Positive Electrode Material with Ni Gradient Charge Transport Channels

Solution Overview

Problem

Existing lithium secondary batteries face issues with increased resistance and reduced lifetime due to high nickel content in positive electrode active materials, which affects charge transport and electrochemical performance.

Innovation Solution

A positive electrode active material with secondary particles featuring concentration gradient sections of nickel, cobalt, and manganese along the circumferential surface, forming charge transport channels to improve electrochemical characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If high nickel content is used in positive electrode active material to increase energy capacity, then energy density is improved, but resistance increases and lifetime is deteriorated

Engineering Contradiction:

Improveenergy capacityVSAvoidresistance characteristics

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies local quality by creating a concentration gradient of nickel, cobalt, and manganese within the particle structure. The surface region has a different composition (lower nickel content) compared to the inner region (higher nickel content), allowing the surface to provide stability and low resistance while the interior provides high capacity. This spatial variation in composition resolves the contradiction between energy density and resistance characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple metal elements (nickel, cobalt, manganese) in a gradient distribution within a single particle structure. This composite approach allows different regions of the particle to contribute different properties: the high-nickel interior provides capacity while the low-nickel surface provides stability, thereby resolving the contradiction between energy capacity and resistance.

Inventive Principle:

Principle #40Composite materials

2Use of energy by moving object

If high nickel content is used in positive electrode active material to increase energy capacity, then energy density is improved, but lifetime is reduced

Engineering Contradiction:

Improveenergy capacityVSAvoidlifetime

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of moving object

Solution Approach 1:

The patent applies local quality by creating a concentration gradient of nickel, cobalt, and manganese within the particle structure. The surface region has a different composition (lower nickel content) compared to the inner region (higher nickel content), allowing the surface to provide stability and low resistance while the interior provides high capacity. This spatial variation in composition resolves the contradiction between energy density and resistance characteristics.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent applies beforehand cushioning by designing a protective surface layer with lower nickel content before the high-nickel interior is exposed during cycling. This surface composition acts as a cushion that prevents degradation and resistance increase during the battery's lifetime, allowing the high-capacity interior to be utilized over extended periods without deterioration.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Power

If nickel content is increased to improve output characteristics, then discharge capacity is improved, but charge transport is hindered

Engineering Contradiction:

Improvedischarge capacityVSAvoidcharge transport

Core Design Contradiction:

PowerVSSpeed

Solution Approach 1:

The patent applies local quality by creating a concentration gradient of nickel, cobalt, and manganese within the particle structure. The surface region has a different composition (lower nickel content) compared to the inner region (higher nickel content), allowing the surface to provide stability and low resistance while the interior provides high capacity. This spatial variation in composition resolves the contradiction between energy density and resistance characteristics.

Inventive Principle:

Principle #3Local quality

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 concentration gradient sections enhance charge transport, leading to improved lifetime and efficiency characteristics of the positive electrode active material.

Implementation Method 1

the concentration of at least one selected from nickel, cobalt and manganese increases and a second concentration gradient section in which the concentration of at least one selected from nickel, cobalt and manganese decreases, along the circumferential surface of the secondary particle... forming charge transport channels

Methodology Applied

Scientific EffectCharge transport: Conduction (electrical)

Data Source

PatentUS12456729B2Positive electrode active material and lithium secondary battery comprising the same

Publication Date: 2025.10.28 ECOPRO BM CO LTD

AI summary

The present invention relates to a positive electrode active material and a lithium secondary battery using a positive electrode containing the positive electrode active material. More particularly, the present invention relates to a positive electrode active material that is able to solve a problem of increased resistance according to an increase in Ni content by forming a charge transport channel in a lithium composite oxide and a lithium secondary battery using a positive electrode containing the positive electrode active material.