Nondestructive Active Area Measurement via Electrode Capacitance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional methods for measuring the active area of electrodes coated with carbon nanotubes are destructive and time-consuming, requiring direct observation under an electron microscope, which is inefficient.

Innovation Solution

A method involving the manufacture of three types of electrodes with different compositions, measuring their capacitance using cyclic voltammetry, and calculating the active area of the electrode active material using a specific formula, allowing for non-destructive and accurate measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional electron microscope observation method is used to measure active area, then measurement accuracy is improved, but measurement time increases and electrode is damaged

Engineering Contradiction:

Improveactive area measurement accuracyVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical/electronic observation system (electron microscope) with an electrochemical measurement system (capacitance measurement). By measuring the capacitance of the electrode and calculating the active area from the capacitance value using the formula C = k × S, the patent achieves accurate measurement without time-consuming image processing and without damaging the electrode structure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces capacitance as an intermediary parameter to indirectly measure the active area. Instead of directly observing and measuring the physical area, the method uses capacitance measurement as a mediator that correlates with active area through the relationship C = k × S, enabling non-destructive and rapid measurement

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If conventional electron microscope observation method is used to measure active area, then measurement accuracy is improved, but electrode is damaged

Engineering Contradiction:

Improveactive area measurement accuracyVSAvoidelectrode damage

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses the electrode's own electrochemical property (capacitance) to measure its active area. The electrode itself serves as the measurement object and the measurement method, eliminating the need for external observation that would cause damage. The capacitance measurement is performed under normal operating conditions without requiring electrode destruction

Inventive Principle:

Principle #25Self-service

3Reliability

If carbon nanotubes are added to electrode mixture, then electrical conductivity is improved, but active area of active material is reduced

Engineering Contradiction:

Improveelectrical conductivityVSAvoidactive area of active material

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent uses capacitance measurement to quantify and optimize the amount of conductive material in the electrode. By measuring capacitance and calculating active area using C = k × S, the method enables parameter optimization to find the balance point where sufficient conductivity is achieved while minimizing the reduction of active material area

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent establishes a feedback mechanism where capacitance measurement provides information about the active area, which in turn guides the optimization of conductive material content. The relationship C = k × S creates a feedback loop that allows adjustment of conductive material amount to achieve optimal balance between conductivity and active area

Inventive Principle:

Principle #23Feedback

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

Enables accurate and rapid measurement of the active area without damaging the electrode, reducing the time required for measurement and improving the efficiency of electrode production.

Implementation Method 1

measuring a capacitance of each electrode used in the monocells from the monocells

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

measuring their capacitance using cyclic voltammetry

Methodology Applied

Scientific EffectCyclic voltammetry:

Data Source

PatentUS11313822B2Nondestructive method for measuring active area of active material

Publication Date: 2022.04.26 LG ENERGY SOLUTION LTD

AI summary

The present invention relates to a method for measuring the active area of an active material in an electrode, comprising: manufacturing three types of electrodes including a first electrode coated with an electrode mixture including both an electrode active material and a conductive material, a second electrode coated with an electrode mixture which includes the electrode active material as a main ingredient and does not include the conductive material, and a third electrode coated with an electrode mixture which does not include the active material and includes the conductive material as a main ingredient; a cell manufacturing step of manufacturing three types of monocells by using the same types of electrodes; a capacitance measuring step of measuring, from the monocells, capacitance of each electrode used in the monocells; and an active area calculating step of calculating the active area of the electrode active material from the capacitance.