Triangular Cathode Active Material for High-Nickel Battery Stability
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Solution Overview
Problem
Existing lithium secondary batteries face challenges in terms of lifespan characteristics and high temperature storage performance, particularly when high nickel content is introduced to enhance capacity.
Innovation Solution
A cathode active material comprising lithium metal oxide particles with a secondary particle structure formed by agglomerated primary particles, where each primary particle has a triangular shape with a minimum internal angle of 45° or more and a maximum height of 0.5 μm or more, is manufactured through a co-precipitation process involving multiple pH and concentration adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high nickel content is introduced to enhance battery capacity, then energy density is improved, but lifespan characteristics and high temperature storage performance deteriorate
Solution Approach 1:
The cathode active material is divided into primary particles (0.5-5 μm) that aggregate to form secondary particles (5-20 μm). This segmentation allows high nickel content (80-95 mol%) to be concentrated in the primary particles where it provides high capacity, while the aggregated secondary particle structure maintains structural integrity and stability, resolving the contradiction between high capacity and long lifespan/high temperature performance
Solution Approach 2:
The invention uses a composite structure where high nickel content lithium composite oxide (providing high capacity) is combined with a specific particle morphology (triangular primary particles with minimum internal angle ≥45°). This composite approach allows the material to simultaneously achieve high energy density and improved reliability through the stabilizing effect of the controlled particle structure
2Quantity of substance
If nickel content is increased to achieve high capacity, then energy density improves, but structural integrity and chemical stability worsen
Solution Approach 1:
By segmenting the cathode material into small primary particles (0.5-5 μm) that aggregate into secondary particles, the invention confines high nickel content (80-95 mol%) within discrete primary particle units. This segmentation prevents structural degradation that would occur in bulk high-nickel materials, as each small primary particle maintains its structural integrity while the aggregate secondary particle structure provides overall stability
Solution Approach 2:
The invention changes the particle size parameter to resolve the stability issue. By controlling primary particle size to 0.5-5 μm with a minimum internal angle of ≥45°, the material achieves both high nickel content (for capacity) and improved structural/chemical stability. The specific particle morphology parameters directly influence the stability of high-nickel lithium composite oxide
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 cathode active material improves the lifespan characteristics and high temperature storage performance of lithium secondary batteries by maintaining structural integrity and chemical stability, even with high nickel content.
Implementation Method 1
performing a co-precipitation reaction in a reaction solution including a metal salt, a chelating agent and a co-precipitating agent; and obtaining a metal hydroxide particle formed by the co-precipitation reaction
Data Source
AI summary
The present invention provides a cathode active material for a secondary battery, which includes a lithium metal oxide particle having a form of a secondary particle in which a plurality of primary particles are agglomerated, wherein the primary particles comprise a particle having a triangular shape which has a size of a minimum internal angle of 45° or more and a maximum height of 0.5 μm or more.