Redox Flow Battery Electrode Oxidation Resistance

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Solution Overview

Problem

Redox flow batteries face challenges with increased cell resistivity over time due to degradation of positive electrodes composed of carbon fiber aggregates, which affects their long-term operation and efficiency.

Innovation Solution

The development of an electrode with a conductive portion resistant to oxidation, composed of elements from group α1, which also functions as a catalyst and enhances adhesion, combined with a catalytic portion, helps suppress degradation and maintain low cell resistivity. This electrode is applied to the substrate, ensuring excellent reactivity and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a carbon fiber aggregate is used as the positive electrode, then electrical conduction and liquid permeability are provided, but the electrode is oxidized and degraded over time, increasing cell resistivity

Engineering Contradiction:
Improveelectrode stabilityVSAvoidoperational life
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent applies composite materials by combining carbon fiber aggregate with metal oxide particles (such as MnO2, Fe2O3, Fe3O4, or Co3O4) to create a positive electrode that maintains the electrical conduction and liquid permeability of carbon fiber while adding oxidation resistance through the metal oxide component. This composite structure prevents the electrode degradation that occurs with pure carbon fiber, thereby extending operational life and maintaining reliability.

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If the positive electrode is operated over a long period, then energy storage function is maintained, but oxidation occurs leading to increased cell resistivity

Engineering Contradiction:
Improveenergy storageVSAvoidoxidation degradation
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful oxidation effect into a beneficial function by incorporating metal oxide particles that can undergo reversible redox reactions. These metal oxides accept oxygen during operation that would otherwise degrade the carbon fiber, transforming the harmful oxidation into a useful electrochemical reaction that maintains energy storage capacity while preventing electrode degradation and controlling cell resistivity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 electrode effectively reduces cell resistivity and extends the operational life of redox flow batteries by preventing oxidation and degradation, allowing for stable long-term performance and improved reactivity.

Implementation Method 1

the conductive portion contains one or more types of elements selected from a group α1 consisting of Sn, Ti, Ta, Ce, In, and Zn... the positive electrode is oxidized and hence degraded in the electrolyte

Methodology Applied
Scientific EffectOxidation resistance: Oxidation

Implementation Method 2

the catalytic portion contains one or more types of elements selected from a group β consisting of Ru, Ir, Pd, Pt, Rh, and Au... provides electrical conduction... having liquid permeability

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 3

providing electrical conduction... the conductive portion... provides electrical conduction

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

a redox flow battery that supplies an electrolyte to an electrode to perform a cell reaction... supplied with a positive electrode electrolyte, a negative electrode supplied with a negative electrode electrolyte

Methodology Applied
Scientific EffectIon transport: Ion Exchange

Data Source

PatentEP3416222B1Electrode for redox flow battery, and redox flow batteries
Publication Date: 2022.03.23 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP3416222B1 patent drawingFigure 1
  • EP3416222B1 patent drawingFigure 2
  • EP3416222B1 patent drawingFigure 3

AI summary

An electrode for a redox flow battery includes a substrate, a conductive portion applied to a surface of the substrate, and a catalytic portion held by the conductive portion, the conductive portion containing one or more types of elements selected from the group α1 consisting of Sn, Ti, Ta, Ce, In, and Zn, the catalytic portion containing one or more types of elements selected from the group β consisting of Ru, Ir, Pd, Pt, Rh, and Au.