High-Nickel Cathode Particle Shape for Stable Lithium Batteries
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Solution Overview
Problem
Lithium secondary batteries face issues with cycle life and stability due to cation disorder in high-nickel lithium oxide cathode active materials, leading to deteriorated performance.
Innovation Solution
The use of lithium-metal oxide particles with specific sphericity and elongation ranges, along with controlled gaps and pores, enhances structural stability and capacity characteristics in the cathode, thereby improving the cycle life and stability of lithium secondary batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-nickel lithium oxide is used as cathode active material to achieve high capacity, then capacity characteristics are improved, but cycle life and operational stability deteriorate due to cation disorder
Solution Approach 1:
The patent applies parameter changes by precisely controlling the sphericity (0.85-0.96) and elongation (0.25-0.5) of lithium-metal oxide particles. These geometric parameter modifications reduce cation disorder in the crystal structure, thereby improving cycle life and operational stability while maintaining high capacity characteristics of high-nickel lithium oxide materials.
2Use of energy by moving object
If high-nickel lithium oxide is used to achieve high energy density, then energy density is improved, but structural stability deteriorates due to cation disorder
Solution Approach 1:
The patent modifies geometric parameters of lithium-metal oxide particles by controlling sphericity and elongation within specific ranges. This parameter optimization reduces structural degradation and cation disorder, thereby maintaining structural stability while achieving high energy density through high-nickel lithium oxide composition.
Data Source
AI summary
A cathode active material for a lithium secondary battery according to embodiments of the present disclosure includes lithium-metal oxide particles having a sphericity of 0.96 or less and an elongation of 0.25 to 0.5. The elongation is calculated as (1−b/a). Here, a denotes the length of the major axis of the lithium-metal oxide particle in a cross-sectional image of the lithium-metal oxide particles observed using SEM, and b denotes the length of the minor axis of the lithium-metal oxide particle in the cross-sectional SEM image of the lithium-metal oxide particles.