Lithium Manganese Oxide Cathode Coating for Cycle Life

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Solution Overview

Problem

Lithium ion batteries experience capacity loss and poor cycling life due to irreversible changes in cathode active materials during charging and discharging cycles, primarily caused by reactions between the cathode active material and organic solvents, which affect the stability and conductivity of the cathode.

Innovation Solution

A cathode composite material is developed with a coating layer of lithium metal oxide, specifically Mn doped Li2TiO3, applied to the surface of spinel type lithium manganese oxide cathode active material particles, enhancing stability and preventing unwanted reactions with the electrolyte.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If cathode active material is used in lithium ion deintercalation state, then high oxidability is achieved, but unwanted reactions with organic solvent occur

Engineering Contradiction:

ImproveoxidabilityVSAvoidunwanted reactions with organic solvent

Core Design Contradiction:

PowerVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary coating layer of Li2SiO3 and amorphous carbon that acts as a barrier between the cathode active material and the organic solvent electrolyte. This intermediary layer allows the material to maintain its high oxidability in the deintercalation state while preventing direct unwanted reactions with the organic solvent, thus protecting the material stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If cathode active material undergoes irreversible structural changes during cycling, then capacity loss occurs, but cycling life is reduced

Engineering Contradiction:

ImprovecapacityVSAvoidcycling life

Core Design Contradiction:

Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The patent applies beforehand cushioning by pre-coating the cathode active material particles with Li2SiO3 and amorphous carbon before cycling begins. This protective coating cushions the material against irreversible structural changes during cycling, preventing capacity loss and extending cycling life by maintaining structural integrity throughout charge-discharge cycles.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 cathode composite material improves the cycling stability and capacity retention of lithium ion batteries, maintaining discharge specific capacity even at high current rates and extending cycle life by suppressing side reactions and enhancing lithium ion mobility.

Implementation Method 1

a coating layer of lithium metal oxide, specifically Mn doped Li2TiO3, applied to the surface of spinel type lithium manganese oxide cathode active material particles, enhancing stability and preventing unwanted reactions with the electrolyte

Methodology Applied

Scientific EffectChemical protection through coating: Coatings

Implementation Method 2

Lithium ion batteries experience capacity loss during charging and discharging cycles... enhancing lithium ion mobility

Methodology Applied

Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentUS9088044B2Cathode composite material and lithium ion battery using the same

Publication Date: 2015.07.21 HON HAI PRECISION INDUSTRY CO LTD

AI summary

A cathode composite material includes a cathode active material and a coating layer coated on a surface of the cathode active material. The cathode active material includes a spinel type lithium manganese oxide. The coating layer comprises a lithium metal oxide having a crystal structure belonging to C2/c space group of the monoclinic crystal system. The present disclosure also relates to a lithium ion battery including the cathode composite material.