Nickel-Rich Cathode Particle Mix for Stable High-Temperature Cycling

Solution Overview

Problem

Nickel-based active materials with high nickel content exhibit excellent capacity characteristics but suffer from deteriorated cycle characteristics, necessitating improvements in stability and longevity.

Innovation Solution

A nickel-based active material comprising 80 mol % or greater nickel, with a specific particle size distribution including large secondary particles, large crystal particles, and small secondary particles, is used to create a positive electrode for lithium secondary batteries, enhancing cycle life and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high nickel content (80 mol % or greater) is used in the positive electrode active material, then capacity characteristics are improved, but cycle characteristics deteriorate

Engineering Contradiction:

ImprovecapacityVSAvoidcycle characteristics

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by creating a multi-size particle distribution where different regions (particle sizes) have different properties. Small secondary particles (1-7 μm) provide high surface area for capacity, while large secondary particles (10-20 μm) and large crystal particles (1-5 μm) provide structural stability. This spatial differentiation of particle sizes allows the system to simultaneously achieve high capacity and good cycle characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple particle size types (small secondary particles, large secondary particles, and large crystal particles) within a single active material system. This composite approach allows the benefits of each particle size to work together: small particles contribute to capacity through high surface area, while larger particles contribute to cycle stability through their robust structure.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If high nickel content is used to achieve excellent capacity characteristics, then energy density is improved, but stability under high-temperature and high-voltage conditions deteriorates

Engineering Contradiction:

Improveenergy densityVSAvoidstability under high-temperature and high-voltage conditions

Core Design Contradiction:

Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating a multi-size particle distribution where different regions (particle sizes) have different properties. Small secondary particles (1-7 μm) provide high surface area for capacity, while large secondary particles (10-20 μm) and large crystal particles (1-5 μm) provide structural stability. This spatial differentiation of particle sizes allows the system to simultaneously achieve high capacity and good cycle characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple particle size types (small secondary particles, large secondary particles, and large crystal particles) within a single active material system. This composite approach allows the benefits of each particle size to work together: small particles contribute to capacity through high surface area, while larger particles contribute to cycle stability through their robust structure.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If uniform particle size is used for simplicity, then manufacturing precision is maintained, but cell resistance increases and cycle life decreases

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidcycle life and cell resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the particle size distribution parameter from a uniform single size to a multi-size distribution. Specifically, it defines three distinct particle size ranges (small secondary particles: 1-7 μm, large secondary particles: 10-20 μm, large crystal particles: 1-5 μm) with controlled proportions. This parameter change optimizes both electrochemical performance and manufacturing feasibility.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250132332A1Nickel-based active material, positive electrode including the same, and lithium secondary battery employing the positive electrode

Publication Date: 2025.04.24 SAMSUNG SDI CO LTD

AI summary

A nickel-based active material, a positive electrode including the same, and a lithium secondary battery including the positive electrode, a negative electrode, and an electrolyte between the positive electrode and the negative electrode are provided. The nickel-based active material includes 80 mol % or more of nickel with respect to the metal elements excluding lithium, and the nickel-based active material includes: i) large secondary particles having a size in a range of 10 μm to 20 μm and including aggregates of primary particles having a size of 1 μm or less; ii) large crystal particles including primary particles having a size in a range of 1 μm to 5 μm; and iii) small secondary particles having a size in a range of 1 μm to 7 μm and including aggregates of primary particles having a size of 1 μm or less.