Nickel-Rich Cathode Particle Structure for Battery Thermal Stability

Solution Overview

Problem

Existing lithium secondary batteries face challenges in achieving high capacity, power output, and stability, particularly in harsh conditions, with cathode active materials lacking sufficient life-span and thermal stability.

Innovation Solution

A lithium secondary battery design incorporating a first cathode active material particle with a concentration gradient and secondary particle structure, and a second cathode active material particle with a single crystalline structure, each containing specific metal compositions, enhances capacity, power output, and stability by preventing ignition and extending life-span.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a cathode active material with high nickel content is used to achieve high capacity and power output, then the battery's energy density improves, but thermal stability and safety deteriorate due to increased risk of ignition

Engineering Contradiction:

Improveenergy densityVSAvoidthermal stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The cathode active material employs a concentration gradient structure where nickel content varies spatially: high nickel concentration in the interior region provides high capacity and power output, while lower nickel concentration in the exterior region ensures thermal stability and safety. This local differentiation of composition allows simultaneous optimization of both energy density and reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The cathode active material is designed as a composite structure combining multiple metal elements (nickel, cobalt, manganese, and optionally other metals) in a concentration gradient arrangement. This composite approach leverages the high capacity of nickel-rich regions while incorporating thermally stable metals in exterior regions, achieving both high energy density and improved safety.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If the cathode active material structure is simplified to reduce manufacturing complexity, then ease of manufacture improves, but life-span and operational stability deteriorate

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidlife-span

Core Design Contradiction:

Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The invention controls the concentration gradient parameter of metal elements within a specific range (e.g., nickel content transitioning from high in interior to lower in exterior, with defined numerical ranges). This parameter optimization ensures sufficient life-span and operational stability while maintaining a manufacturable concentration gradient structure that does not require excessively complex processing.

Inventive Principle:

Principle #35Parameter changes

3Power

If high nickel content is used to improve capacity, then power output increases, but stability in harsh conditions such as high temperature deteriorates

Engineering Contradiction:

Improvepower outputVSAvoidcompositional stability

Core Design Contradiction:

PowerVSStability of the object's composition

Solution Approach 1:

The cathode active material employs a concentration gradient structure where nickel content varies spatially: high nickel concentration in the interior region provides high capacity and power output, while lower nickel concentration in the exterior region ensures thermal stability and safety. This local differentiation of composition allows simultaneous optimization of both energy density and reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The cathode active material is designed as a composite structure combining multiple metal elements (nickel, cobalt, manganese, and optionally other metals) in a concentration gradient arrangement. This composite approach leverages the high capacity of nickel-rich regions while incorporating thermally stable metals in exterior regions, achieving both high energy density and improved safety.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12562372B2Lithium secondary battery and method of manufacturing the same

Publication Date: 2026.02.24 SK ON CO LTD

AI summary

A cathode active material includes a first cathode active material particle and a second cathode active material particle. The first cathode active material particle includes a lithium metal oxide including a concentration gradient and has a secondary particle structure formed from an assembly of primary particles. The second cathode active material particle includes a lithium metal oxide having a single particle structure. The first and second cathode active material particles each includes at least two metals except from lithium, and an amount of nickel is the largest among those of the metals in each of the first and second cathode active material particles.