Negative Electrode Material Evaluation via X-Ray Side-Reaction Kinetics

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Solution Overview

Problem

Existing technologies lack a method to quantify the extent of side reactions in negative electrode active materials for secondary batteries, particularly when using carbon-based materials like graphite or silicon, which affects battery performance and stability.

Innovation Solution

An evaluation method using X-ray diffraction to measure and calculate reaction rate constants for carbon interlayer compounds and decomposed products in the negative electrode active layer, allowing non-destructive assessment of material suitability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If silicon material is mixed with graphite to improve energy density, then energy density is improved, but side reactions increase reducing lithium ion concentration

Engineering Contradiction:

Improveenergy densityVSAvoidlithium ion concentration stability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the negative electrode active material by controlling the ratio of silicon material to graphite, and adjusts the particle size distribution parameters to optimize performance. By precisely controlling these parameters, the patent achieves high energy density while minimizing side reactions that reduce lithium ion concentration.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional evaluation methods are used, then manufacturing process is simple, but side reaction extent cannot be quantified

Engineering Contradiction:

Improveevaluation process simplicityVSAvoidside reaction quantification

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces conventional electrochemical measurement methods with X-ray diffraction technology to detect and quantify side reactions. This substitution enables precise measurement of the extent of side reactions through crystal structure analysis, providing quantitative data that was previously unavailable through conventional methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary evaluation index based on X-ray diffraction patterns to bridge the gap between simple manufacturing processes and precise side reaction quantification. This intermediary index allows for accurate measurement of side reactions while maintaining the simplicity of the overall evaluation process.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If lithium metal is used as negative electrode active material, then charge-discharge cycle cost is reduced, but dendrite formation causes short-circuiting and explosion risk

Engineering Contradiction:

Improvecharge-discharge cycle costVSAvoiddendrite formation

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent uses composite materials consisting of silicon material and graphite mixed in specific ratios to replace pure lithium metal as the negative electrode active material. This composite structure provides the cost advantages of lithium metal while eliminating the dendrite formation problem through the different mechanical and electrochemical properties of the composite components.

Inventive Principle:

Principle #40Composite materials

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 method enables reliable determination of suitable negative electrode materials with high temperature stability and extended life characteristics by quantifying side reactions, ensuring high accuracy and reliability in material selection.

Implementation Method 1

measuring an X-ray diffraction of a battery cell stored in a charged state

Methodology Applied

Scientific EffectX-ray diffraction: X-Ray

Implementation Method 2

calculating intensity integrals of extracted diffraction peaks, wherein the extracted diffraction peaks are extracted from X-ray diffraction peaks for a carbon interlayer compounds

Methodology Applied

Scientific EffectBragg diffraction: Bragg Diffraction

Data Source

PatentUS12613202B2Method for evaluating suitability of negative electrode active material

Publication Date: 2026.04.28 LG ENERGY SOLUTION LTD

AI summary

An evaluation method of a negative electrode active material for secondary battery includes measuring an X-ray diffraction of a battery cell stored in a charged state; calculating intensity integrals of extracted diffraction peaks, where the extracted diffraction peaks are extracted from X-ray diffraction peaks for a carbon interlayer compounds and a decomposed products contained respectively in a negative electrode active layer of a negative electrode from the measured X-ray diffraction; calculating a reaction rate constant k1 for the carbon interlayer compounds or a reaction rate constant k−1 for the decomposed products of the carbon interlayer compounds from the calculated intensity integral; and evaluating a material suitability of the negative electrode active material contained in the negative electrode active layer based on the calculated reaction rate constant.