Lithium Nickel Cathode Oxygen Control for Cycle Life

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Solution Overview

Problem

Lithium nickel composite oxides used in lithium ion batteries have excessive oxygen content, limiting their performance as high-quality cathode active materials.

Innovation Solution

A cathode active material with a specific composition formula LixNi1−yMyO2+α, where M is selected from certain elements and the oxygen content is controlled to maintain a moisture level below 1100 ppm, optimizing battery properties such as capacity, rate characteristics, and cycle retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium nickel composite oxide is used as cathode active material, then battery capacity can be enhanced, but oxygen content becomes excessive and moisture content increases, degrading battery properties

Engineering Contradiction:

Improvebattery capacityVSAvoidbattery properties

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the oxygen content (α) to be greater than 0.1 in the composition formula LixNi1−yMyO2+α, and controlling moisture content to be 1100 ppm or lower. This quantitative parameter control transforms the material properties to achieve both high capacity and good reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by introducing multiple element substitutions (M elements from Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Ga, Ge, Al, Bi, Sn, Mg, Ca, B, and Zr) into the lithium nickel oxide structure. This composite approach allows simultaneous optimization of capacity and stability properties

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If moisture content in cathode active material is high, then material can be easier to manufacture, but battery cycle properties and storage properties deteriorate

Engineering Contradiction:

Improvematerial processingVSAvoidcycle properties

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent applies parameter changes by establishing a specific moisture content threshold (1100 ppm or lower) measured by Karl Fischer titration at 300°C. This quantitative control parameter balances manufacturability with long-term cycle performance and storage stability

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If oxygen content in cathode active material is excessive, then material composition can be simplified, but battery rate characteristics and preservation properties are limited

Engineering Contradiction:

Improvematerial compositionVSAvoidrate characteristics

Core Design Contradiction:

Device complexityVSSpeed

Solution Approach 1:

The patent applies parameter changes by defining a minimum oxygen content threshold (α>0.1) in the composition formula. This parameter control ensures sufficient oxygen for high-rate discharge capability while maintaining compositional simplicity through the general formula LixNi1−yMyO2+α

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9224514B2Cathode active material for lithium ion battery, cathode for lithium ion battery, and lithium ion battery

Publication Date: 2015.12.29 JX NIPPON MINING & METALS CORP

AI summary

There is provided a cathode active material for a lithium ion battery having good battery properties. The cathode active material for a lithium ion battery is represented by a composition formula: LixNi1−yMyO2+αwherein M is one or more selected from Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Ga, Ge, Al, Bi, Sn, Mg, Ca, B, and Zr; 0.9≦x≦1.2; 0<y≦0.7; and α>0.1, and has a moisture content measured by Karl Fischer titration at 300° C. of 1100 ppm or lower.