Low-Cobalt Cathode Active Material for Battery Output and Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cobalt content in lithium transition metal oxides used as cathode active materials for secondary batteries increases manufacturing costs and degrades structural stability and output characteristics.
Innovation Solution
A cathode active material comprising first lithium transition metal oxide particles with a single particle form and second lithium transition metal oxide particles with a secondary particle form, both with reduced cobalt content, are combined to enhance structural stability and output characteristics. The first particles have a cobalt content of 15,000 ppm or less, and the second particles have a cobalt content of 5,000 to 9,000 ppm, with specific particle diameters and crystal structures to improve cycle life and output characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If cobalt content in lithium transition metal oxide is increased, then output characteristics are improved, but manufacturing costs increase
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the inner core particles contain higher cobalt content (11,000-14,000 ppm) for superior output characteristics, while the outer shell particles contain lower cobalt content (5,000-9,000 ppm) to reduce manufacturing costs. This spatial differentiation of composition allows each region to fulfill its functional role optimally.
Solution Approach 2:
The patent employs composite materials by combining two distinct types of lithium transition metal oxide particles with different cobalt contents into a single cathode active material system. The composite structure integrates the high-output core particles with the cost-effective shell particles, achieving a balance between performance and cost.
2Ease of manufacture
If cobalt content in lithium transition metal oxide is reduced, then manufacturing costs decrease, but structural stability degrades
Solution Approach 1:
The patent uses local quality to address structural stability by concentrating higher cobalt content in the core particles, which provide structural reinforcement where it is most needed for maintaining stability during electrochemical cycling. The shell particles with lower cobalt content can then be used more extensively without compromising overall structural integrity.
Solution Approach 2:
The composite material approach combines structurally stable core particles with cost-effective shell particles, creating a hybrid system where the core provides structural backbone and the shell contributes to cost reduction while maintaining adequate stability through the synergistic interaction between the two particle types.
3Ease of manufacture
If cobalt content in lithium transition metal oxide is reduced, then manufacturing costs decrease, but output characteristics degrade
Solution Approach 1:
The patent implements local quality by ensuring that high-output regions (core particles) contain sufficient cobalt content (11,000-14,000 ppm) to deliver superior power performance, while low-cost regions (shell particles) with reduced cobalt content (5,000-9,000 ppm) contribute to cost savings. This localized optimization maintains output characteristics while reducing overall manufacturing costs.
Solution Approach 2:
The composite material system combines high-performance core particles with cost-effective shell particles in specific proportions, allowing the high-output core particles to dominate the electrochemical performance while the shell particles provide cost benefits, achieving an optimal balance between output characteristics and manufacturing costs.
Data Source
AI summary
According to embodiments of the present disclosure, a cathode active material for a secondary battery includes first lithium transition metal oxide particles having a single particle form and including cobalt in an amount of 15,000 ppm or less based on their total weight, and second lithium transition metal oxide particles having a secondary particle form and including cobalt in an amount of 15,000 ppm or less based on their total weight. The cobalt content based on the total weight of the first lithium transition metal oxide particles is greater than the cobalt content based on the total weight of the second lithium transition metal oxide particles.