Whole-flow recovery process of waste power battery

Abstract

The invention provides a full-flow recovery process of a waste power battery, and relates to the technical field of battery recovery, and the full-flow recovery process comprises the following steps: S1, a disassembling stage: splitting a shell and disassembling a fastener by using an electric wrench with the torque of 2-5N. M and the rotating speed of 230-500RPM, and disassembling and recovering a battery pack by matching with an insulating clamp; in the disassembling process, humidity and ultraviolet ray control is implemented, the protective clothing and the eye protection mask are arranged, and the dual effects of personnel safety and environment cleanness are achieved; by means of vacuum constant-temperature injection of the polymer and the bionic cell expansion principle, fine stripping of the binder is achieved, and the metal electrode structure is preserved to the maximum extent; and through low-pressure ultrasonic cavitation and high-frequency magnetic pulse treatment, the removal efficiency of the binder on the surfaces of the metal particles is further improved, and the material loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of battery recycling, and in particular to a full-process recycling process for used power batteries. Background Art

[0002] The technical field of battery recycling mainly involves the recycling of various used or retired batteries to achieve the recycling of resources and avoid environmental pollution and waste of resources.

[0003] However, in the existing technology during battery recycling, the extraction of metals generally relies on the dissolution method using traditional strong acid-base corrosive chemical reagents during the treatment process, which not only causes environmental pollution but also easily generates toxic waste liquid, seriously affecting ecological safety; at the same time, there is a lack of effective technical means in the material separation link, and conventional sorting methods are difficult to achieve high purity, with impurity residues, affecting the quality of recycled materials. Therefore, improvements are needed. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a full-process recycling process for used power batteries.

[0005] To achieve the above purpose, the present invention adopts the following technical solution: A full-process recycling process for used power batteries, including the following steps: S1, Disassembly stage: Use an electric wrench with a torque in the range of 2 - 5 N·m and a rotational speed in the range of 230 - 500 RPM to perform shell opening and fastener removal, and cooperate with insulating pliers to disassemble and recycle the battery pack; Wear corrosion-resistant protective clothing and goggle masks, control the indoor humidity not higher than 50%, and use ultraviolet light to disinfect the workbench; During the disassembly process, isolate the sensors and cables from the module, centrally store each component and label the metal shell, electronic control board, and wire assembly; By separating the plastic shell and insulating washer, sort out the accessories that can be reused again to obtain the disassembled components; S2, Polymer injection: Place the disassembled components in a constant-temperature vacuum chamber, use a pressure maintained in the range of -0.08 MPa to -0.1 MPa, and introduce self-peeling polymer; Adjust the operating temperature in the range of 35 - 45 °C, control the polymer flow rate in the range of 0.5 - 1.0 L / min, and maintain the stirring speed at 150 - 300 RPM; Monitor the coverage of the polymer on the surface of the electrode sheet through a visual flow meter to obtain the injected battery components; S3, Bionic peeling: Draw on the mechanism of plant cell layer division for the injected battery components, allow the contained polymer to slowly expand within 45 - 60 minutes to promote the breakage of the binder; Control the internal humidity in the range of 60 - 70%, simulate the internal moisture environment of biological cells, and maintain the site temperature in the range of 20 - 25 °C; Use an optical microscope to monitor the degree of stripping of the metal active material; At the end, remove the excess moisture through a drying oven to obtain self-peeling electrodes.

[0006] Preferably, it further includes: S4, low-pressure ultrasonic cavitation, performing low-pressure ultrasonic cavitation treatment on the self-peeling electrode, maintaining the reaction environment pressure in the range of 0.08 - 0.12 MPa, and using an ultrasonic frequency of 20 - 40 kHz; when using the cavitation effect to destroy the residual bonding interface, setting the operating water temperature in the range of 25 - 35 °C, the soaking duration of 45 - 60 minutes, and using a polyvinylidene fluoride permeable container to carry the electrode material to obtain cavitation products; S5, high-frequency magnetic pulse, applying a high-frequency magnetic pulse device to the cavitation products, controlling the frequency in the range of 50 - 80 Hz, maintaining the duration of each group of pulses at 0.2 - 0.5 seconds, and applying an alternating magnetic field with a strength of 0.1 - 0.3 T at the excitation coil; metal particles generate micro-vibrations during the pulse period, prompting the residual binder to detach; using an optoelectronic sensor to record the vibration amplitude, and removing agglomerated particles larger than 3 mm through a screening process to obtain the material before magnetic vibration separation; S6, preparation for magnetic levitation separation, adding magnetic particles to the material before magnetic vibration separation, the magnetic particles are formed by the ratio of Fe3O4 powder, CoFe2O4 powder, SiO2, and the ratio is 3:1:1:0.2; using a planetary ball mill to mix at 300 - 400 RPM for 20 - 30 minutes; preparing a magnetic levitation tank with a magnetic field strength of 0.2 - 0.5 T, and setting the angle of the stirring paddle in the range of 30 - 45 degrees to obtain the magnetic levitation raw material; S7, magnetic levitation separation, applying a horizontal magnetic field of 0.2 - 0.5 T to the magnetic levitation raw material, promoting the stratification of the electrode material through the difference in directional force generated by magnetic particles and metal components; setting the liquid viscosity in the tank body in the range of 1.2 - 1.5 mPa·s, maintaining the temperature at 25 - 30 °C, and cooperating with a stirrer with a rotation speed of 100 - 200 RPM to interfere with the flow field; the lower layer is enriched with metal microparticles, and the upper layer retains non-metallic impurities. Different layers are separated by a siphon, and the metal concentrate and light residues are collected to obtain the separated electrode material; S8, preparation for biological leaching, pre-treating the separated electrode material and adding a microbial culture medium; adding a mixed bacterial solution of Bacillus subtilis and Penicillium, the ratio of the bacterial solution is 1:1, and the total bacterial concentration is maintained at 1×10^7 CFU / mL; stirring conditions are 200 - 300 RPM, temperature is 30 - 35 °C, and time is 6 - 8 hours to obtain the material before biological leaching.

[0007] Preferably, it further includes: S9, Green bioleaching. Maintain an aeration rate of 0.2 - 0.5 vvm in the bioleaching feedstock before leaching, and maintain a fermentation process for 30 - 50 hours. Organic acids are produced by microbial metabolism to dissolve metals; monitor the pH in the range of 4.0 - 5.0, stabilize the acidity regularly, and use a rotary shaker to control the mixing intensity at 150 - 250 RPM; track and detect the metal ion concentration by atomic absorption spectrometer, terminate and filter when the leaching efficiency exceeds 80% to obtain the leaching product; S10, Safe treatment. Use a weak base neutralizer for the leaching product; adjust the pH to the range of 7.0 - 7.5 during operation, and add 0.01 - 0.03 wt% of an environmentally friendly antibacterial agent, which is a compound of benzalkonium chloride, chlorhexidine, and polyhexamethylene guanidine in a ratio of 1:1:1; stir well for 15 - 25 minutes and then perform solid-liquid separation to obtain a safe neutralized product; S11, Deep sorting. Separate the cathode material, anode material, electrolyte residue, and separator fiber in the safe neutralized product; select a cyclone separator to handle solid impurities with a particle size greater than 50 µm, and remove fine particles smaller than 10 µm; use a magnetic separator to separate the graphite anode from metal residues, and use a gravity settling tank to separate the electrolyte and separator fiber; collect each part through different flow channel outlets to obtain sorted materials.

[0008] Preferably, it further includes: S12, Material recovery. Transfer the sorted materials to a recovery reactor, and extract lithium, cobalt, and nickel metal components through leaching and precipitation methods; first dissolve lithium salts with ammonia leaching solution, and then dissolve cobalt salts and nickel salts with ammonium sulfate solution; in the precipitation stage, use saturated sodium carbonate solution to control the pH in the range of 8.5 - 9.0, and recover and purify metal salts by centrifugal separation, and obtain reusable raw materials after drying.

[0009] Preferably, in step S2, the self-peeling polymer is composed of polyvinyl alcohol, butyl acrylate, lignin fiber, and chloroprene latex, with a ratio of 2:1:0.5:1.

[0010] Preferably, in step S8, the microbial culture medium is prepared from 10 g / L of glucose, 5 g / L of peptone, 5 g / L of yeast extract, 0.5 g / L of anhydrous potassium dihydrogen phosphate, and 0.2 g / L of magnesium sulfate, and the pH is controlled in the range of 6.5 - 7.0.

[0011] Preferably, in step S10, the weak base neutralizer is composed of sodium hydroxide powder, sodium carbonate powder, calcium hydroxide powder, and sodium citrate, with a ratio of 2:1:0.5:0.2.

[0012] Preferably, in step S12, the ammonia leaching solution is composed of ammonia water, ammonium chloride, sodium citrate, and distilled water, with a ratio of 1:1:0.5:5.

[0013] Compared with the prior art, during the disassembly process of the present invention, humidity and ultraviolet control are implemented, and protective clothing and goggles are equipped to achieve the dual effects of personnel safety and environmental cleanliness; through the vacuum and constant-temperature injection of polymers and the use of the principle of bionic cell expansion, fine peeling of the binder is achieved, and the metal electrode structure is preserved to the greatest extent; through low-pressure ultrasonic cavitation and high-frequency magnetic pulse treatment, the removal efficiency of the binder on the surface of metal particles is further improved, and material loss is reduced; with the help of magnetic levitation technology and special magnetic particles, separation of metal materials and impurities is achieved, and the purity of materials is improved; at the same time, a bioleaching technology is adopted, using the metabolic action of microorganisms to replace traditional strong acid and strong base treatment, realizing green and efficient extraction of metal ions; through refined and safe neutralization treatment, harmful substances in the recycled materials are completely eliminated, and the risk of secondary pollution is controlled; in the deep sorting stage, fine separation of particle size and physical properties is implemented to improve the sorting accuracy and recover various valuable components to the greatest extent; targeted leaching and precipitation treatment is adopted to recover high-value metals such as lithium, cobalt, and nickel, and the quality and reuse value of the recycled materials are improved.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Brief Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a preparation step diagram of a full-process recycling process for waste power batteries proposed by the present invention. Specific Embodiments

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0018] Embodiment 1, a full-process recycling process for waste power batteries, includes the following steps: S1, Disassembly stage: Use an electric wrench with a torque in the range of 5 N·m and a rotational speed of 500 RPM to perform shell dissection and fastener removal, and cooperate with insulating pliers to disassemble and recycle the battery pack; Wear corrosion-resistant protective clothing and safety goggles, control the indoor humidity not higher than 50%, and disinfect the workbench with ultraviolet light; During the disassembly process, isolate the sensors and cables from the modules, centrally store each component and label the metal shell, electronic control board and wire assembly; By separating the plastic shell and insulating washer, sort out the accessories that can be reused again to obtain disassembled components; S2, Polymer injection: Place the disassembled components in a constant-temperature vacuum chamber, keep the pressure at -0.08 MPa, and introduce self-peeling polymer; Adjust the operating temperature to 45 °C, control the polymer flow rate at 1.0 L / min, and maintain the stirring speed at 300 RPM; Monitor the coverage of the polymer on the surface of the electrode sheet through a visual flowmeter to obtain the injected battery components; S3, Bionic peeling: Draw on the mechanism of plant cell layer division for the injected battery components, let the contained polymer slowly expand within 45 minutes to cause the binder to break; Control the internal humidity within the range of 70%, simulate the internal moisture environment of biological cells, and maintain the site temperature within the range of 25 °C; Use an optical microscope to monitor the degree of stripping of the metal active material; At the end, remove the excess moisture through a drying oven to obtain self-peeled electrodes.

[0019] S4, Low-pressure ultrasonic cavitation: Perform low-pressure ultrasonic cavitation treatment on the self-peeled electrodes, keep the reaction environment pressure at 0.08 MPa, and use an ultrasonic frequency of 40 kHz; Use the cavitation effect to destroy the residual bonding interface; Set the operating water temperature at 25 °C, soak for 60 minutes, and use polyvinylidene fluoride through the container to carry the electrode material to obtain cavitation products; S5, High-frequency magnetic pulse: Apply a high-frequency magnetic pulse device to the cavitation products, control the frequency at 80 Hz, keep the duration of each pulse at 0.2 seconds, and apply an alternating magnetic field with a strength of 0.3 T at the excitation coil; The metal particles generate micro-vibrations during the pulse period to promote the detachment of the residual binder; Use an optoelectronic sensor to record the vibration amplitude, and remove the agglomerated particles larger than 3 mm through the screening process to obtain the material before magnetic vibration separation; S6, Preparation for magnetic levitation separation: Add magnetic particles to the material before magnetic vibration separation. The magnetic particles are formed by the ratio of Fe3O4 powder, CoFe2O4 powder, SiO2, and the ratio is 3:1:1:0.2; Use a planetary ball mill to mix at 400 RPM for 30 minutes; Prepare a magnetic levitation tank with a magnetic field strength of 0.5 T, and set the angle of the stirring paddle at 45 degrees to obtain magnetic levitation raw materials; S7, Magnetic levitation separation: Apply a horizontal magnetic field of 0.5 T to the magnetic levitation raw material. Due to the directional force difference between magnetic particles and metal components, it promotes the stratification of the electrode material. Set the liquid viscosity in the tank at 1.5 mPa·s, maintain the temperature at 30 °C, and cooperate with a stirrer rotating at 200 RPM to interfere with the flow field. The lower layer is enriched with metal particles, and the upper layer retains non-metallic impurities. Different layers are separated by a siphon, and the metal concentrate and light residue are collected to obtain the separated electrode material. S8, Biological leaching preparation: Pretreat the separated electrode material and add a microbial culture medium. Add a mixed bacterial solution of Bacillus subtilis and Penicillium, with a bacterial solution ratio of 1:1 and a total bacterial concentration maintained at 1×10^7 CFU / mL. Stirring conditions are 300 RPM, temperature is 35 °C, and the time is 8 hours to obtain the material before biological leaching.

[0020] S9, Green biological leaching: Maintain an aeration rate of 0.5 vvm in the material before biological leaching and maintain a fermentation process for 50 hours. Microbial metabolism produces organic acids to dissolve metals. Monitor the pH in the range of 5.0, regularly stabilize the acidity, and use a rotary shaker to control the mixing intensity at 250 RPM. The metal ion concentration is tracked and detected by an atomic absorption spectrometer. When the leaching efficiency exceeds 80%, terminate and filter to obtain the leaching product. S10, Safety treatment: Use a weak base neutralizer for the leaching product. During operation, adjust the pH to the range of 7.0 and add 0.03 wt% of an environmentally friendly bacteriostatic agent, which is a compound of benzalkonium chloride, chlorhexidine, and polyhexamethyleneguanidine in a ratio of 1:1:1. After fully stirring for 25 minutes, perform solid-liquid separation to obtain a safely neutralized product. S11, Deep sorting: Separate the positive electrode material, negative electrode material, electrolyte residue, and separator fiber in the safely neutralized product. Select a cyclone separator to process solid impurities with a particle size greater than 50 µm and remove fine particles smaller than 10 µm. A magnetic separator separates the graphite negative electrode and metal residue, and a gravity settling tank separates the electrolyte and separator fiber. Each part is collected through different flow channel outlets to obtain sorted materials.

[0021] S12, Material recovery: Transfer the sorted materials to a recovery reactor and extract lithium, cobalt, and nickel metal components through leaching and precipitation methods. First, use ammonia leaching solution to dissolve lithium salts, and then use ammonium sulfate solution to dissolve cobalt salts and nickel salts. During the precipitation stage, use saturated sodium carbonate solution to control the pH in the range of 9.0, and recover and purify metal salts through centrifugal separation. After drying, obtain reusable raw materials.

[0022] In this embodiment, in step S2, the self-peeling polymer is composed of polyvinyl alcohol, butyl acrylate, lignin fiber, and chloroprene latex, with a ratio of 2:1:0.5:1.

[0023] In this embodiment, in step S8, the microbial culture medium is composed of 10 g / L glucose, 5 g / L peptone, 5 g / L yeast extract, 0.5 g / L anhydrous potassium dihydrogen phosphate and 0.2 g / L magnesium sulfate, and the pH is controlled at 6.5.

[0024] In this embodiment, in step S10, the weak base neutralizer is composed of sodium hydroxide powder, sodium carbonate powder, calcium hydroxide powder and sodium citrate in a ratio of 2:1:0.5:0.2.

[0025] In this embodiment, in step S12, the ammonia leaching solution is a mixture of ammonia water, ammonium chloride, sodium citrate and distilled water in a ratio of 1:1:0.5:5.

[0026] Embodiment 2, which is different from Embodiment 1, is a full-process recycling process for waste power batteries, comprising the following steps: S1, disassembly stage, use an electric wrench with a torque of 5N·m and a speed of 500RPM to cut open the shell and remove the fasteners, and use insulating pliers to disassemble and recycle the battery pack; use corrosion-resistant protective clothing and goggles, control the indoor humidity to no more than 50%, and use ultraviolet light to disinfect the workbench; during the disassembly process, isolate the sensor, cable and module, store the components in a centralized manner, and mark the metal shell, electronic control board and wire assembly; by separating the plastic shell and insulating gasket, sort out the accessories that can be put into use again to obtain the disassembled parts; S2, polymer injection, the disassembled parts are placed in a constant temperature vacuum chamber, the pressure is maintained at -0.1MPa, and the self-stripping polymer is introduced; the operating temperature is adjusted at 45°C, the polymer flow rate is controlled at 0.6L / min, and the stirring speed is maintained at 300RPM; the coverage of the polymer on the electrode surface is monitored by a visual flow meter to obtain the injected battery assembly; S3, bionic stripping, draws on the layer division mechanism of plant cells to inject into the battery components, allowing the contained polymer to slowly expand within 45 minutes, causing the binder to break; the internal humidity is controlled within the 70% range to simulate the internal moisture environment of biological cells, and the site temperature is maintained at 45°C; an optical microscope is used to monitor the degree of stripping of metal active substances; at the end, excess moisture is removed through a drying oven to obtain a self-stripping electrode.

[0027] S4, low-pressure ultrasonic cavitation, low-pressure ultrasonic cavitation treatment is performed on the self-stripping electrode, the reaction environment pressure is maintained at 0.08MPa, and an ultrasonic frequency of 40kHz is used; the cavitation effect is used to destroy the residual bonding interface; the operating water temperature is set at 25°C, the immersion time is 60 minutes, and polyvinylidene fluoride is used to pass through the container to carry the electrode material to obtain the cavitation product; S5, High-frequency magnetic pulse. Apply a high-frequency magnetic pulse device to the cavitation products, control the frequency at 60 Hz, keep the duration of each group of pulses at 0.5 seconds, and apply an alternating magnetic field with an intensity of 0.3 T at the excitation coil; the metal particles generate micro-vibrations during the pulse period to promote the detachment of the residual binder; use an optoelectronic sensor to record the vibration amplitude, and remove the agglomerated particles larger than 3 mm through the screening process to obtain the material before magnetic vibration separation; S6, Preparation for magnetic levitation separation. Add magnetic particles to the material before magnetic vibration separation. The magnetic particles are formed by the mixture of Fe3O4 powder, CoFe2O4 powder, SiO2 and a certain ratio, and the ratio is 3:1:1:0.2; use a planetary ball mill to mix at 400 RPM for 30 minutes; prepare a magnetic levitation tank with a magnetic field intensity of 0.5 T, and set the angle of the stirring paddle at 45 degrees to obtain the magnetic levitation raw material; S7, Magnetic levitation separation. Apply a horizontal magnetic field of 0.5 T to the magnetic levitation raw material. Through the difference in the directional force generated by the magnetic particles and the metal components, promote the stratification of the electrode material; set the liquid viscosity in the tank at 1.5 mPa·s, keep the temperature at 30 °C, and cooperate with a stirrer with a rotation speed of 200 RPM to interfere with the flow field; the lower layer is enriched with metal particles, and the upper layer retains non-metal impurities. Take different layers through a siphon, and collect the metal concentrate and the light residue to obtain the separated electrode material; S8, Preparation for biological leaching. Pretreat the separated electrode material and add a microbial culture medium; put in a mixed bacterial solution of Bacillus subtilis and Penicillium, and the ratio of the bacterial solution is 1:1, and the total bacterial concentration is maintained at 1×10^7 CFU / mL; the stirring condition is 300 RPM, the temperature is 35 °C, and the time is 8 hours to obtain the material before biological leaching.

[0028] S9, Green biological leaching. Keep the aeration rate at 0.5 vvm in the material before biological leaching, maintain a fermentation process for 50 hours, and the microorganisms metabolize to produce organic acids to dissolve metals; monitor the pH in the range of 5.0, stabilize the acidity regularly, and use a rotary shaker to control the mixing intensity at 250 RPM; the metal ion concentration is tracked and detected by an atomic absorption spectrometer, and the leaching is terminated and filtered when the leaching efficiency exceeds 80% to obtain the leaching product; S10, Safety treatment. Use a weak base neutralizer for the leaching product; adjust the pH to the range of 7.0 during operation, and add 0.03 wt% of an environmentally friendly antibacterial agent. The environmentally friendly antibacterial agent is compounded by benzalkonium chloride, chlorhexidine and polyhexamethylene guanidine, and the ratio is 1:1:1; stir well for 25 minutes and then carry out solid-liquid separation to obtain the safety neutralized product; S11. Deep sorting: Separate the cathode material, anode material, electrolyte residue, and separator fiber within the safety neutralization product. Use a cyclone separator to process solid impurities with a particle size greater than 50 µm and remove fine particles smaller than 10 µm. Use a magnetic separator to separate the graphite anode from metal residues, and use a gravity settling tank to separate the electrolyte from the separator fiber. Collect each part through different flow channel outlets to obtain sorted materials.

[0029] S12. Material recovery: Transfer the sorted materials to a recovery reactor, and extract lithium, cobalt, and nickel metal components through leaching and precipitation methods. First, use ammonia leaching solution to dissolve lithium salts, and then use ammonium sulfate solution to dissolve cobalt salts and nickel salts. During the precipitation stage, use saturated sodium carbonate solution to adjust the pH within the range of 9.0, and recover and purify metal salts through centrifugal separation. After drying, obtain reusable raw materials.

[0030] Experimental method: Method for measuring metal recovery rate: The metal recovery rate mainly measures the percentage of the actual recovered amount of metal components (such as lithium, cobalt, nickel, etc.) in the total recoverable metal in the initially disassembled battery during the entire power battery recycling process. For accurate measurement, it is first necessary to quantitatively analyze the total metal content in the used power battery in advance. The specific operation is as follows: Before disassembly, select a representative sample of used batteries, and use high-temperature roasting-acid dissolution method or inductively coupled plasma atomic emission spectrometry (ICP-AES) to conduct a reference test on the content of each metal component in the sample and file the records. Subsequently, after completing the entire recycling process, weigh and analyze the content of the finally obtained metal product. A ten-thousandth balance is required during the weighing process, and the recovered metal needs to be pre-dried to ensure that moisture and other impurities do not interfere with the weight data. ICP-AES or atomic absorption spectrometry (AAS) can be continued to be used to quantitatively analyze the metal content respectively. The metal recovery rate is calculated by the ratio of the measured metal mass to the metal mass contained in the original battery. Multiple details need to be noted during the test: First, each batch of tests must be repeated at least three times, and the average value is taken and the standard deviation is calculated to determine the stability of the recovery rate; Second, the analysis of the recovered product should be completed in the same batch or under the same environmental conditions to reduce the impact of environmental humidity and temperature on the sample quality; Third, record the process losses at each stage. If there are abnormal fluctuations, they should be checked in time. Factors such as solvent evaporation, impurity residue, and poor separation efficiency during the process will cause deviations in the final recovery rate results. Finally, perform statistical analysis on all data, and if necessary, calculate the confidence interval to compare the differences between different recycling processes (such as the comparative process, Example 1 and Example 2 of the present invention), so as to obtain the comparison results of the metal recovery rate.

[0031] Method for determining residual binder content: The residual binder content is the percentage of the remaining binder (such as polyvinylidene fluoride, styrene-butadiene rubber, etc.) in the active material of the battery electrode in the total mass of the recycled electrode powder or metal particles. To accurately determine the residual binder content, strict pretreatment and detection steps are required. Specifically, first, select about 1-2 grams of representative samples from the recycled products and conduct constant-temperature drying to eliminate the interference caused by moisture and other volatile components. Subsequently, use the high-temperature pyrolysis-mass loss method or thermogravimetric analysis (TGA) method to test the samples: heat up in a high-temperature furnace at a set rate (such as 5-10°C / min) and record the mass change curve of the samples in different temperature ranges; for common battery binders, obvious pyrolysis or decomposition usually occurs in the temperature range of 300-500°C, and the binder content can be determined according to the mass loss in this temperature range. If there are multiple organic binders in the system, Fourier transform infrared spectroscopy (FTIR) or simultaneous thermal analysis (STA) techniques can also be combined to further confirm the decomposition peak positions and decomposition characteristics of different binders. During the test, it is necessary to note referring to the baseline of the blank crucible and calibrating the temperature measurement system to ensure the accuracy of temperature control and mass measurement. After the test is completed, the proportion of the residual binder content can be calculated based on the mass difference caused by the pyrolysis of the binder in the sample. In addition, during the experiment, it should be considered that fillers, active substances, metal matrices, etc. may also have mass changes at different temperatures, so blank controls or the addition of standard binders with known contents are required for calibration. Finally, compare the results with the original electrodes or samples of different processes to judge the efficiency of this recycling method in removing the binder, thereby reflecting the control level of different recycling processes on binder residues.

[0032] Method for detecting the purity of recycled metal: The purity of recycled metal mainly refers to the proportion of the target metal element in all components in the finally separated metal powder or metal salt. To determine this purity, the recycled metal sample needs to be fully pretreated and then its composition is confirmed through chemical analysis or instrumental analysis. The specific operations are as follows: First step, weigh a certain amount (such as 0.5 g - 1.0 g) of the recycled metal powder or dried metal salt and place it in a clean container; if it is a metal salt, it can be first dissolved in an acid solution with an appropriate concentration (such as hydrochloric acid or nitric acid) to completely dissolve the sample; if it is a metal powder, steps such as pickling, dissolving, and filtering out impurities need to be considered first. Second step, adopt multi-element analysis means, such as inductively coupled plasma atomic emission spectrometry (ICP-AES) or inductively coupled plasma mass spectrometry (ICP-MS), to quantitatively detect the concentration of the target metal (Li, Co, Ni, etc.) in the sample solution, and at the same time detect the impurity elements (such as Fe, Cu, Al, etc.). Third step, combining the total mass of the sample weighed before dissolution and the mass fractions of each element measured by ICP after dissolution, the percentage content of the target metal relative to all components can be calculated. To ensure the credibility of the results, parallel sample detections need to be carried out at least three times, and a reference material (SRM) is used to verify the accuracy and precision of the method. If there are multiple target metals (such as Co, Ni, Mn, etc.), their purities can be measured separately and then comprehensively calculated. The testing personnel should pay attention to avoiding cross-contamination. For example, when using reagent bottles and pipette tips made of different materials, they should be cleaned and blank-determined one by one. Finally, compare and calculate the content of each impurity with the content of the target metal to form the result of the purity of the recycled metal, and compare it with national or industry standards (if any) to evaluate the purity level achieved by the recycling process; it can also be used for intuitive data comparison between different embodiments and comparative examples of the present invention to judge the degree of purity improvement of the recycled metal.

[0033] Bioleaching Efficiency Test Method: The bioleaching efficiency mainly evaluates the leaching effect of metals in the recycled electrode materials by microorganisms such as Bacillus subtilis and Penicillium during the fermentation growth process through the production of organic acids, enzymatic actions, etc. First, it is necessary to prepare a bio - medium with a unified specification and strictly control the culture conditions such as the concentration of the bacterial solution and the aeration rate. This experiment is generally divided into a pre - culture stage and a formal leaching stage: In the pre - culture stage, the mixed bacterial solution (containing Bacillus subtilis and Penicillium) is inoculated into a 250 mL culture flask and incubated at a constant temperature with shaking for 12 - 24 hours to reach the logarithmic growth phase; then in the formal leaching stage, the pre - treated electrode materials (after removing most of the binder and impurities) are added to a reactor or a shaking flask containing the fermentation medium, maintaining the shaking speed (such as 150 - 250 RPM) and a temperature of 30 - 35 °C, and the aeration rate is controlled at 0.2 - 0.5 vvm (aeration volume / volume / minute), so that the microorganisms can react fully within a certain time (such as 30 - 50 hours). Samples are taken regularly during the process (such as every 6 - 8 hours), and the supernatant is separated by filtration or centrifugation, and the concentration of metal ions in the supernatant is detected by atomic absorption spectroscopy (AAS) or ICP - AES. The concentration of metal ions measured each time is compared with the theoretical metal content in the electrode materials before the experiment, and the bioleaching efficiency is obtained after accumulation. When the leaching efficiency exceeds the established target (such as 80%) and the subsequent growth tends to slow down, the leaching can be regarded as completed. Finally, the growth curve of the metal leaching concentration at multiple time points is statistically analyzed to determine the optimal leaching time and efficiency value. After the test, a weak base neutralizer can be used to adjust the pH to ensure biosafety, and the measured results are compared with the comparative examples to confirm the superiority of the present invention in the bioleaching process.

[0034] Environmental Safety Index Evaluation Method: The environmental safety index is a multi-dimensional scoring system set to comprehensively evaluate the environmental impact of the entire recycling process. It can be scored from aspects such as wastewater treatment effect, waste gas emission compliance rate, recyclability of solid residues, and the level of hazardous chemical use, and finally summarized into a comprehensive evaluation value. First, a systematic evaluation index needs to be established in the experiment, including: ① Wastewater discharge detection: Collect the waste liquid or cleaning liquid during the recycling process, detect conventional indicators such as heavy metal ion concentration, pH, COD, and BOD, and compare and score them with relevant environmental protection standards or enterprise internal control standards; ② Waste gas emission detection: If organic solvents or other volatile components are released during the recycling process, VOCs determination of the emissions is required, and the compliance situation is evaluated in combination with on-site protection measures (such as activated carbon adsorption, condensation recovery); ③ Solid residue disposal: including plastic shells, diaphragm fibers, waste brackets, and excess binder residues generated after disassembly, etc., count their reuse or recycling rates, and harmlessly treat the parts that cannot be reused; ④ Chemical reagent usage and hazard: such as extractants, acids and bases, etc., comprehensively score them in combination with the usage amount, safety level, and protection requirements. Finally, the scores of each sub-index are summarized to form a total score (for example, 0-100), which is the environmental safety index. During the operation of this method, it is necessary to ensure that the detection equipment and detection means meet the requirements of metrological certification. For example, the sampling of wastewater, waste gas, and solid waste is carried out in accordance with the environmental protection department or relevant industry standards. At the same time, factors that potentially affect the experimental environment and personnel health need to be recorded. Once high-risk or excessive phenomena are found, preventive measures should be taken in a timely manner. By making a horizontal comparison of the final scores with the comparative examples, the improvement of the present invention in terms of environmental safety can be more intuitively demonstrated.

[0035] Processing efficiency test method: Processing efficiency refers to the amount of waste power batteries that can be recycled per unit time (e.g., kg / h or batches / day). In actual tests, the entire process of disassembly and recycling needs to be continuously operated for a period of time (such as one week or one month), and then the average efficiency index is calculated based on the total number of batteries processed and the net working hours during this period. The specific steps are as follows: First, prepare an experimental line or pilot line that conforms to the recycling process of the present invention, ensuring that it includes all links such as disassembly, polymer injection, bionic peeling, low-pressure ultrasonic cavitation, high-frequency magnetic pulse, magnetic levitation separation, biological leaching, and final material sorting and recycling; Second, confirm in advance that the equipment operating status and parameter settings of each sub-link are within the normal range. For example, torque, rotational speed, temperature, vacuum degree, magnetic field strength, etc. are all set according to a fixed setting; Third, continuously feed the same type or mixed type of waste power batteries during the test period, while recording the total weight or quantity of the batteries fed during this period, and counting the total effective working hours of the equipment operation; Fourth, divide the total processing volume (kg or batches) by the total effective working hours (h) to obtain the processing efficiency value. After the experiment, it is necessary to analyze the key factors affecting efficiency, such as disassembly speed, peeling efficiency, separation speed, and microbial cultivation time, and make a horizontal comparison with the efficiency index obtained by the comparative process under the same conditions. Abnormal downtime such as equipment failure shutdown or special operation debugging should be excluded during the test to make the efficiency data more objective and comparable. In addition, during the recycling efficiency test, the processing beats of each step can also be recorded in segments to facilitate subsequent optimization of the bottleneck links. After comprehensive analysis, the advantages of the processing efficiency of the process of the present invention can be obtained.

[0036] Experiments were conducted on the finished materials prepared in Examples 1-2. Among them, Comparative Example 1 was the full-process recycling process of waste power batteries disclosed in Patent Publication No. CN117317428A. The experimental results are as follows: Table 1 Performance test data Performance indicators Comparative example 1 Example 1 Example 2 Metal recovery rate (%) 76.2 90.1 91.3 Residual binder content (%) 3.2 1.5 1.3 Recycled metal purity (%) 95.6 98.1 98.5 Bioleaching efficiency (%) 68.9 80.4 82.7 Environmental safety index (comprehensive score) 75 88 90 Treatment efficiency (kg / h) 35 48 52 As can be seen from Table 1, Examples 1-2 have higher metal recycling efficiency, lower residual binder content, and better biological leaching performance compared to Comparative Example 1. Moreover, multiple indicators such as the purity of recycled metals, environmental safety, and overall processing efficiency are significantly better than the prior art, and it is suitable for large-scale promotion and application. Generally speaking, the present invention not only improves the resource utilization rate but also reduces the environmental impact of the recycling process, showing good industrial prospects and economic benefits.

Claims

1. A full-process recycling process for waste power batteries, characterized in that, The following steps are involved: S1, disassembly stage, use an electric wrench with a torque of 2-5N·m and a speed of 230-500RPM to cut open the shell and remove the fasteners, and use insulated pliers to disassemble and recover the battery pack; use corrosion-resistant protective clothing and goggles, control the indoor humidity to no more than 50%, and use ultraviolet light to disinfect the workbench; during the disassembly process, isolate the sensor, cable and module, store the components in a centralized manner, and mark the metal shell, electronic control board and wire assembly; By separating the plastic shell and insulating gasket, the accessories that can be put into use again are sorted out to obtain the disassembled parts; S2, polymer injection, placing the disassembled parts in a constant temperature vacuum chamber, maintaining the pressure in the range of -0.08MPa to -0.1MPa, and introducing a self-stripping polymer; adjusting the operating temperature in the range of 35-45°C, controlling the polymer flow rate in the range of 0.5-1.0L / min, and maintaining the stirring speed at 150-300RPM; monitoring the coverage of the polymer on the surface of the electrode sheet by a visual flow meter to obtain an injected battery component; S3, bionic stripping, refers to the layer division mechanism of plant cells for reference in the injected battery assembly, allowing the contained polymer to slowly expand within 45-60 minutes to cause the binder to break; the internal humidity is controlled in the range of 60-70% to simulate the internal moisture environment of biological cells, and the site temperature is maintained in the range of 20-25°C; an optical microscope is used to monitor the degree of stripping of the metal active substance; at the end, excess moisture is removed through a drying oven to obtain a self-stripping electrode.

2. The full-process recycling process of waste power batteries according to claim 1, wherein Also includes: S4, low-pressure ultrasonic cavitation, performing low-pressure ultrasonic cavitation treatment on the self-stripping electrode, maintaining the reaction environment pressure in the range of 0.08-0.12 MPa, and using an ultrasonic frequency of 20-40 kHz; using the cavitation effect to destroy the residual bonding interface; the operating water temperature is set in the range of 25-35°C, the soaking time is 45-60 minutes, and polyvinylidene fluoride is used to pass through the container to carry the electrode material to obtain a cavitation product; S5, high-frequency magnetic pulse, applying high-frequency magnetic pulse equipment to the cavitation product, the frequency is controlled in the range of 50-80Hz, the duration of each group of pulses is maintained at 0.2-0.5 seconds, and an alternating magnetic field with an intensity of 0.1-0.3T is applied to the excitation coil; the metal particles generate micro-vibration during the pulse period, which promotes the separation of residual binder; the vibration amplitude is recorded by a photoelectric sensor, and the agglomerated particles larger than 3mm are removed through the screening process to obtain the pre-magnetic vibration separation material; S6, preparation for magnetic suspension separation, adding magnetic particles to the material before magnetic vibration separation, the magnetic particles are formed by Fe3O4 powder, CoFe2O4 powder and SiO2 in a ratio of 3:1:1:0.2; using a planetary ball mill to mix at 300-400RPM for 20-30 minutes; Prepare a magnetic suspension tank with a magnetic field strength of 0.2-0.5T, set the stirring blade angle in the range of 30-45 degrees, and obtain a magnetic suspension raw material; S7, Magnetic levitation separation: Apply a horizontal magnetic field of 0.2 - 0.5 T to the magnetic levitation raw material. Due to the directional force difference between magnetic particles and metal components, promote the stratification of the electrode material. Set the liquid viscosity in the tank within the range of 1.2 - 1.5 mPa·s, maintain the temperature at 25 - 30 °C, and cooperate with a stirrer with a rotation speed of 100 - 200 RPM to interfere with the flow field. The lower layer is enriched with metal particles, and the upper layer retains non-metallic impurities. Take different layers through a siphon, and collect the metal concentrate and light residue to obtain the separated electrode material. S8, Biological leaching preparation: Pretreat the separated electrode material and add a microbial culture medium. Add a mixed bacterial solution of Bacillus subtilis and Penicillium, with a bacterial solution ratio of 1:1, and maintain the total bacterial concentration at 1×10^7 CFU / mL. Stirring conditions are 200 - 300 RPM, temperature is 30 - 35 °C, and time is 6 - 8 hours to obtain the pre-biological leaching material.

3. The full-process recycling process of waste power batteries according to claim 2, characterized in that, It also includes: S9, Green biological leaching: Maintain an aeration rate of 0.2 - 0.5 vvm in the pre-biological leaching material, and maintain a fermentation process for 30 - 50 hours. Microbial metabolism produces organic acids to dissolve metals. Monitor the pH in the range of 4.0 - 5.0, regularly stabilize the acidity, and use a rotary shaker to control the mixing intensity at 150 - 250 RPM. The metal ion concentration is tracked and detected by an atomic absorption spectrometer. When the leaching efficiency exceeds 80%, terminate and filter to obtain the leaching product. S10, Safety treatment: Use a weak base neutralizer for the leaching product. During operation, adjust the pH to the range of 7.0 - 7.5, and add 0.01 - 0.03 wt% of an environmentally friendly bacteriostatic agent. The environmentally friendly bacteriostatic agent is compounded by benzalkonium chloride, chlorhexidine, and polyhexamethylene guanidine in a ratio of 1:1:

1. After fully stirring for 15 - 25 minutes, perform solid-liquid separation to obtain the safe neutralized product. S11, Deep sorting: Separate the positive electrode material, negative electrode material, electrolyte residue, and separator fiber in the safe neutralized product. Select a cyclone separator to process solid impurities with a particle size greater than 50 µm, and remove fine particles smaller than 10 µm. The magnetic separator separates the graphite negative electrode and metal residue, and the gravity settling tank separates the electrolyte and separator fiber. Each part is collected through different flow channel outlets to obtain the sorted materials.

4. The full-process recycling process of waste power batteries according to claim 3, characterized in that, It also includes: S12, Material recovery: Transfer the sorted materials to a recovery reaction kettle, and extract lithium, cobalt, and nickel metal components through leaching and precipitation methods. First, use ammonia leaching solution to dissolve lithium salts, and then use ammonium sulfate solution to dissolve cobalt salts and nickel salts. During the precipitation stage, use saturated sodium carbonate solution to control the pH in the range of 8.5 - 9.0, and recover and purify metal salts through centrifugal separation. After drying, obtain reusable raw materials.

5. The full-process recycling process of waste power batteries according to claim 1, characterized in that: In step S2, the self-peeling polymer is composed of polyvinyl alcohol, butyl acrylate, lignin fiber, and chloroprene latex, with a ratio of 2:1:0.5:

1.

6. The full-process recycling process of waste power batteries according to claim 2, characterized in that: In step S8, the microbial culture medium is prepared from 10 g / L of glucose, 5 g / L of peptone, 5 g / L of yeast extract, 0.5 g / L of anhydrous potassium dihydrogen phosphate, and 0.2 g / L of magnesium sulfate, and the pH is controlled in the range of 6.5 - 7.

0.

7. The full-process recycling process of waste power batteries according to claim 3, characterized in that: In step S10, the weak base neutralizing agent consists of sodium hydroxide powder, sodium carbonate powder, calcium hydroxide powder and sodium citrate, and the ratio is 2:1:0.5:0.

2.

8. The full-process recycling process of waste power batteries according to claim 4, characterized in that: In step S12, the ammonia leaching solution is made by mixing ammonia water, ammonium chloride, sodium citrate and distilled water, and the ratio is 1:1:0.5:5.

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