Cathode Precursor Particle Distribution for Battery Swelling Suppression
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Solution Overview
Problem
Lithium secondary battery positive electrode active materials often experience battery swelling due to electrolyte decomposition, leading to reduced battery life, and existing methods do not adequately address this issue.
Innovation Solution
A precursor for lithium secondary battery positive electrode active materials with a specific particle size distribution, characterized by D10, D30, D50, and D90 values, is used, which, when mixed with a lithium compound and calcined, produces a material that suppresses battery swelling and extends battery life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional precursors with wide particle size distribution are used, then manufacturing is easier, but battery swelling occurs due to electrolyte decomposition
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution parameters (D10, D30, D50, D70, D90) of the precursor to specific ranges. This control of physical parameters ensures uniform packing density in the final positive electrode active material, which prevents electrolyte decomposition and battery swelling, thereby extending battery life while maintaining manufacturability
Solution Approach 2:
The patent implements preliminary action by controlling the particle size distribution of the precursor before it is mixed with lithium compound and calcined. By pre-establishing the appropriate particle size distribution in the precursor stage, the final positive electrode active material achieves uniform packing density, preventing electrolyte decomposition and battery swelling issues that would occur with conventional precursors
2Reliability
If particle size distribution is not controlled, then production is simpler, but electrolyte decomposition occurs leading to battery swelling
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution parameters (D10, D30, D50, D70, D90) of the precursor to specific ranges. This control of physical parameters ensures uniform packing density in the final positive electrode active material, which prevents electrolyte decomposition and battery swelling, thereby extending battery life while maintaining manufacturability
Solution Approach 2:
The patent replaces mechanical mixing methods with a more precise approach by controlling particle size distribution through laser diffraction measurement and classification. This substitution ensures that particles are distributed uniformly by size rather than relying on mechanical mixing alone, achieving the required manufacturing precision for preventing electrolyte decomposition
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 use of the precursor with controlled particle size distribution results in a more uniform packing density of active material particles, reducing the likelihood of electrolyte decomposition and thereby suppressing battery swelling, leading to a longer battery life.
Implementation Method 1
a step of mixing the precursor for the lithium secondary battery positive electrode active material and a lithium compound and calcining the obtained mixture
Data Source
AI summary
A precursor for a lithium secondary battery positive electrode active material containing at least a nickel atom, in which, in a volume-based cumulative particle size distribution curve that is obtained by laser diffraction type particle size distribution measurement, a particle diameter (µm) at which a cumulative volume fraction from a small particle side becomes 10% is defined as D10, a particle diameter (µm) at which the cumulative volume fraction from the small particle side becomes 30% is defined as D30, a particle diameter (µm) at which the cumulative volume fraction from the small particle side becomes 50% is defined as D50, a particle diameter (µm) at which the cumulative volume fraction from the small particle side becomes 70% is defined as D70, and a particle diameter (µm) at which the cumulative volume fraction from the small particle side becomes 90% is defined as D90, the D10, the D30, the D50, the D70, and the D90 satisfy (1) to (3) below.D50 - D10/D30≤0.6(1)D90 - D50/D70≤0.6(2)0.90≤D50 - D10/D30/D90 - D50/D70≤1.10(3)