CN-122025900-A - Advanced purification and activation pretreatment method and system for waste lithium ion battery anode material

CN122025900ACN 122025900 ACN122025900 ACN 122025900ACN-122025900-A

Abstract

The invention discloses a deep purification and activation pretreatment method for a waste lithium ion battery anode material, which comprises the following steps of S1, plasma assisted friction charge and surface modification, S2, electric-magnetic-flow multi-field coupling precise separation, S3, integrated vortex shaping-cladding-classification and S4, on-line detection and cooperative regulation, wherein compared with the prior art, the method realizes high-efficiency separation and quality improvement of the waste lithium ion battery anode material.

Inventors

LU PENG
Fan Kaixing
LI LIAN
HUANG YAOYAO
LI YONGQIANG
BAI JINWU
Wen Mingji
Shen Langmeng

Assignees

重庆工商大学

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (8)

1. The advanced purification and activation pretreatment method for the anode material of the waste lithium ion battery is characterized by comprising the following steps of: Step S1, placing waste ternary battery black powder and PTFE grinding media in a sealed friction charging unit according to a volume ratio of 1:0.5-1.5, introducing inert gas, starting a dielectric barrier discharge plasma generator, generating low-temperature plasma under the conditions of air pressure of 0.1-0.5 atm and discharge power of 50-500W, and simultaneously starting a stirring device, and running for 60-120S at a stirring rotating speed of 1500-2000 rpm; S2, conveying the powder processed in the step S1 into a multi-field coupling separation unit to separate an anode material enrichment phase and an impurity phase, wherein a parallel electrode plate, a permanent magnet array and a transverse airflow device are arranged in the multi-field coupling separation unit, the electrode plate is applied with voltage of 25-45 kV, the permanent magnet array generates gradient magnetic field of 0.1-0.5T, and the transverse airflow speed is 5-15 m/S; S3, sending the positive electrode material enrichment phase obtained in the step S2 into an integrated vortex shaping-cladding-classifying unit for separation and shaping, wherein the tangential inlet wind speed of the integrated vortex shaping-cladding-classifying unit is 18-25 m/S, a rotary grinding disc with the rotating speed of 500-2000 rpm is arranged at the bottom of the integrated vortex shaping-cladding-classifying unit, and a gas-phase cladding agent is introduced into the integrated vortex shaping-cladding-classifying unit by taking inert gas as a carrier, and the concentration of the gas-phase cladding agent is 0.1-5 vol%; And S4, detecting C, al, cu, F element content and surface functional group information in the finished product in real time by using an LIBS on-line analyzer, and inputting detection data into a cooperative controller, wherein the cooperative controller synchronously adjusts the plasma discharge power and the stirring rotating speed in the step S1, the electric field intensity and the magnetic field intensity in the step S2, the rotating speed of a grinding disc and the concentration of a coating agent in the step S3 according to a preset cooperative regulation strategy, so that the C content in the finished product is less than or equal to 0.5wt%, the Al content is less than or equal to 0.1wt%, the Cu content is less than or equal to 0.05wt%, the F content is less than or equal to 0.1wt%, the sphericity is more than or equal to 0.85, and the surface residual alkali content is less than or equal to 0.1 wt%.
2. The method for advanced purification and activation pretreatment of waste lithium ion battery anode materials according to claim 1, wherein the PTFE grinding medium is spherical or special-shaped, and the special-shaped is plum blossom-shaped, polyhedral or grooved sphere.
3. The method for deeply purifying and activating the anode material of the waste lithium ion battery according to claim 1, wherein the dielectric barrier discharge plasma generator adopts a double-dielectric-layer structure, the discharge gap is 1-5 mm, and the working gas is nitrogen or argon.
4. The method for advanced purification and activation pretreatment of waste lithium ion battery anode materials according to claim 1, wherein the permanent magnet array is of a Halbach array structure.
5. The method for advanced purification and activation pretreatment of waste lithium ion battery anode materials according to claim 1, wherein the transverse airflow device is arranged perpendicular to the parallel electrode plates, and the included angle between the airflow direction and the electric field direction is 60-120 degrees.
6. The method for advanced purification and activation pretreatment of waste lithium ion battery anode materials according to claim 1, wherein radial grooves or concave-convex textures are arranged on the surface of the rotary grinding disc, and a gap between the grinding disc and the inner wall of a cone section of a cyclone of the integrated vortex shaping-cladding-classifying unit is 1-10 mm.
7. The advanced purification and activation pretreatment method for the waste lithium ion battery anode material according to claim 1, wherein the gas phase coating agent is one or more selected from silane coupling agents, titanate coupling agents and aluminate coupling agents, nitrogen or argon is used as a carrier, and the concentration of the gas phase coating agent is 0.5-3 vol%.
8. A pretreatment system for deep purification and activation of a waste lithium ion battery cathode material, for implementing the pretreatment method for deep purification and activation of a waste lithium ion battery cathode material according to any one of claims 1 to 7, comprising: the plasma auxiliary friction charging unit is internally provided with a PTFE grinding medium and is provided with a dielectric barrier discharge plasma generator, a nitrogen protection system and a variable-frequency speed-regulating stirring device; The electric-magnetic-flow multi-field coupling separation unit is characterized in that a material input port of the electric-magnetic-flow multi-field coupling separation unit is connected with a material output port of the plasma auxiliary friction charging unit, a parallel electrode plate, a Halbach permanent magnet array and a transverse air flow device are arranged in the electric-magnetic-flow multi-field coupling separation unit, and an alternating high-voltage direct current power supply and a magnetic field adjusting device are connected; An integrated vortex shaping-cladding-classifying unit, wherein a material input port of the integrated vortex shaping-cladding-classifying unit is connected with a positive electrode material enrichment phase output port of the electric-magnetic-flow multi-field coupling separating unit, and the integrated vortex shaping-cladding-classifying unit is provided with a material output port A tangential feeding structure is adopted, and a spiral guide plate, an adjustable center overflow pipe, a bottom rotary grinding disc and a gas phase coating agent injection device are arranged in the tangential feeding structure; The on-line detection and cooperative regulation and control unit comprises a LIBS detection module, an acoustic emission sensor and a deep reinforcement learning controller, wherein the LIBS detection module is arranged at a finished product output port of the integrated vortex shaping-cladding-classifying unit, a signal input end of the deep reinforcement learning controller is respectively and electrically connected with the LIBS detection module and the acoustic emission sensor, and a control signal output end of the deep reinforcement learning controller is respectively connected with a dielectric barrier discharge plasma generator, a variable-frequency speed regulation stirring device, an alternating high-voltage direct-current power supply, a magnetic field regulation device, a bottom rotary grinding disc and a gas-phase cladding agent injection device.

Description

Advanced purification and activation pretreatment method and system for waste lithium ion battery anode material Technical Field The invention relates to the technical field of waste battery treatment, in particular to a method and a system for advanced purification and activation pretreatment of a waste lithium ion battery anode material. Background With the rapid development of the new energy automobile industry, the number of retired lithium ion batteries is increased in an explosive manner. The ternary positive electrode material is rich in high-value metals such as nickel, cobalt, manganese, lithium and the like, and the efficient recovery of the ternary positive electrode material has important significance for resource recycling and environmental protection. The existing waste lithium ion battery anode material recovery technology is mainly divided into three types: hydrometallurgy, namely extracting valuable metals through acid leaching, extraction and other working procedures, but has the problems of long flow, large discharge amount of waste water and waste acid, high cost and the like; Pyrometallurgy, which is to remove impurities by high-temperature roasting, but has high energy consumption, difficult treatment of fluorine-containing waste gas and larger loss of valuable metals; The physical separation method realizes the separation of the anode material and the impurities through crushing, screening, electrostatic separation and the like, and has the advantages of short flow and no pollution. In recent years, physical sorting methods have received widespread attention. For example, CN113904021a discloses a method of separating a positive electrode material from a current collector by wet milling and washing with an organic solvent, but it still relies on an organic solvent, which presents a risk of secondary pollution. Existing dry electrostatic separation techniques, while avoiding solvent use, still face the following technical bottlenecks: the charging characteristics of fine carbon, aluminum and copper impurities in the black powder are similar to those of the positive electrode material, the electrostatic separation selectivity is poor, and the separation efficiency is low; the traditional friction charge only concerns the charge quantity, and the removal of the residual adhesive on the surface and the improvement of the surface activity are not considered; The recovered positive electrode material particles have sharp edges, high residual alkali content on the surface and poor sphericity, and are difficult to directly recycle to the battery manufacturing and coating process. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a method and a system for advanced purification and activation pretreatment of a waste lithium ion battery anode material, so as to solve the problems of low separation efficiency, low cleaning efficiency, low product quality and the like in the prior art. In order to achieve the above object, the first aspect of the present invention adopts the following technical scheme: a pretreatment method for deep purification and activation of a waste lithium ion battery anode material comprises the following steps: Step S1, placing waste ternary battery black powder and PTFE grinding media in a sealed friction charging unit according to a volume ratio of 1:0.5-1.5, introducing inert gas, starting a dielectric barrier discharge plasma generator, generating low-temperature plasma under the conditions of air pressure of 0.1-0.5 atm and discharge power of 50-500W, and simultaneously starting a stirring device, and running for 60-120S at a stirring rotating speed of 1500-2000 rpm; S2, conveying the powder processed in the step S1 into a multi-field coupling separation unit to separate an anode material enrichment phase and an impurity phase, wherein a parallel electrode plate, a permanent magnet array and a transverse airflow device are arranged in the multi-field coupling separation unit, the electrode plate is applied with voltage of 25-45 kV, the permanent magnet array generates gradient magnetic field of 0.1-0.5T, and the transverse airflow speed is 5-15 m/S; S3, sending the positive electrode material enrichment phase obtained in the step S2 into an integrated vortex shaping-cladding-classifying unit for separation and shaping, wherein the tangential inlet wind speed of the integrated vortex shaping-cladding-classifying unit is 18-25 m/S, a rotary grinding disc with the rotating speed of 500-2000 rpm is arranged at the bottom of the integrated vortex shaping-cladding-classifying unit, and a gas-phase cladding agent is introduced into the integrated vortex shaping-cladding-classifying unit by taking inert gas as a carrier, and the concentration of the gas-phase cladding agent is 0.1-5 vol%; And S4, detecting C, al, cu, F element content and surface functional group information in the finished product in real time by using an L