Positive Electrode Precursor Batch Reactor Stirring for Uniform Particles
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Solution Overview
Problem
Conventional batch-type reactor methods for manufacturing positive electrode active material precursors result in uneven particle size distribution and surface cracking due to continuous nucleation, leading to decreased battery performance and increased production costs.
Innovation Solution
A method involving controlled stirring speeds (200-900 rpm) and overflow of the reaction solution in a batch-type reactor, with specific pH and ammonia concentration, to promote uniform particle growth and prevent cracking, achieving a particle size distribution of 6.5 µm to 13.0 µm and Span value of 0.38.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If batch-type reactor method is used for manufacturing positive electrode active material precursor, then production efficiency is improved, but particle size distribution becomes uneven and surface cracking occurs
Solution Approach 1:
The patent applies dynamics by continuously adjusting the stirring speed throughout the reaction process. The stirring speed is set to decrease over time: initially high to ensure uniform nucleation, then gradually reduced to minimize particle collision and growth variation. This dynamic adjustment of operational parameters resolves the contradiction between maintaining high productivity and achieving uniform particle size distribution.
Solution Approach 2:
The patent employs parameter changes by systematically varying multiple reaction parameters including stirring speed (decreasing over time), temperature, pH, and ammonia concentration. These parameter changes are designed to control the nucleation and growth phases separately, ensuring uniform particle size distribution while maintaining efficient production in batch-type reactors.
2Manufacturing precision
If stirring speed is increased to improve mixing, then particle size distribution becomes more uniform, but particle collision increases causing surface cracking
Solution Approach 1:
The patent applies dynamics by continuously adjusting the stirring speed throughout the reaction process. The stirring speed is set to decrease over time: initially high to ensure uniform nucleation, then gradually reduced to minimize particle collision and growth variation. This dynamic adjustment of operational parameters resolves the contradiction between maintaining high productivity and achieving uniform particle size distribution.
Solution Approach 2:
The patent employs periodic action by dividing the reaction into distinct phases with different stirring speeds. During the nucleation phase, high stirring speed is applied; during the growth phase, stirring speed is reduced. This periodic variation in stirring intensity ensures uniform particle formation while preventing surface cracking from excessive collision.
3Manufacturing precision
If additional processes like Air Classifier Mill or cyclone separation are added to control microparticles, then particle size uniformity is improved, but production efficiency and Line of Balance decrease
Solution Approach 1:
The patent applies the taking out principle by removing the need for additional post-processing equipment such as Air Classifier Mills or cyclone separators. Instead, the desired particle size uniformity is achieved directly within the batch-type reactor through optimized stirring protocols and reaction parameter control, thereby eliminating bottlenecks in the production line and maintaining high productivity.
Solution Approach 2:
The patent employs self-service by enabling the batch-type reactor itself to perform the function of particle size control that would otherwise require separate downstream processing equipment. Through internal stirring speed adjustment and reaction parameter optimization, the reactor produces uniformly sized particles directly, making the process self-sufficient and eliminating additional processing steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces positive electrode active material precursors with uniform particle size distribution and reduced surface cracking, enhancing production efficiency and battery performance without additional processing steps.
Implementation Method 1
a stirring speed in the batch-type reactor is set to be: 200 rpm to 900 rpm during the step S2, 800 rpm or less during the step S3, and 700 rpm or less during the step S4
Implementation Method 2
a reaction solution is designed to overflow when the batch-type reactor is full thereof
Implementation Method 3
there are typically continuous methods using a continuous stirred-tank reactor (CSTR) and batch methods using a batch-type reactor. The continuous method includes co-precipitating raw materials
Implementation Method 4
a co-precipitation reaction is carried out for 1 to 20 hours in the step S2
Data Source
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AI summary
A method for manufacturing a positive electrode active material precursor using a batch-type reactor according the the present disclosure, comprises the steps of: (S1) forming a nucleus of the precursor; (S2) growing the nucleus formed in the step S1; (S3) further growing the nucleus grown in the step S2; and (S4) further growing the nucleus grown in the step S3, wherein a stirring speed in the batch-type reactor is set to be: 200 rpm to 900 rpm during the step S2, 800 rpm or less during the step S3, and 700 rpm or less during the step S4, and a reaction solution is designed to overflow when the batch-type reactor is full thereof.