Mixed Lithium Oxide Precursors with Colloid-Mill Particle Homogeneity
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Solution Overview
Problem
Existing methods for producing mixed lithium oxides with transition metals like Ni, Mn, or Co result in inhomogeneous particle size distributions, affecting the capacity and cycle performance of lithium ion batteries.
Innovation Solution
A method involving a colloid mill to mix cations and anions, followed by precipitation and sintering, which allows for separate nucleation and crystal growth, achieving a homogeneous particle size distribution of ≤ 11.5 µm, improving the homogeneity of precursors and subsequently the mixed lithium oxides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mixing methods are used to prepare precursors for mixed lithium oxides, then the manufacturing process is simple, but the particle size distribution is inhomogeneous (D90 > 11.5 μm) which negatively affects battery capacity and cycle performance
Solution Approach 1:
The patent segments the precursor preparation process into two independent stages: nucleation in a first reactor and crystal growth in a second reactor. This segmentation allows each stage to be optimized separately - nucleation produces fine homogeneous particles while crystal growth increases size and throughput, resolving the contradiction between particle size homogeneity and production efficiency
Solution Approach 2:
The patent introduces an intermediary step where the nucleated particles from the first reactor serve as seeds for crystal growth in the second reactor. This intermediary approach allows the fine homogeneous particles to be preserved while enabling controlled growth to achieve both homogeneity and increased throughput
2Manufacturing precision
If nucleation and crystal growth are carried out in parallel in two different reactors, then particle size homogeneity is improved, but the process complexity increases
Solution Approach 1:
The patent divides the precipitation process into two sequential reactor stages: nucleation in reactor 1 and crystal growth in reactor 2. This segmentation enables independent optimization of each stage - controlled nucleation produces homogeneous nuclei while controlled crystal growth maintains homogeneity while increasing throughput, achieving precision without excessive complexity
3Productivity
If the D90 particle size is kept above 11.5 μm in continuous process, then production efficiency is maintained, but the inhomogeneity negatively affects battery performance
Solution Approach 1:
The patent segments the process to separate nucleation (producing homogeneous fine particles) from crystal growth (increasing size while maintaining homogeneity). This allows continuous production efficiency to be maintained through controlled crystal growth while ensuring battery reliability through the homogeneous particle size distribution achieved in the nucleation stage
Solution Approach 2:
The patent performs preliminary nucleation in the first reactor to establish a homogeneous distribution of fine particles before proceeding to crystal growth in the second reactor. This preliminary action ensures that the particle size homogeneity is established early, which then guides the subsequent crystal growth to maintain both homogeneity and increased throughput
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 enhances the homogeneity of mixed lithium oxides, leading to improved performance of lithium ion battery cathodes and batteries, with increased throughput and better particle size control.
Implementation Method 1
mixing a composition comprising water and at least one cation of at least one M with a composition comprising water and at least one anion selected from the group consisting of hydroxide, hydrogen carbonate, and carbonate, or a mixture of two or more thereof, in a colloid mill
Implementation Method 2
precipitating an oxide or hydroxide or hydrogen carbonate or carbonate, or a mixture of two or more thereof, of M from the milled mixture obtained in step (S1)
Implementation Method 3
The method further comprises step (S4): (S4) sintering the compound isolated in step (S3)
Data Source
AI summary
Method of making an oxide of M, wherein M is at least one transition metal, preferably selected from Ni, Mn, or Co, or a mixture of two or more thereof, comprising at least steps (S1) and (S2): (S1) mixing a composition comprising water and at least one cation of at least one M with a composition comprising water and at least one anion selected from the group consisting of hydroxide, hydrogen carbonate, and carbonate, or a mixture of two or more thereof, in a colloid mill; (S2) precipitating an oxide or hydroxide or hydrogen carbonate or carbonate or a mixture of two or more thereof of M from the milled mixture obtained in step (S1).