Ion-Conductive Carbon Coating for High-Speed Li-Ion Battery Electrodes

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Solution Overview

Problem

Lithium ion batteries face a trade-off between improved electron conductivity and reduced lithium ion conductivity due to carbon coating films, leading to increased internal resistance and voltage decrease during high-speed charging and discharging.

Innovation Solution

A carbon coating film containing an ion-conductive material is formed on electrode-active material particles, with at least a portion of the ion-conductive material exposed or surrounded by the carbon coating film, maintaining high electron conductivity while enhancing lithium ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thickness and coverage of carbon coating film are increased to improve electron conductivity, then electron conductivity is improved, but internal resistance increases and voltage decreases during high-speed charging and discharging

Engineering Contradiction:

Improveelectron conductivityVSAvoidhigh-speed charge-discharge characteristics

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

By incorporating ion-conductive material into the carbon coating film, the patent creates a composite coating that simultaneously provides electron conductivity (from carbon) and lithium ion conductivity (from ion-conductive material). This reduces the overall resistance to charge-discharge processes, enabling high-power performance without sacrificing electron conductivity

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the compositional parameters of the coating film by adding ion-conductive material with specific ionic conductivity properties. This parameter change transforms the coating from a purely electron-conductive barrier into a dual-conductive pathway that supports both electrons and lithium ions, thereby improving high-speed charge-discharge characteristics while maintaining electron conductivity

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

This approach enables high-speed charge-discharge characteristics without impairing lithium ion conductivity, reducing internal resistance and maintaining voltage stability in lithium ion batteries.

Implementation Method 1

carbon in the carbon coating film is interposed between the electrode-active material particles as an electron conductive material

Methodology Applied

Scientific EffectElectron conduction: Conduction (electrical)

Implementation Method 2

a diffusion barrier of lithium ions

Methodology Applied

Scientific EffectLithium ion diffusion: Diffusion

Data Source

PatentUS9941510B2Electrode material, electrode, and lithium ion battery

Publication Date: 2018.04.10 SUMITOMO METAL MINING CO LTD

AI summary

An electrode material is provided in which a carbon coating film containing an ion-conductive material is formed on surfaces of electrode-active material particles, and at least a portion of a surface of the ion-conductive material is exposed without being coated with the carbon coating film or the ion-conductive material is surrounded by the carbon coating film.