Domain-Structured Cathode Material for Thermal Stability

Solution Overview

Problem

Nickel-cobalt-manganese based positive electrode active materials with high nickel content face issues with structural instability and lowered decomposition temperature due to increased nickel content, necessitating improved thermal stability and cycle-life characteristics while maintaining high capacity.

Innovation Solution

A lithium metal oxide particle with multiple domains and doping elements Zr, Al, and Ti within a primary particle structure, stabilizing the structure and enhancing thermal stability and cycle-life by suppressing Ni movement and reducing grain size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high nickel content is used in nickel-cobalt-manganese based positive electrode active material, then capacity is improved, but structural stability deteriorates and decomposition temperature is lowered

Engineering Contradiction:

ImprovecapacityVSAvoidstructural stability

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating distinct domains with different crystal structures (layered and cubic) within the same particle. The layered domain provides high capacity while the cubic domain provides structural stability, allowing each region to have optimized properties for its specific function.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple crystal structures (layered and cubic phases) within a single particle. This composite structure integrates the advantages of both phases: high capacity from the layered structure and thermal/structural stability from the cubic structure.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If high nickel content is used in nickel-cobalt-manganese based positive electrode active material, then capacity is improved, but decomposition temperature is lowered

Engineering Contradiction:

ImprovecapacityVSAvoiddecomposition temperature

Core Design Contradiction:

Quantity of substanceVSTemperature

Solution Approach 1:

The patent applies local quality by creating distinct domains with different crystal structures (layered and cubic) within the same particle. The layered domain provides high capacity while the cubic domain provides structural stability, allowing each region to have optimized properties for its specific function.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple crystal structures (layered and cubic phases) within a single particle. This composite structure integrates the advantages of both phases: high capacity from the layered structure and thermal/structural stability from the cubic structure.

Inventive Principle:

Principle #40Composite materials

3Temperature

If doping elements are added to stabilize structure, then thermal stability is improved, but device complexity increases

Engineering Contradiction:

Improvethermal stabilityVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by precisely controlling the composition ratios of doping elements (Al, Ti, Zr) within specific ranges. By optimizing these parameters, the patent achieves thermal stability without excessive complexity, as the doping elements are incorporated in controlled amounts rather than as complex multi-component systems.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4080613B1Cathode active material and lithium secondary battery comprising same

Publication Date: 2025.09.24 POSCO HLDG INC

Figure 1A~1B
Figure 1C~2A
Figure 2B~2C

AI summary

The present exemplary embodiments relate to a positive electrode active material and a lithium secondary battery including the same. The positive active material for a lithium secondary battery according to an exemplary embodiment includes lithium metal oxide particles including lithium, nickel, cobalt, manganese and doping elements, and includes a first domain and a second domain inside the lithium metal oxide particles.