Nickel-Rich Cathode Sintering With Controlled Spinel Phase
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium nickel composite metal oxides (LiNiO2) exhibit poor thermal stability and reduced stability of the positive electrode due to high nickel content, leading to degradation of secondary battery life characteristics.
Innovation Solution
A method of preparing a nickel-rich positive electrode active material involves primary sintering with a controlled spinel phase ratio of 7% to 16% and subsequent secondary sintering to form a lithium composite transition metal oxide, optimizing the sintering conditions to enhance crystallinity and density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high nickel content is used in lithium nickel composite metal oxide to achieve high reversible capacity, then battery capacity is improved, but thermal stability deteriorates
Solution Approach 1:
The patent uses a composite material approach by forming a spinel phase (LiMn2O4 or similar) as a secondary phase within the lithium nickel composite metal oxide matrix. This spinel phase acts as a stabilizing component that improves thermal stability while the dominant nickel-rich phase maintains high reversible capacity. The composite structure allows simultaneous achievement of high capacity and thermal safety.
Solution Approach 2:
The patent controls the spinel phase ratio parameter within a specific range (7-16%) to optimize both capacity and thermal stability. By precisely adjusting this phase composition parameter during sintering, the material achieves the desired balance between high nickel content for capacity and sufficient thermal stability for safety.
2Quantity of substance
If high nickel content is used to increase reversible capacity, then battery capacity is improved, but positive electrode stability deteriorates
Solution Approach 1:
The spinel phase forms a composite structure with the nickel-rich layered phase, creating a more stable positive electrode material. The spinel component provides structural stability and reduces composition degradation during cycling, while maintaining the high capacity characteristics of the nickel-rich phase.
3Reliability
If cobalt substitution is used to improve thermal stability, then thermal stability is improved, but manufacturing cost increases
Solution Approach 1:
The patent optimizes the substitution level of cobalt with manganese or aluminum to achieve adequate thermal stability at minimal cost. By controlling the substitution ratio within specific ranges and forming the spinel phase, the material achieves thermal stability improvement without excessive cobalt usage, thereby controlling manufacturing costs.
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 improves the life characteristics and resistance of the nickel-rich positive electrode active material, resulting in better capacity retention and reduced resistance increase during cycling.
Implementation Method 1
forming a pre-sintered product by mixing a transition metal precursor having a nickel content of 70 at % or more and a lithium raw material and performing primary sintering; and forming a lithium composite transition metal oxide by performing secondary sintering on the pre-sintered product
Data Source
AI summary
A method of preparing a positive electrode active material includes forming a pre-sintered product by mixing a transition metal precursor having a nickel content of 70 atm % or more and a lithium raw material and performing primary sintering, and forming a lithium composite transition metal oxide by performing secondary sintering on the pre-sintered product, wherein the primary sintering is performed such that a ratio of a spinel phase of the pre-sintered product is in a range of 7% to 16%.