CN-122006882-A - Multi-stage particle size control method and system for nickel-cobalt-manganese ternary positive electrode material precursor

CN122006882ACN 122006882 ACN122006882 ACN 122006882ACN-122006882-A

Abstract

The invention relates to the technical field of material preparation and discloses a method and a system for controlling the multistage particle size of a nickel-cobalt-manganese ternary positive electrode material precursor, wherein the method comprises the steps of ball milling a nickel-cobalt-manganese ternary positive electrode material precursor raw material, collecting acoustic emission signals, detecting collision events based on the acoustic emission signals, dividing collision clusters, and calculating depolymerization dominance; the method comprises the steps of carrying out spectrum analysis based on acoustic emission signals, calculating a spectrum energy distribution entropy value, constructing a two-dimensional state space by combining depolymerization leading degree and the spectrum energy distribution entropy value, controlling ball milling treatment, screening a ball milling product, recording undersize material change curves, carrying out tailing characteristic analysis based on the undersize material change curves, adjusting the ball milling product according to the obtained tailing characteristic area, constructing a two-dimensional constraint area of drying temperature and absolute pressure, and carrying out vacuum drying treatment on the screened product. The invention effectively improves the uniformity of the particle size distribution of the final product.

Inventors

LUO DAJUN
ZHANG XUELIANG
HUANG FANG
LONG HUAN
ZHANG PENGPENG
YAO SHENGYU
WU XINGYI
TIAN DENGLONG

Assignees

贵州理工学院

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (10)

1. The method for controlling the multi-stage particle size of the nickel-cobalt-manganese ternary positive electrode material precursor is characterized by comprising the following steps of: Ball milling is carried out on the nickel-cobalt-manganese ternary cathode material precursor raw material, acoustic emission signals in the ball milling process are collected, collision event detection is carried out on the basis of the acoustic emission signals, collision clusters are divided, and depolymerization dominance is calculated according to different types of collision clusters, wherein the collision clusters comprise depolymerization collision clusters and crushing collision clusters; Performing spectrum analysis based on the acoustic emission signals, calculating a spectrum energy distribution entropy value, constructing a two-dimensional state space by combining the depolymerization dominance and the spectrum energy distribution entropy value, identifying a state track of a ball milling process, and controlling the ball milling process to obtain a ball milling product; Screening the ball-milling product, recording an undersize material quality change curve, carrying out tailing characteristic analysis based on the undersize material quality change curve, and adjusting the ball-milling product according to the obtained tailing characteristic area to obtain a screened product; And constructing a two-dimensional constraint area of drying temperature and absolute pressure based on the spectrum energy distribution entropy value and the tailing characteristic area, and carrying out vacuum drying treatment on the screened product in the two-dimensional constraint area to obtain the nickel-cobalt-manganese ternary positive electrode material precursor with the controlled multi-stage particle size.
2. The method for controlling the multistage particle size of the nickel-cobalt-manganese ternary positive electrode material precursor is characterized in that the method comprises the steps of detecting collision events based on the acoustic emission signals and dividing collision clusters, wherein a sampling period is set, acquiring acoustic emission time domain signals based on the sampling period, monitoring the amplitude of the acoustic emission signals, identifying a period of time when the amplitude of the signals exceeds a background noise reference as collision event time periods, and intercepting signal segments in each collision event time period as collision event signals; Calculating kurtosis values aiming at the high-frequency modal components, arranging kurtosis values of all collision events to generate a kurtosis value distribution curve, carrying out bimodal detection on the kurtosis value distribution curve, and identifying valley positions between two peaks; taking a kurtosis value corresponding to the valley position as a classification boundary, dividing a collision event with the kurtosis value larger than the classification boundary into broken collision clusters, and dividing a collision event with the kurtosis value smaller than or equal to the classification boundary into depolymerized collision clusters; And respectively calculating the accumulated energy of all collision events in the depolymerized collision cluster and the crushing collision cluster, and taking the proportion of the accumulated energy of the depolymerized collision cluster to the total accumulated energy as a depolymerization dominance, wherein the total accumulated energy is the sum of the accumulated energy of the depolymerized collision cluster and the crushing collision cluster.
3. The method for controlling the multistage particle size of the nickel-cobalt-manganese ternary cathode material precursor is characterized in that the method comprises the steps of carrying out frequency spectrum analysis on the basis of the acoustic emission signals, calculating a frequency spectrum energy distribution entropy value, carrying out short-time Fourier transform on the acoustic emission signals, generating a time spectrum chart, setting time windows along a time axis in the time spectrum chart, and extracting power spectrum density distribution in each time window; Dividing the power spectrum density distribution according to frequency bands, calculating an energy duty ratio sequence of each frequency band, calculating shannon entropy according to the energy duty ratio sequence, and carrying out normalization processing to obtain a spectrum energy distribution entropy value.
4. The method for controlling the multistage particle size of the nickel-cobalt-manganese ternary cathode material precursor according to claim 3, wherein the steps of identifying a state track of a ball milling process and controlling the ball milling process comprise the steps of establishing a two-dimensional state space with the depolymerization dominance as a horizontal axis and the spectral energy distribution entropy value as a vertical axis; Acquiring ball milling process data of historical standard-reaching batches, extracting depolymerization dominance and spectrum energy distribution entropy values corresponding to ball milling termination time of each standard-reaching batch as historical end point samples, and marking all the historical end point samples in the two-dimensional state space to form a historical end point sample set, wherein the historical standard-reaching batches refer to batches with the standard-reaching product particle size distribution; Calculating a minimum enclosing ellipse for the historical end point sample set, and defining an inner area of the minimum enclosing ellipse as an optimal end point area; in the current batch ball milling process, marking the depolymerization dominance and the spectrum energy distribution entropy value of each sampling moment in the two-dimensional state space to form a real-time state track, continuously monitoring the latest state point of the real-time state track, and terminating the ball milling process when the latest state point enters the optimal end point area and N continuous state points are all kept in the optimal end point area.
5. The method for controlling the multistage particle size of the nickel-cobalt-manganese ternary cathode material precursor according to claim 4, wherein the step of performing tailing feature analysis based on the undersize mass change curve comprises the steps of performing differential treatment on the undersize mass change curve to obtain instantaneous screening rate, and calculating the ratio of the instantaneous screening rate to the mass of the residual material on the screen at each moment to obtain a real-time rate constant sequence; Selecting the maximum value in the real-time rate constant sequence as an ideal rate constant, and constructing an ideal quality curve by combining a single exponential decay function; Calculating a mass difference value of the undersize material mass change curve and the ideal mass curve at the same moment to generate a mass deviation curve, wherein the mass deviation curve represents the hysteresis degree of the actual screening process relative to the ideal screening state; Integrating the mass deviation curve along a time axis, and taking an integration result as the tailing characteristic area, wherein the larger the tailing characteristic area is, the more the agglomerate residues in the ball milling product are or the higher the critical particle ratio is; Comparing the tailing characteristic area of the current batch with the tailing characteristic area average value of the historical standard-reaching batch, and returning the ball milling product to the ball milling process for reprocessing if the tailing characteristic area of the current batch is larger than the tailing characteristic area average value until the tailing characteristic area is smaller than or equal to the tailing characteristic area average value, so as to obtain the screening product.
6. The method for controlling the multi-stage particle size of the nickel-cobalt-manganese ternary cathode material precursor is characterized in that constructing a two-dimensional constraint area of drying temperature and absolute pressure based on the spectral energy distribution entropy value and the tailing characteristic area comprises acquiring historical drying process data of standard-reaching batches and taking the historical drying process data as an effective sample set, wherein the drying process data comprises the spectral energy distribution entropy value, the tailing characteristic area, the actual drying temperature and the actual absolute pressure corresponding to each batch; extracting the tail characteristic area of each batch in the effective sample set and the corresponding actual absolute pressure, and carrying out regression analysis to obtain a pressure boundary curve; Reading a corresponding upper limit of the drying temperature from the temperature boundary curve according to the frequency spectrum energy distribution entropy value of the current batch, and reading a corresponding lower limit of the absolute pressure from the pressure boundary curve according to the tailing characteristic area of the current batch; And constructing a two-dimensional constraint area by taking the upper limit of the drying temperature as a temperature dimension boundary and the lower limit of the absolute pressure as a pressure dimension boundary.
7. The method for controlling the multistage particle size of the nickel-cobalt-manganese ternary cathode material precursor according to claim 6, wherein the step of performing vacuum drying treatment on the screened product in the two-dimensional constraint area comprises the steps of obtaining a drying process record of historical standard-reaching batches, extracting an actual drying temperature curve and an actual absolute pressure curve of each historical standard-reaching batch, and forming a candidate track set; Carrying out safety screening on the candidate track set based on the two-dimensional constraint area, and reserving tracks, wherein the drying temperature at any moment is smaller than the upper limit of the drying temperature and the absolute pressure at any moment is larger than the lower limit of the absolute pressure, so as to obtain a feasible track set; Calculating total drying time consumption of each track in the feasible track set, and selecting the track with the shortest total drying time consumption as a target drying process track of the current batch; And controlling the vacuum drying equipment to execute the target drying process track to obtain the nickel-cobalt-manganese ternary positive electrode material precursor with the controlled multi-stage particle size.
8. A nickel cobalt manganese ternary cathode material precursor multi-stage particle size control system employing the method of any one of claims 1-7, characterized in that: The device comprises a depolymerization identification module, a detection module and a detection module, wherein the depolymerization identification module is used for performing ball milling on a nickel-cobalt-manganese ternary cathode material precursor raw material, collecting acoustic emission signals in the ball milling process, detecting collision events based on the acoustic emission signals, dividing collision clusters, and calculating depolymerization dominance according to different types of collision clusters; The state identification module is used for carrying out spectrum analysis based on the acoustic emission signals, calculating a spectrum energy distribution entropy value, constructing a two-dimensional state space by combining the depolymerization dominance and the spectrum energy distribution entropy value, identifying a state track of a ball milling process and controlling the ball milling process to obtain a ball milling product; The particle size screening module is used for screening the ball-milling products, recording undersize material quality change curves, carrying out tailing characteristic analysis based on the undersize material quality change curves, and adjusting the ball-milling products according to the obtained tailing characteristic area to obtain screened products; and the drying treatment module is used for constructing a two-dimensional constraint area of drying temperature and absolute pressure based on the frequency spectrum energy distribution entropy value and the tailing characteristic area, and carrying out vacuum drying treatment on the screened product in the two-dimensional constraint area to obtain the nickel-cobalt-manganese ternary positive electrode material precursor with the controlled multi-stage particle size.
9. Computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method according to any of claims 1-7 when executing the computer program.
10. A computer-readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method according to any of the claims 1-7.

Description

Multi-stage particle size control method and system for nickel-cobalt-manganese ternary positive electrode material precursor Technical Field The invention relates to the technical field of material preparation, in particular to a method and a system for controlling the multistage particle size of a nickel-cobalt-manganese ternary positive electrode material precursor. Background In the production link of the nickel-cobalt-manganese ternary cathode material, how to prepare a precursor material which has uniform particle size distribution, complete crystal structure and no agglomeration based on a multistage process in a physical processing process is a problem to be solved at present, in the prior art, an empirical open-loop control method is generally adopted, a ball mill is used for mechanical dispersion, a vibrating screen is used for classification, and a fixed drying program is set for removing water, however, the conventional ball mill control only depends on indexes such as time or total power, and the like, so that the microcosmic stress state of the material in a tank body can not be sensed in real time, and two distinct physical behaviors of agglomerate depolymerization and primary particle breakage can not be effectively distinguished in the processing process, and the crystal structure damage caused by excessive processing or agglomerate residue caused by insufficient processing often occur, so that the severe requirement of high-energy-density batteries on material consistency is difficult to meet. In addition, the existing screening and grading technology is mainly focused on standard detection of the quality of the final screen, lacks modeling of speed change and screen penetration resistance evolution in the screening process, is easy to miss judgment of critical size particle accumulation or fine aggregate pore blocking, is difficult to realize synchronous evaluation of the true dispersion state of the screened product due to physical property fluctuation of raw material batches and interference of environmental humidity in an actual production environment, and on the other hand, the existing drying process is mainly based on fixed process parameters or simple linear programming temperature rise, lacks effective modeling and response of material state difference generated by precursor processing, is difficult to avoid secondary aggregation of particles induced by capillary force in the drying process, and limits microscopic morphology quality of the final product. Disclosure of Invention The present invention has been made in view of the above-described problems. In order to solve the technical problems, the invention provides the technical scheme that the method for controlling the multistage particle size of the nickel-cobalt-manganese ternary positive electrode material precursor comprises the following steps: Ball milling is carried out on the nickel-cobalt-manganese ternary cathode material precursor raw material, acoustic emission signals in the ball milling process are collected, collision event detection is carried out on the basis of the acoustic emission signals, collision clusters are divided, and depolymerization dominance is calculated according to different types of collision clusters, wherein the collision clusters comprise depolymerization collision clusters and crushing collision clusters; Performing spectrum analysis based on the acoustic emission signals, calculating a spectrum energy distribution entropy value, constructing a two-dimensional state space by combining the depolymerization dominance and the spectrum energy distribution entropy value, identifying a state track of a ball milling process, and controlling the ball milling process to obtain a ball milling product; Screening the ball-milling product, recording an undersize material quality change curve, carrying out tailing characteristic analysis based on the undersize material quality change curve, and adjusting the ball-milling product according to the obtained tailing characteristic area to obtain a screened product; And constructing a two-dimensional constraint area of drying temperature and absolute pressure based on the spectrum energy distribution entropy value and the tailing characteristic area, and carrying out vacuum drying treatment on the screened product in the two-dimensional constraint area to obtain the nickel-cobalt-manganese ternary positive electrode material precursor with the controlled multi-stage particle size. The method for controlling the multi-stage particle size of the nickel-cobalt-manganese ternary positive electrode material precursor comprises the steps of detecting collision events based on the acoustic emission signals and dividing collision clusters, setting sampling periods, acquiring acoustic emission time domain signals based on the sampling periods, monitoring the amplitude of the acoustic emission signals, identifying time periods when the amplitude of the signals exceeds