of the battery electrode, and the second roller squeezes the battery electrode to apply a secondary pressure to the surface of the battery electrode. The first roller tensions the battery electrode, and its pressure is relatively small. While fully infiltrating the surface of the battery electrode with the first humidifying medium, it is not easy to have the problem of sticking to the roller; the second roller squeezes the battery electrode, and its pressure is relatively large, making the powder material on the surface of the battery electrode easily stick to the surface of the second roller.

[0015] Further, the battery electrode is a negative electrode. The above recovery method is applicable to the recovery of the powder material of the negative electrode.

[0016] Further, the surface of the battery electrode sheet is humidified by spraying. Humidifying the battery electrode sheet by spraying can more easily control the humidity of the powder on the surface of the battery electrode sheet and more easily maintain the humidity of the powder on the surface of the battery electrode sheet within a set range.

[0017] Further, the powder on the surface of the second roller is scraped off and collected by a scraping method. By scraping off and collecting the powder on the surface of the second roller by a scraping method, the scraping mechanism does not require power and has a simple and reliable structure.

[0018] The present invention also provides a recovery device for battery electrode sheet powder, comprising:

[0019] A working area, including a first humidifying area, a first pressurizing area, a second humidifying area, and a second pressurizing area sequentially arranged between the inlet end and the outlet end of the working area;

[0020] A unwinding mechanism, arranged at the inlet end of the working area, for installing a battery electrode sheet coil and unwinding the battery electrode sheet;

[0021] A first humidifying mechanism, for performing primary humidification on the surface of the battery electrode sheet passing through the first humidifying area;

[0022] A first roller, for tensioning the surface of the battery electrode sheet passing through the first pressurizing area;

[0023] A second humidifying mechanism, for performing secondary humidification on the surface of the battery electrode sheet passing through the second humidifying area;

[0024] A second roller, for extruding the surface of the battery electrode sheet passing through the second pressurizing area;

[0025] A collecting mechanism, for removing and collecting the adhesive substances on the surface of the second roller;

[0026] A winding mechanism, arranged at the outlet end of the working area, for winding the battery electrode sheet unwound by the unwinding mechanism.

[0027] By arranging the unwinding mechanism and the winding mechanism, the battery electrode sheet moves, and the battery electrode sheet sequentially moves to different positions for primary humidification, primary pressurization, secondary humidification, and secondary pressurization, which can not only improve the automation degree of the powder recovery on the surface of the battery electrode sheet, but also improve the efficiency of the powder recovery on the surface of the battery electrode sheet.

[0028] Further, the first humidifying mechanism, the first roller, the second humidifying mechanism, and the second roller are each arranged to correspond to the front and back sides of the battery electrode sheet respectively, and the collecting mechanism is arranged to correspond to the two second rollers respectively. The above-mentioned first humidifying mechanism, the above-mentioned first roller, the above-mentioned second humidifying mechanism, and the above-mentioned second roller are each arranged to correspond to two places on the front and back sides of the battery electrode sheet, and the powder on the front and back sides of the battery electrode sheet can be recycled simultaneously, improving the recycling efficiency of the powder on the surface of the battery electrode sheet.

[0029] Further, both the first humidifying mechanism and the second humidifying mechanism are spray mechanisms. By spraying to humidify the battery electrode sheet, it is easier to control the humidity of the powder on the surface of the battery electrode sheet and keep the humidity of the powder on the surface of the battery electrode sheet within a set range.

[0030] Further, the collecting mechanism is a scraping mechanism. The powder on the surface of the second roller is scraped off and collected by scraping. The scraping mechanism does not require power and has a simple and reliable structure.

[0031] The above technical solution of the present invention has the following advantages compared with the prior art: In the method and device for recycling the powder of the battery electrode sheet of the present invention, before the powder on the surface of the battery electrode sheet is roll-pressed and recycled, the powder on the surface of the battery electrode sheet is humidified once and then humidified twice in sequence, which can make the humidifying medium fully infiltrate the powder on the surface of the battery electrode sheet. Between the first humidification and the second humidification, the battery electrode sheet is pressurized once by the first roller, so that the first humidifying medium fully infiltrates the powder on the surface of the battery electrode sheet and is compacted. The powder on the surface of the battery electrode sheet is not easy to separate from the current collector before entering the second roller. The second humidification further increases the humidity of the powder on the surface of the battery electrode sheet, making it easier to separate from the battery electrode current collector. The battery electrode sheet after the second humidification immediately enters the second roller, thereby improving the stripping rate of the powder on the surface of the battery electrode sheet. The recycled powder has been evaluated by laboratory coin cell testing, and the recycled powder has reusability. Description of the Drawings

[0032] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to the specific embodiments of the present invention in conjunction with the drawings.

[0033] Figure 1 It is a schematic structural diagram of the device for recycling the powder of the battery electrode sheet in the present invention;

[0034] Figure 2 It is a schematic diagram of the battery electrode sheet after the first humidification in Examples 1-4 and Comparative Examples 1 and 2 of the battery electrode sheet in the present invention;

[0035] Figure 3 It is a schematic diagram of the battery electrode sheet after the first humidification in Examples 5 and 6 of the battery electrode sheet in the present invention.

[0036] Description of the reference numerals in the accompanying drawings: 11. First humidification zone; 12. First pressurization zone; 13. Second humidification zone; 14. Second pressurization zone; 2. Battery electrode; 3. First humidification mechanism; 4. First roller; 5. Second humidification mechanism; 6. Second roller; 7. Collection mechanism; 71. Scraping knife; 72. Collection box. Detailed implementation manners

[0037] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the illustrated embodiments are not intended to limit the present invention.

[0038] The method for recycling the powder of the battery electrode provided by the present invention includes the following steps carried out in sequence:

[0039] S1. Humidify the powder on the surface of the battery electrode to a first set humidity with a first humidification medium;

[0040] S2. The first roller pressurizes the surface of the battery electrode once under a first preset pressure, so that the first humidification medium fully infiltrates the powder on the surface of the battery electrode and the powder on the surface of the battery electrode does not stick to the roller;

[0041] S3. Humidify the powder on the surface of the battery electrode to a second set humidity with a second humidification medium;

[0042] S4. The second roller pressurizes the surface of the battery electrode twice under a second preset pressure, so that the powder on the surface of the battery electrode adheres to the second roller, and the powder on the surface of the battery electrode is separated from the current collector;

[0043] S5. The powder adhering to the surface of the second roller is removed and collected.

[0044] The above-mentioned battery electrode generally includes a current collector and an active material (powder). The current collector is used to carry the active material and collect the current. The active material is the main material for the chemical reaction of the battery and is adhered to the current collector through a binder. Therefore, under certain conditions, the active material and the current collector can be separated. The above-mentioned battery electrode can be an unrolled battery electrode or a rolled battery electrode. The above-mentioned unrolled battery electrode means that the battery electrode has not been rolled before the powder recovery. The rolled battery electrode means that the battery electrode has been rolled before the powder recovery.

[0045] The above-mentioned first roller applying pressure to the surface of the battery electrode sheet once means that the first roller applies a certain pressure to the surface of the battery electrode sheet and they are in rolling contact. The pressure of the first roller on the battery electrode sheet and the humidity of the powder on the surface of the battery electrode sheet after the first humidification need to be set within a certain range to ensure that the powder on the surface of the battery electrode sheet after the first humidification does not stick to the first roller. The above-mentioned second roller rolling the surface of the battery electrode sheet means that the second roller applies a certain pressure to the surface of the battery electrode sheet and they are in rolling contact. The pressure of the second roller on the battery electrode sheet and the humidity of the powder on the surface of the battery electrode sheet after the second humidification need to be set within a certain range to ensure that the powder on the surface of the battery electrode sheet after the second humidification can stick to the second roller. In the above steps, the humidity of the first humidification is between 40% - 80%, the humidification time is between 1 - 10S, the first preset pressure is between 5 - 30MPa, the humidity of the second humidification is between 75% - 90%, the humidification time is between 1 - 7S, and the second preset pressure is between 50 - 70MPa.

[0046] The powder of the battery electrode sheet after recovery is stirred again for secondary utilization, and the recovered current collector is recovered at the unit price of the empty foil recovered by the foil supplier.

[0047] Through the above technical solution, before rolling and recovering the powder on the surface of the battery electrode sheet, the powder on the surface of the battery electrode sheet is humidified once and then humidified twice in sequence, which can make the humidification medium fully infiltrate the powder on the surface of the battery electrode sheet. The battery electrode sheet is tensioned between the first humidification and the second humidification, so that the first humidification medium fully infiltrates and compacts the powder on the surface of the battery electrode sheet. The powder on the surface of the battery electrode sheet is not easy to separate from the current collector before entering the second roller. The second humidification further increases the humidity of the powder on the surface of the battery electrode sheet, making it easier to separate from the current collector of the battery electrode sheet. The battery electrode sheet after the second humidification immediately enters the second roller, thereby increasing the stripping rate of the powder on the surface of the battery electrode sheet. The recovered powder is evaluated by laboratory coin cell testing, and the recovered powder has reusability.

[0048] In some preferred embodiments, the above-mentioned first humidification medium and the above-mentioned second humidification medium are both deionized water.

[0049] The above-mentioned deionized water refers to pure water from which impurities in ionic form have been removed. After the deionized water infiltrates the powder on the surface of the battery electrode sheet, it only increases the humidity and does not change the composition of the powder on the surface of the battery electrode sheet, ensuring that the powder on the surface of the recovered battery electrode sheet can be reused again.

[0050] Through the above technical solutions, the powder on the surface of the battery electrode can be very easily separated from the current collector of the battery electrode, and the deionized water only increases the humidity of the powder on the surface of the battery electrode without affecting the composition of the powder on the surface of the battery electrode. For battery electrodes that have not been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased. For battery electrodes that have been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased, but there will be a problem of the electrode wrinkling.

[0051] In some preferred embodiments, the first humidifying medium is alcohol and the second humidifying medium is deionized water.

[0052] The above-mentioned alcohol is a colorless, transparent, volatile, flammable, and non-conductive liquid. It is a good organic solvent and can dissolve the conductive adhesive of the battery electrode.

[0053] Through the above technical solutions, first humidify with alcohol and then with deionized water. First, during the first humidification, alcohol can reduce the bonding strength between the powder of the battery electrode and the current collector, facilitating the subsequent peeling of the powder on the battery electrode, and can prevent the phenomenon of the pre-rolled battery electrode wrinkling after being humidified with deionized water. Second, during the second humidification, it can increase the absorption rate of the powder on the surface of the battery electrode to deionized water, further improving the humidification effect of deionized water. Third, alcohol can volatilize subsequently and does not affect the composition of the powder on the surface of the battery electrode. For battery electrodes that have not been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased. For battery electrodes that have been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased, and there will be no problem of the battery electrode wrinkling.

[0054] In some preferred embodiments, the first humidifying medium is deionized water and the second humidifying medium is alcohol.

[0055] Through the above technical solutions, first humidify with deionized water and then with alcohol. First, during the first humidification, the deionized water wets the powder on the surface of the battery electrode, enabling the powder on the surface of the battery electrode to be more easily separated from the current collector of the battery electrode, and the deionized water only increases the humidity of the powder on the surface of the battery electrode without affecting the composition of the powder on the surface of the battery electrode. Second, during the second humidification, alcohol can reduce the bonding strength between the powder of the battery electrode and the current collector, facilitating the subsequent peeling of the powder on the battery electrode. Third, alcohol can volatilize subsequently and does not affect the composition of the powder on the surface of the battery electrode. For battery electrodes that have not been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased. For battery electrodes that have been pre-rolled, the peeling rate of the powder on the surface of the battery electrode can be increased, but there will be a problem of the battery electrode wrinkling.

[0056] In some preferred embodiments, the first roller is tensioned on the surface of the battery electrode sheet to apply a primary pressure to the surface of the battery electrode sheet, and the second roller squeezes the battery electrode sheet to apply a secondary pressure to the surface of the battery electrode sheet.

[0057] The first roller tensioning the surface of the battery electrode sheet means that there is only one first roller on one side of the battery electrode sheet at the same position, rather than on both sides. When one side of the battery electrode sheet is under pressure, the pressure is not likely to be too large. The second roller squeezing the surface of the battery electrode sheet means that there is a second roller on one side of the battery electrode sheet at the same position and also a second roller or a supporting surface on the other side, so that both sides of the battery electrode sheet are under pressure, and the pressure on the battery electrode sheet can be relatively large.

[0058] Through the above technical solution, the first roller tensions the battery electrode sheet, and its pressure is relatively small. While making the first humidifying medium fully infiltrate the surface of the battery electrode sheet, the problem of sticking rollers is not likely to occur; the second roller squeezes the battery electrode sheet, and its pressure is relatively large, making the powder on the surface of the battery electrode sheet easily stick to the surface of the second roller.

[0059] In other embodiments, it can be: achieving the purpose of preventing the powder on the surface of the battery electrode sheet from sticking to the first roller and sticking to the second roller through other means.

[0060] In some preferred embodiments, the above battery electrode sheet is a negative electrode sheet.

[0061] In actual production, it is found that when the battery electrode sheet is a negative electrode sheet, the stripping rate of the anode material is relatively high.

[0062] In other embodiments, it can also be: the above battery electrode sheet is a positive electrode sheet.

[0063] In some preferred embodiments, the surface of the battery electrode sheet is humidified by spraying.

[0064] Spraying is artificial fog making. Simply put, a high-pressure system sprays liquid in extremely fine water droplets onto the surface of the battery electrode sheet.

[0065] Through the above technical solution, humidifying the battery electrode sheet by spraying can more easily control the humidity of the powder on the surface of the battery electrode sheet and more easily keep the humidity of the powder on the surface of the battery electrode sheet within the set range.

[0066] In other embodiments, it can also be humidifying the surface of the battery electrode sheet by infiltration, such as the battery electrode sheet passing through a container containing a humidifying medium.

[0067] In some preferred embodiments, the powder on the surface of the second roller is scraped off and collected by scraping.

[0068] Scraping the powder on the surface of the second roller means using a scraping tool with a sharp edge to adhere to the surface of the second roller, and moving the scraping tool or the second roller to remove the powder adhering to the second roller.

[0069] Through the above technical solution, the powder on the surface of the second roller is scraped off and collected by scraping. The scraping mechanism does not need to move, so no power is required, and the structure is simple and reliable.

[0070] In other embodiments, it can also be: sucking and collecting the powder on the surface of the second roller by negative pressure.

[0071] In some preferred embodiments, the above recovery method is implemented by using a recovery device for battery electrode sheet powder. Refer to Figure 1 the structural schematic diagram of an embodiment of a recovery device for battery electrode sheet powder provided by the present invention as shown.

[0072] The above recovery device for battery electrode sheet powder includes:

[0073] A working area, including a first humidifying area 11, a first pressurizing area 12, a second humidifying area 13, and a second pressurizing area 14 that are sequentially arranged between the inlet end and the outlet end of the above working area;

[0074] A unwinding mechanism (not shown in the figure), which is arranged at the inlet end of the above working area and is used to install a battery electrode sheet coil and unwind the battery electrode sheet 2;

[0075] A first humidifying mechanism 3, which is used to perform primary humidification on the surface of the battery electrode sheet passing through the above first humidifying area 11;

[0076] A first roller 4, which is used to tension the surface of the battery electrode sheet 2 passing through the above first pressurizing area 12;

[0077] A second humidifying mechanism 5, which is used to perform secondary humidification on the surface of the battery electrode sheet 2 passing through the above second humidifying area 13;

[0078] A second roller 6, which is used to roll-press the surface of the battery electrode sheet 2 passing through the above second pressurizing area 14;

[0079] A collecting mechanism 7, which is used to remove and collect the adhesive substances on the surface of the above second roller 6;

[0080] A winding mechanism (not shown in the figure), which is arranged at the outlet end of the above working area and is used to wind the battery electrode sheet 2 unwound by the above unwinding mechanism.

[0081] The winding mechanism drives the battery pole piece 2 to sequentially pass through the first humidification zone 11, the first pressurization zone 12, the second humidification zone 13 and the second pressurization zone 14. The movement directions of the surfaces of the first roller 4 and the second roller 6 in contact with the battery pole piece 2 are consistent with the movement direction of the battery pole piece 2. Generally speaking, the movement of the battery pole piece 2 drives the first roller 4 to rotate, and the second roller 6 can be provided with a power device to drive it to rotate, and the second roller 6 and the battery pole piece 2 move synchronously.

[0082] Specifically, when the above-mentioned battery pole piece powder recovery device is used, first collect the defective rolled pole pieces of the manufacturing process (coating-rolling-die-cutting) or the pole rolls that need to be scrapped due to batch scratches, dark marks, and bubbles in the coating process; then install the rolled pole piece on the unwinding mechanism, and perform the corresponding threading belt, so that the free end of the outermost layer of the rolled pole piece is pulled through the first humidification zone, the first pressurizing zone, the second humidification zone, and the second pressurizing zone in turn to reach and be fixed on the winding mechanism, and the winding mechanism, the first humidification mechanism, the second humidification mechanism, and the second roller are opened at the same time, so that the powder on the surface of the battery pole piece can be automatically recovered. Finally, the powder is transferred to the second roller for recovery, and the current collector is wound on the winding mechanism for recovery.

[0083] Through the above technical solution, the automation of powder recovery on the surface of battery pole pieces is achieved.

[0084] In some preferred embodiments, the first humidifying mechanism 3, the first roller 4, the second humidifying mechanism 5 and the second roller 6 are each configured to correspond to the front and back sides of the battery electrode 2 respectively, and the collecting mechanism 7 is configured to correspond to the two second rollers respectively.

[0085] The current collector of the battery pole piece 2 includes a front side and a back side, and the current collector has the above-mentioned powder on both the front side and the back side. The two first humidifying mechanisms 3 humidify the powder on the front side and the back side of the battery pole piece 2 respectively. The two first rollers 4 are in contact with the front side and the back side of the battery pole piece 2 respectively. The two first rollers 4 are staggered, that is, they will not clamp the battery pole piece. The two second humidifying mechanisms 5 humidify the powder on the front side and the back side of the battery pole piece 2 respectively. The two second rollers are in contact with the front side and the back side of the battery pole piece 2 respectively. The two second rollers 6 clamp the battery pole piece 2.

[0086] Through the above technical solution, the powder on the front and back sides of the battery pole piece can be recovered at the same time, thereby improving the recovery efficiency of the powder on the surface of the battery pole piece.

[0087] In other embodiments, the first humidifying mechanism, the first roller, the second humidifying mechanism and the second roller are each arranged at a location corresponding to only one of the front side and the back side of the battery electrode.

[0088] In some preferred embodiments, the above-mentioned first humidifying mechanism 3 and the above-mentioned second humidifying mechanism 5 are both spray mechanisms.

[0089] The above-mentioned spray mechanism includes one or more nozzles that face the surface of the battery electrode sheet 2 and spray a humidifying medium onto the surface of the battery electrode sheet 2. Spraying is artificial fog-making. Simply put, it is a high-pressure system that sprays liquid in extremely fine water droplets.

[0090] Through the above technical solution, humidifying the battery electrode sheet by spraying can more easily control the humidity of the powder on the surface of the battery electrode sheet and more easily maintain the humidity of the powder on the surface of the battery electrode sheet within a set range.

[0091] In other embodiments, the above-mentioned first humidifying mechanism and second humidifying mechanism are containers filled with a humidifying medium, and the battery electrode sheet moves through the container when moving, so as to be humidified.

[0092] In some preferred embodiments, the above-mentioned collecting mechanism 7 is a scraping mechanism. The scraping mechanism includes a scraper 71 and a collecting box 72. The positions of the scraper 71 and the collecting box 72 remain unchanged. When the second roller 6 rotates, on the one hand, it causes the powder of the battery electrode sheet 2 to be transferred to the surface of the second roller 6, and on the other hand, it causes the powder on the surface of the second roller 6 to be scraped off by the scraper 71 and fall into the collecting box 72. Scraping the powder on the surface of the battery electrode sheet on the surface of the above-mentioned second roller 6 by scraping means using a scraping tool with a sharp edge to stick to the surface of the second roller to remove the powder on the surface of the battery electrode sheet attached to the second roller 6.

[0093] Through the above technical solution, the scraping mechanism does not need to move, so it does not need power, and the structure is simple and reliable.

[0094] In other embodiments, it may also be that: the above-mentioned collecting mechanism is a negative pressure collecting mechanism.

[0095] Embodiment 1

[0096] The method for recycling the powder of the battery electrode sheet includes the following steps:

[0097] S1. The powder on the surface of the battery electrode sheet that has not been pre-rolled is humidified to 50% by alcohol atomization;

[0098] S2. The first roller applies a primary pressure to the surface of the battery electrode sheet at a pressure of 10 MPa to make the alcohol fully infiltrate the powder on the surface of the battery electrode sheet;

[0099] S3. The powder on the surface of the battery electrode sheet is humidified to 90% by deionized water atomization;

[0100] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 60 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0101] S5. The powder adhered to the surface of the second roller is removed and collected.

[0102] Example 2

[0103] The method for recovering the powder of the battery electrode sheet includes the following steps:

[0104] S1. The powder on the surface of the battery electrode sheet without pre-rolling is humidified with deionized water to 50%;

[0105] S2. The first roller applies primary pressure to the surface of the battery electrode sheet at a pressure of 10 MPa, enabling the deionized water to fully infiltrate the powder on the surface of the battery electrode sheet;

[0106] S3. The powder on the surface of the battery electrode sheet is humidified with deionized water to 90%;

[0107] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 65 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0108] S5. The powder adhered to the surface of the second roller is removed and collected.

[0109] Example 3

[0110] The method for recovering the powder of the battery electrode sheet includes the following steps:

[0111] S1. The powder on the surface of the battery electrode sheet without pre-rolling is humidified with deionized water to 50%;

[0112] S2. The first roller applies primary pressure to the surface of the battery electrode sheet at a pressure of 10 MPa, enabling the deionized water to fully infiltrate the powder on the surface of the battery electrode sheet;

[0113] S3. The powder on the surface of the battery electrode sheet is humidified with alcohol to 90%;

[0114] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 60 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0115] S5. The powder adhered to the surface of the second roller is removed and collected.

[0116] Example 4

[0117] The method for recovering the powder of the battery electrode sheet includes the following steps:

[0118] S1. The powder on the surface of the pre-rolled battery electrode sheet is humidified with alcohol to 50%.

[0119] S2. The first roller presses the surface of the battery electrode sheet at a pressure of 10 MPa to fully infiltrate the powder on the surface of the battery electrode sheet with alcohol.

[0120] S3. The powder on the surface of the battery electrode sheet is humidified with deionized water to 90%.

[0121] S4. The second roller presses the surface of the battery electrode sheet at a pressure of 60 MPa for secondary pressing, so that the powder on the surface of the battery electrode sheet adheres to the second roller, and the powder on the surface of the battery electrode sheet is separated from the current collector.

[0122] S5. The powder adhered to the surface of the second roller is removed and collected.

[0123] Example 5

[0124] The method for recovering the powder of the battery electrode sheet includes the following steps:

[0125] S1. The powder on the surface of the pre-rolled battery electrode sheet is humidified with deionized water to 50%.

[0126] S2. The first roller presses the surface of the battery electrode sheet at a pressure of 10 MPa to fully infiltrate the powder on the surface of the battery electrode sheet with deionized water.

[0127] S3. The powder on the surface of the battery electrode sheet is humidified with deionized water to 90%.

[0128] S4. The second roller presses the surface of the battery electrode sheet at a pressure of 60 MPa for secondary pressing, so that the powder on the surface of the battery electrode sheet adheres to the second roller, and the powder on the surface of the battery electrode sheet is separated from the current collector.

[0129] S5. The powder adhered to the surface of the second roller is removed and collected.

[0130] Example 6

[0131] The method for recovering the powder of the battery electrode sheet includes the following steps:

[0132] S1. The powder on the surface of the pre-rolled battery electrode sheet is humidified with deionized water to 50%.

[0133] S2. The first roller presses the surface of the battery electrode sheet at a pressure of 10 MPa to fully infiltrate the powder on the surface of the battery electrode sheet with deionized water.

[0134] S3. The powder on the surface of the battery electrode sheet is humidified with alcohol to 90%.

[0135] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 60 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0136] S5. The powder adhered to the surface of the second roller is removed and collected.

[0137] Comparative Example 1

[0138] S1. The powder on the surface of the battery electrode sheet without pre-rolling is humidified with alcohol to 50%;

[0139] S2. The first roller applies primary pressure to the surface of the battery electrode sheet at a pressure of 10 MPa, causing the alcohol to fully infiltrate the powder on the surface of the battery electrode sheet;

[0140] S3. The powder on the surface of the battery electrode sheet is humidified with alcohol to 90%;

[0141] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 60 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0142] S5. The powder adhered to the surface of the second roller is removed and collected.

[0143] Comparative Example 2

[0144] S1. The powder on the surface of the pre-rolled battery electrode sheet is humidified with alcohol to 50%, and the humidification time is 1 minute;

[0145] S2. The first roller applies primary pressure to the surface of the battery electrode sheet at a pressure of 10 MPa, causing the alcohol to fully infiltrate the powder on the surface of the battery electrode sheet;

[0146] S3. The powder on the surface of the battery electrode sheet is humidified with alcohol to 90%;

[0147] S4. The second roller applies secondary pressure to the surface of the battery electrode sheet at a pressure of 60 MPa, causing the powder on the surface of the battery electrode sheet to adhere to the second roller, and separating the powder on the surface of the battery electrode sheet from the current collector;

[0148] S5. The powder adhered to the surface of the second roller is removed and collected.

[0149] The following table lists the situations of whether the battery electrode sheet wrinkles after the first humidification and whether the powder on the battery electrode sheet is easily peeled off in each example and comparative example.

[0150]

[0151]

[0152] It can be seen that for the battery electrode sheet without pre-rolling, both the first humidifying medium and the second humidifying medium are deionized water, or the first humidifying medium and the second humidifying medium are deionized water and alcohol respectively, or the first humidifying medium and the second humidifying medium are alcohol and deionized water respectively. After one-time humidification, the battery electrode sheet will not wrinkle, and the powder on the battery electrode sheet is easy to peel off. When both the first humidifying medium and the second humidifying medium are alcohol, the battery electrode sheet will not wrinkle after one-time humidification, but the powder on the battery electrode sheet is not easy to peel off. For the pre-rolled battery electrode sheet, when the first humidifying medium and the second humidifying medium are alcohol and deionized water respectively, the battery electrode sheet will not wrinkle after one-time humidification, and the powder on the battery electrode sheet is easy to peel off. When both the first humidifying medium and the second humidifying medium are deionized water, or the first humidifying medium and the second humidifying medium are deionized water and alcohol respectively, the battery electrode sheet will wrinkle after one-time humidification, but the powder on the battery electrode sheet is easy to be peeled off. When both the first humidifying medium and the second humidifying medium are alcohol, the battery electrode sheet will not wrinkle after one-time humidification, but the powder on the battery electrode sheet is not easy to peel off.

[0153] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A method for recycling battery electrode sheet powder materials, characterized in that, The battery electrode is a pre-rolled battery electrode, and the recycling method includes the following steps carried out in sequence: S1. Humidify the powder on the surface of the battery electrode to a first set humidity with a first humidifying medium; S2. The first roller presses the surface of the battery electrode under a first preset pressure to fully infiltrate the powder on the surface of the battery electrode with the first humidifying medium and the powder on the surface of the battery electrode does not stick to the roller; S3. Humidify the powder on the surface of the battery electrode to a second set humidity with a second humidifying medium; S4. The second roller presses the surface of the battery electrode under a second preset pressure to make the powder of the battery electrode adhere to the second roller, and the powder on the surface of the battery electrode is separated from the current collector; S5. The powder adhered to the surface of the second roller is removed and collected; Wherein, the first humidifying medium is alcohol and the second humidifying medium is deionized water.

2. The recovery method of the battery electrode sheet powder according to claim 1, wherein, The first roller is tensioned on the surface of the battery electrode to perform a first pressing on the surface of the battery electrode, and the second roller squeezes the battery electrode to perform a second pressing on the surface of the battery electrode.

3. The recovery method of the battery electrode sheet powder according to claim 1, wherein, Humidify the surface of the battery electrode by spraying.

4. The recovery method of the battery electrode sheet powder material according to claim 1, characterized in that Scrape and collect the powder on the surface of the second roller by scraping.

5. The recovery method of the battery electrode sheet powder according to claim 1, wherein, Use a recycling device to recycle the powder. The recycling device includes: A working area, including a first humidifying area, a first pressing area, a second humidifying area, and a second pressing area sequentially arranged between the inlet end and the outlet end of the working area; A unwinding mechanism, arranged at the inlet end of the working area, for installing a battery electrode coil and unwinding the battery electrode; A first humidifying mechanism for performing a first humidification on the surface of the battery electrode passing through the first humidifying area; A first roller for tensioning the surface of the battery electrode passing through the first pressing area; A second humidifying mechanism for performing a second humidification on the surface of the battery electrode passing through the second humidifying area; A second roller for squeezing the surface of the battery electrode passing through the second pressing area; A collecting mechanism for removing and collecting the adhesive substances on the surface of the second roller; A winding mechanism, arranged at the outlet end of the working area, for winding the battery electrode unwound by the unwinding mechanism.

6. The recovery method of the battery electrode sheet powder according to claim 5, characterized in that, The first humidifying mechanism, the first roller, the second humidifying mechanism, and the second roller are each arranged to correspond to the front and back of the battery electrode respectively, and the collecting mechanism is arranged to correspond to the two second rollers respectively.

7. The recovery method of the battery electrode sheet powder material according to claim 5, characterized in that, Both the first humidifying mechanism and the second humidifying mechanism are spraying mechanisms.

8. The recovery method of the battery electrode sheet powder material according to claim 5, characterized in that, The collecting mechanism is a scraping mechanism.

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