Lithium Battery Precursor Particle Size Control
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Solution Overview
Problem
The conventional batch-type method for preparing positive electrode active material precursors for lithium secondary batteries faces challenges in achieving uniform particle size control and productivity, particularly due to variations in retention time and particle composition.
Innovation Solution
A method involving a batch-type reactor where a transition metal-containing solution, aqueous alkaline solution, and ammonium ion-containing solution are continuously added, with controlled pH adjustments to form and grow precursor particles, allowing for sedimentation, supernatant discharge, and subsequent re-addition to enhance particle size uniformity and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a batch-type reactor is used to prepare positive electrode active material precursor, then particle size control is improved, but productivity is reduced
Solution Approach 1:
The patent divides the batch-type reactor process into multiple stages: initial particle formation stage and subsequent particle growth stage. By segmenting the reaction process, the patent achieves both uniform particle size (through controlled initial formation) and high productivity (through accelerated subsequent growth), resolving the contradiction between manufacturing precision and productivity
Solution Approach 2:
The patent performs preliminary particle formation in the batch-type reactor before transferring to a continuous stirred tank reactor. This preliminary action ensures uniform particle size distribution is established early, while the subsequent continuous processing maintains high productivity, thus resolving the contradiction between particle size control and production efficiency
2Productivity
If a continuous stirred tank reactor is used to prepare positive electrode active material precursor, then productivity is improved, but particle size uniformity is reduced
Solution Approach 1:
The patent segments the reactor system into two functional units: a batch-type reactor for uniform particle formation and a continuous stirred tank reactor for high-productivity growth. This segmentation allows each reactor to optimize for its specific function, resolving the contradiction between productivity and particle size uniformity
Solution Approach 2:
The patent merges the advantages of both batch-type and continuous stirred tank reactors into a hybrid system. The batch-type reactor provides uniform particle formation while the continuous stirred tank reactor provides high productivity, combining both benefits to resolve the contradiction between manufacturing precision and productivity
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
This approach facilitates easier particle size control and significantly increases productivity by ensuring uniform particle size and improving the yield of positive electrode active material precursors, overcoming the limitations of the conventional batch-type method.
Implementation Method 1
raw materials are added and co-precipitated
Implementation Method 2
a precursor is discharged after the completion of the reaction
Data Source
AI summary
A method of preparing a positive electrode active material precursor for a lithium secondary battery by using a batch-type reactor, which includes the steps of 1) forming positive electrode active material precursor particles while continuously adding a transition metal-containing solution including a transition metal cation, an aqueous alkaline solution, and an ammonium ion-containing solution to a batch-type reactor, 2) sedimenting the positive electrode active material precursor particles formed; 3) discharging a supernatant formed after the sedimentation of the positive electrode active material precursor particles to an outside; 4) adjusting a pH to 10 to 12 by adding the ammonium ion-containing solution; and 5) growing the positive electrode active material precursor particles while continuously again adding the transition metal-containing solution to the batch-type reactor, and a method of preparing a positive electrode active material using the same.