Oxygen-Excess Cathode Material for Lithium Ion Battery Moisture Control

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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 Li(LixNi1-x-yMy)O2+α, where M is selected from certain elements and the oxygen content is optimized to reduce moisture absorption, achieving better battery properties by controlling moisture content through Karl Fischer titration.

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 moisture absorption increases and battery properties deteriorate

Engineering Contradiction:

Improvebattery capacityVSAvoidbattery properties

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the oxygen content parameter in the cathode active material from stoichiometric (O2) to oxygen-excessive (O2+α where α>0). This parameter change reduces moisture absorption while maintaining high capacity, resolving the contradiction between capacity enhancement and property deterioration

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material strategy by combining lithium nickel composite oxide with oxygen excess. The composite structure of Li(Li1-xNix)O2+α provides both high capacity characteristics and improved stability against moisture absorption

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If oxygen content in cathode active material is increased, then moisture absorption is reduced, but manufacturing precision becomes more difficult to control

Engineering Contradiction:

Improvemoisture absorptionVSAvoidoxygen content control

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent establishes a specific parameter range for oxygen content (O2+α where 0<α≤0.5) that balances moisture resistance with manufacturing feasibility. This controlled parameter change reduces moisture absorption while maintaining manufacturability

Inventive Principle:

Principle #35Parameter changes

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 optimized cathode active material exhibits improved battery properties, including capacity, rate characteristics, and capacity retention, with reduced moisture absorption, enhancing lithium ion battery performance.

Implementation Method 1

the amount of moisture absorption of a cathode active material

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

a moisture content measured by Karl Fischer titration at 300° C. is 1100 ppm or lower

Methodology Applied

Scientific EffectKarl Fischer titration:

Data Source

PatentUS9224515B2Cathode 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: Li(LixNi1-x-yMy)O2+α wherein 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≦x≦0.1; 0<y≦0.7; and α>0, and has a moisture content measured by Karl Fischer titration at 300° C. of 1100 ppm or lower.